• Journal of Communications and Networks
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• v.13 no.3
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• pp.205-210
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• 2011

This paper presents an approach to the construction of multiple-rate quasi-cyclic low-density parity-check (LDPC) codes. Parity-check matrices of the proposed codes consist of $q{\times}q$ square submatrices. The block rows and block columns of the parity-check matrix correspond to the hyperplanes (${\mu}$-fiats) and points in Euclidean geometries, respectively. By decomposing the ${\mu}$-fiats, we obtain LDPC codes of different code rates and a constant code length. The code performance is investigated in term of the bit error rate and compared with those of LDPC codes given in IEEE standards. Simulation results show that our codes perform very well and have low error floors over the additive white Gaussian noise channel.

• Journal of Food Hygiene and Safety
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• v.30 no.2
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• pp.150-158
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• 2015

This article reports the development of an effective test procedure for detection of norovirus (NoV) in foods of diverse matrices. In this study, target foods included fermented milk, soybean paste, powders made from uncooked grains and vegetables, sesame leaves preserved in soy sauce, pickled mooli, and mooli. Viral recovery varied depending on the food matrices or elution buffers tested. Buffers were compared to determine effective elution buffers from artificially virus-contaminated foods. The conventional test procedure for concentrating viruses from food (elution-polyethylene glycol(PEG) precipitation-chloroform-PEG precipitation) was modified to save time by eliminating one PEG precipitation step. The modified procedure (elution-chloroform-PEG precipitation) was able to concentrate viruses more effectively than the conventional procedure. It also removed RT-PCR inhibitors effectively. The modified procedure was applied to target food for genogroup II NoV detection. NoV RNA was detected at the initial inoculum levels 3.125-12.5 RT-PCR units per 10-25 g tested food. The use of this newly established procedure should facilitate detection of low levels of norovirus in diverse foods.

• Journal of Korea Multimedia Society
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• v.18 no.9
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• pp.1083-1090
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• 2015

A generalized recursive circulant network(GR) is widely used in the design and implementation of local area networks and parallel processing architectures. In this paper, we investigate the routing of a message on this network, that is a key to the performance of this network. We would like to transmit maximum number of packets from a source node to a destination node simultaneously along paths on this network, where the i^th packet traverses along the i^th path. In order for all packets to arrive at the destination node securely, the i^th path must be node-disjoint from all other paths. For construction of these paths, employing the Hamiltonian Circuit Latin Square(HCLS), a special class of (n x n) matrices, we present O(n²) parallel routing algorithm on generalized recursive circulant networks.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.5
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• pp.10-15
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• 2010

Good performance of spectral-amplitude-coding optical CDMA can be obtained using codes based upon Hadamard matrices, but Hadamard codes have very restrictive code lengths of $2^n$. In this paper a new code family, namely extended Hadamard code, is proposed to relax the code length restriction and the number of simultaneous users. The improved performance of the proposed system is analysed with the consideration of phase-induced intensity noise(PIIN).

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.8
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• pp.5-9
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• 2011

Spectral-amplitude-coding optical CDMA systems using codes based upon Hadamard matrices have very restrictive code lengths of $2^n$ and high phase-induced intensity noise(PIIN). In this paper a new code family, namely modified Hadamard code, is proposed to relax the code length restriction and the number of simultaneous users. The improved performance of the proposed system is analysed with the consideration of noise.

• Journal of Information Technology Services
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• v.5 no.1
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• pp.177-190
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• 2006

Since their first inception a few decades ago, software components have received much attention mainly due to their alleged benefits of quality and productivity improvement. Despite this, it is yet to be agreed upon what and how components should be designed. This paper aims to bridge the gap by proposing a collaborative process where the voice of the customer is captured and documented by employing the event and entity models. These requirement elements (WHAT) are cross-tabulated in three relation matrices in accordance with the weights provided by the business users. The requirements are fed into the algorithm invented by the authors to optimize the component grouping (HOW). This collaborative process has been successfully validated at an enterprise wide software development project. The process was effective to help the users more actively involved in the design of the system and made the whole process faster and more adaptive to the changes.

• Honam Mathematical Journal
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• v.46 no.1
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• pp.101-113
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• 2024

In this paper, we define the generalized tricomplex numbers and give some algebraic properties of them. By using the matrix representation of generalized tricomplex numbers, we determine a motion on the hypersurface M in eight dimensional generalized linear space ℝ⁸_αβγ and show that this is a homothetic motion. Also, for some special cases of the real numbers α, β and γ, we give some examples of homothetic motions in ℝ⁸ and ℝ⁸₄ and obtain some rotational matrices in these spaces, too.

• Industrial Engineering and Management Systems
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• v.3 no.1
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• pp.1-11
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• 2004

This paper proposes a new algorithm for determining an optimal control input for production systems. In many production systems, completion time should be planned within the due dates by taking into account precedence constraints and processing times. To solve this problem, the max-plus algebra is an effective approach. The max-plus algebra is an algebraic system in which the max operation is addition and the plus operation is multiplication, and similar operation rules to conventional algebra are followed. Utilizing the max-plus algebra, constraints of the system are expressed in an analogous way to the state-space description in modern control theory. Nevertheless, the formulation of a system is currently performed manually, which is very inefficient when applied to practical systems. Hence, in this paper, we propose a new algorithm for deriving a state-space description and determining an optimal control input with several constraint matrices and parameter vectors. Furthermore, the effectiveness of this proposed algorithm is verified through execution examples.

• Journal of Communications and Networks
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• v.14 no.2
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• pp.206-212
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• 2012

In this paper, in order to effectively apply unitary space-time modulation to the direct-sequence spread-spectrum multiple-access (DSSS-MA) networks, we propose a low-rate, noncoherent, unitary, and space-time modulated DSSS system supporting any number of transmit antennas based on Walsh matrices. The proposed scheme simultaneously performs bandwidth spreading and space-time coding and outperforms those using high-rate, conventional unitary space-time constellations. Furthermore, the proposed scheme allows for a simple detector structure based on fast Walsh transforms.

• ETRI Journal
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• v.22 no.2
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• pp.1-10
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• 2000

Pattern recognition is one of the most common problems encountered in engineering and scientific disciplines, which involves developing prediction or classification models from historic data or training samples. This paper introduces a new approach, called the Representational Capability (RC) algorithm, to handle pattern recognition problems using radial basis function (RBF) models. The RC algorithm has been developed based on the mathematical properties of the interpolation and design matrices of RBF models. The model development process based on this algorithm not only yields the best model in the sense of balancing its parsimony and generalization ability, but also provides insights into the design process by employing a design parameter (${\delta}$). We discuss the RC algorithm and its use at length via an illustrative example. In addition, RBF classification models are developed for heart disease diagnosis.