• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.10a
• /
• pp.466-469
• /
• 2011

Recently, a new theoretical and methodological approach for computational science is becoming more and more popular for analyzing and solving scientific problems in various scientific disciplines such as Computational fluid dynamics, Chemistry, Physics, Structural Dynamics, Computational Design and applied research. Computational science is a field of study concerned with constructing mathematical models and quantitative analysis techniques and using large computing resources to solve the problems which are difficult to approach in a physical experimentally. In this paper, we present R&D of EDISON open integration platform that allows anyone like professors, researchers, industrial workers, students etc to upload their advanced research result such as simulation SW to use and share based on the cyber infrastructure of supercomputer and network. EDISON platform, which consists of 3 tiers (EDISON application framework, EDISON middleware, and EDISON infra resources) provides Web portal for education and research in 5 areas (CFD, Chemistry, Physics, Structural Dynamics, Computational Design) and user service.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.10a
• /
• pp.245-248
• /
• 2011

Voice over Internet protocol(VoIP) is call's contents using the existing internet. Thus, in common with the Internet service has the same vulnerability. In addition, unlike traditional PSTN remotely without physical access to hack through the eavesdropping is possible. Cyber terrorism by anti-state groups take place when the agency's computer network and telephone system at the same time work is likely to get upset. In this paper is penetration testing for security threats(Call interception, eavesdropping, misuse of services) set out in the NIS in the VoIP. In addition, scenario writing and penetration testing, hacking through the Voice over Internet protocol at the examination center will study discovered vulnerabilities. Vulnerability discovered in Voice over Internet protocol presents an attack and defense plan.

• The KIPS Transactions:PartC
• /
• v.14C no.5
• /
• pp.411-416
• /
• 2007

The General security method of wireless network provides a confidentiality of communication contents based on the cryptographic stability against a malicious host. However, this method exposes the logical and physical addresses of both sender and receiver, so transmission volume and identification of both may be exposed although concealing that content. Covered address scheme that this paper proposes generates an address to which knapsack problem using super increasing sequence is applied, and replaces the addresses of sender and receiver with addresses from super increasing sequence. Also, proposed method changes frequently secret addresses, so a malicious user cannot watch a target system or try to attack the specific host. Proposed method also changes continuously a host address that attacker takes aim at. Accordingly, an attacker who tries to use DDoS attack cannot decide the specific target system.

• Journal of Information Processing Systems
• /
• v.14 no.4
• /
• pp.989-1009
• /
• 2018

Rapid advances in science and technology with exponential development of smart mobile devices, workstations, supercomputers, smart gadgets and network servers has been witnessed over the past few years. The sudden increase in the Internet population and manifold growth in internet speeds has occasioned the generation of an enormous amount of data, now termed 'big data'. Given this scenario, storage of data on local servers or a personal computer is an issue, which can be resolved by utilizing cloud computing. At present, there are several cloud computing service providers available to resolve the big data issues. This paper establishes a framework that builds Hadoop clusters on the new single-board computer (SBC) Mobile Raspberry Pi. Moreover, these clusters offer facilities for storage as well as computing. Besides the fact that the regular data centers require large amounts of energy for operation, they also need cooling equipment and occupy prime real estate. However, this energy consumption scenario and the physical space constraints can be solved by employing a Mobile Raspberry Pi with Hadoop clusters that provides a cost-effective, low-power, high-speed solution along with micro-data center support for big data. Hadoop provides the required modules for the distributed processing of big data by deploying map-reduce programming approaches. In this work, the performance of SBC clusters and a single computer were compared. It can be observed from the experimental data that the SBC clusters exemplify superior performance to a single computer, by around 20%. Furthermore, the cluster processing speed for large volumes of data can be enhanced by escalating the number of SBC nodes. Data storage is accomplished by using a Hadoop Distributed File System (HDFS), which offers more flexibility and greater scalability than a single computer system.

• The KIPS Transactions:PartA
• /
• v.11A no.5
• /
• pp.407-412
• /
• 2004

The e-learning system uses multimedia content for efficiency of a education and learner's convenience. With the web based e-learning, various multimedia services are difficult on account of physical factors such as network state and system performance. Also on the off line based e-learning, we have defects an insufficiency of interactions among learners and instructors, and an insufficiency of an adaptation about the latest information. In this study, we designed a multi-tier e-learning system using hybrid multimedia method, The proposed system can provide interaction and adaptability such as web based systems, and it can provide various multimedia content such as off line based systems. In experiments results, we know the proposed system improved users' convenience and an adaptability about the latest information, and interactions among learners and instructors when compare with existing e-learning system.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.27 no.5
• /
• pp.1129-1140
• /
• 2017

Unidirectional data transmission system, which allows physical one way transmission, removes the backward link physically to prevent the intrusion from the outside through the network. However, the system is difficult to apply to the environment requiring either backward transmissions or bi-directional communications. In this paper, we proposed Limited Two-way communications system, called as LimTway, which only allows outbound TCP two-way communications. LimTway uses two one-way links(forward, backward). While the forward one-way link is staying to be activated so that an allowed outbound UDP traffic could be transmitted one-way always, the backward one-way link is activated while allowed outbound TCP sessions are established. In order to prevent the intrusion from the outside during the period, the software of LimTway is designed to allow only the transmissions of both outbound TCP two-way communication traffics and outbound UDP traffics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.10a
• /
• pp.346-348
• /
• 2017

The speed of technology development is increasing, and high-performance digital devices are spreading. Smart walks that can work effectively anytime and anywhere by being restricted from space and time in wired digital devices such as PC, System security design is needed to secure integrity and availability against various security threats such as physical threats such as lost, stolen and damaged terminals, technical threats such as theft, denial of service, and unauthorized access, compared with the wired environment. In this paper, we analyze smart work network system, wired / wireless link system, and digital smart device. We study security design method for smart work wired system and future wireless system which are used in present work. This study will be used as basic data for building a secure smart work.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.2
• /
• pp.76-82
• /
• 2018

In this present study, in order to update the finite element model considering the boundary conditions, a method has been proposed. The conventional finite element model updating method, updates the finite element model by using the dynamic characteristics (natural frequency, mode shape) which can be estimated from the ambient vibration test. Therefore, prediction of the static response of an actual structure is difficult. Furthermore, accurate estimation of the physical properties is relatively hard. A novel method has been proposed to overcome the limitations of conventional method. Initially, the proposed method estimates the rotational spring constant of a finite element model using the deflection of structure and the rotational displacement of support measurements. The final updated finite element model is constructed by estimating the material properties of the structure using the finite element model with updated rotational spring constant and the dynamic characteristics of the structure. The proposed finite element model updating method is validated through numerical simulation and compared with the conventional finite element model updating method.

• Journal of Internet Computing and Services
• /
• v.11 no.1
• /
• pp.153-165
• /
• 2010

In this paper, we proposed a Proactive Application Service Engine (PASE) supporting tailor-made distributed application services based on the Distributed Object Group Framework (DOGF) efficiently managing distributed objects, in the viewpoint of distributed application, composed application on network. The PASE consists of 3 layers which are the physical layer, the middleware layer, and the application layer. With the supporting services of the PASE, the grouping service manages the data gathered from H/W devices and the object's properties for application by user's request as a group. And the security service manages the access of gathered data and the object according to user's right. The data filtering service executes the filtering function to provide application with gathered data. The statistics service analysis past data. The diagnostic service diagnoses a present condition by using the gathered data. And the prediction service predicts a future's status based on the statistics service and the diagnostic service. For verifying the executability of the PASE's services, we applied to a greenhouse automatic control application in ubiquitous agriculture field.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.12
• /
• pp.2195-2200
• /
• 2008

The use of WLAN technology specially 802.11 b and g has seen huge subscriber growth in a relatively short time period due to low cost and ease of installation of WLAN hardware. These technologies provide multiple data rates ranging from 1 to 54 Mbps depending on modulation used in physical layer. This paper presents the performance of 802.11b and g under different data rates in mobile IPv4 environment. OPNET is used in the study as the network simulator. The performance metrics used in this wort is data traffic received by a WLAN station roaming amongst Access Point(AP) of different ESSs. It is found that much data packets are lost during handover between mobile agents. The traffic received by the roaming station varies based on the data rates provided by two different WLAN technologies.