• Nuclear Engineering and Technology
• /
• v.16 no.3
• /
• pp.169-179
• /
• 1984

An efficient procedure of evaluating the fuel cladding failures occurring in the normal operations of typical PWR's has been investigated through the analysis of fission product(FP) activities in the reactor coolant using an analytical model, FIPREL code. Performed by this code is an extensive study on the sensivities of FP activities to such physical parameters as enrichment, turnup, and operation temperature of failed fuel rod as well as the effective failure size quantified in terms of the magnitude of gap release coefficient. The results of study are generally in agreement with those by PROFIP method. In the presence of tramp uranium the portion of activities released from failed rod is separated by an iterative calculation based on the activity ratios of fission nuclides chemically more stable than iodines. Obtained are the linear power density and the number of failed rods, the effective failure size, and the mass of tramp uranium. The operation experiences of 4 cycles of Kori Unit 1 are analyzed and the results show that the model is highly reliable for the survey and evaluation of fuel rod conditions during reactor operations.

• Korean Journal of Hazardous Materials
• /
• v.6 no.2
• /
• pp.1-6
• /
• 2018

The use of chemicals to enhance and improve life is a widespread practice worldwide. But alongside the benefits of these products, there is also the potential for adverse effects to people or the environment. Thus, If anyone handles hazardous chemicals, they should adhere to specific criteria for hazardous chemicals. This study used hazard statement(H-code) and precautionary statement(P-code) to set specific criteria for handling chemicals. According to the UN GHS, hazard statement means a statement assigned to a hazard class and category that describes. And a precautionary statement is a phrase which describes recommended measures that should be taken to minimize or prevent adverse effects resulting from exposures to a hazardous product, or improper storage or handling of a hazardous product. The study suggests the treatment criteria(Public Notice) of 785 types of hazardous chemicals managed by the Chemical Control Act.

• Fashion & Textile Research Journal
• /
• v.24 no.1
• /
• pp.117-126
• /
• 2022

This study aims to analyze the sizing information of women's ready-to-wear pants as indicated on online retail websites and to suggest better sizing communication that can assist customers in making successful apparel size selections. We gathered size specifications and size reference information for basic straight pants from 34 online apparel retail websites. Although the Korean standard recommends labeling the body dimension-based sizing code and specification, most websites preferred to use various types of sizing codes. Body measurements were only used by a few websites, and garment dimension descriptions were the most common method to indicate product size. Many websites provided size reference information through customer review boards and fit model images, however, there was insufficient body size information to allow customers to infer the fit of their body type. When using the size guidance tools, the major data input points were stature and weight measurements. However, the waist measurements of pants sizes guided only by stature and weight values revealed inconsistent ease allowance for corresponding body size populations, especially in the overweight group. Based on our findings, we propose a more effective method of communicating the size information of pants online. We expect that this will contribute to the efficiency of online apparel product display and build a better shopping environment that satisfies both sellers and consumers.

• Journal of KIISE:Software and Applications
• /
• v.31 no.8
• /
• pp.1010-1026
• /
• 2004

The goal of product line engineering is to support the systematic development of a set of similar software systems by understanding and controlling their common and distinguishing characteristics. The product line engineering is a process that develops reusable core assets and develops a set of software-intensive systems from a common set of core assets in a prescribed way. Currently, many software development technologies are accomplished in context of product line. However, much of the product line engineering research have focused on the reuse of work products relating to the software's architecture, detail design, and code. The product lines fulfill the promise of tailor-made systems built specifically for the needs of particular customers or customer groups. In particular, commonality and variability play central roles in the all product line development processes. These must be treated already during the requirement analysis phase. Requirements in product line engineering are basis of software development just like as traditional system development engineering, and basis of deciding other core assets' property - commonalities and variabilities. However, it is difficult to elicit, analyze and manage correct requirements. Therefore, it is necessary to develop systematic methods which can develop and manage requirement as core asset, which can be stable in anticipative change and can be well adapted to unpredictable change. In this paper, we suggest a method of managing requirements as core asset in product line. Through this method, the reuse of domain requirements can be enhanced. As a result, the cost and time of software development can be reduced and the productivity can be increased.

• The KIPS Transactions:PartD
• /
• v.12D no.1 s.97
• /
• pp.165-178
• /
• 2005

A product classification scheme is the foundation on which product databases are designed, and plays a central role in almost all aspects of management and use of product information. It needs to meet diverse user views to support efficient and convenient use of product information. It needs to be changed and evolved very often without breaking consistency in the cases of introduction of new products, extinction of existing products, class reorganization, and class specialization. It also needs to be merged and mapped with other classification schemes without information loss when B2B transactions occur. For these requirements, a classification scheme should be so dynamic that it takes in them within right time and cost. The existing classification schemes widely used today such as UNSPSC and eCl@ss, however, have a lot of limitations to meet these requirements for dynamic features of classification. Product information implies a plenty of semantics such as class attributes like material, time, place, etc., and integrity constraints. In this Paper, we analyze the dynamic features of product databases and the limitation of existing code based classification schemes, and describe the semantic classification model proposed in [1], which satisfies the requirements for dynamic features of product databases. It provides a means to explicitly and formally express more semantics for product classes and organizes class relationships into a graph.

• Journal of the Korean Institute of Gas
• /
• v.17 no.2
• /
• pp.50-58
• /
• 2013

Various process piping usually carries out high flammable and explosible gas under high pressure and high temperature. Due to frequent change of design and structure it becomes more complicated and compactly located. The safety management level is relatively low since it is considered as simply designed component. In this study a safety assessment procedure is proposed for complicated piping system around a mixing drum in which natural gas and by-product gases were mixed. According to ASME code, pipe stress analysis was conducted for determining design margin at some key locations of the piping. These high stress locations can be used as major inspection points for managing the pipe integrity. Sensitivity analysis with outside temperature of the pipe and support constraint condition. Possible effect of hydroen gas to the pipe steel during the previous use of the by-product gas was also discussed.

• The KIPS Transactions:PartD
• /
• v.13D no.4 s.107
• /
• pp.593-602
• /
• 2006

Software development methodology has been developed for satisfying goals of improvement in productivity and reduction in time-to-market through the reuse of software assets. The current methods that implement software product-line, one of software development methodologies, interfere massively with the core assets, which require high cost in assembly level reducing the effectiveness. In this paper, we introduce Aspect-Oriented Programming (AOP) as a method for improving assembly process in software product-line. The method that assembles core assets and variabilities is described by grammar elements such as Join point, pointcut and advice without code-change. We analyze requirements of a mini-system as an example adapting AOP and design using UML. Our study implements the variabilities, which are from design stage, using an Aspect-Oriented Programming Language, AspectJ and prove usability and practicality by implementing the proposed idea using an Aspect-Oriented Programming Language, AspectJ.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.10C
• /
• pp.936-941
• /
• 2003

Density evolution was developed as a method for computing the capacity of low-density parity-check(LDPC) codes under the sum-product algorithm [1]. Based on the assumption that the passed messages on the belief propagation model can be approximated well by Gaussian random variables, a modified and simplified version of density evolution technique was introduced in [2]. Recently, the min-sum algorithm was applied to the density evolution of LDPC codes as an alternative decoding algorithm in [3]. Next question is how the min-sum algorithm is combined with a Gaussian approximation. In this paper, the capacity of various rate LDPC codes is obtained using the min-sum algorithm combined with the Gaussian approximation, which gives a simplest way of LDPC code analysis. Unlike the sum-product algorithm, the symmetry condition [4] is not maintained in the min-sum algorithm. Therefore, the variance as well as the mean of Gaussian distribution are recursively computed in this analysis. It is also shown that the min-sum threshold under a gaussian approximation is well matched to the simulation results.

• Journal of Positioning, Navigation, and Timing
• /
• v.1 no.1
• /
• pp.7-14
• /
• 2012

Due to inaccurate safe navigation estimates, maritime accidents have been occurring consistently. In order to solve this, the precise positioning technology using carrier phase information is used, but due to high buildings near inland waterways or inclination, satellite signals might become weak or blocked for some time. Under this weak signal environment for some time, the GPS raw measurements become less accurate so that it is difficult to search and maintain the integer ambiguity of carrier phase. In this paper, a method to generate code and carrier phase measurements under this environment and maintain resilient navigation is proposed. In the weak signal environment, the position of the receiver is estimated using an inertial sensor, and with this information, the distance between the satellite and the receiver is calculated to generate code measurements using IGS product and model. And, the carrier phase measurements are generated based on the statistics for generating fractional phase. In order to verify the performance of the proposed method, the proposed method was compared for a fixed blocked time. It was confirmed that in case of a weak or blocked satellite signals for 1 to 5 minutes, the proposed method showed more improved results than the inertial navigation only, maintaining stable positioning accuracy within 1 m.

• 전자공학회논문지 IE
• /
• v.44 no.2
• /
• pp.14-20
• /
• 2007

This paper presents quaternary D flip-flop with advanced performance. Quaternary D flip-flop is composed of the components such as thermometer code output circuit, EX-OR gate, bias inverter, transmission gate and binary D flip-flop circuit. The designed circuit is simulated by HSPICE in $0.35{\mu}m$ one-poly six-metal CMOS process parameters with a single +3.3V supply voltage. In the simulations, sampling frequencies is measured around 100MHz. The PDP parameters and FOM we estimated to be 59.3fJ, 33.7 respectively.