• Journal of the Korean Statistical Society
• /
• v.28 no.3
• /
• pp.347-358
• /
• 1999

Correspondence analysis is an exploratory method for two-way contingency tables intended to display the association pattern between row and column categories. It has been developed for several decades mainly in France and Japan and, nowadays, is popular worldwide. For the special case, however, that the column consists of ordered categories, correspondence analysis may yield ackward result so that it cannot be fully accommodated. That's because the row and column categories are assumed to be nominal in the ordinary correspondence analysis. The aim of this study is to develop the correspondence analysis for two-way contingency tables with ordered column categories. It is based on two specific algorithms,

• The Korean Journal of Applied Statistics
• /
• v.15 no.2
• /
• pp.405-414
• /
• 2002

We consider the problem of estimating the error variance of in a two-way mixed-effects ANOVA model using noninformative priors. First, we derive Jeffreys' prior, a reference prior, and matching priors. We then provide marginal posterior distributions under those noninformative priors. Finally, we provide graphs of marginal posterior densities of the error variance and credible intervals for the error variance in two real data set and compare these credible intervals.

• Journal of Communications and Networks
• /
• v.13 no.3
• /
• pp.250-256
• /
• 2011

A two-way relaying (TWR) system is analyzed, where two source terminals with unequal numbers of antennas exchange data via an amplify-and-forward relay terminal with a single antenna. In the system considered herein, the link quality between the sources and relay can generally be asymmetric due to the nonidentical antenna configuration, power allocation, and relay location. In such a general setup, accurate bounds on the average sum rate (ASR) are derived when beamforming or orthogonal space time block coding is employed at the sources. We show that the proposed bounds are almost indistinguishable from the exact ASR under various system configurations. It is also observed that the ASR performance of the TWR system with unequal numbers of source antennas is more sensitive to the relay location than to the power allocation.

• Journal of Communications and Networks
• /
• v.17 no.5
• /
• pp.463-472
• /
• 2015

This paper considers a limited feedback system for two-way wireless relaying channels with physical network coding (PNC). For full feedback systems, the optimal structure with the PNC has already been studied where a modulo operation is employed. In this case, phase and power of two end node channels are adjusted to maximize the minimum distance. Based on this result, we design new quantization methods for the phase and the power in the limited feedback system. By investigating the minimum distance of the received constellation, we present a code-book design to maximize the worst minimum distance. Especially, for quantization of the power for 16-QAM, a new power quantization scheme is proposed to maximize the performance. Also, utilizing the characteristics of the minimum distance observed in our codebook design, we present a power allocation method which does not require any feedback information. Simulation results confirm that our proposed scheme outperforms conventional systems with reduced complexity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 1999.11a
• /
• pp.93-97
• /
• 1999

This paper describes an architecture platform and a key of features for a two-way pager system that will be commercially serviced in Korea, compares with it and other country's system, and analyzes the result. Also, 1 describes possible service features and new kinds of service for the two-way pager system. From the result of analysis, I presented a technical standard of radio quality for the two-way pager system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.11a
• /
• pp.287-290
• /
• 2004

A structure using the two-way shape memory effect (TWSME) returns to its initial shape by increasing or decreasing temperature under initial residual stress. Through the thermo-mechanical constitutive equation of shape memory alloy(SMA) proposed by Lagoudas et al., we simulate the behavior of a double actuator in which two SMA wires are attached to the tip of panel under the initially given residual stress. Through the numerical results conducted in the present study, the proposed actuator device is suitable for repeated actuation. The simulation algorithm proposed in the present study can be applied extensively to the analysis of the assembled .system of SMA-actuator and host structure in the practical applications.

• Journal of Korea Multimedia Society
• /
• v.10 no.12
• /
• pp.1663-1670
• /
• 2007

One-way hash chains are important cryptographic primitives and have been used as building blocks of various cryptographic applications. Advantages of one-way hash chains are their simplicity and efficiency for generation based on low-powered processors with short time. However, a drawback of one-way hash chains is their difficulty of control to compute interval values of one-way hash chains. That is, when hash values in one-way hash chain are used as encryption keys, if one hash value is compromised, then the attacker can compute other encryption keys from the compromised hash value. Therefore, direct use of one-way hash chains as encryption keys is limited to many cryptographic applications, such as pay per view system and DRM system. In this paper, we propose a new concept which is called interval hash chain using a hash function. In particular, proposed hash chains are made for only computing interval hash values by using two different one-way hash chains. The proposed scheme can be applied to contents encryption scheme for grading and partially usable contents in DRM system.

• Journal of KIISE:Databases
• /
• v.27 no.2
• /
• pp.256-268
• /
• 2000

Multi-way spatial join is a nested expression of two or more spatial joins. It costs much to process multi-way spatial join, but there have not still reported the scheme of parallel processing of multi-way spatial join. In this paper, parallel processing of multi-way spatial join consists of parallel multi-way spatial filter and parallel spatial refinement. Parallel spatial refinement is executed by the following two steps. The first is the generation of a graph used for reducing duplication of both spatial objects and spatial operations from pairs candidate object table that are the results of multi-way spatial filter. The second is the parallel spatial refinement using that graph. Refinement using the graph is proved to be more efficient than the others. In task creation for parallel refinement, minimum duplication partitioning of the Spatial_Obicct_On_Node graph shows best performance.

• English & American cultural studies
• /
• v.14 no.1
• /
• pp.193-218
• /
• 2014

This essay explores Congreve's last play The way of the World in terms of English new identity of the gentry represented by Mirabell in political, social and historical context of the Bloodless Revolution. Particularly, this essay focuses on behavioral differences between Mirabell and Fainall as characters who manage a certain type of acceptable Englishness through their heir. The acceptable Englishness separates what the differences are between two rakes from the outside of normative principle. The Way of the World reflects Lockean republican ideology in personal and familial relationships. Mirabell as a heroic rake represents new expectations for Englishmen who rejects absolute sovereign contrasted by Fainall's foreign tyrannical ways of domesticity. The Foreignness of Fainall's in the play is displaced by corollary change in the new model of English identity exemplified by Mirabell. Through the play, Congreve tends to satirize repressive morality of Hobbesian extremism and emphasizes the Revolution settlement based on consent sand trust instead. Mirabell's normative will harmonizes individual desire for happiness with social demand. In a sense Congreve's The Way of the World is a play reaching typical Restoration ending of intrigue and conspiracy through two rakes's interaction. Accordingly, this essay tries to show what separates the heroic rake from tyrannical libertine through their way of love, money, compromise and negotiation, which is their way of life.

• Journal of Broadcast Engineering
• /
• v.21 no.1
• /
• pp.109-112
• /
• 2016

This paper analyzes the outage performance of a two-way relay network in the presence of interference from multiple interferers. We investigate a two-way relay network where a single user communicates with a selected other user via a relay during three phases. We propose a user selection scheme and analyze an outage probability. Numerical results verify our analysis by comparison with computer simulation and show effects of the number of users and the number of interferers on its the outage probability.