• Journal of Information Technology Applications and Management
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• v.26 no.1
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• pp.77-93
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• 2019

Recently, office workers are increasingly aware of the right to disconnect because of the pressure from strong connections with Internet messengers. In this study, we examined the reason why the perception of the right to disconnect increases and how to deal with it. This research model is that smart working and psychological attachment from work affect right to disconnect, and that open communication and gender moderate the intensity of these effects. To verify this research model, survey questionnaires were distributed to workers in smart working environments, and 400 data were collected and analyzed using Smart-PLS. As results of data analysis, it was verified that smart working and psychological attachment from work had a significant influence on right to disconnect, that open communication group had a lesser effect of psychological attachment from work on right to disconnect than closed communication group, and that women had a lesser effect of psychological attachment from work on right to disconnect than men. Organizations need to maintain a desirable level of right to disconnect in order to improve the quality of working life. But, if it is impossible, They need to change the way of communication more openly so as to absorb the burden of strong connection by Internet. And they need to perform task assignment or stress relief policy reflecting gender characteristics.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.183-193
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• 2018

The purpose of this study was to assess the implications for Daejeon's business management by analyzing the impact on the management performance of human solidarity among CEOs of small and medium venture companies in Daejeon. From 20th March to 20th May 2018, 212 questionnaires were collected from CEOs of small and medium-sized venture companies in Daejeon for this study and verified using the SPSS statistics Analysis Program. As a result, the study confirmed that the "work" and "school" connection factors have positive effects on securing government projects, improving business management, acquiring the necessary information for business growth, and securing competitiveness in 4th industrial revolution era. On the other hand, the "Region or Kin-group" connection factor does not affect the management performance. The following implications were derived fromthese studies on sustainable growth and development of business in Daejeon. First, it requires a higher level of the CEO solidarity. Second, efforts aimed at building mutual trust among CEOs in Daejeon are needed to develop close relationships and strong connections. Third, each operating association established in Daejeon needs to develop various programs for building relationships among CEOs and operate programs to increase the chances of contact.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.8
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• pp.4048-4057
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• 2013

In the composite beam subjected to the hogging moment it is very difficult to evaluate the influence of the reduction of slab stiffness due to cracks and their development on the horizontal shear behavior of shear connection. In this study, a 3D FE model is developed by which one can analyze the composite action in the composite beam subjected to the hogging moment. In this FE model, each structural member and shear connection are modeled as similar as possible to details of the composite beam. Bending behaviour, and composite action which could not be analyzed using the existing 1D or 2D FE model are investigated by the 3D model. Analysis results show that the reinforcement ratio and crack behaviour of the slab are main factors which exert a strong influence on the composite action. According to the analysis results about load-slip behavior, initial crack of slab and yielding of rebars have a influence on the slip stiffness of shear connection. The existing experimental results, that the design of partial interaction can be more efficient in designing of shear connection of the composite beams, are indirectly verified by the FE analysis.

• Journal of Korean Society of Steel Construction
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• v.26 no.1
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• pp.43-53
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• 2014

A single plate connection(SPC) consists of a plate welded to the columns and bolts connected to the beam web. The SPC is widely used for a simple shear connection of steel structure because it is easy-to-fabricated, easy-to-installed and economical. The conventional SPC is used for 2 to 12 bolts in a single vertical row. It is designed to limit the plate thickness by bolt diameter to obtain flexible and ductile connections. The design strength for eccentric shear shall be the lesser of the shear strength of bolts or bearing strength of plate and when the design strength is decided by edge distance failure, the results can be very conservative. Although the research on special solution for 'weak-plate/strong-bolt' model with 2 to 4 bolts has been conducted by L. S. Muir, and W. A. Thonton, 2004, study on generalized design procedures did not conduct. This study proposed design procedure for evaluation of the design strength of eccentric shear bolt groups on a single plate connection based on the actual edge distance and the direction of bolt reaction forces by using elastic vector method(EVM) and instantaneous center of rotation method(ICM).

• International Commerce and Information Review
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• v.11 no.3
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• pp.47-71
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• 2009

In order to implement e-trade infrastructure through the radical innovation of trade process, e-trade platform which is called 'uTradehub' has been developed for three years. After pilot operation of this platform in 2007, the formal service of e-trade such as logistics, customs and foreign exchanges had been provided in 2008. However, the usage of e-Trade platform is not the level of users' satisfaction because trade-related communities have not actively participated into e-trade platform and several functions with users requirements are necessary to develop additionally. In this regard, there are strong demands to suggest some strategies for application and usage proliferation of e-trade platform. Therefore, this paper would like to evaluate the current status of e-trade platform service and usage by the theoretical consideration of preceding researches and practical analysis of statistical data. Then, it will explore several service improvement ideas in terms of system supplementation and integration, electronic documents standardization, radical change of using fee, global connection, user oriented education and advertisement.

• Journal of The Korean Astronomical Society
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• v.49 no.3
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• pp.83-92
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• 2016

The Toothbrush radio relic associated with the merging cluster 1RXS J060303.3 is presumed to be produced by relativistic electrons accelerated at merger-driven shocks. Since the shock Mach number inferred from the observed radio spectral index, M_radio ≈ 2.8, is larger than that estimated from X-ray observations, M_X ≲ 1.5, we consider the re-acceleration model in which a weak shock of M_s ≈ 1.2 - 1.5 sweeps through the intracluster plasma with a preshock population of relativistic electrons. We find the models with a power-law momentum spectrum with the slope, s ≈ 4.6, and the cutoff Lorentz factor, γ_e,c ≈ 7-8×10⁴ can reproduce reasonably well the observed profiles of radio uxes and integrated radio spectrum of the head portion of the Toothbrush relic. This study confirms the strong connection between the ubiquitous presence of fossil relativistic plasma originated from AGNs and the shock-acceleration model of radio relics in the intracluster medium.

• Bulletin of the Society of Naval Architects of Korea
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• v.9 no.1
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• pp.21-31
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• 1972

When one speaks of a concrete ship, most people have an impression of heavy solid rough edged masses of concrete very unlike anything floatable. In the form represented by what is called "MRC", concrete does, however, become light, homogeneous, elastic, resilient, and above all strong still retaining the basic benefit of inexpensive well known concrete properties. The fundamental principal behind this material as a new shipbuilding material is based on the development of "ferro-cement" in the early 1940s by an Italian Engineer Pierre Luigi-Nervi. The "MRC" or Mesh Reinforced Cement has been studied by Korea institute of Science and Technology in connection with a research project "The Small Ship Construction Utilizing Domestic Materials And Its Economic Analysis," of which reports have been issued previously. In this exporsition, some of the basic qualities of "MRC" are discussed in general terms.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.3
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• pp.11-22
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• 1997

The aim of this paper is to develop the B & B type algorithms for globally minimizing concave function under 0-1 knapsack constraint. The linear convex envelope underestimating the concave object function is introduced for the bounding operations which locate the vertices of the solution set. And the simplex containing the solution set is sequentially partitioned into the subsimplices over which the convex envelopes are calculated in the candidate problems. The adoption of cutting plane method enhances the efficiency of the algorithm. These mean valid inequalities with respect to the integer solution which eliminate the nonintegral points before the bounding operation. The implementations are effectively concretized in connection with the branching stategys.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.99-102
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• 1996

I discuss implications of gamma-ray emission from blazars based on electron acceleration by shock waves in a relativistic jet. The number spectrum of electrons turns out to be a broken power law; while at low energies the power law index has a universal value of 2, at high energies it steepens to an index of 3 because of strong radiative cooling. This spectrum can basically reproduce the observed spectral break between X-rays and gamma-rays. I show that energetics of relativistic jets can be well explained by this model. I estimate physical quantities of the relativistic jets by comparing the prediction with observations. The results show that the jets are particle dominated and are comprised of electron-positron pairs. A connection between gamma-ray emission and radiation drag is also discussed.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.34.2-34.2
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• 2012

In the context of structure formation in a hierarchical Universe, the relevance of mergers to radio-loud active galaxies is still under debate. I employ two different observational approaches to investigate the merger history of active galaxies, using several different samples of radio-loud AGN. I will first show results from the investigation of a complete sample of flat-spectrum radio-AGN and their role in a merger-driven evolution of galaxies. In the second part of my talk I will focus on the investigation of the close environment of radio-loud active galaxies, using data from the new VISTA-VIDEO near-infrared survey. Strong evidence is found supporting a close connection between merger events and radio-loud AGN.