• Journal of applied mathematics & informatics
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• v.26 no.1_2
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• pp.107-120
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• 2008

There has been a recent growth of interest in codes with respect to a newly defined non-Hamming metric grown as the Rosenbloom-Tsfasman metric (RT, or $\rho$, in short). In this paper, the definitions of the Lee complete $\rho$ weight enumerator and the exact complete $\rho$ weight enumerator of a code over $M_n_\times_s(Z_4)$ are given, and the MacWilliams identities with respect to this RT metric for the two weight enumerators of a linear code over $M_n_\times_s(Z_4)$ are proven too. At last, we also prove that the MacWilliams identities for the Lee and exact complete $\rho$ weight enumerators of a linear code over $M_n_\times_s(Z_4)$ are the generalizations of the MacWilliams identities for the Lee and complete weight enumerators of the corresponding code over $Z_4$.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.633-636
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• 2017

This paper presents a cloud service called CDLint for checking and analyzing the Javascript code dynamically. The correctness of Javascript code is becoming more important since it can also run on the server side as well as the client side. There are several analysis systems for checking the bad code in JavaScript but they seem like have one or more weaknesses. CDLint is developed based on an existing work named DLint which is a powerful bad JavaScript checker. Compared with similar systems, CDLint shows the best performances with respect to the system extensibility, the freedom to use without installation, the automatic parsing of JavaScript code from website, and the environment configuration for JavaScript code checking.

• Journal of Broadcast Engineering
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• v.24 no.7
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• pp.1221-1227
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• 2019

This paper describes a low-density parity-check (LDPC) coded index modulated orthogonal frequency division multiplexing with quasi-orthogonal sequence (IM-OFDM-QOS) and provides performance evaluations of the proposed system. By using QOS as the spreading code, IM-OFDM-QOS scheme can improve the reception performance than IM-OFDM-SS scheme for a given data rate. On the other hand, LDPC code is widely used to the latest wireless communication systems as forward error correction (FEC) scheme and has Shannon-limit approaching performance. Therefore, by applying LDPC code to IM-OFDM-QOS system as FEC scheme, the reception performance can be further improved. Simulation results show that significant signal-to-noise ratio (SNR) gains can be obtained for LDPC coded IM-OFDM-QOS system compared to the LDPC coded IM-OFDM-SS system and the SNR gain increases with the higher code rate.

• Journal of Positioning, Navigation, and Timing
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• v.7 no.1
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• pp.1-14
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• 2018

The Global Positioning System (GPS) provides more accurate positioning estimation performance by processing L1 and L2 signals simultaneously through dual frequency signal processing technology at the L-band rather than using only L1 signal. However, if anti-spoofing (AS) mode is run at the GPS, the precision (P) code in L2 signal is encrypted to Y code (or P(Y) code). Thus, dual frequency signal processing can be done only when the effect of P(Y) code is eliminated through the L2 signal processing technology. To do this, a codeless technique or semi-codeless technique that can acquire phase measurement information of L2 signal without information about W code should be employed. In this regard, this paper implements L2 signal processing technology where two typical codeless techniques and four typical semi-codeless techniques of previous studies are applied and compares their performances to discuss the optimal technique selection according to implementation environments and constraints.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.217-220
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• 2001

Turbo codes of long block sizes have been known to show very good performance in an AWGN channel and the turbo code has been strongly recommended as error correction code for IMT-2000 in 3GPP(3$^{rd}$ Ceneration Partnership Project). Recently, turbo codes of short block sizes suitable for real time communication systems have attracted a lot of attention. Thus in this paper we consider the turbo code of 1/3 code rate and short frame size of 192 bits in ITU-R channel model. We analyzed the performance of W-CDMA systems of 10MHz bandwidths employing RAKE receiver with not only MRC diversity but also turbo code..

• The Korean Journal of Emergency Medical Services
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• v.21 no.1
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• pp.7-15
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• 2017

Purpose: The purpose of our study was to introduce an oath and ethics code for emergency medical technicians (EMTs). Methods: The proposed oath and ethics code for the EMTs was evaluated using a modified Delphi technique. This oath and ethics code was presented at Korean association of emergency medical technician conference and was revised by experts in emergency medical services. Results: We examined the ethics codes for other allied healthcare professionals regarding the topics of human rights, health promotion, acting as an advocate, ethics, cooperation, observance, human rights, right to know, self-determination, confidentiality, and professionalism. These elements are reflected in our proposed oath and ethics code for EMTs. Conclusion: The proposed oath and ethics code would raise the professional status of EMTs.

• International Journal of Aeronautical and Space Sciences
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• v.14 no.2
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• pp.112-121
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• 2013

An approach for composing a performance optimized computational code is suggested for the latest microprocessors. The concept of the code optimization, termed localization, is maximizing the utilization of the second level cache that is common to all the latest computer systems, and minimizing the access to system main memory. In this study, the localized optimization of the LU-SGS (Lower-Upper Symmetric Gauss-Seidel) code for the solution of fluid dynamic equations was carried out in three different levels and tested for several different microprocessor architectures widely used these days. The test results of localized optimization showed a remarkable performance gain of more than two times faster solution than the baseline algorithm for producing exactly the same solution on the same computer system.

• ETRI Journal
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• v.34 no.4
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• pp.637-640
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• 2012

The Davey-MacKay construction is a promising concatenated coding scheme involving an outer $2^k$-ary code and an inner code of rate k/n, for insertion-deletion-substitution channels. Recently, a lookup table (LUT)-based inner decoder for this coding scheme was proposed to reduce the computational complexity of the inner decoder, albeit at the expense of a slight degradation in word error rate (WER) performance. In this letter, we show that negligible deterioration in WER performance can be achieved with an LUT as small as $7{\cdot}2^{k+n-1}$, but no smaller, when the probability of receiving less than n-1 or greater than n+1 bits corresponding to one outer code symbol is at least an order of magnitude smaller than the WER when no LUT is used.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.8
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• pp.1-10
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• 2001

This paper describes new line code algorithm, called NIDI(Nibble Inversion mock Inversion) which is well suited for interconnection and transmission technology, The proposed line code which includes only one redundancy bit serves primary features of line code and synchronization patterns for byte or frame synchronization in interconnection, Also, this line code provides in-band signals and speciaI characters.

• Journal of Communications and Networks
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• v.5 no.1
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• pp.1-6
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• 2003

In this paper, we extend the derivation of the iterative soft-output Viterbi algorithm (SOVA) for partial response (PR) channels, and modify its decoding process such that it works consistently for arbitrary high code rates, e.g., rate 64/65. We show that the modified SOVA always outperforms the conventional SOVA that appears in the literature with a significant difference for high code rates. It also offers a significant cut down in the trace-back computations. We further examine its performance for parallel and serial concatenated codes on a precoded Class IC partial response (PR4) channel. Code rates of the form $\frac{k_0}{k_0+1}$($k_0$ = 4, 8, and 64) are considered. Our simulations indicate that the loss suffered by the modified SOVA, relative to the APP algorithm, is consistent for all code rates and is at most 1.2 dB for parallel concatenations and at most 1.6 dB for serial concatenations at $P_b$ = $10^{-5}$.