• Structural Engineering and Mechanics
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• v.70 no.2
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• pp.199-207
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• 2019

In this paper, a semi-analytical method will be discussed for free vibration analysis of rotating beams with variable cross sectional area. For this purpose, the rotating beam is discretized through applying the transfer matrix method and assumed the axial force is constant for each element. Then, the transfer matrix is derived based on Euler-Bernoulli's beam differential equation and applying boundary conditions. In the following, the frequencies of the rotating beam with constant and variable cross sections are determined using the transfer matrix method in several case studies. In order to eliminate numerical difficulties in the transfer matrix method, the Riccati transfer matrix is employed for high rotation speed and high modes. The results are compared with the results of the finite elements method and Rayleigh-Ritz method which show good agreement in spite of low computational cost.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.10
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• pp.28-37
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• 2011

Though Korea has introduced CBP(Cost Based pool) power trading system since 2001, long-term Generation system planning has been executed by government for Cost minimization every 2 years. Until currently the model which is used for Generation system planning and best-mix only considers cost minimization and total yearly or quarterly electricity demand every year. In a view point of one day power supply operation, technical characteristics, like the ramp up/down rate of total generation system, minimum up/down time and GFRQ(Governor Free Response Quantity), are very important. this paper analyzes Optimal Fuel-Mix for 2022 Korea generation system satisfying these constraints of each fuel type and considering pump storage plants, construction cost and $CO_2$ emission charge Using MILP(Mixed Integer Linear Programming) method. Also the sensitivity analysis which follows in future power industry environmental change accomplished.

• Industrial Engineering and Management Systems
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• v.9 no.2
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• pp.70-79
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• 2010

Makespan and cost minimization are two important factors in project investment. This paper considers a multi-mode resource-constrained project scheduling problem with the objective of minimizing costs, subject to a deadline constraint. A number of studies have focused on minimizing makespan or resource availability cost with a specified deadline. This problem assumes a fixed cost for the availability of each renewable resource per period, and the project cost to be minimized is the sum of the variable cost associated with the execution mode of each activity. The presented memetic algorithm (MA) consists of three features: (1) a truncated branch and bound heuristic that serves as effective preprocessing in forming the initial population; (2) a strategy that maintains two populations, which respectively store deadline-feasible and infeasible solutions, enabling the MA to explore quality solutions in a broader resource-feasible space; (3) a repair-and-improvement local search scheme that refines each offspring and updates the two populations. The MA is tested via ProGen generated instances with problem sizes of 18, 20, and 30. The experimental results indicate that the MA performs exceptionally well in both effectiveness and efficiency using the optimal solutions or the current best solutions for the comparison standard.

• The KIPS Transactions:PartD
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• v.15D no.2
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• pp.207-212
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• 2008

This paper evaluates software cost estimation models, and presents the most suitable model. First, we transformed a relevant model into variables to make in linear. Second, we evaluated model's performance considering how much suitable the cost data of the actual development software was. In the stage of model performance evaluation criteria, we used MMRE which is the relative error concept rather than the absolute error. Existing software cost estimation model follows Weibull, Gamma, and Rayleigh function. In this paper, Gompertz function model is suggested which is a kind of growth curve. Additionally, we verify the compatability of other different growth curves. As a result of evaluation of model's performance, Gompertz function was considered to be the most suitable for the cost estimation model.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.7
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• pp.181-193
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• 2021

Thailand's tourism industry contributed to over three trillion baht in 2019. Tourist attractions across Thailand attract tourists around the world with their natural scenery, lifestyles, and cultures, especially in those called "second-tier cities". Community enterprises play a vital role to drive the tourism industry to local areas. However, most community enterprises lack professional accounting knowledge. This research aims to provide guidelines for ecotourism cost management of community enterprises in Thailand. Participatory Action Research (PAR) was employed to investigate the current circumstances of the Banlaem enterprise by using in-depth interviews to identify problems in cost management. Then, the focus and small group meetings were organized to monitor and evaluate solutions. The results reveal that the cost of VIP-Two Days trip was generating the highest net profit and margin, followed by VIP-One Day trip, but net losses were detected on the Students-One Day trip, even though income was greater than the variable costs, revenues didn't cover fixed costs. Thus, accounting knowledge could be a major concern of these enterprises. They should systematically record revenues and expenses, set appropriate labor costs, reduce production costs by using seasonal seafood and make use of vegetables in their gardens, and price products according to their production costs.

• Journal of the Korea Convergence Society
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• v.6 no.5
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• pp.1-8
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• 2015

The data of fair value hierarchy is expected to contain different degree of measurement error, information asymmetry, and information risk by the level of hierarchy. Thus, this study examines how hierarchy of fair value discriminately influences on companies' cost of capital. Through regression analysis of corporations listed from 2011 to 2014, it turns out that the regression coefficient of level 1 and 2 of fair value variable vary their rank by cost of capital types, while level 3 contains the highest regression coefficient for every cost of capital variable. In addition, further study of how the relevance between cost of capital and the fair value hierarchy gets affected by market risk management level and audit quality finds no consistent results. However, by analyzing the effect of coincident interaction through the convergence of market risk management and audit quality, when audit quality and market risk management level are high, the effect of relieving cost of capital of Level 3 gets the highest. In conclusion, fair value hierarchy data seems to affect discriminately on cost of capital by involved information risk, and the information risk could decrease by the level of market risk management and audit quality.

• Journal of Korean Clinical Nursing Research
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• v.18 no.2
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• pp.183-195
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• 2012

Purpose: This study was performed to identify the variations of nursing care cost depending on nursing care requirement and calculate nursing care cost per one day and one care requirement point. Methods: Nursing care requirement was measured by classifying 3,855 patients according to KPCS-1(Korean Patient Classification System for nurses-1). Nursing care cost was calculated from personnel expenses and nursing care requirement. Nursing cost factors were identified by multiple regression analysis. Results: Average nursing cost per patient per day was 33,588 won, Average nursing care cost per 1 patient classification score was 3,558 won. The nursing cost per 1 patient classification score was different depending on the types and levels of the hospitals. The 4th patient classification group revealed the highest nursing care cost. Nursing cost factors included the number of beds in the hospitals, seniority, number of nurses and first grade in nurse personnel accreditation ($adj-R^2$ 74.0%. p<.05). Conclusion: Nursing care requirements expressed by patient classification scores don't directly correlate with nursing care cost. Further research is needed to evaluate validity and reliability for refining KPCS-1 and to apply variable criteria to nurse personnel accreditation.

• Proceedings of the Safety Management and Science Conference
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• 2003.11a
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• pp.323-327
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• 2003

The four types of management accounting systems(traditional full costing, direct costing, activity-based costing, throughput accounting) are compared in this study. This paper reviews the differences between throughput and contribution margin. The paper concludes that the definition of totally variable cost(TVC) to calculate throughput is situational specific.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.3
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• pp.663-668
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• 2010

In driving a car, turns such as left turns, right turns, or u-turns, make the speed of the car decrease considerably. A more straight path, therefore, is probably faster to arrive at the destination than zig-zag path with same distance. In this paper, we have newly proposed the turn heuristic to make more straight path. The path navigation algorithm with turn heuristic(called as TA* algorithm) could enhance the straightness of a path by putting the turned-edges to the turn cost. It requires higher cost to use TA* algorithm than traditional A* algorithm because the straight-edge first searching have increased the search space. We have improved the TA* algorithm into the variable TA* algorithm(called as VTA* algorithm) which adopt the turn-heuristic during the a portion of the whole path.

• The Journal of Fisheries Business Administration
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• v.14 no.1
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• pp.1-18
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• 1983

This study has examined the principle of rationalization as a guiding principle in fisheries management. Generally speaking, the guiding principle of business management is the principle of profitability which is oriented to the profit maximization, but it has been insisted by Dr, Mohri that the principle of profitability should be translated into the maximization of ratio of added value on gross capital, According to Dr. Durcker, added value (contributed value) can be used to analyze productivity only if the allocation of costs which together make up the figures is economically meaningful. Therefore, the rationalization of fisheries management can be measured as a result of economic allocation of costs, The analysis of economic allocation of costs divides into macro-allocation of costs and micro-allocation of costs. In fisheries management, the former makes use of the analysis of break-even point, and the latter analyzes the efficiency of individual cost respectively and the state of division of costs which allocate into above-the-line expenses of lay system and management's burden expenses. In macro-allocation of costs, it is advisable that fixed costs be converted into variable costs. This is characteristically possible in fisheries management, because wages belong to variable costs in fisheries management while they are regarde as fixed cost in the other industires. Because we could find that all costs would belong to above-the-line expenses, in micro-allocation analysis, the very costs which are directly related to fisherman's poduction activity should be classified into above-the-line expenses, and the other costs into management's burden expenses. This is a central problem in the rationalization of fisheries management.