• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.1
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• pp.10-15
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• 2003

This paper presents the digital computer performance evaluations of the three-phase self-excited induction generator (SEIG) driven by the variable speed prime mover such as the wind turbine using the nodal admittance approach steady-state frequency domain analysis with the experimental results. The three-phase SEIG setup is implemented for small-scale rural renewable energy utilizations. The experimental performance results give a good agreement with those ones obtained from the digital computer simulation. Furthermore, a feedback closed-loop voltage regulation of the three-phase SEIG as a power conditioner which is driven by a variable speed prime mover employing the static VAR compensator (SVC) circuit composed of the thyristor phase controlled reactor (TCR) and the thyristor switched capacitor(TSC) is designed and considered herein for the wind-turbine driven the power conditioner. To validate the effectiveness of the SVC-based voltage regulator of the terminal voltage of the three-phase SEIG, an inductive load parameter disturbances in stand-alone are applied and characterized in this paper. In the stand-alone power utilization system, the terminal voltage response and thyristor triggering angle response of the TCR are plotted graphically. The simulation and the experimental results prove the effectiveness and validity of the proposed SVC which is controlled by the Pl controller in terms of fast response and high performances of the three-phase SEIG driven directly by the rural renewable energy utilization like a variable-speed prime mover.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.3
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• pp.70-77
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• 2017

Recently, Internet of Things (IoT) and deep learning techniques have affected video surveillance systems in various ways. The surveillance features that perform detection, tracking, and classification of specific objects in Closed Circuit Television (CCTV) video are becoming more intelligent. This paper presents real-time algorithm that can run in a PC environment using only a low power CPU. Traditional tracking algorithms combine background modeling using the Gaussian Mixture Model (GMM), Hungarian algorithm, and a Kalman filter; they have relatively low complexity but high detection errors. To supplement this, deep learning technology was used, which can be trained from a large amounts of data. In particular, an SRGB(Sequential RGB)-3 Layer CNN was used on tracked objects to emphasize the features of moving people. Performance evaluation comparing the proposed algorithm with existing ones using HOG and SVM showed move-in and move-out error rate reductions by 7.6 % and 9.0 %, respectively.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.6
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• pp.582-590
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• 2019

As Korea's low fertility and aging progress, Korea is facing a social change such as an increase of one generation by entering an aging society that has raised 14% of the population. An effective way to prevent a gas fire accident caused by an increase in one generation in an aging society is to install a control valve to forcibly shut off the gas after a set time. In this study, we developed a valve that can be opened and closed by rotating the valve left and right by transmitting power to the worm gear and the helical gear by using a motor by pressing the switch. It is easy to assemble and inspect by developing a dedicated valve that is easy to attach and detach. It was developed to enhance competitiveness by reducing cost by reducing the number of parts and product size. In addition, through endurance test, it was developed to be used for more than 9 years by repeating ON / OFF once every 12 seconds so that it can operate stably for 10,000 times for 34 hours. The instrument and PCB were designed using solid works and Altium Designer tools. Firmware development was developed in IAR Embedded Workbench environment.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.1
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• pp.177-185
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• 2020

Objective: The study was conducted to establish a relationship between inclusion level of Vachellia tortilis (V. tortilis) leaf meal and time spent on different behavioral activities by finishing pigs. Methods: A total of forty-eight male Large White×Landrace finishing pigs with a mean (±standard deviation) body weight of 63.8±3.28 kg aged 14 wks were assigned to individual pens in a completely randomized design. Pigs were fed on diets containing 0, 30, 60, 90, 120, and 150 g/kg dry matter of V. tortilis leaf meal ad libitum with fresh water provided throughout the trial. There were eight pigs in each experimental diet. The behavior of pigs was observed for three wks twice a wk from 0600 to 1800 h using six closed circuit television cameras. Results: Increasing levels of V. tortilis leaf meal caused a linear decrease (p<0.05) in time spent eating, lying down and the number of visit to the feeder. Time spent standing and biting objects increased linearly (p<0.05) with increasing inclusion level of V. tortilis leaf meal. The was a negative linear relationship (p<0.05) between condensed tannins versus time spent eating, lying down and number of feeder visits. Condensed tannins showed a positive linear relationship (p<0.05) with time spent standing and biting objects. Neutral detergent fiber caused a linear decrease (p<0.05) in number of feeder visits, time spent eating, time spent standing. Conclusion: Inclusion level of V. tortilis leaf meal reduces time spent eating, lying down and the number of feeder visit while prolonging time spent standing and biting of objects. Condensed tannins and dietary fiber are among nutritional factors affecting behavioral activities displayed by finishing pigs.

• Journal of Power Electronics
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• v.13 no.4
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• pp.679-691
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• 2013

High-power electromagnetic transmitter power supplies are an important part of deep geophysical exploration equipment. This is especially true in complex environments, where the ability to produce a highly accurate and stable output and safety through redundancy have become the key issues in the design of high-power electromagnetic transmitter power supplies. To solve these issues, a high-frequency switching power cascade based emission power supply is designed. By combining the circuit averaged model and the equivalent controlled source method, a modular mathematical model is established with the on-state loss and transformer induction loss being taken into account. A triple-loop control including an inner current loop, an outer voltage loop and a load current forward feedback, and a digitalized voltage/current sharing control method are proposed for the realization of the rapid, stable and highly accurate output of the system. By using a new algorithm referred to as GAPSO, which integrates a genetic algorithm and a particle swarm algorithm, the parameters of the controller are tuned. A multi-module cascade helps to achieve system redundancy. A simulation analysis of the open-loop system proves the accuracy of the established system and provides a better reflection of the characteristics of the power supply. A parameter tuning simulation proves the effectiveness of the GAPSO algorithm. A closed-loop simulation of the system and field geological exploration experiments demonstrate the effectiveness of the control method. This ensures both the system's excellent stability and the output's accuracy. It also ensures the accuracy of the established mathematical model as well as its ability to meet the requirements of practical field deep exploration.

• Korean Security Journal
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• no.60
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• pp.91-111
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• 2019

Violent crimes have increased continuously due to the development of urban society and have become a threatening factor against the residential safety of citizens. The prevention of these crimes is always a major topic in human society and one of the fundamental elements of the quality of life and safety of citizens. In recent years, much attention has been paid to environmental design through the Crime Prevention Through Environmental Design (CPTED) as a preventive measure. Currently, South Korea is promoting the openness and utilization of public data, and crime prevention is one of the fields that can utilize public data actively. This approach to crime prevention utilizing public data will be helpful for the proposal of policies from new viewpoints departing from the general utilization measures of CPTED that improve streetlights and closed-circuit television (CCTV) installations, whose limitations have been pointed out as they are only mechanical surveillance. Thus, this study sets the research scope based on the statistics of the status of five criminal offenses by administrative district in recent years provided by the data portal in Seoul City, the capital of South Korea, as the utilization data and concentrates on the analysis. Based on the analysis results, this study proposes a method to utilize classical music as a new policy for regions where the improvements are most needed. The open-source Python analysis program was employed as the main data analysis and visualization method.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.6_1
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• pp.567-574
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• 2012

For the past few years, the video surveillance market has shown a rapid growth due to the increasing demand for Closed Circuit Television(CCTV) by the public sector and the private security industry. While the overall utilization of CCTV in the public and private sectors is expanding, its usage in the field of disaster management is less than sufficient. Therefore, the authors of this study, in an effort to revisit the role of CCTV in disaster situations, have carried out a case analysis in the vicinity of the Gangnam Station which has been designated as a natural disaster-prone area. First, the CCTV images around the target location are collected and the time and depth of inundation are measured through field surveys and image analyses. Next, a rainfall analysis was conducted using the Automatic Weather Station(AWS) data and the past inundation records. Lastly, the authors provide an estimate of rainfall for the areas around the station and suggest viable warning systems and countermeasures. The results from this study are expected to make positive contributions towards a significant reduction of the damages caused by the floods around the Gangnam Station.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.140-147
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• 2011

The injection nozzle of an electro-hydraulic injector for the common rail Diesel fuel injection system is being opened and closed by movement of a injector's needle which is balanced by pressure at the nozzle seat and at the needle control chamber, at the opposite end of the needle. In this study, the slenoid actuator was considered as a prime movers in high pressure Diesel injector. Namely a solenoid-driven Diesel injector with different driving current types, as a general method driven by solenoid coil energy, has been applied with a purpose to develop the analysis model of the solenoid actuator to predict the dynamics characteristics of the hydraulic component (injector) by using the AMESim code. Aimed at simulating the hydraulic behavior of the solenoid-driven injector, the circuit model has been developed as a unified approach to mechanical modeling in this study. As this analytic results, we know the suction force and first order time lag for driving force can be endowed in solenoid-driven injector in controlling the injection rate. Also it can predict that the input current wave exerted on solenoid coil is the dominant factor which affects on the initial needle behavior of solenoid-driven injector than the hydraulic force generated by the constant injection pressure.

• PNF and Movement
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• v.5 no.2
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• pp.63-71
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• 2007

Objective : Respiratory muscle weakness and decreased chest mobility has been suggested to result from the deconditioning that accompanied activity level in chronic elderly stokes. The benefits of respiratory exercise programmes on exercise capacity and muscle strength in hemiplegia. This study aimed to determine the effects of selective inspiratory and expiratory muscles training and chest mobility exercise on patients with strokes to establish if an improved exercise capacity can be obtained in patients that are not limited in their daily activities. Methods & Intervention : Twelve patients were assigned to the intensive respiratory exercise group participated in a measures design that evaluated the subjects with pre-treatment and post-treatment. Thirteen subjects who were assigned to a control group received training with breathing exercise and resistance exercise of skeletal muscles. The subjects performed spirometry then undertook a 6-week programme of respiratory muscle and chest mobility training. Training for the two groups was carried out 2 times a week for 6 weeks. Measurements and Results : Spirometry(Forced Vital Capacity: FVC and Closed Circuit Spiromety: CCS) and thoracic mobility were measured before and after the 6 weeks. The experimental group improved significantly compared to control group in FVC, $FEV_1$, MVV, IRV and ERV, and upper chest wall expansion(p<0.05). No significant improvement was seen in thoracic mobility or lung function in control group(p>0.05). Conclusion : The major findings in this study were that a intensive 6week exercise programme of resistive breathing and chest mobility in patients with hemiplegia led to an increase in lung capacity. The resistive breathing exercise programme used here resulted in a significant increase in the chest excursion during breathing.

• Journal of Korean Association for Spatial Structures
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• v.6 no.4 s.22
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• pp.73-80
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• 2006

It is an object of the present paper to investigate a electrochemical properties of Mg-based sacrificial anodes and the effect of calcium added from calcium chloride into magnesium on the melt protection during the melting. Electrochemical data will be correlated with processing control variables, and the microstructural change by the addition of CaCl2. Small addition of calcium into magnesium from CaCl2 imparts beneficial effect in electrochemical properties of Mg alloys, primarily, through microstructural modifications. In addition, the protection effect of the melts surface of Ca with low melting point modification is obtained by adding Ca not more than 0.6%.