3D 적층 DRAM을 위한 실용적인 Partial Row Activation 및 딥 러닝 워크로드에의 적용

학위논문 (석사)-- 서울대학교 대학원 : 공과대학 컴퓨터공학부, 2019. 2. 이재욱.GPUs are widely used to run deep learning applications. Today's high-end GPUs adopt 3D stacked DRAM technologies like High-Bandwidth Memory (HBM) to provide massive bandwidth, which consumes lots of power. Thousands of concurrent threads on GPU cause frequent row buffer conflicts to waste a significant amount of DRAM energy. To reduce this waste we propose a practical partial row activation scheme for 3D stacked DRAM. Exploiting the latency tolerance of deep learning workloads with abundant memory-level parallelism, we trade DRAM latency for energy savings. The proposed design demonstrates substantial savings of DRAM activation energy with minimal performance degradation for both the deep learning and other conventional GPU workloads. This benefit comes with a very low area cost and only minimal adjustments of DRAM timing parameters to the standard HBM2 DRAM interface.GPU는 심층 학습 애플리케이션을 실행하는 데 널리 사용된다. 오늘날의 high-end GPU는 HBM (High-Bandwidth Memory)과 같은 3D 적층 DRAM 기술을 채택하여 엄청난 대역폭을 제공하므로 많은 전력을 소비한다. GPU에서 수천 개의 동시 스레드가 발생하면 빈번한 row buffer conflict로 인해 상당한 양의 DRAM 에너지가 낭비된다. 이러한 낭비를 줄이기 위해 3D 적층 DRAM에 대한 partial row activation 기법을 제안한다. 풍부한 memory-level parallelism 이 있는 딥 러닝 워크 로드의 latency tolerance를 활용해서, DRAM latency를 지불하고 에너지 절감을 얻을 수 있다. 본 제안에서 딥 러닝 및 기타 기존 GPU 워크 로드에서 성능 저하를 최소화하면서 DRAM activation energy의 상당한 절감 효과를 보여준다. 본 제안은 매우 낮은 면적 비용으로 표준 HBM2 DRAM 인터페이스에 대한 DRAM 타이밍의 최소한의 변경만으로 구현할 수 있다는 장점이 있다.Abstract i Contents iv Chapter 1Introduction 1 Chapter 2 Background and Motivation 4 2.1 Deep Learning Workloads 4 2.2 DRAM Access Patterns on GPU 7 2.3 Partial Row Activation 9 2.4 Performance/Area Trade-off in Partial Activation 10 2.5 Latency-Tolerance of Deep Learning Workload on GPU 11 Chapter 3 Practical Partial Row Activation 13 3.1 Overview 13 3.2 BankStructure 13 3.3 DelayedActivation 17 Chapter 4 Evaluation 19 4.1 Methodology 19 4.2 EnergyImprovement 21 4.3 Performance Degradation 22 4.4 AreaOverhead 24 Chapter 5 Conclusion 25 Bibliography 26 국문초록 30 Acknowledgments 31Maste

證券去來法上 不公正去來行爲의 刑事法的 規制에 관한 硏究

학위논문(석사)--서울대학교 대학원 :법학과,2004.Maste

웹에서 연관 규칙 탐사를 이용한 사용자 접근 패턴 분석 기법

Maste

企業所有構造의 決定要因과 所有構造가 企業成果에 미치는 影響에 관한 硏究 : 大株主持分率을 中心으로

학위논문(석사)--서울大學校 大學院 :經營學科 經營學專攻,1996.Maste

배아 얼굴 발생 단계에 따른 신경능세포의 간엽 세포로의 전환

Dept. of Medical Science/석사[한글] 발생 과정에 있어서 배아의 신경능세포(neural crest cells)는 두개안면골격 형성, 특히 두개안면부에서 얼굴 구조 형성에 결정적인 역할을 하는 세포군으로 알려져 있다. 신경능세포에서 기원된 간엽세포들이 얼굴의 뼈나 연골을 형성하는 데 중요한 역할을 한다는 것은 잘 알려져 있지만, 신경능세포에서 간엽세포로의 전환에 대한 연구는 미흡한 실정이다. 따라서, 본 연구자는 조류 배아에서 발생 단계에 따라 얼굴의 신경능세포가 간엽 세포들로 변화화는 과정을 조직학적인 접근과 함께 세포 배양을 통해 생체 외에서 확인하고, 신경능세포에서 간엽 세포로 전환되는 데에 영향을 미치는 인자를 찾고자 하였다.이를 위해, 조류 배아의 발생 단계에 따라 하악과 상악을 micromass 방법을 이용하여 배양하였고, 신경능세포와 관련된 단백질들의 변화, 세포 증식 양상, 연골이나 뼈 형성 능력을 확인하였다. 또한, 신경능세포의 유지, 증식, 분화에 관련하여 Wnt-3a의 영향을 관찰하였다.그 결과, 얼굴 부위에서 이동이 끝난 신경능세포들은 그들의 특성을 잃어버리고 서로 응축되기 시작하였다. 특히, 하악의 세포들은 발생 과정이 진행됨에 따라 후에 연골로 분화되는 세포혹(cellular nodules)의 형성 정도가 증가하였다. 또한, 신경능세포가 그들의 특성을 잃어버리고 간엽세포의 특성을 나타냄에 따라 뼈나 연골을 형성할 수 있는 능력이 증가하였다. Wnt-3a는 신경능세포의 특성을 유지시키고, 간엽세포로의 분화를 억제하였다. [영문]Neural crest cells (NCC), the embryonic precursors of craniofacial mesenchyme, arrive at the presumptive facial region to form the facial structures during early developmental stages. Although the roles of neural crest-derived mesenchymal cells are well known for the formation of craniofacial bone and cartilage, little information is available about their transition into mesenchymal cells. So I wanted to find out the temporal changes of NCC fate in relation to the osetochondrogenic characteristics with their mesenchymal transition in the in vitro culture system as well as in vivo model. I also searched for the control mechanism for the maintenance or differentiation of the NCC fate.In order to answer these questions, I tried a functional assay of mandibular and maxillary cells in different stages of chick embryos by micromass culture. And I examined the NCC-related protein expression profiles, the cell growth pattern, the osteochondrogenic capacities, and the effect of Wnt for the maintenance, proliferation, and differentiation of neural crest precursor cells.The results demonstrated the NCCs in postmigratory developmental stage of facial region lose their fate as the cells are condensed. Especially in mandibular cells, as development proceeds, they are mainly confined to the cellular nodules which will later form the cartilages. And their capabilities to form bone and/or cartilage are increased as they acquire mesenchymal cell natures and lose the NCC characteristics. Moreover, Wnt-3a maintains the characteristics of NCC and suppresses the differentiation of neural crest cells into mesenchymal cells.ope

Construction project performance management using BSC and data warehouse

Thesis(masters) --서울대학교 대학원 :건축학과,2008.2.Maste

미세공간에서의 증기 매핑을 위한 나노탐침 간섭계 연구

DoctorWater vapor in the air, indicated by the relative humidity, is a fundamental physical quantity that influences various fields in science, industry, and society. In particular, with the continuous growth of micro/nanotechnology, vapor in a microscopic handling with very small amounts of water has attracted considerable attention in both physical/chemical phenomena and in technological applications, for example, micro-/nanofluidics, nanofabrication, and micro-robotics. Therefore, vapor mapping has long been an unavoidable task and its technological advancements are highly demanded. Recently, advanced humidity sensors (i.e. hygrometers) with great performance such as high sensitivity, fast response time, and device-configuration compatibility, have been developed by utilizing various nanomaterials to quantitatively measure the amount of vapor. However, most hygrometers still have difficulties for detecting water vapor in microscopic spaces due to the fundamental limitations of conventional hygrometers such as lack of accessibility and positioning accuracy. Therefore, the development of hygrometers with high spatial-resolution and on-demand positioning control in precision that can be accessed in microscopic spaces remains a challenging task that goes beyond the limitations of conventional hygrometers. In this dissertation, a novel approach to map water vapor distribution in a microscopic space is presented based on a scanning probe hygrometry. The key strategy is to develop a freestanding nanoprobe interferometer consisting of a nanowire probe interferometer, fabricated by three-dimensional (3D) nanoprinting of a humidity-responsive nanowire on a tapered optical fiber. Unlike conventional hygrometers, which are limited to surface and surrounding environments sensing, the scanning of the nanoprobe interferometer, can overcome a variety of critical issues such as the precise positioning and access into microscopic spaces due to the advantage of freestanding nanoprobe geometry. First, for fundamental development of nanoprobe interferometer, the nanowire probe interferometer was developed for measuring humidity in a microscopic space. Spatial mapping of humidity was successfully presented by directly observing the interferometric response of the nanoprobe on humidity within a humidity-responsive nanowire during the scanning process. Here, multiscale spatial mapping of humidity with versatile scanning resolutions from ~ 100 nm to a few mm is demonstrated based on scanning of the nanoprobe interferometer. The implication of this work is that it provides novel nanoscale metrology, which is able to answer fundamental questions about humidity-related research and applications in physics, chemistry and biomedicine fields. Second, for applied research of nanoprobe interferometer, the mapping of water vapor inside a microscopic space was demonstrated, for studying humidity-related phenomena, i.e. evaporation. Novel experimental determination of evaporation characteristics from a water meniscus in a micro-capillary was presented, based on quantitative measurement of vapor concentration by scanning the nanoprobe interferometer. In this study, it was found that evaporation flux from the meniscus is always higher at the wall than at the center. In addition, the dependence of the meniscus geometry (e.g. diameter) and ambient conditions (e.g. ambient humidity) on evaporation dynamics was studied based on quantitative measurement of evaporation flux from the meniscus. This work would pave the way for exploring various questions related to microscopic and geometrically constrained evaporation dynamics that have been experimentally inaccessible so far.Chapter 1. Introduction 1 1.1 Research motivation 1 1.2 Critical issue 2 1.3 Dissertation objective 3 References 4 Chapter 2. Literature survey 6 2.1 Nanomaterial-based humidity sensors 6 2.1.1 Nanowire based humidity sensors 6 2.1.2 Thin-film based humidity sensors 8 2.2 Three dimensional (3D) nano-printing: meniscus guided approach 9 Figures 11 References 12 Chapter 3. Nanoprobe interferometer for scalable humidity mapping 14 3.1 Introduction 15 3.2 Methods 17 3.3 Results and discussions 19 3.4 Conclusions 25 Figures 26 References 37 Chapter 4. Nanoprobe interferometer for vapor mapping in a microscopic space 42 4.1 Introduction 43 4.2 Methods 45 4.3 Results and discussions 46 4.4 Conclusions 56 Figures 57 Tables 74 References 76 Chapter 5. Summary 8

베젤라딘 에이와 파마마이신-607, 그리고 에프알901483의 합성에 관한 연구

학위논문(석사) - 한국과학기술원 : 화학과, 1999.2, [ ii, 50 p. ]Synthesis of batzelladine A 1 was proposed by the coupling reaction between β-lactam 72 and diamine 73. β-Lactam 72 was prepared from D-alanine through 8 steps. Synthesis of diamine 73 was variously attempted using regioselective epoxidation of olefin 88a-f, Wittig olefination of aldehyde 97, 99, 104a and 104b with phosphonium salt 100a-c and 103, and substitution of alkyl chain into aziridine 122 and epoxide 123 by organocuprates. Pamamycin-607 28 consists of two subunits, $C_1``-C_11``$ and $C_1-C_18$. For synthesis of $C_1-C_18$ subunits, the coupling component 142 was prepared from 1,4-butanediol using crotylboration in 7 steps. Another coupling segment 152a-c was made from D-mannitol using crotylboration and allylboration in 9 steps. Wittig olefination of 142 with 152c gave 153c, of which the internal olefin was selectively epoxidized to provide 154 and 155. Formation of tetrahydrofuran 156 was attempted under various acidic conditions. For synthesis of FR901483 58, formation of pyrrolidine ring by 5-endo cyclization of homoallylic amine 172b was executed to give 164 as model study. Wittig olefination of ketone 163 with phosphonium salt 164 afforded olefin 168. Tyrosine derivative 161 was coupled with 170b, 178b, 179 and 180 to produce 181a and 181b. Mercury(Ⅱ) ion-induced cyclization of 181a and 181b followed by hydrogenation was attempted to give a 1:1 mixture of the desired product 187a and the undesired 187b.한국과학기술원 : 화학과

Combination of three-dimensional geometric data using grometric characteristics

학위논문(석사) - 한국과학기술원 : 기계공학과, 1991.2, [ iv, 62 p. ]한국과학기술원 : 기계공학과

Construction Project Performance Management Using BSC and Data Warehouse

많은 기업들은 그들의 기업 목적을 달성하기 위해 사업의 성과를 관리한다. 그 중 BSC의 개념을 적용한 성과측정 방법이 널리 사용되고 있고, 현재 건설 산업에서는 BSC 기반의 프로젝트 성과관리가 균형적인 성과 평가를 위해 도입되고 있다. 많은 건설 기업들은 BSC를 적용하는 단계에 있고 성과를 측정하는 데 많은 부분 노력을 기울이고 있다. 그러나 측정된 성과 결과에 대한 분석과 활용이 미비하다. 따라서 본 연구에서는 건설기업에서 성과를 적극적으로 활용할 수 있도록 성과관리 모델을 제시하고 시스템 구축을 최종목표로 한다. 이를 위해 분석 및 활용을 고려한 성과관리 프로세스를 정의하고 이에 따라 프로세스의 각 단계에 따른 방법을 제시한다. 다음으로 성과관리의 전반적인 흐름을 이해하고 시스템 구축을 가능하게 하는 모델을 수립하고 그 기대효과를 검토한다. 결론적으로 이 연구는 건설 산업의 성과관리 시스템과 건설 애플리케이션의 가치를 높이는 기회를 제공한다. Many companies have managed their business performance in order to achieve their enterprise purpose. Performance management which applied concept of BSC (Balanced Scorecard) is widely used all over the world. In the construction industry, BSC-based performance management is currently introduced with needs of balanced performance evaluation. However, most companies actually have intermediate level of adapting BSC. It is important to understand its process or and structure. Therefore, this paper is focused on making performance management process and defining each phase of it. In addition, the model and system are established with putting them together. With developing performance process in construction, the construction companies are supposed to detect the deficiencies of the current performance management systems and take some opportunity to be helped for supporting their decision-making. In conclusion, this paper will provide the construction industry with the opportunities to enhance the values of performance management system and construction application.본 연구는 건설교통부 건설혁신사업 결과의 일부임. 과제번호 05기반구축 D05-01. 본 연구는 건설교통부 건설혁신사업 결과의 일부임. 과제번호 06건설핵심 D10