• Korean Journal of Construction Engineering and Management
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• v.17 no.5
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• pp.54-61
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• 2016

The initial planned annual cost is frequently adjusted under the construction process in construction projects. If the annual cost is reduced than the initial planned cost, the number of possible activities is also reduced from initial planned progress schedule. In such cases, project manager need to replan the progress schedule with possible activities within changed annual cost. However, most project manager will proceed as planned schedule without any change. After the project cost has been exhausted, there are many cases to stop the operation of the construction site. This study developed active 5D CAD system that can replan the progress schedule within changed annual cost and simulate the cost status according to the changed schedule for cost visualization. This system can be used as a decision-making tool in the replaning progress schedule and will be able to increase the practical usability of 5D CAD system.

• The KIPS Transactions:PartD
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• v.13D no.5 s.108
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• pp.717-724
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• 2006

The cost estimation of software is getting more important as the portion of software is increasing in acquiring weapon systems. However, the cost estimation of embedded software in a weapon system follows the cost estimation method for general purpose softwares and uses the PRICE S model as a tool. However, any validation result of the estimated cost through an evaluated software size is not well known. Hence, we propose an approach to estimate the cost through evaluating the embedded software site in weapon systems. In order to achieve our research goal, we evaluate the software size of using the line of codes and function points which are produced by the PRICE S model. Finally, we compare the estimated cost data the actual cost data provided by the production company. As a result, we propose an approach to estimate the size and the cost of embedded software in weapon systems which are not easy to estimate objectively. We also expect that the Proposed approach is used for the cost validation and negotiation in the acquisition of weapon systems in the future.

• Communications of Mathematical Education
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• v.36 no.4
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• pp.627-644
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• 2022

In this study various angle trisection tools based on Archimedes' insertion method were investigated, some tools were fabricated and their characteristics were compared. Through these works, it was found that factors such as the convenience of use, arbitrariness of the trisected angle, and simplicity of structure should be considered in the production and utilization of the trisection tool. Considering the factors described above, attention was paid to the method proposed by Veprtskii A.I. in 1888 as a making method of the angle trisection tool. In this study, we improved the method proposed by Veprtskii A.I., we used two wooden chopsticks and a string to make an angle trisection tool. The improved trisection tool had fewer parts than other trisection tools, a simple structure, and more convenient usage. In particular, this tool divided an arbitrary angle(not a specific angle) into the same three parts, and the production cost was low and the production process was simple. This tool is expected to be widely used in concrete activities related to the properties of the exterior angles of triangles and the properties of isosceles triangles in mathematics classrooms.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.3
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• pp.95-100
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• 2020

Machines and facilities are physically or chemically degenerated by continuous usage. One of the results of this degeneration is the process mean shift. The representative type of the degeneration is wear of tool or machine. According to the increasing wear level, non-conforming products cost and quality loss cost are increasing simultaneously. Therefore a periodic preventive resetting the process is necessary. The total cost consists of three items: adjustment cost (or replacement cost), non-conforming cost due to product out of upper or lower limit specification, and quality loss cost due to difference from the process target value and the product characteristic value among the conforming products. In this case, the problem of determining the adjustment period or wear limit that minimizes the total cost is called the 'process mean shift' problem. It is assumed that both specifications are set and the wear level can be observed directly. In this study, we propose a new model integrating the quality loss cost, process variance, and production volume, which has been conducted in different fields in previous studies. In particular, for the change in production volume according to the increasing in wear level, we propose a generalized production quantity function g(w). This function can be applied to most processes and we fitted the g(w) to the model. The objective equation of this model is the total cost per unit wear, and the determining variables are the wear limit and initial process setting position that minimize the objective equation.

• Clean Technology
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• v.28 no.2
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• pp.182-192
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• 2022

This study provides an overview of the production costs of methane and hydrogen via water electrolysis-based hydrogen production followed by a methanation based methane production technology utilizing CO₂ from external sources. The study shows a comparative way for economic optimization of green methane generation using excess free electricity from renewable sources. The study initially developed the overall process on the Aspen Plus simulation tool. Aspen Plus estimated the capital expenditure for most of the equipment except for the methanation reactor and electrolyzer. The capital expenditure, the operating expenditure and the feed cost were used in a discounted cash flow based economic model for the methane production cost estimation. The study compared different reactor configurations as well. The same model was also used for a hydrogen production cost estimation. The optimized economic model estimated a methane production cost of $11.22/mcf when the plant is operating for 4000 hr/year and electricity is available for zero cost. Furthermore, a hydrogen production cost of $2.45/GJ was obtained. A sensitivity analysis was performed for the methane production cost as the electrolyzer cost varies across different electrolyzer types. A sensitivity study was also performed for the changing electricity cost, the number of operation hours per year and the plant capacity. The estimated levelized cost of methane (LCOM) in this study was less than or comparable with the existing studies available in the literature.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.153-153
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• 2010

The world is moving towards a post-carbon society and needs clean and renewable energy for sustainable development. There are many methodological approaches which are helping this shift based on analyzed data about energy resources and which focus on limited types of energy including liquid fossil, solid fossil, gaseous fossil, and biomass (e.g. IPCC Guidelines, ISO 14064-1, WRI Protocol, etc.). We should also consider environmental impact (e.g. greenhouse gas emissions, water use, etc.) and the economic cost of the renewable energy to make a better decision. Recently, researchers have addressed the environmental impact of new technologies which include photovoltaics, wind turbines, hydroelectric power, and biofuel. In this work, we analyze the environmental impact with a carbon emission factor to present a correlation between $CO_2$ emission and the cost of energy resources standardized by the energy output. In addition, we reviewed Life Cycle Assessment (LCA) as another methodology. Researchers who are studying energy systems have ignored the impacts of entire energy systems, e.g. the extraction and processing of fossil fuels. In power sector, the assessment should include extraction, processing, and transportation of fuels, building of power plants, production of electricity, and waste disposal. Therefore LCA could be more suitable tool for energy cost and environmental impact estimation.

• Health Policy and Management
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• v.14 no.2
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• pp.58-77
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• 2004

Cost containment has become high political issues since financial crisis of the Korean Health Insurance fund in 2000. Korean Government has developed and implemented several measures to reduce the pharmaceutical expenditures. Pharmaceutical economic evaluation can be a tool in decision to allocate scare resource efficiently. In order to increase the quality of economic evaluation for pharmaceuticals, the Korean Health Insurance Review Agency(HIRA) is considering the development of a guideline for economic evaluation. It mandates that pharmaceutical companies could submit the result of an economic evaluation when demanding reimbursement of new pharmaceutical drugs. The purpose of this study is to provide a critical review of the economic evaluations of health care technologies published in the Korean context whether they have been performed according to current guidelines and therefore whether their results are directly useful for decision making. We found there exist important problems and deviation from, good practice' both in the general features of the studies, like the study design and perspective, and in terms of cost measurement and valuation. There are needs to develop clear guidelines and to educate and train researchers in performing economic evaluations.

• Journal of Construction Engineering and Project Management
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• v.5 no.1
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• pp.26-31
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• 2015

Success of the construction companies is based on the successful completion of projects within the agreed cost and time limits. Artificial neural networks (ANN) have recently attracted much attention because of their ability to solve the qualitative and quantitative problems faced in the construction industry. For the estimation of cost and duration different ANN models were developed. The database consists of data collected from completed projects. The same data is normalised and used as inputs and targets for developing ANN models. The models are trained, tested and validated using MATLAB R2013a Software. The results obtained are the ANN predicted outputs which are compared with the actual data, from which deviation is calculated. For this purpose, two successfully completed highway road projects are considered. The Nftool (Neural network fitting tool) and Nntool (Neural network/ Data Manager) approaches are used in this study. Using Nftool with trainlm as training function and Nntool with trainbr as the training function, both the Projects A and B have been carried out. Statistical analysis is carried out for the developed models. The application of neural networks when forming a preliminary estimate, would reduce the time and cost of data processing. It helps the contractor to take the decision much easier.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.3
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• pp.145-153
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• 2018

Taguchi regarded the concept of quality as 'total loss to society due to fluctuations in quality characteristics from the time of supplied to the customer.' The loss function is a representative tool that can quantitatively convert the loss that occurs due to the deviation of the quality characteristic value from the target value. This has been utilized in various studies with the advantage that it can change the social loss caused by fluctuation of quality characteristics to economic cost. The loss function has also been used extensively in the study of producer specification limits. However, in previous studies, only the second order loss function of Taguchi is used. Therefore, various types of losses that can occur in the process can't be considered. In this study, we divide the types of losses that can occur in the process considering the first and second loss functions and the Spiring's reflected normal loss function, and perform total inspection before delivering the customer to determine the optimal producer specification limit that minimizes the total cost. Also, we will divide the quality policy for the products beyond the specification limits into two. In addition, we will show the illustration of expected loss cost change of each model according to the change of major condition such as customer specifications and maximum loss cost.

• Journal of the Korea Safety Management & Science
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• v.13 no.3
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• pp.153-168
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• 2011

In medium and small firm, the management system which is simple and where there is a practicality is required Ill)re than the management system which is complicated and minute of the centered around large company so that the introduction of the standard costs can be activated and it can be usefully used as a tool of management decisions. A difference between the standard costs introduction plan proposed in this paper and the preexistance study literature are as follows. In this paper, by breaking from the whole cost accounting aiming at all item, that is the traditional introduction method, and presenting the product cost accounting method by group the standards setting object was minimized and simplified. In this way, if the standards setting object is simplified, it is quick at the perimeter environment change as the little man power and flexibly it corresponds to and the cost information calculation which is exact with the setting up and maintenance of the efficient cost standard becomes available. As a result of applying for real through S corp., the usability of the method that the standard costs introduction method proposed in this paper produced the standard costs relatively short within period, it manages was verified. And the standard costs introduction method proposed in this paper went by the various cost information for each products, the management class did the management will decision which was objective and reasonable in the putting first.