• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.374-382
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• 2020

The purpose of this study is to improve the learning speed of an ammunition stockpile reliability classification artificial neural network model by proposing a normalization method that reduces the number of input variables based on the characteristic of Ammunition Stockpile Reliability Program (ASRP) data without loss of classification performance. Ammunition's performance requirements are specified in the Korea Defense Specification (KDS) and Ammunition Stockpile reliability Test Procedure (ASTP). Based on the characteristic of the ASRP data, input variables can be normalized to estimate the lot percent nonconforming or failure rate. To maintain the unitary hypercube condition of the input variables, min-max normalization method is also used. Area Under the ROC Curve (AUC) of general min-max normalization and proposed 2-step normalization is over 0.95 and speed-up for marching learning based on ASRP field data is improved 1.74 ~ 1.99 times depending on the numbers of training data and of hidden layer's node.

• Journal of the military operations research society of Korea
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• v.35 no.1
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• pp.1-19
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• 2009

This study aims to improve methodology for a Defense Simulation which is to calculate wartime stockpile requirement of artillery munitions for K-9 against armored vehicles. Due to incorrect data input and distortion in simulation logic, the expected occupancy ratio for each weapon system obtained from applying a traditional method using an analytical Defense Simulation shows considerable discrepancies from what we expect from a war in the future. This study analyzes causes for incorrect data input and phenomena of distortion in simulation logic. By taking measures to control these phenomena, the study aims to present trustworthy methodology for a Hybrid Defense Simulation which is to calculate wartime stockpile requirement of munitions for ground forces by interaction between a controlled training Defense Simulation model and a analytical Defense Simulation model

• Journal of Korean Society for Quality Management
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• v.41 no.1
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• pp.135-148
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• 2013

Purpose: This paper presents a method to evaluate the stockpile reliability of propelling charge for performance and storage safety with storage time. Methods: We consider a performance failure level is the amount of muzzle velocity drop which is the maximum allowed standard deviation multiplied by 6. The lifetime for performance is estimated by non-linear regression analysis. The state failure level is assumed that the content of stabilizer is below 0.2%. Because the degradation of stabilizer with storage time has both distribution of state and distribution of lifetime, it must be evaluated by stochastic process method such as gamma process. Results: It is estimated that the lifetime for performance is 59 years. The state distribution at each storage time can be shown from probability density function of degradation. It is estimated that the average lifetime as $B_{50}$ life is 33 years from cumulative failure distribution function curve. Conclusion: The lifetime for storage safety is shorter than for performance and we must consider both the lifetime for storage safety and the lifetime performance because of variation of degradation rate.

• Journal of Cadastre & Land InformatiX
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• v.47 no.1
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• pp.111-126
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• 2017

Small-scale UAS(Fusion technique of Unmanned Aerial Vehicles platform and Sensors, 'sUAS') opens various new applications in construction fields and so becoming progressively common due to the considerable potentials in terms of accuracy, costs and abilities. The purpose of this study is that the investigation of the validation on the utilization of sUAS for earth stockpile volume calculations on sites. For this, generate 3D models(DSM) with sUAS aerial images on an cone shaped soil stockpile approximately $270m{\times}300m{\times}20m$, which located at Baegot Life Park in Siheung-si, compared stockpile volume estimates produced by sUAS image analysis, against volume estimates obtained by GNSS Network-RTK ground surveying method which selected as the criteria of earth stockpile volume. The result through comparison and examination show(demonstrate) that there was under 2% difference between the volume calculated with the GNSS Network RTK data and the sUAV data, especially sUAS imaged-based volume estimate of a stockpile can be greatly simplified, done quickly, and very cost effective over conventional terrestrial survey methods. Therefore, with consideration of various plan to assess the height of vegetation, sUAS image-based application expected very useful both volume estimate and 3D geospatial information extraction in small and medium-sized sites.

• Korean Chemical Engineering Research
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• v.48 no.6
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• pp.695-699
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• 2010

The propellant KM10, a single propellant manufactured from nitrocellulose, was known to cause natural degradation phenomena at long term storage. In this study, the self-life was estimated using high temperature acceleration aging tests and stockpile analysis test. For the life expectancy estimation, Arrhenius equation and Berthelot equation were used in the high temperature acceleration tests, and the first order regression was used in the Stockpile analysis test. The self-life of propellant KM10 using the Arrhenius equation and Berthelot equation showed significantly different results as 43.73, 16.53 years in the high temperature acceleration test, and it showed 42.94 years in the Stockpile analysis test. The value of self-life predicted by Arrhenius equation was reasonable when compared with the result of E. R. Bixon.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.2
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• pp.93-98
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• 2015

This study was conducted to investigate the effect of different stockpiled periods on the nutritive value and productivity of mixed orchardgrass tall-fescue pasture (MOTP). This experiment was conducted at Jeju (island), South Korea, from Sep. 2012 to Nov. 2012. The DM yield of the MOTP had the highest in treatment in late August (2,983 kg/ha). The DM yields of swards were increased significantly by shortening the stockpiled period. The CP of the MOTP was 16.5% to 18.16%, and there did not appear to be a consistent trend in accordance with the duration of the stockpiled periods. The NDF and TDN content of the MOTP increased with the delay of the stockpiled periods, but there is a significant difference between the short- and long-stockpile periods; however, the ADF content of the MOTP decreased with shortened stockpile periods, but again, there is a significant difference between the two periods. In addition, P, Ca, Mg, Na, and Zn of MOTP increased by delaying the stockpile period, but Mn and Cu of MOTP decreased. As shown in the results of this research, the yield of MOTP was not increased by the atrophy of the growth of MOTP due to high temperatures in case where the MOTP was stockpiled from the beginning of August. The stockpile period of MOTP should therefore be started at the end of August to yield a stockpile of MOTP in the autumn.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.266-273
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• 2015

We studied the financial performance of ammunition stockpile reliability program on the Defense Management. We proposed the direct effect analysis, the indirect effect analysis and the combat power reinforcement effect as the financial performance analysis methodology. And, we estimated the financial performance using the proposed methods and the data of 2013 ASRP's data The financial performance by direct effect and indirect effect analysis was 99.96billion won and 303.7billion won. Also, The financial performance by reinforced Combat power reinforcement was 12.06 billion won. Therefore, the total financial performance of Ammunition Stockpile Reliability Program was 52.43 billion won.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.1
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• pp.124-132
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• 2018

This paper presents a shelf life assessment for K-1 military gas masks in the Republic of Korea using test data of Chemical Materiels Stockpile Reliability Program(CSRP). For the shelf life assessment, over 2,500 samples between 2006 and 2015 were collected from field tests and analyzed to estimate a probability of proper and improper functionality using Bayesian estimation. For this, three stages were considered; a pre-processing, a processing and an assessment. In the pre-processing, major components which directly influence the shelf life of the mask were statistically analyzed and selected by applying principal component analysis from all test components. In the processing, with the major components chosen in the previous stage, both proper and improper probability of gas masks were computed by applying Bayesian estimation. In the assessment, the probability model of the mask shelf life was analyzed with respect to storage periods between 0 and 29 years resulting in between 66.1 % and 100 % performances in accuracy, sensitivity, positive predictive value, and negative predictive value.

• Resources Recycling
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• v.27 no.3
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• pp.66-77
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• 2018

The import amount of rare metal in Korea is about 6,034 million USD, but the self-sufficiency of rare metals is about only 1%. In order to secure the stable supply of rare metals, it is necessary to operate an efficient stockpile system. In this study, we established a system to assess the adequacy of stockpiles by quantifying the risk factors of tangible and intangible risks in order to establish an efficient stockpile strategy. The model developed in this study aims to select the rare metals that need to be stockpiled first and to suggest the direction of the stockpiling policy in accordance with technological change and market change from the mid and long term viewpoint. The evaluation results derived from the model can quantitatively measure the security level of each rare metal and enable relative comparison between the rare metals using criticality matrix. Therefore, it is expected that more efficient stockpile policy will be possible if the proposed model is utilized in the future policy making.

• Journal of Applied Reliability
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• v.18 no.1
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• pp.56-65
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• 2018

Purpose: The purpose of this study is to estimate shelf life of fuze MTSQ (Mechanical Time & Super Quick) KM577A1 from Ammunition Stockpile Reliability Program (ASRP) data. Methods: For many years, ammunition test data had been gathered from ASRP. In this study, lot selection criteria and reliability score of functioning time for fuze are proposed. Reliability score of functioning time and failure data are used to estimate shelf life. Results: The results of this study are as follows; The failure modes of fuze MTSQ KM577A1 are dud, inverse function and mechanical time functioning failure (not operating in intended time). Dud and inverse function are major failure modes. Fuze MTSQ KM577A1's shelf life ($B_5$) is estimated 18.2 years conservatively. Conclusion: Degradation of chemical components in fuze MTSQ KM577A1 is major factor for its reliability. And shelf life ($B_5$) of fuze MTSQ KM577A1 is estimated 18.2 years conservatively.