• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.46 no.1
• /
• pp.35-45
• /
• 2009

In an open environment such as Home Network, ZigBee Cluster comprising a plurality of Ato-cells is required to provide intense security over the movement of collected, measured data. Against this setting, various security issues are currently under discussion concerning master key control policies, Access Control List (ACL), and device sources, which all involve authentication between ZigBee devices. A variety of authentication methods including Hash Chain Method, token-key method, and public key infrastructure, have been previously studied, and some of them have been reflected in standard methods. In this context, this paper aims to explore whether a new method for searching for neighboring devices in order to detect device replications and Sybil attacks can be applied and extended to the field of security. The neighbor detection applied method is a method of authentication in which ACL information of new devices and that of neighbor devices are included and compared, using information on peripheral devices. Accordingly, this new method is designed to implement detection of malicious device attacks such as Sybil attacks and device replications as well as prevention of hacking. In addition, in reference to ITU-T SG17 and ZigBee Pro, the home network equipment, configured to classify the labels and rules into four categories including user's access rights, time, date, and day, is implemented. In closing, the results demonstrates that the proposed method performs significantly well compared to other existing methods in detecting malicious devices in terms of success rate and time taken.

• Journal of Advanced Marine Engineering and Technology
• /
• v.39 no.7
• /
• pp.760-764
• /
• 2015

Wireless sensors, installed on machinery, and Time Division Multiple Access (TDMA) transmission make an ideal system for monitoring machine conditions in industrial plants because there is no need for electronic wiring. However, there has not yet been a successful field application of such a system, capable of continuously transmitting data at sample rates greater than 100 Hz. In this research, a TDMA network protocol capable of acquiring data from multiple sensors at sample rates greater than 100 Hz was developed for field application. The protocol was implemented in a single cluster-star topology network, and the system was evaluated based on the node number and transmission distance. Network simulator 2 (ns-2) was used for a real field simulation. Non-TDMA and TDMA protocol cases were compared using four sensor nodes. In the cases of 20-s and 40-s transmission times, there was little difference between the reception rates of the non-TDMA and TDMA systems. However, the difference was much greater when using a 60-s transmission time.

• Journal of the Korea Society of Computer and Information
• /
• v.18 no.6
• /
• pp.29-36
• /
• 2013

In wireless sensor networks, energy is the most important consideration because the lifetime of the sensor node is limited by battery. Most of the existing energy efficient routing protocols use the minimum energy path to minimize energy consumption, which causes an unbalanced distribution of residual energy among nodes. As a result, the power of nodes on energy efficient paths is quickly depletes resulting in inactive. To solve these problems, a method to equalize the energy consumption of the nodes has been proposed, but do not consider the link error rate in the wireless environment. In this paper, we propose a uniform energy consumption of cluster-based multi-hop routing mechanism considering the residual energy and the link error rate. This mechanism reduces energy consumption caused by unnecessary retransmissions and distributes traffic evenly over the network because considering the link error rate. The simulation results compared to other mechanisms, the proposed mechanism is energy-efficient by reducing the number of retransmissions and activation time of all nodes involved in the network has been extended by using the energy balanced path.

• Molecules and Cells
• /
• v.28 no.5
• /
• pp.423-430
• /
• 2009

In order to elucidate the precise phylogenetic relationships of Korean wild boar (Sus scrofa coreanus), a partial mtDNA D-loop region (1,274 bp, NC_000845 nucleotide positions 16576-1236) was sequenced among 56 Korean wild boars. In total, 25 haplotypes were identified and classified into four distinct subgroups (K1 to K4) based on Bayesian phylogenetic analysis using Markov chain Monte Carlo methods. An extended analysis, adding 139 wild boars sampled worldwide, confirmed that Korean wild boars clearly belong to the Asian wild boar cluster. Unexpectedly, the Myanmarese/Thai wild boar population was detected on the same branch as Korean wild boar subgroups K3 and K4. A parsimonious median-joining network analysis including all Asian wild boar haplotypes again revealed four maternal lineages of Korean wild boars, which corresponded to the four Korean wild boar subgroups identified previously. In an additional analysis, we supplemented the Asian wild boar network with 34 Korean and Chinese domestic pig haplotypes. We found only one haplotype, C31, that was shared by Chinese wild, Chinese domestic and Korean domestic pigs. In contrast to our expectation that Korean wild boars contributed to the gene pool of Korean native pigs, these data clearly suggest that Korean native pigs would be introduced from China after domestication from Chinese wild boars.

• KIPS Transactions on Computer and Communication Systems
• /
• v.8 no.8
• /
• pp.191-200
• /
• 2019

In an Ad-hoc network, a method of time synchronizing all the nodes in a network centering on one reference node can be used. A representative algorithm based on a reference node is Flooding Time Synchronization Protocol (FTSP). In the process of sending and receiving messages, predictable and unpredictable delays occur, which should be removed because it hinders accurate time synchronization. In multi-hop communications, hop delays occur when a packet traverses a number of hops. These hop delays significantly degrade the synchronization performance among nodes. Therefore, we need to find a method to reduce these hop delays and increase synchronization performance. In the FTSP scheme, hop delays can be greatly increased depending on the position of a reference node. In addition, in FTSP, a node with the smallest node ID is elected as a reference node, hence, the position of a reference node is actually arbitrarily determined. In this paper, we propose an optimal reference node election algorithm to reduce hop delays, and compare the performance of the proposed scheme with FTSP using the network simulator OPNET. In addition, we verify that the proposed scheme has an improved synchronization performance, which is robust to topology changes.

• Journal of Korea Port Economic Association
• /
• v.37 no.4
• /
• pp.33-40
• /
• 2021

Currently, the shipping and port industries are implementing strategies to improve port processing capabilities through the expansion and efficient operation of port logistics resources to survive fierce competition with rapidly changing trends. The calculation of the port's processing capacity is determined by the loading and unloading equipment installed at the dock, and the port's processing capacity can be improved through various methods, such as additional deployment of logistics resources or efficient operation of resources in use. However, it is difficult to expect an improvement effect in a short period of time because the additional deployment of logistics resources is clearly limited in time is clear. Therefore, it is a feasible way to find an efficient operation method for resources being used to improve processing capacity. Domestic ports are also actively promoting informatization and digitalization with the development of the 4th industrial revolution technology. However, the calculation of the number of Y/T (Yard Tractor) assignments in the current unloading process depends on expert experience, and related previous studies also focus on the allocations of Y/T or Calculation of the total number of Y/T required. Therefore, this study analyzed the factors affecting the number of Y/T allocations using the loading and unloading information of incoming ships, and based on this, cluster analysis, regression analysis, and deep neural network(DNN) model were used.

• Journal of Korea Technology Innovation Society
• /
• v.21 no.1
• /
• pp.64-91
• /
• 2018

This study explores the interactive pattern among social issue, academic research, and governmental policy on science and technology during the last 20 years. In particular, we try understand wether the science and technology policy research and governmental policy meets social needs appropriately. In order to do this, we have collected text data from news articles, papers, and governmental documents. Based on these data, social network analysis and cluster analysis has been carried out. According to the results, we have found that science and technology policy researches tend to focus on fragmented technological innovation meeting urgent practical needs at the initial stage. However, recently, the main characteristics of science and technology policy research shows co-evolutionary patterns responding to society. Furthermore, time lag also has been observed in the process of interaction among the three bodies. Based on these results, we put forward some suggestions for upcoming researches in science and technology policy. Firstly, analysis levels are needed to be shifted from micro level to mezo or macro level. Secondly, more research efforts are required to be focused on policy process in science technology and its public management. Finally, we have to enhance the sensitiveness to social issues through studies on agenda setting in science and technology policy.

• The Journal of Industrial Distribution & Business
• /
• v.12 no.1
• /
• pp.47-62
• /
• 2021

Purpose: Our purpose in this study was to examine the strategies for the development of watermelon industry using unstructured big data analysis. That is, this study was to look the change of issues and consumer's perception about watermelon using big data and social network analysis and to investigate ways to strengthen the competitiveness of watermelon industry based on that. Methodology: For this purpose, the data was collected from Naver (blog, news) and Daum (blog, news) by TEXTOM 4.5 and the analysis period was set from 2015 to 2016 and from 2017-2018 and from 2019-2020 in order to understand change of issues and consumer's perception about watermelon or watermelon industry. For the data analysis, TEXTOM 4.5 was used to conduct key word frequency analysis, word cloud analysis and extraction of metrics data. UCINET 6.0 and NetDraw function of UCINET 6.0 were utilized to find the connection structure of words and to visualize the network relations, and to make a cluster of words. Results: The keywords related to the watermelon extracted such as 'the stalk end of a watermelon', 'E-mart', 'Haman', 'Gochang', and 'Lotte Mart' (news: 015-2016), 'apple watermelon', 'Haman', 'E-mart', 'Gochang', and' Mudeungsan watermelon' (news: 2017-2018), 'E-mart', 'apple watermelon', 'household', 'chobok', and 'donation' (news: 2019-2020), 'watermelon salad', 'taste', 'the heat', 'baby', and 'effect' (blog: 2015-2016), 'taste', 'watermelon juice', 'method', 'watermelon salad', and 'baby' (blog: 2017-2018), 'taste', 'effect', 'watermelon juice', 'method', and 'apple watermelon' (blog: 2019-2020) and the results from frequency and TF-IDF analysis presented. And in CONCOR analysis, appeared as four types, respectively. Conclusions: Based on the results, the authors discussed the strategies and policies for boosting the watermelon industry and limitations of this study and future research directions. The results of this study will help prioritize strategies and policies for boosting the consumption of the watermelon and contribute to improving the competitiveness of watermelon industry in Korea. Also, it is expected that this study will be used as a very important basis for agricultural big data studies to be conducted in the future and this study will offer watermelon producers and policy-makers practical points helpful in crafting tailor-made marketing strategies.

• Journal of the Korean Geographical Society
• /
• v.41 no.1 s.112
• /
• pp.1-21
• /
• 2006

Abstract The purpose of this paper is to analyze production and innovation networks of manufacturers in the rural, long-live areas of Gangwon Jeju and to suggest an ideal regional development model of rural areas in the knowledge-based information age. For this purpose, we compared the areas of Gangwon Jeju with the long-live belt areas in the rural pan of the Honan region and Gwangju Jeonju, the urban part of Honam. The findings from the study are summarized as follows. Firstly, the stronger the local networks in terms of supply of the necessary input materials and labor, the more successful the manufacturing industry is in the given area. Secondly, the more diverse and lasting the networks (in terms of the location of manufacturers, local area and national area) and cooperation agents(businesses, research institutions, the local government, the central government) they have, the more prosperous the manufacturing industry is. These results indicate that the successful development model for rural areas requires that we take the approach of fostering potential innovation capabilities of total areas by fully utilizing their innate resources so as to create an internal cooperative network and further build extensive networks encompassing external entities to create a virtual innovation cluster.

• 한국노년학
• /
• v.37 no.3
• /
• pp.707-726
• /
• 2017

Korea is proceeding to aging society at much faster pace than other countries. To alleviate various problems (health, environment, social relationships, psychology and emotion, and financial problems) of the elderly caused by aging society, there has been increasing attention to social capital. This study investigated types of ways that the elderly at individual level are aware of social capital and the characteristic. In addition, factors that influence the types were studied. Data from 1060 elderly with the age of 65 and older were collected in Korea. Excluding missing data on variables used in the study, data of 960 elderly were used for analyses. K-mean cluster analysis was conducted to investigate types of elderly awareness on social capital at individual level. Multinominal logistic regression was used to find out factors of the types. K-mean cluster analysis resulted in three types of awareness on social capital among the elderly: (1) potential of social capital; (2) severance of social capital; and (3) wealth of social capital. Multinominal logistic regression resulted in that compared to potential of social capital type, when the elderly were younger, inclination of politics was more progressive, they did not have religion, they did not reside in rural, and they did not live in multiplex housing, the elderly were more likely to be in severance of social capital type. Also, when the elderly were women, had higher education and standard of living, were Christian, and did not reside in rural regions. they tended to be in wealth of social capital type. Based on the study results about awareness on social capital among the elderly and factors related to the awareness types, practical and political suggestions that promote social capital to solve problems of the elderly were provided.