• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.4
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• pp.272-279
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• 2003

In this work Zn$_4$GeSe$_{6}$ :CO$^{2+}$ single crystals were grown by the chemical transport reaction method in which the iodine was used as the transporting agent. The Zn$_4$GeSe$_{6}$ :CO$^{2+}$ single crystal was found to have a monoclinic structure. The optical absorption spectra of grown crystals were investigated using a temperature-controlled UV-VIS -NIR spectrophotometer. The temperature dependence of band-edge absorption was in a good agreement with the Varshni equation. The observed impurity absorption peaks could be explained as arising from the electron transition between energy levels of Co$^{2+}$ ion sited at the T$_{d}$ symmetry point.

• The Journal of the Korea Contents Association
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• v.18 no.3
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• pp.148-159
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• 2018

This study empirically examined the influence of ownership structure(public/private) and revenue structure (high dependency on advertisement/low dependency on advertisement) of broadcasting companies upon journalists' perceptions regarding the degree of freedom in news reporting, the factors that limit freedom of press, satisfaction with the work autunomy and satisfaction with company's policies of news reporting and editing in light of resource dependency theory. The result showed that both the ownership structure and revenue structure of broadcasting companies influenced the journalists' perception regarding the degree of freedom in news gathering and reporting. It was also confirmed that only the revenue structure affected the level of satisfaction with work autonomy while the degree of satisfaction with the company's policies on editing and programing was influenced by the ownership structure. The perception of the factors that limit the freedom of press was found to be influenced only by the ownership structure, as did the satisfaction with policies on editing and programing. These results are very significant as they show that the level of dependence on advertising revenue affects journalists' news reporting, and that journalists of public broadcasting companies are influenced by the dependence on government or other political powers as well as on advertising revenue.

• Journal of the Korean Society of Safety
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• v.31 no.5
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• pp.95-101
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• 2016

This study proposes a multi-scale dynamic system reliability analysis of control system as a method of quantitative evaluation of its performance in probabilistic terms. In this second paper, we discuss the control effect of the viscous damper on the seismic performance of the structure-level failure. Since the failure of one structural member does not necessarily cause the collapse of the structural system, we need to consider a set of failure scenarios of the structural system and compute the sum of the failure probabilities of the failure scenarios where the statistical dependence between the failure scenarios should be taken into account. Therefore, this computation requires additional system reliability analysis. As a result, the proposed approach takes a hierarchial framework where the failure probability of a structural member is computed using a lower-scale system reliability with the union set of time-sequential member failures and their statistical dependence, and the failure probability of the structural system is again computed using a higher-scale system reliability with the member failure probabilities obtained by the lower-scale system reliability and their statistical dependence. Numerical results demonstrate that the proposed approach can provide an accurate and stable reliability assessment of the control performance of the viscous damper system on the system failure. Also, the parametric study of damper capacity on the seismic performance has been performed to demonstrate the applicability of the proposed approach through the probabilistic assessment of the seismic performance improvement of the damper system.

• Journal of the Korean Data and Information Science Society
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• v.25 no.1
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• pp.245-254
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• 2014

The traditional methods of simulating daily precipitation have paid little attention to the inherent dependence structure between the total precipitation amount and the precipitation frequency for a fixed period of time. To address this issue, we propose a new simulation algorithm using copula in order to incorporate the dependence into the traditional methods. The algorithm consists of two parts: First, while reflecting the observed dependence, we generate the total precipitation amount (S) and the frequency (N) during the period of interest; then we simulate the daily precipitation whose aggregation matches the pair of (N; S) generated in the first part. Our result shows that the proposed method substantially improves the traditional methods.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.208-208
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• 2009

We used Brewster's Law to examine the mechanism of liquid crystal (LC) alignment on an organic insulation layer when subjected to ion-beam irradiation. Brewster's Law implies that the maximum rate polarized ray on a slanted insulation layers on the substrate and it illustrates the dependence of polarization and themechanical structure on the ion beam irradiation process. The pretilt angle of nematic LCs on the organic insulation surface was about $1.13^{\circ}$ for an ion beam exposure of $45^{\circ}$ for 1 minute at 1800eV. This shows the dependence of LC alignment on the polarization ratio in a slanted organic insulation layer.

• Industrial Engineering and Management Systems
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• v.13 no.1
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• pp.15-28
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• 2014

Evaluation of the implementation and performance of a firm's green supply chain management (GSCM) is an ongoing process. Balanced scorecard is a multi-criteria evaluation concept that highlights implementation and performance measures. The literature on the framework is abundant literature but scarce on how to build a hierarchical framework under uncertainty with dependence relations. Hence, this study proposes a hybrid approach, which includes applied interpretive structural modeling to build a hierarchical structure and uses the analytic network process to analyze the dependence relations. Additionally, this study applies the fuzzy set theory to determine linguistic preferences. Twenty dependence criteria are evaluated for a GSCM implemented firm in Taiwan. The result shows that the financial aspect and life cycle assessment are the most important performance and weighted criteria.

• Progress in Superconductivity and Cryogenics
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• v.17 no.4
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• pp.8-11
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• 2015

We studied on the visible emission of Cu-ion-doped perovskite hafnate $SrHfO_3$ (SHO:Cu) with the photo-excitation energy dependence. The polycrystalline SHO:Cu samples were newly synthesized in the solid state reaction method. From the X-ray diffraction measurement it was found that the crystalline structure of SHO:Cu is nearly identical to that of undoped $SrHfO_3$. Interestingly, the photoluminescence excitation (PLE) spectra change significantly with the emission energy, which is linked to the strong dependence of the visible emission on the photo-excitation energy. This unusual emission behavior is likely to be associated with the mixed valence states of the doped Cu ions, which were revealed by X-ray photoelectron spectroscopy. We compared our finding of tunable visible emission in the SHO:Cu compounds with the cases of similar materials, $SrTiO_3$ and $SrZrO_3$ with Cu-ion-doping.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.47
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• pp.101-112
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• 1998

Recently, researchers show growing interest on product quality characteristic dependence and designing acceptance sampling plans under the quality dependence. This research intends to resolve a few theoretical and practical questions for better application of acceptance sampling when the quality characteristic of product items exhibits a statistical dependence and samples are inspected according to the production order. In this research, a mathematical programming model is developed for the economic modeling of sampling plans based on two evaluation criteria : the average outgoing quality(AOQ) and the average total inspection cost. An efficient solution procedure is then proposed using the functional structure of the two evaluation criteria and the procedure is numerically illustrated.

• The Korean Journal of Financial Management
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• v.21 no.1
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• pp.149-181
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• 2004

In this study we perform empirical tests using KOSPI return to investigate the existence of nonlinear characteristics in the generating process of stock returns. There are three categories in empirical tests; the test of nonlinear dependence, nonlinear stochastic process and nonlinear deterministic chaos. According to the analysis of nonlinearity, stock returns are not normally distributed but leptokurtic, and appear to have nonlinear dependence. And it's decided that the nonlinear structure of stock returns can not be completely explained using nonlinear stochastic models of ARCH-type. Nonlinear deterministic chaos system is the feedback system, which the past incidents influence the present, and it is the fractal structure with self-similarity and has the sensitive dependence on initial conditions. To summarize the results of chaos analysis for KOSPI return, it is the persistent time series, which is not IID and has long memory, takes biased random walk, and is estimated to be fractal distribution. Also correlation dimension, as the approximation of fractal dimension, converged stably within 3 and 4, and maximum Lyapunov exponent has positive value. This suggests that chaotic attractor and the sensitive dependence on initial conditions exist in stock returns. These results fit into the characteristics of chaos system. Therefore it's decided that the generating process of stock returns has nonlinear deterministic structure and follow chaotic process.

• Journal of Preventive Medicine and Public Health
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• v.51 no.1
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• pp.1-5
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• 2018

Smokers keep smoking despite knowing that tobacco claims many lives, including their own and others'. What makes it hard for them to quit smoking nonetheless? Tobacco companies insist that smokers choose to smoke, according to their right to self-determination. Moreover, they insist that with motivation and willpower to quit smoking, smokers can easily stop smoking. Against this backdrop, this paper aims to discuss the addictive disease called tobacco use disorder, with an assessment of the addictiveness of tobacco and the reasons why smoking cessation is challenging, based on neuroscientific research. Nicotine that enters the body via smoking is rapidly transmitted to the central nervous system and causes various effects, including an arousal response. The changes in the nicotine receptors in the brain due to continuous smoking lead to addiction symptoms such as tolerance, craving, and withdrawal. Compared with other addictive substances, including alcohol and opioids, tobacco is more likely to cause dependence in smokers, and smokers are less likely to recover from their dependence. Moreover, the thinning of the cerebral cortex and the decrease in cognitive functions that occur with aging accelerate with smoking. Such changes occur in the structure and functions of the brain in proportion to the amount and period of smoking. In particular, abnormalities in the neural circuits that control cognition and decision-making cause loss of the ability to exert self-control and autonomy. This initiates nicotine dependence and the continuation of addictive behaviors. Therefore, smoking is considered to be a behavior that is repeated due to dependence on an addictive substance, nicotine, instead of one's choice by free will.