• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1161-1164
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• 1996

In this paper, a parameter optimization technique for a mobile robot navigation is discussed. Authors already have proposed a navigation algorithm for mobile robots with sonar sensors using fuzzy decision making theory. Fuzzy decision making selects the optimal via-point utilizing membership values of each via-point candidate for fuzzy navigation goals. However, to make a robot successfully navigate through an unknown and cluttered environment, one needs to adjust parameters of membership function, thus changing shape of MF, for each fuzzy goal. Furthermore, the change in robot configuration, like change in sensor arrangement or sensing range, invokes another adjusting of MFs. To accomplish an intelligent way to adjust these parameters, we adopted a genetic algorithm, which does not require any formulation of the problem, thus more appropriate for robot navigation. Genetic algorithm generates the fittest parameter set through crossover and mutation operation of its string representation. The fitness of a parameter set is assigned after a simulation run according to its time of travel, accumulated heading angle change and collision. A series of simulations for several different environments is carried out to verify the proposed method. The results show the optimal parameters can be acquired with this method.

• The Journal of the Acoustical Society of Korea
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• v.22 no.7
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• pp.539-544
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• 2003

This paper describes how to reduce the effect of an occupation threshold by that the transform of mixture components of HMM parameters is controlled in hierarchical tree structure to prevent from over-adaptation. To reduce correlations between data elements and to remove elements with less variance, we employ PCA (Principal component analysis) and ICA (independent component analysis) that would give as good a representation as possible, and decline the effect of over-adaptation. When we set lower occupation threshold and increase the number of transformation function, ordinary MLLR adaptation algorithm represents lower recognition rate than SI models, whereas the proposed MLLR adaptation algorithm represents the improvement of over 2% for the word recognition rate as compared to performance of SI models.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.229-236
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• 2004

A new three-node triangular shell element based on higher order zig-zag theory is developed for laminated composite shells with multiple delaminations. The present higher order zig-zag shell theory is described in a general curvilinear coordinate system and in general tensor notation. All the complicated curvatures of surface including twisting curvatures can be described in an exact manner in the present shell element because this element is based on geometrically exact surface representation. The displacement field of the proposed finite element includes slope of deflection. which requires continuity between element interfaces. Thus the nonconforming shape function of Specht's three-node triangular plate bending element is employed to interpolate out-of-plane displacement. The present element passes the bending and twisting patch tests in flat surface configurations. The developed element is evaluated through the buckling problems of composite cylindrical shells with multiple delaminations. Through the numerical examples it is demonstrated that the proposed shell element is efficient because it has minimal degrees of freedom per node. The accuracy of the present element is demonstrated in the prediction of buckling loads and buckling modes of shells with multiple delaminations. The present shell element should serve as a powerful tool in the prediction of buckling loads and modes of multi-layered thick laminated shell structures with arbitrary-shaped multiple delaminations.

• Journal of the Korean Institute of Telematics and Electronics
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• v.9 no.1
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• pp.17-24
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• 1972

A method utilizing vector representation is investigated for determining a faulty elenlent in passive and active networks by simple external measurements. A large system may be considered as an interconnection of a number of subnetlvorks. By utilizing the relationships between the magintudes of a transfer function at various frequencies and the deviations of a circuit element, the fault simulation curves can be drawn. The fault identification regions are defined from the fault simulation curves. A fault identlfication matrix is constructed corresponding the defined fault identification regions. The fault identification matrix, when premultiplied by a vector whose components are measured from a network, yieldg another vector whose components identify a network element which is faulty. A test procedure for the fault identification method is presented and verified by experiments.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.1
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• pp.14-25
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• 1995

The main contribution of this paper can be summarized in two items as follws. Firstly, a modelling of mobile communication channel with Rayleigh fading characteristics is presented. Actual signal environments can be approximated as being real measurements by a proper mathematical representation of fluctuation of channel parameters due to Doppler effect, that is determined by the relative speed between transmitter and receiver, and noises, that vary at each sampling time. Secondly, an alternative procedure of synthesizing an adaptive equalizers is presented for recovering original signals that have been corrupted through the modelled channel. In order to compute the optimal tap coefficients for a high speed data(512 k symbol/sec) on a real-time basis, the CGM that guarantees fast and stable convergency is adopted during the training period of each frame. The coefficients obtained by the CGM are used as initial values for the LMS algorithm to trace the optimal coefficients during the data period that vary at each sampling time due to the mobility and noise at the receiver. Using the modelling presented in this paper, distributions of received signal power in various signal environments are demonstrated. The performance of the eqalizer proposed in this paper is shown as a function of BER under the various signal circumstances of mobile communications.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.4
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• pp.22-27
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• 2000

In this paper, new neural network called dynamic multidimensional wavelet neural network (DMWNN) is proposed. The resulting network from wavelet theory provides a unique and efficient representation of the given function. Also the proposed DMWNN have ability to store information for later use. Therefore it can represent dynamic mapping and decreases the dimension of the inputs needed for network. This feature of DMWNN can compensate for the weakness of diagonal recurrent neural network(DRNN) and feedforward wavelet neural network(FWNN). The efficacy of this type of network is demonstrated through experimental results.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.3
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• pp.48-54
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• 2000

This paper exploits the use of don't cares on software synthesis for embedded systems. Embedded systems have extremely tight real-time and code size constraints. We propose applying BDD minimization techniques in the presence of a don't care set to synthesize code for extended Finite State Machines from a BDD-based representation of the FSM transition function. The don't care set can be derived from local analysis as well as from external information. We show experimental results, discuss their implications, the interactions between BDD-based minimization and dynamic variable reordering, and propose directions for future research.

• Journal of the Korean Society of Costume
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• v.38
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• pp.101-122
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• 1998

The purpose of this study is to define the fundamentals of one symbolic concept, so calles vestment-sign, based on the logical relationship of sign system about the trichotomy by charles S. Peice's sign concept for the communication system of meaning in the non-linguistic image domain. To prove the argument of vestment-sign, I selected 3 type of vestment language by styliste, Elsa Schiaparel-li. The third image vestmental chosen here, titled“Larme-Illusion(1938)”,printed by Salvad-or Dali will produce one symbolic proposition as a logical result which is generated and developed through the interpretation of other images. First of all the text, which is manifested by Elsa Schiaparelli's first image vestmental, tit-led“Notation Musical(1937)”and is symbolized as one category in the representation of the form, is regarded symbolic and metaphorical from a standpoint that the title and the meaning is connected to the form. The second image vestment, titled“Ruches Noirs(1938)”represents externally splendid feminity man-ifested by the symbolic and metaphorical expression. And the purity of sensitivity aiming to humanity in the detail of the poetic feeling of naturalism makes us imagine the battle fild of furious sensitivity. Like as the result of the battle, the third image stimulated our eyesight with the“absence”of dressing function. The proposition of the text,《Death》which the third image delivers, constructs sign system to bring up a meaning with the disappearance of physical“signifier”. This establishment of the symbolic concept presents the etymological authority of symbol generation called“Design”.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.69-72
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• 2004

A new three-node triangular shell element based on higher order zig-zag theory is developed for laminated composite shells with multiple delaminations. The present higher order zig-zag shell theory is described in a general curvilinear coordinate system and in general tensor notation. All the complicated curvatures of surface including twisting curvatures can be described in an exact manner in the present shell element because this element is based on geometrically exact surface representation. The displacement field of the proposed finite element includes slope of deflection, which requires continuity between element interfaces. Thus the nonconforming shape function of Specht's three-node triangular plate bending element is employed to interpolate out-of-plane displacement. The present element passes the bending and twisting patch tests in flat surface configurations. The developed element is evaluated through the eigenvalue problems of composite cylindrical shells with multiple delaminations. Through the numerical examples it is demonstrated that the proposed shell element is efficient because it has minimal degrees of freedom per node. The present shell element should serve as a powerful tool in the prediction of natural frequency and modes of multi-layered thick laminated shell structures with arbitrary-shaped multiple delaminations.

• Journal of the Korean Society for Library and Information Science
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• v.44 no.4
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• pp.115-130
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• 2010

In the archival field, the last decade has witnessed much discussion on archives' broad responsibilities for social memory. Considering that the social role of archives has stemmed from postmodern thinking suggests a paradigm shift from viewing archives as static recorded objects to viewing them as dynamic evidence of human memory. The modern archives and archivists are products of nineteenth-century positivism, limiting their function to archiving written documents within stable organizations. The new thoughts on the social role of archives provide a chance to realize that traditional archival practices have preserved only a sliver of organizational memory, thus ignoring fluid records of human activities and memory. Archival description is the primary method for users to access materials in archives. Thus, it can determine how archival materials will be used (or not used). The traditional archival description works as the representation of archival materials and is directly projected from the hierarchy of organizational documents. This paper argues that archivists will need to redefine archival description to be more sensitive to atypical types of archival materials from various cultural contexts. This paper surveys the postmodern approaches to archival concepts in relation to descriptive practices. It also examines some issues related to representing historically marginalized groups in archival description who were previously neglected in traditional archival practices.