• ETRI Journal
• /
• v.44 no.6
• /
• pp.936-944
• /
• 2022

The mobile network allows redundant transmission via disjoint paths to support high-reliability communication (e.g., ultrareliable and low-latency communications [URLLC]). Although redundant transmission can improve communication reliability, it also increases network costs (e.g., traffic and control overhead). In this study, we propose a reliability-guaranteed multipath allocation algorithm (RG-MAA) that allocates appropriate paths by considering the path setup time and dynamicity of the reliability paths. We develop an optimization problem using a constrained Markov decision process (CMDP) to minimize network costs while ensuring the required communication reliability. The evaluation results show that RG-MAA can reduce network costs by up to 30% compared with the scheme that uses all possible paths while ensuring the required communication reliability.

• Journal of Korean Society of Forest Science
• /
• v.97 no.3
• /
• pp.274-284
• /
• 2008

For forest valuation, various input data were generally required: for example, slope, timber stocks, logging costs, hauling costs, market values of timber, afforestation costs, thinning costs, and so on. To enhance the efficiency of forest valuation process, it would be helpful to guide how and where to acquire such data sets. Moreover, to make an appraisal of timber assets through the Forestry Household Economy Survey, it would be inevitable to use standardized input data by region or tree species. Therefore, this research intended to develop a methodology of standardizing each input data, and to present its available data sources. Also, a guidance was presented to explain how to control input data within the appraisal process. Then, the appraisal process were analyzed and summarized in four types of information such as system flowchart, process flowcharts, detail flowcharts, and skimmer data, which are essential elements in developing an appraisal software, named EnVAST (Engine of Valuation System for Timber Assets). The software was designed to generate 'the standard forest valuation table' by species and province as the final output that is applicable for the forest valuation through the Forestry Household Economy Survey in Korea.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.4
• /
• pp.517-527
• /
• 2021

While the two principles of lean manufacturing and time-driven activity-based costing (TDABC) have been established out of multiple incentives and do not follow the same particular targets, there is substantial commonality between them. In these conditions, the supply management of a multi-product system needs a rigorous production model to minimize costs. In this sense, this paper proposes an interactive model with the consideration of optimizing product-mix decisions using both lean development tools and TDABC. This paper proposes a qualitative approach using the case study of the Iraqi state company for battery production. The suggested model decreased manufacturing time and costs, along with some substantial reduction in idle production capacity by 26 percent in 2019, based on the findings of the case study. On the other hand, the proposed model gives two side advantages: an efficient division of costs on goods due to the use of time spent as a cost factor for products and cost savings due to the introduction of the lean manufacturing approach that reduces all additional costs and increases product-mix decisions. Furthermore, the analytical data gathered here suggests that the incorporation of lean management concepts and TDABC has a strong and important influence on product-mix decisions.

• Journal of the Society of Naval Architects of Korea
• /
• v.61 no.2
• /
• pp.88-97
• /
• 2024

This study performed the analysis on an economic feasibility of each marine fuel, potential fuel pathways and the relevance of compliance measures to ensure compliance with the FuelEU Maritime regulation. Additionally, it identified certain regulatory gaps to encourage the use of alternative marine fuels. Regarding GHG emissions calculations, the existing GHG regulations for ships applies the Tank-to-Wake (TtW) method, whereas FuelEU Maritime applies the Well-to-Wake (WtW) method. The main results present that important information to establish response strategy for FuelEU Maritime including the costs and benefits of each marine fuel, the minimum blending ratio of alternative fules, and compliance impacts of measures. For the regulatory costs and benefits of marine fuels following the implementation of the FuelEU Maritime from 2025, our findings indicate that while most fossil fuels incur regulatory costs from 2025, most of biofuels and RFNBO fuels do not incur costs until 2050. This will play a role to narrow the price gap between fossil fuels and alternative fuels.

• Journal of Korean Academy of Nursing
• /
• v.46 no.4
• /
• pp.562-571
• /
• 2016

Purpose: In this study the costs and benefits of a home health care program were examined to evaluate the economic feasibility of the program. Methods: The study participants included 349 patients in the community who had been registered at a home health care center for 5 years. The costs and benefits of the program were analyzed using performance data and health data. The benefits were classified as the effects of pressure ulcer care, skin wound care and catheters management. The program effect was evaluated on the change of progress using transition probability. Benefits were divided into direct benefit such as the savings in medical costs and transportation costs, and indirect benefits which included saving in productivity loss and lost future income. Results: Participants had an average of 1.82 health problems. The input cost was KRW 36.8~153.3 million, the benefit was KRW 95.4~279.7 million. Direct benefits accounted for 53.4%~81.2%, and was higher than indirect benefits. The net benefit was greater than 0 from 2006 to 2009, and then dropped below 0 in 2010. Conclusion: The average net benefit during 5 years was over 0 and the benefit cost ratoi was over 1.00, indicating that the home health care program si economical.

• Journal of Korean Society for Quality Management
• /
• v.36 no.3
• /
• pp.76-86
• /
• 2008

This paper examines when a consumer in existent telecommunication 2G applies to new telecommunication service 3G from the viewpoint of an option pricing theory. To improve telecommunication quality of service, the consumer applies to 3G. The application means an exchange of 2G for 3G with extra costs such as searching and conversion costs. Since the option to exchange is a right that the consumer can exercise or not, application to 3G is deemed an exercise of the option to exchange at most suitable value of the option. The timing to exercise the option depends on the extra costs and the additional communication benefit from new telecommunication quality of service. These affect an optimal timing to apply to 3G. The optimal applying or switching timing to 3G is when an economic value of the option to exchange is equal to an economic value of the extra costs plus the additional telecommunication quality from new telecommunication service. The option analysis used in this paper is applicable to various industries.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.38 no.3
• /
• pp.150-155
• /
• 2018

This study was conducted to determine grazing intensity of growing Korean native goats(Capra hircus coreanae) on mountainous pasture. It was carried out to obtain basic information for improvement of mountainous pasture management and establishing feeding system of Korean native goat. A total of 20 goats were grouped by feeding systems [A mountainous pasture grazing group (Concentrated feed of 1.5% body weight, treatment 1, T1, n=10) and a barn feeding group (TMR, treatment 2, T2), n=10] to conduct study from April to September. The average forage productivity of the mountain pasture was $500.9{\pm}61.41kg/ha$. The average dry matter intake in T1 was 0.64 and the calculated grazing intensity was 21 head/ha. In productivity, when the two treatments(T1, T2) were compared, the dry matter intake was about two to three times the difference. The average daily gain per day during the experiment was 63.3 in the mountain pasture and 120 g in barn feeding. When grazing, considering mountainous pasture productivity it is necessary to increase the productivity through proper feeding. The feed costs of black goats raised by grazing on the grassland in the same period showed an average 75% reduction compared to barn feeding. As a result of this study, it can be expected that a considerable reduction of feed costs can be expected in the breeding of Korean native black goat using the mountain pasture.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.67 no.3
• /
• pp.155-163
• /
• 2022

The tillering potential of panicle number type (PNT) rice greatly varies with planting density. Moreover, grain filling and ripening differ depending on the panicle position, which may further affect rice grain quality. The present study evaluated the grain quality of PNT rice sparsely planted to reduce production costs. The physicochemical characteristics of starch from the grains of PNT type rice 'Ilpum' planted at different densities (37, 50, 60, and 80 plants/3.3 m²) and at different positions of panicles (upper or lower on the culm) were determined. Overall, as the planting density decreased, the number of panicles increased but the starch content decreased, which further reduced the 1,000-grain weight. In particular, at the lowest density (37 plants/3.3 m²), protein content increased but particle size, enthalpy, and relative crystallinity decreased. The effects were more pronounced at lower than at upper panicle positions. These findings indicate that tillering potential differs with planting density, ultimately affecting the palatability of rice grains. Based on these findings, we propose restricting rice transplantation to a planting density of ≤37 plants/3.3 m² to achieve the best quality of grains at lower costs and with less labor.

• Journal of the Korea Society of Computer and Information
• /
• v.26 no.4
• /
• pp.223-229
• /
• 2021

This study investigated the determinants of debt ratio in public institutions. For this purpose, we analyzed the impact of inefficient management as internal factors on debt ratio. In this paper, inefficient management included total costs, payment, and employee benefit. The results of this study are as follows. First, we find that there is a significant positive relation between total costs and debt ratio. This result means that the higher total costs, the higher debt ratio. Second, we find that there is not a significant relation between payment and debt ratio. And we also find that there is not a significant relation between employee benefit and debt ratio. These results are empirical results that can be answers about some concerns that inefficient management of public institutions worsen debt ratio.

• KDI Journal of Economic Policy
• /
• v.34 no.2
• /
• pp.17-40
• /
• 2012

We study externality costs of capital investment under limited commitment. We solve for the constrained efficient allocation with a limited commitment environment and find positive externality costs of capital investment provided that full-risk-sharing is not feasible. In a decentralized version of limited commitment environment, a one unit increase of capital investment by an agent increases all individuals' autarky values in the economy and generates externality costs in the economy. This externality cost provides a rationale for positive capital taxation even in the absence of government expenditure. In order to internalize this costs, the government use a positive rate of linear capital tax in the decentralized economy.