• Journal of the military operations research society of Korea
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• v.30 no.2
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• pp.13-31
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• 2004

This paper aims at efficient determining the economic life of weapon systems. Specifically, the procedure to estimate the life cycle cost at initial acquisition state or at development state using the PRICE model is proposed. The PRICE model is a parametric cost estimation which is widely used in the field of national defense. The model includes the estimation of the cost in life cycle of weapon systems such as research and development, acquisition, operation and support. Using this model, economic life of weapon systems can be determined. Based on an equivalent annual cost (EAC) method which sums the capital recovery with return (CR) and the equivalence cost (EC), the economic life will be calculated. A case study is accomplished to illustrate the proposed procedure.

• Journal of the military operations research society of Korea
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• v.16 no.2
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• pp.1-13
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• 1990

The life of an equipment depends upon its operating characteristics and physical environment factors. This paper presents the economic life length of 2 1/2 ton truck considering the operation terrains. For this specific research, the operation terrains are categorized into seacoast area, mountain area and plain area. To compute the life length, the method of equivalent annual cost is employed. The sample vehicles from each corresponding area are randomly selected from those vehicles whose ages exceed 9 years. This research finds the following results : (1) The life length operated at seacoast area is 9.75 years, (2) The life length operated at mountain area is 11.25 years, (3) The life length operated at plain area is 14 years. This research argues that the key factor such as characteristics of operating enviroment for allocation of operating and maintaining cost should be considered.

• Journal of the military operations research society of Korea
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• v.28 no.1
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• pp.97-114
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• 2002

An estimation of economic life for a new weapon system is a critical issue in aquisition process. In general a life cycle cost consists of, development cost, aquisition cost, and maintenance cost. These costs are not identified and obtained in the beginning of the aquisition process. This paper deals with an economic life for KlAl tank which is being deployed recently, using PRICE model. In order to estimate an KlAl economic life, we use equivalent annual cost method which is sum of capital recovering with return and equivalent O&M cost method. This method determines an economic life by minimizing annual investment cost and operation and maintenance cost. In this paper, an aquisition cost of KlAl is obtained from PRICE H and O&M cost from PRICE HL model. We obtained various results depending upon production quantity. An economic life for KlAl is estimated 18 years when 300 tanks are produced.

• Journal of the military operations research society of Korea
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• v.23 no.1
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• pp.138-150
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• 1997

The life-cycle of the K-1 tank has been 10 years simply applying that of the U.S. M-1 tank. Therefore, this paper is focused on determination of an economic life-cycle for the K-1 tanks. The current operation cost is adjusted by interest rate and the depreciation cost is applied in this study for more reliable estimation of the life-cycle cost. The Equivalent Annual Method is utilized and then various regression techniques are applied for deriving an effective economic life-cycle. The economic life-cycle of the K-1 tank results in 13 years in this study. considering 95% confidence interval, the life cycle of the K-1 tank is between 10.5 years and 15.5 years.

• BMB Reports
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• v.57 no.2
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• pp.71-78
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• 2024

Melanoma is one of the most aggressive skin tumors, and conventional treatment modalities are not effective in treating advanced melanoma. Although immunotherapy is an effective treatment for melanoma, it has disadvantages, such as a poor response rate and serious systemic immune-related toxic side effects. The main solution to this problem is the use of biological materials such as hydrogels to reduce these side effects and amplify the immune killing effect against tumor cells. Hydrogels have great advantages as local slow-release drug carriers, including the ability to deliver antitumor drugs directly to the tumor site, enhance the local drug concentration in tumor tissue, reduce systemic drug distribution and exhibit good degradability. Despite these advantages, there has been limited research on the application of hydrogels in melanoma treatment. Therefore, this article provides a comprehensive review of the potential application of hydrogels in melanoma immunotherapy. Hydrogels can serve as carriers for sustained drug delivery, enabling the targeted and localized delivery of drugs with minimal systemic side effects. This approach has the potential to improve the efficacy of immunotherapy for melanoma. Thus, the use of hydrogels as drug delivery vehicles for melanoma immunotherapy has great potential and warrants further exploration.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.1
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• pp.191-197
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• 2000

This paper provides the test results of tracked vehicle at each driving condition and life cycle. Fatigue Damage Spectrum(FDS) has evaluated with the Power Spectrum Density(PSD) and the life time of equipment. Finally, provisional vibration qualification test level is evaluated.

• Journal of the military operations research society of Korea
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• v.9 no.2
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• pp.39-43
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• 1983

In this paper, we derive the likelihood function for the independent random order statistic whose underlying lifetime distribution is a two parameter Weibull form. For this purpose we first discuss the order statistic which represent a characteristic feature of most life and fatigue tests that they give rise to ordered observations. And, we describe the properties of the underlying Weibull model. The derived likelihood function is essential for establishing the statistical life test plans in the case of Weibull distribution using a likelihood ratio method.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.1
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• pp.26-37
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• 2000

This research paper deals with the problem of determining the optimal life time in terms of economical sense for a self-propelled artillery. Equivalent Annual Cost Method(EACM) is used to evaluate the optimal life time, based on the acquisition cost, and the operation and maintenance cost. It is assumed that the operation and maintenance cost includes the costs for spare parts, petroleum and ammunition for training. From the result of this study, the optimal life time for a self-propelled artillery is between 13.9 years and 16.1 years with 95% confidence interval.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.1 s.24
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• pp.13-23
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• 2006

A propellant mainly consisting of nitric ester including nitrocellulose and nitroglycerine is characteristic of being decomposed naturally. And this phenomenon is known as being affected mostly by its storing temperature and humidity. In this research, the effect of storing temperature and humidity on self life has been studied by measuring the contained quantity of residual stabilizer of propellant KM30Al, which are parts of 155MM propelling charge K676 and K677; the method for the measurement is acceleration aging test, and decomposition reaction equation, Eyring Equation and Berthlot Equation were used for the calculation. As result of this study, it was found that the storing temperature influenced seven times as large as the storing humidity upon the self life of the propellant KM30Al, Furthermore, especially in the high temperature region, the storing temperature had a dominant effect on the self life.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.3
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• pp.200-207
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• 2007

Single base propellant using a nitrate ester compound NC decomposes naturally during storage time. Therefore, the research for storage life extension is necessary to single base propellant. In this research, $CaCO_3$ inorganic stabilizer had been added into single base propellants up to 0.3%, and the accelerated aging test of the propellant was started. And then, with applying the Arrhenius equation, the storage life of the test of the propellant was contrasted with that of reference propellant. As a result, the storage life of the propellant containing $CaCO_3$ inorganic stabilizer was about twice longer than the reference propellant.