• 대한치과보철학회지
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• 제43권6호
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• pp.727-735
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• 2005

Statement of problem. Platform switching in implant prosthesis has been used for esthetic and biological purpose. But there are few reports for this concept. Purpose. The purpose of this study is evaluation of platform switching in wide implant by three dimensional finite element analysis. Materials and Methods. The single implant and prosthesis was modeled in accordance with the geometric designs for Osstem implant system. Three-dimensional finite element models were developed for (1) a wide diameter 3i type titanium implant 5 mm in diameter, 13 mm in length with wide cemented abutment, titanium alloy abutment screw, and prosthesis (2) a wide diameter 3i type titanium implant 5 mm in diameter, 13 mm in length with regular cemented abutment, titanium alloy abutment screw and prosthesis(platform switching) was made for finite element analysis. The abutment screws were subjected to a tightening torque of 30 Ncm. The amount of preload was hypothesized to 650N, and round and flat type prostheses were loaded to 200 N. Four loading offset point (0, 2, 4, 6 mm from the center of the implants) were evaluated. Models were processed by the software programs HyperMesh and ANSA. The PAM-CRASH 2G simulation software was used for analysis of stress. The PAM-VIEW and HyperView were used for post processing. Results. The results from experiment were as follows; 1. von Mises stress value is increased in order of bone, abutment, implant and abutment screw. 2. von Mises stress of abutment screw is lower when platform switching. 3. von Mises stress of implant is lower when platform switching until loading offset 4 mm. 4. von Mises stress of abutment is similar between each other. 5. von Mises stress of bone is slightly higher when platform switching. Conclusion. The von Mises stress pattern of implant components is favor when platform switch ing but slightly higher in bone stress distribution than use of wide abutment. The research about stress distribution is essential for investigation of the cortical bone loss.

• 한국지반공학회논문집
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• 제27권2호
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• pp.5-15
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• 2011

일본에서 개발된 원추형 팽이기초(Top-Base Foundation)와 국내에서 개발된 부양형 팽이기초(Floating Top-Base Foundation)를 대상으로 대표 점토질 연약지반인 저압축성점토, 점토질 실트, 점토질 모래에 타설하여 실내모형실험을 수행하였다. 본 실험을 통해 하중-침하량, 기초측면 히빙량, 지중응력분포 등을 측정하여 두 가지 팽이기초의 성능을 비교 평가하였다. 또한, 단변길이 증가에 따른 침하량 변화를 분석하였다. 실내모형실험 결과 부양형 팽이기초가 지지력 증진, 침하량 저감, 응력분산효과, 측방구속력에 대해서 좀 더 우수한 성능을 발휘하는 것으로 나타났으며, 기초폭증가에 따른 침하량은 팽이기초 $5{\times}5$배열을 기점으로 수렴하였다.

• 한국농공학회지
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• 제8권2호
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• pp.1124-1140
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• 1966

'This hydraulic experiment have been practised Juk an Reservoir spillway and discharge 'channel which the province Kyong Buk was constructed and designed U. hook, for seizing all state of hydraulic. As result of the experimellt planning and making the model test, it has gained the necessary data at the amendment, projection of the most rational and economical result. 1. Project (1) Experiment project....1/30 of the discharge (2) project flood....0.01945 $m^3$/sec (rapidly) 2. Design Experiment It were sighted the water level for the nine point (L. & R. sides of No. O, L. & R. of No.1, L. side of NO.2, NO.3, No. 4 and NO.5), but it appeared each other that the lowest water level was 0.63 m at spillway (No.5) and the highest water level 0.735m less than planning water level O.75 m at No. 0. It was regarded as the phenomena appearing the difference from the calculation of the rational formular and coefficient of discharge. 3. Experiment examine E. ${\circled1}$ As a table (2) it had not a difference in comparision with design and was some lower value than design experiment's. E ..${\circled2}$) !twas same table (3) in a consequence of Experiment contracted Rocky cutting. E.${\circled3}$. ${\circled4}$ It was done amend.ment Experiment by elevating G.H. in only control point, but was not sure result as a table (2)(3)(4), and so it was changed largely in ${\circled5}$ Experiment. E. ${\circled5}$ Increasing water level was understanded to be proportion to $V^2$ in consideration of centrifugal force in the curve part and showed velocity contracting in curve the effect order's being regular in consequence of 1/6 sloped extending G.H. attached from 5 No. 0 to 1. 50 m, to S No. 0+5m. (S; discharge channel number).

• 한국멀티미디어학회논문지
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• 제15권4호
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• pp.472-484
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• 2012

보행자의 안전한 보행을 위해 점자형 또는 일반 보도블록이 널리 쓰이고 있다. 불량한 시공 및 유지상태와 장애물은 보행자의 사고를 유발한다. 본 연구는 안전한 보행을 위해 영상에서 가시거리에 위치한 블록의 형태 패턴과 텍스처 특징을 분석하여 보도블록을 검출하는 방법을 제안한다. 보도는 특정모양의 블록이 일정 간격에 반복 배치되어 규칙성을 띄며, 주변 환경 또는 용도에 따라 그 형태는 다양하다. 높은 빈도를 띄는 단일 모양의 다각형을 분석하여 형태 패턴을 추출한다. 일부영역은 이물질 또는 조각난 블록이 원래의 형태를 왜곡시켜 검출되지 않는다. 이 문제는 텍스처 특징벡터 값을 분석하여 해결한다. 앞서 검출된 모든 영역에 대해 분석된 텍스처 특징벡터는 가우시안 분포를 나타내고, 미검출 영역에 대해 분석한 텍스처 특징벡터가 가우시안 분포를 만족하는지 판단한다. 만족된 영역은 보도블록으로 검출한다. 본 실험은 다양한 형태의 보도블록을 인식하였고 95.9%의 정확성을 보였다.

• 한국도서관정보학회지
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• 제13권
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• pp.85-111
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• 1986

Dewey Decimal Classification (DDC) was first published in 1876. Since its first edition it has been revised, on an average, 6 years, and now it has become the widely used library classification system of which the scheme was translated in various languages. The purpose of this study is to find out the chief causes for the development of the DDC. The results of the study can be summarized as follows: 1. It allows materials to be shelved in a relative location as the collection expands. before the DDC was introduced, libraries used a fixed location for materials in which each item was assigned to a certain location set aside for a subject. 2. It is a practical system. The fact that it has survived many storms in the past hundred years and is still the most widely used classification scheme in the world today attests to its practical value. 3. The pure notation of arabic numerals is universally recognizable. People from any cultural or language background can adapt to the system easily. 4. The use of the decimal system enable infinite expansion and sub-division. And it has adaptability for use in libraries of various size and kinds because of its hierarchically expressive notation which permits varying degrees of inclusiveness and exclusiveness within its decimal structure. 5. The notation is simple and easily understood. The self-evident numerical sequence facilitates filing and shelving. And the mnemonic nature of the notation helps the readers to memorize and recognize the class numbers. 6. The relative index brings together different aspects of the same subject scattered in different disciplines. 7. We can avail of DDC numbers for specific titles easily because of its use by many central bibliographic services. 8. It is being continuously revised by a permanent office established in the library of congress in 1933. This office has been responsible for editing all editions of the DDC since the 16th (1958). And the periodic revision at regular intervals ensures the currentness of the scheme. 9. It has adaptability both for conventional (manual) shelf or classed catalogue analysis and also, through its meaningful nation, for retrieval through mechanization and computerized systems.

• 한국안전학회지
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• 제23권1호
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• pp.35-45
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• 2008

This study was performed to compare the kinematics among three different safety shoes(type 1: ergonomically designed and high quality shoes, 2: curved and cushioned safety shoes, and 3: regular safety shoes) and to find the effect of insole during walking. Ten healthy subjects were recruited for this study. The range of motion of knee and ankle joint, angle of rear foot and angle of heel contact were measured using a three dimensional motion analysis system. In the second peak, the angle of heel contact showed statistically significant difference between safety shoes and insole, however, there was no statistical significance among three different safety shoes. The angle of ankle increased significantly at initial contact, first peak, the second peak and the toe off phase compared with type 1 and 2 safety shoes, and the angle of ankle showed statistically significant difference between with and without applying the insole. During the first peak, the second peak and the toe off phase, the angle of knee was statistical significance between safety shoes and insole. In heel contact, the angles of Achilles' tendon showed statistically significant difference between safety shoes and insole. The rear foot angles showed statistically significant difference between safety shoes and insole during heel contact and early heel contact. These results suggest that the type 1 safety shoes were superior to others in the statistics, and applying insole could be a possible method to prevent fatigue of lower extremity and musculoskeletal disorders. Further studies are needed to find the effect of ergonomically designed safety shoes and insole on practical value in prevention of musculoskeletal disorder, fatigue and satisfaction of workers.

• 한국전기전자재료학회논문지
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• 제24권7호
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• pp.578-583
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• 2011

We report on the design of a holographic homogenizer composed of a periodic hologram and a condensing lens. If the hologram is periodic, the homogenizer is free from the alignment error of the incident laser beam. Holographic homogenizer also has an advantage of the flexibility in the size of the target beam. We calculated theoretically the Fraunhofer diffracted wave function when a rectangular laser beam is incident on a periodic hologram. The diffracted wave is the sum of sinc functions at regular distance. The width of each sinc function depends on the size of the incident laser beam and the distance between the sinc functions depends on the period of the hologram. We calculated numerically the diffracted light intensity for various ratios of the size of the incident laser beam to the period of the hologram. The results show that it is possible to make the diffracted beam uniform at a certain value of the ratio. The uniformity is high at the central part of the target area and low near the edge. The more sinc functions are included in the target area, the larger portion of the area becomes uniform and the higher is the uniformity at the central part. Therefore, we can make efficient homogenizer if we design a hologram so that the maximum number of the diffracted beams may be included in the target area.

• 한국전기전자재료학회논문지
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• 제26권6호
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• pp.425-428
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• 2013

In this paper, we present a novel hydrophilic coating material (Wellture Finetech, Korea) which can be utilized as a coating layer for anti-contamination for electrical and electronic system. The coating material was deposited on 4 inch silicon wafer with several different film thickness. The film thickness was controlled by spin coating speed. After curing of the film, we have scratched by permanent marker to check self-cleaning property of the film. Also we have executed several mechanical tests of the films. As the spin coating speed is increased, the film thickness was thinned from 230 nm to 125 nm. Contact angle of the film was lowered from $30^{\circ}$ to $12^{\circ}$ as the spin coating speed is increased from 700 to 2,500 rpm. On permanent marker scratched film surface coated at 1,000 rpm, we have poured regular city water to investigate self cleaning property of the film. The scratches were gradually separated from the film surface due to super-hydrophilicity of the film. Hardness of spin coated film was 9H measured by ASTM D3363 method. and adhesion of all film was 5B tested by ASTM D3359 method. Also, to get exact hardness value of the film, we have utilized a nano-indenter. As spin speed is increased, the hardness of film was increased from 3 GPa to 5 GPa.

• 한국가스학회지
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• 제18권3호
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• pp.44-52
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• 2014

높은 지가로 인해 초기 설치투자비가 많이 필요한 수도권의 경우 간이 주유취급소는 광범위하게 보급할 수 있는 큰 잠재력을 가지고 있다. 본 연구에서는 향후 국내에 설치 보급될 수 있는 간이 주유취급소에 대하여 편의성 및 안전성을 갖는 합리적인 시설기준을 제시하고자 하였다. 이를 위해 현실적으로 간이 주유취급소에서 발생할 수 있는 상황을 고려한 누출 시나리오를 선정하고, 피해예측 프로그램인 PHAST v.6.5를 이용하여 화재 및 폭발 사고의 피해범위를 산출하고, 그 피해영향을 해석하였다. 위험성 평가결과를 바탕으로, 간이 주유취급소의 주유공지, 전용탱크 상한용량, 고정주유설비 설치위치 및 방화벽 높이에 대한 기준을 현행 위험물안전관리법상의 일반 주유취급소와 비교하여 제안하였다.

• Journal of Chest Surgery
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• 제12권4호
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• pp.442-449
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• 1979

Although anoxic cardiac arrest produces a dry, quiet field, the ability of the myocardium to withstand the anoxic insult is uncertain. The current growth of interest in the use of various cardioplegic solutions ` has resulted in the development of a number of different solutions. In this study, 51 consecutive cases of elective open heart surgery with the aid of extracorporeal circulation were reviewed retrospectively to compare two methods of myocardial preservation. All of these open heart operations had been performed, using hemodilution principle under the moderate hypothermia at the Department of Thoracic and Cardiovascular Surgery, College of Medicine, Kyungpook National University from December, 1975 to July, 1979. In the 31 consecutive cases that form the anoxic arrest group, the operations were done with intermittent aortic cross-clamping and topical cardiac hypothermia. The heart was cooled topically by cold normal saline, which was converted to ice slush before application to the pericardial sac. Twenty of 51 consecutive cases were assigned to the cold cardioplegic method [the cardioplegic group], in which two kinds of cold cardioplegic solutions [Young solution and G IK solution] were infused into the aortic root proximal to the aortic cross clamp for myocardial preservation. Mean total aortic cross clamp times were 43 minutes in the anoxic arrest group and 67 minutes in the cardioplegic group. In the post-operative period, spontaneous regular heart beatings were recovered in 80 percent of the cardioplegic group as opposed to 25.7 percent of the anoxic arrest group. Ventricular fibrillation requiring DC shock was seen in 32.3 percent of the anoxic arrest group and 10 percent of the cardioplegic group. In the cardioplegic group, mean CPK-MB was one positive value on the first post-operative day, and mean LDH 1 was elevated to 51 0 units/ml on the 2nd post-operative day. These results indicate that protecting the myocardium with cold cardioplegia is superior to use of the anoxic cardiac arrest.