• ETRI Journal
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• v.28 no.4
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• pp.502-505
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• 2006

A new class-based histogram equalization method is proposed for robust speech recognition. The proposed method aims at not only compensating the acoustic mismatch between training and test environments, but also at reducing the discrepancy between the phonetic distributions of training and test speech data. The algorithm utilizes multiple class-specific reference and test cumulative distribution functions, classifies the noisy test features into their corresponding classes, and equalizes the features by using their corresponding class-specific reference and test distributions. Experiments on the Aurora 2 database proved the effectiveness of the proposed method by reducing relative errors by 18.74%, 17.52%, and 23.45% over the conventional histogram equalization method and by 59.43%, 66.00%, and 50.50% over mel-cepstral-based features for test sets A, B, and C, respectively.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.2
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• pp.71-79
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• 1998

In this paper, we propose a new mART(modified ART) neural network by combining the winner neuron definition method of SOM(self-organizing map) and the real-time adaptive clustering function of ART(adaptive resonance theory) and construct it in a modular structure, for the purpose of organizing the feature maps of three dimensional targets. Being constructed in a modular structure, the proposed modular mART can effectively prevent the clusters from representing multiple classes and can be trained to organze two dimensional distortion invariant feature maps so as to recognize targets with three dimensional distortion. We also present the recognition result and self-organization perfdormance of the proposed modular mART neural network after carried out some experiments with 14 tank and fighter target models.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.55-60
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• 1992

The IEEE 802.4 priority mechanism can be used to handle multiple data access classes of traffic. Several timers are used to realize the priority mechanism. The performance and stability of a token bus network depend on the assignment of such timers. In this peper, we present a dynamic timer assignment algorithm for the token passing bus network. The presented algorithm has simple structure for real-time applications and adaptively controls the set of initial timer values according to the offered traffic load. The assignment of the set of timers becomes easy due to the presented algorithm. Based on the iterative algorithm, some solutions such as mean waiting time are derived.

• English Language & Literature Teaching
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• v.13 no.4
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• pp.59-85
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• 2007

This study examined patterns of engaging in "reading in connection to writing" (hereafter reading-writing practices) in the context of two ESL college composition classrooms. The purpose of this study was to explore whether the L2 proficiency level could be a key construct in explaining similarities and differences in reading-writing practices which students engaged in during the composing process. Multiple sources of data collected over the semester included interview protocols, written products, and observational notes. The results showed that the three proficiency groups under examination differed widely in the ways reading was connected to writing and in the types of intermediate texts produced during the composing process. The students in the high proficiency group produced more intermediate texts through an engagement in reading-writing practices connected to each other. On the contrary, the students in lower proficiency groups engaged in a limited range of reading-writing practices without support of intermediate texts. This study provides insight into the different ways ESL college students coordinate reading and writing while composing essays.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.32
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• pp.53-62
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• 1994

This paper deals with the analysis of the PC communication service system performance which will be installed as a gateway between PSTN and PSDN. Firstly, we classify the data traffic pattern into interactive, conversational, and file transfer type from the actual statistics. Secondly, we model the system structure as a closed queueing network model with multiservers and multiple customer classes and derive the analytic method to be able to measure the system performance using Mean Value Analysis. Finally, the simulation results indicate that the analytic method obtained is a good approximation method to measure the system performance of the PC communication service system as a gateway between PSTN and PSDN.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1601-1608
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• 2000

This paper is concerned with the forced flexural vibration analysis of hard disk drive (HDD) spindle systems with multiple thin disks, supported by two ball bearings based on the finite element model. This is the extension of the previous work which analytically modeled every system component taking into account its structural flexibility and also the centrifugal stiffening effect especially for the disks. Among the end results, the forced time response is expectedly useful for the vibration control of the spindle itself or the position servo control of the magnetic head. On the other hand, the steady state responses such as the frequency response function and the unbalance response are useful for system identification. Futhermore, through a coordinate transformation the equations of motion is also derived with respect to the inertial frame for convenient analyses of certain classes.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.2
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• pp.9-17
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• 1994

This paper proposes Double queue threshold QLT(Queue Length Threshold) algorithm and Hysteresis effect QLT algorithm. as being DPS(Dynamic Priority Scheduling) techniques. in order to advance the processing of multiple class traffics. Also, the performance of the proposed algorithms is analyzed through computer simulations,and the priority scheduling is analyzed using a retrial queue with two types of calls. Our simulation results show that the performance of the proposed Double queue length threshold QLT algorithm is superior to that of the conventinal QLT algorithm for 2 or more classes delay sensitive traffics. Also we find that Hysteresis effecT QLT algorithm is better mechanism than that of the existing QLT for real time and non-real time traffics.

• Research in Mathematical Education
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• v.15 no.2
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• pp.181-196
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• 2011

In mathematical modeling tasks, where students are exposed to model-eliciting for real and open problems, students are supposed to formulate and use a variety of mathematical skills and tools at hand to achieve feasible and meaningful solutions using appropriate problem solving strategies. In contrast to problem solving activities in conventional math classes, math modeling tasks call for varieties of mathematical ability including mathematical creativity. Mathematical creativity encompasses complex and compound traits. Many researchers suggest the exhaustive list of criterions of mathematical creativity. With regard to the research considering the possibility of enhancing creativity via math modeling instruction, a quantitative scheme to scale and calibrate the creativity was investigated and the assessment of math modeling activity was suggested for practical purposes.

• Journal of Korean Society for Quality Management
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• v.26 no.2
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• pp.27-38
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• 1998

Consider a life testing experiment in which multiple two-component shared parallel systems are put on test, and the test is terminated at a specified number of system failures. The bivariate data obtained from such a system-level life testing can be classified into three classes: 1) the case of failed two components with known failure times, 2) the case of censored two components, and 3) the case of one censored component and the other failed component of which the failure time might be known or unknown. Under this censoring scheme and the assumption of Freund's bivariate exponential life distribution, the maximum likelihood estimators are obtained. Results of comparative studies based on Monte Carlo simulation are presented.

• Genomics & Informatics
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• v.9 no.4
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• pp.173-180
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• 2011

Recent trends in generating multiple, large-scale datasets provide new challenges to manipulating the relationship of different types of components, such as gene expression and drug response data. Integrative analysis of compound response and gene expression datasets generates an opportunity to capture the possible mechanism of compounds by using signature genes on diverse types of cancer cell lines. Here, we integrated datasets of compound response and gene expression profiles on NCI60 cell lines and constructed a network, revealing the relationship for 801 compounds and 341 gene probes. As examples, obtusol, which shows an exclusive sensitivity on a small number of colon cell lines, is related to a set of gene probes that have unique overexpression in colon cell lines. We also found that the SLC7A11 gene, a direct target of miR-26b, might be a key element in understanding the action of many diverse classes of anticancer compounds. We demonstrated that this network might be useful for studying the mechanisms of varied compound response on diverse cancer cell lines.