• Journal of information and communication convergence engineering
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• 제15권4호
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• pp.199-204
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• 2017

A compact dual-band half-ring-shaped (HRS) bent slot antenna fed by a coplanar waveguide for wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) applications is presented. The antenna consists of two HRS slots with different lengths and widths. The two HRS slots are connected through an arc-shaped slit, and the upper HRS slot is bent in order to reduce the size of the antenna. The optimized dual-band HRS bent slot antenna operating in the 2.45 GHz WLAN and 3.5 GHz WiMAX bands is fabricated on an FR4 substrate with dimensions of 30 mm by 30 mm. The slot length of the proposed dual-band slot antenna is reduced by 35%, compared to a conventional dual-band rectangular slot antenna. Experimental results show that the proposed antenna operates in the frequency bands of 2.40-2.49 GHz and 3.39-3.72 GHz for a voltage standing wave ratio of less than 2, and measured gain is larger than 1.4 dBi in the two bands.

• 한국건축시공학회지
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• 제9권6호
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• pp.169-174
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• 2009

기존의 평면으로 배치된 와이어 메쉬의 단점을 조사하고 이를 개선하기 위한 3차원으로 굴곡한 를 개발하기 위한 타당성을 분석하고자 다양하게 굴곡시킨 경우에 대한 구조해석을 수행하였다. 상부슬래브 전체 및 편측 등분포하중을 재하 한 모든 경우에서 wire mesh 굴곡각도 $45^{\circ}$인 경우가 정모멘트구간 및 부모멘트구간 모두 휨인장응력은 가장 적게 발생되고 횡방향으로 $45^{\circ}$ 굴곡시킨 경우가 전단응력이 가장 적게 발생된다. 변위도 종방향 굴곡각도 $45^{\circ}$인 경우가 변위가 가장 적게 발생된다. 따라서 기존의 평면으로 배치한 와이어 메쉬보다 굴곡시켜 배치하면 휨인장응력, 전단응력, 변위가 줄어들게 되므로 구조적으로 성능이 개선되며 와이어 메쉬를 $45^{\circ}$로 굴곡하는 것이 가장 구조적으로 유리하다.

• 한국광학회지
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• 제8권6호
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• pp.492-499
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• 1997

굽은 비선형 도파로를 이용한 완전 광 스위치와 굽은 비선형 Y 분기각을 갖는 도파로를 이용한 완전 광 논리 연산소자를 제안하였다. 제안된 완전 광 스위치와 완전 광 논리 연산소자는 굽은 비선형 도파로를 따라가는 비선형파의 전파에 기초를 두고 있다. 빔의 전파특성은 도파로의 비선형성과 입력 파워, 도파로의 굽은 각도 등의 파라미터에 의해 좌우되므로 파라미터를 변화시켜 가면서 파워의 출력 특성을 계산해 보았다. 또한, 비선형 물질로 빠져 나오는 파워를 다양한 위치의 검출기에서 계산함으로써 특정한 검출기의 위치에서 가장 이상적인 디지털 스위칭 특성을 찾았고 도파로 끝과 비선형 물질로 빠져 나오는 파워의 비율에 의해 다양한 논리 함수(AND, OR, XOR)를 구현해 보았다.

• 한국방재학회 논문집
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• 제6권3호
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• pp.37-45
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• 2006

다주교각의 횡방향 철근비에 따른 연성도 및 소성힌지 영역을 단주교각과 비교하여 평가하였다. 횡방향 철근비가 높을수록 연성도 증가는 뚜렷하며 다주교각의 경우 교축직각방향 거동시에는 단주보다 더 큰 연성도 증가를 보였다. 또한 횡철근 배근을 위한 소성힌지영역을 산정하였으며 목표연성도를 크게 할수록 횡구속 철근비의 증가와 함께 횡구속 되어야 하는 소성힌지영역 또한 높아져야함을 밝혔다. 다주교각의 방향별 거동에 따른 소성힌지 영역에는 차이가 있으며, 다주교각의 교축직각방향 거동시에는 모멘트 분포의 차이에 의해 보다 낮은 구간에서 소성변형을 보인다.

• 한국의류산업학회지
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• 제20권6호
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• pp.704-712
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• 2018

This study analyzed working postures using the Ovako Working Posture Analysis System (OWAS) to improve work clothes for construction workers. A video taken at a construction work site was stopped at regular intervals and the postures of relevant body parts proposed by OWAS was recorded. Additionally, based on analysis of the working postures code, the level of work action for each postures was classified from stage I to IV. General workers frequently straightened or bent forward at the waist, and used their legs to stand, bend, or walk. Wood workers moved extensively from the waist, keeping their legs relatively straight and their arms held below their shoulders, repeatedly tapping with a hammer weighing less than 10.0kg. Rebar bending workers mainly bent forward at the waist, with both legs bent or standing with one leg bent. Rebar transport and fixing workers walked with the waist straight, and occasionally one or both hands held above the shoulders. Their work also involved holding a hook, which weigh less than 10.0kg, in their hands, and the difficult task of lifting and placing long rebars, which weigh from 10.0 to 20.0kg or more. Concrete pouring workers bent or twisted their back to the side. Therefore, this study suggests that design goals should be different when developing workwear for each type of worker.

• Current Photovoltaic Research
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• 제11권2호
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• pp.54-57
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• 2023

Recently, requirements for improving the convenience of constructing BIPV (Building Integrated Photo Voltaic) modules had increased. To solve this problem, we fabricated shingled PV modules integrated with bent steel plates for building integrated photovoltaics. These PV modules could be constructed directly on the roof without the installation structure. We found optimal lamination conditions with supporting structures to fabricate a module on a bent steel plate. Moreover, we applied a shingled design to PV modules integrated with bent steel plates to achieve a high electrical output power. The shingled module with bent steel plates shows 142.80 W of solar-to-power conversion in 0.785 m² area.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.1088-1094
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• 1993

One of the important restraint conditions for determination of rotary tiller parameters is whether the outside of front cutting surface on blade in rotary tiller pushes untilled soil in operation. By theoretical analysis and graphic verification on computer, no sil-push conditions is put forward and formula for calculating the position angle of its bent line derived, as is convenient for selection of rotary tiller parameters and design and drawing of its blade.

• 한국공간구조학회논문집
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• 제6권2호
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• pp.131-136
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• 2006

It is important to evaluate energy absorption capacity of frames required during a design earthquake. An inelastic computer analysis based on mathematical modelling of energy absorbing frames and elements makes it possible to evaluate required energy absorption capacity. But such an analysis sometimes consumes much computation time particularly in case of complicated structural system. This paper presents a proposal to predict energy absorption of multi-bent steel frames by simple equivalent linear method.

• 한국가구학회지
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• 제12권2호
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• pp.11-18
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• 2001

Steaming has been used for bending wood for a long time, but the steam-bent wood is subject to spring-back and a relatively large radius of curvature. Liquid ammonia is known as an excellent wood plasticizer swelling both crystal and amorphous cellulose. Liquid ammonia technique for wood plasticization was developed and applied for bending alder and padauk pieces, which were used as parts of wooden furniture. The study confirmed that liquid ammonia bent wood can be used for various wood working design.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.633-636
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• 2009

New polyesters with bent-shaped mesogens were synthesized varying the central unit with 1,6- and 2,3- naphthylenes, and introducing the dodecamethylene flexible spacer. The mesogenic properties of the polymers were characterized by FT-IR spectroscopy, DSC, polarizing optical microscopy.