• Journal of the Korea Society of Computer and Information
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• v.22 no.1
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• pp.71-76
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• 2017

Recently, there are various researches using inaudible high frequencies like as wireless communication based smart devices, data transmission algorithm, indoor positioning trace technologies. However, when they use high frequencies of inaudible range, they have a problem that the accuracy of data transmission with high frequencies was low because of interference from ambient noise in our real life. To solve this problem, in this paper, we proposed an application based on smart phone and server system for collection of ambient noise and detection of robust high frequency range. The server system could detect the robust high frequency range from statistical analysis of collected noise and the robust high frequency could avoid interference from ambient noise. We tested the proposed application's ability to gather noise and high frequencies for a certain period of time to evaluate performance. According to the testing results, we confirmed that the proposed application and server system could detect a robust high-frequency range via noise analysis in real life. Therefore, the proposed application and server could be a useful technology for future research on inaudible high frequencies.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1538-1543
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• 2016

Strabismus is a non-aligned state;the visual axis of each eye is not directed toward the same direction at the same time. Clinically, the degrees of strabismus are measured by prism cover test, corneal reflex test (Hirschberg test), prism reflex test (Krimsky prism test), But corneal reflex test and prism reflex test is a possibility that errors occur. we suggest a computer-aided diagnosis for strabismus. We made a mobile application to measure angles of strabismus. For 34 patients, we tested our application. The result of comparing between two methods, It showed a difference 7 Prism Diopter(PD). Our application gives strabismus angles just using a camera and a smart device. Therefore, it can reduce the cost and make the diagnosis of strabismus accurate.

• Journal of the Korea Society of Computer and Information
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• v.4 no.1
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• pp.15-20
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• 1999

In this paper, we propose some essential requirements for CBM(Computer Based Multimedia) based distance education. This is a class of multimedia distance education in which the multimedia technique is combined with the distance home education application that is real time collaborative application on cyber-space using the information super highway. Requirements in this paper is observed standard at ITU(International Telecommunication Union). international standardization organization for multimedia communication. And. a structure for integrated home information service on the information super highway is based on IEEE 1394 serial communication and POF(Plastic Optical Fiber) home backbone that is study for application service according to the multimedia based distance home study system.

• Journal of Environmental Impact Assessment
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• v.1 no.1
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• pp.41-50
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• 1992

To prevent unwanted visual impacts of proposed projects before they are actually built, Visual Impact Assessment(VIA) is conducted in current landscape planning and management process. The application of VIA to actual projects raises some important questions: "What views will the project affect?" "What tools and techniques are effective for predicting and portraying future landscape conditions?" "Who should determine the value of the impacts?" and "How can the impacts be measured?" Types and levels of visual impacts should be decided through analyzing both the existing landscape and the proposed project. Computer-based visual simulations will play a pivotal role as effective prediction and communication tools. With professionals' assistance, the public participation in the VIA process will produce meaningful solutions for planning and managing the future landscape. Also, the use of a proper response format and sensitive assessment criteria in measuring the public's opinion will enrich outcomes of the assessment. Based on the methodological framework, the case study briefly explains an application of VIA to an actual project.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.4
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• pp.2149-2170
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• 2017

Application-layer Distributed Denial-of-Service (DDoS) attack is one of the leading security problems in the Internet. In recent years, the attack strategies of application-layer DDoS have rapidly developed. This paper introduces a new attack strategy named Path Vulnerabilities-Based (PVB) attack. In this attack strategy, an attacker first analyzes the contents of web pages and subsequently measures the actual response time of each webpage to build a web-resource-weighted-directed graph. The attacker uses a Top M Longest Path algorithm to find M DDoS vulnerable paths that consume considerable resources when sequentially accessing the pages following any of those paths. A detection mechanism for such attack is also proposed and discussed. A finite-state machine is used to model the dynamical processes for the state of the user's session and monitor the PVB attacks. Numerical results based on real-traffic simulations reveal the efficiency of the attack strategy and the detection mechanism.

• 한국정보교육학회:학술대회논문집
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• 2011.01a
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• pp.59-65
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• 2011

The purpose of this paper is to develop an application that utilizes educational tools on the Smart-Phone, which will make it possible for student education in any environment. Strengths that a Smart-Phone application has include always being carried by the student, short boot time to open the program and rather than having to use a traditional computer for access. Tests can be taken repeatedly, so students prepare before class and keep their motivation level high, thus raising overall test outcomes.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.12
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• pp.723-731
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• 2005

The $4{\times}4$ homogeneous transformation matrix is a compact representation of orientation and position of an object in robotics and computer graphics. A coordinate transformation is accomplished through the successive multiplications of homogeneous matrices, each of which represents the orientation and position of each corresponding link. Thus, for real time control applications in robotics or animation in computer graphics, the fast multiplication of homogeneous matrices is quite demanding. In this paper, a parallel-architecture vector processor is designed for this purpose. The processor has several key features. For the accuracy of computation for real application, the operands of the processors are floating point numbers based on the IEEE Standard 754. For the parallelism and reduction of hardware redundancy, the processor takes column vectors of homogeneous matrices as multiplication unit. To further improve the throughput, the processor structure and its control is based on a pipe-lined structure. Since the designed processor can be used as a special purpose coprocessor in robotics and computer graphics, additionally to special matrix/matrix or matrix/vector multiplication, several other useful instructions for various transformation algorithms are included for wide application of the new design. The suggested instruction set will serve as standard in future processor design for Robotics and Computer Graphics. The design is verified using FPGA implementation. Also a comparative performance improvement of the proposed design is studied compared to a uni-processor approach for possibilities of its real time application.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.3
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• pp.471-489
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• 2013

Data compression at the transport layer could both reduce transmitted bytes over network links and increase the transmitted application data (TCP PDU) in one RTT at the same network conditions. Therefore, it is able to improve transmission efficiency on Internet, especially on the networks with limited bandwidth or long delay links. In this paper, we propose an on-the-fly TCP data compression scheme, i.e., the TCPComp, to enhance TCP performance. This scheme is primarily composed of the compression decision mechanism and the compression ratio estimation algorithm. When the application data arrives at the transport layer, the compression decision mechanism is applied to determine which data block could be compressed. The compression ratio estimation algorithm is employed to predict compression ratios of upcoming application data for determining the proper size of the next data block so as to maximize compression efficiency. Furthermore, the assessment criteria for TCP data compression scheme are systematically developed. Experimental results show that the scheme can effectively reduce transmitted TCP segments and bytes, leading to greater transmission efficiency compared with the standard TCP and other TCP compression schemes.

• Journal of Service Research and Studies
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• v.1 no.1
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• pp.113-122
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• 2011

In this research, we developed an practical service module as a application which operating on the smart phones based on the Android operating system. The service module supports on the voice processing function and inquiry windows also. After some documents and screens related on system analysis, service module are designed and implemented. The details about these modules are explained. We can expect to enhance the learning effects of english words memorizing competence for smart-phone users.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.156-159
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• 2019

The damage from voice phishing reaches one trillion won in the past 5 years following report of Business Korea on August 28, 2018. Voice phishing and mobile phone scams are recognized as a top concern not only in Korea but also in over the world in recent years. In this paper, we propose an efficient system to identify the caller and alert or prevent of dangerous to users. Our system includes a mobile application and web server using client and server architecture. The main purpose of this system is to automatically display the information of unidentified callers when a user receives a call or message. A mobile application installs on a mobile phone to automatically get the caller phone number and send it to the server through web services to verify. The web server applies a machine learning to a global phone book with Blacklist and Whitelist to verify the phone number getting from the mobile application and returns the result.