2021/08/26

Deep Learning: threshold θ and bias b

The output y of a single-node neural network can be represented as:

y = a(Σw_ix_i - θ)

where a is the activation function, x_i is the i^th input, w_iis the i^th weight, and θ is the threshold.

When the summation of wighted input Σw_ix_i is less than θ, the neuron does not output. Hence we call θ the threshold, which is similar to the threshold potential in a physical neuron.

We may replace θ by -b and get

y = a(Σw_ix_i + b)

where b is called the bias parameter.

So b = - θ is a more generalized representation for the threshold.

References:

A Beginner’s Guide to Neural Networks: Part Two

Hinton Neural Networks課程筆記2b：第一代神經網路之感知機

深度學習的數學：用數學開啟深度學習的大門(博碩) p.12-16

Audacity: Silence the selection of the sound track 將選取的一段音軌靜音

This is a function of Audacity.

To mute a selection in Audacity, simply click the button for 'Silence audio selection'.

Result:

Related Information:

Audacity: Change audio speed and keep the pitch of the talker unchanged (StudyEECC)

Audacity: Change the sample rate from 44.1 kHz to 16 kHz (StudyEECC)

2021/08/25

在LaTex使用中文 How to show Chinese characters in LaTex

對於LaTex新手來說，使用中文可能會遇到一點小麻煩，不過其實並不困難，只要使用CJK套件，然後在中文的部分載入bsmi(明體)或bkai(楷書)字體即可。本文以Mac TeXShop環境為例：

LaTex程式碼：

\documentclass{article}

\usepackage{CJKutf8}

\begin{document}

The blog `StudyEECC' (\begin{CJK}{UTF8}{bsmi}電機、電子、通訊、電腦資訊工程的學習筆記\end{CJK}) was started in August 2016.

\vspace{\baselineskip}

\begin{CJK}{UTF8}{bkai}已經5年了！\end{CJK}

\end{document}

輸入後：

\end{document}

按Typeset鍵，執行結果如下：

以上程式可在IEEE格式 \documentclass{IEEEtran} 中執行

參考資料：

LaTex 的中文設定(陳鍾誠的網站)

2021/08/09

This Study or Research? 談談「這個研究」

講到研究，很自然想到Research這個英文字，例如做研究- do research.

因此，在寫理工領域的英文paper、文章時，當我們想要說明「本研究」、「這個研究」時，很自然會想要寫 "this research"

然而，當你請以母語是英文的人來使用修改文章時，他們常會告訴您：research是複數型(但文法上是單數)。

這個時候，困擾就來了！我的「這一個研究」是單數，所以能用research這個字嗎？用study比較好？

網路上寫說：

If you find yourself writing "a research" or "in this research," change it to "a study" or "in this study."

我個人的理解是，如果是某個領域研究的統稱，包括了許多的studies，這種大範圍的研究集合起來可稱為research，例如人工智慧的研究，稱為artificial intelligence research，或AI research。

當然，我的研究也包含了不少東西，因此可以說my research，我的研究興趣則是my research interests

然而在正式的論文中，提到「這個研究」時，寫this study通常比較正確。

我找了5位英文母語作者，都是我所研究的領域中有名的專家，國籍包括了美國、英國和澳洲，每個人的一兩篇期刊papers中，study這個字頻繁地出現，只有一篇在最後提到this research was supported by 某某機構，而其中的幾篇paper中甚至從未出現 research這個字！

上述的papers，講到「在這個研究中」時，大概都是說：

in this study

in the present study (有些同一篇文章後面再簡稱為in the study)

因此，以上的兩種study的用法看來比較正確

我想，再多的解釋都不如自己做點「研究」，您可試著用Google Scholar，找幾篇自己研究領域的papers，而且作者都是以英文為母語的人，搜尋看看每篇paper中他們怎用study跟research～😄

以上是個人淺見僅供參考，若您有不同的想法或更棒的解釋，歡迎在下面分享～

本文只是對於research和study名詞的一點心得，至於「研究」的動詞，有機會再分享吧～

Reference:

Research vs. Study

2021/08/07

How to search for a specific journal with Google Scholar? 如何用Google Scholar找特定的期刊

用Google Scholar找特定的期刊一點都不難，只要加關鍵字source即可！

To Search for a journal with Google Scholar, simply add this:

source:"Journal Name"

For example:

dnn pattern recognition source:"ieee transactions on biomedical engineering"

sound classification source:"Journal of the Acoustical Society of America"

covid vaccine iot source:"science"

Reference:
How to search for articles from a specific journal in Google Scholar when the journal name is a subset of other journal names (e.g., Science)?

2021/07/10

Audacity: Change the sample rate from 44.1 kHz to 16 kHz

To change the sample rate of a sound file is easy. Just use Audacity.

Select the sound tracks and then select Tracks/Resample.

Enter the new sample rate, e.g. 16000.

Press OK. The sample rate becomes 16000 Hz.

Related Information:

Audacity: Change audio speed and keep the pitch of the talker unchanged (StudyEECC)

2021/06/12

Audacity: Change audio speed and keep the pitch of the talker unchanged

If the speed of a sound file is increased, the pitch is also increased. This experiment can be easily made using Audacity.

Select Effect/Change Speed to change the speed of the sound file.

Increase the speed by 50% in this example.

The sound file is shorten to 2/3 of the original length.

By playing the new sound file, the pitch of the sound is increased. This phenomenon is known as the chipmunk effect. In the very early video clip for Chip 'n' Dale, "Private Pluto" video clip in 1943, the voices of the two chipmunk roles were produced by speeding up normal speech. (Wikipedia)

If we want to speech up without changing pitch to higher frequencies like chipmunks, simply choose Effect/Change Tempo instead.