• Journal of Advanced Marine Engineering and Technology
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• v.40 no.7
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• pp.663-670
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• 2016

This paper introduces the concept of the computer-aided engineering(CAE) design method for a bypass valve in a system that is used for the safe lifting of mineral resources in deep-seabed mining. Although the bypass valve has a simple mechanism, its design is very difficult because of various influencing factors. This equipment, which has a complex design process, should be developed by CAE-based design method. The method can perform the design, design verification, and virtual experiment at the same time. In this study, the CAE-based method for the design of the bypass valve has been developed using fluid dynamics, multi-body dynamics, and optimization method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.374-383
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• 2020

This study verified the difference in the influence on the value principles held by the consumers while examining the influence of the characteristics of the online shopping mall on the purchase intent by using a TAM2 model. First, the characteristics of online shopping malls were proven to have a positive effect on the perceived ease of use and perceived utility. Second, a look at the effect of the online shopping mall characteristics on the emotional response shows that only the system quality and product quality variables had a positive effect on the emotional response. Third, the perceived ease of use, perceived utility and emotional response of online shopping mall users had a positive effect on their perceived value. Fourth, multi-group analysis was conducted to examine the difference between utilitarian goods and hedonic goods by categorizing what was purchased at online shopping malls. The results showed differences between the groups. This study is attempted to investigate various influencing factors on consumers' intention to revisit online shopping malls. In addition, the author also attempted to understand the behavior of online shopping mall visitors by dealing with more than the technical attributes and emotional aspects of shopping malls.

• Korean Security Journal
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• no.39
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• pp.241-268
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• 2014

This paper is a study on the industrial security specialists of organizations in possession of industrial technology and their compliance motivations towards security policies. The focus is on organizational justice, organizational attachment and empowerment based on our hypothesis that compliance motivations are shaped, not only by the organization itself but, also by the attitude and principle of the organization's members. The objective is to propose a direction for administrative security policy to increase prevention of industrial technology leakage by identifying the factors' significance through hypothesis testing and thereafter investigating the influencing relationship. Survey questionnaires are collected from the participants of a regular educational program provided by the Korean Association for Industrial Technology Security (KAITS) and analyzed using SPSS 21.0 and AMOS 21.0 software. Through various statistical analyses, following results are acquired. First, procedural fairness and organizational attachment are found to motivate security supervisors to comply with security policies. Particularly, the relationship between procedural fairness and compliance motivations towards security policies is fully mediated by organizational attachment, suggesting that improved fairness at the organizational level will lead to an increase in organizational attachment, which will encourage the individuals to comply with security policies. Additionally, empowerment of the individuals in organizations partially mediates the relationship between procedural fairness and organizational attachment, confirming that procedural fairness empowers each individual and increases his organizational attachment. Specifically, in order to maximize compliance of security policies, businesses should demonstrate procedural fairness when compensating their employees for their work to empower them and increase their organizational attachment, which can increase their will to comply with existing security policies. This research provides insights into how to encourage security supervisors to comply with security policies by increasing their empowerment and organizational attachment.

• Journal of Preventive Medicine and Public Health
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• v.30 no.4 s.59
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• pp.870-883
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• 1997

The health center has to play an important role in promoting community health and satisfying a variety of community health needs and demands in the decentralized Korea. The nearly enacted Community Health Act compels every health center to make its own health plans which intend to deal with local health problems and plan its future health care. This obligation is obviously a big burden to most health centers. They do not have experiences in and abilities of making local health care plans. In order to establish a systematic community health plan, health centers have to concentrate their efforts on enhancing the ability of making health care plan through gathering and analysing the local health informations. However, it is very difficult in reality. This is simply because it will take long time to accomplish these activities. It seems natural that various professionals and researchers participate in carrying out the process of making community health plan in the initial stage. No standardized methodology and analysing framework exist even in the health professional society. Nonetheless, it is common to introduce survey research methodologies in analysing consumer's health care utilization and cost, and in identifying factors influencing health behaviors. Many researchers and professionals have applied social survey methodologies in obtaining information on providers and health policy makers as well. The authors have found that few studies have ever utilized local health data stored at the self-employed medical insurance society as the data source of planning activities. The purpose of this study is to illustrate the usefulness of the data stored at the Sung-Dong Gu Self-employed Medical Insurance Society in establishing the community health plan. The major contents of this study are as follows ; 1. frequency of utilization by age, area, sex, type of medical care institutions, and some major diseases 2. Medical treatment by type of medical care institutions, by classification of 21 diseases, by frequency of three-character categories 3. Medical treatment of major neoplasm and some chronic diseases by age, sex, and area. The conclusion of this study is that it is of great potentiality to find out the local health problems and to use them in blueprinting the community health plan through comparing the frequency of medical utilization analyzed by a variety of variables with NHI health data or the health data from survey research.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.1
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• pp.40-48
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• 2017

RC flat plates may be governed by a serviceability as well as a strength condition, and a construction sequence and its impact on the distributions of gravity loads among slabs tied by shores are decisive factors influencing short and long term behaviors of flat plate. Over-loading and tensile cracking in early-aged slabs significantly increase the deflection of a flat plate system under construction, and a reshoring work may be helpful in reducing slab deflections by controlling the vertical distributions of loads in a multi-shored flat plate system. In this study, a effect of reshoring works on short and long term deflections of flat plate systems are analyzed. The slab construction loads with various reshoring schemes and slab design and construction conditions are defined by a simplified method, and the practical calculation of slab deflections with considering construction sequences and concrete cracking and long term effects is applied. From parametric studies, the reshoring works are verified to reduce slab deflections, and the optimized conditions for the reshoring works and slab design and constructions are discussed.

• KSBB Journal
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• v.20 no.3
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• pp.205-209
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• 2005

Studies for the commercial production of sesame oil using th supercriticl carbon dioxide were made. Characteristics of sesame oil containing one of natural antioxidant 'sesamol', which only exist at sesame seed were also studied during the supercritical fluid extraction. Among the various factors influencing the sesamol contents in the sesame oil, the roasting time and temperature were checked, because sesamol can be converted from sesamol in through pyrolysis. We found that the sesamol content was increased rapidly under the condition of roasting temperature over $200^{\circ}C$ with longer roasting time. The sesamol content was increased as the temperature and pressure increased, which was caused by increase of solubility of sesamol against sesamol oil. And the sesamol content was increased also with lower speed of supercritical fluid, which increased the contact time with the raw material. The sesamol content was also increased using water increase up to $1\%$ as the entrainer. When the extraction performance with the supercritical fluid was compared to the conventional compressed extraction, the sesamol content was increased up to 11.5 times with the entrainer.

• Journal of Periodontal and Implant Science
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• v.23 no.3
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• pp.359-373
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• 1993

The ultimate objective of periodontal therapy is not only stopping the progression of periodontal disease, but also promoting the regeneration of lost periodontal tissue. Guided Tissue Regeneration, which is based on the principle that the goal of periodontal regeneration can be achieved by preventing apical migration of gingival epithelium and blocking cells originating from connective tissue, has been developed and used as a clinical procedure, and although it has shown excellent results in connective tissue healing, there have not been many studies showing its effect on the regeneration of alveolar bone loss due to periodontal disease. The objectives of this study are to investigate the result of 12 months-long treatment following guided tissue regeneration using expanded polytetrafluoroehylene membrane, and to observe the presence of regenerated alveolar bone. Forty-one teeth from 28 patients with clinical diagnosis of periodontitis has been selected. In fifteen of those interproximal intrabony defects, only flap operation had been carried out, and designated as the control group. Twenty-six intrabony defects received e-PTFE membrane following flap operation, and designated as the experimental group. Eleven teeth whose membrane had been exposed were excluded from the experiment. Various measurements including probing depth, loss of attachment, probing bone level and gingival recession have been recorded at 6th month and 12th month, and the significance of the changes has been analyzed. The results are as follows: 1. Probing depth at 6th and 12th month has shown a significant decrease in both groups (p<0.01), but significantly higher decrease was found in the experimental group compared to the control at the month(p<0.05). 2. Loss of attachment at 6th and 12th month has shown a significant decrease in both groups, but significantly higher decrease was found in the experimental group compared to the control (p<0.05). 3. Probing bone level at 6th and 12th month has shown a insignificant decrease in the control group and significant decrease in the experimental group (p<0.01). Significantly higher decrease in probing bone level was found in the experimental group (p<0.05). 4. Gingival recession at 6th and 12th month has shown a statistically significant increase (p<0.05), and the control group showed higher increase compared to the experimental group although no statistical significance was found. As these results have shown, the use of e-PTFE membrane in intrabony pockets results in marked decrease in the loss of attachment and probing bone level. This seems to indicate that e-PTFE membrane may play a role in alveolar bone regeneration in intrabony defects.

• Journal of Periodontal and Implant Science
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• v.23 no.3
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• pp.374-390
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• 1993

Regeneration of periodontal tissue after a loss of attachment due to disease or trauma repesents an important issue in dentistry, and various bone graft materials have been used to regenerated lost periodontal tissue and restore proper fuctions. Among those, allografts have been extensively researched and widely used clinically, since they are known to possess an excellent osteoinduction capability and result in proper topography of alveolar bone. Regeneration of periodontal tissue in supraalveolar defects may be technically difficult. However, a large amount of regeneration has been observed by complete tissue coverage of involved teeth. In this study, supraalveolar defects in adult dogs were treated with periodontal surgery, decalcified freez-dried bone allograft, complete tissue coverage was attained, and effects on repair and regeneration of alveolar bone, cementum and periodontal ligament were studied. Exposure of premolar furcation of adult dogs was attained by removing marginal alveolar bone down to 5mm from CEJ, and root surfaces were planed with curettes. On the left side, defects were treated without any allograft(Control Group). On the right side, a DFDB was used(Experimental Group). In all groups, flaps were coronally positioned and sutured, completely submerging the treated defects. At two weeks, the crown were exposed 2-3mm. Healing progresses were histologically observed after eight weeks and the results were as follows : 1. Distance from CEJ to AJE was : $2.82{\pm}0.66mm$ in the control group, $1.71{\pm}0.51mm$ in experimental group, with significant differences between groups.(P<0.01) 2. Periodontal repair was : $2.18{\pm}0.66mm$ in the control group, $3.29{\pm}0.51mm$ in experimental group, with significant differences between groups.(P<0.01) 3. Connective tissue repair was : $1.43{\pm}0.52mm$ in the control group, $0.76{\pm}0.47mm$ in experimental group, with significant differences between groups.(P<0.01) Orientation of connective tissue fibers in relation to root surfaces was : mostly parallel in the control group, vertical or parallel or irregular in experimental group. 4. The amount of cementum formation was : $1.66{\pm}0.58mm$ in the control group, $2.86{\pm}0.66mm$ in experimental group, with significant differences between groups. 5. The amount of alveolar bone formation was : $0.76{\pm}0.72mm$ in the control group, $2.53{\pm}0.56mm$ in experimental group, with significant differences between groups.(P<0.01)

• Journal of the Korean Geographical Society
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• v.51 no.6
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• pp.837-851
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• 2016

The growth and development of Gwangyang city was a result of the POSCO Gwangyang Works, and Gwangyang city is one of typical firm citys in Korea. The objective of this study is to identify and examine the change of migration and population structure in Gwangyang city from 2001 to 2010. Since 1981, total number of population of Gwangyang city increased from 78,478 in 1981 to 145,512 in 2010. The population structure by age was changed with population increase since 2001, and 30-40 aging group was 35% of total in 2010. During 2001-2010, the netmigraion showed -2,925 people, however, the number of inmigrants were overtaking the number of out-migrants since 2008. The most common reason of in-migrants was occupation(49.5%). Factors influencing Gwangyang City's population growth and oversupply are the location of POSCO Gwangyang Works and steel-related enterprises, opening and construction of Gwangyang container berth, the related development projects and establishment of Gwangyang Bay Area Free Economic Zone, and the local policies of Gwangyang City connected with these large-scale national projects. As a result, the number of manufacturing-related businesses increased due to various regional development projects conducted in Gwangyang City, and the growth of the business continued to increase due to the increase of younger people and births.

• Journal of Internet of Things and Convergence
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• v.6 no.2
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• pp.57-64
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• 2020

The purpose of this study was to investigate the smartphone addition, which effects sleep, scholastic achievement and mental health in nursing students. The study subjects consisted of 185 nursing students in grade 2nd, 3rd who completed a informed consent. The date were collected from 13th of May to 3rd of June 2019. Data were analyzed descriptive statistics, Independent t-test, one-way ANOVA, Pearson correlation and stepwise multiple regression using by IBM SPSS/WIN 24.0. The score for Smart Phone addition was 36.99 out of 60. The more addicted a smartphone is, the more likely shows lower score of sleep (r=.19, p=.009), mental health (r=.34, p<.001) was found to be negative. The key variable for effecting nursing students' mental health was smartphone addiction, quality of sleep and time, level of grade. Among them, smartphone addiction (β=.27) was found to have the highest influence for all. Explanation that by influencing factors was 20.4%. Therefore, for the mental health of nursing students, various programs that can reduce smartphone addiction should be applied and sleep management should be done.