• Journal of Astronomy and Space Sciences
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• v.4 no.2
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• pp.101-106
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• 1987

The current distribution of galaxies may contain clues to the condition of the universe when the galaxies condensed and to nature of the subsequent expansion of the universe. The development of this large scale structure can be studied by employing N-body computer simulations. The present paper describes the code developed for this purpose. The computer code calculates the motion of collisionless matter acting under the force of gravity in an expanding flat universe. The test run of the code shows the error less than 0.5% in 100 iterations.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.12
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• pp.1886-1902
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• 1989

In this paper we discuss the generating algorithm of Kumar code sequences which are based on generalized bent sequences for FH-CDMA. The code sequence generator was constructed for the shift register stages n=4 over GF (5). Finally we analyze the characteristics fo Hamming correlation between two code sequences and the time-frequency correlatins of the complete waveform with the sinusoidal chips as the elemental waveforms.

• ETRI Journal
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• v.37 no.2
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• pp.338-347
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• 2015

The multi-carrier transmission signal in Multi-Carrier Code Division Multiple Access (MC-CDMA) has a high peak-to-average power ratio (PAPR), which results in nonlinear distortion and deteriorative system performance. An n-tuple selective mapping method is proposed to reduce the PAPR, in this paper. This method generates $2^n$ sequences of an original data sequence by adding n-tuple of n PAPR control bits to it followed by an interleaver and error-control code (ECC) to reduce its PAPR. The convolutional, Golay, and Hamming codes are used as ECCs in the proposed scheme. The proposed method uses different numbers of the n PAPR control bits to accomplish a noteworthy PAPR reduction and also avoids the need for a side-information transmission. The simulation results authenticate the effectiveness of the proposed method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.400-403
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• 2022

This paper propose a GPU-based N-body collision detection algorithm using LBVH (Linear Bounding Volume Hierarchy) technique. This algorithm introduces a new modified Morton code scheme where the codes use an information about how much each body takes a space in the screen space. This scheme improves the GPU sorting performance of the N-Body because it culls out invisible objects in natural manner. Through the experiments, we verifies that the proposed algorithms can have at least 15% performance improvement over the existing methods

• Nuclear Engineering and Technology
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• v.49 no.5
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• pp.996-1005
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• 2017

In this paper, nuclear data for cross sections of the $^{64}Zn(n,2n)^{63}Zn$, $^{64}Zn(n,3n)^{62}Zn$, $^{64}Zn(n,p)^{64}Cu$, $^{66}Zn(n,2n)^{65}Zn$, $^{66}Zn(n,p)^{66}Cu$, $^{67}Zn(n,p)^{67}Cu$, $^{68}Zn(n,p)^{68}Cu$, and $^{68}Zn(n,{\alpha})^{65}Ni$ reactions were studied for neutron energies up to 40 MeV. In the nuclear model calculations, TALYS 1.6, ALICE/ASH, and EMPIRE 3.2 codes were used. Furthermore, the nuclear data for the (n,2n) and (n,p) reaction channels were also calculated using various cross-section systematics at energies around 14-15 MeV. The code calculations were analyzed and obtained using the different level densities in the exciton model and the geometry-dependent hybrid model. The results obtained from the excitation function calculations are discussed and compared with literature experimental data, ENDF/B-VII.1, and the TENDL-2015 evaluated data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9A
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• pp.1276-1284
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• 1999

We have evaluated the BER's and CLP's of Wireless ATM (WATM) cells employing the concatenated FEC code with pilot symbols for fading compensation through the simulation in indoor wireless channel modeled as a Rayleigh and a Rician fading channel, respectively. The results of the performance evaluation are compared with those obtained by employing the convolutional code in the same condition. In Rayleigh fading channel, considering the maximum tolerance BER ( $10^-3$) as a criterion of the voice service, it is blown that the performance improvement of about 4 dB is obtained in terms of $E_b/N_o$ by employing the concatenated FEC code with pilot symbols rather than the convolutional code with pilot symbols.When the values of K parameter which means the ratio of the direct signal to scattered signal power in Rician fading channel are 6 and 10, it is shown that the performance improvement of about 4 dB and 2 dB is obtained, respectively, in terms of $E_b/N_o$ by employing the concatenated FEC code with pilot symbols 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 improvement of about 3.5 dB and1.5 dB is obtained, respectively, in terms of $E_b/N_o$ by employing the concatenated FEC code with pilot symbols.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.4
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• pp.393-402
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• 2000

The Unified Modeling Language(UML) became the standard object oriented modeling language approved by Object Management Group(OMG). However, C++ codes which are generated by some CASE tools supporting UML do not reflect the correct semantics of one-to-many relationship and aggregation relationship. Additionally, since the commercial CASE tools support too many programming languages on one UML class diagram, they do not support efficiently the characteristics of C++ language. Our C++ code generator supports one-to-many relationship, aggregation relationship, code patterns and design patterns. In this paper, we describe design and implementation of the efficient C++ code generator based on UML class diagram.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.6
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• pp.1510-1521
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• 1996

This paper presents acquisition algorithm and an improved detection technique for the DS/CDMA (direction sequence code division multiple access) RAKE receiver in multipath fading channel. The DS/CDMA systems use the RAKE receiver, an accurate code acquisition is required for the RAKE branches. The algorithmis able to findthe pseudonoise (PN) code delay estimates for the RAKE branches in a multipath fading channel. In this paper a numerical method and computer simulation simulation have been developed for the acquisition system. The detection probability and mean acquisition time are investigated asa performance measure of the system using the Monte Carlo method. And also in order to analyze the effect of the acquisition on the RAKE receiver this paper bring out the effect of integration time, doppler frequency, processing gain and the number of users on the acquired code phase.

• Journal of the military operations research society of Korea
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• v.15 no.2
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• pp.56-77
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• 1989

A new concept, namely the error discrimination of a code defined as the capability to not only detect errors from two distinct error sets but also to distinguish between them has been introduced in [SAKA 89a]. Consider $E_+\;and\;E_-$ as the two distinct error sets, namely the positive error set and the negative error set respectively. If a code C is not only capable of detecting any error e in {$E_+,\;E_-$}, but also able to identify the error set to which e belongs then the code is said to be an $E_+\;&\;E_-$ error discriminating code. The error discriminating property enables construction of unidirectional error detecting/correcting codes using asymmetric error control code. We derive here theory for asymmetric t error correcting and d error detecting codes. Furthermore, unidirectional error control code construction methods are introduced using asymmetric error control codes and $E_+\;&\;E_-$ error discriminating codes.

• Nuclear Engineering and Technology
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• v.45 no.5
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• pp.665-674
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• 2013

This paper presents the development and validation methods of the FUTURE (FUel cycle analysis Tool for nUcleaR Energy) code, which was developed for a dynamic material flow evaluation and economic analysis of the nuclear fuel cycle. This code enables an evaluation of a nuclear material flow and its economy for diverse nuclear fuel cycles based on a predictable scenario. The most notable virtue of this FUTURE code, which was developed using C# and MICROSOFT SQL DBMS, is that a program user can design a nuclear fuel cycle process easily using a standard process on the canvas screen through a drag-and-drop method. From the user's point of view, this code is very easy to use thanks to its high flexibility. In addition, the new code also enables the maintenance of data integrity by constructing a database environment of the results of the nuclear fuel cycle analyses.