• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.3
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• pp.185-197
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• 2001

Recently, the design method by VHDL coding and synthesis has been used widely. As the integration ratio increases, the amount design by VHDL at a time also increases so many coding errors occur in a design. Thus, lots of time and effort is dissipated to detect those coding errors. This paper proposed a method to verify the coding errors in VHDL behavioral-level designs. As the methodology, we chose the method to detect the coding error by applying the generated set of verifying patterns and comparing the responses from the error-free case(gold unit) and the real design. Thus, we proposed an algorithm to generate the verifying pattern set for the coding errors. Verifying pattern generation is peformed for each code and the coding errors are classified as two kind: condition errors and assignment errors. To generate the patterns, VHDL design is first converted into the corresponding CDFG(Control & Data Flow Graph) and the necessary information is extracted by searching the paths in CDFG. Path searching method consists of forward searching and backward searching from the site where it is assumed that coding error occurred. The proposed algorithm was implemented with C-language. We have applied the proposed algorithm to several example VHDL behavioral-level designs. From the results, all the patterns for all the considered coding errors in each design could be generated and all the coding errors were detectable. For the time to generate the verifying patterns, all the considered designed took less than 1 ［sec］ of CPU time in Pentium-II 400MHz environments. Consequently, the verification method proposed in this paper is expected to reduce the time and effort to verify the VHDL behavioral-level designs very much.

• The Journal of Society for e-Business Studies
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• v.20 no.2
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• pp.27-36
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• 2015

Current leakage of industrial technologies with revealing state secret against nation is gradually increasing and scope of the spill is diversified from technology-oriented leakage to new economic security sector like information and communication, electrical and electronic, defense industry, illegal export of strategic material, economic order disturbance by foreign country, infringement of intellectual property, etc. So the spill damage can affect not only leaked company but also national interests and entire domestic industry. According to statistics from National Industrial Security Center of National Intelligence Service, a major cause of technology leakage is not only by external things about hacking and malignant code, but internal leakage of former and current employees account for about 80%. And technology leakage due to temptation of money and personal interests followed by technology leakage of subcontractor is steadily increased. Most studies in the field of security have tended to focus on measuring security capability of company in order to prevent leakage core assets or developing measurement Indicators for management rather than security activities of the company members that is most important. Therefore, this study analyzes the effect of most underlying security education in security activities on security capabilities of enterprise. As a result, it indicates that security education have a positive(+) correlation with security capabilities.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9B
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• pp.1742-1754
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• 1999

In this paper, we propose a rate control scheme, using histogram based rate-distortion (R-D) estimation, which produces a consistent picture quality between consecutive frames. The histogram based R-D estimation used in our rate control scheme offers a closed-form mathematical model that enable us to predict the bits and the distortion generated from an encoded frame at a given quantization parameter (QP) and vice versa. The most attractive feature of the R-D estimation is low complexity of computing the R-D data because its major operation is just to obtain a histogram or weighted histogram of DCT coefficients from an input picture. Furthermore, it is accurate enough to be applied to the practical video coding. Therefore, the proposed rate control scheme using this R-D estimation model is appropriate for the applications requiring low delay and low complexity, and controls the output bit-rate ad quality accurately. Our rate control scheme ensures that the video buffer do not underflow and overflow by satisfying the buffer constraint and, additionally, prevents quality difference between consecutive frames from exceeding certain level by adopting the distortion constraint. In addition, a consistent considering the maximum tolerance BER of the voice service. Also in Rician fading channel of K=6 and K=10, considering CLP=$10^{-3}$ as a criterion, it is observed that the performance improment of about 3.5 dB and 1.5 dB is obtained, respectively, in terms of $E_b$/$N_o$ by employing the concatenated FEC code with pilot symbols.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.6B
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• pp.1082-1091
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• 2000

In this paper, the efficient equalization method for OFDM(Orthogonal Frequency Division Multiflexing) System using the QAM(Quadrature Amplitude Modulation) in multipath fading channel is proposed in order to faster and more efficiently equalize the received signals that are sent over real channel. In generally, the one-tap linear equalizers have been used in the frequency-domain as the existing equalization method for OFDM system. In this technique, if characteristics of the channel are changed fast, the one-tap linear equalizers cannot compensate for the distortion due to time variant multipath channels. Therefore, in this paper, we use one-tap non-linear equalizers instead of using one-tap linear equalizers in the frequency-domain, and also use the linear equalizer in the time-domain to compensate the rapid performance reduction at the low SNR(Signal-to-Noise Ratio) that is the disadvantage of the non-linear equalizer. In the frequency-domain, when QAM signals, consisting of in-phase components and quadrature (out-phase) components, are sent over the complex channel, the only in-phase and quadrature components of signals distorted by the multipath fading are changed the same as signals distorted by the noise. So the cross components are canceled in the frequency-domain equalizer. The time-domain equalizer and the adaptive algorithm that has lower-error probability and fast convergence speed are applied to compensate for the error that is caused by canceling the cross components in the frequency-domain equalizer. In the time-domain, To compensate for the performance of frequency-domain equalizer the time-domain equalizes the distorted signals at a frame by using the Gold-code as a training sequence in the receiver after the Gold-codes are inserted into the guard signal in the transmitter. By using the proposed equalization method, we can achieve faster and more efficient equalization method that has the reduced computational complexity and improved performance.

• International Commerce and Information Review
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• v.14 no.1
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• pp.345-366
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• 2012

The country using factoring actively today is England. The history of factoring could throw back to the Middle Ages, but modern factoring was developed in colonial age of the United States and it was known throughout England in 1960s. At the beginning, it performed mercantile agent who works in local area in order to get rid of uncertainty and inconvenience of a distant trade, but it was getting developed into a today's factoring system which focusing more on financial function. The factoring is called 'account receivable financing' in the United States and it is started out as sales agent and getting developed to 'del credere agent' who guarantee the payment. The activities of factors have been expanded to not only consignment sale and payment guarantees but also advance financing service. However, at the end of the 19th century, the direct sales(direct marketing) was expanded by the development of telecommunication and transportation technology, and then the marketing service by factor was degraded, but the collection of payment and advance finance had been maintained until now and developed into today's factoring system. Especially, the establishment of Uniform Commercial Code in 1931 had formed the basis for activating factoring in the United States through preparing a legal basis of factoring. Due to changes of international trade environment, most of commercial bank in Korea have to deal with export factoring as a trade finance service and it is desirable to specialize as a financing for small and medium company.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.8-14
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• 2020

Recently, there was an increasing demand for an integrated access control system which is capable of user recognition, door control, and facility operations control for smart buildings automation. The market available door lock access control solutions need to be improved from the current level security of door locks operations where security is compromised when a password or digital keys are exposed to the strangers. At present, the access control system solution providers focusing on developing an automatic access control system using (RF) based technologies like bluetooth, WiFi, etc. All the existing automatic door access control technologies required an additional hardware interface and always vulnerable security threads. This paper proposes the user identification and authentication solution for automatic door lock control operations using camera based visible light communication (VLC) technology. This proposed approach use the cameras installed in building facility, user smart devices and IoT open source controller based LED light sensors installed in buildings infrastructure. The building facility installed IoT LED light sensors transmit the authorized user and facility information color grid code and the smart device camera decode the user informations and verify with stored user information then indicate the authentication status to the user and send authentication acknowledgement to facility door lock integrated camera to control the door lock operations. The camera based VLC receiver uses the artificial intelligence (AI) methods to decode VLC data to improve the VLC performance. This paper implements the testbed model using IoT open-source based LED light sensor with CCTV camera and user smartphone devices. The experiment results are verified with custom made convolutional neural network (CNN) based AI techniques for VLC deciding method on smart devices and PC based CCTV monitoring solutions. The archived experiment results confirm that proposed door access control solution is effective and robust for automatic door access control.

• Korean journal of communication and information
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• v.20
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• pp.141-176
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• 2003

This paper examined how Korean courts conceptualized and applied public interest defense of Penal Code to the libel cases raised by socially influential persons. For this, this paper analyzed a total of 58 libel cases in which 'public interest' was mentioned by Korean courts between 1981 and 2000. It was found that whereas truth or believed-to-be-true defense is emphasized In libel cases by politicians or public officials, public interest defense was emphasized in the cases by private figures. It was also found that Korean courts tended to think of matters related with 1) national security and social order, 2) prevention of asocial crime, 3) enlightening of public, and 4) protection of consumers' interest as public interest. Conclusively, 'public interest' is not simply applied as an independent legal defense, because Korean courts insistently concentrated on the truth of a story and did not even specifically define what is public interest. Constitution Court recently maintained that the slope of legal defense should be broadened when a story is about public matters. However, Korean courts will not be likely to accept public interest defense as an independent one for the time being.

• Korean journal of communication and information
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• v.26
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• pp.7-44
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• 2004

This paper proposed semiotic model to explain representation process of time in cinema. Limitations of cinematic narratology which explain representation process of time in cinema were indicated, then alternative explanations of Deleuzian philosophy of cinema were proposed. After discussion about articulations of cinematic code, Deleuzian concept of movement-image was suggested as semiotic minimal unit of cinema. In cinema, Movement-image is divided two different aspects ; "normal movement-image" and "abnormal movement-image". Therefore, two different semiotic representation process of time was reconstructed in accordance with Peircean semiosis theory. In this two different semiotic process, modern cinema emphasize the direct representation process of time with "abnormal movement-image". As Deleuze indicated, The "time-image" is presented in this semiotic process. The "time-image" makes it possible to consider "time itself" as philosophical fact which is laid between reality and cinema, This semiotic process more emphasizes pure expressionality than representationality. Deleuzian philosophical journey through cinema was started in this point.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.12A
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• pp.2027-2035
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• 2001

In this paper, we present an audio stream delivery using the AMR (Adaptive Multi-Rate) coder that was adopted by ETSI and 3GPP as a standard vocoder for next generation IMT-2000 service in which includes combined sender (FEC) and receiver reconstruction technique in the Internet. By use of the media-specific FEC scheme, the possibility to recover lost packets can be much increased due to the addition of repair data to a main data stream, by which the contents of lost packets can be recovered. The AMR codec is based on the code-excited linear predictive (CELP) coding model. So we use a frame erasure concealment for CELP-based coders. The proposed scheme is evaluated with ITU-T G.729 (CS-ACELP) coder and AMR - 12.2 kbit/s through the SNR (Signal to Noise Ratio) and the MOS (Mean Opinion Score) test. The proposed scheme provides 1.1 higher in Mean Opinion Score value and 5.61 dB higher than AMR - 12.2 kbit/s in terms of SNR in 10% packet loss, and maintains the communicab1e quality speech at frame erasure rates lop to 20%.

• Spatial Information Research
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• v.15 no.2
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• pp.111-121
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• 2007

The GPS positioning offer 3D position using code and carrier phase measurements, but the user can obtain the precise accuracy positioning using carrier phase in Real Time Kinematic(RTK). The main problem, which RTK have to overcome, is the necessary to have a reference station(RS) when using RTK should be generally no more than 10km on average, which is significantly different from DGPS, where distances to RS can exceed several hundred kilometers. The accuracy of today's RTK is limited by the distance dependent errors from orbit, ionosphere and troposphere as well as station dependent influences like multipath and antenna phase center variations. For these reasons, the author proposes Network based GPS Carrier Phase Differential Positioning using Multiple RS which is detached from user receiver about 30km. An important part of the proposed system is algorithm and software development, named DAUNet. The main process is corrections computation, corrections interpolation and searching for the integer ambiguity. Corrections computation of satellite by satellite and epoch by epoch at each reference station are calculated by a Functional model and Stochastic model based on a linear combination algorithm and corrections interpolation at user receiver are used by area correction parameters. As results, the users can obtain the cm-level positioning.