• The KIPS Transactions:PartC
• /
• v.18C no.1
• /
• pp.23-30
• /
• 2011

Recently internet protocol television (IPTV) service is becoming a typical emerging service enabled on broadband networks. Through the Internet which cannot support quality of service (QoS) beyond best-effort (BE) policy, how to manage and maintain its service quality is an important and essential issue for successful deployment and settlement of IPTV service. In particular, the current measurement scheme that mostly depends on specific equipments should be replaced with one that supports realtime and constant measurement achieved on a user's own will. Therefore, this paper proposes a scheme so-called 'user centric realtime measurement' of IPTV service. The developed software, which is installed in a set-top box (STB) at a user's premise, measures and reports the quality of IPTV service in realtime. In order to verify the performance and accuracy of the developed software, a number of tests are performed comparing to the measurement values from two major measurement equipments. The result of the tests shows that the measurement by the implemented software is significantly reliable.

• Asia pacific journal of information systems
• /
• v.16 no.2
• /
• pp.143-158
• /
• 2006

This paper considers probable determinants of the application software outsourcing costs and focuses on the service level agreement (SLA) influence. Recently, outsourcing clients and vendors have contracted SLA and tried to reflect them on outsourcing prices. While application software maintenance has been one of the most frequently outsourced functions, its cost did not reflect the service level requirements by the client. This paper empirically shows that the service urgency requirement on SLA increases the maintenance programmers' effort and thus increases the vendor's cost. This result can be used by vendors for program allocation purposes.

• Journal of Information Technology Services
• /
• v.9 no.4
• /
• pp.151-167
• /
• 2010

Recently, SaaS(Software as a Service) as a new type of information systems has become popular. Many information systems practitioners and academics, consequently, pay their attention to SaaS. However, there are very few empirical studies on SaaS success factors because of its short adoption history. This study, therefore, tries to identify a variety of success factors of its adoption and examines how these factors affect organizational performance using an exploratory approach. For this purpose, this study collects data from 132 Korean companies and analyzes the relationship between success factors and organizational performance. Our results are likely to help provide useful guidelines for the successful SaaS adoption.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.12
• /
• pp.1913-1920
• /
• 2017

Software Defined Networking creates totally new concept of networking and its applications which is based on separating the application and control layer from the networking infrastructure as a result it yields new opportunities in improving the network security and making it more automated in robust way, one of these applications is Denial of Service attack mitigation but due to the dynamic nature of Denial of Service attack it would require dynamic response which can mitigate the attack with the minimum false positive. In this paper we will propose a new mitigation Framework for DDoS attacks using Software Defined Networking technology to protect online services e.g. websites, DNS and email services against DoS and DDoS attacks.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.8
• /
• pp.3701-3727
• /
• 2016

Recently Service Function Chaining (SFC) is promising to innovate the network service mode in modern networks. However, a feasible implementation of SFC is still difficult due to the need to achieve functional equivalence with traditional modes without sacrificing performance or increasing network complexity. In this paper, we present a configurable network service chaining (CNSC) mechanism to provide services for network traffics in a flexible and optimal way. Firstly, we formulate the problem of network service chaining and design an effective service chain construction framework based on integrating software-defined networking (SDN) with network functions virtualization (NFV). Then, we model the service path computation problem as an integer liner optimization problem and propose an algorithm named SPCM to cooperatively combine service function instances with a network utility maximum policy. In the procedure of SPCM, we achieve the service node mapping by defining a service capacity matrix for substrate nodes, and work out the optimal link mapping policies with segment routing. Finally, the simulation results indicate that the average request acceptance ratio and resources utilization ratio can reach above 85% and 75% by our SPCM algorithm, respectively. Upon the prototype system, it is demonstrated that CNSC outperforms other approaches and can provide flexible and scalable network services.

• Journal of Information Technology Services
• /
• v.11 no.4
• /
• pp.295-308
• /
• 2012

Software and Systems Product Line(SSPL) is a paradigm that has been developed and applied by European Union(EU) to achieve the productivity and competitiveness of EU industries on the world market. It is not just a simple system or software development methodology, but a sophisticated technology requiring capabilities for a high level of mass customization, platforms, processes and convergence of software and systems. EU has applied SSPL for the five selected industrial sectors including aerospace, automobile, medical equipment, consumer electronics and telecommunication equipment since 1990s and led the way to other industry sectors to stimulate the application of SSPL from 2006. In order for Korea to secure competitiveness in the manufacturing and service industries in the competitive borderless market, it is essential to gain the high level of capabilities for software development and convergence of software and systems. SSPL can be a powerful means to achieve this end. This paper discusses the paradigmatic concept of SSPL, how EU's major industries and companies have secured competitiveness through SSPL, key capabilities that are necessary for successful institutionalization of SSPL in Korea, and finally suggestions on core strategies to materialize the benefits of SSPL for Korea.

• Journal of Internet Computing and Services
• /
• v.22 no.6
• /
• pp.1-8
• /
• 2021

With the rapid growth of intelligent devices and communication technologies, 5G network environment has become more heterogeneous and complex in terms of service management and orchestration. 5G architecture requires supportive technologies to handle the existing challenges for improving the Quality of Service (QoS) and the Quality of Experience (QoE) performances. Among many challenges, traffic steering is one of the key elements which requires critically developing an optimal solution for smart guidance, control, and reliable system. Mobile edge computing (MEC), software-defined networking (SDN), network functions virtualization (NFV), and deep learning (DL) play essential roles to complementary develop a flexible computation and extensible flow rules management in this potential aspect. In this proposed system, an accurate flow recommendation, a centralized control, and a reliable distributed connectivity based on the inspection of packet condition are provided. With the system deployment, the packet is classified separately and recommended to request from the optimal destination with matched preferences and conditions. To evaluate the proposed scheme outperformance, a network simulator software was used to conduct and capture the end-to-end QoS performance metrics. SDN flow rules installation was experimented to illustrate the post control function corresponding to DL-based output. The intelligent steering for network communication traffic is cooperatively configured in SDN controller and NFV-orchestrator to lead a variety of beneficial factors for improving massive real-time Internet of Things (IoT) performance.

• Informatization Policy
• /
• v.24 no.3
• /
• pp.42-66
• /
• 2017

This study investigated the ecological change of public software industry, comparing the pre and post structure of industry network based on the application of the regulation restricting large company participation in public software market. For this purpose, we used big data of the software market from Korea Public Procurement Service and used the SNA(Social Network Analysis) methodology which is being actively used in the area of social science recently. Finally, we highlighted the contribution of open public data. By analyzing order and contract data of the public software industry for 3 years - from 2013 to 2015 - we found out two main things. First, we observed that Power Law distribution had been going on in the public software industry, regardless of the external impact of regulation. Second, despite the existence of such Power Law distribution, we also observed the ecological change of industry structure from year to year. We presented the implication of such findings and discussed the advantage of open public data as the original motivator of this study.

• Journal of The Korean Association of Information Education
• /
• v.25 no.4
• /
• pp.621-632
• /
• 2021

This study is about development and application of a curriculum to implement physical computing education in an online environment for pre-service teachers. First, a 15-week software and physical computing curriculum was designed according to the ADDIE instructional design model. As a tool that can be used online, education was conducted on a program using various sensors using Pocket Code, an EPL based on a smartphone. As a result of the application of the program, Personal efficacy, Pedagogical knowledge, Technology teaching content knowledge, Result expectation, and Student belief were all significantly improved. In the software attitude part, Software interest and Software value part increased significantly, and the Perception of software engineers did not change. In general, in the case of physical computing, it is difficult to execute in an online environment because it involves a lot of manipulation activity. Through various studies that can continue education in a non-face-to-face environment or a blended environment in the post-corona era, it is hoped that it will be possible to provide a high-quality curriculum to pre-service teachers in charge of future education.

• Journal of information and communication convergence engineering
• /
• v.8 no.3
• /
• pp.245-250
• /
• 2010

To support various bandwidth requirements for many kinds of devices such as PC, notebook, PDA, cellular phone, a transcoding proxy is usually necessary to provide not only adapting multimedia streams to the client by transcoding, but also caching them for later use. Due to huge size of streaming media, we proposed the 3 kinds of segmentation - PT-2, uniform, bitrate-based segmentation. And to reduce the CPU cost of transcoding video, we proposed the DQS service policy. In this paper, we simulate the combined our previous two researches that are bitrate-based segmentation and DQS(Degraded Quality Service) policy. Experimental results show that the combined policy outperforms companion schemes in terms of the byte-hit ratios and delay saving ratios.