• Journal of Korean Academy of Nursing
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• v.50 no.2
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• pp.191-199
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• 2020

Purpose: The purpose of this study was to compare sociodemographic characteristics of a normal cognitive group and mild cognitive impairment group, and establish prediction models of Mild Cognitive Impairment (MCI). Methods: This study was a secondary data analysis research using data from "the 4th Korea Longitudinal Study of Ageing" of the Korea Employment Information Service. A total of 6,405 individuals, including 1,329 individuals with MCI and 5,076 individuals with normal cognitive abilities, were part of the study. Based on the panel survey items, the research used 28 variables. The methods of analysis included a χ²-test, logistic regression analysis, decision tree analysis, predicted error rate, and an ROC curve calculated using SPSS 23.0 and SAS 13.2. Results: In the MCI group, the mean age was 71.4 and 65.8% of the participants was women. There were statistically significant differences in gender, age, and education in both groups. Predictors of MCI determined by using a logistic regression analysis were gender, age, education, instrumental activity of daily living (IADL), perceived health status, participation group, cultural activities, and life satisfaction. Decision tree analysis of predictors of MCI identified education, age, life satisfaction, and IADL as predictors. Conclusion: The accuracy of logistic regression model for MCI is slightly higher than that of decision tree model. The implementation of the prediction model for MCI established in this study may be utilized to identify middle-aged and elderly people with risks of MCI. Therefore, this study may contribute to the prevention and reduction of dementia.

• Journal of information and communication convergence engineering
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• v.7 no.1
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• pp.7-12
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• 2009

The advanced computer network and Internet technology enables connectivity of computers through an open network environment. Despite the growing numbers of security threats to networks, most intrusion detection identifies security attacks mainly by detecting misuse using a set of rules based on past hacking patterns. This pattern matching has a high rate of false positives and can not detect new hacking patterns, making it vulnerable to previously unidentified attack patterns and variations in attack and increasing false negatives. Intrusion detection and prevention technologies are thus required. We proposed a network based hybrid Probe Intrusion Detection model using Fuzzy cognitive maps (PIDuF) that detects intrusion by DoS (DDoS and PDoS) attack detection using packet analysis. A DoS attack typically appears as a probe and SYN flooding attack. SYN flooding using FCM model captures and analyzes packet information to detect SYN flooding attacks. Using the result of decision module analysis, which used FCM, the decision module measures the degree of danger of the DoS and trains the response module to deal with attacks. For the performance evaluation, the "IDS Evaluation Data Set" created by MIT was used. From the simulation we obtained the max-average true positive rate of 97.064% and the max-average false negative rate of 2.936%. The true positive error rate of the PIDuF is similar to that of Bernhard's true positive error rate.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.32
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• pp.243-253
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• 1994

Work environments have been changed with the advent of new technologies, such as computer technology. The newer technologies, the more changes in our work conditions. However, human cognitive limits can't keep up with the change of work environments. Mental workload has been an important factors in designing modem work environments such as human-computer interaction. Designing man-machine systems requires knowledge and evaluation of the human cognitive processes which control information flow workload. Futhermore, under an urgent situation, human operator may suffer the work stress, work error, and resultant deleterious work performance. To describe the work performance in the urgent work situations, with time stress and dynamic event occurence, a new concept of information density was introduced. For a series of experiments performed for this study, three independent variables(information amount system processing time, information density) were evaluated using such dependent variables as reaction time, number of error, and number of failure. The results of statistical anlysiss indicate that the amount of information effected on all of five dependent measure. Number of failure and number of secondary task score were effected by both amount of information and operational speed of system, but reaction time of secondary task were effected by both amount of information and information density.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.1
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• pp.81-108
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• 2018

In this paper, we derive the theoretical Symbol Error Probability (SEP) of cooperative systems with best relay selection for Nakagami-m fading channels. For Amplify and Forward (AF) relaying, the selected relay offers the best instantaneous Signal to Noise Ratio (SNR) of the relaying link (source-relay-destination). In cooperative networks using Decode and Forward (DF), the selected relay offers the best instantaneous SNR of the link between the relay and the destination among the relays that have correctly decoded the transmitted information by the source. In the second part of the paper, we derive the SEP when all participating AF and DF relaying is performed. In the last part of the paper, we extend our results to cognitive radio networks where there is interference constraints : only relays that generate interference to primary receiver lower than a predefined threshold T can transmit. Both AF and DF relaying with and without relay selection are considered.

• Cross-Cultural Studies
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• v.33
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• pp.287-307
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• 2013

One cat caused a big wave in Russian literature. This cat revived the heroine of Russian classics. Her light breath was scattered in the world, in the cloudy sky and in the cold spring wind about one hundred years ago. And the cat gave an opportunity of turning to Russian classics to Russian readers. Thanks to this cat, a Russian dreamer changed his typical thinking, as well as many ordinary readers start to read works of creator of this wonderful cat. Pelevin accomplished these works with one cat, which he has made. Of course "Nika" is not only caused to make readers to return to Russian classics. I think, the cat and "Nika" are the symbols of writer's purpose in Russian literature. In this study the understanding of "Nika" is following the steps of realization of writer's purpose. In the second chapter it is analyzed to the textual relationship between "Nika" and "Light breath". Apart from existing analyses to be emphasized the succession of thematic aspect of two works as well. Existence of observers to each heroine stress this succession of thematic aspect of two works. In the third chapter it is analyzed the use of technique of mystification in "Nika". This intentional use of mystification has been demanded to read a "Nika" from another point of view(internal speculation of hero-narrator). The purpose of writer was to expose the cognitive error of a human being. I think this purpose was effectively explained by Pelevin's Buddhist world view which was introduced in his several works.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.12
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• pp.4664-4681
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• 2020

Modulation recognition (MR) plays a key role in cognitive radar, cognitive radio, and some other civilian and military fields. While existing methods can identify the signal modulation type by extracting the signal characteristics, the quality of feature extraction has a serious impact on the recognition results. In this paper, an end-to-end MR method based on long short-term memory (LSTM) and the gated recurrent unit (GRU) is put forward, which can directly predict the modulation type from a sampled signal. Additionally, the sliding window method is applied to fast-changing mixed-modulation signals for which the signal modulation type changes over time. The recognition accuracy on training datasets in different SNR ranges and the proportion of each modulation method in misclassified samples are analyzed, and it is found to be reasonable to select the evenly-distributed and full range of SNR data as the training data. With the improvement of the SNR, the recognition accuracy increases rapidly. When the length of the training dataset increases, the neural network recognition effect is better. The loss function value of the neural network decreases with the increase of the training dataset length, and then tends to be stable. Moreover, when the fast-changing period is less than 20ms, the error rate is as high as 50%. As the fast-changing period is increased to 30ms, the error rates of the GRU and LSTM neural networks are less than 5%.

• Korean Journal of Construction Engineering and Management
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• v.25 no.2
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• pp.69-80
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• 2024

Currently rebar spacing inspection is carried out by human inspectors who heavily rely on their individual experience, lacking a guarantee of objectivity and accuracy in the inspection process. In addition, if incorrectly placed rebars are identified, the inspector need to correct them. Recently, laser scanning and AR technologies have been widely used because of their merits of measurement accuracy and visualization. This study proposes a technology for rebar spacing inspection and fixing by combining laser scanning and AR technology. First, scan data acquisition of rebar layers is performed and the raw scan data is processed. Second, AR-based visualization and fixing are performed by comparing the design model with the model generated from the scan data. To verify the developed technique, performance comparison test is conducted by comparing with existing drawing-based method in terms of inspection time, error detection rate, cognitive load, and situational awareness ability. It is found from the result of the experiment that the AR-based rebar inspection and fixing technology is faster than the drawing-based method, but there was no significant difference between the two groups in error identification rate, cognitive load, and situational awareness ability. Based on the experimental results, the proposed AR-based rebar spacing inspection and fixing technology is expected to be highly useful throughout the construction industry.

• Therapeutic Science for Rehabilitation
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• v.10 no.4
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• pp.81-94
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• 2021

Objective : Response time plays a prominent part in research on cognitive ability and the aging effect. This study aimed to identify the impact of cognitive ability on information processing by conducting cognitive response time (CRT) using a computer program. Methods : This study was conducted in 30 normal elderly (NE) and 30 elderly with amnestic MCI (aMCI), aged 65-79 years old living in Daegu and Gyeongbuk. The results were analyzed using the statistical analysis program R 4.0.2 (University of Auckland, New Zealand). Results : In the three sub-areas of CRT, the total response time showed a significant difference depending on group or age, and the error rate showed a significant difference depending on age or group in some sub-areas. In the aMCI group, the performance of CRT significantly correlated with that of the overall cognition and memory test. Conclusion : Information processing depending on aging or cognitive ability and the differential performance of processing speed could be observed through CRT. The performance of this test was found to be significantly correlated with that of the overall cognition and memory test. Therefore, CRT could be used meaningfully as a simplified tool to predict the initial cognitive disorder of the elderly in the community.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.10
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• pp.3-10
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• 2014

In this paper, the performances of the presented D2D (device-to-device) systems under the environment of the cognitive convergent overlay networks are evaluated based upon the locations of the D2D users' terminals, the power consumptions of the terminals and the reductions of the interference levels. As the capabilities of the users' terminals improve, the optimization of the system is crucial to the efficient utilization of the radio resources of the individual networks considering their mobility and the features of their networks. Users' mobility model is given for the performance evaluation of the D2D system. In this paper, the performances of the D2D systems are evaluated in terms of the performance index of the FER (frame error rate) employing multiantenna techniques (MIMO:multiple input multiple output) for the various network environments.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.55-63
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• 2013

In cognitive radio networks, acquirement of position information of primary user is very important to secondary network since localization information of primary users can be utilized for improving the spectrum efficiency of secondary network and for avoiding harmful interference to primary users by using proper power control. Among various location methods, Received Signal Strength (RSS)-based localization has been widely used for distance measurements in the location detection process despite its inherent inaccuracy because it can be easily implemented without any additional hardware cost. In the RSS-based localization, the distance is measured by the received signal strength, and distance error can be caused by many factors such as fading, shadowing and obstacle between two nodes. In the paper, therefore we propose a localization scheme based on estimation of path-loss exponent to localize the location of primary users more accurately. Through simulations, it is shown that the proposed scheme can provide less localization error and interference rate to primary users than other schemes.