• Title/Summary/Keyword: 효율 성

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A Study on Composition and Utilization of Waste Heat Recovery System Assuming Aerobic Liquid-composting Fermentation heat (호기성 액비화 발효열을 가정한 폐열회수시스템 구성 및 활용 연구)

  • Lim, Ryugap;Jang, Jae Kyung;Kang, Taegyung;Son, Jinkwan;Lee, Donggwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.4
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    • pp.56-66
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    • 2021
  • In this study, a waste heat recovery system was devised and the performances of components incorporated to recover the heat generated during the processing of aerobic liquid-composting in a livestock manure treatment facility were analyzed. In addition, the availability of recovered heat was confirmed. The heat generated by liquid fermentation in the livestock manure treatment facility was also checked. Experimental temperatures were set at 35, 40, and 45 ℃ based on considerations of the uniformity of aerobic liquid-composting fermentation tank temperature and its operating range (34.5 ~ 43.9 ℃). Recovered heat energies from the combined heat exchanger, which consisted of PE and STS pipes, were 53.5, 65.6, 74.4 MJ/h, The heat pump of capacity 5 RT was heated at 95.6, 96.1, 98.9 MJ/h and the heating COPs of the pump were 4.53, 4.62, and 4.65, respectively. The maximum hot water production capacity of the heat exchanger assuming a fermentation tank temperature of 45 ℃ confirmed an energy supply of 56 360 kcal/day. The heating capacity of the FCU linked to the heat storage tank was 20.8 MJ/h, and the energy utilization efficiency was 96.1%. When livestock manure was dried using the FCU, it was confirmed that the initial function rate was reduced by 50.5 to 45.8 % after drying.

A Comparative Model Study on the Intermittent Demand Forecast of Air Cargo - Focusing on Croston and Holts models - (항공화물의 간헐적 수요예측에 대한 비교 모형 연구 - Croston모형과 Holts모형을 중심으로 -)

  • Yoo, Byung-Cheol;Park, Young-Tae
    • Journal of Korea Port Economic Association
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    • v.37 no.1
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    • pp.71-85
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    • 2021
  • A variety of methods have been proposed through a number of studies on sophisticated demand forecasting models that can reduce logistics costs. These studies mainly determine the applicable demand forecasting model based on the pattern of demand quantity and try to judge the accuracy of the model through statistical verification. Demand patterns can be broadly divided into regularity and irregularity. A regular pattern means that the order is regular and the order quantity is constant. In this case, predicting demand mainly through regression model or time series model was used. However, this demand is called "intermittent demand" when irregular and fluctuating amount of order quantity is large, and there is a high possibility of error in demand prediction with existing regression model or time series model. For items that show intermittent demand, predicting demand is mainly done using Croston or HOLTS. In this study, we analyze the demand patterns of various items of air cargo with intermittent patterns and apply the most appropriate model to predict and verify the demand. In this process, intermittent optimal demand forecasting model of air cargo is proposed by analyzing the fit of various models of air cargo by item and region.

Studies on Efficient Extraction of Limonene from Citron and Immune-modulation Activity for Development of Environmentally Friendly Material (친환경 소재 개발을 위한 유자에서의 효율적 Limonene 추출 및 면역기능 조절활성에 관한 연구)

  • Ahn, Jong-Ho;Lim, Hyun-Hee;Hwang, Seong-Gu;Nam, In-Sik
    • Korean Journal of Organic Agriculture
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    • v.28 no.4
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    • pp.591-604
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    • 2020
  • The objectives of this study were to find out the best condition of extracting methods of limonene from citron and to determine effects of limonene on immune modulation activity by measuring cytokine secretion using RAW 264.7 mouse macrophage cells. When distilled water was used as a solvent instead of organic solvents to extract limonene from citron, addition of refluxing process to simultaneous steam distillation extraction method was found to be much effective in extracting limonene. However, it required longer extraction time than using other organic solvents. Limonene extracts showed increased IL-β and IL-6 but decreased the TNF-α gene expression in limonene concentration dependant manner. However oral administration of limonene extracts to mice did not influence significantly compared to control in in vivo experiment. It might be due to that the mice were kept in well controlled and complete environment. Limonene, a natural material from citron has been approved to have a immune-modulation activity in the present study and have a potential as a feed additive that is environmentally friendly and no harmful. Further study with protected limonene, for example, for the protection of limonene from oxidation or bypass the ruminal degradation in order consequently to increase immune-modulation activity might be useful as a further research.

An Analysis of the Determinants of Foreign Direct Investment in the Western China, 1990-2007 (중국 서부지역 외국인직접투자(FDI)의 결정요인에 관한 분석: 1990-2007 기간을 중심으로)

  • Peng, Xian-Feng;Choi, Sung-Il
    • International Area Studies Review
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    • v.15 no.3
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    • pp.471-491
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    • 2011
  • This study is to analyze the determinants of inflow FDI with panel data of 12 provinces in western region of China for the period, 1990-2007, from the perspective of market-oriented FDI and production-efficiency-oriented FDI. The empirical findings are following. First, the empirical results prior to the start of western development program show that the GRDP, the intense of industrialization and university graduates per 10,000 residents have positive coefficient signs at the significant level, while wage level has a negative and significant value. Second the empirical results using the data after the launching of the western development program show that the GRDP, the intense of industrialization have positive relations with FDI, while openness in terms of the ratio of international trade to GRDP and the wage level have negative coefficients. Finally, this thesis finds that the empirical results for both periods are very similar, which suggest that the economic structure in western region has not changed significantly even though almost a decade passed since the western development program launched.

Development of HLA-A, -B and -DR Typing Method Using Next-Generation Sequencing (차세대염기서열분석법을 이용한 HLA-A, -B 그리고 -DR 형별 분석법 개발)

  • Seo, Dong Hee;Lee, Jeong Min;Park, Mi Ok;Lee, Hyun Ju;Moon, Seo Yoon;Oh, Mijin;Kim, So Young;Lee, Sang-Heon;Hyeong, Ki-Eun;Hu, Hae-Jin;Cho, Dae-Yeon
    • The Korean Journal of Blood Transfusion
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    • v.29 no.3
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    • pp.310-319
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    • 2018
  • Background: Research on next-generation sequencing (NGS)-based HLA typing is active. To resolve the phase ambiguity and long turn-around-time of conventional high resolution HLA typing, this study developed a NGS-based high resolution HLA typing method that can handle large-scale samples within an efficient testing time. Methods: For HLA NGS, the condition of nucleic acid extraction, library construction, PCR mechanism, and HLA typing with bioinformatics were developed. To confirm the accuracy of the NGS-based HLA typing method, the results of 192 samples HLA typed by SSOP and 28 samples typed by SBT compared to NGS-based HLA-A, -B and -DR typing. Results: DNA library construction through two-step PCR, NGS sequencing with MiSeq (Illumina Inc., San Diego, USA), and the data analysis platform were established. NGS-based HLA typing results were compatible with known HLA types from 220 blood samples. Conclusion: The NSG-based HLA typing method could handle large volume samples with high-throughput. Therefore, it would be useful for HLA typing of bone marrow donation volunteers.

The Research on Job Analysis of Horse-Riding Instructor (승마지도사에 관한 직무분석 연구)

  • Lee, Byung-Wook;Kang, Kyoung-Kyoon;Yi, Joo-Wook;Lee, In-Kyung
    • Journal of vocational education research
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    • v.33 no.3
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    • pp.145-167
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    • 2014
  • The purpose of this research is to prepare the measures for evaluating the job of horse-riding instructor and improvement related to it and for distributing horse-riding industry effectively. Forsuch, we tried to analyze job of horse-riding instructor. Inparticular, we have developed DACUM chart of horse-riding instructor through DACUM method and experts related to it. As result, we found out eight duties and hundreds of job and arranged seven duty areas in total and eighty-two executed works. In addition, as experts said, the horse-riding instructor is the one who 'instructs people learning horse-riding in horse-riding facility and manages horses, horse-riding equipment and man-power.' Such results provide the procedure of horse-riding instructor cultivation which has been presently underway with many viewpoints. Especially, there are three educational processes and subject materials related to horse-riding instructor's examination(Hipologia, Horse-treatment technique, Horse Health management). However, as result of analysis on duty, we found out that racecourse management and horse-riding education theory has been needed to be added and complemented as well. In addition, the work and duty of analysis can be used to be made use up of as work profile and specification and such data can be also made use of as standard of training and submission. Through this study there should be a necessary work to distinguish between re-drafting and role of duty in its own right related to certification of horse-riding instructor in future and it would be necessary to develop study that is able to connect them all to certificate. What is more, there should be work and measure required for rethinking of utility of certification.

A Qualitative Analysis on Supervisors' Dysfunctional Leadership Behaviors, Antecedents, and Results (상사의 역기능 리더십 행동, 선행요인 그리고 결과에 대한 질적 분석)

  • Im, Chang-Hyun;Lee, Hee-Su
    • Journal of vocational education research
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    • v.30 no.4
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    • pp.1-22
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    • 2011
  • Paradoxically, leadership has not only positive effects but also negative effects. The purpose of this study is to examine supervisors' dysfunctional leadership behaviors, antecedents and results in order to draw HRD implications for protecting organizations and employees from dysfunctional leaders and provide implications for leadership development. A qualitative research method based on semi-organized interviews with 28 employees from S-group was used. The results of this study show that the dysfunctional leadership behaviors were associated with ten behavioral categories: belittling and insulting the subordinates, authoritative and arbitrary behaviors, self-aggrandizement, biased preference for certain personnel, arrogance, micro-managing, inability to change and adapt, discordance between words and actions, over-dependance on supervisor, lack of ethics and values. Dysfunctional leadership behaviors were casually attributed to 'personal traits & experience', 'task characteristics', and 'internal & external environments of the organization'. Finally, the results of supervisor's dysfunctional leadership behaviors on employees and the organizational effects were 'increased turnover rate', 'declining work efficiency', 'collapsing morale', 'retraining innovative thinking', 'passive working culture', 'discouraging organizational vitality', 'discouraging organizational synergy', 'losing loyalty' and 'declining trust on supervisor'.

Effects of Pollen Viability and Pistil Receptivity on Seed Set for Artificial Pollination in Strawberry (딸기 인공 수분시 화분 활력 및 암술의 수정 능력이 결실률에 미치는 영향)

  • Kim, Dae-Young;Yoon, Moo- Kyung;Do, Kyung-ran;Kim, Tae il
    • Korean Journal of Breeding Science
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    • v.41 no.4
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    • pp.496-501
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    • 2009
  • In order to promote the efficiency of strawberry breeding programs, pollen viability of strawberry, 'Seolhyang' was investigated using the fluorochromatic reaction test and seed set under controlled environment. Pistil receptivity was also assessed by hand pollination. Four varieties including 'Maehyang' were used for the test of pistil receptivity with 'Seolhyang' as a pollen parent. Pollen viability remained high for several days under dry conditions as below 33% relative humidity while the greatest loss of viability occurred at 76% relative humidity. The viability was rapidly decreased at high humidity and almost all grains were unviable in 7 days after storage. Pollen viability does not appear to be drastically reduced if the relative humidity is low. Therefore, humidity is more important factor than temperature for the pollen viability in Fragaria${\times}$ananassa. The rate of seed set by hand pollination lasted higher than the average of 77.2% from 2 to 8 days after emasculation when the daily average temperature was around $15^{\circ}C$ in plastic house. It began to decline gradually from 10 days and had decreased dramatically after 12 days except several cultivars. Based on the daily mean accumulated temperature, it is recommended to have an artificial pollination between the range of $45{\sim}140^{\circ}C$ after the emasculation to increase the rate of seed set in strawberry.

The Relationship between Job Stress and Career Resilience of Fire Fighting Officers: The Mediation Effect of the Job Efficacy (소방공무원의 직무스트레스와 경력탄력성의 관계: 직무효능감의 매개효과)

  • Han, Hye Kyung;Kim, Gab Sook
    • Fire Science and Engineering
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    • v.33 no.2
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    • pp.155-163
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    • 2019
  • The purpose of this study was to investigate the mediation effect of the job efficacy on the relationship between job stress and career resilience of fire fighting officers. The participants of this study were 151 Jeju Island local fire fighting officers. The research tools used were job stress scale, career resilience scale and job efficacy scale. The data were analyzed using the SPSS statistical program. Pearson's correlation analysis, hierarchical multiple regression analysis and the Sobel test were conducted. The results of this study are as follows: First, there was a significant negative correlation between the job stress and the career resilience and between the job stress and the job efficacy, while there was a significant positive correlation between the job efficacy and the career resilience. Second, the job efficacy of fire fighting officers was found to have a perfect mediation effect on the job stress and the career resilience. As a result, it was found that job efficiency as a mediator to cope with job stress can improve the work efficiency by improving the career resilience of fire fighting officers. Finally, the discussion and implication are provided based on the results.

The Suggest for improving the operation process of vocational education and training institutions (a beauty major of the vocational college) (직업교육 훈련기관 운영과정 개선에 대한 제안 (전문대 미용계열 중심으로))

  • Kim, Yun-Jung;Hong, Mi-Sook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.2
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    • pp.368-377
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    • 2019
  • The purpose of this study is to examine the present operation process and to suggest the points of improvement so that vocational education and training institutions can be activated more effectively. The subjects of this study were 250 college students who completed or attended the vocational education and training course in Seoul and Gyeonggi-do, and collected 230 data, excluding inappropriate responses. Data analysis was performed by using the statistical package program SPSS Statistics (Ver. 24: IBM, USA). In this study, frequency analysis was conducted to examine the characteristics of data, and crossover analysis was conducted mainly to investigate the correlation between categorical data. The results of this study are as follows: First, it provides information about vocational education and training course to all general high school students at the beginning of the first year of high school, and then, from the first semester of the second grade, do. Second, it is to open four major courses in beauty education at the same time. This makes it possible to acquire qualifications according to four beauty courses during the training period at the training institute rather than the private education institute where private education expenses are incurred. By training all major courses in skin, hair, make-up, and nail art, you will be given the opportunity to carefully determine the major course that fits your aptitude. Based on the results of this research, we propose a plan to improve the vocational education system for vocational high school students who are majoring in cosmetology.