Sunday, May 25, 2014

On skin allergy

I've been chronically suffering from skin allergy, at least since when I was three, for more than 46 years. The fear of itchiness haunting me and distracting me from focusing onto what I'm doing is so deep that I still really don't want to freely talk about it.

I will write about it anyway, however, to speak up about my own weakness, and unfair discrimination against me due to the skin allergy.

My history on allergic skin

During my childhood and teenage years I got a lot of severe allergic reactions on many parts of my body. The toughest one was on my right eye which caused cataract.

The second toughest allergic reaction was during May to June 2002, when the percentage of the eosinophils among the white blood cells exceeded 33% of the whole white blood cells, whose regular value for healthy people was between one to five percents. I was suffering from chronic oozing of blood and lymph from damaged skin on my legs and elsewhere I had to scratch due to simply unbearable itchiness. I was on the verge of sepsis, which would be lethal. I got hospitalized and had IV treatment of pulse steroid therapy for a few weeks, and had a daily skin-protection treatment for two years.

The third toughest allergy-related attacks on my skin are chronic shingles appearing on my left inner thigh in 1979, and on my face and neck, on 1983, 1987, 1988, 1992, 1995 (twice), and 2002. Before anti-VZV medicine became available in 1990s, I had to suffer the pain of damaged skin and nerves for more than a week after every shingles attack. While I am lucky enough that no visual sign of shingles is left on my face, the deep and untreatable pain still often emerges, especially when I'm under a server mental and physical stress. Fortunately, since 2002, I've never experienced a severe attack at all.

I am still suffering from skin rash, nevertheless, especially on my neck and genital area due to the chronic persistent damage. This is one of the reasons I don't want to wear ties and white business shirts; I usually wear cotton-made polo shirts or T-shirts and a loose-fit pair of pants (cargo or chino), to get rid of the possible sources of skin allergy.

Skin allergy is about the immune system

There are lots of misunderstandings on allergic reactions, and the medicines and treatments used to deal with the symptoms. I was one of them who didn't really treat the disease or symptoms in the right way until the year 2002, when I was 37. Note well: you need to discover your own way to find out how you treat yourself. My stories are not necessarily applicable to you.

Ointments, creams, or lotions with steroids are essential and necessary to alleviate or mitigate the irritation and inflammation. The problem is that you shouldn't use those with antibiotics unless absolutely necessary; they are often too strong. And when you use steroids, you need to monitor your immunological condition regularly (once a month or even more); otherwise your skin or immune system in general may over- or under-react and will cause a fatal consequence.

I should also say that you can't stop scratching your skin when you feel itchy. Can you stop the reaction of coughing or asthma? You can't (or otherwise you will suffocate). So don't advise the patients of skin allergy to endure the torture of itchiness; instead help them solve the systematic immune problem by consulting to a dermatology and/or immunology specialist. The treatment strategy will not be accurately defined unless checking out the portfolio of the white blood cells and other notable markers of the patients.

Discrimination against skin allergy patients

The social stigma of having skin allergy, eczema or dermatitis, is enormous in Japan. Having damaged skin especially on the parts of the body exposed to the public will significantly degrade the self confidence of the patients. The damaged parts of skin are not infectious to other people, but quite often the patients themselves are prone to get infected by the common germs and viruses such as staphylococcus aureus.

Japanese social norm of forcing all business people (especially men) to wear ties and white-collar dress shirts (which are also stiff and cause more damage to the skin) is inherently very discriminative to the patients of skin allergy. Quite often the patients are targets of bullying and social exclusion. The easiest way to solve this is to allow wearing the less intrusive shirts and pants, unless absolutely necessary due to the external or more formal dress code (which I try to avoid as much as possible).

Patients of skin allergy or any forms of allergic reactions should not be victimized just because they are suffering from the symptoms. They are suffering from diseases which are not responsible on their own. People should recognize some people need regular intake of pills and ointments to survive, and don't laugh at them because of the needs. I've once been orally harassed from colleagues when I took necessary pills after a lunch meeting.

What I've lost and I've gained

I've lost many chances due to the skin allergy. I have to stay in the area where I can get the sufficient medical treatment in affordable manners, and I should be very cautious on exposing myself in outdoor activities. I don't swim (though I can), because I don't want to get myself damaged by the chloride in the pool water or even the sea salt. I don't enjoy natural hot springs by the same reason.

On the other hand, suffering from skin allergy makes me pursue more modest way of life, and makes me very self conscious on the medical condition of myself. After all, you've got to live with what you've got and what you've got to suffer from.

I always thank my partner Kyoko for living together with me for 22 years, before, during, and after the whole allergic skin mess in my life. And I know it's not over so I've got to be very careful as always.

Thursday, April 24, 2014

My new startup: Kenji Rikitake Professional Engineer's Office

This is an announcement of my new startup business.

I've started my own business, as a Japanese government-licensed Professional Engineer of Information Technology (in Japanese it's called Gijyutsushi), since April 21, 2014. It's called Kenji Rikitake Professional Engineer's Office (KRPEO).

KRPEO provides the consulting and engineering services on information technology in general, including but not limited to: information and network security, the design, deployment, implementation and performance tuning of Erlang/OTP, FreeBSD, and Riak. KRPEO will provide all services in both Japanese and English.

I had been looking for a full-time job since October 2013, and I made a conclusion that the job market near Osaka was mostly for energy-consuming legacy programming tasks due to the fact that most of the high-end software engineering companies were only located in Tokyo. Most of the employers in Japan do not accept remote teleworking due to the cultural and legal reasons either. So I had to lean out from the traditional corporate culture of Japan, for a more sustainable business model, making myself, my family, and my customers happy at the same time. I understand this is a hard challenge, but I will definitely take it.

My involvement in the open-source developer and network operator communities in Japan and the world will remain the same and unchanged.

The English announcement site for KRPEO is at The Japanese site URL is:

Update 28-APR-2014: add the URL of the English site, correct the URL of the Japanese site.

Thursday, April 3, 2014

Erlang Factory SF Bay 2014: list of some notable talks

(Photo: a shot during my talk by Yoshihiro Tanaka, used by permission)

(Disclaimer: there were too many talks I wanted to listen to, but I couldn't.)

Here's the list of talks I thought intriguing for Erlang Factory SF Bay 2014 (links are to the slides or videos):

I also wanted to listen to the following talks, and found the slides intriguing:

I will post my impressions for the above talks in later articles. I would like to note some personal impressions for the audiences this year:

  • Erlang is no longer an exotic language or system. The audiences want the real solutions and hints.
  • Elixir is gaining popularity, and will surely contribute to reduce resentment against BEAM (Erlang VM) and the ecosystem.
  • The implementation talks were getting more detailed and hard core, and the questions were also more specific.

Video quality

Thanks to the hard-working video and audio recording and editing team, this year's video quality is very high in overall. While the live streaming was not possible due to the prohibitive cost, some videos were made available within six hours from the end of the talk. I think this was impressive and a practical solution to make a trade-off between the turn-around time for the availability and the quality of video of the talks.

[To be continued in another article]

Monday, March 31, 2014

Erlang Factory SF Bay 2014: erltrek and the beginning

(Badge photo by Kenji Rikitake)

It's already been near a month since Erlang Factory SF Bay 2014 as I'm writing this blog article. It was my fifth Erlang Factory, consecutive once a year since 2010. The topic I've talked are so diverse:

  • 2010: SSH RPC
  • (sponsored by NSIRG, NICT, Japan)
  • 2011: SFMT on Erlang
  • (sponsored by ACCMS, Kyoto University)
  • 2012: IPv6 example of DNS simultaneous resolution with IPv4
  • (sponsored by IIMC/ACCMS, Kyoto University)
  • 2013: Riak on amateur radio data analysis
  • (sponsored by Basho Technologies)
  • 2014: Star Trek game revisited
  • (this year no sponsorship - I paid all by myself - thanks Erlang Solutions for accepting my talk proposal!)

The topic list shows how broad range of subjects and topics which Erlang and OTP can cover.

Highlights of this year

There are so many things I have to write about for Erlang Factory in this year 2014. Listing the topics (before I forget) here:

  • My erltrek implementation of the Star Trek game (immediately modified into a completely new thing, with a great help and massive contribution from Andreas Stenius)
  • Erlang Foundation and Intermediate Certificates
  • (Foundation: passed, Intermediate: failed.)
  • Concuerror (invitation-only) workshop by Kostis Sagonas
  • Elixir tutorial by one of the Erlang Gang of Four, Robert Virding
  • Fréd Hébert's presentation and autograph on LYSE
  • ... and many more

So let's start from the erltrek.

Why Star Trek?

The ultimate reason is: no one seemed to did it. Period. It was a completely improvised idea, after I was browsing the FreeBSD old games library, reading the BSD Trek code, written by Eric Allman (one of the Sendmail people), in ANSI C89. The BSD trek's last update date was in 1993, so it was a 20-year old code. I decided to rebuild the game in the following procedure:

  • Read the C code
  • Port it to Lua so that I can at least read through all the C functions
  • Rebuild the Lua code (luatrek) into more Erlang-ish one

Was the strategy successful? I think it was not bad, but the part of rebuilding into Erlang was revealed utterly insufficient, soon after I opened up the code. I will describe the reason later in another article, but the main reason of failure was that my thinking and design of the code were completely procedural, neither fully functional, nor Erlang process-based. I have to write that I've been doing the coding and reviewing of the erltrek software even after I come back to Japan from the Erlang Factory event; that is one of the reason why this article gets so late. It's still a work in progress, as of 31-MAR-2014.


Marines' Memorial Club and Hotel again hosted the Erlang Factory. In fact they also hosted a part of JavaScript event series called JSFest at the theatre (a very nice and large one) on Sunday 9-MAR-2014. There was no fire alarm this year (as it happened in the 2011 and 2013 events.) I didn't socialize much, as I don't as usual (I'm not really an extrovert person), but this year I had a few dinner hangouts with the Erlang all stars and I really enjoyed them. The hotel service was very good and my favorite chicken-flavored S.O.S. Oatmeal was always there at the breakfast; and the catering was very good as well.


I met a lot of people. Monika, Andra, and Alison of Erlang Solutions, and all the staff members including the volunteers, kept running the conference and all the other events very smoothly. Meeting with old Erlang friends, especially the Francophones including Fréd Hébert, Loïc Hoguin, and Benoit Chesneau, was always intriguing (especially when the three were having a very heated discussion in French.) Greeting Basho people was also nice. I will not mention all the people in this article, but it was nice to meet a newcomer from Japan, Keisuke Takahashi; he showed a strong interest into the Elixir language and I'm sure he'll drive a community in Tokyo soon.

[To be continued in another article]

Monday, September 30, 2013

Leaving Basho - many thanks!

I will resign from Basho. 30-SEP-2013 will be the last day.

I'd like to thank everyone in Basho, especially Basho Japan KK members. Having been a part of the teams will be an unforgettable experience.

I will continue supporting Riak and Erlang/OTP after leaving Basho, as I've been doing so since long before I joined the company.

My next step is yet unclear for the time being, but I'm sure I will still be a part of computer and internet professional dev and op communities. There will be a lot of challenges, but I will take them.

Thanks again to the people who supported me during my Basho days.

Tuesday, August 20, 2013

Learn You Some Erlang for Great Good! (a review)

Learn You Some Erlang for Great Good! (LYSE) is one of the best books to learn about the programming language and the system Erlang/OTP. This article includes a brief review about LYSE of No Starch Press version, my impression about the author Fred Hébert (Fred), and related miscellaneous things.

Fred is a young person. I assume he was born in the late 1980s. That itself makes LYSE extraordinary. The writing style of LYSE is purely casual and conversational; it's quite different from other Erlang classics, such as Joe Armstrong's Programming Erlang (I'm eagerly waiting for the Second Edition!) and Erlang Programming of Francesco Cesarini and Simon Thompson (I'm also eagerly waiting for a new book from the authors with Robert Virding this time!), let alone the first book of Erlang called Concurrent Programming in Erlang published in the 1990s. Those classic books are written by much older people, and they follow the traditional textbook format. LYSE does not. You will also be surprised by the illustrations drawn by Fred. Those drawings are so creative that I've even got distracted with them while reading the otherwise very technical and detailed contents. Maybe I've got too old. Nevertheless, you need to know LYSE is not an ordinary textbook.

I've seen no book on Erlang about the complete coverage of the language and the OTP library other than the online manual at and the source code repository at GitHub. LYSE is not a manual either; it is rather a collection of live stories and practical examples of Erlang based on the hard-earned experience of Fred himself. It's written for those who actually write the code, develop the packages, and release the products. For those who want to study from the very beginning, I recommend Simon St. Laurent's Introducing Erlang.

I will avoid digging into explaining the whole contents of LYSE, because the explanation will take the same amount of words the book has. LYSE is a thick book which has approximately 600 pages, so it's not something for an easy reading. I have to confess there are many things I didn't know and I haven't tested yet in the book. The book hyper-comprehensively covers the necessary topics for dealing with the day-to-day tasks on Erlang/OTP development, from the language basics to gen_server, (the rage against the) finite state machines, package release, Mnesia and the OTP internal database modules, and a proposal of how to read all the Erlang punctuations in English.

In LYSE, the semantic details of the language and system elements of Erlang/OTP are meticulously well-written. One of the most impressive contents is about the intentional avoidance of tail-call optimization in the try-catch exception handling; Fred simply writes:

The protected part of an exception can't be tail recursive.
(Chapter 7, “Protecting The Right Thing")

I will not explain the reason here, but this sort of caremad attitude in the details makes LYSE a professional handbook, if not a textbook (and it is not, I repeat.)

Fred is a very talkative and energetic person. I really admire the level of his English fluency especially when he makes a thunderstorm-like (real) lightning talk. He is also helpful and has assisted a lot of newcomers as his erlang-questions mailing list articles show. The book represents his personality very well. If you are an experienced programmer, LYSE is also an interesting book as a general reading, because the book will remind you of how you have been self-teaching yourself.

I recommend LYSE to all those who want to learn Erlang and OTP, especially to those who want to experiment and self-learn the language and system. If you want to know the contents first, check out the free online version.

Appendix: about the book title

When I saw the title of LYSE first time, and when I saw the title of the cousin book of LYSE about Haskell called Learn You a Haskell for Great Good! (LYAH), I thought there was something severely wrong with the grammar, even from a speaker of English as a second language. I've learned at school that the verb learn will not take a person as the object, and so does my New Oxford American Dictionary built into OS X say. I had a hard time to explain the meaning of this sentence to some Japanese experts who are not familiar with this type of non-standard English sentence. And I have to confess the phrase “Great Good” looked non-standard to me too.

On the other hand, the title of LYSE looks much more understandable to me if I see it as a literal translation of a non-English Indo-European language. Fred is a proud francophone Quebecker, and he is also an excellent English speaker and writer. I can imagine Fred reads and understands the title of LYSE in a complete different manner than I do. So I will complain no more about the title of LYSE or LYAH.


I've been sent a review copy of LYSE from No Starch Press on January 2013. In this article I mostly refer to the No Starch Press version, though I also have read the online free version. Note well: I have ordered and purchased my own copy of LYSE from No Starch by myself before receiving the review copy!

I should also note that I've met Fred at least three times at Erlang Factory SF Bay Area 2011, 2012, and 2013, so this review may be heavily biased. (I hope this review is not too late, Fred!)


Thanks to Jessica Miller of No Starch Press for sending me a copy of LYSE and helping me about what to do with the 600 pages of paper :)

Wednesday, August 7, 2013

AM Radio: No Longer Practical?

Noise from modern electronic devices are killing the media

This is a popular article among my pieces of writing at

(Photo by Patrick Fitzgerald/Barelyfitz)

History tells the pollution has been the repeating problem which the civilization must solve. The radio airwaves are getting polluted too. I fear that AM radio broadcast will no longer be practical if modern electronic devices with the switching power supplies and computers become ubiquitous and necessary to maintain our lifestyle. Conversion or migration from AM to the FM radio will be an easiest way to solve this problem, at least for the dense population areas.

I’ve been struggling to listen to the AM radio inside my house for many years. I think the listening condition in my house might be still better than that of the other people. If I tolerate the buzzing tones,I will still be able to enjoy the programs. I have to keep the small radio receiver away from the cell phone units or anything running computers or other wireless devices, though.

I can no longer listen to the radio near my LCD displays, the laptop computers, and the tablet devices, without proper shielding of the radio and the external antenna outside the house in the open space. I can’t listen to the radio when I’m in the restroom equipped with a Washlet; the water spraying unit is driven with a switching power supply, which generates the noise effectively blocking the radio station signals.

AM radio, or the medium wave frequency broadcasting on 540-1710kHz in the Americas (531-1611kHz in the rest of the world including Japan), has been popular for more than a hundred years. The transmitter often requires nearly a few hundred kilowatts to cover the entire nation, but it works very well, especially during the nighttime when the ionospheric propagation enables the airwaves to reach much further than that in the daytime. For example, in Japan, NHK Radio Two Tokyo at 693kHz transmits 500kW from the antenna site in Kawaguchi City, Saitama, covers nearly twenty million households even during the daylight hours, and is heard very well regularly in Osaka and the other regions nationwide.

The AM in the AM radio stands for Amplitude Modulation. AM radio listeners only needs a simple equipment to convert the radio signals into the sounds. Crystal radio receivers, which have been widely used since the beginning of the 20th Century, are the simplest form of radio. They still work well when the transmission site is near enough. Most of the modern radio receivers convert the frequency of the received signals to the audio frequency range signals, however; superheterodyne receivers is the de facto standard since the transistors got commoditized in 1960s. You can even listen to the AM radio through the digital signal processing technology, on the software-defined radio receivers. So the technology is still alive and thriving very well.

The problem is, however, that more and more electronic devices emit various type of noises on the same frequency spectrum which is used for the AM radio, from the power suppies. It’s not just Washlet; it’s everywhere from the laptop computers to the LED ceiling lamps.

Modern power supplies use the technology called switching voltage regulation; the power supply acts as a high-frequency automatic switch to control the energy flowing into itself,and sends the energy to the devices. The output voltage is controlled by the ratio of the periods of turning the switch on and off. The switch is rapidly controlled to maintain the stable output voltage in the frequency of many hundred thousands times per second. This rapid-switching technology is essential to maintain high power conversion efficiency and low power loss, which cannot be achieved by the legacy power regulation technology called series voltage regulation, which does not use the rapid and abrupt switching, but generates considerably more heat and is much less efficient energy-wise for continuous voltage regulation.

Unfortunately, power switching causes generation of strong electromagnetic noise of the very wide spectrum, and the switching frequency itself is close to the one for the AM radio. The first switching power supply I saw was that built into Apple II computer in 1979. It was large, but still much smaller than the equivalent legacy series-regulated one. I immediately noticed that the sound coming out from the radio near the Apple II suggested how the CPU was working; computers then were not shielded well. I could also hear the power switching sound, emitted from the small voltage transformer inside.

The switching voltage regulation technology is so pervasive that now I see virtually all digital device around me are attached to the switching power supplies; the USB wall warts, laptop PC AC adapters, and the units built into various appliances from computers and even to the commercial and amateur radio transceivers, for more efficiency with less energy consumption. Reverting back to the age of series voltage regulation is simply impractical; no one will want to carry around a power supply which weighs many kilograms for a small laptop or a smartphone.


Modern radio modulation schemes are robust against various sources of noise. AM radio uses the voltage level, or the amplitude, of the airwaves to carry the information, and there’s no effective way to prevent the noise coming into the received signal. On the other hand, FM radio, whose FM stands for the Frequency Modulation, uses the pitch or frequency of the airwaves to carry the information, and the level of the signal is irrelevant unless it is very weak. So FM radio is more robust against the airwave noise than the AM radio and far less affected by the digital devices such as computers.

Then why don’t we convert or migrate from AM radio to FM radio? FM radio consumes much wider frequency spectrum to broadcast, and much higher frequency to broadcast about a hundred times of the AM radio (88~108MHz in most parts of the world; in Japan it’s 76~90MHz). Airwaves of that frequency range cannot use the ionospheric propagation, so FM radio stations do not reach as farther as AM radio stations do, and require considerably higher cost for the simultaneous nationwide coverage.

Let us get back to the original question: can we stick to the AM radio for direct broadcasting to indoor radio receivers, even under the condition that the number of devices emitting noise will be continuously increasing? My answer is no. AM radio will still be useful for serving outdoor and rural area listeners, and in case of disasters and emergencies, because the receiver cost is relatively low. For the urban areas, however, people will no longer be able to listen to the AM radio in adequate quality without erecting the external antennas; conversion or migration to the FM radio will be a practical and feasible plan.

Note that the AM-to-FM conversion is nothing new, especially for people in North America; many stations there have AM and FM simulcasting stations. And in Japan, especially on a coverage of important events, simulcasting between AM, FM and TV stations is frequently conducted. I am talking about the conversion, however, simply from the listening quality perspective, under the noise-bombarded radio spectrum environment in modern houses and buildings.

I’d like to propose providing simulcast in at least one FM radio channel for each AM radio stations in the urban areas. I think this is one of the most practical way to raise the listening quality of radio programs.


Note 1: some may claim internet radio stations will completely substitute the radio services over airwaves. I do not buy that idea because internet radio stations usually suffer a lot of delay of tens of seconds, which renders them useless for emergency or disaster warnings, unless another dedicated side channel is provided.

Note 2: some other people will also claim FM radio is very hard to listen to without an external antenna, which is unfortunately true. I think listening to the FM radio of quality sound is still much easier than to the AM radio based on my experience; FM radio antenna is smaller and less prone to electromagnetic noise inside the house, and is easier to erect.

Exported from Medium on August 7, 2013.

View the original