• Phonetics and Speech Sciences
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• v.1 no.3
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• pp.19-28
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• 2009

This paper reports experimental findings about the duration feature of the acoustic components of English stops in Korean speakers' voicing perception. In our experiment, 35 participants discriminated between recorded stimuli and digitally transformed stimuli with different duration features from the original stimuli. 72 sets of paired stimuli are generated to test the effects of the duration feature in various phonetic contexts. The result of our experiment is a complicated cross-tabulation with 540 cells defined by five categorical independent variables plus one response variable. To find a meaningful generalization out of this complex frequency table, we ran logit log-linear regression analyses. Surprisingly, we have found that there is no single effect of the duration feature in all phonetic contexts on Korean speakers' perception of the voicing contrasts of English stops. Instead, the logit log-linear analyses reveal that there are interaction effects among phonetic contexts (=C), the places of articulation of stops (=P), and the voicing contrast (=V), and among duration (=T), phonetic contexts, and the places of articulation. To put it in mathematical terms, the distribution of the data can be explained by a simple log-linear equation, logF=${\mu}+{\lambda}CPV+{\lambda}TCP$.

• Journal of Yeungnam Medical Science
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• v.4 no.2
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• pp.83-88
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• 1987

An analytic expression for equivalent square fields and a table are derived using the empirical representations obtained from the measured field size dependence of output for square field in a phantom. The expression is applicable to radiation fields that consistent with the following two assumptions Imposed on these representations. 1) It is a linear function of the logarithm of the field area, and 2) It is approximately the same function for both square and circular field of similar areas. In this paper, the derived tables and BJR table were consulted.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.4
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• pp.430-439
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• 2011

In this paper, we design a digital predistortion(DPD) for linearity enhancement of RF power amplifier operating in 900 MHz band. We verify improvement of linearity by comparing the proposed DPD using tanh as a nonlinear indexing function and the DPD using linear indexing function based on signal amplitude. The digital predistortion is realized by look-up table(LUT) method, and the Saleh model is employed for power amplifier modeling, then a commercial power amplifier module is used for measurement. The LUT has 256 tables, and the NLMS(Normalized Least Mean Square) algorithm was utilized for an adaptive algorithm for estimation. As a result, we improve the ACLR(Adjacent Channel Leakage Ratio) by around 15 dB.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.905-912
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• 2009

1-g shaking table test is conducted to evaluate the dynamic behavior of a soil-structure system under seismic loading condition. A consistent similitude law between the model and prototype is needed to predict the behavior of the prototype structure, quantitatively. The natural frequency of geomaterial decreases with the increase of shaking intensity because of the non-linear property of the geomaterial. This phenomenon affects the applicability of similitude laws in 1-g shaking table tests. In this study, a simple method is suggested to determine the frequency of the input motions in 1-g tests in order to enhance the applicability of similitude laws. Modified input frequency is calculated using the frequency ratio with consideration of the variation of the natural frequency according to the intensity of input ground acceleration. To verify the applicability of the suggested method, a series of 1-g shaking table tests were performed for three different sizes of model piles having an overburden mass on their heads by varying the acceleration and the frequency of input motion. The acceleration amplification ratio on the overburden mass, the lateral displacement at the pile head and the maximum bending moment along the pile depth were measured. The projected behaviors of the virtual prototype based on the measured values of the model tests, where the input frequencies were calculated by the new method, showed good consistency, verifying the applicability of the suggested method.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.7
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• pp.62-70
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• 1999

To achieve precision positioning, working area is required within $5mm{\times}5mm$ and positioning error is allowed within minimum ${\pm}4{\mu}m$. As a general three-layered table takes working range from several centimeters and a few tens of centimeters, it has disadvantages compared with precision positioning table, such as larger working range and rough accuracy. In this paper we design and implement a parallel $XY{\theta}$ table with three linear actuators, where one is on the horizontal direction and the others on the vertical direction on behalf of a degree of $XY{\theta}$ freedom. Finally, the experimental results of precision positioning is showed by using new image processing algorithms with two CCD cameras.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.2
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• pp.149-156
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• 2011

In the recent years, power analysis attacks were widely investigated, and so various countermeasures have been proposed. In the case of block ciphers, masking methods that blind the intermediate values in the en/decryption computations are well-known among these countermeasures. But the cost of non-linear part is extremely high in the masking method of block cipher, and so the countermeasure for S-box must be efficiently constructed in the case of AES, ARIA and SEED. Existing countermeasures for S-box use the masked S-box table to require 256 bytes RAM corresponding to one S-box. But, the usage of the these countermeasures is not adequate in the lightweight security devices having the small size of RAM. In this paper, we propose the new countermeasure not using the masked S-box table to make up for this weak point. Also, the new countermeasure reduces time-complexity as well as the usage of RAM because this does not consume the time for generating masked S-box table.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1989.04a
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• pp.66-70
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• 1989

Methods for identification of modal properties of linear structures are presented. The extended Kalman filtering technique is empolyed. The state equation is formulated by two different ways, namely by the time domain and frequency domain approaches. Verifications are carried out by using simulated records of ground acceleration and structural response. Then the techniques are applied to the estimation of modal parameters of a scaled model for a 3-story building which is installed on a shaking table.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.795-800
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• 2001

Two evaluation techniques of the tunnel lining concrete using ultra sonic velocity method are developed. Modified linear regression technique is proposed to enhance the corelation between the pulse velocity and the compressive strength of core specimens. And bivariate normal distribution is assumed to evaluate the quality of concrete as a terms of compressive strength. A simple corelation table between the pulse velocity and the compressive strength of core specimens are proposed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.04b
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• pp.272-276
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• 1993

We made to develop CNC Tool Grinding Machine automating the linear motion of X,Y,Z axis of table, and thetilting and rotation of tool holding vice by using Encorder to increase the efficiency of tool grinding for the Conventional Tool Grinding Machine. We did not consider the part of static, dynamic and thermal behavior that must necessary consider when wedesign, because we used existing Conventional Tool Grinding Machine as it is. We investigated simulation to make existing Conventional Tool Grinding Machine like CNC. We also designed it, and we compared the capability of existing Conventional Tool Grinding and CNC Tool Grinding Machine, and we investigated, too.

• Journal of the Korean Statistical Society
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• v.25 no.4
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• pp.489-497
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• 1996

Lower bounds for the full level probabilities are derived under order restrictions in weights. Discussions are made on typical isotonic cones such as linear order, simple tree order, and unimodal order cones. We also discuss applications of these results for constructing conditional likelihood ratio tests for ordered hypotheses in a contingency table. A real data set on torus mandibularis will be analyzed for illustrating the testing procedure.