전력시장 시뮬레이션 기법을 활용한 재생에너지 확대가 전력시스템 유연성 및 경제성에 미치는 영향 분석

학위논문 (박사) -- 서울대학교 대학원 : 공과대학 협동과정 기술경영·경제·정책전공, 2021. 2. 이종수.전 세계적으로 온실가스 감축 목표를 달성하기 위해서 재생에너지 비중을 확대하는 에너지 전환 정책이 시행되고 있다. 하지만, 출력 변동성과 불확실성 특성을 가지고 있는 재생에너지 확대는 전력시스템의 유연성에 문제를 일으킬 수 있으며, 낮은 운영 비용과 국가 정책상의 목적 등에 의해 전력 시장에서 우선 구매되면서 전통 발전원의 급전 우선순위 결정에도 많은 영향을 주게 된다. 이와 같은 맥락에서, 본 연구는 한국의 재생에너지 확대 정책에 의해 재생에너지 발전 비중이 20%를 초과 하는 2031년을 대상으로 전력 시스템의 유연성 평가 및 재생에너지 확대가 전력 시장에 미치는 경제적 영향 분석을 목적으로 한다. 이를 위해서 우선, 혼합정수계획법을 활용하여 하루 전 발전계획 수립 모형을 구축하고, 재생에너지 발전 비중이 6.2%로 상대적으로 낮은 2018년을 기준으로 2031년의 전력 시장 운영 실적과 비교하기 위해서, 구축한 발전계획 수립 모형을 기반으로 전력 시장 시뮬레이션을 수행하였다. 2031년 전력 시스템의 유연성 평가를 위해서 5가지 유연성 공급 용량 산정 시나리오를 설정하고 각 시나리오에 따른 유연성 공급량과 순수요 변동 폭인 유연성 요구량의 시간 단위 비교를 통해서 총 8,760시간에 대한 증∙감발 유연성 부족 횟수를 산출하였다. 유연성 공급 자원으로 운영 예비력만을 고려할 경우, 증발 유연성 측면에서 재생에너지 변동성을 약 94%까지 대응할 수 있지만, 운영 예비력 확보량보다 큰 변동 폭인 약 6% 변동성에 대해서는 속응성 자원의 역할이 필요한 것으로 분석되었다. 반면에, 감발 유연성 측면의 유연성 부족 횟수는 약 18회 수준으로 매우 낮은 발생확률을 보였다. 재생에너지 변동성 분포에 대한 분석 결과를 보면, 고정적으로 운영하던 전통적인 운영 예비력 기준과 다르게 재생에너지 변동성 대응을 위한 유연성 자원은 확보 기준을 탄력적으로 운영할 필요가 있는 것으로 나타난다. 또한, 유연성 측면에서 효율적 대응을 위한 물리적 특성인 높은 증•감발률과 짧은 기동 준비시간을 보유한 발전원들이 운영 예비력에 포함되게 하려면 현행 발전출력 상한제약 방법 개선 및 예비력 보조 서비스 시장의 분리 운영을 검토할 필요가 있겠다. 이때 고려할 수 있는 예비력 보조 서비스 시장 최소 규모는 약 1,620억 원으로 추정되었다. 재생에너지 확대로 인해 2031년의 계통한계가격이 평균적으로 13.7원/kWh 낮아질 것으로 분석되었으며, 더욱이 재생에너지 발전량 비중이 높아질수록 전통 발전원으로 충족시켜야 하는 순수요 크기가 감소하면서 계통한계가격 하락은 더욱 심화할 수도 있다. 이와 같은 시장 가격 하락은 판매사업자의 전력 도매 요금의 동반 하락을 유도할 것처럼 보이지만, 기후변화 대응을 위한 RPS 제도와 배출권거래제를 고려한 전력 구입비 변화에 대한 분석 결과를 보면, 전력량 정산금을 제외한 용량 정산금, 배출권거래비용 및 RPS 의무이행 비용이 상승할 것으로 예측되었다. RPS 의무이행비율, 배출권 유상할당비율 및 배출권 가격 시나리오에 따른 전력 시장 시뮬레이션 결과에 의하면, 평균 전력 구매 단가는 2018년 93.87원/kWh에서 2031년 106.03원/kWh까지 최대 약 13% 상승할 수 있으며, 이는 향후 전력 소매 요금의 인상 압력 요인으로 작용할 수 있다. 본 연구 결과를 종합해보면 다음과 같은 정책적 함의를 끌어낼 수 있다. 첫째, 2031년 전력 시스템의 유연성을 적정 수준으로 확보하기 위해서는 운영 예비력 확보 방법을 발전출력 상한 제약 방식 대신 유연성 요구사항을 충족하는 자원들을 대상으로 한 경쟁 입찰을 통해 확보하는 방안 등 새로운 운영예비력 확보 대안이 고려되어야 한다. 또한, 재생에너지 변동성 대응 목적으로 운영 예비력과 별도로 운영하는 속응성 자원을 차질없이 계획대로 보급하고, 각 유연성 공급 자원별 변동성 대응 메커니즘을 고려하여 재생에너지 발전량 예측시스템을 정교화하여 속응성 자원에 대한 탄력적인 유연성 공급량 확보 기준을 적용해 나가야 할 것이다. 둘째, 재생에너지 확대와 관련한 정책을 개정하거나 신설하고자 할 때는 직접적인 정책의 기대효과뿐만 아니라 판매사업자의 전력 구입비 증가로 인한 전기 요금 인상 압력과 같은 간접적인 파급효과까지 함께 고려해 주어야겠다. RPS 의무할당비율, 배출권거래제 유상할당비율, 배출권 거래 비용 등의 변화로 최대 13%까지 전력 도매가격이 상승할 수 있기 때문이다. 셋째, 재생에너지 발전량과 시장 가격이 점점 상반된 패턴으로 변화할 것으로 예측되기 때문에, 변동비 반영 시장의 정산 규칙이나 시장 가격 산정 방법에 대한 개선 검토 시 이런 패턴 변화를 반드시 고려해야 한다. 또한, 유연성 공급에 참여한 발전사업자들의 보상이 적정한 수준으로 설정되어야 에너지 시장 대비 보조 서비스 시장 참여가 활성화 될 것이다. 마지막으로, 미래 전력 시장에서는 수요 피크와 시장 가격 피크의 불일치가 점점 증대될 수 있으므로, 수요 관리, 경제성 DR, 전기 요금 산정 등 수요 패턴을 고려하는 다양한 정책들이 향후에는 순수요 패턴도 함께 고려하는 방향으로 재검토되어야 할 것이다.To achieve the reduction target of greenhouse gas emissions, energy transition policy is being implemented to expand the share of renewable energy worldwide. However, the expansion of renewable energy not only causes the flexibility problem of the power system due to volatility and uncertainty of renewable energy output, but also affects the merit order of traditional power generation sources due to low operating costs of renewables or national policy objectives. These effects give rise to a huge transformation in power systems with a high share of renewable energy. In this context, this study evaluates the flexibility of the power system and analyzes the economic impact on the power market in 2031, when the share of renewable energy exceeds 20% due to Koreas energy transition policy. First, a mixed-integer linear programming approach was used to formulate the power system day-ahead unit commitment and economic dispatch model, and a power market simulation was conducted to compare the performance of the electricity market in 2031 based on 2018 figures, when the share of renewable energy is relatively low at 6.2%. To assess the flexibility of the power system in 2031, the number of periods of flexibility deficit for 8,760 hours was calculated by comparing the supply of flexibility according to the scenario of available flexibility resources with the flexibility requirement, which is the fluctuation in net load over an hour. The results show that if only the operational reserve is considered as a flexibility supply resource, about 94% of the renewable energy volatility can be dealt with in terms of upward flexibility, but the role of the quick-start generation resources is found to be important for 6% of the ramping event greater than the reserve capacity. On the other hand, the number of times flexibility deficit occurs in terms of downward flexibility is expected to be about 18, showing a very low probability of occurrence. The analysis of the distribution of renewable energy volatility reveals that, unlike the standard for operational reserve, which was traditionally fixed, the resource for responding to flexibility problem in renewable energy needs to operate the flexible securing standard. In addition, it is necessary to review the improvement of the current upper limit method of power output level and the separate operation of the reserve auxiliary service market from the energy service market to ensure that power generation sources suitable for supplying flexibility with physical characteristics for response to flexibility are included in the operational reserve. At this time, the minimum market size of the reserve auxiliary service that could be considered was estimated to be about KRW 162 billion. The expansion of renewable energy will lower the system marginal price by 13.7 KRW/kWh on average in 2031. As the share of renewable energy generation increases, the capacity of net load to be met by traditional power generation decreases, and the drop in the system marginal price may be even worse. Such a decrease in electricity market prices seems to lead to the accompanied decline in the power vendors wholesale electricity price. However, when looking at the result of power purchase cost analysis considering the renewable portfolio standard (RPS) and the emissions trading scheme (ETS) to expand renewable energy, it was predicted that the capacity settlement amount, the emission trading cost, and the RPS obligation fulfillment cost, excluding the electricity settlement amount, would increase. According to the analysis of power market simulation by RPS obligatory rate, paid allocation ratio for emissions trading, and emissions price per unit scenarios, the average power purchase cost may increase up to about 13% from 93.87 KRW/kWh in 2018 to 106.03 KRW/kWh in 2031. This suggests that it could act as a pressure factor to raise electricity rates in the future. The results of this study have the following policy implications. First, to secure the flexibility of the power system to an appropriate level in 2031, it is necessary to consider the alternative method of securing the operating reserve via competitive bidding for flexibility resources that meet the power system requirement instead of the upper limit constraint on generation output. In addition, for the purpose of responding to variability of renewable energy, quick-start generators operated separately from the operational reserve should be implemented as planned. It is also necessary to refine the system for predicting the amount of renewable energy generation in consideration of the mechanism for responding to the variability of each flexibility resource to realize the flexible regulation of flexibility supply amount. Second, if policy makers consider revising or establishing a new policy related to the expansion of renewable energy, it is necessary to examine not only the expected direct effect of the policy but also the indirect ripple effect, such as the pressure to increase electricity rates due to the hike in power purchase costs of vendors. Third, since the amount of renewable energy generation and electricity market price are expected to change in an increasingly inconsistent pattern, it is also important to reconsider the design for the settlement rules of the cost-based pool market or method of deciding the market price. Finally, in the future power market, the pattern difference between the demand peak and the market price peak may increase. Therefore, various policies that consider demand patterns, such as demand management, economical demand response, and electricity fee system, should be reviewed in the direction of considering the net load pattern in the future.Chapter 1. Introduction 1 1.1 Research Background 1 1.2 Research Objectives 6 1.3 Research Outline 9 Chapter 2. Literature Review 12 2.1 Power System Flexibility 12 2.1.1 Sources of Flexibility 15 2.1.2 Studies on Flexibility Evaluation 19 2.2 Generation Scheduling 23 2.2.1 Unit Commitment and Economic Dispatch Model 23 2.2.2 Optimization techniques for solving UC problem with High Renewable Energy Sources Penetration 25 2.3 Research of the Energy policy in Korea 28 2.4 Limitations of previous research and Research Motivation 33 Chapter 3. Methodology 36 3.1 Methodological Framework 36 3.2 Unit Commitment and Economic Dispatch Modeling 40 3.2.1 Generation scheduling using MILP 42 3.2.2 An empirical model for day-ahead unit commitment and economic dispatch 49 3.2.3 Model Input data 58 3.2.4 Evaluation of the power system flexibility 68 3.2.5 Economic impact analysis 72 3.3 Model validation 79 3.3.1 Overview of model validation 79 3.3.2 Model validation result 82 Chapter 4. Empirical Studies 87 4.1 The study on evaluating the power system flexibility 87 4.1.1 Overview of flexibility evaluation and premises of analysis 87 4.1.2 Net load variability and calculation of flexibility requirement 91 4.1.3 Unit commitment and economic dispatch simulation and calculation of flexibility supply amount 96 4.1.4 Empirical results of evaluating the power system flexibility 103 4.2 Composition of flexibility resources and ability to respond to volatility 111 4.2.1 Incentive effect for participation in operational reserve service 112 4.2.2 Composition of operational reserve resources for flexibility supply 117 4.2.3 Volatility response mechanism of operational reserves and quick–start generators 123 4.2.4 Improvement of reserve system and separation of the auxiliary service market 128 4.3 Analysis of the economic impact 132 4.3.1 Premises for economic impact analysis 132 4.3.2 Forecasting SMP and electricity settlement amount 134 4.3.3 Analysis of the impact of policies related to the expansion of renewable energy 138 4.3.4 Empirical results and discussion 143 Chapter 5. Summary and Conclusion 146 5.1 Concluding Remarks and Contribution 146 5.2 Limitations and Future Studies 148 Bibliography 151 Appendix 1: The results of power generation scheduling of pumped-storage power plants 164 Appendix 2: Power market operation performance trend (2001-2019) 166 Abstract (Korean) 168Docto

중장기 SOC 투자전략에 관한 연구(The middle and long term investment strategies of transporation social overhead capitals)

노트 : 이 연구보고서의 내용은 국토연구원의 자체 연구물로서 정부의 정책이나 견해와는 상관없습니다

Type I saikosaponins a and d inhibit osteoclastogenesis in bone marrow-derived macrophages and osteolytic activity of metastatic breast cancer cells

Many osteopenic disorders, including a postmenopausal osteoporosis and lytic bone metastasis in breast and prostate cancers, are linked with a hyperosteoclast activity due to increased receptor activator of nuclear factor kappa-B ligand (RANKL) expression in osteoblastic/stromal cells. Therefore, inhibition of RANKL-induced osteoclastogenesis and osteoclast-induced bone resorption is an important approach in controlling pathophysiology of these skeletal diseases. We found that, of seven type I, II, and III saikosaponins isolated from Bupleurum falcatum, saikosaponins A and D, type I saikosaponins with an allyl oxide linkage between position 13 and 28 and two carbohydrate chains that are directly attached to the hydroxyl groups in position 3, exhibited the most potent inhibition on RANKL-induced osteoclast formation at noncytotoxic concentrations. The stereochemistry of the hydroxyl group at C16 did not affect their activity. Saikosaponins A and D inhibited the formation of resorptive pits by reducing the secreted levels of matrix metalloproteinase- (MMP-) 2, MMP-9, and cathepsin K in RANKL-induced osteoclasts. Additionally, saikosaponins A and D inhibited mRNA expression of parathyroid hormone-related protein as well as cell viability and invasion in metastatic human breast cancer cells. Thus, saikosaponins A and D can serve as a beneficial agent for the prevention and treatment of osteoporosis and cancer-induced bone loss.ope

충돌각과 종말 받음각 구속조건을 고려한 미사일 유도법칙

학위논문 (석사)-- 서울대학교 대학원 : 기계항공공학부, 2014. 2. 김현진.This paper proposes a guidance law considering constraints on impact angle and terminal angle of attack for a homing missile. In the proposed structure, the guidance law generates angle of attack command and the controller tracks the generated command. For deriving the angle of attack command, the differential game problem with terminal boundary conditions is proposed and solved. Then, the sliding mode control is applied in order to derive the actual command input from the guidance command. Because the guidance command is the angle of attack, the terminal angle of attack constraint can be easily handled and the controller needs not deal with non-minimum phase characteristics. This capability to control the terminal angle of attack is the main contribution of the paper. The performance of the proposed law is evaluated using a two-dimensional nonlinear simulation. The result demonstrates that the proposed law allows the missile to intercept the maneuvering target with the constraints on impact angle and terminal angle of attack.Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi Chapter 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Literature Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2 Thesis Contribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Thesis Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2 Problem Formulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1 Guidance Formulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.2 Missile Dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3 Guidance Law and Autopilot Design . . . . . . . . . . . . . . . . . . . . . . . . 10 3.1 Derivation of the Terminal Angle of Attack Constrained Guidance Law . . 10 3.2 Angle of Attack Controller Design . . . . . . . . . . . . . . . . . . . . . . . 14 3.3 Angle of Attack Observer Design . . . . . . . . . . . . . . . . . . . . . . . 15 3.4 Synthesis of Guidance Law, Controller and Observer . . . . . . . . . . . . 16 4 Simulation Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.1 Performance Analysis of TAACG . . . . . . . . . . . . . . . . . . . . . . . 18 4.2 Comparison with Other Guidance Laws . . . . . . . . . . . . . . . . . . . . 19 5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30Maste

RTCVD 다결정 실리콘 게르마늄 박막을 이용한 PMOS 트랜지스터의 제조 및 특성 연구

Maste

구강편평상피세포암 침습에서 CXCL5–CXCR2의 역할

open박

U-곡관에서의 이차 유동이 예혼합 분젠화염에 미치는 영향에 관한 실험적 연구

학위논문(석사)--서울대학교 대학원 :기계공학과,1999.Maste

Bisphosphonate계열의 약물인 Clodronate와 Pamidronate가 조골세포의 활성 및 파골세포유사세포 생성에 미치는 영향

학위논문(석사)--서울대학교 대학원 :치의학과 치과약리학 전공,1999.Maste

시야 제한이 있는 유도탄의 충돌각 및 충돌시간 제어 유도 법칙

학위논문 (박사)-- 서울대학교 대학원 : 공과대학 기계항공공학부, 2018. 8. 김현진.Homing guidance aims at guiding a missile to its intended target using information acquired from an on-board seeker. In real applications of homing guidance laws, a field-of-view restriction of the missile seeker is a significant issue because maintaining the seeker lock-on condition is an important task for acquiring the target information. Especially, when implementing advanced guidance laws to impose terminal constraints on impact angle and time, considering the field-of-view constraint is particularly essential since the curved trajectory may let the seeker's look angle exceed the confined field-of-view limit. This dissertation presents guidance laws whose contributions are classified into three parts: i) impact angle control guidance law with the field-of-view constraint, ii) impact time control guidance law with the field-of-view constraint, and $iii)$ impact angle and time control guidance law with the field-of-view constraint. First, an impact angle control guidance law that confines the missile look angle during homing in order not to exceed a seeker's field-of-view limit is proposed. A sliding surface variable whose regulation guarantees the interception of a stationary target at the desired impact angle is designed, and the guidance law is derived to make the surface variable go to the sliding mode. Using a magnitude-limited sigmoid function in the surface variable, the proposed law prohibits the look angle from exceeding the specified limit during the entire homing. This capability to confine the missile look angle is valuable when a seeker's field-of-view is restricted, since imposing the terminal impact angle constraint demands the missile to fly a curved trajectory. Furthermore, the proposed law only needs the line-of-sight angle and look angle among the target information. Thus, the proposed law can easily be implemented into a homing missile equipped with a structurally simple passive strapdown seeker. Theoretical analysis in this part indicates that the proposed law accomplishes the impact angle constraint without violating the look angle limit although it only uses the information of bearing angles. Second, a guidance law that achieves the desired impact time without violating the seeker's field-of-view limit is presented. For the development of the law, kinematic conditions for impact time control are defined, and the backstepping control-based approach is adopted for the satisfaction of the conditions. The missile look angle is utilized as a virtual control input for the backstepping structure, and its magnitude is limited by a prescribed limit by restricting the controller gain. Consequently, the impact time constraint can be achieved with satisfying the look angle limit under the proposed law. Since few papers considering the field-of-view limit under the impact time control are available in open literature, the capability to confine the seeker's look angle with achieving the desired impact time is the main contribution of this part. Finally, a guidance law for impact angle and time control with taking into account the field-of-view constraint is developed. Basically, the law in this part is formed as a look angle-limited impact angle control guidance law that has an additional guidance gain. Since the length of the trajectory under this law is calculated as a function of this gain, the terminal impact time can be controlled by adjusting the gain. As a result, the proposed guidance law in this part can intercept the stationary target at the desired impact angle and time with satisfying the field-of-view limit. The proposed law is expected to achieve the accurate performance in real applications owing to its closed-loop structure without using any numerical routine such as off-line optimization or the shooting method. To evaluate the performance of the proposed laws, numerical simulations are conducted for each part. The results demonstrate that the proposed laws accomplish the desired terminal tasks with preventing the look angle from exceeding the prescribed limit.Table of Contents Page Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii Chapter 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Background and motivations . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Literature survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2.1 Impact angle control guidance . . . . . . . . . . . . . . . . . . . . . 3 1.2.2 Impact time control guidance . . . . . . . . . . . . . . . . . . . . . 6 1.2.3 Impact angle and time control guidance . . . . . . . . . . . . . . . 8 1.3 Research objectives and contributions . . . . . . . . . . . . . . . . . . . . . 9 1.3.1 Impact angle control guidance law with _x000C_eld-of-view constraint . . . 9 1.3.2 Impact time control guidance law with _x000C_eld-of-view constraint . . . 10 1.3.3 Impact angle and time control guidance law with _x000C_eld-of-view constraint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1.4 Thesis organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2 Impact Angle Control Guidance with Field-of-View Constraint . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.1 Problem statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.2 Design of impact angle control guidance law . . . . . . . . . . . . . . . . . 15 2.2.1 Kinematic conditions for impact angle control guidance . . . . . . . 16 2.2.2 Derivation of guidance law . . . . . . . . . . . . . . . . . . . . . . . 18 viii 2.3 Analysis of the proposed law . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.3.1 Look angle analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2.3.2 Stability analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2.3.3 Convergence analysis of error variables e1 and e2 . . . . . . . . . . . 22 2.4 Simulation results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2.4.1 Performance analysis of the proposed law . . . . . . . . . . . . . . . 27 2.4.2 Performance comparison with other guidance laws . . . . . . . . . . 31 2.4.3 Performance analysis in a realistic scenario . . . . . . . . . . . . . . 35 3 Impact Time Control Guidance with Field-of-View Constraint . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 3.1 PROBLEM FORMULATION . . . . . . . . . . . . . . . . . . . . . . . . . 39 3.2 IMPACT TIME CONTROL GUIDANCE LAW WITH CONSTRAINED FIELD-OF-VIEW LIMITS . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 3.2.1 Kinematic conditions for impact time control guidance . . . . . . . 40 3.2.2 Guidance law design . . . . . . . . . . . . . . . . . . . . . . . . . . 42 3.3 ANALYSIS OF THE PROPOSED GUIDANCE LAW . . . . . . . . . . . . 46 3.3.1 Guidance command analysis . . . . . . . . . . . . . . . . . . . . . . 46 3.3.2 Stability analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 3.3.3 Look-angle analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 3.3.4 Discussion about achievable impact time . . . . . . . . . . . . . . . 55 3.4 SIMULATION RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 3.4.1 Performance analysis of the proposed law . . . . . . . . . . . . . . . 60 3.4.2 Performance comparison with other guidance laws . . . . . . . . . . 64 3.4.3 Salvo attack in a realistic engagement . . . . . . . . . . . . . . . . . 67 4 Impact Angle and Time Control Guidance with Field-of-View Constraint . . . . 71 4.1 Problem formulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 4.2 Impact angle control guidance law with look angle constraint . . . . . . . . 74 4.2.1 Look angle shaping based on nonlinear formulation . . . . . . . . . 74 ix 4.2.2 Design of the guidance law to follow the look angle pro_x000C_le . . . . . 76 4.3 Impact angle and time control guidance law with look angle constraint . . 79 4.3.1 Calculation of time-to-go . . . . . . . . . . . . . . . . . . . . . . . . 79 4.3.2 Impact time control based on time-to-go calculation . . . . . . . . . 82 4.4 Numerical simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 4.4.1 Performance analysis of the proposed guidance law . . . . . . . . . 86 4.4.2 Performance comparison with other guidance laws in realistic scenarios 89 5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 Abstract (in Korean) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105Docto

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학위논문(석사)--서울대학교 대학원 :경영학과 경영학전공,2000.Maste