• Advances in aircraft and spacecraft science
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• v.4 no.5
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• pp.585-611
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• 2017

This article covenants with the post buckling witticism of carbon nanotube reinforced composite (CNTRC) beam supported with an elastic foundation in thermal atmospheres with arbitrary assumed random system properties. The arbitrary assumed random system properties are be modeled as uncorrelated Gaussian random input variables. Unvaryingly distributed (UD) and functionally graded (FG) distributions of the carbon nanotube are deliberated. The material belongings of CNTRC beam are presumed to be graded in the beam depth way and appraised through a micromechanical exemplary. The basic equations of a CNTRC beam are imitative constructed on a higher order shear deformation beam (HSDT) theory with von-Karman type nonlinearity. The beam is supported by two parameters Pasternak elastic foundation with Winkler cubic nonlinearity. The thermal dominance is involved in the material properties of CNTRC beam is foreseen to be temperature dependent (TD). The first and second order perturbation method (SOPT) and Monte Carlo sampling (MCS) by way of CO nonlinear finite element method (FEM) through direct iterative way are offered to observe the mean, coefficient of variation (COV) and probability distribution function (PDF) of critical post buckling load. Archetypal outcomes are presented for the volume fraction of CNTRC, slenderness ratios, boundary conditions, underpinning parameters, amplitude ratios, temperature reliant and sovereign random material properties with arbitrary system properties. The present defined tactic is corroborated with the results available in the literature and by employing MCS.

• Structural Engineering and Mechanics
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• v.66 no.6
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• pp.729-736
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• 2018

This paper studies thermal buckling and post-buckling behaviors of functionally graded materials (FGM) tubes subjected to a uniform temperature rise and resting on elastic foundations via a refined beam model. Compared to the Timoshenko beam theory, the number of unknowns of this model are the same and no correction factors are required. The material properties of the FGM tube vary continuously in the radial direction according to a power function. Two ends of the tube are assumed to be simply supported and in-plane boundary conditions are immovable. Energy variation principle is employed to establish the governing equations. A two-step perturbation method is adopted to determine the critical thermal buckling loads and post-buckling paths of the tubes with arbitrary radial non-homogeneity. Through detailed parametric studies, it can be found that the tube has much higher buckling temperature and post-buckling strength when it is supported by an elastic foundation.

• Structural Engineering and Mechanics
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• v.67 no.6
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• pp.617-628
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• 2018

This paper deals with the maximization of the critical buckling load of simply supported antisymmetric angle-ply plates resting on Pasternak foundation subjected to compressive loads using teaching learning based optimization method (TLBO). The first order shear deformation theory is used to obtain governing equations of the laminated plate. In the present optimization problem, the objective function is to maximize the buckling load factor and the design variables are the fibre orientation angles in the layers. Computer programming is developed in the MATLAB environment to estimate optimum stacking sequences of laminated plates. A comparison also has been performed between the TLBO, genetic algorithm (GA) and differential evolution algorithm (DE). Some examples are solved to show the applicability and usefulness of the TLBO for maximizing the buckling load of the plate via finding optimum stacking sequences of the plate. Additionally, the influences of different number of layers, plate aspect ratios, foundation parameters and load ratios on the optimal solutions are investigated.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.3
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• pp.181-190
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• 2009

Module is an object file that can be loaded into operating system dynamically and has complete privileged access to all resources in kernel. Therefore trivial misuses in a module may cause critical system halts or deadlock situations. In this paper, we propose Kernel Resource Protector(KRP) scheme to reduce the various problems caused by module. KRP provides protections of a variety of kernel resources such as memory, major number and work queue resource. We implement the scheme onto linux kernel 2.6.18, and experimental results show that our scheme can protect kernel resources effectively.

• Journal of Information Technology Services
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• v.17 no.2
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• pp.207-218
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• 2018

Recently, it becomes a big trend in the banking industry to apply a big data analytics technique to extract essential knowledge from their customer database. Such a trend is based on the capability to analyze the big data with powerful analytics software and recognize the value of big data analysis results. However, there exits still a need for more systematic theory and mechanism about how to adopt a big data analytics approach in the banking industry. Especially, there is no study proposing a practical case study in which big data analytics is successfully accomplished from the marketing perspective. Therefore, this study aims to analyze a target marketing case in the banking industry from the view of big data analytics. Target database is a big data in which about 3.5 million customers and their transaction records have been stored for 3 years. Practical implications are derived from the marketing perspective. We address detailed processes and related field test results. It proved critical for the big data analysts to consider a sense of Veracity and Value, in addition to traditional Big Data's 3V (Volume, Velocity, and Variety), so that more significant business meanings may be extracted from the big data results.

• Journal of Information Technology Services
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• v.19 no.5
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• pp.15-31
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• 2020

This study explores the process in which employees adopt the information security policy. The results of this study, which surveyed 234 employees in three call centers and four hospitals, show that the employees adapt the information security policy through the social structuring process suggested by the AST model. In particular, this study identifies roles of two appropriation activities (FOA : Faithfulness of Appropriation & COA : Consensus on Appropriation) observed in the social structuring process. Regarding to the interactions between the two appropriation activities, FOA, which indicates a better understanding of the information security policy, is examined as a more critical factor than COA, which indicates the degree of agreement among employees about how to use it. FOA not only has a direct effect on compliance intention toward the information security policy, but also indirectly through COA, whereas COA has only a indirect effect through FOA. This result shows that, in order for a company to successfully implement a new information security policy, it is important for employees to understand its purpose and intention. The adaption of information security policy through two appropriation activities is observed in both hospitals and call centers, but due to the different working environments, there were differences in the preceding variables affecting the appropriation activities. The results of this study are expected to provide guidelines for companies who want to successfully adopt information security policy.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.1_2
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• pp.112-117
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• 2004

In this paper, we propose a suitable multiplication architecture for cellular automata in a finite field $GF(2^m)$. Proposed least significant bit first multiplier is based on irreducible all one Polynomial, and has a latency of (m+1) and a critical path of $ 1-D_{AND}＋1-D{XOR}$.Specially it is efficient for implementing VLSI architecture and has potential for use as a basic architecture for division, exponentiation and inverses since it is a parallel structure with regularity and modularity. Moreover our architecture can be used as a basic architecture for well-known public-key information service in $GF(2^m)$ such as Diffie-Hellman key exchange protocol, Digital Signature Algorithm and ElGamal cryptosystem.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.224-228
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• 2007

It is focused on a methodology to establish a optimal inspection cycle of electrical facility of railroad Decision method of optimal inspection cycle is a process which establishes maintenance plan for facilities' immanent function as using reliability theory in operation term In order to ensure normal operation in a given condition, the decision method is logical for selecting effective maintenance plan to consider characteristic of system In estimation of failure rate, critical facility is selected firstly. After that, proper distribution function on each facility is decided to investigate distribution function for extraction of failure rate. Next, cost produced by the case that facility's failure is occurred is surveyed. Finally, maintenance method developed until now is investigated, before suitable model for the facility applying maintenance method is developed, and that maintenance decision is made. Therefore, this process is the method to find optimal inspection cycle for reasonable cost and effective reliability on facility.

• Knowledge Management Research
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• v.14 no.5
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• pp.101-120
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• 2013

The effective management of knowledge has become one of the critical success factors in current organizations. In spite of the extensive use of Knowledge Management System (KMS), useful information and knowledge resources are still transmitted through personal networks among people in organizations. Thus, social network theory which focuses on social relationships in organization can be a fruitful theoretical resource for enhancing Knowledge Management (KM) performances. In this study, we investigate the effects of intra-team network characteristics (i.e., group density and degree of centralization) and external boundary spanning activities on knowledge management performances of a team. We also acknowledge that all group members do not necessarily agree on the team goal and actively disseminate useful information and knowledge. Drawing on the political perspective on KM which emphasizes the role of trust among group members, we examine the mediating effects of team trust between internal/external network characteristics and KM performances. From the data of 220 teams in financial companies in Korea, we found that: (1) group density had positive effects on KM performances (i.e., knowledge creation, sharing, and use). (2) However, centralization was not significantly associated with KM performances. (3) Team trust was found to be an important factor mediating the relationship between intra-team network characteristics, boundary spanning activities, and KM performances. Based on these results, we discuss and suggest possible implications of the findings when designing and implementing KM practices.

• Bulletin of the Korean Mathematical Society
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• v.55 no.1
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• pp.267-296
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• 2018

This paper studies the Cauchy problem and blow-up phenomena for a new generalized Camassa-Holm equation with cubic nonlinearity in the nonhomogeneous Besov spaces. First, by means of the Littlewood-Paley decomposition theory, we investigate the local well-posedness of the equation in $B^s_{p,r}$ with s > $max\{{\frac{1}{p}},\;{\frac{1}{2}},\;1-{\frac{1}{p}}\},\;p,\;r{\in}[0,{\infty}]$. Second, we prove that the equation is locally well-posed in $B^s_{2,r}$ with the critical index $s={\frac{1}{2}}$ by virtue of the logarithmic interpolation inequality and the Osgood's Lemma, and it is shown that the data-to-solution mapping is $H{\ddot{o}}lder$ continuous. Finally, we derive two kinds of blow-up criteria for the strong solution by using induction and the conservative property of m along the characteristics.