• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권6호
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• pp.485-493
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• 2007

Introduction: Although several types of calcium-phosphate coumpound have been frequently applied to osseous defects at maxillofacial area for many years, there is a controversy about its efficiency on bone conductivity comprared to xenograft bone substitute. Alloplastic carbonapatite has been introduced to improve disadvantages of hydroxyapatite and to mimic natural bone containing carbon elements. However, a preclinical study about its efficiency of osteoconductivity has not been reported. This study was performed to evaluate the early osteoconductive potential of synthetic carbonapatite with multiple pores relative to anorganic bovine xenograft. Materials and methods: Total 5 beagle dogs were used for maxillary augmentation model. The control (anorganic bovine xenograft) and experimental groups (synthetic carbonapatite) were randomly distributed in the mouth split design. After bone graft, all animals were sacrificed 4 weeks after surgery. Histological specimens with Masson Trichrome staining were made and histomorphometrically analysed with image analyser. The statistical analysis was performed using paired t-test. Results: In both groups, all animals had no complications. The experimental group showed relatively much new bone formation around and along the bone substitutes, whereas it was clearly reduced in the control group. The ratios of new bone area to total area, to material area and to the residual area excluding materials were higher in the experimental group ($0.13{\pm}0.03,\;0.40{\pm}0.13,\;0.20{\pm}0.06$ respectively) than in the control group ($0.01{\pm}0.01,\;0.03{\pm}0.02,\;0.03{\pm}0.03$, respectively). And the differences between both groups were statistically significant (p<0.001, <0.01, <0.01, respectively), while the ratio of material area to total area in two groups was not significant. Conclusion: Carbonapatite showed a high osteoconductivity in the early stage of bone healing compared to bovine derived anorganic bone substitute. This study suggests that this bone materials can be applied as a reliable bone substitute in the clinical treatment.

• 대한치과보철학회지
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• 제52권2호
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• pp.105-112
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• 2014

연구 목적: 이 연구의 목적은 임플란트 식립 초기 수회의 의원성 동요가 최종 골결합에 미치는 영향을 확인하는 것이다. 연구 재료 및 방법: 순수한 티타늄(Grade IV) 으로 직경 3.75 mm, 길이 8 mm의 실험용 임플란트를 제작한 후, 하방 4 mm에 RBM 표면처리($MegaGen^{(R)}$: Ca-P)를 하였다. 임플란트의 하부만 골에 식립되었으며 비침하시켰다. 수술은 3.5 kg이상의 토끼의 좌우 경골의 단층 치밀골에 각각 2개씩 130개를 통상적인 방법으로 식립하였다(Female, New Zealand White). 비틀림 제거 간격에 따라, 다음과 같은 13개의 군으로 나누었다; Group I (1일), Group II (1일 + 2일), Group III (1일 + 2일 + 3일), Group IV (1일 + 2일 + 3일 + 4일), Group V (2일), Group VI (2일 + 4일), Group VII (2일 + 4일 + 6일), Group VIII (2일 + 4일 + 6일 + 8일), Group IX (4일), Group X (4일 + 7일), Group XI (4일 + 7일 + 10일), Group XII (4일 + 7일 + 10일 + 14일), 그리고 대조군. 대조군은 식립 후 8주의 치유기간을 준 후 최종 비틀림 제거력을 측정하였다(Mark-10, USA). 실험군은 각각의 조건에 맞추어 1회에서 4회에 걸쳐 비틀림 제거력을 측정하였다. 비틀림 제거력을 측정한 이후에 대체적으로 임플란트를 측정 전의 위치로 재위치시켰다. 모든 실험군에서 임플란트 식립 후 8주간의 치유기간을 준 다음 최종 비틀림 제거력을 측정하여 대조군, 각 실험군의 1, 2, 3, 4번째 비틀림 제거력과 비교하였다. 결과: 실험군 간에 최종 비틀림 제거력을 비교한 결과에서, XII군을 제외한 실험군의 비틀림 제거력은 대조군과 유의할만한 차이를 보이지는 않았다. 그리고 실험 I군과 II군의 값은 VI, VIII, X, XI, XII군의 값보다 유의하게 높게 나타났다. 그리고 III, IV, V군은 XI, XII군의 값보다 유의하게 높게 나타났다. 각 실험군간 비틀림 제거력 비교에서, 최종 비틀림 제거력은 VIII, X, XI, XII군을 제외한 모든 군에서 높게 나타났다. 결론: 충분한 치유기간이 주어진다면, 토끼에게 임플란트 식립 후 매우 이른 초기에 지대주에 가해지는 약간의 동요는 임플란트 골결합에 영향을 미치지 않았다.

• 대한간호학회지
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• 제19권1호
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• pp.63-80
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• 1989

This study was undertaken at Yonsei University Medical Center to identify the crisis responses and nursing problems of patients who had been diagnosed with cancer, and changing patterns of grieving over time periods, and to analyse the effectiveness of follow up care through home visiting nursing. This study was carried out in three stages. The 1st study data were collected from a total of 205 patients who had been diagnosed with cancer from Sept.1 to Dec. 31, 1987 using a cross-sectional method. The 2nd study data were collected three times from 30 patients with cancer at 4 weeks intervals from March 1 to June 31, 1988 using a longitudinal method. The 3rd study data were collected from two different groups from March 1 to June 31, 1988. One was an experimental group who was visited by nurses and the other one was a control group not visited by nurses. The subjects of the 3rd study consisted of 60 patients with cancer and a Quasi-experimental research design was used. The results were as follows ; 1. The patients did not experience one stage at a time among the five stages of grieing, denial anger, bargaining, depression and acceptance, as identified by Kubler Ross. They experienced a combination of stages, especially of the bargaining and the depression stages. This stages did not change with the passing of time. 2. The patients expressed more physical and socioecounomical problems than emotional problems. And they used more problem coping methods than emotional coping methods. 3. Follow up care through home visiting nursing positively influenced the patient's quality of life, especially their physical well-being and symptom control The patients responded positively to the home visiting nursing, stating that it was helpful In them. It was concluded that the development of a home visiting nursing program is needed for the effective home care of patients with cancer.

• 대한간호학회지
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• 제36권3호
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• pp.514-522
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• 2006

Purpose: The purpose of this study was to identify effects of a tilting training program on lower extremities function, depression, and self-efficacy among stroke inpatients. Method: The subjects were 60'stroke patients hospitalized in an oriental medical hospital; 31 in the experimental group and 29 in the control group. A nonequivalent control group pretest-posttest design was used. The tilting training program consisted of 3 sessions and was implemented for 30 minutes daily during 3 weeks. Data was collected from Feb to July 2003, and analyzed by percentage, Fisher's exact probability, $\chi^2-test$, and t-test using the SPSS/Win 10.0 computerized program. Result: After treatment with the tilting training program, the experimental group was significantly increased in the mean score for function of lower extremities (t=2.72, p=.009) compared to the control group, especially for keeping standing balance (t=2.78, p=.007) and standing by oneself (t=3.32, p=.002). However, in the mean scores of depression and self-efficacy, there were no significant differences between the two groups. Conclusion: The tilting training program was effective for increasing the function of lower extremities and to improve walking ability earlier among stroke inpatients. Therefore, the tilting training program is applicable to increase the balance level in standing and walking ability at the early rehabilitation stage for stroke patients.

• 한국음향학회지
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• 제35권3호
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• pp.183-191
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• 2016

자동차의 저소음 보기류 구동 시스템을 개발하는 체계적인 방법론이 전산해석과 리그 실험을 통해 제시되었다. 벨트 구동 소음 예측의 두 가지 난제는 1) 벨트와 풀리 접촉면에서의 스틱-슬립 비선형성과 2) 벨트 구동 시스템과 파워트레인 회전진동계와의 연성이다. 본 연구에서는 최근 개발된 해석 방법을 이용하여 벨트 구동시스템과 엔진 회전진동계를 통합한 해석 모델을 구축하였고, 다양한 파워트레인 운전 조건에서 정합성을 확보하였다. 통합 모델을 이용하여 스틱-슬립 소음이 발생하는 벨트 시스템을 개선할 수 있음을 확인하였다. 또한 새로운 방법론을 통해 신엔진 개념설계에서 NVH (Noise, Vibration and Harshness), 기능, 연비 등을 고려한 개념 설계안을 제시하였다.

• Geomechanics and Engineering
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• 제10권6호
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• pp.737-755
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• 2016

The load transfer depth of a ground anchor is the minimum length required to transfer the initial prestressing to the grout column through the bonded part. A thorough understanding of the mechanism of load transfer as well as accurate prediction of the load transfer depth are essential for designing an anchorage that has an adequate factor of safety and satisfies implicit economic criteria. In the current research, experimental and numerical studies were conducted to investigate the load transfer mechanism of ground anchors based on a series of laboratory and field load tests. Optical FBG sensors embedded in the central king cable of a seven-wire strand were successfully employed to monitor the changes in tensile force and its distribution along the tendons. Moreover, results from laboratory and in-situ pullout tests were compared with those from equivalent case studies simulated using the finite difference method in the FLAC 3D program. All the results obtained from the two proposed methods were remarkably consistent with respect to the load increments. They were similar not only in trend but also in magnitude and showed more consistency at higher pullout loading stages, especially the final loading stage. Furthermore, the estimated load transfer depth demonstrated a pronounced dependency on the surrounding ground condition, being shorter in hard ground conditions and longer in weaker ones. Finally, considering the safety factor and cost-effective design, the required bonded length of a ground anchor was formulated in terms of the load transfer depth.

• 예술인문사회 융합 멀티미디어 논문지
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• 제8권11호
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• pp.523-530
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• 2018

전력 변환 시스템의 고효율, 고전력 밀도를 위한 많은 연구가 활발하게 되어 왔다. 스위칭 주파수를 높임으로써 컨버터의 소형화 및 경량화를 꾀할 수 있으나 스위칭 주파수를 높이게 되면 스위칭 손실이 증가하게 된다. 따라서 스위칭 손실을 저감하기 위한 기법이 적용되어야 한다. 본 연구에서는 이 중 부가적인 회로 없이 변압기의 누설 인덕턴스와 스위치의 출력 커패시터를 이용하여 영전압 스위칭이 가능한 영전압 스위칭(Zero-Voltage Switching) 위상천이(Phase Shift) 풀 브리지 컨버터를 이용하여, 영전압 위상천이 풀 브리지 컨버터의 동작원리를 해석하고 2kW의 출력을 갖는 영전압 스위칭 풀 브리지 컨버터를 설계한다. 각 모드별 동작을 스위치 도통 상태와 전압 전류 파형으로 분석하였다. 분석 결과, 영전압 스위칭이 도통 스위치들의 각 쌍 사이의 위상 변화에 의해 최대 효율을 달성하는 것을 확인하였다. 제안된 영전압 위상천이 풀 브리지 컨버터 설계를 검증하기 위해 컴퓨터 시뮬레이션 툴인 PowerSIM사의 PSIM을 이용하여 설계된 2kW 출력 전력을 갖는 영전압 스위칭 위상천이 풀 브리지 컨버터의 성능을 확인하였고, 실험을 통해 연구의 타당성을 입증하였다.

• 한국주거학회논문집
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• 제19권5호
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• pp.93-102
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• 2008

In Korea, a movement for forming intentional communities is gathering people's interests to improve individualistic living environment, and to create a humanistic lifestyle. However, it is difficult to say if its management is successful or not, because intentional community is just in the experimental stage in Korea. The purpose of this study is to identify actual condition of residents' participation in forming process, shared activities in their daily lives, residents' regulation, common facilities and its management in order to offer basic information for revitalization of intentional communities in Korea. 7 intentional communities including eco-friendly villages, religious communities and a cooperative housing community were collected as the study objects. Upon analysis, those communities were divided into two groups according to their purpose of establishment; "HC (Housing-life focused Community includes cooperative housing community and eco-friendly community)" and "IC (Ideology focused Community includes ideology community and religious community)" in order to identify difference in residents' participation between the two groups. In-dept interviews with representatives of 7 intentional communities by a structured questionnaire were used as study method. The findings of this study are as follows; In general, more active residents' participation is identified in ICs than in HCs. There is no common house, which is considered as essential in intentional community, in HCs, while it was facilitated in all ICs. Role of leader seems more important in ICs than in HCs. About the ownership of housing and land, private owned is common in HCs, while community owned is common in ICs. Shared activities and residents' regulations are evidently less in most HCs than in ICs. Furthermore, in order to run a community sustainable, it is crucial to encourage sense of community among residents, and developing common house and activity programs. Common house design, which can promote proactive residents' participation in shared activity should be studied fitted to Korean circumstances. Above all, proactive participation in the shared activities is one of the most important factors in intentional community.

• 한국터널지하공간학회 논문집
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• 제13권3호
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• pp.243-260
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• 2011

성공적인 TBM의 적용을 위해 설계단계에서 TBM의 굴진성능을 사전에 예측하는 것이 매우 중요하다. 대표적인 TBM 굴진성능 예측모델 중의 하나인 NTNU 모델에서는 TBM의 시추코어를 활용한 세 가지 시험들로부터 얻어지는 DRI와 CLI에 근거히여 TBM의 굴진율과 디스크커터의 수명 예측이 가능하다. 본 연구에서는 NTNU모델의 기본 입력변수인 DRI와 CLI를 측정하는 NTNU 시험방법과 국내에서 구축된 NTNU 시험장비를 소개하고, 구축된 장비를 사요하여 측정된DRl와 CLI를 일축압축강도, 석영함유량 등익 암석 특성과 비교 분석하여 각각의 상관관계를 도출하였다. 마지막으로 NTNU의 시험 데이터베이스와의 비교를 통하여 국내에서 수행된 NTNU 시험결과의 신뢰성을 확인하였다.

• 한국초지조사료학회지
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• 제5권2호
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• pp.100-105
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• 1985

본(本) 시험(試驗)은 Tall fescue(Festuca arundinarea s. 의 Alta품종(品種)에 있어서 채종재배(採種栽培)를 위(爲)한 질소비료(窒素肥料)의 시비수준(施肥水準) 및 분시방법(分施方法)을 구명(究明)코자 3 시비수준(施肥水準)(120, 180, 240kg/ha)과 4 분시방법(分施方法)((1)봄 : 100%%, (2) 가을, 봄 : 각각 50%, (3)봄, 출수전 : 각각 50%, (4) 가을 : 50%, 봄, 출수전 : 각각 25%)으로 분할구(分割區) 4 반복(反覆)으로 포장(圃場) 배치(配置)하여 1979년(年) 9월(月)부터 1981년(年) 10월(月까)지 축산시험장(畜産試驗場)에서 실시(實施)되었다. 1. 톨 페스큐의 출수기(出穗期)는 5월(月) 21일(日), 개화기(開花期)는 이보다 10여일 늦은 6월(月) 1-3 일경(日頃)이었으며 종자(種子) 수확기(收穫期)는 개화성기(開花盛期) 22-23일(日) 후(後)인 6월(月) 25일경(日頃)이었다. 채종시(採種時)의 평균(平均) 초장(草長)은 127cm, 수장(穗長)은 2.72g였으며 $1m^2$당(當) 수수(穗數)는 85-107개(個)였다. 3. 누년(累年) 평균(平均) 종자수량(種子收量) 678.8kg/ha였으며 N-240kg/ha를 가을에 50%, 봄과 출수전(出穗前)에 각각(各各) 25% 시용(施用)한 것이 채종량(採種量) 781.9kg/ha로서 가장 많았다. 4. 채종(採種)된 종자(種子)의 평균(平均) 발아율(發芽率)은 87.0%였으며 분시방법(分施方法)이 다양(多樣)할수록 발아율(發芽率)이 높은 경향(傾向)이었다. 5. 채종후(採種後) 2회(回) 예취(刈取)한 재생목초(再生牧草)의 전체(全體) 평균(平均) 건물수량(乾物收量)은 6155kg/ha였고 질소시비량(窒素施肥量)이 많을수록 생산량(生産量)은 증가(增加)하였으며, 분시방법(分施方法)에 있어서는 봄에 전량시용(全量施用)한 것이 우수(優秀)하였다.