• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.1057-1069
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• 2017

The applications of Wireless Sensor Networks (WSN) are progressively adopting for various smart home services such as home automation, controlling smart home household appliances, constrained application services in a smart home, etc. However, enabling a seamless and ubiquitous WSN communication between the smart home appliances is still a challenging job. Therefore, in this paper, we propose a smart home control system using an Actuator based ZigBee networking (AZNET). The working of the proposed system is further divided into three phases, 1) an interference avoidance system is adopted to mitigate the effect of interference caused due to the co-existence of IEEE 802.11x based wireless local area networks (WLAN) and WSN, 2) a sensor-based smart light control system is used to fulfill the light requirement in the smart home using the sunlight with light source, and 3) an autonomous home management system is used to regulate the usage time of the electronic appliances in the smart home. The smart is tested in real time environment to use the sunlight with light sources in a various time of the day. Similarly, the performance of the proposed smart home is verified through simulation using C# programming language. The results and analysis revealed that the proposed smart home is less affected by the interference and efficient in reducing the energy consumption of the appliances available in the smart home scenario.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.5
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• pp.1938-1962
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• 2015

Security of information during transmission is a major issue in this modern era. All of the communicating bodies want confidentiality, integrity, and authenticity of their secret information. Researchers have presented various schemes to cope with these Internet security issues. In this context, both steganography and cryptography can be used effectively. However, major limitation in the existing steganographic methods is the low-quality output stego images, which consequently results in the lack of security. To cope with these issues, we present an efficient method for RGB images based on gray level modification (GLM) and multi-level encryption (MLE). The secret key and secret data is encrypted using MLE algorithm before mapping it to the grey-levels of the cover image. Then, a transposition function is applied on cover image prior to data hiding. The usage of transpose, secret key, MLE, and GLM adds four different levels of security to the proposed algorithm, making it very difficult for a malicious user to extract the original secret information. The proposed method is evaluated both quantitatively and qualitatively. The experimental results, compared with several state-of-the-art algorithms, show that the proposed algorithm not only enhances the quality of stego images but also provides multiple levels of security, which can significantly misguide image steganalysis and makes the attack on this algorithm more challenging.

• Convergence Security Journal
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• v.20 no.3
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• pp.99-108
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• 2020

The COVID-19 pandemic have been spreading continuously across the world, hence it is difficult to expect coming to an end in a short period of time. The use of digital technology has shown tangible results in suppressing COVID-19, but raised privacy and data-protection concerns. In the context of the global efforts to deal with the coronavirus pandemic, various digital technologies are taking on a role in surveillance, monitoring, and forecasting. Also the Korea government manages Corona crisis based on legal basis. In this paper, Korea and each country's response to the Corona 19 pandemic are shown, and suggests ways to protect personal information while using digital tools. Large-scale data collection and processing is essential for the suppression of pandemic, but it should be limited to the level and scope required privacy. Also international cooperation, temporary and transparent use of personal information, the corresponding legal basis are necessary. As the use of data and algorithms is expected to continue to increase, technical and institutional efforts to reinforce privacy protection must continue.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.1
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• pp.84-93
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• 2018

In this paper, we propose an Elman recurrent neural network to predict and analyze a time series of power energy consumption. To this end, we consider the volatility of the time series and apply the sample variance and the detrended fluctuation analyses to the volatilities. We demonstrate that there exists a correlation in the time series of the volatilities, which suggests that the power consumption time series contain a non-negligible amount of the non-linear correlation. Based on this finding, we adopt the Elman recurrent neural network as the model for the prediction of the power consumption. As the simplest form of the recurrent network, the Elman network is designed to learn sequential or time-varying pattern and could predict learned series of values. The Elman network has a layer of "context units" in addition to a standard feedforward network. By adjusting two parameters in the model and performing the cross validation, we demonstrated that the proposed model predicts the power consumption with the relative errors and the average errors in the range of 2%~5% and 3kWh~8kWh, respectively. To further confirm the experimental results, we performed two types of the cross validations designed for the time series data. We also support the validity of the model by analyzing the multi-step forecasting. We found that the prediction errors tend to be saturated although they increase as the prediction time step increases. The results of this study can be used to the energy management system in terms of the effective control of the cross usage of the electric and the gas energies.

• Journal of the Korean association of regional geographers
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• v.8 no.3
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• pp.396-411
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• 2002

This paper aims to explore organisational change and learning involving spatial processes and outcomes. In particular, it focuses on the context specific nature of corporate learning and organisational change that can be found in the case of a large Korean firm facing radical economic change. Drawing on the case study of a large Korean firm, the Samsung Electronics Company, three main claims can be followed. First, territorial sources of learning influence the way in which the firm makes use of space/place. Second, corporate learning practices, however, are not based merely on specific localised sources or geographical proximity but on bringing together the local and the global sources by harnessing the properties of relational proximities. It reveals that firms are concerned less on specialising specific local knowledge than promoting organisational knowledge and competences by integrating a variety of knowledge distributed in and out of the boundaries of the firm. Finally, to learn and innovate in a continual basis, firms would attempt to combine codified knowledge with tacit knowledge.

• Journal of the Korean housing association
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• v.20 no.6
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• pp.111-118
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• 2009

In modern Asia major cities had same problem with lack of affordable housing for families. So they had to concentrate to the mass supply of housing and made some physical counter effects like high density of cities, limitation of parking space. Also people who lived in those cities could suffer from broken traditional community culture. To rebuild traditional community and increase land usage, Block housing is suggested as a new kind of multi-family housing for old town redevelopment. Now some governments are trying to make urban code to give some initiative for new block housing development in old city blocks. They expect this new housing type can help to solve serious problems like lack of parking area, green space and context of block. Also they hope that block housing development can help to increase safety of town and reduce cost of development. The purpose of this study is to review the establishment and development process of Block Housing and to confirm the aspect which has been changed with urban organization together. Also this study tried to find out the intentional characteristics of similarities and differences with comparison of Korea and Japan. And as a result we could find critical physical viewpoint, and provide considerations for future study and plan. Several cases of block housing in Korea and Japan were reviewed for comparative study and Post Occupancy Evaluation (POE) survey was examined to find satisfaction factors and problems which were expected to improved.

• Journal of the Korean Society of Safety
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• v.26 no.6
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• pp.130-136
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• 2011

Since out of a lot of traffic problems traffic accidents cause damage to life and properties of people, it stands out as one of traffic problems which needs improvement, and the loss due to traffic accident negatively affects not only the parties to the accident but also the national economy. Thus, continual concern of the government toward traffic safety is getting bigger and lately each local government is preparing a basic plan for traffic safety and vitalizing traffic safety policies. As expanding the responsibility and role of local governments for traffic safety, traffic safety measures which are based on the characteristics of each local government should be studied. Most of analytical methods in the existing traffic accidents prediction models with macroscopic vision focus on socioeconomic variables such as local population and the number of registered vehicles, and present a great deal of prediction error when they are applied in practice. In this context, this study proposed a traffic accident prediction model in respect of macroscopic level for autonomous districts (administrative districts) of Seoul City. The model development was not based on the entire city but on the type of local land usage (development density) whose relationship with traffic accident frequency was analyzed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.464-466
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• 2018

In this paper, a dense cellular network is considered in which each base station equipped with multiple antennas simultaneously communicates with multiple single-antenna users. Based on limited feedback, each user feeds back its quantized channel state information (CSI) to its associated transmitter, and the transmitter broadcasts multiple data streams prepared for the scheduled users using a space-division multiple access scheme. As the amount of CSI is limited at the transmitter, the downlink throughput increases with the number feedback bits. However, the increased number of feedback bits requires the correspondingly increased amount of uplink resources. Thus, an appropriate balance between the downlink throughput and the uplink resource usage should be considered in realistic systems. A net spectral efficiency defined in this context is used in this paper, and the optimal number of feedback bits that maximizes the net spectral efficiency is analyzed. This paper particularly focuses on the case when the received signal power is much smaller than the noise power.

• Culinary science and hospitality research
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• v.21 no.1
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• pp.159-173
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• 2015

This study performed to examine the effects of the characteristics of SNS information, SNS site, and perceived usefulness of information on the visiting intention of SNS user in context of restaurant. Customers use SNS for navigation to find useful information and confirm the information about the destination they would like to visit. To achieve purpose of the current study, we developed a research model based on theoretical backgrounds and conducted a questionnaire survey targeting who is using SNS for searching a useful information. The results were as follow. 1) SNS information reliability, neutrality and amusement had a positive effect on the perceived usefulness of the information. 2) SNS site interaction, usage simplicity and reliability had a positive influence on the perceived usefulness of the information. 3) SNS user's perceived usefulness of the information had a positive effect on the perceived usefulness of the information.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.30 no.4
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• pp.197-216
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• 2019

The study aimed to investigate the motivation and user satisfaction of medical school graduate students using specific academic information sites, and examines the effect of usage motivation factors on user satisfaction. This study was conducted from September 10, 2018 to September 21, 2018 by a large medical school graduate student in Seoul, and analyzed 135 valid responses. According to the analysis, the degree of reliability and interactivity of PubMed is higher than that of Google Scholar in medical school graduate students' use of academic information sites. It was found to have a significant effect on user satisfaction of academic information sites. In particular, convenience has the greatest influence on users' choice of academic information sites. The results of the study are of theoretical implications in that the discussion of academic information services through web sites is explained in terms of use and satisfaction in the context of medical information. On the other hand, specific research results provide practical implications for improving the services of medical-related academic search engines.