• Journal of KIISE:Computing Practices and Letters
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• v.16 no.1
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• pp.23-34
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• 2010

As the number of user increases according to the improvement of the network, the multi-thread schemes are used to process the service requests of several users who are connected simultaneously. The static thread pool scheme has the problem of occupying a static amount of system resources. On the other hand, the dynamic thread pool scheme can control the number of threads according to the users' requests. However, it has disadvantage that this scheme cannot react to the requests which are larger than the maximum value assigned. In this paper, a web server using a learning-based dynamic thread pool scheme is suggested, which will be running on a server programming of a multi-thread environment. The suggested scheme adds the creation of the threads through the prediction of the next number of periodic requests using Auto Regressive scheme with the web server apache worker MPM (Multi-processing Module). Unlike previous schemes, in order to set the exact number of the necessary threads during the unchanged number of work requests in a certain period, K-Nearest Neighbor algorithm is used to learn the number of threads in advance according to the number of requests. The required number of threads is set by comparing with the previously learned objects. Then, the similar objects are selected to decide the number of the threads according to the request, and they create the threads. In this paper, the response time has decreased by modifying the number of threads dynamically, and the system resources can be used more efficiently by managing the number of threads according to the requests.

• Journal of Distribution Science
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• v.5 no.1
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• pp.57-73
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• 2007

There are more problems in distributing agricultural and special products than industrial products because they have such restrictions as seasonal fluctuation in the quantity, indeterminate and diverse shapes, many farm households, a small amount of shipment, and mandatory guide and maintenance. However, with social atmosphere called well-being, there are increasing concerns about inorganic agricultural products and direct trade with farmers. It is therefore urgent to stabilize the price of agricultural and special products and to correctly grasp and improve logistics activities for those dealing with agricultural and special products in order to supply fresh ones. This study aimed at examining logistics activities and the information technology level for agricultural and special products, determining how these factors affect logistics performance, and eventually suggesting a scheme to improve the logistics achievements for agricultural and special products. For this purpose, it selected information technology and logistics activity levels as independent variables and logistics performance as a dependent variable. The information technology level was measured for utility, holding level, and concern, respectively, and the logistics activity level was tested for the level of using the logistics information system in those companies concerned. From the above-mentioned findings, it is urgent to enhance distribution technology and its level immediately since distribution of agricultural and special products is poor in Korea and good distribution can contribute to a reduction of logistics costs or improvement of customer service.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.245-251
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• 2018

This study was conducted to investigate the status of the installation, maintenance and management of automatic external defibrillators (AEDs) in all mandatory institutions and buildings of the providence to be equipped with AEDs. The study was conducted from November 20, 2017 to December 20, 2017, during which time 169 AED units were surveyed. The collected data was analyzed by frequency analysis and the percentage was determined using the SPSS/WIN 20.0 program. A total of 168 units (99.41%) of AEDs were installed inside. Additionally, 47 units (27.80%) were available 24 hours a day, and 44 units (26.00%) were available outside business hours of the institution. Moreover, 87 units (51.43%) of the responsible managers received rescue and first aid training. Evaluation of the management status of the AEDs revealed two (1.20%) that had problems with their battery state of charge battery charge and seven (4.10%) for which the AED pads were past the expiration date. A management system for the manager of AEDs should be established and a regular training program for their systematic maintenance should be developed and applied. It is also suggested that awareness of the necessity of continuous management be raised through reinforcement of laws and legal system reorganization.

• Journal of the Korean association of regional geographers
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• v.10 no.1
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• pp.67-82
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• 2004

There is a general agreement that the global social-economic system is undergoing fundamental changes, which can be explained in terms of the transformation of production system from the Fordism to Post-Fordism since the 1980s. These fundamental changes have resulted in the 'new urbanization' process in the most of large cities in the developed countries. The aim of this paper is to identify the 'new urbanization' process in a large city in Korea that is, Daejon. For the propose, this paper tries to examine and conceptualize empirically the changes of economic, political, social-cultural, and spatial aspects of Daejon metropolis in the respect of 'new urbanization'. The major findings of this essay are summarized as follows. First of all, Daejon economy has experienced new changes, that is the development of service economy and high tech industry. But the old industry still remain important in the urban economy. Secondly, in the political aspect, new civil movements flourish in the city, while the political power of Jaminlyeon, a pro-conservative and narrow-regionalism party, once dominated this region, has decreased its influence. Thirdly. the original CBD of Daejon has been declined while new (sub-)CBBs have emerging in Daejon spatial structures. In conclusion, we can find some clues of the new urbanization process in Daejon, but this process is still quite slow and somewhat different from those of large cities of the developed countries.

• Microbiology and Biotechnology Letters
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• v.36 no.2
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• pp.87-95
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• 2008

Probiotics are live organisms that when administered in adequate amounts confer a health benefit on hosts. The administration of direct-fed microbials (DFM) such as lactobacilli and bacillus, may be a more direct approach to beneficially alter gastrointestinal microflora than altering dietary ingredients or supplementing with growth-promoting levels of antibiotics. It is apparent that microbes have an important influence on immune development and resistance to infection; that microbes are not static colonizers of our bodies, but are dynamic, symbiotic coresidents. And it can improve the surrounding environments; decrease the malodor caused by degrade the excrement. Recently, new paradigm such as environment protection and safe food have been settled. In domestic farm house, there is a great demand for probiotics as a substitute of antibiotics for the improvement of environmental quality and the production of a competitive goods. Probiotics circulated in a country have three categories: an animal medicine permitted by national veterinary research quarantine service (NVRQS), a support feed registered in city or country house, and not-registered goods. However, lots of unqualified goods were produced and circulated. And thus, it is in urgent need of evaluating the present situation and effect of probiotics. This study was conducted to evaluate the system of a probiotics as a livestock-environment improving agents for the alternation of antibiotics and quality control of it.

• The Journal of the Korea Contents Association
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• v.18 no.10
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• pp.320-334
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• 2018

The purpose of this study is to analyze research trends in international development and cooperation on education and to suggest directions for the Korean teachers and teacher education to achieve 'Sustainable Development Goals (SDGs).' The examination of 8 databases resulted in the identification of 2,945 studies, and 6 of these references met the inclusion criteria for systemic review. Major findings revealed that pre- and in-service teachers recognized the necessity of international development education but had a low degree of teacher efficacy. The teachers who participated in ODA education programs have experienced difficulties due to insufficient understanding of local sites and role performance. Then, a couple of studies of mathematics and early childhood education compared the Korean national curriculum and education system with developing countries'. Lastly, it is important to have a sustainable system which promotes all teachers, including retired ones, in global development and cooperation on education. For the successful achievement of SDGs, Korean teachers should develop their expertise, a deep understanding of partner countries, and stable quality education for the underprivileged.

• Journal of Satellite, Information and Communications
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• v.2 no.2
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• pp.29-35
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• 2007

COMS satellite is a multipurpose satellite in the geostationary orbit, which accommodates multiple payloads of the Ka band Satellite Communication Payload, Meteorological Imager, and Geostationary Ocean Color Imager into a single spacecraft platform. In this paper, Korea's first innovative geostationary Communication, Ocean and Meteorological Satellite (COMS) program is introduced which is fully funded by Korean Government. The satellite platform is based on the Astrium EUROSTAR 3000 communication satellite, but creatively combined with MARS Express satellite platform to accommodate three different payloads efficiently for COMS. The goals of the Ka band satellite communication mission are to in-orbit verify the performances of advanced communication technologies and to experiment wide-band multi-media communication service. The Meteorological Imager mission is to continuously extract meteorological products with high resolution and multi-spectral imager, to detect special weather such as storm, flood, yellow sand, and to extract data on long-term change of sea surface temperature and cloud. The Geostationary Ocean Color Imager mission aims at monitoring of marine environments around Korean peninsula, production of fishery information (Chlorophyll, etc.), and monitoring of long-term/short-term change of marine ecosystem. The system design difficulties are in the different kinds of payload mission requirements of communication and remote sensing purposes and how to combine them into one to meet the overall satellite requirements. In this paper, Ka band communication payload system is more highlighted.

• The Transactions of the Korea Information Processing Society
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• v.3 no.2
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• pp.295-304
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• 1996

Toprovide economical BISDN service, with which integration process of many types of media is possible, it is necessary to construct a system with ground network and satellite network combined. The method for this type of transmission using satellite is TDMA that can provide services to many users in various area. However, the most difficult task to connect TDMA which uses synchronous method to ATM which used asynchronous transfer mode is the deterioration n of ATM transmission quality such as cell delay variation. Therefore, it is necessary to develop delay variation compensation method which can confront to the ATM. Efficient ways to use satellite links under the conditions such that maximum efficiency of the delay variation is limited under the required value, and the burst characteristic of transmission cell does not increase are being researched for translation between in ATM and TDMA. This paper points out the problems when time stamp method, reviewd in ground network, is applied to the satellite links to compensate the delay variation .To solve the problem, discrete cell count method is introduced along with the calculation of transmission capacity and error rate.Also, from the observation of stab-ility of the system and verification of reliability even when singal error occurred in the cell transmission timing information, the proposed compensation method appeared to be excellent.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11B
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• pp.1383-1388
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• 2011

Due to many recent activities on enforcement of the intensified environmental regulation such as the policies of curbing the greenhouse gas and the Restriction of Hazardous Substances (RoHS), the usage of Light emitting diode (LED) has been rapidly increased and energy efficient management of LED light system is regarded as an important technology to enhance the energy efficiency. In this paper, we propose an energy-efficient control scheme of LED light, being composed of multiple light sources. The proposed scheme controls the intensity of LED light source to minimize the total intensity while providing the quality of lighting service. The intensity of light is assumed to be proportional to power consumption, thus the objective is to minimize the total power consumption. A linear programming problem is formulated to find the optimal intensity of each light source and procedure to apply the proposed scheme in the real system is suggested. The performance evaluation results elucidate that the proposed scheme achieves over 20% improvement in power consumption of light intensity in comparison with the conventional dimming control scheme.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.355-362
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• 2016

The pipe material is selected according to the physical and chemical properties of the fluid flowing within it. Because the fluid used in fire extinguish systems is water, the various foreign substances dissolved in it cause scale to form on the pipe wall and accelerate the corrosion and aging of the pipe itself. This results in an increase in the friction loss and eventually degrades the efficiency of the pump. The use of CPVC (Chlorinated Poly-Vinyl Chloride) pipes was confirmed to reduce the friction loss compared to conventional steel pipes in the design and construction stages. The friction loss was found to be 76.64MPa with a C-value of 120 for the steel pipe and 50.72 MPa with a C-value of 150 for the CPVC pipe in an actual apartment construction environment. It was confirmed that the friction loss was improved by about 34% when using the CPVC pipe. When the steel and CPVC pipes were employed in the construction, the construction costs were 1,585,158 and 931,842 won, respectively. Therefore, it was shown that the construction cost was reduced by about 41%. We investigated the safety of the fire extinguishing system and the improvement in the economic performance due to the reduction in the total installed capacity by studying practical applications in the field.