• 대한기계학회논문집B
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• 제25권11호
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• pp.1650-1658
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• 2001

An electret filter is composed of permanently charged electret fibers and is widely used in applications requiring high collection efficiency and low-pressure drop. In this work, the fractional collection efficiency of the filter media used in manufacturing cabin air filters was investigated by using highly monodisperse particles ranging from 0.02 to 0.6 $\mu\textrm{m}$ in diameter at three different charging states: singly charged, uncharged, and equilibrium charged. The face velocity was varied from 2.4 to 20.4 crus. It was fecund that the fractional efficiency curve fur singly charged particles shows a typical trend that the collection efficiency is minimum at about 0.3 $\mu\textrm{m}$ in diameter. The fractional efficiency of equilibrium charged particles were not severely varied with the particle diameter. The collection efficiency curve fur uncharged particles has a minimum near 0.1 $\mu\textrm{m}$ in diameter. Another experiment was conducted for a cartridge filter to examine the effect of charge depletion on the collection efficiency in a cabin air filter. The result shows that the charge depletion of the cartridge filter can significantly lower the collection efficiency.

• 한국조경학회지
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• 제28권4호
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• pp.91-104
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• 2000

The traditional village, which is subject for this paper, can be defined as a community having unique combinations of natural, cultural, and social characteristics of that nation, which reflects settlement environments during hundreds of years. Now, in spite of tis potential power of traditional village, national strategies do not find satifsactory directions in Korea. In terms of this concenrs, this paper tries to analyze and diagnose about successful precedents(Tsumage village and Shiragawa village, Japan) with focus on the village management. And this paper aims to explore concrete management systems of Japanese cases, to find clues for practical application, and to suggest several instructive concepts in the light of management system of traditional village management. The analysis is progressed in three viewpoints(village space, village attraction, and village community). And it is extracted that diverse management systems are necessary to secure sustainable traditional village and their way of life, particularly in the face of the pressure of tourism. As a result of exploring of Japanese two cases, representative characteristics, which are found, are as follow; Fist, objective of management is not tourism development but maintenance of sustainable life system. Second, management systems are having not compulsory but spontaneous open decision making process, and in particular, village management is mainly operated by the local government and semipublic institute(inhabitants-oriented0 which have the strongest influential power in village composition units. Finally, village management programs are mostly experience-type and are composed of public law and regulations, diverse operation program, and individual efforts of inhabitants for village management. Because this paper mainly focused on two precedents, there should be more diverse cases. however, extracted conclusions have practical meanings for village management and can be used in re-establishing management concepts of Korean traditional villages.

• 한국안광학회지
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• 제12권4호
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• pp.19-22
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• 2007

산악 인구 증가와 더불어 해외원정 등반 인구도 크게 늘고 있다. 6천 미터 이상의 고소등반 시 발생하는 조난사고의 많은 부분이 설맹 때문이다. 설맹의 직접적 원인은 자외선에 의한 각막 및 망막의 손상이다. 고소에서의 자외선의 강도는 기압강하에 따른 고도효과와 설면에서 반사효과의 상승작용에 의해 크게 높아진다. 해발 4천 미터 설산에서의 자외선 강도는 지상에서보다 약 3배, 8천 미터에서는 약 4배 증가하는 것으로 나타났다. 고소등반에서 설맹을 방지하기 위해서는 고글보다 선글라스 형태가 바람직하다. 또 고소등반용 선글라스는 기계적 강도가 높은 프레임, 자외선을 100% 차단하는 플라스틱 렌즈의 사용이 요구된다. 얼굴과 선글라스 틈 사이로 들어오는 자외선을 차단하기 위해 탈부착식 차단막이 필요하다. 또 선글라스가 쉽게 탈착되지 않기 위하여 템플은 귀를 감을 수 있도록 길고 유연성이 좋아야 한다. 안구 주위의 동상을 방지하기 위해 메탈프레임을 합성수지로 피복하는 것이 바람직하다.

• 분석과학
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• 제15권3호
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• pp.256-262
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• 2002

평균입자크기가 200 ${\mu}m$인 코디어라이트 분말을 사용하여 다공성 필터를 제조한 후, 진공함침법으로 $V_2O_5$, CuO, $LaCoO_3$ 촉매를 담지시킨 후 NO와 $SO_2$ 기체를 촉매 담지 세라믹필터에 동시 통과시키면서 NOx/SOx의 동시제거효율을 측정하였다. 제조된 다공성 필터의 기공률은 61.6%였고, 압축강도는 12.3 MPa이었으며, 면속도 5 cm/sec에서의 차압은 147 Pa이었다. NO와 $SO_2$의 동시제거효율을 분석해 본 결과, 페로브스카이트계 $LaCoO_3$ 촉매의 동시제거효율이 가장 우수함을 확인하였으며, $LaCoO_3$ 촉매의 NO에 대한 제거효율은 90% 이상, $SO_2$에 대해서는 80% 이상이었다.

• 대한두경부종양학회지
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• 제7권1호
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• pp.24-34
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• 1991

Lymphangioma is a benign, growth of lymphatic tissue that is present at birth or develops in early childhood, which may cause serious alterations in growth and developmemt. The problems with facial lymphangioma is usually releated directly to their size and to the area of the face which is involved. The lesions themselves may range from small, localized blemishes to huge facial masses involving both soft tissue and underlying bone and causing great distortion and asymmetry. The facial bones are seldom involved, but the natutal evolution of an individual lesion often cannot be accurately predicted when the child is first seen. Any changes in the underlying facial bone could be due either to a direct growth of the lesion into the bone, or secondary to pressure of the lesion growing outside the bone itself. A case of cystic lymphangioma extending from the neck to the tongue is reported. A six-year-old female was admitted because of swelling of the tongue. At that time, the tongue reportedly reached the extraoral size of 7x5x2.5cm and a soft, diffuse swelling of left anterior neck was revealed. The removal of cystic mass including left neck dissection and partial glossectomy were undertaken. The another case of lymphangioma is located on mandibular cheek. A twenty nine-year-old male was admitted because of palpable mass of the left mandibular area and fissure of palate. The radical excision of mass with mandibulectomy of body were undertuken. Thus we reported such a rare case and reviewed the lymphangioma.

• 보건행정학회지
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• 제22권3호
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• pp.365-382
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• 2012

Background : Public hospitals suffer worsening shortage of physicians and face great pressure of recruiting doctors. This study is aim to identify the factors associated with retention of physicians who are working in public hospitals. Methods : We conducted a cross-sectional and self-administered questionnaire survey in July, 2011. A total of 333 physicians responded from the 31 public hospitals. We analyzed the difference of job retention across the variables among doctors stratified as salaried and public health doctors. We used chi-square test and multiple logistic regression analysis. Results : To the salaried doctor, longer work period(OR=2.04 in 3rd quartile), professional autonomy(OR=2.69), and positive attitude toward public health(OR=2.39) affect to the higher job retention whereas complain of low income(OR=0.33) and complain of poor clinical environment(OR=0.26) affects to the lower job retention. To the public health doctors, community connections such as hometown(OR=6.27), spouse factors(OR=3.49), and positive attitude toward public health(OR=3.19) affect to the higher job retention. But longer work period(OR=0.17 in 3rd quartile) affects to the lower job retention. Conclusions : Associated factors of job retention vary across physician's status. Professional autonomy has major impact on the job retention to the salaried doctor. And familial factors as well as community relationship have greatest impact to the public health doctor. Positive attitude toward public health is associated with the higher job retention to the both of salaried and public health doctors.

• 한국안전학회지
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• 제21권2호
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• pp.138-142
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• 2006

직업성 천식은 시안화물의 폭로에 의해 발생되는 것으로 알려져 있다. 남호주에 있는 가구산업에서는 일반적으로 목재판 위를 피복하기 위해 이중분사도포를 할 때 이소시안화물 도포제가 사용된다. 이 연구는 이와 관련 된 분야의 자료부족으로 관련 산업에서의 환경 및 피부와 안구폭로에 대한 모니터링을 위하여 수행되었다. 이 연구결과에 의하면 저압다량(HVLP)의 분사기 사용, 페인트 용액중의 저농도 경화제 및 전면 호흡보호구와 같은 적절한 보호구의 사용시에는 대기로부터 오염물질의 유입은 거의 없었고, 분사실 주변의 일반적인 작업범위에도 HDI 가 거의 감지되지 않았다. 페인트분사시의 일회용 장갑착용으로 피부폭로는 발견되지 않았으나, 칼라 모니터링에 의하면 장갑을 착용하지 않거나 청결하게 관리할 수 있는 공정이나 안전한 장소에 보관하지 않으면 작업장으로부터 피부폭로가 있었다. 페인트분사로부터 눈의 오염은 감지되지 않았고, 호흡기, 피부 및 안구에도 폭로되지 않았으며 유입과 가장 관련성이 있는 것은 작업형태이다.

• 한국해안해양공학회지
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• 제2권2호
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• pp.104-111
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• 1990

부산연안에서 태풍으로 인한 수위변화특성을 파악하고 수위예측을 위하여 태중 Thelma 통과 기간증 한국남해안에 위치한 6개 검조소의 조위관측자료와 기상자료를 분석하였다. 수치모델에 있어서는 해면기압의 공간분포로 인한 수위변화를 고려하였다. 폭풍해일(storm surge)의 계산결과 부산연안의 최대수위편차의 출현시각과 수위편차곡선은 가덕도의 조위실측치로부터 구한 수위편차곡선과의 상당히 유사한 결과를 나타냈다. 그러나 부산검조소 위치에서 조위실측치로부터 구한 수위편차곡선은 검조소가 수로에 위치한 관계로 일반적인 해일 곡선을 나타내지 못한다. 본 계산결과에 의하면 낙동강 하구역에서는 지형적인 영향으로 최대 2.5m 이상의 수위편차가 나타났으며, 그 밖의 해안에서는 약 60cm 전후의 수위편차가 나타났다.

• 한국지반환경공학회 논문집
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• 제7권6호
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• pp.23-34
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• 2006

본 연구에서는 보강재의 침하를 허용하는 침하형 보강토 옹벽의 거동을 평가하기 위하여 원심모형실험을 수행하였다. 실험결과는 연결부의 침하를 허용하지 않는 일반형 보강토옹벽에 대한 결과와 비교 분석하여 침하형 보강토 옹벽의 안정성을 평가하였다. 모형실험에서 전면판은 알루미늄판을 사용하였으며, 보강재는 알루미늄 호일을 이용하였으며, 뒤채움지반은 화강풍화토를 사용하였다. 실험결과, 침하자유형 보강토옹벽은 80g의 중력수준에서 완전한 파괴상태에 도달하였으며, 일반형 보강토 옹벽이 69g의 중력수준에서 파괴된 것을 감안하면 침하자유형 보강토 옹벽이 안정성이 우수하다는 것을 확인할 수 있었다. 또한, 69g에서 침하자유형 보강토옹벽 저면에서의 수직토압이 일반형에 비해 16% 정도 크게 측정되었다.

• 대한조선학회논문집
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• 제49권6호
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• pp.461-468
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• 2012

In this study, a Cartesian-grid method based on finite volume approach is applied to simulate the ship motions in large amplitude waves. Fractional step method is applied for pressure-velocity coupling and TVD limiter is used to interpolate the cell face value for the discretization of convective term. Water, air, and solid phases are identified by using the concept of volume-fraction function for each phase. In order to capture the interface between air and water, the tangent of hyperbola for interface capturing (THINC) scheme is used with weighed line interface calculation (WLIC) method which considers multidimensional information. The volume fraction of solid body embedded in the Cartesian grid system is calculated using a level-set based algorithm, and the body boundary condition is imposed by a volume weighted formula. Numerical simulations for the two-dimensional barge type model and Wigley hull in linear waves have been carried out to validate the newly developed code. To demonstrate the applicability for highly nonlinear wave-body interactions such as green water on the deck, numerical analysis on the large-amplitude motion of S175 containership is conducted and all computational results are compared with experimental data.