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pISSN : 1975-7700 / eISSN : 2734-0570

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2014, Vol.9, No.5

  • 1.

    The Development of a Computer Based ICT Ethics Learning System Applying a Storytelling Learning Model

    Lee, Jae Mu , 이희순 | 2014, 9(5) | pp.533~543 | number of Cited : 4
    Abstract PDF
    This study has developed a learning system based on a storytelling model for information ethics education. The developed system has been applied to learners and the learning effects have been analyzed. A computer-based learning system applying a learning model whose learning effect has been approved by scholars would be able to enhance student learning effects. This study has therefore redefined the storytelling learning model to make the education of elementary school students in information communication ethics more efficient. To do this, we have developed a learning system and have analyzed its learning effect by applying it to elementary information communication ethics education. The results indicate that the learning process of the storytelling learning model has a positive effect on both cognitive and affective domain learning. In particular, self-regulated learning could be realized in the stage of the storytelling model.
  • 2.

    A Prediction Model of Traffic Flooding in Limited Network Environments

    이상우 , 백현철 , 홍석원 and 1 other persons | 2014, 9(5) | pp.545~554 | number of Cited : 1
    Abstract PDF
    The subjective of this study is to analyze a possibility of occurring traffic flooding in order to ensure stable services as bandwidth exhausting attacks are presented to users who use limited network bandwidths. Also, a model that can improve service availability and maintain service consistency through rapid responses is proposed. As abnormal traffics occur in a limited network environment, it makes possible to quickly response to traffic flooding attacks, which may occur in future, through estimating changes in subjective traffics. For achieving it, a traffic state model in normal users is extracted as samples of continuous and discrete values in a specific range and the error between these values and its transition process are also used as prediction and detection models. Then, the detection data extracted from normal users are compared and analyzed with the traffics in bandwidth exhausting attacks. Based on the results, the availability and consistency in Internet access services are improved through rapid responses for different unexpected traffics.
  • 3.

    Improved STUN Algorithm for Testing Network Address Translation

    TRAN THI THU HA , LeeBaeHo , JInsul Kim | 2014, 9(5) | pp.555~562 | number of Cited : 0
    Abstract PDF
    Peer-to-Peer (P2P) network is a group of computers communicating directly with each other without through a central server. P2P network is used for file sharing, multi-player online games, to avoid the expense and delay of traffic at the server. However, P2P communication has problems dealing with Network Address Translation (NAT) traversal. Conventional Simple Traversal of UDP through NATs (STUN) protocol was given to discover the type of NATs behind Clients. In conventional STUN processing, the tests follow the sequence of time that means the first test is needed to get the result before performing the second test and so on. Thus, the system testing has the delay of time. So, in this paper, we propose an improved STUN algorithm that separating tests of the conventional STUN algorithm and perform all tests in parallel. So, the execution time will be shortened significantly. We also have reality experiment in which is applied improved STUN algorithm for testing NATs.
  • 4.

    A Two-way Packet Transmission to Reduce Network Fragmentation for 802.11p WAVE

    Gea-Hee Kim , HyunJu Kim , Kim Chang Geun | 2014, 9(5) | pp.563~570 | number of Cited : 1
    Abstract PDF
    VANET (Vehicular Ad-hoc Network) is largely influenced by the characteristic of the street and the mobility of the vehicles in an inner-city intersection as a network. In this model, an insufficient amount of vehicles can often leads to network connection failure. In addition, there will be increase in the number of nodes secondary to the switching in between different modes in order to find the next node, which can further delay the packet transfer process. In this study, we are proposing a new algorithm by improving the GBSR protocol to transfer a packet in a forward direction and sending the copy in a reverse direction concurrently. Because this method transfers the same packet to two different directions, there will be a decrease in the probability of network failure as even if the packet transferred to one direction fails to deliver, the other packet can still reach the destination via another direction. In addition, the network traffic will not worsen due to the fact one can choose to send a packet in a direction without being influenced by the amount of available vehicles as one copy of the packet will be directed to a shorter distance to the destination while another copy will be directed to a different route.
  • 5.

    A LSB-first Word-Level Normal Basis Multiplier over GF(2m)

    Cho Yong Suk , Jae-Yeon Choi | 2014, 9(5) | pp.571~578 | number of Cited : 1
    Abstract PDF
    Finite field multipliers are the basic building blocks in many applications such as error-control coding, cryptography and digital signal processing. Hence, the design of efficient dedicated finite field multiplier architectures can lead to dramatic improvement on the overall system performance. In this paper, LSB-first word-level normal basis multiplier with low latency in Galois field is presented. To speed up multiplication processing, we divide the product polynomial into several parts and then process them in parallel. The proposed multiplier operates in normal basis of GF(2m) and is faster than bit serial ones but with lower area complexity than bit parallel ones. The most significant feature of the proposed architecture is that a trade-off between hardware complexity and delay time can be achieved.
  • 6.

    QoE Analysis based on Inverse Filtering For Video Quality Assessment

    Yogiraj S. Jadhav , Jungdae Kim , JInsul Kim | 2014, 9(5) | pp.579~587 | number of Cited : 0
    Abstract PDF
    The quality of experience (QoE) can assess the video quality with the service parameters and their relative importance at the network layer. The service providers are also examining the level of multimedia service quality to a particular aspect hence, internet service provider is also willing to provide all the services through a single line. Considering the above facts the factors associated with the user perceived experiences are responsible for the development of such digital systems, For analyzing the user perceived experience the QoE parameters play an important role. In this paper, considering QoE factor we have determined an approach that helps to estimate the user’s QoE, which uses a full reference model. This method uses an image restoration technique like inverse filtering, which improves the overall appearance of the video. It also helps to evaluate factors that measure the video quality effectively.
  • 7.

    Adaptive Set-Division Replacement Policy for Increasing Cache Efficiency

    Youngil Cho , Lee Sang Jeong | 2014, 9(5) | pp.589~598 | number of Cited : 0
    Abstract PDF
    Modern processors have large on-chip caches to mitigate off-chip memory latency. The Least Recently Used(LRU) replacement policy represents the cache blocks in a set as LRU stack. This policy picks the LRU block as the replacement candidate. In most condition, it can accomplish the work well, but for some memory-intensive workload it can not provide a long enough access history for a given cache size and associativity. Also in some workload, the majority of lines go through the cache space without making any sense. Cache performance can be improved if a long range of access history can be held so that some period of records can contribute to cache hits. In this paper, we propose an Adaptive Set-division Replacement Policy(ASRP) for effective cache management. In ASRP policy, the set of the last-level cache is divided into several subsets, only one subset is activated when replacement happens and the replacement area is limited to this subset using LRU policy. The cache misses are counted when a certain subset is activated. When the miss-count exceeds a threshold, the next subset is activated. So the threshold can indirectly decide the range of access history through the last-level cache. We use a sample method to dynamically determine the threshold for different workloads and different run-time phases of a certain workload. The experiment results show that ASRP reduces the average MPKI of the baseline 1MB 16-way L3 cache by 4.6%.
  • 8.

    User Tolerance on Switching Performance of Touchscreen Interfaces in Smart Devices

    이재명 , Lee Ju-Hwan | 2014, 9(5) | pp.599~606 | number of Cited : 0
    Abstract PDF
    The present study has tried to find out the users’ tolerance levels when they use touchscreen swipe interaction on the conditions of content type, screen size, and stability situations. For this purpose the present study was conducted in the two experimental settings: the user tolerance levels with three screen sizes(4, 7, 10 inch) and three content types(text, image, home-screen) were measured in the sitting condition and the walking condition. Five levels of screen switching performance from 0.1 sec to 0.5 sec was designed and picked which setting the participants felt uncomfortable to use. As the result, most of participants generally noticed the difference of screen switching lag by their touch input from about 0.3 sec. To each independent variables, the participants showed the tolerance levels go higher when more text information is in content and the display is bigger. For the feature of smart devices, many users are frequently used in the walking situation. We checked if there is difference between the sitting and walking conditions. In the comparison, when they were walking the tolerance levels were higher.
  • 9.

    The VOD Service is Based on Cloud File System Which is Used to Fixed-Node Server of Private Dedicated Network

    정명기 , Kim Jae Woong | 2014, 9(5) | pp.607~615 | number of Cited : 1
    Abstract PDF
    A company or organization that provides a VOD service inside the media by using a private dedicated network, in preparation for the connection’s rush to the service at the same time, is adopted how to get service from the relay server or the branch point or that and transfer the specific media to the relay server. However, these methods have a problem that needs to be added the storage of the relay server, which increases the number and size of the media. In order to solve this problem, the method to distribute to a plurality of relay servers that you specify only a portion by dividing the media is used. Also, in order to be able to reduce the load connected to the main streaming server, they allow the list of splitting media files to be created and to be viewed by selecting the optimum relay server among a plurality of relay servers, which are stored and divided into a base point of a branch point or that. Then it is possible to realize a VOD services with a stability, lower cost, and high efficiency.
  • 10.

    An Efficient Recognition Method using 2 Layer Hidden Markov Models for Human Driving Behavior

    Eun-Jae Shin , Yun Inho , Dinh Xuan Hao and 2 other persons | 2014, 9(5) | pp.617~628 | number of Cited : 2
    Abstract PDF
    This paper proposes a stochastic model for human driving behavior using a double layer Hidden Markov Model (HMM) with continuous observations. In the proposed model, gas pedal’s position, steering wheel’s angle, velocity and angular velocity of the vehicle is used and recorded in every 100 msec for recognizing driving task. Data acquisition is done during a simulated driving task, after that data is segmented and clustered into 9 different cases. The lower-layer with one-dimensional continuous HMM is used for recognizing translational acceleration of a vehicle. The upper-layer with one dimensional continuous HMM is used for recognizing angular velocity of a vehicle. For recognizing a user’s behavior, we used sliding windows with size of 10 samples and length of sequence with size of 30 samples. We apply a Kalman filter to reduce noise. After the filtering, the data was processed by sorting into three groups for a pedal, a steering wheel, and speed. We used two main features, which are angular velocity and the translational acceleration, in order to present driving behavior. We constructed a driving simulator based on Logitech G27 Racing platform to evaluate the proposed method. Using the developed driving simulator, some experiments were conducted for comparing the accuracy rate of the proposed method with that of the conventional method. Futhermore, we compared the average learning time of the proposed method with that of the conventional method because Learning time becomes also an important factor for investigating the performance of stochastic models. The experimental results confirm the accuracy of the proposed approach by revealing recognition accuracy around 96%-97%. Furthermore, the proposed method decreases learning time around 40%.
  • 11.

    Develope the Assessment Items and Evaluation Matrix of Task Performance Evaluation of Multimedia Audio Editing Software for the Visually Impaired

    서인희 , Kim Jae Woong | 2014, 9(5) | pp.629~635 | number of Cited : 1
    Abstract PDF
    The purpose of using multimedia application software SF10 is sound editing. SF10 is a sound editing software made by sony corp.. It is very good software for the visually impaired person to get a job in the multimedia industry specially sound creating area because the companies in this area are always looking for the engineer who can get the good sensibility of sound and can operate the sound editing software very skillful. It is common known visually impaired person has good sensibility of sound so they can catch the noise better and can adjust the sound more precisely than not visually impaired person. Sound editing with SF10 is a creative task that requirers not only operator’s artistic expression for the sound but also the ability to combinate many editing tools. Thus, assessment items of task performance evaluation of SF10 must consist of ‘creative task commands’. Creative task means a complex operation that uses a combination of various tools and selects the variables to achieve goals whereas simple tasks are working with one command. In this study, assessment items are developed by extracting the complex task commands of SF10 and evaluation matrix of task performance evaluation is developed for the visually Impaired. The result of this test is an indicator of the usability of the program. On the other hand it will helpful not only to design the education program to improve the proficiency of program for the visually impaired but also to set the working range of the visually impaired.
  • 12.

    A Development of Checklists for Operation Audit in the Mobile Web Information System

    김만환 , DongSooKim , Hee Wan Kim | 2014, 9(5) | pp.637~651 | number of Cited : 2
    Abstract PDF
    According to rapid growth of smart phone usage in Korean mobile market, many companies has been expending their mobile market and constructing the mobile web information system. Although mobile web information system has been consistently grown up, the study of operation audit did not show any significant progress, and the perception of the mobile web information systems audit is low. There were not many cases that performed the mobile web information systems operation audit so far. The risk factors in operating a mobile web information systems courses at public institutions are the lack of professional business management for outsourced development, lacks of information sharing and specific technical review system for redundant investment, and the weakness of system stability. Thus, we needs the operation audit of mobile web information systems. You can see the effect of increasing the effectiveness of the quality to improve the mobile web information business management and process improvement. In this paper, we compared the ITIL checklists to apply the effective operation audit of the mobile web information systems. We derived the checklists of operation audit by each domain of service strategy, service design, service transition, service operation, and continual service improvement which is ITIL V3 life cycle. As the result, this study appear to have more than average satisfaction the suitability results were.
  • 13.

    Asymmetric Stereoscopic Video Transmission using Hierarchical Modulation

    장연수 , Kwangmin Hyun | 2014, 9(5) | pp.653~662 | number of Cited : 1
    Abstract PDF
    In this paper, we evaluated stereoscopic video performance transmitted through wireless channel. Human’s visual perception capabilities of two eyes are different and one of two eyes is predominant one for visual perception. Thus using this human visual characteristic, there is no problem to recognize the 3D perception even if we sent relatively low quality of one of two video information for reducing the amount of data. If we use the constituting gain channel with Gray mapping for hierarchical 16-QAM (Quadrature Amplitude Modulation) called as (16-HQAM), we allocated the predominant video compressed data using H.264/AVC(Advanced Video Compression) to high gain channel and the compressed data of the other side video to low gain channel and send them. The simultaneously compressed video information of two views is sent through AWGN(additive White Gaussian Noise) channel environment. Controlling the channel gain, we discuss PSNR(Peak Signal to Noise Ratio) and CDF(Cumulative Distribution Function) performance.