• International Journal of Reliability and Applications
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• v.1 no.1
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• pp.89-104
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• 2000

Accelerated testing consists of a variety of test methods for shortening the life of products or hastening the degradation of their performance. This paper presents practical, modern statistical methods for evaluating the reliability of Nickel-Cadmium batteries at their design temperature of 2$0^{\circ}C$ by accelerated life test. Batteries have been life tested at three high temperature conditions, 50, 60, 7$0^{\circ}C$, respectively to yield failures quickly. The failures have been observed and judged by means of charge and discharge current integration. Analyses of life data from those conditions resulted in the Weibull distribution, which has been verified on the ground of the Kolmogorov-smirnov test and the pairwise t-test. Life data are modeled according to the Arrhenius life-temperature relationship. The mean life of tested batteries is assessed at about 590 cycles, and the activation energy of this chemical reaction is concluded to be 0.39eV as results. This study provides procedures for estimating the reliability of batteries in a short period, which has little been possible in domestic industries. The results can be applied in many fields such as proof testing, acceptance testing, and estimating assurance periods.

• Food Science of Animal Resources
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• v.29 no.6
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• pp.673-679
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• 2009

To develop ready-to-eat (RTE) style Korean traditional Galbi-jjim, the optimal conditions for sous-vide cooking and cookchill preparation and the sensory properties of the cooked products were investigated. During heating, the meat core temperatures reached $85^{\circ}C$ within 30 min and 45 min when a water bath and combination oven were used, respectively. Chilling to $3^{\circ}C$ within 45 min was conducted to meet the standards for microbiological safety set by the UK Department of Health and Social Security (DHSS) Guideline. Galbi-jjim that was vacuum-cooked in a water bath was much more tender than that of Galbi-jjim prepared using the cook-chill method, but had no difference in any reheating methods. The average sensory scores of juiciness and the overall acceptance of Galbi-jjim were significantly higher when water bath cooking was used, and there were no differences in reheating methods. In conclusion, the serial methods of sous-vide processing and rapid chilling can be applied to produce RTE traditional Galbi-jjim, and this can be conducted while meeting the standards specified in safety guidelines.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.414-422
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• 2022

Presented in this paper is a methodology for combining a Bayesian statistical approach with Data Quality Objectives (a structured decision-making method) to provide increased levels of confidence in analytical data when approaching a waste boundary. Development of sampling and analysis plans for the characterisation of radioactive waste often use a simple, one pass statistical approach as underpinning for the sampling schedule. Using a Bayesian statistical approach introduces the concept of Prior information giving an adaptive sample strategy based on previous knowledge. This aligns more closely with the iterative approach demanded of the most commonly used structured decision-making tool in this area (Data Quality Objectives) and the potential to provide a more fully underpinned justification than the more traditional statistical approach. The approach described has been developed in a UK regulatory context but is translated to a waste stream from the Fukushima Daiichi Nuclear Power Station to demonstrate how the methodology can be applied in this context to support decision making regarding the ultimate disposal option for radioactive waste in a more global context.

• Proceedings of the KSRS Conference
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• v.2
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• pp.797-799
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• 2006

The Electro-optical camera subsystem as a payload of a satellite system consists of OM (optical module) and CEU(camera electronics unit), and most performances of the camera subsystem depend a lot on the CEU in which TDI CCDs(Time Delayed Integration Charge Coupled Device) take the main role of imaging by converting the light intensity into measurable voltage signal. Therefore it is required to specify and design the CEU very carefully at the early stage of development with overall specifications, design considerations, calibration definition, test methods for key performance parameters. This paper describes the overview of CEU development. It lists key requirement characteristics of CEU hardware and design considerations. It also describes what kinds of calibration are required for the CEU and defines the test and evaluation conditions in verifying requirement specifications of the CEU, which are used during acceptance test, considering the fact that CEU performance results change a lot depending on test and evaluation conditions such as operational line rate, TDI level, and light intensity level, so on.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.445-450
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• 2003

This study was performed 10 develop the accelerated life test method using Weibull-IPL(Inverse Power Law) model for mechanical components. Weibull-IPL model is concerned with determining the assurance life with confidence level and the accelerated life test time From the relation of weibull distribution factors and confidence limit, the testing times on the no number of failure acceptance criteria arc determined. The mechanical components generally represent wear and fatigue characteristics as a failure mode. IPL based on the cumulative damage theory is applied effectively the mechanical components to reduce the testing time and to achieve the accelerating test conditions. As the actual application example, accelerated life test method of agricultural tractor transmission was described. Life distribution of agricultural tractor transmission was supposed to follow Weibull distribution and life test time was calculated under the conditions of average life (MTBF) 3,000 hours and 90% confidence level for one test sample. According to IPL, because test time call be shorten in case increase test load test time could be reduced by 482 hours when we put the load 1.1 times of rated load than 0.73 times of rated load that is equivalent load calculated by load spectrum of the agricultural tractor. This time, acceleration coefficient was 11.7.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.3
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• pp.261-270
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• 2021

This study was conducted to optimize the processing of seasoned salmon Oncorhynchus keta jerky (SSJ) using response surface methodology (RSM). For seasoning sauces-blending conditions of jerky using the RSM program, salt [X₁, % (w/v)] and amino-basic material [X₂, % (w/v)] were chosen as independent variables, and salinity (Y₁) and amino-N (Y₂) were chosen as dependent variables. The optimum conditions of X₁ and X₂ were 1.2% and 12.9%, respectively. To optimize drying conditions of seasoned salmon jerky using RSM program, soaking time (X₁, min), drying temperature (X₂, ℃) and drying time (X₃, min) were chosen as independent variables, and moisture content (Y₁), hardness (Y₂) and overall acceptance (Y₃) were chosen as dependent variables. Optimum conditions of X₁, X₂ and X₃ were 183.0 min, 62.5℃ and 351.0 min, respectively. In the sensory evaluation, the scores for taste, flavor, and texture for of SSJ were higher than those for a commercial product. The results suggest that the developed seasoned salmon jerky can be industrialized.

• Proceedings of the IEEK Conference
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• summer
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• pp.355-360
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• 2004

With the growing acceptance of XML technologies, XML will be the most common tool for all data manipulation and data transmission. Meeting security requirements for privacy, confidentiality and integrity is essential in order to move business online and it is important for security to be integrated with XML solutions. Many policies require certain conditions to be satisfied and actions to be performed before or after a decision is made. Binary yes/no decision to an access request is not enough for many applications. These issues were addressed and formalized as provisions and obligations by Betti et Al. In this paper, we propose an authorization model with provisions and obligations in XML. We introduce a formal definition of authorization policy and the issues involving obligation discussed by Betti et Al. We use the formal model as a basis to develop an authorization model in XML. We develop DTDs in XML for main components such as authorization request, authorization policy and authorization decision. We plan to develop an authorization system using the model proposed.

• Asia pacific journal of information systems
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• v.34 no.2
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• pp.620-634
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• 2024

Recently, active research has been conducted on the metaverse as a new education platform. However, only a few studies analyze the specific characteristics of this platform from potential users' perspectives. Therefore, based on literature reviews and expert surveys on education, this study specifies the attributes and levels to be considered in developing metaverse education platforms. An online survey was conducted among university students in South Korea, and conjoint analysis was performed to propose the conditions for education platforms optimized for university education. The results revealed that 85% of respondents were willing to use metaverse education platforms, and preferred virtual classrooms that enable indirect experience in a web-based personal computer environment. In particular, the respondents showed a high preference for the education platforms that were available at $5 per month and used newly created three-dimensional avatar characters of themselves. This study is significant since its results have strategic implications for expanding the metaverse's use as a new educational space.

• Journal of Radiation Industry
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• v.17 no.4
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• pp.501-508
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• 2023

There are various factors that have a negative impact on safety over a long period of time after the closure of a radioactive waste disposal facility. In particular, it is important to limit substances that accelerate radionuclide migration while inhibiting adsorption between radionuclides and the subsurface medium. Through this study, a method for deriving a quantitative criteria evaluation method is proposed for cellulose among materials that accelerate the movement of these radionuclides after closure of the disposal facility. Since Sweden's SKB is representative worldwide for preparing criteria for cellulose in disposal facilities, it analyzed Sweden's acceptance criteria method and presented a method that can be applied domestically. The decomposition characteristics of cellulose and the adsorption and dissolution characteristics of ISA among degradation products were reviewed, and quantitative analysis of cement materials that create a high pH environment favorable for cellulose decomposition was also included. In addition, the total amount of the finally disposable cellulose material can be derived by using the volume information of the waste containing the cellulose material. Through this methodology for calculating the total amount of cellulose, it is expected that subsequent studies will be conducted to secure data reflecting the environmental conditions of radioactive waste disposal facilities in Korea. In addition, it is expected to be utilized as a good method to evaluate the impact of other complexing agents other than cellulose and to suggest the amount of disposal.

• The Korean Journal of Food And Nutrition
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• v.30 no.3
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• pp.560-567
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• 2017

In this study, we investigated the quality characteristics and optimum conditions of porridge containing rice incubated with Phellinus linteus mycelium (PLMR). Composition measurements of PLMR were moisture 13.05%, ash 0.88%, carbohydrate 78.65%, crude protein 6.29%, and crude lipid 1.13%, also glutinous rice composition was moisture 13.99%, ash 0.32%, carbohydrate 77.18%, crude protein 7.85%, and crude lipid 0.66%. The water absorption rate of PLMR increased with increasing soaking time during 6 hours. However, the water absorption rate of glutinous rice increased until 30 minutes of soaking time. The pH of porridge was decreased as PLMR contents increased. The viscosity of porridge was increased as PLMR contents increased, and it was the lowest for the control at 914.77 cP. However, spreadability of porridge was decreased as PLMR contents increased. In terms of color, lightness was the highest for the 50% level, redness was the highest for the 75% level, and yellowness was the highest for the 25% level. In terms of textural characteristics, hardness and fracturability were increased as PLMR contents increased, whereas springiness, cohesiveness and resilience showed reverse results. In terms of consumer acceptance, flavor, appearance, viscosity, delicate taste, and overall acceptability were not significantly different between samples. Hot taste was decreased as PLMR contents increased, whereas grittiness showed reverse results. In conclusion, the results indicate that adding 25~50% PLMR to porridge is optimal for a recipe.