• 대한기계학회논문집A
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• 제38권3호
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• pp.329-335
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• 2014

U 자형 전자석 하나로 부상력과 안내력을 동시에 얻는 중 저속 자기부상열차는 안내제어기 없이 곡선을 주행한다. 때문에 곡선, 특히 곡률반경이 매우 작은 곡선 주행 시에 차량이 레일과 물리적 접촉을 방지하기 위해서는 곡선형상의 결정이 세심하게 이루어져야 한다. 특히 완화곡선의 형상이 중요하다. 본 논문에서는 완화곡선 선로를 구성하는 형상 매개변수들의 차량 안내 성능에의 영향도를 분석하는데 목적이 있다. 이를 위하여 차량, 전자석, 부상제어기, 곡선가이드웨이가 통합된 3 차원 자기부상열차 다물체 동역학 모델을 개발하였고, 개발된 모델을 이용하여 곡선형상을 구성하는 매개변수 연구를 수행하였다. 연구 결과는 곡선형상의 결정이나 차량의 대차구조를 설계하는데 이용이 가능하다고 할 수 있다.

• 대한치과보철학회지
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• 제55권4호
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• pp.419-426
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• 2017

임플란트는 자각증상을 느끼기 어렵고, 완충역이 없으므로 응력 분포를 고려하지 않는 경우 기계적 실패를 야기할 수 있다. 다수의 상악 전치부 임플란트 수복의 경우 하악의 기능 운동 시 유도를 담당함으로써, 임플란트에 가해지는 측방력의 분산에 중요한 역할을 하므로, 적절한 가이드의 설정이 중요하다. T-scan system을 이용하는 방법은 교합지나 shimstock을 사용하는 기존의 정성적인 방법에 비해, 시간에 따른 교합의 변화와 기능 운동시 접촉되는 치아의 기여정도 및 육안으로 관찰하기 어려운 후방 구치나 반대편 치아의 접촉을 파악하는 등 동적인 교합평가에 유리하다. 본 논문에서는 다수의 상악 임플란트 보철물에 조화로운 전방유도를 부여하기 위하여 T-scan 분석을 활용하는 방법에 관하여 증례를 통해 살펴보고자 한다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.335-338
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• 2006

The more deeply the researches make progress in ocean researches including the seabed resource investigation or the oceanic ecosystem investigation, the more important the role of UUV gets. In case of study on the deep sea, there are difficulties in telecommunications between AUV and ships, and in data communication and recharging. Therefore, docking is required. In AUV docking system, the AUV should identify the position of docking and make contact with a certain point of docking device. MOERI (Maritime & Ocean Engineering Research Institute), KORDI has conducted the docking testing on AUV ISIMI in KORDI Ocean Engineering Water Tank. As AUV ISIMI approachs the docking device, it is presented that attitude is unstable, because the lights Which is on Image Frame are disappeared. So we fix the rudder and stem, if the lights on Image Frame are reaching the specific area in the Image Frame. In this paper, we intend to solve the problems that were found in the testing, which, first, will be identified via simulation.

• Journal of Oral Medicine and Pain
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• 제22권1호
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• pp.167-181
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• 1997

The aim of this study was to investigate the relationship between velocity and factors which could affect the velocity of mandibular movement. For this study, 30 dental students without any masticatory signs and symptoms and 90 patients with temporomandibular disorders(TMD) were selected as the control group and the patients group, respectively. After determining Angle's classification and lateral guidance pattern of occlusion, clinical examination for TMD was perfomed. Velocity and distance of mandibular movements were recorded with BioEGN, reproducibility index of lateral excursions was evaluated by Pantronic(PRI) and BioEGN (BERI) activity in masticatory and cervical muscles were measured with BioEMG, and occlusal contact time and cross-arch unbalance(Total left-right statistics, TLR) on clenching were recorded with T-scan, respectively. The results of this study were as follows : 1. Velocity in the patients was faster than that in the controls in most mandibular movements, but on wide opening and closing movement, result was reverse. 2. Velocity on closing movements were faster than that on opening movements in the control group and a similar tendency was also shown in the patients group. 3. Patients with muscle disorders showed a tendency to have the highest value of velocity of all diagnostic subgroups, while patients with degenerative joint diseases showed a tendency to have the lowest value. 4. Patients with canine guidance showed a tendency to have the highest value of velocity in three subgroups by lateral guidance pattern, while patients with group function showed a tendency to have the lowest value. 5. BERI had a positive correlation with opening velocity on lateral excursion, while TLR had a negative correlation with opening velocity on swallowing. 6. EMG activity on clenching in masticatory muscles had negative correlation with opening velocity on border movements, and on swollowing, while the activity in rest correlated positively with opening velocity on border movements. 7. There were positive correlation between the velocity and the distance in long components of mandibular trajectory.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권3호
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• pp.872-885
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• 2015

The rapid increase of smart mobile devices and mobile applications has led to explosive growth of data traffic in cellular network. Offloading data traffic becomes one of the most urgent technical problems. Recent work has proposed to exploit opportunistic communications to offload cellular traffic for mobile data dissemination services, especially for accepting large delayed data. The basic idea is to deliver the data to only part of subscribers (called target-nodes) via the cellular network, and allow target-nodes to disseminate the data through opportunistic communications. Human mobility shows temporal and spatial characteristics and predictability, which can be used as effective guidance efficient opportunistic communication. Therefore, based on the regularity of human mobility we propose NodeRank algorithm which uses the encounter characteristics between nodes to choose target nodes. Different from the existing work which only using encounter frequency, NodeRank algorithm combined the contact time and inter-contact time meanwhile to ensure integrity and availability of message delivery. The simulation results based on real-world mobility traces show the performance advantages of NodeRank in offloading efficiency and network redundant copies.

• 대한치과의사협회지
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• 제54권3호
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• pp.198-205
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• 2016

The purpose of this paper was to investigate the significance of splinted and non-splinted implant-supported restorations with an internal connection for multiple consecutively missing teeth. Upon examination of the effects of fixture-abutment connection, the distribution of occlusal load was favorable in splinted implant-prosthesis with an external connection, but effect of strain distribution was not significant in splinted implant-prosthesis with an internal connection. In splinted implant-prostheses for short implants, strain distribution was not affected by the method of retention. For cement-retained prostheses, the effect of strain distribution due to splinting was not significant. In clinical studies, non-splinted prostheses with an internal connection for multiple consecutively missing teeth showed high survival rate, mild marginal bone loss, and stable periodontal condition. However, failure to achieve optimal proximal contact between single-unit prostheses may lead to food impaction, and veneer fracture may be inevitable when the framework provides inadequate support in the proximal region. In conclusion, splinted implant-prosthesis is not an indication in all cases, and clinical consideration of its use should be based on the patient's oral condition, such as location and number of implants, formation of proximal contact, canine guidance, existence of parafunctional habit, and oral hygiene, when multiple consecutively missing teeth are replaced by internal connection type implant.

• 대한치과보철학회지
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• 제53권2호
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• pp.128-137
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• 2015

목적: 교합접촉 분석에 대한 연구는 외국인을 대상으로 이루어져왔다. 이번 연구에서는 T-Scan을 이용하여 하악 측방운동시 교합접촉 분석을 통해 한국인의 교합 양상을 파악해보고자 한다. 재료 및 방법: 87명을 대상으로 T-Scan을 이용하여 하악 측방운동시 교합접촉을 분석하였다. 최대교두감합위에서 측방으로 3 mm범위까지 교합접촉을 측정하였으며, 최대교두감합위, 우측방운동, 좌측방운동을 각각 3회씩 측정하였다. 교합접촉은 thin metal foil을 이용하여 재확인하였다. 결과는 균형측 교합접촉 고려하지 않은 경우와 고려한 경우로 나누어 정리하였다. 결과: 하악 측방운동시 균형측 접촉 고려 유무에 따라 결과에서 많은 차이가 관찰되었으며, 두가지 분류 모두에서 군기능유도가 가장 우세하게 나타났다. 작업측에서는 견치에서 가장 많은 접촉빈도가 관찰되었으며, 견치에서 구치부로 멀어질수록 접촉빈도는 감소하는 양상을 보였다. 균형측에서는 제 2대구치에서 압도적으로 많은 빈도로 관찰되었다. 성별에 따른 균형측 접촉 빈도는 여성에서 더 높은 균형측 교합접촉이 관찰되었으며 이는 통계적으로 유의성이 있었다(${\alpha}$=.05). 결론: 전방유도의 양상 중 군기능유도가 가장 우세하게 나타났다. 작업측에서는 견치에서 가장 높은 접촉빈도가 관찰되었으며, 균형측에서는 제 2 대구치에서 가장 높은 접촉빈도가 관찰되었다.

• 제어로봇시스템학회논문지
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• 제9권10호
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• pp.798-807
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• 2003

We propose a blind mobile robot force control algorithm that uses force information as a guidance toward to the goal position. Based on the mobile robot dynamics, the control law is formed from explicit force errors. Simulation studies are conducted based on the kinematics and the dynamics of the mobile robot. Simulation results show that good force tracking can be achieved. In order to confirm simulation results, experiments are performed. The robot is commanded to follow unknown environment with maintaining a certain desired force. Experimental results show that the blind mobile robot successfully maintains contact with a regulated desired force and arrives at the goal position.

• Nuclear Engineering and Technology
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• 제41권3호
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• pp.355-364
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• 2009

Circular plates with holes are extensively used in mechanical components. The existence of a hole in a circular plate results in a significant change in the natural frequencies and mode shapes of the structure. Especially if the hole is located eccentrically, the vibration behavior of these structures is expected to deviate significantly from that of a plate with a concentric hole. In addition, if the plate is in contact with or submerged in fluid, the situation is more complex. Therefore, in this study, an analytical method to determine the modal characteristics of a plate submerged in fluid is developed based on the finite Fourier-Bessel series expansion and Rayleigh-Ritz method and is verified by the finite element analysis using a commercial program. Also, the relationship between parameter variations and vibration modes is investigated. These results can be used as guidance for the modal analysis and damage detection of a circular plate with a hole.

• Child Health Nursing Research
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• 제8권4호
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• pp.414-421
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• 2002

The purpose of this study is to analyze the concept of caretaking behavior for children. This study adopts the methode of Walker and Avant in analysis. Based on the results of the study, the attributes, precedents, and consequences of caretaking behavior for children are follows ; 1. The affirmative attributes of caretaking behavior are affection binding, nutritional guidance, education, caring, protection moral training and acquisition of parents' role. The negative attributes of caretaking behavior are inconsistent moral training, incapability of affection binding and overprotection. 2. The precedent of caretaking behavior are postpartum contact with their babies, cognizance capacity of child-caretaking, economic support, level of preparation for child-caretaking and self-consciousness as parents. 3. The affirmative consequences of caretaking behavior are promotion of child growth and development, formation of maternal-infantile attachment, development of children sociality, satisfaction of parental role and reinforcement of relationship between the members of family. The negative consequences of caretaking behavior are burden and conflict to parental role, children's illness, role conflict and role stress among the members of the family and family breaking up.