• Journal of Mechanical Science and Technology
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• v.17 no.3
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• pp.329-335
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• 2003

EALQR (Linear Quadratic Regulate. design with Eigenstructure Assignment capability) has the capability of exact assignment of eigenstructure with the guaranteed margins of the LQR for MIMO (Multi-Input Multi-Output) systems. However, EALQR undergoes a restriction on the state-weighting matrix Q in LQR to be indefinite with respect to the region of allowable closedloop eigenvalues. The definiteness of the weighting matrix is closely related to the robustness property of a given system. In this paper, we derive a relation between the indefinite weighting matrix Q and the robustness property for EALQR. The modified frequency domain inequality, that could be guaranteed by EQLQR with an indefinite weighting matrix, is presented.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1987.10a
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• pp.35-35
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• 1987

Consider a job shop that is modelled as an open queueing network of the Jackson(l957) type. All work stations in the shop have the same number of parallel servers. Two problems are studied : the loading of stations and the assignment of servers, which are represented by loading and assingment vectors, respectively. Ma jorization and arrangement orderings are established to order, respectively, the loading and the assignment vectors. It is shown that reducing the loading vector under ma jorizat ion or increasing the assignment vector under arrangement ordering will reduce the congestion in the shop in terms of reducing the total number of jobs(in the sense of likelihood ratio ordering), the maximum queue length(in the sense of stochastic ordering), and the queue-length vector( in the sense of stochastic majorization). The results can be used to supprot production planning in certain job shops, and to aid the desing of storage capacity. (OPEN QUEUEING NETWORK; WJORIZATION; ARRANGEMENT ORDERINC; LIKELIHOOD RATIO ORDERINC; STOCHASTIC ORDERING)

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.2
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• pp.145-152
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• 2004

In this paper, an S(stochastic)-eigenvalue and its corresponding S-eigenvector concept for linear continuous-time systems with probabilistic uncertainties are proposed. The proposed concept is concerned with the perturbation of eigenvalues due to the stochastic variable parameters in the dynamic model of a plant. An S-eigenstructure assignment scheme via the Sylvester equation approach based on the S-eigenvalue/-eigenvector concept is also proposed. The proposed control design scheme based on the proposed concept is applied to a longitudinal dynamics of an open-loop-unstable aircraft with possible uncertainties in aerodynamic and thrust effects as well as separate dynamic pressure effects. These results explicitly characterize how S-eigenvalues in the complex plane may impose stability on the system.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.3
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• pp.21-30
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• 2013

Powell-Miller theory is a good method to express or treat incorrect information. But it has limitation that requires too much time to apply to actual situation because computational complexity increases in exponential and functional way. Accordingly, there have been several attempts to reduce computational complexity but side effect followed - certainty factor fell. This study suggested expanded Approximation Algorithm. Expanded Approximation Algorithm is a method to consider both smallest supersets and largest subsets to expand basic space into a space including inverse set and to reduce Approximation error. By using expanded Approximation Algorithm suggested in the study, basic probability assignment function value of subsets was alloted and added to basic probability assignment function value of sets related to the subsets. This made subsets newly created become Approximation more efficiently. As a result, it could be known that certain function value which is based on basic probability assignment function is closely near actual optimal result. And certainty in correctness can be obtained while computational complexity could be reduced. by using Algorithm suggested in the study, exact information necessary for a system can be obtained.

• ETRI Journal
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• v.35 no.1
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• pp.120-130
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• 2013

This paper presents an analysis of resource assignment for multihop communications in millimeter-wave (mm-wave) wireless personal area networks. The purpose of this paper is to figure out the effect of using directional antennas and relaying devices (DEVs) in communications. The analysis is performed based on a grouping algorithm, categorization of the flows, and the relaying DEV selection policy. Three schemes are compared: direct and relaying concurrent transmission (DRCT), direct concurrent transmission (DCT), and direct nonconcurrent transmission (DNCT). Numerical results show that DRCT is better than DCT and DCT is better than DNCT for any antenna beamwidths under the proposed algorithm and policy. The results also show that using relaying DEVs increases the throughput up to 30% and that there is an optimal beamwidth that maximizes spatial reuse and depends on parameters such as the number of flows in the networks. This analysis can provide guidelines for improving the performance of mm-wave band communications with relaying DEVs.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.7-12
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• 2003

In this paper, S(stochastic)-eigenvalue concept and its S-eigenvector for linear continuous-time systems with probabilistic uncertainties are proposed. The proposed concept is concerned with the perturbation of eigenvalues due to the probabilistic variable parameters in the dynamic model of a plant. S-eigenstructure assignment scheme via the Sylvester equation approach based on the S-eigenvalue concept is also proposed. The proposed design scheme is applied to the longitudinal dynamics of open-loop-unstable aircraft with possible uncertainties in aerodynamic and thrust effects as well as separate dynamic pressure.

• Bulletin of the Korean Chemical Society
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• v.24 no.6
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• pp.717-722
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• 2003

The structure, force field and vibrational spectra of triphenylene are studied by $B3LYP/6-31G^*$(5d) level of theory. The results are compared to those of the related system, phenanthrene. The scale factors in nonredundant local coordinates obtained after fitting the DFT frequencies to the experimental numbers of phenanthrene-$d_0 and -d_{10}$ are transferred to predict the spectra and assignment of triphenylene for in-plane modes. The frequencies based on scaling methodology due to Lee et al. are also obtained. These frequencies are compared with the predicted numbers based on scale factors from phenanthrene. Probable assignment for out-of-plane modes is proposed based on simple scaling of Scott and Radom (scale factor 0.9614) as well as by scaling methodology by Lee et al.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.10
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• pp.1-7
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• 2003

In this paper, we propose load balanced routing and wavelength assignment (RWA) algorithm for static model. The proposed algorithm arranges the routing paths over the link uniformly and assigns routing paths according to the length of routing paths orderly. Thus, the proposed algorithm can efficiently utilize the network resources. Through the computer simulation on layered-graph model, we prove that the proposed algorithm improves network throughput and reduces blocking probability comparing to first-fit algorithm [1］. Moreover, the proposed algorithm considerably reduces computational time.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.1-19
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• 1998

In this Kdynote address, two types of information granules are considered : (ⅰ) one for set assignments of a concept descriptor and (ⅱ) the other for truthood assignment to the concept description verifier. The first is, the process which specifies the assignment of an object to a clump, a class, a group, etc., and hence defines the set membership with a relational constraint. the second is the assignment of the degree of truthood or the membership specification of the abstract concept of truthood which specifies the " veristic" constraint associated with the concept descriptor. The combination of these two distinct assignments let us generate four set and logic theories. This then leads to the concern of normal forms and their derivation from truth tables for each of these theories. In this regard, some of the fundamental issues arising in this context are discussed and certain preliminary answers are provided in order to highlight the consequences of these theories.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.5 no.2
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• pp.63-72
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• 1996

In order to regulate the cutting force at a desired level during peripheral end milling processes a feedrate override Adaptive Control Constraint (ACC) system was developed. The feedrate override function was accomplished through a development of programmable machine controller (PMC) interface technique on the NC controller, Nonlinear model of the cutting process was linearized as an adaptive model with a time varying process parameter. An integral type estimator was introduced for on-line estimation of the cutting process parameter, Zero order hold digital control methodology which uses pole-assignment concept for tuning of PI controllers was applied for the ACC system. Performance of the ACC system wsa confirmed on the vertical machining center equipped with fanuc OMC through a large amount of experiment.