• 전기의세계
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• v.31 no.5
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• pp.355-360
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• 1982

In numerical computation, it is desirable to access any row or column, the main diagonal, subarrays, of a matrix without any conflict for successful parallel processing. To meet this requirement special storage scheme is used for conflict-free access of necessary data. Interconnection network, which connects processing elements and processing element memory modules, is required to execute the necessary operations. In this paper we discuss the skewing method for conflict-free, access to various bit slices and single-stage interconnection networks.

• Annual Conference of KIPS
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• 2010.11a
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• pp.1046-1049
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• 2010

Custody transfer method is often managed by the general architecture of Delay Tolerant Network (DTN) to provide reliability in the communications through storage and forward paradigm, but can be inefficient when the acknowledgment messages are lost, or the network becomes congested. In this paper we describe a new architecture that is particularly efficient for the custody transfer method. Because, it provides an additional control of acknowledgment messages, consolidate knowledge and services, using the advantage of the cross-over architectures and distribution control through local and global services.

• Journal of Radiation Protection and Research
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• v.40 no.2
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• pp.92-100
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• 2015

For the purpose of improving the efficiency of the radiation impact assessment of dry interim storage facilities for the spent nuclear fuel of pressurized water reactors (PWRs), radiation impact assessment was performed after the application of sensitivity assessment according to the radiation source term designation method, development of a 2-step calculation technique, and cooling time credit. The present study successively designated radiation source terms in accordance with the cask arrangement order in the shielding building, assessed sensitivity, which affects direct dose, and confirmed that the radiation dosage of the external walls of the shielding building was dominantly affected by the two columns closest to the internal walls. In addition, in the case in which shielding buildings were introduced into storage facilities, the present study established and assessed the 2-step calculation technique, which can reduce the immense computational analysis time. Consequently, results similar to those from existing calculations were derived in approximately half the analysis time. Finally, when radiation source terms were established by adding the storage period of the storage casks successively stored in the storage facilities and the cooling period of the spent nuclear fuel, the radiation dose of the external walls of the buildings was confirmed to be approximately 40% lower than the calculated values; the cooling period was established as being identical. The present study was conducted to improve the efficiency of the Monte Carlo shielding analysis method for radiation impact assessment of interim storage facilities. If reliability is improved through the assessment of more diverse cases, the results of the present study can be used for the design of storage facilities and the establishment of site boundary standards.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.437-445
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• 2020

Smoke grenades are the primary means of protection used by tanks to disrupt enemy detection systems. Such smoke grenades are a critical factor that determines the survival of tanks in the engagement of ground weapon systems, but it can only be used once. Owing to its destructive property, the performance and safety of the smoke grenade cannot be confirmed prior to use. Therefore, the reliability of smoke grenades can be evaluated through various tests during the storage period. This paper presents the results of estimating the reliability and shelf life of IR screening smoke grenade launchers based on the result of the Ammunition Stockpile Reliability Program conducted in 2019. Among the smoke grenade launcher lots currently stored, 16 lots and samples were selected for each year of manufacture and tested. The reliability and shelf life were estimated by examining the number of defects and the change in quality characteristics of each test item. The results of this study can be used to assess the reliability of the smoke grenade launchers and to improve the quality of manufacturing sites.

• Journal of Korea Water Resources Association
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• v.53 no.11
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• pp.961-971
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• 2020

The Intergovernmental Panel on Climate Change (IPCC) reported that the amount of precipitation in South Korea would increase regardless of the reduction of Greenhouse Gas (GHG) emissions. Moreover, the temporal and spatial rainfall variation would also increase in the future. Due to the geographic allocation of Korea, more than 80% of the annual precipitation occurs in the wet season from early July to late September. It is expected that the average precipitation in this period will increase from the Representative Concentration Pathways (RCP) scenario projections. These predictions imply an increased variability of available water resources. Rainwater harvesting system is widely used as an alternative water resources today. This study introduces a RBSN (rain barrel sharing network) as an efficient way to utilize alternative water resources under the RCP scenarios. The concept of RBSN combines individual rainwater harvesting system to a sharing network, which make the whole system more reliable. This study evaluated a RBSN in South Korea composed of four users based on a storage-reliability-yield (SRY) relationship. The study area comprises all 17 provincal areas in South Korea. The result showed a huge benefit from a RBSN in Korea under the historical rainfall condition. Even in the climate change condition, the results showed that a RBSN is still beneficial but the changes in reliability are different depending on provinces in Korea. The results of this study shows that a RBSN is a very effective and alternative measure that can deal with the impacts of climate change in the near future.

• Journal of the Korean Geotechnical Society
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• v.38 no.11
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• pp.107-118
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• 2022

The social need for stable hydrogen storage technologies that respond to the increasing demand for hydrogen energy is increasing. Among them, underground hydrogen storage is recognized as the most economical and reasonable storage method because of its vast hydrogen storage capacity. In Korea, low-depth hydrogen storage using artificial protective structures is being considered. Further, establishing corresponding safety standards and ground stability evaluation is becoming essential. This study evaluated the hydro-mechanical behavior of the ground during a hydrogen gas leak from a low-depth underground hydrogen storage facility through the HM coupled analysis model. The predictive reliability of the simulation model was verified through benchmark experiments. A parameter study was performed using a metamodel to analyze the sensitivity of factors affecting the surface uplift caused by the upward infiltration of high-pressure hydrogen gas. Accordingly, it was confirmed that the elastic modulus of the ground was the largest. The simulation results are considered to be valuable primary data for evaluating the complex analysis of hydrogen gas explosions as well as hydrogen gas leaks in the future.

• The Korean Journal of Applied Statistics
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• v.31 no.5
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• pp.611-620
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• 2018

Limitations on human and material resources make it is difficult to conduct Ammunition Stockpile Reliability Program (ASRP) tasks for the entire ammunition. Stockpile ammunition life prediction studies can contribute to efficient ASRP tasks. This study assess the shelf-life of ammunition, using survival analysis based on ASRP results for 60mm and 81mm mortar ammunition from 2003 to 2016. Traditional assessments often use solely storage duration as the only main independent variable; however, this assessment used other factors such as ammunition magazine shape and weather factors with the stockpile shelf-life as independent variables to conduct a Cox's proportional hazard model analysis. This was then followed by an assessment of ammunition magazine type, maximum temperature and rainfall factors influence on the shelf-life of 60mm and 81mm mortar ammunition. As a result, the type of ammunition magazine, maximum temperature and the rainfall influence the shelf-life of 60mm and 81mm mortar ammunition.

• Elastomers and Composites
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• v.55 no.2
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• pp.81-87
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• 2020

Service life prediction and evaluation of rubber components is the foundational technology necessary for securing the safety and reliability of the product and to ensure an optimum design. Even though the domestic industry has recognized the importance thereof, technology for a systematic design and analysis of the same has not yet been established. In order to develop this technology, identifying the fatigue damage parameters that affect service life is imperative. Most anti-vibration rubber components had been damaged by repeated load and aging. Hence, the evaluation of the fatigue characteristics is indispensable. Therefore, in this paper, we propose a method that can predict the service life of rubber components relatively accurately in a short period of time. This method works even in the initial designing stage. We followed the service life prediction procedure of the proposed rubber components. The weak part of the rubber and the maximum strain were analyzed using finite element analysis of the rubber bushing for the tracked vehicles. In order to predict the service life of the rubber components that were in storage for a certain period of time, the fatigue test was performed on the three-dimensional dumbbell specimen, based on the results obtained by the rubber material acceleration test. The service life formula of the rubber bushing for tracked vehicles was derived using both finite element analysis and the fatigue test. The service life of the rubber bushing for tracked vehicles was estimated to be about 1.7 million cycles at room temperature (initial stage) and about 400,000 cycles when kept in storage for 3 years. Through this paper, the service life for various rubber parts is expected be predicted and evaluated. This will contribute to improving the durability and reliability of rubber components.

• The Journal of Korean Institute of Information Technology
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• v.17 no.11
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• pp.17-26
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• 2019

RAID-5 technology is one of the choice for flash storage device to enhance its reliability. However, RAID-5 has inherent parity update overhead, especially, parity overhead for partial stripe write is one of the crucial issues for flash-based RAID-5 technologies. In this paper, we design efficient parity log architecture for RAID-5 to eliminate runtime partial parity overhead. During runtime, partial parity is retained in buffer memory until full stripe write completed, and the parity is written with full strip write. In addition, parity log is maintained in memory until whole the stripe group is used for data write. With this parity log, partial parity can be recovered from the power loss. In the experiments, the parity log method can eliminate partial parity writes overhead with a little parity log writes. Hence it can reduce write amplification at the same reliability.

• Journal of the Korean Institute of Gas
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• v.27 no.4
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• pp.27-33
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• 2023

In a petrochemical plant, various mechanical equipments and structures are interconnected to ensure operability. Since the production activities of petrochemical plants have a great impact on the national economy, it is very important to maintain not only structural safety but also the operability of the facilities. However, the current seismic design standards present the design requirements of facilities mainly aimed at preventing collapse, and do not provide the requirements for securing operability of facilities. Depending on the behavioral characteristics of the facility, operability of the facility can be secured by seismic performance levels other than the collapse prevention level, so it is necessary to present seismic design methods that can apply various seismic performance levels. Spherical (ball) storage tanks are supported by columns and braces and exhibit complex nonlinear behavior because of buckling and yielding of support members. In this study, nonlinear seismic behavior characteristics were statistically analyzed and a new performance-based seismic design method was proposed based on them.