• Journal of Korean Society of Steel Construction
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• v.16 no.5 s.72
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• pp.621-628
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• 2004

This paper introduces a new theory, that in a stiffened plate, a steel stiffener could be substituted a composite material in order to prevent from buckling. Changing a steel stiffener into a composite material would not only preclude welding, but could also prevent damage to the material due to fatigue and corrosion.A composite material is assumed to adhere to a steel plate, and is never separated from the plate until the steel plate reaches buckling.Such plate has variable shapes, with different lengths and widths, and also shows an anisotropic material property. LUSAS, a commercial finite element analysis package, was used in the buckling analysis.This paper investigated buckling behavior in anisotropic composite plates with variable parameters.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.454-459
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• 1985

The structure of the seed of Lupinue angustifolius was studied in order to investigate the Food quality of lupin seed in comparision with soybean. The cotyledonary cells of lupinseed was in egg-like shape and much (more than 4 times) larger than those of soybean. The microstructure of cotyledonary cells of lupinseed was characterized with thick cell wall having distinct pit-pairs. The protein bodies in lupinseed cotyledon cell contained numerous crystaloids, which was absent in soybean. The middle lamella of soybean cell was partially disintegrated by excessive heat treatment ($120^{\circ}C$, 20 min), whereas those of lupinseed did not change much by heting at $120^{\circ}C$ for 130 min.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.805-805
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• 1995

핵연료저장시설의 화재 등 극단적인 사고조건하에서 $UO_2$ 소결펠렛의 습식산화와 건식산화에 대한 연구를 수행하였다. 손상된 지르칼로이 피복관 속의 $UO_2$ 소결펠렛을 산성분위기의 습윤조건하에서 산화시킬 때의 $UO_2$ 펠렛의 산화속도는 IDR(mg/$\textrm{cm}^2$.min) = 1.55 [H$^{+}$]$^{1.21}$ 로 나타났다. 또한 습윤조건하에서 $UO_2$ 분말에 알카리 및 알카리 토금속 산화물, 그리고 백금족 및 회토류 산화물 등과 같은 불순물들이 존재할 때의 산화속도를 조사하였으며 이들에 대한 영향도 관찰하였다. 핵연료저장시설의 가상화재를 바탕으로 한 400~$700^{\circ}C$의 온도범위에서, 피복관이 씌워진 $UO_2$ 소결펠렛의 건식산화반응을 조사한 바 $UO_2$ 소결펠렛은 산화초기에 U$_4$O$_{9}$ 또는 U$_3$O$_{7}$ 등의 중간상 형성에 따른 3-4%의 부피축소에 의해 결정립계 균열이 일어나고, $600^{\circ}C$ 이하에서는 온도증가에 따라 중간상에서 U$_3$O$_{8}$ 상으로의 상변화에 의한 부피팽창으로 피복관의 변형과 함께 산화속도의 가속을 발견할 수 있었고, $600^{\circ}C$ 이상에서는 핵연료소자의 소성변형으로 인한 산화속도의 지연을 발견할 수 있었다. 또한 $UO_2$ 펠렛의 건식산화거동은 기체-고체 반응시의 전형적인 형태인 shrinking core model에 잘 적용될 것으로 판단되었다.

• Journal of the Earthquake Engineering Society of Korea
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• v.16 no.2
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• pp.1-13
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• 2012

Seismic fragility functions are derived for probabilistic evaluation of seismic control performance of energy dissipation devices installed in reinforced concrete structures. Displacement-dependent dampers are added to the nonlinear single-degree-of-freedom systems with different natural periods and hysteretic characteristics of which stiffness and strength has uncertainty. Nonlinear time history analysis is conducted for those SDOF systems and the result is processed statistically to obtain seismic fragility functions in the form of log normal distribution. Variation of seismic fragility functions for different parameters of SDOF systems and dampers are investigated and the seismic control performance is assessed probabilistically.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.300-303
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• 2015

Digital imaging process has been put to practical use in various application sectors due to a rapid advancement such as memory devices, etc. However, noises are being generated due to various reasons during the image processing and a variety of methods are being studied in order to eliminate these noises. Generally, images are damaged due to a mixed noise having different characteristics. In this paper, a filter algorithm which switches according to the noise types was proposed in order to mitigate the influence of mixed noise included in the image. And using the PSNR as the standard for objective decision making of the improvement effect, it was compared with the existing methods.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2163-2165
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• 2001

화력 발전소 드럼수위의 제어는 보일러 시스템의 효율적인 운용을 위해 중요한 위치를 차지하고 있다. 드럼수위의 제어 목적은 드럼수위를 외란에 관계없이 항상 설정치로 유지하는 것이다. 정상 운전중에는 드럼의 중앙이하 부분에는 물이 차 있고, 상부에는 증기가 차 있으나 만일 수위가 너무 높아지면 carry over 현상이 발생하며 반대로 너무 낮으면 드럼 하부의 과열 및 튜브의 손상을 초래하여 대사고를 유발하게 되므로 드럼수위는 항상 정상으로 유지해야 한다. 드럼수위 제어루프는 처음에는 드림수위만을 제어입력으로 취하는 PI 제어기에 의해 이루어지다가, 주증기량이 일정량 이상 유지되면 드럼수위가 일정한 설정치를 유지하도록 급수량, 드럼수위, 주증기량에 의한 PI-PI 캐스케이드 형태의 제어로 절환되어 제어가 이루어진다. 또한 드럼 수위는 차압검출기에 의해서 측정되어지는데, 드럼의 압력에 따라 물과 증기의 밀도가 변하기 때문에 차압검출기에 의한 드럼수위 지시치는 드럼압력에 의한 보상도 요구되어진다. 본 논문에서는 중용량 화력발전소를 대상으로 드럼수위 보상과 드럼수위 제어기를 구현하고, 적용하여 실제 발전출력 증발시의 드럼수위 제어결과를 보임으로서 구현한 드럼수위 제어기의 효용성을 보인다.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.322-322
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• 2018

우리나라의 기후는 대부분 지역의 강수량이 약 1,350mm 이상의 습윤지역이다. 하계 집중형 강수형태로, 우리나라는 연강수량의 50%이상이 여름철(6월~9월)에 집중된다. 또한 제방이 제 기능을 발휘할 수 있는 시기도 6~9월이 되기 때문에 이전에 제방의 적절한 점검과 보강이 이루어져야 홍수와 태풍과 같은 자연재해를 막을 수 있다(Cha et al, 2010). 제방이 제 기능을 발휘하기 위해서는 홍수나 범람 등에 얼마나 견딜 수 있는지를 알아야 한다. 그러기 위해서는 무엇보다도 제방이 자연재해로부터 손상을 입게 되는 원인과 과정, 하천수의 침투로 인한 제체내부의 역학적 거동 등에 대한 충분한 이해와 지식을 함양해야 한다. 본 연구에서는 하천 제방에 대한 홍수취약성을 평가하는 새로운 기법을 기후변화에 따라 달라지는 하천의 수위변화를 고려하여 제방의 취약성 변화 정도를 파악해보고자 한다. 이를 위해 미래 기후변화 시나리오를 기반으로 대상유역의 홍수량을 산정하여 홍수위를 구하고 제방의 2차원 지하수침투 모형인 SEEP/W를 이용하여 침투거동을 분석함으로써 침투안정성을 평가하였다. 대상지역은 한강 본류 서울 구간으로 선정하여 대표 제방을 선정한 후, 대표 제방의 현재 계획홍수위와 기후변화를 고려한 홍수위를 고려하여 제방의 안전율을 분석하였다. 제방의 취약성 분석에 필요한 인자를 도출하고 이를 활용하여 기후변화 시나리오에 따른 제방의 수위변화를 고려한 제방의 취약성 분석을 실시하였으며 분석결과를 본 연구자가 기 개발한 제방홍수취약성지수(Levee Flood Vulnerability Index, LFVI) 값을 이용하여 제방의 취약성에 미치는 영향을 분석하였다.

• Archives of design research
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• v.13 no.3
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• pp.221-234
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• 2000

This thesis aims to study the space concept of the constructive mode in the work space of the postmodernism artists since 1970s. According to the changing view of the world artists, they are searching for the characteristics of having the parameter of formative organization on how they are related to the constructive system which represents the work styles. First, this study searches for the theoretical approaches of the constructive system and parameters that were studied by Le Corbusier - the module concept as the meaning of order system being used for the basic formative construction Second, when it is regarded as a formative construction in making art as the'principles of organization'(the law of living form), which was defined by Suzanne Langer in the formative theory as the organized structure shown in growth structure in mu and ecological system, the principles governing the module rules were arthmetically analysed art-work space through the dynamic symmetry of Jay Hambidge. Therefore, this study shows the principles working on the parameters for new formative organization as follows: First, the module in the work space should be designed and built from the dynamic symmetry. Second, the module should satisfy the human needs that it must be acceptable, efficient, flexible, which are the necessary and sufficient condition for the dynamic symmetry. Third, the dynamic symmetry which has the principle of Reciprocity and the principle of Complement as its primary construction principle has the common properties and the reciprocity in the construction of the work space and when it has the self similarity, it segments organically the total space without damaging the continuum.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.5 no.2
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• pp.113-125
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• 2010

Objectives: We have evaluated the effects of conservative treatment on one patient who was diagnosed to thoraco-lumbar junction and lumbo-sacral junction transitional zone syndrome. so, we investigate thoraco-lumbar junction and Jumbo-sacral junction tranzitional zone syndrome that was suggested by Maigne R. Methods : One patient was diagnosed as T12-L1 herinated intervetebral disc through MRI. We diagnosed the patient to transitional zone syndrome by symptoms and physical examination and used Acupuncture therapy, Cox technique to the patient. We measured Visual Analog Scale(VAS) before and after treatment. Results: After treating Acupuncture therapy, Cox technique in the case, We find out that the patient was improved. VAS score changed from 7 to 2 and physical examinations are improved. Conclusions: We improved the patient who had thoraco-lumbar junction and lumbo-sacral junction transitional zone syndrome by Cox technique and Acupuncture therapy, and we found that thoraco-lumbar junction related lumbo-sacral junction.

• Journal of Veterinary Clinics
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• v.30 no.5
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• pp.346-352
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• 2013

The study was aimed to investigate the influence of diode laser on osteoarthritis (OA) of stifle joint induced by anterior cruciate ligament transection (ACLT). Sixty 10-week-old male Sprague-Dawley rats were used in this study. Right stifle joint was operated to create ACLT or sham. There were five study groups: control, Sham, ACLT, ACLT + Laser irradiation (ACLT+L) and ACLT + meloxicam administration (ACLT+M). Low-level laser therapy (LLLT) was applied at the operated stifle joint twice a week using an 808-nm indium-gallium-arsenide (InGaAs) diode laser during 8-week experimental period. Radiographical, gross morphological and histopathological findings were examined at 2, 4 and 8 weeks post-surgery. Radiography, CBC and chemistry tests showed no significant difference between groups. ACLT+L group showed remarkable cartilage damages compared with sham group morphologically and histopathologically at 2, 4 and 8 weeks after surgery. ACLT+M group also had more cartilage damages compared with sham group. Low-level laser therapy (LLLT) showed limitation to prevent progression of OA in the rat anterior cruciate ligament transection models; on the contrary it accelerated cartilage damage. It is assumed that the aggravating results of LLLT in this study might be due to excessive unstable movement of stifle joint from the pain-relieving effect of LLLT, rather than direct damaging effect of irradiation since LLLT did not affect cell viability.