• Defense and Technology
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• no.2 s.144
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• pp.36-49
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• 1991

Leclerc 전차는 "혁명적'방식의 장갑을 탑재하고 있다. 이 장갑은 주하중-베아링 축에 부착되는 module화된 복합 물질 요소로 구성되었으며, 손쉽게 맞춰 달수 있고, 교체가 가능하다. 이에 따라 전장에서 신속한 수리가 가능하며, 최신기술의 장갑 장착이 용이하다. 또한 기동성의 면에서 Lecerc 전차는 최신세대의 초압축형 1천5백마력 과급기형 디젤엔진을 탑재한 최초의 전차이다. 그 결과 이 전차의 차체는 Leopard 2나 M1과 같은 제2세대 전차에 비해 현저히 짧다. 현재 M1A2, 신형 Leopard 2, Challenger 2 등과 영국의 치프텐 전차 대체사업 수주를 위해 경쟁중에 있다

• Magazine of the Korea Concrete Institute
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• v.11 no.2
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• pp.127-137
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• 1999

In the previous study in relation to the current study, a test program for the verification of the proposed design equation was carried with fourteen prestressed concrete beams with unbonded tendons. Experimental results were compared with the computed results by the proposed design equations. The previous design equations are ACI code, AASHTO LRFD code, the analysis equation with the strain compatibility, Harajli/Kanj' design equation, Chakrabarti' design equation. As a result of comparative studies, it turned out that the proposed design equation could predict the ultimate tendon stress with comparatively high accuracy.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.92-92
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• 2003

본 연구는 부착규조류에 따른 부착성 요각류 Tigriopus japonicus의 nauplius 생산력을 알아보기 위하여 실시하였다. 실험에 사용된 T. japonicus는 부산 동백섬 부경대학교 수산과학연구소 부근에 있는 tidal pool에서 동물성부유생물망으로 채집하였다. 먹이생물로는 부경대학교 한국해양 미세조류 은행에서 보관중인 부착규조류 중 중형종인 Caloneis schroder를 대표종으로 이와 크기가(14.8~27.5$\mu\textrm{m}$) 유사한 종들을 대상으로 형태를 현미경 하에서 관찰하고, 지역과 분리일자 등을 고려하여 유사종을 선별한 후 최종적으로 종의 유전적 유사성을 밝히기 위하여 RAPD-PCR (random amplified polymorphic DNA polymerase chain reaction)을 실시하였다. 이 중 Caloneis schroder와 유전적으로 유사성이 낮은 Navicula spp. (KMCC B-245, 393, 394, 581) 4종을 선별하여 T. japonicus의 먹이로 사용하여 포란한 암컷의 nauplius 생산력을 3반복 조사하였다. Genomic DNA는 대부분의 종에서 성공적으로 검출되었으며, 종에 따라 PCR 증폭산물이 나타나지 않은 경우도 있었으므로, PCR 산물이 나타난 종에 대해서만 분석하였고, 증폭된 DNA band는 대부분 크기 0.5~2.0kb 범위에서 나타났다. 실험에 사용된 부착규조류 간의 유사성을 알아보기 위하여 similarity matrix를 분석한 결과 F값의 범위는 0.00에서 1.00까지 였으며, Caloneis schroder와 유사성이 낮은 종들에 비하여 유사성이 높은 종들이 더 많이 나타났다. 이들을 먹이로 하여 포란한 T. japonicus의 실험구별 nauplius 평균 개체수를 살펴보면, KMCC B-394가 255.7마리로 가장 높았던 반면 KMCC B-581가 29.7마리로 가장 낮았다. 그 외 KMCC B-245가 120.0마리, KMCC B-393가 76.0마리, Caloneis schroder가 32.3마리 각각 나타났다. 이와같은 결과를 볼 때 T. japonicus의 nauplius 생산력은 규조 종에 따라 큰 차이가 있는 것으로 판단된다.

• Computational Structural Engineering
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• v.8 no.4
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• pp.75-85
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• 1995

The purpose of the present study is to develop a computer program which can be used to analyze prestressed concrete structures containing either bonded or unbonded tendons. To accomplish this, first, the concrete, nonprestressed, and prestressed steels are modeled with cyclic constitutive laws to take into account the various loading effects. Then, the hybrid-type element method is derived to improve the computations capability of stresses and strains, especially for the unbonded tendon. Since it allows one to determine the cross-sectional deformations in an element without any assumptions for its deformed shape, the element length can be much longer than that of the conventional finite element method. In order to achieve such a long element, various integral schemes are examined to implement them into the program. Then, the computational method for prestressing effects is developed consistently with the analytical method for the structure. Finally, analytical studies for actual tests were carried out to verify the program developed in this study.

• Journal of Korea Game Society
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• v.10 no.6
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• pp.47-55
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• 2010

In this research, a chair type game controller has been developed. We implement pressure sensors on a chair so that user's whole body movements can be signalized. The signals linked to a game system. This process occurs a meaningful exercise effect. Because users can play exergame setting on the chair type game controller, it is reduces risk of physical injury such as falling down and the Joint pressure compared existing exergame controllers. Based on the advantages of seating, elderly and obese can be provided appropriate exergame.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.1
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• pp.59-68
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• 2013

This paper presents the fundamental study on the field applicability of new-type steel fiber improved the existing shape. In this study, the theoretical reviews and the laboratory test programs were carried out to evaluate the mechanical characteristic of the new-type of steel fiber. The steel fiber sticking coefficient of new-type steel fiber was estimated from the test results. The laboratory scaled shotcrete rebound tests were also performed to analysis the field applicability of New-type steel fiber shotcrete and the mechanical behaviour of New-type steel fiber shotcrete were compared with that of the existing steel fiber shotcrete. It was found that the strength characteristic of New-type steel fiber shotcrete was increased.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.6A
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• pp.395-404
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• 2012

In general, WBAN environment which use wearable devices on the human body show the different characteristics from other personal area networks. It is usually composed of sensors contacting the body and user terminal collecting the data from the sensors. The sensors are under the significant constraint of the energy resources, but the user terminal is different because it can be recharged and relatively have large energy resources. Under this characteristics, we design a new MAC protocol considering this requirements. The proposed MAC protocol can increase the energy efficiency of sensors and loads the unavoidable energy consumption to the user terminal for high energy efficiency of sensors. Additionally, the proposed MAC protocol provides the low delivery delay of the emergency information for the differentiated QoS because the emergency data requires more rapid transmission than the periodic sensed data. For this requirement, we employ the IFS (Inter Frame Space). For the efficient and objective evaluation of the proposed MAC protocol, IEEE 802.15.6 MAC is used to compare with it and we show that the advantage of the proposed MAC meet our expectation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.2
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• pp.58-65
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• 2021

As increasing social needs of pavement maintenance, pattern frame method has been constructed in Korea. The pattern frame not only increases the skid resistance of pavements but also improve the scenery. However, construction of the pattern frame currently relies on imported materials. In this paper, we localize the materials used in pattern frame and conduct performance verification on them. The important performance indicators are the adhesion strength of undercoating materials and the skid resistance of finished pattern frames. The adhesion strength was targeted at 1.4MPa, and the localization alternative material met the target performance with 2.35MPa, the skid resistance performance was targeted at 40BPN, and the localization alternative material met the target performance with 75BPN. In the case of localized materials, approximately 40% cost reduction (per 1m²)compared to imported materials was confirmed.

• The korean journal of orthodontics
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• v.36 no.5
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• pp.331-338
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• 2006

Objective: The purpose of this study was to evaluate whether the bond strength of polycarbonate brackets can be increased through surface treatment. Methods: One hundred polycarbonate brackets (Alice) were bonded to bovine incisors with light-cured adhesive. The bracket bases were treated with one of three methods; sandblasting, plastic conditioner application, and combined treatment with sandblasting and plastic conditioner. The brackets without any suraace treatment served as the control. The shear bond strength was tested with a universal testing machine, and failure pattern was assessed with the adhesive remnant index. Results: The shear bond strength in all experimental groups was higher than that of the control group (p < 0.001). The group treated with plastic conditioner after sandblasting showed statistically higher shear bond strength than the sandblasting only group to (p < 0.05). The group treated with plastic conditioner after sandblasting showed higher shear bond strength than plastic conditioner only group, but the difference was not statistically significant. Conclusion: The above results suggest that the surface treatments of polycarbonate bracket is mandatory to improve bond strength, and the most effective method is an application of plastic conditioner after sandblasting.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3A
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• pp.207-214
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• 2011

Ultra High Performance Concrete (UHPC), which is characterized by its high strength and advanced ductile behavior that is much superior to those of convention concrete, is a useful material to make thinner and longer bridges. The precast segmental construction method utilizing UHPC has been mainly studied because cast-in-place UHPC is very difficult and complicate to be achieved. As a part of those research, the structural performance evaluation of different types of joint connection method for hybrid cable-stayed bridge utilizing UHPC by using nonlinear analyses is performed in this study. The bond stress at joint is obtained by section force analyses for a 600 m cable-stayed bridge deck, and compared with the required bond stress at joint. Analysis results show that the U Type connection and straight type connection resist the highest ultimate load and bond strength, respectively. In addition, all considered joint connection systems satisfy the bond performances at joint required in the final stage of cable-stayed bridge utilizing UHPC.