Resource Allocation Policies for Loosely Coupled Applications in Heterogeneous Computing Systems

Hwang, Eunji,Kim, Suntae,Yoo, Tae-kyung,Kim, Jik-Soo,Hwang, Soonwook,Choi, Young-ri IEEE 2016 IEEE transactions on parallel and distributed syst Vol.27 No.8

<P>High-Throughput Computing (HTC) and Many-Task Computing (MTC) paradigms employ loosely coupled applications which consist of a large number, from tens of thousands to even billions, of independent tasks. To support such large-scale applications, a heterogeneous computing system composed of multiple computing platforms with different types such as supercomputers, grids, and clouds can be used. On allocating heterogeneous resources of the system to multiple users, there are three important aspects to consider: fairness among users, efficiency for maximizing the system throughput, and user satisfaction for reducing the average user response time. In this paper, we present three resource allocation policies for multi-user and multi-application workloads in a heterogeneous computing system. These three policies are a fairness policy, a greedy efficiency policy, and a fair efficiency policy. We evaluate and compare the performance of the three resource allocation policies over various settings of a heterogeneous computing system and loosely coupled applications, using simulation based on the trace from real experiments. Our simulation results show that the fair efficiency policy can provide competitive efficiency, with a balanced level of fairness and user satisfaction, compared to the other two resource allocation policies.</P>

특허 IPC 공통분류와 연관규칙 마이닝을 통한 수산분야 기술동향과 융합특성 분석

황순욱(Soonwook Hwang),천동필(Dongphil Chun) 한국기술혁신학회 2020 기술혁신학회지 Vol.23 No.2

수산산업은 식량안보와 산업의 고용효과 측면에서의 중요성에도 불구하고, 기술혁신을 통한 산업경쟁력 강화를 위한 노력이 비교적 경시되고 있다. 최근 한국 정부는 이를 개선하기 위해 관련 연구개발에 노력하고 있으나, 여전히 타 산업과 비교하여 규모가 열세에 있다. 효과적이고 효율적인 기술혁신을 위해 증거기반 자원배분이 필요하다. 본 연구는 이러한 현실을 반영하여 수산 주요국의 수산산업 기술동향, 기술 간의 상호 연관성, 그리고 융합특성을 분석하였다. 이를 위해 유럽 특허청의 특허 정보 서비스인 Espacenet에서 2007년부터 2016년까지의 등록특허 데이터를 수집하여 OECD의 수산분야 기술 분류에 따라 Harvesting Technology, Aquaculture Technology, New Product Technology로 분류하고 국가별, 기술별 특허 동향을 살펴보았다. 또한 기술의 융합 특성을 파악하기 위해 수산분야 국제특허분류 코드에 연관규칙 마이닝 분석을 통하여 기술 간의 상호 연관성과 융합의 양상을 분석하였다. 이를 기반으로 수산분야 연구개발 계획에 대한 시사점 도출과 국내 수산산업의 경쟁력 강화를 위한 전략적 방향을 모색하였다. Efforts to improve industrial competitiveness through technological innovation remain largely neglected, given the importance of food security and employment. The Korean government has recently made efforts to improve it in R&D-related fields, but the size is still smaller than other industries. Resource allocation based on evidence is important for effective and efficient innovation. This research examined the patent patterns in major fisheries industry countries and the inter-relationship and convergence between technologies to represent these needs. We obtained patent information from Espacenet DB from 2007 to 2016 for this reason and grouped it into three groups according to the technical classification of the fishing sector of OECD: harvesting technology, aquaculture technology and new product technology. We applied the association rule mining to fisheries IPC code to examine innovation trends and convergence patterns to understand the convergence characteristics of technology. Through reviewing the effects of the association rule mining, they propose consequences for fisheries R&D strategies to improve Korean fisheries" competitiveness.

Rapid surface kinetics enhancement via flash light sintering for low-temperature solid oxide fuel cells

Hong, Soonwook,Lim, Yonghyun,Lee, Hojae,Chung, Wanho,Hwang, Hyunjun,Kim, Haksung,Kim, Young-Beom Elsevier 2019 JOURNAL OF ALLOYS AND COMPOUNDS Vol.778 No.-

<P><B>Abstract</B></P> <P>“Samaria-doped ceria (SDC), with exceptional electrochemical catalyzing characteristics, is a promising material for the operating temperature of solid oxide fuel cells (SOFC). Despite its extraordinary electrochemical reactivity, its chemical unstable behavior in terms of reduction phenomenon has made its application to SOFC electrolyte challenging. In regard to the defect chemistry, however, this instability can enhance the oxygen incorporation rate at the surface of the electrolyte. Here, we report a rapid surface treating method for SDC thin films via flash light sintering, which revealed an outstanding crystallinity development with nano-grains and increment of mobile dopant cation-induced oxygen vacancies within few milliseconds. We demonstrated that the flash light sintering-induced rapid development of crystallinity and reduction of ceria increases oxygen reducing surface kinetics, leading to an improvement in the oxygen incorporation rate of the cathodic reaction in SOFCs. The performance of SOFC sintered by flash light indicated more than two-folds enhancement comparing the pristine cell.”</P> <P><B>Highlights</B></P> <P> <UL> <LI> Successful rapid flash light sintering for samaria-doped ceria thin films. </LI> <LI> Enhanced crystallinity and surface oxygen vacancy concentration of thin films. </LI> <LI> Application of samaria-doped ceria interlayer to increase surface oxygen kinetics. </LI> <LI> Two-folds enhanced performance of low-temperature SOFC. </LI> </UL> </P>

High-performance Ni/Pt Composite Catalytic Anode with Ultra-Low Pt Loading for Low-temperature Solid Oxide Fuel Cells

Yonghyun Lim,Soonwook Hong,Kyung-Lim Jang,Hwichul Yang,Sehoon Hwang,Taek-Soo Kim,Young Beom Kim 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.1

In this study, we developed a Ni/Pt bilayer catalytic anode that has high electrochemical activity and significantly reduced Pt loading amount, for low-temperature solid oxide fuel cells (LT-SOFCs). The Ni/Pt bilayer anodes with various thicknesses of the Pt catalytic active layer were fabricated on yttria-stabilized zirconia substrates via the direct current sputtering technique, and their performances were evaluated for the LT-SOFCs. The optimal thickness of the Pt catalytic layer for the Ni/Pt bilayer was found to be 10 nm based on the results for the fuel cell performance and electrochemical impedance spectroscopy (EIS) analysis. The optimal Pt10/Ni140 anode showed a cell performance and polarization resistance very similar to those of a reference single-phase Pt anode, while having only 7% of the Pt loading amount of the reference Pt anode. For the detailed morphological analysis of the bilayer structure anode, we employed the pull-off delamination process to analyze both the surface and interface morphologies of the bilayer anodes and the interface morphology of the Ni/Pt bilayer anodes after the operating test was analyzed. The results presented herein indicate the suitability of the methodology for the morphological analysis of thin-film bilayer structures and contribute to reduce the cost of membrane electrode assembly fabrication for LT-SOFCs, thus facilitating the commercialization of these systems.

Designing metadata catalog system for ecological information

Geunchul Park,Soonwook Hwang,Taesang Huh 한국콘텐츠학회 2014 한국콘텐츠학회 ICCC 논문집 Vol.- No.-

LTER Platform: Requirement, Technology and Trend

Sunil Ahn,Soonwook Hwang,Ji-Hoon Jang,Sung-Hee Lee,Seok-Kyoo Kim 보안공학연구지원센터 2015 International Journal of Software Engineering and Vol.9 No.5

Objective of the long-term ecological research is to monitor environmental changes due to climate change and track the consequences, to cope with the environmental issues that may arise now and in the future. Long-term ecological research addresses the temporal gap between short-term studies by studying processes on time scales from months to decades. For long-term ecological researches, a system (Cyber Infrastructure) is essential, which can continuously harvest and manage the data about ecosystem changes. Requirements of a long-term ecological research system are very diverse; standardized interface, sharing and data integration, flexibility, standardized vocabulary, and so on. To deal with these issues, countries around the world have been building platforms that can harvest and manage the data about ecosystem changes for long-term ecological researches. This paper presents requirements and technologies for the long-term ecological research platform, and examines current technological trends in order to meet various requirements of the long-term ecological research.

원격 SGE(Sun Grid Engine) 연동을 위한 Ganga 플러그인 설계 및 구현

김한기(Hangi Kim),황순욱(Soonwook Hwang) 한국정보과학회 2010 한국정보과학회 학술발표논문집 Vol.37 No.1B

고에너지 물리나 바이오 인포매틱스 연구 분야는 대량의 컴퓨팅 자원을 필요로 한다. 이를 위해서 클러스터 컴퓨팅, 그리드 컴퓨팅, 슈퍼 컴퓨팅, 클라우드 컴퓨팅 자원 등의 여러 컴퓨팅 자원이 사용된다. 사용자는 각 컴퓨팅 자원을 이용하기 위해서 각각의 사용 방법을 배우고, 저마다의 방법으로 각 컴퓨팅 자원을 사용한다. 사용자가 각 컴퓨터 자원의 사용 방법을 습득하기 위해서는 많은 비용과 시간이 필요하다. 사용자가 보다 쉽고 빠르게 컴퓨팅 자원을 활용하기 위하여 여러 컴퓨팅 자원을 사용하기 위한 동일 인터페이스 개발이 필요하다. 본 논문에서는 한국과학기술정보연구원의 타키온 슈퍼컴퓨터를 이용하는 사용자에게 동일한 사용자 인터페이스를 제공하기 위한 Ganga의 원격 SGE 백엔드(Backend) 플러그인을 설계하고 구현하였다.

Implementation of AMGA Manager Using an Authentication Module on the g-Eclipse

Taesang Huh,Geunchul Park,Soonwook Hwang 한국콘텐츠학회 2011 한국콘텐츠학회 ICCC 논문집 Vol.- No.-

Cost-Aware Dynamic Resource Allocation in Distributed Computing Infrastructures

Gianni M. Ricciardi,Soonwook Hwang 한국콘텐츠학회 2011 International Journal of Contents Vol.7 No.2

Parameter Study on Solid Oxide Fuel Cell Heat-up Process to Reaction Starting Temperature

Jonghyun Son,Sehoon Hwang,Soonwook Hong,Suhaeng Heo,Young Beom Kim 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.6

Solid oxide fuel cell (SOFC) is a promising fuel cell type for use in distributed generation owing to its high energy efficiency, ability to use various fuels, generation of additional heat energy, etc. These advantages arise from its high operating temperature, but this in turn imposes limitations like difficulty in selecting proper materials, restrictions in the operating environment, difficulty of thermal management, and long on/off time. A good deal of research has been conducted on thermal analysis of SOFCs, however little or none on the heat up process parameter study; such studies are required because the heat up process influences thermal stability and efficiency in terms of both time and energy. The level of effects changes depending on the heat up conditions. Accordingly, the present work deals with two heat up conditions and their effects upon the results; these conditions are hot air mass flow rate and the hot air temperature, represented as a temperature difference relative to the SOFC stack. This study is accomplished by means of modeling using MATLAB, including validation of the model by comparison to an International Energy Agency benchmark test. The results show that both conditions affect the saturation time and temperature transition of the model, but to different degrees and in different ways. Especially, saturation time depends primarily on the temperature difference, and changes in the temperature difference between the inlet and outlet is determined by linear equation with the temperature difference as domain and the mass fl ow rate as slope. From the results, optimal heat up conditions proper to each SOFC geometry or material can be found by changing these variables appropriately.