• 설비공학논문집
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• 제30권4호
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• pp.195-203
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• 2018

Mohair is widely used as an airtight material for filling the gap between a window frame and sash. The purpose of this study is to investigate infiltration rate and opening force of sliding windows according to the mohair installation conditions. Infiltration experimental apparatus was set up, and the experimental results were applied to windows to find a correlation between infiltration rates and opening forces. When 4 rows of mohair were installed, the infiltration rate increase became 27.1% per clearance length increase of 1 mm, and the infiltration rate decrease became 5.7% per shortened length increase of 0.1 mm. For 4 rows of mohair, the opening force decreased by 28.2% as the clearance increased by 1 mm, and it increased by 9.3% as the shortened length increased by 0.1 mm.

• Journal of Welding and Joining
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• 제21권6호
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• pp.71-76
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• 2003

For the purpose of clarifying the influence of welding residual stress to the fatigue crack propagations behaviour, an analytical investigation based on finite element method is performed to examine the opening behaviour of tip-closed crack in the compressive residual stress. A finite element model comprised of contact elements for the crack plane and plane stress elements for the base material is used to evaluate crack opening stress of the crack existing in the residual stress field. Also an analytical method based on the superposition principle to estimate the length of opened part of tip closed crack and the stress distribution adjacent to the crack during uploading is applied to the finite element model. The software for the analysis is ABAQUS, which is a general purpose finite element package. The results show that stresses distributed on the crack surfaces are reduced and approached to zero as the applied stresses are increased up to crack tip opening stress and no mechanical discontinuity is found at the boundary of contact elements and plane stress elements. It is verified that the opening behavior of the fatigue crack in the residual stress can be predicted by finite element method with the proposed analytical method.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.517-520
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• 2003

The purpose of this paper is to investigate the effect of arc current and contact velocity on the erosion of silver contact to be used in low voltage circuit breakers. The arc current range from $2kA_{rms}$ to $20kA_{rms}$. A test system allows the control of the opening velocity profiles with contact velocities up to 10m/s and also enables the synchronization of the contact opening with a point on the arc current waveform. Contact erosion is evaluated by measuring the mass change of the cathode and anode. The results show that increase the opening velocity from 2m/s to 6m/s leads to an decrease in the contact erosion. The material transfer from one electrode to another is shown to depend on the transfer charge and the opening velocity of the contacts.

• 한국추진공학회지
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• 제19권5호
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• pp.98-103
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• 2015

가속도추종 유로개방장치는 고속 비행체의 가압식 연료탱크에서 연료가 쏠림현상으로 인해 단절되는 것을 막아 연속적으로 흐르게 한다. 기개발된 이 유로개방장치를 실제 고속으로 시험하는 것은 까다로운 시험조건과 비용문제로 많은 어려움이 따른다. 따라서 본 논문에서는 저속 항공기에 탑재해 기본적인 역중력 시험(Negative-g test)을 수행하고 RecurDyn으로 해석한 결과와 비교하였다. 그리고 고속비행체의 비행궤적에 따른 유로개방장치의 동역학적 거동을 RecurDyn으로 알아보았다.

• 한국수학교육학회지시리즈A:수학교육
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• 제48권1호
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• pp.21-32
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• 2009

The purpose of this study is to diagnose the current states and the problems of student assessment of Elementary School Mathematics. For that purpose, this study conducted a survey and had the individual interviews. The surrey items consisted of the six main parts: questions about the development of assessment tools, the method to assess, the grading, the special supplementary courses, the opening of learning effect, and the follow-up guidances. The results of this study are as the follow First, elementary teachers depended heavily on internet sites for developing assessment problems. Second, elementary teachers made use of a performance assessment, a unit assessment, and a term examination at ordinary times. Third, unit assessment was largely referred for grading by elementary teachers. Fourth, in selecting the students for the special supplementary courses, both criterion-referenced assessment and norm-referenced assessment were considered. After finishing the special supplementary courses, additional tests were usually taken. Fifth, elementary teachers took a negative attitude in opening of learning effect. specialty opening of test paper to parents of students was done under 30%. Sixth, fellow-up guidances were the most through the classroom guidances. but consulting with parents of students was not frequently conducted by teachers.

• 한국추진공학회지
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• 제18권3호
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• pp.78-83
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• 2014

항공기 또는 유도무기와 같은 고속 비행체의 가압식 연료탱크에는 연료가 한 방향으로 몰려 이송이 단절되는 것을 방지하기 위해 특별한 유로개방장치가 필요하다. 이러한 필요에 의해 가속도추종 방식의 유로개방장치가 발명되었으며 본 논문에서는 이 장치의 구동성능을 예측하고 성능에 영향을 미치는 주요 파라미터의 선정을 위해 동역학 해석 프로그램인 RecurDyn을 이용해 해석을 수행하였다. 해석결과를 통해 장치의 내부 균형추가 연료의 쏠림을 잘 추종해 유로를 개방시키는 것을 확인하였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제41권
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• pp.18.1-18.10
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• 2019

Background: Temporomandibular joint (TMJ) ankylosis during early childhood may lead to disturbances in growth and facial asymmetry and to serious difficulties in eating as well as in breathing during sleep. The purpose of this study is to describe the effectiveness of an interocclusal splint (IOS) for active mouth opening exercises in the treatment of TMJ ankylosis. Methods: A total of nine patients with 13 instances of TMJ ankylosis from 2008 to 2010 were included in this study, of which five patients were male and four patients were female. Five patients demonstrated unilateral ankylosis, while five patients showed bilateral symptoms. Ankylosed mass resection with coronoidectomy, fibrotic scar release, and resection of stylohyoid ligament calcification was performed with gap arthroplasty without an interpositional graft, and all patients were assessed for maximum mouth opening (MMO) during a mean 6.6-year follow-up period. Results: All patients were subjected to postoperative mouth opening exercises from the day of the operation with the help of an IOS, which was based on an impression taken during surgery. All patients were sufficiently comfortable moving their mandible according to the IOS's guiding plane and impingement, and satisfactory results were achieved, in which MMO was improved by 35 mm more than 6 years after surgery. Conclusions: Complete and adequate resection of the ankylosed mass and postoperative active mouth opening exercises are essential in the treatment of TMJ ankylosis. Moreover, a more comfortable mouth opening guide and interdigitation can be achieved using an IOS, and newly organized fibrosis in the gap space between the newly made resected condylar head and temporal fossa can be suggested.

• 한국응용곤충학회지
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• 제56권3호
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• pp.253-259
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• 2017

이산화염소 훈증 처리는 저곡해충에 대한 방제 가능성을 가지고 있다. 특히 체내로 독성 가스의 침투력을 높이기 위해 기문의 개방화를 유도하면 이 훈증 가스 처리 효과를 증가시킬 수 있다. 이 가설을 증명하기 위해 본 연구는 이산화염소 훈증 처리에 감수성을 보이는 화랑곡나방(Plodia interpunctella)을 대상으로 기문 개방 활동을 분석하였다. 화랑곡나방 유충의 기문은 모두 9쌍으로 앞가슴에 1쌍 그리고 복부에 8쌍을 각각 지니고 있다. 이들은 몸 내부에 가로 및 세로기관지와 연결된 구조를 지녔다. 기문 개방 유무는 염색액 침투 방법으로 판정하였으며 이를 토대로 분석한 결과 주변 온도 증가에 따라 기문 개방화는 약 60% 까지 증가하였다. 특히 이산화탄소에 노출되면 기문개방화는 약 95%까지 증가하였다. 반면에 이산화염소에 노출되면 화랑곡나방 유충의 기문은 대부분 닫혀 기문개방율이 약 25%로 줄었다. 이산화염소 처리에 이산화탄소를 추가한 결과 기문개방율은 이산화탄소 단독 처리만큼 크게 증가하였다. 이를 토대로 두 혼합 가스를 처리하여 살충효과를 분석한 결과 이산화염소 단독 처리에 비해 혼합처리가 현격하게 높은 살충력을 나타냈다.

• Journal of Oral Medicine and Pain
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• 제11권1호
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• pp.29-35
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• 1986

18 TMD patients who received occlusal adjustment in PNUH though Jan.1984 to 1985 were followed up for short-term(2-6yrs.) and long-term(1-2yrs.) evaluation. The obtained results were as follows : 1. Pain index showed gradual decrease after occlusal adjustment and significant change on long-term evaluation. 2. Noise index had no significant change throughout the all follow-up evaluation. 3. Opening limitation index showed gradual decrease after occlusal adjustment and significant change on both long-term and short-term evaluation. 4. Maximum comfortable opening exhibited more and more increase and significant change on long-term evaluation.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2006년도 추계학술발표대회 논문집
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• pp.223-226
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• 2006

The purpose of this design plan is a method for opening the church to regional society to contribute to make up the community within regional society and to achieve the desirable common society of christianity like following. 1)For opening churchs to regional society, the church has to make up exterior spaces sufficiently. 2)The main chapel has to planned with mutipurpose for fiexibility and various functions of contemporary church. 3)The whole facilities have to be organized with a kind of the complex or multifunctional building which can accommodate activities of education, recreation and culture, therefore, content with the community's requirements. 4)The architectural form of the church has to planned with human scale, considering harmonization with regional environment. Modern church architecture needs a centralized plan, a variety of shapes such as square, round oval and polygon rather then a rectangular which is able to bring about a closer reationship between the priest and the congregation in the church.