• 건축사
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• 7호통권267호
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• pp.57-65
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• 1991

• 건축사
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• 2호통권262호
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• pp.47-55
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• 1991

• 건축사
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• 5호통권265호
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• pp.50-59
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• 1991

• 건축사
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• 1호통권261호
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• pp.60-67
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• 1991

• 대한치과보철학회지
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• 제36권2호
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• pp.258-272
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• 1998

This investigation evaluated patients who received Steri-Oss implants from the Dental Hospital of Chosun University during the period from March 1989 to August 1997. 346 fixtures of 127 patients were included in this study. The results were as follows ; 1.The follow-up period was defined as the period between the surgical placement of the implants and the last follow-up examination. The mean follow-up period was $2.17{\pm}1.21$ years. 2.The period between fixture installation and second surgery was $0.71{\pm}0.44$ years in the maxilla and $0.46{\pm}0.21$ years in the mandible. 3.The number of fixtures which were installed in the upper jaw(112) was less than that in the lower jaw(234) and in the posterior region(260) was more than in the anterior region(86). 4.The length of fixture which was most frequently used was 12 mm and least was 8mm. Screw implants were installed more than cylindrical implants. 3.8mm implant was the most common implans, followed by 4.5mm and 3.25mm. 5.The number of augmentation cases was more than that of non-augmentation cases and the rate of augmentation cases in the maxilla was more than that in the mandible. 6.Implant restorations for partial edentulos patients(94cases) were more than single- tooth implant restorations(33cases) or implant restorations for complete edentulos patients(10cases). 7.Free-standing prostheses for partially edentulous patients were more commom than any other type of connection between implants and natural teeth. 8.Plaque Index($0.95{\pm}0.74$) and Gingival Index($0.31{\pm}0.52$) were very similar around the natural teeth and reflected an acceptable level of plaque and gingivitis control. Mean value for keratinized mucosa index($1.93{\pm}1.20$) remained fairly constant around level 2(1-2 mm keratinized epithelium). 9.Patients were generally satisfied with implant in terms of comfort, function, speech and esthetics. 10.There was not a statistically significant differences in overall survial rate between implants placed in the maxilla (91.5%) and those placed in the mandible (93.8%). Fourteen implants lost before the prosthetic rehabilitation and eleven implants lost following variable periods in function after the prosthetic phase of the treatment. 11.Cause of implant failures was exfoliation or removal of fixture due to non-osseointegration before the prosthetic rehabilitation or due to fracture of fixture, masticatory pain after the prosthetic rehabilitation. 12.The survival rate of Steri-Oss implants using the Kaplan-Meier statistical analysis was 93.8% at 2 year and 86.6% at 5 year, In all cases, implant losses occured predominantly in the healing period. There was a steep decline in the rate of implant loss after the first year. 13.The survival rate of Steri-Oss implants in the anterior region was 94.8% at 2 year and 94.8% at 5 year and that in the posterior region was 92.8% at 2 year and 75.9% at 5 year. In conclusion, this study revealed a number of parameters and guidelines for achieving an optimal success rate in osseointegration.

• 한국철도학회논문집
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• 제20권3호
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• pp.423-431
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• 2017

본 연구는 일제강점기 조선철도 관료의 이력과 경력을 중심으로 철도국 주요관료의 학력과 경력 및 퇴직 후 활동을 분석하였다. 주요 특징으로는 첫째, 조선철도 관료들은 철도에 관한 전문성이 높고 폐쇄적 조직에서 장기간 근무하였으며 관료 대부분이 일본인이었다. 둘째, 조선철도를 일본 본토와 달리 자신들의 생각대로 운영하고자 하는 의지가 비교적 강했다. 조선철도국의 철도운영의 만철(남만주철도주식회사) 위탁 반대, "조선철도 12년 계획"수립, 자체적인 종업원 양성제도가 활성화된 것도 이와 같은 맥락에서 설명이 가능하다. 셋째, 철도관료의 학력은 도쿄제국대학 출신이 약 60%를 차지하고 있는데 이는 조선총독부 타 조직과 거의 비슷한 분포이다. 넷째, 전문가의 비율이 타부서보다 높고 철도의 특성상 전문직 임용이 높았는데, 특히 초기 철도 건설시기가 이러한 현상이 두드러졌다. 다섯째, 철도관료의 출신분포를 보면 초기에는 일본 철도 작업국 출신이 많았지만 이후 만철, 조선철도국 출신이 점차 많아졌다. 이는 조선철도에 대한 관료의식을 변화시키는 계기로 작용했다. 여섯째, 기술 관료의 임용은 1910년 이전 충원이 많았으며 일본 철도 작업국출신, 경부철도주식회사를 통한 임용이 대부분으로 임용제도의 특성상 학력이나 인맥 등이 작용 가능성이 컸다.

• 대한가정학회지
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• 제34권2호
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• pp.355-365
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• 1996

This is a study of divorce cases under new family law in Korea specifically during the period of May 1991 to November 1995. This study comprises 33 cases that appeared on two daily newspapers, Chosun-ilbo and Kookmin-ilbo during that period. This study contains the analysis on the rights of Korean women at the time of divorce.

• Journal of Korean Dental Science
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• 제3권1호
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• pp.25-31
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• 2010

This study sought to evaluate the effect of the type of grafts used in sinus lifting. A review of literature through MEDLINE search covering the period 1980 ~ 2006 was performed. After screening, this study was narrowed down to 2,452 patients receiving sinus lift grafts wherein 7,151 implants were placed. In this study, the types of grafts used in sinus augmentation were autogenous bone, allogenic bone, corticocancellous block bone, and various alloplastic materials. The success rate varied from 69% to 100% depending on the graft material type. The highest success rate was reported for the autogenous bone, with high success rates recorded for the most part in most studies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권2호
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• pp.406-423
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• 2014

The recent advances in wireless communication systems and semiconductor technologies are paving the way for new applications over wireless sensor networks. Health-monitoring application (HMA) is one such emerging technology that is focused on sensing and reporting human vital signs through the communication network comprising sensor devices in the vicinity of the human body. The sensed vital signs can be divided into two categories based on the importance and the frequency of occurrence: occasional emergency signs and regular normal signs. The occasional emergency signs are critical, so they have to be delivered by the specified deadlines, whereas the regular normal signs are non-critical and are only required to be delivered with best effort. Handling the occasional emergency sign is one of the most important attributes in HMA because a human life may depend on correct handling of the situation. That is why the underlying network protocol suite for HMA should ensure that the emergency signs will be reported in a timely manner. However, HMA based on IEEE 802.15.4 might not be able to do so owing to the lack of an appropriate emergency-handling mechanism. Hence, in this paper, we propose a new emergency-handling mechanism to reduce the emergency reporting delay in IEEE 802.15.4 through the modified superframe structure. A fraction of an inactive period is modified into three new periods called the emergency reporting period, emergency beacon period, and emergency transmission period, which are used opportunistically only for immediate emergency reporting and reliable data transmission. Extensive simulation is performed to evaluate the performance of the proposed scheme. The results reveal that the proposed scheme achieves improved latency and higher emergency packets delivery ratio compared with the conventional IEEE 802.15.4 MAC.

• Journal of Periodontal and Implant Science
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• 제37권3호
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• pp.543-551
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• 2007

When clinicians faced with an insufficient volume of supporting bone on ideally esthetic and bio-mechanical position for dental implantation, guided bone regeneration(GBR) was indicated. Although GBR has wide application at clinic, proper time of membrane removal remains qustionable in using non-resorbable membrane, such as non-expanded polytetrafluoroethylene(PTFE), The aim of this study was to compare the effect of maintenance period of PTFE membrane on bone regeneration in rabbit calvarial defects. Eight adult New Zealand white female rabbits were used in this study. Four defects were surgically made in their calvaria. Using a trephine bur, 4 'through and through' defects were created and classified into 3 groups, which were consisted of control group(no graft), experimental group 1(autogenous bone)and experimental group 2(deproteinized bovine bone; $OCS-B^{(R)}$). The defects were covered with PTFE membrane($Cytoplast^{(R)}$). Membranes were removed after 1, 2, 4 and 8 weeks post-GBR procedure in 2 rabbits repectively, All rabbits were sacrificed after 8 week post-GBR procedure. Specimens were harvested and observed histologically. The results were as follow; 1) The use of graft material and membrane was necessary in GBR procedure. 2) When PTFE membranes were removed early, the most favorable bone regeneration was revealed in experimental group T, followed by experimental group II and control group. 3) On GBR, it is recommended that membrane should maintain for 4 weeks with autogenous graft. As well, the use of xenograft need longer maintenance period than autogenous bone. Further evaluations will be needed, such as histomorphologic research, more species and different kinds of graft materials. And on the basis of these studies, clinical researches would be required.