• KIEAE Journal
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• v.10 no.4
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• pp.59-66
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• 2010

Natural ventilation is major strategy of 'sustainable building'. It aims to supply fresh air to the indoor, and to remove heat from the indoor during summer. In the latter point of view, natural ventilation can be grouped into two main strategies, daytime ventilation and night cooing. If we take advantage of these two natural ventilation strategies, indoor thermal comfort can be significantly improved. This study focused on grasping the current situation and problem of indoor thermal comfort of the naturally ventilated residential buildings to seek for direction of later studies. Additionally, thermal comfort of residence where the interior blind and exterior insulation were applied was analyzed. It was analyzed that the percentage of the time which satisfy the indoor acceptable operative temperature during summer was 90 ~ 95% and the heat control performance of natural ventilation has a limitation. When the interior blind and exterior insulation were applied, indoor thermal comfort was significantly improved. However, it still need more improvement.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.6
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• pp.307-314
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• 2008

Retinal prostheses are being developed to restore vision for the blind with retinal diseases such as retinitis pigmentosa (RP) or age-related macular degeneration (AMD). Among the many issues for prosthesis development, stimulation encoding strategy is one of the most essential electrophysiological issues. The more we understand the retinal circuitry how it encodes and processes visual information, the greater it could help decide stimulation encoding strategy for retinal prosthesis. Therefore, we examined how retinal ganglion cells (RGCs) in in-vitro retinal preparation act together to encode a visual scene with multielectrode array (MEA). Simultaneous recording of many RGCs with MEA showed that nearby neurons often fired synchronously, with spike delays mostly within 1 ms range. This synchronized firing - narrow correlation - was blocked by gap junction blocker, heptanol, but not by glutamatergic synapse blocker, kynurenic acid. By tracking down all the RGC pairs which showed narrow correlation, we could harvest 40 functional connectivity maps of RGCs which showed the cell cluster firing together. We suggest that finding functional connectivity map would be useful in stimulation encoding strategy for the retinal prosthesis since stimulating the cluster of RGCs would be more efficient than separately stimulating each individual RGC.

• Korean Journal of Biological Psychiatry
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• v.13 no.4
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• pp.252-259
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• 2006

Sexual dysfunction is a relatively common adverse effect in the use of antidepressants. The sexual side effects may result in a lack of compliance with the prescribed antidepressants. The author reviewed the prevalence and updated treatment for the antidepressant-induced adverse effects focusing on sexual dysfunction. The incidence of sexual dysfunction is reported to exceed more than 50% especially with SSRIs. In order to obtain a quantified baseline and as an ongoing evaluation tool, clinicians may use some of the established questionnaires and validated instruments such as the Arizona Sexual Experience scale and Changes in Sexual Functioning Questionnaire. Clinicians should be aware that delayed ejaculation and orgasm, symptoms most frequently associated with antidepressants, are not usually associated with depression itself. Although many antidotes have been proposed, few have been subjected to double-blind trials. Some evidences have suggested that bupropion and buspiron may be the effective antidotes for SSRI induced sexual dysfunction. Additional trials will be requied to define what role, if any, bupropion and buspiron might have in the treatment of SSRI-induced sexual side effects. The available evidence is rather limited, with only small number of trials assessing each strategy. While further randomized data is awaited, for men with antidepressant induced erectile dysfunction, the addition of sidenafil or tadalafil may appear to be an effective strategy.

• The Journal of Economics, Marketing and Management
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• v.5 no.3
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• pp.12-20
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• 2017

The study examined effects of psychological change of distribution environment upon commercial areas to investigate consumers' experience and theory and to suggest power of new management strategy for growth of retailers A The study investigated actual conditions of business transaction of hyper market by blind interview. In April, 2016, the author visited 6 manufacturers to do depth interview. The questionnaire between food manufacturers and hyper market investigated the Association of Food Industries in Korea, NH Nonghyup and large manufacturers in July 2012. Questionnaires of 25 companies were used after excluding questionnaire having poor and inadequate answers. The sales commission with large scaled distribution business decreased (0.3 ~ 0.7) to increase additional expenses such as number of salesmen, interior expenses and economic costs (0.7 ~ 40%). (source: Fair Trade Commission). Fair Trade Commission released types and notice of unfair trade of large scaled retail business based on monopoly regulation and fair trade (hereinafter called 'notice of large scaled retail) to prevent large scaled distribution business from doing unfair trade. The notice controled unfair trade at different position between large scaled distribution business and small vendors.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.11
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• pp.4224-4243
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• 2021

Cognitive radio (CR) is a feasible intelligent technology and can be used as an effective solution to spectrum scarcity and underutilization. As the key function of CR, cooperative spectrum sensing (CSS) is able to effectively prevent the harmful interference with primary users (PUs) and identify the available spectrum resources by exploiting the spatial diversity of multiple secondary users (SUs). However, the open nature of the cognitive radio networks (CRNs) framework makes CSS face many security threats, such as, the malicious user (MU) launches Byzantine attack to undermine CRNs. For this aim, we make an in-depth analysis of the motive and purpose from the MU's perspective in the interweave CR system, aiming to provide the future guideline for defense strategies. First, we formulate a dynamic Byzantine attack model by analyzing Byzantine behaviors in the process of CSS. On the basis of this, we further make an investigation on the condition of making the fusion center (FC) blind when the fusion rule is unknown for the MU. Moreover, the throughput and interference to the primary network are taken into consideration to evaluate the impact of Byzantine attack on the interweave CR system, and then analyze the optimal strategy of Byzantine attack when the fusion rule is known. Finally, theoretical proofs and simulation results verify the correctness and effectiveness of analyses about the impact of Byzantine attack strategy on the throughput and interference.

• Journal of Information Technology Applications and Management
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• v.10 no.2
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• pp.61-71
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• 2003

Ad-hoc networks are characterized by multi-hop wireless links, frequently changing network topology and the need for efficient dynamic routing protocols. In an Ad-hoc network, each host assumes the role of a router and relays packets toward final destinations Because a packet is broadcast to all neighboring nodes, the optimality criteria of wireless network routing is different from that of wired network routing. tn this paper 1 point out the more important cost factor than the number of links in the Ad-hoc network. A class routing protocols called on-demand protocols has recently found attention because of their low routing overhead since it performs a blind flooding to look for a path. In this paper, 1 propose the method which reduces overhead by using the information of neighboring nodes and doing a selective flooding. Simulation results demonstrate better reduction of routing overheads with this scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9C
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• pp.898-907
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• 2003

In this paper, we propose a new blind watermarking method that embeds a watermark on the lowest wavelet subband coefficients, while most watermarking techniques embed watermarks in the middle frequency range for robustness and fidelity. A new embedding algorithm for watermarking is proposed that embeds a bi-level watermark sequence into randomly selected wavelet coefficients on the lowest subband(LL) using a quantization in order to be robust. Experimental results prove our novel embedding strategy is invisible and good rate-distortion-robustness performance.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.6
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• pp.70-76
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• 2019

This paper presents a methodology for priority decision of performance evaluation of small-and-medium-sized highway bridges. This methodology could be used for establishing a maintenance strategy of those bridges which are not liable to the law of the Special Act on the Safety Control and Maintenance of Establishments and are thought laid under blind spot. The risk index are calculated considering vulnerability and social influence, then the bridges are classified as three types, one requiring immediate evaluation, the other one requiring evaluation within next year, and the third one observing, according to the index. The suggested method was applied to a small bridge under service and its field applicability verified. From this study, it was judged that this methodology could be used appropriately for establishing maintenance strategy and saving the maintenance budget.

• Nuclear Engineering and Technology
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• v.46 no.6
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• pp.803-816
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• 2014

Defense-in-depth is a fundamental safety principle for the design and operation of nuclear power plants. Despite its general appeal, defense-in-depth is not without its drawbacks, which include its potential for concealing the occurrence of hazardous states in a system, and more generally rendering the latter more opaque for its operators and managers, thus resulting in safety blind spots. This in turn translates into a shrinking of the time window available for operators to identify an unfolding hazardous condition or situation and intervene to abate it. To prevent this drawback from materializing, we propose in this work a novel safety principle termed "observability-in-depth". We characterize it as the set of provisions technical, operational, and organizational designed to enable the monitoring and identification of emerging hazardous conditions and accident pathogens in real-time and over different time-scales. Observability-in-depth also requires the monitoring of conditions of all safety barriers that implement defense-in-depth; and in so doing it supports sensemaking of identified hazardous conditions, and the understanding of potential accident sequences that might follow (how they can propagate). Observability-in-depth is thus an information-centric principle, and its importance in accident prevention is in the value of the information it provides and actions or safety interventions it spurs. We examine several "event reports" from the U.S. Nuclear Regulatory Commission database, which illustrate specific instances of violation of the observability-in-depth safety principle and the consequences that followed (e.g., unmonitored releases and loss of containments). We also revisit the Three Mile Island accident in light of the proposed principle, and identify causes and consequences of the lack of observability-in-depth related to this accident sequence. We illustrate both the benefits of adopting the observability-in-depth safety principle and the adverse consequences when this principle is violated or not implemented. This work constitutes a first step in the development of the observability-in-depth safety principle, and we hope this effort invites other researchers and safety professionals to further explore and develop this principle and its implementation.

• Journal of Korean Academy of Nursing
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• v.31 no.5
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• pp.871-884
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• 2001

this study was to investigate the perception gap on nursing service between consumers and providers. Method: the questionnaire founded on the SERVQUAL was developed and distributed to 300 patients and 210 nurses at the three subjected general hospitals in three provincial city, Korea during February to March, 2001. For data analysis, Cronbachs' Alpha, frequency, t-test, and paired t-test were used. Result: 1. In the gap analysis on the 20 properties constituting nursing service, providers almost all perceived higher than consumer in quality. Among them, the number of properties being statistically significant was 7 in the expectation, 18 in the important and 7 in the performance. 2. In the comparison analysis of the perception gap on the expectation-performance and the important-performance, it turned out that the subjected hospitals had to improve their equipment and facilities immediately. It was suggested a good strategy to strengthen the responsiveness factor and the assurance factor of nursing service. Conclusion: it could be concluded that nurses have to recognize the blind spot of their perception and endeavor to take away the perception gap between consumers and providers.