• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.462-465
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• 2011

본 논문에서는 다중 반송파, 특히 OFDM 시스템의 PAPR 을 감소시킬 수 있는 CFR 알고리즘을 다룬다. 기존의 피크 윈도윙 기법이 윈도우 길이 내에 피크들이 여러 개 있을 경우, 과도 clipping 으로 인하여 성능이 열화되는 현상을 개선하기 위하여 포락선 기반 피크 윈도윙 기법을 적용한다. 뿐만 아니라, 피크 윈도윙이 가지고 있는 EVM 열화를 완화하기 위하여 기존의 단순 clipping 기법과 혼합하여 시스템에서 요구하는 EVM 성능뿐 아니라 ACLR 성능까지도 만족하도록 한다. MATLAB 을 이용하여 알고리즘을 검증하고, 하드웨어 구현을 위하여 Xilinx Virtex5 를 이용하여 검증하여 제안하는 기법의 복잡도는 높지만 EVM 과 ACLR 성능이 우수함을 알 수 있다. 효율적인 주파수 이용과 수신 성능 측면에서 우수한 성능을 보인다. 따라서 DVB-T 나 LTE, IEEE 802.16m 등의 차세대 방송 및 통신의 전송에 이용되는 OFDM 신호의 PAPR 을 효과적으로 줄일 수 있는 기법으로 적용될 수 있다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.39 no.11
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• pp.17-21
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• 2010

고효율 난방기기인 멀티히트펌프의 소비전력분석을 통해, 멀티히트펌프 보급이 동계 전력피크에 미치는 영향을 분석한다.

• Journal of Radiation Protection and Research
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• v.30 no.3
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• pp.107-112
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• 2005

Cascade summing occurs when two gamma-rays emitted in the decay of a single nucleus both deposit energy in a detector. The effect may cause systematic errors that can reach levels of more than ten percent for some radionuclides. A method for estimation of the effect of these coincidences was developed. It is based on direct computation of the effect by means of peak to total ratio measured for the place around the detector. It has been shown that the P/T ratio for the given energy in the working space around the detector may not be a constant value and must use its mean value. Some results from a peak to total calibration study in the presence of scattering materials are also given.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.285-285
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• 2010

$Cu(In,Ga)Se_2$ (CIGS) 박막 태양전지 제조에는 동시증발법 (co-evaporation)으로 Cu, In, Ga, Se 각 원소의 증발을 세 단계로 제어하여 CIGS 박막을 증착하는 3-stage 방법이 널리 이용된다[1]. 3-stage 중 1st-stage에서는 In, Ga, Se 원소 만을 증발시켜 $(In,Ga)_2Se_3$ 전구체 (precursor) 박막을 성장시킨다. 고효율의 CIGS 태양전지를 위해서는 $(In,Ga)_2Se_3$ 전구체 증착의 공정 변수와 이에 따른 박막 특성의 이해가 중요하다. 본 연구에서는 Mo 박막이 증착된 소다석회유리 (soda lime glass) 기판에 동시증발장비를 이용하여 280 380 의 기판 온도에서 In, Ga, Se 물질을 증발시켜 $(In,Ga)_2Se_3$/Mo/glass 시료를 제작하였으며 XRD, SEM, EDS 등의 방법을 이용하여 특성을 분석하였다. XRD 분석 결과 기판 온도 $280{\sim}330^{\circ}C$에서는 $(In,Ga)_2Se_3$ 박막의 (006), (300) 피크가 관찰되었으며, 기판 온도가 증가할수록 (006) 피크 세기는 감소하였고 (300) 피크 세기는 증가하였다. $380^{\circ}C$에서는 (110)을 포함한 다수의 피크가 관찰되었다. 그레인 (grain) 크기는 기판 온도가 증가할수록 커지며 Ga/(In+Ga) 조성비는 기판 온도에 따라 일정함을 각각 SEM과 EDS 측정을 통해 알 수 있었다. $(In,Ga)_2Se_3$ 전구체의 (300) 배향은 CIGS 박막의 (220/204) 배향을 촉진하고[2], 이것은 높은 광전변환효율에 기여하는 것으로 알려져 있다. 때문에 $(In,Ga)_2Se_3$의 (300) 피크의 세기가 가장 큰 조건인 $330^{\circ}C$를 1st-stage 증착 온도로 하여 3-stage CIGS 태양전지 공정을 수행하였으며, $MgF_2$/Al/Ni/ITO/i-ZnO/CdS/CIGS/Mo/glass 구조의 셀에서 광전변환효율 16.96%를 얻었다.

• Journal of the Korean Society of Radiology
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• v.17 no.2
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• pp.175-184
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• 2023

Based on the actual shape of the detector and the data provided by the manufacturer, the shape of the detector was implemented through Penelope simulation and applied to the appropriate four-layer thickness based on the efficiency obtained from the measurements. Efficiency calculations to determine the effect of the simulated number of Full Energy Peak Efficiency(FEPE) channels in the detector and the outside contact layer in the crystal on the Full Energy Peak Efficiency were performed for various four-layer thicknesses of 0.3, 0.5, 0.7, 1.0, 1.2, and 1.4 mm using the Penelope Code. When the thickness of the external contact layer was increased by 5 times, the Full Energy Peak Efficiency decreased by about 36% for 59.50 keV, and the Full Energy Peak Efficiency decreased by 10% for 1836. In addition, as it increased by 10 times, the Full Energy Peak Efficiency decreased by about 20% for 59.54 keV, and 7% for 1836.01 keV. The Penelope simulated Full Energy Peak Efficiency channel decreases exponentially with the increase in the four layers. In addition, it was confirmed that the total effect curve was well matched with a relative difference of less than 3.5% in the 0.3-1.4 mm dead layer thickness region. However, it was found that the inhomogeneous dead layer is still a parameter in the Monte Carlo model.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2017.05a
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• pp.845-872
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• 2017

우리나라 과학기술계 정부출연연구기관은 고령화 하에서 연구생산성을 향상시키기 위하여 다양한 정책을 추진하고 있는데, 그 중 임금피크제는 조직의 효율성 증진을 통해 연구생 산성을 높일 수 있는 제도로 기대할 수 있다. 그럼에도 불구하고 2015년 임금피크제 도입을 둘러싸고 발생했던 정부와 과학기술계 정부출연연구기관 연구자들 간 갈등의 원인은 무엇이었는가? 본 연구는 이러한 의문에서 출발하며, 정책옹호연합모형(ACF)을 활용하여 과학기술계 정부출연연구기관의 임금피크제 정책결정과정을 분석하였다. 연구결과를 요약하면 첫째, 정책환경으로서의 외부변수들은 대부분 찬성 측 옹호연합에 유리한 자원으로 작용하였다. 둘째, 과학기술계 정부출연연구기관을 관리 통제의 대상으로 바라보는 신념과 독립적 자율적 대상으로 보는 신념 간 차이는 갈등의 근본적인 원인이었다. 셋째, 임금피크제의 일괄적 도입, 정책중개자의 미비한 역할은 옹호연합 간의 갈등을 더욱 증폭시켰다. 이러한 연구결과는 첫째, 정책은 정책대상의 특성이 반영되도록 설계 적용되어야 한다는 점을 시사한다. 둘째, 정책중개자로서의 역할이 기대되는 정책참여자가 있는 경우, 이들의 역할에 따라 갈등이 증폭 또는 완화될 수 있으므로 올바른 정책중개자로서의 역할이 필요할 것이다. 셋째, 정부출연연구기관이 기타 공공기관에서 제외되어야 한다는 정부출연연구기관 관계자들의 주장을 경청할 필요가 있다.

• 한국사회정책
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• v.23 no.2
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• pp.25-48
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• 2016

This study stemmed from the notion that effects of wage peak system were investigated exclusively on management efficiency from the perspective of workplace. As a way to overcome the limitation of previous studies, This study examined the effects of wage peak system on age integration of senior workers. Quantitative analyses with data from workplace panel survey were executed. Results revealed that percent of workers aged 50 and over was significantly higher in work places that implemented wag peak system than that of those did not. Also Average year of employment for full time workers was higher in work places that implemented wag peak system than that of those did not, suggesting that wage peak system was related to labor market integration of aged workers in some ways.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.224-234
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• 2017

This paper compares the realities of the salary Peak Policy's status and management processes in Korea and Japan, with the aim of determining the development direction for Korea's salary Peak Policy's. Unlike Japan, which successfully achieved close cooperation between government, firms and workers in implementing the Retirement Age Extension Type salary Peak Policy, Korea experienced many problems due to lack of preparation. In order to rationally develop the salary Peak Policy, the government, firms, and workers must cooperate to increase the policy's efficiency via the following steps. First, gradually increase the proportion of retirement age extension. Second, career development that takes into account the various employment types, flexible working hours and aged workers. Third, development of training programs for senior citizen workers, as well as increasing support for changing of jobs and startups. Fourth, expansion of re-employment after retirement age and ways to make use of the skilled labor. Fifth, increasing work efficiency through bonuses and work evaluation that is specialized for aged workers. This paper argues that such measures are necessary for the co-existence of firms and workers, as well as for improving employment stability and labor market flexibility.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.776-779
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• 2010

Implementation for Gated Peak Detector CSAM (C Scanning Acoustic Microscope) based on One Chip processor is proposed in this paper. GDP (Gated Peak Detector) is implemented with VHDL tool. The proposed method leads to be available for its application and integration in all systems as well as acoustic microscope and the method is compared with the conventional methods. The technique results in efficiency in size and application.

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.821-831
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• 2021

In order to calibrate energy and efficiency using the PENELOPE Code, a PENELOPE simulation was performed using a volume source. Here, we want to verify peak efficiency and usefulness by performing simultaneous measurement and correction. calculate the coincident sum correction for all volumes, first subdivide the volumes of the cylinder and the four Marinelli beakers into three heights again. Therefore, the simultaneous measurement correction coefficient in three areas and the simultaneous measurement correction coefficient for the entire volume source are calculated as output. At low energies, the j value for each source volume (50-300 ml) is small and increases significantly in the high energy range. Simulation results showed good agreement within 2.5% for all source volumes except for 50 ml and 300 ml, which were up to 4%. This means that the correction for the simultaneous measurement effect during measurement is effective. In addition. Based on this, it can be confirmed that there is an advantage to improve the detection efficiency when measuring various sources and environmental samples.