• Journal of Broadcast Engineering
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• v.12 no.1 s.34
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• pp.41-52
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• 2007

The 3DTV services can be seen as a general case of the multi-view video that has been receiving a significant attention lately. However, the key factors that influence the success of 3DTV are the availability of content, the ease of use, the quality of contents, and the reduction of cost. This paper deals primarily with the perceptual improvement in image quality, especially based on human factors. An optimal asymmetrical coding method for binocular and multi-view images is presented. The quantitative value of asymmetrical rate to maintain optimized subjective image quality is explored. Also we analyze how edges of 2D images affect on 3D perceptions and propose an edge-preserving algorithm to perform perceptual improvements. Experimental results demonstrate that the proposed algorithm enhances subjective image quality much better than conventional methods.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.4
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• pp.81-94
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• 2010

This paper presents a high efficiency resonant asymmetrical half-bridge flyback converter. The primary half-bridge circuit of the converter operates by a soft-switching type using the asymmetrical pulse-width modulation (PWM) method with the resonant capacitance and transformer leakage inductance. The secondary flyback circuit of the proposed converter utilizes a synchronous rectifier, which operates by a new voltage-driven method with a simple drive circuit. Thus the proposed converter improves the total efficiency. This paper explains the operational principle of the proposed converter by each mode and shows the converter design consideration and a design example for the prototype converter, respectively. After that, the proposed simple driving technique of the synchronous rectifier by a voltage-driven method is explained, briefly. The designed prototype converter has wide input voltage (AC $V_{in,rms}$=75~265[V]), 5[V] DC output voltage, and 100[W] output power. To verify the excellent performance of the proposed converter, the designed prototype is implemented and experimented. The good performance of the proposed converter is shown through the experimental results.

• The korean journal of orthodontics
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• v.25 no.2 s.49
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• pp.143-152
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• 1995

This study was performed, by Finite Element Method, to evaluate the stress distribution on the periodontal tissue according to activation of the various closing loops and to predict the pattern of movement of maxillary incisors. At the same time, bull loop, key-hole loop, T-loop, combination loop and asymmetrical T-loop which were used for retraction of maxillary incisors was analysed by Finite Element Method. The following results were obtained 1. Horizontal force was the greatest in bull loop, the followed by key-hole loop, combination loop, T-loop and initial tooth movement exhibited uncontrolled tipping. 2. Horizontal force in asymmetrical T-loop compared to other closing loops was remarkably decreased, and the intrusive force on the incisors occurred. 3. As torque was increased, the moment was increased as a linear increment. 4. As moment was increased, initial movement of tooth changed to root movement from uncontrolled tipping.

• Journal of Oral Medicine and Pain
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• v.40 no.3
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• pp.115-123
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• 2015

Purpose: The aim of this study was to elucidate the coordination patterns of the sternocleidomastoid and posterior cervical muscles in response to symmetrical and asymmetrical jaw functions in normal adults. Methods: Twenty-seven healthy volunteers (8 females, 19 males; mean age, $30.4{\pm}2.5$ years) participated in this study. Surface electromyography (EMG) was used to record activities in the masseter, suprahyoid, sternocleidomastoid, and posterior cervical muscles at rest and during maximum tooth clenching, biting of a cotton roll with the anterior teeth, unilateral biting of a cotton roll with the posterior teeth, bilateral biting of cotton rolls with the posterior teeth, and jaw opening while seated. Normalized amplitude, activity indices, and asymmetry indices were compared between the muscles and the jaw tasks. Results: During symmetrical jaw functions (e.g., tooth clenching, biting with the anterior teeth, bilateral biting with the posterior teeth, jaw opening), the sternocleidomastoid and posterior cervical muscles showed elevated EMG amplitudes compared with the resting condition. The co-activation pattern of the sternocleidomastoid muscle was more pronounced than those of the posterior cervical muscles during these tasks. During asymmetrical jaw functions (e.g., unilateral biting with the posterior teeth), the ipsilateral sternocleidomastoid and masseter muscles showed higher contraction activity than did the contralateral muscles, but the contralateral posterior cervical muscles were more active than the ipsilateral muscles. Conclusions: The sternocleidomastoid and posterior cervical muscles were shown to be co-activated and coordinated anteroposteriorly or bilaterally according to symmetrical or asymmetrical jaw function. These results suggest an integrated neural control mechanism for the jaw and neck muscles, and provide further evidence supporting the intimate functional coupling between the trigeminal and cervical neuromuscular systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4A
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• pp.259-270
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• 2005

This paper proposes a mathematical model to analyze call-and packet-level performance of the TD-CDMA/TDD system which could serve a flexible radio resource management against multi-type heterogeneous and asymmetrical traffic conditions. On call-level analysis, the mathematical model based on queueing theory performs multi-dimensional operations using random vectors or matrices to consider multiple types of traffic and also deal with asymmetrical up- and down-direction transmissions separately. Employing the mathematical model, we obtain rail blocking probability for each type of traffic and also the optimum switching-point with the smallest call flocking probability. And on packet-level analysis, employing a non-prioritized queueing scheme between circuit and packet calls, we solve 2-dimensional random vector problem composed of the queue length for packets and the number of circuit calls being served. Finally, packet-level performance is analyzed in terms of the packet loss probability and the buffer size required under mixed-traffic conditions of multiple types of circuit and packet calls.

• Journal of Sport and Applied Science
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• v.7 no.1
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• pp.21-29
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• 2023

Purpose: This study was to investigate the effects of isometric exercise on muscle activity and body balance ability in asymmetrical walkers. Research design, data, and methodology: Twenty gait asymmetry people were divided to unilateral exercise group (UG, n=10) and bilateral exercise group (BG, n=10). UG were performed unilateral exercise for 60 minutes, three times a week, and 16 weeks, and BG were performed one side and then the other side alternately for 60 minutes, three times a week, and 16 weeks. Muscle activity and body balance ability were measured before, after 4 and 16 weeks isometric exercise. Moreover, SI (symmetry index; SI) was calculated from the measured value of SL (step length). Statistical analyses were conducted using one-way ANOVA and two-way ANOVA with repeated measures, a paired t-test, and multiple comparisons according to Scheffe. Results: In the muscle activity, ST decreased significantly in short step length(S-SL) and BG of LS compared to before isometric exercise(p<.05), and GCM decreased significantly in BG of S-SL(p<.05). As for body balance ability, the mSEBT-A difference between L-SL and S-SL was decreased significantly in UG(p<.05). And the respective total scores of L-SL and S-SL, mSEBT-PM and mSEBT-PL were increased significantly in BG(p<.05). Conclusions: As a result, in this study above, it was confirmed that isometric exercise improved muscle activity and body balance ability in asymmetrical walkers.

• Journal of Power Electronics
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• v.5 no.1
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• pp.67-75
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• 2005

A high efficiency ZVS PWM asymmetrical half bridge converter for a plasma display panel (PDP) sustaining power modules is proposed in this paper. To achieve the ZVS of power switches for the wide load range, a small additional inductor L/sub 1kg/, which also acts as an output filter inductor, is serially inserted into the transformer's primary side. At that point, to solve the problem of ringing in the secondary rectifier caused by L/sub 1kg/, the proposed circuit employs a structure without the output filter inductor, which helps the voltages across rectifier diodes to be clamped at the output voltage. Therefore, no dissipative RC (resistor capacitor) snubber for rectifier diodes is needed and a high efficiency as well as low noise output voltage can be realized. In addition, since it has no large output inductor filter, the asymmetrical half bridge converter features a simpler structure, lower cost, less mass, and lighter weight. In addition, since all energy stored in L/sub 1kg/ is transferred to the output side, the circulating energy problem can be effectively solved. The operational principle, theoretical analysis, and design considerations are presented. To confirm the operation, validity, and features of the proposed circuit, experimental results from a 425W, 385Vdc/170Vdc prototype are presented.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.221-224
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• 2005

This paper discribes the nonlinear distortion of a pHEMT power amplifier. In the paper, we have used some commercially available power amplifiers for analyzing the relationship between the $IMD_3$ and ACPR for wireless LAN. And the $IMD_3$ results using two-tone test have been compared with ACPR to satisfy the requited 802.11g standard ACPR value. Measurement result shows that $IMD_3$ of 20MHz tone-spacing need to be more than 18.45dBc for power amplifiers. The WCDMA signal is fed into the power amplifier, for analyzing relationship between the asymmetrical $IMD_3$ and ACLR. With measurement result, the asymmetrical $IMD_3$ characteristic has increased with the increase of two-tone spacing. $IMD_3$ measurement result with maximum 20MHz of the two-tone spacing, shows that the difference between $IMD_3(lower)$ and $IMD_3(upper)$ is about 7dB. And the measured ACLR shows 5dB difference at -4MHz and +4MHz offset from center frequency.

• Applied Microscopy
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• v.8 no.1
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• pp.53-66
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• 1978

An attempt has been made to discriminate the synapses in the striatum consisting caudate nucleus, putamen and fundus striati of the cat with emphasis on the characteristic structures of axon terminals and postsynaptic profiles. The differentiation is based on the size and shape of vesicle in the bouton terminal, and the symmetrical or asymmetrical thickening the pre- and postsynaptic membrane. Four types of synapses could be differentiated: Type I: the bontons with asymmetrical,synaptic thickenings contain round 45 nm diameter vesicles and contact cell soma, dendritic shafts and dendritic spines (74%). Type II : the boutons contain round 45nm diameter vesicles and are associated with symmetrical membrane thickenings. These synapses are formed on the soma and dendritic shafts (6%). Type III: the boutons with symmetrical membrane thickenings contain 50-60 nm diameter pleomorphic vesicles, and contact soma and dendritic shafts (18%). Type IV: the terminals contain flattened vesicles ($25{\times}45 nm$) and are associated with symmetrical membrane thickenings. These synapses are found in contact with soma and dendritic shafts. Additionally, the bouton en passant, which is expanded from myelinated or unmyelinated axons containing round vesicles (45nm diameter) contacts the dendritic shaft or dendritic spine with asymmetrical membrane thickenings. Two unusual types of synapses, axo-axonic and dendro-dendritic, are found occasionally.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.1
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• pp.63-69
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• 2010

In this paper, a new design method of asymmetrical configuration of main amplifier and peaking amplifier using changed bias point is proposed for excellent linearity, instead of the conventional Doherty structure. We have utilized the uneven wilkinson power divider for the unequal power drive at the input network of amplifiers. And we proposed a compensating method of the decreasing efficiency due to improving linearity using 3-stage Doherty structures. From the simulation results of asymmetrical Dohertry power amplifier and asymmetrical 3-stage Doherty power amplifier with uneven power drive are implemented. From the implementation and measurement results of the each amplifier, IMD characteristics have -55 dBc as the good efficiency of 13% compensates the decreased entire efficiency due to the improving linearity characteristics.