• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.2
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• pp.178-188
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• 2016

The traffic in the wired and wireless networks has increased exponentially because of increase of smart phone and improvement of PC performance. Multimedia services and file transmission such as Facebook, Youtube occupy a large part of the traffic. CDN is a technique that duplicates the contents on a remote web server of content provider to local CDN servers near clients and chooses the optimal CDN server for providing the content to the client in the event of a content request. In this paper, the content request message between CDN servers and the client used the SCRP algorithm utilizing the MST algorithm and the traffic throughput was optimized. The average response time for the content request is reduced by employing HC_LRU cache algorithm that improves the cache hit ratio. The proposed SCRP and HC_LRU algorithm may build a scalable content delivery network system that efficiently utilizes network resources, achieves traffic localization and prevents bottlenecks.

• The KIPS Transactions:PartB
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• v.11B no.2
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• pp.207-212
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• 2004

This paper presents a reinforcement learning framework for stock trading systems. Trading system parameters are optimized by Q-learning algorithm and neural networks are adopted for value approximation. In this framework, cooperative multiple agents are used to efficiently integrate global trend prediction and local trading strategy for obtaining better trading performance. Agents Communicate With Others Sharing training episodes and learned policies, while keeping the overall scheme of conventional Q-learning. Experimental results on KOSPI 200 show that a trading system based on the proposed framework outperforms the market average and makes appreciable profits. Furthermore, in view of risk management, the system is superior to a system trained by supervised learning.

• Korean Journal of Community Nutrition
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• v.17 no.1
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• pp.91-100
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• 2012

This study aimed to evaluate the effectiveness of the foodservice management support program focusing on menu management in community child centers. The support program provided reference menus, staff training, and field consulting to 10 community child centers in the Jeollanam-do province for one month, August in 2010. One month menus were developed, based on children's preference for menu items, foodservice personnel's preference for food materials, and availability of local specialty foods, and offered as reference menus. In addition, staff training and field consulting focusing on menu management were conducted before and during the pilot period, respectively. To evaluate the support program, menus, foodservice personnel's knowledge level and perceived performance in foodservice management, and children's level of satisfaction for foodservice were analyzed before and after the support program. As a result of analysis of 222 and 210 menus of before and after the support program, respectively, the number of dishes per meal increased from five to six on average, and the proportion of meals including five food groups, which were grain, meat, vegetable, fruit, and milk and dairy product, rose from 2% to 24%. Foodservice personnel's knowledge level regarding foodservice management increased significantly (p = 0.007), however, their perceived performance in foodservice management did not show any significant changes. Children were more satisfied with 'food' (p = 0.001), 'sanitation' (p = 0.001), and 'environment' (p < 0.008) of foodservice in community child centers after the support program. In conclusion, the foodservice management support program focusing on menu management in this study was effective for improving menu quality of and children's satisfaction with foodservice in community child centers.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.3 s.162
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• pp.343-350
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• 2007

This study compared and studied the clothing mobility of two types of aerobic clothes - those made of currently popular stretch materials and those made of new stretch materials that were specially developed for this study. The focus of the comparison was on the range of joint movement during activity, and the physiological burden imposed on the body by the clothes. In total, 18 experiments were carried out under controlled conditions in an artificial climatic chamber with a temperature of $25{\pm}1^{\circ}C$, air humidity of $60{\pm}5^{\circ}C$ and negligible air movement. Each exercise program consisted of a 30-minute of aerobic workout and a 20-minute rest following the exercise. Measurements were taken to determine the following: physiological reactions (whole-body and local sweat rates), subjective sensations(of temperature, humidity, comfort, tightness, and clothing wetness), joint angle(measured with a goniometer), and so on. The results of the study us as follows: Material B excels in clothing mobility. Material C excels in sweat absorbency and drying speed. Material A was found to be the hottest material, while material C was found to be slightly hot through the analysis of the change in pre- and post-exercise bodyweight(= amount of sweat). Regarding the amount of evaporated sweat, material A>material C>material B. Material B produced the smallest amount of evaporated sweat. The wider the range of joint movement, the smaller the amount of sweat and the lower the average skin temperature.

• Journal of Biosystems Engineering
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• v.27 no.2
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• pp.151-160
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• 2002

Cow image processing technique would be useful not only for recognizing an individual but also for establishing the image database and analyzing the shape of cows. A cow (Holstein) has usually the unique speckle pattern. In this study, the individual recognition of cow was carried out using the speckle pattern and the content-based image retrieval technique. Sixty cow images of 16 heads were captured under outdoor illumination, which were complicated images due to shadow, obstacles and walking posture of cow. Sixteen images were selected as the reference image for each cow and 44 query images were used for evaluating the efficiency of individual recognition by matching to each reference image. Run-lengths and positions of runs across speckle area were calculated from 40 horizontal line profiles for ROI (region of interest) in a cow body image after 3 passes of 5$\times$5 median filtering. A similarity measure for recognizing cow individuals was calculated using Euclidean distance of normalized G-frame histogram (GH). normalized speckle run-length (BRL), normalized x and y positions (BRX, BRY) of speckle runs. This study evaluated the efficiency of individual recognition of cow using Recall(Success rate) and AVRR(Average rank of relevant images). Success rate of individual recognition was 100% when GH, BRL, BRX and BRY were used as image query indices. It was concluded that the histogram as global property and the information of speckle runs as local properties were good image features for individual recognition and the developed system of individual recognition was reliable.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.3
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• pp.107-113
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• 2005

A calorimeter of 2-ton thrust level rocket engine chamber has been developed to measure the wall heat flux. The liner of the chamber is made of copper-chromium alloy to maximize the heat transfer performance and structural strength. 1-D design code based on empirical correlations has been used for the prediction of the global thermal characteristics while 3-D CFD has been applied for the verification of local cooling performance. The predicted average wall heat flux at the throat is 43 $MW/m^{2}$ for the combustion chamber pressure of 53 bar. The chamber structure is confirmed to be safe at the pressure of 150 bar through 2-D stress analysis and measurement of the strain of the test species. Finally, the test of pressurizing the calorimeter chamber has been performed with water at the pressure of 150 bar in room temperature environment. No thermal damage has been detected after the hot-fire test in the test nozzle of same cooling performance with the developed calorimeter though the measured throat heat flux is higher than the design value by 10%.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.11
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• pp.1112-1120
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• 2009

In this paper, the authors introduced a new approach to find the target orbits of each satellite in order to establish a temporary reconnaissance constellation mission to minimize the average revisit time (ART) while satisfying the constraint on fuel limit. Two distinct problems are dealt with: the first is to reconnoiter the local area with discriminating fuel constraint the second is to reconnoiter ground moving target with same fuel constraint. A preliminary effort in applying a genetic algorithm to those problems has also been demonstrated through simulation study. The results show that current ARTs of each mission are reduced by 41% and 42%, respectively, by relocating the orbit of each satellite. Naturally, the final result may depend on satellite orbits, sensor characteristics, allowable fuel cost, thruster capability, and maneuver strategies.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.3
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• pp.291-300
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• 2018

The purpose of the present work is to establish an ultra-minimal invasive percutaneous puncture inoculation method for a VX2 orthotopic lung cancer rabbit model with fewer technical difficulties, lower mortality of rabbits, a higher success rate and a shorter operation time, to evaluate the growth, metastasis and apoptosis of tumor by CT scans, necropsy, histological examination, flow cytometry and immunohistochemistry. The average inoculation time was 10-15 min per rabbit. The tumorbearing rate was 100%. More than 90% of the tumor-bearing rabbits showed local solitary tumor with 2-10 mm diameters after two weeks post-inoculation, and the rate of chest seeding was only 8.3% (2/24). The tumors diameters increased to 4-16 mm, and irregularly short thorns were observed 3 weeks after inoculation. Five weeks post-inoculation, the liquefaction necrosis and a cavity developed, and the size of tumor grew further. Before natural death, the CT images showed that the tumors spread to the chest. The flow cytometry and immunohistochemistry indicated that there was less apoptosis in VX2 orthotopic lung cancer rabbit model compared to chemotherapy drug treatment group. Minimal invasive percutaneous puncture inoculation is an easy, fast and accurate method to establish the VX2 orthotopic lung cancer rabbit model, an ideal in situ tumor model similar to human malignant tumor growth.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.2 no.3
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• pp.3-8
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• 2009

Environmental pollution caused by fossil fuel use and energy sources, the big concern is the rise of the current situation, one of the ways to overcome the interest in renewable energy is Gozo. Located on the west coast, especially the Saemangeum area and the northwest wind, the big advantage of the vast area that's got quite a number of wind turbines is expected. This study affirms that these expectations can be a wind energy resource survey sea area of the average wind speed of Kunsan 5 ~ 7m / s is enough, books are linked to the local marine wind farms can safely say that none of choejeokji said. In addition, the emergence of the wind resource to determine the density of the Weibull distribution is calculated using the number 1, the shape factor as a parameter to calculate the density of the wind a result, Gunsan Province was able to predict the emergence of the wind. In addition, by controlling the remote monitoring through the measurement exceeded the convenience and reliability at the same time you can achieve great results.

• Journal of the Korean Institute of Landscape Architecture
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• v.21 no.4
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• pp.113-129
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• 1994

This study is designed to analyze the trends of professional services in Landscape Architecture during the past 5 years(1987-1991) in Korea. The data were collected from 1,117 projects from 56 engineering and landscape architecture firms. The findings are summarized as follows: 1) The projects have been increased annually by 19 percent in numbers and by 47 percent in money terms. 2) The main sources of projects are local governments and corporations. However the private sector comprise 31 percent in projects number and 46 percent in money terms. 3) The public park and tourism site development comprise a half of the projects. Recently recreational forest, golf, amusement and large housing site development have increased very rapidly. 4) In terms of workscope they are devided by 'complex' project which include extensive engineering works and 'simple' project which contain mostly planting design. The former include receational project with average 5 or 6 months contract period, and the later include housing and building site design with 2 or 3 months period. 5) Two types of consulting firms are typical. One is comprehensive engineering firms with urban planning section and few landscape section. The other is specialized professional firms with urban planning or landscape architecture. 50 percent of the project was done by comhensive engineering firms and 60 percent was done by urban planning section. The implication of these findings are broad: Firstly, We have to meet the demands in private secter mostly in recreation and leisure related projects. Secondly, landscape architects and project managers need more professional skills and coordination ability to deal with 'complex' projects. Thirdly, to enhance the quality of professional services it is required to have enough work time and higher service fee through legal and institutional enforcements.