• 상하수도학회지
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• 제23권4호
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• pp.447-458
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• 2009

Energy loss at manholes, often exceeding friction loss of pipes under surcharged flow, is considered as one of the major causes of inundation in urban areas. Therefore, it is necessary to analyze head loss at manholes, especially in case of surcharged flow. Hydraulic experiments were conducted with three cases. Case A is to test whether the shapes of the manholes influence head loss coefficients. Case B and C were proposed to further reduce head losses by improving the manhole hydraulic efficiency. In case B, the joining part of the pipe at both shapes of manholes is shifted from central part to side part. The test in case C is to check the average head loss coefficient by installing the side benching in square manhole, based on shifted joining part model. The average head loss coefficient for circular and square manhole on case A was 1.6. This did not show much difference of the head loss coefficients in spite of the discharge variation in this case. However, case B and C show large difference between head loss coefficients due to the strong oscillation of water surface and the horizontal swirl motion. The circular and square manholes in case B reduced the head loss by 30% and 6% than ones in case A, respectively. The average head loss coefficient for circular manhole in case B was 1.1. Case C reduced average loss coefficients of the square manhole in case A from 1.6 to 1.1. Accordingly, the circular manhole in case B and the square manhole in case C showed the effective way to reduce the head loss. These head loss coefficients could be available to apply to the urban sewer system with surcharged flow.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.258-264
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• 2012

The overall aim of this paper is to determine coupling loss factor of welding point between shell and cylinder using loss factor and structural loss factor. For this purpose, two kinds of loss factor were adopted. One is loss factor of each sub structure, another is structural loss factor based on the complex welded or assembled structure. Using these two parameters, it is possible to derive the coupling loss factor which represents characteristic condition of SEA theory. Coupling loss factor of conjunction in complex structure was expressed as power balance equation. The derived equation for a coupling loss factor has been simplified on the assumption of one way (uni-directional) power flow between multi-sub structures. Using these conditions, it is possible to find the equation of coupling loss factor expressed as above two loss factors. To check the effectiveness of above equation, this paper used two-stage application. The first approach was application between simple cylinder and shell. The next was adopted rotary compressor. Rotary compressor has three main conjunctions between shell and internal vibration part. This equation was applied to find out the optimum welding point with respect to reduce the noise propagation. It shows the effective tool to evaluate the coupling loss factor in complex structure.

• Journal of Periodontal and Implant Science
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• 제45권3호
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• pp.82-93
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• 2015

Purpose: This retrospective study evaluated the relationship between the timing of peri-implantitis diagnosis and marginal bone level after a 5-year follow-up of non-surgical peri-implantitis treatment. Methods: Thirty-three patients (69 implants) were given peri-implantitis diagnosis in 2008-2009 in Seoul National University Bundang Hospital. Among them, 31 implants from 16 patients were included in this study. They were treated non-surgically in this hospital, and came for regular maintenance visits for at least 5 years after peri-implantitis treatment. Radiographic marginal bone levels at each interval were measured and statistical analysis was performed. Results: Timing of peri-implantitis was one of the significant factors affecting initial bone loss and total bone loss not additional bone after peri-implantitis diagnosis. Patients with cardiovascular disease and diabetic mellitus were positively influenced on both initial bone loss and total bone loss. Patients who needed periodontal treatment after implant placement showed a negative effect on bone loss compared to those who needed periodontal treatment before implant placement during entire periods. Implant location also significantly influenced on amounts of bone loss. Mandibular implants showed less bone loss than maxillary implants. Among surgical factors, combined use of autogenous and xenogenic bone graft materials showed a negative effect on bone loss compared to autogenous bone graft materials. Use of membrane negatively affected on initial bone loss but positively on additional bone loss and total bone loss. Thread exposure showed positive effects on initial bone loss and total bone loss. Conclusions: Early peri-implantitis diagnosis led to early non-surgical intervention for peri-implantitis treatment, which resulted in the maintenance of the bone level as well as preservation of the implant.

• 전기학회논문지
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• 제66권6호
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• pp.911-915
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• 2017

Recently, there has been an increasing interest in the non-contact power transmission method of magnetic gears. Since there is no mechanical contact, noise caused by friction can be reduced, and even if a sudden large force is applied, the impact of the gear is close to zero. Further, since the power is transmitted by the magnetic flux, it has high reliability. However, there is a problem that a loss due to a magnetic field due to use of a magnetic flux. The loss caused by the magnetic field of the magnetic gear is a joule loss called eddy current loss. In addition, the eddy current loss in the magnetic gear largely occurs in the permanent magnet, but it is a fatal loss to the permanent magnet which is vulnerable to heat. Particularly, magnetic gears requiring high torque density use NdFeB series permanent magnets, and this permanent magnets have a characteristic in which the magnetic force decreases as temperature increases. Therefore, in this paper, the eddy current loss of the permanent magnet according to the permanent magnet attaching method is analyzed in order to reduce the eddy current loss of the permanent magnet. We have proposed a structure that can reduce the eddy current loss through the analysis and show the effect of reducing the loss of the proposed structure.

• 한국심리학회지 : 문화 및 사회문제
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• 제13권2호
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• pp.17-32
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• 2007

상실이란 일반적으로 개인이 가장 의미 있다고 생각하는 물건, 사람, 소유 혹은 생각을 박탈 당하는 것으로 일생에 있어 불가피한 경험이며, 특히 고령자의 특성상 이와 같은 경험에 노출될 가능성이 높다. 상실로 인한 부정적 정서, 즉 상실감은 자연스럽고 정상적인 것이지만, 이를 원활히 극복하지 못하는 경우 심리·사회적인 부적응을 겪을 수 있다. 따라서 본 연구에서는 고령자의 상실감이 어떤 요소들로 구성이 되어있는지 알아보고, 이것이 고령자의 자아통합감에 어떤 영향을 미치는지 알아보고자 하였다. 만 65세 이상의 고령자 97명을 대상으로 자료를 수집하여 분석한 결과, 상실감의 요인은 '경제적 상실', '사별 상실', '건강 상실', '관계의 상실'로 구분되었으며 이들 요인들이 전체적으로 '죽음에 대한 수용'을 제외한 나머지 자아통합감의 요인들과 부적인 상관을 보였다. 특히 '경제적 상실'로 인한 상실감은 '죽음에 대한 수용'과 '노령에 대한 수용'을 제외한 나머지 자아통합감 하위요인들에 부적인 영향을 미치고 있었으며, '건강 상실'과 '관계의 상실'도 각각 '노령에 대한 수용' 및 과거부터 현재까지를 포함하는 생에 대한 태도 및 만족도에 부적인 영향을 미치는 것으로 나타났다. 한편, 고령자 상실감 척도의 '사별 상실' 요인과 자아통합감의 '죽음에 대한 수용' 요인은 모든 분석단계에서 통계적으로 유의한 결과를 보이지 않았다.

• 한국심리학회지 : 문화 및 사회문제
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• 제13권2호
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• pp.1-15
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• 2007

본 연구는 고령자들이 경험하는 상실감이 주관적 안녕감에 어떠한 영향을 미치는 살펴보고자 하였다. 이를 위해서 만 65세 이상 고령자 총 100명을 대상으로 자료를 수집하여 분석한 결과, 고령자 상실감 요인인 '건강 상실', '관계의 상실', '경제적 상실', '사별 상실'은 '생활 만족도'와는 부적인 상관을 나타냈으며, '정적 정서'와는 '사별 상실'을 제외한 세 요인들이 부적인 상관을 나타냈다. 그리고 '부정 정서'와는 '경제적 상실'을 제외한 나머지 세 요인들과는 정적인 상관을 가지고 있었다. 그리고 경로분석을 통해 상실감 하위요인들이 주관적 안녕감에 이르는 과정을 살펴보았다. 그 결과, '건강 상실'요인은 주관적 안녕감의 '정적 정서'와 '부적 정서'에 영향을 미치는 요인으로 나타났다. 그리고 '관계의 상실'요인은 '생활 만족도'와 '정적 정서'에 유의한 영향을 미치는 것으로 나타났다. 한편 '경제적 상실'과 '사별 상실'요인은 주관적 안녕감에 미치는 유의한 영향력이 없는 것으로 나타났다. 이것은 고령자들의 건강문제와 가족관계에서는 정서적 지원이 중요하고, 특히. 고령자의 건강문제와 가족관계에서 가족의 지원이 중요함을 시사한다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.1943-1948
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• 2014

Purpose: The prevalence of weight loss in esophageal carcinoma patients is high and associated with impairment of physical function, increased psychological distress and low quality of life. It is not known which factors may contribute to weight loss in patients with esophageal carcinoma during radiotherapy in China. The objective of this study was to identify the associated demographic and clinical factors influencing weight loss. Methods: We evaluated 159 esophageal carcinoma patients between August 2010 and August 2013 in a crosssectional, descriptive study. Patient characteristics, tumor and treatment details, psychological status, adverse effects, and dietary intake were evaluated at baseline and during radiotherapy. A multivariate logistic regression analyss was performed to identify the potential factors leading to weight loss. Results: 64 (40.3%) patients had weight loss ${\geq}5%$ during radiotherapy. According to logistic regression analysis, depression, esophagitis, and loss of appetite were adverse factors linked to weight loss. Dietary counseling, early stage disease and total energy intake ${\geq}1441.3$ (kcal/d) were protective factors. Conclusions It was found that dietary counseling, TNM stage, total energy intake, depression, esophagitis, and loss of appetite were the most important factors for weight loss. The results underline the importance of maintaining energy intake and providing dietary advice in EC patients during RT. At the same time, by identifying associated factors, medical staff can provide appropriate medical care to reduce weight loss. Further studies should determine the effect of these factors on weight loss and propose a predictive model.

• 대한물리의학회지
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• 제15권3호
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• pp.61-68
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• 2020

PURPOSE: The purpose of this study was to investigate the current state of rapid weight loss and physical and mental complaints among elite combat athletes who were selected and trained as national representatives. METHODS: A total of 127 combat athletes who had trained at the national training center in 2019 were enrolled. The questionnaire used as the survey tool was interpreted as words that Korean athletes could easily understand based on the Portuguese version of the 'Rapid Weight Loss Questionnaire' (RWLQ). χ² tests was performed to determine the differences in physical and mental changes according to sports and weight loss method. RESULTS: Combat athletes in Korea regularly undergo rapidly weight loss within a short period of time prior to competition. There were statistically similar results in terms of weight loss method, physical and mental changes and information about weight loss according to the sport. Weight loss methods often limit food and water intake and dehydrate. The physical complaints associated with them are symptoms such as "no energy", "dizziness", and "muscle spasms". The mental complaints include "irritability", "concentration loss" and "anxiety". These symptoms can be caused by side effects such as food intake limitation, water restriction and dehydration. Information sources for weight loss were in the order of "senior or colleagues", "supervisor or coach", and "Internet". No information was obtained from a doctor or dietitian. CONCLUSION: These results provide a baseline for predicting proper weight loss in athletes and provide useful information for developing performance enhancement as well as weight loss.

• 한국잠사곤충학회지
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• 제36권1호
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• pp.53-57
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• 1994

견방사와 PET로 구성된 혼섬유 재료에 대해 여러가지 조건에서 알칼리 감량을 실시하여 감량율을 조사하고, 감량촉진제가 정련, 감량에 미치는 영향에 대해 검토한 결과를 요약하면 다음과 같다. 1) 감량촉진제와 농도 증가에 따라 견방사의 감량은 감소하여 강알칼리욕에서도 적당한 정도의 감량율을 얻을 수 있었다. 2) PET "A", "B"와 견방사로 된 혼섬유의 감량에서 견방사는 피브로인의 손상이 없는 정도의 적당한 감량이 얻어졌고, PET의 감량도 동시에 이루어 질 수 있었다. 3) PET "D", "E"와 견방사로 된 혼섬유의 감량에서, 견방사는 적당한 감량이 이루어 질 수 있었으나 PET의 감량율은 미미하였다. 4) 견방사와 PET로 된 교직물의 감량에 있어서, 견방사 분분은 전형적인 연감곡선 형태를 나타내 감량평형을 보였으나 PET는 처리시간의 경과에 따라 감량율이 계속해서 증가하였다. 보였으나 PET는 처리시간의 경과에 따라 감량율이 계속해서 증가하였다.

• Journal of Periodontal and Implant Science
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• 제38권1호
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• pp.15-22
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• 2008

Purpose: The attachment level is strongly associated with tooth loss and provides useful information on patterns of destruction of the periodontium. The presence of horizontal attachment loss would not be detected in clinical measurement. Therefore, the purpose of the present study was to estimate the patterns of periodontal destruction based on the attachment area and horizontal attachment loss in extracted teeth due to severe periodontitis. Materials and Methods: 307 teeth satisfied the criteria for assessment. An indirect method, based on digital images obtained from a digital camera and an image analysis program, was used to calculate the area of root surface and attachment loss and the extent of horizontal attachment loss. The data were analysed using SPSS. Results: No statistically significant differences among root surfaces were observed in anterior teeth on the loss of attachment area. However, in posterior teeth statistically significant differences in palatal surfaces of maxillary and mandibular premolar and molar surfaces compared with buccal surfaces were observed. Horizontal attachment loss was observed in 21.5% of the teeth examined. Frequency of horizontal attachment loss was highest in the maxillary first premolar (34.8%), followed by the maxillary second premolar (27.3%) and maxillary canine (25%). The mean length of horizontal attachment loss was 1.5mm. Conclusion: More meticulous examination will be needed of the palatal surfaces of maxillary and mandibular premolar and molar teeth. The percentage of teeth with horizontal attachment loss greater than 2.1 mm was 5.2%. Considering the length of curette blades, about 5.2% of teeth were not properly debrided. Therefore, Additional supportive therapy such as local drug delivery has to be considered in treatment of the first maxillary, second premolar and canine due to the high prevalence of horizontal attachment loss.