• Title/Summary/Keyword: Evaluating Method

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Quantification of Uncertainty Associated with Environmental Site Assessments and Its Reduction Approaches (부지 오염도 평가시 불확실성 정량화 및 저감방안)

  • Kim, Geonha;Back, JongHwan;Song, Yong-Woo
    • Journal of Soil and Groundwater Environment
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    • v.19 no.1
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    • pp.26-33
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    • 2014
  • Uncertainty associated with a sampling method is very high in evaluating the degree of site contamination; therefore, such uncertainty affects the reliability of precise investigation and remediation verification. In particular, in evaluating a site for a small-sized filling station, underground utilities, such as connection pipes and oil storage tanks, make grid-unit sampling impossible and the resulting increase in uncertainty is inevitable. Accordingly, this study quantified the uncertainty related to the evaluation of the degree of contamination by total petroleum hydrocarbon and by benzene, toluene, ethylene, and xylene. When planning a grid aimed at detecting a hot spot, major factors that influence the increase in uncertainty include grid interval and the size and shape of the hot spot. The current guideline for soil sampling prescribes that the grid interval increase in proportion to the area of the evaluated site, but this heightens the possibility that a hot spot will not be detected. In evaluating a site, therefore, it is crucial to estimate the size and shape of the hot spot in advance and to establish a sampling plan considering a diversity of scenarios.

An Enumeration Algorithm for the Rolling Stock Requirement Plan (철도차량소요계획을 위한 열거알고리듬)

  • Kim Seongho;Kim Dong-Hee;Choi Tae-Sung
    • Proceedings of the KSR Conference
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    • 2004.06a
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    • pp.514-521
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    • 2004
  • A routing is the path that an actual train set follows as it moves from one train to another train in a timetable. The number of routings is equivalent to the number of trainsets required to cover the timetable. The primary factors of rolling stock requirement plan include evaluating the minimum number of routings. This can be formulated as a set partitioning problem and solved using enumeration method or column generation method. In this paper we presents an enumeration algorithm which is useful to implement the enumeration method for the rolling stock requirement plan.

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On the generation of robotic assembly sequences using disassemblability based on separable direction (분해도를 이용한 조립순서 추론에 관한 연구)

  • 신철균;조형석
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.507-512
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    • 1992
  • This paper presents a method for the automatic generation of assembly sequences based on the recursive extraction of a preferred part along with the verification of its disassemblability. To verify the disassemblability of the part we inference the geometric precedence constraints using a method of extracting separable directions for the part and determine the disassemblability cost by the separability and stability cost. The proosed method provides a local optimal solution of finding a cost effective assembly plan, and the feasibility of calculating robot motion programs by evaluating separable directions in flexible manufacturing application. A case study is given to illustrate the concepts and procedure of the proposed scheme.

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Wind design spectra for generalisation

  • Martinez-Vazquez, P
    • Wind and Structures
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    • v.30 no.2
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    • pp.155-163
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    • 2020
  • Previous research has shown that wind acceleration components produce a signal that can vibrate single-degree of-freedom oscillators, whose dynamic responses enable to configure design spectra for structures subject to wind. These wind design spectra present an alternative method for evaluating the dynamic response of structures and are a suitable tool for running modal analyses. Here, a generalised method for producing wind design spectra is proposed. The method consists of scaling existing spectra to adjust to a wider range of building properties and terrain conditions. The modelling technique is tested on a benchmark building to prove that its results are consistent with experimental evidence reported in the past.

Stiffness Determination Of A Bolted Member Using Optimization Technique (최적화 기법을 이용한 보울트 체결체의 강성 평가)

  • 김태완;조덕상;성기광;손용수;박성호
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.04a
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    • pp.151-157
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    • 1993
  • In this paper a useful method on evaluating the joint stiffness of bolted memeber was introduced using optimization technique on the basis of Finite Element Method. A finite element model having one directional gap element at bo undary area was introduced to compensate the prying force in jointed members which might caused by geometrical configuration of members. Results showed a good aggrement with classical method in certain range and will be available to definine the design margine of pre-load design.

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Usability Evaluation Method of Information Technology Product (정보기술 제품의 사용성 평가방법)

  • 임치환;이민구
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.16 no.28
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    • pp.69-75
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    • 1993
  • The evaluation of product may be classified by technical tests or by ergonomics assessments. If an ergonomics assessment is required, then the three types of interface dimension are available to the researcher. In this paper, we proposed the heuristic evaluation method for usability of product in the three types of interface dimension The evaluation method is used the fuzzy weighted checklist technique computerized for evaluating or comparing prototype of system and IT product.

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On the Robustness of Watermarking in the Frequency Domain for Still Images

  • Miyazaki, Akio;Ejima, Masataka
    • Proceedings of the IEEK Conference
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    • 2000.07b
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    • pp.861-864
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    • 2000
  • This paper aims to establish fundamentals of measuring and evaluating the performance of water-marking systems. We first present the general model of a watermarking method for still images. Based on this model, we propose a statistical method of measuring the performance and robustness of the watermarking system. Then, the DCT-based watermarking system is analyzed and its performance is evaluated by using the proposed method.

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Behaviour of Concrete Building with High Temperature (콘크리트의 고온에서의 거동)

  • 이병곤;태순호
    • Journal of the Korean Society of Safety
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    • v.12 no.2
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    • pp.140-145
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    • 1997
  • The main purpose of this study is to establish the reliable method for evaluating fire damage of reinforced concrete building, by using the rational procedure, and to develope the rehabilitation methods of fire damaged concrete structures. Especially, this proposed evaluation method is applied to the fire damaged concrete buildings of domestic, and the rehabilitation methods on the basis of these applied results are proposed and those example are shown. The proposed rational evaluation method for fire damaged concrete building proceeds is estimating the reduction of the mechanical properties of concrete of fire damaged structural members in comparison with the experimental results which are obtained from the compression tests of heated concrete specimens under various temperatures.

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A Method for Design of Discrete Variable Stochastic Systems using Simulation (이산형 변수 시스템의 설계를 위한 시뮬레이션 활용 기법 연구)

  • 박경종
    • Journal of the Korea Society for Simulation
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    • v.8 no.3
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    • pp.1-16
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    • 1999
  • This paper deals with a discrete simulation optimization method for designing a complex probabilistic discrete event system. The proposed algorithm in this paper searches the effective and reliable alternatives satisfying the target values of the system to be designed through a single run in a relatively short time period. It tries to estimate an autoregressive model, and construct mean and confidence interval for evaluating correctly the objective function obtained by small amount of output data. The experimental results using the proposed method are also shown.

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Mathematical Approach to Determine the Level of Demand/Effort Model (Demand/Effort모형의 수준결정을 위한 수리적 방법 연구)

  • Chung, Bong-Jo;Jang, Myung-Soon;Kim, Jung-Young;Park, Jae-Wan
    • Journal of the Ergonomics Society of Korea
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    • v.24 no.1
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    • pp.9-17
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    • 2005
  • 81.1% of traffic accidents is attributed to the drivers. In this regard, D/E model is a practical and effective method in terms of the cost and time in evaluating the road hazardousness. To examine the validity of the threshold values by the levels of demand We selected 10 subjects and collected their physiological signals while they were driving on Honam Highway (Jeonju ${\leftrighttarro}$ Hoideog section). Based on the collected data, the hazardous road condition was evaluated using the new threshold values of the effort level determined by cluster analysis. In applying the D/E model, a decision method based on the demand level was suggested, using a traffic accident prediction model. Additionally, the limit value of the effort level was determined using the drivers' physiological signal data collected at the highway. A comparison analysis of the two D/E models revealed no significant difference: The existing method and the clustering method determined 9 and 7 hazardous road zones, respectively, while actual traffic accidents were reported in 6 and 4 zones, respectively among the predicted road hazardous zones. However, the latter method suggested a more scientific and rational basis in determining the limit value of the Effort level. In conclusion, although D/E model has a great merit as a pioneering method to reflect human factors in evaluating the road hazardousness, it is believed that this method could be improved by a more dynamic method that considers the traffic conditions and the individual physiological signal of the drivers simultaneously in determining a better limit.