• Journal of Korea Multimedia Society
• /
• v.14 no.3
• /
• pp.449-461
• /
• 2011

In the field of computer science, operating system concept is taught in university, but we now teach it in the middle and/or high school. Computer is also taught not only in college but also in middle and high school. If we look up the education of computer that is trained in school, basic principles or core techniques of computer science is educated only with its theory. If the theoretical education of computer science is just trained, sometimes students are not interested in it because of lack of shortage of mass media. Therefore, we could say that it is important that the computer education features a diverse range of media, including prints, paintings, sculpture, digital photographs, mixed media, and a simulation program. For all this reason, we design and implement a program for simulation with computer operating systems especially, CPU scheduling. There are many CPU scheduling algorithms we suggest to make students understand scheduling with some different examples in practical use. In this paper, we practically propose a new approach to be used with a study tool to make a motivation for students. We design a simulation program for teaching computer operation systems to show CPU scheduling and we implement a program to make use of comparison of FCFS, SJFS, PS, and RR scheduling algorithms. With our simulation program we present a comparative analysis between scheduling algorithms could be possible.

• The KIPS Transactions:PartC
• /
• v.16C no.2
• /
• pp.245-256
• /
• 2009

Pastry overlay network is one of structured P2Ps using DHT(Distributed Hash Table). To reduce the number of messages among nodes, Rosary and LAR have been proposed by exploiting spatial locality and caching, respectively, in the Pastry. Rosary consists of Inter-Pastry and Intra-Pastry. A root node is assigned as a representative in each Intra-Pastry and it has the responsibility of Inter-Pastry and Intra-Pastry routing. Therefore, Rosary has several disadvantages; 1) low fault tolerance in case of root node failure 2) routing hop count increases because of the use of root nodes compared to the existing structured P2Ps, and 3) the communication load is concentrated in some specific areas. LAR has inefficient problems in that caching is not distributed among nodes in Intra-Pastry and caching is used by only nodes in the Intra-Pastry. In this paper, we propose an improved Pastry called Doughnut to overcome the above problems of Rosary and LAR. By dividing nodes with the local characteristics, the Doughnut consists of Inter-Pastry and Intra-Pastry, and all nodes have the responsibility of Inter-Pastry and Intra-Pastry routing. This results in that all nodes perform the role of the existing root node. This solves the problems of the reducing of fault-tolerance, the increasing of routing hop count, and the not-distributed communication load. Also Doughnut can use cache effectively because it guarantees the even cache distribution in local(Intra-Pastry) and the cache contents in local can be used in the other local. The proposed algorithm is implemented using simulator and the experimental results show the effectiveness of the proposed method compared to the existing method.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.26 no.6
• /
• pp.477-484
• /
• 2016

Small industrial appliances such as fan, audio, electric rice cooker mostly consist of ABS, PP, PS materials. In colored plastics, it is possible to classify by near infrared(NIR) spectroscopy, while in black plastics, it is very difficult to classify black plastic because of the characteristic of black material that absorbs the light. So the RBFNNs pattern classifier is introduced for sorting electrical and electronic waste plastics through LIBS(Laser Induced Breakdown Spectroscopy) spectrometer. At the preprocessing part, PCA(Principle Component Analysis), as a kind of dimension reduction algorithms, is used to improve processing speed as well as to extract the effective data characteristics. In the condition part, FCM(Fuzzy C-Means) clustering is exploited. In the conclusion part, the coefficients of linear function of being polynomial type are used as connection weights. PSO and 5-fold cross validation are used to improve the reliability of performance as well as to enhance classification rate. The performance of the proposed classifier is described based on both optimization and no optimization.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.11A
• /
• pp.1117-1123
• /
• 2008

Applications for mobile multimedia are testing the performance limits of present day CPUs with variety. However, hardwired solutions are inflexible and expensive to develop. CPUs with flexibility have limitation of performance. So, the requirement for both ASIC-like performance and CPU-like flexibility has led to reconfigurable processor. Mobile systems require low power and high performance concurrently. In this paper, we propose reconfigurable processor for mobile multimedia with high energy efficiency. Reconfigurable processor with 121MOPS/mW is developed by 130nm CMOS technology. And the processor was simulated for energy efficiency with 539MOPS/mW by 90nm CMOS technology and effective use of instructions. And we tested its applications for multimedia field. We tested the case of inverse MDCT for MP3 and DF for MPEG4 and ME for H.264.

• 전자공학회논문지 IE
• /
• v.45 no.4
• /
• pp.33-41
• /
• 2008

Telematics system includes the "vehicle remote diagnosis technology", "driving pattern analysis technology" which are commercially attractive in the real life. To implement those technologies, we need vehicle signal interface, vehicle diagnosis interface, accelerometer/yaw-rate sensor interface, GPS data processing, driving pattern analysis, and CDMA data processing technique. Based on these technologies, we analyze the error existence by diagnosing the EMS(Engine Management System), TMS(Transmission Management System), ABS/TCS, A/BAG in real time. And we are checking about a driving pattern and management of the vehicle, which are sent to the information center through the wireless communication. These database results will make the efficient vehicle and driver management possible. We show the effectiveness of our results by field driving test after completing the H/W & S/W design and implementation for vehicle remote diagnosis and driving pattern analysis.

• Radiation Oncology Journal
• /
• v.11 no.1
• /
• pp.175-181
• /
• 1993

Radiosurgery requires integral procedure where special devices and computer systems are needed for localization, dose planning and treatment. The aim of this work is to verify the overall mechanical accuracy of our LINAC and develop dose calculation algorithm for LINAC radiosurgery. The alignment of treatment machine and the performance testing of the entire system were extensively carried out and the basic data such as percent depth dose, off-axis ratio and output factor were measured. A three dimensional treatment planning system for stereotactic radiosurgery has been developed. We used an IBM personal computer with C programming language (IBM personal system/2, Model 80386, IBM Co., USA) for calculating the dose distribution. As a result, deviations at isocenter on gantry and table rotation for our treatment machine were acceptable since they were less than 2 mm. According to the phantom experiments, the focusing isocenter were successful by the error of less than 2 mm. Finally, the mechanical accuracy of our three dimensional planning system was confirmed by film dosimetry in sphere phantom.