• Korean Institute of Interior Design Journal
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• no.27
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• pp.162-167
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• 2001

The true space is the physical world affected a gravity but the cyber space is the world that rise above physical status and show developed space. This study shows that the factors of objective valuation and the indicators for the behavior analysis. It is established that the structural design indicators using the simulation have 4 steps; The indicator of complex space, the diagram of cognitive image, is the analysis of emotion and stimulation, and the dependent variables. Moreover the indicator of complex space is illustrated the connection degree, the symmetry, the axis of sight, and the degree of space division. For the effective analysis, the simulation is to be made matched with the true environment. Thus the simulation has the capability of the objective and correct more than those of true architectural environment. And it could establish immediately the experimental data and response.

• Journal of the Ergonomics Society of Korea
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• v.23 no.1
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• pp.13-22
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• 2004

Due to economical or technological reasons. humans are responsible for inspection functions in many cases. Humans. however. are rarely perfect. thus allowing non-confirming parts to be processed. As the attributes of interest or the variety of products increases. the inspection system becomes less effective because of the sensory and cognitive limitations of human inspectors. Any means that can support or aid the human inspectors is necessary to compensate for inspection difficulty. Augmented reality (AR) offers a new approach in designing an inspection system as a means to augment the cognitive capability of inspectors by providing the 3D spatial proximity between two information channels. The experimental results suggest that AR might be an effective tool that reduces inspection time without sacrificing the measuring accuracy.

• Journal of Advanced Navigation Technology
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• v.21 no.4
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• pp.347-352
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• 2017

In this paper, we propose a method that reduces mobile user's handover call dropping probability by using cognitive radio technology(CR) in cellular - based wireless cognitive radio networks. The proposed method predicts a cell to visit by Ziv-Lempel algorithm, and then supports mobile user with prediction of spectrum holes based on CR technology when allocated channels are short in the cell. We make neural network predict spectrum hole resources, and make handover calls use the resources before initial calls. Simulation results show CR technology has the capability to reduce mobile user handover call dropping probability in cellular mobile communication networks.

• Journal of Advanced Navigation Technology
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• v.12 no.2
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• pp.132-138
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• 2008

Recently, many frequency sharing technology including CR (Cognitive Radio) technology have been studied actively because of frequency scarcity. For implementing CR systems, spectrum sensing technology plays key role. In IEEE 802.22 WRAN, the first standard aimed at Internet service in a TV channel with CR technology. This paper explained the various spectrum sensing schemes detecting narrowband ATSC signal in the IEEE 802.22 such as Energy detector, Spectral Correlation Sensing scheme, Covariance based Sensing algorithm and analyzed in terms of the probability of misdetection when the probability of false alarm is 10%. Based on simulation results, this paper proposed a duplex sensing scheme based on Energy detector and analyzed the capability of the proposed sensing scheme comparing with each sensing scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8A
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• pp.768-776
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• 2010

In this paper, we consider a linear precoding for the effective spectrum sharing in multiple-input multiple-output (MIMO) cognitive radio system where a secondary user coexists with primary users. The secondary user employs the orthogonal space time block coding (OSTBC) at the transmitter. Assuming a flat fading channel and a maximum-likelihood receiver, the optimum precoder forces transmission referred to as eigen-beamforming. In this paper, to eliminate the interference, ZF criterion based eigen-beamforming is not only used but also the precoding weight is chosen to cancel the remaining interference. This weight is computed by vector's likelihood. Simulation results show stronger interference suppression capability, better SER performance, and higher capacity than the algorithm in [4].

• ETRI Journal
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• v.39 no.5
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• pp.683-694
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• 2017

Several studies have focused on multimedia transmission over wireless sensor networks (WSNs). In this paper, we propose a comprehensive and robust model to transmit images over cognitive radio WSNs (CRWSNs). We estimate the spectrum sensing frequency and evaluate its impact on the peak signal-to-noise ratio (PSNR). To enhance the PSNR, we attempt to maximize the number of pixels delivered to the receiver. To increase the probability of successful image transmission within the maximum allowed time, we minimize the average number of packets remaining in the send buffer. We use both single- and multi-channel transmissions by focusing on critical transmission events, namely hand-off (HO), No-HO, and timeout events. We deploy our advanced updating method, the dynamic parameter updating procedure, to guarantee the dynamic adaptation of model parameters to the events. In addition, we introduce our ranking method, named minimum remaining packet best channel selection, to enable us to rank and select the best channel to improve the system performance. Finally, we show the capability of our proposed image scrambling and filtering approach to achieve noticeable PSNR improvement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.531-540
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• 2019

The purpose of this study was to establish the relationship between social support(MOS-SSS) and cognitive impairment(MMSE-K) to the elderly in long-term care facilities. The study subjects were 372 aged 65 and older who were admitted to care facilities located in D metropolitan city. Data were collected through a personal interview conducted by interviewers who visited each care facility in October 2018. As a result, the levels of cognitive impairment(MMSE-K) was significantly higher in the group with lower social support(MOS-SSS) scores. In correlation to the cognitive impairment and social support, the cognitive impairment score showed a significant positive correlation between the social support score (r=0.250, p<0.001). Therefore, the lower the social support level, the higher the level of cognitive impairment. In result of the logistic regression, the risk ratio of critical cognitive impairment increased significantly from 2.8 times (ORs=2.75, 95% CI=1.40 to 5.79) in the low group(Q1) than in the very high group(Q4) of social support scores. A hierarchical multiple regression analysis shows that the lower the social support, the higher the cognitive impairment. As such research suggests that the cognitive impairment of the elderly in care facilities increases with lower social support, it is necessary to seek concrete measures to improve social support as part of the measures to enhance the recognition capability of the elderly in care facilities.

• Spatial Information Research
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• v.14 no.4 s.39
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• pp.433-449
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• 2006

Two primary objectives of this study were to determine important personal factors in performing cognitive distance mapping, and to understand how human's cognitive distance mapping capabilities were influenced by reference and subjects' locations using Global Positioning System (GPS). Undergraduate and graduate students at the University of Kansas, USA were interviewed and surveyed throughout the campus area giving them a paper-and-pencil test. Study results showed that females had more accurate cognitive mapping capability than males regardless of ethnic background and academic levels. Generally, subjects with longer affiliation with the university, higher ages and academic levels had less variability in their mapping accuracy. Subjects tended to more accurately map the target locations closer to the reference points than those located farther away, and subjects who were closer to a reference point performed their distance mapping better than those farther away. A correlation analysis reported that male subjects used reference-to-target and subject-to-reference distances more sensitively than females to estimate the locations of the targets. This result indicates that males might have used the reference point-based map scale more strenuously than females.

• Journal of Korean Society for Quality Management
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• v.41 no.4
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• pp.513-525
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• 2013

Purpose: The purpose of this paper are to propose a strategic map for hotel industry through analyzing the relationship between service resource, operational capabilities, and performance. Methods: A phone survey was conducted among Korean hotels, and 102 data sets were collected. Measurement items are assessed using both cognitive and objective scales. Results: As results, 'superior group', which is superior in both physical resources and human resources, is excellent in all capabilities and also in room occupancy rate. On the other hands, 'inferior group', which is inferior in both physical resources and human resources, shows lower achievements is in most areas except speed. In addition, physical superior group is better than human superior group in most capabilities except speed, but human superior group shows better results than physical superior group in both room occupancy rate and customer satisfaction. Conclusions: Through the empirical analysis, the conclusions attained are as follows; First, human resources affect customer satisfaction more directly that physical resources. Second, the balancing between physical resources and human resources has an importance to improve operational capabilities.

• The Journal of Information Systems
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• v.27 no.4
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• pp.189-202
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• 2018

Purpose As job market squeezes and more institutions have been requiring NCS(National Competency Standards) based recruitments, the importance of NCS has been growing. Among the 10 domains of NCS, the most relevant one with MIS(Management Information Systems) field is 'information ability', which is becoming more important with the advent of the fourth industrial revolution era. The purpose of this study is to investigate the effect of college students' information ability on their career preparation behavior. Design/methodology/approach In this study, we set up a process model to comprehend the effect of college students' information ability on career preparation behavior based on social cognitive career theory. For research model testing, 561 questionnaires were used for empirical analysis through structural equations modeling. Findings Empirical analysis showed that information ability positively influenced college students' career preparation behaviors for employment. In addition, this study presented a process model explaining the effect of information capability on career preparation behavior. In order to strengthen the information ability of college students, not only university-level efforts, but also MIS discipline efforts should be accompanied. Other academic and practical implications are discussed.