• KIISE Transactions on Computing Practices
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• v.23 no.8
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• pp.487-491
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• 2017

Open source software allows the users to freely use, copy, distribute and modify source code without any particular limitations, and this offers the advantages of low entry cost, fast and flexible development, compatibility, reliability and safety. The emergence of many useful open source projects has the advantage of achieving high levels of output with lower costs and time commitment for software development. However, this also increases the risks caused by the security vulnerabilities of the used open source software. There is still no separate process to verify security in using open source software. In this paper, we analyze the security weakness in open source and propose a secure coding scheme in adopting open source, which is known to be highly reliable from a security point of view.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.5
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• pp.496-505
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• 2000

Clusters of workstations (COW) are becoming an attractive option for parallel scientific computing, a field formerly reserved to the MPPs, because their cost-performance ratio is usuallybetter than that of comparable MPPS, and their hardware and software can be easily enhanced to thelatest generations. In this paper we present the design and implementation of our runtime library forclusters of workstations, called "Collective I/O Clustering". The library provides a friendlyprogramming model for the I/O of irregular applications on clusters of workstations, being completelyintegrated with the underlying communication and I/O system. In the collective I/O clustering, two I/Oconfigurations are possible. In the first I/O configuration, all processors allocated can act as I/Oservers as well as compute nodes. In the second I/O configuration, only a subset of processors canact as I/O servers, The compression and software caching facilities have been incorporated into thecollective 1/0 clustering to optimize the communication and I/O costs. All the performance results wereobtained on the IBM-SP machine, located at Argonne National Labs.

• KIISE Transactions on Computing Practices
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• v.22 no.11
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• pp.601-613
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• 2016

With the increasing need for big data processing, building a shared big data processing platform is important to minimize time and monetary costs. In shared big data processing, multitenancy is a major requirement that needs to be addressed, in order to provide a single isolated personal big data platform for each user, but to share the underlying hardware is shared among users to increase hardware utilization. In this paper, we explore two well-known shared big data processing platform models. One is to use a native Hadoop cluster, and the other is to build a virtual Hadoop cluster for each user. For each model we verified whether it is sufficient to support multi-tenancy. We also present a method to complement unsupported multi-tenancy features in a native Hadoop cluster model. Lastly we built prototype platforms and compared the performance of both models.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5184-5191
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• 2013

The automated quantity take off technique using BIM authoring tools has been recently issued, and the studies of this method for the accuracy, efficiency, and the unit computing for the simple volume, area and number have been developed. Meanwhile the main concerns such as the details for the level of modelling, and the costs and time for the calculating BOQ item are still required to study. In this paper, the earth works, drainage works, pavement works, and facility works using BIM authoring tools are designed in 3D, and the applicability of automated quantity take off technique using BIM authoring tools is discussed, respectively. As a result, automated quantity take off are limited in the earth works, drainage works, pavement works, and facility works. But Most items of BOQ can be supported in Re-bar model.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.333-336
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• 2007

We propose a simple method for tracking a nonparameterized subject contour in a single video stream with a moving camera and changing background. Then we present a method to eliminate the tracked contour object by replacing with the background scene we get from other frame. Our method consists of two parts: first we track the object using LOD (Level-of-Detail) canny edge maps, then we generate background of each image frame and replace the tracked object in a scene by a background image from other frame that is not occluded by the tracked object. Our tracking method is based on level-of-detail (LOD) modified Canny edge maps and graph-based routing operations on the LOD maps. To reduce side-effects because of irrelevant edges, we start our basic tracking by using strong Canny edges generated from large image intensity gradients of an input image. We get more edge pixels along LOD hierarchy. LOD Canny edge pixels become nodes in routing, and LOD values of adjacent edge pixels determine routing costs between the nodes. We find the best route to follow Canny edge pixels favoring stronger Canny edge pixels. Our accurate tracking is based on reducing effects from irrelevant edges by selecting the stronger edge pixels, thereby relying on the current frame edge pixel as much as possible. This approach is based on computing camera motion. Our experimental results show that our method works nice for moderate camera movement with small object shape changes.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.444-448
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• 2005

This paper presents a developing procedure of the CAN-based real-time simulator for car body control, aiming at replacing the actual W/H (Wiring Harness) and J/B(Junction Box) couple eventually. The CAN protocol, as one kind of field-bus communication, defines the lowest 2 layers of the ISO/OSI standard, namely, the physical layer(PL) and the data link layer(DLL), for which the CSMA/NBA protocol is generally adopted. For CPU, two PIC18Fxx8x's are used because of their built-in integration of CAN controller, large internal FLASH memory (48K or 64K), and their costs. To control J/B's and actuators, 2 controller boards are separately implemented, between which CAN lines communicate through CAN transceivers MCP255. A power motor for washing windshield, 1 door lock motor, and 6 blink lamps are chosen for actuators of the simulator for the first stage. For the software architecture, a polling method is used for the fast global response time despite its slow individual response time. To improve the individual response time and to escape from some eventual trapped-function loops, High/Low ports of the CPU are simply used, which increases the stability of the actuator modules. The experimental test shows generally satisfactory results in normal transmitting / receiving function and message trace function. This simulator based on CAN shows a promising usefulness of lighter, more reliable and intelligent distributed body control approach than the conventional W/H and J/B couple. Another advantage of this approach lies in the distributed control itself, which gives better performance in hard real-time computing than centralized one, and in the ability of integrating different modules through CAN.

• The Journal of Society for e-Business Studies
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• v.11 no.1
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• pp.69-89
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• 2006

Due to the technological developments and industrial changes , studying for the future has been attached great importance. According to the forthcoming ubiquitous computing environment or smart environment, it is necessary for a country and an enterprise to forecast the future or foresight the future technologies . Although many countries have been doing the foresight, it is difficult for the enterprise to try future foresight activity, because the foresight activity needs lots of the costs and time for good results. Also, almost methodologies used in foresight are suitable for country level foresight projects. In this research, a methodology is developed for an enterprise to use easily, and a case based on the proposed methodology is presented. The proposed foresight methodology is developed based on the traditional forecasting methods, FAR, Future Wheel, and Scenario. Especially, the methodology focused on the customers of a company.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.2
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• pp.1-8
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• 2011

Traffic congestion is a source of significant economic and social costs in urban areas. Intelligent Transportation Systems (ITS) are a promising means to help alleviate congestion by utilizing advanced sensing, computing, and communication technologies. This paper proposes and investigates a basic and advanced ITS framework Advanced Traveler Information System (ATIS) using wireless Vehicle to Roadside (Centralized ATIS model: CA model) and Vehicle to Vehicle (DeCentralized ATIS model: DCA model) communication and assuming an ideal communication environment in the typical $6{\times}6$ urban grid traffic network. Results of this study indicate that an ATIS using wireless communication can save travel time given varying combinations of system characteristics: traffic flow, communication radio range, and penetration ratio. Also, all tested metrics of the CA and DCA models indicate that the system performance of both models is almost identical regardless of varying traffic demand and penetration ratios. Therefore, DCA model can be a reasonable alternative to the fixed infrastructure based ATIS model (CA model).

• Journal of the Korea Computer Graphics Society
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• v.7 no.2
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• pp.21-28
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• 2001

As a result of the recent explosive growth of scientific data, extremely large volume datasets have become increasingly commonplace. While several texture-based volume rendering algorithms have been proposed, most of them focused on volumes smaller than the hardware's available texture memory. This paper presents a new parallel volume rendering scheme for very large static and time-varying data on a multipipe system architecture. Our scheme subdivides large volumes dynamically into smaller bricks, and assigns them adaptively to graphics pipes to minimize the costs of texture swapping. With the new method, Phong shaded images can be easily created by computing the gradients on the fly and using the color matrix feature of OpenGL. We report experimental results on an SGI Onyx2 for the various large datasets.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7A
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• pp.706-714
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• 2010

In wireless sensor networks, real-time data delivery schemes typically achieve a desired delivery speed by performing one-hop lookahead. Recently, to reduce the deadline miss ratio against the desired delivery speed, a study has proposed a real-time routing protocol based on proactively performing two-hop lookahead. However, the study might cause heavy message exchange overhead and high computing complexity to carry out obtainment of two-hop neighborhood speed information in the entire sensor nodes whether data are delivered or not. Moreover, although multi-hop lookahead provides the least deadline miss ratio, due to the restriction from the overhead and the complexity, the recent study merely adopts the two-hop lookahead manner. In this paper, we propose a novel real-time routing protocol that adopts on-demand neighborhood multi-hop information obtainments only around data forwarding paths. Simulation results prove that the proposed routing protocol offers better performances with respect to deadline miss ratio, total communication costs, energy efficiency, and network lifetime.