• 한국안광학회지
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• 제12권3호
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• pp.83-87
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• 2007

본 연구는 안질환이 없고 양안시 기능이 정상인 20대에서 50대 사이의 근시성 난시를 가지고 있는 남, 녀 대학생 57명(114 eye)을 대상으로 난시안의 굴절이상도를 완전교정한 상태에서 교정축 만을 $5^{\circ}$, $10^{\circ}$, $15^{\circ}$ 회전하여 완전교정상태와의 시력상태를 비교 분석하였다. 난시 교정안경 착용자의 30.8%가 난시축이 정확하게 교정되지 않은 안경을 착용하고 있었으며, 난시안을 정확하게 교정한 후의 시력과 난시량을 완전교정하고 교정축을 $5^{\circ}$, $10^{\circ}$, $15^{\circ}$ 이동한 시력을 비교한 결과 한 줄 이상의 시력 감소가 나타나는 눈이 각각 56.1%, 84.2%, 93.8%로 조사되었다. 교정축을 완전교정 했을 때와 축이 이탈했을 때와의 시력감소의 폭은 이탈 각도가 클수록 크다는 것을 알 수 있었으며, 난시 교정축의 이탈 각도에 따른 평균 시력변화는 완전교정 했을 때와 비교할 때 $5^{\circ}$에서는 0.94, $10^{\circ}$에서는 0.87, $15^{\circ}$에서는 0.79로 조사되었다. 또한, 완전 교정축에서 $5^{\circ}$ 이탈했을 때는 문자시표에서는 약 한 줄 정도의 시력차이가 있었고, $10^{\circ}$이탈 했을 때는 약 1.8줄 정도의 시력차이가 있었고, $15^{\circ}$ 이탈 했을 때는 약 2.6줄 정도의 차이가 발생하는 것으로 조사되었다. 즉, 난시 교정안경의 교정축이 이탈되었을 경우 시력감소가 발생하는 것을 확인할 수 있었고, 난시안의 교정축 이탈은 안정피로를 유발할 수 있으므로 시력검사 과정에서 정확한 난시축의 교정은 중요한 요소이므로 처방을 토대로 한 난시 교정안경 조제가공 후 교정축의 정확도 확인을 반드시 실시하여 축 오류를 최소화해야 한다고 사료된다.

• 한국강구조학회 논문집
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• 제22권3호
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• pp.281-291
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• 2010

본 연구에서는 횡력을 받는 구조물 거동에 대한 보-기둥 접합부의 영향을 확인하기 위하여 5층 철골구조물을 KBC2005 건축구조 설계기준에 맞게 구조설계 하였으며 접합부를 완전 강접합부로 이상화한 경우와 반강접 접합부로 설계하였다. 철골 보 및 기둥의 모멘트-곡률관계는 화이버모델을 이용하여 확인하였으며 반강접 접합부의 모멘트-회전각 관계는 파워모델 그리고 철골 보, 기둥 및 접합부의 이력거동은 3-매개변수 모델을 이용하여 나타내었다. 5층 철골구조물은 개별골조와 연결골조의 2차원 구조물로 이상화하였다. 4개 지진파의 재현주기 수준별로 산정한 최대지반가속도와 푸쉬오버해석의 최대밑면전단력을 위한 지반가속도에 대하여 시간이력해석을 실시하여 지붕층 변위, 밑면전단력, 층간변위, 접합부 요구연성도, 기둥, 보 및 접합부의 최대모멘트 그리고 소성힌지 분포 등을 확인하였다. 반강접 접합부 골조는 완전 강접합 골조에 비해 적은 밑면전단력이 발생하였으며 기둥, 보 및 접합부에 발생하는 휨모멘트의 크기와 증가율도 적었다. TSD 접합부는 우리나라 설계수준의 지진하중에 대하여 예제 구조물에서 경제성과 안전성을 확보 할 수 있음을 확인할 수 있었다.

• 한국강구조학회 논문집
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• 제29권2호
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• pp.135-145
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• 2017

본 연구는 춤이 큰 하이브리드 합성보의 1차 휨 성능 평가 후, 2차 연구로써 춤이 큰 하이브리드 합성보와 기둥 접합부의 내진성능평가 실험이다. 실험 변수는 보 춤, 부모멘트 철근 수, 브라켓과 보 이음부의 볼트 수 등으로 3개의 실험체를 제작하였다. 접합부 상세는 기둥에 브라켓을 접합 후, 브라켓에 하이브리드 보를 이음하였다. 브라켓과 보 이음은 하부와 웨브는 볼트접합, 상부는 용접접합하였다. 실험결과 내력은 정 부모멘트 모두 소성모멘트($M_p$) 이상을 확보하였으며, 변형능력은 3% 이상의 층간변위각을 확보하여 합성중간모멘트골조의 요구조건을 만족하는 것으로 나타났다. 그러므로 춤이 큰 하이브리드 합성보에 철골철근콘크리트 기둥을 적용하는 경우 본 연구결과의 접합부상세를 적용하면, 중간모멘트골조의 내진성능을 확보할 수 있다고 판단된다.

• 한국공간구조학회논문집
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• 제16권4호
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• pp.75-82
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• 2016

Building hardware joints are welded in most cases, which have risks of fire and explosion. Besides, the secondary damage of the destruction of the welded parts can be caused by the horizontal displacement of the structure due to earthquake or wind load. This paper compared the horizontal displacement following abilities of welded building hardware and non-welded building hardware. To do this, We conducted actual formation shake table test, and checked on the horizontal displacement following ability of structure by comparing their responses to earthquake load. We made the 2m-high framework to examine the responses of the actually constructed building hardwares, and analyzed the displacement responses of the welded-typed, non-welded-typed, and cruciform bracket building hardwares. We conducted the test by increasing acceleration rate until displacement reached 40mm corresponding to allowable relative story displacement II. The result of the test showed that the building hardware using welding work made cracking and breakage on welded connections of welded building hardware, but non-welded building hardware with no use of welding work and cruciform bracket building hardware make no problem, and that non-welded building hardware is superior to that of the welded building hardware in the horizontal displacement following ability due to earthquake or wind load.

• 시큐리티연구
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• 제1호
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• pp.123-134
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• 1997

Our conuntry have come out to the phenomenon to the atrocity crimes, make into a intellecture crims and specialization with them due to various change to the expension of economy growth, drift of population to cities and sense of value is plunged in confution, Now that things have come to this day, since foundation of the security guard law it first begin, ten years, civilian securities guard law was include to the civil service securities law due to amendment fo the civility secuties law newly on Dec. 30, 1995. According to the amendment, the part of the public peace of peoples livelihood were slough of the visual angle in knowledge which function of the civilies security were only be in under the government dimension were put in order to be tointly according to the such state of affairs, should found the consider a counterplan fundamentally regarding to the what to doing efforts foster the civilities securitylaw and qualitalive elevation of presidential guards. To make a long story short by few words, the question resolves itself into the following five points. The first, peoples arrengements for the attitude fo public duty service with devotedly Sustaining publicity work activities for the thire divert of the understanding of civilian security guard. The secondly, Existing security traders and security association should to support to the civilian security works. The third, The government office concerned should strengthen the licensing system in order to improve the quality of existings in order to may establishment newly systems of license and technical institute of regarding to them. The fourth, Should be newly organixed the exclusive organization of personal protective works in the police buroau for the sustaining development of civirity guard works and soundness of the upbringing. The fifth, It is necessary to found the reserch institute for the study on oretical, scholarly, study for the technical reserch and enlargement of effeciveness And try to find a solution to the Universitys function and duty, activity plan, support plan to the Department of security specialist for the come forward in succession it under the national assistance. The finally, I am sure that the Korean security association could be transiormed into the organization which reliable and receive a love from the peoples when doing best utmost to do pursuit of the structure to be a securitys legalism, specialization and total security systems.

• 한국강구조학회 논문집
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• 제23권1호
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• pp.83-97
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• 2011

본 논문에서는 콘크리트 채움 U형 강재보와 철근콘크리트 기둥으로 구성된 접합부의 내진 상세를 개발하였다. 접합부 내진성능을 평가하기 위하여 세 개의 보-기둥 접합부 실험체를 반복주기하중에 대하여 실험하였다. 보춤과 기둥 단면 형상을 실험 변수로 하였다. 합성보의 춤은 슬래브 두께를 포함하여 610mm, 710mm이며, 철근콘크리트 기둥은 사각단면과 원형단면이 사용되었다. 접합부를 보강시키기 위하여 사각단면 기둥과 원형단면 기둥에 각각 대각 철근과 외다이어프램 강판을 사용한 특수 상세가 사용되었다. 실험 결과 실험체는 강도와 변형능력, 에너지 소산에 있어서 우수한 성능을 보여주었다. 변형능력은 특수모멘트골조 기준인 4% 이상의 층간변위각을 발휘하였다.

• 제어로봇시스템학회논문지
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• 제19권6호
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• pp.569-575
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• 2013

This paper proposes a method for PDR (Pedestrian Dead-Reckoning) using a low cost IMU. Generally, GPS has been widely used for localization of pedestrians. However, GPS is disabled in the indoor environment such as in buildings. To solve this problem, this research suggests the PDR scheme with an IMU attached to the pedestrian's waist. However, despite the fact many methods have been proposed to estimate the pedestrian's position, but their results are not sufficient. One of the most important factors to improve performance is, a new calibration method that has been proposed to obtain the reliable sensor data. In addition to this calibration, the PDR method is also proposed to detect steps, where estimation schemes of step length, attitude, and heading angles are developed. Peak and zero crossings are detected to count the steps from 3-axis acceleration values. For the estimation of step length, a nonlinear step model is adopted to take advantage of using one parameter. Complementary filter and zero angular velocity are utilized to estimate the attitude of the IMU module and to minimize the heading angle drift. To verify the effectiveness of this scheme, a real-time system is implemented and demonstrated. Experimental results show an accuracy of below 1% and below 3% in distance and position errors, respectively, which can be achievable using a high cost IMU.

• 대한치과교정학회지
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• 제45권6호
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• pp.289-298
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• 2015

Objective: To evaluate and compare the effects of two appliances on the en masse retraction of the anterior teeth anchored by temporary skeletal anchorage devices (TSADs). Methods: The sample comprised 46 nongrowing hyperdivergent adult patients who planned to undergo upper first premolar extraction using lingual retractors. They were divided into three groups, based on the lingual appliance used: the C-lingual retractor (CLR) group (group 1, n = 16) and two antero-posterior lingual retractor (APLR) groups (n = 30, groups 2 and 3). The APLR group was divided by the posterior tube angulation; posterior tube parallel to the occlusal plane (group 2, n = 15) and distally tipped tube (group 3, n = 15). A retrospective clinical investigation of the skeletal, dental, and soft tissue relationships was performed using lateral cephalometric radiographs obtained pretreatment and post en masse retraction of the anterior teeth. Results: All groups achieved significant incisor and canine retraction. The upper posterior teeth did not drift significantly during the retraction period. The APLR group had less angulation change in the anterior dentition, compared to the CLR group. By changing the tube angulation in the APLR, the intrusive force significantly increased in the distally tipped tube of group 3 patients and remarkably reduced the occlusal plane angle. Conclusions: Compared to the CLR, the APLR provides better anterior torque control and canine tipping while achieving bodily translation. Furthermore, changing the tube angulation will affect the amount of incisor intrusion, even in patients with similar palatal vault depth, without the need for additional TSADs.

• 한국해양공학회지
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• 제29권6호
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• pp.418-426
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• 2015

Recently, shipping operators have been making efforts to reduce the fuel cost in various ways, such as trim optimization and bulb re-design. Furthermore, IMO restricts the hydro-dioxide emissions to the environment based on the EEDI (Energy Efficiency Design Index), EEOI (Energy Efficiency Operational Indicator), and SEEMP (Ship Energy Efficiency Management Plan). In particular, ship speed is one of the most important factors for calculating the EEDI, which is based on methods suggested by ITTC (International Towing Tank Conference) or ISO (International Standardization Organization). Many shipbuilding companies in Korea have carried out speed trials around the Korea Straits. However, the conditions for these speed trials have not been exactly the same as those for model tests. Therefore, a ship’s speed is corrected by measured environmental data such as the seawater temperature, density, wind, waves, swell, drift, and rudder angle to match the conditions of the model tests. In this study, fundamental research was performed to evaluate the ship resistance performance due to changes in the water temperature and salinity, comparing the ISO method and numerical simulation. A numerical simulation of a KCS (KRISO Container ship) with a free-surface was performed using the commercial software Star-CCM+ under three conditions that were assumed based on the water temperature and salinity data in the Korea Straits. In the simulation results, the resistance increased under low water temperature & high salinity conditions, and it decreased under high water temperature & low salinity conditions. In addition, the ISO method showed the same result as the simulation.

• 산업경영시스템학회지
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• 제33권2호
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• pp.154-161
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• 2010

The conning display which is located in the ship bridge shows the various important information such as ship position, ship speed, track data, rate of turn, thruster rpm so on, and is one of the IBSs(Integrated Bridge Systems). In this study, the survey was conducted for ten officers to find the importance and using frequency of the information which were displayed in the conning display. The results showed that the information of drift speed, ship speed, wind direction and wind force, rate of turn, sea water depth, ship position, heading, thrust rpm, alarm, rudder command and angle got high scores and it meant that these information were very important and high frequency of use during the navigation. The optimized contents arrangement in conning display was suggested based on importance and using frequency of information. The experiment using eye-tracking system was conducted to compare the performance time and error rate of nine different scenarios for suggested arrangement display and three other existing displays. The results showed that the suggested arrangement was the best in performance time and error rate. The scenario concerning the direction and speed of wind showed faster performance time and lower error rate than other scenarios. The movement of subject's eye tended to search from the center and to avoid the comer, called 'the comer effect.' It is expected that the results of this study could help for the bridge staff to grasp the sailing information easily and to cope with the given situations promptly.