• 한국주거학회논문집
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• 제1권2호
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• pp.49-66
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• 1990

This study is a case study to grasp residents` trade-off preference and opinions for selected interior environmental attributes of muilti-family housing. Interiew with structured questionnaire was carried out through pilot and main survey. On the basis of the result of pilot survey, interior environmental attributes for the main survey were selected. Selected attributes were the size of each residential room, the degree of openness between two rooms and interior facilities. Among them, trade-off approach was applied to the size of each residential room and interior facilities. For the main survey. 45 housewives living in 31 pyung apartment of a selected construction company to grasp the residents` trade-off preference and opinions on the selected attributes. In terms of the size of each room, subjects wanted the room to be lager, whereas master bedroom smaller, and family bathroom larger, wheareas toilet near master bedroom smaller. In terms of the degree of openness between two rooms, the present degree of openness between private and service area such as living room and balcony, and second bedroom and adjacent balcony need to be more open, whereas the present degree of openness between living room and dining room and between living room and kitchen need to be more closed. The comparative orders of important intems were the ventilation facility in the bathroom, drying poles for clothes in the balcony, interior landscape, and workable for hand washing clothes. In conclusion, measurement of preference using trade-off approach about selected interior environmental attributes in post-occupancy evaluation was regarded as a promising evaluation method to grasp the practical and comparative preference under constraints comparing to the typical existing methods.

• 한국환경복원기술학회지
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• 제21권1호
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• pp.31-40
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• 2018

Since the Millennium Ecosystem Assessment Report was published in 2005, the conflict between development and the preservation of the ecological environment has turned to paying attention to value assessments in rational decision-making. In recent years, the concept of ecosystem services has been recognized as a viable one for making significant decisions. However, a trade-off between increase and decrease occurs between the ecosystem services sub-categories (cultural service, regulating service, supporting service, and provisioning service), for which research centering on target sites is needed. To this end, the present study aims to investigate the trade-off relationship between service categories to search for reasonable decision-making strategies. As the research method, a survey was conducted using the translated version of SoIVES(Social Value for Ecosystem Services) 3.0 questionnaire of the United States Geological Survey. The research findings demonstrate the economic value, based on the derived monetary value of each service category, the economic value of the target site was compared among landscape aesthetic value 8,050,000 won, recreation value 6,750,000 won, biodiversity value 4,610,000 won, healing value 3,970,000 won, life-sustaining value 2,090,000 won, and productive value 220,000 won. And then the primarily recognized value criteria of the Tancheon ecosystem services illustrate landscape aesthetic and recreation value. Besides, this study illustrates visualized trade-off relationships based on user perception, and the derived relations illustrate the trade-off relationship between the cultural service, regulating service, supporting service, and provisioning service, as well as relationships between the components of the sub-categories.

• 한국환경복원기술학회지
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• 제27권1호
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• pp.45-54
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• 2024

This study developed a model to evaluate the co-benefits and trade-off effects between biodiversity and carbon storage capacity based on the implementation locations of nature-based solutions. The model aims to propose optimal implementation locations by using the conceptual idea of edge effects for carbon storage and connectivity for biodiversity. The co-benefits were considered by simultaneously taking into account two effects rather than a single effect. Trade-off effects were observed among optimal plans through a comparison of benefits. The NSGA-II multi-objective optimization algorithm was utilized, confirming the identification of Pareto-optimal solutions. The implementation patterns of Pareto-optimal solutions for green areas were examined. This study holds significance in proposing optimal locations by evaluating various co-benefits and trade-off effects of nature-based solutions. By advancing models based on this evaluation framework, it is anticipated that the assessment of co-benefits and trade-off effects among various benefits of nature-based solutions, such as climate change mitigation, enhancement of biodiversity, and provision of ecosystem services, can be accomplished.

• 시스템엔지니어링학술지
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• 제10권1호
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• pp.17-32
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• 2014

The trade-off studies in the concept development stage to assess the relative goodness of alternative systems concepts for AE (architect engineering) design for the Barge Mounted SMR (BMSMR) is introduced. With respect to design margin, system performance, schedule and risk, the design selection is cond ucted using the following characteristics; barge mobility, system safety under the natural disaster (seismic), power output, interfacing with the other system, and the additional supporting functions as desalination. There are three findings that should be remedied; deficiencies in the assumed characteristics of the system being modeled, deficiencies in the test model, and excessively stringent system requirements. This study is performed using systems engineering approach with trade off matrix method. In order to execute this work, concept development stage is divided into three (3) phases as NA (needs analysis), CE (concept exploration), and CD (concept definition).

• 산업공학
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• 제20권1호
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• pp.87-93
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• 2007

Burn-in is an engineering method for screening out products containing reliability defects which would cause early failures in field operation. Previously, various burn-in models have been proposed mainly focused on the trade-off of shop repair cost and warranty cost ignoring manufacturing yield. From the view point of a manufacturer, however, burn-in decreases warranty cost at the expense of yield reduction. In this paper, we provide a general model quantifying a trade-off between product yield and reliability, in which any defect distribution from previous yield models can be used. A profit function is expressed in burn-in environments for determining an optimal burn-in time. Finally, the method is illustrated with gate oxide failures which is an important reliability concerns for VLSI CMOS circuits.

• International Journal of Reliability and Applications
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• 제2권4호
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• pp.269-280
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• 2001

The objective of this paper is to provide a model for effective implementation of costing RAM management in the design and procurement of production facility considering the system cost-performance trade-off. This research proposes a two-step approach of costing RAM design and test of system RAM for production facility. In Step 1, a static model is proposed to find an initial system configuration to meet the required performance based on system RAM and LCC and analyzes the trade-off relationships between various factors of RAM and LCC. In the second Step, we developed time and failure truncated models for system reliability test and analysis. For the computational purpose, we developed computer programs and have shown the sample results. By the sample test run, the proposed model has shown the possibilities to provide a good method to analyze system performance evaluation for both design and operational phase, This model can be applied to a wide variety of systems not only for costing RAM of the production facilities but also for the other kinds of equipment.

• Journal of information and communication convergence engineering
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• 제5권1호
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• pp.59-63
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• 2007

In this paper, a CLB-based CPLD low-power technology mapping algorithm considered a Trade-off is proposed. To perform low-power technology mapping for CPLDs, a given Boolean network has to be represented in a DAG. The proposed algorithm consists of three steps. In the first step, TD(Transition Density) calculation has to be performed. Total power consumption is obtained by calculating the switching activity of each node in a DAG. In the second step, the feasible clusters are generated by considering the following conditions: the number of inputs and outputs, the number of OR terms for CLB within a CPLD. The common node cluster merging method, the node separation method, and the node duplication method are used to produce the feasible clusters. In the final step, low-power technology mapping based on the CLBs packs the feasible clusters. The proposed algorithm is examined using SIS benchmarks. When the number of OR terms is five, the experiment results show that power consumption is reduced by 30.73% compared with TEMPLA, and by 17.11 % compared with PLA mapping.

• Industrial Engineering and Management Systems
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• 제12권4호
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• pp.351-358
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• 2013

This paper proposes a multiobjective model describing the trade-offs involved in selecting the locations of drop-off boxes for collecting used products and transporting these products to designated locations. We assume the following reverse flow of used products. Owners of used products (cellular phones, digital cameras, ink cartridges, etc.) take them to the nearest drop-off box when the distance is reasonably short. We also assume that owners living closer to drop-off boxes dispose of more used products than do owners living farther from drop-off boxes. Different types of used products are collected, with each type requiring its own drop-off box. A transportation destination for each product is specified. Three objectives are considered: maximizing the volume of used products collected at drop-off boxes; minimizing the cost of transporting collected products to designated locations; and minimizing the cost of allocating space for drop-off boxes. We formulate the above model as a multiobjective integer programming problem and generate the corresponding set of Pareto optimal solutions. We apply the model to an area using population data for Chofu City, Tokyo, Japan, and analyze the trade-offs between the objectives.

• 한국추진공학회지
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• 제16권6호
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• pp.16-22
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• 2012

액체로켓 추력실의 성능 예측 및 초음속 노즐부 형상 설계에 활용 중인 in-house 해석 도구를 이용하여 재생냉각 연소기에 대한 성능/냉각 통합해석을 수행하였으며, 막냉각 유량 및 외곽 분사기열의 혼합비 변화에 따른 연소 성능과 냉각 성능 간 trade-off 경향을 고찰하였다. 향후 막냉각 및 주요 설계 인자의 최적화 도구로 활용될 수 있도록 개발 연소기에 대한 시험 결과와의 비교 등을 통하여 수치해석 도구를 검증/개선해나갈 계획이다.

• Journal of Electrical Engineering and Technology
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• 제11권4호
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• pp.829-838
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• 2016

This paper focuses on the engineering trade-offs in designing capacitor voltage balancing schemes for modular multilevel converters (MMC) HVDC: regulation performance and switching loss. MMC is driven by the on/off switch operation of numerous submodules and the key design concern is balancing submodule capacitor voltages minimizing switching transition among submodules because it represents the voltage regulation performance and system loss. This paper first introduces the state-of-the-art MMC-HVDC submodule capacitor voltage balancing methods reported in the literatures and discusses the trade-offs in designing these methods for HVDC application. This paper further proposes a submodule capacitor balancing scheme exploiting a control signal to flexibly interchange between the on-state and the off-state submodules. The proposed scheme enables desired performance-based voltage regulation and avoids unnecessary switching transitions among submodules, consequently reducing the switching loss. The flexibility and controllability particularly fit in high-level MMC HVDC applications where the aforementioned design trade-offs become more crucial. Simulation studies for MMC HVDC are performed to demonstrate the validity and effectiveness of the proposed capacitor voltage balancing algorithm.