LDF-CLOCK : The Least-Dirty-First CLOCK Replacement Policy for PCM-based Swap Devices

Seunghoon Yoo,Eunji Lee,Hyokyung Bahn 대한전자공학회 2015 Journal of semiconductor technology and science Vol.15 No.1

Phase-change memory (PCM) is a promising technology that is anticipated to be used in the memory hierarchy of future computer systems. However, its access time is relatively slower than DRAM and it has limited endurance cycle. Due to this reason, PCM is being considered as a high-speed storage medium (like swap device) or long-latency memory. In this paper, we adopt PCM as a virtual memory swap device and present a new page replacement policy that considers the characteristics of PCM. Specifically, we aim to reduce the write traffic to PCM by considering the dirtiness of pages when making a replacement decision. The proposed replacement policy tracks the dirtiness of a page at the granularity of a sub-page and replaces the least dirty page among pages not recently used. Experimental results with various workloads show that the proposed policy reduces the amount of data written to PCM by 22.9% on average and up to 73.7% compared to CLOCK. It also extends the lifespan of PCM by 49.0% and reduces the energy consumption of PCM by 3.0% on average.

LDF-CLOCK: The Least-Dirty-First CLOCK Replacement Policy for PCM-based Swap Devices

Yoo, Seunghoon,Lee, Eunji,Bahn, Hyokyung The Institute of Electronics and Information Engin 2015 Journal of semiconductor technology and science Vol.15 No.1

Phase-change memory (PCM) is a promising technology that is anticipated to be used in the memory hierarchy of future computer systems. However, its access time is relatively slower than DRAM and it has limited endurance cycle. Due to this reason, PCM is being considered as a high-speed storage medium (like swap device) or long-latency memory. In this paper, we adopt PCM as a virtual memory swap device and present a new page replacement policy that considers the characteristics of PCM. Specifically, we aim to reduce the write traffic to PCM by considering the dirtiness of pages when making a replacement decision. The proposed replacement policy tracks the dirtiness of a page at the granularity of a sub-page and replaces the least dirty page among pages not recently used. Experimental results with various workloads show that the proposed policy reduces the amount of data written to PCM by 22.9% on average and up to 73.7% compared to CLOCK. It also extends the lifespan of PCM by 49.0% and reduces the energy consumption of PCM by 3.0% on average.

LDA와 Inverse Term Popularity Rank를 활용한 미래 국방 무기체계 핵심기술 개념 추출 자동화에 관한 연구

유승훈(Seunghoon Yoo),이민준(Minjoon Lee),김우주(Wooju Kim) 한국콘텐츠학회 2023 한국콘텐츠학회논문지 Vol.23 No.1

개착식 지하철 역사구조물의 지진 취약도 함수 개발 및 적정성 평가

양승훈(Seunghoon Yang),곽동엽(Dongyoup Kwak),김석중(Seokjung Kim),유병수(Byeungsoo Yoo),유민택(Mintaek Yoo) 한국철도학회 2024 한국철도학회논문집 Vol.27 No.3

본 논문에서는 선행 개발된 지하철 역사의 수치해석 모델을 활용하여 지진 취약도 함수를 개발하는 과정을 설명한다. 국내 지하 역사 구조물의 대표단면에 대해 국내에서 발생한 지진 가속도 시간이력 및 국내 설계 기준 입력 지진 하중을 적용한 동적 수치해석 결과를 활용하였다. 이전 연구의 수치 모델은 지반의 깊이 및 토양의 분류에 따라 총33개의 사례에 대해 개발되었으며, 표준설계스펙트럼에 매칭된 입력 지진파를 사용하였다. 개발된 모델에서 취약도 함수의 개발 절차를 손상 지수와 손상 정도에 따라 나누어 제시하였으며 이를 기반으로 하여 취약도 함수를 정립하였다. 그 후, 개발된 취약도 함수를 기존에 개발된 다른 선행 연구들의 지진 취약도 함수와 비교하였다. 이러한 비교를 통해 취약도 함수의 적정성에 대한 평가를 수행하였다. In this paper, the process of developing seismic fragility functions using a numerical model of previously developed underground structures is explained. The numerical model presented in previous studies was developed for a total of 33 cases, considering input motion using Koreas standard design spectra and applying the model based on the depth of the ground and soil classification. The development procedure of the fragility function in the developed model is presented and categorized by damage index and damage state; these results are used to establish the fragility function. Subsequently, the developed fragility function was compared with seismic fragility functions from previous studies. Through this comparison, an evaluation of the adequacy of the fragility function was conducted.

대학생의 우주 교육을 위한 라즈베리 파이 기반 캔위성 수업자료 개발과 적용

유승훈(Seunghoon Yoo),이상현(Sanghyun Lee),이상구(Sangku Lee),이영건(Younggun Lee) 한국공학교육학회 2023 공학교육연구 Vol.26 No.1

The purpose of this study is to develop Raspberry Pi-based CanSat instruction materials for liberal arts classes to be used in university space education. The educational satellite simulation program is developed by applying the ADDIE program consisting of analysis, design, development, execution, and evaluation of 15 lessons per semester. The usefulness of the instruction materials is evaluated by a validity test of a total of 6 experts. The proposed materials are applied to 100 college students from various majors. To analyze the impact on creative problem-solving ability, a questionnaire is conducted before and after class, and as a result, it is confirmed that there is a significant improvement in all areas after class. The class satisfaction survey is conducted for a total of 10 questions, and the average score is 4.41 out of 5, which is high. In conclusion, the proposed instruction materials make it possible to achieve successful space education using Raspberry Pi and improve creative problem-solving ability in universities.

롱샷 무인기를 활용한 유무인 협업 공대공 전술 개발

유승훈(Seunghoon Yoo),박명환(Myunghwan Park),황성인(Seongin Hwang),설현주(Hyeonju Seol) 한국산업경영시스템학회 2021 한국산업경영시스템학회지 Vol.44 No.3

Manned-unmanned teaming can be a very promising air-to-air combat tactic since it can maximize the advantage of combining human insight with the robustness of the machine. The rapid advances in artificial intelligence and autonomous control technology will speed up the development of manned-unmanned teaming air-to-air combat system. In this paper, we introduce a manned-unmanned teaming air-to-air combat tactic which is composed of a manned aircraft and an UAV. In this tactic, a manned aircraft equipped with radar is functioning both as a sensor to detect the hostile aircraft and as a controller to direct the UAV to engage the hostile aircraft. The UAV equipped with missiles is functioning as an actor to engage the hostile aircraft. We also developed a combat scenario of executing this tactic where the manned-unmanned teaming is engaging a hostile aircraft. The hostile aircraft is equipped with both missiles and radar. To demonstrate the efficiency of the tactic, we run the simulation of the scenario of the tactic. Using the simulation, we found the optimal formation and maneuver for the manned-unmanned teaming where the manned-unmanned teaming can survive while the hostile aircraft is shot-downed. The result of this study can provide an insight to how manned aircraft can collaborate with UAV to carry out air-to-air combat missions.

PCM 기반 스왑 장치를 위한 클럭 기반 최소 쓰기 우선 교체 정책

유승훈(Seunghoon Yoo),이은지(Eunji Lee),반효경(Hyokyung Bahn) Korean Institute of Information Scientists and Eng 2015 정보과학회논문지 Vol.42 No.9

In this paper, we adopt PCM (phase-change memory) as a virtual memory swap device and present a new page replacement policy that considers the characteristics of PCM. Specifically, we aim to reduce the write traffic to PCM by considering the dirtiness of pages when making a replacement decision. The proposed policy tracks the dirtiness of a page at the granularity of a sub-page and replaces the least dirty page among the pages not recently used. Experimental results show that the proposed policy reduces the amount of data written to PCM by 22.9% on average and up to 73.7% compared to CLOCK. It also extends the lifespan of PCM by 49.0% and reduces the energy consumption of PCM by 3.0% on average.

Long Video Generation with Memory Efficient Bidirectional Transformers

Jaehoon Yoo,Semin Kim,Jinwoo Kim,Seunghoon Hong 한국기상학회 2022 한국기상학회 학술대회 논문집 Vol.2022 No.10

The Effect of Aging Treatment for Microleakage within Composite Resin Restoration

유승훈,Yoo, Seunghoon Korean Academy of Pediatric Dentistry 2013 大韓小兒齒科學會誌 Vol.40 No.4

본 연구는 시효처리가 세 가지 상아질 접착제의 미세누출에 미치는 영향을 MicroCT를 이용하여 조사하였다. 5세대 상아질 접착제인 Adper$^{TM}$ Single bond Plus(3M-ESPE, USA)와 6세대 상아질 접착제인 AdheSE$^{(R)}$(Ivoclar Vivadent, Lichtenstein)와 Adper$^{TM}$ Prompt$^{TM}$ L-Pop$^{TM}$(3M-ESPE, USA)을 이용하였다. 세 가지 상아질 접착제를 이용하여 3MESPE 사의 Filtek$^{TM}$ Z250을 V급 와동에 수복하고 24시간 생리식염수에 보관한 군(I군), 열 순환을 시행한 군(II군), 인공 칫솔질 법을 적용한 군(III군), 인공 타액에 6개월간 보관한 군(IV군)으로 분류하였다. Adper$^{TM}$ Single bond Plus를 이용한 시편은 II군과 III군에서 미세누출의 양이 늘어났으며 IV군에서 감소하였다. I군에 비해 II군이 많은 미세누출을 보였으며(p < 0.05), II군과 III군에 비하여 IV에서 적은 미세누출을 보였다(p < 0.05). AdheSE$^{(R)}$를 이용한 시편은 차이를 보이지 않았다(p > 0.05). Adper$^{TM}$ Prompt$^{TM}$ L-Pop$^{TM}$을 이용한 시편은 차이를 보이지 않았다(p > 0.05). I군에서는 AdheSE$^{(R)}$가 Adper$^{TM}$ Single bond Plus와 Adper$^{TM}$ Prompt$^{TM}$ L-Pop$^{TM}$에 비해 미세누출이 많다(p < 0.05). II군에서는 상아질 접착제간 차이가 없었다(p > 0.05). III군에서는 AdheSE$^{(R)}$가 Adper$^{TM}$ Single bond Plus와 Adper$^{TM}$ Prompt$^{TM}$ L-Pop$^{TM}$에 비해 미세누출이 많았다(p < 0.05). IV군에서는 Adper$^{TM}$ Single bond Plus에 비해 AdheSE$^{(R)}$와 Adper$^{TM}$ Prompt$^{TM}$ L-Pop$^{TM}$의 미세누출이 많았다(p < 0.05). In this study, researchers tried to find the effect, if any, of aging treatment to the specimens with three different dentin bonding agents using MicroCT. One, 5th generation - [Adper$^{TM}$ Single bond Plus] and two 6th generation [AdheSE$^{(R)}$, Adper$^{TM}$ Prompt$^{TM}$ L-Pop$^{TM}$] dentin bonding agents were used in this study. Specimens were divided into 4 groups according to aging treatment method used. Group I : control group, Group II : thermocycled between $5^{\circ}C$ and $55^{\circ}C$ for 60 seconds dwell time 5,000 times, Group III : aged as Group II and artificially brushed 20,000 times, Group IV : aged as Group III and were stored in artificial saliva for 6 months. With Single bond Plus, Group II showed more microleakage than Group I (p < 0.05). Group II and Group III showed more microleakage than Group IV (p < 0.05). There were no statistically significant differences among the groups using AdheSE$^{(R)}$ and Prompt$^{TM}$ L-Pop$^{TM}$ (p > 0.05). Among Group I, AdheSE$^{(R)}$ showed more microleakage than Single bond Plus and Prompt$^{TM}$ L-Pop$^{TM}$ (p < 0.05). Among Group II, there were no statistically significant differences (p > 0.05). Among Group III, AdheSE$^{(R)}$ showed more microleakage than Single bond Plus and Prompt$^{TM}$ L-Pop$^{TM}$ (p < 0.05). Among Group IV, AdheSE$^{(R)}$ and Prompt$^{TM}$ L-Pop$^{TM}$ showed more microleakage than Single bond Plus (p < 0.05).

장애인 고용장려금 정책의 사중손실 분석

한승훈(SeungHoon Han),유은주(Eun-ju Yoo),손호성(Hosung Sohn) 한국정책분석평가학회 2020 政策分析評價學會報 Vol.30 No.4