• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.746-754
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• 2016

Smart healthcare systems, a convergent industry based on information and communications technologies (ICT), has emerged from personal health management to remote medical treatment as a distinguished industry. The smart healthcare environment provides technology to deliver vital information, such as pulse rate, body temperature, health status, and so on, from wearable devices to the hospital network where the physician is located. However, since it deals with the patient's personal medical information, there is a security issue for personal information management, and the system may be vulnerable to cyber-attacks in wireless networks. Therefore, this study focuses on a key-development and device-management system to generate keys in the smart environment to safely manage devices. The protocol is designed to provide safe communications with the generated key and to manage the devices, as well as the generated key. The security level is analyzed against attack methods that may occur in a healthcare environment, and it was compared with existing key methods and coding capabilities. In the performance evaluation, we analyze the security against attacks occurring in a smart healthcare environment, and the security and efficiency of the existing key encryption method, and we confirmed an improvement of about 15%, compared to the existing cipher systems.

• Korean Security Journal
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• no.44
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• pp.169-198
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• 2015

The purpose of present study is to provide an efficient 'Disaster Emergency Communication System' (below DECS) to deal with serious disaster situations in national levels. Currently, DECSs such as the VHF, UHF, and TRS are worked to control some disaster situations in the world. However, new system such as for sending the correct image and big data is more likely to need than current the DECSs in the comtemporary societies. Several serious disaster events such as the Sam-Poong Department Store Collapse, Daegu Subway Fire, and Sewol Submerge event, nevertheless, there was not the DECS based on the field in South Korea. In July 2014, finally, South Korean government started to provide a PS-LTE system which is the new and one system with fire fighting, police, army, railway. however, there are no many academic studies for DECSs to deal with disaster situations in South Korea. The present research highlights to explore an efficient DECS of Korean styles to fix some national security and public safety. The paper provides three key findings: first is how to make a unified Korean DECS based on PS-LTE. Second is how to make sure the frequency of 700MHz levels to communicate in the shady areas. Three is what kinds of communication facility is adequate for fixing PS-LTE DECS.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.43-49
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• 2000

That modem society is an information society, information society has placed a high value on information and knowledge. Therefore, modem civilization depends largely on information and knowlege so the most valuable sources of all intelligence activities. This paper was studied on the new developmental direction for intelligent network service. The results of this study is as follow: first, intelligent network service must be systematic development. Second, intelligent network service must be promoted, presenting the development and establishment direction in future society. Third, intelligent network service must be able to unify ail the networks. Fourth, intelligent network service must be development for customers. Fifth, the cost of intelligent network service is determined by Telecommunication Reguration Commission. Sixth, the number system of intelligent network service must be accomplished by number system for future

• Journal of The Korean Association For Science Education
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• v.40 no.4
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• pp.375-383
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• 2020

In this study, we investigated the effects of the multiple representation-based learning strategies using augmented reality in terms of students' conceptual understanding, achievement, and enjoyment of science lessons. 136 8^th-grade students in a coed middle school were randomly assigned to the treatment and the control group. The students learned the concept of the particulate nature of matter related to the properties of substances for four class periods. The multiple representation-based learning strategies designed to facilitate the connecting and integrating representations provided from augmented reality were developed and administered to the students of the treatment group. Results of two-way ANCOVA revealed that the scores of a conceptions test and enjoyment of science lessons test of the treatment group were significantly higher than those of the control group, regardless of their prior science achievement. In a conceptions test, there was a significant difference in the concept of preservation of particles. However, the difference was not statistically significant in the concept of distribution and motion of particles. In terms of an achievement test, there was a significant interaction effect by their prior science achievement. The scores of low-level students were significantly improved, but the effects were not significant to high-level students. On the bases of the results, educational implications for effective teaching and learning using augmented reality are discussed.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.7
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• pp.97-103
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• 2004

In this paper, we propose a high speed block turbo code decoding algorithm and an efficient hardware architecture. The multimedia wireless data communication systems need channel codes which have the high-performance error correcting capabilities. Block turbo codes support variable code rates and packet sizes, and show a high performance due to a soft decision iteration decoding of turbo codes. However, block turbo codes have a long decoding time because of the iteration decoding and a complicated extrinsic information operation. The proposed algorithm using the threshold that represents a channel information reduces the long decoding time. After the threshold is decided by a simulation result, the proposed algorithm eliminates the calculation for the bits which have a good channel information and assigns a high reliability value to the bits. The threshold is decided by the absolute mean and the standard deviation of a LLR(Log Likelihood Ratio) in consideration that the LLR distribution is a gaussian one. Also, the proposed algorithm assigns '1', the highest reliable value, to those bits. The hardware design result using verilog HDL reduces a decoding time about 30% in comparison with conventional algorithm, and includes about 20K logic gate and 32Kbit memory sizes.

• Spatial Information Research
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• v.7 no.1
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• pp.1-12
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• 1999

The DTM(Digital Terrain Model) in GIS(Geographical Information System) shows the elevation from interpolation using data points surveyed. In panoramic flat landform, pixel size, resolution of source data may not be the problem in using DTM However, in mountainous landform like Korea, appropriate resolution accuracy of source data are important factors to represent the topography concerned. In this study, the difference in contour interval of source data, the resolution after interpolation, and different data structures were compared to figure out the accuracy of slope calculation using DTM from the topographic maps of Togyusan National Park Two types of GIS softwares, Idrisi(grid) ver. 2.0 using the altitude matrices and ArcView(TIN) ver. 3.0a using TIN were used for this purpose. After the analysis the conclusions are as follows: 1) The coarser resolution, the more smoothing effect inrepresenting the topography. 2) The coarser resolution the more difference between the grid-based Idrisi and the TIN-based ArcView. 3) Based on the comparison analysis of error for 30 points from clustering, there is not much difference among 10, 20, 30 m resolution in TIM-based Airview ranging from 4.9 to 6.2n However, the coarser resolution the more error for elevation and slope in the grid-based Idrisi. ranging from 6.3 to 10.9m. 4) Both Idrisi and ArcView could net consider breaklines of lanform like hilltops, valley bottoms.

• The Korean Journal of Elementary Counseling
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• v.8 no.1
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• pp.123-139
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• 2009

The purpose of this study was to verify the effects of a conflict resolution program on conflict resolution strategies and friendship quality of children. The subjects of this study were higher-grader students of elementary school. Out of the students, 18 were into the experimental group, while the rest were into the control-group. The experimental design was the pretest-posttest control group design, and the 50-minutes conflict resolution program was treated for the experimental group twice per week (a total of 11 sessions). The scale of conflict resolution strategies presented by Ha Ji Wean (2005) and the scale of friendship quality of children presented by Rhee Un Hai and Koh Yun Joo (1999) were used as the measurement tools in this study. In order to supply the limitations of quantitative data, the journals of group participation of each session and the participation reports after the completion of the program were qualitatively analyzed. The results of hypotheses verification were as follows; First, conflict resolution strategies conflict was significant difference in enhancement of the compromising-integrating strategy and the obliging strategy, and reduction of the dominating strategy. Second, friendship quality was significant difference in enhancement of the friendship positive function, and friendship satisfaction, and in reduction of the friendship negative aspect, The results of the study confirmed that the conflict resolution program affected both conflict resolution strategies and the friendship quality of children.

• Journal of Broadcast Engineering
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• v.20 no.6
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• pp.901-911
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• 2015

Many studies tried to develop a 3D display based stereo test as a substitute for the conventional stereo test. Although many 3D monitor based stereo tests have various advantages over the conventional stereo tests with printed stimuli, they have a crucial limitation in manipulating disparity. The least value for disparity manipulation is one pixel, which is too big to screen the normal stereo acuity in pc environment with a short viewing distance. In this explorative study, a Gabor image was employed as a test stimulus, because its position can be manipulated by changing its phase information, which allows sub-pixel manipulation for disparity. Instead of employing the methods of the conventional stereo tests where measurement was made only once for each of a wide range of disparity values, 10 replications were administrated for each of 6 disparity levels. The results from the test using Gabor images were compared with those using random dot stimulus because the latter stimulus was exactly the same as that of the conventional stereo test. The correlation coefficient between two tests was found to be moderate. After one month later, the whole test was repeated in the same settings. The correlation coefficient between test and retest results from Gabor images was found to be as high as that from a random dot stimulus, implying high test-retest reliability. These results suggest that a Gabor stimulus could be used as a test stimulus for the valid and reliable stereo test, even in the limited condition, such as 3D environment with a short viewing distance and a condition for evaluating the stereo acuity very precisely.

• Korean Security Journal
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• no.14
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• pp.125-140
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• 2007

This study was to analyze structural equation modeling of organizational culture, human resource management and organization performance in the private security corporation. To attain the goal of the study described above paragraphs, the employee of private security corporation located in Seoul, 2006 year were set as a collected group. Then, using the cluster random sampling method, finally drew out 300 peoples and analyzed 250 peoples in total. The material collection device was the brochure named . The validity of instrument was confirmed by confirmatory factor analysis(CFA) The result of reliability check up was here below; Chronbach' ${\alpha}=.724$. To analyze materials, correlation analysis, CFA, SEM were used as statistic analysis techniques. The conclusion based on above study method and the result of material analysis are follows; First, organizational culture influences on the human resource management. Second, organizational culture influences on the organizational performance. Third, human resource management influences on the organizational performance. Particularly, organizational culture influences indirectly on organizational performance throughout human resource management. Human resource management is very important variable mediating organizational culture and performance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.85-90
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• 2017

Indoor location-based services have been developed based on the Internet of Things technologies which measure and analyze users who are moving in their daily lives. These various indoor positioning technologies require separate hardware and have several disadvantages, such as a communication protocol which becomes complicated. Based on the fact that a reduction in signal strength occurs according to the distance due to the physical characteristics of the transmitted signal, RSSI technology that uses the received signal strength of the wireless signal used in this paper measures the strength of the transmitted signal and the intensity of the attenuated received signal and then calculates the distance between a transmitter and a receiver, which requires no separate costs and makes to implement simple measurements. It was applied calculating the value for the average RSSI and the RSSI filtering feedback. Filtering is used to reduce the error of the RSSI values that are measured at long distance.It was confirmed that the RSSI values through the average filtering and the RSSI values measured by setting the coefficient value of the feedback filtering to 0.5 were ranged from -61 dBm to - 52.5 dBm, which shows irregular and high values decrease slightly as much as about -2 dBm to -6 dBm as compared to general measurements.