• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.3
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• pp.1193-1209
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• 2015

Network coding is promising to maximize network throughput and improve the resilience to random network failures in various networking systems. In this paper, the problem of providing efficient confidentiality for practical network coding system against a global eavesdropper (with full eavesdropping capabilities to the network) is considered. By exploiting a novel combination between the construction technique of systematic Maximum Distance Separable (MDS) erasure coding and traditional cryptographic approach, two efficient schemes are proposed that can achieve the maximum possible rate and minimum encryption overhead respectively on top of any communication network or underlying linear network code. Every generation is first subjected to an encoding by a particular matrix generated by two (or three) Vandermonde matrices, and then parts of coded vectors (or secret symbols) are encrypted before transmitting. The proposed schemes are characterized by tunable and measurable degrees of security and also shown to be of low overhead in computation and bandwidth.

• Journal of Industrial Technology
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• v.25 no.B
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• pp.171-174
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• 2005

In this paper, we propose a new data encoding algorithm for a two-dimensional bar code system. In general, the one-dimensional bar code is just a key which can access detailed information to the host computer database. But the two-dimensional bar code is a new technology which can obtain high density information without access to the host computer database. We implemented the encoding algorithm for Data Matrix bar code which is the most widely used among the many kinds of two-dimensional bar codes in the field of marking using Digital Signal Processor (TMS320C31). The performance of the proposed algorithm is verified by comparing the imprinted symbols on the steel surfaces with the codes which are decoded by a bar code reader.

• Journal of Korean Academy of Nursing
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• v.21 no.2
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• pp.168-185
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• 1991

A written association test has been conducted to establish the concept, the meaning and the process of hope. The test consists of the major question : List of three words related to “hope”. The question was given to 55 nurses(rehabilitation /cancer /internal medicine care wards units) and 61 patients. A total of 289 words have been collected, and the collection was analyzed with categorization by the value or meaning of listed words. The analysis yields three major categories, namely, componants of hope, metaphores /symbols, and synonyms. The three major categories may be further partitioned into subcategories. The results are significant to define the nature of the hope and process of the hope. These understanding will facilitate the development of effective methods of nursing or chronic or cancer patients disabled.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.3
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• pp.161-168
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• 1998

This paper presents the on-vehicle information system that displays the states of the vehicle in brief words instead of symbols. Main functions of this system include a system check function, trip function, warning function, and clock function. With this system, a driver can obtain all sorts of useful information related to various conditions of the vehicle, and if any problem arises in the vehicle, he can recognize it by the displayed words with a warning sound. Also, this system is very helpful for safety driving because it displays whatever a driver wants to have concerning trip information. By experimental test and driving test, the development system shows good results for each function.

• Proceedings of the IEEK Conference
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• 2000.09a
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• pp.281-285
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• 2000

This paper proposes context-based coding methods for variable length coding of inter-frame DCT coefficients. The proposed methods classify run-level symbols depending on the preceding coefficients. No extra overhead needs to be transmitted, since the information of the previously transmitted coefficients is used for classification. Two entropy coding methods, arithmetic coding and Huffman coding, are used for the proposed context-based coding. For Huffman coding, there is no complexity increase from the current standards by using the existing inter/intra VLC tables. Experimental results show that the proposed methods give ～ 19% bits gain and ～ 0.8 dB PSNR improvement for adaptive inter/intra VLC table selection, and ～ 37% bits gain and ～ 2.7dB PSNR improvement for arithmetic coding over the current standards, MPEG-4 and H.263. Also, the proposed methods obtain larger gain for small quantizaton parameters and the sequences with fast and complex motion. Therefore, for high quality video coding, the proposed methods have more advantage.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.2
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• pp.1-10
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• 1997

In this paper, an improved lower bound on the burst-error correcting capability of th ecyclic product code is presented and through the analysis of this new bound clustered cyclic product (CCP abbr.)code is proposed. The CCP code, to improve the burst-error correcting capability, combines the idea of clustering and the transmission method of cyclic product code. That is, a cluster which is defined in this paper as a group of consecutive code symbols is employed as a new transmission unit to the code array transmission of cyclic product code. the burst-error correcting capability of the CCP code is improved without a loss in the random-error correcting capability and performance comparison in the digital video camera records (DVCR) system shows the superiority of the proposed CCP code over conventional product codes.

• The Mathematical Education
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• v.45 no.1 s.112
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• pp.61-74
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• 2006

The ability of understanding the number and number systems, grasping the properties of number systems, and manipulating number systems is the foundation to understand algebra. It is useful to deepen students' mathematical understanding of number systems and operations. The authentic understanding of numbers and operations can make it possible for the students to manipulate algebraic symbols, to represent relationship among sets of numbers, and to use variables to investigate the properties of sets of numbers. The high school students need to understand the number systems from more abstract perspective. The purpose of this study is to study on understanding and application ability of eleventh graders of basic properties of operations with real numbers.

• Journal of electromagnetic engineering and science
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• v.8 no.2
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• pp.59-63
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• 2008

The adaptive symbol selection scheme(ASSS) is popular in reducing peak to average power ratio(PAPR) for orthogonal frequency division multiplexing(OFDM) signals. The probability density function(pdf) of the samples' amplitudes of the adaptively selected OFDM signal without over-sampling has been considered to be approximately equal to the Rayleigh pdf. In this paper, we derive a more precise pdf which shows the relationship between the probability distribution of the samples' amplitudes and the number of the candidate symbols for ASSS. Using the newly derived pdf in the theoretical analysis, more accurate calculation results can be obtained.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.3
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• pp.49-57
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• 2010

We extended a general attack tree to apply cyber attack model for network vulnerability analysis. We defined an extended cyber attack tree (E-CAT) which extends the general attack tree by associating each node of the tree with a transition of attack that could have contributed to the cyber attack. The E-CAT resolved the limitation that a general attack tree can not express complex and sophisticate attacks. Firstly, the Boolean expression can simply express attack scenario with symbols and codes. Secondary, An Attack Generation Probability is used to select attack method in an attack tree. A CONDITION-composition can express new and modified attack transition which a aeneral attack tree can not express. The E-CAT is possible to have attack's flexibility and improve attack success rate when it is applied to cyber attack model.

• The Mathematical Education
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• v.44 no.4 s.111
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• pp.525-534
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• 2005

The purpose of this study is to analyze difficulties in the density word problem solving process of seventh graders and to search for the way to increase their problem solving ability in the density word problem. The results of this study could help teachers diagnose students' difficulties involved in density word problem and remedy the understanding of the concept of density, algebraic expressions, and algebraic symbols.