• Korean Journal of Applied Biomechanics
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• v.15 no.1
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• pp.111-125
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• 2005

This study was intended to assist athletes in having a technical understanding of the Yega motion and provide basic material for improving their competitive ability by analyzing the kinematic variable of the Yega motion during the competition of the uneven parallel bar of female gymnastics. For this purpose, the game of female gymnastics participating in the uneven parallel bar game was personally videotaped using the DLT(direct linear transformation) method. An attempt was made to make a comparative analysis of the Yega motion by dividing the final first to third places into the upper group('A' group) and the sixth to eighth places into the lower group('B' group). Based on the results of actual analysis on the scenes of actual game, the following conclusion was concluded: 1. Athletes in the 'A' group showed the shorter required time on the flight phase(P3) than counterparts in the 'B' group. 2. Athletes in the 'A' group showed the little width in the horizontal displacement of the center of gravity than counterparts in the 'B' group. But athletes in the 'A' group exhibited the somewhat greater relative vertical height of the center of the body. 3. Athletes in the 'A' group showed the greater resultant velocity at the lowest point of the center of the body(E2) and at the point in time of release(E3) compared to counterparts in the 'B' group.

• The Journal of Korean Academy of Prosthodontics
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• v.21 no.1
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• pp.67-72
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• 1983

Path of insertion(1) can be defined that the direction of movement of an appliance from the point of initial contact of its rigid parts with the supporting teeth to the place of final rest. Krol(2) described that in the conventional path of insertion, all the rests are seated more or less simultaneously but in the use of the rotational path one segment of the partial denture is seated first then the remainder of the prosthesis is rotated into position. The rotational path of insertion is limited primarily to the tooth borne prosthesis. Its great advantages are the elimination of anterior clasps to improve ethetic and reduction of tooth coverage to minimize plaque accumulation. Either a rigid minor connector or proximal plate provides retention through its intimate contact with a proximal tooth surface below the height of contour as indicated at a o-degree tilt. A specially designed rest in conjunction with this retentive component satisfies the basic requirements of clasp design. The purpose of this study was a clinical evaluation of rotational path removable partial dentures. Author delivered rotational path removable partial dentures to three different cases of patients and evaluated function of the dentures, difficulties of removal and insertion of the dentures and supporting structures of the abutment teeth by means of clinical and X-ray examinations for eighteen months. According to the examination data author came to the conclusion that the prognosis of the rotational path removable partial dentures was excellent.

• Journal of Korea Multimedia Society
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• v.17 no.6
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• pp.741-750
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• 2014

This paper presents a real-time motion restoration system for people who need remedial exercise of musculoskeletal based on Inverse Kinematics. A new approach is suggested to recognize a gesture based on restored human motion which is calculated the 3D positions of intermediate joints using 3D positions of body features estimated from images. For generating the 3D candidate positions of intermediate joints which cannot be extracted from images, we apply an Inverse Kinematics theory to compute the target position of intermediate joints. And we can reduce the number of candidate positions by applying the various physical constraints of body. Finally, we can generate the more accurate final position using the Kalman filter for a motion tracking and the relationship between the previous frame information and the candidate positions. The system provide motion information which are rotation angle and height in real-time, therefore the rehabilitation exercises can be performed based on the information and figured out proper exercise for individual status.

• Environmental Engineering Research
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• v.23 no.2
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• pp.195-204
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• 2018

A pilot scale study was conducted on a down-flow hanging sponge (DHS) reactor installed at a sewage treatment plant in Banda Aceh, Indonesia for treatment of desludging septic tank wastewater. Raw wastewater with an average biochemical oxygen demand (BOD) and total suspended solids of 139 mg/L and 191 mg/L, respectively, was pumped into the reactor. Two different hydraulic retention times (HRTs, 3 h and 4 h) were investigated, equivalent to organic loadings of 1.11 and $0.78kg\;BOD/m^3/d$, respectively. The average BOD concentration in the final effluent was 46 and 26 mg/L at HRTs of 3 and 4 h, respectively. The concentration of retained sludge along the reactor height was 10.2-18.7 g VSS/L-sponge, and the sludge activities were 0.24-0.32 and 0.04-0.40 mg/g VSS/h for heterotrophs and nitrification, respectively. Values of water hold-up volume, dispersion coefficient, and number of tank in-series found from tracer studies of clean sponge and biomass-loaded sponge confirmed that growth of retained sludge on the sponge module improved hydraulic performance of the reactor. Adoption of the DHS reactor by this Indonesian sewage treatment plant would enhance the role of the current desludging septic tank wastewater treatment system.

• Structural Engineering and Mechanics
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• v.68 no.4
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• pp.485-495
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• 2018

This paper presents the results of an experimental study on the structural performance of an innovative GFRP-concrete composite beam construction, which is reinforced with longitudinal GFRP pultruded box-profile and transverse steel stirrups. GFRP perfobond (PBL) shear connectors are employed to enhance the bonding performance between the GFRP profile and the concrete portion. To investigate the shear and flexural performance of this composite system, eight specimens were designed and tested under three-point and four-point bending. The main variables were the height of the composite beam and the shear span-to-depth ratio. The test results indicated that bonding cracks did not occur at the interface between the GFRP profile and the concrete until the final stage of the test. This shows that the specimens performed well as composite beams during the test and that the GFRP PBL connectors were reliable. Based on the test results, two calculation methods were used to determine the flexural and shear capacity of the composite beams. A comparative study of the test and theoretical results suggests that the proposed methods can reasonably predict both the flexural and shear capacities of the specimens, whereas the provisions of ACI 440 are relatively conservative on both counts.

• Journal of Biosystems Engineering
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• v.27 no.3
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• pp.203-210
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• 2002

In this study, the leveling control system for a tractor has been developed. The experimental model showed that the implementation of the proposed hydraulic control system fur the prototype design of a slope land tractor was feasible. The front axle was designed as a center pin type and the rear axle was designed as a trailing arm type. The leveling control of the body on the slope land was accomplished by controlling the height of the right and left trailing arms using the electronic controlled hydraulic cylinder. The maximum leveling control angles were ${\pm}$15$^{\circ}$ for roll angle and 7$^{\circ}$far pitch angle. The front and rear wheel drives were transmitted by gears from the main shaft to the final drive. The adaptability of the hydraulic control system was tested and investigated by analyzing the system response in time and frequency domain. The hydraulic control system on a step input showed a linearly increasing trend without any overshoot state. The hydraulic control system on a frequency input showed a little phase differences and gain drops within the range of 0.3Hz.

• Transactions of Materials Processing
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• v.27 no.4
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• pp.236-243
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• 2018

A multi-point forming die (MPFD), which has been used for producing curved plates, is capable of forming various curved plates with just one MPFD. However, in real industries, an MPFD is difficult to be adopted since the structural properties, punch strength, elastic recovery correction and dimensional accuracy become problems. In order to overcome these problems, the hot multi-point forming die (HMPFD) was proposed in this study. This HMPFD commonly provide more less spring-back and forming load than conventional MPFD. Nevertheless, this process is very difficult to form the curved plate, because the final curved shape of the plate depends on many process variables such as the punch/nozzle arrangement (height and distance), the radius of punch, contact conditions between plate and punch. In this study, the forming characteristics of HMPFD and conventional MPFD are compared with each other through the finite element analysis.

• Speech Sciences
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• v.10 no.2
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• pp.287-301
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• 2003

The purpose of this study was to examine whether the same vowel sounds are perceived differently by the two local dialect speakers, Seoul dialect speakers (SDS) and Kyungnam dialect speakers (KDS), whose vowel systems differ each other. In the first experiment SDS and KDS heard vowels synthesized in vowel space with F1 by F2 and categorized them into one of 10 Korean monophthongs. The results showed that SDS and KDS perceived the synthesized vowels differently. For example, /$\varepsilon$ versus /e/ contrast, ${\o}$/, and /y/ are differentiated by SDS, whereas they are perceptually confused by KDS. We also observed that /i/ could not be perceived unless the vowel synthesis included F3 or higher formants. In the second experiment SDS and KDS performed the similarity rating task of 10 synthesized Korean monophthongs. Two-dimensional MDS solution based on the similarity rating scores was obtained for each dialect group. The first dimension can be named 'vowel advancement' and the second 'vowel height'. The comparison of the two MDS solutions showed that the overall psychological distances among the vowels are shorter in KDS than SDS and that especially the distance between /$\Lambda$/ and /i/ is shorter in KDS than SDS. The result suggested that perception or mental representation of vowels depends on the vowel system of the listener's dialect or language. Further research problems were discussed in the final section.

• Computers and Concrete
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• v.19 no.5
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• pp.509-514
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• 2017

Concrete retaining walls are the most common types of geotechnical structures for controlling instable slopes resulting from lateral pressure. In analytical stability, calculation of the concrete retaining walls is regarded as a rigid mass when its safety is required. When cracks in these structures are created, the stability may be enforced and causes to defeat. Therefore, identification, creation and propagation of cracks are among the important steps in control of lacks and stabilization. Using the numerical methods for simulation of crack propagation in concrete retaining walls bodies are among the new aspects of geotechnical analysis. Among the considered analytical methods in geotechnical appraisal, the boundary element method (BEM) for simulation of crack propagation in concrete retaining walls is very convenient. Considered concrete retaining wall of this paper is Pars Power Plant structured in south side in Assalouyeh, SW of Iran. This wall's type is RW6 with 11 m height and 440 m length and endurance of refinery construction lateral forces. To evaluate displacement and stress distributions (${\sigma}_{1,max}/{\sigma}_{3,min}$), the surrounding, especially in tip and its opening crack BEM, is considered an appropriate method. By considering the result of this study, with accurate simulation of crack propagation, it is possible to determine the final status of progressive failure in concrete retaining walls and anticipate the suitable stabilization method.

• Transactions of Materials Processing
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• v.17 no.5
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• pp.322-327
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• 2008

LGP is a key component of LCD back light unit because it determines brightness and sharpness of the display image. Usually, it has optical patterns fabricated on the bottom surface. These optical patterns convert point or line sources placed in the side of LGP to plane source at the top surface by changing the propagating direction of the incident light. In the present paper the LiGA-reflow method was applied to fabricate the LGP mold. Furthermore, the optical simulation considering the replication ratio of pattern height was applied to the pattern design. The optical simulation through systematic correction scheme was adopted to find the optimum distribution of pattern density. Finally, the stamper fabricated by this method was installed in the mold and LGP was produced by injection molding. As a result of luminance measurement for the final product, the average luminance and luminance uniformity was measured 3,180 nit and 84%, respectively. Consequently, the mold fabrication method using the LiGA-reflow and optical simulation(CAE) can save the expense and time compared with the existing fabrication methods(laser ablation and chemical etching).