• The Journal of the Acoustical Society of Korea
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• v.27 no.3E
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• pp.104-111
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• 2008

Recently, a method for robust time reversal focusing has been introduced to extend the period of stable focusing in time-dependent ocean environments [S. Kim et al., J. Acoust. Soc. Am. 114, 145-157, (2003)]. In this study, concept of focal-size broadening based on waveguide invariant theory in an ocean time reversal acoustics is described. It is achieved by imposing the multiple location constraints. The signal vector used in multiple location constraints are found from the theory on waveguide invariant for frequency band corresponding the extended focal range. The broadening of foci in an ocean waveguide can play an important role in the application of time reversal processing, particularly to the underwater acoustic communication with moving vehicles. The proposed method is demonstrated in the context of the underwater acoustic communication from the transmit/receive array (TRA) to a slowly moving vehicle.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.10
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• pp.1217-1224
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• 1999

이동 호스트들의 위치 정보를 관리하는 것은 이동 컴퓨터 시스템에서 중요한 문제이다. 이동 호스트가 이동할 때 위치 수정과 위치 탐색간에는 상반관계가 존재한다. 본 논문에서는 위치 서버를 이용한 간단한 quorum 기반 분산 동적 위치 관리 방법을 제안한다. 이 방법에서는 이동 호스트들의 위치 정보가 모든 위치 레지스터가 아닌 위치 레지스터들의 부분집합에서 효율적으로 관리되기 때문에 위치 수정 비용과 위치 탐색 비용이 감소된다. 그리고 위치 레지스터들의 부분집합은 동적으로 변하고, 각 위치 서버의 부하는 이동 호스트에 대한 질의율을 고려하므로 균등해진다. 제안된 알고리즘의 성능은 위치 수정비용과 위치 탐색비용의 전체비용으로 평가되었고, Prakash의 알고리즘과 비교되었다.Abstract Managing location information of mobile hosts is an important issue in mobile computing systems. There is a trade-off between location update and search, when a mobile host moves. This paper proposes a simple quorum-based distributed dynamic location management method using location registers. The cost of location updates and searches is reduced by our method because the location information of mobile hosts is managed efficiently in a subset of location registers instead of in all location registers. In our method, the subset of location registers is dynamically changed, and the load of each location register is balanced by considering query rate for mobile hosts. The performance of proposed algorithm is evaluated in terms of the total cost of a location update and a location search, and is compared with Prakash's algorithm.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.3
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• pp.92-104
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• 2007

This paper aims to discussion the characteristics of location and spatial organization on Hongneung and Yureung(royal tomb) in Namyangju through the interpretation of traditional oriental philosophy including Feng-Shui theory. To do this, we studied in two ways; analysis of the present conditions and photographing research materials about the form of physical structure and review of historical document. The result of analysis in sight of the location and spatial structure was good matched. Main finding of this paper are as follows: The location and landscape structure was characterized by the harmony with natural following traditional thinking and the Korean view of nature, while maintaining the dignity of the King. The spatial organization were placed in a straight line following the hierarchy of metaphysics by order of Neungchim(Tombs Vicinity) - Changmyungdeung(Stone Lantern) - Chungjakak(Pavilion) - Hongsalmun(Gate for Heavenly Gods) and was based on the Confucianism value, the natural contour and inner value. Through this study, we find the principles made it possibles to re-evaluate nature in modem society and provided us with new ways to conserve nature with the help of environmental theory.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.10 s.181
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• pp.2487-2495
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• 2000

The acoustic characteristics of expansion chamber will be changed with the variation of inlet/outlet location due to the higher order acoustic mode in a high frequency in which the plane wave theory is not available. In this paper, the acoustic performance of reactive type expansion chamber with circular cross-section is analyzed by using the modified mode matching theory. The sensitivity analysis of four-pole parameters with respect to the location of inlet and outlet is also suggested to increase the acoustic performance. The acoustic power transmission coefficient is used as cost function, and the location of inlet and outlet is used as design variables. The steepest descent method and SUMT algorithm are used for optimization technique. Several results showed that the expansion chamber with optimally located inlet/outlet had better acoustic performance than concentric expansion chamber.

• Journal of the Economic Geographical Society of Korea
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• v.12 no.1
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• pp.67-82
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• 2009

This paper examines the regional economic development policies of the Welsh Development Agency for attracting companies from the perspective of industrial location theory. The Welsh Development Agency has succeeded in attracting domestic or international capital, as a core actor for the regional economic development, and responded to the changing business environment and to the specific and various needs of the investors. The analysis of the Welsh case provides an important theoretical and practical implications. First, the Welsh case shows the importance of the role of the public sectors for the regional economic development. As the behavioral approach and the industrial location theory argue, the attraction of domestic or international capital led to the regional economic development. Second, the effective activities for attracting capital played an important role in the development. The quality and quantity of the information, in the industrial location theory, and the capacity of the business groups, in the behavioral approach, are significant factors of the development. Third, incentives by the Agency are also important. This finding not only supports the classical location model based on the cost and profits, but also the behavioral approach. Finally, the Welsh case could not succeeded in gaining regional economic competitiveness, even though attracting companies, by disregarding the industrial specialization strategy at the local level. This implies that we need to build industrial clusters. In sum, the behavioral approach has significant implications to the understanding of the public policies for attracting companies.

• Journal of the Korean Data and Information Science Society
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• v.5 no.2
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• pp.11-18
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• 1994

Sample sizes for experiments concerned with inference on R=Pr(X

• International Journal of Internet, Broadcasting and Communication
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• v.4 no.2
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• pp.7-11
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• 2012

In this paper, we defined constructivism and ontology theory and associate it in ubiquitous learning. The typical ubiquitous learning involving the Context Aware Intelligent system was presented. Also the Architecture for learning environment including the key idea and technical concept is being presented in this paper. Guided with these principles and with the advancement of information and communication technology the context-awareness based on Artificial intelligence for Location based Service for ubiquitous Learning was conceptualized.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2007.05a
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• pp.351-356
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• 2007

Factory location selection is very important to the success of operation of the whole supply chain, but few effective solutions exist to deliver a good result, motivated by this, this paper tries to introduce a new factory location selection methodology by employing the artificial neural networks technology. First, we reviewed previous research related to factory location selection problems, and then developed a (neural network-based factory selection model) NNFSM which adopted back-propagation neural network theory, next, we developed computer program using C++ to demonstrate our proposed model. then we did case study by choosing a Korean steelmaking company P to show how our proposed model works,. Finnaly, we concluded by highlighting the key contributions of this paper and pointing out the limitations and future research directions of this paper. Compared to other traditional factory location selection methods, our proposed model is time-saving; more efficient.and can produce a much better result.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.9
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• pp.82-87
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• 2008

Faster, safer and cheaper mailing of the postal matter is essential for surviving in the competitive market of home-delivery service. In the past, the domestic delivery business has been nu by only a few number of companies. But more and more number of companies including medium size ones are participating in the business, and the competition is getting severe. This paper proposes a method to select the optimal location of mail distribution centers that minimally connect the local mail centers of some major cities in Korea using the Steiner Tree theory, which is about connecting a finite number of points with a minimal length of paths and has been used in the distribution system optimization and optimal routing of the transmission lines of the electric power system. By using Steiner Tree theory in finding the best location of the postal delivery hub, we may expect the reduction of transportation cost and the increase of profit, resulting in acquiring the superior position in the competitive delivery business. It is expected that we may use the Steiner Tree theory in finding the best location of the electric power substation for the nott higher EHV(extreme high voltage) transmission network.

• Journal of the Korean Institute of Rural Architecture
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• v.25 no.4
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• pp.17-24
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• 2023

This study is about the traditional house of Kim Myeong-Gwan, the founder of Gwangsan Kim clan(光山金氏) and the 30th grandson of Heunggwang, the 49th king of the Unified Silla Dynasty. He sought a place to take refuge due to a plot and built a house in Jeongeup, adjacent to Yeonsan or Nonsan, Chungcheong-do, which is the home of the Gwangsan Kim clan. The location of old houses was analyzed through Hyeongselon(形勢論) and hyeongguklong(形局論) of Pungsu theory. The results of fengshui analysis of the house through fengshui literature that was presumed to have been used at the time are as follows.The dragon(龍) shows an auspicious condition in which the dragon vein is well connected from its roots in the Honam vein to Guksabong Mountain on Josan Mountain, Bibongsan Mountain on Sojo Mountain, and Mt. Changhasan reaching Jusan Mountain. Hyeol(穴) is a type of Wahyeol(窩穴) and is a Hwalwa(濶窩). Hyeolseong(穴星) is a Jeongche-Hyeolseong(正體穴星) and is a Suseong Hyeol(水星穴). HyeolJung(穴證) and Hyeolgi(穴忌) have the conditions to create hyeol. As for Sa(砂), the height of Hyeonmu(玄武) is not that high, but the Jujak(朱雀) is relatively high, the left blue dragon(左靑龍) is complemented by the outer blue dragon(外靑龍), and the right white tiger(右白虎) does not sufficiently surround the house. To compensate for this, Bibosu trees(裨補樹) were planted at the time of the construction of the house. As for the Water element, it appears to be auspicious as it approaches the old house in the form of a curve, but it has the disadvantage of not sufficiently surrounding the house, so an artificial pond is dug as a Bibo Pungsu(裨補風水). Through this study, it was found that Pungsu was applied as an important consideration factore in selecting the location of the house, and that Pungsu was not just a theory but had a practical effect in preserving the life and property of the family under the risky circumstances of the time.