• International Journal of Computer Science & Network Security
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• v.24 no.4
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• pp.60-66
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• 2024

Host's data during transmission. Data tempering results in loss of host's sensitive information, which includes number of VM, storage availability, and other information. In the distributed cloud environment, each server (computing server (CS)) configured with Local Resource Monitors (LRMs) which runs independently and performs Virtual Machine (VM) migrations to nearby servers. Approaches like predictive VM migration [21] [22] by each server considering nearby server's CPU usage, roatative decision making capacity [21] among the servers in distributed cloud environment has been proposed. This approaches usage underlying server's computing power for predicting own server's future resource utilization and nearby server's resource usage computation. It results in running VM and its running application to remain in waiting state for computing power. In order to reduce this, a decentralized decision making hybrid model for VM migration need to be proposed where servers in decentralized cloud receives, future resource usage by analytical computing system and takes decision for migrating VM to its neighbor servers. Host's in the decentralized cloud shares, their detail with peer servers after fixed interval, this results in chance to tempering messages that would be exchanged in between HC and CH. At the same time, it reduces chance of over utilization of peer servers, caused due to compromised host. This paper discusses, an roatative decisive (RD) approach for VM migration among peer computing servers (CS) in decentralized cloud environment, preserving confidentiality and integrity of the host's data. Experimental result shows that, the proposed predictive VM migration approach reduces extra VM migration caused due over utilization of identified servers and reduces number of active servers in greater extent, and ensures confidentiality and integrity of peer host's data.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.8
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• pp.730-740
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• 2000

The software rejuvenation method for highly available multiplex systems uses a pro-active fault-tolerant approach to handle system failures. The software rejuvenation prevents failures from occurring, while the previous methods recover from failures after happening. Especially, since the software aging proceeds fast in the software used for the multimedia mobile computing due to the loss of communications or data, the preventive method from failures using software rejuvenation can be used for the multimedia mobile computing. In this paper, according to the operational parameters such as rejuvenation period, rejuvenation time, failure rate and repair rate of the servers, number of running servers, duration of running time, and type of running modes, we calculate steady-state probabilities, downtime, availability, and cost of the multiplex systems using software rejuvenation method. We validate the closed-form solutions of the mathematical model by experiments based on various operational parameters and find that the software rejuvenation method can be adopted as preventive fault-tolerant technique. The failure rate and unstable rate of the servers are essential factors for the decision making of the rejuvenation policies.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.793-799
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• 2011

A comprehensive analysis of wheel force spectrum is conducted to provide the KTX safety evaluation with structural behaviour of Pre-Stressed Concrete (PSC) box bridge due to various high speeds. The wheel spectrum for KTX locomotive running over road and PSC bridge tracks is compared using irregular track responses with numerical models of 170m approach road track and 40m span length of PSC box bridge The high-speed railway locomotive is used as 38-degree of freedom system. Three displacements (vertical, lateral, and longitudinal) and three rotational components (pitching, rolling, and yawing) for one car-body and two bogies are considered in the 38-degree of freedom model. Three dimensional frame element of finite element method (FEM) is used to model of the simply supported PSC box bridge. The irregulation of rail-way is derived using the experiential spectrum density function under assumption of twelve level tracks conditions based on the normal probability procedure. The dynamic analyses by Runge-Kutta method which are able to analyze the high frequency wheel force spectrum. A dynamic behaviour of KTX due to high speeds until 450km/h developing speed with relative time is analysed and compared the characteristics running over the road and PSC box bridge tracks. Finally, the KTX integrated evaluation method of safety between high speed train and bridge is presented.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.6
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• pp.95-103
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• 2006

Wheel treads of E.M.U. are usually under a heavy thermal load by brake frictional heat between wheel and brake shoe and damaged by repeated thermal and mechanical loads. To examine the cause of wheel tread damage of E.M.U.'s in service running, a systematic approach has been used. This study is composed of three parts. Frictional heat analysis was conducted in the first part by finite element method. Two kinds of brake shoes in service were considered. In the second part, experimental study was carried out on a brake dynamometer. Temperatures were measured for the two brake shoes. And experimental study in service running E.M.U.'s was performed. Wheel and brake shoe temperatures were measured by using thermocouples and temperature indicating strips. Finally metallurgical characteristics were examined by a SEM/EDS and the cause of the wheel damage was analyzed. It seems that aggregated ferrous component is a main cause of the wheel tread damage.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.10
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• pp.1095-1102
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• 2014

In this paper, We proposed the approach of GPU and motion vector to analysis the Human activity in real-time surveillance system. The most important part, that is detect blob(human) in the foreground. We use to detect Adaptive Gaussian Mixture, Weighted subtraction image for salient motion and motion vector. And then, We use motion vector for human activity analysis. In this paper, the activities of human recognize and classified such as meta-classes like this {Active, Inactive}, {Position Moving, Fixed Moving}, {Walking, Running}. We created approximately 300 conditions for the simulation. As a result, We showed a high success rate about 86~98%. The results also showed that the high resolution experiment by the proposed GPU-based method was over 10 times faster than the cpu-based method.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.4
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• pp.224-228
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• 2017

Recently, in order to improve the efficiency of freight transportation on existing lines, a new freight train model is needed to develop urgently. The weight balance of the cargo for the freight vehicle is very important for the stability of the running train and the safe transportation of the cargo. For achieving the cargo weight balance, we proposed a Cargo Balancing Control(CBC) system on the Freight vehicle equipped in between under frame of car body and bogie system. The Cargo Safety Monitoring(CSM) system was designed to supervise status of the Cargo on freight train. The monitoring system can display real time status data from sensors and various signals effectively. We suggested that this paper is a very useful approach for keeping the safety of running freight trains on existing lines.

• Structural Engineering and Mechanics
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• v.76 no.2
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• pp.163-173
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• 2020

As a vehicle moves on multiple equal-span beams at constant speed, the running vehicle would be subjected to repetitive excitations from the beam vibrations under it. Once the exciting frequency caused by the vibrating beams coincides with any of the vehicle's frequencies, resonance would take place on the vehicle. A similar resonance phenomenon occurs on a beam subject to sequential moving loads with identical axle-intervals. To reduce both resonant phenomena of a vehicle moving on guideway girders, this study proposed an additional feedback controller based the condensed virtual dynamic absorber (C-VDA) scheme. This condensation scheme has the following advantages: (1) the feedback tuning gains required to adapt the control currents or voltages are directly obtained from the tuning forces of the VDA; (2) the condensed VDA scheme does not need additional DoFs of the absorber to control the vibration of the maglev-vehicle/guideway system. By decomposing the maglev vehicle-guideway coupling system into two sub-systems (the moving vehicle and the supporting girders), an incremental-iterative procedure associated with the Newmark method is presented to solve the two sets of sub-system equations. From the present studies, the proposed C-VDA scheme is a feasible approach to suppress the interaction response for a maglev vehicle in resonance moving on a series of guideway girders.

• Communications for Statistical Applications and Methods
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• v.25 no.4
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• pp.397-409
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• 2018

The world financial markets are inter-linked in ways that varies according to market and time. We examine the causality of change focusing on the Korean market as related to the U.S. (S&P 500), Japan (Nikkei 225), Hong-Kong (HSI), and European (DAX) markets. In order to capture time-varying causality running from and to the Korea stock market, we apply the Granger causality test under a VAR model with a wild bootstrap rolling-window approach. We also propose a new concept of a significant causality ratio to measure the intensity of the Granger causality in each time unit. There are many asymmetric strengths in mutual Granger causal relationships. Moreover, there are cases with significant Granger causal relations only in one direction. The period with the most severe Granger causality both running from and to the KOSPI market is the GFC. The market that formed the two-way Granger causal relationship with the KOSPI market for the longest period is the S&P 500. The HSI and DAX markets have the strongest two-way Granger causal relationship with the KOSPI shortly after 2000, and the Nikkei market had the strongest two-way Granger causal relationship with the KOSPI market before the Asian financial crisis.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.545-552
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• 2008

It becomes to make its necessity of getting more closer approach for the design and the detailed analysis of implementation method and study with respect that the plan is put into shape for the interconnection between Seoul Line No.9 and the AREX line which has been on commercial running since it had been opened on March 2007. We introduce the concrete analysis and the rasied problems and a way how to solve as well for the characteristics of interconnection train and signaling 시스템tem structure between two lines in order to design and implement the interconnection running. Also,

• Journal of the Korea Society of Computer and Information
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• v.15 no.7
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• pp.1-10
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• 2010

The power of computational Grid resources can be utilized on users desktop by employing workflow managers. It also helps scientists to conveniently put together and run their own scientific workflows. Generally, stage-in, process and stage-out are serially executed and workflow systems help automate this process. However, as the data size is exponentially increasing and more and more scientific workflows require multiple processing steps to obtain the desired output, we argue that the data movement will possess high portion of overall running time. In this paper, we improved staging time and design a new scheduler where the system can execute concurrently as many jobs as possible. Our simulation study shows that 10% to 40% improvement in running time can be achieved through our approach.