• 한국석유지질학회:학술대회논문집
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• 한국석유지질학회 1998년도 제5차 학술발표회 발표논문집
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• pp.29-37
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• 1998

The sedimentary succession on the northern coast of Jindo and the adjacent area comprises the thinly bedded, fine-grained deposits of an epiclastic sandstone, siltstone, black shale/mudstone, and cherty mudstone (ca. 200m in vertical thickness), which are interpreted as the finely stratified turbidites mainly by density underflow-induced currents. Most deposits can be divided into eight facies: thin-bedded, ash-rich massive sandstone layer (mS), graded and laminated mudstone layer (glM), graded mudstone layer with ripple lamination (rM), laminated and graded siltstone layer (lgZ), finely laminated black shale layer (IBS), structureless mudstone layer (mM), thin-bedded cherty mudstone layer (lCM), and contorted and laminated mudstone layer (dlM), The thin-bedded, ash-rich sandstone facies is interpreted to be deposited from high-density turbid underflows during a relatively large flooding. Most thinly bedded mudstone facies would be deposited from low-density turbid underflows (turbidity currents) with some different hydrodynamic condition and sediment concentration during the high discharge of river water. Whereas the structureless mudstone facies may result from raining down of suspended sediment intermittently supplied by overflows and interflows. From the entire succession, graded and laminated mudstone layers interbedded with thin-bedded, ash-rich massive sandstone are dominant in the lower part of the succession, and graded mudstone layers with ripple lamination ripple lamination occur mainly in the middle part of it. On the other hand, iaminated/raded siltstone and contorted/laminated mudstone layers prevail in the upper part. The transition of facies association is suggestive of the continuous change of main depositional setting from basin plain to lower slope, which could be due to the movement of depocenter by the increase of sediment supply (volcanic activity).

• Journal of Electrical Engineering and Technology
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• 제10권2호
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• pp.603-609
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• 2015

Dry air is an excellent alternative to $SF_6$ gas and is used as an insulation gas in Eco-friendly Gas Insulated Switchgears (EGISs), which has gained popularity in industry. Solid insulators in EGIS play an important role in electrical insulation. On the other hand, surface discharge can occur easily when solid insulators are used. This paper explored the surface discharge characteristics on the structure of three-layered laminated solid insulators to elevate the flashover voltage. A laminated solid insulator was inserted after the quasi-uniform electric field was formed in the test chamber. Dry air was then injected to set the internal pressure to 1 ~ 6 atm, and the AC voltage was applied. When identical solid insulators were stacked, the surface discharge characteristics were similar to those of a single solid insulator. On the other hand, the flashover voltage rose when the middle part was thicker and had lower permittivity than the top and bottom parts in the laminated solid insulator. Based on experimental results, when stacking a solid insulator in three layers, the middle part of the solid insulator should be at least four times as thick as the top and bottom parts and have lower permittivity than the others. In addition, the flashover voltage increased with increasing gas pressure on the surface of the laminated solid insulator due to the gas effect. This study may allow insulation design engineers to have useful information when using dry air for the insulation gas where the surface discharge can occur.

• Journal of the Korean Wood Science and Technology
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• 제45권6호
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• pp.746-752
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• 2017

Cross-laminated timber (CLT) is a relatively new engineered wood for timber construction. It is a great shear wall material. It was known that the shear performance of the CLT wall depends on the performance of connections. In connection, nail or screw has to be installed with a certain distance from the end of the timber. Current building code specifies the distance on the name of end distance. The end distance was decided as a minimum distance not to make splitting or tearing out in lumber or glued laminated timber. As a relatively new engineered wood, the end distance of CLT connection need to be identified because CLT is cross-wisely glued lumber products like plywood. Different from glued laminated timber or lumber, cross layer of CLT may prevent wood from splitting or tearing-out. As a result, the end distance of CLT was expected to be reduced than glued laminated timber. The shorter end distance may let more versatile connector design possible. In this study, prior to developing novel connection for CLT, the end distance of CLT connection was experimentally investigated to identify the end distance limitation. The experiments showed that the end distance can be reduced from 7D to 6D, in case of the tested CLT combination and screw in this study.

• Journal of Advanced Marine Engineering and Technology
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• 제33권5호
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• pp.762-769
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• 2009

A canoe is one of the most popular boats in leisure on the water. Generally canoe has been built by good wooden strips. And canoe built by FRP is used for business recently. But by the users' demands for good quality and the restriction to environmental pollution the wooden canoes are required for personal and canoe building business. The modern wooden canoes were built by the strip construction method are used typically. However it is not suitable for the mass productivity requires effective resource operations and managements of men, materials, times, and price. On this paper the new construction method, called the piling-up laminated construction method, is studied to building a canoe using the piling-up with the laminated wooden plates gives more productivity than the others. First a canoe with various curved surfaces is designed from 3D design system. And the hull of canoe model is divided horizontally to generating the laminated plates that will be converting real wooden plates available from the market and will be routed by the manufacturing machine. After the simulating and analyzing of piling-up with the laminated plates, the canoe is building with less times, less men, less resources, and lower price than other method, avoid of the requirements of additional building tools. On the next paper the constructing of a real canoe using the manufactured wooden plates will be studied.

• Journal of the Korean Wood Science and Technology
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• 제38권6호
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• pp.457-462
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• 2010

적절한 용도개발이 필요한 조선산업 폐합판의 흡음성능과 기계적 성질을 파악하고자 메이플과 메란티 폐합판을 적층하고 재단하여 폐합판재활용보드를 만들어 전달함수법으로 흡음율을 측정하고 휨강도를 측정하였다. 메이플과 메란티에서 제작된 폐합판 적층 보드의 최대강도는 각각 534와 414 kgf/$cm^2$으로 나타나 상용합판과 비교하여 비슷한 강도성능을 나타내었다. 측정주파수범위에서 메란티 폐합판재활용보드의 흡음율은 0.25 전후의 수치를 나타내어 비교 대상인 섬유판과 신갈나무 시험편보다 높은 흡음율을 나타내었다. 폐합판 재활용보드의 측면을 슬라이스절삭하여 제작한 보드는 우수한 강도적 성능과 흡음성능으로 실내장식재로의 재활용이 기대되었다.

• 한국강구조학회 논문집
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• 제12권3호통권46호
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• pp.291-302
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• 2000

복합적층 구조물에서 복합재료는 그 자체의 높은 강성, 강도와 내구성등의 특성을 갖고 있을 뿐 아니라, 구조물의 역학적 특성에 따라 얼마든지 재료의 특성을 합리적으로 구성하여 배치할 수 있는 매우 우수한 장점이 있다. 본 연구에서는 등분포로 재하된 복합적층경사판의 처짐에 관한 해석으로서 복합적층 경사판의 처짐을 나타내는 단일 4차 편미분방정식을 3개의 종속변수를 갖는 3원2차 연립방정식을 이용하여 해석하는 수치해석 법을 제시하였으며, 대칭 앵글-플라이 각도로 적층, 역대칭 앵글-플라이 각도로 적층, 비대칭 앵글-플라이 각도로 적층한 경우에 처짐과 단면력을 비교 검토하였다.

• 한국공간구조학회논문집
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• 제10권4호
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• pp.75-83
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• 2010

복합적층판은 다른 금속재료에 비해 높은 비강도, 비강성 등의 우수한 역학적 특성을 지니므로, 최근 다양한 분야에서 사용하고 있다. 그러나 이러한 복합적층판은 충격에 약하다는 단점이 있다. 그리하여 복합적층판의 충격거동에 대한 많은 연구가 이루어지고 있다. 충격거동을 조사하기 위해서는 우선 충격체와 복합적층판사이의 접촉력을 계산하여야 한다. 접촉력을 알기 위해서는 운동방정식, 복합적층판의 운동방정식 그리고 압입량에 관한 관계식을 동시에 풀어야 한다. 본 연구에서는 고전적인 헤르츠식, 썬식, 썬&양식 그리고 썬&탄식을 포함한 유한요소프로그램을 이용하여 복합적층판의 저속충격거동을 조사한다.

• 조명전기설비학회논문지
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• 제30권1호
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• pp.72-78
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• 2016

In terms of power components which use environmentally-friendly dry air that can substitute SF6, there have been studies on the electrical properties of the solid insulation "spacer" for the purpose of securing dielectric strength as they become smaller. This study laminated solid insulation to keep the creeping distance the same in the dry air and investigated vertical surface discharge characteristics by shape. The three sheets of disk-type solid insulation(Bakelite) were laminated in a manner to keep the creeping distance the same. The lamination was categorized as follows: "Type A" in which the insulations with the same disk diameter were laminated; "Type B" in which the insulations whose middle disk diameter was large were laminated; and "Type C" in which the ones whose middle disk diameter was small were laminated. For a vertical surface discharge experiment, dry air was injected into the test chamber depending on the shape of the laminated solid insulation, and chamber pressure was adjusted in a range of 0.1-0.6MPa. As volume decreased, surface discharging voltage by unit volume increased. This was because of dielectric polarization according to the structural characteristics of the shape of lamination. The highest surface discharging voltage was found in "Type C."

• 한국산학기술학회논문지
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• 제11권7호
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• pp.2661-2669
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• 2010

본 연구에서는 매트릭스가 손상된 적층복합판의 비선형 거동을 분석하기 위한 일차전단변형이론에 기초한 유한요소 정식을 유도하였다. Duan and Yao가 제안한 Matrix 균열의 강성 치환 방법을 적용하여 다방향 강성저하식을 구성하였다. 발생된 Matrix 균열은 탄성계수, 전단탄성계수 및 프아송비의 변화로 표현할 수 있으며, 이를 이용하여 판의 국부 강성 변화를 예측할 수 있다. 가정된 자연변형률 방법을 적용한 쉘요소를 이용하여 면내 및 전단잠김 현상이 발생하지 않았다. 적층복합판의 선형해석은 물론 비선형 해석결과들은 참고문헌의 결과들에 수렴되었다. 매트릭스가 손상된 적층복합판의 해석 결과들은 향후 연구에 비교자료로 활용될 수 있을 것이다.

• 한국강구조학회 논문집
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• 제18권2호
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• pp.251-259
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• 2006

최근 환경문제의 대두로 친환경 재료를 사용하는 건축물에 대한 연구가 주목을 받고 있다. 특히, 북미나 일본 등지에 서는 목질구조를 이용한 4층 정도의 사무소건축이나 교외형 호텔, 학교 등의 중층 목조 건축물을 실현하기 위한 연구가 진행되고 있다. 이러한 구조물은 하부층은 RC조로 하고 상부층은 목조로 하는 하이브리드 구조형식으로 보급되고 있다. 기존의 볼트나 드리프트 핀을 목재 중에 접합구를 삽입하는 방식으로 준 내화성능의 확보나 외관상의 이점이 있으나, 하중을 전달하는 지압면적이 작어 목재의 내부로 접합장치가 파고들기 때문에 목재에 균열을 발생시키는 약점이 있다. 본 연구에서는 목질 하이브리드 구법으로서 비교적 큰 하중을 받을 수 있는 2방향 라멘접합부 개발을 목표로 새로운 모멘트저항형 접합법을 검토하고자 한다. 이러한 시스템을 구축하기 위하여 H형강을 이용한 이음접합 단순보의 휨 실험을 행하였으며, 주요한 변수는 구조용집성재와 H형강의 삽입길이(보춤의 1배, 1.5배, 2배)와 H형강 상 하 플랜지와 구조용집성재 상하면 사이의 틈새에 에폭시의 충전유무이다. 실험결과, H형강의 보춤의 2배를 확보함으로써 목재의 강도 및 강성을 충분하게 발휘할 수 있었다.