• 한국수자원학회논문집
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• 제55권5호
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• pp.357-370
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• 2022

본 연구는 공공하수처리시설의 다양한 운영방식(직영, 공공 위탁, 민간 대행)에 따른 성과의 차이를 분석하고 연구 결과를 토대로 국민에게 가장 효율적이고 높은 수준의 하수처리 서비스를 제공할 수 있는 운영방식과 개선방안을 도출하고자 하는 목적을 가진 연구이다. 이를 위해 경제적 성과지표(하수처리 비용, 하수도 요금)와 사회적 성과지표(수질, 민원 수)를 선정하여 횡단 분석(cross-section data)과 종단 분석(longitudinal analysis)의 방법으로 세 집단 이상의 평균 차이 검증을 일원분산분석(ANOVA)을 통해 실시하였다. 분석 결과 횡단 분석에서의 경제적 성과 차원에서는 운영방식에 따라 차이가 나타나지 않았으나, 사회적 성과 차원에서는 운영방식별로 차이가 나타나는 것을 알 수 있었다. 수질 지표의 경우 공공 위탁에서, 민원 발생 건수에서는 민간 대행에서 직영 대비 우수한 성과를 보이고 있었다. 종단 분석에서는 대부분 성과지표에서 운영방식별로 유의미한 차이가 나타나지 않았다. 따라서 공공서비스의 효율성 제고와 서비스 수준 제고를 위해서는 공공 위탁이나 민간 대행 도입 논리 외에 서비스별 특성에 맞는 다양한 접근이 요구된다고 하겠다. 아울러 향후 지자체가 하수도 위탁을 추진한다면 서비스의 성격과 지자체별 특수성, 서비스 이용자의 니즈 등을 잘 파악하여 추진하는 것이 필요하다.

• 한국항공운항학회지
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• 제23권3호
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• pp.94-104
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• 2015

Recently the departments of aviation-related in the college are increased as the aviation industry is rapidly expanded. To enhance their competitiveness and have differentiation, it is emphasized for each department to manage and teach their students well. Therefore this study aims to examine self-efficacy and academic adjustment of aviation-related college students and investigate the relationship between self-efficacy and academic adjustment. To achieve the objectives, it conducted a survey of aviation-related college students in C university from Apr. 27th. 2015 to May. 22th. 2015. A total of 225 questionnaires were analyzed using SPSS 18.0 statistical package program and frequency analysis, factor analysis, reliability analysis, multiple regression analysis, correlation analysis and one-way ANOVA were conducted. The result released that general self-efficacy was recognized higher at the department of aviation operation than aviation maintenance and aviation service and social self-efficacy was recognized higher at the department of aviation service than aviation maintenance and aviation operation. Also general self-efficacy had an influence on the motivation, application and performance and social self-efficacy affected motivation, performance and academic environment. The implication of these findings would help to manage aviation-related college students, develop their departments and provide the directions for future research.

• Earthquakes and Structures
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• 제26권3호
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• pp.175-189
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• 2024

Aiming at studying the plastic hinge (PH) evolution regularities and failure mode of rocking wall moment frame (RWMF) structure in earthquakes, the whole-working history analysis of seismic performance state of RWMF structure based on co-operation performance and PH evolution was carried out. Building upon the theoretical analysis of the elastic internal forces and deformations of RWMF structures, nonlinear finite element analysis (FEA) methods were employed to perform both Pushover analysis and seismic response time history analysis under different seismic coefficients (δ). The relationships among PH occurrence ratios (R_ph), inter-story drifts and δ were established. Based on the plotted curve of the seismic performance states, evaluation limits for the R_ph and inter-story drifts were provided for different performance states of RWMF structures. The results indicate that the R_ph of RWMF structures exhibits a nonlinear evolution trend of "fast at first, then slow" with the increasing of δ. The general pattern is characterized by the initial development of beam hinges in the middle stories, followed by the development towards the top and bottom stories until the beam hinges are fully formed. Subsequently, the development of column hinges shifts from the bottom and top stories towards the middle stories of the structure, ultimately leading to the loss of seismic lateral capacity with a failure mode of partial beam yield, demonstrating a global yielding pattern. Moreover, the limits for the R_ph and inter-story drifts effectively evaluate the five different performance states of RWMF structures.

• 대한인간공학회지
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• 제32권1호
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• pp.17-26
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• 2013

Objective: The aim of this study is ergonomic analysis of tele-operation tasks using modified remote handling devices dedicated to the cell of PRIDE(PyRoprocess Integrated inactive DEmonstration facility) in KAERI(Korea Atomic Energy Research Institute). Background: Tele-operation manipulators of the PRIDE are applied to perform the remote handling and management of pyroprocessing facilities. Generally, these kinds of systems are composed of master-slave system and its peripherals installed along a wall or ceiling of the cell, and the manipulators transmit the user's own motion to grippers directly. However, a user convenience and intuitiveness while operating the manipulators have not been fully considered in research fields. Method: This study tries to analyze the ergonomic performance of remote handling manipulators in the developed cell facility. It was included that the analysis of operator's capability for his/her own motion range of upper arm while manipulating the MSM, considerations of its manipulation margin and related tool modifications to improve the remote handling performance. Conclusion: The test results of several remote handling tasks performed in PRIDE are represented, and adequate operation strategies for the tele-operation system of hot-cell type facilities are proposed. Application: The knowledge represented in this study can be utilized to improve a tele-operation system operated in a large-scale hot-cell system.

• 한국태양에너지학회 논문집
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• 제27권2호
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• pp.29-35
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• 2007

Monitoring system is constructed for evaluating and analyzing performance of installed 50kW grid-connected PV system and have been monitored since October 2005. As climatic and irradiation conditions have been varied through long-term operation, there is necessity for evaluating numerical values of PV(Photovoltaic) system performance to observe the overall effect of environmental conditions on their operation characteristics. This paper presents performance monitoring results and analysis on component perspective(PV array and power conditioning system) and global perspective(yield, losses) of PV system for one year monitoring periods.

• 한국인터넷방송통신학회논문지
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• 제19권5호
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• pp.169-173
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• 2019

본 논문에서는 SAR 탑재체의 운용모드 설계방안 및 설계결과 그리고 주요성능에 대한 분석 결과를 제시하였다. SAR 시스템 설계는 요구사항을 만족하는 주요변수의 설계값 도출로 진행된다. 저궤도에서 운용하는 100kg 미만의 초소형위성을 가정하고 고해상의 영상을 위하여 X-대역의 주파수를 선정하였다. 주어진 설계 요구사항을 반영하여 주파수 대역폭, 관측영역 설계, 안테나 설계를 진행하고, 설계결과를 반영하여 목표 영상품질인 NESZ 만족여부를 확인하였다. 또한 설계값을 반영하여 관측영역별로 최적의 PRF를 설계하였다. 또한 소형, 경량화를 위한 안테나 형태를 제안하였다. 또한 설계된 변수를 적용하여 체계성능을 확인하였다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2000년도 추계학술대회 및 정기총회
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• pp.275-278
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• 2000

This paper focuses on a performance analysis model for optimizing the freight terminal design and layout using AutoMod simulator and numerical analysis. We developed a model to analyze the freiht terminal performance per unit time and the material handling cost based on both throughput and waiting due to conjestion. We developed computer program for this model and some sample results by both numerical method and AutoMod simulator are compared.

• 한국콘텐츠학회논문지
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• 제7권10호
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• pp.283-292
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• 2007

최근 여행업 경영성과에 대한 연구들에서는 재무적 측면이외에 비재무적측면에 대한 중요성을 언급하고 있으며 여행업에서 경영성과를 높이기 위해서는 여행업이 당면한 상황을 파악하여 가장 경쟁력 있는 핵심적 요인을 강조하여야한다. 지금까지 여행업 경영성과 분석 및 경영과 관련된 연구 논문들을 분석한 결과 관광관련기업과의 관계, 전자상거래 및 지식경영의 도입, 종사원의 서비스, 브랜드인지도 및 광고등의 요인이 여행업경영에영향을 주는 주된 요인들로 연구되었다. 본 논문에서는 위의 요인들에 대한 연구사례를 분석하여 효율적인 여행업경영에 대한 제안을 하고자 하였다. 연구방법으로는 문헌적 연구방법으로 이루어졌으며 I장 서론, II장 이론적배경, III장 선행연구분석, IV장 분석결과 및 시사점으로 구성되었다.

• Smart Structures and Systems
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• 제21권5호
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• pp.705-713
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• 2018

High-speed rail (HSR) has been in operation and development in many countries worldwide. The explosive growth of HSR has posed great challenges for operation safety and ride comfort. Among various technological demands on high-speed trains, vibration is an inevitable problem caused by rail/wheel imperfections, vehicle dynamics, and aerodynamic instability. Ride comfort is a key factor in evaluating the operational performance of high-speed trains. In this study, online monitoring data have been acquired from an in-service high-speed train for condition assessment. The measured dynamic response signals at the floor level of a train cabin are processed by the Sperling operator, in which the ride comfort index sequence is used to identify the train's operation condition. In addition, a novel technique that incorporates salient features of Bayesian inference and time series analysis is proposed for outlier detection and change detection. The Bayesian forecasting approach enables the prediction of conditional probabilities. By integrating the Bayesian forecasting approach with time series analysis, one-step forecasting probability density functions (PDFs) can be obtained before proceeding to the next observation. The change detection is conducted by comparing the current model and the alternative model (whose mean value is shifted by a prescribed offset) to determine which one can well fit the actual observation. When the comparison results indicate that the alternative model performs better, then a potential change is detected. If the current observation is a potential outlier or change, Bayes factor and cumulative Bayes factor are derived for further identification. A significant change, if identified, implies that there is a great alteration in the train operation performance due to defects. In this study, two illustrative cases are provided to demonstrate the performance of the proposed method for condition assessment of high-speed trains.

• 산업경영시스템학회지
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• 제47권2호
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• pp.84-92
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• 2024

The purpose of this study is to analyze effect of Army Risk Assessment System(ARAS) which is used to prevent safety accident in ROK army. Based on prior research, we select 4 indicators which are related to accident prevention effect and analyze the differences before and after ARAS operation for each indicators by using Paired-Samples T-Test. Also, we analyze the correlation between degree of ARAS operation and status of safety accidents of 112 ROK Army units. We conduct an evaluation of each function within the system using IPA method. The results of this study are as follows; All 4 indicators are improved compared to before ARAS operation, and the differences are statistically significant. Also, there is negative correlation between the degree of ARAS operation and the occurrence of safety accidents. So, the operation of ARAS has a positive effect on preventing safety accidents. Finally among the 15 functions of ARAS, 4 functions require improvement. The findings of this study have implications for proposing necessity of computerized system in enforcing Risk Assessment. Also, whether or not operating ARAS is important, but it is also important to operate it well. Lastly, We propose improvement plans for each function to operate it well.