• Journal of Radiation Protection and Research
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• 제37권2호
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• pp.70-74
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• 2012

Silicon carbide (SiC) is a promising material for neutron detection at harsh environments because of its capability to withstand strong radiation fields and high temperatures. Two PIN-type SiC semiconductor neutron detectors, which can be used for nuclear power plant (NPP) applications, such as in-core reactor neutron flux monitoring and measurement, were designed and fabricated. As a preliminary test, MCNPX simulations were performed to estimate reaction probabilities with respect to neutron energies. In the experiment, I-V curves were measured to confirm the diode characteristic of the detectors, and pulse height spectra were measured for neutron responses by using a $^{252}Cf$ neutron source at KRISS (Korea Research Institute of Standards and Science), and a Tandem accelerator at KIGAM (Korea Institute of Geoscience and Mineral Resources). The neutron counts of the detector were linearly increased as the incident neutron flux got larger.

• 한국축산식품학회지
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• 제30권2호
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• pp.232-235
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• 2010

This study examined the photostimulated luminescence (PSL) detection method suggested by the Korean Food and Drug Administration to assess whether the method can be used to identify irradiated spices in restructured pork patties, which served as a model system for processed meat products. Red and black pepper powders were irradiated at 0, 5.0, 7.5, and 10 kGy, and pork patties were formulated with the spice at irradiated pepper concentrations of 0.1% and 0.5%. PSL was then used to estimate amounts of light derived from the spice itself and pork patties. The results of PSL analysis showed that red and black pepper powders were determined as positive and presumptive positive, respectively, when irradiated at more than 7.5 kGy. However, when used in pork patties, all samples were negative for irradiation. Thus, PSL may not be useful in detecting irradiated ingredients used in processed meat products.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.422-425
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• 2010

The infrared radiation of exhaust plume was investigated numerically by a finite volume method (FVM) with anisotropic scattering particles. The exhaust plume is considered to absorb, emit and scatter radiant energy isotropically as well as anisotropically. The spatial and spectral distribution characteristics were obtained for the detection wavelength with $2.7{\mu}m$. The radiative intensities were presented for the different detective direction.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2002년도 추계 학술대회논문집
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• pp.88-94
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• 2002

Curved intakes are commonly used from commercial aircraft to military missile. Sound radiation from the intake of air vehicle affects cabin noise, community noise and military detection. In this paper, Sound radiation from curved intake is computed using the high order, high resolution scheme. The generalized characteristic boundary conditions, adaptive nonlinear artificial dissipation model and conformal mapping for high order, high resolution scheme are used. The geometric change of curved intake and the frequency of acoustic source are considered. Two dimensional Euler equations are solved for theses analyses.

• 전자공학회논문지
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• 제53권5호
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• pp.143-151
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• 2016

본 연구의 목적은 별도의 방사선 외부 검출장치 없이 스마트폰 자체의 CMOS 반도체 소자만을 활용하여 의료용 방사선 발생장치에서 발생하는 방사선을 효율적으로 검출하기 위한 최적의 조건과 알고리즘을 개발하는 것이다. 본 연구를 통하여 스마트폰에 내장된 CMOS 반도체 소자에 X-선의 선량을 증가시켜가면서 CMOS 영상 센서에서 반응하는 픽셀의 개수 및 밝기 등을 측정하였다. 스마트폰의 전면 카메라가 후면 카메라보다 노이즈가 적고 X-선과 같은 방사선에 대한 반응 특성이 우수하였다. 섬광결정을 사용한 간접 검출방식에 보다 CMOS 자체에 X-선을 반응시키는 직접 검출방식이 더 적은 선량까지 정확하게 검출이 가능하였다. 또한 X-선에 대한 선량의존성은 역치값을 넘어가는 픽셀의 개수를 계산한 Pixel number에 비해 개별 반응한 픽셀의 밝기까지 이용한 Pixel intensity가 더욱 선형적으로 나타났다. 컬러모델에 의한 실험에서는 스마트폰의 컬러모델인 YUV 컬러모델의 값 중 픽셀의 밝기값의 정보를 가지고 있는 Y값을 활용하면 방사선 검출에 있어 효율적일 것으로 사료된다. 향후 이와 같은 방사선 검출을 위한 최적의 조건들과 효율적 검출 알고리즘들에 대한 추가적인 연구가 진행된다면 방사선 선량의 관리가 효율적이며 체계적으로 이루어 질 수 있기 때문에 국민보건건강에 일조 할 수 있을 것으로 사료된다.

• Journal of Radiation Protection and Research
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• 제35권2호
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• pp.81-84
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• 2010

A CSA(Charge Sensitive Amplifier) was designed and fabricated for application in a radiation detection system based on a semiconductor detector such as Si, SiC, CdZnTe and etc.. A fabricated hybrid.type CSA was evaluated by comparison with a commercially available CSA. A comparison was performed by using calculation of ENC (Equivalent Noise Charge) and by using energy resolutions of fabricated radiation detectors based on Si. In energy resolution comparison, a fabricated CSA showed almost the same performance compared with a commercial one. In this study, feasibility of a fabricated CSA was discussed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1371-1374
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• 1997

We had developed the on-line environmental monitoring system which has installed around Kori Nuclear Power Plants and will be taken the place of the existing system. The system consists of a main computer and 11 sets of radiation monitoring post equipments. Nal(Tl) scintillation detectro was adopted in addition to ion-chamber detector and implemented with DCU(Dose Conversion Unit) and SCA(Single Channel Analyzer). Compared with the existing system, it has revised feature in the radiation measurements which are detection of artificial radioactivity and 2-ways of the radiatiion detectors. The field test trsults show that the developed radiation detecting equipments can measure environmental radiation withn 5.0% of the theoretical value.

• Journal of Radiation Protection and Research
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• 제26권3호
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• pp.231-236
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• 2001

A brief introduction is presented on the radiation safety studies at Tohoku University Cyclotron & Radioisotope Center. Studies on two subject are described; (1) measurement of the thick target neutron yield and radioisotope production / activation cross section for ten's of MeV neutrons and ions using K=110 Tohoku University cyclotron to provide basicdata for accelerator shielding, and (2) development of techniques for high sensitive radiation detection and profile measurement using an Imaging Plate which is a high sensitive two-dimensional radiation sensor. Application of the Imaging Plate techniques to localization of very weak radioactivity and to neutron profile measurement is described.

• 한국군사과학기술학회지
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• 제14권2호
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• pp.299-304
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• 2011

In this paper, we developed the semiconductor neutron radiation detector and the multi-purpose radiation detection technologies for the next generation military personal surveymeter. The PIN type semiconductor neutron detector and the prototype measure the neutron radiation dose upto 1,000cGy with ${\pm}20%$ error. It also have a good performance about the Gamma, Alpha and Beta radiation and MIL-STD-810F.

• Radiation Oncology Journal
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• 제18권3호
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• pp.205-213
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• 2000

Purpose : 백서의 간에서 나타나는 방사선조사에 의한 조직손상에서 IL-1, IL-4, IL-6, TNF 등의 cyokine과 apoptosis와의 상관관계를 알아보고자 하였다. 대상 및 방법 : 백서의 전신에 8 Gy의 방사선조사 후 각 1일, 3일, 5일, 7일, 14일에 간 조직의 변화를 현미경으로 관찰하고, apoptosis의 발현빈도를 확인하였으며, IL-1, IL-4, IL-6군 및 TNF 등의 cytoklne에 대해서 면역조직화학염색 방법과, 간 조직과 혈액에서의 IL-6의 생물학적 활성도 측정 및 방사선 면역측정 등의 실험을 하였다. 결과 : 방사선조사에 의한 간 손상은 광학현미경 소견상 방사선조사 후 1일부터 관찰되어, 3일과 5일에 염증세포의 침윤과 함께 가장 심하게 나타났고, 7일 이후부터는 섬유화가 시작되었다. Apoptosis의 발현빈도는 광학현미경 소견과 in situ detection method 모두에서 방사선조사 후 1일에 가장 높게 나타났다. 면역조직화학 염색소견상, IL기과 TNF의 발현은 조사 후 1일과 3일에 보였고, IL-4는 모든 군에서 발현되지 않았다. IL순는 방사선조사 후 1일과 3일에 강양성으로 나타난 후 점차 감소하였고, 간 조직과 혈액에서의 IL푼의 생물학적 활성도와 방사선면역측정에서도 방사선조사 후 1일에 가장 높고 이후 점차 감소하였다. 결론 : 간에 방사선조사를 시행한 결과 IL-1, IL-6군 및 TNF와 같은 cytokine의 발현이 증가되었으며, 이들 cylokine의 분비가 apoptosis를 유도함으로써 apoptosls가 방사선조사에 의한 간 손상에 중요한 기전의 하나로 작용할 것으로 생각된다.