• 환경정책연구
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• 제9권1호
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• pp.109-135
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• 2010

본 연구는 선호불확실성을 고려한 다항선택형조건부가치측정법을 이용하여 울산광역시에서 추진하는 태화들 생태공원조성사업의 사회적 편익을 추정하였다. 로짓모형을 이용한 4개의 지불의사 함수의 추정결과 4개 모형 모두에서 소득과 제시금액이 가장 중요한 지불의사의 경쟁요인으로 나타났고 태화들 생태공원 조성사업의 사업 적절성에 대한 평가와 1차 사업 만즉도가 높을수록 남자가 여자보다 통계적으로 유의하게 지불의사 확률이 높은 것으로 나타났다. WTP 추정 효율성이 가장 높은 MBYES모형의 추정결과 절단평균 WTP는 가구 당 월 2,409.4원이다. 이를 기반으로 계산된 태화들 생태공원의 울산시 가구의 연간 편익은 112.6억원이며 5%의 할인율을 적용한 총편익의 현재가지는 2,364.6억원으로 추정되어 토지매입비를 포함한 태화들 생태공원 조성사업의 직접비용인 1,133억원의 2배 이상인 것으로 나타나고 있다. 또한 4개 모형중 가장 엄격한 편익추정인 DFYES모형의 경우에도 5% 할인율 적용 시 총편익의 현재가치는 평균 1,173.9억원으로 편익이 비용보다 높게나타났다.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1165-1203
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• 2024

In the paper we validate theoretical models of the pulse against experimental data from the Jozef Stefan Institute TRIGA Mark II research reactor. Data from all pulse experiments since 1991 have been collected, analysed and are publicly available. This paper summarizes the validation study, which is focused on the comparison between experimental values, theoretical predictions (Fuchs-Hansen and Nordheim-Fuchs models) and calculation using computational program Improved Pulse Model. The results show that the theoretical models predicts higher maximum power but lower total released energy, full width at half maximum and the time when the maximum power is reached is shorter, compared to Improved Pulse Model. We evaluate the uncertainties in pulse physical parameters (maximum power, total released energy and full width at half maximum) due to uncertainties in reactor physical parameters (inserted reactivity, delayed neutron fraction, prompt neutron lifetime and effective temperature reactivity coefficient of fuel). It is found that taking into account overestimated correlation of reactor physical parameters does not significantly affect the estimated uncertainties of pulse physical parameters. The relative uncertainties of pulse physical parameters decrease with increasing inserted reactivity. If all reactor physical parameters feature an uncorrelated uncertainty of 10 % the estimated total uncertainty in peak pulse power at 3 $ inserted reactivity is 59 %, where significant contributions come from uncertainties in prompt neutron lifetime and effective temperature reactivity coefficient of fuel. In addition we analyse contribution of two physical mechanisms (Doppler broadening of resonances and neutron spectrum shift) that contribute to the temperature reactivity coefficient of fuel. The Doppler effect contributes around 30 %-15 % while the rest is due to the thermal spectrum hardening for a temperature range between 300 K and 800 K.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1520-1526
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• 2014

This paper presents a probabilistic method to evaluate the total transfer capability (TTC) by considering the sequential quadratic programming and the uncertainty of weather conditions. After the initial TTC is calculated by sequential quadratic programming (SQP), the transient stability is checked by time simulation. Also because power systems are exposed to a variety of weather conditions the outage probability is increased due to the weather condition. The probabilistic approach is necessary to evaluate the TTC, and the Monte Carlo Simulation (MCS) is used to accomplish the probabilistic calculation of TTC by considering the various weather conditions.

• 한국물환경학회지
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• 제28권3호
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• pp.347-358
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• 2012

The SWAT (Soil and Water Assessment Tool) should be calibrated and validated with observed data to secure accuracy of model prediction. Recently, the SWAT-CUP (Calibration and Uncertainty Program for SWAT) software, which can calibrate SWAT using various algorithms, were developed to help SWAT users calibrate model efficiently. In this study, three algorithms (GLUE: Generalized Likelihood Uncertainty Estimation, PARASOL: Parameter solution, SUFI-2: Sequential Uncertainty Fitting ver. 2) in the SWAT-CUP were applied for the Soyang-gang dam watershed to evaluate these algorithms. Simulated total streamflow and 0~75% percentile streamflow were compared with observed data, respectively. The NSE (Nash-Sutcliffe Efficiency) and $R^2$ (Coefficient of Determination) values were the same from three algorithms but the P-factor for confidence of calibration ranged from 0.27 to 0.81 . the PARASOL shows the lowest p-factor (0.27), SUFI-2 gives the greatest P-factor (0.81) among these three algorithms. Based on calibration results, the SUFI-2 was found to be suitable for calibration in Soyang-gang dam watershed. Although the NSE and $R^2$ values were satisfactory for total streamflow estimation, the SWAT simulated values for low flow regime were not satisfactory (negative NSE values) in this study. This is because of limitations in semi-distributed SWAT modeling structure, which cannot simulated effects of spatial locations of HRUs (Hydrologic Response Unit) within subwatersheds in SWAT. To solve this problem, a module capable of simulating groundwater/baseflow should be developed and added to the SWAT system. With this enhancement in SWAT/SWAT-CUP, the SWAT estimated streamflow values could be used in determining standard flow rate in TMDLs (Total Maximum Daily Load) application at a watershed.

• 한국산학기술학회논문지
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• 제22권5호
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• pp.207-220
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• 2021

본 연구는 자궁양성종양 환자의 수술 사전 교육이 불안, 불확실성, 통증에 미치는 효과를 분석하기 위해 수행된 체계적 문헌고찰 및 메타분석 연구이다. 문헌검색을 위해 PubMed, OVID MEDLINE, CINAHL, Google Scholar 및 학술연구정보서비스(RISS), 한국학술정보(KISS)등의 데이터베이스를 활용하였으며, 2020년 1월까지 검색하였다. 총 401개의 연구가 확인되었으며 선택배제 과정을 거쳐 최종적으로 13편이 분석에 포함되었다. 문헌의 비뚤림 위험은 RoB(Risk of Bias)와 Robans를 이용해 평가하였으며, 전반적으로 비뚤림 위험은 낮은 것으로 평가하였다. 연구결과 수술사전 교육은 불안 (Hedges's g= -0.89, 95 % CI -1.39, -0.47)과 통증 (Hedges's g= -0.49, 95 % CI -0.95, -0.02)에는 통계적으로 유의한 차이가 있는 것으로 나타났으나, 불확실성( Hedges's g = -1.38, 95 % CI -3.98, 1.23)은 통계적으로 유의한 차이가 없는 것으로 나타났다. 하위그룹 분석결과 중재방법에 따라 인지행동프로그램, 시범교육, 이완요법이 효과가 있는 것으로 나타났으며, 출판 편향의 위험은 낮았다. 이를 토대로 향후 자궁양성종양 환자의 수술 사전 교육에 적용할 수 있을 것이라 사료된다.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4447-4464
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• 2023

This paper focuses on the development of a new computational model of the CNESTEN's TRIGA Mark II research reactor using the 3D continuous energy Monte-Carlo code TRIPOLI-4 (T4). This new model was developed to assess neutronic simulations and determine quantities of interest such as kinetic parameters of the reactor, control rods worth, power peaking factors and neutron flux distributions. This model is also a key tool used to accurately design new experiments in the TRIGA reactor, to analyze these experiments and to carry out sensitivity and uncertainty studies. The geometry and materials data, as part of the MCNP reference model, were used to build the T4 model. In this regard, the differences between the two models are mainly due to mathematical approaches of both codes. Indeed, the study presented in this article is divided into two parts: the first part deals with the development and the validation of the T4 model. The results obtained with the T4 model were compared to the existing MCNP reference model and to the experimental results from the Final Safety Analysis Report (FSAR). Different core configurations were investigated via simulations to test the computational model reliability in predicting the physical parameters of the reactor. As a fairly good agreement among the results was deduced, it seems reasonable to assume that the T4 model can accurately reproduce the MCNP calculated values. The second part of this study is devoted to the sensitivity and uncertainty (S/U) studies that were carried out to quantify the nuclear data uncertainty in the multiplication factor k_eff. For that purpose, the T4 model was used to calculate the sensitivity profiles of the k_eff to the nuclear data. The integrated-sensitivities were compared to the results obtained from the previous works that were carried out with MCNP and SCALE-6.2 simulation tools and differences of less than 5% were obtained for most of these quantities except for the C-graphite sensitivities. Moreover, the nuclear data uncertainties in the k_eff were derived using the COMAC-V2.1 covariance matrices library and the calculated sensitivities. The results have shown that the total nuclear data uncertainty in the k_eff is around 585 pcm using the COMAC-V2.1. This study also demonstrates that the contribution of zirconium isotopes to the nuclear data uncertainty in the k_eff is not negligible and should be taken into account when performing S/U analysis.

• 전기학회논문지P
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• 제51권2호
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• pp.94-98
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• 2002

QFT(Quantitative Feedback Theory) is a very practical design technique that emphasizes the use of feedback for achieving the desired system performance tolerances in despite of plant uncertainty and disturbance. The gain-phase loop shaping procedure of QFT is employed to design controller, until the bounds at desired frequencies are satisfied. This paper presents a transfer function synthesis using TLS(Total Least Squares) and offers a loop shaping method with the suggested technique. An example illustrates a feasibility of the presented algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.116.4-116
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• 2001

We consider a robust configuration problem of inertial sensors for inertial navigation system(INS). Fault detection and isolation(FDI) is necessary to improve reliability of the system. For FDI, there used to be more than three mutually orthogonal sensors and thus we have to consider configuration methods of sensors. Various studies in this area have been done, but the former results did not consider effect of uncertainty(misalignment, scale factor error) to determine the configuration of the sensors. In this paper robust configuration of sensors is proposed through sensitivity analysis. Also total least square(TLS) method ...

• 환경위생공학
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• 제23권4호
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• pp.65-71
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• 2008

To drive efficiently total water pollution load management, needs to calculate the exact load emissions, pollution load allocation and implementation evaluation in each unit area of watershed and accurate and regular flow of data. For these reasons, the Nakdong River TMDL Research Center has produced directly or indirectly in the average interval of eight days (30 times or more / year) 41 points for unit area of the total water pollution load management and 8-point of municipal requirement for a total of 49 branches as a flow data in 2004 from August. This acquired the survey flow is evidence of trends and changes each point in the Nakdong River based on time, such as 10 years based on average design flow available to the foundation of the summit as the major water policy is to be utilized. This study was performed on actual discharge measuring data and introduced performance results each drainage basin of Nakdong River from 2004 to 2008 over the total of past five years.

• 디지털융복합연구
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• 제16권8호
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• pp.253-261
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• 2018

본 연구는 혈액투석환자의 자아존중감 예측요인을 분석하기 위한 연구이다. 예측적 상관관계의 서술 연구로써, 서울에서 혈액투석을 받고 있는 154명을 편의 표집 하였다. SPSS 22.0프로그램을 사용하여 기술통계, 피어슨 상관관계 및 단계적 회귀분석을 실시하였다. 연구결과, 자아존중감에 가장 영향을 미치는 요인은 불확실성(${\beta}=-.33$, p<.001), 경제수준(${\beta}=.18$ p<.05), 직업유무(${\beta}=.17$ p<.05), 건강상태(${\beta}=.16$ p<.05)순으로 나타났다. 이들 변수는 혈액투석환자의 자아존증을 설명하는 변수로써 30.0%의 설명력을 보였다(Adjust $R^2=.30$). 불확실성을 관리 예방하고, 투석환경을 고려한 직업교육을 실시, 일자리를 제공하여 경제적 수준을 높이고, 양호한 건강상태를 유지하는 것이 자아존중감을 향상시키는 요소라 할 수 있다. 본 연구는 혈액투석환자들의 기계 의존적 특성을 고려하여 자아존중감을 살핀 연구로써 의의가 있으며, 향후 환자들의 자아존중감 향상을 위한 연구의 지초자료를 제공할 수 있을 것이다. 또한, 연구결과를 바탕으로 간호 중재의 필요성이 있다.