• Title/Summary/Keyword: 결정성 검증

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Assessment of Flood Vulnerability to Climate Change Using Fuzzy Model and GIS in Seoul (퍼지모형과 GIS를 활용한 기후변화 홍수취약성 평가 - 서울시 사례를 중심으로 -)

  • Kang, Jung-Eun;Lee, Moung-Jin
    • Journal of the Korean Association of Geographic Information Studies
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    • v.15 no.3
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    • pp.119-136
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    • 2012
  • The goal of this study is to apply the IPCC(Intergovernmental Panel on Climate Change) concept of vulnerability to climate change and verify the use of a combination of vulnerability index and fuzzy logic to flood vulnerability analysis and mapping in Seoul using GIS. In order to achieve this goal, this study identified indicators influencing floods based on literature review. We include indicators of exposure to climate(daily max rainfall, days of 80mm over), sensitivity(slope, geological, average DEM, impermeability layer, topography and drainage), and adaptive capacity(retarding basin and green-infra). Also, this research used fuzzy model for aggregating indicators, and utilized frequency ratio to decide fuzzy membership values. Results show that the number of days of precipitation above 80mm, the distance from river and impervious surface have comparatively strong influence on flood damage. Furthermore, when precipitation is over 269mm, areas with scare flood mitigation capacities, industrial land use, elevation of 16~20m, within 50m distance from rivers are quite vulnerable to floods. Yeongdeungpo-gu, Yongsan-gu, Mapo-gu include comparatively large vulnerable areas. This study improved previous flood vulnerability assessment methodology by adopting fuzzy model. Also, vulnerability map provides meaningful information for decision makers regarding priority areas for implementing flood mitigation policies.

The Influence of Teacher-Librarians' Autonomy Support on Middle School Library Users' Satisfaction and Continuance Intention: The Mediating Role of Three Basic Psychological Needs (사서교사의 자율성 지지가 중학생의 학교도서관 만족도와 지속의도에 미치는 영향 - 기본심리욕구의 매개효과를 중심으로 -)

  • Kim, Jiwon;Park, Ji-Hong
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.32 no.1
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    • pp.59-87
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    • 2021
  • The purpose of this study is to investigate the influence of teacher-librarians' autonomy support on the school library users' satisfaction and continuance intention. Based on SDT(self-determination theory), it focuses on the mediating effect of BPN(basic psychological needs) between the autonomy supports and the satisfaction of the school library users. A survey was administered to 331 middle school students and the research model was examined by using regression analysis and Hayes' parallel multiple mediator model. The findings show that the teacher-librarians' support for autonomy directly and indirectly has a positive effect on the students' satisfaction with the school library, and perceived autonomy and competence among the sub-factors of basic psychological needs are found to have a significant mediating effect between the support of the librarian's autonomy and satisfaction with the school library. In addition, students' satisfaction with the school library shows a significant effect on the continuance intention. This study is meaningful in that it presents the role of teacher-librarians as a factor affecting students' motivation to use school libraries and provides implications for revitalizing school libraries.

Optimal Process Planning of CNG Pressure Vessel by Ensuring Reliability and Improving Die Life (CNG 압력용기의 최적 공정설계를 통한 공정의 신뢰성 확보 및 다이 수명 향상)

  • Bae, Jun Ho;Lee, Hyun Woo;Kim, Moon Saeng;Kim, Chul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.7
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    • pp.865-873
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    • 2013
  • The deep drawing and ironing (DDI) process involving the use of a high-capacity horizontal press is used for manufacturing acompressed natural gas (CNG) pressure vessel. However, some variables of the DDI process have been determined based on the experiences of workers, and the short die life needs to be improved for manufacturing the pressure vessel withhighquality and lowcost. In this study, process variables such as the draw ratio, distance between dies, radius of rounding of drawing die, and angle of ironing die are chosen to enhance the reliability and improve the die life based on previous studies and experiences. The draw ratio limits at which no tearing or wrinkling occurs are determined using FEA, and the distances between dies, radius of rounding of drawing die, and angle of ironing die are optimized by the DOE method. The results of the optimal process variables are compared with those of the existing DDI process for verifying their effectiveness.

Selecting Aquifer Artificial Recharge Methods Based on Characteristics of the Target Aquifer (주입대상 대수층의 특성을 고려한 인공함양 방법 선정 연구)

  • Lee, Yeoung-Dong;Shin, Dong-Min;Kim, Byeong-Jun;Kim, Gyoo-Bum
    • The Journal of Engineering Geology
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    • v.29 no.4
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    • pp.483-494
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    • 2019
  • This study aimed to determine the extent of artificial aquifer recharge and to evaluate appropriate recharge techniques based on field investigations and comparative analysis of each recharge method. Characteristics of the aquifer determine the target aquifer and the recharge method for artificial groundwater recharge. Electrical conductivity surveys, drilling, permeability tests, and grain-size analysis indicate that the hydraulic conductivity of weathered soil and weathered rock is higher than that of upper unconsolidated soil. Pumping tests indicate that the groundwater level was stable at a depth of 12 m until 9 hours of pumping, but after that it dropped again, indicating anisotropic aquifer characteristics. Three types of artificial recharge method were reviewed, including recharge wells, ditches, and ponds, and a combination of two methods is proposed: a recharge well system directly injecting into weathered soil and rock sections with good permeability, and an injection ditch that can increase the recharge effect by line-type injection in the upstream area. The extent of groundwater recharge by the selected methods will be evaluated through on-site tests and if their applicability is verified, they will contribute to securing water in areas of water shortage.

A Study on a Decision Making Model of Prioritization of Supporting Policies for Regional Strategic Industries in Chung-nam (충남지역 전략산업 지원사업의 투자우선순위 결정모형에 관한 연구)

  • Lee, Bo-Hyung;Kyung, Jong-Soo;Suh, Sang-Hyuk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.9
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    • pp.3196-3203
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    • 2010
  • The regional strategic industry support has been increasingly developed due to the change of environmental and political conditions for the last 10 years. As the paradigm changed from the central government-sponsored system to regional government-sponsored system, the policy has been diversified into various support systems such as regional strategic industry, specialized industry, supporting technology, supporting business, etc. It is crucial to establish the overall development plans and project strategies for the regional industry in terms of effectiveness and efficiency which will generate an integrated strategic frame to adjust overlapped supporting policies and offer a consumer-oriented service. Not only does the study focus on performance-based outcome regarding to a regional business (supporting policy) portfolio, but it also analyzes and proves an empirical decision-making model to draw out the priority and relative importance according to the regional strategic industry and support cases by analyzing the case of Chungnam area's strategic industry support in 2009. Following a priority list of 20 support cases selected from this research model by the Analytic Hierarchy Process (AHP), the result shows that the diverse support plans are needed according to the different strategic industries or the size of enterprise due to the fact that priority of project type varies upon the characteristics of strategic industry. Thus, the support project needs to generate various strategic industries and develop differentiated support policy to consolidate competitiveness of regional enterprises and revitalize the regional economy.

A Method of Assigning Weight Values for Qualitative Attributes in CBR Cost Model (사례기반추론 코스트 모델의 정성변수 속성가중치 산정방법)

  • Lee, Hyun-Soo;Kim, Soo-Young;Park, Moon-Seo;Ji, Sae-Hyun;Seong, Ki-Hoon;Pyeon, Jae-Ho
    • Korean Journal of Construction Engineering and Management
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    • v.12 no.1
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    • pp.53-61
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    • 2011
  • For construction projects, the importance of early cost estimates is highly recognized by the project team and sponsoring organization because early cost estimates are frequently a foundation of business decisions as well as a basis for identifying any changes as the project progresses from design to construction. However, it is difficult to accurately estimate construction cost in the early stage of a project due to various uncertainties in construction. To deal with these uncertainties, cost estimates should be made several times over the course of the project. In particular, early cost estimates are essential process for successful project management. For accurate construction cost estimates, it is necessary to compare cost estimates with actual costs based on historical project data. In this context, case-based reasoning (CBR), which is the process of solving new problems based on the solutions of similar past problems, can be considered as an effective method for cost estimating. To obtain this, it is also required to define the attribute similarities and the attribute weights. However, no existing method is capable of determining attribute weights of qualitative variables. Consequently, it has been a well-known barrier of accurate early cost estimates. Using Genetic Algorithms (GA), this research suggests the method of determining the attribute weight of qualitative variables. Based on building project case studies, the proposed methodology was validated.

A Study on the Liability Limitation Provision and Firms' Cost Behavior (이사책임감면규정 도입이 기업의 원가형태에 미치는 영향)

  • Rhee, Chang Seop;Woo, Sohee
    • The Journal of the Korea Contents Association
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    • v.19 no.4
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    • pp.423-431
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    • 2019
  • This study examines the effect of the liability limitation provision (LLP) adoption on firm's cost behavior. In April 2011, Korea introduced the LLP with the purpose of improving the management efficiency by mitigating the risks caused by the manager's failure to make decisions related to business operation. However, there are concerns that the adoption of LLP may lead the manager's moral hazard, so the need for empirical research to verify the effect of the LLP adoption is emphasized. In this study, we analyze the effect of the LLP adoption empirically, focusing on the cost behavior that is affected by the manager's decision making. From the empirical result, we find that LLP adopted companies have strengthened the cost stickiness of selling, general, and administrative costs rather than non-adopted companies. This suggests that the manager of LLP adopted company makes a more active decision to consider adjusting costs in order to prepare for future recovery in sales when sales is reduced. This study presents empirical evidence to prove the policy validity of the adoption of LLP, and we expect that our results can contribute to the capital market and academia.

Determinants of U.S. Buyer Loyalty toward Gobizkorea.com: A Study Focused on Country Image, E-Service Quality, and Satisfaction (미국 바이어의 고비즈코리아에 대한 충성도 결정요인: 국가이미지, 서비스 품질 및 만족도를 중심으로)

  • Chung, Jae-Eun;Oh, Jeong Suk;Jeong, So Won
    • Korea Trade Review
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    • v.43 no.5
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    • pp.203-232
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    • 2018
  • Gobizkorea is an online B2B matching platform operated by the Small & Medium Business Corporation. Gobizkorea provides an opportunity for resource-poor SMEs to promote their products and exploit new market opportunities at low cost. The successful operation of Gobizkorea will contribute to the increased exports of Korean SMEs. Accordingly, the present study examined determinants of foreign buyer loyalty toward Gobizkorea.com focusing on country image, e-service quality, and satisfaction. One hundred two survey questionnaires were collected from U.S. buyers registered with Gobizkorea.com. Exploratory and confirmatory factor analysis confirmed three dimensions of e-service quality including information & efficiency, reliability & privacy, and prompt communication & delivery. The path analysis results showed that the country image of Korea significantly and positively affected these three dimensions of e-service quality. Information & efficiency and reliability & privacy positively influenced buyer satisfaction. Reliability & privacy and satisfaction had a positive impact on buyer loyalty. This study enhances the understanding of the foreign buyers use of the domestic e-market platform by examining of determinants of U.S. buyer loyalty toward Gobizkorea.

Development of a Feasibility Evaluation Model for Apartment Remodeling with the Number of Households Increasing at the Preliminary Stage (노후공동주택 세대수증가형 리모델링 사업의 기획단계 사업성평가 모델 개발)

  • Koh, Won-kyung;Yoon, Jong-sik;Yu, Il-han;Shin, Dong-woo;Jung, Dae-woon
    • Korean Journal of Construction Engineering and Management
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    • v.20 no.4
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    • pp.22-33
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    • 2019
  • The government has steadily revised and developed laws and systems for activating remodeling of apartments in response to the problems of aged apartments. However, despite such efforts, remodeling has yet to be activated. For many reasons, this study noted that there were no tools for reasonable profitability judgements and decision making in the preliminary stages of the remodeling project. Thus, the feasibility evaluation model was developed. Generally, the profitability judgements are made after the conceptual design. However, decisions to drive remodeling projects are made at the preliminary stage. So a feasibility evaluation model is required at the preliminary stage. Accordingly, In this study, a feasibility evaluation model was developed for determining preliminary stage profitability. Construction costs, business expenses, financial expenses, and generally sales revenue were calculated using the initial available information and remodeling variables derived through the existing cases. Through this process, we developed an algorithm that can give an overview of the return on investment. In addition, the preliminary stage feasibility evaluation model developed was applied to three cases to verify the applicability of the model. Although applied in three cases, the difference between the model's forecast and actual case values is less than 5%, which is considered highly applicable. If cases are expanded in the future, it will be a useful tool that can be used in actual work. The feasibility evaluation model developed in this study will support decision making by union members, and if the model is applied in different regions, it will be expected to help local governments to understand the size of possible remodeling projects.

Development of a Detection Model for the Companies Designated as Administrative Issue in KOSDAQ Market (KOSDAQ 시장의 관리종목 지정 탐지 모형 개발)

  • Shin, Dong-In;Kwahk, Kee-Young
    • Journal of Intelligence and Information Systems
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    • v.24 no.3
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    • pp.157-176
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    • 2018
  • The purpose of this research is to develop a detection model for companies designated as administrative issue in KOSDAQ market using financial data. Administration issue designates the companies with high potential for delisting, which gives them time to overcome the reasons for the delisting under certain restrictions of the Korean stock market. It acts as an alarm to inform investors and market participants of which companies are likely to be delisted and warns them to make safe investments. Despite this importance, there are relatively few studies on administration issues prediction model in comparison with the lots of studies on bankruptcy prediction model. Therefore, this study develops and verifies the detection model of the companies designated as administrative issue using financial data of KOSDAQ companies. In this study, logistic regression and decision tree are proposed as the data mining models for detecting administrative issues. According to the results of the analysis, the logistic regression model predicted the companies designated as administrative issue using three variables - ROE(Earnings before tax), Cash flows/Shareholder's equity, and Asset turnover ratio, and its overall accuracy was 86% for the validation dataset. The decision tree (Classification and Regression Trees, CART) model applied the classification rules using Cash flows/Total assets and ROA(Net income), and the overall accuracy reached 87%. Implications of the financial indictors selected in our logistic regression and decision tree models are as follows. First, ROE(Earnings before tax) in the logistic detection model shows the profit and loss of the business segment that will continue without including the revenue and expenses of the discontinued business. Therefore, the weakening of the variable means that the competitiveness of the core business is weakened. If a large part of the profits is generated from one-off profit, it is very likely that the deterioration of business management is further intensified. As the ROE of a KOSDAQ company decreases significantly, it is highly likely that the company can be delisted. Second, cash flows to shareholder's equity represents that the firm's ability to generate cash flow under the condition that the financial condition of the subsidiary company is excluded. In other words, the weakening of the management capacity of the parent company, excluding the subsidiary's competence, can be a main reason for the increase of the possibility of administrative issue designation. Third, low asset turnover ratio means that current assets and non-current assets are ineffectively used by corporation, or that asset investment by corporation is excessive. If the asset turnover ratio of a KOSDAQ-listed company decreases, it is necessary to examine in detail corporate activities from various perspectives such as weakening sales or increasing or decreasing inventories of company. Cash flow / total assets, a variable selected by the decision tree detection model, is a key indicator of the company's cash condition and its ability to generate cash from operating activities. Cash flow indicates whether a firm can perform its main activities(maintaining its operating ability, repaying debts, paying dividends and making new investments) without relying on external financial resources. Therefore, if the index of the variable is negative(-), it indicates the possibility that a company has serious problems in business activities. If the cash flow from operating activities of a specific company is smaller than the net profit, it means that the net profit has not been cashed, indicating that there is a serious problem in managing the trade receivables and inventory assets of the company. Therefore, it can be understood that as the cash flows / total assets decrease, the probability of administrative issue designation and the probability of delisting are increased. In summary, the logistic regression-based detection model in this study was found to be affected by the company's financial activities including ROE(Earnings before tax). However, decision tree-based detection model predicts the designation based on the cash flows of the company.