• Journal of information and communication convergence engineering
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• v.8 no.1
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• pp.40-44
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• 2010

opportunistic spectrum access (OSA) allows unlicensed users to share licensed spectrum in space and time with no or little interference to primary users, with bring new research challenges in MAC design. We propose a cognitive MAC protocol using statistical channel information and selecting appropriate idle channel for transmission. The protocol based on the CSMA/CA, exploits statistics of spectrum usage for decision making on channel access. Idle channel availability, spectrum hole sufficiency and available channel condition will be included in algorithm statistical information. The model include the control channel and data channel, the transmitter negotiates with receiver on transmission parameters through control channel, statistical decision results (successful rate of transmission) from exchanged transmission parameters of control channel should pass the threshold and decide the data transmission with spectrum hole on data channel. A dynamical sensing range as a important parameter introduced to maintain the our protocol performance. The proposed protocol's simulation will show that proposed protocol does improve the throughput performance via traditional opportunistic spectrum access MAC protocol.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.55
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• pp.243-264
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• 2012

This study is aimed to analyze problems related to FTA country of origin of goods verification which is increasing from 2006 and thereby to grope for solution of such problems and seek adequate FTA performance administration. It is found, through comparative analysis and statistics of last 8 FTAs so far Korea has concluded that there are major problems such as excessive verification processing due to complicated country of origin regulation etc. This paper suggests following policies of country of origin administration ; (1) Simplification of FTA country of origin rules (2) reciprocal cooperation between each country's Customs Authorities based on trust (3) rational measurement against corresponding country's Customs Authorities' misbehavior (4) enhancement of transparency in relation to processing rule of country of origin verification (5) securing FTA country of origin verification experts. For these improvements, upcoming FTA shall rule country of origin reasonably, simplification and transparency of rule is needed for established FTAs in relation to FTA performance administration with corresponding countries. Also it is necessary to revise FTA preferential tariff law and its related laws, and carry forward policies in accordance with medium and long term plan.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.21 no.4
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• pp.380-391
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• 2014

Purpose: This was a descriptive research study to examine the patient safety risk factors and the level of safety management of nurses in emergency service, hospitals and to analyze the relationship between the two factors. Method: Data for analysis were collected from 232 nurses in emergency service, hospitals in Busan and Gyeongnam from July 30 to September 7, 2013. Data were analyzed using descriptive statistics, t-test, one-way ANOVA, and Pearson correlation coefficients. Results: Therapeutic agents showed the highest risk level. The prevention of transfusion errors showed the highest performance. As the nurses were working in regional emergency medical centers and received education more than 7 sessions on patient safety, they readily recognized the riskiness of the safety risk factors. In addition, as the nurses were older than 40, married, having more education about safety and understood the incident report registration system well, they performed safety management better. There were significant correlations between perception of the patient safety risk factors and performance for safety management. Conclusion: Nurses in emergency service, hospitals should try to improve safety management to reduce the risk factors shown to be higher based on the results and ensure the patient safety.

• The Korean Journal of Emergency Medical Services
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• v.16 no.1
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• pp.19-29
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• 2012

Purpose: This study was focused on the training effects of the cardiopulmonary resuscitation(CPR) which is based on the AHA guideline 2010 for lay person. The purpose of this study was to investigate the effectiveness of the CPR training for civilian by checking the performance ability of the subjects before and after the CPR education. Method: This study was a single primary experimental study designed with pre and post test. Study subjects were 55 apartment managers who participated in all test on December 5 and December 11, 2011. The tools of this study were CPR performing evaluation sheet and CPR teaching program(AHA). Data were analysed by descriptive statistics, t-test, repeated ANOVA and Bonferroni with SPSS 18.0 program. Result: The CPR practice performing ability was significantly increased by test. The CPR practice performing ability of the learning experience group had significantly higher score than that of non-experience group. The self-confidence on CPR practice when faced emergency situation was highly increased after practice training. Conclusion: Practical performance evaluation score has improved step by step. The primary and secondary practical evaluation showed a significant difference in all items and practice-oriented education was found to be effective in CPR training.

• Journal of Korean Academy of Nursing Administration
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• v.11 no.4
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• pp.371-384
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• 2005

Purpose: The aim of this study was to analysis path model of the research variables. Methods: The subjects of this study were 647 nurses who were working in the 8 general hospitals located in Seoul and Incheon area. The data were collected by self-reporting questionnaires. The data were analyzed using descriptive statistics and path analysis. Results: In the modified path model, overall fitness indexes were $X^2$= 223.27, goodness of fit index=0.90, root mean square residual=0.039, root mean square error of approximation=0.12, non-normed fit index=0.96, and normed fit index=0.90. From the model, among research variables that influence organizational effectiveness motivator, job satisfaction and organizational identification affected directly work performance. In internal marketing factors, paid-leave, communication and reward affected directly motivator. Motivator and hygiene factors affected directly job satisfaction, organizational commitment and organizational identification. Conclusion: With these findings, paid-leave, communication, reward, motivator, job satisfaction and organizational identification were direct or indirect predictors of the work performance. Therefore nursing managers ought to develop internal marketing strategies and motivation enhancing system for nurses based on this path model in order to improve the nursing organizational effectiveness.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.7
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• pp.3286-3300
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• 2016

High Efficiency Video Coding (HEVC) Standard, as the latest coding standard, introduces satisfying compression structures with respect to its predecessor Advanced Video Coding (H.264/AVC). The new coding standard can offer improved encoding performance compared with H.264/AVC. However, it also leads to enormous computational complexity that makes it considerably difficult to be implemented in real time application. In this paper, based on machine learning, a fast partitioning method is proposed, which can search for the best splitting structures for Intra-Prediction. In view of the video texture characteristics, we choose the entropy of Gray-Scale Difference Statistics (GDS) and the minimum of Sum of Absolute Transformed Difference (SATD) as two important features, which can make a balance between the computation complexity and classification performance. According to the selected features, adaptive decision trees can be built for the Coding Units (CU) with different size by offline training. Furthermore, by this way, the partition of CUs can be resolved as a binary classification problem. Experimental results have shown that the proposed algorithm can save over 34% encoding time on average, with a negligible Bjontegaard Delta (BD)-rate increase.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.703-722
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• 2016

Passive wireless devices have increasing civilian and military applications, especially in the scenario with wearable devices and Internet of Things. In this paper, we study indoor localization of a target equipped with radio-frequency identification (RFID) device in ultra-wideband (UWB) wireless networks. With known room layout, deterministic multipath components, including the line-of-sight (LOS) signal and the reflected signals via multipath propagation, are employed to locate the target with one transmitter and a single inaccurate receiver. A factor graph corresponding to the joint posterior position distribution of target and receiver is constructed. However, due to the mixed distribution in the factor node of likelihood function, the expressions of messages are intractable by directly applying belief propagation on factor graph. To this end, we approximate the messages by Gaussian distribution via minimizing the Kullback-Leibler divergence (KLD) between them. Accordingly, a parametric message passing algorithm for indoor passive localization is derived, in which only the means and variances of Gaussian distributions have to be updated. Performance of the proposed algorithm and the impact of critical parameters are evaluated by Monte Carlo simulations, which demonstrate the superior performance in localization accuracy and the robustness to the statistics of multipath channels.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.10
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• pp.2563-2578
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• 1996

In this paper, channel error characteristics are investigated to alleviate the channel error propagation problem of the digital TV transmission systems. First, error propagation problems, which are mainly caused by the inter-frame dependancy and variable length coding of the MPEG-2 baseline encoder, are intensively analyzed. Next, existing channel resilient schemes are systematically classified into two kinds of schemes; one for the encoder and the other for the decoder. By comparing the performance and implementation cost, the encoder side schemes, such as error localization, layered coding, error resilience bit stream generation techniques, are described in this paper. Also, in an effort to consider the parcticality of the real transmission situation, an efficient error detection scheme for a decoder system is proposed by employing a priori information of the bit stream syntas, checking the encoding conditions at the encoder stage, and exploiting the statistics of the image itself. Finally, subsequent error concealment technique based on the DCT coefficient recovery algorithm is adopted to evaluate the performance of the proposed error resilience technique. The computer simulation results show that the quality of the received image is significantly improved when the bit error rate is as high as 10$^{-5}$ .

• Structural Engineering and Mechanics
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• v.50 no.5
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• pp.653-664
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• 2014

Wind fragility analysis provides a quantitative instrument for delineating the safety performance of civil structures under hazardous wind loading conditions such as cyclones and tornados. It has attracted and would be expected to continue to attract intensive research spotlight particularly in the nowadays worldwide context of adapting to the changing climate. One of the challenges encumbering efficacious assessment of the safety performance of existing civil structures is the possible incompleteness of the structural appraisal data. Addressing the issue of the data missingness, the study presented in this paper forms a first attempt to investigate the feasibility of using the expectation-maximization (EM) algorithm and Bayesian techniques to predict the wind fragilities of existing civil structures. Numerical examples of typical linear or hysteretic shear frames are introduced with the wind loads derived from a widely used power spectral density function. Specifically, the application of the maximum a posteriori estimates of the distribution parameters for the story stiffness is examined, and a surrogate model is developed and applied to facilitate the nonlinear response computation when studying the fragilities of the hysteretic shear frame involved.

• Journal of Korean Society for Quality Management
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• v.46 no.4
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• pp.821-842
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• 2018

Purpose: To derive key requirements and key technologies for weapon system acquisition business by using Qualify Function Deployment (QFD), and to reduce business cost by setting the target performance and key expense of weapon system. Methods: We propose a QFD methodology that can induce rational decision-making by translating analyst's subjective opinions into quantitative values when analyzing requirements at the initial stage of weapon system development project. Based on QFD methodology, QFD application model combining house of quality, value engineering, and analogy cost estimating technique is presented. Results: It was possible to analyze the specific requirements necessary for the development of the weapon system, to solve the communication problem of the participants, to set clear development direction and target. Conclusion: By applying the QFD application model at the early stage of the weapon system acquisition project, it is possible to reduce the business cost by establishing clear development direction and goal through the procedural analysis process.