• The Transactions of the Korea Information Processing Society
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• v.7 no.4
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• pp.1227-1235
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• 2000

In this paper, we propose new concepts that the distributed counter value with the distributed EC system identify each user who users the distributed system. The web user should register his/her own user ID in the cyber shopping mall system. Instead of registration, this paper proposes the proprietary mechanism that is distributing counter. The counter assigns the distinguished number to each client. The distributed lock algorithm is used for mutual assignment of the counter to each client. The proposed algorithm is the best solution in the distributed environment system such as cyber shopping mall. If a user should register his/her own ID in every EC system, he/she may not try to use these uncomfortable systems. The mutual counter is used to identify each client. All of these features are designed and implemented on Windows NT web server. Also these features were experiments with 5 clients for 300 times. According to the experiments, clients have their own mutual counter value. The proposed algorithm will be more efficient in internet application environment. Moreover, it will improve the number of internet users.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.3
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• pp.855-868
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• 2012

In this paper, we consider the discrete memoryless user relaying channel (DMURC) in which a user-relay switches its operational mode symbol-by-symbol. In particular, we obtain upper and lower bounds on the channel capacity for the general DMURC and then show that these the upper and lower bounds coincide for degraded DMURC. It is also shown that the capacity of the degraded DMURC can be achieved using two separate codebooks corresponding to the two UR states. While the UR is assumed to switch states symbol-by-symbol, the results in this paper is the same as when the UR switches states packet-by-packet.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.12
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• pp.4324-4342
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• 2014

Previous papers analyzed the throughput performance of the CDMA ALOHA system in Rayleigh fading channel, but they assume that the channel coefficient of Rayleigh fading was the same in the whole packet, which is not realistic. We recently proposed the finite-state Markov channel (FSMC) model to the throughput analysis of DS uncoded CDMA/unslotted ALOHA networks for fixed length data traffic in the mobile environment. We now propose the FSMC model to the throughput analysis of coded DS CDMA/unslotted ALOHA networks with variable length data traffic and one or two user classes in the mobile environment. The proposed DS CDMA/unslotted ALOHA wireless networks for two user classes with access control can maintain maximum throughput for the high priority user class under high message arrival per packet duration.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.3
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• pp.235-250
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• 2009

An understanding of performance of database driven network applications is critical in combating slow performance of e-commerce web sites, besides efficient web page design, and high quality and well-maintained web server equipment. This paper describes a method of measuring performance from the user viewpoint, which can help enormously in making realistic assessment of true performance of database driven applications. The performance measurements were taken at user locations by using several specially designed JavaScript functions along with ASP scripts. A performance study is presented in this paper, comparing performance of data access using stored procedures with the traditional way of querying a database. It is generally believed that stored procedures have performance benefits as they are pre-compiled. However, our study shows that the data access approach using stored procedures provides significant benefits(by about 30%) over the traditional approach for querying a commercial MySQL database, only when retrieving a substantial amount of data(at least 10,000 rows of data).

• Journal of the Korea Society of Computer and Information
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• v.8 no.2
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• pp.122-128
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• 2003

There are many development methods to implement wireless internet service. These methods are WAP(Wireless Application Protocol) based services and Java based service WAP based service has been proposed to support limited convenience for user But Java based service can support many convenience and GUI(Graphic User Interface) and easy to use to access for user. This paper will be propose a WAP based application development method and Java based application development method. As an illustrative experiment, WAP based service and Java based service are used to show performance for each systems.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.9 no.1
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• pp.24-28
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• 2010

The Quality of Experience (QoE) of next Generation wired/wireless network services based upon IP networking is becoming a popular issue in recent years. The user experience of Internet services such as IPTV, online game, web surfing and etc, are becoming the most desirable factors to service providers to improve service performance and customer's satisfaction. However, collecting user experience from customers and obtaining the QoE parameters from the Quality of Service (QoS) parameters such as bandwidth, delay, jitter or admission control algorithm, are difficult subjects because of the various service types and user characteristics. In this paper, we propose a framework which contains service classification, QoE analysis and service enhancement steps for a suitable QoE measurement and management protocol. We define the user satisfaction indicators of the Internet services, classify the categories of each type of services, and analyse the Key Performance Indicator (KPI) in each type of services to perform the QoS parameters and improving the service qualities.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.1
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• pp.177-190
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• 2011

The purpose of this study is to explore the determinants of actual demand for wireless broadband (WiBro) services in Korea. To this end, this study identifies conceptual definitions of diverse latent variables and determines the significance of the causal relationship between independent and dependent variables. It then presents the nomadic user concept by testing the moderator effect. This study also proposes a revised Unified Theory of Acceptance and Use of Technology (UTAUT) model, which is an appropriate model for wireless communication services and users' attributes. Prior research has concentrated exclusively on the Technology Acceptance Model (TAM) based on future potential users. Compared to previous studies, the current research model and analysis results are useful in not only academic but also industry contexts.

• Journal of Information Management
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• v.33 no.2
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• pp.49-66
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• 2002

In this paper, the recent trends of user-centered information communication are reviewed, especially focused on Computer-Mediated Communication(CMC) based on internet, Human Factors Engineering, and Human-Computer Interaction(HCI). The result is that human-centered information communication process has influence on the extension of user interface.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.9
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• pp.4771-4787
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• 2019

Aimed at the disclosure risk of mobile terminal user's location privacy in location-based services, a location-privacy protection scheme based on similar trajectory substitution is proposed. On the basis of the anonymized identities of users and candidates who request LBS, this scheme adopts trajectory similarity function to select the candidate whose trajectory is the most similar to user's at certain time intervals, then the selected candidate substitutes user to send LBS request, so as to protect user's privacy like identity, query and trajectory. Security analyses prove that this scheme is able to guarantee such security features as anonymity, non-forgeability, resistance to continuous query tracing attack and wiretapping attack. And the results of simulation experiment demonstrate that this scheme remarkably improve the optimal candidate' trajectory similarity and selection efficiency.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.143-148
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• 2022

In this paper, we employ deep neural network (DNN) to discern Android user interaction data distribution from artificial data distribution. We utilize real Android user interaction trace dataset collected from [1] to evaluate our DNN design. In particular, we use sequential model with 4 dense hidden layers and 1 dense output layer in TensorFlow and Keras. We also deploy sigmoid activation function for a dense output layer with 1 neuron and ReLU activation function for each dense hidden layer with 32 neurons. Our evaluation shows that our DNN design fulfills high test accuracy of at least 0.9955 and low test loss of at most 0.0116 in all cases of artificial data distributions.