origin : http://edition.cnn.com/2016/07/17/asia/china-migrant-worker-good-will-hunting/index.html   

 China's 'Good Will Hunting?' Migrant worker solves complex math problem

Beijing (CNN)A Chinese migrant worker with no college degree has found a solution to a complex math problem -- in what appears to be a real life version of the Oscar-winning movie "Good Will Hunting."

Yu Jianchun, who works for a parcel delivery company, said he'd always had a passion for numbers and has created an alternative method to verify Carmichael numbers.
    His solution amazed academics, who said his proof was much more efficient than the traditional one.
    "It was a very imaginative solution," said Cai Tianxin, a math professor at Zhejiang University.
    "He has never received any systematic training in number theory nor taken advanced math classes. All he has is an instinct and an extreme sensitivity to numbers."
    Carmichael numbers are sometimes described as "pseudo primes" -- they complicate the task of determining true prime numbers, which are divisable only by 1 and itself. They play an important role in computer science and information security.
    Yu worked on his proof during his free time while building a new home in his village last year.
    "I was overwhelmed with joy, because my solution was completely different to the classic algorithm," said Yu.

    Exciting discovery

    William Banks, a mathematician at the University of Missouri, who works with Carmichael numbers said, if verified, an alternative proof would be an exciting discovery for his field.
    He said that the only construction of an infinite family of Carmichael number was done by academics 20 years ago.
    "There have been additional theoretical results in this area -- including several by myself and my co-authors -- but these are all variations on a theme," he said.
    Yu presented his proof -- along with solutions to four other problems -- to the public on June 13 at a graduate student seminar on the invitation of Cai.
    However, it took Yu more than eight years of writing letters to prominent Chinese mathematicians to get any recognition for his talent.
    Cai, the professor, says he will include Yu's solution in an upcoming book.

    Posted by 구레이더

    High school students built a bomb-seeking robot for the RNC

    During the summer, you'll likely find most kids in swimming pools, collecting Pokemon or at camp.

    Most kids.

    But for 20 Cleveland high school students, their summer has been devoted to building an all-terrain, bomb-seeking robot.

    A team from the Youth Technology Academy at Cuyahoga Community College built the bot in anticipation of the Republican National Convention, to rove the grounds around the Quicken Loans Arena.

    Professor George Bilokonsky oversees the program.

    "The robot's purpose is to scout ahead of time," he said.

    And thus, "Scoutbot" was born.

    The Cleveland Police Department needed something speedy and agile. And after encountering the team of wiz kids at a routine training session at the college, they thought the students were the perfect candidates for the job.

    "I wanted something simple, to check suspicious packages or whatever, and do it quickly," Sargent Tim Maffo-Judd of Cleveland Police's bomb squad told CNN. That was six months ago.

    Now, the RNC is upon us -- and thanks to Bilkonsky's "technology gang," as he calls them, "Scoutbot" is ready to hit the streets.

    But why was it needed in the first place?

    "Our main bomb bot can go up and down stairs, shoot things, and blow things up," said Maffo-Judd. "But it takes 20 minutes to set up."  

    That's precious time that officers could be using to disarm the threat.

    "Scoutbot," which looks a lot like a supped-up toy car, can be rolling in just five minutes. It has six wheels and is equipped with a 360-degree camera, night vision and has a range of 400 feet. Made mostly of aluminum and some 3-D printed parts, Scoutbot is just 12 inches tall, 18 inches long, and 6 inches wide. Its small size enables it to get into tight spaces, like under cars, to look for bombs or other suspicious items.

    The robot was funded by a $500 grant from a Cleveland Police foundation and the rest was put together with spare parts from around the shop at Cuyahoga Community College, according to Bilokonsky.

    "You have to think outside the box as a bomb tech, and that's what these kids did," Maffo-Judd said.

    The students were thrilled to be tasked with the assignment.

    "It feels like an honor and privilege to be able to work with the bomb squad on a project that they can use for the future and help keep people safe," Mark Hairston, 17, told CNN. "It was a little daunting at first, but over time, as it developed into the actual robot and we could see what it was becoming, it felt pretty good."

    For many of the students, it was their first time interacting with police.

    "You know, I never thought I'd be building a robot with a bunch of high school kids," said Maffo-Judd. "I'm proud to be apart of it, and those kids are a thousand times smarter than I'll ever be."

    Posted by 구레이더

    <개요 및 프로젝트 목적>

    이번에 작성하는 글은 안드로이드의 UI와는 전혀 상관이 없는 오직 오직 기능만을 위한 주제입니다.

    UI를 꾸미지 않는 것은 UI가 아닌 휴대폰의 CPU사용량에 따라 베터리 소모를 줄이는 것이 핵심이기

    때문입니다. 이 어플리케이션은 이미 개발이 완료된 상태이며 단계적으로 글을 쓸 것입니다.

    정확도는 낮을 수 있겠지만 일단 제가 8일동안 이것만 붙들고 처음 접하는 방식의 프로그램이기 때문에

    이렇게 포스팅하게 되었습니다.


    1. 움직임 포착

    2. 걸음수 판별

    3. 위치파악

    3-1. GPS 사용

    3-2 WIFI SCAN 사용

    4. 메모장에 기록하여 TextView에 뛰우기


     [CPU 사용량을 확인하는 방법 - battery historian 설치하기 + 

    2단계 adb.ext를 이용한 bugreport.txt 추출하기]의 결과

    이미지를 보시면 cpu가 잡혔닥 풀렸다가 하는게 보이시죠? 그리고 GPS WIFI도 사용할때만 잡는게 보이시죠?

    안드로이드가 제공하는 베터리 히스토리안을 이용하면 이런 것들을 확인하실수 있습니다.

    <사전 설치하기>

    그럼 본론으로 들어가보겠습니다.

    1. 베터리 히스토리안 설치하기 (battery historian)

    (이미 설치되어 있는 것은 패스) 

    • Go 

    • Git 

    • Python 2.7 

    • Java

    이렇게 4개를 설치하셔야 베터리 히스토리안을 사용하실수 있습니다. 하핫 귀찮으시다구요? 

    하지만 사용하셔야죠

    git 이나 파이썬 java는 다들 깔려있거나 까실수 있으시죠? 그럼 go만 잠깐 언급할께요

    https://golang.org/doc/install  를 들어가셔서 go를 까시구요

    그리고 cmd 창에 go를 쳐서 설치되었는지 확인해보세요

    잘되죠? 그 다음이 중요합니다. 모든 파일 설치는 battery hitorian을 설치하기 위한 것이죠 ㅎㅎ

    여기까지가 기본 설치고 이제 battery historian을 설치하고 실행해볼께요.


    <battery historian 설치하기>

    cmd 창에 Go get –d –u github.com/google/battery-historian/... 

    를 입력하셔서 battery historian을 설치합니다.

    그다음 디렉토리를 확인하시면 

    C:\Go\work\src\github.com\google\battery-historian이 존재하는

    것을 확인하실 수 있습니다.

    (환경변수에 따라 다릅니다. 저는 위에 적힌대로 환경변수 설정해서 그래요)

    그다음은 cmd 창에 • go run setup.go 를 쳐주세요

    그러면 모든 설치가 끝납니다.

    <battery historian 실행하기>

    이제 battery historian을 실행해볼까요?

    실행 명령어는 go run cmd/battery-historian/battery-historian.go 인데요 일단

    저는 C:\Go\work\src\github.com\google\battery-historian 위치에 설치 되었기에 

    cd C:\Go\work\src\github.com\google\battery-historian

    를 쳐서 cmd 창에서 이동한 뒤에 

    go run cmd/battery-historian/battery-historian.go 를 쳐주세요.

    그러면 저는 액세스허용이 뜨는데요 만약 안된다면 관리자모드로실행해주세요

    다음 브라우져에서 localhost:9999를 입력해주시면

    battery historian이 실행된 것을 알수 있죠?

    참 쉽죠? ㅎㅎ

    여기까지가 battery-hitorian 사용법입니다.

    다음은 안드로이드로 설치된 어플리케이션의 베터리 사용량을 알아보는 방법에 대해서 이야기 해드리겠습니다.

    2단계는  battery-historian을 위한 bugreport.txt 만들기 입니다.

    Posted by 구레이더