• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.210-216
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• 2007

A study was conducted to find mechanism and spray characteristics of a mini-sprinkler with downward spray to develop a new design type to be able to prevent drop water. The experiments were executed in a plastic greenhouse to minimize the effect of the wind. Data was collected at five different operation pressures and at 4 different raiser heights. Spray characteristics of the sprinkler such as effective radius, effective area, mean application depth, absolute maximum application depth, effective maximum application depth and coefficient of variation were determined. In order to analyze the mechanism and packing supporter of sprinkler, the numerical simulation using ABAQUS was performed. The optimum pressure for preventing drop water was determined.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.35 no.3
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• pp.22-31
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• 2017

The purpose of this study is to illuminate historical sensitivity and design in the days of the Joseon era and examines the phenomenon of acculturation as revealed in the planting of Sophora japonica and Zelkova serrata in the garden grove by looking into the purpose underlying the construction, formative intention and the process of change in Pohang's Chirinjeong wonlim. Chirinjeong, also called Sanggaejeong(雙槐亭) after the fact that two Zelkova serrata trees were planted there, is a hermit pavilion in Sa-il village, Chogok-ri, built in the 9th year of King Taejong(1409) by Jang, Pyo(張彪, 1349~?) of an officer of bureaucratic origin toward the end of the Goryeo Dynasty, the Chirinjeong garden grove is an element essential to Chogok, the 3rd Gok of Sanggaegoogok(雙溪九曲). The wonlim of Chirinjeong is divided into the pavilion section composed of the entrance area, Chirinjeong, composed of Zelkova serrata and Sophora japonica, and the pond section composed of a quadrangular pond and island(方池方島), and Lagerstroemia indica. In view of the intent of the name Chirinjeong or of the fact that the pavilion was named based on that the royal seal string was hung on the Sanggwaesoo(雙槐樹) or two Zelkova serrata trees, it is reasonable to view it as Zelkova serrata trees having been planted early in the days of the Joseon Dynasty and those additionally planted later on that symbolizes the position of the three nobles and the Sophora japonica. In addition, in spite of the fact that the type of trees supplementarily planted in the 21st year of King Yeongjo(1745) is known as Sophora japonica, it is impossible to rule out the possibility of the tree planted outside of Chirinjeong being Zelkova serrata. In short, the three Zelkova serrata trees planted along with Sophora japonica must certainly be evidence that Zelkova serrata planted along with Sophora japonica in Chirinjeong wonlim indicates that the off spring of the Indong Jang family could tell the difference between Sophora japonica and Zelkova serrata. In the recognition process of Zelkova serrata trees finding their way into Korea, it was known as Zelkova serrata on the one hand and as Sophora japonica on the other, and the former, which enjoys a comparative advantage over in terms of the easiness with which to purchase, growth speed and possibility of growing into a long-lived tree was interchanged with Zelkova serrata, a case of acculturation as manifested in the planting of Sophora japonica in the Chirinjeong garden grove.

• Journal of Intelligence and Information Systems
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• v.17 no.3
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• pp.131-146
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• 2011

It is becoming more essential than ever for office professionals to become competent in information collection/gathering and problem solving in today's global business society. In particular, office professionals do not only assist simple chores but are also forced to make decisions as quickly and efficiently as possible in problematic situations that can end in either profit or loss to their company. Since office professionals rely heavily on their tacit knowledge to solve problems that arise in everyday business situations, it is truly helpful and efficient to refer to similar business cases from the past and share or reuse such previous business knowledge for better performance results. Case-based reasoning(CBR) is a problem-solving method which utilizes previous similar cases to solve problems. Through CBR, the closest case to the current business situation can be searched and retrieved from the case or knowledge base and can be referred to for a new solution. This reduces the time and resources needed and increase success probability. The main purpose of this study is to design a system called COKRS(Case-based reasoning Office Knowledge Recommender System) and develop a prototype for it. COKRS manages cases and their meta data, accepts key words from the user and searches the casebase for the most similar past case to the input keyword, and communicates with users to collect information about the quality of the case provided and continuously apply the information to update values on the similarity table. Core concepts like system architecture, definition of a case, meta database, similarity table have been introduced, and also an algorithm to retrieve all similar cases from past work history has also been proposed. In this research, a case is best defined as a work experience in office administration. However, defining a case in office administration was not an easy task in reality. We surveyed 10 office professionals in order to get an idea of how to define a case in office administration and found out that in most cases any type of office work is to be recorded digitally and/or non-digitally. Therefore, we have defined a record or document case as for COKRS. Similarity table was composed of items of the result of job analysis for office professionals conducted in a previous research. Values between items of the similarity table were initially set to those from researchers' experiences and literature review. The results of this study could also be utilized in other areas of business for knowledge sharing wherever it is necessary and beneficial to share and learn from past experiences. We expect this research to be a reference for researchers and developers who are in this area or interested in office knowledge recommendation system based on CBR. Focus group interview(FGI) was conducted with ten administrative assistants carefully selected from various areas of business. They were given a chance to try out COKRS in an actual work setting and make some suggestions for future improvement. FGI has identified the user-interface for saving and searching cases for keywords as the most positive aspect of COKRS, and has identified the most urgently needed improvement as transforming tacit knowledge and knowhow into recorded documents more efficiently. Also, the focus group has mentioned that it is essential to secure enough support, encouragement, and reward from the company and promote positive attitude and atmosphere for knowledge sharing for everybody's benefit in the company.

• Journal of Intelligence and Information Systems
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• v.17 no.4
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• pp.241-254
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• 2011

Financial time-series forecasting is one of the most important issues because it is essential for the risk management of financial institutions. Therefore, researchers have tried to forecast financial time-series using various data mining techniques such as regression, artificial neural networks, decision trees, k-nearest neighbor etc. Recently, support vector machines (SVMs) are popularly applied to this research area because they have advantages that they don't require huge training data and have low possibility of overfitting. However, a user must determine several design factors by heuristics in order to use SVM. For example, the selection of appropriate kernel function and its parameters and proper feature subset selection are major design factors of SVM. Other than these factors, the proper selection of instance subset may also improve the forecasting performance of SVM by eliminating irrelevant and distorting training instances. Nonetheless, there have been few studies that have applied instance selection to SVM, especially in the domain of stock market prediction. Instance selection tries to choose proper instance subsets from original training data. It may be considered as a method of knowledge refinement and it maintains the instance-base. This study proposes the novel instance selection algorithm for SVMs. The proposed technique in this study uses genetic algorithm (GA) to optimize instance selection process with parameter optimization simultaneously. We call the model as ISVM (SVM with Instance selection) in this study. Experiments on stock market data are implemented using ISVM. In this study, the GA searches for optimal or near-optimal values of kernel parameters and relevant instances for SVMs. This study needs two sets of parameters in chromosomes in GA setting : The codes for kernel parameters and for instance selection. For the controlling parameters of the GA search, the population size is set at 50 organisms and the value of the crossover rate is set at 0.7 while the mutation rate is 0.1. As the stopping condition, 50 generations are permitted. The application data used in this study consists of technical indicators and the direction of change in the daily Korea stock price index (KOSPI). The total number of samples is 2218 trading days. We separate the whole data into three subsets as training, test, hold-out data set. The number of data in each subset is 1056, 581, 581 respectively. This study compares ISVM to several comparative models including logistic regression (logit), backpropagation neural networks (ANN), nearest neighbor (1-NN), conventional SVM (SVM) and SVM with the optimized parameters (PSVM). In especial, PSVM uses optimized kernel parameters by the genetic algorithm. The experimental results show that ISVM outperforms 1-NN by 15.32%, ANN by 6.89%, Logit and SVM by 5.34%, and PSVM by 4.82% for the holdout data. For ISVM, only 556 data from 1056 original training data are used to produce the result. In addition, the two-sample test for proportions is used to examine whether ISVM significantly outperforms other comparative models. The results indicate that ISVM outperforms ANN and 1-NN at the 1% statistical significance level. In addition, ISVM performs better than Logit, SVM and PSVM at the 5% statistical significance level.

• Journal of Global Scholars of Marketing Science
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• v.20 no.1
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• pp.70-79
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• 2010

There has been some research conducted that addressed immoral consumer behaviors in Korea; however, most of this research focused on purchasing counterfeits or shoplifting. High return rates of apparel and used apparel returns have been acknowledged as problem areas within the fashion industry. However, very few researchers have addressed this issue. Therefore, the goal of this research was to explore consumer's retail borrowing experience using a mixed methods approach. In study 1 Korean consumer's retail borrowing experiences was explored through focus group interviews. Findings informed study 2 an examination of apparel consumers' attitudes toward retail borrowing behavior via an online survey. Findings assist both researchers' and practitioners' understanding of retail borrowing behaviors and provide insight into retail borrowing issues in the apparel retail industry. For study 1, five focus-group interviews were conducted with seven panels of individuals that had retail borrowing experience within the past year. Thirty-five Korean consumers who lived in a metropolitan area participated in the focus group interviews. Most of consumers were in their 20's (n=21) and were women (n=24). Most participants purchased apparel items from a retail store and returned the worn items for either a full refund or exchanged the worn item for another item. Motives underlying retail borrowing behavior included social needs, job-related needs, fashion needs, and "smart shopping." Similar to existing research findings from other countries, social needs were the most frequently mentioned cause of retail borrowing in fashion stores. Consumers' moral values, attitude toward large corporations, and prior retail borrowing experience were mentioned as possible factors affecting consumers' retail borrowing behavior. For study 2, the questionnaire used to gather the data was developed based on the findings of part I and existing research. Questions concerning consumers' moral beliefs, sensation seeking tendencies, self-worth, past retail job experience, retail borrowing experience, and some demographic characteristics were included in the questionnaire. The data were collected via an online survey using an online panel provided by a commercial online research company located in Seoul, Korea. In order to obtain various consumers, a quota sample was (male: female=1:1, 20's:30's:40's=1:1:1, retail experience: no retail experience=1:3) obtained from the company. A total of 401 consumers who had shopped for apparel items during the prior 6 months participated in the online survey. The results indicated that 19.7% of the respondents reported they had experience borrowing fashion merchandise. Among these individuals, male borrowers (57%) outnumbered female borrowers. In terms of age distribution, x2 revealed that there was a statistical difference between respondents with and without retail borrowing experiences: 41.8% of the respondents with retail borrowing experience were in their 40's, while respondents without retail borrowing experience were evenly distributed between their 20's to 40's. There was also a significant difference between respondents with and without retail borrowing experience in terms of income: respondents with retail borrowing experience tended to have higher incomes than those without retail borrowing experience. T-tests were performed to compare respondents' fashion shopping behavior, moral beliefs, sensation-seeking tendencies, and attitudes toward retail borrowing behavior between participants with and without retail borrowing experience. As compared to those with no borrowing experience, respondents with experience tended to shop for fashion items more frequently and spent more on shopping for fashion items. Consumers with experience borrowing tended to have higher sensation-seeking tendencies than consumers without retail borrowing experience. A regression analysis revealed that attitudes toward fashion retail borrowing were negatively related to consumers' moral beliefs, but positively related to monthly fashion shopping frequency, sensation-seeking tendencies, and past fashion retail borrowing experience. Among these variables, past retail borrowing experience was the most significant predictor, followed by moral beliefs. This research serves as an initial attempt to address the motives that underlie retail borrowing behaviors and the factors affecting those behaviors. The findings of this study may facilitate an understanding of the consumer's retail borrowing, which will provide a basis for approaches that may help decrease retail borrowing and inappropriate returns at fashion retail stores. The findings may also provide materials for consumer education over the long term. In order to better understand fashion retail borrowing behavior, more research is needed in the future.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.8
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• pp.52-59
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• 2007

In this paper, we analyzed and measured implant isolation characteristics for a 1.25 Gbps monolithic integrated hi-directional (M-BiDi) optoelectronic system-on-a-chip, which is a key component to constitute gigabit passive optical networks (PONs) for a fiber-to-the-home (FTTH). Also, we derived an equivalent circuit of the implant structure under various DC bias conditions. The 1.25 Gbps M-BiDi transmit-receive SoC consists of a laser diode with a monitor photodiode as a transmitter and a digital photodiode as a digital data receiver on the same InP wafer According to IEEE 802.3ah and ITU-T G.983.3 standards, a receiver sensitivity of the digital receiver has to satisfy under -24 dBm @ BER=10-12. Therefore, the electrical crosstalk levels have to maintain less than -86 dB from DC to 3 GHz. From analysed and measured results of the implant structure, the M-BiDi SoC with the implant area of 20 mm width and more than 200 mm distance between the laser diode and monitor photodiode, and between the monitor photodiode and digital photodiode, satisfies the electrical crosstalk level. These implant characteristics can be used for the design and fabrication of an optoelectronic SoC design, and expended to a mixed-mode SoC field.

• Journal of the Korea Convergence Society
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• v.11 no.11
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• pp.321-335
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• 2020

Given that with the development of the 4th industry, interest and desire for smart cities are gradually increasing and related technologies are developed as a way to strengthen urban competitiveness by utilizing big data, information and communication technology, IoT, M2M, and AI, the purpose of this study is to find out how to achieve this goal on the premise of the idea of smart well fair city. In other words, the purpose is to devise a smart well-fair city in the care area, such as health care, medical care, and welfare, and see if it is feasible. With this recognition, the paper aimed to review the concept and scope of smart city, the discussions that have been made so far and the issues or limitations on its connection to social security and social welfare, and based on it, come up with the concept of welfare city. As a method of realizing the smart welfare city, the paper reviewed characteristics and features of a social security platform as well as the applicability of smart city, especially care services. Furthermore, the paper developed discussions on the standardization of the city in terms of political and institutional improvements, utilization of personal information and public data as well as ways of institutional improvement centering on social security information system. This paper highlights the importance of implementing the digitally based community care and smart welfare city that our society is seeking to achieve. With regard to the social security platform based on behavioral design and the 7 principles(6W1H method), the present paper has the limitation of dealing only with smart cities in the fields of healthcare, medicine, and welfare. Therefore, further studies are needed to investigate the effects of smart cities in other fields and to consider the application and utilization of technologies in various aspects and the corresponding impact on our society. It is expected that this paper will suggest the future course and vision not only for smart cities but also for the social security and welfare system and thereby make some contribution to improving the quality of people's lives through the requisite adjustments made in each relevant field.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.1
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• pp.21-33
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• 2013

The purpose of this study is to find applicabilities of human bioclimatic maps, using human thermal sensation(comfort) in summer, with microclimatic in situ data and computer simulation results at the study site of downtown Daegu. This includes the central business district(CBD) area and two urban parks, the Debt Redemption Movement Memorial Park and the 2.28 Park, for urban and landscape planning and design. Climatic data and urban setting information for the analysis of human thermal sensation were obtained from in situ measurement and the geographic information system data. As a result, the CBD had higher air temperature than the parks when the wind speed was low. Relative humidities were opposite to the air temperature. Especially, same directional streets with local wind direction had lower air temperature than streets perpendicular to the wind direction. The most important climatic variable of human thermal sensation in summer was direct beam solar radiation. Also, creating shadow areas would be the most relevant method for modifying hot thermal environments in urban areas. The most effective method of creating shadow patterns was making a tree shadow over a pergola, and the second best one was making a tree shadow on the front of north directional building walls. Moreover, how to plant trees for creating shadow patterns was important as well as what kind of trees should be planted. The results of human thermal sensation were warm to very hot at sunny areas and neutral to warm at shaded ones. At the sunny areas, wide, squared shape areas had a little bit higher thermal sensation than those of narrow streets. The albedo change of building walls 0.15 and ground surface 0.1 could change 1/6 of a sensation level at the shaded areas and 1/3 at the sunny ones. These microclimatic approaches will be useful to find appropriate methods for modifying thermal environments in urban areas.

• The Journal of Sustainable Design and Educational Environment Research
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• v.16 no.3
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• pp.27-36
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• 2017

The purpose of this study is to provide a basis for determining when a school established long term school plans accepted by analyzing the trend of increase or decrease elementary school students 30 years to target of following city, 323 elementary schools in Busan - 16 administration zone for this purpose. Results of this study are as follows: First, type 5 occupies 55.4% of the total, followed by the second most, type 10, 21.4%> type 11> type 13> type 15, which is the most urgent object of the student placement plan Can be. Second, the results of the Conflict Model I and Conflict Model II showed that Type1 and Type7 were not needed to be adopted. Third, we can see through the case analysis that the effect of excessive school opening on the decrease of the number of students in the nearby school is serious. Fourth, as a result of analyzing the current number of students in Busan, the number of schools with less than 150 students accounted for 12.4% of the total 323 elementary schools, 30.0% for schools with less than 300 students, and 60.4% for students with less than 600 students. Fifth, when the elementary school student induction rate of urban redevelopment area in Busan was examined, the average induction rate was 0.37.

• Journal of Broadcast Engineering
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• v.12 no.5
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• pp.460-479
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• 2007

When culture took large part in industrial area, every country has tried to utilize own cultural contents for educational or commercial purpose and the various cultures and histories are recognized as a main concept or subject so that a number of scholars who study history increase. In video game field, special characteristics of interface that audiences participate in the game to complete story-telling is considered as efficient material for learning process. As observed above, it is important to analyze the games that every country makes and export to the world in which the video games is understood as a play of human in general. This Paper has firstly analyzed the most favorite historical games developed in Korea, the USA, Japan, Taiwan and Germany from 1980 to 2005 and secondly, compared that wars and historical origin appears in game scenario, a world view and background story and finally after point out the preferable era and genre of the countries then propose the promising way of design for historical video games. In the process of analysis of a view and heroes in historical games, we compared the real persons, the real historical events and novel in which 11.8% only employed the real persons in 8 out of 68 games. Also the real history and background story are appeared in 37 games which is 54.4% of them. We discovered that the main material that is popular for each country is the historical backing rather than real persons where the favorite historical background is chosen at which they are proud of; 3-Throne era with strong ancient Gogurye for Korea, the 1st and 2nd World Wars and the Independence War for the USA, the tide of war around Middle age for Japan, ancient history of Europe for Germany. The favorite age for video games is Ancient times with 37 games for 54.4%, Middle Age with 7 games fer 10.3%, the prehistoric age with 5 games for 7.35%, remote age with 1 for 1.47%, while current historical games favor Ancient or Modern Age.