• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.2
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• pp.276-282
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• 2006

PID controller has been widely used in industry. Because it has a simple structure and robustness to modeling error. But it is difficult to have uniformly good control performance in system parameters variation or different velocity command. In this paper, we propose an adaptive PID controller based on a gradient descent learning. This algorithm has a simple structure like conventional PID controller and a robustness to system parameters variation and different velocity command. To verify performances of the proposed adaptive PID controller, the speed control of nonlinear DC motor is performed. The simulation results show that the proposed control systems are effective in tracking a command velocity under system parameters variation.

• Proceedings of the KIEE Conference
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• summer
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• pp.959-961
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• 2004

A multi pole SRM(switched reluctance motor) is applied by the regulated current in regular sequence. So, it can be started by itself. But a single phase SRM can not be started by itself because the positive torque is only generated in the limited zone which the inductance is increased. Therefore, it is required auxiliary device for self starting which place the rotor in start position. The prototype was designed and fabricated in the previous research. It has the permanent magnet, which is installed in the bottom of the rotor, for self starting. But the permanent magnet affect the prototype during operation and cause the decrease of the torque and speed. The influence of the permanent magnet on the average torque and speed was already confirmed. On this paper, the instant torque of the prototype was calculated from the experiment results which is the inductance and current according to installed permanent magnet or not.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.6
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• pp.1032-1038
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• 2008

RFID is applied in various industry area. The purpose of RFID system is authentication of objects. After Tag's certification, RFID system start to process to be wanted. A RFID electric motor recognizes Tag's action and tails. The application of this system is very wide. For example, a cart in shopping Mall follows customer with a proper Tag. Customer may be very convenient if the cart follows customer autonomously as recognizing the direction of Tag. In this parer, we studied about RFID system that follow objects with a Tag. Finally, we experimented and analysed the proposed system, with Tag, Reader, host computer and electric motion motors.

• Journal of Power Electronics
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• v.19 no.1
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• pp.146-157
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• 2019

The inverter is an essential part of permanent magnet synchronous motor (PMSM) drive systems. The performance of an inverter is greatly influenced by its modulation strategy. Using a proper management of modulation strategies can guarantee high performance from a PMSM under various speed conditions. Switching between modulations is a pivotal technique that determines the performance of a PMSM. Most works on hybrid methods focus on two-level induction motors drive systems. In this paper, in order to improve the performance of PMSMs under various speed conditions, a hybrid method of a pulse width modulation (PWM) control scheme based on a neutral-point-clamped (NPC) three level topology was proposed. This hybrid PWM modulation comprised space vector PWM (SVPWM) and selective harmonic elimination PWM (SHEPWM). Under low speed conditions, the SVPWM is employed to cause the PMSM to start smoothly, and to obtain a rapid response from the control system. Under high speed conditions, the SHEPWM is employed to reduce the switching frequency and to eliminate particular current harmonics. Moreover, the harmonic characteristics of different modulations are analyzed to obtain a smooth transition between the SHEPWM and the SVPWM. Experimental and simulation results indicated the effectiveness of the proposed control method.

• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.1-12
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• 2022

In order to overcome the power fluctuation issues in photovoltaic (PV) smart grid-connected systems and the inverter nonlinearity model problem, an adaptive backstepping command-filter and a double second order generalized Integrators (DSOGI) controller are designed in order to tune the AC current and the DC-link voltage from the DC side. Firstly, we propose to present the filter mathematical model throughout the PV system, at that juncture the backstepping control law is applied in order to control it, Moreover the command filter is bounded to the controller aiming to exclude the backstepping controller differential increase. Additionally, The adaptive law uses Lyapunov stability criterion. Its task is to estimate the uncertain parameters in the smart grid-connected inverter. A DSOGI is added to stabilize the grid currents and eliminate undesirable harmonics meanwhile feeding maximum power generated from PV to the point of common coupling (PCC). Then, guaranteeing a dynamic effective response even under very unbalanced loads and/or intermittent climate changes. Finally, the simulation results will be established using MATLAB/SIMULINK proving that the presented approach can control surely the smart grid-connected system.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.2
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• pp.148-154
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• 2005

As the exciting point of each phase is determined by the position of rotor, the rotor's accurate position-information is needed for the Switched Reluctance Motor(SRM). When using an absolute-encoder or a resolver, to detect the location of rotor the initial starting is possible, as early sensing of rotor's location is possible. However, this is not appropriate, considering the economical efficiency, and in case of using the incremental-encoder, there's a problem at initial starting as it is not easy to track down the location of rotor at the very beginning. When using Hall-ICs, there's a fault, as it needs a special ring magnet. Considering the initial starting and economical efficiency, the optical sensor technique using a slotted-disk and an opto-interrupter is appropriate, however, this method needs three opto-interrupters and a slotted-disk when using the 6/4 pole SRM. Nevertheless, in this paper, it used only two optical sensors to operate 6/4 pole SRM and made the start up and also forward and reverse operation possible. By excluding the slotted-disc md shortening a optical sensor, it improved the convenience and economical efficiency of the production. Also, as the space for slotted-disc is no more needed, it was able to reduce the size of motor.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.529-535
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• 2018

The range extender vehicle runs on a mechanism that allows the small power generation engine to start in the most efficient specific operating range to charge the battery and extend the mileage. In this study, we developed a step motor type intake air supply system that replaces existing throttle body system to develop a simple low cost control logic system. The system was applied to the existing base engine, and in order to improve the performance by increasing the amount of intake air, the effect of changing the length of the intake and exhaust manifold was experimentally examined. As a result, the Type B intake air control actuator operated by one step motor showed higher performance than the Type A in all the operation region, but the performance was lower than that of the base engine due to the increase of flow resistance. To improve this, it was confirmed that the engine performance was improved at both speeds of 2200rpm and 4300rpm when the 140mm adapter was installed in the intake manifold and when the newly designed 70mm exhaust manifold was applied. Through this process, high - precision operation control was realized by connecting the generator load to the optimized engine for the range extender electric vehicle. Experimental results showed that the speed change rate was within ${\pm}2.5%$ at 2200rpm in 1st stage and 4300rpm in 2nd stage and the speed follow-up result of 610 rpm/s was obtained when the speed was increased from 2200rpm to 4300rpm.

• Korean Parent-Child Health Journal
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• v.3 no.2
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• pp.49-66
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• 2000

Pregnancy is a task of creation in which a women mobilizes her self and the resources available to her in the generation of a new person. Through the pregnancy, a mother has formed the new human relationship with a fetus. Maternal-fetal relationship is considered one of mechanism making the relationship of mother and child. It is important to well-being of mother and fetus, too. The earliest interaction between a mother and her child is during prenatal period. Maternal-fetal dyad is unique and perceived interactions with the fetus make the pregnancy real for the mother. Maternal behavior is "instinctive" and is formed in early childhood by copy of the mother. But, Rubin argues that this behavior is an open intellectual system rather than a prepackaged bundle of traits. There is openness to new learning and a high value placed on knowing which occurs with silent organization in thought. Thus, nurses and other health professionals provide prenatal care that optimally is part of the environment in which the maternal-fetal dyad develops. Thus it is appropriate for nurses to increases their understanding of the dyad and to explore ways to enhance its development. This study focusses on the interaction ability and response of fetus, and the maternal-fetal interaction. The research of fetal responses that involve physiological changes and motor movement have been shown to coccur to both external sensory stimuli and to maternal emotional states. The fetus does also have sensory capacity to be aware of some maternal behaviors, and the motor ability to respond in a way the mother can notice. Thus, very rudimentary interactions appear to be possible. Maternal awareness of fetal activity was supported by several studies. More interesting to the present study are description of maternal-fetal interaction and the finding that there appear to be levels of sensitivity to the fetus involved in maternal-fetal interactions. First, recognition comes that the fetus is separate from the maternal self. Next, the fetus engages in. Lastly, the parent may describe active interaction with the fetus, believing that mother and fetus are communicating on a meaningful level. Several interventions, developed to promote more active interaction between mother and fetus, have been reviewed. In general, the parents were taught to stimulate the fetus and to notice the fetus' responses. This type of intervention might increase the mother's sensitivity to her unborn baby, and she may have a head start toward learning how to res pond sensitivity to the newborn infant. Research In the area of maternal-fetal interaction is scarce. Sensitive behavior is construed as an appropriate and timely response to a signal of need from another person, but no such signal of need can be claimed regarding the fetus. The highest level of maternal-fetal interaction, therefore, might be based more on maternal representations of the imagined fetus than on factual evidence of fetal participation.

• Journal of Appropriate Technology
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• v.7 no.1
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• pp.51-58
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• 2021

This study proposes the design and implementation of a low-cost emergency ventilator which can be helpful during the COVID-19 pandemic where the supply of automatic ventilators is not smooth compared with the urgent demand worldwide. Easy implementation and lower price were made possible by using AMBU-bag and off-the-shelf embedded micro-controller board. Moreover, while 3D printing is used by companies and experts around the world to build prototype hardware, materials which are readily available from surrounding environments so that people in countries where it is difficult to access many advanced technologies could manufacture the system. The design features AMBU-bag automation, not use 3D printing, and it can contrl speed. By allowing speed control, ventilation can be performed according to the conditions of the patient being used. A complementary point in the study is that it is difficult to fix the start point of the wiper motor used first. A method for complementing this is a method for replacing the brush DC motor with a position feedback function. Secondly, the AMBU-bag may wear out in the long-term process of compressing the AMBU-bag because the arm and the fixing frame are made of wood. To complement this, the part of fixing frame and arm parts that the AMBU-bag touches need to be wrapped in a material such as silicon to minimize friction.

• Culinary science and hospitality research
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• v.23 no.6
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• pp.173-183
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• 2017

Conditions related to body composition and aging, such as osteopenic obesity, sarcopenia/ sarcopenic obesity, and the newly termed osteosarcopenic obesity(triad of bone, muscle and adipose tissue impairment), are beginning to gain recognition. Currently, it has begun to attract the attention of scholars from all over the world, however, for this disease, it still needs a more clear understanding and perception. Therefore, this article considered the osteoporosis, muscle depression, and obesity, these diseases as a gate to study the relationship among muscle, bone, and fat. In addition, in the aging process, the formation of IGF-cortisol, testosterone, and estrogen is sensitive. These hormones can not only absorb muscle protein metabolism, but also affect alienation. The decrease in IGF-cortisol in the elderly resulted in increased visceral fat, decreased muscle mass and bone mineral density, and then affected decreased skeletal muscle atrophy and decreased quality. The reduction of skeletal muscle quality and strength and increase body fat affected the adipose tissue to produce inflammatory cytokines, thereby reduced skeletal muscle, promoted cardiovascular disease, metabolic syndrome and insulin resistance in chronic diseases. Almost all chronic inflammatory diseases were associated with bone, muscle and fat. These mechanisms were complex and interrelated. Inflammation reduces bone formation, increases fat and reduces muscle mass. And thus not only had a significant impact on the motor system, but also made the incidence increase of fracture, osteoporosis, fragile syndrome, fall, osteomalacia and other bone disease. This article aimed to start from the interaction between the muscles and bones of the elderly, extended to obesity, muscle deficiency, osteoporosis and other diseases, finally, from a nutritional point of view, to discuss how to treat osteoporosis obesity.