• The Journal of Korean Academy of Prosthodontics
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• v.45 no.3
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• pp.362-374
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• 2007

Statement of problem. The intial stability for osseointegration of implant has been an interesting factor. Especially, in the case of poor bone quality or immediately loaded implant, various strategies have been developed focusing on the surface of materials to improve implant fixation to bone. The microscopic properties of implant surfaces play a major role in the osseous healing of dental implants. Purpose. The aims of this study are to perform a histologic and histomorphometric comparison of the healing characteristics of three different surfaces and the comparison of resonance frequency analysis (RFA) values measured by $Osstell^{TM}$ and perio-test values (PTV) measured by Periotest. Material and methods. A total of 24 screw titanium implants (Dentium Co., Seoul, Korea) with 6mm in length and 3.4mm in diameter, were placed in the mandible of 4 beagle dogs. Implants were divided into three groups following the surface treatment methods: Group I is machined(control group). Group II is anodically oxidized. Group III is coated 500nm in thickness with hydroxyapatite(HA) by ion beam assisted deposition(IBAD) on the anodized oxidization. Bone blocks from 2 dogs were caught after 3 weeks of covered healing and another blocks from 2 dogs after 6 weeks. RFA values and PTV were measured right after insertion and at 3 and 6weeks. Histomorphometric analysis was made with Kappa Image Base System to calculate bone-to-implant contact (BIC) and bone area inside the threads. Pearson's correlation analyses were performed to evaluate the correlation between RFA and PTV, BIC and bone area ratio of three different surfaces at 3 and 6 weeks. Results. 1) In all surface treatment methods, the RFA values decreased and the PTV values increased until 6 weeks in comparison to initial values. 2) At 3 weeks, no significant difference was found from bone-to-implant contact ratio and bone area ratio of three different surface treatment methods(P>0.05). However, at 6 weeks, different surface treatment methods showed significantly different bone-toimplant contact ratio and bone area ratio(P<0.05). 3) In the implants with the IBAD on the anodic oxidization, significant difference was found between the 3 weeks and the 6 weeks bone area ratio(P<0.05). 4) Correlation was found between the RFA values and the bone area ratio at 3 and 6 weeks with significant difference(P<0.05). Conclusions. These results indicate that the implants with the IBAD on the anodic oxidization may have a high influence on the initial stability of implant.

• Management & Information Systems Review
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• v.39 no.3
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• pp.99-125
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• 2020

This study analyzes the priority according to the importance of the government's oyster industry support policy using AHP (analytic hierarchy process), and it compares and confirms the satisfaction level of direct and indirect workers using this policy in contribution to the development of the oyster industry. The results of the importance analysis by AHP analysis are as follows: As a result of the evaluation of the importance of the entire sample, it is found that the most important factor is the production facilities of the production supply of the competitiveness enhancement, the purchase of raw materials of the production supply of the competitiveness enhancement, and the aging of the structural risks of risk reduction. Also, significant differences among the workers in the ranking of importance are identified. According to the comprehensive evaluation results of indirect workers, which consist of public officials, the National Federation of Fisheries Cooperatives, and related professors, raw materials, production facilities, and high-quality products are produced in order to increase competitiveness. There are differences among workers in order of marine pollution of environmental risks, structural fish population reduction, and structural aging of risk factors.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.206-212
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• 2018

As many consumers prefer good quality food, farms have used various facilities to cultivate products for satisfying their desires. Among them, the most representative facilities are plastic and glass multi-span greenhouse. The height of both plastic greenhouse and glass greenhouse is around three meters high in Korea. As a result, the crop productivity is limited. The solution is to increase the height of the greenhouses to improve the greenhouses' environment. The device for raising columns consists of a stop device, a pneumatic cylinder, and a vertical member. Pneumatic cylinders were designed with a diameter of 160 mm and a stroke length of 50 mm, taking into consideration the safety factor of 1.5. In addition, the air flow was controlled by nozzle to achieve a time of less than 30 seconds per stroke. It was calculated that $21.5L{\cdot}min^{-1}$ of air was needed to complete in less than 30 seconds. Accordingly, the diameter of the nozzle is designed to be 0.5 mm. When the pressure was 0.9 MPa, the average raising force was 13,805N, which was close to the calculated value of 15,612N. The field test results show that any inconsistency in the row columns was not generated. and that it is considered applicable to the actual glass and plastic greenhouses.

• Journal of the Korean Magnetics Society
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• v.7 no.5
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• pp.237-242
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• 1997

The microstructure and soft magnetic properties of as-deposited Fe-Hf-O thin film alloys, which are produced at $P_{O2}=10%$ by rf magnetron sputtering method in $Ar+O_2$ mixed gas atmosphere, is investigated. Newly developed $Fe_{82}Hf_{3.4}O_{14.6}$ film exhibits good soft magnetic properties with $4{\pi}M_s=17.7$ kG, $H_c=0.7$ Oe and ${\mu}_{eff}$(0.5~100MHz)=2,500, respectively. The Fe-Hf-O films are composed of $\alpha$-Fe nanograins and amorphous phase with larger amounts of Hf and O elements which chemically combine each other. With increasing Hf area fraction, Hf and O contents increased proportionally. It was considered that O content in films was determined by Hf contents, because O was chemically combined with Hf. It results from decreasing the $\alpha$-Fe grain size by precipitates (Hf and O), high electrical resistivity. The $Fe_{82}Hf_{3.4}O_{14.6}$ film exhibits the quality factor (Q=$\mu$'/$\mu$") of 25 at 20 MHz. These good frequency characteristics are considered to be superior to other films already reported.o other films already reported.

• Korean Journal of Social Welfare
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• v.56 no.3
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• pp.279-301
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• 2004

Relations of factors associated with burnout were investigated among 124 child protective service workers currently working in Korean Child Abuse Prevention Centers nationwide. Three categories of factors associated with burnout were examined; (1) individual characteristics, (2) job-related characteristics, and (3) job-satisfaction. Social survey method using questionnaires by mail was employed. MBI(Maslach Burnout Inventory) for measuring burnout, a part of Smith, Kendal & Hulin's JDI(Job Description Index) for job-satisfaction, and a scale measuring the special characteristics of job developed by researchers were used. Mann-Whitney test and Kruskal-Wallis test were employed to analyze the data. Across all burnout sub-scales(emotional depletion, dehumanization of clients, lack of feelings of achievement), subjects reported a high degree(above the cutting point) of burnout. Several factors were identified as associated with burnout. Child protective service workers who are young, single with front line worker status reported higher burnout. Lack of education and training before the job location were another factors which contributed to worker burnout. Lack of proper supervision stood out as another burnout provoking factor. Job-satisfaction was negatively correlated with all three burnout sub-scales, which meant the lower the job-satisfaction, the higher the burnout of service workers. The findings implicate that the administrators of Child Abuse Prevention Centers should pay close attention to their workers' sign of burnout and develop carefully designed support system which include provision of excellent supervision, proper education and training opportunities and organizational effort to strengthen employees' overall job-satisfaction to secure their quality of services toward abused children and their family.

• Culinary science and hospitality research
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• v.17 no.5
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• pp.57-73
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• 2011

This study was conducted to examine the overall perception of importance and possibility of Korean food and globalization of Korean food. Analyzing the factors influencing globalization of Korean food, this study suggests development strategies and basic data for globalization of Korean food and development of high skilled manpower. The survey was carried out from April 1, 2011 to April 30, 2011, targeting students majoring in foodservice, who will play a key role in globalization of Korean Food. Analysis methods included frequency analysis, descriptive statistics, t-test, ANOVA, factor analysis, correlation analysis, and multiple regression analysis. The findings are summarized as follows: (1) Students recognized Korean food as a nutritionally balanced healthy food. (2) Standardization of Korean cuisine and food names was the most important. (3) Students were very interested in globalization of Korean Food. (4) Perception of Korean food and its globalization were significantly different according to the levels of education. (5) As a result of analyzing the effect on globalization, quality and healthfulness of Korean food had a positive effect on globalization of Korean food.

• Convergence Security Journal
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• v.11 no.5
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• pp.65-76
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• 2011

Purpose of this study is examining closely special guard's Organizational Culture and job stress and relation of Organizational Commitment. This study established to special guards who is working at the capital region (Incheon) airport in 2011, and sample used finally on interpretation analyzed being 203 people, and uses Purposive Sampling Method. Analytical method executed Frequency Analysis, Factor Analysis, Reliability analysis, correlation analysis Multiple Regression Analysis using SPSSWIN ver.18.0. Reliability of questionnaire appeared Cronbach's ${\alpha}$ value more than .671. Conclusion proved in this study is as following. First, special guard's formation culture affects to Job Stress. In other words, stress about compensation career development increases if the development, hierarchically organized is not formed. On the other hand, job special quality, human relations stress decreases if developmental culture is form ed, and if culture is formed developmental, the mutual agreement, role stress decreases. Second, special guard's Organizational Culture affects in Organizational Commitment. That is, if is formed developmental and hierarchically organized, rises the Affective Commitment, Continuance Commitment, Normative Commitment. Third, special guard's job stress affects in Organizational Commitment. That is, if compensation career development is achieved unfairly Affective Commitment, Continuance Commitment is low. On the other hand, if own business is achieved spontaneously pre sent, Affective Commitment, Normative Commitment appears high.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.505-510
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• 2014

Kojongsi persimmon (Diospyros kaki L.) is the major cultivar of dried persimmon in Korea. The purpose of this study was to investigate the antioxidant and anti-inflammatory activities of water-soluble extracts from the calyx (PCE), peel (PPE) and leaf (PLE) of Kojongsi persimmon. PCE showed the highest total phenolic and flavonoid contents. In addition, the antioxidant activities (diphenylpicrylhydrazyl, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), nitric oxide and reducing power) of PCE were higher than those of PPE and PLE. Moreover, PCE, PPE and PLE significantly suppressed the production of inflammatory mediators (nitric oxide and $prostaglandinE_2$) and pro-inflammatory cytokines (tumor necrosis factor-${\alpha}$ and interluekin-$1{\beta}$) by lipopolysaccharide-stimulated RAW 264.7 cells in a dose-dependent manner. PCE showed the highest anti-inflammatory activity. Thus, these results suggest that the calyx of Kojongsi persimmon may be highly valuable as a natural product owing to its high-quality functional components as well as its-antioxidant, ant-iinflammatory activities.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.1
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• pp.59-68
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• 1999

Recently, research and developmental direction of communication system is concurrent adopting voice data and face image in speaking to provide more higher recognition rate then in the case of only voice data. Therefore, we present a method of lipreading in speech image sequence by using the 3-D facial shape model. The method use a feature information of the face image such as the opening-level of lip, the movement of jaw, and the projection height of lip. At first, we adjust the 3-D face model to speeching face image sequence. Then, to get a feature information we compute variance quantity from adjusted 3-D shape model of image sequence and use the variance quality of the adjusted 3-D model as recognition parameters. We use the intensity inclination values which obtaining from the variance in 3-D feature points as the separation of recognition units from the sequential image. After then, we use discrete HMM algorithm at recognition process, depending on multiple observation sequence which considers the variance of 3-D feature point fully. As a result of recognition experiment with the 8 Korean vowels and 2 Korean consonants, we have about 80% of recognition rate for the plosives and vowels. We propose that usability with visual distinguishing factor that using feature vector because as a result of recognition experiment for recognition parameter with the 10 korean vowels, obtaining high recognition rate.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.362-369
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• 2013

Phytoplankton and zooplankton communities were investigated from 8 weir sites of the Nakdong River system to provide basic information on plankton community after weir construction and to estimate its effects on major water quality parameters. The relationship between plankton community structure and environmental factors was analysed with CCA (Canonical Correspondence Analysis). The results suggested that discharge and total phosphorus and nitrogen concentrations are important factors determining the phytoplankton species composition. For zooplankton community, the difference in discharge between September and October induced different distribution pattern of zooplankton community with more homogeneous distribution with extreme dominance of rotifers during the high discharge season. Chlorophyll a concentration representing phytoplankton biomass has been suggested as the main environmental factor affecting zooplankton community followed by COD and total nitrogen concentration.