• KIPS Transactions on Software and Data Engineering
• /
• v.2 no.8
• /
• pp.527-534
• /
• 2013

The software is changed according to the changing businesses and the user requirement, it involves increasing complexity and cost. Considering the repetitive changes required for the software, replacement is more efficient than maintenance at some point. In this study, the replacement time was predicted using the service dissatisfaction index and replacement point assessment index by the software group for each task. First, fuzzy inference was used to develop the method and indicator for the user's service level dissatisfaction. Second, the replacement point assessment method was established considering the quality, costs, and new technology of the software. Third, a replacement time prediction technique that used the gap between the user service measurement and replacement point assessment values was proposed. The results of the case study with the business solutions of three organizations, which was conducted to verify the validity of the proposed prediction technique in this study, showed that the service dissatisfaction index decreased by approximately 16% and the replacement point assessment index increased by approximately 9%.

• Asia Marketing Journal
• /
• v.7 no.2
• /
• pp.47-69
• /
• 2005

With the explosive growth of mobile products industry, tons of newer versions of products are putting on the market. From the marketer's perspective, understanding consumers' replacement purchases, especially the replacement timing, is essential to product planning and selling. This study presents an approach to finding out factors influencing the timing of buyers' replacement purchases of cell phones, using duration analysis; a hazard function specification is applied to describe consumers' replacement timing decision. Based on the data collected from a mobile telecommunication company, five categories of factors have been inspected. These are consumer's innovative service usage, data service usage, voice service usage, participation in loyalty programs, and the demographic characteristics. The results of the study are as follows. Firstly, the positive coefficient of 'the number of related services used' suggests that the consumers who have more usage knowledge tend to replace faster. Secondly, customers participating in the membership service are positively associated with early replacement purchases. Lastly, younger customers(vs. older) and male(vs. female) customers turned out to replace cell phones earlier.

• Journal of Korean Society for Quality Management
• /
• v.32 no.3
• /
• pp.62-67
• /
• 2004

This paper presents and compares two block replacement policies under random use durations. The units are put in service altogether and then idle for some time. The time durations during which units are put in service are random variables. Two block replacement policies, called N-policy and T-policy, are presented. Under N-policy, units are replaced altogether after the Nth use. Under T-policy, units are replaced altogether at the end of the use after cumulative use time T elapses. The failures during use durations are replaced by new ones individually. The cost rate expressions under the policies are derived for exponential use durations. Numerical examples are presented to compare the performances of the two policies.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.6 no.1
• /
• pp.36-42
• /
• 2018

GGBFS(Ground Granulated Blast Furnace Slag)-replacement is very effective for improving resistance to chloride attack and this can induce a long service life for RC(Reinforced Concrete) structures exposed to chlorides. In the work, the design parameters such as cover depth, surface chloride content, critical chloride content, and replacement ratio of GGBFS are considered, and optimum replacement ratio of GGBFS are derived with intended service life. The changes of surface chloride content and cover depth show 3.16~3.38 and 3.02~3.34 times of service life variation, which are most influencing parameters. Critical chloride content shows 1.53~1.57 times of service life variation regardless of w/b(Water to Binder) ratios. In the case of surface chloride content $18.0kg/m^3$, the most severe condition, cover depth over 70 mm and GGBFS replacement ratio over 42% are required with concrete containing w/b ratio under 0.42 for 100 years of intended service life. The condition of $13.0kg/m^3$, GGBFS replacement over 35% is required. For reasonable durability design, quantitative exterior condition and critical chloride content should be determined, and the criteria in Domestic Specification is evaluated to be conservative.

• Corrosion Science and Technology
• /
• v.11 no.6
• /
• pp.225-231
• /
• 2012

Fitness-for-Service is a useful technology to determine replacement timing, next inspection timing or in-service when nuclear power plant's buried pipes are damaged. If is possible for buried pipes to be aged by material loss, cracks and occlusion as operating time goes by. Therefore Fitness-for-Service technology for buried pipe is useful for plant industry to perform replacement and repair. Fitness-for-Service for buried pipe is studied in terms of existing code and standard for Fitness-for-Service and a current developing code case. Fitness-for-Service for buried pipe was performed according to Code Case N-806 developed by ASME (American Society of Mechanical Engineers).

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.713-720
• /
• 2008

This article deals with a case study on determining the replacement interval for the extraction motor in KTX. The reliability is analysed with the field data from 42 months. The effect of the replacement interval on service reliability, availability, safety and lifecycle cost are evaluated through simulation which is done by the commercial tool, Availability Workbench AvSim Module. As the results of the analyses, a new replacement interval is presented to reduce the lifecycle cost while service reliability, safety and availability are satisfactory.

• Journal of Korean Society of Water and Wastewater
• /
• v.23 no.3
• /
• pp.279-285
• /
• 2009

In this study, applied to the industrial water service, it is verified feasibility of break-even analysis method which has not been introduced in Korea. The On-san water pipeline of 7.1km among the Ul-san industrial water service is selected and the optimal replacement time calculated by break-even analysis method is year 2033 to 2044 which will be 53 to 67 years since the pipes were buried. If indirect cost such as the value of lost water and traffic disruption, service interruption, etc. is calculated as 30 and 100% of the direct cost, the financially optimum replacement time is advanced 3 to 9 years. These ways present rational criteria to establish long-term plan for budget and to execute the limited budget efficiently.

• East Asian Journal of Business Economics (EAJBE)
• /
• v.10 no.3
• /
• pp.75-91
• /
• 2022

Purpose - This study aims to predict the future market and draw policy implications by analyzing the trend of outsourcing housework through the food subscription service. Research design, data, and methodology - Content analysis was conducted on the consumption value emphasized in advertisements by item targeting food subscription service advertisements. Advertisements used as research data were extracted via keyword searches on Google web pages. A total of 30 advertisements selected were used for the final analysis. Result -The consumption values emphasized in the advertisements for staple foods, refreshments, and special foods were analyzed by considering the following factors: price, convenience, health, and pleasure. Convenience and health were emphasized in the staple foods, and price and pleasure were emphasized in the snacks. In the case of special foods, convenience and pleasure appeared together with a focus on health. Conclusion - Based on the trend of food subscription services, the implications for the market and policies for outsourcing housework through home meal replacement can be presented. Considering that the consumption value of a food subscription service is differentiated by item, it is necessary to formulate a plan to develop the market and policies related to outsourcing housework.

• Korean Journal of Clinical Pharmacy
• /
• v.27 no.1
• /
• pp.38-43
• /
• 2017

Objective: Seoul City has implemented the Safe Pharmacy in 2013. This study aimed to ascertain the success factors of the smoking cessation service of the Safe Pharmacy. Methods: The data for the smoking cessation registration cards were obtained from the pharmacies which participated in 2014 Safe Pharmacy. The sample included 289 smokers in 6 districts who participated at least one sessions of smoking cessation service. the service included both behavioral intervention and nicotine replacement therapy. In order to identify the effectiveness of the smoking cessation service, logistic regression analysis was used. The dependent variable was the success of quitting smoking at the 4th week. The independent variables included age, sex, employment, chronic disease, district, smoking amount, registration path, supporters for quitting smoking and number of service sessions. Results: Fifty eight point eight percent of the sample successfully quit smoking at the 4th week. Unemployment, higher smoking amount, and less service sessions were negatively related to the success of quitting smoking. There were differences in the success rate across districts. Age, sex, chronic disease, registration path, and anti-smoking supporters were not related to the success rate. Conclusion: Pharmacy can be an effective community resource for smoking cessation. Factors that could increase the effectiveness of smoking cessation service of the Safe Pharmacy and possible ways to enhance the participation of pharmacies in smoking cessation services were also discussed.

• Proceedings of the KIEE Conference
• /
• 1999.07b
• /
• pp.737-739
• /
• 1999

All equipment generally has a specified design service life. As an equipment nears the end of its design service life, replacement must be considered. In some cases, it is possible and more economical to continue the usage of the existing equipment for a longer period. So, replacement should be carefully decided considering the feasibility and economic benefits of the existing equipments' life extension. In this paper, assessment procedure for deciding between life extension and replacement of the electronic control system is presented with an application example. In particular estimation of the electronic control system's remaining life is focused on.