• 한국인터넷방송통신학회논문지
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• 제22권1호
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• pp.35-43
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• 2022

본 논문에서는 10W급 MMIC를 결합하여 20W급으로 상향시킨 단위 전력 증폭기를 8-way 공간결합기와 결합하여 100W급 SSPA를 제작하는 연구를 진행하였다. SSPA는 TWTA에 비해 상대적으로 낮은 단일 소자의 출력으로 높은 출력을 충족하기 위해 저손실, 고효율의 결합 기술을 필요로 한다. 본 논문에서 설계 및 제작된 SSPA는 20dB 이상의 반사 손실과 94% 이상의 우수한 결합효율을 갖는 8-way 공간결합기에 20W급 고출력증폭모듈 8대를 장착하여 100W급 SSPA로 제작되었다. -10dBm 인가시 20kHz 20%에서 112.2~169.8W, 400kHz 40%에서 125.9~173.8W, 800kHz 40%에서 117.5~162.2W로 나타나 PRF 3가지 조건에서 모두 이득 60dB 이상과 100W 이상의 성능을 보였다.

• 산업융합연구
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• 제21권1호
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• pp.77-86
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• 2023

본 연구는 정신장애인 동료지원활동의 보다 발전적인 고용 활성화 방안을 모색하고자 하는데 그 목적이 있다. 그리하여 정신장애인 동료지원활동 리더양성 일자리 지원사업을 담당하고 있는 직업재활실무자들을 대상으로 초점집단인터뷰(FGI)를 실시하였다. 연구결과, 연구참여자들은 본 사업을 통해 역량강화에 대한 기대를 갖고 있었고, 동료지원활동가의 역할에 대해 동료들에 대한 정서적 지원, 프로그램 계획 및 진행, 자조모임 운영, 사업 및 시설홍보, 직원 보조지원의 역할 등으로 인식하고 있었다. 또한 금전적인 보상과 의미있는 역할 수행이 된다면 보다 동기부여 될 수 있다고 보았으며, 사업참여를 통해 힘들지만 보람을 느끼며, 전문성 향상을 위해 스스로 노력하는 모습을 보였다. 본 연구결과를 토대로 정신장애인 동료지원 활동 고용 활성화를 위한 논의 및 실제적인 제언을 하였다.

• 농업과학연구
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• 제49권4호
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• pp.845-855
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• 2022

The purpose of this study is to develop a self-propelled underground crop harvester and its performance was evaluated by measuring the load during actual potato harvesting operations. This study was conducted at a constant working speed of 1 km·h^-1. A load measurement system was installed to measure the actual load and the required working power was analyzed. A hydraulic pressure sensor was also installed to measure the hydraulic pressure. The required hydraulic power was calculated using the hydraulic pressure and flow rate. The results showed that the engine speed, torque, and power during harvesting operation were in the range of 845 - 1,423 rpm, 95 - 228 Nm, and 9 - 31 kW, respectively. Traction power, excluding the hydraulic pump of the tractor and power take-off (PTO) output, was in the range of 9 - 28 kW, and it was confirmed that it occupies a ratio of 16.2 to 50% of the engine rated output. The engine can supply the minimum required traction power to move the vehicle. This means that the engine used in this study could be down-sized to be suitable for an underground crop harvester. In this study, the gear stages of the tractor were not considered. This research thus shows the possibility of developing a self-propelled underground crop harvester.

• 산업융합연구
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• 제21권4호
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• pp.13-22
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• 2023

COVID-19로 인해 기업은 재택근무와 유연근무를 확대하고, 스마트워크 공간을 확충하여 일하는 방식을 빠르게 변화시키고 있다. 스마트워크 상황에서 근로자는 자신이 수행하는 업무 방법, 업무 시간, 업무 장소 등을 선택하는 직무자율성이 향상되었다. 하지만 기존 연구는 스마트워크 상황을 반영하지 못하고 기존 직무자율성 개념과 측정도구를 여전히 사용하는 한계가 있다. 이러한 문제점을 극복하기 위해 본 연구는 스마트워크 환경에 적용가능한 직무자율성 유형(방법, 일정계획, 기준, 시간, 장소)을 도출하고, 5개 유형의 직무자율성이 창의적 행위에 통계적으로 유의한 정(+)의 영향을 준다는 점을 검증하였다. 본 연구는 전통적인 직무자율성 개념(방법, 일정계획, 기준)에 시간과 장소 유연성을 추가하여 스마트워크에서 적용 가능한 직무자율성을 유형화하고, 다차원의 직무자율성 검증을 통해 스마트워크의 운영 성과를 세분화하여 평가하는 근거를 제공하였다는데 시사점이 있다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.174-174
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• 2023

The impact of global warming on the south Asian summer monsoon is of critical importance for the large population of this region. This study aims to investigate the future changes of the precipitation extremes during pre-monsoon and monsoon, across this region in a more organized regional structure. The study area is divided into six major divisions based on the Köppen-Geiger's climate structure and 10 sub-divisions considering the geographical locations. The future changes of extreme precipitation indices are analyzed for each zone separately using five indices from ETCCDI (Expert Team on Climate Change Detection and Indices); R10mm, Rx1day, Rx5day, R95pTOT and PRCPTOT. 10 global climate model (GCM) outputs from the latest CMIP6 under four combinations of SSP-RCP scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) are used. The GCMs are bias corrected using nonparametric quantile transformation based on the smoothing spline method. The future period is divided into near future (2031-2065) and far future (2066-2100) and then the changes are compared based on the historical period (1980-2014). The analysis is carried out separately for pre-monsoon (March, April, May) and monsoon (June, July, August, September). The methodology used to compare the changes is probability distribution functions (PDF). Kernel density estimation is used to plot the PDFs. For this study we did not use a multi-model ensemble output and the changes in each extreme precipitation index are analyzed GCM wise. From the results it can be observed that the performance of the GCMs vary depending on the sub-zone as well as on the precipitation index. Final conclusions are made by removing the poor performing GCMs and by analyzing the overall changes in the PDFs of the remaining GCMs.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.622-627
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• 2009

Business process engineering (BPE) is a top-down management approach for increasing efficiency and productivity through radical and fundamental changes to the business processes of the organization. BPE requires firms to initially develop a model of the existing business processes of the firm to distinguish functional tasks from processes used for coordinating inputs, activities and outputs. The model is used for understanding the business processes in the organization and to simulate the effect of changes to the processes. The model can also be used to justify business processes, which involves assessing whether the business process provides value to the customer in its current configuration. Justification requires a careful examination of the key business processes used by the firm to identify systemic shortcomings in the process and to create a new business process to produce greater efficiency. BPE also considers automating as many business processes as possible to increase operational efficiency and the integration of business process tasks. The construction industry has been slow to adopt BPE because of its project approach in which a major firm contracts with various functional service providers and regards each project as unique. The industry focuses on functional task efficiency rather than business process efficiency. There is no formal methodology or criteria for determining whether a business process is effective for a construction firm in its current configuration. The use of performance measures such as costs, task duration times or other metrics can be useful in evaluating the effectiveness of an existing business process and for modeling the possible outcome of a fundamental and radical change to the process.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.345-353
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• 2009

The success and failure of any project depends upon many factors, the Project Manager is considered to be the key contributor to the success of any project, as well as a guide to the team members to achieve the client satisfaction (Cost, Time and Quality). Therefore the main aim of this paper is to provide a practical approach for understanding the importance of the Project Manager and his effectiveness to the success of the construction projects. In addition, the Project Manager's roles, responsibilities and duties have direct impact to the success of the construction projects. In order to identify the thoughts and opinion of the construction industry on this particular assertion, a quantitative study was carried out within the UK construction industry. The result of the study shows that there is an extremely strong correlation between the Project Manager and the success of the construction projects. In construction projects the Project Manager is considered to be one of the most important people who can lead and drive the projects in the right direction and conclude construction projects successfully. Moreover, these can play the most important role regarding the improvement of the organization's performance, the organization's profitability and the client's satisfaction. The research confirmed that the Project Manager is a very essential element to the success of the construction project and have an impact at every stage of the construction project. So it concluded that selection of a Project Manager should be carefully done with regard to experience, knowledge, power/authority and good understanding to the kind of the project.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.1013-1016
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• 2005

Accounts of the development of a successful construction project often stress the importance of team relationship, project environment and senior management commitment. Numbers of studies carried out in the past decades indicate there needs to be a change of culture and attitude in the construction industry. In order for a turn around in the industry, relational contracting approaches have become more popular in recent years. However, not all relational contracting projects were successful. This paper details the fundamental principles of relational contracting. It further reports findings of a research currently taking place in Australia, how effective is relational contracting in practice. The problem addressed in this research is the implementation of relational contracting: • Throughout a range of projects • With a focus on client body staff The context within which the research was undertaken is: • Empowerment, regional development and promotion of a sustainable industry • The participating organisations have experience of partnering and alliancing • Success has been proven on large projects but performance is variable • Need has been identified to examine skill sets needed for successful partnering/alliancing The practical rationale behind this research is that: • Partnering and alliancing require a change of mind set - a culture change • The Client side must change along with contracting side • A fit is required between organisation structure and organisation culture Research Rationale: The rationale behind this project has been to conduct research within participating organisations, analyse, rationalise and generalise results and then move on to produce generic deliverables and "participating organisation specific" deliverables. This paper sets out the work so far, the links between the various elements and a plan for turning the research output into industry deliverables.

• 한국군사과학기술학회지
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• 제26권1호
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• pp.10-21
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• 2023

For various target tracking applications, it is well known that the Kalman filter is the optimal estimator(in the minimum mean-square sense) to predict and estimate the state(position and/or velocity) of linear dynamical systems driven by Gaussian stochastic noise. In the case of nonlinear systems, Extended Kalman filter(EKF) and/or Unscented Kalman filter(UKF) are widely used, which can be viewed as approximations of the(linear) Kalman filter in the sense of the conditional expectation. However, to implement EKF and UKF, the exact dynamical model information and the statistical information of noise are still required. In this paper, we propose the recurrent neural-network based Kalman filter, where its Kalman gain is obtained via the proposed GRU-LSTM based neural-network framework that does not need the precise model information as well as the noise covariance information. By the proposed neural-network based Kalman filter, the state estimation performance is enhanced in terms of the tracking error, which is verified through various linear and nonlinear tracking problems with incomplete model and statistical covariance information.

• 임상간호연구
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• 제15권1호
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• pp.149-165
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• 2009

Purpose: This study was done to identify the causes of turnover in nursing staff in small and medium‐size hospitals and prepare measures to decrease turnover. Nurses in these hospitals were surveyed focusing on their nursing activities, reasons for turnover, and content of their work. Method: A mail survey of hospitals with 300 beds or less was conducted using a questionnaire including items on the current state of nursing, performance of nursing tasks, turnover of nurses, working conditions, and supports and policies related to insufficient number of nurses. Results: The average number of nurses per 100 beds was 37.5, 3.3 less than the prescribed level of 40.8. The turnover rate was higher when the level of remuneration for nursing care was low, and the most frequent reason for nurses leaving was 'move to another hospital', showing that there is a continuous chain of moves for nurses. Other frequent reasons were situations related to working conditions such as childbirth, child care, irregular working hours, night work, and low wages. Conclusion: To guarantee adequate nursing coverage in these hospitals, working conditions for nurses should be improved, including higher wages, a more flexible work system, and installation and operation of 24-hour child care facilities.