• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1993.04a
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• pp.140-146
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• 1993

Active noise control uses the intentional superposition of acoustic waves to create a destructive interference pattern such that a reduction of the unwanted sound occurs. In active noise control system the choice of a control structure and design of the controller are the main issues of concern. In real acoustic fields there are a vast number of noise sources with time-varying nature and the characteristics of transducers and the geometric set-up of control system are subject to change. Accordingly the control system should be designed to adapt such circumstances so that required level of performance is maintained. In this paper, the adaptive control algorithm for self-tuning adaptive controller is presented for the application in active noise control system. Self-tuning is a direct integration of identification and controller design algorithm in such a manner that the two processes proceed sequentially. The least mean square algorithm was used for the identification schemes and adaptive weighted minimum variance control algorithm was applied for self-tuning controller. Computer simulation results for self-tuning feedback controller are presented. And simulation results was shown to be useful for the situation in which the periodic noise sources act on the acoustic field.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.558-561
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• 2001

SIP(Soil cement Injected Precast pile) that inserts a precast pile after injecting a cement paste into a boring has been applied rapidly through the change of construction circumstances. But there isnt any logical equation of a bearing capacity fitted to SIP yet. So Meyerhof equation has mainly been used to predict a bearing capacity in a design stage instead. But it has shortcomings such as lack of confidence because it has derived not from a theory but from an experience obtained from the result of SPT (Standard Penetration Test) and because a penetration depth tends to be deeper by an excessive design that depends on an end bearing capacity of a pile more than a skin frictional resistance. In this study, thereupon, a direct shear test in the laboratory was performed to both SM and SC soils in variable conditions to verify skin friction properties for the purpose of presenting some reasons capable of reducing penetration depths. Through the tests, soil to soil of SM in cohesion, rough panel to soil of SM in friction angle and soil to soil of SM in shear strength tended to be high. And a shear strength increased as its total unit weight increased in all cases.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.1
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• pp.39-49
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• 2014

Morphological and positional characteristics of anchovy aggregations, confirmed by trawling, were examined in two locations of the southern part of theWest Sea (T1) and the western side of South Sea (T11) of South Korea. Morphological characteristics (mean length, height and area) of the anchovy aggregations at T1 were smaller than those at T11, however the positional characteristics (distributional depth and bottom depth) of the aggregations at T1 were larger than those at T11. Diverse dataset such as the ship's cruise track, the cruse map, and interpolated three-dimensional-like water temperature were visualized in multiple dimensions. For a comprehensive understanding of the anchovy aggregations within their surrounding circumstances, the interpolated water temperature transferred to the location of anchovy aggregations at both stations were visualized based on geospatial information. Using quantitative investigation, the overall range of change in water temperature and salinity of anchovy aggregations at stations was considerably small. However, the water temperature and salinity of anchovy aggregations at T11 were somewhat higher than those at T1.

• Journal of Korean Library and Information Science Society
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• v.28
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• pp.355-383
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• 1998

In this study it is surveyed how the educational objectives of orientation in Library & Information Science under current school system should be formed and presented as follows; First, there are many obstacles in overcoming problems and setting successfully education of Library & Information Science under the school system by Ministry of Education. To get over this clear objectives and goals of education must be presented. According to clarified goal of education curriculums must be formed systematically. As a result it is suggested that setting goal of education emphasizing on paralleling of fortifying of theory and conducting practical business rather than training of Information specialist. Second, in analysis of curriculum of library & Information Science it is divided into five categories; (1) 'information organization', (2) 'reference/bibliographical information', (3) 'management of library/ information center', (4) 'informatics' (5) 'library & Information science in general', then courses of each category are arranged and analyzed. As a result balanced development among categories and education is required. In short educational goal of library & Information Science must show basic philosophy, ideal, and direction of education. In addition it is ideal that educational goal of Library & Information Science be presented concretely and in feasible way. Thus in this context the goal and objectives of library & Information Science must be devised and amended, su n.0, pplement as circumstances change.

• Knowledge Management Research
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• v.21 no.2
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• pp.21-40
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• 2020

Korea Credit Guarantee Fund(KODIT) is a public financial institution under the provision of the Korea Credit Guarantee Fund Act. Facing the waves of change both locally and globally, KODIT will serve as 'social value creator' in making a paradigm shift from a large corporation(Conglomerate-dominated) economy to a social enterprise-oriented one based on social economy. This study focuses on the supporting service programs for social enterprises and job creation how it affects the performance of social value creation of KODIT. There is currently no detailed research of the social value in terms of the business and management academic agenda. Therefore, the present study describes the importance of social value creation on the policy financial institution. This study conducted in-depth case study for social value performance. As a public policy financial institution, KODIT exert diverse efforts to correct market failure and achieve inclusive growth. For example, KODIT extends credit guarantee services for the liabilities of promising corporations and stimulates financial and non-financial supporting programs for social enterprises. Although the role of social value and social economy has gained business field attention, few investigations have been conducted to explain how social value is achieved. The present study can thus act as the foundation for exploring the social value creation in the circumstances of public financial institution.

• Journal of the Korean Institute of Navigation
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• v.13 no.1
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• pp.55-61
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• 1989

Nowadays much efforts for evaluating the productivity of port physical distribution system to meet the rapid change of the port and shipping circumstances has been made continuously all over the world. The major part of these efforts is the improvement of the productivity of cargo handling system. The cargo equipment system as infrastructure in the cargo handling system is organized well in some degrees, but the management system of manpower as upper structure is still remained in an insufficient degree. There is little study, so far, on a systematic research for the management of port labor gang, and even those were mainly depended on rule of thumb. The object of this study is to introduce the method of optimal allocation and assignment for the labor gang in single ship, which was suggested as a first stage in dealing with them generally. The problem of optimal allocation and assignment of the labor gang can be (I) formalized with multi-stage allocation and assignment of the labor gang can be. (II) dealt with two stages in form of hierarchic structure and moreover, (III) The optimal size of labor gang was obtained through dynamic programming from the point of minimizing the summation of labor gang in every stage, (IV) For the problem of optimal assignment, the optimal policy was determined at the point of minimizing the summation of movement between hatches.

• Journal of Construction Engineering and Project Management
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• v.2 no.3
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• pp.8-16
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• 2012

After the 2008 global financial crisis, the construction environment in South Korea continued change in the construction environment. Construction orders in 2011 have shown a downward trend compared with the previous year. Along with these changes in the construction market, the professional capabilities of construction project managers that are perceived as important also changed after the global financial crisis. Accordingly, this study was conducted to identify the major business capabilities of the current construction project managers and to determine which of these capabilities have undergone changes in terms of the importance accorded to them after the global financial crisis, and ultimately, to derive the construction project manager capability areas that need to be strengthened according to the changes in the construction environment. The capabilities of construction project managers were surveyed at two different time points: in 2007 and in 2010. The results show that the year 2010, after the global financial crisis, an increase in the perceived important capabilities of construction project managers compared with 2007. This results the impact of the changes in the construction environment on the importance of construction project managers. This study derived the ramifications of the early identification of systems and prospects according to the changes in the construction circumstances on more efficient onsite and human resources management, by considering the appropriate capabilities of the construction project managers.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.4B
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• pp.599-609
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• 2010

Korean government has recently abrogated WIPI policy to open domestic mobile phone market to the world, which may result in the influx of foreign smart phones. This circumstance has given users more wide range of choices to buy a product and also has brought benefit to buy mobile phone cheaply. On the other hands, this change might have brought potential danger of mobile malware incidents which have only occurred in foreign countries. There are standardized analysis methods and response guides for computer malwares, not but for mobile malwares in our country. In this paper, we introduce existing mobile malwares and available tools for their analysis. Considering domestic circumstances which might not be properly protected against mobile malwares, we propose analysis methods and response guide of mobile malwares.

• Research in Mathematical Education
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• v.9 no.1 s.21
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• pp.69-96
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• 2005

Motivation for learning is important for positive learning outcomes as well as for measured achievement levels. When students come to our classes, they bring with them learning histories in which we as individual teachers, most likely, did not have an input. Our students do not only bring with them different levels of prerequisite leanings but also different levels of affect for what they will be learning. If we leave their final learning at the mercy of these entry characteristics, a test given the first day before the course will have almost isomorphic results with their achievement levels on the last day. The ones who had 'it' on the first day will be the ones who in the future will also have 'it', not too different from what the present situation is all over the world. These circumstances will tend to be the case ad infinitum, unless of course, we want to change the situation. This research clearly shows that effective instructional methodologies coupled with cooperative peer interactions not only have an impact on achievement but also on positive attitudes toward one's learning.

• Nuclear Engineering and Technology
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• v.39 no.5
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• pp.655-662
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• 2007

Most decision makers in the electricity industry plan their electric power expansion program by considering only a least cost operation, even when circumstances change with differing complexities. It is necessary, however, to analyze a long-term power expansion plan from various points of view, such as environmental friendliness, benefit of a carbon reduction, and system reliability, as well as least cost operation. The objective and approach of this study is to analyze the proper role of nuclear power in a long-term expansion plan by comparing different scenarios in terms of the system cost changes, $CO_2$ emission reduction, and system reliability in relation to the Business-As-Usual (BAU). The conclusion of this paper makes it clear that the Korean government cannot but expand the nationwide nuclear power program, because an increased energy demand is inevitable and other energy resources will not provide an adequate solution from an economic and sustainability point of view. The results of this analysis will help the Korean government in its long-term resource planning of what kinds of role each electric resource can play in terms of a triangular dilemma involving economics, environmental friendliness, and a stable supply of electricity.