• Proceedings of the Korean Society of Laser Processing Conference
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• 2006.06a
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• pp.97-100
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• 2006

Picosecond (ps) laser micro-machining has emerged as an attractive method of fabricating high-precision microstructures, especially in metals. In this paper, a metallic mold for diffraction gratings is fabricated with a mode-locked 12 ps $Nd:YVO_4$ laser. Laser pulses with a wavelength of 355nm are irradiated on the surface of NOK 80, a mold material, to generate line patterns. In order to minimize the line width, laser power is set just above the ablation threshold of NOK 80. Results show that the spectrum from the fabricated mold is good enough for some industrial application.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.152-155
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• 2011

최근 폭발 등 극한하중에 대한 관심의 증대와 함께 방폭 및 연쇄붕괴방지를 위한 연구가 활발히 진행되고 있다. 이에, 본 연구에서는 폭발하중하의 강구조물의 손상도와 저항성능을 수치적으로 평가하고자 하였다. 이를 위해 구조물의 폭발피해경감을 위해 가장 중요한 구조부재인 기둥을 대상으로 폭발물과 구조물과의 이격거리를 달리하여 폭발하중을 적용하였다. 유한요소해석을 수행한 결과를 토대로 기둥의 손상도와 잔여압축강도를 비교하고 관계를 도출하였다. 본 연구의 목적은 폭발에 의해 기둥이 손상된 경우 구조물 전체의 연쇄붕괴저항성능에의 손상된 기둥의 기여도를 평가하는 것이다.

• Environmental Analysis Health and Toxicology
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• v.21 no.4 s.55
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• pp.323-330
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• 2006

The aim of current study was to evaluate the toxicity of nonylphenol(NP) on soil nematode, Caenorhabditi elegans. The stress-related gene expression, growth, reproduction and development have been employed to monitor soil toxicity. The 24-h median effect concentrations $(LC_{50s})$ of NP was $0.15mg/L$. The expressions of vitellogenin-6, vitellogenin-2, cytochrome P450 family protein 35a2 and apoptosis enhancer-1 genes were upregulated in C. elegans by NP exposure. Alterations in growth, reproduction and development were also observed in NP-exposed group and especially hatching failure was observed. The overall results indicate that C. elegans has considerable potential as sensitive markers for NP toxicity monitoring.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10c
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• pp.484-486
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• 2000

인터넷 비디오 방송 같은 멀티미디어 응용 프로그램들은 네트워크를 통한 비디오 전송을 필요로 한다. 그런데 네트워크 자원에 제약이 많은 경우에는 전송되는 비디오 스트림의 손실이 불가피하며 이러한 손실이 클라이언트나 네트워크에서 일어난다면 네트워크 자원의 낭비가 생기게 된다. 이에 본 논문에서는 제약이 많은 네트워크를 통해 계층적 인코딩이 적용된 비디오 스트림을 전송할 때 서버가 프레임 전체를 버리지 않고 가능하면 덜 중요한 계층만을 최적으로 버리는 선택적 계층 삭제 알고리즘을 제안하였다. 어떤 계층을 버리는데 드는 비용을 클라이언트 측에서 얻을 수 있는 QoS와 연관지어 볼 때, 제안하는 선택적 계층 삭제 알고리즘은 네트워크 자원 제약이 커질수록 기존의 선택적 프레임 삭제 알고리즘보다 높은 QoS를 보여주었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.706-708
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• 2017

노지에서 재배되는 실외작물의 경우 외부 환경에 노출되어 재배되기에 생육 또는 수학시기가 외부 요인에 많은 영향을 받는다. 이러한 외부 요인 중 과일의 당도 및 수확량에 많은 영향을 미치는 요인은 바로 날씨이다. 고온의 날씨 또는 저온의 날씨가 지속되거나 강한 풍속, 적절한 강수가 이루어지지 않을 경우 과일의 당도가 낮아지거나, 흠집이 발생할 수 있어 과일 도매가격에 영향을 미치게 된다. 본 논문에서는 월별 평균 온도, 강우량, 습도, 일사량, 최대풍속 등의 날씨 관련 데이터와 제사 또는 명절에 자주 사용되는 과실류인 배, 단감, 사과, 수박의 도매가격간의 상관관계를 분석을 통해 얻은 결과로 추후 농산물 가격 예측 또는 과일 가격 예측 연구에 기여를 하고자 한다.

• Journal of agricultural medicine and community health
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• v.19 no.1
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• pp.25-29
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• 1994

In order to find out the effects of vinyl house body, the author compared the physical and laboratory examinations between 96 cases of vinyl house farmers and 96 cases of land farmers who lived in 3 Gun's in Kyoungnam Province from July, 1st through September, 30, 1993. The examination included blood pressure, CBC, urinalysis, and blood chemistry. Systolic blood pressure and alkaline phosphates levels were lower in vinyl house farmers than in land farmers. But white blood cell counts were higher in vinyl house farmers and the other results were not different between two groups. It suggests that the environment of vinyl house - small, poorly ventilating, hot and humid environment - affected human body, then those facts should be considered during construction of vinyl houses.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.7_spc
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• pp.495-502
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• 2016

In this paper, time and frequency domain characteristics of Gyeong-ju earthquakes were investigated, and nonlinear time history analyses were conducted for bi-linear hysteretic structures excited by short-duration ground accelerations. Previous studies showed that larger inelastic displacements than the peak displacement of the corresponding elastic system were observed especially for the structures with structural period shorter than 0.3s, and the similar results could be obtained when long-duration ground accelerations were used as excitation loads. For the short-duration earthquakes, however, the inelastic displacements were not so large and almost identical to the peak elastic displacements.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.7_spc
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• pp.503-508
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• 2016

In this study, effectiveness of seismic retrofitting methods using passive damping devices was investigated through numerical analyses of short-period structures under earthquakes which have short-duration and high-frequency impulse characteristics similar to Geyongju earthquakes. Displacement spectra of elastic systems and ductility demand of inelastic systems were evaluated by increasing viscous or friction damping. The damping devices could reduce responses of the structures with shorter structural period than 0.2s. The earthquakes similar to impulse load did not induce the responses of the structures with longer period than 0.4s, and the effects of the damping devices which generates damping forces proportional to structural responses became insignificant.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.5
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• pp.3-8
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• 2013

We consider some adaptive iteration schemes that provide lower complexity of the iterative receiver by reducing unnecessary iterations. While conventional iterative receiver considers only fixed number of iterations, we apply adaptive iteration schemes, taking into account quality of the received frame. Based on simulation results, proposed schemes reduce average number of iterations while maintaining BER performance compared to the conventional scheme.

• Journal of The Korea Institute of Healthcare Architecture
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• v.18 no.2
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• pp.55-64
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• 2012

Recently, our country is caused with economic growth and development and city intensive brazier being caused by industrial accident, crime accident and suicide of traffic facility, it is caused by with Western dietary life and the emergency patient is to an increase tendency. And the life increases with medical development and the medical emergency demand of the old people are increasing. Approximately 80% of the patients are non-emergent patients who receive ambulatory care and the rest 20% of the patients are serio us- emergent patients Emergency patients because non-strategy it is doing with function as imported medical treatment and provides, equipment, the operation is being impossible with manpower tribal etc.