http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Daeyong Lim 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.5I
Hexagonal manganite LuMnO3 has a well defined on-site Mn d-d optical transition at 1.7 eV, which shows a strong correlation with antiferromagnetic ordering. Femtosecond optical pump-probe spectroscopy was used to separate the contributions of the electron-phonon and the spin degrees of freedom to the on-site Mn d-d optical transition energy Edd. Experimental results show that the Mn d-d transition is mainly coupled to the spin degree of freedom. Furthermore, the Mn d-d transition energy was found to depend on the spin temperature even well above the Neel temperature. A short-range antiferromagnetic ordering of the frustrated LuMnO3 spin system is suggested to be responsible for this behavior.
Estimated Interval-Based Checkpointing (EIC) on Spot Instances in Cloud Computing
Jung, Daeyong,Lim, JongBeom,Yu, Heonchang,Suh, Taeweon Hindawi Limited 2014 Journal of applied mathematics (JAM) Vol.2014 No.-
<P>In cloud computing, users can rent computing resources from service providers according to their demand. Spot instances are unreliable resources provided by cloud computing services at low monetary cost. When users perform tasks on spot instances, there is an inevitable risk of failures that causes the delay of task execution time, resulting in a serious deterioration of quality of service (QoS). To deal with the problem on spot instances, we propose an estimated interval-based checkpointing (EIC) using weighted moving average. Our scheme sets the thresholds of price and execution time based on history. Whenever the actual price and the execution time cross over the thresholds, the system saves the state of spot instances. The Bollinger Bands is adopted to inform the ranges of estimated cost and execution time for user's discretion. The simulation results reveal that, compared to the HBC and REC, the EIC reduces the number of checkpoints and the rollback time. Consequently, the task execution time is decreased with EIC by HBC and REC. The EIC also provides the benefit of the cost reduction by HBC and REC, on average. We also found that the actual cost and execution time fall within the estimated ranges suggested by the Bollinger Bands.</P>
Task Balanced Workflow Scheduling Technique considering Task Processing Rate in Spot Market
Jung, Daeyong,Lim, JongBeom,Gil, JoonMin,Lee, Eunyoung,Yu, Heonchang Hindawi Limited 2014 Journal of applied mathematics (JAM) Vol.2014 No.-
<P>Recently, the cloud computing is a computing paradigm that constitutes an advanced computing environment that evolved from the distributed computing. And the cloud computing provides acquired computing resources in a pay-as-you-go manner. For example, Amazon EC2 offers the Infrastructure-as-a-Service (IaaS) instances in three different ways with different price, reliability, and various performances of instances. Our study is based on the environment using spot instances. Spot instances can significantly decrease costs compared to reserved and on-demand instances. However, spot instances give a more unreliable environment than other instances. In this paper, we propose the workflow scheduling scheme that reduces the out-of-bid situation. Consequently, the total task completion time is decreased. The simulation results reveal that, compared to various instance types, our scheme achieves performance improvements in terms of an average combined metric of 12.76% over workflow scheme without considering the processing rate. However, the cost in our scheme is higher than an instance with low performance and is lower than an instance with high performance.</P>
임희수(Hesoo Lim),정대용(Daeyong Jeong),이종태(Jongtai Lee) 한국자동차공학회 2002 한국자동차공학회 Symposium Vol.2002 No.11
In order to analyze a spray characteristics in ultra high pressure region, ultra high pressure injection equipment was developed and the characteristics of free spray injected under atmosphere condition were analyzed. Ultra high pressure over 4,OOObar is realized by 2 stage compression with quick motion using hydraulic system. As injection pressure became higher, spray penetration and spray angle were increased and droplet size was decreased continuously. But the rates of these enhancement become moderate and spray characteristics was constant or reversed.
모바일 클라우드에서 소셜 네트워크 기반 신뢰적인 자원 관리 기법
박지수 ( Jisu Park ),정대용 ( Daeyong Jung ),임종범 ( Jongbeom Lim ),유헌창 ( Heonchang Yu ) 한국정보처리학회 2012 한국정보처리학회 학술대회논문집 Vol.19 No.2
최근 스마트폰 및 타블릿PC 등 모바일 장치의 성능(쿼드코어)이 급격히 성장하고, 사용자의 증가, 무선 통신 환경(LTE, Wibro 등)의 발전으로 모바일 장치들을 연산 가능한 자원으로 고려하는 모바일 클라우드 연구가 이루어지고 있다. 그러나 자원 제공자인 모바일 장치의 자율적 연산 참여와 탈퇴가 가능하기 때문에 기존의 시스템들은 수행중인 연산이 중단되어 연산의 완료 시간이 지연되며, 시스템의 결함으로 이어지게 된다. 따라서 모바일 장치의 안정적인 연산 수행을 위한 안정적인 모바일 자원을 제공해야 한다. 본 논문에서는 신뢰적인 모바일 자원을 제공하기 위해 소셜 네트워크 정보를 이용하여 그룹화 함으로써 모바일 자원 관리를 제공한다.
Tilera 다중코어와 x86-64 멀티코어 시스템의 성능 비교
최희석 ( Heeseok Choi ),유태묵 ( Taemuk Lyoo ),박지수 ( Jisu Park ),정대용 ( Daeyong Jung ),임종범 ( Jongbeom Lim ),이정하 ( Jungha Lee ),서태원 ( Teaweon Suh ),유헌창 ( Heonchang Yu ) 한국정보처리학회 2013 한국정보처리학회 학술대회논문집 Vol.20 No.1
최근 멀티코어 시스템은 컴퓨터의 성능을 향상시키기 위해 더 많은 수의 코어를 연결시키는 다중코어 시스템으로 발전하고 있다. 그러나 멀티코어 시스템은 사용하는 코어의 아키텍처 구조와 개수에 따라 성능 차이가 발생한다. 이에, 본 논문에서는 코어의 아키텍처 구조와 코어의 개수가 성능에 미치는 영향을 분석하기 위해 Tilera의 다중코어 시스템인 Tile-Gx36, TilePro64와 Intel의 x86-64 멀티코어 시스템인 Core i5의 성능을 비교하였다. 코어의 사용률이 늘어남에 따른 성능차이를 알아보기 위해 벤치마크 프로그램인 SPEC CPU 2006을 이용하여 각 시스템 내 단일코어의 성능을 측정하고, OpenMP 벤치마크 프로그램을 이용하여 시스템의 모든 코어를 사용했을 때의 입력 데이터 크기에 따른 성능을 측정하였다. 실험 결과, 단일코어에서의 성능은 정수형 데이터를 사용하여 측정하였을 경우 Core i5가 Tile-Gx36보다 약 87%, 실수형 데이터를 사용하여 측정하였을 경우 약 94% 더 빠른 것으로 나타났다. 그러나 코어 전체를 이용한 성능 결과에서는 정수형 배열 크기가 이상일 경우 Tile-Gx36 시스템의 처리 속도가 Core i5 시스템 보다 평균적으로 약 7.6배 향상됨을 확인할 수 있었다. 따라서 Tilera의 다중코어 시스템은 클럭 속도와 아키텍처 구조의 영향으로 단일코어의 성능은 떨어지나, 병렬 처리를 이용한 고속연산에서는 성능이 향상된다고 할 수 있다.
전문일(Chun Moon-il),김창선(Kim Changsun),윤대영(Youn DaeYong),이진(Lee Jin),임장섭(Lim JangSeob) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.7
The topology of active clamp forward converter provides ZVS characteristic and also the stress of voltage and current is smaller than that of the conventional forward converters. The benefits of this technique include a higher efficiency at a high switching frequency, lower EMI/RFI. In this paper, the active clamp forward converter is designed for operation in wide range voltage and has 19.5V/120W ratings with efficiency more than 90%.
Woo-Yeol Shin,Gi-Moon Hong,Hyongmin Lee,Jae-Duk Han,Kyu-Sang Park,Dong-Hyuk Lim,Sunkwon Kim,Daeyong Shim,Jung-Hoon Chun,Deog-Kyoon Jeong,Suhwan Kim IEEE 2013 IEEE transactions on components, packaging, and ma Vol.3 No.5
<P>In this paper, we introduce an impedance-matched bidirectional multidrop (IMBM) DQ bus, together with a 4.8-Gb/s transceiver for a memory controller that supports this bus. Reflective ISI is eliminated at each stub of the IMBM DQ bus by resistive unidirectional impedance matching. A prototype memory controller transceiver is designed and fabricated in a 0.13-μm CMOS process and operates with a 1.2-V supply voltage. Its effectiveness is shown on various multidrop channel configurations. At 4.8 Gb/s, this transceiver with a 4-slot, 8-drop IMBM DQ bus has an eye opening of 0.39 UI in TX mode and 0.58 UI in RX mode, at a threshold of 10<SUP>-9</SUP> BER, whereas a comparable transceiver with a conventional 4-slot, 8-drop stub series terminated logic has no timing margin under the same test conditions. Our transceiver consumes 14.25 mW/Gb/s per DQ in TX mode, and 13.69 mW/Gb/s per DQ in RX mode.</P>