• 제목/요약/키워드: Quantitative & Qualitative Comparison

검색결과 254건 처리시간 0.03초

Soft Set Theory Oriented Forecast Combination Method for Business Failure Prediction

  • Xu, Wei;Xiao, Zhi
    • Journal of Information Processing Systems
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    • 제12권1호
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    • pp.109-128
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    • 2016
  • This paper presents a new combined forecasting method that is guided by the soft set theory (CFBSS) to predict business failures with different sample sizes. The proposed method combines both qualitative analysis and quantitative analysis to improve forecasting performance. We considered an expert system (ES), logistic regression (LR), and support vector machine (SVM) as forecasting components whose weights are determined by the receiver operating characteristic (ROC) curve. The proposed procedure was applied to real data sets from Chinese listed firms. For performance comparison, single ES, LR, and SVM methods, the combined forecasting method based on equal weights (CFBEWs), the combined forecasting method based on neural networks (CFBNNs), and the combined forecasting method based on rough sets and the D-S theory (CFBRSDS) were also included in the empirical experiment. CFBSS obtains the highest forecasting accuracy and the second-best forecasting stability. The empirical results demonstrate the superior forecasting performance of our method in terms of accuracy and stability.

어류양식장의 입지선택을 위한 계층분석과정(AHP)모형 (AHP Model for Selecting a Fish Farm Site)

  • 이강우
    • 수산경영론집
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    • 제38권1호
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    • pp.19-45
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    • 2007
  • There have not been many studies which considered both quantitative and qualitative location factors on the issues of site selection problems for a fish farm. This study develops AHP(analytic hierarchy process) model to resolve site selection problem for a fish raising farm by using quantitative and qualitative factors. In order to evaluate the validity of the location factors found in the literature review, the study used advice from fish raising farmers and related academic experts. Four major factors have been selected as economic factors, social factors, natural environmental factors and infrastructures. An AHP structural diagram has developed by considering the factors and potential sites proposed for fish farming. Through the survey on the preference of factors and potential sites, pairwise comparison matrices have been estimated and used to calculated the relative weights of each potential site. The AHP model process shown in the study can be applied to resolve site selection problems for fish raising farmers.

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열차제어시스템 안전성 확보를 위한 리스크 평가 방법 분석 (Risk Assessment Method for Guaranteeing Safety in the Train Control System)

  • 조현정;황종규;윤용기
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2006년도 추계학술대회 논문집
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    • pp.870-877
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    • 2006
  • Recently, failures of equipments are linked directly to extensive damages of human lives or financial losses from the increasing uses of train control equipments utilizing computers. Then safety activities have to progress for guaranteeing safety during the system life-cycle. In this paper, we examine the methods for risk analysis and assessment of safety activities and propose optimized one method for risk assessment. There are original risk assessment methods; risk graph and risk matrix method under the qualitative analysis, IRF(Individual Risk Formula) calculations and statistical calculations method under the quantitative analysis. Best-Practice(BP) risk analysis method is proposed for combining advantages of the qualitative and the quantitative analysis. In the comparison of risk graph and risk matrix method for safety estimation, BP method has no applications published up to now, but we can expect that this method will be utilized widely for the risk assessment due to various strong points.

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Dynamic fracture instability in brittle materials: Insights from DEM simulations

  • Kou, Miaomiao;Han, Dongchen;Xiao, Congcong;Wang, Yunteng
    • Structural Engineering and Mechanics
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    • 제71권1호
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    • pp.65-75
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    • 2019
  • In this article, the dynamic fracture instability characteristics, including dynamic crack propagation and crack branching, in PMMA brittle solids under dynamic loading are investigated using the discrete element method (DEM) simulations. The microscopic parameters in DEM are first calibrated using the comparison with the previous experimental results not only in the field of qualitative analysis, but also in the field of quantitative analysis. The calibrating process illustrates that the selected microscopic parameters in DEM are suitable to effectively and accurately simulate dynamic fracture process in PMMA brittle solids subjected to dynamic loads. The typical dynamic fracture behaviors of solids under dynamic loading are then reproduced by DEM. Compared with the previous experimental and numerical results, the present numerical results are in good agreement with the existing ones not only in the field of qualitative analysis, but also in the field of quantitative analysis. Furthermore, effects of dynamic loading magnitude, offset distance of the initial crack and initial crack length on dynamic fracture behaviors are numerically discussed.

Comparison between Siderophores Production by Fungi Isolated from Heavy Metals Polluted and Rhizosphere Soils

  • Hussein, Khalid A.;Joo, Jin Ho
    • 한국토양비료학회지
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    • 제45권5호
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    • pp.798-804
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    • 2012
  • Although siderophores are induced primarily in response to iron deficiency, soil and other ecological factors can affect on this process. This study was to evaluate the production of siderophores by different fungal species isolated from heavy metal contaminated and uncontaminated soils. More than thirty fungal strains were isolated from heavy metal contaminated and rhizosphere uncontaminated soils. Chrome azurol sulfonate (CAS) was used for both quantitative and qualitative evaluation of siderophores production. No significant correlations were observed between the tested variables such as ultraviolet (UV) irradiation method and CAS-agar plate and heavy metal concentration in both soils. The production of siderophores in rhizosphere fungi was higher than those isolated from the contaminated soil; however, the difference was not significant. The siderophore production (%) by fungi isolated from heavy metal contaminated soil using UV irradiation method was positively correlated with the qualitative values using CAS-plate method (P<0.05). Pearson correlation test indicated a positive correlation between the quantitative and qualitative methods of detection for fungi isolated from rhizosphere and also those isolated from heavy metal contaminated soil.

Change of MS Method and Comparison of SIFT-MS Method

  • CHOI, Jong-Sun;KWON, Lee-Seung;LEE, Ji-Hoon;KIM, Romertta;KWON, Woo-Taeg
    • 웰빙융합연구
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    • 제5권1호
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    • pp.37-46
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    • 2022
  • Purpose: This study examines the history of the evolution of MS analysis and intends to consider the future direction of technological development through the difference from the latest technology, SIFT-MS. Research design, data and methodology: A method of analysis will be described in detail at the below by SIFT-MS (Selected Ion Flow Mass Spectrometry), which is a technology developed by a company called SIFT Technologies. Results: The initial concept of mass spectrometry was begun in the late 1890s, and it continues to evolve even after the 21st century through the ripening stage of the 20th century. The development process of mass spectrometry by year has been described in detail in the Main text. Conclusions: Mass spectrometry, qualitative and quantitative analysis of substances plays a very important role in the research and medical fields. The development of these analytical methods is expected to continue in the future, and faster and more accurate qualitative analysis and mass spectrometry will be developed than the level currently reached. In addition, it is expected that hardware and software will be configured so that non-analysis experts can handle it easily, and it will be used as a technology that is more closely related to our lives.

Land Use, Land-Use Change and Forestry 매트릭스 작성을 위한 공간정보 특성 고찰 (Analysis of Spatial Information Characteristics for Establishing Land Use, Land-Use Change and Forestry Matrix)

  • 황진후;장래익;전성우
    • 한국지리정보학회지
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    • 제21권2호
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    • pp.44-55
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    • 2018
  • 기후변화에 대응하기 위한 정책 수립과 이행을 위해 온실가스 인벤토리 작성의 중요성이 대두되고 있다. 이에 따라, 토지이용 항목과 변화들에 대해 공간 명시적으로 나타낸 Approach 3 수준의 Land Use, Land-Use Change and Forestry(LULUCF) 매트릭스 구축 필요성이 제기되고 있다. 본 연구에서는 LULUCF 매트릭스의 산림 항목을 중심으로 연속지적도, 중분류 토지피복지도, 임상도, 도시생태현황지도를 활용하여 LULUCF 매트릭스 구축에 적합한 공간정보를 검토하였다. 각 공간정보에 대한 분류 속성 비교를 실시하였고 충청남도 보령시를 대상으로 양적(면적) 비교, 질적(특성) 비교를 실시하였다. 양적 비교 결과 산림의 면적이 임상도에서 최고 50.42%($303.79km^2$), 지적도에서 최저 46.09%($276.65km^2$)의 차이를 보였다. 질적 비교 결과 자료 구축 범위 차이, 자료 구축 목적 차이, 분류 항목 차이, 일필일목의 원칙 적용 여부의 차이, 자료구축 시기 차이 등 5가지 질적 특성의 차이를 확인하였다. 연구 결과 도시생태현황지도가 LULUCF 매트릭스 구축에 가장 적합한 공간 정보로 판단되었으나 전국구축이 되어있지 않은 한계로 토지피복지도가 가장 적합한 것으로 검토되었다. 또한, 도시생태현황지도, 임상도, 토지피복지도 등을 서로 종합하여 LULUCF 매트릭스를 구축하게 될 경우 각 공간정보의 한계를 보완할 수 있을 것으로 사료된다. 추후 전국토를 대상으로 하는 1:5,000 수준의 세분류 토지피복지도 및 도시생태현황지도가 완료될 경우 LULUCF 매트릭스 작성의 정밀도를 향상시킬 수 있을 것으로 판단된다.

개선된 RBI 기법을 이용한 석유화학설비의 위험도평가 (Risk Assessment of Petrochemical Equipments Using Enhanced RBI Technique)

  • 이상민;송기훈;장윤석;최재붕;김영진;한상인;최송천
    • 대한기계학회논문집A
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    • 제29권10호
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    • pp.1392-1398
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    • 2005
  • API 581 guideline provides a methodology for calculating the risks of equipments in refinery or petrochemical plant. However, especially in part of the consequence of failure, there is a major limitation of its application to the petrochemical plant directly since only a representative material is considered in calculating the risk while the equipment is composed of numerous materials. The objectives of this paper are to propose an enhanced risk-based inspection (RBI) technique to resolve shortcomings inclusive of the above issue and to assess the risks of typical petrochemical equipments. In this respect, a program incorporating material database was developed to fully incorporate the characteristics of different materials. The proposed RBI program consists of qualitative, semi-quantitative and quantitative risk evaluation modules in which toxic materials as well as representative materials were selected automatically for comparison to those in the current guideline. It has been applied to assess the risks of equipments in ethylene facilities of petrochemical plants. Thereby, more realistic evaluation results were obtained and applicability of the proposed RBI program was proven.

공공도서관 평가의 최근 변화 분석 및 향후 방향에 대한 제안 (Analysis of Recent Changes in Public Library Evaluation and Recommendations for Future Directions)

  • 감미아;이지연
    • 한국비블리아학회지
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    • 제34권1호
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    • pp.189-207
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    • 2023
  • 본 연구는 2022년 전국 도서관 운영평가 중 공공도서관에 집중하여, 최근 변화 양상을 분석하고 향후 방향성을 논의하고자 하였다. 본 연구에서는 공공도서관 평가의 정성·정량평가 비율 변화 및 변화 전·후 평가 결과의 특성을 분석하였다. 우선 각 정성평가 및 정량평가의 비율 변화에 따른 과거와 현재의 평가 결과 비교 분석을 수행한 후, 도서관의 규모에 따른 그룹화에 대해 실효성을 논하고자 하였다. 더 나아가서는 각 평가점수에 대한 계산 방식의 변화 및 총점과의 상관계수 분석을 통한 새로운 정량평가 변수의 발견을 시도하였다. 이러한 과정을 통해 표준화 및 개별화를 적용한 변수의 계산 방식, 다양한 영역에 대한 비중의 균형화, 도서관들의 자발적인 평가 참여를 고무할 방안을 제안하였다.

지면.비지면점 분류를 위한 라이다 필터링 알고리즘의 종합적인 비교 (Comprehensive Comparisons among LIDAR Fitering Algorithms for the Classification of Ground and Non-ground Points)

  • 김의명;조두영
    • 한국측량학회지
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    • 제30권1호
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    • pp.39-48
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    • 2012
  • 수치표고모델(DEM : Digital Elevation Model)을 생성하거나 지상의 객체를 추출하기 위해서 라이다 자료에서 지면점과 비지면점을 분리하는 필터링(filtering) 과정은 중요하다. 본 연구에서는 라이다 자료에서 지면점을 추출하는 데 사용되는 기존의 필터링 방법을 대상으로 정성적 분석과 정량적 분석을 통해 가장 효과적인 필터링 알고리즘을 선정하는 것을 목적으로 하였다. 이를 위해 Adaptive TIN, Perspective Center Based Filtering Algorithm, Elevation Threshold with Expand Window, Progressive Morphology의 4가지 필터링 방법을 산악지역, 도시지역, 건물과 산이 공존하는 3가지 지역에 적용하여 각각의 방법에 대한 특징을 분석하였다. 실험에 사용된 4가지 필터링 방법의 정성적인 비교는 음영기복도를 생성한 후 시각적인 방법을 적용하였고 정량적인 비교는 GPS로 관측한 검사점을 이용한 절대적인 비교와 국토지리정보원의 수치표고모델을 이용하여 상대적인 비교를 수행하였다. 라이다 필터링 실험을 통하여 Adaptive TIN 알고리즘은 산악지역과 도시지역에서 지면점을 가장 효율적으로 추출하였고 건물과 산이 공존하는 지역에서는 Progressive Morphology 알고리즘이 가장 양호한 결과를 나타내었다. 또한 정성적, 정량적 비교 결과 전반적으로 지역적 특성에 관계없이 적용가능한 필터링 알고리즘은 ATIN 알고리즘으로 나타났다.