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

2020 KCI Impact Factor : 0.4
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2015, Vol.20, No.4

  • 1.

    CL-Tree: B+ tree for NAND Flash Memory using Cache Index List

    Hwang Sang-Ho | Kwak, Jong Wook | 2015, 20(4) | pp.1~10 | number of Cited : 4
    Abstract PDF
    NAND flash systems require deletion operation and do not support in-place update, so the storage systems should use Flash Translation Layer (FTL). However, there are a lot of memory consumptions using mapping table in the FTL, so recently, many studies have been proposed to resolve mapping table overhead. These studies try to solve update propagation problem in the nand flash system which does not use mapping table. In this paper, we present a novel index structure, called CL-Tree(Cache List Tree), to solve the update propagation problem. The proposed index structure reduces write operations which occur for an update propagation, and it has a good performance for search operation because it uses multi-list structure. In experimental evaluation, we show that our scheme yields about 173% and 179% improvement in insertion speed and search speed, respectively, compared to traditional B+tree and other works.
  • 2.

    Block Smart Rack Technology Development for Increased Efficiency

    태효식 | park koo rack | 2015, 20(4) | pp.11~16 | number of Cited : 0
    Abstract PDF
    Data center, not only the development of globally of cloud-based IT solutions, As the big data, education, use of development electronic equipment of communication means is increased, Demand of domestic and international data center has increased steadily. Due to the increase of data center demand, heat generation of server rack due to the development of IT equipment is also increasing continuously. Calculating heat value of the data center, because more than 99% of the power usage of IT server is converted into heat, the calorific value as the size and capacity of the server is larger will increase. In this paper, to center the cooling system of air-cooled, and research and development of air conditioning systems for energy reduction of data center, through performance analysis and simulation, it has been analyzed that there is energy savings.
  • 3.

    Two-Phase Clustering Method Considering Mobile App Trends

    허정만 | So-Young Park | 2015, 20(4) | pp.17~23 | number of Cited : 0
    Abstract PDF
    In this paper, we propose a mobile app clustering method using word clusters. Considering the quick change of mobile app trends, the proposed method divides the mobile apps into some semantically similar mobile apps by applying a clustering algorithm to the mobile app set, rather than the predefined category system. In order to alleviate the data sparseness problem in the short mobile app description texts, the proposed method additionally utilizes the unigram, the bigram, the trigram, the cluster of each word. For the purpose of accurately clustering mobile apps, the proposed method manages to avoid exceedingly small or large mobile app clusters by using the word clusters. Experimental results show that the proposed method improves 22.18% from 57.48% to 79.66% on overall accuracy by using the word clusters.
  • 4.

    Effective Robot Path Planning Method based on Fast Convergence Genetic Algorithm

    서민관 | Jaesung Lee | DaeWonKim | 2015, 20(4) | pp.25~32 | number of Cited : 0
    Abstract PDF
    The Genetic algorithm is a search algorithm using evaluation, genetic operator, natural selection to populational solution iteratively. The convergence and divergence characteristic of genetic algorithm are affected by selection strategy, generation replacement method, genetic operator when genetic algorithm is designed. This paper proposes fast convergence genetic algorithm for time-limited robot path planning. In urgent situation, genetic algorithm for robot path planning does not have enough time for computation, resulting in quality degradation of found path. Proposed genetic algorithm uses fast converging selection strategy and generation replacement method. Proposed genetic algorithm also uses not only traditional crossover and mutation operator but additional genetic operator for shortening the distance of found path. In this way, proposed genetic algorithm find reasonable path in time-limited situation.
  • 5.

    A Design and Implementation of Educational Mobile Robot System including Remote Control Function

    CHUNG, JOONG SOO | 정광욱 | 2015, 20(4) | pp.33~40 | number of Cited : 0
    Abstract PDF
    This paper presents the design and implementation of the educational remote controlled robot system including remote sensing in the embedded environment. The design of sensing information processing, software design and template design mechanism for the programming practice are introduced. LPC1769 using Cortex-M3 core as CPU, LPCXPRESSO as debugging environment, C language as firmware development language and FreeRTOS as OS are used in development environment. The control command is received via RF communication by the server and the robot system which is operated by driving the various sensors. The educational procedure is from robot demo operation program as hands-on practice and then compiling, loading of the basic robot operation program, already supplied. Thereafter the verification is checked by using the basic robot operation to allow demo operation such as hands-on-training procedure. The original protocol is designed via RF communication between server and robot system, and the satisfied performance result is presented by analyzing the robot sensing data processing.
  • 6.

    An Algorithim for Converting 2D Face Image into 3D Model

    최태준 | Heeman Lee | 2015, 20(4) | pp.41~48 | number of Cited : 3
    Abstract PDF
    Recently, the spread of 3D printers has been increasing the demand for 3D models. However, the creation of 3D models should have a trained specialist using specialized softwares. This paper is about an algorithm to produce a 3D model from a single sheet of two-dimensional front face photograph, so that ordinary people can easily create 3D models. The background and the foreground are separated from a photo and predetermined constant number vertices are placed on the seperated foreground 2D image at a same interval. The arranged vertex location are extended in three dimensions by using the gray level of the pixel on the vertex and the characteristics of eyebrows and nose of the nomal human face. The separating method of the foreground and the background uses the edge information of the silhouette. The AdaBoost algorithm using the Haar-like feature is also employed to find the location of the eyes and nose. The 3D models obtained by using this algorithm are good enough to use for 3D printing even though some manual treatment might be required a little bit. The algorithm will be useful for providing 3D contents in conjunction with the spread of 3D printers.
  • 7.

    Implementing Solar System Simulator using Python Script

    최은영 | Lee, Im Geun | 2015, 20(4) | pp.49~56 | number of Cited : 0
    Abstract PDF
    In this paper, we introduce a simulation tool for solar system using 3D animation tool MAYA. It accurately models solar system’s astronomical features, such as each planet’s orbital period, orbital speed, relative size, and texture, etc. This simulator visualize the solar system in 3D, which can be used to easily understands the system’s positioning and astronomical movements. With a conventional Maya modeling process using menus and UI windows, it is difficult to assign correct physical attributes of planets. We use Python script to set up each planet’s astronomical parameters. The proposed simulator is rendered as real as possible to be used for virtual reality and educational purpose.
  • 8.

    Measure Radiation and Correct Radiation in IR camera Image

    정준호 | 김재협 | 2015, 20(4) | pp.57~67 | number of Cited : 2
    Abstract PDF
    The concept of detection and classification of objects based on infrared camera is widely applied to military applications. While the object detection technology using infrared images has long been researched and the latest one can detect the object in sub-pixel, the object classification technology still needs more research. In this paper, we present object classification method based on measured radiant intensity of objects such as target, artillery, and missile using infrared camera. The suggested classification method was verified by radiant intensity measuring experiment using black body. Also, possible measuring errors were compensated by modelling-based correction for accurate radiant intensity measure. After measuring radiation of object, the model of radiant intensity is standardized based on theoretical background. Based on this research, the standardized model can be applied to the object classification by comparing with the actual measured radiant intensity of target, artillery, and missile.
  • 9.

    Application of Hyperspectral Imaging System to Analyze Vascular Alteration for Preclinical Models

    Se-woon Choe | Woo, Young Woon | 2015, 20(4) | pp.69~76 | number of Cited : 2
    Abstract PDF
    We present microscopy based hyperspectral imaging system that successively shows high spatial (micrometer) and temporal resolutions (milisecond), and acquired pseudocolor hemoglobin saturation map a result of various image processing techniques can provide additional information such as oxygen transport, abnormal vascularity and therapeutic effects besides structural and physiological measurements in various diseases. To increase understanding of vascular defects several optical methods of imaging for preclinical/clinical assessment have been developed so far. However, they have some limitations for outcoming resolution and user satisfaction level compared to its cost. A hyperspectral imaging system has shown a wide range of vascular characteristics associated with hypervascularity, aberrant angiogenesis or abnormal vascular remodeling in many diseases. This vascular characteristic is considered as a key component to diagnose and detect a type of disease as evidenced by them.
  • 10.

    Clustering Algorithm for Extending Lifetime of Wireless Sensor Networks

    김선철 | 최승권 | Yonghwan Cho | 2015, 20(4) | pp.77~85 | number of Cited : 4
    Abstract PDF
    Recently, wireless sensor network(WSN) have been used in various fields to implement ubiquitous computing environment. WSN uses small, low cost and low power sensors in order to collect information from the sensor field. This paper proposes a clustering algorithm for energy efficiency of sensor nodes. The proposed algorithm is based on conventional LEACH, the representative clustering protocol for WSN and it prolongs network and nodes life time using sleep technique and changable transmission mode. The nodes of the proposed algorithm first calculate their clustering participation value based on the distance to the neighbor nodes. The nodes located in high density area will have clustering participation value and it can turn to sleep mode. Besides, proposed algorithm can change transmission method from conventional single-hop transmission to multi-hop transmission according to the energy level of cluster head. Simulation results show that the proposed clustering algorithm outperforms conventional LEACH, especially non-uniformly deployed network.
  • 11.

    An Efficient Algorithm for Constructing a Maximal Request Bandwidth Tree on Public-shared Network

    Kyun Rak Chong | 2015, 20(4) | pp.87~93 | number of Cited : 0
    Abstract PDF
    Recently, an idea has been suggested in which members construct the network by sharing their surplus bandwidth of their own access point. This kind of network is called public-shared network. As an application, SVC video streaming delivery system on public-shared network has been proposed. To send video stream from the stream server to clients, a tree structure is constructed where the root is a stream server, internal nodes are sharable access points, and leafs are clients. The previous researches have focused on constructing the minimal sharable-bandwidth tree which can serve all video streaming requests using the minimal sharable bandwidth. In this paper, we have shown that the problem of constructing a tree structure with given sharable access points to serve maximal video streaming requests is NP-hard. We also have developed an efficient heuristic algorithm for this problem and evaluated experimentally our algorithm.
  • 12.

    A Selection-Deletion of Prime Implicants Algorithm Based on Frequency for Circuit Minimization

    Sang-Un, Lee | 2015, 20(4) | pp.95~102 | number of Cited : 1
    Abstract PDF
    This paper proposes a simple algorithm for circuit minimization. There are currently two effective heuristics for circuit minimization, namely manual Karnaugh maps and computable Quine-McCluskey algorithm. The latter, however, has a major defect: the runtime and memory required grow 3n/n times for every increase in the number of variables n. The proposed algorithm, however, extracts the prime implicants (PI) that cover minterms of a given Boolean function by deriving an implicants table based on frequency. From a set of the extracted prime implicants, the algorithm then eliminates redundant PIs again based on frequency. The proposed algorithm is therefore capable of minimizing circuits polynomial time when faced with an increase in n . When applied to various 3-variable and 4-variable cases, it has proved to swiftly and accurately obtain the optimal solutions.
  • 13.

    Potentials and Challenges of the Usability of Art Museum Mobile Applications

    Rhee Boa | 2015, 20(4) | pp.103~110 | number of Cited : 0
    Abstract PDF
    The biggest challenge of managing mobile interpretative device is that visitors do not have the mobile experience. Thus, in the research of the mobile application of the Leeum (Samsung Museum of Art), a short orientation session as a treatment was provided to survey participants to make them use of a mobile experience. The orientation solved the problem of hesitancy of using smartphone in other researches, it was simultaneously the uniqueness of the methodology. Based on the research data, their satisfaction with visiting experience and with using the application appeared to be relatively high. A half of participants used the application for 10 minutes which is accounted for 20-30% of the total viewing time. Participants (80.3%) engaged in each exhibit with the application in less than 30 sec.-1 minute. Comparing with the average time of engagement (10-30 sec.) for each exhibit without using mobile applications, it is possible to conclude that the mobile application notably contributed to make participants engage with exhibits longer.
  • 14.

    Chromatic Number Algorithm for Exam Scheduling Problem

    Sang-Un, Lee | 2015, 20(4) | pp.111~117 | number of Cited : 0
    Abstract PDF
    The exam scheduling problem has been classified as nondeterministic polynomial time-complete (NPcomplete) problem because of the polynomial time algorithm to obtain the exact solution has been unknown yet. Guéret et al. tries to obtain the solution using linear programming with O(m4) time complexity for this problem. On the other hand, this paper suggests chromatic number algorithm with O(m) time complexity. The proposed algorithm converts the original data to incompatibility matrix for modules and graph firstly. Then, this algorithm packs the minimum degree vertex (module) and not adjacent vertex to this vertex into the bin Bi with color Ci in order to exam within minimum time period and meet the incompatibility constraints. As a result of experiments, this algorithm reduces the O(m4) of linear programming to O(m) time complexity for exam scheduling problem, and gets the same solution with linear programming.
  • 15.

    Moderating roles of strategy suitability factors between enterprise characteristics and IT adoption performance

    임길재 | Yi, Seon Gyu | 2015, 20(4) | pp.119~130 | number of Cited : 1
    Abstract PDF
    This study empirically analyzed at domestic manufacturing and service firms to find any moderating effects of enterprise management strategies and information-oriented development strategies between enterprise characteristic factors and IT adoption performance. Task characteristics were analyzed based on information provision extent, system quality and perceived effects while environmental characteristics based on competition extent, external pressure, environmental uncertainty, etc. As a result it was found that strategic suitability factors had a moderating effect between adoption performance and task characteristic variables such as system quality and perceived effect, environmental characteristics such as competition level, external pressure and environmental uncertainty. However, strategy suitability was found not to have any moderating role between task characteristic information provision extent and adoption performance. These findings indicate that enterprises need to plan and implement corporate management strategies and information-oriented development strategies in close coordination for new IT adoption and spread.
  • 16.

    Analysis of SNS(Social Networking Service) functions applicable to electronic commerce for building regular relationship with customers

    김미수 | WonSeokWoo | 2015, 20(4) | pp.131~138 | number of Cited : 3
    Abstract PDF
    One of the most conspicuous characteristics of a business model that pursues expanding customer relationship is that it tries to lock in customers by encouraging them to repeat purchase in the long-term with the help of “Follow” function in Social Networking Service (SNS), which enables producers to automatically register the customers as potentially important ones and to offer them customized marketing services. In the value chain of the agriculture sector, producers of agricultural products can use SNS functions to provide loyal customers with valuable information and experiences such as the real-time information of their farm and products, hidden stories about the whole process from seeding to harvesting, and the storage and cooking methods of their products. These activities help the producers invoke customers’ desire to live in the farm and to grow the products themselves. They also raise the accessibility of the producers’ websites as customers are able to share a variety of news and knowledge such as the release of new products. This means that the producers’s websites are now functioning to enable the producers to perform sales and promotion related activities. It is a big leap from the traditional e-commerce business model where sales and promotion of a product were separated and could be connected only through outside links. This two-way, viral characteristics of marketing services using SNS facilitate customers to share product information and their purchase experience with each other, which leads to more effective and efficient communication within the customer community.
  • 17.

    Problems and Solutions for the Term of Existence of the Housing Lease in the Digital age

    Jong-Ryeol Park | 2015, 20(4) | pp.139~146 | number of Cited : 1
    Abstract PDF
    The Housing Lease Protection Act was enacted from March 5, 1981 as Law No. 3379 to guarantee the stability of residential life and legal status. After then, there were many problems, but through several times revision, it had improved insufficient part. However, in order to give guarantees actually the position strengthen for homeless poor people many issues still need to be solved and it has been raised. Along the way, with the introduction of the tenant renewal claims, in February 14, 2015, the National Assembly planned to discuss current issues by operating the Special Committee for housing welfare of ordinary people in the extra session. In the current, however, the conflict of the pros and cons is shown clearly. Meanwhile, because the contract renewal claim of tenant was not guaranteed, if the minimum duration of the lease will be lapsed, contract renewal is dependent on the intention of landlord. Thus, the residential stability of homeless poor could become unstable. Therefore, in this paper, to stabilize the residential living for tenants who are in poor status, analyze our term of existence regulation and through the compared to the national legislation about the term of existence, it will try to propose the specific legislative approach to the problem.
  • 18.

    A Design of Smart-based collaborative learning model for programming education of elementary school

    Young-Hoon Sung | 2015, 20(4) | pp.147~159 | number of Cited : 6
    Abstract PDF
    This paper is to design smart based collaborative learning model for programming education of fifth graders of elementary school and applies it to a class and analyze its result. Designed learning model is composed of understanding of concept, realization, learning and sharing and it includes step by step learning materials and smart based collaborative learning activities. Scratch traffic light learning materials at leaning stage classify content to be checked in programming by colors and write to support programming internalization of learners. Provision of smart based collaborative learning activities that considered learning conditions of learners makes it possible for beginners to participate in and keep study actively. This study showed that there was statistically significant difference in learners’ programming interest and those who achieved over 8 out of 10 points were 60.7% at three stage evaluations for achievement level that applied learning model which suggests that satisfactory achievement level is achieved.