• The Korean Journal of Applied Statistics
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• v.25 no.5
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• pp.847-857
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• 2012

This article is concerned with choice-based conjoint analysis versus rating-based and ranking-based conjoint analysis. Choice-based conjoint analysis has a definite advantage in that the respondent's task of choosing the most preferred profile from several competing profiles adequately mimics consumer marketplace behavior. It is crucial to design the choice sets appropriate for the choice-based conjoint. Thus, this article suggests a new method to design the choice sets that are well-balanced. It augments the balanced incomplete block design and then obtains the dual design of the result to accommodate various numbers of profiles. In consequence, the choice sets designed by the new method have the desirable characteristics that each profile is presented to the same number of respondents, and pairs of any two distinct profiles occur together in the same number of choice sets. The balancing of the design increases the efficiency of the conjoint analysis. In addition, the pair-comparison scheme can improve the quality of data through the identification of contradictory responses.

• Communications for Statistical Applications and Methods
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• v.12 no.1
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• pp.181-189
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• 2005

This paper suggest a method of inclusion probability proportional to size sampling that provides a non-negative and stable variance estimator. The sampling procedure is quite simple and flexible since a sampling design is easily obtained using mathematical programming. This scheme appears to be preferable to Nigam, Kumar and Gupta's (1984) method which uses a balanced incomplete block designs. A comparison is made with their method through an example in the literature.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.2
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• pp.119-124
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• 2015

In this paper, we analyze the effect of line-width of optical sources on the performance of spectral amplitude coding (SAC) optical code division multiple-access (OCDMA) systems. For a performance analysis we use a symmetric balanced incomplete block design (BIBD) code as the code sequence because we can construct a series of code families by choosing different values of q and m. The ideal BIBD code (m=2) requires narrower line-width than the nonideal BIBD codes when the effective power is large ($P_{sr}=-10dBm$). But the nonideal BIBD codes (m>2) need narrower line-width than the ideal BIBD code when $P_{sr}=-25dBm$.

• Journal of Communications and Networks
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• v.14 no.6
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• pp.682-691
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• 2012

Key agreement protocol is a fundamental protocol in cryptography whereby two or more participants can agree on a common conference key in order to communicate securely among themselves. In this situation, the participants can securely send and receive messages with each other. An adversary not having access to the conference key will not be able to decrypt the messages. In this paper, we propose a novel identity-based authenticated multi user key agreement protocol employing a symmetric balanced incomplete block design. Our protocol is built on elliptic curve cryptography and takes advantage of a kind of bilinear map called Weil pairing. The protocol presented can provide an identification (ID)-based authentication service and resist different key attacks. Furthermore, our protocol is efficient and needs only two rounds for generating a common conference key. It is worth noting that the communication cost for generating a conference key in our protocol is only O($\sqrt{n}$) and the computation cost is only O($nm^2$), where $n$ implies the number of participants and m denotes the extension degree of the finite field $F_{p^m}$. In addition, in order to resist the different key attack from malicious participants, our protocol can be further extended to provide the fault tolerant property.

• Journal of the East Asian Society of Dietary Life
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• v.5 no.3
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• pp.239-246
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• 1995

This study was prepared to optimize $\alpha$-azuki bean powder content by sensory evaluation method when manufacturing bread with added $\alpha$-azuki bean powder. These sensory characteristics were designed to investigate sensory evaluation about appearance, color, texture, taste and overall acceptability of small red bean bread by balanced incomplete block design. According to evaluated mean of adjusted treatments, appearance was represented high value in bread with added 3% and 6% $\alpha$-azuki bean powder than bread without $\alpha$-azuki bean powder. Bread without $\alpha$-azuki bean powder was revealed maximum sensory score value of color among whole treatments and vread with added 6% $\alpha$-azuki bean powder was revealed second highest sensory value. As $\alpha$-azuki bean powder content increased, sensory score of texture, taste and overall acceptability increased. and bread added 12% $\alpha$-azuki bean powder revealed maximum sensory score. On the results of this research about sensory characteristics for manufacturing bread with added $\alpha$-azuki bean powder, bread with added $\alpha$-azuki bean powder was considered optimum when12% $\alpha$-azuki bean powder was added wheat flour because of highest score of texture, taste and overall acceptability in spite of lower score of appearance and color.

• Communications for Statistical Applications and Methods
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• v.9 no.1
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• pp.33-38
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• 2002

We prove that blocked complete dialler crosses using balance incomplete block design are A-, D-, E-optimal design. Also, we provide such blocked complete dialled crosses and their average efficiency with table.

• Journal of the Korean Data and Information Science Society
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• v.26 no.2
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• pp.347-354
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• 2015

This paper deals with a method for intrablock anlaysis of balanced incomplete block designs on the basis of projections under the assumption of mixed effects model. It shows how to construct a model at each step by the stepwise procedure and discusses how to use projection for the analysis of intrablock. Projections are obtained in vector subspaces orthogonal to each other. So the estimates of the treatment effects are not affected by the block effects. The estimability of a parameter or a function of parameters is discussed and eigenvectors are dealt for the construction of estimable functions.

• The Korean Journal of Applied Statistics
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• v.28 no.2
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• pp.151-158
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• 2015

This paper discusses how to use projections for the analysis of data from balanced incomplete block designs. A model is suggested as a matrix form for the interblock analysis. A second set of treatment effects can be found by projections from the suggested interblock model. The variance and covariance matrix of two estimated vectors of treatment effects is derived. The uncorrelation of two estimated vectors can be verified from their covaraince structure. The fitting constants method is employed for the calculation of block sum of squares adjusted for treatment effects.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.27-32
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• 2014

Two-dimensional hybrid codewords are generated by using each row of identity matrix for spatial encoding and nonideal symmetric balance incomplete block design(BIBD) code for spectral encoding. This spatial/spectral optical code-division multiple-access (OCDMA) network uses single-balanced detectors to abstract the desired information bits and to eliminate the multiple-access interference(MAI). Analytical results show that the number of simultaneous users increases significantly by using the proposed hybrid codes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.2
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• pp.386-393
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• 2004

In order to maintain load balancing in distributed systems in a decentralized manner, every node should obtain workload information from all the nodes on the network. It requires $Ο({v^2})$ traffic overheads, where v is the number of nodes. This paper presents a new synchronous dynamic distributed load balancing algorithm for a ( v,k+1,1)-configured network topology, which is a kind of 2k regular graph, based on symmetric balanced incomplete block design, where v equals ${k^2}+k+1$. Our algorithm needs only Ο(v√v) message overheads and each node receives workload information from all the nodes without redundancy. And load balancing in this algorithm is maintained so that every link has same amount of traffic by √v for transferring workload information.