• Journal of Korea Multimedia Society
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• v.12 no.9
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• pp.1323-1332
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• 2009

In this paper, we analyze security weakness of 4-Way Handshake in IEEE 802.11i and propose fast and secure 2-Way Handshake mechanism. Compute PTK(Pairwise Transient Key) using sequence number instead of random numbers in order to protect Replay attack and DoS attack. Also, proposed 2-Way Handshake mechanism can mutual authenticate between mobile station and access point and derive PTK using modified Re-association Request and Re-association Response frames. And, compare with others which are fast and secure Handoff mechanisms.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.2
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• pp.93-103
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• 2009

In this paper, we propose a USIM-based Authentication Scheme for 3GPP Network Access. The proposed scheme improves the problems of existing authentication protocol in 3GPP Network such as sequence number synchronization problem, the storage overhead of authentication data, and bandwidth consumption between Serving Network and Home Network. Our proposal is based on the USIM-based Authentication and Key Agreement Protocol that is defined in 3GPP Specification. In our scheme, mobile nodes share a SK with Serving Network and use a time stamp when mobile nodes are performing an authentication procedure with Serving Network. By using time stamp, there is no reason for using sequence number to match the authentication vector between mobile nodes and networks. So, synchronization problem can be solved in our scheme. As well as our scheme uses an authentication vector, the storage overhead of authentication data in Serving Network and bandwidth consumption between networks can be improved.

• Journal of Korean Society for Quality Management
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• v.17 no.1
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• pp.69-81
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• 1989

This study is concerned with a job sequencing method using the concept of sampling technique in the case of Job Shop. This is the follow study of Kang and Ro (1988) which examined the possibility of application of sampling technique to determine the Job Sequence in the case of Flow Shop. Not only it is very difficult, but also it takes too much time to develop the appropriate job schedules that satisfy the complex work conditions. The most job sequencing algorithms have been developed to determine the best or good solution under the special conditions or assumptions. The application areas of these algorithms are also very narrow, so it is very hard to find the appropriate algorithm which satisfy the complex work conditions. In this case it is very desirable to develop a simple job sequencing method which can select the optimal job sequence or near optimal job sequence with a little effort. This study is to examine the effect of sampling job sequencing which can select the good job of 0.01%~5% upper good group. The result shows that there is the sets of 0.05%~23% job sequence group which has the same amount of performance measure with the optimal job sequence in the case of experiment of N/M/G/$F_{max}$. This indicates that the sampling job sequencing method is a useful job sequencing method to find the optimal or good job sequence with consuming a small amount of time. The results of ANOVA show that the only one factor, number of machines is the significant factor for determining the job sequence at ${\alpha}=0.01$. It takes about 10 minutes to compare the number of 10,000 samples of job sequence by personal computer and it is proved that the selection rate of the same job sequence with optimal job sequence is 23.0%, 3.9% and 0.065% in the case of 2 machines, 3 machines and 4 machines, respectively. The area of application can readily be extended to the other work condition.

• Journal of the Korean Mathematical Society
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• v.40 no.6
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• pp.921-932
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• 2003

A number of variants of Hofstadter's original sequence have been investigated. Here we investigate a collection of similarly defined such sequences which give rise to intriguingly different results.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.4
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• pp.402-406
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• 1991

In this paper, we find a set of conditions on weights under which a recursive weighted median filter preserves monotone or localy monotone sequence and under which any input sequence converges to a locally monotone sequence after a finite number of passes.

• Journal of Information Technology and Architecture
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• v.9 no.1
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• pp.11-19
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• 2012

Generally, a suffix tree is an efficient data structure since it reveals the detailed internal structures of given sequences within linear time. However, it is difficult to implement a suffix tree for a large number of sequences because of memory size constraints. Therefore, in order to compare multi-mega base genomic sequence sets using suffix trees, there is a need to re-construct the suffix tree algorithms. We introduce a new method for constructing a suffix tree on secondary storage of a large number of sequences. Our algorithm divides three files, in a designated sequence, into parts, storing references to the locations of edges in hash tables. To execute experiments, we used 1,300,000 sequences around 300Mbyte in EST to generate a suffix tree on disk.

• Kyungpook Mathematical Journal
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• v.62 no.2
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• pp.347-361
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• 2022

Two virtual knot diagrams are said to be equivalent, if there is a sequence S of Reidemeister moves and virtual moves relating them. The difference of writhes of the two virtual knot diagrams gives a lower bound for the number of the first Reidemeister moves in S. In previous work, we introduced a polynomial q_K(t) for a virtual knot diagram K which gave a lower bound for the number of the third Reidemeister moves in the sequence S. In this paper we define a new polynomial from a coloring of a virtual knot diagram. Using this polynomial, we give a lower bound for the number of the second Reidemeister moves in S. The polynomial also suggests the design of the sequence S.

• Journal of IKEEE
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• v.1 no.1 s.1
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• pp.83-92
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• 1997

Multipath ATM switch architectures have the potential to accommodate easily the design of high-speed and large capacity ATM switches which can handle a very large amount of switching throughputs. However, the multipath architecture inevitably encounters out-of-sequence problems. We propose a multipath switch model to analyze the out-of-sequence phenomenon. And we analyze the out-of-sequence performance dependency on the architecture parameters : the number of multipath, the trunk utilization, the switch size, and the number virtual channels/trunk. Indexing terms : ATM switch, Multipath archltecture, Out-of-sequence performance, Cell sequence integrity, Analytical model.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.11
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• pp.2033-2035
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• 2007

This paper proposes a novel iterative LMS-based decision feedback equalizer for short burst transmission with relatively short training sequence. In the proposed equalizer, the longer concatenated training sequence can provide the more sufficient channel information and the reused original training sequence can provide the correct decision feedback information. In addition, the overall adaptive processing is performed using the low complexity LMS algorithm. The study shows the performance of the proposed method is enhanced with the number of iterations and, furthermore, better than that of the conventional LMS-based DFEs with the training sequence of longer or equal length. Computational complexity is increased linearly with the number of iterations.

• ALGAE
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• v.26 no.3
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• pp.229-235
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• 2011

Spliced leader (SL) trans-splicing is a mRNA processing mechanism in dinoflagellate nuclear genes. Although studies have identified a short, conserved dinoflagellate SL (dinoSL) sequence (22-nt) in their nuclear-encoded transcripts, whether the majority of nuclear-coded transcripts in dinoflagellates have the dinoSL sequence remains doubtful. In this study, we investigated dinoSL-containing gene transcripts using 454 pyrosequencing data (Cochlodinium polykrikoides, 93 K sequence reads, 31 Mb; Prorocentrum minimum, 773 K sequence reads, 291 Mb). After making comparisons and performing local BLAST searches, we identified dinoSL for one C. polykrikoides gene transcript and eight P. minimum gene transcripts. This showed transcripts containing the dinoSL sequence were markedly fewer in number than the total expressed sequence tag (EST) transcripts. In addition, we found no direct evidence to prove that most dinoflagellate nuclear-coded transcripts have this dinoSL sequence.