• Journal of KIISE:Information Networking
• /
• v.31 no.6
• /
• pp.573-581
• /
• 2004

Recently, the rapid growth of Internet technology and the deployment of high speed networks make many kinds of multimedia services possible. Preexisting multimedia services are designed based on the client/server model which has the problems such as the network failure and the low speed communication due to the high load on the central server. In order to solve these problems, peer-to-peer networks are introduced and expanded through Internet environments. In this paper, we propose a pure peer-to-peer network based resource discovery mechanism for multimedia services. In the proposed scheme, each host maintains the location information of resources which are recently requested by other hosts as well as that oi the replicas of local resources. The proposed scheme has the faster response time and incurs the smaller traffic than the preexisting discovery schemes in pure peer-to-peer network environments. Also, by decentralizing the location information and differentiating the reply path, our proposed scheme can solve the search result loss problem that occurs when the network is unsettled.

• Journal of Information Processing Systems
• /
• v.20 no.3
• /
• pp.375-390
• /
• 2024

Edge computing architecture has effectively alleviated the computing pressure on cloud platforms, reduced network bandwidth consumption, and improved the quality of service for user experience; however, it has also introduced new security issues. Existing anomaly detection methods in big data scenarios with cloud-edge computing collaboration face several challenges, such as sample imbalance, difficulty in dealing with complex network traffic attacks, and difficulty in effectively training large-scale data or overly complex deep-learning network models. A lightweight deep-learning model was proposed to address these challenges. First, normalization on the user side was used to preprocess the traffic data. On the edge side, a trained Wasserstein generative adversarial network (WGAN) was used to supplement the data samples, which effectively alleviates the imbalance issue of a few types of samples while occupying a small amount of edge-computing resources. Finally, a trained lightweight deep learning network model is deployed on the edge side, and the preprocessed and expanded local data are used to fine-tune the trained model. This ensures that the data of each edge node are more consistent with the local characteristics, effectively improving the system's detection ability. In the designed lightweight deep learning network model, two sets of convolutional pooling layers of convolutional neural networks (CNN) were used to extract spatial features. The bidirectional long short-term memory network (BiLSTM) was used to collect time sequence features, and the weight of traffic features was adjusted through the attention mechanism, improving the model's ability to identify abnormal traffic features. The proposed model was experimentally demonstrated using the NSL-KDD, UNSW-NB15, and CIC-ISD2018 datasets. The accuracies of the proposed model on the three datasets were as high as 0.974, 0.925, and 0.953, respectively, showing superior accuracy to other comparative models. The proposed lightweight deep learning network model has good application prospects for anomaly traffic detection in cloud-edge collaborative computing architectures.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.44 no.4
• /
• pp.639-656
• /
• 2020

Consumers' shopping experience has recently expanded to mobile and social networks; in addition, online fashion retailers started to focus on real-time interaction services as an emerging marketing tool. This study explores the consumer' shopping experience based on social live streaming services (SLSS) to investigate consumer's response behavior and effects through perceived service quality. An online survey method was conducted and a total of 186 female consumer panels were collected. The results indicate that cognitive communion of co-experience had a significant effect on perceived SLSS service quality (responsiveness, contents informativeness, playfulness, system availability). Service quality of SLSS (responsiveness, contents informativeness, and playfulness) had significant effect on trust in SLSS seller while system availability had no significant effect. Also, trust in seller showed significant effect on purchase intention. Last, it was confirmed that the moderating effect of purchasing experience of SLSS was significant in the relationship between cognitive communion and responsiveness/playfulness. There was also an additional significant moderating effect of purchasing experience between system availability and trust in seller.

• Journal of the Korean Regional Science Association
• /
• v.9 no.1
• /
• pp.79-99
• /
• 1993

This paper identifies the mechanisms governing the industrial location changes in Korea by focusing upon the emergence of the country's large conglomerate business organizations (chaebols). As the country has distinctive industrial organization, production systems, and government-business relations, this study tries to develop an ideal conceptual framework for the analysis of industrial location changes in Korea. It perceives the Korean economy as a system within which 'space-organizing', lage business organizations interact over time with government, smaller firms and multinational corporations at different geographical scales. The usefulness of the model is assessed using a case study of Korea's most representative chaebol, the Samsung Group. This study identifies chaebols as the dominant institutions in Korean society. Their growth and business strategies have been influenced by the Korean Government through its power to allocate capital resources. Regional dynamics of industry and labor, therfore, have been strongly influenced by changes in the location, industrial structure, and production system of chaebols. With econmic power concentrated within a few giant business groups and their major areas of operation restricted, unbalanced regional development has resulted. Dissatisfaction from residents in less-developed areas has pressured the Government to advise chaebols to disperse their production facilities. Most small and medium-sized firms are closely linked to large corporations through subcontracting. By forming hierarchical subcontracting. By forming hierarchical subcontracting systems, chaebols have indirectly exploited scattered, part-time, home-based, female and lower-paid laborers organized by subcontractors. Further, chaebols have expanded their business arena to encompass overseas locations in a bid to overcome the problem of a small domestic market, trade regulations and increased market, trade regulations and increased labor costs. Through their international business networks Korea's local and regional economies are integrated into the world economy. Indeed, the identification of the changing relationships of chaebols with both the Korean Government and smaller firms is the key to explaining the nations's spatial dyanmics of industry and labor.

• Journal of Korean Society of Transportation
• /
• v.27 no.6
• /
• pp.129-137
• /
• 2009

Operation of intelligent transport systems technologies in transportation networks and more detailed analysis give rise to necessity of dynamic traffic analysis model. Existing static models describe network state in average. on the contrary, dynamic traffic analysis model can describe the time-dependent network state. In this study, a dynamic traffic model for the expressway system using FTMS data is developed. Time-dependent origin-destination trip tables for nationwide expressway network are constructed using TCS data. Computation complexity is critical issue in modeling nationwide network for dynamic simulation. A subarea analysis model is developed which converts the nationwide O-D trip tables into subarea O-D trip tables. The applicability of the proposed model is tested under various scenario. This study can be viewed as a starting point of developing deployable dynamic traffic analysis model. The proposed model needs to be expanded to include arterial as well without critical computation burden.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.4
• /
• pp.831-840
• /
• 2010

While Wireless Internet services were activated, many users got possible to use various Internet services without limitation in location. In particular, the demands to Wireless Internet Services are getting expanded because mobile devices that support high mobility are getting smarter. However, if a user uses various wireless networks, much limitation occurs in network setting when they move to another network. This is because there are few appropriate Handover Mechanisms to support Heterogeneous Network. So, this paper propose that Fast-Handover for Vertical Network Handover with MIH in PMIPv6 to support heterogeneous network and to reduce the handover latency time. Analysis result presented in this paper shows that by carefully selecting suitable system configuration model and parameters, suggestion has reduced latency time of 26% and packet losses of 90% (Avg.) at the maximum in comparison with original PMIPv6 handover.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.17 no.11
• /
• pp.1206-1218
• /
• 1992

Token ring systems which control to switch the data stream of networks by passing the token have been widely used to medium access controls in many ring or bus topology LANs. The system could be modeled for analysis as single-server-multi-queue system of the cyclic service method. These concepts could be expanded to multi-token ring systems interconnected with single ring consisting of bridges implemented simply to be stored and transmitted. In the proposal for the performance analysis of the interconnected token ring system, in has been assumed M/G/1 queueing model that frame arrivals are the Poisson process at each station queue and frame sizes are independently and identically distributed. And the average time delays were analyzed mathematically for arbitrary frame transferred from source station to destination area. The time delay of the frame transmission could be explained as the sum of the average time which the token passed from arbitrary position to source station, such as the waiting time in the source station transferring the previous arrival frames, and the propagation time from source station to interdestinated point. These delays were given as the sum of the duration from inner and outer bridge queues, the time delays from inner and outer bridge queues, and the time from outer bridge queue to destination station. These results were investigated by varing parameters effected to total time delays. In the results, those factors to be effected to dominant the total time delays were increased were in the cases of the high arrival rates and the high ration of destination of the other outerring. The system were shown the time delays increased exponentially in spite of the priority service policy. In order to decreasing the number of outerrings and increasing the number of nodes in backbone relatively, so the systems could be decreased the total delay in the interconnected token ring system.

• Journal of Distribution Science
• /
• v.13 no.2
• /
• pp.95-104
• /
• 2015

Purpose - This is a comparative study of the market development and characteristics of Ulsan in South Korea, Fukuoka in Japan, and Yanji in China, which are major East Sea Rim cities with adjacent areas of similar natural characteristics of the sea and the country. Particularly, it considers these aspects while focusing on the evolution of networks that appear in the distribution system and at the same time examining the institutions of market activation and regulations that are handled by the central and the local government and the changing logistics due to the development of transportation and the concern of food safety, using a meso-analysis approach. Research design, data, and methodology - The study used a historical and comparative approach with a focus on case studies. It made use of various materials such as local newspaper articles, reports, literature, interviews with experts, discussions with local merchants, discussions with customers, and so forth. Results - In the case of Fukuoka, from the 1960s, due to the entry of supermarkets, supermarkets expanded and they have now come to a dominant market position in the current market. They offer a convenient and comfortable environment while providing a large mall offering a variety of educational and cultural activities for customers to meet the customers' needs, such as the preferences of Korean tourists, who appear to prefer Japanese foods. The Fukuoka City Central Wholesale Market has been exporting fruits and vegetables as well as seafood products to Korea, China, and so forth. In the case of Ulsan, as in the early 2000s, due to the expansion of supermarkets, the traditional markets have been shrinking and further, the modernization of traditional markets was conducted under the auspices of the Small Business Administration. In addition to the large discount malls, the expansion of SSM is expected to further drive the small trader bay. Shopping malls, department stores, and traditional markets contend with each other in Yanji, China, but a large number of citizens appear to prefer traditional markets and imported milk in the supermarket after the melamine scandal in China. Recently, the WanYuan (萬源) wholesale market has been partially completed and made an attempt to become a logistics hub in Northeast Asia. Conclusions - For the development of Korea's retail industry, it is important to offer the government with proposals regarding desired regulation. On the other hand, in order to enable the business of traditional markets, it requires an association for cultural tourism. At present, it would be better to provide a venture fund for the youth rather than infrastructure support. This study emphasizes the importance of institutions and policy to develop networks in the East Sea Rim. Future studies should conduct a survey on customers, managers, and merchants more carefully and systematically to understand the market situation while considering the size of the city and its evolution of markets, as well as policies and institutions.

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.2 s.34
• /
• pp.187-197
• /
• 2005

All sensors in Ubiquitous sensor network have to communicate with limited battery If we adopt current authentication, there are difficulties to keep sensor network because heavy calculation in each sensor needs more power and lifetime of sensor could be short relatively because of the effect. This paper suggests network structure which is using RM(RegisterManarer) and AM(AuthenticationManager) to solve power Problem on authentication, and su99ests mutual-authentication protocol with low Power which supports a session key by mutual-authentication. RM and AM manage algorithm with fast calculation to keep the safety by doing key generation. encryption/decryption. authentication instead of each sensor node . Processing time to authenticate sensor node is 2.96$\%$ fast in the same subnet, and 12.91$\%$ fast in different subnet. Therefore. the suggested way Provides expanded lifetime of censor node and is more effective as sensor network size is bigger and bigger.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.3A
• /
• pp.219-224
• /
• 2008

In the c-DSDV routing protocol proposed to improve the scalability of DSDV, clusterheads manage a routing table that has only clusterheads as potential destinations and flood update request message to its neighbor clusterheads periodically or at the time of topology change. Accordingly, the convergence range of topology change by a single update request message was expanded nine times as wide as that of DSDV, increasing routing correctness; however, c-DSDV suffers from the congestion of clusterheads since data packets always go through clusterheads of the clusters on the routing path. To improve this problem, we propose an adaptive routing scheme that judges if detouring clusterhead is possible on the fly while packets are forwarded. As a result, a routing path length is shortened and an end-to-end delay is improved by the reduced queue length. It shows that the end-to-end delay is reduced by almost 40% through simulation.