• 유공압시스템학회논문집
• /
• 제7권2호
• /
• pp.19-26
• /
• 2010

The typical trunk lid system for vehicle is composed of a hinge having 4-bar link and gas lifter. Here, the energy regenerative brake of hydraulic driven systems is applied to the tail gate system for vehicle and removed the gas lifter. The new tail gate system is composed of a hydraulic pump by electric motor, a hydraulic motor, four check valves, an accumulator, a relief valve and a directional control valve. The dynamic characteristics of the hydraulic motor system, such as the surge pressure and response time, are investigated in both brake action and acceleration action. The capacity selection method of accumulator by mathematical model is based upon trial and error approach and computer simulation by AMEsim software is carried out.

• 한국연소학회지
• /
• 제20권2호
• /
• pp.36-39
• /
• 2015

The combustion characteristics of metal fiber burner fueled natural gas with tail gas produced from reforming process were analyzed on the point of flame stability and excess air conditions. Also, it was analyzed the effect of energy efficiency improvement due to decrease the fuel input in reforming system by using residue gases. As a results, it was confirmed that tail gas including hydrogen, CO and $CO_2$ could be directly injected without any change of air control system in natural gas burner and also energy efficiency was increased up to 30% maintained stable combustion.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2004년도 춘계학술대회 논문집
• /
• pp.424-428
• /
• 2004

A wind turbine system converts wind energy into electric energy, the system operated under normal environmental conditions. In case of particular turbulent wind flow such as typhoon, hurricane etc, the control of a blade used to a yaw control and a pitch control method. A small wind turbine has not a speed control system to only a manual tail safety brake. This paper shows a automatic tail safety brake controller based on feedback control using wind velocity. The controller composed of wired motor, relay system, steel wired motor him down a perpendicular to wind flow and then the blade speed reduced high to zero. The operation of automatic tail safety controller verified by manual test.

• Nuclear Engineering and Technology
• /
• 제41권5호
• /
• pp.723-728
• /
• 2009

The response property of the CZT detector ($5{\times}5{\times}5\;mm^3$), widely used in photon spectroscopy, was evaluated by considering the charge collection efficiency, which depends on the interaction position of incident radiation, A quantitative analysis of the energy spectra obtained from the CZT detector was also performed to investigate the tail effect at the low energy side of the full energy peak. The collection efficiency of electrons and holes to the two electrodes (i.e., cathode and anode) was calculated from the Hecht equation, and radiation transport analysis was performed by two Monte Carlo codes, Geant4 and MCNPX. The radiation source was assumed to be 59.5 keV gamma rays emitted from a $^{241}Am$ source into the cathode surface of this detector, and the detector was assumed to be biased to 500 V between the two electrodes. Through the comparison of the results between the Geant4 calculation considering the charge collection efficiency and the ideal case from MCNPX, an pronounced difference of 4 keV was found in the full energy peak position. The tail effect at the low energy side of the full energy peak was confirmed to be caused by the collection efficiency of electrons and holes. In more detail, it was shown that the tail height caused by the charge collection efficiency went up to 1000 times the pulse height in the same energy bin at the calculation without considering the charge collection efficiency. It is, therefore, apparent that research considering the charge collection efficiency is necessary in order to properly analyze the characteristics of CZT detectors.

• 전자공학회논문지A
• /
• 제32A권3호
• /
• pp.100-109
• /
• 1995

A new Hydrodynamic model for the high energy tail electrons(Tail Electron Hydrodynamic Model : TEHD) is developed using the moment method. The Monte Carlo method is applied to a $n^{+}-n^{-}-n^{+}$ device to calibrate the TEHD equations. the discretization method and numerical procedures are explained. New models for the impact ionization and injection into the gate oxide using the tail electron density are proposed. The simulated results of the impact ionization rate for a $n^{+}-n^{-}-n^{+}$ device and MOSFET devices, and the gate injection experiment are shown to give good agreement with the Monte Carlo simulation and the measurements.

• 전자공학회논문지SC
• /
• 제46권2호
• /
• pp.47-51
• /
• 2009

본 논문은 다중 입력을 가진 터보 코드 구조에 대한 연구로서 tail-biting 기법에서 효율적으로 Latency를 줄이는 터보 부호 알고리즘 및 하드웨어를 제안하였다. Mobile WiMAX 및 DVB-RCS 등에 적용된 이중 입력 터보 부호기의 고유 특성을 이용, 병렬 처리 하드웨어로 구현한 결과 tail-biting 기법을 위해 필요한 Latency를 기존 대비 약 47%로 줄이는 동시에 파워 소모량도 감소를 시켰다.

• 한국식품과학회지
• /
• 제31권4호
• /
• pp.906-911
• /
• 1999

저선량으로 조사된 곡류의 방사선 조사 여부를 판별 하는데 DNA 'Comet Assay'의 활용이 가능한지를 검토하였다. 참깨, 들깨, 밀, 보리 및 쌀을 0, 0.1, 0.3, 0.5, 0.7, 1.0 kGy로 조사하여 시료로 사용하였다. 시료에 PBS 용액을 가하여 세포 현탁액을 조제하고 agarose gel과 혼합하여 microscope slide 상에서 lysis한 후 전기영동하여 염색한 다음 DNA 절편의 이동에 의해 형성된 ‘comet’의 tail length를 측정하여 분석하였다. 0.3 kGy 이상으로 조사한 모든 시료에서 tail length가 비조사한 시료와 차이를 나타내어 조사 여부를 확실히 판별할 수 있었다. 또한 비조사된 시료에서는 tail이 없거나 아주 짧은 tail을 가진 세포들이 관찰되었으며, 조사된 시료에서는 조사선량의 증가에 따라 DNA의 손상정도가 증가함으로서 tail length가 길어지는 것이 관찰되었다. 특히 참깨, 들깨 및 밀의 경우는 0.1 kGy의 낮은 조사선량에서도 현미경을 통하여 육안으로 비조사한 시료와의 구별이 가능하였다. 따라서 DNA 'Comet Assay'는 간단하고 신속하며 비교적 저렴하게 실시할 수 있는 곡류의 방사선 조사 여부를 판별하는 데 활용할 수 있음을 확인하였다.

• Nuclear Engineering and Technology
• /
• 제55권12호
• /
• pp.4350-4356
• /
• 2023

Radiation detection systems working at high count rates suffer from the overlapping of their output electric pulses, known as pulse pile-up phenomenon, resulting in spectrum distortion and degradation of the energy resolution. Pulse tail extrapolation is a pile-up correction method which tries to restore the shifted baseline of a piled-up pulse by extrapolating the overlapped part of its preceding pulse. This needs a mathematical model which is almost always nonlinear, fitted usually by a nonlinear least squares (NLS) technique. NLS is an iterative, potentially time-consuming method. The main idea of the present study is to replace the NLS technique by an integration-based non-iterative method (NIM) for pulse tail extrapolation by an exponential model. The idea of linear extrapolation, as another non-iterative method, is also investigated. Analysis of experimental data of a NaI(Tl) radiation detector shows that the proposed non-iterative method is able to provide a corrected spectrum quite similar with the NLS method, with a dramatically reduced computation time and complexity of the algorithm. The linear extrapolation approach suffers from a poor energy resolution and throughput rate in comparison with NIM and NLS techniques, but provides the shortest computation time.

• 한국수소및신에너지학회논문집
• /
• 제20권1호
• /
• pp.31-37
• /
• 2009

An ejector is a machine utilized for mixing fluid, maintaining a vacuum, and transporting fluid. The Ejector enhances system efficiency, are easily operated, have a mechnically simple structure, and do not require a power supply. Because of these advantages, the ejector has been applied to a variety of industrial fields such as refrigerators, power plants and oil plants. In this work, an ejector was used to safely recycle anode tail gas in a 5 kW Molten Carbonate Fuel Cell system at KEPRI(Korea Electric Power Research Institute). In this system, the ejector is placed at mixing point between the anode tail gas and the cathode tail gas or the fresh air. Commercial ejectors are not designed for the actual operating conditions for our fuel cell system. A new ejector was therefore designed for use beyond conventional operating limits. In this study, the entrainment ratio is measured according to the diametrical ratio of nozzle to throat in the designed ejector. This helps to define important criteria of ejectors for MCFC recycling.

• 한국식품영양과학회지
• /
• 제31권4호
• /
• pp.594-598
• /
• 2002

과일의 방사선 조사 여부 확인과 저장에 따른 변화를 측정하기 위해 감마선 조사로 유도된 DNA손상을 comet assay로 확인하였다. 키위, 오렌지, 배를 구입하여 0.1, 0.3, 0.5, 0.7, 1.0 kGy의 저 선량으로 조사하고 비 조사 시료와 조사 시료간의 DNA 손상정도를 tail length와 tail moment로 측정하였다. 과일 씨의 DNA를 형광 염색하여 이미지 분석기를 이용하여 comet 양상을 관찰한 결과, 모든 시료에서 비 조사 시료보다 조사시료의 tail length가 더 길었으며 조사 선량이 증가할수록 tail length가 유의적으로 길게 나타났다. Tail moment로 나타난 결과도 이와 비슷하였으나 전체적으로 tail length에 비해 그 민감도가 낮았다. 방사선 조사한 과일을 저온에서 3개월 동안 저장한 후에도 저장 전과 마찬가지로 모든 시료에서 비 조사시료보다 조사 시료의 tail length가 더 길었으며, 조사 선량이 증가할수록 tail length가 길게 나타나, 저장 후에도 comet assay를 이용해 조사 시료와 조사 시료의 방사선 조사여부를 검지할 수 있었다 따라서 본 연구결과 comet assay는 신선한 과일과 일정기간 저장한 과일의 방사선 조사여부 판별에 유용하게 사용될 수 있음을 알 수 있었다.