• Title/Summary/Keyword: Efficient operation

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Characteristics of Fish Utilization of the Nature-like Fishway Installed at the Beakjae Weir (백제보에 설치된 자연형 어도의 어류 이용 특성 분석)

  • Kim, Jeong-Hui;Yoon, Ju-Duk;Park, Sang-Hyeon;Lee, Jin-Woong;Baek, Seung-Ho;Jang, Min-Ho
    • Korean Journal of Ecology and Environment
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    • v.48 no.4
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    • pp.212-218
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    • 2015
  • In South Korea, various nature-like fishways recently been installed for use by a wide variety of fish species. However, limited attempts have been made to monitor the fish utilization. The present study was conducted to ascertain the frequencies and patterns of utilization of the fishway installed at Beakjae Weir. We collected fish species that use the fishway by installing a fyke net at the exit of the fishway at least once a month from April 2013 to October 2013. Additionally, in order to identify all fish species that can potentially use the fishway, we investigated the fish fauna downstream to Beakjae Weir (mainstream of the Geum River). We found that 10 species belonging to 2 families used the fishway; this accounted for 64% of the total species inhabiting the mainstream. The species that used the fishway most frequently were Microphysogobio jeoni, followed by Squaliobarbus curriculus and Opsariichthys uncirostris amurensis. The highest number of fish using the fishway was observed in August, which was positively correlated with the water temperature (Spearman rank correlation, $r_s$=0.743, P=0.035). The sizes of the fish using the fishway varied widely, with the total body length ranging from 39 mm to 550 mm. Analysis of the time-dependent utilization frequency revealed that most fish used the fishway during the night (20:00~08:00). Compared to other fishways installed along the Geum River, the fishway installed at Beakjae Weir was used by fewer species and fish. This may be attributed to the structural inadequacy of the fishway, thereby resulting in a low attraction efficiency. Therefore, measures should be adopted to enhance the fishway attraction and passage efficiency. The results of this study can be used to ensure efficient operation and management of the Beakjae Weir fishway as well as serve as basic data for developing and building nature-like fishways tailored to Korean situations.

A Study on the Model Regulation's Improvement for Control of Aeronautical Obstacles in Korea (항공장애물관리규정 개선을 위한 연구)

  • Lee, Kang-Seok
    • Journal of Korean Society of Transportation
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    • v.23 no.3 s.81
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    • pp.21-34
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    • 2005
  • To control the obstacles surrounding aerodrome is significant for preventing air accident and ensuring the long sustaining of aerodromes. On the other hand, within a scope of ensuring safe flight operations, the application of Shielding is one of the issues to be importantly considered to manage efficiently the obstacles limitation around aerodromes, to dissolute the private asset privilege limitation from regulation on aerodrome circumference, and to decrease the pains to manage the obstacles, in terms of not only operating safely but also utilizing efficiently the airspace around aerodromes. The ICAO and other aviation-advanced states mitigate the construction limitation or exempt the obligation of obstacle sign by applying the shielding theory that the obstacles are not regarded as obstacles where are below the shadow surface. The Republic of Korea inserted the new regulation including the applying shielding similar to ICAO on Aviation Act and regulations. It is, however, hard to manage the aviation obstacles around aerodrome efficiently with these new regulation. Particularly, there exists much rooms to dispute because it cannot suggest the specific standard which is necessary to apply shielding theory at airspace of aerodromes. Therefore, in this study, the international standards on aviation obstacles were reviewed, analyzed and compared with those of domestic status. The direction of which guideline for control of aeronautical obstacles applicable within domestic circumstances as well as correspondent with international standard was suggested. Particularly, as far as the disputable application of shielding theory is concerned, the alternatives for aviation safety and efficient airspace operation by suggesting the clear standards alternatives were suggested.

Evaluating the Removal Efficiency of Organic Compounds and Nitrogen Depending on Loading Rate in Wastewater Treatment from Fisheries Processing Plant Using an Entrapped Mixed Microbial Cell Technique (미생물 강제포획기술을 이용한 수산물 가공공장 폐수처리에서 부하율에 따른 유기물 및 질소의 제거 효율성 평가)

  • Jeong Byung-Cheol;Chang Soo-Hyun;Jeong Byung-Gon
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.9 no.1
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    • pp.14-20
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    • 2006
  • In this study, the feasibility of simultaneous removal of organic materials and nitrogen in the waste-water from fisheries processing plant was evaluated using entrapped mixed microbial cell technique(EMMC) process. The experiment was performed using activated sludge from municipal sewage treatment plant which was immobilized with gel matrix by cellulose triacetate. It was found that the stable operation at the treatment system which is composed of anoxic and oxic tank, was possible when the organic and nitrogen loading rates were increased stepwise. The organic and nitrogen loading rates were applied from 0.65 to $1.72kgCOD/m^3/d$ and from 0.119 to $0.317kgT-N/m^3$ with four steps, respectively. The maximum nitrogen loading rate which could satisfy the regulated effluent standard of nitrogen concentration, was $0.3kgT-N/m^3/d$. The removal efficiency of total nitrogen was decreased apparently as increasing nitrogen loading rates, whereas the removal efficiency of ammonium nitrogen was effective at the all tested nitrogen loading rates. Therefore, it was concluded that nitrification was efficient at the system. Nitrate removal efficiency ranged from 98.62% to 99.51%, whereas the nitrification efficiency at the oxic tank ranged 94.0% to 96.9% at the tested loading rates. The removal efficiencies of chemical oxygen demand(COD) and those of total nitrogen at the entire system ranged from 94.2% to 96.6% and 73.4% to 83.4%, respectively.

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Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2008 (설비공학 분야의 최근 연구 동향: 2008년 학회지 논문에 대한 종합적 고찰)

  • Han, Hwa-Taik;Choi, Chang-Ho;Lee, Dae-Young;Kim, Seo-Young;Kwon, Yong-Il;Choi, Jong-Min
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.12
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    • pp.715-732
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    • 2009
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2008. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends in thermal and fluid engineering have been surveyed in the categories of general fluid flow, fluid machinery and piping, new and renewable energy, and fire. Well-developed CFD technologies were widely applied in developing facilities and their systems. New research topics include fire, fuel cell, and solar energy. Research was mainly focused on flow distribution and optimization in the fields of fluid machinery and piping. Topics related to the development of fans and compressors had been popular, but were no longer investigated widely. Research papers on micro heat exchangers using nanofluids and micro pumps were also not presented during this period. There were some studies on thermal reliability and performance in the fields of new and renewable energy. Numerical simulations of smoke ventilation and the spread of fire were the main topics in the field of fire. (2) Research works on heat transfer presented in 2008 have been reviewed in the categories of heat transfer characteristics, industrial heat exchangers, and ground heat exchangers. Research on heat transfer characteristics included thermal transport in cryogenic vessels, dish solar collectors, radiative thermal reflectors, variable conductance heat pipes, and flow condensation and evaporation of refrigerants. In the area of industrial heat exchangers, examined are research on micro-channel plate heat exchangers, liquid cooled cold plates, fin-tube heat exchangers, and frost behavior of heat exchanger fins. Measurements on ground thermal conductivity and on the thermal diffusion characteristics of ground heat exchangers were reported. (3) In the field of refrigeration, many studies were presented on simultaneous heating and cooling heat pump systems. Switching between various operation modes and optimizing the refrigerant charge were considered in this research. Studies of heat pump systems using unutilized energy sources such as sewage water and river water were reported. Evaporative cooling was studied both theoretically and experimentally as a potential alternative to the conventional methods. (4) Research papers on building facilities have been reviewed and divided into studies on heat and cold sources, air conditioning and air cleaning, ventilation, automatic control of heat sources with piping systems, and sound reduction in hydraulic turbine dynamo rooms. In particular, considered were efficient and effective uses of energy resulting in reduced environmental pollution and operating costs. (5) In the field of building environments, many studies focused on health and comfort. Ventilation. system performance was considered to be important in improving indoor air conditions. Due to high oil prices, various tests were planned to examine building energy consumption and to cut life cycle costs.

The Organization Commitment and Perception of Human Resource Management by Employment Types of School Foodservice Employees (학교급식 직원의 고용유형에 따른 인적 자원 관리 활동에 대한 인식과 조직 몰입도)

  • Lee, Ok;Cho, Minju;Chang, Hyeja
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.1
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    • pp.162-171
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    • 2014
  • As the foodservice industry is labor intensive, the efficient management of human resources is an essential element for improving operational efficiency. This study was designed to investigate the performance level of human resource management in self-operated school foodservices and to examine the relationship between human resource management, organizational commitment, and productivity. Whether these factors rated differently by employment and job types was also examined. Data were collected through questionnaires distributed to 60 dieticians and 240 cooks in Seongnam and Yongin. Frequency analysis, factor analysis, the t-test and multiple regression analysis were tested using Minitab. Human resource management practices rated highly in the dimension of employee training (3.51), followed by working environment (3.39), and turnover management (3.37). In contrast, reward management (1.73) and working condition (1.56) received the lowest score. Organizational commitment scored 3.65 points, and showed that dedication (3.82) was the highest score; however, self-esteem (3.50) was the lowest score. For human resource management, there were significant differences between employment types as full time workers (3.85) rated management more highly than part-time worker (3.43). Overall productivity was fairly high, especially in high school foodservices. Only the performance appraisal had an influence on organizational commitment (${\beta}$=0.292, P<0.05). Productivity was positively correlated with human resource management (r=0.432, P<0.001) and organizational commitment (r=0.36, P<0.01). In conclusion, school foodservices need to establish objective performance standards, and increase employee morale by enhancing reward systems and working conditions. In particular, irregular employees require training with job performance standards and given a proper reward program, depending on their performance, to improve organizational commitment.

Transhiatal Esophagectomy in Cardia and Esophageal Cancer (위분문부 및 식도암 환자에서 경열공 식도절제술)

  • Choi Dong-Hui;Jung Kyoung-Won;Kim Dong-Heon
    • Journal of Gastric Cancer
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    • v.5 no.1
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    • pp.1-9
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    • 2005
  • Purpose: The debate is still on-going as to whether a transthoracic esophagectomy (TTE) or a transhiatal esophagectomy(THE) is the proper treatment for patients with cardia and esophageal cancers. This study tries to demonstrate and assess the efficacy and the validity of both surgeries. Materials and Methods: In a retrospective study, data from 52 cases of patients with esophageal and/or cardia cancer who received a surgical operation during the last decade were analyzed. Results: A TTE was done in 20 cases and a THE in 32 cases. The average times for the operations were 558.0 min for a TTE and 451.7 min for a THE (P>0.05). The estimated blood loss was 1,825.0 ml in a TTE and 1459.4 ml in a THE (P>0.05). The amounts of transfusion during the operations were 3.9 units in a TTE and 2.6 units in a THE (P<0.05). Post-operative complications occurred in 15 cases of TTE and 23 cases of THE. The average length of stay in the hospital was 25.6 days for a TTE and 20.6 days for a THE. The 5-year survival rate was $10\%$ for TTE patients and $28\%$ for THE patients (P>0.05). Conclusion: For most factors, including morbidity and mortality, there was no statistically significant difference between a TTE and a THE. However, a THE is expected to be more convenient, leading to a shorter operative duration, a shorter post-operative hospitalization and lesser amounts of hemorrhage and transfusion. Hence, the THE may be a more valid or efficient surgical method for those patients with cardia and esophagus cancer who require a resection of the esophagus. (J Korean Gastric Cancer Assoc 2005;5:1-9)

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A Study on the Effect of Quality of Medicinal Food on Perceived Values, Repurchase Intention and Recommendation Intention (약선 요리 품질이 지각된 가치와 재구매 의도 및 추천의도에 미치는 영향)

  • Choi, Sung-Woong;Ahn, Hyung-Ki;Cho, Sung-Ho
    • Culinary science and hospitality research
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    • v.18 no.5
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    • pp.1-15
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    • 2012
  • This study analyzed the influence of the quality of medicinal food on perceived values, repurchase intention and recommendation intention. The objective of this study is to suggest the efficient operating direction for specialized medicinal food restaurants to grow as an axis of the food service industry by showing the future direction of medicinal food and establishing marketing strategies to maintain/secure customers. From June 15th to July 2nd, 2009, the survey was conducted for the customers of medicinal food restaurants, located in Seoul and Gyeonggi-do. After distributing 250 copies of questionnaire, 195 of them were collected and total 192 were used for the analysis after excluding three copies due to lack of showing sincerity. The analysis results of this study can be summarized as follows. First, the quality of medicinal food was found to have a significant influence on 'functional value(t=5.519)' while having no influence on 'social value.' Second, the 'nutritional quality' of medicinal food was analyzed as having a significant influence on 'social value(t=10.954)' and 'functional value'(t=8.237).' Third, the 'medicinal quality' of medicinal food was analyzed as having no significant influence on 'social value(t=1.191)' and 'functional value(t=0.022).' Fourth, it was found that 'social value' had a significant influence on repurchase intention(t=9.743) and recommendation intention(t=9.154). Fifth, the functional value was analyzed as having a significant influence on repurchase intention(t=7.895) and recommendation intention(t=8.143). The results of the empirical analysis shown in this study properly support the theoretical standard system to achieve successful performance and useful information necessary for systematic operation of specialized medicinal food restaurants.

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Verifying the Classification Accuracy for Korea's Standardized Classification System of Research F&E by using LDA(Linear Discriminant Analysis) (선형판별분석(LDA)기법을 적용한 국가연구시설장비 표준분류체계의 분류 정확도 검증)

  • Joung, Seokin;Sawng, Yeongwha;Jeong, Euhduck
    • Management & Information Systems Review
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    • v.39 no.1
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    • pp.35-57
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    • 2020
  • Recently, research F&E(Facilities and Equipment) have become very important as tools and means to lead the development of science and technology. The government has been continuously expanding investment budgets for R&D and research F&E, and the need for efficient operation and systematic management of research F&E built up nationwide has increased. In December 2010, The government developed and completed a standardized classification system for national research F&E. However, accuracy and trust of information classification are suspected because information is collected by a method in which a user(researcher) directly selects and registers a classification code in NTIS. Therefore, in the study, we analyzed linearly using linear discriminant analysis(LDA) and analysis of variance(ANOVA), to measure the classification accuracy for the standardized classification system(8 major-classes, 54 sub-classes, 410 small-classes) of the national research facilities and equipment established in 2010, and revised in 2015. For the analysis, we collected and used the information data(50,271 cases) cumulatively registered in NTIS(National Science and Technology Service) for the past 10 years. This is the first case of scientifically verifying the standardized classification system of the national research facilities and equipment, which is based on information of similar classification systems and a few expert reviews in the in-outside of the country. As a result of this study, the discriminant accuracy of major-classes organized hierarchically by sub-classes and small-classes was 92.2 %, which was very high. However, in post hoc verification through analysis of variance, the discrimination power of two classes out of eight major-classes was rather low. It is expected that the standardized classification system of the national research facilities and equipment will be improved through this study.

A Comparison on the Characteristics of Cerebrovascular Disease Patients Admitted to Some Western and Oriental Hospitals (일부 양·한방 병원에 입원한 뇌혈관질환 환자의 특성 비교)

  • Yu, Dae-Jin;Ryu, So-Yeon;Park, Jong;Kim, Ki-Soon
    • Journal of agricultural medicine and community health
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    • v.26 no.1
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    • pp.65-79
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    • 2001
  • Cerebrovascular disease(CVD) is one of the major causes of death in Korea as well as most countries in the world and the disease gives great burden to humans socio-economically due to its high fatality and common occurrence of disability as the sequelae. This study was performed to investigate the utilization of western hospital(WH) or oriental hospital(OH) due to CVD and compare the type and the clinical characteristics of patients with CVD between WH and OH located in Kwangju City, Chonnam Province and Chonbuk Province. We reviewed the medical records of 1,070 patients who were discharged from 12 WIT and 6 OH from January to March, 2000 and confirmed for the diagnosis of CVD. Fifty-one percent of the subjects were treated at WH and forty-nine percent at OH. Females were more prevalent than males. As well, the most common age group among these subjects was found to be 70 years and older. About 92% in W~H and 80% in OH received brain imaging diagnostic procedures such as CT or MRI. The cerebral infarction was the most common type of CVD when compared by the kind of utilized hospitals, sex, age group except patient Group who was treated at WH and whose age was lower than 50 years old. The cerebral hemorrhage was more frequent than cerebral infarction among this group. The proportion of cerebral hemorrhage was decreasing and that of cerebral infarction was increasing with age. The most common clinical manifestations of undetermined type of CVD was paralysis of lower extremity in WIT and paralysis of upper extremity in OH. In cerebral hemorrhage loss of consciousness in WIT and dysarthria in OH were most frequently manifested, while in the case of cerebral infarction hemiplegia in WIT and dysarthria in OH were the most common complaints. The interval from the onset of disease to admission to the hospital was 5.5 days in WH arid 31.4 days in OH and the difference was statistically significant. Average admission duration of patients at OH was longer than WH, but it was not statistically significant. In conclusion these results suggest that the effort for systematic and efficient management of CVD patients was necessary for close co-operation and role arrangement between WH and OH considering the positive and negative points of western and oriental medicines.

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The Effect of Wedding Industry Employees Exchange Relationship on their Job Satisfaction and Voluntary Service Intentions (웨딩산업종사자의 교환관계가 직무만족과 자발적 서비스 의도에 미치는 영향에 관한 연구)

  • Byun, Sang-Woo;Lee, Hyang-Sook
    • Management & Information Systems Review
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    • v.32 no.5
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    • pp.69-88
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    • 2013
  • This study aimed to analyze the effects that the exchange relationship among employees engaged in the wedding industry in Busan, Ulsan and Gyeongnam area exerted on job satisfaction and voluntary service intentions. For this purpose, a theoretical model was presented based on previous studies and the relationship among variables was analyzed based on the analysis results through a survey. There have recently been great difficulties in the whole wedding industry due to the global economic depression and the low birthrate. Moreover, it is hard to optimize the future business environment. In particular, the low birthrate has weakened the demand base of the wedding industry. As a result, it is expected that the competition among companies will be more fierce in the wedding industry. Employees' voluntary service intention become much more important to overcome difficulties in this industry. Employees' voluntary service intentions can be possible when their job satisfaction is achieved. Many studies report the result that this job satisfaction can naturally be achieved when the high quality exchange relationship among a leader, team members (co-workers) and customers is formed. It is viewed that employees' voluntary service intentions should be induced through job satisfaction to improve the profitability through the efficient operation and management of the system. A leader of the organization should make an effort to form the high-quality exchange relationship with members, support so that team members(coworkers) and other employees can get along together and the teamwork can be improved and induce them to improve a high level of service quality with friendly customer services. In spite of the significance of the study discussed above, there are the following limitations in this study. There is a limit to a certain extent in generalizing study conclusions because the study was limited to the Busan, Ulsan and Gyeongnam area. If practical surveys which full- and part-time employees are included in the composition of samples are conducted for wedding suppliers in the country in the future, the quality of study will be able to improve.

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