• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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• pp.606-606
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• 2003

There have been many studies that have evaluated success and failure of endodontic treatment (Nair, Sjogren), but there is remarkably limited information concerning the specific microorganisms that are involved in the teeth with treatment failure. Microorganisms that survive root canal treatment to cause a persistent infection must possess specific characteristics to avoid the host defense. These can be broadly classified as; 1. Sequestration：A physical barrier between the microbe and the host. 2. Cellular evasion：Microorganisms avoid leukocyte dependent antibacterial mechanisms. 3. Humoral evasion：Extracellular bacteria avoid the hosts antibodies and complement.(omitted)

• 한국항해학회지
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• 제6권1호
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• pp.41-59
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• 1982

In the Sailing Rules of International Regulation for Preventing Collisions at Sea, 1972, any definite distance between two vessels approaching each other is not referred for adequate maneuvering to avoid collision. At sea the officer in charge of bridge duty is required to guess safe distance before he takes maneuvering actions needed to avoid collision. Papers on safe distances calculated on the base of the motiional characteristics of ships for collision avoiding actions are very few. In this paper, the minimum safe approaching distances necessary for actions to be taken to avoid collision are calculated in numerical numbers definitely by mathematic formula based on the maneuvering indices got from experiments of actual ships. On the assumption that two vessels same in size and conditions are approaching each other, the author calculated the minimum safe approaching distance as 4.5 times, sufficient safe approaching one as 9.0 times the length of the ship involved in head-on situation and 5.0 times, 10 times respectively the length of the ship in each case mentioned above in crossing situation.

• Structural Engineering and Mechanics
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• 제37권6호
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• pp.633-648
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• 2011

This paper investigates the aspect-ratio locking of the isoparametric 8-node quadrilateral (QUAD8) element. An important finding is that, if finite element solution is carried out with in exact arithmetic (i.e., with no truncation and round off errors), the locking tendency of the element is completely avoided even for aspect-ratios as high as 100000. The current finite element codes mostly use floating point arithmetic. Thus, they can only avoid this locking for aspect-ratios up to 100 or 1000. A novel method is proposed in the paper to avoid aspect-ratio locking in floating point computations. In this method, the offending terms of the strain-displacement matrix (i.e., $\mathbf{B}$-matrix) are multiplied by suitable scaling factors to avoid ill-conditioning of stiffness matrix. Numerical examples are presented to demonstrate the efficacy of the method. The examples reveal that aspect-ratio locking is avoided even for aspect-ratios as high as 100000.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.145-150
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• 2006

The paper deals with integrated navigation and sense & avoid systems for small unmanned aerial vehicles (UAV). First an introduction to the current UAV activities of the institute is given. It is followed by an overview about the integrated navigation system developed for small UAVs. The system is based on a tightly-coupled GPS/INS architecture. But instead of using delta-ranges, time-differenced carrier phases are used to aid the INS. Finally, results from navigation filter validation in flight tests are presented. After that an overview about sense and avoid strategies for application in small unmanned aircraft is given. From this a guideline for developing such a system for the institute's UAVs is presented.

• 한국항해학회지
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• 제12권1호
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• pp.71-84
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• 1988

For traffic proceeding in random directions on a plane surface the frequency of collision, if no avoiding action in taken ,is approximately proportional to the square of the traffic density and directly proportional to the size and speed of the ship, Avoiding is normally taken and the rte of collisions is therefore also governed by additional factors such as the visibility, the effectiveness of the collisionavoidance rules, the competence of personnel or watchkeeping attitude, the maneuverability of the ship and the efficiency of radar and other equipments. From the viewpoint of watchkeeper who is responsible for maneuvering, watchkeeping attitude such as lookout and action to avoid collision is the most controllable factor among those mentioned above. In practice, according to the investigation of the institution of marine courts, about 50% co collisions occurred is caused by disorbedience to steering and sailing rules of international regulations for preventing collision at sea including lookout. So we classify the process of collisions with first sight of another ship , assessment of risk of collisions and action to avoid collisions and make a factural survey about lookout and action to avoid collisions from the point on "time" and " distance", namely relationship among ship's size, speed, first sight time of another ship, action to avoid collisions ,and distance from sight of another ship to collision occurred. According to the results of the actual survey , we come to conclude that most of collisions occurred are due to improper lookout and ineffective action to avoid collision which means time lag from first sight of another ship to time of action taken to avoid collision is relatively long. is relatively long.

• 디지털융복합연구
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• 제18권12호
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• pp.217-229
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• 2020

세계적으로, 정보보호는 조직의 필수적인 관리 조건이 되고 있으며, 조직들은 정보보안을 위하여 높은 수준의 자원을 지속적으로 투자하고 있다. 조직 내부자들의 보안 위협은 감소하지 않고 있어, 정보보안 행동 준수를 위한 관심이 필요한 상황이다. 본 연구의 목적은 조직원들의 보안 회피 행동의 원인인 역할갈등을 완화시키기 위한 선행 요인을 제시하는 것이다. 연구는 정보보안 정책을 보유한 조직에서 근무하는 조직원을 대상으로 설문을 실시하였으며, 383개의 표본을 활용하여 구조방정식모델링을 통한 가설 검증을 하였다. 가설 검증 결과, 역할갈등이 회피행동을 증가시키는 것으로 나타났으며, 목표 난이도와 세밀성, 공정성, 신뢰가 역할갈등을 완화하는 것으로 나타났다. 특히, 공정성은 신뢰를 통해 역할갈등과 회피 행동 감소에 영향을 주는 것으로 나타났다. 연구 결과는 조직원의 정보보안 회피행동 원인과 완화 요인을 제시함으로써, 정보보안 수준 향상을 위한 정보보안 전략 수립에 영향을 줄 것으로 판단한다.

• 대한조선학회논문집
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• 제55권4호
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• pp.321-329
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• 2018

Resonance phenomena occurs at large vertical pump which is operating to cool down the hot steam using sea water in the power plant. To avoid the resonance, the natural frequency needs to be isolated about 20% from motor operating speed. Yet, excessive vibration occurs especially at low tide. At first, natural frequency of the whole pump system and each part is calculated using ANSYS. As it is revealed in the previous journal papers that only circular pipe part is related to resonance, the FSI technique is applied for free vibration analysis. The natural frequency is reduced to 60% (compared to that) of the frequency measured in air as it is similar to other published results. And the frequency obtained by finite element analysis is almost same to that obtained from modal test. Based on the accurate finite element model and analysis, design change is tried to avoid the resonance by changing the thickness of pipe and base supporting plate. In stead of doing optimization process, design sensitivity is computed and used to find such designs to avoid resonance.

• 논리연구
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• 제16권3호
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• pp.381-406
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• 2013

이 논문은 크립케 스타일의 초완전성 견해가 거짓말쟁이 역설을 적절하게 해소할 수 있는지를 다룬다. 초완전성 견해에 따르면, 참도 거짓도 아닌 문장이 있고, 거짓말쟁이 문장이 바로 그런 문장이다. 크립케의 초완전성 견해는 복수의 문제를 해결하지 못한다는 비판이 제기되었는데, 최근 모들린은 토대론적 의미론을 통해서 복수의 문제를 야기하지 않는 초완전성 견해를 제시할 수 있다고 주장했다. 이 글의 목적은 모들린의 견해를 포함해서 초완전성 견해는 복수의 문제를 해결하지 못하고 진리와 관한 일상적인 직관과 부합되지 않음을 논증하고, 모들린의 견해는 복수의 문제를 피하기 위한 단순한 미봉적 제안일 뿐임을 주장한다.

• 대한한방부인과학회지
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• 제21권3호
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• pp.143-166
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• 2008

Purpose: The purpose of this study is to ascertain the awareness or incidence of SHP and postnatal care. Methods: We analyzed the results of Questionnaires for 104 women who have experienced childbirth within the last 10 years and examined June 2007 to December 2007. We divided to three groups according to age and investigated. Results: 1. Awareness of SHP and postnatal care. Responses about "How informed are you about the syndrome known in Korea as SHP?", Person's ration who know is 72.11%. Responses about "Are you aware of current traditional postnatal practices in Korea?", Person's ration who know is 80.77%. "Do you think that postnatal care as practised is Korea is necessary?", Person's ration who know is 84.62%. "Do you think that in general postnatal care is necessary?", Person's ration who know is 93.27%. "Do you believe, if you are unable to practice postnatal care, you will subsequently develop health problems?", Person's ration who know is 91.35%. 2. Relevant comments of postnatal care. Responses about lifestyle after childbirth are Prevent bodily hard work 35.37%, Prevent cold stimulus 27.21 %, Hold body warmly 17.69%, Psychologically comfortably 7.48%, Eat good food 7.48% Etc 10.88%. Foods after childbirth are Avoid cold foods 22.38%, Avoid hard foods 17.48%, avoid hot foods 16.78%, avoid salty foods 10.49%, avoid excitative foods 8.39%. Medication after childbirth are Oriental medicine and restorative medicine 21.24%, iron was 15.04%, pumpkin 15.04%, vitamin 9.73%, calcium and snakehead each 7.96%. 3. Postnatal care practices Correlation postnatal care practices with present health condition are 19 items of 31 items. Conculsion: We hope these results could be helpful to diagnosis and treatment of SHP.

• 한국항공운항학회지
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• 제25권4호
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• pp.83-90
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• 2017

Unmanned Aerial Vehicles(UAVs) require collision avoidance capabilities equivalent to the capabilities of manned aircraft to enter the airspace of manned aircraft. In the case of Visual Flight Rules of manned aircraft, collision avoidance is performed by 'See-and-Avoid' of pilots. To obtain those capabilities of UAVs named as 'Sense-and-Avoid', sensor-system-based intruder tracking and collision avoidance methods are required. In this study, a multi-sensor-based tracking, data fusion, and collision avoidance algorithm is designed by using a model-based design tool MATLAB/SIMULINK, and validations of the designed model and code using numerical simulations and processor-in-the-loop simulations are performed.