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pISSN : 1598-849X / eISSN : 2383-9945

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2011, Vol.16, No.7

  • 1.

    Analysis on the Cooling Efficiency of High-Performance Multicore Processors according to Cooling Methods

    강승구 , 최홍준 , 안진우 and 3 other persons | 2011, 16(7) | pp.1~12 | number of Cited : 0
    Abstract PDF
    Many researchers have studied on the methods to improve the processor performance. However, high integrated semiconductor technology for improving the processor performance causes many problems such as battery life, high power density, hotspot, etc. Especially, as hotspot has critical impact on the reliability of chip, thermal problems should be considered together with performance and power consumption when designing high-performance processors. To alleviate the thermal problems of processors, there have been various researches. In the past, mechanical cooling methods have been used to control the temperature of processors. However, up-to-date microprocessors causes severe thermal problems, resulting in increased cooling cost. Therefore, recent studies have focused on architecture-level thermal-aware design techniques than mechanical cooling methods. Even though architecture-level thermal-aware design techniques are efficient for reducing the temperature of processors, they cause performance degradation inevitably. Therefore, if the mechanical cooling methods can manage the thermal problems of processors efficiently, the performance can be improved by reducing the performance degradation due to architecture-level thermal-aware design techniques such as dynamic thermal management. In this paper, we analyze the cooling efficiency of high-performance multicore processors according to mechanical cooling methods. According to our experiments using air cooler and liquid cooler, the liquid cooler consumes more power than the air cooler whereas it reduces the temperature more efficiently. Especially, the cost for reducing 1℃ is varied by the environments. Therefore, if the mechanical cooling methods can be used appropriately, the temperature of high-performance processors can be managed more efficiently.
  • 2.

    Multi-Objective Job Scheduling Model Based on NSGA-Ⅱ for Grid Computing

    김솔지 , 김태호 , LEE, Hong Chul | 2011, 16(7) | pp.13~24 | number of Cited : 1
    Abstract PDF
    Grid computing is a new generation computing technology which organizes virtual high-performance computing system by connecting and sharing geographically distributed heterogeneous resources, and performing large-scaled computing operations. In order to maximize the performance of grid computing, job scheduling is essential which allocates jobs to resources effectively. Many studies have been performed which minimize total completion times, etc. However, resource costs are also important, and through the minimization of resource costs, the overall performance of grid computing and economic efficiency will be improved. So in this paper, we propose a multi-objective job scheduling model considering both time and cost. This model derives from the optimal scheduling solution using NSGA-Ⅱ, which is a multi objective genetic algorithm, and guarantees the effectiveness of the proposed model by executing experiments with those of existing scheduling models such as Min-Min and Max-Min models. Through experiments, we prove that the proposed scheduling model minimizes time and cost more efficiently than existing scheduling models.
  • 3.

    X-Putt : A Golf Putting Training System based on Ultrasonic sensors

    안재곤 , 나대영 , Young-Tae Lim and 1 other persons | 2011, 16(7) | pp.25~34 | number of Cited : 0
    Abstract PDF
    In this paper, we propose a new golf putting training system which we call "X-Putt". X-Putt analyzes putting strokes by measuring putter face angle and path. To do this, we improved the sonar-based localization scheme used by previous localization techniques. As a result, X-Putt can measure putter's location within the error range, 0.9㎝ and putter face angle within 1.5°. Additionally, we built an user application that has an easy-to-use interface for analyzing the strokes after training.
  • 4.

    OWL/Relational Mapping Rules to Use Relational Databases as OWL 2 Web Ontologies

    최지웅 , Myung Ho Kim | 2011, 16(7) | pp.35~48 | number of Cited : 2
    Abstract PDF
    This paper proposes a set of rules to automatically generate OWL ontologies from relational databases. The purpose of the rules is to allow semantic access to existing RDB data without any database schema transformation and data migration process. In other words, the rules help a RDBMS play as a web ontology repository as well. However, the use of the mapping rules between RDB and OWL proposed by other studies for the objective causes troubles as follows. First, databases including the tables with a specific structure can't be translated into OWL. Second, the process for extracting an OWL individual unnecessarily lead to database join operations, or several SQL queries. On the other hand, our rules is designed to prevent these problems, can generate OWL classes and properties from database schemas and can generate OWL individuals from the database instances. In addition, an ontology generated by our rules is an OWL 2 DL ontology.
  • 5.

    A Development of a Framework for Building Knowledge based Augmented Reality System

    Woo Chong Woo , 이두희 | 2011, 16(7) | pp.49~58 | number of Cited : 3
    Abstract PDF
    Augmented Reality(AR) assists human's cognitive ability through the information visualization by substantiating information about virtual situation. This technology is studied in a variety of ways including education, design, industry, and so on, by various supply of information devices equipped with cameras and display monitors. Since the most of the AR system depends on limited interaction that responds to the order from user, it can not reflect diverse real world situation. In this study, we suggest a knowledge based augmented reality system, which is composed of context awareness agent that provides recognized context information, along with knowledge based component that provides intelligent capability by utilizing domain knowledges. With this capability, the augmented object can generate dynamic model intelligently by reflecting context information, and can make the interaction possible among the multiple objects. We developed rule based context awareness system along with 3D model generation, and tested interaction among the augmented objects. And we suggest a framework that can provide a convenient way of developing augmented reality system for user.
  • 6.

    Video Quality Improvement Method of Up-sampling Video by Relationship of Intra Prediction Data and DCT Coefficient

    YoonSoo Lee | 2011, 16(7) | pp.59~66 | number of Cited : 0
    Abstract PDF
    Korea DMB Service is popularized, and is used by many users. But latest display devices compared to the DMB content resolution support higher resolution and a variety of video resampling technologies has been used. Generally, subjective video quality is determined by object recognition rate in video, and increased as the edge space between objects are more clear. An edge is the boundary between an object and the background, and indicates the boundary between overlapping objects. the predicted direction in intra prediction used in H.264/AVC has the similarity up to 80% for the edge information. In the study, we propose an effective up-sampling mothed using the edge information that is extracted for the relationship between the intra prediction data and the DCT coefficient data of H.264 video encoding.
  • 7.

    A Semantic Annotation Method for Efficient Representation of Moving Objects

    이진활 , Myungduk Hong , 이기성 and 2 other persons | 2011, 16(7) | pp.67~76 | number of Cited : 1
    Abstract PDF
    Recently, researches for semantic annotation methods which represent and search objects included in video data, have been briskly activated since video starts to be popularized as types for interactive contents. Different location data occurs at each frame because coordinates of moving objects are changed with the course of time. Saving the location data for objects of every frame is too ineffective. Thus, it is needed to compress and represent effectively. This paper suggests two methods; the first, ontology modeling for moving objects to make users intuitively understandable for the information, the second, to reduce the amount of data for annotating moving objects by using cubic spline interpolation. To verify efficiency of the suggested method, we implemented the interactive video system and then compared with each video dataset based on sampling intervals. The result follows : when we got samples of coordinate less than every 15 frame, it showed that could save up to 80% amount of data storage; moreover, maximum of error deviation was under 31 pixels and the average was less than 4 pixels.
  • 8.

    Development of a Békésy Audiometry System based on PC

    강덕훈 , 송복득 , Shin bum joo and 2 other persons | 2011, 16(7) | pp.77~84 | number of Cited : 2
    Abstract PDF
    The Békésy audiometry makes possible to determine not only hearing threshold but also assumption of recruit phenomenon. Additionally, it is helpful to investigate cause of hearing loss. In this paper, we describe a development of PC based Békésy audiometer which complies with ANSI standards and provides cost competitiveness. It dynamically produces sound having required frequency and sound pressure level and supports audiogram interface showing test result at realtime. To provide ANSI defined maximum sound level, an amplifier has been developed. We have been verified our system whether it conforms to ANSI standards.
  • 9.

    A Polynomial Time Algorithm for Vertex Coloring Problem

    Sang-Un, Lee , MyeongBok Choi | 2011, 16(7) | pp.85~94 | number of Cited : 3
    Abstract PDF
    The Vertex Coloring Problem hasn't been solved in polynomial time, so this problem has been known as NP-complete. This paper suggests linear time algorithm for Vertex Coloring Problem (VCP). The proposed algorithm is based on assumption that we can't know a priori the minimum chromatic number for graph . This algorithm divides Vertices of graph into two parts as independent sets and cover set , then assigns the color to . The element of independent sets is a vertex that has minimum degree and the elements of cover set are the vertices that is adjacent to . The reduced graph is divided into independent sets and cover set again until no edge is in a cover set . As a result of experiments, this algorithm finds the perfectly for 26 Graphs that shows the number of selecting is less than the number of vertices .
  • 10.

    Processing of ρ-intersect Operation on RDF DataUsing Suffix Array

    Sung Wan Kim , 김연희 | 2011, 16(7) | pp.95~104 | number of Cited : 1
    Abstract PDF
    The actual utilization of Semantic Web technology which aims to provide more intelligent and automated service for information retrieval over the Web becomes gradually reality. RDF is widely used as the one of standard formats to present and manage the voluminous data on the Web. Efficient query processing on RDF data, therefore, is one of the ongoing research topics. Retrieving resources having a specific association from a given resource is the typical query processing type and several researches for this have done. However the most of previous researches have not fully considered discovering the complex relationship among resources such as returning the association between resources as the query processing result. This paper introduces the indexing and query processing for ρ-intersect operation which is one of the semantic association retrieval types. It includes an indexing scheme using suffix array and optimal processing approaches for handling ρ-intersect operation. The experimental evaluations shows that the average execution times for the proposed approach is 3~7 times faster than the previous approach.
  • 11.

    Adaptive Segmentation Approach to Extraction of Road and Sky Regions

    박경환 , Kwang Woo Nam , Rhee Yang Weon and 1 other persons | 2011, 16(7) | pp.105~116 | number of Cited : 0
    Abstract PDF
    In Vision-based Intelligent Transportation System(ITS) the segmentation of road region is a very basic functionality. Accordingly, in this paper, we propose a region segmentation method using adaptive pattern extraction technique to segment road regions and sky regions from original images. The proposed method consists of three steps; firstly we perform the initial segmentation using Mean Shift algorithm, the second step is the candidate region selection based on a static-pattern matching technique and the third is the region growing step based on a dynamic-pattern matching technique. The proposed method is able to get more reliable results than the classic region segmentation methods which are based on existing split and merge strategy. The reason for the better results is because we use adaptive patterns extracted from neighboring regions of the current segmented regions to measure the region homogeneity. To evaluate advantages of the proposed method, we compared our method with the classical pattern matching method using static-patterns. In the experiments, the proposed method was proved that the better performance of 8.12% was achieved when we used adaptive patterns instead of static-patterns. We expect that the proposed method can segment road and sky areas in the various road condition in stable, and take an important role in the vision-based ITS applications.
  • 12.

    A Study on the YCbCr Color Model and the Rough Set for a Robust Face Detection Algorithm

    변오성 | 2011, 16(7) | pp.117~126 | number of Cited : 0
    Abstract PDF
    In this paper, it was segmented the face color distribution using YCbCr color model, which is one of the feature-based methods, and preprocessing stage was to be insensitive to the sensitivity for light which is one of the disadvantages for the feature-based methods by the quantization. In addition, it has raised the accuracy of image synthesis with characteristics which is selected the object of the most same image as the shape of pattern using rough set. In this paper, the detection rates of the proposed face detection algorithm was confirmed to be better about 2~3% than the conventional algorithms regardless of the size and direction on the various faces by simulation.
  • 13.

    A Method for Recommending Learning Contents Using Similarity and Difficulty

    박재욱 , YONG KYU LEE | 2011, 16(7) | pp.127~136 | number of Cited : 2
    Abstract PDF
    It is required that an e-learning system has a content recommendation component which helps a learner choose an item. In order to predict items concerning learner's interest, collaborative filtering and content-based filtering methods have been most widely used. The methods recommend items for a learner based on other learner's interests without considering the knowledge level of the learner. So, the effectiveness of the recommendation can be reduced when the number of overall users are relatively small. Also, it is not easy to recommend a newly added item. In order to address the problem, we propose a content recommendation method based on the similarity and the difficulty of an item. By using a recommendation function that reflects both characteristics of items, a higher-level leaner can choose more difficult but less similar items, while a lower-level learner can select less difficult but more similar items, Thus, a learner can be presented items according to his or her level of achievement, which is irrelevant to other learner's interest.
  • 14.

    Incentive Design Considerations for Free-riding Prevention in Cooperative Distributed Systems

    신규용 , 유진철 , 이종덕 and 1 other persons | 2011, 16(7) | pp.137~148 | number of Cited : 0
    Abstract PDF
    Different from the traditional client-server model, it is possible for participants in a cooperative distributed system to get quality services regardless of the number of participants in the system since they voluntarily pool or share their resources in order to achieve their common goal. However, some selfish participants try to avoid providing their resources while still enjoying the benefits offered by the system, which is termed free-riding. The results of free-riding in cooperative distributed systems lead to system collapse because the system capacity (per participant) decreases as the number of free-riders increases, widely known as the tragedy of commons. As a consequence, designing an efficient incentive mechanism to prevent free-riding is mandatory for a successful cooperative distributed system. Because of the importance of incentive mechanisms in cooperative distributed system, a myriad of incentives mechanisms have been proposed without a standard for performance evaluation. This paper draws general incentive design considerations which can be used as performance metrics through an extensive survey on this literature, providing future researchers with guidelines for the effective incentive design in cooperative distributed systems.
  • 15.

    Effectiveness of Edge Selection on Mobile Devices

    Kang Seok-Hoon | 2011, 16(7) | pp.149~156 | number of Cited : 0
    Abstract PDF
    This paper proposes the effective edge selection algorithm for the rapid processing time and low memory usage of efficient graph-based image segmentation on mobile device. The graph-based image segmentation algorithm is to extract objects from a single image. The objects are consisting of graph edges, which are created by information of each image’s pixel. The edge of graph is created by the difference of color intensity between the pixel and neighborhood pixels. The object regions are found by connecting the edges, based on color intensity and threshold value. Therefore, the number of edges decides on the processing time and amount of memory usage of graph-based image segmentation. Comparing to personal computer, the mobile device has many limitations such as processor speed and amount of memory. Additionally, the response time of application is an issue of mobile device programming. The image processing on mobile device should offer the reasonable response time, so that, the image segmentation processing on mobile should provide with the rapid processing time and low memory usage. In this paper, we demonstrate the performance of the effective edge selection algorithm, which effectively controls the edges of graph for the rapid processing time and low memory usage of graph-based image segmentation on mobile device.
  • 16.

    Real Time Pose Control for the Horizontal Maintenance and driving of Mobile Inverted Pendulum

    Kang Jin-gu | 2011, 16(7) | pp.157~164 | number of Cited : 1
    Abstract PDF
    In this paper, configuration control for the Horizontal Maintenance and driving of the mobile inverted pendulum robot has been studied using ARS(Attitude Refrence System). The inverted pendulum technique is getting attention and there have been many researches on the seg-way since the US. Using its 2 freedom, a mobile inverted pendulum robot can move in various modes and Our robot performs goal reaching ARS. Mobile inverted pendulum robot fall down to the forward or reverse direction to converge to the stable point. Kalman Filter is normally used for the algorithm and numerous research is progressing at the moment. To calculate the attitude in ARS using 2 axis gyro(roll, pitch) and 3 axis accelerometers (x, y, z). In this paper we present a two wheel robot system for an autonomous mobile robot. This paper realized the robot control method which is much simpler but able to get desired performance by using the IMU and PID control.
  • 17.

    A Study on the Factors Promoting the Usage of WiBro Service

    Jongsoo Yoon | 2011, 16(7) | pp.165~172 | number of Cited : 1
    Abstract PDF
    This study was to investigate which factors promote the usage of WiBro service, and to propose a few of research propositions on the relationships between these factor and characteristics of mobile Internet usage. To accomplish these research purposes, the study defined research variables such as factors promoting the usage of WiBro service, characteristic of mobile Internet usage, and types of user based on the review of mobile Internet service related studies. The study performed various statistical analyses using survey questionnaires on mobile Internet users, and finally proposed some research propositions, based on the analysis results, that could be used in the future studies.
  • 18.

    Effects of Self Concept on Impulsive Cellular Phone Purchase and Emotional Response

    Sohn Jun Sang | 2011, 16(7) | pp.173~182 | number of Cited : 7
    Abstract PDF
    This study investigated the effects of self concept on impulsive purchase and after-buying emotional response. For these purposes, researcher compared the impulsive purchasing and after-buying emotional response by socially independent-dependent groups in self concept. The results of present research were as follow: First, impulsive purchase led to high after-buying emotional response such as guilt, regret, happiness, but it did not in pride. non-impulsive purchase led to high pride. Second, socially independent self concept led high impulsive purchase. Third, socially independent self concept moderated the effect of impulsive buying on guilt, regret, happiness, but it did not in pride also. These results show that socially independent consumers in self concept purchase cell-phone impulsively and have high guilt, regret, happiness in after-buying emotion. But the low pride would be interpreted that they don't think their impulsive purchases desirable.
  • 19.

    Estimating the Determinants of Loan Amount of Housing Mortgage : A Panel Data Model Approach

    Kim Hee Chul , Shin Hyun Cheul | 2011, 16(7) | pp.183~190 | number of Cited : 3
    Abstract PDF
    Loan amount of housing mortgage is composed of various factors. This study paper studies focuses on estimating the determinants of a loan amount of housing mortgage. The region for analysis consist of seven groups, that is, metropolitan city (such as Busan, Daegu, Incheon, Gwangiu, Daejeon, Ulsan.) and Seoul. Analyzing period be formed over a 45 time points(2007. 01.~ 2010. 09). In this paper the dependent variable setting up loan amount of housing mortgage, explanatory(independent) variables are composed of the consumer price index, unemployment rate, average monthly household income per household, expenditure rate of health care, composite stock price index and overdue rate of household loans for commercial bank. In looking at the factors which determine loan amount of housing mortgage, evidence was produced supporting the hypothesis that there is a significant positive relationship between the consumer price index and unemployment rate. The study also produced evidence supporting the view that there is a significant negative relationship between expenditure rate of health care. The study found that average monthly household income per household, expenditure, composite stock price index and overdue rate of household loans for commercial bank were not significant variables. The implications of these findings are discussed for further research.