• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1982.10a
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• pp.47-50
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• 1982

A baseband data transimission system is implemented on a microcomputer for performance study on some NRS line codes. These codes are compared in terms of eye width, BER, and power spectrum.

• Journal of the Korean Society for Library and Information Science
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• v.22
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• pp.1-27
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• 1992

Librarians long ago proclaimed themselves professionals. Until recently, however, librarians and information professionals gave very little thought to professional ethics, which have corne to play an increasingly important role in all areas in modern society. They have been stimulated to consider their specific domain within an ethical context now. Professional norms express obligations which include prescribing standards, principles of responsibilities, and rules of duties. Professional codes attempt to formulate the norms of professional ethics and are the basis for disciplinary measures of various kinds. This paper discusses professional properties and characteristics of libarianship with a special reference to the code of professional ethics. The codes of ethics of the American Library Association, the Library Association, and of the Japanese Library Association have been reviewed and compared. The arguments on the enforcibility of the professional codes of ethics, therefore, on their effectiveness have been discussed. Author concludes that, despite some doubts on the practical effectiveness of the ethics code expressed by a number of scholars, a code of ethics is very much required in the information professions. Properly disseminated, a code would enhance the status and standing of the profession by demonstrating concerns for the maintenance of the highest possible level of standards of professional services. It would also play an important role in raising consciousness of the clients by communicating the value of the works.

• Journal of Korean Society of Archives and Records Management
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• v.18 no.3
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• pp.145-163
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• 2018

The act was designed to identify the introductory cases of the use of quick response (QR) codes in records management by public institutions and propose measures to enhance users' satisfaction with their work. This study looked at the definition of the QR codes and the user services that can be provided by the records depository and reviewed the introduction cases using the codes. The reason QR codes are used by records depositors is that public institutions currently have a single-person system that specializes in records management. With the number of employees and the number of records becoming more extensive, explaining the contents of all tasks accurately as well as other professional contents to employees who lack understanding of the records management life cycle is becoming more difficult. The introductory cases were divided into information on how to register nonelectronic records, information on location and history of important records and administrative museum, and education on standard records management. The research was conducted by dividing the research team's "Records Management Guide" (QR code status) into experimental groups and control groups for officials of the Busan Metropolitan Government. There were significant differences in the level of satisfaction with records management guidance depending on whether or not QR codes were used. When the first and second surveys were compared in December 2017 and March 2018, the results of the first survey averaged 2.94, but the second survey showed high results at 3.75 and was statistically significant. This can be said to be more satisfactory by introducing QR codes than guidance provided by existing type. Although this research examines introductory cases of records management by public institutions using QR codes and user satisfaction, future tasks are to be applied to Records Management System and document production systems so that completion can be improved.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.9C
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• pp.846-852
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• 2006

The ${\kappa}$-error linear complexity is a ky measure of the stability of the sequences used in the areas of communication systems, stream ciphers in cryptology and so on. This paper introduces an efficient algorithm to determine the ${\kappa}$-error linear complexity and the corresponding error vectors of $p^m$-periodic binary sequences, where : is a prime and 2 is a primitive root modulo $p^2$. We also give a new sense about the ${\kappa}$-error linear complexity in viewpoint of coding theory instead of cryptographic results. We present an efficient algorithm for decoding binary cyclic codes of length $p^m$ and derive key properties of the minimum distance of these codes.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.10
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• pp.11-15
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• 2015

In this paper, we introduce three modulation codes of the code rate 1/2 with different minimum distances, respectively, and investigate the performance of the codes according to the minimum distance. We simulate the codes in accordance with blur and misalignment. As the minimum distance increases, the complexity of encoder and decoder also grows. However, it can improve the error correcting capability and shows good performance with blur and misalignment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.4
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• pp.1987-2001
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• 2017

Low-density parity-check (LDPC) codes have attracted a great attention because of their excellent error correction capability with reasonably low decoding complexity. Among decoding algorithms for LDPC codes, the min-sum (MS) algorithm and its modified versions have been widely adopted due to their high efficiency in hardware implementation. In this paper, a self-adaptive MS algorithm using the difference of the first two minima is proposed for faster decoding speed and lower power consumption. Finding the first two minima is an important operation when MS-based LDPC decoders are implemented in hardware, and the found minima are often compressed using the difference of the two values to reduce interconnection complexity and memory usage. It is found that, when these difference values are bounded, decoding is not successfully terminated. Thus, the proposed method dynamically decides whether the termination-checking step will be carried out based on the difference in the two found minima. The simulation results show that the decoding speed is improved by 7%, and the power consumption is reduced by 16.34% by skipping unnecessary steps in the unsuccessful iteration without any loss in error correction performance. In addition, the synthesis results show that the hardware overhead for the proposed method is negligible.

• Journal of Communications and Networks
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• v.11 no.6
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• pp.538-543
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• 2009

A wiretap channel I is one of the channel models that was proved to achieve unconditional security. However, it has been an open problem in realizing such a channel model in a practical network environment. The paper is committed to solve the open problem by introducing a novel approach for building wiretap channel I in which the eavesdropper sees a binary symmetric channel (BSC) with error probability p while themain channel is error free. By taking advantage of the feedback and low density parity check (LDPC) codes, our scheme adds randomness to the feedback signals from the destination for keeping an eavesdropper ignorant; on the other hand, redundancy is added and encoded by the LDPC codes such that a legitimate receiver can correctly receive and decode the signals. With the proposed approach, unconditionallysecure communication can be achieved through interactive communications, in which the legitimate partner can realize the secret information transmission without a pre-shared secret key even if the eavesdropper has better channel from the beginning.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.5
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• pp.861-868
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• 2001

In this paper, the performance of Reed Solomon(RS)/convolution리 concatenated codes and turbo code using semi random interleaver over the radio communication channel was analyzed. In the result, we proved that the performance of decoder was excellent as increase the interleaver size, constraint length, and iteration number. When turbo code using semi random interleaver and Hsiconvolutional concatenated codes was constant constraint length L=5, BER=10-4 , each value of $E_b/N_o$ was 4.5〔dB〕 and 2.95〔dB〕. Therefore, when the constraint length was constant, we proved that the performance of turbo code is superior to RS/Convolutional concatenated codes about 1.55〔dB〕 in the case of BER=10-4.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1A
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• pp.43-50
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• 2012

The use of an error-correcting code is essential in digital communication systems where the channel is noisy. Unless a receiver has accurate channel coding parameters, it becomes difficult to decode the digitized encoding bits correctly. In this paper, estimation algorithm for RM(Reed-Muller) codes using FHT (Fast Hadamard algorithm) is proposed. The proposed algorithm estimates the channel coding parameters of RM codes and then decodes the codes using the characteristic of FHT. And we also verify the algorithm by performing intensive computer simulation in additive white gaussian noise (AWGN) channel.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12A
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• pp.1966-1973
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• 1999

In this paper, we introduce the concept of a HAPS(High Altitude Platform Station) system which is expected to be a next generation communication system and suggest several error correcting codes to provide high quality services. Since a HAPS system encounters serious signal attenuation due to rain and scattering in the air, concatenated codes which have a high coding gain is considered to be a proper error correcting method. In this paper, we provide performance analyses result of two candidate coding schemes for a HAPS. The first one is a conventional concatenated coding scheme, and the second one is a iterative decoding method known as Turbo Codes.