• 마이크로전자및패키징학회지
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• 제8권1호
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• pp.1-4
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• 2001

새로운 구조의 APF optical link용 Si pin photodetector를 제작하고 그 특성을 분석하였다. 제작된 소자는 금속-반도체 접촉주위에 $p^{+}$-guard ring구조와 광이 입사되는 수광면에 그물망 모양의 얕은 $p^{+}$-확산영역을 갖는다. 제작된 소자의 전기.광학적 특성을 -5 V의 동작전압에서 측정한 결과, 접합 커패시턴스와 암전류는 각각 4 pF와 180 pA로 나타났으며 광신호 전류와 감도특성는 670 nm이 중심파장을 갖는 2.2 $\mu$W의 입사광 전력 아래에서 각각 1.22 $\mu$A와 0.55 A/W로 나타났다. 제작된 소자는 650~700 nm의 파장영역에서 최대 spectral response를 보이고 있으며 낮은 점한 커패시턴스와 우수한 신호분리능력으로 인해 red light optics응용에서 광신호 검출에 적합하게 사용될 수 있을 것으로 기대된다.

• Journal of the Korean Data and Information Science Society
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• 제28권3호
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• pp.533-545
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• 2017

분위수 회귀모형은 반응변수의 조건부 분포에 대하여 포괄적이고 유용한 통계적 정보를 제공한다. 그러나 많은 실제 자료는 설명변수와 반응변수가 비선형의 관계를 갖고 있어 전통적인 선형 분위수 회귀모형은 왜곡되고 잘못된 결과를 초래할 수 있다. 또한 자료의 복잡성이 증가하여 반응변수가 여러개인 다변량 자료의 분석에 대한 보다 정확한 예측과 더불어 풍부한 해석에 대한 요구가 증가하고 있다. 이러한 이유로 본 연구에서는 다변량 분위수 회귀나무 모형을 제안하였다. 본 연구에서는 기존의 다변량 회귀나무 모형의 분할변수 선택 알고리즘의 문제점을 지적하고 향상된 분할변수 선택 알고리즘을 제안하였다. 제안한 알고리즘은 합리적인 계산시간으로 적용 가능하며 분할변수 선택에서 편향 발생의 문제를 갖지 않는 동시에 기존 방법보다 더 정확하게 분할변수를 선택할 수 있있다. 본 연구에서는 모의실험과 실증 예제를 통해 제안한 방법의 우수한 성능과 유용성을 확인하였다.

• 한국재료학회지
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• 제11권4호
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• pp.247-250
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• 2001

광이 입사되는 수광면에 그물망(web)모양의 얕은 $P^{+}$ -diffusion 영역을 갖는 새로운 구조의 적색광 검출 Si pin photodiode를 제작하고 그 특성을 분석하였다. 제작된 소자의 전기.광학적 특성을 -5V의 동작전압에서 측정한 결과, 접합 커패시턴스와 암전류는 각각 4pF와 235pA로 나타났으며 670nm의 중심파장을 갖는 1.6㎼의 입사광 전력 아래에서 광신호 전류와 감도특성은 각각 0.48$\mu\textrm{A}$와 0.30A/W로 나타났다. 제작된 소자는 종래의 circular type photodiode에 비해 개선된 감도 특성을 나타내었으며 670~700nm의 파장영역에서 최대 spectral response를 보였다. 본 연구에서의 web-patterned Si photodiode는 red light optics 응용에서 디지털 신호처리시 우수한 신호분리 능력을 나타낼 것으로 기대된다.

• Nuclear Engineering and Technology
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• 제55권3호
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• pp.1021-1030
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• 2023

We propose an overall procedure for measuring and unfolding fast neutron spectra using a trans-stilbene scintillation detector. Detector characterization was described, including the information on energy calibration, detector resolution, and nonproportionality response. The digital charge comparison method was used for the investigation of neutron-gamma Pulse Shape Discrimination (PSD). A pair of values of 600 ns pulse width and 24 ns delay time was found as the optimized conditions for PSD. A fitting technique was introduced to increase the trans-stilbene Proton Response Function (PRF) by 28% based on comparison of the simulated and experimental electron-equivalent distributions by the Cf-252 source. The detector response matrix was constructed by Monte-Carlo simulation and the spectrum unfolding was implemented using the iterative Bayesian method. The unfolding of simulated and measured spectra of Cf-252 and AmBe neutron sources indicates reliable, stable and no-bias results. The unfolding technique was also validated by the measured cosmic-ray induced neutron flux. Our approach is promising for fast neutron detection and spectroscopy.

• Asian-Australasian Journal of Animal Sciences
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• 제21권5호
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• pp.677-684
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• 2008

Accurate estimation of dry matter intake (DMI) is a prerequisite to meet animal performance targets without penalizing animal health and the environment. The objective of the current study was to evaluate some of the existing models in order to predict DMI when lactating dairy cows were offered a total mixed ration containing a high level of concentrates and locally produced agricultural by-products. Six popular models were chosen for DMI prediction (Brown et al., 1977; Rayburn and Fox, 1993; Agriculture Forestry and Fisheries Research Council Secretariat, 1999; National Research Council (NRC), 2001; Cornell Net Carbohydrate and Protein System (CNCPS), Fox et al., 2003; Fuentes-Pila et al., 2003). Databases for DMI comparison were constructed from two different sources: i) 12 commercial farm investigations and ii) a controlled dairy cow experiment. The model evaluation was performed using two different methods: i) linear regression analysis and ii) mean square error prediction analysis. In the commercial farm investigation, DMI predicted by Fuentes-Pila et al. (2003) was the most accurate when compared with the actual mean DMI, whilst the CNCPS prediction showed larger mean bias (difference between mean predicted and mean observed values). Similar results were observed in the controlled dairy cow experiment where the mean bias by Fuentes-Pila et al. (2003) was the smallest of all six chosen models. The more accurate prediction by Fuentes-Pila et al. (2003) could be attributed to the inclusion of dietary factors, particularly fiber as these factors were not considered in some models (i.e. NRC, 2001; CNCPS (Fox et al., 2003)). Linear regression analysis had little meaningful biological significance when evaluating models for prediction of DMI in this study. Further research is required to improve the accuracy of the models, and may recommend more mechanistic approaches to investigate feedstuffs (common to the Asian region), animal genotype, environmental conditions and their interaction, as the majority of the models employed are based on empirical approaches.

• 인지과학
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• 제28권3호
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• pp.133-147
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• 2017

인간의 지각은 외부환경을 객관적으로 반영하기 보다는 다양한 요인들에 의해 영향을 받은 결과이다. 이 요인들 중 행동-특정 지각은 환경에 대한 행위가능성에 의해 지각이 달라지는 현상이다. 기존 연구들은 행동-특정 지각이 과제를 수행하는 중에 발생하는지 아니면 수행 후 결과에 대한 지식 혹은 기억왜곡에 의한 것인지에 대해 상충된 결과를 보고하였다. 본 연구에서는 행동-특정 지각이 언제 발생하는지 확인하기 위해 다트를 사용하여 세 개의 실험을 실시하였다. 참가자들은 일정한 거리에서 다트를 수행하였으며 각 시행 후 지각된 표적의 크기를 응답지에 보고하였다. 그 결과 실험 1, 2에서 참가자들은 다트를 실패했을 때 보다 성공했을 때 표적을 더 크게 지각하였으며, 그 효과는 수행 후 표적을 볼 수 없을 때 더 강하게 발생하였다. 그러나 참가자들이 자신의 수행결과에 대해 알 수 있었기 때문에 응답에서 편파가 발생했을 가능성이 있었다. 이 가능성을 제거한 실험 3에서도 행동-특정 지각이 발생하였으며, 따라서 행동-특정 지각은 과제수행 후가 아닌 과제를 수행하는 동안 발생한다는 결론을 내릴 수 있었다.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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• pp.65-65
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• 2000

Microwave response of intrinsic Josephson junctions in mesa structure formed on HgI2-intercalated Bi2Sr2CaCu2O8+x single crystals was studied in a wide range of microwave frequency. With irradiation of 73${\sim}$76 GHz microwave, the supercurrent branch becomes resistive above a certain onset microwave power. At low current bias, the current-voltage characteristics show linear behavior, while at high current bias, the resistive branch splits into multiple sub-branches. The voltage spacing between neighboring sub-branches increase with the microwave power and the total number of sub-branches is almost identical to the number of intrinsic Josephson junctions in the mesa. All the experimental results suggest that each sub-branch represents a specific mode of collective motion of Josephson vortices generated by the microwave irradiation. With irradiation of microwave of microwave of frequency lower than 20 GHz, on the other hand, no branch splitting was observed and the current-voltage characteristics exhibited complex behavior at hlgh blas currents. This result can be explained in terms of incoherent motion of Josephson vortices generated by non-uniform microwave irradiation.

• Asian Pacific Journal of Cancer Prevention
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• 제16권14호
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• pp.5755-5762
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• 2015

Background: Short-course preoperative radiation (SCRT) with delayed surgery was found to increase pathologic complete response (pCR) rates in several trials. However, there was no clear answer on whether SCRT or long-course chemo-radiotherapy (LCRT) is more effective. Therefore we conducted this meta-analysis to evaluate the safety and efficacy of SCRT versus LCRT, both with delayed surgery, for treatment of rectal cancer. Materials and Methods: The literature was searched from PubMed, EMBASE, Web of Science, Cochrane Library and clinicaltrials.gov up to November, 2014. Quality of the randomized controlled trials (RCTs) was evaluated according to the Cochrane's risk of bias tool of RCT. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to rate the level of evidence. Review Manager 5.3 was employed for statistical analysis. Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were calculated. Results: Three RCTs, with a total of 357 rectal cancer patients, were included in this systematic review. Metaanalysis results demonstrated there were no significantly differences in sphincter preservation rate, local recurrence rate, grade 3~4 acute toxicity, R0 resection rate and downstaging rate. Compared with SCRT, LCRT was associated with significant increase in the pCR rate [RR=0.49, 95%CI (0.31, 0.78), P=0.003]. Conclusions: In terms of sphincter preservation rate, local recurrence rate, grade 3~4 acute toxicity, R0 resection rate and downstaging rate, SCRT with delayed surgery is as effective as LCRT with delayed surgery for management of rectal cancer. LCRT significantly increased pCR rate compared with SCRT. Due to risk of bias and imprecision, further multi-center large sample RCTs were needed to confirm this conclusion.

• Asian Pacific Journal of Cancer Prevention
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• 제13권7호
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• pp.3253-3258
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• 2012

Objective: To evaluate the efficacy and safety of whole brain radiotherapy (WBRT) plus chemotherapy versus WBRT alone for treating brain metastases (BM) from lung cancer by performing a meta-analysis based on randomized controlled trials (RCTs). Methods: The PubMed, Embase, CENTRAL, ASCO, ESMO, CBM, CNKI, and VIP databases were searched for relevant RCTs performed between January 2000 and March 2012. After quality assessment and data extraction, the meta-analysis was performed using the RevMan 5.1 software, with funnel plot evaluation of publication bias. Results: 19 RCTs involving 1,343 patients were included. The meta-analyses demonstrated that compared to WBRT alone, WBRT plus chemotherapy was more effective with regard to the objective response rate (OR = 2.30, 95% CI = 1.79 - 2.98; P < 0.001); however, the incidences of gastrointestinal reactions (RR = 3.82, 95% CI = 2.33 - 6.28, P <0.001), bone marrow suppression (RR = 5.49, 95% CI = 3.65 - 8.25, P < 0.001), thrombocytopenia (RR = 5.83, 95% CI = 0.39 - 86.59; P = 0.20), leukopenia (RR = 3.13, 95% CI = 1.77 - 5.51; P < 0.001), and neutropenia (RR = 2.75, 95% CI = 1.61 - 4.68; P < 0.001) in patients treated with WBRT plus chemotherapy were higher than with WBRT alone. There was no obvious publication bias detected. Conclusion: WBRT plus chemotherapy can obviously improve total efficacy rate, butalso increases the incidence of adverse reactions compared to WBRT alone. From the limitations of this study, more large-scale, high-quality RCTs are suggested for further verification.

• 노동경제논집
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• 제39권3호
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• pp.99-124
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• 2016

본 연구는 한국노동패널 자료를 사용하여 노동조합이 우리나라 여성근로자들의 임금에 미치는 영향을 실증분석하였다. 분석에는 여성근로자들의 임금함수 추정과정에서 경제활동참여에 의한 선택편의를 고려하였고, 종업원 수가 무응답인 경우 그 값을 보정하여 분석하였으며, 직장에 노동조합이 있고 노동조합에 가입한 조합원 근로자와 가입하지 않은 비조합원 근로자를 직장에 노동조합이 없는 근로자와 비교하여 분석하였다. 그 결과, 고정효과 모형 추정에서 조합원 및 비조합원 더미변수 모두 통계적으로 유의하지 않은 것으로 나타났다. 이로부터 OLS 모형 추정에서 나타난 노동조합의 임금효과는 능력이 높은 여성근로자들이 유노조 사업체에 취업하는 것을 더 선호한 결과이며, 비조합원의 무임승차 효과는 없다고 보는 것이 타당하다는 결론을 도출하였다.