• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.2
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• pp.157-165
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• 2014

Skeletal anchorage is recommended as an orthodontic treatment for an impacted immature permanent tooth. Among these methods, C-tube is relatively safe because it is fixed to the cortical bone of interdental and the lower part of the root with several short miniscrews, which causes less damage to the root in patients of early permanent dentition. As it can be easily bent, the traction direction can be adjusted to favorable bone density sites. However, patient cooperation is important and traction based on physiological force in order to gain root and dentoalveolar tissue development in immature permanent teeth is required. Periodic follow-ups should be mandatory.

• Journal of Broadcast Engineering
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• v.10 no.4 s.29
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• pp.463-473
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• 2005

In this paper, we propose Adaptive GOP Structure to enhance the coding performance of scalable video coding in JVT. Adaptive GOP Structure considers temporal variances of video sequence. In general, SVC encodes a video sequence with fixed GOP size. The coding performance is varying according to the temporal variance of a video sequence. Thus, Adaptive GOP Structure method is proposed. It selects GOP size adaptively by considering temporal variance of video sequence. In the experiments, the propose method showed the enhanced coding performance in most sequences. The PSNR gain of Crew sequence is up to 0.63 dB.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.8
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• pp.57-66
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• 2009

The conventional fixed gain PI controller is very sensitive to step change of command speed, parameter variation and load disturbances. The precise speed control of interior permanent magnet synchronous motor(IPMSM) drive becomes a complex issue due to nonlinear coupling among its winding currents and the rotor speed as well as the nonlinear electromagnetic developed torque. Therefore, there exists a need to tune the PI controller parameters on-line to ensure optimum drive performance over a wide range of operating conditions. This paper proposes hybrid intelligent-PI(HIPI) controller of IPMSM drive using adaptive learning mechanism(ALM) and fuzzy neural network(FNN). The proposed controller is developed to ensure accurate speed control of IPMSM drive under system disturbances and estimation of speed using artificial neural network(ANN) controller. The PI controller parameters are optimized by ALM-FNN at all possible operating condition in a closed loop vector control scheme, The validity of the proposed controller is verified by results at different dynamic operating conditions.

• Journal of the Korean Operations Research and Management Science Society
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• v.1 no.1
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• pp.111-125
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• 1976

This study investigates the one-year performance of the Seoul Metropolitan Rail Transit(SMRT) operation. It intends to provide a basic understanding for railway operation in Seoul Metropolitan Area and thereby for making rational transport policy. The paper is conceptually comprised of four sections; analysis of passenger travel characteristics; SMRT costing and traffic cost function: its operating characteristics in terms of finance and utilization; primary social benefits of SMRT and suggestions. In the first year of operation (1974), the average daily traffic was about 335,000, After the drastic increases of fare in both Subway and KNR rail-lines, the travel volume has been cut by almost 10 percent, though most pronounced on intra-Subway line. The spatial distribution of passengers indicates that travelers use the SMRT line mainly for uninterrupted direct travel toward the CBD. In the prospective costing, the opereting expenses are divided into three groups; those which vary directly with volume; those partially variable with volume; and those entirely unrelated to volume change, With this information, cost function was derived for varying schedules of operation. Primary social benefits of the SMRT are assessed, though preliminary. Account should be taken of the nature of common costs of the SMRT in fare-rate making, especially when much of the operating expenses are accounted for by the fixed costs such that the revenue may not readily turn into break-even. The accounting results of the one-year operation coincide reasonably well with the prospective costing estimates. According to the findings of this annd another travelers' behavior studies, managerial effort would bring more revenue gain to the SMRT than fare increase does, not to speak of greater social benefits by so doing.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.3
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• pp.465-479
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• 2020

Objective: This study performed a meta-analysis of published trials to determine the effects of zinc on the immune response and production performance of broilers. Methods: A database was built from published literature regarding the addition of zinc forms or doses and their relation to the immune response and production performance of broilers. Different doses or forms of zinc were identified in the database. The recorded parameters were related to the immune response and production performance. The database contained a total of 323 data points from 41 studies that met the criteria. Then, the data were processed for a meta-analysis using a mixed model methodology. The doses or different forms of zinc were considered fixed effects, different studies were treated as random effects, and p-values were used as the model statistics. Results: An increase in zinc dose increased (p<0.05) pancreas metallothionein (MT) and zinc concentrations in the plasma, tibia and meat, all in quadratic patterns, but linearly decreased (p<0.05) the heterophil/lymphocyte (H/L) ratio. Regarding the different zinc forms, both inorganic and organic zinc increased (p<0.05) the zinc concentrations in the plasma and tibia, the calcium and phosphorus contents in the tibia, and the antioxidant activity of superoxide dismutase in meat as compared to control. An increase in zinc dose increased average daily gain (ADG) and decreased feed conversion ratio (FCR) following a quadratic pattern (p<0.05). Inorganic and organic zinc decreased (p<0.05) FCR and H/L ratio than that of control, but these two forms were similar for these parameters. Conclusion: Zinc addition has a positive impact on immunity and broiler production. Zinc can suppress stress and inhibit the occurrence of lipid peroxidation in broilers, and it can also improve ADG, FCR, and the quality of broiler carcasses.

• The Korean Journal of Applied Statistics
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• v.22 no.6
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• pp.1315-1329
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• 2009

The panel survey is need to have a more concern about a response due to a secession and non-response of a sample. And generally a population is not fixed and continuously changed. Thus, the rotation sample design can be used by the method replacing the panel research. This paper is the study of comparison to equal weight method, Duncan weight, Design weight method, weight share method in rotation sample design. More specifically, this paper compared variance estimators about the existing each method for the efficiency comparison, and to compare the precision using the relative efficiency gain by the Coefficient Variance(CV) after getting the design weight from the actual data.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.9
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• pp.41-45
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• 2014

In this paper, a high-efficiency power amplifier is implemented by using a drain bias control circuit operated at low input power for WPT(Wireless Power Transfer). Adaptive bias control circuit was added to high-efficiency class-E amplifier. It was possible to obtain the overall improvement in efficiency by adjusting the drain bias at low input power. The proposed adaptive class-E amplifier is implemented by using the input and output matching network and serial resonant circuit for improvement in efficiency. Drain bias control circuit consists of a directional coupler, power detector, and operational amplifier for adjusting the drain bias according to the input power. The measured results show that output powers of 41.83 dBm were obtained at 13.56 MHz. At this frequency, we have obtained the power added efficiency(PAE) of 85.67 %. It was confirmed increase of PAE of an average of 8 % than the fixed bias from the low input power level of 0 dBm ~ 6 dBm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.718-723
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• 2017

We propose a pilot hopping scheme that improves the limited system capacity due to pilot contamination in multi-cell environment with large-scale antenna arrays at a base station, assuming the infinite number of antennas. In the conventional fixed pilot scheme, each user obtains the same signal-to-interference ratio (SIR) over a long period of time. Therefore, a user with strong interference has continuously low SIR which degrades its service quality. In the proposed pilot hopping scheme, different pilot signals are used for each time slot, and different amounts of interference are received every time. When such a pilot hopping technique is applied, the SIR fluctuates at every time slot. When the Hybrid Automatic Repeat & reQuest (HARQ) technique is applied in such a channel, the outage probability and transmission rate are improved. We show that there is the performance gain of the proposed scheme over the conventional scheme through computer simulations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5C
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• pp.464-471
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• 2010

The demand for high quality of multimedia applications, which far surpasses the rapid evolution of transmission and storage technologies, makes better compression coding capabilities ever increasingly more important. In order to provide enhanced video coding performance, this paper proposes an efficient competition-based motion vector coding scheme. The proposed algorithm adaptively forms the motion vector predictors based on the contexts of scene characteristics such as camera motion and nearby motion vectors, providing more efficient candidate predictors than the previous competition-based motion vector coding schemes which resort to the fixed candidates optimized by extensive simulations. Up to 200% of compression gain was observed in the experimental results for the proposed scheme applied to the motion vector selection for skip mode processing.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.1
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• pp.8-17
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• 2002

This paper suggests that the immune algorithm can effectively be used in tuning of a PID controller. The artificial immune network always has a new parallel decentralized processing mechanism for various situations, since antibodies communicate to each other among different species of antibodies/B-cells through the stimulation and suppression chains among antibodies that form a large-scaled network. In addition to that, the structure of the network is not fixed, but varies continuously. That is, the artificial immune network flexibly self-organizes according to dynamic changes of external environment (meta-dynamics function). However, up to the present time, models based on the conventional crisp approach have been used to describe dynamic model relationship between antibody and antigen. Therefore, there are some problems with a less flexible result to the external behavior. On the other hand, a number of tuning technologies have been considered for the tuning of a PID controller. As a less common method, the fuzzy and neural network or its combined techniques are applied. However, in the case of the latter, yet, it is not applied in the practical field, in the former, a higher experience and technology is required during tuning procedure. In addition to that, tuning performance cannot be guaranteed with regards to a plant with non-linear characteristics or many kinds of disturbances. Along with these, this paper used immune algorithm in order that a PID controller can be more adaptable controlled against the external condition, including moise or disturbance of plant. Parameters P, I, D encoded in antibody randomly are allocated during selection processes to obtain an optimal gain required for plant. The result of study shows the artificial immune can effectively be used to tune, since it can more fit modes or parameters of the PID controller than that of the conventional tuning methods.