• 한국안전학회지
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• 제17권1호
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• pp.72-78
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• 2002

Among the disposal techniques of inorganic wastewater sludges from industries most of sludges were dealed with buring underground inefficiently. But we have tried to recycle the resources that exhausted inorganic sludges were properly blended to certain ratioes to make lightweight aggregate, that means manufacturing of it can be possible through blending of various components, drying, sintering, cooling and crushing to certain sizes that are needed by consumers. As disposal method of inorganic wastewater sludge is changed to environmentally fraternative method, this method could be very useful to make lightweight aggregates for decoration of building and the other so many purposes of those usages. That could be economically useful due to expected income for buring costs of ordinary disposal method form industries and sales income after manufacturing it. The second important profit is saving foreign currency from purchasing self-developed lightweight aggregate insteas of importing expensive foreign product. This product will be also very impressive to user because of the fraternative lightweight to be composed of apatite structure that is important part of human body.

• 산업공학
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• 제17권spc호
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• pp.122-130
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• 2004

Since the cost of software maintenance occupies about 50~75% in a general successful organization, the software maintenance plays an important role in software life cycle. In particular, if the managed system needs to be operated in a long term or the system is very large and complex, then the maintenance is especially more important. Software maintenance is defined as software modification activities after customer delivery, such as improvement of performance or functionality, error correction, adaptation to environmental changes, etc. In this paper, software cost estimation models are proposed, that is based on productivity of manpower in maintenance projects. In order to do this, the activities of maintenance are classified into function change, non-function change, user support and application operation. The proposed models are constructed and verified based on the real size and cost information of projects in the real world. The approach in this paper is to discriminate the heterogeneous activities in maintenance projects, and then to calculate the respective cost of each discriminated activity. By using the proposed models, the total cost of maintenance project is summed from the costs of four activities. In addition the number of conflicts between owner and order receiver about the amount of cost will be reduced and the reasonable cost estimation system will be established.

• 한국시스템다이내믹스연구
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• 제16권4호
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• pp.129-153
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• 2015

Mandatory shutdown policy of the juvenile protection act was enforced in December 2011 to prevent game addiction of the youth. However, the size of game market in Korea seems to be reduced significantly after implementation of the shutdown policy. The purpose of this study is to investigate the impact of current government regulations on Korean online game market. Based on empirical evidences and results from the related literature, we developed several causal loop diagrams(CLD) and system dynamics models. The CLD include sub-diagrams of innovation processes, user commitments, and operational costs. We conducted simulation analyses under various policy scenarios, adopting Normalized Unit Modelling By Elementary Relationship(NUMBER). Our results show that first, the impact of time regulation on the number of users is greater than the impact of content regulation. Second, the quality of domestic online game appears more elastic to regulations than the quality of foreign online game. The results of this study suggest that the deregulation in Korean online game market can narrow the gap in market outcomes between domestic and foreign online games. Some recommendations for future study are suggested.

• 한국실내디자인학회논문집
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• 제21권2호
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• pp.186-196
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• 2012

Information technology has changed the human life as well as the societal and economic paradigm. New office environments have been proposed to cope with emerging changes and to support working performances by reducing costs of office operation and business. Recently, office environments have adopted ubiquitous computing with a focus on collaboration to promote real-time enterprises. They become equipped with various mobile devices and pervasive technologies in wireless networks. This study aims to propose a direction for the adoption of mobile and pervasive computing on the new office environment. We investigate relate works and analyze new office types including mobile offices, telework centers and home offices. Using a customized questionnaire, the current conditions of the office environments and officers' demands were investigated and analyzed. In the end, we propose the direction for a ubiquitous office environment with a focus on two attributes, ubiquity and mobility. This research will be a basis for the development of ubiquitous offices that support the professionalism of works in practices.

• 대한안전경영과학회지
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• 제18권1호
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• pp.119-129
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• 2016

This study analyzed symptoms of MSDs(Musculokeletal Disorders) associated with characteristics of smartphone usage based on questionnaire survey. This study also tried to identify their relationship based on the results from questionnaire survey. A total of 943 subjects participated for the survey. The results in terms of symptoms associated with smartphone usage were as follows; 1) 49.8% of respondents experienced symptoms associated with MSDs, 2) 35.9%, 34.0%, 22.1%, 21.7% and 20.9% of respondents had symptoms at shoulder, neck, elbow, wrist, and fingers respectively, 3) The effect of 'daily time of data use', 'monthly costs' for MSDs of respondents was significant. Specifically, this study has some significance since it tries to identify the relationship between MSDs symptoms and characteristics of smartphone usage. The results of the study can be good basis for better design and user guidelines of smartphone to prevent MSDs associated with smartphone usage.

• 한국컴퓨터정보학회논문지
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• 제12권6호
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• pp.123-130
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• 2007

본 논문은 객체모델에서 표현되는 객체와 관련성을 형식명세의 상태와 오퍼레이션 도메인으로의 변환 규칙을 제시하였다. 즉 정보모델의 요소인 객체와 관련성을 형식명세 표현에서 상태영역으로 변환하였다. 동적모델의 상태, 이벤트, 행위를 오퍼레이션 영역으로 변환하였다. 비형식적인 객체모델을 형식 명세 언어로 변환하므로써 객체모델을 정형화된 방법으로 검증할 수 있다. 검증과정을 통해 소프트웨어 개말 초기단계에서 모델링 과정의 편리함과 신뢰성을 제공할 수 있다 또한 검증된 모델과 사용자 요구사항 사이의 일관성을 위해 시뮬레이션 도구를 구현하였다. 시뮬레이션 도구는 적합한 모델의 선택과 검증이 가능하도록 하므로 소프트웨어 개발비용과 노력, 개발 시간을 최소화할 수 있다.

• 한국해양공학회지
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• 제12권3호통권29호
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• pp.86-95
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• 1998

CAD/CAM program developers have made substantial progress in enabling engineers to design, analyze, visualize, visualize, and simulate the performance of structures and systems. Many researchers, however, agree that there is still a way to go before the existing commercial computer software can be used in ship structural analysis to their full potential as solvers which can identify opportunities to reduce man-hours and cut costs. CAD systems used for these works in ship yards are general-purposed and not custom-tailored for ship structures, which force end-users to do tiresome and routine works. The new preprocessor "MeshGen" announced in this study can load several ship types and user-friendly generate their FE meshes employing the object-oriented approach based on the parametric and top-down design. Also "MeshGen" reduces dramatically the time required to prepare CAD models under window-based environments on desktop personal computers and makes it much easier and faster for end-users to change topology and material properties.

• Journal of Information Technology Applications and Management
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• 제16권4호
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• pp.93-107
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• 2009

This study investigated consumer preferences for Internet medical information service in China using the multi-attribute utility theory. The multi-attribute utility theory is a compositional approach for modeling consumer preferences wherein researchers calculate the overall service utility by summing up the evaluation results for each attribute. We found that Chinese Internet medical information users consider the availability of information and quick response to be the most important attributes. Further, they think that the comment feature is less important as compared to other attributes such as costs and updates. In addition, we found that the Internet users having more Internet experience consider these attributes to be more important as compared to the people who are just beginning to surf the Internet. For any successful Internet business, Internet marketers should assess individual-level preference and accordingly organize a fresh campaign. As of now, Internet marketers need estimation methods to predict the market performance of new services in many different business environments. We believe that the multi-attribute utility theory is a useful approach in this regard.

• 한국주거학회논문집
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• 제20권3호
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• pp.97-104
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• 2009

Today, apartment is the most common residence type and various behavior occurs in living room space of apartments. Active usage of living room in modem life increases user's desire of wanting a better environment and leads to find various methods such as remodeling. At the point when considering moving or remodeling, this study focuses on the change of lighting color as it is one of the methods for initial stage with moderate price. As living room is easily influenced by lighting, providing active environment to support inhabitant's behavior through the use of various lighting sources will cut down unnecessary remodeling costs and may be the most simple method to actualize lighting environment for inhabitant's behavior. To give change with the least effort, change in artificial lighting environment was attempted with combinations of lighting color and switching on lights according to illuminating location. This study suggested the capability of changing lighting environment of previous living room area by exchanging lighting sources in lighting equipment in order to satisfy the required behaviors of inhabitant.

• 품질경영학회지
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• 제30권1호
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• pp.74-96
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• 2002

The objectives of this study is to suggest the rectifying sampling inspection plan considering quality cost. Limiting quality level(LQL) plans(also called LTPD plans) and outgoing quality(OQ) plans are considered. The Hald's linear cost model is discussed with and without a beta prior for the distribution of the fraction of nonconforming items in a lot. It is assumed that the sampling inspection is error free. We consider the design of reliability acceptance sampling plan (RASP) for failure rate level qualification at selected confidence level. The lifetime distribution of products is assumed to be exponential. MIL-STD-690C and K C 6032 standards provide this procedures. But these procedures have some questions to apply in the field. The cost of test and confidence level(1-$\beta$ risk) are the problem between supplier and user. So, we suggest that the optimal life test sampling inspection plans using simple linear cost model considering product cost, capability of environment chamber, environmental test cost, and etc. Especially, we consider a reliability of lots that contain some nonconforming items. In this case we assumed that a nonconforming item fail after environmental life test. Finally, we develope the algorithm of the optimal sampling inspection plan based on minimum costs for rectifying inspection and RASP. And computer application programs are developed So, it is shown how the desired sampling plan can be easily found.