• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.2
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• pp.205-213
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• 1987

A linear thermoviscoelastic material model, whose basis is on incremental constitutive equation that takes complete strain and temperature histories into account, is derived and computerized in the finite element code. The thermoviscoelastic F.E.M. code which is intended primarily to analyze the cylinder model during the cool-down period, embodies the assumption of linearly elastic bulk and visco-elastic shear responses, thermo-rheologically simple response to temperature change and isotropic thermal expansion. The verification of computer program is accomplished by first testing it against a closed form solution of A.M. Freudenthal & M. Shinozuka's. The stress and strain analyses of five cylindrical models are presented and compared with experimental results. Analytical results are good agreement with experimental results. Margins of safety are evaluated and its allowable ranges are presented.

• Ocean Systems Engineering
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• v.12 no.3
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• pp.359-384
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• 2022

We develop in this work a new well-balanced preserving-positivity path-conservative central-upwind scheme for Saint-Venant-Exner (SVE) model. The SVE system (SVEs) under some considerations, is a nonconservative hyperbolic system of nonlinear partial differential equations. This model is widely used in coastal engineering to simulate the interaction of fluid flow with sediment beds. It is well known that SVEs requires a robust treatment of nonconservative terms. Some efficient numerical schemes have been proposed to overcome the difficulties related to these terms. However, the main drawbacks of these schemes are what follows: (i) Lack of robustness, (ii) Generation of non-physical diffusions, (iii) Presence of instabilities within numerical solutions. This collection of drawbacks weakens the efficiency of most numerical methods proposed in the literature. To overcome these drawbacks a reformulation of the central-upwind scheme for SVEs (CU-SVEs for short) in a path-conservative version is presented in this work. We first develop a finite-volume method of the first order and then extend it to the second order via the averaging essentially non oscillatory (AENO) framework. Our numerical approach is shown to be well-balanced positivity-preserving and shock-capturing. The resulting scheme could be seen as a predictor-corrector method. The accuracy and robustness of the proposed scheme are assessed through a carefully selected suite of tests.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.11
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• pp.3204-3217
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• 2023

In this paper, the downlink of the multicast based spatial modulation systems is investigated. Specifically, physical layer multicasting is introduced to increase the number of access users and to improve the communication rate of the spatial modulation system in which only single radio frequency chain is activated in each transmission. To minimize the bit error rate (BER) of the multicast based spatial modulation system, a joint optimizing algorithm of antenna selection and multicast precoding is proposed. Firstly, the joint optimization is transformed into a mixed-integer non-linear program based on single-stage reformulation. Then, a novel iterative algorithm based on the idea of branch and bound is proposed to obtain the quasioptimal solution. Furthermore, in order to balance the performance and time complexity, a low-complexity deflation algorithm based on the successive convex approximation is proposed which can obtain a sub-optimal solution. Finally, numerical results are showed that the convergence of our proposed iterative algorithm is between 10 and 15 iterations and the signal-to-noise-ratio (SNR) of the iterative algorithm is 1-2dB lower than the exhaustive search based algorithm under the same BER accuracy conditions.

• Journal of KIISE
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• v.44 no.8
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• pp.832-841
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• 2017

Bug reports are essential documents for developers to localize and fix bugs. These reports contain information regarding software bugs or failures that occur during software operation and maintenance phase. Information Retrieval-based Bug Localization (IR-BL) techniques have been proposed to reduce the time and cost it takes for developers to resolve bug reports. However, if a low-quality bug report is submitted, the performance of such techniques can be significantly degraded. To address this problem, we propose a quality prediction method that selects low-quality bug reports. This process; defines a Quality property of a Bug report as a Query (Q4BaQ) and predicts the quality of the bug reports using machine learning. We evaluated the proposed method with 3 open source projects. The results of the experiment show that the proposed method achieved an average F-measure of 87.31% and outperformed previous prediction techniques by up to 6.62% in the F-measure. Finally, a combination of the proposed method and traditional automatic query reformulation method improved the MRR and MAP by 0.9% and 1.3%, respectively.

• Korean Journal of Agricultural Science
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• v.40 no.2
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• pp.131-137
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• 2013

The inhibitory effect of citrus peel extract, onion peel extract, calcium lactate and phosvitin on microbial growth was investigated in seasoned chicken breast meat during aerobic storage at $4^{\circ}C$, $10^{\circ}C$ and $20^{\circ}C$. Citrus peel and onion peel extract significantly improved (p<0.05) the microbial quality of the sample by reducing the initial counts of the microbial flora compared to control and other two treatments. Data clearly revealed that the counts of the total aerobic bacteria significantly increased with the increase in storage temperature. The shelf life of all samples stored under $20^{\circ}C$ was less than 6 days, while the shelf life of citrus and onion treatment can be extended more than 9 days at $4^{\circ}C$ and more than 6 days at $10^{\circ}C$ in aerobic storage condition. These results indicated that citrus and onion peel extracts are efficient treatment methods to prevent microbial spoilage of seasoned chicken products during storage at $4^{\circ}C$. However, there was an adverse effect of addition of citrus and onion peel extract on several sensory attributes which need to be improved by reformulation of seasoning.

• The Journal of the Convergence on Culture Technology
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• v.5 no.2
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• pp.111-116
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• 2019

This paper considers the historical background of the emergence of 'thinking-machine,' that has changed the ontological statue of human and machine. In particular, British mathematician Charles Babbage's Calculating Engines is examined as a material iteration of thinking-machine, focusing on the discursive process by which thought is not the faculty of human, but the function of machine. In Chapter II, I review the dualism of René Descartes who denied the possibility of machine intelligence by separating the substance of body and mind. In Chapter III, Babbage's philosophical assertions which emphasized the function of human associated with thought by rejecting the fundamental opposition between human and machine. Therefore, this paper verifies that the conception of 'thinking-machine' essentially causes the reorganization and reformulation of concepts involved with human identity, and provides the sophisticated sources to prepare new perspective on the artificial technology nowadays.

• Journal of Korea Technology Innovation Society
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• v.10 no.3
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• pp.580-603
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• 2007

This paper examines accountability trend for government supported research institutes through the analysis of what aspects of accountability have been emphasized in the institute evaluation from 1991 to 2005. We divided research period into pre-research council period(1991-1998) and post-research council period(1999-2005). In pre-research council period, we find four kinds of accountability for government supported research institutes, that is, compliance accountability for regulation, managerial accountability, performance accountability and social accountability and great emphasis has been put on compliance accountability for regulation and managerial accountability. In post-research council period, financial accountability for soundness has been added to the above four kinds of accountability and great emphasis has been put on performance accountability and managerial accountability, especially performance accountability. The concrete contents of an accountability has been also changed between pre-research council period(1991-1998) and post-research council period(1999-2005). Regulation accountability in the pre-research council period are related to conforming to government rules for institute operation and regulation defining institute function for reformulation, but in post-research council period, it has been focused on rules for the rationalization of management. Managerial accountability has been changed from emphasizing on management efficiency approximately to focusing on more specific management efficiency like the appropriateness of personnel management, the efficiency of budget management and project management, reasonableness of evaluation and compensation. Performance accountability has been changed in methods for measuring performance, in the pre-research council period, it has been taken quantitative method for measuring productivity, but, in post-research council period, qualitative approach like objective management has been complemented. Finally, accountability for government supported research institutes has been changed towards being concrete in many sided accountabilities and focusing on performance accountability.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.4678-4702
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• 2018

Traffic Matrix estimation has always caught attention from researchers for better network management and future planning. With the advent of high traffic loads due to Cloud Computing platforms and Software Defined Networking based tunable routing and traffic management algorithms on the Internet, it is more necessary as ever to be able to predict current and future traffic volumes on the network. For large networks such origin-destination traffic prediction problem takes the form of a large under- constrained and under-determined system of equations with a dynamic measurement matrix. Previously, the researchers had relied on the assumption that the measurement (routing) matrix is stationary due to which the schemes are not suitable for modern software defined networks. In this work, we present our Compressed Sensing with Dynamic Model Estimation (CS-DME) architecture suitable for modern software defined networks. Our main contributions are: (1) we formulate an approach in which measurement matrix in the compressed sensing scheme can be accurately and dynamically estimated through a reformulation of the problem based on traffic demands. (2) We show that the problem formulation using a dynamic measurement matrix based on instantaneous traffic demands may be used instead of a stationary binary routing matrix which is more suitable to modern Software Defined Networks that are constantly evolving in terms of routing by inspection of its Eigen Spectrum using two real world datasets. (3) We also show that linking this compressed measurement matrix dynamically with the measured parameters can lead to acceptable estimation of Origin Destination (OD) Traffic flows with marginally poor results with other state-of-art schemes relying on fixed measurement matrices. (4) Furthermore, using this compressed reformulated problem, a new strategy for selection of vantage points for most efficient traffic matrix estimation is also presented through a secondary compression technique based on subset of link measurements. Experimental evaluation of proposed technique using real world datasets Abilene and GEANT shows that the technique is practical to be used in modern software defined networks. Further, the performance of the scheme is compared with recent state of the art techniques proposed in research literature.

• Journal of Science and Technology Studies
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• v.1 no.1 s.1
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• pp.201-234
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• 2001

Sociology(or social science in general) is often diagnosed as in the state of 'crisis' after the collapse of socialism and the erosion of national societies because of rapid globalization. This paper introduces some recent work within science and technology studies(STS) and discusses its potentials to reinvigorate sociology. Although sociologists have rarely regarded STS as contributing to 'mainstream' issues in sociology, an increasing number of STS writers and sociologists have recently started to notice such possibilities. One main reason of this recent change is that STS is no longer merely concerned to convey substantive findings about science and technology, but instead attempts to reconstruct key notions of sociology such as 'social', 'society' and 'agency'. It is in this respect that the discussion below aims to introduce, discuss, and assess the potential contribution of some recent work of STS to sociology. In particular, it is 'actor-network theory'(ANT) that explicitly attempts to examine and suggest the ways in which STS ran help innovate sociology. One major characteristics of ANT is to impute 'agency' to things(nonhumans) unlike traditional sociology. ANT argues that if sociology studies heterogeneous relationships between humans and nonhumans instead of human relations only, it can become once again a vigorous discipline which is able to provide alternative worlds central to the basis of sociology. So this paper focuses on, not the diverse approaches of STS, the characteristics of ANT and its potential contribution to sociology. The author concludes that ANT can not only rejuvenate sociology by implicating new forms of alternative worlds but also open the possibility to contribute to the democratic reformulation of human-nonhuman relationships.