• Journal of the Korean Mathematical Society
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• v.47 no.6
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• pp.1167-1182
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• 2010

We study codes meeting a generalized version of the Singleton bound for higher weights. We show that some of the higher weight enumerators of these codes are uniquely determined. We give the higher weight enumerators for MDS codes, the Simplex codes, the Hamming codes, the first order Reed-Muller codes and their dual codes. For the putative [72, 36, 16] code we find the i-th higher weight enumerators for i = 12 to 36. Additionally, we give a version of the generalized Singleton bound for non-linear codes.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.266-267
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• 2009

According to researches [1], good image quality and amount of hiding information is a main point of steganography. In this point of view, [3] is a very good scheme to hide in an image. However, it cannot hide a lot of information. In order to solve this problem, we propose new method to hide more information than that of [3]. In addition, it can be reduced distortion of an image than that of [4]. Thus, our method is a very efficient and novel scheme.

• Journal of IKEEE
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• v.20 no.4
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• pp.449-453
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• 2016

Failures would occur because of the hostile nature environment in Wireless Sensor Networks (WSNs) which is deployed randomly. Therefore, considering faults in WSNs is essential when we design WSN. This paper classified fault model in the sensor node. Especially, this paper proposed new error correcting code scheme and fault recovery algorithm in the CH(Cluster Head) node. For the range of the small size information (<16), the parity size of the proposed code scheme has the same parity length compared with the Hamming code, and it has a benefit to generate code word very simple way. This is very essential to maintain reliability in WSN with increase power efficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1B
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• pp.31-41
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• 2000

It has been known that the optical code division multiple access (OCDMA) is a prominent future technology to support many simultaneous users and to increase transmission capacity of optical fiber. In this paper, we proposed the new construction of 2 dimensional code, which can be used as a codeword in temporal/wavelength OCDMA networks. New code family is obtained by extending the concept of Hamming correlation. All optical encoder and decoder for newly proposed code were also developed. In considering bit error ratio, we verified that new coding scheme outperforms conventional coding scheme by simulation. This system is applicable to asynchronous fast local area network, which needs a high security level and a flexible network configuration.

• Journal of IKEEE
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• v.26 no.3
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• pp.506-509
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• 2022

In a secret sharing scheme, secret information must be distributed and stored to users, and confidentiality must be able to be reconstructed only from an authorized subset of users. To do this, secret information among different code words must not be subordinate to each other. The minimal code is a kind of linear block code to distribute these secret information not mutually dependent. In this paper, we present a novel extension technique for minimal codes. The product of an arbitrary vector and a minimal code produces a new minimal code with an extended length and Hamming weight. Accordingly, it is possible to provide minimal codes with parameters not known in the literature.

• Journal of Advanced Navigation Technology
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• v.15 no.5
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• pp.781-788
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• 2011

A sphere-packing problem is to find an arrangement of the spheres to fill as large area of the given space as possible, and covering problems are optimization problems which are dual problems to the packing problems. We generalize the concepts of the weight and the Hamming distance for a binary code to those of Boolean algebra. In this paper, we define a weight and a distance on a Boolean algebra and research some properties of the weight and the distance. Also, we prove the notions of the sphere-packing bound and the Gilbert-Varshamov bound on Boolean algebra.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.13 no.6
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• pp.535-544
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• 1988

In this paper, the hybrid ARQ scheme, which is incorporated the selective-repeat ARQ system with the finite receiver buffer and the single-error-correcting and double-error-detecting(63.56) cyclic Hamming code system, has been investigated. As a result of simulation, the proposed hybrid ARQ scheme shows that that throughput efficiencies are improved by one error correction, and that the reversed codewords due to retransmission are delivered to the user in order by means of detecting two errors. The hybrid ARQ scheme significantly outperforms the FEC or the ideal selective-repeat ARQ system in the respect of throughput and reliability, especially when the channel error rate is approximately in the range from $10^{-2}$~$10^{-3}$.

• Journal of KIISE:Databases
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• v.27 no.1
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• pp.79-89
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• 2000

For processing signature file in parallel, an effective signature file declustering method is needed. The Linear Code Decomposition Method(LCDM) used for the Hamming Filter may give a good performance in some cases, but due to its static property, it fails to evenly decluster signature file when signature are skewed. In addition, it has other problems such as limited scalability and non-determinism. In this paper we propose a new signature file declustering method, called Inner-product method, which overcomes those problems in the LCDM. The Inner-product method declusters signature file dynamically based on the signature difference which is computed by using signature inner product. we show through the simulation experiment that the Inner-product outperforms the LCDM under various data workloads.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.3
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• pp.357-362
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• 2005

Iris recognition system is the one of the most reliable biometries recognition system. An algorithm is proposed to determine the localized iris from the iris image received from iris input camera in client. For the first step, the algorithm determines the center of pupil. For the second step, the algorithm determines the outer boundary of the iris and the pupillary boundary. The localized iris area is transformed into polar coordinates. After performing three times Wavelet transformation, normalization was done using a sigmoid function. The converting binary process performs normalized value of pixel from 0 to 255 to be binary value, and then the converting binary process is compared pairs of two adjacent pixels. The binary code of the iris is transmitted to the server by the network. In the server, the comparing process compares the binary value of presented iris to the reference value in the database. The process of recognition or rejection is dependent on the value of Hamming Distance. After matching the binary value of presented iris with the database stored in the server, the result is transmitted to the client.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.7B
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• pp.664-672
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• 2002

This paper analyzes a sequential estimator with flexible structure for rapid acquisition of the m-sequence signals. If the received PN chips stored in the estimator's internal registers as initial loading values include one error, this chip with error can be corrected through multiple local PN code generators to achieve high-speed acquisition performance. Hamming distance between regenerated local PN codes from the proposed system and received PN code is compared with given threshold to choose a possible correct path and to declare success of the code acquisition. Using signal flow graph, average acquisition time that depends on detection and false alarm probability is calculated. By modifying generally used matched filter structure for PN code acquisition, the proposed system provides flexible structure and rapid acquisition process.