• Title/Summary/Keyword: unit solution

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이산 최적 $H_{\infty}$-제어 문제의 최적해를 구하는 방법에 대한 연구 (Study on an optimum solution for discrete optimal $H_{\infty}$-control problem)

  • 하철근
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.565-568
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    • 1996
  • In this paper, a solution method is proposed to calculate the optimum solution to discrete optimal H$_{.inf}$ control problem for feedback of linear time-invariant system states and disturbance variable. From the results of this study, condition of existence and uniqueness of its solution is that transfer matrix of controlled variable to input variable is left invertible and has no invariant zeros on the unit circle of the z-domain as well as extra geometric conditions given in this paper. Through a numerical example, the noniterative solution method proposed in this paper is illustrated.

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Topology Optimization of the Decking Unit in the Aluminum Bass Boat and Strength Verification using the FEM-program

  • Seo, Kwang-Cheol;Gwak, Jin;Park, Joo-Shin
    • 해양환경안전학회지
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    • 제24권3호
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    • pp.367-372
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    • 2018
  • The objective of this paper is to optimize the cross-section of aluminum decking units used in the bass boats under operating conditions, and to verify the optimized model from the results via by ANSYS software. Aluminum decking unit is needed to endure specific loading while leisure activity and sailing. For a stiffer and more cost-neutral aluminum decking unit, optimization is often considered in the naval and marine industries. This optimization of the aluminum decking unit is performed using the ANSYS program, which is based on the topology optimization method. The generation of finite element models and stress evaluations are conducted using the ANSYS Multiphysics module, which is based on the Finite Element Method (FEM). Through such a series of studies, it was possible to determine the most suitable case for satisfying the structural strength found among the phase-optimized aluminum deck units in bass boats. From these optimization results, CASE 1 shows the best solution in comparison with the other cases for this optimization. By linking the topology optimization with the structural strength analysis, the optimal solution can be found in a relatively short amount of time, and these procedures are expected to be applicable to many fields of engineering.

Staged Finite Element Modeling with Coupled Seepage and Stress Analysis

  • Lee, Jae-Young
    • 한국전산구조공학회논문집
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    • 제23권6호
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    • pp.703-714
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    • 2010
  • This paper proposes an approach for staged finite element modeling with coupled seepage and stress analysis. The stage modeling is based on the predefined inter-relationship between the base model and the unit stage models. A unit stage constitutes a complete finite element model, of which the geometries and attributes are subject to changes from stage to stage. The seepage analysis precedes the mechanical stress analysis at every stage. Division of the wet and dry zone and the pore pressures are evaluated from the seepage analysis and used in determining input data for the stress analysis. The results of the stress analysis may also be associated with the pore water pressures. For consolidation analysis, the pore pressure and the displacement variables are mixed in a coupled matrix equation. The time marching solution produces the dissipation of excess pore pressure and variation of stresses with passage of time. For undrained analysis, the excess pore pressures are computed from the stress increment due to loading applied in the unit stage and are used in revising the hydraulic head. The solution results of a unit stage are inherited and accumulated to the subsequent stages through the relationship of the base model and the individual unit stages. Implementation of the proposed approach is outlined on the basis of the core procedures, and numerical examples are presented for demonstration of its application.

Tertiary Structure of PreSl(21-47) of Hepatitis B Virus Studied by NMR Spectroscopy

  • Kyeunghee Yu;Cho, Eun-Wie;Shin, Song-Yub;Kim, Kol-Lyong;Kim, Yangmee
    • 한국자기공명학회논문지
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    • 제4권1호
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    • pp.41-49
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    • 2000
  • To design more efficient peptide antagonist against the HBV, preSl(21-47) which carries the HBV receptor binding site for hepatocytes was synthesized and the solution structure of preSl(21-47) was investigated using CD spectroscopy and NMR spectroscopy in membrane-mimicking environments. According to CD spectra, preSl(21-47) has a random structure in aqueous solution, while conformational change was induced by addition of TFE and SDS micelle. Tertiary structures as determined by NMR spectroscopy shows that preSl(21-47) has a very flexible structure even in SDS micelle.

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활동기반 업무처리를 위한 객체기반 정보화 (Realizing an Object-Oriented Informationalization for Activity-Based Business Processing)

  • 황종호
    • 한국IT서비스학회지
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    • 제12권1호
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    • pp.309-321
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    • 2013
  • In current complex nature of management with task-structures, a method to reach the enterprise's informationalization success is not common. To satisfy these various requirement, improving the usability of information technology (IT) is a key factor which defining the level of organizational requirement first. Imposing an IT-solution which has excess service of the organization's previous task-environment, procedure and scope is not effective to SME-level unit, which unit could not have a formal organization structure and task structure. SME level informationalization will be success if each function realizes easier on the task-employee's viewpoint. Achieving this objective, a solution provider or department must reflect their work characteristics of nature which has least level of work performing resistance. It is most useful system for SME level unit, if a provider develops single programs which based on task activities, and each program can configure network-linking.

An Improved Dynamic Programming Approach to Economic Power Dispatch with Generator Constraints and Transmission Losses

  • Balamurugan, R.;Subramanian, S.
    • Journal of Electrical Engineering and Technology
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    • 제3권3호
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    • pp.320-330
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    • 2008
  • This paper presents an improved dynamic programming (IDP) approach to solve the economic power dispatch problem including transmission losses in power systems. A detailed mathematical derivation of recursive dynamic programming approach for the economic power dispatch problem with transmission losses is presented. The transmission losses are augmented with the objective function using price factor. The generalized expression for optimal scheduling of thermal generating units derived in this article can be implemented for the solution of the economic power dispatch problem of a large-scale system. Six-unit, fifteen-unit, and forty-unit sample systems with non-linear characteristics of the generator, such as ramp-rate limits and prohibited operating zones are considered to illustrate the effectiveness of the proposed method. The proposed method results have been compared with the results of genetic algorithm and particle swarm optimization methods reported in the literature. Test results show that the proposed IDP approach can obtain a higher quality solution with better performance.

PSO알고리즘에 기초한 발전기 보수정지 (Generating unit Maintenance Scheduling based on PSO Algorithm)

  • 박영수;김진호;박준호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
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    • pp.222-224
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    • 2006
  • This paper addresses a particle swarm optimization-based approach for solving a generating unit maintenance scheduling problem(GMS) with some constraints. We focus on the power system reliability such as reserve ratio better than cost function as the objective function of GMS problem. It is shown that particle swarm optimization-based method is effective in obtaining feasible schedules such as GMS problem related to power system planning and operation. In this paper, we find the optimal solution of the GMS problem within a specific time horizon using particle swarm optimization algorithm. Simple case study with 16-generators system is applicable to the GMS problem. From the result, we can conclude that PSO is enough to look for the optimal solution properly in the generating unit maintenance scheduling problem.

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Optimal Scheduling in Power-Generation Systems with Thermal and Pumped-Storage Hydroelectric Units

  • Kim, Sehun;Rhee, Minho
    • 한국경영과학회지
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    • 제15권1호
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    • pp.99-115
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    • 1990
  • This paper is concerned with the unit commitment problem in an electric power system with both thermal and pumped-storage hydroelectric units. This is a mixed integer programming problem and the Lagrangean relaxation method is used. We show that the relaxed problem decomposes into two kinds of subproblems : a shortest-path problem for each thermal unit and a minimum cost flow problem for each pumped-storage hydroelectric unit. A method of obtaining an incumbenet solution from the solution of a relaxed problem is presented. The Lagrangean multipliers are updated using both subgradient and incremental cost. The algorithm is applied to a real Korean power generation system and its computational results are reported and compaired with other works.

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An Innovative Scalp-Dyeing Technique with Gentian Violet Solution During Follicular Unit Extraction for White-Haired Follicular Units

  • Moon, Min Seon;Choi, Jong Pil
    • Archives of Plastic Surgery
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    • 제44권2호
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    • pp.170-172
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    • 2017
  • There exist some restrictions and difficulties in performing follicular unit extraction (FUE) in white-haired patients, for several reasons. In this paper, we introduce a novel technique for visualizing white hair during the punching procedure and graft preparation in FUE for white-haired patients. In white-haired older male patients, we dyed the surrounding scalp skin purple with a gentian violet solution-stained toothpick. Our method has several advantages: surgeons can easily focus on the center of the follicular unit and rapidly perform punching, they can recognize the condition of the harvested follicular units during FUE, and the hair transplant team can secure a clear view for trimming and loading into the implanter. We suggest that scalp dyeing in difficult FUE procedures, especially in patients with white hair, may be a simple method that provides a good visualization for donor site harvesting and for microdissection.