큰 그래프 상에서의 개인화된 페이지 랭크에 대한 빠른 계산 기법

학위논문 (박사) -- 서울대학교 대학원 : 공과대학 전기·컴퓨터공학부, 2020. 8. 이상구.Computation of Personalized PageRank (PPR) in graphs is an important function that is widely utilized in myriad application domains such as search, recommendation, and knowledge discovery. Because the computation of PPR is an expensive process, a good number of innovative and efficient algorithms for computing PPR have been developed. However, efficient computation of PPR within very large graphs with over millions of nodes is still an open problem. Moreover, previously proposed algorithms cannot handle updates efficiently, thus, severely limiting their capability of handling dynamic graphs. In this paper, we present a fast converging algorithm that guarantees high and controlled precision. We improve the convergence rate of traditional Power Iteration method by adopting successive over-relaxation, and initial guess revision, a vector reuse strategy. The proposed method vastly improves on the traditional Power Iteration in terms of convergence rate and computation time, while retaining its simplicity and strictness. Since it can reuse the previously computed vectors for refreshing PPR vectors, its update performance is also greatly enhanced. Also, since the algorithm halts as soon as it reaches a given error threshold, we can flexibly control the trade-off between accuracy and time, a feature lacking in both sampling-based approximation methods and fully exact methods. Experiments show that the proposed algorithm is at least 20 times faster than the Power Iteration and outperforms other state-of-the-art algorithms.그래프 내에서 개인화된 페이지랭크 (P ersonalized P age R ank, PPR 를 계산하는 것은 검색 , 추천 , 지식발견 등 여러 분야에서 광범위하게 활용되는 중요한 작업 이다 . 개인화된 페이지랭크를 계산하는 것은 고비용의 과정이 필요하므로 , 개인화된 페이지랭크를 계산하는 효율적이고 혁신적인 방법들이 다수 개발되어왔다 . 그러나 수백만 이상의 노드를 가진 대용량 그래프에 대한 효율적인 계산은 여전히 해결되지 않은 문제이다 . 그에 더하여 , 기존 제시된 알고리듬들은 그래프 갱신을 효율적으로 다루지 못하여 동적으로 변화하는 그래프를 다루는 데에 한계점이 크다 . 본 연구에서는 높은 정밀도를 보장하고 정밀도를 통제 가능한 , 빠르게 수렴하는 개인화된 페이지랭크 계산 알고리듬을 제시한다 . 전통적인 거듭제곱법 (Power 에 축차가속완화법 (Successive Over Relaxation) 과 초기 추측 값 보정법 (Initial Guess 을 활용한 벡터 재사용 전략을 적용하여 수렴 속도를 개선하였다 . 제시된 방법은 기존 거듭제곱법의 장점인 단순성과 엄밀성을 유지 하면서 도 수렴율과 계산속도를 크게 개선 한다 . 또한 개인화된 페이지랭크 벡터의 갱신을 위하여 이전에 계산 되어 저장된 벡터를 재사용하 여 , 갱신 에 드는 시간이 크게 단축된다 . 본 방법은 주어진 오차 한계에 도달하는 즉시 결과값을 산출하므로 정확도와 계산시간을 유연하게 조절할 수 있으며 이는 표본 기반 추정방법이나 정확한 값을 산출하는 역행렬 기반 방법 이 가지지 못한 특성이다 . 실험 결과 , 본 방법은 거듭제곱법에 비하여 20 배 이상 빠르게 수렴한다는 것이 확인되었으며 , 기 제시된 최고 성능 의 알고리 듬 보다 우수한 성능을 보이는 것 또한 확인되었다1 Introduction 1 2 Preliminaries: Personalized PageRank 4 2.1 Random Walk, PageRank, and Personalized PageRank. 5 2.1.1 Basics on Random Walk 5 2.1.2 PageRank. 6 2.1.3 Personalized PageRank 8 2.2 Characteristics of Personalized PageRank. 9 2.3 Applications of Personalized PageRank. 12 2.4 Previous Work on Personalized PageRank Computation. 17 2.4.1 Basic Algorithms 17 2.4.2 Enhanced Power Iteration 18 2.4.3 Bookmark Coloring Algorithm. 20 2.4.4 Dynamic Programming 21 2.4.5 Monte-Carlo Sampling. 22 2.4.6 Enhanced Direct Solving 24 2.5 Summary 26 3 Personalized PageRank Computation with Initial Guess Revision 30 3.1 Initial Guess Revision and Relaxation 30 3.2 Finding Optimal Weight of Successive Over Relaxation for PPR. 34 3.3 Initial Guess Construction Algorithm for Personalized PageRank. 36 4 Fully Personalized PageRank Algorithm with Initial Guess Revision 42 4.1 FPPR with IGR. 42 4.2 Optimization. 49 4.3 Experiments. 52 5 Personalized PageRank Query Processing with Initial Guess Revision 56 5.1 PPR Query Processing with IGR 56 5.2 Optimization. 64 5.3 Experiments. 67 6 Conclusion 74 Bibliography 77 Appendix 88 Abstract (In Korean) 90Docto

시퀀스 기반 3차원 다인 자세 추정을 위한 기하학적 데이터 증강 기법

학위논문(석사) -- 서울대학교대학원 : 데이터사이언스대학원 데이터사이언스학과, 2023. 2. 이준석.3D pose estimation is an invaluable task in computer vision with various practical applications. Recently, a Transformer-based sequence-to-sequence model, MixSTE [60], has been successfully applied to 3D single-person pose estimation by decoupling the 2Dto-3D modeling from pixel-level details. We propose a natural extension of this model from single-person to multi-person problem, adding a novel inter-personal attention for 2D-to-3D lifting. Naturally referring to neighboring frames, this design is highly robust in handling occlusions. However, 3D multi-person pose estimation is still challenging due to extreme data scarcity. From an observation that our 2D-to-3D lifting approach is free from pixel-level details, we propose a novel geometry-aware data augmentation that allows us to infinitely generate diverse training examples from existing single-person trajectories. From extensive experiments on standard benchmarks, we verify that our model and data augmentation method achieve the state-of-the-art, not just on accuracy but also on smoothness. We also qualitatively demonstrate the effectiveness of our approach both on public benchmarks and with in-the-wild videos.컴퓨터 비전에 기반한 3차원 자세 추정(3D Pose Estimation)은 매우 다양한 분야에 응용될 수 있기 때문에 큰 가치가 있다. 최근, 트랜스포머(Transformer) 모델 기반의 시퀀스-시퀀스(Sequence-tosequence) 모델인 MixSTE [60] 은 단일 객체(사람) 3차원 자세 추정에서 2차원 자세로부터의 3차원 자세 추정(2D-to-3D Lifting)의 방법을 활용하여 성공적인 결과를 거둔 바 있다. 본 연구는 이의 확장으로써 다중 객체 3차원 자세 문제를 다루며, 기존 연구와 비교해 등장하는 객체간 정보의 상호 참조(Inter-Personal Attention) 모듈을 새로이 추가하였다. 모델 구조에 기반하여 상호 인접 프레임 정보를 자연스럽게 참조함으로써, 본 연구에서 고안한 모델은 상호 가려짐 현상에 강인한 성능을 보였다. 하지만, 다중 객체 3차원 자세 추정은 데이터 부족 현상이라는 고질적인 문제를 지닌다. 본 연구의 방법론은 픽셀 수준의 디테일에서 벗어나, 2차원 자세와 3차원 자세 간의 관계를 다루기에, 주어진 데이터와 카메라 파라미터에 기반하여 데이터를 사실상 무제한적으로 증강할 수 있다는 강점을 지닌다. 본 분야에서 성능 측정 및 비교를 위한 대표적인 실험용 데이터셋에서 성능을 측정한 결과, 본 연구에서 고안한 모델은 정확도 뿐만 아니라 출력 결과의 부드러움 두 측면에서 모두 여타 기존 모델과 비교해 가장 훌륭한 성능을 보였다. 나아가, 테스트용 데이터셋 뿐만 아니라 다양한 시중 비디오에서도 훌륭한 성능을 보임으로써 연구의 상업적 가치 또한 입증하였다.Chapter 1. Introduction 1 Chapter 2. Related Work 5 Chapter 3. Problem Formulation and Notations 8 Chapter 4. The POTR-3D Model 9 Chapter 5. Geometry-Aware Data Augmentation 16 Chapter 6. Experiments 22 Chapter 7. Summary 35 Bibliography 37 Abstract in Korean 44석

A Study on the Effect of Navy CollaborativeLeadership on Organizational Effectiveness

Korea is currently faced with China’s military growth, denuclearization talks with North Korea, preparations against non-military transnational threats, and changes in the security environment where there is an increased use of peace-keeping forces. Furthermore, Korea must create a powerful military force that can be victorious by strengthening the efficiency of military organizations and future-orientation based on information science technologies, while also being reborn as a military that can defeat any threat. A key element to solve this imperative task is leadership. Military leadership today is changing from the push method to encourage subordinates to achieve the goal of the organization by exercising direct influence towards a pull method of setting examples as a leader for hard and difficult tasks so that subordinates can follow suit. It is shifting from being based on rank that uses authority by position as the main source of influence to being based on functions that use one’s operational functions as the source of influence. Trust, communication and the level of cooperation is closely associated within an organization. Due to globalization, emphasis on environment, spread of information technologies, and the shift to a scientific and social paradigm, today’s society emphasizes the importance of leadership within an organization. Recent leadership research trends are shifting from single leadership by individuals to shared leadership, and from position-based leaders to team work processes, and from competition with other departments to mutual cooperation, and from systematic leadership to flexible leadership. Collaborative leadership is the series of processes that forms trust among members, communicating horizontally, and delegating authorities to members during the course of decision-making and pursuing operations so that members can voluntarily participate in duties so that the leader can complete a given mission. Studies on collaborative leadership are being carried out in some foreign countries and excluding conceptual research at the naval leadership center and a handful of studies made in Korea’s administrative academic circles, there are very few research outcomes in Korea. Accordingly, in order to construct a theoretical basis through literary research, this study reviewed domestic and foreign research theses including collaborative leadership books published by the naval education institutes to explore the sub-components of collaborative leadership and analyzed its impact on organizational effectiveness (job satisfaction, Organizational Commitment) using statistical methods. Furthermore, in empirical research, surveys were administered to officers of naval ships and land units located in C to empirically analyze the impact of collaborative leadership on organizational effectiveness to verify the hypothesis through statistical analysis. When considering the special characteristics of military organizations, there must be a leadership theory targeting a military organization. The army has developed mission-based commands so that all commanding officers can lead missions within their given authority, but mission-based commands have not been theoretically established to fit naval missions and work environments. Naval missions are often conducted over-the-horizon and outside of visible ranges, and traditionally, battle functions under network systems and cooperative combat capacities with different echelons are given particular importance. Naval fleets are comprised of complex weapons systems and it is has a complex composition of various departments and personnel that are in charge of specialized functions and roles. Therefore, operation of naval vessels can also be successful only through organic cooperation of various specialized work competence systems and thus, I judged that it was necessary to conduct empirical research on the effectiveness of collaborative leadership to emphasize the critical importance of applying collaborative leadership in the navy. Hence, the purpose of this study is to examine the impact of collaborative leadership on organizational effectiveness and to empirically analyze sub-factors that affect organizational effectiveness. The results of this study can be summarized as follows. Hypothesis 1 is ‘Collaborative leadership should affect job satisfaction’ and a more detailed Hypothesis 1-1 is ‘The level of procedural collaboration within an organization should affect the level of job satisfaction’. Results of verification of this showed that procedural collaboration had a positive (+) impact on work satisfaction (β=.532, p<.001) and the descriptive power was analyzed to be 28.2%, thus having the same results as the hypothesis, and therefore, Hypothesis 1-1 was adopted. Hypothesis 1-2 was ‘The level of cognitive collaboration within an organization should affect job satisfaction’. Results of verification on this showed that cognitive collaboration had a positive (+) impact on job satisfaction (β=.418, p<.001) and therefore, Hypothesis 1-2 was also adopted. Hypothesis 1-3 was ‘The level of structural collaboration within an organization should affect work satisfaction’. Results of verification on this showed that structural collaboration had a positive (+) impact (β=.485, p<.001) and its descriptive power was analyzed to be 23.4%, and since the results were consistent with the hypothesis, Hypothesis 1-3 was adopted. Hypothesis 2 was‘Collaborative leadership should affect organizational commitment’. The more detailed Hypothesis 2-1 was ‘The level of procedural collaboration within an organization should affect organizational commitment’. Results of verification on this showed that procedural collaboration had a positive (+) impact on Organizational Commitment (β=.561, p<.001) and descriptive power on this was analyzed to be 31.1%, thus having results consistent with the hypothesis, and therefore, Hypothesis 2-1 was adopted. Hypothesis 2-2 was ‘The level of cognitive collaboration within an organization should affect organizational commitment’. Results of verification on this showed that cognitive collaboration had a positive (+) impact on organizational commitment (β=.437, p<.001) and the descriptive power was analyzed to be 19.0% and results were consistent with the hypothesis, so Hypothesis 2-2 was also adopted. Hypothesis 2-3 was ‘The level of structural collaboration within an organization should affect organizational commitment’. Results of verification on this showed that structural collaboration had a positive (+) impact (β=.485, p<.001) and the descriptive power for this was 20.3%, thus being consistent with the hypothesis, and therefore, Hypothesis 2-3 was also adopted. Among the sub-components of collaborative leadership, procedural collaboration had high impact on job satisfaction (R2=.282, p<.001) and organizational commitment (R2=.313, p<.001), and this shows that procedural collaboration is a very important component in applying collaborative leadership in naval organizations. Meanwhile, the level of cognitive cooperation was the component with the smallest impact on job satisfaction (R2=.173 p<.001) and organizational commitment (R2=.190, p<.001). It is evident that in order to overcome this, it is necessary to complete duties through assertive development of competencies such as continuous learning and education for individuals, while also providing opportunities to enhance the expertise of individuals. This study investigated the sub-components of collaborative leadership that stopped short as conceptual studies and sought after sub-components that included the concepts of trust, horizontal communication and delegation of authorities proposed by the naval leadership center. Furthermore, it empirically analyzed the relationship of effects between collaborative leadership and organizational effectiveness for military officers currently serving in the navy to provide basic data for practical use of collaborative leadership, thus making this study significant. Furthermore, the components of collaborative leadership were checked based on various definitions in preceding studies, while scales for measuring this were revised and supplemented to fit naval organizations to systematically verify the feasibility of the contents and composition, thus making this study significant. This study is practically the first study that set up the concept of collaborative leadership. It is anticipated that research on collaborative leadership fitting the characteristics of the navy will continue to expand in the future and such research results will contribute to the development of naval organizations.제1장 서 론 1 제1절 연구의 배경과 목적 1 1. 연구의 배경 1 2. 연구의 목적 5 제2절 연구의 방법 및 논문의 구성 6 제2장 이론적 배경 7 제1절 리더십 개념 7 1. 리더십의 정의 7 2. 리더십 연구의 변천 과정 7 제2절 협력적리더십 10 1. 협력적리더십의 개념 및 정의 10 2. 협력적리더십의 선행 연구 14 3. 협력적리더십의 구성 요소 17 제3절 협력적리더십과 조직유효성 26 1. 조직유효성의 개념 26 2. 협력적리더십과 직무만족 30 3. 협력적리더십과 조직몰입 32 제3장 국방환경 변화와 해군리더십 34 제1절 국방환경 변화 34 1. 국방개혁 개요 34 2. 국방환경 변화 추세 35 제2절 군 리더십 변화 41 1. 군 리더십의 정의 41 2. 군 리더십의 특성 42 3. 군 리더십의 변화 43 4. 군 리더십 연구 경향의 문제점 45 제3절 해군 리더십의 특성 47 1. 해군 작전환경에 적합한 리더십 특성 47 2. 해양환경에 적합한 리더십 특성 48 3. 해군리더십 교육현황 분석 50 제4장 연구의 설계 52 제1절 연구모형 및 가설의 설정 52 1. 연구모형 설계 52 2. 가설설정 52 3. 변수의 조작적 정의 54 제5장 실증분석 57 제1절 조사의 개요 57 1. 설문조사의 개요 57 2. 수집된 자료의 특성 59 제2절 타당성 및 신뢰도 검증 62 1. 타당성 검증 62 2. 신뢰성 검증 68 제3절 가설의 검증결과 69 1. 가설검증 결과 69 2. 추가 통계분석 76 제 6 장 결 론 92 제1절 연구결과의 요약 92 제2절 연구의 시사점 95 제3절 연구의 한계점 및 향후 연구방향 97 감사의 글 98 참고문헌 99 설 문 지 113Docto

The Prophylactic Impact of Low Molecular Weight Heparin on Occurrence of Venous Thromboembolism after Colorectal Cancer Resection

Purpose: In western society, prophylaxis for venous thromboembolism (VIE) is the standard treatment under colorectal surgery for colorectal cancer. However, the incidence of VIE after colorectal surgery and the effect of prophylactic methods are not well known in Korea. The aim of this study is to evaluate the incidence of VIE and assess the efficacy and safety of low molecular weight heparin (enoxaparin) after major colorectal surgery in Korean patients with compression stockings. Methods: From Jan. 2006 to Dec. 2008, 1,727 consecutive patients underwent major colorectal surgery. Thirty-six were excluded due to the therapeutic use of enoxaparin. A final number of 1,691 patients were included. Graduated compression stockings were used in all patients and 654 were perioperatively given enoxaparin. Only compression stocking group (group A) and compression stocking with enoxaparin group (group B) were compared in terms of VTE. The event of VIE within 6 months after surgery was counted by clinical symptoms, then imaging findings were used for confirmation. Results: Total VIE developed in 10 patients (0.6%). Three with deep vein thrombosis had pulmonary embolism. Two had only pulmonary embolism. The rates of VTE were not different between group A and B (0.8% vs. 0.3%, P=0.333). Also, postoperative major bleeding was not significantly different. However, postoperative transfusion was higher in group B (P<0.001). Conclusion: The incidence of VTE was very low after colorectal surgery in Korean patients with compression stockings. The additional use of enoxaparin for colorectal cancer patients with compression stockings seems to have little benefit for VIE prophylaxis. 수술 후에 발생되는 정맥 혈전색전증은 임상적으로 중요하면서도 예방 가능한 합병증으로 알려져 왔다. 서양에서는 일반 수술의 경우 하지 심부 정맥혈전증 발생률이 20%정도이며 대장절제술의 경우는 30% 정도로 알려져 있다.(1)반면, 동양인들을 대상으로 한 연구들에서 수술 후 임상적으로 진단된 하지 심부 정맥혈전증은 0.27%의 환자에서 발생하였고, 폐동맥 색전증은 0.8% 이내로 서양에 비해 낮게 보고되었다.(2-5) 특히, 대장암 수술이 다른 일반 개복 수술에 비해서 정맥 혈전색전증 발생이 많은 것으로 보고되고 있고, 폐동맥 색전증의 빈도 또한 높다고 알려져 있다.(6)아시아에서 대장암 수술 후에 임상적으로 진단된 하지 심부 정맥혈전증의 빈도는 4.7%, 그리고 폐동맥 색전증은 1.7∼3.8%로 보고되었으며,(7,8) 서양에서는 수술 후 하지 심부정맥혈전증이 3.1∼51.7%에 이른다는 보고가 있다.(9-11)아직까지 국내에서는 대장절제술후의 정맥 혈전색전증의 발생률에 대한 연구가 거의 없었으며, 저분자량 헤파린(low molecular weight heparin)을 대장절제술을 시행하는 모든 환자에서 투여하는 것에 대한 의견도 정립되지 않은 상태이다. 본 연구에서는 대장암으로 대장절제술을 시행한 환자들을 대상으로 수술 시 압박스타킹(graduated compression stocking)만 사용한 군과 압박스타킹과 저분자량 헤파린을 같이 사용한 군으로 나누어서 정맥 혈전색전증의 발생 빈도와 저분자량 헤파린의 효용성 및 출혈 위험에 대해서 비교해 보았다.Cheung HYS, 2008, ASIAN J SURG, V31, P63Beekman R, 2006, CAN J SURG, V49, P197Bauduer F, 2005, MOL GENET METAB, V86, P91, DOI 10.1016/j.ymgme.2005.04.002Almawi W, 2005, J THROMB THROMBOLYS, V19, P189, DOI 10.1007/s11239-005-1313-xCheuk BLY, 2004, BRIT J SURG, V91, P424, DOI 10.1002/bjs.4454Otten HMMB, 2004, ARCH INTERN MED, V164, P190Kim YH, 2003, J BONE JOINT SURG BR, V85B, P661, DOI 10.1302/0301-620X.85B5.14012ANDERSON FA, 2003, CIRCULATION, V107, P19WILLEJORGENSEN P, 2003, COCHRANE DB SYST REV, DOI DOI 10.1002/14651858.CD001217CHUNG CC, 2003, COLORECTAL DIS, V5, P528GREENE FL, 2002, AJCC CANC STAGING MALee FY, 2001, ANZ J SURG, V71, P637McLeod RS, 2001, ANN SURG, V233, P438Marshall NJ, 2000, AUST NZ J SURG, V70, P6392000, DIS COLON RECTUM, V43, P1037Ho YH, 1999, DIS COLON RECTUM, V42, P196Schwenk W, 1998, SURG ENDOSC-ULTRAS, V12, P7Yoo MC, 1997, INT ORTHOP, V21, P399HO YH, 1996, DEEP VENOUS THROMBOS, P38REES DC, 1995, LANCET, V346, P1133IDO K, 1995, SURG ENDOSC-ULTRAS, V9, P310GREM JL, 1994, J CLIN ONCOL, V12, P560KUM CK, 1993, ANN ACAD MED SINGAP, V22, P895HUBER O, 1992, ARCH SURG-CHICAGO, V127, P310KIM YH, 1988, J BONE JOINT SURG AM, V70A, P878TORNGREN S, 1982, DIS COLON RECTUM, V25, P563TSAKOK FH, 1974, ANN AC AD MED SINGAP, V3, P399HWANG WS, 1968, SINGAPORE MED J, V9, P276TINCKLER LF, 1964, BRIT MED J, V1, P502

소비자의 가격반응성을 고려한 피크요금제 파라미터 설계

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2016. 2. 윤용태.Recent introduction of deregulation in the power industries offers electricity retailers the chance to make profit through electricity retail business. Accordingly, the retailers need to establish proper strategies for designing and implementing their pricing schemes to grab the chance. Many other pricing schemes can be used for the purposes, however, critical peak pricing (CPP) is chosen in this thesis as a tool for the profit maximization for the following reasons. One, to our knowledge, it is less highlighted compared to other retail pricing schemes despite of its advantages. The other, it contains several designable components for the retailer perspective, for example, base and peak rates, number of events, and event duration. In terms of the profit maximization, this thesis aims at presenting several analyses and intuitive guides for designing CPP scheme based on the price responsiveness of customers. The guides and designs include selection of the CPP parameters such as peak rate, number of events, and event duration. To achieve the goals, we first investigated how these parameters affect profit of the retailers. In this process, simple price-response model is adopted for the analyses. The results of the analyses allow us to provide the following three important guidelines. First, the optimal peak rate is approximately inversely proportional to price responsiveness of customers. Second, the optimal peak rate does not change a lot as the number of events varies. Third, the optimal peak rate for single critical event case can be safely used even in case of the multi-events situations in terms of the profit. Fourth, we can ensure existence of a minimum number of events not to lose profit compared the uniform pricing or real-time pricing schemes. Finally, it is a reasonable choice to set event duration as an hour and number of the events as equal time period to total events hour, instead of evaluating each combination of two variables. They are verified by the illustrative examples. In addition to examining the profit maximization of the retailers, we also explored the benefits that a CPP scheme would afford customers. The results showed that CPP could be advantageous to both customers and the retailer if the customers were sufficiently responsive to price fluctuations. It should be emphasized that such a win-win situation may be only achieved if the CPP scheme is properly designedthis, in turn, requires an analysis of the effects of the CPP parameters on profit and a methodology for selecting appropriate parameter values, which were presented in this thesis. On the other hands, we pointed out that CPP is not free from the payback phenomenon: a rise in consumption after a critical event, like other time-varying retail pricing schemes. Also, we showed that this payback has a negative effect on profits and thus must be appropriately considered when designing a CPP scheme by the illustrative example which proves that CPP scheme which is designed without considering payback may not be an optimal anymore if the payback takes place. However, few studies have examined CPP scheme design considering payback. This thesis thus characterizes payback using three parameters (duration, amount, and pattern) and examines payback effects on the optimal schedule of critical events and on the optimal peak rate for two specific payback patterns. All the analysis is verified through numerical simulations. The results demonstrate the need to properly consider payback parameters when designing a profit-maximizing CPP scheme.Chapter 1. Introduction 1 1.1 MOTIVATIONS AND PURPOSES 1 1.2 LITERATURE SURVEY AND CONTRIBUTIONS 6 1.3 THESIS ORGANIZATION 9 Chapter 2. Backgrounds 10 2.1 STRUCTURE OF THE ELECTRICITY WHOLESALE MARKET AND RETAIL SECTOR 10 2.1.1 ENTITIES IN THE ELECTRICITY RETAIL SECTOR 10 2.1.2 ASSUMPTIONS ON ELECTRICITY MARKET 12 2.2 CRITICAL EVENTS SCHEDULING PROBLEM OF THE LSE 14 2.3 PRICE RESPONSIVENESS MODEL OF THE CUSTOMERS 17 Chapter 3. Profit-Maximizing CPP Scheme considering Customers Price-Responsiveness 20 3.1 PROFIT INDEX 20 3.2 SELECTION OF THE OPTIMAL PEAK RATE 22 3.2.1 ANALYSIS FOR SIMPLIFIED CASE 22 3.2.2 EXPANSION FOR GENERALIZED CASE 23 3.3 SELECTION OF THE NUMBER OF EVENTS 27 3.3.1 DETERMINING MINIMUM NUMBER OF THE EVENTS 27 3.3.2 ANALYSIS ON MINIMUM NUMBER OF THE EVENTS 31 3.3.3 REMARK ON MAXIMUM NUMBER OF THE EVENTS 32 3.4 SELECTION OF THE EVENTS DURATION 33 Chapter 4. Payback Effects on CPP Implementation 35 4.1 CHARACTERIZING PAYBACK PHENOMENON 35 4.1.1 PAYBACK RATIO 36 4.1.2 PAYBACK FUNCTION 37 4.2 PAYBACK EFFECTS ON CPP DESIGN 40 4.2.1 PAYBACK EFFECTS ON EVENT SCHEDULING PROBLEM 40 4.2.2 PAYBACK EFFECTS ON OPTIMAL PEAK RATE 42 Chapter 5. Illustrative Examples 48 5.1 DESIGNING PROFIT-MAXIMIZING CPP SCHEME 48 5.1.1 CONFIGURATIONS 48 5.1.2 EVENTS SCHEDULING PROBLEM AND PROFIT INDEX 50 5.1.3 OPTIMAL PEAK RATE 51 5.1.4 NUMBER OF THE EVENTS 55 5.1.5 EVENT DURATION 59 5.1.6 DISCUSSION ON THE BENEFIT OF CUSTOMERS 61 5.2 RESULTS IN PAYBACK PHENOMENON 63 5.2.1 CONFIGURATIONS 63 5.2.2 PAYBACK EFFECTS ON THE OPTIMAL EVENT SCHEDULE 64 5.2.3 PAYBACK EFFECTS ON THE OPTIMAL PEAK RATE 65 Chapter 6. Conclusions and Future Works 70 6.1 CONCLUSIONS 70 6.2 FUTURE WORKS 72 Appendix 74 A. NOVEL ALGORITHM FOR EVENTS SCHEDULING PROBLEM 74 B. NOMENCLATURE 76 B.1 VARIABLES 76 B.2 LIST OF ABBREVIATIONS 79 BIBLIOGRPHY 81 논문 초록 89Docto

위성과 재분석자료의 물수지 자료를 활용한 수증기 수송과 관련된 열대 순환 경향 연구

Thesis(doctor`s)--서울대학교 대학원 :지구환경과학부,2007.Docto

Study on home energy management system for optimizing consumer's energy cost under various tariff

학위논문 (석사)-- 서울대학교 대학원 : 전기. 컴퓨터공학부, 2011.2. 윤용태.Maste

Study of HCI ionization on ice and interaction between low energy Cs+ ion and thin ice film

Maste

Study of elementary reactions on ice by reactive ion scattering spectroscopy

Docto

N1 초중력-물질 상호작용 계에 대한 게이지 대칭 라그랑지안 꾸밈

Thesis (master`s)--서울대학교 대학원 :물리학과,1998.Maste