• Journal of Korean Society of Transportation
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• v.25 no.4
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• pp.123-133
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• 2007

This study analyzed whether a transit network with hierarchy is efficient or not, and if transit network hierarchy has cost efficiency, then which condition guarantees the efficiency of the transit network hierarchy. The authors modeled the total cost of the transit network and suggested the conditions in which the transit network hierarchy has cost efficiency through comparing the cost of the transit network with and without hierarchy. The efficiency of transit network hierarchy is guaranteed when the travel cost savings induced by using a higher hierarchy transit network is larger than the increasing non-travel cost, which is the sum of access cost, waiting cost, and operating cost, induced by the introduction of a higher hierarchy transit network. This result is consistent with common sense and with the concept of cost and benefit analysis. If a passenger traveling within the area divided by a higher hierarchy transit network uses only a lower hierarchy transit network and the passenger traveling out of the area divided by the higher hierarchy transit network uses both lower and higher hierarchy transit networks, the travel demand using the higher hierarchy transit network is inversely proportional to the square of the line spacing. This means that the transit network becomes more efficient and small increases of travel demand guarantee the efficiency of the transit network hierarchy as the connectivity of the network becomes higher. This result shows that transit networks have economies of aggregation. This study is the first analytical research on transit network hierarchy and is expected to be a basis for numerical research. However, numerical research should complement this study, since analytical research has some limitations for considering a real network.

• Health Policy and Management
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• v.17 no.2
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• pp.1-17
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• 2007

Limited coverage for health care services of National Health Insurance(NHI) in Korea has been ongoing policy issue but additional NHI financing through raising contribution or taxes in order to improve coverage faces substantial obstacles. Private health insurance(PHI) is often considered as an alternative financing source to improve coverage. Recent reform that attempted to stretch the role of PHI allowed life insurance companies to provide complementary PHI, indemnity plan which will pay for uncovered services by NHI and out-of-pocket spending for covered services. Although complementary PHI may relieve financial burden of patients, it may significantly raise NHI spending as well as total health expenditure since little out-of-pocket spending may increase utilization of health care. So far, there has not been enough discussion about concerns of potential adverse effect resulting from extended role of PHI. This study investigated potential increase of NHI spending followed by extension of complementary PHI through sensitivity analysis. The amount of NHI spending for services that would be covered by complementary PHI was calculated using 2005 NHI statistics and expected complementary PHI enrollment rate by age and sex. Expected utilization increases were obtained based on price elasticities$(-0.2{\sim}-0.5)$ from previous studies and expected coverage rate$(50{\sim}80%)$ of complementary PHI and then converted to monetary figures. Because coverage rate of complementary PHI has not been determined yet, we employed the sensitivity analysis using coverage rate of $50{\sim}80%$. Findings demonstrate that additional spending for health care services is expected to be $426{\sim}1,702$ billion won, corresponding amount payed by NHI $298{\sim}1,192$ billion won. In conclusion, since complementary PHI may raise NHI spending significantly, there should be an agreement whether this additional cost would be accountable and acceptable in our society. Potential inefficiency resulting from extended role of complementary PHI should be considered since public and private financing do not operate in isolation and there should be more discussion on proper role of PHI in Korea.

• Korean Journal of Construction Engineering and Management
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• v.15 no.1
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• pp.11-19
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• 2014

The Construction industry is a labor-intensive industry that its labor cost takes up about 30~40% out of the whole construction cost. However, due to a stereotype that on-site work is a 3D job there is a shortage of the labor forces. Modular construction method is to produce modular units in the plant so that workers could work stably. Also, after delivering the module from plant to the site, there will be only installment to be required that shortens construction duration. Even though the modular market is currently expanding based on military facilities in Korea, its best strengths are not demonstrated well which are shortened construction period and low cost. It also causes labor problem of production due to minimum utilization of the modular construction method. Multi-skilled labor means a technician that is able to perform more than two kinds of work with more than two techniques. Multi-skilled labor can proceed smoothly by figuring out the connectivity between the precedent and following operations. Therefore, this research is to apply the concept of Multi-skilled labors, suggest solutions and allocate manpowers efficiently. As a result, it helps to decrease idle manpowers during the operation and the total labor forces can be saved. Low cost is the original strength of the modular which can stand out so the modular market is expected to expand.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.6
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• pp.570-582
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• 2017

In recent years, national and local government's air quality management and climate change adaptation policy has been significantly strengthened. The measures in the two policies may be in a relationship of trade-off or synergy to each other. Greenhouse gases and air pollutants are mostly emitted from the same sources of using considerable amounts of fossil fuels. Co-benefits, in which either measure has a positive effect on the other, may be maximized by reducing the social costs and by consolidating the objectives of the various policies. In this study, the co-benefits were examined by empirically analyzing the effects of air pollutants and greenhouse gas emission reduction, social cost, and cost effectiveness between the two policies. Of the total 80 projects, the next 12 projects generated co-benefits. They are 1) extend restriction area of solid fuel use, 2) expand subsidy of low-$NO_x$ burner, 3) supply hybrid-vehicles, 4) supply electric-vehicles, 5) supply hydrogen fuel cell vehicles, 6) engine retrofit, 7) scrappage of old car, 8) low emission zone, 9) transportation demand management, 10) supply land-based electric of ship, 11) switching anthracite to clean fuel in private sector, 12) expand regional combined-energy supply. The benefits of air pollutants and greenhouse gas-related measures were an annual average of KRW 2,705.4 billion. The social benefits of the transportation demand management were the highest at an annual average of KRW 890.7 billion, and followed by scrappage of old cars and expand regional combined-energy supply. When the social benefits and the annual investment budgets are compared, the cost effectiveness ratio is estimated to be about 3.8. Overall, the reduction of air pollutants caused by the air quality management policy of Gyeonggi-do resulted in an annual average of KRW 4,790.2 billion. In the point sources management sector, the added value of $CO_2$ reduction increased by 4.8% to KRW 1,062.8 billion, while the mobile sources management sector increased by 3.6% to KRW 3,414.1 billion. If social benefits from $CO_2$ reduction are added, the annual average will increase by 7.2% to KRW 5,135.4 billion. The urban and energy management sectors have shown that social benefits increase more than twice as much as the benefits of $CO_2$ reduction. This result implies that more intensive promotion of these measures are needed. This study has significance in that it presents the results of the empirical analysis of the co-benefits generated between the similar policies in the air quality management and the climate change policy which are currently being promoted in Gyeonggi-do. This study suggested that the method of analyzing the policy effect among the main policies in the climate atmospheric policy is established and the effectiveness and priority of the major policies can be evaluated through the policy correlation analysis based on the co-benefits. It is expected that it could be a basis for evaluation the efficiency of the climate change adaptation and air quality management policies implemented by the national and local governments in the future.

• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.51-64
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• 2014

Small and medium Enterprises (SMEs), which have a manufacturing method of small quantity batch production produce goods using a general-purpose equipment and attached auxiliary tools. Many previous studies have focused on finding the effective resource allocations for improving the firms' productivity. It is very important for SMEs to keep costs low in assigning jobs to each resource, because they should meet the future uncertain demand of consumers under the limited budget. Using the concept of salvage cost, this paper proposes how to effectively allocate the tasks to main resources in the production process. The salvage cost is defined that purchasing cost minus decrease in value by workload, the method considering this is expected to reduce total purchasing costs during business period. To validate the effect of the proposed method, we proceed the real case study targeting on S company, PCB manufacturer to compare purchase amounts and its costs between the allocation proposed based salvage cost and current allocation method of current S company. As a results, In short-term (3 year) business period, salvage allocation have remarkable superior outcome to existing method, but gradually have cancelled out the effects in long-term (8 year) plans. Unlike the cycle allocation method, there exists the idle-equipments in allocation based salvage value. we additionally analyze the profits with respect to rental strategy of them during business period.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.2
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• pp.63-72
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• 2016

An expected-discounted cost model based on RRP(Renewal Reward Process), referred to as a stochastic decision model, has been developed to estimate the optimal period of in-depth inspection which is one of critical issues in the life-cycle maintenance management of harbor structures such as rubble-mound breakwaters. A mathematical model, which is a function of the probability distribution of the service-life, has been formulated by simultaneously adopting PIM(Periodic Inspection and Maintenance) and CBIM(Condition-Based Inspection and Maintenance) policies so as to resolve limitations of other models, also all the costs in the model associated with monitoring and repair have been discounted with time. From both an analytical solution derived in this paper under the condition in which a failure rate function is a constant and the sensitivity analyses for the variety of different distribution functions and conditions, it has been confirmed that the present solution is more versatile than the existing solution suggested in a very simplified setting. Additionally, even in that case which the probability distribution of the service-life is estimated through the stochastic process, the present model is of course also well suited to interpret the nonlinearity of deterioration process. In particular, a MCS(Monte-Carlo Simulation)-based sample path method has been used to evaluate the parameters of a damage intensity function in stochastic process. Finally, the present stochastic decision model can satisfactorily be applied to armor units of rubble mound breakwaters. The optimal periods of in-depth inspection of rubble-mound breakwaters can be determined by minimizing the expected total cost rate with respect to the behavioral feature of damage process, the level of serviceability limit, and the consequence of that structure.

• Journal of Preventive Medicine and Public Health
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• v.27 no.4 s.48
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• pp.807-814
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• 1994

This study is to find out changes in medical practice at a university hospital before and after covering intraocular lens (IOL) from the health insurance benefit. The coverage started on March 1, 1993 and a total of 596 cases who were discharged from July 1 to December 31, 1992 and 580 cases who were discharged from July 1 to December 31, 1993 were analyzed. Since the standard reimbursement scheme was changed from March 1, 1993, the charges for 1992 were transformed into 1993 scheme. Major findings are as follows: Average length of stay was statistically significantly decreased from 8.24 days in 1992 to 6.86 days in 1993. Charges except IOL has been statistically significantly decreased from 501,000 Won in 1992 to 444,000 Won in 1993. Charges for drugs and injection have been reduced. However, charge per day for them was not much different. This is due to decrease in length of stay. Charges for laboratory tests and radiologic examination were quite the same. Charges which are not covered by the insurance remained the same. The revenue of the hospital was reduced as expected. However, the hospital reduced the length of stay and increase the turnover rate In order to compensate the potential loss of revenue due to the difference of reimbursement between the out-of-pocket expense and the insurance coverage. By introducing the IOL benefit in the insurance, the insured pays less, hospital generates more revenue through shortening the hospital stay, and the total medical care cost becomes less nationwidely.

• The Journal of Art Theory & Practice
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• no.1
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• pp.93-108
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• 2003

The aim of this thesis is to evaluate visual arts policy during Kookmin government period(1998-2002). In the beginning, many artists had expected president Kim Dae Jung to enlarge arts support But the evaluation of them was very negative because the government was only interested in the development of cultural industry. First, I analysed the government expenditure in the visual arts. Department of Culture and Tourism took the responsibility of visual arts policy. The budget of arts and culture increased to 1 % of total government expenditure in this period. But the main factor was the increasement of cultural industry and tourism expenditure. The budget of visual arts in 2002 was only 6,600million won. Second, I analysed visual arts support programs. (1) The government introduced studio programs for the first time. For 5 years, 2 national studios and 23 public studios were established. (2) The number of art museum was increased to 62. (3) It introduced alternative space support program and supported 200million won annually. (4) Percent for art scheme reduced from 1% to 0.7% of total construction cost, but still 27 public sculpture gardens were built. (5) Business support for visual arts reduced because of IMF. (6) Also arts market froze and many commercial galleries were closed. (7) In order to revitalize region through arts and to promote international exchange of culture, Gwangju Biennale was created. Third, I analysed Arts Plan 2002. It had a radical limitation because it was established in the last year of Kookmin government period. Also it showed special favors to some arts organizations. In general, I think that positive outcomes are the introductions of the studio program and the alternative space support program. Especially alternative space support program enforced the diversity of visual arts, and encouraged creative young artists. But policy of arts market failed because of IMF and visual artists had to go through rough times.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.4
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• pp.55-63
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• 1997

Constructed wetland system which can be applied to the rural wastewater treatment system was examined by pilot plant in Kon-Kuk University. Hydraulic loading rate of wastewater was about 0.16m$^3$/m$^2$. day and theoretical detention time in the system was 1.38 days. The effluent of the septic tank for the school building was applied as inflow to the system. The influent concentration of DO was zero but effluent was up to 4.37mg/${\ell}$ which implies that oxygen was supplied enough from atmosphere by reaeration to support biological activity of the system. Average influent concentration of BOD was 104mg/${\ell}$ and effluent was 24mg/${\ell}$ with average removal rate of 76%. Average influent concentration of COD was 215mg/${\ell}$ and effluent was 63mg/${\ell}$ with average removal rate of 70 % . Average influent concentration of SS was 78mg/${\ell}$ and effluent was 10mg/${\ell}$ with average removal rate of 87%. Two components, BOD and SS, are regulated by law to keep maximum water quality standard of 80mg/${\ell}$ when daily outflow rate is less than 100$m^3$/day which is the case of most rural communities. Therefore, the results from the experiment showed that constructed wetland system can meet the water quality standard easily. Average influent concentration of total nitrogen was 165mg/lwhich is relatively higher than normal wastewater, and effluent was about 156mg/${\ell}$ with average removal rate of only 6%. Average influent concentration of total phosphorus was 41 mg/${\ell}$ and effluent was 6mg/${\ell}$ with average removal rate of 87%. Overall, constructed wetland system was thought to be effective to treat wastewater if nitrogen removal mechanism is improved. Considering low cost, less maintenance, and high treatability, this system can be a practical alternative for the wastewater treatment in rural area The experiment was performed during the summer and fall season, and treatment efficiency of the system is expected to decrease in low temperature. therefore, further study including temperature is required to evaluate feasibility of the system more in detail.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.371-381
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• 1983

This study is aimed at identifying the economic effects of drainage improvement projects. The total area of poor drainage is equivalent to 170,000ha, 13% of the total area of paddy field in Korea. The development of poor drained paddy is an urgent problem considering the low rate of self-sufficiency of food grain and the limitation of farmer's income increase. Rapid development of Korean economy has brought labor shoriage in rural farming sector. Accordingly farm mechanization is an important agricultural policy to hike labor productivity and to save production costs of rice farming. The expected economic benefits of the drainage improvement project are derived from increasing land productivity, expanding double cropped area and farming the farm mechanization base in paddy fields. The economic and financial rate of return of the project are considered very important decision making criteria for project implementation by resource allocation. Therefore this study covered benefit and cost analysis of the sampled area, the estimated financial rate of returns in $Buy{\check{o}}$ and Jinsung are represented 15% and 51% respectively and the economic rate of returns in both project area are also showing 1% and 26% respectively. The rate of return of the projects has showed an outstanding variance according to the locational and natural characteristics of the project area. As showing the above economic rate of return, $Buy{\check{o}}$ is very low Jinsung is very high. But the financial rate of return of both projects are considered comparatively high. Cosequently, the drainage improvement projects should be promoted from the view point of farm income increase to make narrow the income gap between rural and urban incomes and farm mechanization to solve labor shortage in the rural area.