• Speech Sciences
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• v.15 no.3
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• pp.31-38
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• 2008

The aim of this study was to find how English vowels affect the pronunciation of English sibilants /$d_3,\;{_3}$, z/ by Korean learners of English. Fifteen nonsense syllables composed by five vowels /a, e, i, o, u/ were pronounced six times by twelve Korean learners of English. Test scores were measured from the scoreboard made by a speech training software program, which was designed for English pronunciation practice and improvement. Results show that 1) the subjects had the lowest scores in /a_a/ position, and 2) subjects had lower scores in the /i_i/ position than in /e_e/, /o_o/ and /u_u/ positions when they pronounced $/d_3/,\;/{_3}/$, and /z/ in their respective inter-vocalic position. This study found that for the group studied Korean learners of English have more difficulty in pronouncing sibilants in /a_a/ and /i_i/ positions than in the other positions.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.675-678
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• 1989

This paper proposes two types of the preview algorithms to predict the joint velocities and joint positions, and deals with a control approach using the preview algorithms for the precise trajectory control. Specifically, a predictor an the form of discrete time state equations is proposed based on the robot dynamics model linearized by the computed torque method. And another state predictor is proposed by the beat line fitting in the least square sense, where present joint velocities and positions and several past positions are employed. Then computer simulations are performed for the SCARA robot with two d.o.f. to show the validities of the proposed algothrithms.

• Speech Sciences
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• v.6
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• pp.7-24
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• 1999

Eleven Korean learners of English took part in an experiment where the production and perception of English /r/ and /l/ in four different word positions was investigated. Overall the subjects made more errors on /l/ in both production and identification tests. The frequency of the subjects' errors was also sensitive to word positions in which the two English liquids occur. Especially the subjects made noticeably fewer errors in intervocalic medial position. It is suggested that the Korean subjects' acquisitional pattern in this particular case of foreign phone learning can be explained more by language particular 'interference' effects rather than 'universal' acoustic arguments such as those given in Dissosway et a1. (1982) and Sheldon and Strange (1982). The results of the experiment also support the minority position among second language educators that in some cases of non-native phone acquisition, learners' production abilities can be developed earlier than their perceptual abilities.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.153.4-153
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• 2001

Skilled typists can type characters or wrds without looking at keyboard, relying on the finger´s relative position. If the relative positions of the fingers can be identified, a virtual keyboard may be accomplished by applying the concept of "DataGlove" or "FingerRing". The virtual keyboard may be efficient as a new mobile input device supporting QWERTY keyboard layout. For the purpose of investigating skilled typing pattern, in this paper the touch-positions of the fingers are measured with a touchscreen while four skilled typists type a long sentence. From these measurements it can be observed that the groups of touch-positions are classified into alphabet characters. Though there are some overlapped groups we can find constant distances capable of being discriminated ...

• Journal of KSNVE
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• v.10 no.4
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• pp.648-654
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• 2000

A procedure to determine the realizable optimal positions of rigid supports is suggested to get a maximum fundamental natural frequency. a measured frequency response function based substructure-coupling technique is used to model the supported structure. The optimization procedure carries out the eigenvalue sensitivity analysis with respect to the stiffness of supports. As a result of such stiffness optimization, the optimal rigid-support positions are shown to be determined by choosing the position of the largest stiffness. The optimally determined support conditions are verified to satisfy the eigenvalue limit theorem. To demonstrate the effectiveness of the proposed method, the optimal support positions of a plate model are investigated. Experimental results indicate that the proposed method can effectively find out the optimal support conditions of the structure just based on the measured frequency response functions without any use of numerical model of the structure.

• Korean Journal of Computational Design and Engineering
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• v.5 no.4
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• pp.393-402
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• 2000

Recently 5-axis NC machines are widely used in Korea. Since 5-axis machines have two more degrees of freedom than 3-axis machines, it is very important to find desirable tool positions(locations and orientations) in order to make an efficient use of expensive 5-axis NC machines. In this research an algorithm to determine “optimal” tool positions for 5-axis machining of sculptured surfaces is developed. For given CC(Cutter Contact) points, this algorithm determines the cutter axis vectors which minimize cusp heights and satisfy constraints. To solve the optimal problem, we deal with following major issues: (1) an approximation method of a cusp height as a measure of optimality (2) Identifying some properties of the optimal problem (3) a search method for the optimal points using the properties. By using a polyhedral model as a machining surface, this algorithm applies to sculptured surfaces covering: overhanged surface.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.2 no.2
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• pp.99-104
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• 1990

A Study has been conducted experimentally on heat transfer characteristics of louvered fin heat exchangers with various louvered positions in air. The experimental results are as follows; 1. Mean heat transfer coefficient is increased with increasing air velocity and decreasing temperature difference. The maximum value of heat transfer coefficient shows at 10㎜ backward louvered fins. 2. Pressure drop is increased with increasing air velocity and apparently depended on the louvered positions at V>10m/sec. 3. $\bar{h}/{\Delta}P$ is decreased with increasing air velocity and its maximum value shows at 10mm forward louvered fins and its minimum value shows at plate fins.

• Journal of the Korean Society for Nondestructive Testing
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• v.9 no.2
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• pp.37-41
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• 1989

The purpose of this paper is to estimate the effect of wobble and nonconcentricity of tubes or rods in eddy current test with encircling test coils. Because the eddy current induced in a sample is related to the total magnetic flux linkages, the information about magnetic field distribution in a coil is important. In theoretical study, magnetic field distribution in a single turn coil was calculated and variation of impedance according to the difference of sample positions was presumed. Magnetic field intensity at inside of a solenoidal coil was measured and compared with the theoretical estimation. In experiment, impedance loci of a coil encircling an aluminum rod were measured at different sample positions. The effect of crack positions was examined at same sample positons.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.835-840
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• 2000

The purpose of this study is developing concrete Mixing & placing method that could be adjusted to vertical joint at top-down method. Basic test was consists of general, high fluidity, and high quality mixing concretes and Mock-up test had several placing ways, placing positions. They were examined several placing ways, placing positions with Mock-up model comparison with three mixing concrete to know fluidity characterics. Used with Mock-up model to know packing ability from placing ways and positions. The result of the study like this; High fluidity and High quality concretes show favorable packing ability, especially, in sheath placing way. It was expected to good result in next planned real structure test.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.4
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• pp.470-480
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• 2008

Loading steel coil products on a specialized packing case called pallet can be represented as a bin-packing problem with the special constraint where objects should be loaded on designated positions of bins. In this paper, under assuming that there exist only two types of objects, we focus on finding the optimum number of positions in a bin which minimizes the number of bins needed for packing a collection of objects. Firstly, we propose a method to decide the number of positions and prove that the method is optimum. Finally, for the packing problem using bins designed by the method, we show that the well-known algorithm, First-Fit Decreasing(FFD), is the optimum algorithm.