• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.43-44
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• 2002

Langmuir-Blodgett mono- and multilayer films from 2,4-heneicosanedione have been examined as lubrication coatings In the process of wear. Tribological properties of the films have been studied by atomic force microscopy and microtribometer. It has been observed that the wear resistance of silicon surface coated with OTS/LB multilayer system increased by several orders of magnitude compared to uncoated surfaces at low normal load. The results obtained suggest that the system constructed on silicon surface reduces surface energy, friction coefficient and increases life of substrate due to a possibility of LB film self-repairing during frictional contact.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.507-512
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• 2002

In road pavements, it is known that cement concrete pavement has superior durability. But in repairing pavement, cement concrete pavement is not usually applied because of the length of time while the road is interrupted when using Ordinary and Rapid-hardening Portland Cement. And Super High Early Strength Cement and Ultra Super High Early Strength Cement are not favorable for ready mixed concrete because of rapid setting time, high slump loss and other restrictions. We developed special cement developing 1 day strength of over 30.0N/$mm^2$ to open the road within 1 day and workable time is maintained over 1 hour so that it can be used as ready mixed concrete. We performed experimental overlay construction with concrete and evaluated the properties of the fresh and hardened concrete. The flexural strength was over 5.0N/$mm^2$ and the compressive strength was over 30N/$mm^2$ at 1 day. So it is thought that the road can be open to traffic within 1 day after placement.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.416-421
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• 2005

Concrete are brittle materials and they are which come to brittle fracture rapidly by progress of cracks. Therefore, what the time for repairing the damage portion is understands importantly by such cracks. When they happened the glass pipe similar to concrete was used. Such a glass pipe can insert repair material in an inside, or can use it by switch. They are interested in the crack monitoring of structure using FM radio sensor and PZT sensor. In this study, the monitoring to a crack was studied using FM radio sensor and PZT sensor. Therefore, the purpose of this study is the fundamental research which detects damages of main members using the compound sensor which consisted of the radio sensors of resistance, PZT, and FM system.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.41-44
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• 2007

In repairing and reinforcing modem architecture, altering the features must be minimized. We concluded that inserting CFRP(Carbon Fiber Reinforcement Polymer) plate method is the most appropriate reinforcing method that minimize altering the features. This study focuses on the effect of reinforcement by inserting CFRP plate in the timber beam of the modem architecture's roof truss. We concluded that inserting CFRP plate method is highly influenced by its parent material, however, it is obvious that materials had reinforced by this method in general. We guess that this method is applicable to reinforcement in the modern architecture's roof truss in various ways.

• Journal of the Korean Society of Costume
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• v.51 no.4
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• pp.97-112
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• 2001

The purposes of this study were to investigate consumers preference and dissatisfied factors in knitted golf wear The 430 questionnaires were sent to consumers who live in the Seoul Metropolitan district including Pundang-city and Iisan-city, The return rate was 89.5%. Statistical devices were t-test, ANOVA, $X$2. frequency with SAS program. The results of this study were as follows: First, Preferred colors were pastel, straw yellow, and black in descending order. Preferred coordination was analogous rather than complementary coordination. The classical look with T-neck, pullover, and V-neck was preferred. The preferred materials were pure cotton and cotton/wool blend in solid colors or plain and intasia structure. There were significant differences that pure cotton was preferred the forties and fifties or housewife, and cotton blend was preferred the thirties or service jobholders. Second, dissatisfied factors were pilling, deformation and de-coloration. The pilling problem was indicated in all income levels. Customers complained about no exchange and no refund policy with sales persons'discourtesy and time delay for repairing.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.233-238
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• 2001

In road Pavements, it is known that cement concrete pavement has superior durability, safety compared with asphalt pavement. But in repairing pavement, cement concrete pavement is not usually applied because of the length of time while the road is interrupted when using Ordinary and Rapid-hardening Portland Cement. And Super High Early Strength Cement and Ultra Super High Early Strength Cement are not favorable for ready mixed concrete because of rapid setting time, high slump loss and other restrictions. We aim to develope special cement and concrete developing 1 day strength of over 300 kg/$\textrm{cm}^2$ to open the road within one day and workable time is maintained over 1 hour that can be used as ready mixed concrete. In this study, we produced cement using rapid-hardening cement, Hauyne clinker, anhydride gypsum and accelerator and studied on its properties. The comperssive strength was over 400 kg/$\textrm{cm}^2$ and tensile at 1 day and workable time was maintained for over 1 hour.

• IE interfaces
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• v.11 no.3
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• pp.103-114
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• 1998

This paper suggests a computer software system which generates standard times for assembly products. The system called "computer aided logical system for standard times(CALS4ST)" incorporates a modified bill of materials, BOM4ST(BOM for standard time) to deal with auxiliary operations which are not directly related to parts and assemblies listed in the standard BOM. Typical examples of the operations include inspection, adjustment, and repairing works to be done before or after assembly operations. Once standard time data bases for both the part assembly operations and the auxiliary operations are set up, the system relates the BOM4ST to the standard time data bases so as to calculate the standard time for a assembly part concerned. According to the structure of parts and auxiliary operations in the BOM4ST, their standard times stored in the data bases are to be sequentially added up considering the specified assembly-operation characteristics. To illustrate the feasibility of the system, the case study of L company is provided.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.325-330
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• 1999

The objectives of this study were to compare the development of compressive strength of epoxy resin mortars used as repairing materials with respect to maturity, and to propose a predictive model for strength development of epoxy resin mortar. A series of tests were carried out for the hardener contents of 30, 40 and 50 percentage of resin and compressive strength were measured at the of 6, 12, 24, 72, 120 and 168 hours respectively under temperature of 0, 10, 20 and 3$0^{\circ}C$. The datum temperature was estimated by measured strength, and the maturity is calculated with the estimated datum temperature. The compressive strength of epoxy resin mortar could be predicted by regression analysis from the maturity-compressive strength relationship.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.285-288
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• 2006

Recently, polymer mortar has been developed not only more improving the performance of modified mortar with polymer, but also protecting and repairing materials of structures, especially in marine environment because of their excellent performance to improve compressive strength, flexural strength, and adhesive strength. however, in fact, these rehabilitation techniques in marine environment, which consist of removing delaminated areas of concrete, cleaning affected steel and patching with polymer mortar, have proven to be ineffective for marine structures. Also, repairs are often repeated every several years. Therefore, it is neccessary to research performance evalution of chloride ion penetration of polymar mortar for section restoration.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.11a
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• pp.37-40
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• 2003

This present paper mainly contains adhesion part disconnection type exposure composition waterproof method using embossing PVC sheet. The existing polymer resin coating and sheet waterproofing construction method have, however, some weak point such as being decrease life cycle of concrete with water leaking from materials be affected by crack and movement dash bond concrete through the whole-adhere construction. Above the reason, this paper has particular method increasing crack-defending performance from stress occurred concrete movement by part disconnection, adds maintain waterproofing performance subordinate sheet, that can be contributed a convenience of maintenance which is decreasing industrial waste and repair construction cycle through the part repair in case of leaking water.