• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5A
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• pp.823-832
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• 2006

To ensure the serviceability requirements of PSC composite girder bridges, it is essential to predict the stresses and deformations of the structure under service load conditions. Stresses and deformations vary continuously with time due to the effects of creep and shrinkage of concrete and relaxation of prestressing steel. The importance of these time-dependent effects is much more pronounced in precast prestressed concrete structures built in stages than in those constructed in one operation. In this paper, time-dependent analyses for PSC composite bridges using 30m standard girders have been conducted considering with the variation of the times of introducing initial prestressing forces and casting concrete. A computer program has been developed for the time-dependent analysis of simple or continuous PSC composite girders and parametric studies are conducted. Based on the numerical results, it is investigated the long-term behaviors of PSC composite girder bridges and discussed the limitations of the current codes for the prestress loss.

• Journal of Korean Public Health Nursing
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• v.28 no.3
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• pp.565-573
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• 2014

Purpose: Health Insurance Review & Assessment Service (HIRA) launched an Acute Myocardial Infarction(AMI) assessment for the Payment For Performance(Quality Incentives) Pilot Project from July 2007. Assessment measures of AMI were composed of five process measures and one outcome measure, and each measure was incorporated into one composite quality score to Pay for Performance. Method: For calculation of composite quality score, we considered weighting for the measures using the Delphi method. The questionnaire was composed of three measure groups, 'Reperfusion rate'(Fibrolytic therapy received within 60 minutes of hospital arrival, Primary Percutaneous Coronary Intervention within 120 minutes of hospital arrival), 'Medication prescription rate'(Aspirin at arrival, Aspirin prescribed at discharge, Beta-blocker prescribed at discharge) and 'Survival Index'(30-day mortality rate). Result: A panel composed of 18 and completed a questionnaire by allocation of 10 scores to the three above mentioned measure groups. The Delphi was carried out until three rounds of surveys. In conclusion, each measure group was weighted differently and the 10 scores were allocated as 4.5 to 'Reperfusion rate', 2.5 to 'Medication prescription rate', and 3.0 to 'Survival Index'. Conclusion: The results of this study proposed the calculation method for weighting of Acute Myocardial Infarction quality indicators.

• Korean Journal of Veterinary Service
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• v.24 no.4
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• pp.347-352
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• 2001

This study was carried out to investigate the status of hoof diseases and to develope treatment method for cattle with hoof diseases during the period of January to December in 2000. Out of 435 heads, 34 heads(7.8%) had hoof diseases. In respect to season, incidence rate was higher in August to September than that of other seasons. The incidence rates of hoof rot, pododermatitis verrucosae, laminitis, other cases and trauma were 14 cases(41％), 10 cases (29%), 7 cases(21%), 2 cases(6%) and 1 case(3％), respectively. In respect to age and milk production, Incidence rate was higher in the cattle with high milk production. Incidence rate of hoof diseases on the hind-limbs was higher than that of the fore-limbs. E. coli(8 strains), Clostridium spp(8 strains), Staphylococcus spp(6 strains), Fusobacterium spp(6 strains), and Bacteroides spp(6 strains) were isolated from the hoof lesions. All isolates were sensitive to composite preparation made of mainly formalin with picric acid and phenol. (Treatment against each strains isolated was sensitive to composite preparation made out of the main constitutions of formalin with picric acid and phenol).

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.539-542
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• 2005

In the ubiquitous computing environment, service providers should able to deliver their services to various devices, such as PDA Smart Phone, Telematics devices. For this, W3C announced 'Composite Capabilities/Preference Profile (CC/PP) Standard' for delivery-context description. But at present, only a small number of mobile phone supports the CC/PP standard, most of contents servers do not support the CC/PP profiles. In this paper, a rule-based CC/PP profiling method in ubiquitous environment is developed. A rule-based profiles are generated by analyzing request headers which are received from various ubiquitous devices. Service providers can use these profiles to provide optimized services to the various devices which have different capabilities.

• Journal of the Korea Society of Computer and Information
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• v.13 no.6
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• pp.233-241
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• 2008

The overlay multicast that has been recently presented as an alternative for the IP multicast needs scheduling method that can apply the system resource and the network bandwidth for the many users. We propose a efficient overlay multicasting network policy for multimedia services with composite stream service topology. And in order to evaluate the ability of the proposed scheme's performance, We test the performance of multi_casting nodes with RTT values, the bandwidth attrition rate for building the network topology and MOR effects with Overcast[5] The result of simulation shows improves about $8{\sim}20%$ of performance.

• International Journal of Highway Engineering
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• v.15 no.1
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• pp.11-21
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• 2013

PURPOSES: As pavement generally provides service shorter than an expected life cycle, maintenance cost increases gradually. In order to help extending the service life and reduce maintenance cost, a new multi-functional composite pavement system is being developed in Korea. METHODS: This study is a part to develop the multi-functional composite pavement and is to investigate the mechanical performances of fiber-reinforced lean concrete for pavement subbase. The inherent problem of fiber reinforced concrete is dispersion of fibers in concrete mix. This study additionally evaluated fiber dispersion characteristics with respect to different fiber types. RESULTS: From the test results, the compressive strengths of the concretes satisfied the required limit of 5MPa at 7days. The standard deviation of the measured number of fibers were lower in the order of nylon, steel fiber and polypropylene. CONCLUSIONS: Reject ash was shown to be satisfactory as a replacement material to Portland cement in lean concrete base. The fiber volume fraction is suggested to be 0.4% even though the fracture toughness did not vary significantly with respect to fiber types. However, fracture energy absorbed up to complete failure increased with the increased fiber volume fraction increment.

• Steel and Composite Structures
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• v.18 no.2
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• pp.357-374
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• 2015

Orthotropic decks composed of deck plate, ribs, cross beams and wearing surface are frequently used in industry to span long distances due to their light structures and load carrying capacities. As a result they are broadly preferred in industry and there are a lot of bridges of this type exist in the world. Nevertheless, some of them cannot sustain the anticipated service life and damages in form of cracks develop in steel components and wearing surface. Main reason to these damages is seen as the repetitive wheel loads, namely the fatigue loading. Solutions to this problem could be divided into two categories: qualitative and quantitative. Qualitative solutions may be new design methodologies or innovative materials, whereas quantitative solution should be arranging dimensions of deck structure in order to resist wheel loads till the end of service life. Wearing surface on deck plate plays a very important role to avoid or mitigate these damages, since it disperses the load coming on deck structure and increases the bending stiffness of deck plate by forming a composite structure together with it. In this study the effect of Elastic moduli, Poisson ratio and thickness of wearing surface on the stresses emerged in steel deck and wearing surface itself is investigated using a FE-model developed to analyze orthotropic steel bridges.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.585-593
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• 2021

The service industry has become the driving force of economic development in recent years. With the current fierce competitive situation, competing businesses have continually provided a superior quality of service, and an excellent perceived brand image to gain customer satisfaction and customer loyalty. This study's current purpose is to empirical research the linking between service quality, brand image, customer satisfaction, and customer loyalty. We collect research data from 299 consumers who bought goods at supermarkets in Ho Chi Minh City, Vietnam, using a convenient sampling technique. We proposed the conceptual model from prior studies and considered it in Vietnam's context. PLS-SEM was conducted to test the relationships in the conceptual model. We have estimated the scale's reliability by Cronbach's alpha values and composite reliability values. Moreover, we have evaluated discriminant validity by the Fornell-Larcker standard. The findings showed that service quality positively affects the brand image, customer satisfaction, and customer loyalty. Likewise, the results also confirmed brand image had a positive impact on customer satisfaction and customer loyalty. Moreover, the outcomes also disclosed that customer satisfaction had a positive relationship with customer loyalty. The research suggested implications for managers, limitations, and directions for future research from the above findings.

• Journal of the Korea Concrete Institute
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• v.27 no.5
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• pp.471-480
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• 2015

The building structure is planned to maximize the use of space in recent. It was developed of a hybrid OCB (Optimized Composite Beam) for trying to take advantage of the maximize space. The OCB is composed of the steel h-beam section reinforced by open strands in negative moment zone and the psc concrete section in positive zone. Flexural behaviors of typical architectural bybrid OCB section was investigated. The 15 m OCB specimen was tested under three point static loading system. Following results are obtained from the tests; 1) The OCB with 15 m span develop initial flexural crackings under the 171% of full service loading. 2) Overall deflections of OCB under the service loads are less than those of the allowable limit in KCI Code provision. 3) The crack patterns, failure mode and ultimate load capacity of test specimen and F.E. model in this paper and they are compared to each other. The OCB is verified of structural reliability from the experimental results.

• The Korean Journal of Applied Statistics
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• v.32 no.3
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• pp.375-389
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• 2019

Sample attrition according to a long-term tracking reduces the representativeness of the sample data in a panel study. Most panel surveys in South Korea and other countries have prepared response adjustment weights in order to solve problems regarding representativeness due to sample attrition. In this paper, we divided the panel data into continuous response group and non-continuous response group according to response patterns and considered a weighting adjustment method to reduce the bias of the non-continuous response group. A simulation indicated that the proposed composite estimation type weighting method, which reflected the characteristics of non-continuous response groups, could be more efficient than other weighting methods in terms of reducing non-response bias. As a case study, the proposed methods are applied to the Korean Longitudinal Study of Ageing (KLoSA) data of the Korea Employment Information Service.