• Journal of Biosystems Engineering
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• 제25권5호
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• pp.351-358
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• 2000

This study was conducted to develop a speed control system of a DC motor which drove a barley seeder mounted on a combine harvester. Barley seeder mounted on a combine has been known to reduce labor and cost of barley cultivation. However, development of the seeder has been unsuccessful because the combine, a dedicated rice and barley harvester has not enough space and proper power take-off for barley seeder. To develop a barley seeder, small powered motor speed controller was required. A proximity sensor for detecting working speed of the combine and a programmable one board microprocessor was used to develope a control system. Motor parameters and motor constant, relationship between seeding rate, motor speed, groove volumes of a tested roller, torque were measured. The proximity sensor sent a frequency signal to the microprocessor. In laboratory experiments, the excitation voltage of the motor was shown not to be proportional to the size of pulse width (duty ratio). A table transforming frequency signal, that represented for working speed to proper pulse width was developed from seeding rate experiments. However, seeding rate at low frequency signal was not proportional to the working speed. Seeding rate control proportional to the frequency signal was achieved by shifting of the frequency signal.

• International Journal of Computer Science & Network Security
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• 제21권3호
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• pp.141-144
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• 2021

Modern concepts of management of construction production systems require solving the problems of harmonization of the distribution of structural elements on the way to overcoming global destabilization processes. An effective ratio of functional subsystems of production in an environment of mutual influence create sustainable opportunities for production management and contribute to the logical development of the system as a whole in achieving the main goal of harmonious management. The purpose of the study is to develop the concept of effective management of production systems in construction with the harmonious formation of organizational structures. The results of the study allowed to reveal the harmonization approach in improving the interaction of structural elements of production and accelerating their functional sensitivity to changes in the environment. Harmonious production system more effectively adapts to the diversity of interests, goals and actions at all levels of management of different subsystems in any environment.

• 아태비즈니스연구
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• 제11권2호
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• pp.189-206
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• 2020

Purpose - The purpose of this study is to clarify the mediating effect of profitability and activity in the relationship between productivity and stock return, assuming that the productivity of the company will affect share prices with the parameters of profitability and activity. Design/methodology/approach - The study extracted productivity indicators, profitability indicators, activity indicators, and share price-related indicators from 1999 to 2018 of non-financial enterprises listed on the securities market, and then classified them into three factors: productivity (labor productivity LP, capital productivity CP), activity (TT), and profitability (net profit rate NI, operating profit ratio OI) through the factor analysis method, and analyzed the impact of each factor on the stock return through steps 1 to 3. Findings - The regression analysis shows that productivity has a significant positive effect on the stock return through the full mediating effect of profitability and activity. Research implications or Originality - In a situation where the relationship between productivity and profitability is not clear, this study is meaningful in that it has empirically analyzed that productivity has a positive effect on the stock return by mediating effects of profitability and activity.

• 수산해양기술연구
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• 제59권2호
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• pp.181-187
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• 2023

Laver aquaculture, which occupies a large proportion in the aquaculture industry in Korea, is still highly dependent on human labor. Therefore, it is necessary to study the development of an automatic system to improve the working environment and increase the efficiency of aquaculture production systems. The purpose of this study is to evaluate the economic feasibility of an improved system in a study for the loading-unloading and automatic weighing systems in laver aquaculture industry. Economic analysis of the developed unloading and automatic weighing system were implemented under various conditions to calculate more accurate benefits and costs. As a result of this study, the economic feasibility was found to be very high in the three models: net present value (NPV), benefit-cost ratio (B/C), internal rate of return (IRR). Moreover, the results of sensitivity analysis showed that the economical efficiency of the automatic loading, unloading, and weighing system in laver aquaculture was very high.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.247-248
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• 2021

Recently, the government is pursuing to reduce the serious accidents in most industries, including the construction industry, by enacting laws on punishment. The accident rate tends to be depended on the size and type of construction sites, and the accidents occur frequently due to inadequate implementation of safety management system and management standards, especially, in small and medium-sized sites. This study has performed the profiling of 265,000 accident cases on construction sites by attribute analysis such as the ratio of days lost to work, and pattern of days lost to work compared to the size of the construction. It turned out that the proportion of accident cases was high mainly in small-scale construction sites, and long-term labor losses occurred. Shortly, it is necessary to establish an institutional standard for applying a realistic safety management cost calculation and management system centered on small-scale sites. Therefore, this study is expected to be used as fundamental data or guideline for developing a customized safety management and accident prevention system for a worker reflecting the conditions of a construction site in the future.

• 한국사회복지학
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• 제56권3호
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• pp.159-181
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• 2004

본 연구는 청년실업과 신규대졸자 실업의 실태 및 원인을 분석해 본 후, 청년 및 신규대졸자 실업 완화에 도움이 될 수 있는 대안을 탐색해 보았다. 청년실업과 신규대졸자 실업의 실태 및 원인 분석을 요약해보면, 첫째 외환위기로 급증한 청년실업률은 2000년 이후 상당히 완화되었으나 아직도 외환위기 이전에 비해 상당히 높은 편이며, 둘째 외환위기로 급증한 신규대졸자 실업률은 2000년 이후 완화되어 현재 외환위기 이전과 비슷한 수준이나 신규대졸자 실업자 수는 외환위기 이전에 비해 많이 증가하였고, 셋째 청년실업의 원인분석 결과 경제성장률과 경제성장의 고용탄력성(고용창출력)이 낮을수록, 대학진학률이 높을수록 실업률이 높은 것으로 나타났으며, 넷째 신규대졸자 실업 원인분석 결과 경제성장률과 경제성장의 고용탄력성이 낮을수록, 신규대졸자 증가율, 청년층 대비 대졸자 비율, 시간추세가 클수록 실업률이 증가한 것으로 나타났다. 청년 및 신규대졸자 실업 완화를 위한 정책과제로, 첫째 노동수요 확대를 위해 경제성장률을 높일 수 있는 경제환경을 조성해야 하고, 경제성장의 고용탄력성을 높일 수 있도록 고용창출력이 높은 산업 직업을 육성해야 하며, 둘째 노동공급 측면으로 신규대졸자 실업 완화를 위해 대졸자 수를 산업수요에 맞게 조절할 필요가 있고, 셋째 노동 수요와 공급의 불일치 완화를 위해 중.고등학교에서의 직업교육 활성화, 대학교육의 현장성 강화 등 학교교육과정을 개선하고, 청년실업 문제를 체계적, 종합적으로 지원할 수 있는 통일된 프로그램을 마련할 필요가 있다.

• 대한지역사회영양학회지
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• 제10권6호
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• pp.905-919
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• 2005

This study raised the necessity of developing performance indicators for measuring the management efficiency and effectiveness of school food service, and as a means of helping its implementation, a balanced score card (BSC) approach developed by Norton and Kaplan was adopted. This study established BSC in seven phases through literature: Phase 1 Defining a school food service and the scope of working activities, Phase 2 Establishing the vision of a school food service, Phase 3 Setting strategic goals, Phase 4 Identifying critical success factors (CSFs), Phase 5 Developing Key Performance Indicators (KPIs), Phase 6 Extracting cause and effect relationship, and Phase 7 Completing a preliminary BSC. The preliminary BSC was fumed into a survey, which was administered to food service related people working at the Office of Education and School Food Service including 16 offices,209 dietitians, 48 school administrators both from self-operated and contract-managed, and 9 experts in areas related to school food service. They were asked questions about strategies from 4 different perspectives,12 CSFs, 39 KPls, and the cause and effect relationships among them. As a result, among the CSFs based on 4 different perspectives, all factors other than ' zero sum on profit/loss ' from the financial perspective turned out to be valid. In terms of KPIs, manufacturing cost percentages, casualty loss count/reduction rates, school foodervice participation rates, and sales goal achievement rates were found to be valid from the financial perspective, while student satisfaction index, faculty satisfaction index, leftover ratio, nutrition educational performance count, index of evaluating nutrition education, customer claim count/reduction rate, handling customer claim count/reduction rate, and parent satisfaction index were found to be valid from the customers' perspective. Besides, nutritional requirement sufficient ratio, nutritional management score, food poisoning outbreak count, employee safety accident count, sanitary inspection assessment index, meals per labor hour (productivity index), computerization ratio, operational management index, and purchase management assessment index were also found to be valid from the perspective of internal business processes. From the perspective of innovation and learning, employee turnover ratio/rate of absenteeism, annual education and training count, employee satisfaction index, human resource management assessment index, annual menu-related customer feedback, food service information index for employees and parents/schools were also found to be valid. The significance of this study is to present indices for measuring overall performance of school lunch food service operations without putting any limitation on types of school food service management, and to help correctly assess the contribution of the current types of school food service management to schools and students. (Korean J Community Nutrition 10(6) : $905\∼919$, 2005)

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2003년도 하계 학술대회 논문집
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• pp.309-316
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• 2003

참깨탈곡의 생력기계화를 위해 일관작업이 가능한 참깨탈곡기를 개발하여 시험한 결과를 요약하면 다음과 같다. 가. 타격식 탈곡요인시험 결과 타격수 14, 17cpm에서 탈곡률은 98.5, 98.7%, 미탈곡률은 1.1, 1.0%, 배출구 손실률은 0.4. 0.3%로 가장 양호하게 나타났다. 나. 타격식 탈곡물의 정선요인시험결과 경사 12$^{\circ}$, 요동수 220cpm일 때 탈곡률과 미정선 손실률이 각각 97.2%와 0.6%로 가장 양호하게 나타났다. 다. 타격식 탈곡부와 정선부를 조합한 시작기의 성능시험결과 공급량 15단/min, 타격수 14cpm, 정선체 요동수 220cpm에서 탈곡률은 98.7%, 탈곡부 손실률은 1.3%, 정선율은 97.0%, 미정선 손실률 0.7%로 나타났다. 라. 시작기는 10a당 작업성능이 0.5시간으로 인력 4.8시간에 비해 9.6배 능률적이고 소요경비가 17,471원으로 인력 32,290원에 비해 45.9% 절감되는 것으로 나타났다

• 한국인구학
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• 제18권2호
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• pp.115-168
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• 1995

한국경제의 장기적 발전은 총투자의 지속적 증가와 이를 가능케 해줄 국민저축의 착실한 증가에 크게 의존한다고 보겠다. 이러한 국민저축 중에서도 가계저축은 우리나라의 투자재원 조달에 가장 중요한 역할을 담당할 것으로 기대되고 있다. 본고는 가계저축의 결정요인을 찾아내기 위하여 우리나라 가계소비율의 결정요인을 살펴본 다음에 이를 이용하여 간접적으로 가계저축의 결정요인을 원용하였다. 이와 같이 가계소비율의 추정을 통하여 가계저축율을 추정하고자 한 이유는 일반적으로 소비함수는 안정적인 성향을 가진 반면 저축함수는 불안정적인 성향이 강하기 때문이다. 가계소비율 추정을 위해서는 우리나라의 도시가계조사 및 농가경제 조사자료를 기초자료로 이용하였는 바, 가계소비율에 대한 회귀분석의 결과를 요약하면, 첫째로 가계소득의 증가와 취업가구원수의 증가는 가계소비율을 낮추는 방향으로 작용하고 있는 반면, 둘째로 가구주의 연령, 교육수준, 가구원수의 증가는 가계소비율을 저하시키는 경향이 있는 것으로 나타났다. 2000년대의 우리나라는 소득의 괄목할 만한 증가, 여성의 노동시장 참가율 제고로 인한 취업가구원수의 증가 및 핵가족화의 영향으로 인한 평균 가구원수의 감소로 가계소비율의 저하가 예상되는 반면에, 인구의 노령화에 기인한 가구주의 평균연령의 상승, 교육수준의 향상에 따른 가계소비율의 상승이 예상되지만, 총체적으로는 가계소비율의 감소를 통한 가계 저축율의 착실한 증가가 있을 것으로 예측되므로 한국경제의 장기적 발전을 위한 투자재원의 조달에는 큰 어려움이 없을 것으로 전망된다.

• 한국산림과학회지
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• 제101권3호
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• pp.426-433
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• 2012

본 연구는 곰취 임간재배 개선방안을 모색하고 필요한 정책수립 및 컨설팅을 위한 기초자료 마련을 위해 수행되었다. 이를 위해 인제군 산림복합경영자 중 곰취를 재배하는 8개 임가를 대상으로 심층면접 설문을 실시하여 조성단계에서 수확작업에 이르는 각 단계별 노동투입량 등 총비용과 조수입, 순수익을 계산하여 경영실태를 분석하였다. 수익성은 수익비용비율, 순현재가치법, 내부수익률법을 이용하여 분석하였다. 분석결과 할인율 3%를 적용할 경우 IRR 48.6%, B/C ratio 1.5, NPV 41,419천원/ha으로 수익성이 높은 것으로 나타났다. 사례 임가별로 IRR 147.9%~3.5%의 심한 편차를 보였는데, 이는 곰취 임간재배가 현재 초기단계로 아직 표준재배법이 정립되지 않아 재배자마다 재배기술의 차이가 있기 때문인 것으로 사료된다. 재배의 각 단계별로 보다 체계적인 작업법을 정립하고, 이에 필요한 정책적 지원이 따른다면 곰취 임간재배는 국내 임가의 소득창출은 물론이고 안전한 먹거리 공급과 도 시민의 휴양 체험지 제공에도 큰 역할을 할 것으로 기대된다.