subsidiary verbs - Just like "ら抜き" is there also "い抜き" such as "見 ている" --> (い抜く) --> "見てる"?

With ichidan verbs, you create potential, and passive voice, as such:

食べられません

If you want to get slangy, you can do "ら抜き" as such:

食べれません

So, is there い抜き as well?

長い間ロンドンに住んでて、いろいろな民族を見ている。

do the "い抜き':

長い間ロンドンに住んでて、いろいろな民族を見てる。

Now:
1. 見てる is actually written in a book.
2. I don't understand how 見てる is a word.
3. In my analysis, 見てる and 見ている have the same meaning.
4. So, just like you can do ら抜き, there is also い抜き?
5. like ら抜き, い抜き is considered slang?

If there is no such thing as い抜き, how is 見てる a word?

Answer

Yes 見てる is a very common contracted form of 見ている. Generally, -ている/-でいる can be contracted into -てる/-でる, and -ています/-でいます can be contracted into -てます/-でます.

見てる as opposed to 見ている may be technically called い抜き, but the word い抜き is far less common than ら抜き. It's because that "い抜き" phenomenon is very common now, and virtually no one thinks い抜き is wrong in not-so-polite conversations. I would say inserting い even sounds weird in casual conversations (for example 今なにしてるの？ is probably more than 100 times more common than 今なにしているの？ in conversations among friends). Native speakers don't have to talk about "い抜き" because they know when and when not to use it even without learning at school.

On the other hand, as of 2016, ら抜き is still considered "non-standard," "slangy," or even "ungrammatical" by some, and there are a lot of debate regarding ら抜き among native speakers.

I don't want to say opinionated things here, but generally, you may eventually need to know how to use "い抜き" properly, but you may not need to use ら抜き at all.

sexuality - What are reasons of מצוות עונה marital sex?

Besides the reason of having children, are there other reasons to the מצוות עונה (marital sex)?

linear algebra - Looking for integral-free DSP textbooks

I am looking for a treatment of fundamental DSP theory where only discrete/finite signal models are used. To make a concrete example, every time standard textbooks write a convolution as a continuous integral, I would like to see instead a product between a Toeplitz matrix and a vector. It seems to me that developing such a theory from linear algebra would make implementing concrete DSP algorithm much easier. Think also of multirate/filter banks, etc... Except maybe for the book of Strang on Wavelets I have not seen any other book based this approach. Any book titles I have missed?

word choice - Which is the most correct (or common): 話 or 話し?

The meaning of 話, as a kanji, is "tale, talk", but as a word, it means the same as 話し: "Talk; speech; chat; story; conversation."
In the official jouyou kanji chart, there's only 話, for the isolated word, and 話し in a composed word (like　話し合い).
On the dictionary it says that　話し is "irregular".
Searching on Google for both variations, 話 have 25,5 million more matches than 話し.

Also, the dictionaries have both 話言葉 and 話し言葉, but there's no indication of what is the most appropriate or if there is a irregularity on the し.

With all this,　would 話 be the most adequate/common for use? Or not?

Answer

This is the descriptive answer.

Google hits

A word of warning about google hits. They are not accurate. Google tries everything to reduce computation time and costs, and it will not give you an accurate full-text search of the entire (public) net. Try going to page 20 or 30, and Google informs you it cannot provide any more results.

Furthermore, a search for 話 is going to turn up many false positives, such as (1) read わ as part of a compound, eg. 対話, and most importantly (2) read はな as part of the word 話す. Searching for 話 includes results such as 話しを.

You should always inspect some of the results manually and look for possible unwanted results.

Trying to avoid these false positives, a google search yields:

• 面白い話を 9 pages, 460,000 hits


• 面白い話しを 12 pages, 30000 hits

As this is kind of inconclusive, I tried a different corpus.

The noun form 話

A balanced corpus of contemporary written Japanese, searchable via shonagon yields the following results. I add particles before and after 話/話し to avoid false positives.

• の話しを 56 results


• の話を 4420 results

And with other particles to make sure these results are not specific to の話を:

• の話しに 19 results


• の話に 1496 results

Thus, the spelling 話 for the noun form appears to be about 80 times more frequent than 話し.

話し vs. 話

This article on bunsho-labo gives a prescriptive rule: Use 話し when used as a verb semantically, and 話 when used as a noun.

For example, the correct spelling would be

• 最近、とある女子中学生とお話しをする機会がありました。


• それは、学校生活での悩みに関する話でした。

See the link above for more examples.

The official okurigana rules prescribe added okurigana for nouns nominalized from verbs, but list 話 and several other words as exceptions.

However, the "translation" of the official guidelines for okurigana usage on wikipedia are concerned with semantic extension: Use 話し in the sense of the act of talking, and 話 in the extended sense of story.

I think it can makes a difference in a sentence such as this one taken from the bunsho-labo page above.

PCの向こう側には、彼女が話しをしているときの深刻な表情が浮かぶようでした。

They use 話し because this sentence is about the action, but she might as well be telling a story, which would suggest the non-okurigana form. But never mind grey areas, let us take a look at the actual usage.

Querying the above-mentioned corpus for this distinction:

• お話しして 174


• お話して 181

Therefore, the prescriptive rule does not seem to be observed in written Japanese, at least as far as the form おXをする is concerned, and this form clearly uses it in the sense of 'speaking`.

Furthermore,

• お話しを 65 results



• お話をし 238 results

The second search yields about 4 times as many results, even though it is more specific by following 話を with the verb する.

However, regarding the compound 話し言葉, it seems to be the preferred spelling:

• 話し言葉 129 results


• 話言葉 4 results

Conclusion

At the very least, I cannot find much evidence supporting the rule concerning the distinction in usage between 話し and 話 used as the nominalization speaking in this corpus. If used as a noun talk, the spelling 話 occurs more frequently in this corpus.

Also, as the rule is concerned with the semantic interpretation of the nominalized form and whether it is used in an extended sense, there may be some grey areas.

Note that prescriptive rules exists, be they observed on average or not. In formal writing, you may be well advised to stick to any rules you are expected to follow.

halacha - Fitting for an animal to eat besides a dog

In many halachos about food (Kashrus, owning Chametz on Pesach, etc.), a standard for determining if something retains its status as food is if it is "fitting for a dog to eat."

What about other animals? If a pig or chicken would eat it, does it count? Is a dog just the archetype of a non-picky eater, or is there something specific about the dog that gives it that status?

estimation - Estimating a low frequency signal corrupted by high frequency noise

This is a follow-up to this question. Suppose we take discrete samples of a low frequency signal currupted by high frequency noise. We know the signal has no frequencies higher than 20% of the Nyquist rate. We also know all the noise is at or above 50% of the Nyquist rate, and below the Nyquist rate. I will use the folowwing as a specific example to experiment with.

\begin{align}&\textrm{measurement}(t) = \textrm{signal}(t) + \textrm{noise}(t)\\ &\textrm{signal}(t) = 4.4+\sin(0.06\pi t-0.1) + \sin(0.14\pi t+0.07) + \sin(0.2\pi t+0.4)\\ &\textrm{noise}(t) = \sin(0.06+0.5\pi t) + \sin(0.1-0.68\pi t) - \sin(0.04-0.74\pi t) + \sin(0.03-0.93\pi t) \end{align}

The measurement is sampled at integer values of ($t$). A plot of the measurement samples and the continuous signal is below.

How well can we estimate $\textrm{signal}(t)$ at integer values of ($t$) using the current and past measurements? I was able to filter it using the Kalman filter below.

A plot of the signal and Kalman filter output is in the next plot. The final plot shows the error in the Kalman filter output which has a maximum magnitude of 1.865 and the RMS error is 0.7895. Can we make a Kalman filter that does better than the Kalman filter above? What known filter method would give the best estimates, and how good would the estimates be?

I learned about discrete lowpass filters 25 years ago, and I always assumed a problem such as the one above was a common application for them. At that time I didn't know this problem is called estimation, and I didn't know about the Kalman filter. Then I recently took this course, and another course Georgia Tech provided that goes into the details of estimation algorithms. However, the Georgia Tech courses mention nothing about using a discrete lowpass filter for estimation. I check several books on estimation, and found nothing about discrete lowpass filters. I work with a computer scientist who has been doing research in data fusion for 20 years, and he knows nothing about z-transforms, transfer functions, etc. Why is it that the estimation community ignores the use of a discrete lowpass filter for estimation? As far as I can tell it's the best approach to estimate the signal above.

Answer

To answer your final question:

Why is it that the estimation community ignores the use of a discrete lowpass filter for estimation? As far as I can tell it's the best approach to estimate the signal above.

That's because you're feeding them the wrong signal model.

TL;DR: Use the right tool for the job!

Gory Details

Any time you start in with the Kalman Filter, you are assuming that the signal (measurement in your equations above) was generated as: $$ x[k+1] = \mathbf{A} x[k] + u[k]\\ \mbox{measurement}[k] = \mathbf{H} x[k] + v[k] $$ where $$ \mathbf{A} = \left [ \begin{array}{cc} 1 & 1 \\ 0 & 1 \end{array} \right]\\ \mathbf{H} = \left [ \begin{array}{cc} 1 & 0 \end{array} \right]\\ $$ and $u$ and $v$ are zero mean, Gaussian distributed, independent random variables with covariances $$ \mathbf{Q} = \left [ \begin{array}{cc} 1.6 & 2.4 \\ 2.4 & 4.8 \end{array} \right] \times 10^{-9}\\ \mathbf{R} = 2.35 \times 10^{-6}\\ $$ At least for the equations you cite. More general application of the KF is possible, but usually not done.

So, one thing that might be done to improve your estimates is to ensure that $\mathbf{Q}$ and $\mathbf{R}$ are closer to reality. From the look of things, your process noise ($u[k]$) has about the same variance as your measurement noise ($v[k]$). Make them closer.

More importantly, your signal is correlated with your noise because, rather than stochastic noise, you have harmonic noise. Even worse: you have synchronized harmonic noise (meaning the noise moves in lockstep with your signal).

So: the problem is that by using the Kalman Filter your signal model is all wrong.

A better model for the signal is in the frequency domain: the signal is low frequency. The noise is high frequency. So, a low pass filter will do a much better job of improving things that the Kalman Filter can hope to do.

If I apply the Kalman filter to your problem (with some modifications to your equations to take account of the difference between $\mathbf{X}[k|k-1]$ and $\mathbf{X}[k|k]$) then I get the picture below.

The black curve with dots is the measurement. The red curve is signal. The blue curve is the output of the Kalman filter. The green curve is the output of a 5 point moving average filter (a simple low pass filter).

The sum of squared errors for the Kalman filter is 118.63722. The same figure for the low pass filter is 14.18046. Clearly, the signal model of a low pass filter fits better because the error is smaller.

R code to implement this is below.

---

# 26489

T <- 128;
t <- 0:(T-1)/T*70

signal <- 4.4 + sin(0.06*pi*t - 0.1) + sin(0.14*pi*t + 0.07) + sin(0.2*pi*t + 0.4)
noise <- sin(0.06 + 0.5*pi*t) + sin(0.1 - 0.68*pi*t) - sin(0.04 - 0.74*pi*t) + sin(0.03 - 0.93*pi*t)

measurement <- signal + noise


xkm1km1 <- matrix(c(4.4, 0),2,1)

Pkm1km1 <- matrix(c(1,0,0,1),2,2)
H <- matrix(c(1,0),1,2) 
A <- matrix(c(1,1,0,1),2,2)
Q <- 10^-6 * matrix(c(1.6,2.4,2.4,4.8),2,2)
R <- 10^-6 * matrix(c(2.35),1,1)

library("MASS") # For pseudo inverse ginv()

zhat <- t*0


for (k in 1:T)
{
  xkkm1 <- A %*% xkm1km1
  Pkkm1 <- A %*% Pkm1km1 %*% t(A) + Q
  K <- Pkkm1 %*% t(H) %*% ginv( H %*% Pkkm1 %*% t(H) + R)
  z <- matrix(c(measurement[k]), 1, 1)
  xkm1km1 <- xkkm1 + K %*% (z - H %*% xkkm1)
  Pkm1km1 <- (matrix(c(1,0,0,1),2,2) - K %*% H) %*% Pkkm1  
  zhat[k] <- as.numeric(H %*% xkkm1)
}


plot(t, measurement, type="b", pch=19)
lines(t, signal, col="red",  lwd=10)
lines(t, zhat, col="blue", lwd=5)

lpf <-  filter(measurement, c(0.2,0.2,0.2,0.2,0.2), circular = TRUE)
lines(t,lpf, col="green", lwd=4)

errs <- c(sum((signal - zhat)^2), sum((signal - lpf)^2))
print(errs)

grammar - What is やってけんのかな？

What does the けん mean in this sentence? Is this a dialect?

やってけんのかな

Answer

やっていけるのかな changed to やっていけんのかな and it changed to やってけんのかな.

Some contexts are necessary to explain the meaning.

fixed point - Are SOS structures better for linear phase FIR filters?

I've seen many discussions suggesting that SOS's are often/usually the preferred structure for fixed point hardware filter implementations, since they preserve conjugate pairs, etc., but I've never seen any specific arguments explaining why they are better for FIR filters.

Do these advantages still apply for direct form, linear phase FIR filters which allow the number of multipliers to be reduced by a factor of 2?

Finally, are there any good resources discussing these trade-offs? I'm trying to implement fairly long FIR filters with small multipliers, i.e. 40+ taps with 8-10b coefficients, and am looking for resources that might shorten this effort.

archaeology - Using archaeological findings for determining weights and measurements

Halacha uses many units of length (amot/cubits), volume (k'zayit/olive), etc. There are multiple opinions regarding how to translate these into modern equivalent units. For instance, the Chazon Ish says an amah/cubit is 56-58 cm, while Rabbi Chayim Na'eh says it is 45-48 cm.

There have been a great deal of archaeological findings in Israel in the last 200 years regarding how Jews lived during the Biblical and post-Biblical periods. Has anyone attempted to apply these findings to determine accurate conversions for these various halachic measurements?

For example, Yisrael Finkelstein, the lead archaeologist in the Shiloh excavations believes he has identified the location of the original Mishkan (Tabernacle) based on excavated foundation stones along a length of approx. 25 meters (about 50 amot, the length of the Mishkan). Has anyone (presumably in the academic world), made a detailed study of such findings in order to weigh in on the relevant halachic debates?

particle まで - 私まで嬉しい is translated as "I am happy", what function of まで is this?

Why is it used this way instead of は for example?　

ergodic - Does the determination of the ergodicity of a signal force any changes in methodology?

In mathematics, the term ergodic is used to describe a dynamical system which, broadly speaking, has the same behavior averaged over time as averaged over space. -from wikipedia

From the perspective of engineering a signal processing system, does knowing whether a signal is ergodic change the plan of attack for analyzing the signals? I've always found this a fascinating concept, but I don't really know what do do with it once the determination is made. What analysis methods would be more pertinent knowing this information?

Answer

The concept of space as used in the statement ascribed to Wikipedia is presumably that of the ensemble of all possible signals, not space as in "Space: the final frontier...". In the absence of parallel universes in which different signals from the ensemble can be observed simultaneously, it is rare for engineers to determine that a signal is ergodic by comparing time averages to ensemble averages. More commonly, signals are assumed to be ergodic so that the values of time averages can be used as estimates of ensemble averages. For example, an engineer takes $1000$ samples of a stochastic signal and plots a histogram of values. This looks vaguely bell-shaped and so the signal is modeled as a Gaussian random process whose mean is the mean of the $1000$ samples etc. Ultimately, the proof of the pudding is in the eating. If this Gaussian model leads to predictions that differ wildly from observed results, the assumption of ergodicity might be discarded, or maybe $10,000$ samples, or $100,000$ samples might be tried (for example, predicting traffic at $5:30$ pm based on observations of traffic between $2:00$ am and $3:00$ am is rarely accurate, but observations over several weeks might lead to a better model).

parshanut torah comment - Why is the heart labeled the seat of emotion?

Throughout Tanach, the heart is used as the seat of emotion. For instance:

• The heart understands (Melachim Aleph 3:9)


• Thought comes from the heart (this seems to be the straightforward understanding of verses like Koheles 1:16 that discuss speaking with the heart)


• The heart can view things prophetically (see Melachim Beis 5:26 and commentaries there)


• The heart falls (Shmuel Aleph 17:32)


• The heart gives endurance during times of crisis (Yechezkel 22:14)


• The heart rejoices (Tehillim 16:9)



• The heart cries (Eichah 2:18)


• The heart is comforted (Yeshaya 40:1-2)


• The heart is pained (Devarim 15:10)

This is an excerpt of Koheles Rabbah 1:38 (Warsaw numbering; 1:16 in Vilna numbering), which lists 58 such emotions and traits that come from the heart.

Scientifically, emotions and thoughts come from the brain. Rav Chaim Miller says that emotions come from the Ruach-level of the Neshamah. But either way, it doesn’t come from the heart. So where do all of these descriptions come from?

kanji - Has anyone come across the word 畸端?

I've started reading my first Japanese book and the word 畸端検査官 keeps popping up. I know 検査官 means inspector, but I can't find a reference anywhere to 畸端.

Can anyone help?

Answer

I googled 畸端 and found that this question comes at the top :D Aside from this question, the word is used almost exclusively in グウィノール年代記. Is this what you're reading? 畸端 is clearly a made-up word. In the middle of the sample here, it explains its (supposed) definition in the story:

それまでメルは畸端検査官というのは、市場で肉や野菜の検査をするお役人のことだと思っていた。緑と赤のお仕着せを着た畸端検査官たちは市場に入ってくる荷の中から野菜や肉や卵を抜き取って調べ、《呪肉》が見つかったらその荷はすべて没収して焼き捨てることになっている。

畸 means "out-of-the-way" or "disabled", and 端 means "borderline" or "edge", so its basic intended meaning should be "abnormality", "deformation", "corruption", or something along these lines. But you may come up with a better translation if you keep reading, since they seem to have some secret roles. It's probably pronounced as きたん. 異端 (いたん, "heresy") is a much more common word that resembles this.

halacha - Seven Brochos at a Wedding

I just read What do I need to make a Jewish Wedding. Is there a requirement for seven different people to say each of the seven Brochos, or can one say all of them?

Answer

I heard on a R' Hershel Shachter shiur @yutorah that the older practice was in fact to have one rabbi (often the officiating one) to recite them all. Just as a haftorah or the like has multiple blessings, recited by one person.

In order to spread the honors, today people will often give one (or more) blessings per person. If that works for you, fine; if you want one person to do them all, that's fine too. (But if your cousin's father-in-law's chiropractor's best friend gets upset that he didn't get one, please don't blame me!)

Rabbi Yoel Teitelbaum of Satmar, reacting to the recent divvy-'em-up trend, remarked that pretty soon, they'll have one person say BA and another person say RUCH!

counters - 「二番」 vs. 「二番目」 confusion

I am confused by 「二番」vs.「二番目」、「三番」vs.「三番目」etc.

While 「一番速い人。」 seems grammatically correct and sounds ok to me, 「二番速い人。」 sounds so unnatural to me I am thinking the grammar might be wrong. But, if 「一番速い」 is correct, certainly 「二番速い」 must also correct, right?

With regard to modifying nouns with adjectives such as "second", "third", etc. this is how I've heard it done:
「それは、二番目に高い建物です。」
「三番目の好きな日本料理はお好み焼きです。」
「四番目に速い人は、田中さんです。」 ...

Personally, but for 「一番」、 I never just say 「＿番」. I say 「＿番目」. But in forums such as this, I observe 「＿番」 used more often than 「＿番目」。 So, I am getting worried / confused about this.

Also, in this context. 「目」 must be consider a counter right? It is the counter of positions in an ordered list. If it's not officially a counter, what is it?

Answer

I think that the sequence beginning 一番・二番・三番 corresponds roughly to number one, number two, number three. Each word in this sequence is formed from the combination of a numeral (一・二・三) with a counter meaning number (番).

You can take this list and add the ordinal suffix 目 to each word, producing the list 一番目・二番目・三番目, corresponding roughly to first, second, third.

What may be confusing here is that an adverb has been derived from 一番, but not from the other words formed with 番. As a result, 一番 can represent either number one or first/most, but 二番 and 三番 mean number two and number three. You can see this if you compare dictionary entries; the entries for 一番 in 大辞林 and 大辞泉 list it as both a noun and an adverb, while the corresponding entries for 二番 don't list a derived adverbial sense.

So, if you're talking about the tallest, second tallest, and third tallest buildings, I think the list naturally looks like this:

• 一番高い建物


• 二番目に高い建物


• 三番目に高い建物

And your example 二番速い人 is, I think, ungrammatical.

As for whether 〜目 is a counter, I don't think so. It doesn't combine directly with numbers like counters do. Instead, it's a suffix that attaches to words that consist of a number and a counter. If we check 大辞林, we find the following:

二 （ 接尾 ）
① 数を表す語に付いて，順序を表す。 「一つ目」 「三番目」

You'll notice that it says this is a 接尾語 (suffix). I've bolded the actual definition, which I'll translate here as "attaches to words that express number, and expresses ordinality."

You'll note the definition includes an example where 目 attaches to a word with つ, as well as another example where it attaches to a word with 番. With 目 attached, both 一つ目・二つ目・三つ目 and 一番目・二番目・三番目 express first, second, third, but of course the つ list can only count to nine, while the 番 list can be used to express arbitrary positions in a list.

furigana - Are there any patterns for okurigana?

Sometimes, when learning kanji, I get tripped up because I can't remember which kana are the furigana of the kanji, and which are the okurigana.

Take たべる(食) for example. I might think that たべ are the furigana for 食, and る is the okurigana, which is obviously not true. I can tell easily enough when the word is a verb, and it ends in る or す or some such, but it's not always easy to remember whether sounds in the middle are part of the kanji or not.

Is there a system behind all of this? Or do you simply have to know the kanji readings and memorise the okurigana?

Answer

As had been pointed out, as a general rule, that part of the word - in terms of kana syllables - that changes or inflects is written with okurigana.

See also 「送り仮名の付け方『国語を書き表すための送り仮名の付け方のよりどころ」』・単独の語１・活用のある語・通則１」, which states as a general principle that the inflectional ending is added in kana.

活用のある語（通則2を適用する語を除く。）は,活用語尾を送る。

When kanji had been introduced to Japan, and when people began to write Japanese with kanji as well, there was the problem that when writing everything in kanji, you had to indicate somehow which inflection of a word was intended. Chinese didn't have these inflections and thus the writing system had to be adapted.

What the Japanese people came up with was (a) the 弖爾乎波【てにをは】 system(s) which consisted of adding small dots and strokes to indicate a certain inflection (e.g. ~たり or ~て) or particle (e.g. に or を); and (b) - like with Egyptian hieroglyphs - a more flexible dual system, some kanji used for their meaning (semantically) and some for their sound (phonetically).

For example, you could write 恐美多利 for 恐【かしこ】みたり, the last three kanji used phonetically. The latter became man'yougana, then hentaigana and evolved into the well-known kana eventually.

Today, there are 五段 ("u", e.g. 泣く) and 一段 ("ru", e.g. 語る) verbs, but historically, there had been slightly different groups. If you take a verb like taberu, its conjugation had been:

終止形【しゅうしけい】　たぶ

連体形【れんたいけい】　たぶ

連用形【れんようけい】　たべ

未然形【みぜんけい】　たべ

已然形【いぜんけい】　たぶれ

命令形【めいれいけい】　たべよ

That's called the 下二段【しもにだん】 conjugation; 二段 because the vowel changes between e and u (cf. the ablaut in German singen-sang-gesungen-Song, and English sing-sang-sung-song or tooth-teeth), 下 because these vowel come last (=at the bottom in vertical writing) in the Japanese order a-i-u-e-o.

二段 verb became 一段, getting rid of the vowel change, and the 終止形【しゅうしけい】 fell out of use, leaving you with only a final る that changes during inflection. But as a remnant of Classical Japanese, the correct spelling with okurigana is 食べる instead of ✘食る, which would be analogous to 見【み】る. The same principle holds for many other verbs.

The same story holds true for 起きる・起こる, 掛かる・掛ける and many other pairs. They are usually derived from some earlier form of one (shorter) verb, e.g. 掛【か】く.

One reason why new verbs such as 掛かる and 掛ける were formed from an existing verb 掛く was to create transitive/intransitive pairs, or potential/causative verbs such as 見【み】る・見える or 覚【さ】める・覚ます, which gives the explanation for this pattern detailed in the answer by @fosskers.

Furthermore, okurigana help to distinguish between the two words, 起る could theoretically be either おきる or おこる.

For 五段 verbs, historically 四段 (=four vowels; a, i, u, e) verbs, only the last syllable changes, thus 食【は】む, 蝕【むしば】む, 読【よ】む 坐【ましま】す, 嗤【わら】う, 貪【むさぼ】る etc. The inflection of 読む is, for reference:

終止形　よむ

連体形　よむ

連用形　よみ

未然形　よま

已然形　よめ

命令形　よめ

To illustrate this, consider the two verbs 統【す】べる and 滑【すべ】る. 統べる derives from the 二段 verb 統ぶ (inflection: すぶ・すぶる・すべ・すべ・すぶれ・すべよ), thus its non-inflecting stem is す and it is written 統べる. On the other hand, 滑る is a perfectly normal 四段 (now 五段) verb on る (inflection: すべる・すべる・すべり・すべら・すべれ・すべれ), whose non-inflecting stem just happens to be すべ, thus it is spelled 滑る. In classical Japanese, these two verbs were referred to in their dictionary forms すぶ and すべる and were as different as 行く and 言う, which just happen to exhibit the same past form いった.

Verbs derived from other words retain their inflectional endings. 怪【あや】しむ・怪しがる and the adjective 怪【あや】し, 悲【かな】しむ and 悲し, 苦【くる】しむ and 苦し.

The story continues with adjectives. As for i-adjectives, the conjugation is as follows for 赤【あか】い:

終止形　あかし

連体形　あかき　／　あかい

連用形　あかく　／　あこう

あこう is a dialectical variation (and used before ございます, as in 有【あり】難【がと】うごさいます, from 難【かた】い) and arose from あかく→あかう→あこう via a sound shift. Thus, only the last syllable is inflected and the proper spelling is 赤い, 赤う, 赤く.

There is a variation of this conjugation for adjectives whose last syllable before the inflecting one is し, e.g. 美【うつく】しい:

終止形　うつくし

連体形　うつくしき　／　うつくしい

連用形　うつくしく　／　うつくしゅう

The final inflectional し is not added for the 終止形 (dictionary-form), thus the proper spelling is 美し or otherwise it would not get any okurigana to indicate it is an adjective, thus it is written 美しい and 美しく.

The same applies to the compound conjugation of adjectives. 赤くない, because that is 赤く + the word 無い. 赤かった, because that is 赤し+あり+つ+あり→あかかりたり→あかかった.

Some adjectives that are formed from an inflected form of another word retain that inflection, e.g. 羨【うらや】ましい, derived from the verb 羨【うらや】む, plus し + the adjectival inflectional ending い; or 頼【たの】もしい, from 頼む.

Next are compound words whose elements are buried under etymology and may have become obscure. The suffix is rarely written with kanji and left in kana, which may look like okurigana.

The proper spelling is 速【すみ】やか, 艶【あで】やか, 健【すこ】やか, 雅【みやび】やか, 明【あき】らか, 滑【なめ】らか, 朗【ほが】らか, 安【やす】らか etc. because they are compounds containing the suffices -やか and -らか, e.g. 艶【あで】+やか and 安【やす】+らか.

静【しず】か, 愚【おろ】か, 確【たし】か, 豊【ゆた】か, 僅【わず】か consist of a combination with some suffix -か. The above -やか might be a combination of や+か.

See this question concerning the three suffixes -ら, -や, -か.

嬉しげ, 在【あ】りげ, 大人【おとな】げ, 可愛【かわい】げ etc. contains the suffix -気【げ】, now often written in kana only.

古【ふる】めく, 唐【から】めく, 春【はる】めく ひしめく, ざわめく etc. contain the auxiliary verb めく ("appear/look like").

欲【ほし】しがる, 強【つよ】がる, 度【た】がる etc. contain the auxiliary verb がる "show signs of".

昂【たか】ぶる (高【たか】+ぶる), 偉【えら】ぶる, 揺さぶる etc. contain the auxiliary verb ぶる (振【ぶ】る) "pose as, pretend to".

綺麗【きれい】の, 綺麗【きれい】な because they are compounds containing the particle の and the verb (as a copula) なり shortened to な.

全【ま(っ)た】く, 全【すべ】て, 決【けっ】して, 妄りに because they are derived from the adjective 全【また】し, the verb すべる, the Sino-Japanese (on-reading + する) verb 決【けっ】する, and the verb 乱【みだ】る, respectively.

曰【いわ】く (from 言う), 見【み】らく, 散【ち】らく etc. because they are all formed with some old element く.

Some nouns derived from verbs can be written without okurigana, e.g. 話【はなし】, 取調室【とりしらべしつ】, 折紙【おりがみ】, 振仮名【ふりがな】, 受付嬢【うけつけじょう】, 立入【たちいり】禁止【きんし】. Sometimes, the okurigana other than for the last verb are omitted in verbal compounds, e.g. 問合【といあわ】せ, 振舞【ふるま】う, 受付【うけつ】ける.

Some words are written with additional okurigana: 後【うし】ろ, 蔑【ないがし】ろ (from 無【な】きが代【しろ】). Sometimes you can find variant okurigana spellings such as 既【す】でに, 故【ゆ】えに and 此【こ】れは (instead of 既に, 故に, and 是は).

Additionally, おこなう used to be written as 行う (行ふ), but the spelling 行なう has gained in popularity.

Thinking about おこなう, I would suggest that the main motivation behind these okurigana usages is to help the reader and to avoid ambiguity. 行って could be either おこなって or いって (or ゆって), but　行なって must be おこなって. Likewise, 後 could possibly be のち, ご or うしろ with only the context left to decide which, but 後ろ must be うしろ, no argument about the context required.

既 or 蔑 might be hard to read for some people, but giving part of its reading as 既で or 蔑ろ helps you to guess the word from context, even if you didn't know the kanji at all.

There are explanations for these pattern regarding okurigana usage, and they require some basic understanding of the earlier stages of the language. However, that doesn't change the fact that there are patterns, and even without understanding them in full detail, you will soon start to notice them and be able to tell how to spell a word. For example, you don't need to know about the history of the suffix -やか to notice that many words ending on -やか are spelled with やか as the okurigana.

product recommendation - What is the best English translation of the Tanakh (hard copy, not online)?

I'm looking for the best available English translation of the Tanakh, and because I prefer to hold an actual book in my hands, I'd rather have a hard copy as opposed to an online version.

Some insight on what I'm looking for: The most important factor is the accuracy of the translation in relation to either the best extant early manuscripts or the most widely accepted version of the text. If I have a choice between accuracy in a "word-for-word" sense and a "thought-for-thought" sense (this is one of the ways Christian bibles are distinguished from one another - rendering each word as accurately as possible versus rendering each idea as accurately as possible), I would prefer the former.

I would also prefer a version that provides insightful commentary from respected textual critics who are reputable and well regarded, but this isn't strictly necessary.

Is there a good English translation available?

halacha - Laws of Shemirat Einayim

I'm looking for a comprehensive summary of the halachas of shemiras einayim (guarding the eyes).

I am not looking for those things which are midat chasidut (extra piety) but rather only those things which are binding halacha.

halacha - Is a Jew allowed to be knighted? Problem with kneeling?

Is there any halachik problem with going through the knighting (or Damehood for women) process of kneeling etc?

The current ceremony does not contain many of the Christian or pagan overtones of the past. However it does include kneeling before the sovereign. Essentially the question then is may one participate in previously idolatrous ceremony that still contains some elements of the original ritual but has generally lost its religious nature?

halacha - What is the halachic point of view on homosexual intercourses between Gentiles males different from anal coitus?

I am an Italian son of Noah.

The prohibition of the homosexual intercourses between Gentiles males is an integral part of the Noachide Precepts (see Mishneh Torah-Melacim uMilchamot 9: 5; it does not seem that lesbian relations are explicitly forbidden to Gentiles women ).

Now, in the Babylonian Talmud there is a passage in which the male homosexual intercourse would seem to be related to the specific practice of anal coitus:

Sanhedrin 54a

GEMARA: From where do we derive the prohibition and punishment for homosexual intercourse with a male? It is as the Sages taught in a baraita with regard to the verse: “And if a man lies with a male as with a woman, both of them have committed an abomination; they shall be put to death, their blood shall be upon them” (Leviticus 20:13): (….) the phrase “as with a woman [mishkevei isha],” referring to lying with a woman, appears in the plural. The verse teaches you that there are two manners of lying with a woman for which one who engages in intercourse with a woman forbidden to him is punished, vaginal and anal intercourse.

I therefore wonder if the halachic sources allow Gentiles males to perform homosexual acts that are different from anal coitus, such as oral sex, mutual masturbation and intercrural coitus, also because Gentiles men are not bound by the obligation of procreation and the prohibition of spread the seed in vain.

I specify that my question has no personal interest, but is exclusively set up for study purposes pertaining to the precise provisions of the Noachide Law.

wave - Audio Signal Separation - Identifying Interest points

I asked this question here: Audio Separation of .wav signal but it wasn't clear, so, here is my second attempt:

First off, assume that I have a .wav file containing a sentence as follows:

"My name is Michael" I would like to extract, from this, the following:

"My" -> Phoneme (1)

"Name" -> Phoneme (2)

"Is" -> Phoneme (3)

"Michael" -> Phoneme (4)

This means that I have taken my 1D signal, and split it into a 2D signal (vector) that contains these particular words/phonemes which I can then analyse and identify. I would therefore, like to compute this in the time domain and not the frequency domain. Just to clarify again:

I take in a 1D signal containing a sentence, split this sentence up into different parts which contain this data: vect[0], vect[1], .... vect[4] Let's say in matlab I did the following command wavwrite(vect[0], ....) then it would output the word "My" and putting all the blocks together would give me the full sentence back.

Here is my "real-world problem" instead of Phonemes, I have bat calls, the length of each bat call is unknown at this stage. But here is a typical sample of a bat call: Here and for each of these bat calls, these need to be separated from the inputted signal and stored inside a vector (Just like the example above), this, then allows me to identify each of the bats and perform analysis on them.

This, like, the sample would give me a 2D vector containing each of the bat calls: "Bat1", "Bat2" ..... "Bat[n]" it is unknown the amount of time the bats have been recorded for, or, what the length of each of the bat call therefore is.

What I have done so far:

I have obtained the bat signal, processed it and I am given the following (Which is plotted):

I have also Emphasised the signal using the following formula:

rawSignal[i] = rawSignal[i] - (0.95 * rawSignal[i-1]);

And then I have Compressed the signal using the following:

    float param = 1.0;
for(unsigned i=0; (i < rawSignal.size()); i++)
{
    int sign = getSignOf(rawSignal[i]);
    float norm = normalise_abs_value(rawSignal[i]);
    norm = 1.0 - pow(1.0 - norm, param);
    rawSignal[i] = denormalize_value(norm, sign);

}

Which then gives me an output of the following:

I'm unclear to where I should go from here in identifying single elements ("calls") from this signal. Since, if I use zero-crossing and/or calculating the total energy of the signal and thus using a threshold then it will just remove the noise and I'm left with a compressed version of the signal.

Speaking to someone, they suggested that I should try and use the Cochleagram domain however, I'm not familiar with this and there is very little research on this available.

If anyone has any suggestions, or the algorithms that I could use then please suggest them.

Answer

(a follow-up to my suggestion on the previous question), you can use the spectrogram and ICA to help:

A similar shorter sound file:

import wave, struct, numpy as np, matplotlib.mlab as mlab, pylab as pl
def wavToArr(wavefile):
    w = wave.open(wavefile,"rb")
    p = w.getparams()
    s = w.readframes(p[3])
    w.close()
    sd = np.fromstring(s, np.int16)
    return sd,p

def wavToSpec(wavefile,log=False,norm=False):

    wavArr,wavParams = wavToArr(wavefile)
    print wavParams
    return  mlab.specgram(wavArr, NFFT=256,Fs=wavParams[2],detrend=detrend_mean,window=window_hanning,noverlap=128,sides='onesided',scale_by_freq=True)

wavArr,wavParams = wavToArr("bat_speech.wav")
hf = pl.figure(); ax=hf.add_subplot(1,1,1)
ax.plot(wavArr)

Now take a look at the spectrogram:

Pxx, freqs, bins = wavToSpec("bat_speech.wav")
Pxx += 0.0001
freqs += (len(wavArr) / wavParams[2]) / 2.
hf=pl.figure(figsize=(12,12));
ax = hf.add_subplot(2,1,1);
#plot spectrogram as decibals
hm = ax.imshow(10*np.log10(Pxx),interpolation='nearest',origin='lower',aspect='auto')
hf.colorbar(hm)
ylcnt = len(ax.get_yticklabels())
ycnt = len(freqs)

ylstep = int(ycnt / ylcnt)
ax.set_yticklabels([ int(freqs[f]) for f in xrange(0,ycnt,ylstep) ])

We can clip this at 8000Hz or so it looks like, or don't bother cleaning it up.

Now you have frequencies which can proxy for multiple sources in BSS, so you can play with PCA, ICA, normalization, etc. For example, see if you have some components you can isolate:

from sklearn.decomposition import PCA, FastICA
ncomps = 7
# reduce dimensionality with PCA
pca = PCA(n_components=ncomps)

y = Pxx.copy().T
pc = pca.fit(y).transform(y)
# run ICA 
ica = FastICA(n_components=ncomps,random_state=42)
z = ica.fit(pc).transform(pc).T
hf = pl.figure()
for p in xrange(ncomps):
    ax = hf.add_subplot(ncomps,1,p+1)
    ax.plot(z[p])    

or see if the spectrogram is enough to let you do your segmentation:

hf = pl.figure()
ax = hf.add_subplot(1,1,1)
ax.plot(np.sum(Pxx,axis=0))

EDIT: Just realized you said you didn't want to use the frequency domain, but it may help you isolate your phonemes which you can extract. Anyway, running on your SeroWeb.wav I get this:

minhag - Which Knot to Use on Tefillin Shel Rosh

When I was a child, I saw that all people had the same knot on their Tefillin Shel Rosh - a Double Daled (Ashkenazi community).

Recently I saw a comment that even those who grew up with a Double Daled, and even if their Father's minhag was a Double Daled, that they should all switch to a Single Daled.

My questions are:

1. What are the sources for this, if any?


2. Why is the Single Daled supposed to be "better"? Is this only for Kabbalistic reasons, or is there a real Halachic reason for this?


3. Are these poskim who require this change in minhag correct to do so?


4. Are there any Ashkenazi Poskim and/or Groups today that specifically say that a Double Daled is preferable?

Answer

As @NoachmiFrankfurt mentioned above, and suggested I convert into an answer:

Here's a partial answer: The MMA madrich gives requires a double-dalet knot http://www.moreshesashkenaz.org/en/guide.

Furthermore, there are Sephardim, such as the London community, who also maintain this practice: https://sites.google.com/site/londonsephardiminhag/tephillin

grammar - What's the meaning of 〜ておきます?

What exactly does 〜ておきます mean in this context?

旅行{りょこう}する前{まえ}にホテルを予約{よやく}しておきます。

Is this trying to say something like "Before traveling, reserve a room". Is this a suggestion? An order? (If so, why aren't they using ください at the end instead of おきます?)

Answer

This sounds like a sentence taken from a travel agency's website, an instruction sheet or something along those lines. If that's the case, this 〜しておきます contains two grammatical points.

Before explaining the grammatical points, here's my (very loose) translation of the sentence:

Make sure to book a hotel before you leave.

The first grammar point is the combination of a te-form verb and auxiliary verb おく. While this combination can have multiple meanings, in your particular example, it carries the sense that someone does the action referred to by the verb in advance or make sure that it will have been done when its effect becomes important. Usually the action is a good or important thing to do now such as preparation or a precaution. The doer typically has some purpose or objective, but it can be that the doer just does it for no particular reason other than "just in case." In your example, 予約 in 予約しておく is the action, which you do before the event "旅行" happens.

The second grammar point is 〜ます. You probably already know that this makes a sentence polite. And actually this is what this auxiliary verb is doing here too. Then how come this sentence is telling you what to do? You might find it easier to see the reason why the whole sentence sounds like an instruction or order of some sort if you think of your sentence this way:

ホテルを予約よやくしておく + ます = Book a hotel (i.e., grammatical imperative form) + Please.

It's not exactly "Please do it." But 〜します is a very common phrase in an instruction and the like. For example, an instruction

Click here to edit your post.

on an online forum can be translated as

自分の投稿を編集するにはここをクリックします.

depending on context.

So if your context actually suggests that it's very likely an instruction of some sort, you can say it's a strong suggestion or request.

As for why it's not 下{くだ}さい, it's just the writer's choice of words. This 〜します version as a request can sound stronger or more forceful than the 下さい alternative if you say it the wrong way at the wrong time. But it's a very common phrase for when the speaker tells you how something is supposed to be done or how you're supposed to do something, which makes it a handy phrase when writing instructions, manuals, guides, etc.

conversion to judaism - Why does a Na'arah Me'orasah convert who has illicit relations not receive Skilah?

Kesuvos 4:3:

הַגִּיּוֹרֶת שֶׁנִּתְגַּיְּרָה בִתָּהּ עִמָּהּ, וְזִנְּתָה, הֲרֵי זוֹ בְּחֶנֶק. [...] הָיְתָה הוֹרָתָהּ שֶׁלֹּא בִקְדֻשָּׁה וְלֵדָתָהּ בִּקְדֻשָּׁה, הֲרֵי זוֹ בִסְקִילָה. [...] הָיְתָה הוֹרָתָהּ וְלֵדָתָהּ בִּקְדֻשָּׁה, הֲרֵי הִיא כְבַת יִשְׂרָאֵל לְכָל דָּבָר.

A women who converted with her daughter, and [the daughter] committed adultery [as a Na'arah with Kiddushin], she receives choking. [...] If [the daughter's] conception was not in holiness [i.e. the mother hadn't converted yet] but her birth was in holiness [i.e. the mother had converted already], she receives stoning. [...] If her conception and birth were [both] in holiness, she is like the daughter of a Yisrael for all matters.

The pesukim explicitly prescribe stoning as the penalty for adultery as a Na'arah (Devarim 22:20); however, as the Bartenura points out, this is only in the context of v. 21:

כי עשתה נבלה בישראל

For she has done this disgusting thing in Yisrael

which excludes a convert, who is not part of the general community.

Is this just a Gezeiras HaKasuv that a Na'arah convert doesn't receive stoning for adultery? Or is there a conceptual distinction between a convert and a born Jewess which explains this ruling?

words - Is the grammar of 心の冷たい人 idiomatic?

The phrase 心の冷たい人 (which is given by Japanese-English dictionary on OS X) looks wrong to me, but given that it's an example in a respected dictionary and confirmed by tens of thousands of Google hits, I have to assume it's correct. It's a lot less clumsy than how I'd naïvely write it, 冷たい心がある人, but its word order still doesn't line up with anything else I've seen. Is this just an idiomatic saying that I should just accept as correct, or is this a pattern that shows up a lot?

Answer

This doesn't strike me as the slightest bit unusual. Relative phrases such as this are very common in Japanese. You can easily substitute similar phrases for 心が冷たい, such as 背が高い:

• あの人は背が高いです。 ("That person is tall.")


• 背が高い人 (lit. "A person who is tall"; "A tall person" [with the emphasis on 背])


• 背の高い人 (lit. "A person who is tall"; "A tall person" [with no particular emphasis])

背が高い, being a complete phrase, is perfectly legal as a modifier on a noun (although the が does often change to の depending on the emphasis).

Pink ($1/f$) pseudo-random noise generation

What are some algorithms for generating a good pseudo-random approximation to $1/f$ (pink) noise, yet suitable for implementation with low computational cost on an integer DSP?

Answer

There are several. This site has a reasonable (but possibly old) list:

physical chemistry - What are dipole moments in a molecule supposed to act upon?

In a $\ce{CO_2}$ molecule, a total of four electron pairs are shared between the carbon and oxygen atoms, such that 2 pairs are shared between the carbon atom and each oxygen atom. Oxygen has a greater electronegativity hence the atoms of oxygen will spend greater time with shared pairs and are partially negative. Since both oxygen atoms will exhibit this same behavior, the carbon atom will become partially positive.

I was reading about the dipole moment of $\ce{CO2}$ (e.g., as here), in which it said that the net polarity of the $\ce{CO_2}$ molecule is zero because if we add the individual dipole moment vectors directed from the positive pole (carbon) to the negative poles (the oxygen atoms), the resultant will be zero which implies the polarity of the molecule is zero.

My problem is this:

If these individual dipole moments (vectors) are showing the opposite and equal pull of shared pairs of electrons toward more electronegative atoms (oxygen atoms), then the carbon atom should stay partially positive with the oxygens remaining partially negative.

Given this, though, it seems that the molecule should remain polar on whole. This is because these dipole moment vectors are acting on different shared pairs: the first vector acts on the two shared electron pairs between the carbon atom and one of the oxygen atoms, and the other acts on the two shared electron pairs between the carbon atom and the other oxygen atom. According to the following law, then, these vectors cannot cancel each other and thus $\vec u \neq\vec 0$:

Two equal and opposite vectors do not cancel each other out when acting on different bodies.

My best attempt to resolve this contradiction:

Since in reality it is the case that the net polarity of $\ce{CO_2}$ is null, I think that both vectors (viz., the 'pull' from both oxygen atoms) must be acting individually on all electrons of carbon atom and therefore they cancel each other out resulting in molecule to be non-polar on whole. This explanation isn't all that satisfying to me, however.

prefixes - How to speak about "one" thing in Japanese?

I know the title does not make much sense, sorry about that.

In short, what I mean is, how can I mention about one certain thing (not one thing in amount) in Japanese?

For example "one morning" in the following sentence:

As Gregor Samsa awoke one morning from uneasy dreams he found himself transformed in his bed into a gigantic insect.

I come accross some usages like "あるX". For instance:

• One morning -> ある朝


• One day -> ある日

Is this ある may be what am I looking for?

Sorry if I am not clear. This is all I could express myself.
Thanks.

Answer

As Gregor Samsa awoke one morning from uneasy dreams he found himself transformed in his bed into a gigantic insect.

One morning -> ある朝

Is this ある may be what am I looking for?

I can confirm it is the one, as a native speaker.

The kanji version is 或る, but more often it appears in ひらがな: ある人が…, ある時, あるところにおじいさんとおばあさんが, etc.

We also sometimes say とある: とある日曜の午後 (with rather a feel of popular literature).

某｛ぼう｝ is yet another possibility, in the same manner: ex. 某日｛ぼうじつ｝, 某会社社長{ぼうかいしゃしゃちょう}, 某ファーストフード店｛てん｝, etc.

wedding - How to explain to friends/family that one will not attend an intermarriage

Suppose a friend or family member becomes engaged to a non-Jew. For the sake of this question, also assume that a trusted rabbi has been consulted and he has ruled (after considering any relevant personal details) that you should not attend the wedding.

What is an effective way of conveying to relevant people that you will not be attending the wedding, given it is a wedding that others would reasonably assume you would not miss (such as for a sibling or a close friend)? Has anybody ever been in this situation and found something that worked successfully while causing a minimum of ill-will?

Answer

Like many things in life, this will obviously depend on the specific situation. For example, if the relevant people understand your lifestyle and why you would be sensitive to this issue before it came up would be a very different question than if they are militantly opposed to your zealous bigotry.

I had a close relative marry a non-Jew, and I actually had one party (the immediate family of the person getting married) who appreciated my lifestyle choices, understood I meant no offense, and needed very little explanation other than answering the question "you won't be able to come, will you?" and another party (other relatives) who were mortally offended that I wouldn't come.

I tried two things - the more effective point which I made was that as someone who many of my non-religious relatives looked to as a representatives of religious Judaism, and whether or not I would like to attend, I couldn't give off the impression of condoning something which is against my belief system. The less effective argument that I made (although I don't know if it was worthless) was that they can't appreciate what this issue means to me because they see it as a matter of personal preference, and why should my preferences mean offending someone else. I explained that to me, this is something objectively not okay, and just as they wouldn't ask me to attend a murder, they shouldn't ask me to attend this event. (In retrospect, the murder example was a bad one - despite the fact that it is logically a good point, people don't like what they are doing to be compared to murder.)

With one particularly vociferous relative, I pointed out that he was accusing me of being close minded while he was guilty of being close minded against my prerogative to my own beliefs - I wasn't trying to cancel the wedding, I was just choosing not to participate. If they have the right to make the wedding, I have the right to not join in. I was very surprised that this was well-taken.

Like I said, everyone's family and situation is different, and this is what (seemingly) worked for me.

shabbat - Should a minyan that never recites Tachanun at Mincha say Tzidkatcha Tzedek?

This site states:

The minhag of many Chassidish kehilos is not to say tachanun at mincha. This minhag is recorded in many Chassidic and Sefardic sources. A number of explanations are offered:

1 they often daven until after shkiya, and according to many opinions tachanun may not be said after shkiya, so a blanket rule was instituted so as never to come to saying after shkiya, which in some kabbalistic sources danger is associated with this practice.

2 tachanun by mincha requires intense concentration, which most people don’t have in the middle of their day

3 after it is night in Israel tachanun should not be said even in other parts of the world

In numerous siddurim that I have seen, there is an instruction next to Tzidkatcha Tzedek (said after the Chazan's Amidah repetition of Shabbat mincha) that says that Tzidkatcha Tzedek is omitted on occasions when tachanun would be omitted. I understand this means Erev Yom Tov, Hol Hamo'ed, Rosh Hodesh, etc. But, would this include those places that never recite Tachanun at mincha, as well?

In viewing the above reasons, I can see not saying it if either it is after Sheki'ah in your local area on Shabbat, or if you wish to follow rule #3. (According to rule #3, it seems that in North America, you'd never be able to say it as even at the earliest time allowable for mincha, it's already night in Israel.) But rule #2 seems vague. I don't know what the "intense concentration" aspect is, here. Do they mean specifically business concerns or is it something else?

If places do / should say it, please explain why this is not a "contradiction".

discrete signals - Where is the flaw in this derivation of the DTFT of the unit step sequence $u[n]$?

This question is related to this other question of mine where I ask for derivations of the discrete-time Fourier transform (DTFT) of the unit step sequence $u[n]$. During my search for derivations I found one which is amazingly simple. I first saw it on page 138 of this book by B.A. Shenoi. I also came across it on mathematics.SE in this answer.

Since the argument is short and simple I will repeat it here for convenience.

The unit step sequence can be written as $$u[n]=f[n]+\frac12\tag{1}$$ with $$f[n]=\begin{cases}\frac12,\quad n\ge 0\\-\frac12,\quad n<0\end{cases}\tag{2}$$ Obviously, $$f[n]-f[n-1]=\delta[n]\tag{3}$$ Applying the DTFT on both sided of $(3)$ gives $$F(\omega)\left(1-e^{-j\omega}\right)=1\tag{4}$$ where $F(\omega)$ is the DTFT of $f[n]$. From $(4)$ we get $$F(\omega)=\frac{1}{1-e^{-j\omega}}\tag{5}$$ From $(5)$ and $(1)$ we get for the DTFT of $u[n]$ $$U(\omega)=F(\omega)+\pi\delta(\omega)=\frac{1}{1-e^{-j\omega}}+\pi\delta(\omega),\quad -\pi\le\omega <\pi\tag{6}$$ where I've used $\text{DTFT}\{1\}=2\pi\delta(\omega)$, $-\pi\le\omega <\pi$.

Eq. $(6)$ for the DTFT of $u[n]$ is no doubt correct. However, the derivation is flawed.

The question is: find and explain the flaw in above derivation.

Please prepend your answer with the spoiler tag >!.

Answer

There are infinitely many signals that make the following equality hold: $$y[n]-y[n-1]=\delta[n] \qquad (1)$$ The only thing that matters is that $y[0]-y[-1]=1$, and then the rest of the coefficients of $y$ can be determined under the restriction that Eq. $(1)$ states (i.e. the substraction of consecutive samples must be $0$ for $n\neq 0$). In other words, Eq. $(1)$ will be achieved by any signal $y[n]$ such that $$y[0]=y[-1]+1 \land y[n]=y[n-1] \ \forall n\neq0$$ Another way to see this is that any function that is basically $u[n]$ with an offset (a constant value added) will satisfy $(1)$. This explains the statement made by robert bristow-johnson in his answer: differentiators destroy this information (such as taking a derivative in continuous time destroys evidence of any constant value in the original function).

To sum up, I believe that the proof is flawed because the procedure followed could use any function of the form $u[n]+C$ with $C\in\mathbb{R}$, and this would lead to many functions having the same Fourier transform, which is indeed wrong as the Fourier transform is a bijection. Maybe the author deliberately decided to ignore anything related to DC values, conscious that in order to show that $F(\omega)$ is the DTFT of $f[n]$ he would need the accumulation property (whose most popular proof is derived from the DTFT of the unit step - ergo, a pretty circular proof). The proof is not strictly wrong, as everything it states (the formulae for $F(\omega)$ and $U(\omega)$, the decomposition of the unit step, the difference equation) is true, but it would require the accumulation property to show why $F(\omega)$ doesn't have any Dirac deltas.

grammar - Perspective of "億劫にならない" in this statement

顔面偏差値の差か、それとも日頃の行いのせいか、とにかく翔はいつも通り俺の隣でモテまくる。

まあ今に始まった話じゃないけど、翔のヤツこれでよく色々と億劫にならないな。

Context: 翔 is being popular with the ladies at the moment.

Maybe its cuz of his good looks, or how he conducts himself on a daily basis, anyways, kakeru like always, is beside me with the girls fawning over him.

... or maybe what I just said isn't the case, kakeru, this bastard, must (want/) to be so variously annoying. (kakeru is the host of a meetup, and probably doesn't want to get the way of the development of possible relationships).

Is the speaker not wanting 翔 to これでよく色々と億劫 or is the speaker saying that 翔 doesn't want to これでよく色々と億劫?

The latter makes more logical sense but the sentence still feels very strange.

Answer

「（よく/よくも）　～～～～（ね/な）」 is a commonly used phrasing that indicates amazement at how someone is able to accomplish something, although not always on a positive note.

あんなに汚かった部屋をよくこんなに綺麗に掃除できたね。

It's amazing how you were able to clean up such a messy room.

目の前で９０歳のおばあさんが立っているのによくもすわっていられるな。

It's amazing how you can stay seated when there's a 90 year old grandma standing right in front of you.

So in this case,

よく色々と億劫にならないな。

would mean something close to

It's amazing how he doesn't get annoyed at all that

halacha - plastic utensil absorption and kashering

Does a plastic utensil swallow up taste and excrete it out like metal,or is it like glass.

Also can plastic be kashered if it became treif?

What are the sources that discuss this?

tznius modesty - Is swimming unclothed ok?

Historically "bathing suits" are a relatively new phenomenon... all swimming / bathing in rivers / lakes / seas was unclothed. Culturally things have changed but does that affect halacha? There seem to be places in the Gemara which mention swimming without saying anything about the unclothed issue. The question assumes that it is in a place where one would not be observed (i.e. deserted area in nature or one's own backyard pool)

However, when you contrast this with the strict halachos about being covered in the bathroom, it seems to be a contradiction.

Answer

I'm not so sure that the premise of the question ("all swimming... was unclothed") is necessarily correct. If you look back a century or so - on the contrary, their idea of "bathing suits" was actually clothing that covered all, or at least most, of the body. That may well have been true in earlier times too.

In halachah, we find a discussion about crossing a river on Yom Kippur (Yoma 77b, and from there in Shulchan Aruch, Orach Chaim 613:5); there are cases when one is allowed to walk through water up to his neck (despite the prohibition against bathing on that day), "provided that he doesn't stick his hands out from under the hem of his garment." If I'm understanding this correctly, a person in this situation on weekdays would typically raise up the bottom of his robe to chest level or so, drape it over his arms, and walk through the water; whereas nowadays we might expect a person in such a situation to take his clothes off and carry them on his head. Granted that this is talking about walking rather than swimming, it still seems to show that it was quite normal to go into the water at least partially clothed.

On the other hand, of course, people commonly bathed in rivers and ponds, and naturally they'd do so naked. Shulchan Aruch Harav (Mahadura Basra 2:4), summarizing information from the Gemara (Shabbos 41b), Magen Avraham (2:4), and Pri Megadim (2:4), says that (a) it's not a problem, any more so than in a bathhouse; (b) one should undress and re-dress as close to the riverbank as possible, so as to minimize unnecessary nudity; (c) a man shouldn't cover his privates when going down into the river, since that makes it seem like he's embarrassed about being circumcised; (d) on the other hand, he should cover them (with his hand, or by crouching) when he comes out of the river, since then he's facing other people.

Based on this, it sounds like skinny-dipping isn't necessarily a problem, provided that standards of tznius are maintained out of the water.

Is it kosher to eat live fish

In some countries people like to eat animals that are still alive (e.g. dancing squid / octopus). Clearly these animals are not kosher, but it is also possible to eat kosher-types fish that are either still alive, or that may appear to be alive (e.g. still moving).

1) The Noahide laws (when translated to English) prohibit eating flesh taken from an animal while it is still alive. But, are fish considered to be animals in this case? 2) According to my research, the act of removing fish from water qualifies as slaughtering them. But, removing fish from water doesn't actually kill it.

So, is it kosher to eat a live fish? There's a mention that it is kosher here: Why do Fish not need Shechita? , but there's limited discussion on the matter.

edit- to restate my question: Is it kosher to eat a live fish?

Answer

Rama on Yoreh De'ah 13:1 says that it is forbidden to eat a fish while it's alive due to it being disgusting. (Baal Teshakzu)

Mishna Torah Hilchos Shechita 1:4 says it is permitted to eat live fish.

messianism - Is the chabad performing under valid Orthodox Judaic rules

I see many Chabad centers around , is Chabad an Orthodox Jewish organisation ? And which major authorities (Like Chief Rabbinate of Israel) recognize them as such?

To clarify further , is Chabad an Orthodox Jewish organization or a Messianic one?

history - What should our response be to ancient scripts that mirror the Torah?

There are quite a number of ancient documents that have been found that (supposedly) predate the Torah, and yet they share many lines practically verbatim. If the Torah is truly divine, how could this be? Seems as if many lines were directly copied and borrowed from other, earlier works.

Another example of this would be that there have been ancient plans discovered that are almost exactly the design/layout of the Mishkan, but, of course, predate the Mishkan by quite a while. How, then, can the Mishkan be divine, as we would say that it is?

What should our response be to these sorts of issues?

Answer

You make a mistake in assuming that in order for something to be divine it must be completely original.

To understand the Torah and G-d's intentions and its applicability to modern times does not require cutting off and ignoring the societal backdrop of the Torah's historical time period. This means that although there may be some slight similarities in certain laws to the Code Of Hammurabi or similar themes in the flood story to the Epic of Gilgamesh, its not concerning. The Torah does not claim to be the sole source and originator of judicial law, society's were governed by law, way before the Torah was given i.e. Derech Eretz.

Rather, the Torah is coming "to set the record straight". Meaning that the intention of "re-stating" the laws either to infuse mundane societal laws with divinity and the novel concept of a G-d centered moral code which up until then was primarily dictated by rulers.

Regarding the flood story, the Torah repeats it in order actually tell the "true story" of the flood, devoid of all the idolatrous aspects that crept in over the generation as a result of it being retold again and again. (IIRC Rav Dovid Z Hoffman makes this argument, but I can’t seem to find where)

Furthermore, without an intimate knowledge of Akkadian or Hyroglyphics or other ancient Semitic language its almost impossible to claim that verses were taken from one source to the other. The nuances of these languages can sometimes change the entire meaning of a inscription. (Heard from Rav Aharon Lopiansky)

In regards to similarities to the building of the Mishkan. Human history is rife with mans desire to reach out to G-d in many forms of altars and worship centers. But the difference in Judaism is that the commandment to build the Miskhan: "ועשו לי מקדש ושכנתי בתוכם": marks the first time that G-d reached out to man to build. That alone suffuses the keilim - holy vessels in the Mishkan with profound divinity.

Thus, you could find similar, or even the exact same floor plans of the Mishkan anywhere in the world, but at its core and essence it is completely different entity from the Mishkan. (Heard from Rav Yechiel Perr, in writing here as well)

I suggest the Shiurim of Rav Ahron Lopiansky on the topic archaeological evidence and the Torah which can be found here.

grammar - How to use the inflection "やがる"?

こんなくそみたいな帽子{ぼうし}かぶせやがって！

"こんな仕事{しごと}させやがって！"

"こんなまずいものを食{く}わせやがって！"

"あいつは本当{ほんとう}に良{い}いものを作{つく}りやがる"

I was recently acquainted with the inflection "やがる," as illustrated in the examples above. Would it be right to describe it as a 活用形 (inflection)? Can anyone explain how to use it and what role it serves?

Answer

やがる is a verb since the endings it takes is the same as the other verbs:

食べやがる non-past
食べやがった past
食べやがれ imperative

etc.

やがる attaches to stems; it is an affix that attaches to a verb and creates a verb.

Its meaning is to add the first person's feeling that the act was done disfavorably or turned out to be disfavorable to the first person. It is the opposite of -てくれる, which expresses the first person's feeling that the act was favorable. Unlike -てくれる, though, やがる is colloquial and mildly insulting.

帽子を被せる
'put a hat on someone' [Neutral]

帽子を被せてくれる
'put a hat on someone' [Favorable]

帽子を被せやがる

'put a hat on someone' [Disfavorable]

In your last example, the reason やがる is used despite the positive connotation from よいもの is because the first person is expressing jealousy (serious or not). From the point of view of the first person, it is not a good thing that the other person made a good thing.

---

Traditional grammar confuses classification of words based on their meaning and classification based on the (morphological) form. It considers whatever word or morpheme that has the meaning comparable to the meanings expressed by auxiliaries in western languages (such as modaility, etc.) as 助動詞 'auxiliary verb'. However, parts of speech is a morphological (and syntactic) notion. It is a classification of words and morphemes based on their forms. It has nothing to do with the meaning. The traditional classification is inappropriate.

Furthermore, in modern analysis of Japanese, there is no such thing as 活用形. All there is is the verb stem, and an affix that attaches to it. What traditional grammar calls 活用語尾, on which 活用形 manifests, is actually the initial vowel of the affix (and/or some few sounds surrounding it). For example, traditional grammar says that the negative form verb 書かない consists of the stem 書, its 活用語尾 か and a 助動詞 ない. But notice how unsophisticated and complicated that analysis is. In modern analysis, all there is is the verb stem kak- and the negative affix -anai　(which is itself an i-adjective).

halacha - The Rambam's Nekudah Neflah (נקודה נפלאה)

I heard two people learning about Issur Kolel and Issur Moisif. They kept talking about the Rambam's Nekudah Niflaah. What is it?

Answer

from here:

The RAMBAM (Perush ha'Mishnayos to Kerisus 3:4) explains that when the Torah prohibits eating meat with milk, and benefiting from a mixture of meat and milk, it uses the same phrase, "Lo Tevashel." The use of the same word teaches that when the Isur of Achilah does not apply, the Isur of Hana'ah also does not apply. With regard to a mixture of Neveilah with milk, if the prohibition to eat meat and milk does not take effect because "Ein Isur Chal Al Isur" (since the mixture is already prohibited to be eaten because of the Isur of Neveilah), then the Isur of Hana'ah also does not take effect, and thus it cannot be an "Isur Mosif"! (The Rambam refers to this explanation as a "Nekudah Nifla'ah" -- a "wonderful point.")

A link to the Perush ha'Mishnayos inside.

gentiles - Marriage to a non Jew

Can a Rabbi, marry two people, in the United States,where one is not Jewish, and have this to be valid to receive a marriage certificate by state, and also rabinnical standards.

I looked through the 613 http://www.jewfaq.org/613.htm and did not find the answer.

tisha bav - Disparate Zemanim in the same local community

Someone pointed out on a local email list that the ending time for Tish'ah BeAv is listed differently - significantly so - at various institutions in our local community. He noted the following times published:

Large Orthodox A and Large Orthodox B 9:20

Chabad 9:08

Sephardic 8:55

According to the Orthodox Union, none of the above times is even close (within a minute or two) of the Zemanim I would expect:

Tzeis 42 Minutes 9:14 P Tzeis 72 Minutes 9:44 P

The closest is Chabad, which is posting a time 6 minutes earlier than the earliest time listed at the OU. Furthermore, the differences in times seem to only occur on fast days; this year's 9 Av schedule appears, to me, to have the most widely divergent times published here.

What accounts for this disparity? What formula(e) might these organizations be using that they disagree so markedly?

FFT-like algorithm for fast DTFT computation?

Good morning!

I'm coding up a project on a microcontroller to read in some analog audio (specifically, the sound of someone whistling: a near perfect sine wave) and determine which piano note tones are present in the signal.

Although the FFT is the obvious first choice, the frequencies I wish to detect in the signal don't line up with the FFT frequencies. Furthermore, I only want to detect around 10-15 frequencies, not the whole spectrum.

So my thoughts quickly turn to the DTFT, which can be implemented with a matrix multiplication (here is my prototype MATLAB code. Details provided on request). However, surprisingly, it still takes more computation than an entire FFT!

This brings me to my question. I've made all the obvious google searches ("fast DTFT", "FFT for specific frequencies") without much luck. Does anyone here know of an efficient DTFT method?

rambam - How would the splitting of the sea have been done with magic if magic is just trickery?

In the spirit of the recent Mi Yodeya discussion of the Rambam's view of magic, a question that has bothered me for some time:

The Rambam ostensibly doesn't accept that there is any reality to magic, everything is done through slight of hand and trickery, and the Torah's prohibition is against exactly that trickery. (See here for more on that.)

However, in Yesodei HaTorah 8:1 the Rambam writes that Moshe would not have been relied upon absolutely due to any of the wonders he performed, because they could have been done through magic:

משה רבינו לא האמינו בו ישראל מפני האותות שעשה. שהמאמין על פי האותות יש בלבו דופי שאפשר שיעשה האות בלט וכשוף.

The Jewish people did not believe in Moshe Rabbeinu as a result of the wonders that he performed, for one who believes according to wonders always has some doubt in his heart, maybe it was done through magic.

The Rambam then procedes to give examples of some of those miracles which were not done to produce belief. All the examples seem difficult to pull off as a slight-of-hand trick, but here's just one:

היה צריך להשקיע את המצריים קרע את הים והצלילן בתוכו

He needed to drown the Egyptians, so he split the sea and sunk them in it

If magic is fake, how could these things have possibly been performed through "magic"?

kiruv outreach - How to convince your Jewish athiest friend to become shomer mitzvot?

If one has a friend who's and atheist--someone who believes in evolution, big bang, etc--what methods can you use to convince him to abandon his old ways and start keeping some of the mitzvot?

Bible codes can be chalked up to coincidence. Proofs from the laws of the kashrut can be said to be generalized and not conclusively proven. Predictions prophesied can be retorted by saying that if you look for something in such a vast collection of texts anything could be found. If you try to suggest torah lectures for them to watch, they will say that they don't have an hour to listen to nonsense.

Granted atheism can be used as a device to rationalize not following the Torah or God, can any method in particular penetrate this particular mindset?

Answer

One of my teachers at KBY told me the following story:

A chossid went to his rebbe and asked for a segula for his son to grow up to be a talmid chochom.
The rebbe said "Go, sit down, and learn."
"I'm sorry, rebbe, I didn't say that clearly enough. I'm looking for a segula for my son to be a talmid chochom."
"Go, sit down, and learn."

"But rebbe, I'm not asking for myself; I'm asking for my son!"
Finally, the rebbe explained, "Don't you understand? The most important thing you can possibly do to get your son to devote himself to learning Torah and becoming a talmid chochom is to do that yourself. Your example is the most powerful influence you have on him."

I think this principle applies to influencing friends, as well. The most powerful tool you have for inspiring others toward belief in God and observance of His Torah is to strengthen your own belief and observance as much as possible. You probably don't have a connection with your friends like a father has with his son, but to the degree that you are able to maintain a relationship of mutual love and respect, your friend will have a chance of being influenced by your example.

טוב לצדיק טוב לשכינו
Good for the righteous one; good for his neighbor.

Abbaye, Sukka 56b

halacha - changing one's Hebrew name

Sometimes a sick person changes his Hebrew name or adds to it.

Is there a problem (halachically or otherwise) with changing one's Hebrew name, for someone who is not sick? For example, he prefers a different name for whatever reason.

I am especially interested in halachic problems with this.

Answer

According to the Halacha a person has the right to change his name to whatever he or she likes.

But the Minhag is not to do so without a valid reason, and only after consulting a prominent Rabbi, due to many complications that could arise in result of that, and for other reasons as well.

source: Kobetz Ginas Verdim

halacha - Are "clickbait" links permissible?

Wikipedia defines "clickbait" as follows:

Clickbait is a pejorative term describing web content that is aimed at generating online advertising revenue, especially at the expense of quality or accuracy, relying on sensationalist headlines to attract click-throughs and to encourage forwarding of the material over online social networks. Clickbait headlines typically aim to exploit the "curiosity gap", providing just enough information to make the reader curious, but not enough to satisfy their curiosity without clicking through to the linked content.

Is it permissible to use this sort of technique in ads, social media posts, etc., to drive traffic to one's content?

I expect that the main issue would be, to the degree that it's present, tricking people through false representation of what's on the other side of the link. If that's the case, are there guidelines about how to determine what's too dishonest that could apply here?

hashkafah philosophy - How to go about finding a personal Rav

The mishna in Avot (1:6) tells us:

יהושוע בן פרחיה וניתאי הארבלי קיבלו מהם. יהושוע בן פרחיה אומר, עשה לך רב, וקנה לך חבר; והוי דן את כל האדם לכף זכות

When living in different areas I have gone about this in different ways. Having moved to Israel I have struggled finding a personal Rav. Relying on Rabbeim that I had in my previous country of residence is not an option since many minhagim are different, as are the specific laws of the land, and (in particular) very current issues relating to kashrut.

I know many that rely on their Rabbeim from their time in yeshiva; I don't feel that I those connections are the correct ones for me.

I am looking for advice or experience that could help a person in this process.

grammar - Can ごとに be replaced by それぞれ in this question?

正月は家ごとに門松を立てる。

For example, could I say

正月はそれぞれの家に門松をたてる。

If so, the meaning remains the same, or are there any subtle nuances that comes with each word? It seems to me, whenever i see sentences with either words, that sometimes they can be interchangeable and sometimes it just seems weird replacing one with the another. More specifically, some sentences with ごとに could be rewritten using the pattern それぞれの (which in this case acts as a pronoun), for example:

木村さんは会う人ごとに挨拶している。 -> 木村さんはそれぞれの会う人に挨拶している。 Is the second sentence above by any chance correct?