Parallel Genetic Algorithms with GPU Computing

Genetic algorithms (GAs) are powerful solutions to optimization problems arising from manufacturing and logistic fields. It helps to find better solutions for complex and difficult cases, which are hard to be solved by using strict optimization methods. Accelerating parallel GAs with GPU computing have received significant attention from both practitioners and researchers, ever since the emergence of GPU-CPU heterogeneous architectures. Designing a parallel algorithm on GPU is different fundamentally from designing one on CPU. On CPU architecture, typically data or tasks are distributed across tens of threads or processes, while on GPU architecture, more than hundreds of thousands of threads run. In order to fully utilize the computing power of GPUs, the design approaches and implementation strategies of parallel GAs should be re-probed. In the chapter, a concise overview of parallel GAs on GPU is given from the perspective of GPU architecture. The concept of parallelism granularity is redefined, the aspect of data layout is discussed on how it will affect the kernel performance, and the hierarchy of threads is examined on how threads are organized in the grid and blocks to expose sufficient parallelism to GPU. Some future research is discussed. A hybrid parallel model, based on the feature of GPU architecture, is suggested to build up efficient parallel GAs for hyper-scale problems

Controlling processes of pCO2 under coastal fast ice around Syowa Station during austral summer; implication for high productive "stealth polynya"

第2回極域科学シンポジウム　共通セッション「海氷圏の生物地球化学」 11月16日（水） 統計数理研究所 3階セミナー

ナンタイヨウ オーストラリア ク ニ オケル ヒョウソウ カイヨウ チュウ ノ ニサンカタンソ ブンアツ ノ ケイネン ヘンカ ト キセツ ヘンカ

全球の炭素循環を解明する上で,大気-海洋間の二酸化炭素(CO_2)交換を定量化することは最重要課題のひとつである.高緯度海域は風が強く,表層海洋中のCO_2 分圧(以下,pCO_2)が大気よりも低いために,CO_2 の吸収域として重要な海域である.特に,全海洋面積のおよそ20% を占める南大洋は,巨大なCO_2 の吸収源と考えられている.しかし,他海域に比べて観測機会が限られており,CO_2 吸収量の正確な評価に結びつくpCO_2 のデータの蓄積は十分ではない. 本報告では,「しらせ」の東経110度における長期pCO_2 観測から,pCO_2 が大気中のCO_2 濃度よりも若干低い増加率で経年変化していること,また,2001年12月～ 2002年3月に実施された東経140度における複数船時系列観測から,pCO_2 の夏季の詳細な時間変化とその要因を明らかにした.In order to elucidate the secular trends of oceanic CO_2 uptake in the Indian sector of the Southern Ocean, pCO_2, the partial pressure of CO_2 in the ocean surface layer, has been measured since 1987 on board the icebreaker Shirase. Meridional distributions of pCO_2 along 110゜E in early December clearly show steep changes at such fronts as the subtropical front, subantarctic front, and polar front. Although pCO_2 of each zone shows interannual variation, secular trend is detectable. For example, the estimated rate of increase of pCO_2 in the permanent open ocean zone between the polar front (around 53゜S) and the northern edge of winter ice cover (63゜S) is about 1.3 μatm y, which is slightly lower than the rate of increase of the atmospheric CO_2 concentration. From the results obtained by multi-ship observations with 4 research vessels in the Southern Ocean in summer, we found that the values of pCO_2 off the coast of the Antarctic Continent (66゜S) varied temporally by 100 μatm for 5 months. We also found that nDIC decreased with time from December 2001 to March 2002 in the upper layer from 100 to 200 m due to biological activity during summer

タモクテキ ハイブリッドガタ イデンテキ アルゴリズム ニ ヨル シンカテキ ネットワーク セッケイ ニ カンスル ケンキュウ

京都大学0048新制・論文博士博士(情報学)乙第11919号論情博第71号新制||情||49(附属図書館)UT51-2006-S663工学院大学大学院工学研究科電気工学専攻(主査)教授 片井 修, 教授 熊本 博光, 教授 喜多 一学位規則第4条第2項該当Doctor of InformaticsKyoto UniversityDA

Optical emission diagnostics of H2+CH4 50-Hz–13.56-MHz plasmas for chemical vapor deposition

The emission spectra of H2+CH4 plasmas excited at 50 Hz–13.56 MHz were measured. The emission intensity ratios of Hα/H*2 (3Σg→3Σu) from H2+CH4 plasma at 50 Hz and 13.56 MHz were about 0.7 and 0.05, respectively. The electron temperature was obtained from the two-line radiance ratio method using the Balmer lines (Hα and Hβ), and rapidly decreased with an increase above 200 kHz. The electron temperature for H2+CH4 plasma is 16 000 K at 1 kHz and 8200 K at 13.56 MHz. The plasma-maintaining voltages for H2 and H2+CH4 mixtures were also measured. The maintaining voltages were constant below 200 kHz, and rapidly decreased between 200 kHz and 13.56 MHz. The position dependence of emission intensity was also measured for Hα, Hβ, and H*2 at 50 Hz and 13.56 MHz. The results are interpreted in terms of the electron distribution in the plasma

Introduction to Evolutionary Algorithms

Evolutionary algorithms (EAs) are becoming increasingly attractive for researchers from various disciplines, such as operations research, computer science, industrial engineering, electrical engineering, social science, economics, etc. This book presents an insightful, comprehensive, and up-to-date treatment of EAs, such as genetic algorithms, differential evolution, evolution strategy, constraint optimization, multimodal optimization, multiobjective optimization, combinatorial optimization, evolvable hardware, estimation of distribution algorithms, ant colony optimization, particle swarm opt