• The Journal of Korean Society for School & Community Health Education
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• v.9 no.2
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• pp.65-80
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• 2008

Objectives: To identify the relationship between the internet addition of elementary school students, and their health behavior and VDT syndrome, and thereby to detect the impact of internet addiction on the health behavior of elementary school students, to get the basic information necessary to develop a prevention program for internet addiction and to plan for VDT syndrome prevention program. Methods: We conducted this study during the period from jun 27, 2007 through July 8, 2007. The subjects of this study were 416 children whose grades were in 4th through 6th grades of elementary schools located in the city A in Kyung Pook Providence. Data were obtained from self-rating questionnaires. The questionnaires were composed of Korean Internet Addiction Self-examination on Internet Use Patterns (K-scale), Health Behavior Profile, VDT Syndrome, and general characteristics. We used t-test, AVOVA with Ducan method for Post-hoc comparison in means comparison between groups, $X^2$-test for frequency analysis and Pearson's correlation coefficient. We used SPSS/PC(12.0 ver) program and the LISREL 8.53 Win program for covariance structural analysis. Results: Major results were as follows. 1. The internet addiction propensity distribution based on the distribution of scores were investigated according to the self diagnosis scale on internet addiction. 6.5% of them were high risk user group, 14.4% were potential risk users and 79.1% of them were common user groups. 2. Internet addictions by sex, internet use duration, frequency (days/week), time(hours/day), purpose, position, brightness of internet, attitude of parents and frequency of conversation of family members were statistically significant(p<0.01). 3. There was a statistically significant difference in VDT syndrome according to internet addiction groups(p<0.001) besides ocular symptoms, dry mouth and GI troubles. 4. The health behavior score was the lowest in high risk user group(p<0.001). There were significant differences between internet addiction groups in personal hygiene and habits of daily living(p<.002), the prevention of accidents(p<.002), the practice concerned with the prevention of infectious disease(p=.002), and mental health(p<.001). 5. There was also a significant negative correlation between internal addiction and health profile(r=-0.365, p<0.01) and a significant positive correlation between internal addiction and VDT syndrome(r=0.331, p<0.01). 6. As the result of structural model analysis, internet use time(/day), days of internet use(/1week), conversation frequency among family members, degree of brightness of internet use had significant direct effects on internet addiction. Conclusions: The results will help the development of an effective intervention program for the prevention and treatment of internal addiction by clarifying the effect of the internal addiction upon elementary school students' VDT syndrome and health behavior.

• Journal of Electrochemical Science and Technology
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• v.11 no.2
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• pp.172-179
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• 2020

The impact of effective parameters on the electrodeposition rate optimization of Au-Cu alloy at high thicknesses on the silver substrate was investigated in the present study. After ensuring the formation of gold alloy deposits with the desired and standard percentage of gold with the cartage of 18K and other standard karats that should be observed in the manufacturing of the gold and jewelry artifacts, comparing the rate of gold-copper deposition by direct and pulsed current was done. The rate of deposition with pulse current was significantly higher than direct current. In this process, the duty cycle parameter was effectively optimized by the "one factor at a time" method to achieve maximum deposition rate. Particular parameters in this work were direct and pulse current densities, bath temperature, concentration of gold and cyanide ions in electrolyte, pH, agitation and wetting agent additive. Scanning electron microscopy (SEM) and surface chemical analysis system (EDS) were used to study the effect of deposition on the cross-sections of the formed layers. The results revealed that the Au-Cu alloy layer formed with concentrations of 6gr·L^-1 Au, 55gr·L^-1 Cu, 24 gr·L^-1 KCN and 1 ml·L^-1 Lauryl dimethyl amine oxide (LDAO) in the 0.6 mA·cm^-2 average current density and 30% duty cycle, had 0.841 ㎛·min^-1 Which was the highest deposition rate. The use of electrodeposition of pure and alloy gold thick layers as a production method can reduce the use of gold metal in the production of hallow gold artifacts, create sophisticated and unique models, and diversify production by maintaining standard karats, hardness, thickness and mechanical strength. This will not only make the process economical, it will also provide significant added value to the gold artifacts. By pulsating of currents and increasing the duty cycle means reducing the pulse off-time, and if the pulse off-time becomes too short, the electric double layer would not have sufficient growth time, and its thickness decreases. These results show the effect of pulsed current on increasing the electrodeposition rate of Au-Cu alloy confirming the previous studies on the effect of pulsed current on increasing the deposition rate of Au-Cu alloy.

• Journal of Broadcast Engineering
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• v.13 no.6
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• pp.781-795
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• 2008

This paper focuses on effects that IPTV will have on domestic broadcasting market in the point of view of customers. The purpose of the paper is to present the future landscape of competitive media market when IPTV is launched, and to research how IPTV will have impact on terrestrial broadcasting, cable TV and satellite broadcasting industry. The paper integrates two known theories, such as the niche-gratification model and the value-expectancy model, to analyze competitive media market. The value expected model makes it possible to overcome the weakness of the niche-gratification model and to forecast competitiveness more accurately. According to this research, competitive power will be in the order of Cable TV, IPTV, and satellite broadcasting. Terrestrial broadcasting does not show strong competitive relationships with others statistically. As a result, Cable TV will be the most competitive medium in the future. IPTV will be stuck in the middle and can rapidly substitute for existing broadcasting services. While IPTV will severely threaten the satellite broadcasting company which has a relatively small number of subscribers, cable TV will be in a superior position to IPTV.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.2
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• pp.45-60
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• 2014

In recent year's we have seen that due to education and social position there has been a significant increase in the number of women engaging in entrepreneurial activities. Concurrently research into the activities of women currently engaged in entrepreneurial activities has increased. This research has focused on the individuals themselves, their motivations and the performance of their ventures but there is not enough systematic research on the subject. Therefore it is necessary expand the criteria of the current research to examine every aspect of how these emergent entrepreneurs operate and to provide others with the same goals the appropriate skills and knowledge needed to succeed. This study wants to identify and evaluate the psychological, environmental and personal characteristics that these women possess and to assess the impact these factors have on the level of their success. This study will focus on those women who were empirical in their methods as this lends itself better to a detailed systematic analysis. It will examine the concept of entrepreneurial self-efficacy with regard to how they searched, planned, marshaled and implemented steps to influence the environmental and personal factors that affected them. In addition the searching phase of entrepreneurial self-efficacy directly influences entrepreneurial motivation and thus performance. The results of this study will suggest that as Korean women's interest in entrepreneurship grows it will have wide reaching theoretical implications and affect the direction of the policy that supports it.

• Asia pacific journal of information systems
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• v.3 no.2
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• pp.3-54
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• 1993

Recently, executives learned of the strategic impact that information systems (IS) and information technology (IT) could provide to their organizations. In other words, through IS/IT companies could squelch competition, secure suppliers, obtain customer loyalty, reduce the threat of new entrants, and identify new opportunities. Because of these potential benefits, organizations are investing ever-increasing amount of organizational resources in IS/IT to make their organizations as information-based ones. Information-based organizations depend largely upon computer hardwares and softwares for their ongoing operations and management. Thus, organizations must manage their information resources, especially hardwares and softwares very effectively to remain competitive. Information resource management (IRI) is a program of activities directed at making effective use of information technology within an organization. These activities cover from corporate IS/IT planning to application system development, implementation, and maintenance. In more detail, IRV activities include planning for and acquiring computer hardwares and communication equipments, planning for, selection, and management of software development projects, and re-engineering business processes as IS/IT are integrated into organizational management. Among these activities, planning for and acquisition of computer hardwares, and planning for and management of software projects are the most critical ones since these activities require enormous amount of such important corporate resources as money, people, and time. Furthermore, corporate's eventual success largely depends upon whether corporate's policy on IS/IT is effective one or not. Numerous approaches and concepts to specific IRM activities have been proposed. However, many organizations have experienced various problems in the process of applying these approaches to their IRM activities mainly because existing methodologies and guidelines are too general to adapt to each firm's unigue situation. Also, these approaches are having its own strengths and weaknesses. Thus, people in charge of organization's IRM policy should come up with effective guidelines to maintain his position very long. In this study, we reviewed some existing approaches for planning, evaluation, and acquisition of computer hardware. Then, real experiences from Taechang Steel Co., Ltd. located in Taegu, which is one of the largest Coil Service Centers in Korea, are discussed. The major purposes of the study are : (1) to discuss the tradeoffs of existing approaches on hardware evaluation and acquisition, (2) to provide a real experience of a company to facilitate the application of theoretical concepts to the real environment.

• Progress in Medical Physics
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• v.28 no.1
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• pp.1-10
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• 2017

The difference between three-dimensional (3D) and four-dimensional (4D) dose could be affected by factors such as tumor size and motion. To quantitatively analyze the effects of these factors, a phantom that can independently control each factor is required. The purpose of this study is to develop a deformable lung phantom with the above attributes and evaluate the characteristics. A phantom was designed to simulate diaphragm motion with amplitude in the range 1~7 cm and period up to ${\geq}2s$ of regular breathing. To simulate different tumors sizes, custom molds were created using a 3D printer and filled with liquid silicone. The accuracy of the phantom diaphragm motion was assessed by comparing measured motion with predicted motion. Because the phantom diaphragm motion is not identical to the tumor motion, the correlation between the diaphragm and tumor motions was calculated by a curve fitting method to emulate user-intended tumor motion. Tumors of different sizes were located at same position, and tumor set-up positions were evaluated. The accuracy of phantom diaphragm motion was better than 1 mm. The diaphragm-tumor correlation showed that the tumor motion in the superior-inferior direction increased with increasing diaphragm motion. The tumor motion was larger in the $10cm^3$ tumor than in the $90cm^3$ tumor. The range of difference between the tumor set-up positions was 0 to 0.45 cm. This phantom showed independently adjusting factors such as tumor size and motion to facilitate quantitative analysis of the dosimetric impact of respiratory motion according to these factors.

• Korean Security Journal
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• no.18
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• pp.39-54
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• 2009

The purpose of this research, the importance of security and the means to carry out the spirit of Taekwondo is to identify. First, the target of more than 2 years of taekwondo training has continued to set as a guard, and experience to respond faithfully to the general staff to the administrator from 9 respondents were selected to accomplish this purpose. Through the course of a series of studies which have drawn the following conclusions. First, taekwondo training is created through the politeness, lot of nerve, patience, self-mastery, indefatigable the spirit of taekwondo in the security mission is a positive impact. Typically, the bodyguards make a statement through the body and mind will acquire the spirit of taekwondo. The spirit of taekwondo becomes an important material on the process of security mission as the stress and the occurrence of the situation, such as conflicts within the organization to overcome the negative situation. Second, it requires the right attitude in life, mental health, flexible social attitudes based on the taekwondo spirit. Therefore, the security guards needed in the organization the opportunity to learn the position could get the hierarchy between protection and bodyguard, or supervisor bodyguards and low class bodyguard.

• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.61-68
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• 2006

Soil washing techniques coupled with high pressure air jet were applied for diesel-contaminated soils sampled by an underground oil reservoir of which the initial total petroleum hydrocarbon (TPH) ($2,828{\pm}206\;mg/kg$) exceeded 5 times of current standard level (500 mg/kg) regulated by the Soil-Environment Conservation Law. Through several tests, we found that the position of impeller has a critical impact for washing efficiencies. The highest washing efficiency was obtained at an oblique angle (30 degree) for the impeller and optimized mixing speed (300 rpm) that could have high shearing forces. Considered economical and feasible aspects, the optimum mixing time was 10 min. Rate constants of TPH removal derived from the first-order equation were not linearly increased as mixing speed increased, indicating that mechanical mixing has some limits to enhance the washing efficiencies. Application of high-pressure air jet in washing process increased the washing efficiency. This increase might be caused by the fact that the surface of micro-air bubbles strongly attached hydrophobic matters of soil particles. As the pressure of air jet increased, the separation efficiencies of TPH-contaminated soil particles increased. In the combined process of high-pressure air jet and mixing by impeller, the optimum mixing speed and air flow-rate were determined to be 60 rpm and $2\;kg/cm^2$, respectively. Consequently, the washing technique coupled with high-pressure air jet could be considered as a feasible application for remediating petroleum-contaminated soils.

• Journal of KIISE:Information Networking
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• v.32 no.3
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• pp.391-403
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• 2005

Several nv6 mobility support protocols for mobile Internet services are proposed in IETP : Mobile Ipv6, Hierarchical Mobile Ipv6, and Fast Handovers over Mobile Ipv6. Recently, IEEE 802.11 network has also been widely deployed in public areas for mobile Internet services. In the near future, IPv6 mobility support over IEEE 802.11 network is expected to be a key function to actualize the All If-based mobile various services. For appropriate application of these protocols, the IPv6 mobility support protocols should be analyzed according to their characteristics in terms of signaling, handover latency, lost packets, and required buffer sire as well as the impact of lower layer such as IEEE 802.11 network. In this paper, we analyze the performance of the protocols over IEEE 802.11 network. We define a packet-level traffic model, a network system model, and a mobility model. From these models, we construct a framework for the performance analysis. We also make cost functions to formalize each protocol's performance. Lastly, we analyze the effect of varying parameters used to show diverse numerical results, and compare with each other. From the analysis results, it is concluded that each Protocol has contrary or contrastive advantages with other Protocols, so there is no protocol that holds a dominant position.

• Journal of Radiation Protection and Research
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• v.33 no.1
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• pp.1-12
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• 2008

International Standardization in all technical area is gaining its momentum as its impact and implication over global trade is directly linked. The worldwide competition to secure a dominant position in the standardization process is ever growing over the years. In 2005, the International Technical Committee on Nuclear Instrumentation, which is a subunit of International Electro-technical Commission (IEC), was held in Korea under the auspices of MOST (Ministry of Science and Technology). Korea has adopted its Rule and Regulation as the National Standard. As a part of a link to National Mid-and Long-term Atomic Energy R&D Program of MOST, the technical development of a performance test for the radiation monitors was carried out under mechanical environment and electromagnetic immunity conditions. The characteristics of the radiation fields were also evaluated under the conditions and introduced to a techniques of performance test for the radiation protection instrumentation adopted IEC61526 standards and it's results was analyzed. We would like to share the experience gained in these efforts, failure as well as success, and to discuss the problems encountered and serious consideration to be taken into account in the future endeavor.