• 제목/요약/키워드: allowable strategy

검색결과 27건 처리시간 0.024초

관리전략평가(Management Strategy Evaluation) 방법에 의한 현행 TAC (Total Allowable Catch) 의사결정 검토: 고등어(Scomber japonicus) 어업의 경우 (A Management Strategy Evaluation of the Current TAC (Total Allowable Catch) Regulation in Korea: The Case of Chub Mackerel Scomber japonicus Fisheries)

  • 김도율;서영일;현상윤
    • 한국수산과학회지
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    • 제55권6호
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    • pp.946-953
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    • 2022
  • Using the management strategy evaluation methods and data on the Korea chub mackerel Scomber japonicus where the state-space logistic production model is used as the operation and the estimation model respectivley, we examined the effects of both Dorn's rule, α and the buffer value for ABC (allowable biological catch), which are used by the Korea fishery managers for decision rules. We set scenarios that have different pairs of buffer and α values, which include those currently used in the management in Korea. Under each sceanario, we projected the fish population biomass until year 2050, during which ABC is determined in each year with the decision rule. We used three kinds of performance measures: (i) whether the biomass in 2050 is overfished; (ii) the average of annual yields over the simulation period; and (iii) the variability of annual yields over the period. We found that the current practice (buffer=0.9, and α = 0.05) resulted in the best performance in terms of avoiding the "overfished" status. However, the current practice failed to reach the maximum average of the annual yields and led to larger uncertainty in the annual yields.

포트폴리오 기법을 이용한 복수어종의 최적 생산관리 전략 (A Strategy for Optimal Production Management of Multi-Species Fisheries using a Portfolio Approach)

  • 김도훈
    • 수산경영론집
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    • 제45권1호
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    • pp.109-119
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    • 2014
  • This study aimed to examine the applicability of a portfolio approach to the ecosystem-based fisheries management targeting the large purse seine fishery. Most fisheries are targeting multispecies and species are biologically and technically interacted each other. It enables a portfolio approach to be applied to find optimal production of each species through expected returns and risk analyses. Under specific assumptions on the harvest quota by species, efficient risk-return frontiers were generated and they showed a combination of optimal production level. Comparisons between portfolio and actual production provided a useful information for targeting strategy and management. Results also showed the possibility of effective multispecies fisheries management by imposing constraints on each species such as total allowable catch quotas.

A Study on the Voltage Stabilization Method of Distribution System Using Battery Energy Storage System and Step Voltage Regulator

  • Kim, Byung-ki;Park, Jae-Beom;Choi, Sung-Sik;Jang, Moon-Seok;Rho, Dae-Seok
    • Journal of Electrical Engineering and Technology
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    • 제12권1호
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    • pp.11-18
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    • 2017
  • In order to maintain customer voltages within the allowable limit($220{\pm}13V$) as much as possible, tap operation strategy of SVR(Step Voltage Regulator) which is located in primary feeder, is widely used for voltage control in the utilities. However, SVR in nature has operation characteristic of the delay time ranging from 30 to 150 sec, and then the compensation of BESS (Battery Energy Storage System) during the delay time is being required because the customer voltages in distribution system may violate the allowable limit during the delay time of SVR. Furthermore, interconnection of PV(Photovoltaic) system could make a difficultly to keep customer voltage within the allowable limit. Therefore, this paper presents an optimal coordination operation algorithm between BESS and SVR based on a conventional LDC (Line Drop Compensation) method which is decided by stochastic approach. Through the modeling of SVR and BESS using the PSCAD/EMTDC, it is confirmed that customer voltages in distribution system can be maintained within the allowable limit.

RCD success criteria estimation based on allowable coping time

  • Ham, Jaehyun;Cho, Jaehyun;Kim, Jaewhan;Kang, Hyun Gook
    • Nuclear Engineering and Technology
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    • 제51권2호
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    • pp.402-409
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    • 2019
  • When a loss of coolant accident (LOCA) occurs in a nuclear power plant, accident scenarios which can prevent core damage are defined based on break size. Current probabilistic safety assessment evaluates that core damage can be prevented under small-break LOCA (SBLOCA) and steam generator tube rupture (SGTR) with rapid cool down (RCD) strategy when all safety injection systems are unavailable. However, previous research has pointed out a limitation of RCD in terms of initiation time. Therefore, RCD success criteria estimation based on allowable coping time under a SBLOCA or SGTR when all safety injection systems are unavailable was performed based on time-line and thermal-hydraulic analyses. The time line analysis assumed a single emergency operating procedure flow, and the thermal hydraulic analysis utilized MARS-KS code with variables of break size, cooling rate, and operator allowable time. Results show while RCD is possible under SGTR, it is impossible under SBLOCA at the APR1400's current cooling rate limitation of 55 K/hr. A success criteria map for RCD under SBLOCA is suggested without cooling rate limitation.

A Novel Multi-Function PV Micro-Inverter with an Optimized Harmonic Compensation Strategy

  • Zhu, Guofeng;Mu, Longhua;Yan, Junhua
    • Journal of Power Electronics
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    • 제16권6호
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    • pp.2284-2293
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    • 2016
  • With the rapid development of clean energy, photovoltaic (PV) generation has been utilized in the harmonic compensation of power systems. This paper presents a novel multi-function PV micro-inverter with three stages (pseudo-two-stage). It can inject active power and compensate harmonic currents in the power grid at the same time. In order to keep the micro-inverter working under the maximum allowable output power, an optimized capacity limitation strategy is presented. Moreover, the harmonic compensation can be adjusted according to the customized requirements of power quality. Additionally, a phase shedding strategy in the DC/DC stage is introduced to improve the efficiency of parallel Boost converters in a wide range. Compared with existing capacity limitation methods, the proposed strategy shows better performance and energy efficiency. Simulations and experiments verify the feasibility of the micro-inverter and the effectiveness of the strategy.

자동화추론의 성능개선을 위한 퍼지관계요구의 응용 및 구현 (Application and Implementation of Fuzzy Relational Request for Improving the Performance of Automated Reasoning)

  • 조재희;진정애;김용기
    • 한국정보처리학회논문지
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    • 제5권8호
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    • pp.2050-2060
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    • 1998
  • 가중치전략(weighting strategy)은 인공지능의 한 분야인 자동화추론(automated resaonnimg) 분야에서, 허용 가능한 시간과 기억공간내에서 해를 구하기 위해서 필수적으로 사용되는 방법이다. 그러나 가중치전략의 적용은 문제에 대한 사용자의 지식이나 경험에 주로 의존할 뿐 아니라, 각각의 단계에서 프로그램화되지 못하여 수작업으로인한 시간의 소모가 많다. 수작업을 필요로 하던 기존의 시스템을 자동화하여, 관계계층구조(thesaurus)를 시스템이 자동으로 구축하는 도구를 개발하고, 이를 기존의 자동정리증명기에 통합하여, 그 성능을 개선하는 시스템을 제안한다.

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Rate Modulation Strategy for Behaviors of a Mobile Robot

  • Kim, Hong-Ryeol;Kim, Joo-Min;Kim, Dae-Won
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.1109-1114
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    • 2003
  • In this paper, task control architecture is proposed for a mobile robot with behaviors based on cognition theory to endow the robot intelligence. In the task control architecture, task manager is introduced especially for the management of computational resource. The management is based on classical RMS (Rate Monotonic Strategy), but with online rate modulation strategy. The rate modulation is performed using the value variances of behavior execution for the task. Because the values are based on natively uncertain sensor information, they are modeled using PDF (probability Density Function). As a rate modulation process, the range of the rate modulation is defined firstly by real-time constraints of RMS and discrete control stability of behaviors. With the allowable range, rate modulations are performed considering harmonic bases to maintain utilization bound without decrease. To evaluate the efficiency of the proposed rate modulation strategy, a simulation test is performed to compare the efficiency between the control architecture with the proposed strategy and previous one. A performance index with the formalization of propensity of resource allocation is proposed and utilized for the simulation test. To evaluate the appropriateness of the performance index, the performance index is compared with practical one through a practical simulation test.

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승용디젤엔진의 과도구간 입자상물질 저감 및 운전성능 향상을 위한 연료분사량 및 커먼레일압력 제어전략 (A Control Strategy of Fuel Injection Quantity and Common-rail Pressure to Reduce Particulate Matter Emissions in a Transient State of Diesel Engines)

  • 홍승우;정동혁;선우명호
    • 한국자동차공학회논문집
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    • 제23권6호
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    • pp.623-632
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    • 2015
  • This study proposes a control strategy of the common rail pressure with a fuel injection limitation algorithm to reduce particulate matter (PM) emissions under transient states. The proposed control strategy consists of two parts: injection quantity limitation and rail pressure adaptation. The injection limitation algorithm determines the maximum allowable fuel injection quantity to avoid rich combustion under transient states. The fuel injection quantity is limited by predicting the burned gas rate after combustion; however, the reduced injection quantity leads to deterioration of engine torque. The common rail pressure adaptation strategy is designed to compensate for the reduced engine torque. An increase of the rail pressure under transient states contributes to enhancement of the engine torque as well as reduction of PM emissions by promoting atomization of the injected fuel. The proposed control strategy is validated through engine experiments. The rail pressure adaptation reduced the PM emission by 5-10% and enhanced the engine torque up to 2.5%.

서비스 납기가 주어진 다목적차량일정문제를 위한 혼성유전알고리듬의 개발 (A Hybrid Genetic Algorithm for the Multiobjective Vehicle Scheduling Problems with Service Due Times)

    • 한국경영과학회지
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    • 제24권2호
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    • pp.121-134
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    • 1999
  • In this paper, I propose a hybrid genetic algorithm(HGAM) incorporating a greedy interchange local optimization procedure for the multiobjective vehicle scheduling problems with service due times where three conflicting objectives of the minimization of total vehicle travel time, total weighted tardiness, and fleet size are explicitly treated. The vehicle is allowed to visit a node exceeding its due time with a penalty, but within the latest allowable time. The HGAM applies a mixed farming and migration strategy in the evolution process. The strategy splits the population into sub-populations, all of them evolving independently, and applys a local optimization procedure periodically to some best entities in sub-populations which are then substituted by the newly improved solutions. A solution of the HCAM is represented by a diploid structure. The HGAM uses a molified PMX operator for crossover and new types of mutation operator. The performance of the HGAM is extensively evaluated using the Solomons test problems. The results show that the HGAM attains better solutions than the BC-saving algorithm, but with a much longer computation time.

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배전계통의 전압안정화를 위한 선로전압조정장치와 전지전력저장장치의 협조제어 알고리즘에 관한 연구 (A Study on the Coordination Control Algorithm of Step Voltage Regulator and Battery Energy Storage System for Voltage Regulation in Distribution System)

  • 김병기;왕종용;박재범;최성식;유경상;노대석
    • 전기학회논문지
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    • 제65권2호
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    • pp.269-278
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    • 2016
  • In order to maintain customer voltages within allowable limit($220{\pm}13V$) as much as possible, tap operation strategy of SVR(Step Voltage Regulator) installed in distribution system is very important, considering the scheduled delay time(30 sec) of SVR. However, the compensation of BESS(Battery Energy Storage System) during the delay time of SVR is being required because the customer voltages in distribution system interconnected with PV(Photovoltaic) system have a difficultly to be kept within allowable limit. Therefore, this paper presents the optimal voltage stabilization method in distribution system by using coordination operation algorithm between BESS and SVR. It is confirmed that customer voltage in distribution system can be maintained within allowable limit($220{\pm}13V$).