• Title/Summary/Keyword: Covering Problem

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Validation of Load Calculation Method for Greenhouse Heating Design and Analysis of the Influence of Infiltration Loss and Ground Heat Exchange (온실 난방부하 산정방법의 검증 및 틈새환기와 지중전열의 영향 분석)

  • Shin, Hyun-Ho;Nam, Sang-Woon
    • Horticultural Science & Technology
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    • v.33 no.5
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    • pp.647-657
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    • 2015
  • To investigate a method for calculation of the heating load for environmental designs of horticultural facilities, measurements of total heating load, infiltration rate, and floor heat flux in a large-scale plastic greenhouse were analyzed comparatively with the calculation results. Effects of ground heat exchange and infiltration loss on the greenhouse heating load were examined. The ranges of the indoor and outdoor temperatures were $13.3{\pm}1.2^{\circ}C$ and $-9.4{\sim}+7.2^{\circ}C$ respectively during the experimental period. It was confirmed that the outdoor temperatures were valid in the range of the design temperatures for the greenhouse heating design in Korea. Average infiltration rate of the experimental greenhouse measured by a gas tracer method was $0.245h^{-1}$. Applying a constant ventilation heat transfer coefficient to the covering area of the greenhouse was found to have a methodological problem in the case of various sizes of greenhouses. Thus, it was considered that the method of using the volume and the infiltration rate of greenhouses was reasonable for the infiltration loss. Floor heat flux measured in the center of the greenhouse tended to increase toward negative slightly according to the differences between indoor and outdoor temperature. By contrast, floor heat flux measured at the side of the greenhouse tended to increase greatly into plus according to the temperature differences. Based on the measured results, a new calculation method for ground heat exchange was developed by adopting the concept of heat loss through the perimeter of greenhouses. The developed method coincided closely with the experimental result. Average transmission heat loss was shown to be directly proportional to the differences between indoor and outdoor temperature, but the average overall heat transfer coefficient tended to decrease. Thus, in calculating the transmission heat loss, the overall heat transfer coefficient must be selected based on design conditions. The overall heat transfer coefficient of the experimental greenhouse averaged $2.73W{\cdot}m^{-2}{\cdot}C^{-1}$, which represents a 60% heat savings rate compared with plastic greenhouses with a single covering. The total heating load included, transmission heat loss of 84.7~95.4%, infiltration loss of 4.4~9.5%, and ground heat exchange of -0.2~+6.3%. The transmission heat loss accounted for larger proportions in groups with low differences between indoor and outdoor temperature, whereas infiltration heat loss played the larger role in groups with high temperature differences. Ground heat exchange could either heighten or lessen the heating load, depending on the difference between indoor and outdoor temperature. Therefore, the selection of a reference temperature difference is important. Since infiltration loss takes on greater importance than ground heat exchange, measures for lessening the infiltration loss are required to conserve energy.

Evaluation for Rehabilitation Countermeasures of Coal-mined Spoils and Denuded Lands (폐탄광지(廢炭鑛地)의 산림훼손지복구(山林毁損地復舊) 및 폐석유실방지대책(廢石流失防止對策)에 관한 연구(硏究))

  • Woo, Bo-Myeong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.3 no.2
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    • pp.24-34
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    • 2000
  • The project for rehabilitation and revegetation of the abandoned coal-mine lands is a very important national environmental restoration project in the view point of rehabilitation and revegetation of denuded forest-lands caused by coal mining as well as restoration of disturbed natural environment and control of the variable pollutions. In Korea, because a large number of coal mines had been developed in order to fill up abundantly consumption of coal as a major energy source in the developing period, a lot of denuded forest-lands caused by coal mining had distributed in the whole country. And, due to the absence of effective rehabilitation and revegetation works on the denuded forestlands caused by coal-mining, most of them had been remained with being damaged. In 1990, area of the abandoned coal-mine lands, requiring the rehabilitation and revegetation works, was about 1,437.1 ha. For the past ten years ('90~'99), about 1,081.8 ha out of them had been rehabilitated and revegetated, and the rehabilitation planning area was about 33.0 ha in 2000. So, remaining area out of abandoned coal-mine lands will be about 322.3 ha after 2000. In principle, after abandoning coal-mine, mine owners must carry out the rehabilitation and revegetation works on the abandoned mine lands by themselves. But, most of mine owners were in financial difficulty after abandoning coal-mine, so that principle couldn't have obtained the desired effects. To solve this problem, from 1995, Coal Industry Promotion Board (CIPB) have carried out the rehabilitation and revegetation works on the abandoned coal-mine lands at government budgets, and they have obtained good results in the construction area. However, due to application of the "conventional erosion control measures and techniques" to the rehabilitation and revegetation measures on the abandoned coal-mine lands, the results and effects of the works excuted have not been successful. Therefore, unique measures and techniques for rehabilitation and revegetation of the abandoned coal-mine lands will have to be developed, especially including development of new techniques on the soil-dressing and soil-covering, seed spray and hydro-seeding measures with seed-fertilizer-soil materials as the mechanized measures, and using of new materials for the tree planting and seedling measures.

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"Servicescape" Differentiation in a Hair Salon (헤어살롱 서비스스케이프 차별화 성공사례)

  • Lee, Sang-Hyun;Park, Chul-Ju
    • Journal of Distribution Science
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    • v.13 no.9
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    • pp.71-79
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    • 2015
  • Purpose - The purpose of this paper is to find out the effect of changes in the differentiated "servicescape" on the business performance in the hair salon industry using a case study. For this, we selected hair salon M located in Suwon. The shop is innovatively different from existing shops in terms of spatial layout and functionality. We conducted in-depth research, beginning with the launch of the shop concept through investment and ongoing stable sales. Research design, data, and methodology - The M hair salon is a start up shop providing a differentiated servicescape (physical environment where the service takes place) located in Suwon, Yeongtong-gu. We conducted research to investigate how spatial layout and functionality of the servicescape impact customers' perceived quality. The interview period and case analysis was May 2014 through March 2015, covering 11 months. To conduct the case analysis, we analyzed the spatial layout and functionality of existing shops and interviewed customers and experts about the difference between hair salon M and existing shops. Results - Our results found clues to the positive effect of spatial layout and functionality among servicescape factors on perceived service quality at the salon. The shop showed a fast payback of the principal investment, growth potential in contrast to competitors near the salon, and 45 percent returning customers. The problem with the spatial layout at existing shops was that customers were aware of the way other people were looking at them, since viewing angles overlapped, therefore there was a limitation to the relationship intensity with an exclusive hair designer. In contrast, the layout of the stands at the M salon kept the number of dressing stands limited to maximize the customer's emotional response. Additionally, because of the new layout of dressing stands hiding other customer voices and appearance in the salon, customers perceived their service space as independent. Therefore, they did not have to focus on their personal emotional response, which was one of the advantages of the new layout. Conclusions - This study conducted case study analysis by offering a new perspective focusing on spatial layout, previously not considered as an independent variable of quality evaluations and customer satisfaction in existing literature on hair salon management. Therefore, this study contributes to the field by offering an opportunity to discover the causal relationships between the overlooked physical environment and a customer's perceived quality. However, a process objectifying the results of the study through empirical analysis and hypotheses is needed to overcome the limitations of the case study approach and generalize the results. Moreover, it would be beneficial to conduct further empirical study of the relationship between the spatial layout provided in the case and a customer's emotional response and change in mood. In addition, an analysis is needed regarding how customers feel about the factors using the Kano Model. These suggestions would be considered in further study.

An analysis of problems and countermeasures in the installation of plastic greenhouse on reclaimed lands (간척지에 플라스틱 온실 설치 시의 문제점 분석 및 개선방안)

  • Yu, In-Ho;Ku, Yang-Gyu;Cho, Myeong-Whan;Ryu, Hee-Ryong;Moon, Doo-Gyung
    • Korean Journal of Agricultural Science
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    • v.41 no.4
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    • pp.473-480
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    • 2014
  • Upon setting up a dedicated plastic greenhouse for tomato cultivation developed by the Rural Development Administration on the Gyehwa reclaimed land, this study was aimed at analyzing the problems can be occurred in the installation of plastic greenhouse on reclaimed lands as well as finding out solutions for improvement. A relatively cheaper wooden pile was used in the installation in order to supplement the soft ground conditions. Based on the results of ground investigation of the installation site, both the allowable bearing capacity and pulling resistance of the wooden pile with a diameter of 150 mm and a length of 10 m were computed and came out to be 30.645 kN. It was determined that the values were enough to withstand the maximum compressive force (17.206 kN) and the pullout force (20.435 kN) that are generally applied to the greenhouse footing. There are three problems aroused in the process of greenhouse installation, and the corresponding countermeasures are as follow. First, due to the slightly bent shape of the wooden pile, there were phenomenon such as deviation, torsion, and fracture when driving the pile. This could be prevented by the use of the backhoe (0.2) rotating tongs, which are holding the pile, to drive the pile while pushing to the direction of the driving and fixing it until 5 m below ground and applying a soft vibrating pressure until the first 2 m. Second, there exists a concrete independent footing between the column of the greenhouse and the wooden pile driven to the underground water level. Since it is difficult to accurately drive the pile on this independent footing, the problem of footing baseplate used to fix the column being off the independent footing was occurred. In order to handle with this matter, the diameter of the independent footing was changed from 200 mm to 300 mm. Last, after films were covered in the condition that the reinforcing frame and bracing are not installed, there was a phenomenon of columns being pushed away by the strong wind to the maximum of $11m{\cdot}s^{-1}$. It is encouraged to avoid constructions in winter, and the film covering jobs always to be done after the frame construction is completely over. The height of the independent footing was measured for 9 months after the completion of the greenhouse installation, and it was found to be within the margin of error meaning that there was no subsidence. The extent to the framework distortion and the value of inclinometers as well showed not much alteration. In other words, the wooden pile was designed to have a sufficient bearing capacity.

Developing a water discharge anchor & trap bolt to prevent basic salt from penetrating to harbor structures (해수 염기 침투방지를 위한 항만구조물 보수보강용 물배출 앵커 및 트랩볼트 개발에 관한 연구)

  • Ock, Jong-Ho;Moon, Sang-Deok;Lee, Hwa-Sun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.3
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    • pp.535-541
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    • 2018
  • Most construction methods for the repair and reinforcement of old reinforced concrete harbor structures involve a process of applying a fiber complex or fiber complex panel just like wallpaper to the bottom of structures, such as slabs or beams. On the other hand, these techniques result in the sealing of repaired and reinforced portions of the structures by the fiber products, preventing moisture, such as rainwater entering the structures through the upper surfaces of the slabs or beams from being released, and causing the entire concrete covering of the structures to be peeled off in the long run. To prevent this, it is necessary to develop a technique to protect the basic salt from the sea water from penetrating into the structures while expelling the water absorbed in the structures swiftly. This study attempted to solve the problem by modifying the anchor bolts currently used to repair and reinforce the port structure. That is, by drilling holes into the body of anchor bolts and modifying the caps of the bolts to produce a structure that would let the water flow like a toilet trap, the moisture inside of the structure could be drained through the holes in the anchor bolts. The water discharge anchor bolts developed were tested and observed for 6 months; the water was discharged in 73% of the anchors (200 anchor installation, 145 anchors).

An Investigation into the College Students' Awareness of 'Library and Information' in the Library and Information Science (문헌정보학의 '문헌정보'에 대한 대학생 인식 조사)

  • Kang, Mi-Hee
    • Journal of Korean Library and Information Science Society
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    • v.45 no.3
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    • pp.297-319
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    • 2014
  • This research started from bringing up a problem about special situation of the library and information science, which is not easy to investigate its academic characteristics, although it has settled down as a powerful science studying related phenomena as well as education required for the whole process from production of information to consumption of it. Therefore, the purpose of this research is to questingly investigate whether the personal specialty and the experience of taking courses affect recognition of the term 'library and information', and if so, through which channel it influences. In this background, data were collected from 328 students of Chonnam National University for this research, and the following are the analysis results: first, as for the personal characteristics, differences were not generated according to gender and age, but according to scholastic year the results were different; second, as for the experience of taking courses, there were not differences according to whether or not of the experience, but the results varied according to the number and type of the experience; and third, most of the respondents surveyed understood the meaning of a term 'library and information' as the conception of covering the information contained in literature and information of it, regardless of the personal characteristics and the experience of taking courses. Through these results, it can be identified that the term 'library and information' meant in the library and information science is generally understood as expansion of range, rather than chemical combination of literature and information, it is a terminology with various meanings sometimes understood differently according to the special personal experiences, and it also needs scientific investigation of it.

Evaluation of Amending Materials to Reduce Soil Loss from Sloping Remediated Agricultural Land (급경사 복원 농경지 토양 유실 저감을 위한 개량제 효율 및 현장 적용성 평가)

  • Hwang, Wonjae;Park, Minseok;Hyun, Seunghun;Ji, Won hyun;Lee, Sang-Hwan
    • Ecology and Resilient Infrastructure
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    • v.4 no.3
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    • pp.180-185
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    • 2017
  • Restoration of min-impacted arable land is often performed through stabilization of trace elements by amendment treatment combined with (clean) soil covering on the surface. Recently, soil loss problem from sloping remediated agricultural lands has risen as an emerging concern. In this study, efficacy of aggregation formation was assessed by single and binary treatments of four potential amendments (bentonite, lime, organic matter, and steel slag) applied on three cover soils having different clay contents (9.4, 14.7, and 21.2% for A, B, and C soils respectively). In results of single treatments, 5% organic matter for A soil and 5% lime for B and C soils were found most effective for the aggregation formation compared to the respective controls (without amendments). Among nine binary treatments, 3% organic matter + 1% lime for A soil and 1% organic matter + 3% lime for both B and C soils led to the highest formation of aggregation (30.4, 25.0, and 36.5% for A, B, and C soils). For a site-application, the soil erodibility difference between the cover soils (0.045, 0.051, and 0.054 for A, B, and C soils, respectively) and the national average of arable land (0.032) was assumed to be compensated by amendment addition, which is equivalent to 29.1% aggregation formation. To achieve the aggregation goal, 5% lime for A and B soils and 3% lime for C soil were best in the consideration of benefit/cost, thereby effectively and economically reducing soil loss from sloping remediation site. Soil alkalinity induced by lime treatment was not considered in this work.

A Study on the Incidence of Carbon Monoxide Poisoning (연탄(煉炭)가스중독(中毒)의 발생실태(發生實態)에 관(關)한 연구(硏究))

  • Cho, Soo-Hun;Shin, Young-Soo;Lee, Doek-Hyoung;Kim, Yong-Ik;Yun, Dork-Ro
    • Journal of Preventive Medicine and Public Health
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    • v.18 no.1
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    • pp.1-11
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    • 1985
  • A decade ago a survey on the population-base incidence rate of anthracite coal gas (mainly carbon monoxide) poisonig in Seoul area was investigated, resulting in the incidence rate of 306/10,000 risk population and 1 death/10,000. Another survey on the carbon monoxide poisoning was investigated during 1 year period from Apr. 1983 to Mar. 1984. Total subjects of risk population were 67,740 households covering 353,287 persons. The major findings of this survey are as follows: 1. Household-base incidence rate was 8.4% spell-base 10.4%. 2. The incidence rate was the highest in houses having each of slate roof, cement wall, vinyl floor of bedroom and direct 'ondol' heating system. 3. Average 2.1 person was attacked from one incidence of the poisoning; severity-wise person-base incidence rates per 10,000 were 352 in mild poisoning, 54 in severe poisoning and 1.4 in death-overall incidence rate 407. Several facts were identified which supported that this figure was moderately underestimated. As the incidence of the poisoning is affected by socioeconomic and environmental factors, it is natural that one expects the incidence will decrease in proportion to genernal improvement of the above factors. Thus the results of these two surveys seemed preposterous. But further study suggested that the incidence rate (306/10,000) decade before had been significantly underestimated and corrected-rate should have been 478/10,000 level. 4. Age and sex distribution by the degree of the poisoning was uniform with little statistical difference; overall incidence rates by sex were 339/10,000 in male and 475/10,000 in female with significant statistical difference(p<.01). 5. 5.3% of the patients were treated at hospital or local clinic; 3.0% of the patients were hospitalized. Admission rate in comatose patient(severe poisoning) was 14.2%. In conclusion, carbon monoxide poisoning remains a major health problem by now.

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Usefulness of Partial Muscle Flaps and Combination Method for Coverage of Prosthetic Material in Chest Wall Reconstruction (흉벽 재건에서 합성 물질의 피복을 위한 부분 근피판 조합의 효용성)

  • Ryoo, Suk-Tae;Pyon, Jai-Kyong;Lim, So-Young;Mun, Goo-Hyun;Bang, Sa-Ik;Oh, Kap-Sung
    • Archives of Plastic Surgery
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    • v.38 no.3
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    • pp.228-234
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    • 2011
  • Purpose: Reconstruction of chest wall has always been a challenging problem. Muscle flaps for chest wall reconstruction have been helpful in controling infection, filling dead space and covering the prosthetic material in this challenge. However, when we use muscle flaps, functional and cosmetic donor site morbidities could occur. The authors applied and revised various partial muscle flaps and combination use of them to cover the prosthetic material for the chest wall reconstruction and evaluated the usefulness of partial muscle flaps. Methods: This study included 7 patients who underwent chest wall reconstruction using partial muscle flap to cover prosthetic material from 2004 to 2008. The pectoralis major muscle was used in anterior 2/3 parts of it leaving lateral 1/3 parts of it. The anterior 2/3 parts of the pectoralis major muscle were used while lateral 1/3 parts were left. In case of the rectus abdominis muscle flap, we used upper half of it, or we dissected it around its origin and then advanced to cover the site. The latissimus dorsi muscle flap was elevated with lateral portion of it along the descending branch of the thoracodorsal artery. If single partial muscle flap could not cover whole prosthetic material, it would be covered with combination of various partial muscle flaps adjacent to the coverage site. Results: Flap coverage of the prosthetic material and chest wall reconstructions were successfully done. There occurred no immediate and delayed post operative complications such as surgical site infection, seroma, deformity of donor site and functional impairment. Conclusion: When we use the muscle flaps to cover prosthetic material for chest wall reconstruction, use of the partial muscle flaps could be a good way to reduce donor site morbidity. Combination of multiple partial flaps could be a valuable and good alternative way to overcome the disadvantages of partial muscle flaps such as limitation of volume and size as well as flap mobility.

Development of Workplace Bullying in Nursing-Consequence Inventory (WPBN-CI) (간호사가 경험하는 직장 내 괴롭힘 결과 측정도구 개발)

  • Lee, Younju
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.2
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    • pp.479-488
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    • 2016
  • This study developed an instrument to assess the effects of the bullying of nurses in the workplace and evaluated the developed instrument. A literature review and a field study were conducted to identify the concepts related to the bullying of nurses in the workplace. These attributes served as building blocks to produce a 28-item WPBN-CI. The content validity was used to determine the content and face validities, and the number of instrument items was reduced to 14. The final WPBN-CI instrument was evaluated using the SPSS 18.0 program with the data collected from October 21-28, 2013 from 458 nurses from general hospitals in the metropolitan area. The WPBN-CI consisted of 13 items covering three distinct factors (physical and psychological withdrawal, poor quality of patient care, and increasing distrust), with a total variance of 62.9%. The convergent and determinant validities for the WPBN-CI were 100% and 89.7%, respectively. The known-groups validity was proven through the mean difference in the level of depression. The satisfied criterion validity for the WPBN-CI was more than 0.70. The reliability of the WPBN-CI was demonstrated by its Cronbach's ${\alpha}$ of 0.90. The WPBN-CI will identify in advance the results due to the bullying of nurses in the workplace and will help to find solutions to the problem and ensure program effectiveness.