• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.974-987
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• 2021

This paper presents ductile fracture simulation of full-scale cracked pipe for nuclear piping materials using the cohesive zone model (CZM). The main objective of this study is to investigate the applicability of CZM to predict ductile fracture of cracked pipes with various crack shapes and under quasi-static/dynamic loadings. The transferability of the traction-separation (T-S) curve from a small-scale specimen to a full-scale pipe is demonstrated by simulating small- and full-scale tests. T-S curves are calibrated by comparing experimental data of compact tension specimens with finite element analysis results. The calibrated T-S curves are utilized to predict the fracture behavior of cracked pipes. Three types of full-scale pipe tests are considered: pipe with circumferential through-wall crack under quasistatic/dynamic loadings, and with 360° internal surface crack under quasi-static loading. Computational results using the calibrated T-S curves show a good agreement with experimental data, demonstrating the transferability of the T-S curves from small-scale specimen.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.235-235
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• 2012

The "Widefield ASKAP L-band Legacy All-sky Blind surveY" (WALLABY) is an extragalactic HI survey which aims to examine HI properties and large-scale distribution of ~500,000 galaxies out to z ~ 0.27, covering a wide range of science goals associated with galaxy formation and evolution (P.I.: B. Koribalski & L. Staveley-Smith). The combination of ASKAP's exquisite column density sensitivity and a large primary beam will make it possible to systematically investigate the rarely explored low column-density HI in the universe. Ultimately, the largest and most homogeneous data set from WALLABY will drastically improve and broaden our knowledge on galaxy formation and evolution. ASKAP will be on-line in 2013, so to ensure timely and efficient reduction and analysis of the large WALLABY data set, we have been developing and testing reliable source finding tools and data analysis pipelines. In this talk I present recent progress of WALLABY, especially on the kinematic parameterisation pipeline for the spatially resolved galaxies detected by WALLABY.

• Electronics and Telecommunications Trends
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• v.14 no.4 s.58
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• pp.1-9
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• 1999

In this paper, we summarize the lessons learned from the applications of the software reliability engineering to a large-scale software project. The considered software is the software system of the TDX-10 ISDN switching system. The considered software consists of many components, called functional blocks. These functional blocks serve as the unit of coding and test. The software is continuing to be developed by adding new functional blocks. We are mainly concerned with the analysis of the effects of these software components to software reliability and with the analysis of the reliability evolution. We analyze the static characteristics of the software related to software reliability using failure data collected during system test. We also discussed a pattern which represents a local and global growth of the software reliability as version evolves. To find the pattern of software of the TDX-10 ISDN system, we apply the S-shaped model to a collection of failure data sets of each evolutionary version and the Goel-Okumoto (G-O) model to a grouped overall failure data set. We expect this pattern analysis will be helpful to plan and manage necessary human/resources for a new similar software project which is developed under the same developing circumstances by estimating the total software failures with respect to its size and time.

• Journal of Korea Multimedia Society
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• v.12 no.10
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• pp.1457-1465
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• 2009

In MMORPG development process, spreadsheet based data management has advantages in the handling of functions and analysis of large data set. But it has limitations in inserting, deleting, searching and relational management of that. In this paper, we proposed the spreadsheet based tool model for large data set for MMORPG development. Our system can reduce the risk of data management failure in MMORPG development process and improve the efficiency of data handling in the large-scale team.

• Journal of Distribution Science
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• v.12 no.11
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• pp.55-65
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• 2014

Purpose - This study aims to investigate the process of political changes in Japan, which has introduced regulatory policies for large-scale retail stores since the 1930s, as well as the examples, and suggests improvement schemes for our policies in Korea, which imposes restrictions on business hours and forced holidays in accordance with the current Distribution Industry Development Act. Research design, data, and methodology - After examining the political change processes related to large-scale retail stores in japan, this study analyzes individually regulated cases based on the ordinances enacted by each local government. Through case analysis in Japan, this study makes political suggestions that may be helpful for our country substantially. Results - Since there is an obvious possibility that our economic restrictions on business hours and mandatory holidays do not coincide with WTO GATS, it is necessary for large-scale distributors to introduce new social and environmental regulations similar to Japan, rather than imposing controls to restrict free competition and also introduce a policy to induce cooperation with small businesses for the advancement of the distribution industry. Thus, it is desirable to take measures on noise, waste, traffic, and parking for the preservation of the living environment in the surroundings when building new large-scale retail stores. It is also important to establish measures to improve the welfare of neighborhood residents and consumers, create a pleasant urban environment, and make it mandatory to make presentations at public hearings among residents. Furthermore, it should be mandatory to establish regional contribution plans when a retail store is established, and take measures to solve various civil complaints or problems that may occur after entering the market. Moreover, it is desirable for large-scale retail stores that entered the market to induce cooperation in performing various activities in the area with a strong sense that they are all members of the local economy. Conclusions - If introducing social regulations like in Japan, there is probably an advantage that the conflicts seen when large-scale retail stores enter the market are absorbed by adjusting the persons concerned within the established institution in order to establish a field to solve such conflicts systematically. In contrast, there are still concerns regarding chaotic operation without any active attempts to have a conversation with large-scale retail stores and local small merchants due to a sharp conflict among the persons concerned, and if it is a briefing session without any decision of the restrictions on their opening itself, there may be doubts with regard to their effectiveness. Moreover, if the de facto opening is restricted by the introduction of such a briefing session procedure, the choice of whether to protect the existing rights of large-scale retail stores might become problematic. However, such problems could be minimized in a way by forming a separate consultative group for all persons concerned including residents, local governments, professionals, civic organizations, small merchants, and massive retail store-related persons.

• Journal of the Korean Society of Safety
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• v.29 no.4
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• pp.42-47
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• 2014

This paper is aimed to investigate and analyze of characteristic for electrical equipment and work environment for the small-scale site. In order to investigate and analyze electrical equipment and work environment for preventing electric shock disaster in construction sites, 50 small-scale construction sites and 12 large-scale construction sites are selected. This paper completed site investigations of low-voltage equipment and the portable electric machine and equipment in 12 large-scale construction sites and 50 small-scale construction sites. The findings were about the electric shock environment relevant to the ground-relevant equipment, the panel board, the protection tools, the sockets, the temporary wiring system, the portable and movable electric machines and equipments in small-scale construction sites. Finally, this study analyzed the domestic and foreign relevant standards and regulations and these findings can be utilized as educational data warning electric shock risk caused by electric equipment in small-scale construction site.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.8
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• pp.726-732
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• 2016

Clustering analysis is widely used in data mining to classify data into categories on the basis of their similarity. Through the decades, many clustering techniques have been developed, including hierarchical and non-hierarchical algorithms. In gene profiling problems, because of the large number of genes and the complexity of biological networks, dimensionality reduction techniques are critical exploratory tools for clustering analysis of gene expression data. Recently, clustering analysis of applying dimensionality reduction techniques was also proposed. PCA (principal component analysis) is a popular methd of dimensionality reduction techniques for clustering problems. However, previous studies analyzed the performance of PCA for only full data sets. In this paper, to specifically and robustly evaluate the performance of PCA for clustering analysis, we exploit an improved FCBF (fast correlation-based filter) of feature selection methods for supervised clustering data sets, and employ two well-known clustering algorithms: k-means and k-medoids. Computational results from supervised data sets show that the performance of PCA is very poor for large-scale features.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.1
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• pp.94-100
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• 2010

Data Mining is mainly used for pattern extracting and information discovery from collected data. However previous methods is difficult to reflect changing patterns with time. In this paper, we introduce Streaming Decision Tree(SDT) analyzing data with continuity, large scale, and changed patterns. SDT defines continuity data as blocks and extracts rules using a Decision Tree's learning method. The extracted rules are combined considering time of occurrence, frequency, and contradiction. In experiment, we applied time series data and confirmed resonable result.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.8
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• pp.1915-1925
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• 1998

The switching system software is large scale, real-time multi-task system which requires high reliability. The reliability assessment of large-scale software is very important for the success of software development project. For this raeson, the software quality measurement is much more important. In this paper, we have learned about the software reliability, metho of the analysis of failure data and estimation of software quality. To estimate the software reliability, using the failure data found during of the system test. We apply the two software reliability growth models, named Goel-Okumoto(G-O) and S-shaped model, to estimate the software reliability. Also, we compared with the results and we reviewed fully not only development cycle but validation and verification of the test data, for each software versions. This paper presents a software reliability model that suitale the software development project and the activeity of quality control for the switching system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.4
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• pp.735-741
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• 2009

This paper presents an algorithm for the permanent magnet shape optimization of a large scale BLDC(Brushless DC) motor to minimize the cogging torque. A response surface method (RSM) using multiquadric radial basis function is employed to interpolate the objective function in design parameter space. In order to get a reasonable response surface with relatively small number of sampling data points, additional sampling points are added on the basis of design sensitivity analysis computed by using FEM. The algorithm has 2 stages: the first stage is to determine the PM arc angle, and the 2nd stage is to optimize the magnet pole shape. The developed algorithm is applied to a 5MW BLDC motor to get a minimum cogging torque. After 3 iterations with 4 design parameters, the cogging torque is reduced to 13.2% of the initial one.