• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.1
• /
• pp.25-32
• /
• 2010

The paper proposes a hierarchical fault detection method for the high voltage equipment using a microphone array which detects the location of fault and the thermal imaging and CCD cameras which verifies the fault and stores the image, respectively. There are partial arc discharges on the faulty insulators, which generates a specific pattern of sound. Detecting the signal using the microphone array, the location of the faulty insulator can be estimated. The 6th band-pass filter was applied to remove noise signal from wind or external influence. When the mobile robot carries the thermal and CCD cameras to the possible place of the fault insulator, the fault insulators or power transmission wires can be detected by the thermal images, which are caused by the aging or natural erosion. Finally, the CCD camera captures the image of the fault insulator for the record. The detection scheme of fault location using the microphone array and the thermal images have been proved to be effective through the real experiments. As a result of this research, it becomes possible to use a mobile robot with the integrated sensors to detect the fault insulators instead of a human being.

• Journal of the Korean Institute of Gas
• /
• v.23 no.5
• /
• pp.15-23
• /
• 2019

42.5% of domestic gas accident due to human factors, and 38% occurred in residential area. Also gas accident caused by deterioration / malfunction increased more than 2 times for last 1 year. In this study we developed IoT based gas safety platform service for Home-gas safety, which secured 99.32% of data transmit accuracy, monitoring and remote control through LPWA bidirectional communication.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.05a
• /
• pp.137-140
• /
• 2002

For the satisfying performance of a oil lubricator, design of a oil controller for the system which meets the required specifications and its supporting hardware that keep their functioning is important. Among the hardware of a control system, oil system are most vulnerable to malfunction. Thus it is necessary to keep track of accurate and reliable oil readings for good fusion oil lubricator performance. In case of oil lubricator, data loss, ssr trigger error faults, they are detected by examining the data system output values and the major values of the system, and then the faults are recognized by the analysis of symptoms of faults. If necessary electronic-sensor values are synthesized according to the types of faults, and then they are used for the controller instead of the raw data. In this paper, a fast-32bit cpu micorprocessor applied to the control of flexible link system with the sensor fault problems in the error module for exact positioning to show the applicability. It is shown that the fusion oil lubricator can provide a satisfactory loop performance even when the sensor faults occure

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.10a
• /
• pp.561-562
• /
• 2017

Software defined networking technology allows centralized and powerful network control by separating packet processing and network control. However, powerfulness of software-defined networking technology threats the network itself. Most security researches of software-defined networking focus on discovering and defending network vulnerabilities. But, there is not much security for this technology itself. In this paper, the security vulnerabilities that can occur in this networking technology are analyzed and the security requirements of it are proposed. The biggest threats are the threats to the controller, the reliability problem between the controller and the switch must be solved, and a technique to detect attacks that malfunction by manipulating configuration information are needed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.11a
• /
• pp.486-489
• /
• 2004

The active magnetic bearing (AMB) systems mounted in moving vehicles are exposed to the disturbances due to the base motion, often leading to malfunction or damage as well as inaccurate positioning of the systems. Thus, in the controller design of such AMB systems, robustness to base disturbances becomes an essential requirement. In this study, effective control schemes are proposed for the homo-polar AMB system, which uses permanent magnets for generation of bias magnetic flux, when it is subject to base motion, and its control performance is experimentally evaluated. The base motion of AMB system is modeled as the dynamic disturbances in the gravity and base excitation forces. To effectively compensate for the disturbances, the angle feed-forward controller based on the inverse dynamic model and the acceleration feed-forward controller based on the normalized filtered-X LMS algorithm are proposed. The performance test of the prototype AMB system is carried out, when the system is mounted on rate table. The experimental results show that the performance of the proposed controllers for the AMB system is satisfactory in compensating for the disturbances due to the base motion.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.29 no.2
• /
• pp.288-293
• /
• 2000

This study was carried out to investigate the effect of crude saponin fracton from Korean red ginseng on physiological events of ovariectomized rats. The saponin fractions was prepared by Diaion HP-20 adsorption chromatography and spirit. Total 50 rats were divided into 5 groups : normal control (NC), sham-ovariectomized (SO), ovariectomized (OR), ovariectomized and saponin treated (OS), and normal control treated with saponin (NS). Saponin was intraperitonally administered for 8 weeks. Ovariectomy was carried out at 1 st and 2nd weeks of experiment. Right-side ovary of rat was removed at 1st week, the otehr was done at 2nd week. The body weights fo ovariectomized rats showed no significant changes but that of NS group showed significant increase (p<0.05) compared with NC group. Ovariectomy of rats reduced the weights of femur by 6 to 8% compared with that of NC group. In addition, femur weight of NS group was 5 to 6% higher than that of NC. Uterus weight showed no significant differences by saponin treatment or ovariectomy. Serum testosterone level of ovariectomized rats increased by 60 times compared with that of NC. However, administration of crude saponin to ovariectomized rat attenuated testosterone level to almost that of NC. These results suggest that Korean red ginseng saponin attenuates physiological disorders induced by malfunction of ovary.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.10
• /
• pp.1481-1486
• /
• 2013

The small wind generator with existing mechanical control system has a frequent failure and malfunction, and its maintenance is difficult. In this paper, an electric control method using a boost converter for small wind generator was suggested. The suggested 2-level boost converter control device was manufactured and its experimental operation were conducted on a wind generator with 200 [W] capacity. As a result of experimental device, the control by a boost converter was executed at the point that the output voltage of a wind generator became 36 [V] so it could be identified that the output voltage of a wind generator diminished and then it became 0 [V] after 5 [sec]. Besides, in case of applying the method suggested in this paper to a small wind power generation facility for street lights, it is expected to reduce its maintenance by preventing a frequent failure of a generator and to improve its utilization rate.

• Journal of Advanced Marine Engineering and Technology
• /
• v.38 no.6
• /
• pp.723-729
• /
• 2014

When the bluetooth technology of smartphone is applied to a remote control system, communication errors caused by wave attenuation and interference results in the shortening of communication distance, loss of the target device control and malfunctioning. In this study, we propose a method to adopt a retransmission persistence controlled S/W ARQ in bluetooth communication to minimize the effect of the communication failure and to detect and handle the state where the target device gets lost control. We implemented a motor-driven RC car equpped with a bluetooth communication module and a steering application program on smartphone to test the proposed method. The experiments are conducted in three communication environments, and have resulted in the increase of the communication distance by at least 30% when S/W ARQ is applied. Moreover, when the communication was disrupted due to environmental disturbances, the S/W ARQ based system stopped immediately any undergoing operations to avoid possible malfunction.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.16 no.4
• /
• pp.630-636
• /
• 2002

After The Yellow Emperor's Canon of Internal Medicine, The text researches of pathologic change to the liver disease concluded the next, 1, The category of liver-disease(肝病) include the Symptoms of abnormality due to vital energy and blood motion, emotion and intention, muscular and reproductive function, and legions around descending liver channel. 2. In the theory that Liver-Yang energy(肝陽氣) is always overproducing, Liver-Yin blood(肝陰血) is always lacking, pathologic characteristics for liver disease is functional change of malfunction of the use of body(體用失調), So nourishing the liver and kidney is used for the principal aspects of a disease. regulating and calm the liver is used for the secondary aspects of a disease as the treatment plan, 3. If malfunctioning of the functions of dispersion and discharge(疏泄), Iiver-energy(肝氣) is becoming degected, So overproduct and overflow of ascent and exhalation of liver-yang(肝陽) is becoming blood are ascending following energy. complete usage of Yin-blood(陰血) is responsible for some kinds of mass formed by blood stasis in the early stage of pathogenesis of liver disease syndrome of the energy system as the progession of disease extravasated blood is forming. the pathologic characteristics is appeared loss of control of the vital energy and blood(體用失調) at the liver disease. 4. Sthenia-syndrome of liver(肝實證) and liver-heat syndrome(肝熱證) is appered that overproducing and overflow of dispersion(疏泄太過) and discharge is responsible for overfunctioning of liver disease or some kinds of heat syndrome such as liver fire(肝火), Sthenia of liver-yang(肝陽上亢), the syndromes of sthenic liver heat(肝實熱) are appered. deficiency of the liver(肝虛證) and cold syndrome of liver(肝寒證) is classified pathologic characteristics of cold and heat, deficiency and excess that regression of sensory, motor, mental due to lack of dispersion and discharge(疏泄不及), or intruding of the cold miasma, are degected. 5. The liver is close relation of physiologic function and internal organ such as spleen, stomach, lung, heart, kidney, gall bladder by the meridian channels, because of property of wind Zang, rapid progession is classified by phthologic charateristics.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.12
• /
• pp.2968-2974
• /
• 2014

When lighting has installed indoor, we control lighting using human-detecting sensors for people who pass at night and places that are lack of quantity of light. However, malfunction can be caused by positions of inappropriate sensors, and in the case of passages of big buildings, it is a problem that even after a person pass, light apparatuses are turned on for a long time. In this paper, we propose lighting control system based on location positioning for energy saving that control lighting in accordance with passers's position through indoor location positioning. This system use the fingerprinting technology that is one of the location positioning technologies and RSSI data that is collected by a smart device. Using those, it can turn on only lightings that are included in the positioned location and reduce unnecessary power consumption. As a result of experiment, on condition that four people were existing and illumination was 308 lux, we assured reduction effect of 49 Wh.