• Progress in Medical Physics
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• v.16 no.4
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• pp.176-182
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• 2005

Stereotactic radiosurgery (SRS) is a technique to deliver a high dose to a target region and a low dose to a critical organ through only one or a few irradiation. The SRS must be planned exactly. Currently the surgery plan is peformed by trial and error method. There are many questions about the reliability and reproducibility of the plan result. This study Improve each step of the Oh's method based on heuristic target shaping to obtain the better result. The target was reconstructed using cylinders with same height and the neighbored cylinders were combined according to the difference of each center and diameter. Then, spheres were packed within each cylinders by the packing rules. Two virtual targets were used to compare this method with Oh's method. As a result, the numbers of isocenter were successfully reduced - more than $35\%$ and $26\%$ - without serious differences of proscription isodose to tumour volume ratio (PITV) and maximum dose to proscription dose ratio (MDPD). This technique using cylinder piling and sphere packing will be a helpful tool to planner in stereotactic radiosurgery.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.9
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• pp.1147-1152
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• 2018

In the recent, Chinese insurance market has taken a introduction of InsurTech. It is a combination of insurance and fintech. This means that the policyholder design their own insurance and take out the policy on-line without insurance planner. This trend is remarkable issue. Growth rate of InsurTech in China have significantly been growing. In addition, Chinese insurance market has kept generally stable and fast growth rate, although Chinese forecasting economic growth is subject to massive uncertainties. Nevertheless, the increase in the number of Korean insurance companies fails to settle into Chinese insurance market due to lack of awareness about newness of Chinese insurance market. Moreover, Korean insurance company in China or planning to enter are not prepared for InsurTech yet. Chinese insurance market is valuable for Korean insurance companies. This paper suggests implications of re-entry into Chinese insurance market to Korean insurance companies by analyzing policies which could make environment to endorse Chinese insurtech and case of Chinese insurtech companies.

• The Journal of the Korea Contents Association
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• v.11 no.3
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• pp.230-240
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• 2011

A gallery provides the function to make opportunities for artist to meet the customers who would buy the products from them. And there was performed the place where artist who production provider, planner, managers and private collectors met to distribute artworks and to educate fine art for public and provide a chance sending leisure time. We investigated this galleries at old urban center in daegeon region by the deep interview and Delphi method. A galleries was operated by a sense of duty and pride. Though its environment is poor, it grows up the young artist and art trends. By delphi results, the role of gallery is recognized as the discovery of an unknown young artist and provider of art trend and paradigm. Also they was recognized as the space for social and cultural responsibility operation culture. Galleries was recognized as key factors as literary value, marketability and harmony between gallery and artworks. Artist was known as a key factors as gallery's expertise, gallery awareness and capacity for artworks selling. Gallery will be considered the functions as the various cultural experience space and culture service space. Although galleries are passive and one dimensional functions.

• Journal of Korea Port Economic Association
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• v.26 no.1
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• pp.43-60
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• 2010

The purpose of this paper is to show the clustering measurement way for Korean container terminals by using neural network based SOM(Self Organizing Map). Inputs[Number of Employee, Quay Length, Container Terminal Area, Number of Gantry Crane], and output[TEU] are used for 3 years(2002,2003, and 2004) for 8 Korean container terminals by applying both DEA and SOM models. Empirical main results are as follows: First, the result of DEA analysis shows the possibility for clustering among the terminals and reference terminals except Gamcheon and Gwangyang terminals because of the locational closeness. Second, the result of neural network based SOM clustering analysis shows the positive clustering in clustering positions 1, 2, 3, 4, and 5. Third, the results between SOM clustering and DEA clustering show the matching ratio about 67%. The main policy implication based on the findings of this study is that the port policy planner of Ministry of Land, Transport and Maritime Affairs in Korea should introduce the clustering measurement way for the Korean container terminals using neural network based SOM with DEA models for clustering Korean ports and terminals.

• Journal of the Korean association of regional geographers
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• v.13 no.6
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• pp.724-737
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• 2007

The purpose of this study is to examine festival visit motivation, satisfaction, loyalty the differences between festival local residents and visitors. Data were collected with a structures questionnaire at the Jun Nam Yeosu-city of Geobuksun of festival during 10$\sim$15 apr. 2007, 430 sample were used for statistical analysis SPSS. Data analysis method were used to Crombach's $\alpha$, reliability, kaiser measurement sample adequacy, factor analysis, t-test, regression analysis. As the results of this research, first, festival visitor's motivation were composed of five factors: a new & escape, exciting & enjoy, socialization, family togetherness, local culture understand and satisfaction were composed of three factors: event program & service, convenience facilities, enjoy, shopping & food, transportation. And second, local residents were found satisfied with the interesting & enjoy. Otherwise, Visitors were satisfied with new & escape. And third, local residents of satisfaction factor were affected interesting & enjoy, Otherwise, visitors of satisfaction factor were affected interesting & enjoy, family togetherness. And fourth, local residents of event program & service factor were affected re-visit, Otherwise, visitors of satisfaction factor were affected event program, enjoy, transportation. The final local residents of event & service factor were affected recommend intension, Otherwise, visitors of event program & service, transportation were affected recommend intension. The result of this paper may help local festival planner and marketers for festival marketing strategy.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.1
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• pp.36-41
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• 2011

Configuration space(C-space) including configuration obstacle(C-obstacle) is one of the most important concepts in mobile robot path planning. Using C-space and C-obstacles, the robot with different shapes and moving mechanisms can be considered as a point in the C-space. And, as a result, the collision-free path for the robot can be easily achieved. To make C-space including C-obstacle, many researchers used circular approximation method for the efficient caluculation time. This method can help us to save our time by approximating the shape of a robot as the minimum sized circle which can cover all the area of robot. But, by using the circle larger than the robot, more space are considered as the part of robot and, as a result, some obstacles which are very near each other may be considered as a combined one obstacle. To solve this problem, multi-level configuration space is proposed by this paper. This multi-level method also use the circular approximation method as the initial step. But, after finding the initial path, it will check how many obstacles are combined. And then, for each combined obstacle, more accurate C-space generation will be continued. To check the efficiency of the proposed algorithm, time for c-space generation are compared with the well-known accurate C-space generation method using various types of robot shape.

• Journal of the Korea Society of Computer and Information
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• v.15 no.8
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• pp.59-66
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• 2010

In this paper, the internal antenna for mobile communication handset which is able to control both coupling coefficient and resonant frequency without any major modification of radiator and ground plane of antenna. Novel internal antenna with its controllable resonant frequency is presented for triple-band or over mobile handsets. The operating range can include GSM(880~960 MHz), GPS($1,575{\pm}10MHz$), DCS(1,710~1,880MHz), US-PCS(1,850~1,990 MHz), and W-CDMA(1,920~2,170 MHz). The proposed antenna is realized by combination of a half wavelength loaded line antenna and PIFA(Planner Inverted F Antenna). A single shorting and feeding points are used and they are common to both antenna structures. One of two inductors which is placed at each shorting post, one inductor is for adjusts amount of coupling, and the other controlling the resonant frequency in DCS/US-PCS/WCDMA bands. The inductance range for control of input impedance is between 0nH and 6.8nH, and each of gain variation in GSM, GPS and DCS/US-PCS/WCDMA band is under 0.15dBi, 0.73dBi and 0.29dBi. The inductance range for control of the resonant frequency is between 1640MHz and 2500MHz, and each of gain variation in GSM, GPS and DCS/US-PCS/WCDMA band is under 0.46dBi, 0.53dBi and 0.8dBi.

• Journal of Korea Port Economic Association
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• v.30 no.4
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• pp.151-168
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• 2014

The purpose of this paper is to show the brief efficiency and clustering measurement way by using the game cross-efficiency model which is newly introduced in this paper for 13 container ports during 3 years(2009, 2010, and 2013) with 3 input variables(depth, total area, and number of crane) and 1 output variable(container TEU). The main empirical results are as follows. First, the average rankings of game cross-efficiency model are Ningbo, Hongkong, Shanghai, Dubai, Singapore, Qingdao, Kaosiung, Busan, Tokyo, Incheon, Nagoya, Manila, Gwangyang ports in order. Second, according to ANOVA analysis, three models show the similar results in terms of the efficiency rankings. Third, in the clustering analysis using dendrogram, group A(Shangahi and Busan), group B(Ningbo and Nagoya), and group C(Incheon and Manila) show the common clustering ports during 3 or 2 years. The policy implication of this paper is that Korean port policy planner should introduce the game cross-efficiency method when measuring the individual port efficiency. Also port authority should consider the merits of the clustering ports for improving the port management and operations.

• Korean Journal of Construction Engineering and Management
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• v.19 no.4
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• pp.93-101
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• 2018

A city is like a living organism that is born, grows and become extinct within an ecosystem. In recent years, more and more cities have been planned by designers rather than spontaneously growing over time. This planning means that if a city is not appropriately designed at the beginning, it is very hard to fix or adjust it later. A poor urban design inconveniences many people, and forces them to adjust to it. For this reason, it is important to design a city as optimally as possible at the design phase. One of the reasons why a city is not designed optimally is complexity. Previous urban design methods have attempted to resolve the complexity by using a top-down problem-solving method based on the experience and knowledge of the urban planner. However, such an approach does not have the organic characteristics of a bottom-up problem-solving method of an artificial life, based on the creation principle of the ecosystem. Therefore, in this study the general principle of artificial life, which can provide a solution to the bigger problems that accumulate as a result of the solutions to small units of problems, is adopted. This enables us to draw various urban design alternatives, and it proves that the alternatives, despite being drawn through a limited modeling method, have almost no differences from those designed by an expert, and its possibilities of future development has also been verified.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.1-9
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• 2007

To decide the number of road lane is very important and related to the 30th design hourly factor in the design of transportation facilities. But, as the quantitative division of road types is difficult, most planner and designer for deciding the 30th design hourly factors have used the fixed values in our country. In this study, we have analyzed the time series property of the design hourly factors in national highways and developed the model capable of estimating the 30th design hourly factors using real data. The presented model is a simple regression model(DHV = K*AADT), which is applied to the division of road lanes(2 or 4 lanes) and the level of AADT(3 levels). As a results, the simple regression model have better performance than the existing method with respect to MAPE and $R^2$. Also, the variations of the 30th design hourly factors are small. The more traffic volume increase, the more the factors decrease. But, the limitation of this study is to use the exiting method estimating the values of the factors, it is subject to study hereafter.