• Journal of Electrical Engineering and Technology
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• 제7권4호
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• pp.501-512
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• 2012

Social welfare maximization in a double-sided auction market is performed by implementing an aggregation-based particle swarm optimization (CAPSO) algorithm for optimal placement and sizing of one Static Synchronous Series Compensator (SSSC) device. Dallied simulation results (without/with line flow constraints and without/with SSSC) are generated to demonstrate the impact of SSSC on the congestion levels of the modified IEEE 14-bus test system. The proposed CAPSO algorithm employs conventional quadratic smooth and augmented quadratic nonsmooth generator cost curves with sine components to improve the accurate of the model by incorporating the valve loading effects. CAPSO also employs quadratic smooth consumer benefit functions. The proposed approach relies on particle swarm optimization to capture the near-optimal GenCos and DisCos, as well as the location and rating of SSSC while the Newton based load flow solution minimizes the mismatch equations. Simulation results of the proposed CAPSO algorithm are compared to solutions obtained by sequential quadratic programming (SQP) and a recently implemented Fuzzy based genetic algorithm (Fuzzy-GA). The main contributions are inclusion of customer benefit in the congestion management objective function, consideration of nonsmooth generator characteristics and the utilization of a coordinated aggregation-based PSO for locating/sizing of SSSC.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2006년도 춘계 종합학술대회 논문집
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• pp.499-502
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• 2006

정보통신의 미래가 인터넷과 디지털 콘텐츠 기술 확보에 달려있다는 전문가들의 예측은 이제 현실이 되어 있으며, 영상 산업 및 게임, 가상현실 등의 디지털 콘텐츠 산업에서는 소비자들에게 시각적으로 사실적이고 화려한 영상을 제공하기 위하여 다양한 특수효과를 필요로 한다. 이중 불꽃, 폭발, 연기, 액체, 눈, 비, 먼지와 같은 실시간 특수효과 재현에 관한 연구는 무엇보다 시급한 상태이며 제작의 편리함을 위해 실시간으로 구현된다. 본 논문에서는 각종 디지털 콘텐츠 상에 자연현상 등의 특수효과를 손쉽게 적용할 수 있는 상위 수준의 그래픽스 라이브러리 형태인 입자시스템 라이브러리를 구현하고 위치, 속도, 색상, 투명도, 크기, 수명, 2차 위치, 2차 속도 등의 속성 조절을 통해 손쉽게 특수효과를 생성할 수 있는 실시간 특수효과 생성기를 개발하고자 한다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2002년도 추계학술발표회요약집
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• pp.387.2-387
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• 2002

• 대한기계학회논문집B
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• 제24권6호
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• pp.753-759
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• 2000

Photoelectric charging is a very efficient way of charging small particles. This method can be applied to combustion measurement, electrostatic precipitator, metal separation and control of micro-contamination. To understand the photoelectric charging mechanism, particle charging of silver by exposure to ultraviolet is investigated in this study. Average charges and charge distributions are measured at various conditions, using two differential mobility analyzers, a condensation nucleus counter, and an aerosol electrometer. The silver particles are generated in a spark discharge aerosol generator. After that process, the generated particles are charged in the photoelectric charger using low-pressure mercury lamp that emits ultraviolet having wavelength 253.7 nm. The results show that ultra-fine particles are highly charged by the photoelectric charging. The average charges linearly increase with increasing particle size and the charge distribution change with particle size. These results are discussed by comparison with previous experiments and proposed equations. It is assumed that the coefficient of electron emission probability is affected by initial charge. The results also show that the charge distribution of a particle is dependent on initial charge. Single changed particle, uncharged particle and neutralized particle are compared. The differences of charge distribution in each case increase with increasing particle size.

• Nuclear Medicine and Molecular Imaging
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• 제41권1호
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• pp.1-8
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• 2007

This review discusses the production of alpha-particle-emitting radionuclides in radioimmunotherapy. Radioimmunotherapy labeled with alpha-particle is expected to be very useful for the treatment of monocellular cancer (e.g. leukemia) and micrometastasis at an early stage, residual tumor remained in tissues after chemotherapy and tumor resection, due to the high linear energy transfer (LET) and the short path length in biological tissue of alpha particle. Despite of the expected effectiveness of alpha-particle in radioimmunotherapy, its clinical research has not been activated by the several reasons, shortage of a suitable a-particle development and a reliable radionuclide production and supply system, appropriate antibody and chelator development. Among them, the establishment of radionuclide development and supply system is a key factor to make an alpha-immunotherapy more popular in clinical trial. Alpha-emitter can be produced by several methods, natural radionuclides, reactor irradiation, cyclotron irradiation, generator system and elution. Due to the sharply increasing demand of $^{213}Bi$, which is a most promising radionuclide in radioimmunotherapy and now has been produced with reactor, the cyclotron production system should be developed urgently to meet the demand.

• 대한기계학회논문집B
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• 제24권6호
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• pp.760-768
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• 2000

Filter efficiency of electrically charged particle in uncharged fibrous filter was measured. In previous studies, the effect of charged particle on filter efficiency was investigated but there was difficulty in measuring of image effect that is appeared at the charged small particle. We could easily measure the image effect with charging small particles by photoelectric charging. The spark discharge aerosol generator and a differential mobility analyzer (DMA) were used to generate sub-micron monodisperse particles (${\leq}200$ nm). The generated particles were charged in photoelectric charging process using ultraviolet lamp and electric field. The filter efficiency of the charged particles, classified by another DMA, was measured in filter tester using a condensation nucleus counter (CNC) as function of particle diameter, particle charge and airflow velocity. It is shown that the filter efficiency increases with increasing charge number of the particle and is affected by particle size and flow velocity. Single fiber filter efficiency mainly depends on image force parameter and peclet number. The peclet number was not considered at previous other papers. We propose a modi fied experimental correlation as function of image force parameter and peclet number.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.333-333
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• 2011

We have investigated the breakdown properties in liquids by high voltage pulse system. High voltage pulse power system is consisted of the Marx-generator with two capacitors (0.5 ${\mu}F$, withstanding voltage is 40 kV), to which the charging voltage can be applied to maximum 30 kV DC, spark gap switch and charging resistor of 20 $M{\Omega}$. We have made use of tungsten pin electrodes of anode-cathode (A-K), which are immersed into the liquids. The breakdown voltage and current signals are measured by high voltage probe (Tektronix P6015A) and current monitor (IPC CM-1.S). Especially the high speed breakdown or plasma propagation characteristics in the pulsed A-K gap have been investigated by using the high speed ICCD camera. We have measured the electron temperature through the Boltzmann plot method from the breakdown spectrums. Here the A-K gap has been changed by 1 mm, 2 mm, and 3 mm. The used liquids are distilled water and solution of salt (0.9 %). The output voltage and current signals at breakdown in distilled water are shown to be bigger than those in saline solution. The breakdown voltage and current characteristics in liquids will be discussed in accordance with A-K gap distances. It is also found that the electron temperatures and plasma densities in liquids are decreased in conformity with A-K gap.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제36회 춘계학술대회논문집
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• pp.375-378
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• 2011

덕티드로켓 추진기관에 사용되는 불완전연소 가스발생기를 설계/제작하고 연소시험을 수행하여 그 연소특성을 분석하였다. 추진시스템 설계요구조건을 바탕으로 가스발생기를 설계하고 산화제 함유량을 줄이고 금속연료 함량을 증가시킨 불완전연소용 고체연료 조성을 개발하여 가스발생기를 제작하였고, 이를 이용한 연소시험을 통해 다상 유동의 불완전연소 가스가 존재하는 가스발생기의 성능예측을 위해서는 별도의 해석기법이 요구됨을 확인하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1510-1515
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• 2004

The effects of additive ions on the generation of metallic nanoparticles were evaluated using a corona induced supersonic nozzle. Applying the corona discharge to the nanoparticle generator, a tungsten needle and the supersonic nozzle are used as an anode electrode and a cathode electrode respectively. The corona ions act as nuclei for the silver vapor condensation. The ion density was controlled precisely as varying the applied voltage between electrode and nozzle. The mean diameter of the silver particle decreases as the ion density increases. However, the number concentration of the silver particle tended to increase with the ion density. The size distribution is more uniform as the ion density increases.

• 한국대기환경학회지
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• 제17권6호
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• pp.441-450
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• 2001

A three stage impactor with the cutoff diameters of 1, 2.5, and 10$\mu\textrm{m}$ in aerodynamic diameter was developed and tested. The gravimetric method and the particle counting method were utilized to evaluate the collection performance of each stage. A vibrating orifice aerosol generator was employed to generate monodisperse test aerosols larger that 2$\mu\textrm{m}$ in diameter. Polystyrene latex (PSL) particles smaller than 2$\mu\textrm{m}$ in diameter were generated by an atomizer and the particle number concentration was measured by an Aerodynamic Particle Sizer Spectrometer. The experimental cutoff diameters obtained from the particle collection efficiency curves are in good agreement with the designed values. The square roots of Stokes number at 50% collection efficiency for stage 1, 2, and 3 are 0.42, 0.48, and 0.45, respectively. Effects of the particle bounce and the impaction plate on the collection efficiency were investigated. The collection efficiency curves including effect of the particle bounce were also compared with those of the MOUDI cascade impactor.