Bovine tuberculosis in an Asian small-clawed otter (<i>Aonyx cinerea</i>) in the Republic of Korea

Lee, Hyunkyoung,Kim, Jae-Myung,Jang, Yunho,Lee, Kyunghyun,Baek, Kanghyun,Lee, Boram,Kim, Ha-Young,Lee, Myoung-Heon,Ryoo, Soyoon,Bae, You-Chan,Choi, Eun-Jin,So, ByungJae SAGE Publications 2015 Journal of veterinary diagnostic investigation Vol.27 No.5

<P>Bovine tuberculosis caused by <I>Mycobacterium bovis</I> has a wide range of hosts including cattle and humans, but its incidence in otters is very rare. Our report describes a case of bovine tuberculosis in an Asian small-clawed otter (<I>Aonyx cinerea</I>). A deceased female otter ~2–3 years of age that was raised in an aquarium was submitted to the Animal and Plant Quarantine Agency (Anyang, Republic of Korea) for autopsy in June 2013. Following gross pathological examination, many white nodules were observed in the lungs and mesentery. The nodules showed central necrosis infiltrated with lymphocytes and macrophages and surrounded by fibrous tissue. Acid-fast bacteria were detected in the necrotic foci, but no fungi were observed. Molecular analysis led to the detection of <I>M. bovis</I>, which is identified in otters in some European countries such as Spain and France.</P>

Characterizing Memory References for Smartphone Applications and Its Implications

Soyoon Lee,Hyokyung Bahn 대한전자공학회 2015 Journal of semiconductor technology and science Vol.15 No.2

As smartphones support a variety of applications and their memory demand keeps increasing, the design of an efficient memory management policy is becoming increasingly important. Meanwhile, as nonvolatile memory (NVM) technologies such as PCM and STT-MRAM have emerged as new memory media of smartphones, characterizing memory references for NVM-based smartphone memory systems is needed. For the deep understanding of memory access features in smartphones, this paper performs comprehensive analysis of memory references for various smartphone applications. We first analyze the temporal locality and frequency of memory reference behaviors to quantify the effects of the two properties with respect to the re-reference likelihood of pages. We also analyze the skewed popularity of memory references and model it as a Zipf-like distribution. We expect that the result of this study will be a good guidance to design an efficient memory management policy for future smartphones.

Characterizing Memory References for Smartphone Applications and Its Implications

Lee, Soyoon,Bahn, Hyokyung The Institute of Electronics and Information Engin 2015 Journal of semiconductor technology and science Vol.15 No.2

As smartphones support a variety of applications and their memory demand keeps increasing, the design of an efficient memory management policy is becoming increasingly important. Meanwhile, as nonvolatile memory (NVM) technologies such as PCM and STT-MRAM have emerged as new memory media of smartphones, characterizing memory references for NVM-based smartphone memory systems is needed. For the deep understanding of memory access features in smartphones, this paper performs comprehensive analysis of memory references for various smartphone applications. We first analyze the temporal locality and frequency of memory reference behaviors to quantify the effects of the two properties with respect to the re-reference likelihood of pages. We also analyze the skewed popularity of memory references and model it as a Zipf-like distribution. We expect that the result of this study will be a good guidance to design an efficient memory management policy for future smartphones.

Popularity and adjacency based prefetching for efficient IPTV channel navigation

Soyoon Lee,Hyewon Moon,Hyokyung Bahn,Taeseok Kim,Ik-Soon Kim IEEE 2011 IEEE TRANSACTIONS ON CONSUMER ELECTRONICS - Vol.57 No.3

<P>As Internet Protocol Television (IPTV) is becoming increasingly popular, users can enjoy a variety of contents from hundreds of IPTV channels. However, the increased number of channels makes users even more difficult to find their desired contents. Along with this problem, the channel zapping time of IPTV incurs serious user-perceived latency. To alleviate these problems, this paper presents a new channel prefetching scheme that can be implemented on the IPTV set-top box. The scheme basically fetches the contents of adjacent channels before they are actually requested, similar to the adjacency-based prefetching scheme. However, it differentiates the number of channels to be prefetched among up-direction and down-direction channels based on the popularity of channels. Trace-driven simulations with various experimental conditions show that the proposed prefetching scheme performs better than existing prefetching schemes in terms of the prefetching hit rate to find the desired channel. Specifically, when the number of IPTV channels is 150, the average improvement of the hit rate is 22.3% compared to the adjacency-based prefetching scheme.</P>

CLOCK-DWF: A Write-History-Aware Page Replacement Algorithm for Hybrid PCM and DRAM Memory Architectures

Soyoon Lee,Hyokyung Bahn,Noh, Sam H. IEEE 2014 IEEE TRANSACTIONS ON COMPUTERS - Vol.63 No.9

<P>Phase change memory (PCM) has emerged as one of the most promising technologies to incorporate into the memory hierarchy of future computer systems. However, PCM has two critical weaknesses to substitute DRAM memory in its entirety. First, the number of write operations allowed to each PCM cell is limited. Second, write access time of PCM is about 6-10 times slower than that of DRAM. To cope with this situation, hybrid memory architectures that use a small amount of DRAM together with PCM have been suggested. In this paper, we present a new memory management technique for hybrid PCM and DRAM memory architecture that efficiently hides the slow write performance of PCM. Specifically, we aim to estimate future write references accurately and then absorb frequent memory writes into DRAM. To do this, we analyze the characteristics of memory write references and find two noticeable phenomena. First, using write history alone performs better than using both read and write history in estimating future write references. Second, the frequency characteristic is a better estimator than temporal locality in predicting future memory writes. Based on these two observations, we present a new page replacement algorithm called CLOCK-DWF (CLOCK with Dirty bits and Write Frequency) that significantly reduces the number of write operations that occur on PCM and also increases the lifespan of PCM memory.</P>

MEMS 기반 저장장치를 위한 병렬성 기반 스케줄링 기법

이소윤(Soyoon Lee),반효경(Hyokyung Bahn),노삼혁(Sam H Noh) 한국정보과학회 2007 정보과학회논문지 : 시스템 및 이론 Vol.34 No.1·2

MEMS 기반 저장장치는 높은 대역폭과 저전력성, 고집적도, 저가 등의 특성으로 인해 모바일 기기에서 대용량 서버 시스템에 이르는 다양한 환경에서 사용가능한 차세대 저장장치이다. MEMS 기반 저장장치는 원판이 회전하는 하드디스크와 달리 매체가 사각형 구조로 되어 있으며, 하나의 매체에 동시에 읽고 쓸 수 있는 수천 개의 헤드가 존재한다. 본 논문에서는 이와 같은 MEMS 기반 저장장치의 물리적 특성에 적합한 새로운 입출력 요청 스케줄링 기법을 제안한다. 새롭게 제안한 알고리즘은 사각형 평면 상에서의 헤드의 탐색 시간뿐 아니라 수천 개의 헤드에 의한 병렬적인 입출력을 고려한다. 또한, 기아 현상(starvation)을 극복하기 위해 알고리즘에 노화 요소(aging factor)를 반영한다. 트레이스 기반 모의 실험을 통해 본 논문이 제안한 스케줄링 알고리즘이 기존의 대표적인 알고리즘인 SPTF(Shortest Positioning Time First) 알고리즘에 비해 평균 응답 시간과 응답 시간의 편차 측면에서 각각 39.2%와 62.4%가 향상됨을 보였다. MEMS-based storage is being developed as a new storage media. Due to its attractive features such as high-bandwidth, low-power consumption, high-density, and low cost, MEMS storage is anticipated to be used for a wide range of applications from storage for small handheld devices to high capacity mass storage servers. However, MEMS storage has vastly different physical characteristics compared to a traditional disk. First, MEMS storage has thousands of heads that can be activated simultaneously. Second, the media of MEMS storage is a square structure which is different from the platter structure of disks. This paper presents a new request scheduling algorithm for MEMS storage that makes use of the aforementioned characteristics. This new algorithm considers the parallelism of MEMS storage as well as the seek time of requests on the two dimensional square structure. We then extend this algorithm to consider the aging factor so that starvation resistance is improved. Simulation studies show that the proposed algorithms improve the performance of MEMS storage by up to 39.2% in terms of the average response time and 62.4% in terms of starvation resistance compared to the widely acknowledged SPTF (Shortest Positioning Time First) algorithm.

PCM과 DRAM의 혼합형 메모리 환경을 위한 페이지 교체 기법 설계

이소윤(Soyoon Lee),반효경(Hyokyung Bahn),노삼혁(Sam H. Noh) 한국정보과학회 2012 정보과학회논문지 : 시스템 및 이론 Vol.39 No.2

최근 PCM(phase change memory)을 컴퓨터 시스템의 메인메모리로 사용하고자 하는 시도가 늘고 있다. 그러나, PCM은 기존 DRAM 메모리에 비해 쓰기 속도가 8배 이상 느리고 쓰기 횟수 제한이 있는 문제가 있다. 본 논문은 PCM 기반 메모리에 소량의 DRAM을 함께 사용해서 쓰기 연산의 상당 부분을 DRAM이 흡수하는 새로운 기법을 제안하여 이러한 문제를 해결한다. 제안하는 기법은 메모리 쓰기 참조의 특성을 분석하여 미래에 쓰기 참조 가능성이 높은 페이지를 식별하고 이를 DRAM에 보관한다. 운영체제를 통한 소프트웨어적인 관리로 PCM에 전달되는 쓰기 연산의 양을 크게 줄여 기존 DRAM 기반 시스템에 비해 성능 저하가 거의 없으면서 전력 소모를 크게 줄임을 보인다. Phase change memory (PCM) has emerged as one of the most promising technologies to incorporate into the memory hierarchy. However, PCM has two critical weaknesses compared to DRAM. First, the number of write operations allowed to each PCM cell is limited. Second, write access time of PCM is about 8 times slower than that of DRAM. To cope with this situation, this paper presents a new memory management scheme that uses a small amount of DRAM together with PCM to absorb most memory writes into DRAM. To do this, we analyze the characteristics of memory write references and present a new page replacement scheme that significantly reduces the number of write operations that occur on PCM and also reduces power consumption.

트랙 기반 MEMS 저장 장치 스케줄링 알고리즘

이소윤(Soyoon Lee),반효경(Hyokyung Bahn) 한국정보과학회 2005 한국정보과학회 학술발표논문집 Vol.32 No.2

MEMS 저장 장치는 기존의 디스크 저장 장치와는 다른 물리적 특성을 가지고 있는 차세대 저장 장치이다. 때문에 MEMS 저장 장치의 물리적 특성을 고려하는 디스크 스케줄링과는 다른 관리 기법이 필요하다. 본 연구에서는 MEMS 저장장치의 물리적 특성을 고려한 트랙 기반 스케줄링 방법에 대하여 제안하였다. 트랙 기반 스케줄링 기법은 스케줄링에서의 문제 상태 공간과 스케줄링을 위한 연산 횟수를 줄이고 상대적으로 정착시간에 많은 크기를 갖는 물리적 특성을 고려하여 정착시간의 추가 횟수를 줄임으로서 요청에 대한 빠른 서비스를 가능하게 해주고 요청에 대한 대기 시간을 고려함으로서 동시에 기아상태를 방지한다.

PCM과 DRAM의 혼합형 메모리를 위한 페이지 교체 기법

이소윤(Soyoon Lee),반효경(Hyokyung Bahn),노삼혁(Sam H. Noh) 한국정보과학회 2011 한국정보과학회 학술발표논문집 Vol.38 No.2A

최근 PCM(phase change memory)을 컴퓨터 시스템의 메인메모리로 사용하고자 하는 시도가 늘고 있다. 그러나 PCM은 기존 DRAM 메모리에 비해 쓰기 속도가 8배 이상 느리고 쓰기 횟수 제한이 있는 문제가 있다. 본 논문은 PCM 기반 메모리에 소량의 DRAM을 함께 사용해서 쓰기 연산의 상당 부분을 DRAM이 흡수하는 새로운 기법을 제안하여 이러한 문제를 해결한다. 제안한 기법은 운영체제를 통한 소프트웨어적인 관리로 PCM에 전달되는 쓰기 연산의 양을 크게 줄여 기존 DRAM 기반 시스템만큼의 성능을 유지하면서 전력 소모를 크게 줄인다.

가로림만 해양보호구역의 해양정원 조성사업과 정책적 함의

이주아, 이소윤, 이 훈 신한대학교 2020 신한대학교 논문집 Vol.43 No.

This research reviewed the Marine Protected Areas(MPAs) system of Garorim Bay and carried the following 4 policy implications for the marine garden project. First, it becomes the leading model for marine MPAs management with the new paradigm of leisure and the systematic operations. Second, it removes the regional conflicts by the restoration of marine and aquatic ecosystem and its improvement for local residents’s living conditions. Third, it establishes the vital foothold in the balanced marine ecotourism both at home and abroad over the harmony among nature, marine, mudflat, people, and so on. Finally, it finds out the sustainable models for fishing communities through the valuable marine ecosystem, the revitalized regional growth, the win-win cooperative system between the locals and the youth, etc. The Ministry of Maritime Affairs and Fisheries is preparing the legal basis upon which to promote the marine garden project as the national focal project. In this regard, this study has some notable achievements that stress the importance of the national marine garden project based on the above implications.