• Title/Summary/Keyword: 흡수판

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Reduction of specific absorption rate(SAR) in multiple cylindrical-human models (복수 원통형 인체모델에서의 흡수전력 저감)

  • Yang, Jun-Won;Kim, Hyung-Ho
    • Journal of Digital Convergence
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    • v.10 no.1
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    • pp.271-276
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    • 2012
  • As applications of electromagnetic waves increase, biological effects caused by the EM waves are worried about. Many studies about the biological effects are reported. However, there are only a few reports on protection against the EM waves. The protection should be considered for the researchers who use strong EM waves in their experiments. In this paper, a method of reducing SAR in a cylindrical human model by a shield plate is proposed for RF engineers exposed to strong electromagnetic waves. The shield plate modeled as an arc structure is shown effectively to protect the cylindrical human model from the exposed field.

Stress Analysis of Plate-Spring-Type Landing Gear Materials (판스프링형 랜딩기어의 재질에 따른 응력 해석)

  • Kim, Kyeong-Hwan;Lee, Young-Shin;Han, Jae-Do
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.3
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    • pp.303-308
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    • 2014
  • Aircraft are an indispensable mode of modern transportation. They are also used as in a wide variety of other fields. For example, aircraft are used for accommodating passengers, carrying freight, and for military reconnaissance. Aircraft ground operations include landing and taking off. During landing, a higher load is applied to the landing gear than during takeoff. The landing gear should absorb impact energy and prevent damage to the main body of the aircraft in the case of an accident. In this study, simulations were performed for two types of plate-spring-type landing gear: that made of composite materials and that constructed with aluminum. The structural safety of landing gear made of each material was also evaluated.

The Study of Kogas Membrane Performance Test for LNG Storage Tank (Kogas 멤브레인 성능평가에 관한 연구)

  • Kim Y.K.;Hong S.H.;Yoon I.S.;Oh B.T.;Seo H.S.
    • Journal of the Korean Institute of Gas
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    • v.6 no.4 s.18
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    • pp.17-22
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    • 2002
  • LNG demand has been rapidly increasing in Korea for a variety of reasons including stable supply, non-polluting, and high combustion efficiency characteristics. One of the most important structural core element of the LNG storage tank is the membrane, consisting of stainless steel. The membrane to be applied inside of LNG storage tank is provided with corrugations to absorb thermal contraction and expansion caused by LNG temperature. Experimental studies are presented to investigate the deformation and strength of the membrane which is designed by Kogas. All experiments are conducted on the basis of RPIS, and we found the results is fully satisfied with the RPIS.

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Complications After Meniscus Allograft Transplantation (동종 반월상 연골 이식술 후 합병증)

  • Chun, Churl-Hong;Bae, Kyu-Hwan
    • Journal of the Korean Arthroscopy Society
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    • v.15 no.1
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    • pp.42-49
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    • 2011
  • Recently, meniscal allograft transplantation has been regarded as a successful procedure in terms of pain relief and functional improvement for the symptomatic patients previously underwent subtotal or total meniscectomy. However, the likelihood of a successful outcome would be reduced by various complications including graft tear, shrinkage, extrusion, infection, progressive chondral injury, and granuloma due to nonabsorbable suture material. Therefore, knee surgeons need to be all aware of the complications and to make an effort to minimize them. The purpose of this article is to review the current literatures regarding clinical results and complications after meniscus allograft transplantation.

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A MODIFICATION OF THE MICHELET TECHNIQUE FOR SLIDING HORIZONTAL OSTEOTOMY;A CASE REPORT (MICHELET 테크닉의 변형을 이용한 이부성형술의 치험례)

  • Lee, Jin-Gew;Davis, Isaac E.;Swift, James Q.
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.16 no.2
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    • pp.145-151
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    • 1994
  • 앞 턱 부위가 짧고 후방으로 위치해 있을 때 턱의 높이를 증가시키고 전방으로 돌출시키는 축조 이부성형술의 방법으로는, 매식체 삽입술, 골 절단술, 골 절제술 또는 이들을 동시에 시행하는 혼합술등이 행해져 왔다. 그러나 매식체 삽입술에서는 감염 또는 매식체의 유동성 등의 합병증의 발병이 빈발하고 매식체의 밑 부위에 골이 흡수된다든지 연조직의 변화를 예측하기 어렵다든지 하는 복잡한 문제점들이 종종 보고되고 있다. 따라서 매식체를 이용하지 않는 골 절단술이나 골 절제술만을 이용한 다양한 방법의 이부성형술이 많이 시행되고 있다. 하악골이 전후방 관계로 발육부전인 환자에게 양측 하악지 시상분할술을 시행하여 전방 이동시킨 후 앞 턱의 위치를 좀더 개선하기 위하여 $Michel{\'{e}}t$ 테크닉의 변형법을 이용한 이부성형술을 추가로 시행하였다. 이 방법의 이부성형술은 턱의 수직적, 수평적 길이를 증가시키기 위하여 하악결합면 부위에 장부와 장붓구멍 모양을 한 골 절단술을 시행하고 광범위한 연조직경을 보존하여 골편으로의 혈류 차단을 최소화하였으며 나사를 이용한 견고한 고정을 용이하게 하였다. 이 술식은 턱을 수직적으로 증가시킬 때 두 골편 사이의 공간에 골 이식을 시행할 필요가 없으며, 금속판을 이용하지 않아도 정확한 위치에 골편을 고정하기가 용이하고, 또한 고정용 나사가 향후 골형성 부위에 위치하게 된다는 장점을 경험하게 되어 이에 한 증례를 보고하는 바이다.

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Numerical Analysis and Experimental Measurement of Hygroscopic Warping Effects for Cellulose Fibres (셀룰로스 복합소재에서의 수분에 의한 뒤틀림 변형효과를 위한 수치해석적 실험적 연구)

  • Kim, Byeong-Sam;Kim, Ki-Jun
    • Journal of the Korean Society of Safety
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    • v.19 no.1
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    • pp.117-123
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    • 2004
  • The prediction to the hydroscopic moisture warping behaviors is analyzed for cellulose-based laminates using a numerical method base on a modified classical laminate(MCL) theory for hygroscopic moisture deformations with cycling testing data. The experimental measurement of the interferometric hygroscopic warping effects, moisture generator, and curvature of cellulose reinforced epoxy laminates is studied under cyclic environmental conditions using a Moire interferometer coupled. Accurate determination of curvatures provides a description of dimensional stability evolution; the tools for validation of computational internal stress and for the warpage prediction in model safety.

Real-time photolithography employing a transparent LCD panel as a configurable mask (투과형 LCD 패널을 이용한 실시간 포토리소그래피)

  • Pieh, Sung-Hoon;Park, Byoung-Ho;Jang, Yu-Jin;Kim, Kang-Hyun;Ahn, Seung-Eon;Kang, Byung-Hyun;Youm, Min-Soo;Sung, Man-Young;Kim, Gyu-Tae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.132-135
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    • 2003
  • 핸드폰에 장착된 반투과형 LCD (Liquid Crystal Display) 패널에서 반사판을 제거하면 투과형 LCD 마스크로 이용할 수 있다. LCD 패널의 광 흡수 실험에서 얻은 스펙트럼을 참고하여 다양한 파장대의 광원으로 리소그래피 하였다. 컴퓨터 이미지 프로그램으로 편집한 그림을 핸드폰 전용 통신 케이블을 통하여 LCD 패널로 전송하여, 다양한 모양의 패턴을 기판위에 전사하는데 성공하였다. 픽셀간의 경계가 현상되어 끊어지는 패턴이 형성되는 LCD 마스크의 단점을 극복하여 연속적인 패턴결과를 얻는데도 성공하였다. 이로부터 프로젝션 리소그래피의 응용에 쉽게 접근할 수 있는 발판이 마련된 것으로 생각된다.

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An Assessment on the Urban Riverfront in Shincheon, Daegu - Focused on a Universal Design Concept - (대구광역시 신천의 친수공간 평가 연구 - 유니버설디자인 개념을 중심으로 -)

  • Choi, Dong-Sik;Moon, Ji-Won;Kim, Shang-Hee
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.2
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    • pp.1-14
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    • 2012
  • The purpose of this study is to derive a desirable riverfront construction plan to me for the activities of citizens through the evaluation and analysis of the urban riverfront space from the perspective of universal design. Therefore, previous studies were examined in order to induce evaluation tools that bhve been grafted from the universal design concept; in addition, a field survey was conducted in Shincheon, Daegu, which was selected as the study target, in order to induce problems and improvement directions from the perspective of universal design. The major results can be summarized as follows. (1) In the 'fairness' aspect, all the items such as installation of integrated functional signage, showing pictures, symbols, foreign language signs, and restroom entrances signage were determined to be 'All Unsuitable' for all sections; and therefore, it is necessary to improve the fairness of usage for everybody. (2) In the 'Functionality(Usability)' aspect, all items such as installation of bicycle paths beside access roads, installation of integrated functional signs, and night light signs were determined to be 'All Unsuitable' for all sections; therefore, it is necessary to improve the functionalities of these facilities. (3) In the 'Convenience' aspect, all items such as the installation of bicycle parking areas, continuous rest facilities, and back and ann support(handles) at resting facilities were determined to be 'All Unsuitable' for many sections; therefore, it is necessary to improve these facilities for the convenience of usage. (4) In the 'Information(Recognizability)' aspect, all items such as showing pictures, symbols, foreign languages and installation of night light signs, and restroom entrances signage were determined to be 'All Unsuitable' for all sections; therefore, it is necessary to improve the recognizability to minimize misunderstandings and confusion. (5) In the 'Safety' aspect, all items such as the installation of safe pedestrian paths in parking areas, using anti-slip and shock absorption materials on restroom floors, and the continuous installation of pedestrian paths that are separate from bicycle paths were determined to be 'All Unsuitable' for all sections; therefore, it is necessary to improve the safety to prevent accidents. (6) In the 'Amenity' aspect, access roads, parking areas, hygiene facilities, convenience facilities, and waterside facilities for many sections were determined to be 'All Unsuitable'; therefore, it is necessary to conduct more concentrated hygiene management. (7) In the 'Accessibility(Mobility)' aspect, all items such as the installation of safe pedestrian paths in parking areas, and continuous pedestrian paths that are separate from bicycle paths were determined to be 'All Unsuitable' for all sections; therefore, it is necessary to improve the accessibility to provide safety and convenience. (8) In the 'Durability' aspect, access roads, parking areas, rest facilities, convenience facilities, fitness facilities, and waterside facilities were determined to be 'All Unsuitable' for many sections, therefore, it is necessary to improve sunken or damaged areas by inspecting facilities by section.

Dosimetry for Total Skin Electron Beam Therapy in Skin Cancer (피부암치료를 위한 전자선 전신피부 치료방법과 선량분포 측정)

  • Chu, Sung-Sil;Loh, John-Jk;Kim, Gwi-Eon
    • Radiation Oncology Journal
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    • v.10 no.1
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    • pp.107-113
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    • 1992
  • Increasing frequency of skin cancer, mycosis fungoides, Kaposi's sarcoma etc, it need to treatment dose planning for total skin electron beam (TSEB) therapy. Appropriate treatment planning for TSEB therapy is needed to give homogeneous dose distribution throughout the entire skin surface. The energy of 6 MeV electron from the 18 MeV medical linear accelerator was adapted for superficial total skin electron beam therapy. The energy of the electron beam was reduced to 4.2 MeV by a $0.5\;cm\times90\;cm{\times}180\;cm$ acryl screen placed in a feet front of the patient. Six dual field beam was adapted for total skin irradiation to encompass the entire body surface from head to toe simultaneously. The patients were treated behind the acryl screen plate acted as a beam scatterer and contained a parallel-plate shallow ion chamber for dosimetry and beam monitoring. During treatment, the patient was placed in six different positions due to be homogeneous dose distribution for whole skin around the body. One treatment session delivered 400 cGy to the entire skin surface and patients were treated twice a week for eight consecutive weeks, which is equivalent to TDF value 57. instrumentation and techniques developed in determining the depth dose, dose distribution and bremsstrahlung dose are discussed.

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Uncooled Metallic Thin-film Thermopile Infrared Detector (비냉각 금속 박막형 열전퇴 적외선 검지기)

  • Oh, Kwang-Sik;Cho, Hyun-Duk;Kim, Jin-Sup;Lee, Yong-Hyun;Lee, Jong-Hyun;Lee, Jung-Hee;Park, Se-Il
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.37 no.2
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    • pp.5-12
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    • 2000
  • Uncooled metallic thin-film thermopile infrared detectors have been fabricated, and the figures of merit for the detectors were examined. The hot junctions of a thermopile were prepared on a $Si_{3}N_{4}/SiO_{2}/Si_{3}N_{4}$-membrane which acts as a thermal isolation layer, the cold junctions on the membrane supported with the silicon rim which functions as a heat sink, and Au-black was used as an infrared absorber. Infrared absorbance of Au-black, which strongly depends on the chamber pressure during Au-evaporation and its mass per area, was found to be about 90 % in the wavelength range from 3${\mu}{\textrm}{m}$ to 14${\mu}{\textrm}{m}$. Voltage responsivity, noise equivalent power, and specific detectivity of Bi-Sb thermopile infrared detector at 5 Hz-chopping frequency were about 10.5V/W, 2.3 nW/Hz$^{1/2}$, 및 $1.9\times10^{7}$ cm.Hz$^{1/2}$/w at room temperature in air, respectively.

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