• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.743-751
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• 2016

It is critical to effectively change the measures of prevention from the breakdown maintenance proceeding an apartment housing maintenance task scope. It is necessary that systematization be performed for a series of tasks, such as facility inspection, diagnosis and replacement. In addition, it is preceded by establishing a standardization for maintenance work scope. Therefore, this study examined the problems related to public rental housing maintenance work scope to manage it more systematically. In addition, the study suggests a work process section for facility repairs, long term replacement and general maintenance using one on one interviews with experts to classify the occupants, management office and head office. This study's standard work system is expected to provide fairness and transparency in addition to improving the productivity in public rental housing maintenance via an efficiency promotion plan. In addition, it is used as the basic reference for developing a system of public rental housing maintenance costs and diagnosis actions. Finally, it is necessary to create improvements that provide a more objective work system standardization throughout the analysis of the productivity data according to the work flow and the review of the occupants, management office and head office in the future applications of the pilot site.

• Journal of Energy Engineering
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• v.26 no.3
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• pp.105-112
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• 2017

A lot of piping systems have been used from nuclear power systems to water supply systems. The maintenance of the piping systems is needed to ensure proper operation of the piping systems. Failure of the large pipe systems especially such as KDHC(Korea District Heating Corporation) can be a matter directly related to the enterprise productivity and profitability. It can also lead to very important issues in promoting public safety and convenience. Therefore a method of quick and safety repairs have been emerged as the most important problem. In this study, freezing seal isolation method using liquid nitrogen cryogenic refrigerant was developed for the maintenance of a pre insulated heat transport pipe of KDHC with a diameter of 300 mm. In this study, by employing computational analysis techniques we performed the flow and heat transfer analysis for the targeted pre insulated heat transfer pipe and freezing seal jacket(ice-Plug) and have selected for optimal system. The detailed design model based on the results of the computational analysis finally was produced. A laboratory-scale test apparatus were designed and the freezing seal isolation self-test carried out. Also the performance assessment tests in the test bed of KDHC were carried out for on-site application.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.1
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• pp.85-91
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• 2020

The descendants of Jang, Chang-woo(張昌雨) reconstructed the Mangwijung (晩歸亭), which is currently located at Seha-dong, Seo-gu, Gangju Metropolitan City, in the context of succeeding the work of their ancestor. This study investigated the management viewpoint of Mangwijung that has been altered in going through the reconstruction and repairs processes, and examined the chronological history for a landscape of the Mangwijung Garden. First, in the Mangwijung Garden, three gazebos such as Mangwijung, Seubhyanggag(襲香閣) and Mukamjeongsa(墨庵精舍) stand in a row with three bridges between each of them in the middle of a wide pond. This is a group of gazebos that is a quite unique structure. Second, Hyowoodang(孝友堂) Jang, Chang-woo (張昌雨) built Mangwijung as a role of thatched cottage in order to teach younger students and enjoy the arts in his later life. The Mangwijung was reconstructed by the descendants of Jang, Chang-woo at the collapsed place later on in order to commemorate the achievements of their ancestor. By the way, it was revealed that the management of Mangwijung has been altered during the process of reconstruction. Third, when comparing the current appearance with those depicted in the 8 scenic views(八景) by Jang, Chang-woo and the literary works of his descendants, it was confirmed that the landscape and shape of the pond were damaged due to a road expansion caused by a construction of Seubhyanggag and Mukamjeongsa as well as an advancement of the city. Fourth, it is speculated that the pond of Mangwijung Garden is probably a spring not a reservoir to store the water stream that flows in.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.1
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• pp.128-135
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• 2011

In this study, in order to develop ultra rapid hardening mortar(URHM) for tunnel repairs using bottom ash of low recycle ratio and Admixture as Eco concept, fundamental properties of URHM on temperature condition of construction field were performed. Test result, URHM of three types for fluidity and setting time were as in the following : B > C > A. Those for low temperatures were later than the standard condition. Compressive, bending and bond strength were similar with three types as follow. In compressive strength, initial strength of the low were smaller than the standard but the low in the long-term were similar with the standard. On the contrary to this, bending strength were similar in initial strength but the low in the long-term were smaller than the standard. The low in bond strength was average 35% less than the standard. Length changes was as in the following : A > C > B. the low is two times much as the standard but the case using blast furnace slag particles noticeably reduced length changes. Water absorption coefficient and water vapor resistance were as in the following : C > A > B. In case of URHM added bottom ash, water absorption coefficient and water vapor resistance were increased because bottom ash is porous material.

• International Commerce and Information Review
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• v.14 no.4
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• pp.227-252
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• 2012

This paper is to study for causality validation of relation of the repair justice and repair satisfaction, relation between repair satisfaction and re-purchasing with South Korea's most important express service users. Through this research, we would like to confirm to seriousness of the failure express service and effects of controlling effectively adjust in relation between repair impartiality and satisfaction of repairs. The results of the study show as below. First, the result shows the justice outcome in express service, interaction justice, outcome justice in the relation of satisfaction with repair have regardful effects to the satisfaction of repair. This result explains that interaction justice has a positive influence. Second, in the relations between the procedural justice in express service and the satisfaction of repair, it is presented that the procedural justice has not regardful effects and results show differences from other leading researches. This result explains that procedural justice has not a positive influence. Third, as analyzing seriousness of the failure express service, controlling regulation effect in the relation of repair justice and repair satisfaction, seriousness of interaction and controlling regulation effect are not regardful effect in this relationship. These results are explained that the seriousness or controlling of the failure express service have not a positive influence to the relation of repair justice and repair satisfaction. Finally, in the relation between repair satisfaction and the intention to use again, repair satisfaction has a regardful effect to intention to use again. This result explained that it has positive influence to repair satisfaction and the intention to use again.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.2
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• pp.47-57
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• 2007

Real-time oceanographic information system was developed using platforms of aquaculture farms to examine causes of mass mortality of hatchery fishes, and to reduce the damage of mass mortality which has been occurred frequently off coast by abnormal change of ocean conditions. The system had the advantages of direct data distribution to fishermen at the farm and instant maintenance of equipments due to easy access to the farms and residents at the farms in comparison with offshore mooring buoy system. To avoid discontinued measurement of the system, repairs caused by malfunction of equipments, bimonthly preventive maintenances and daily monitoring of measured data were systematized. Confidence intervals calculated by a statistical method using accumulated data were applied to data management. Such activities could minimize discontinuance of measurement and keep information more trustful. In addition, the system has various ways of data distribution. Through homepage and e-mail in the internet, information was provided to public. Display units which were connected to equipments at the farm gave the measured data directly to fishermen, which guided them to run their farm scientifically. Finally large display unit was installed at a fish market and showed the measured data at the nearest station with tide and weather information. Proper region for aquaculture and wintering region were studied using temperature data obtained by the system in 2006. The system will contribute to reduce economic damage of coastal fishery and to understand coastal marine environment.

• Korean Journal of Construction Engineering and Management
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• v.15 no.2
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• pp.62-70
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• 2014

An apartment house, a private facility, is a house built for many persons to live independently in a building. An apartment house is a building where life damage can happen most in case of a safety accident due to insufficient inspections. However, formal inspections are being realized due to awareness shortage of managing bodies about safety inspection and low-price order-receiving of diagnosing enterprises via the lowest bidding method. This is because it is judged that remarkable costs are inputted in repairs and reinforcement such as maintenance of a structure and that there is a large possibility of human damage in case of a safety accident in a structure. So, this paper aims to derive the points to improve in the current criterion to execute an efficient detailed inspection. As its method, the design price and execution price situation of 66 buildings inspected in detail for recent 3 years for the class 2 facilities in Gwangju Metropolitan City and Jeonranam-do are examined and analyzed. The state2 object buildings to inspect are selected through this. And this paper aims to present the points to improve through the analysis of current problems by evaluating the detailed inspection report and the detailed inspection execution price calculation criterion for the selected 10 apartment houses.

• Journal of the Korean Electrochemical Society
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• v.2 no.4
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• pp.183-189
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• 1999

A study on the destruction of organic cation and anion exchange resins by electro-generated Ag(II) as a mediator was carried out to develop the ambient-temperature aqueous process, known as Ag(II)-mediated electro-chemical oxidation (MEO) process, for the treatment of a large quantity of spent organic ion exchange resins as the low and Intermediated-level radioactive wastes arising from the operation, maintenance and repairs of nuclear facilities. The effects of controllable process parameters such as applied current density, temperature, and nitric acid concentration on the MEO of organic ion exchange resins were investigated. The cation exchange resin was completely decomposed to $CO_2$. The current efficiency increased with a decrease in applied current density while nitric acid concentration and temperature on the MEO of cation exchange resin did not affect the MEO. On the other hand, anion exchange resins were decomposed to CO and $CO_2$. The ultimate conversion to CO was about $10\%$ regardless of temperature. The destruction efficiencies to $CO_2$ were dependent upon temperature and the effective destruction of anion exchange resin could be obtained above $60^{\circ}C$.

• Journal of Korean Orthopaedic Sports Medicine
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• v.1 no.1
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• pp.102-107
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• 2002

Purpose: The aim of this retrospective study were to report the short-term results of inferior capsular shift procedure using splitting subscapularis and capsule for the patients who had shoulder instability and were apt to recur after arthroscopic stabilization procedure. Materials & Methods : Fifteen cases of instability of the shoulder were included with an average follow-up of 2 years (range: 1$\~$3 years). There were 13 men and 2 women with an average age of 27years. Multidirectional instability was found in 4 cases, voluntary instability in 3 cases, bony Bankarte lesion in 2 cases and 6 cases were contact sportmen. Thirteen shoulders underwent the inferior capsular shifts and Bankart repairs and 2 shoulders without Bankart lesion underwent the inferior capsular shift only. Average 19 mm of shift (range: 10$\~$25 mm) was done. Results : Fourteen patients showed good and excellent results with one subluxation and one positive apprehension test. Postoperative ranges of motions did not change in forward elevation, external rotation at side and external rotation at 90$^{\circ}$ abduction (p>0.05). Conclusion : Inferior capsular shift procedure using splitting subscapularis and capsule can be helpful in shoulder instability patients who were high-risk group of recurrence with arthroscopic procedure.

• Journal of Chest Surgery
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• v.30 no.6
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• pp.607-612
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• 1997

Between March 1963, and December 1994, fifty-three patients with a ruptured aneurysm of sinus of Vasalva(RSV) were operated. The RSV originated from the right coronary sinus in 43 patients(81%), from the non coronary sinus in 7 patients(13%), and from combined sinuses in 2 patients. The RSV from the right coronary sinus mainly drained to the right ventricle(81.4%), and the RSV from the non coronary sinus mainly drained to the right atrium(71.4%). Recently, we are using patch to repair the RSV through a double approach. During the operation, concomitant . procedures were performed; 32 Patch repairs of VSD, 14 aortic valvuloplasty, 10 aortic valve replacement, 2 tricuspid valvuloplasty, and one Bentall's procedure. During the follow up period between 1 and 31 years(mean 8 years, 94% follow up), there were 2 late deaths and 14 late complications. Actuarial 10-year survival rate .was 95%, and 10-year actuarial freedom from late event was 53 %. Factor analysis revealed that the combined SBE is a risk factor of late event. Actuarial freedom from failure of aortic valvuloplasty was 55% at 9 years. Although surgical repair of RSV achieved excellent long term survival, aortic regurgitation and endocarditis revealed significant risk factor in long-term results. Therefore, more attention should be required in patients of RSV associated with aortic regurgitation or endocarditis.