• Journal of Radiation Protection and Research
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• v.29 no.4
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• pp.269-273
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• 2004

The hybrid dead time model adopting paralyzable (or extendable) and non-paralyzable (or non-extendable) dead times has been introduced to extend the usable range of G-M counters in high counting rate environment and the relationship between true and observed counting rates is more accurately expressed in the hybrid model. GMSIM, dead time effects simulator, has been developed to analyze the counting statistics of G-M counters using Monte Carlo simulations. GMSIM accurately described the counting statistics of the paralyzable and non-paralyzable models. For G-M counters that follow the hybrid model, the counting statistics behaved in between two idealized models. In the future, GMSIM may be used in predicting counting statistics of three G-M dead time models, which are paralyzable, non-paralyzable and hybrid models.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.05a
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• pp.389-393
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• 1998

방사성 핵종의 인위적 방사능 측정과 환경방사능의 측정에 있어서, 발생된 펄스의 에너지와 발생 상대시간을 동시에 측정하여 계수함으로써, 채널분해능과 시간분해능 및 처리속도를 향상시킬 수 있는 ADC 시스템을 개발하였다. 다양한 크기를 갖는 입력펄스의 파고와 관계없이 일정한 불감시간(deadtime)을 갖는 방식으로 시간보정 과정을 필요로 하지 않으며, 측정된 파고와 상대적 불감시간은 동시에 계수되어 방사능 분석을 위한 자료로 제공된다. 본 연구는, 기존에 측정효율을 감소시키는 주요 원인이 되었던 불감시간 보정 과정을 배제하고 전체 스펙트로스 코피(spectroscopy)의 정확도 및 안정도를 유지할 수 있는 변환체계를 개발하며, 특히 측정 환경에 따라 다양하게 적용할 수 있는 불감시간 측정방식을 제공하는 것이다.

• Nuclear Engineering and Technology
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• v.3 no.1
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• pp.3-7
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• 1971

A method for determining dead times of a G.M. detector as a function of the count rate has been investigated using the Mn$^{56}$ radioactive sample. The formula, (equation omitted), seems to be useful for determining a relation between the dead time and the count rate. Here (equation omitted)(N$_1$) is the dead time for the count rate N$_1$, N$_1$is the count rate at time zero, Nt is the count rate at time t, λ is the radioactive decay constant of the sample used, and t is the time between the first and second runs. When all the counting data were corrected for the dead times evaluated with this formula and then a variation of these corrected counting data with rime was observed, the results showed quite a good agreement with the published data for the radioactive decay of Mn$^{56}$ . Besides, it appears that the dead time decreases as the count rate increases in a dead time-to-count rate relation obtained by the same formula.

• Nuclear Engineering and Technology
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• v.10 no.3
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• pp.137-144
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• 1978

A method is presented here in order to determine a nonlinearity correction of observed counter rates in a GM counter. An expression, which is developed under the assumption of dead time dependence on counting rates, gives good agreement with the results obtained from the experimental work. The variation of pulse voltages from a GM counter with counting rates was measured with the aid of pulse height analyzer. This method gives accurate values for the dead time over a wide range of counting. The technique as outlined allows tile exact correction of the nonlinearity caused by dead time loss. It was observed that the dead time decreases as the counting rate increases.

• Proceedings of the Korean Nuclear Society Conference
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• 2003.10a
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• pp.415.1-415.1
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• 2003

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.375.2-375
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• 2002

• ETRI Journal
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• v.10 no.4
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• pp.33-39
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• 1988

본 고는 자기동조 제어기 구성에 관한 논문으로 제어기는 공정의 매개변수 변화와 외란, 잡음에 대하여 운용자의 조작없이 스스로 제어 특성을 만족하도록 동작하며, 공장자동화 시스팀의 일부로서 계층제어 시스팀 구성이 가능한 통신기능을 가지고 있다. 또한, 공정의 시간지연, 불감시간, 비선형 등에 대해서 만족할만한 제어효과를 나타내며, 범용자기동조 제어모드와 PID제어모드를 갖는다. 본문에서는 자기동조 제어기의 시스팀구성, 하드웨어구성, 소프트웨어구성에 대하여 기술한다.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.4
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• pp.46-52
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• 2001

In this paper it was examined both imaging system and processing algorithm for imaging's high speedization of fluorescent X-ray computed tomography using synchrotron radiation, The electronic system was used for dead time by about 6% but shortening of measure time was achieved by 2 seconds per 1 point. Also efficiency of reconstruction algorithm was proved, and memory and calculation amount was decreased by about 1/100 The fixed quantity was confirmed by physical phantom, and iodine distribution was presumed from image of thyroid gland in vitro These result shows realization possibility of fluorescent X-ray computed tomography measure in vivo.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.872-878
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• 1995

방사성폐기물 드럼내에 포함되어 있는 방사성 핵종의 양이 핵종분석장치로 측정할 수 있는 검출 하한치 이하이거나, 혹은 너무 높아 불감시간이 크게 증가될 경우에는 순수 Ge 검출기를 장착한 핵종분석장치로는 분석이 불가능하게 되므로 본 연구에서는 표면선량율과 Scaling Factor를 이용하여 드럼속에 포함되어 있는 핵종들의 양을 평가하는 방법을 제시하였으며, 불균일성이 높을 경우의 가능한 평가방법을 알아보기 위하여 점선원을 이용한 실험을 실시하였다. 그 결과 비균질 드럼에 대해서는 점선원을 이용한 자료를 이용하는 것이 합리적이고 기하학적 산술평균을 취함으로써 보다 정확도가 증가됨을 알 수 있었다. 그러나 그 오차범위는 -25%∼5.5%로서 실제보다 상당히 낮게 평가되는 경향이 있으므로 적절한 비균질성 보정인자를 적용할 필요가 있는 것으로 생각된다.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.2
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• pp.93-102
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• 2005

The Nyquist robust stability margin is proposed as a measure of robust stability for systems with Affine TFM(Transfer Function Matrix) parametric uncertainty. The parametric uncertainty is modeled through a Affine TFM MIMO (Multi-Input Multi-Output) description with dead-time, and the unstructured uncertainty through a bounded perturbation of Affine polynomials. Gershgorin's theorem and concepts of diagonal dominance and GB(Gershgorin Bands) are extended to include model uncertainty. Multiloop PI/PID controllers can be tuned by using a modified version of the Ziegler-Nichols (ZN) relations. Consequently, this paper provides sufficient conditions for the robustness of Affine TFM MIMO uncertain systems with dead-time based on Rosenbrock's DNA. Simulation examples show the performance and efficiency of the proposed multiloop design method for Affine uncertain systems with dead-time.