• Proceedings of the KIPE Conference
• /
• 2013.07a
• /
• pp.36-37
• /
• 2013

This paper presents high voltage operation sensing boost converter with high side current. Proposed topology has three functions which are high voltage driving, high side current sensing and low voltage boost controller. High voltage gate driving block provides LED dimming function and switch function such as a load switch of LED driver. To protect abnormal fault and burn out of LED bar, it is applied high side current sensing method with high voltage driver. This proposed configuration of boost converter shows the effectiveness capability to LED driver through measurement results.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.6
• /
• pp.809-817
• /
• 2020

In the design and development process of Small-Sat power distribution and transmission module, the stability of dynamic resources was evaluated by a deep learning algorithm. The requirements for the stability evaluation consisted of the power distribution function of the power distribution module and demand module to the SAR radar in Small-Sat. To verify the performance of the switching power components constituting the power module PDM, the reliability was verified using a dynamic neural network. The adoption material of deep learning for reliability verification is the power distribution function of the payload to the power supplied from the small satellite main body. Modeling targets for verifying the performance of this function are output voltage (slew rate control), voltage error, and load power characteristics. First, to this end, the Coefficient Structure area was defined by modeling, and PCB modules were fabricated to compare stability and reliability. Second, Levenberg-Marquare based Two-Way NARX neural network Sigmoid Transfer was used as a deep learning algorithm.

• The Journal of Korean Academic Society of Nursing Education
• /
• v.7 no.1
• /
• pp.143-156
• /
• 2001

This is a survey in order to provide basic information for smoking cessation teaching as investigate adolescent smoking, stress, family function and vital power. Data collection was done at the high school(12 class) and middle school(12 class) with quota sampling during 2 weeks from October 27, 2000. in the metropolitan area of Taegu. Total subjects of this study were 1710 students. The instruments for this study were the Life Event Checklist, Family APGAR, and vital power item among in the SF-36. Frequency, percentage, t-test, ANOVA, and multiple logistic regression by SPSS/PC Win Ver7.5 program were used to analyze the data. The results of this study were as fellows; 1) The subjects of this study was consisted with middle school student (876, 51.2%) and high school students. The students that they have used smoking at past or current smoker was reported 18.9%. Most of the smoking adolescents reported that they started smoking during middle school age, and there were more smoking rate among vocational high school students than academic high school students. 2) There were more stress among high school, men, and vocational high school. In aspect of family function, there were reported high score among women and middle school. At the vital power, there were reported more score among men students than women students. 3) Current smokers were more likely than nonsmokers to report more stress, low family functioning. 4) In order to identify predicting factor for adolescent smoking, family function and stress were tested significant variables statistically.

• Journal of Power Electronics
• /
• v.8 no.4
• /
• pp.371-380
• /
• 2008

This paper describes the Utility Interactive PV (UIPV) system which can improve the peak-cut effect by adding an energy storage device of batteries to the power converter. The proposed system has three possible operation modes depending on relative condition of PV output, which can have the power shaping function covering the peak power for 3 hours. A new power circuit and an application algorithm have been applied to the UIPV system which is based on working PV system during a 3-hour peak time. The energy relationship by the proposed system is analyzed theoretically and experimentally. The proposed system is evaluated at the viewpoint of cost and total spacing, which enables the proposed UIPV system to have the reduction of the peak power demand and hence to improve the power capacity of peak cut.

• Journal of Power Electronics
• /
• v.19 no.6
• /
• pp.1554-1565
• /
• 2019

When grid voltage is unbalanced, the grid-connected output current and power of Virtual Synchronous Generators (VSGs) are distorted and quadratic. In order to improve the power quality of a grid connected to a VSG when the grid voltage is unbalanced, a comprehensive coordinated control strategy is proposed. The strategy uses the positive sequence current reference command obtained by a VSG in the balanced current control mode to establish a unified negative sequence current reference command analytical expression for the three objectives of current balance, active power constant and reactive power constant. In addition, based on the relative value of each target's volatility, a comprehensive wave function expression is established. By deriving the comprehensive wave function, the corresponding negative sequence current reference value is obtained. Therefore, the VSG can achieve the minimum comprehensive fluctuation under the premise that the three targets meet the requirements of grid connection, and the output power quality is improved. The effectiveness of the proposed control strategy is verified by simulation and experimental results.

• Journal of the Korean Society of Physical Medicine
• /
• v.16 no.1
• /
• pp.63-71
• /
• 2021

PURPOSE: The purpose of this study was to investigate the effects of trigger finger on pain, muscle strength and function in carpal tunnel syndrome (CTS) patients. METHODS: A total of 60 subjects (30 carpal tunnel syndrome with trigger finger and 30 carpal tunnel syndrome without trigger finger) were assessment for pain, muscle strength (power grip, key pinch , tip to tip pinch, three jaw pinch) and function. The effect sizes of the two groups were compared, and the correlation between the trigger finger and each variable was analyzed. RESULTS: The results showed that there were significantly difference in the pain, muscle strength excluding three jaw pinch and function (p < .05). The results also showed correlation between trigger finger and pain (r = .552), muscle strength excluding three jaw pinch (power grip r = -.296, key pinch r = -.260, tip to tip pinch r = -.285), and function (r = .375). The function of carpal tunnel syndrome patients was related to pain (r = .550) and power grips (r = -.324) of muscle strength. CONCLUSION: In carpal tunnel syndrome patients with trigger finger compared to carpal tunnel syndrome, muscle weakness, pain increase, and function reduction were shown. In addition, trigger finger are correlated with muscle strength, pain and function, and muscle weakness and increased pain affect the daily living of carpal tunnel syndrome patients with triggers finger. Therefore, physical therapy interventions of carpal tunnel syndrome patients with trigger finger should be combined with treatment for muscle strength enhancement as well as pain reduction.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.14 no.6
• /
• pp.160-170
• /
• 2006

If hydraulic pump controlled by mechanical type regulator has more than one control function, the construction of regulator will be very complicated and control performance falls drastically. It is difficult to have more than one control function for hydraulic pump controlled by electronic type hydraulic valve due to the inconsistency of controllers. This paper proposes a multi-function control technique which controls continuously flow, pressure and power by using EPPR(Electronic Proportional Pressure Reducing) valve in swash plate type axial piston pump. Nonlinear mathematical model is developed from the continuity equation for the pressurized control volume and the torque balance for the swash plate motion. To simplify the model we make the linear state equation by differentiating the nonlinear model. A reaction spring is installed in servo cylinder to secure the stability of the control system. We analyze the stability and disturbance by using the state variable model. Finally, we review the control performances of flow, pressure and power by tests using PID controller.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.12
• /
• pp.74-80
• /
• 2013

Generator faults does not happen more often than the transmission and substation facility faults. However, impacts on the power system by generator faults are very large. In order to minimize the impact of generator faults, generator protection and control system with high reliability is required. Most of the generator relay in generator protection and control system of large power plant of Korea is operated by imports from abroad. Accordingly, in order to accumulate source technology and increase the import substitution effect, localization of multi-function generator protection IED is being developed. This paper deals with the implementation of a multi-function prototype IED H/W, which can be command and data exchange through communication for measuring, monitoring, protection and control. And the IED specification, various relay elements, measurement elements, communication functions, module function, and test system for the prototype IED H/W are described.

• Proceedings of the SCSK Conference
• /
• 2003.09a
• /
• pp.1-12
• /
• 2003

Instead of sensory evaluation, we designed an evaluation method of the setting function of hairstyling products, based on an original theory focusing on changes in bending stress observed when a load with continuous bending is applied to human hair. Specifically, we developed a device to measure bending stress to quickly and objectively evaluate the condition of human hair, particularly its dynamic properties such as the setting function, following the application of hairstyling products. This device generates a load with continuous bending while applying a pendulum motion to a hair tress, one end of which is anchored. The setting function and holding power of resins of various molecular weight and ionic properties were evaluated using this device. The results demonstrated a close correlation with those obtained by experts' sensory evaluation. The evaluation results of bending stress and holding rate confirmed that the combined use of two different resins could improve the function of setting preparations. Evaluation using this device was able to substitute for sensory evaluation, and offers quick objective evaluation and detection of changes in the holding power of hairstyling products over time. We conclude that evaluation using this device is a promising new method.

• The Journal of Korean Physical Therapy
• /
• v.20 no.1
• /
• pp.75-79
• /
• 2008

Purpose: The purpose of this study was to investigate the effect of $\alpha$-wave music and art appreciation on hand function. Methods: A total of 22 university students participated in this study (10 males and 12 females). Twelve subjects received $\alpha$-wave music and art appreciation. The other subjects received neither. All subjects were assessed for hand function (manual dexterity, power grip, pinch, lateral pinch, tactile sense) using a Purdue pegboard, dynamometer, pinch gauge, and Semmes-Weinstein monofilament wire. The data were analyzed using paired and independent t-tests. Results: The results were as follows: 1. In the experimental group, manual dexterity and tactile sense were significantly increased between pre- and post-intervention (p<0.05). Within the control group, manual dexterity and power grip were significantly increased between pre- and post-test (p<0.05). 2. With regard to dexterity and tactile sense, the experimental group experienced a significant post-intervention increase compared to the control group (p<0.05). There was no significant difference in power grip, pinch, or lateral pinch changes between the two groups (p>0.05). Conclusion: The results of this study show that $\alpha$-wave music and art appreciation affect hand function with regard to manual dexterity and tactile sense.