• The Journal of Korean Academy of Prosthodontics
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• v.54 no.2
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• pp.103-109
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• 2016

Purpose: This study is to evaluate the clinical significance of implantation with simultaneous bone graft by comparing the marginal bone loss around maxillary anterior implants with or without bone graft. Materials and methods: Patients treated with implant-retained restorations on maxillary anterior region at Implant Center, Dental Hospital, Wonkwang University between June 2011 and May 2014 were included in this study. Date of implant placement, implant diameter, implant length, implant-abutment connection type and whether the bone graft was done were investigated. The patient's periapical radiographs taken immediately after implantation and at the most recent visit were compared. Marginal bone loss was measured using Emago advanced v5.6 program (Oral diagnostic systems, Amsterdam, Netherlands). Statistical analysis was done in independent t-test by using SPSS 22.0 program. Results: As a result of observing on 83 implants (without bone graft: 44, with bone graft: 39) of 52 patients for 6 - 45 months (average: 18.4 months), implants without bone graft showed $1.42{\pm}0.42mm$, implants with bone graft showed $1.28{\pm}0.45mm$ of marginal bone loss. Conclusion: In limitations of this study, implants with simultaneous bone graft had significantly less marginal bone loss than implants without bone graft.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.4
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• pp.24-35
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• 2006

The vascular plants of the studied area was listed 384 taxa of 90 families, 234 genera, 331 species, 1 subspecies, 45 varieties and 7 forms. The flora of each reservoir, 285 taxa of 83 families, 190 genera, 247 species, 1 subspecies, 30 varieties, 7 forms in Osongjae, 117 taxa of 39 families, 87 genera, 100 species, 17 varieties in Ogongjae, 83 taxa of 30 families, 67 genera, 73 species, 8 varieties, 2 forms in Shinyongjae and 86 taxa of 33families, 70 genera, 75 species, 1 subspecies, 10 varieties in Eodujae. Based on the list of the rare plants by the Forest Research Institute, 3 taxa were recorded in the studied areas; Magnolia kobus (Preservation priority order : No. 187), Penthorum chinense (No. 144), Prunus yedoensis (No. 110) and based on the list of Korean endemic plants, 4 taxa were recorded; Populus tomentiglandulosa, Clematis trichotoma, Prunus yedoensis, Paulownia coreana. Specific plant species by floral region were total 15 taxa; Prunus yedoensis in class V, 2 taxa (Carex idzuroei, Magnolia kobus) in class IV, 2 taxa (Monochoria korsakowi, Poncirus trifoliata ) in class III, 10 taxa (Sagittaria aginashi, Salix glandulosa, Clematis brachyura, Nymphoides peltata, etc.) in class I. The naturalized plants in this site were 13 families, 29 genera, 43 species, 1 varieties, 44 taxa and naturalization rate was 11.5% and based on the list of an ecosystem disturbance plants, 3 taxa were recorded in the studied areas : Paspalum distichum, Solanum carolinense, Ambrosia artemisiifolia var. elatior. The hydrophytes was listed 31 taxa of 15 families, 20 genera, 29 species, 2 varieties and Eleocharis mamillata var. cyclocarpa, Penthorum chinense, Soirodela polyrhiza were recorded in Osongjae, Sagittaria aginashi, Eleocharis kuroguwai, Scirpus juncoides, Scirpus triqueter, Monochoria korsakowi, Monochoria vaginalis var. plantaginea were recorded in Ogongjae. Besides, Scirpus fluviatilis, Trapa pseudoincisa were recorded in Shinyongjae and Scirpus triangulatus, Nymphoides peltata, Myriophyllum verticillatum were recorded in Eodujae. This site is located in the urban area and ecosystem-disturbing wild animal and plant has been imported here, therefore ecosystem has been disturbed more and more. The wetland here rapidly has changed into upland, so it needs conservation measures through long-term monitoring.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.1
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• pp.1-13
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• 2012

Short implants are used in parts which have anatomical structures like maxillary sinus, inferior alveolar nerve and limited alveolar height due to severe alveolar bone resorption. In these case, there are no need of additional bone augmentation so there are advantages like reduced entire treatment time, reduced patient's discomfort and protection of important anatomical structures. The aim of this study is, in implants whose length is less than 10mm, to analyze the impact of implant length, diameter, location of implant placement, presence of bone graft, presence of prosthesis splinting on survival rates and marginal bone resorption. The samples used in this study were 227 implants, less than 10mm, placed in 137 patients in Wonkwang university dental hospital implant center. From dental charts the information about implant length, diameter, location of implant placement, presence of bone graft, presence of prosthesis splinting were obtained. Emago advanced v5.6(Oral diagnostic systems, Amsterdam, The Netherlands)program was used to measure the amount of marginal bone resorption. Out of total 227 implants, resulting in 96.5 % of survival rate. There was a tendency toward higher failure rates for the maxilla and bone graft site. No significant difference in marginal bone resorption was found associated with length of implants(p>0.05) and neither with the diameter of implants. Among the risk factors examined, more failure rates of short implants can be attributed to poor bone quality in the maxilla and presence of bone graft. At implants under 10mm, length, diameter, location of implant placement, bone graft and splinting of prosthesis didn't affect marginal bone loss.

• Journal of Periodontal and Implant Science
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• v.35 no.4
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• pp.961-974
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• 2005

Various biological approaches to the promotion of periodontal regeneration have been used. These can be divided into the use of growth and differentiation factors, application of extracellular matrix proteins and attachment factors and use of mediators of bone metabolism. The purpose of this study was to evaluate the effect of enamel matrix protein and platelet-rich plasma on the treatment of intrabony defect, with bovine-derived bone powder in humans by digital subtraction radiography. 12 teeth(experimental I group) were treated with enamel matrix protein combined with bovine-derived bone powder and 12 teeth(experimental II group) were treated with platelet-rich plasma combined with bovine-derived bone powder. The change of bone density was assessed by digital subtraction radiography in this study. The change of mineral content was assessed in the method that two radiography were put into computer program to be overlapped and the previous image was subtracted by the later one. Both groups were statistically analyzed by Wilcoxon signed Ranks Test and Mann-whitney Test using SPSS program for windows(5% significance level). The results were as follows: 1. The radiolucency in 3 months after surgery was significantly increased than 1 month after surgery in both groups(experimental I and II groups)(p<0.05). 2. The radiopacity in 6 months after surgery was significantly increased than 3 months after surgery in both groups(experimental I and II groups) (p<0.05). 3. In experimental I group, there was no significant difference between 1 month and 6 months after surgery. 4. In experimental II group. the radiopacity in 6 months after surgery was significantly increased than 1 month after surgery(p<0.05). 5. There was no significant difference between experimental I and II group at 1 month and 3 months after surgery, but the radiopacity in experimental II group was significantly increased at 6 months after surgery(p<0.05). In conclusion, platelet-rich plasma can enhance bone density than enamel matrix protein until 6 months after surgery.

• Korean Business Review
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• v.13
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• pp.159-178
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• 2000

Tax assistance system in Korea is a one that is designed by the central government to achieve specific policy objectives through the tax relief for economic activities or specific industries, leading to the development of the industries, Thus, the purpose of this study is to see if the government's direct tax assistance system for small and medium manufacturing firms is effective and then to contribute to establishing necessary policies for an effective tax assistance system based on the identification of a direct assistance system that is substantially useful to those firms. T- test was performed to see if there was a difference in tax burden between small and medium manufacturing firms and small and medium non-manufacturing firms and also to see whether the direct assistance system was effective. The results obtained from the statistical analyses are as follows: (1) The tax reduction rule applied to small and medium firms was turned out to be effective based on the fact that the effective tax rates of the small and medium firms to which the rule was applied were, on the average, significantly lower than those of the Listing large corporation which did not receive the tax benefit and also on the fact that the tax savings rates of the small and medium firms which could apply the rule were, on the average, significantly higher than those of the Listing large corporation to which the rule was not applied. (2) The tax credit rule applied to small and medium manufacturing firms was also turned out effective based on the same fact as described in the case of the application of the tax reduction rule.

• Journal of agricultural medicine and community health
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• v.31 no.3
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• pp.219-236
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• 2006

Objectives: To develop a model of a official management system for agricultural disease, injury and accidents, We analyzed current Korean status and management system about occupational injury and accident of farmers. Methods: For national management systems of industry safety and health and current status of occupational injuries and accidents of farmers, related literature such as books, theses, articles, and web documents were collected and analyzed. Results and Conclusion: The regulations of protecting occupational injury and accidents of farmers are suggested as follows: (1)insurance and compensation act for occupational injury and accident of farmers, (2)setting standards of occupational injuries and accidents of farmers, (3)mandating the usage of safety devices for agricultural vehicles and equipments, (4)reporting occupational injuries and accidents that occur among farmers, (5)registering pesticides and assessing safety usage, (6)implementing safety training, (7)supporting personal protective equipments and agricultural safe facilities etc.

• Korean Journal of Construction Engineering and Management
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• v.16 no.6
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• pp.112-123
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• 2015

Many disputes are happened with various causes in overseas construction projects. One of major disputes is closely related with nominated subcontractors (NSC). This paper investigates 30 judical precedents for Singapore, Malaysia and Hongkong to analyze the detailed disputes related with the NSC, and then the judical precedents are classified into 6 categories: Delay and Defect Trouble (T1), Contract Relation (T2), Payment Trouble (T3), Set-off (T4), Liquidation (T5) and so forth (T6). According to the analytical results, the frequency of occurrence of disputes is considerably related with social and economical changes, and the dispute between NSC and employer for residential and commercial building projects is the most frequently happened case. As the results of analysis, therefore, it is concluded that the employer needs to response aggressively to the problems related with NSC, and it is also important to make the council for communication among related bodies. Furthermore, the institutional reform that make the role and the responsibility of employer consistent under considering contract terms and conditions is considered as the most important and fundamental issue.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.219-224
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• 2007

As use of construction equipment has been increasing continuingly, the proportion of equipment expense to the total construction cost has become higher. However, there is a difference between the equipment expenses section in 'Poom-Sam' and practical data, because 'Poom-sam' does not consider non-working days due to weather conditions, legal holidays and management conditions. Therefore, 'Poom-Sam' does not present a reasonable standard for estimating construction equipment expenses. In this study, to estimate realistic construction equipment operating hours, firstly, construction equipment was classified according to work, and weather conditions, in which each work could not be executed, were established. Then, weather data on Seoul and Busan(2004${\sim}$2006) and legal holidays were analyzed to suggest annual standard operating hours. The annual standard operating hours of earthmoving & excavating, compaction, and drilling equipment was estimated to be 1,430 hours, and lifting equipment, concrete paving equipment, asphalt paving equipment, concrete equipment, and crushing & conveying equipment were estimated to be 2,124 hours, l,156hours, 1,188hours, 1,688hours, and 2,152hours respectively.

• Korean Security Journal
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• no.16
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• pp.265-282
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• 2008

This research aims to provide a solution for the improvement of private security according to the change in criminal environment. The main cause of crime can be found in the anti-functional dimensions including value set disorder, social phenomenon variation, information-based, globalization and urbanization. In this environment, the private security sector has dramatically increased in a quantitative viewpoint, but it is insufficient in a qualitative viewpoint. This paper recognized this problem and demonstrates a solution for improvement through classifying elements of private security into relevant legislation, education institutions, security companies and security associations. The analysis result is a follows: First, motivation and satisfaction rate of escort and security related major has shown to be high. However, respondents evaluated the guard educational institution negatively. Second, the motivation of entering into the private security sector for internal staffs has shown to be positive and sound. However, the job satisfaction rate has shown to be low due to excessive competition, negative perception of occupation and low earning. Third, respondents gave an average mark to the Security Association's management and operation. In addition, the mutual-aid project received the same mark. Negative feedbacks were given to the protection of member's interest and to association operation and policy, while positive feedbacks were given to the degree of member's cooperation towards association policies.

• Korean Journal of Heritage: History & Science
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• v.52 no.1
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• pp.148-169
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• 2019

The purpose of this paper is to understand characteristics and trends of calligraphy styles through the analysis of handwriting. Renowned Calligraphy of Korea (海東名迹, Haedong Myeongjeok) is the first collection of famous Korean calligraphers' masterpieces and was published by Shin Gongje (申公濟, 1469-1536) in the early sixteenth century. While my previous studies have focused on analyzing the publishing backgrounds of and differences among the wood block editions and stone-carved editions of the various remaining copies of Renowned Calligraphy of Korea, this study examines the calligraphy style in the early Joseon period as represented within the collection itself. This study tries to identify the aspects of style transitions among two categories of calligraphy: (1) the calligraphy style of scribes who were in charge of documentation in the central administrative institutions (館閣) and (2) the calligraphy style passed down among the Goryeong Shin clan (高靈申氏). This study verifies that various styles which emerged based on the influence of the revivalism of the late Yuan dynasty gained acceptance in the early Joseon period while the traditional Wang Xizhi style was still in use. The most notable revelation of this study is that the calligraphy style of Kangli Naonao (康里??), a Yuan dynasty calligrapher from a remote region to the west of China, appears to have become acceptable during this period. Indeed, various Yuan dynasty styles were flowing into Korea during the late Goryeo and the early Joseon period that stand in contrast to Zhao Mengfu's "pine-snow calligraphy style." Finally, the authenticity of the Eo Sukguan (魚叔權)'s record in A Storyteller's Miscellany (稗官雜記, Paegwanjapgi) is reviewed in this study. Eo claims that writing attributed to Park Gyeong in Renowned Calligraphy of Korea was actually Shin Jageon's. However, the analysis of the relationship between Shin and Park based on their backgrounds and their political positions suggests that Eo's claim is not valid.