• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.3
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• pp.13-21
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• 1987

The object of this study was to evaluate the management alternatives with respect to the attainable water quality and total cost(construction+O & M cost) in order to devise a reasonable water quality management system. Joong Ryang-cheon stream located Seoul, Korea was taken as the study area, and dissolved oxygen concentration as the water quality index. Water quality simulation model QUAL2E and linear programming optimization technique were used for scientific and rational analyses. It was assumed that the improvement of water quality could be obtained by the treatment of major point sources where imaginary treatment plants were constructed. And by this, the relationship between total cost of the treatment plants and the stepwise improvement of water quality was studied. The result showed that 3.5mg/l of DO(=dissolved oxygen) level at best could be attained in Joong Ryang-cheon stream during summer. When the DO standard was set 3.0mg/l in the severely polluted regions, more than 5.0mg/l of DO level can be achieved by the construction of 4 treatment plants. Also, the cost comparisons showed that the uniform treatment method is economically inefficient(\$24.8{\times}10^8$) in comparison with the least cost method(\$22.9{\times}10^8$), and there is little difference between the least cost method and the the zoned treatment method(\$23.0{\times}10^8$) that is regarded as more equitable, which shows the characteristics of this basin.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.19
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• pp.8229-8237
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• 2014

Background: Organized cervical screening has decreased the incidence of cervical cancer. However, screening strategies vary in different countries. Objectives: We performed a systematic review to evaluate the economic aspects of different screening methods. Materials and Methods: We searched databases and then data were abstracted from each study. We evaluated articles based on different types of screening tests as well as screening age and intervals, and using incremental cost effectiveness ratio via calculating quality adjusted life years (QALY), or life years gained (LYG) per cost. We compared the incremental cost-effectiveness ratio (ICER) of each study using GDP per capita. Furthermore, we compared national guidelines with recommendations of cost-effectiveness studies in different countries. Results: A total of 21 articles met our criteria, of which 19 studies showed that HPV DNA testing, 13 suggested an age of 30 years or more, and 10 papers concluded that at least a 5-year or longer interval were the most cost-effective strategies. In some countries, the national guidelines did not match the recommendations of the cost-effectiveness studies. Conclusions: HPV testing, starting at age 30 years or older and repeated at 5-year or longer intervals, is the most cost-effective strategy in any setting. Closer collaboration with health economists is required during guideline development.

• Water for future
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• v.28 no.1
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• pp.153-168
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• 1995

The purpose of this study is to develop an efficient model for the least cost design of multisite detention systems. The IDP (Incremental Dynamic Programming) model for optimal design is composed of two sub-models: hydrologic - hydraulic model and optimization model. The objective function of IDP is the sum of costs; acquisition cost of the land, construction cost of detention basin and pumping system. Model inputs include channel characteristics, hydrologic paramenters, design storm, and cost function. The model is applied to the Jung- Rang Cheon basin in Seoul, a watershed with detention basins in multiple branching channels. The application results show that the detention system can be designed reasonably for various conditions and the model can be applied to multi-site detention system design.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.4
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• pp.180-187
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• 2002

Many real-time multimedia applications, such as video conferencing have stringent end-to-end delay constraints and consume large amount of network resources. In order to support these applications efficiently, multicast routing algorithms computing least cost multicast trees that satisfy a given end-to-end delay constraint are needed. However, finding such a tree is known to be computationally expensive. Therefore, we propose a heuristic distributed multicast routing algorithm that reduces a “finding multicast tree”that satisfies a given end-to-end delay constraint and minimizes the average resulting tree cost. Also, simulation results show that the proposed algorithm has much better average cost performance than other existing algorithms.

• Journal of Information Technology Applications and Management
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• v.17 no.1
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• pp.35-54
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• 2010

Why does e-Learning service for individuals remain in the early development stage? To find the answers of this question, we adopted usefulness and intention to continued use as dependent variables based on technology acceptance model and inferred convenience, cost-effectiveness, social presence, interactivity, concentration, and procrastination as independent variables based on literature review and interview with e-Learning users. Convenience and cost-effectiveness of e-Learning tend to enhance usefulness and/or intention to continued use, while lack of social presence, interactivity, and concentration of e-Learning and academic procrastination tend to hinder usefulness and/or intention to continued use. To prove this research model, we used a data set collected from the survey. The respondents of survey were the undergraduate students who used voluntarily e-Learning. Data analysis was conducted using 275 respondents by partial least square. The analysis result of causal relation indicated that convenience and cost-effectiveness influenced both usefulness and intention to continued use, and that cost-effectiveness and concentration influenced only intention to continued use. But, interactivity and procrastination did not influence usefulness and intention to continued use.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.1
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• pp.98-107
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• 2008

The purpose of this paper is to present an optimization scheme that aims at minimizing the expected cost per unittime. This study considers a linear connected-(r, s)-ouI-of-(m, n):f lattice system whose components are orderedlike the elements of a linear (m, n)-matrix. We assume that all components are in the state 1 (operating) or 0(failed) and identical and s-independent. The system fails whenever at least one connected (r, s)-submatrix offailed components occurs. To find the optimal threshold of maintenance intervention, we use a simulatedannealing(SA) algorithm for the cost optimization procedure. The expected cost per unit time is obtained byMonte Carlo simulation. We also has made sensitivity analysis to the different cost parameters. In this study,utility maintenance model is constructed so that minimize the expense under full equipment policy throughcomparison for the full equipment policy and preventive maintenance policy. The full equipment cycle and unitcost rate are acquired by simulated annealing algorithm. The SA algorithm is appeared to converge fast inmulti-component system that is suitable to optimization decision problem.

• Journal of Soil and Groundwater Environment
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• v.20 no.5
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• pp.11-15
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• 2015

The three processes of 1) high- & low-temperature microwave heatings, 2) the soil washing, and 3) the thermal desorption processes in soil remediation are analysed on the treatment cost data for 2003-2012 years. The cost of microwave heating method with at temperature 500-700℃, for 30 minutes, and at 4-6 kW is approximately 10 $/ton (13,000 ₩) due to the deep through heating of micro-wave, the soil washing with chemicals is about 80 $/ton (85,000 ₩) due to the chemicals & duration, and the thermal desorption process is around 40 $/ton (41,000 ₩) from the less efficiency. Furthermore the sustainability has been assessed, and suggestions are made. 1) Green; the minimal environmental footprint, 2) Growth; the least cost, 3) Shared; the social & environmental justice, 4) Smart; the microwave characteristics of deep through irradiation & heating, and 5) Mutuality; the flexibility of the technology. More additives including water, the government support, and public relation are suggested realizing the microwave in this condition is not harmful to human beings.

• Journal of Korean Academy of Nursing Administration
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• v.8 no.2
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• pp.283-293
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• 2002

Purpose: The purpose of this study was to define cost-countable perioperative nursing activities and to analyze the cost of each nursing activities based on the Resource-Based Relative Value Scale (RBRVS). Method: Researcher and 3 research assistants observed and documented the 83 operating patients in order to measure nursing time for each of the perioperative nursing activities. And then, 35 operating room nurses with at least one year of perioperative nursing experience were observed for the RBRVS of perioperative nursing activities. Finally, the direct and indirect nursing costs were estimated. Result: Nursing costs of 25 nursing activities were estimated using the RBRVS. Most expensive nursing activities were delivery of the instrument and implement for OP team (9,780 won per hour) and behavior of wash, pack, disinfect the instrument (6,770). Conclusion: Based on the relative values of each perioperative nursing activities estimated in this study, proper medical reimbursement system should be established in a near future.

• Journal of Families and Better Life
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• v.29 no.4
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• pp.205-216
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• 2011

Unequal distribution of shares among children during intergenerational transference of assets has been prevalent in Korea. This study intends to examine whether parental contribution, in the form of a cash gift, is differentiated between the bride's side and the bridegroom's side at marriage and by age group. This pattern may also change according to the generation. Questionnaires were equally distributed to members of three previously delineated age groups: 20' s-30' s, 40's -50's, and 60's and above who are married or have been married at least once and reside in Seoul or Gyeonggi province. A total of 700 questionnaires were analyzed using SPSS and the data were sorted by age group. The results indicate an apparent difference between the husband's side and the wife's side in providing funding for housing at marriage in that a large portion of the funding is provided by the husband's side. Among various funding sources, a cash gift from the couple's parents appears to fund the largest portion of the total cost for housing and marriage. Results show that a cash gift from the couple's parents funds a larger portion of housing expenses for younger generations, a phenomenon that becomes more severe and apparent the younger the couple is.

• Journal of Korean Academy of Nursing
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• v.34 no.1
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• pp.191-201
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• 2004

Purpose: This study aimed to evaluate economic viability of public health center visiting nurse services for the low-income elderly with long-term care needs. Method: The sample consisted of 252 community dwelling elderly who enrolled in public health center visiting nurse services for three months or more. Data was collected on physical (ADL and IADL) and cognitive impairments of the elderly, contents and frequency of visiting nurse services, cost per visit, and costs of alternative services for long-term care. Result: The mean score of ADL and IADL levels of the elderly was 2.80.4904, which indicated these patients were mostly independent. Eighty four percent of the elderly subjects were cognitively intact. Among visiting nurse services supplied, providing assessment was 34%, followed by education and counseling 26%, medication 22%, and referral. The mean cost per visit was 17,824.1 won, which transformed into a total cost per person per year of 161,130.2 won. Comparing the cost of a visiting nurse service with those of other long-term care alternatives, the visiting nurse service was the least costly alternative, followed by an outpatient clinic, hospital based home care, and nursing home. Conclusion: Overall, the results of the study provide evidence of the economic viability of visiting nurse services for the low-income elderly among long-term care alternatives.