• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.2
• /
• pp.276-285
• /
• 2008

These days the automobile industry, which has rapidly progressed, has been an indispensable part in social and economic activities as well as its research and development have been activated in response to various needs of consumers and markets. The second and third generation control system, getting count on safety and convenience differently than early circuits, cause the hypertrophy of wire harness. The J/Box(Junction Box), which distributes power and wires, was developed to solve the problem. As vehicles have been better in quantity and intelligence, however, environment-friendly electric apparatus system has continuously increased and ITS(Intelligent Transport System) has been introduced in earnest. In result, wires got complicated and multilateral and also there has been a stronger probability that vehicles are out of order due to various problems including mechanical failure. In this study, ISJB(Intelligent Smart Junction Box) was introduced to solve the problem. The diagnosis system was applied to prevent the overload and short of ISJE. Also, the state of vehicles displayed so that drivers monitor it in motion. Likewise error data are saved in the memory so that such data can be analyzed retrospectively. The busbar was adopted in to the main power terminal and the part of power pattern was coverd by lead. Because ISJB is more sensitive to heat in comparison to the busbar type J/Box. With regard the circuits related with safe, alternative circuits were set up in order that electronic devices may be normally operated even when an error arises. ISJB is expected to improve the safety and quality of vehicles.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.433-434
• /
• 2015

Dictionary meaning of circuit-breaker is a mechanical switching device, capable of making, carrying and breaking currents under normal circuit conditions and also making, carrying for a specified time and breaking currents under specified abnormal circuit conditions such as those of short circuit. and it had been recognized as being operated simultaneously. Controlled Switching System(CSS), which is technology for individual pole operation, are widely used to reduce transient phenomenon, for example switching surges, inrush current, for a all switching cases and nowadays it have become and economical solution for a switching place. The conventional solution to these problem is the use of pre-insertion resistors of $520{\Omega}$. However, it is recognised that the cost for products and maintenance are expensive and this apparatus makes more complex the circuit-breaker mechanism. Korea Electric Power Cooperation (KEPCO) has been study for relevant CCS technology since pilot application in substation in 2003 and plan to apply the actual power grid in 2017. This paper deals with the investigation of international CCS operation status and preview for application in KEPCO power grid.

• Journal of the Korean Society of Safety
• /
• v.33 no.1
• /
• pp.62-65
• /
• 2018

The rapid progress toward the 4th industrial society has led to possibilities of fire increase. It is pointed out that, though initial fire suppression is emphasized, the current legal systems do not sufficiently recognize the importance of initial fire suppression. In order to resolve this, problems of the current legal systems and regulations, as well as fire-fighting facilities to be equipped according to the size of specific fire-fighting objects, were diagnosed. Also, suggestions for improvement were provided through comparative analysis with relevant laws and technical regulations of Korea and other countries. According to fire safety standards such as NFPA, IMO, ISO, and Russian standards, automatic fire extinguishers are to be installed as per the adaptability criteria of fire extinguishers and automatic fire extinguishers. In Korea, the "Act on Fire Prevention and Installation, Maintenance, and Safety Control of Fire-fighting Systems" cover the types and scope of fire fighting facilities that include specific fire protection objects, such as electric room, power room, and substation room. This study has identified that, in case of a place with a floor area of less than $300m^2$, the installation requirement is not clearly specified. Therefore, in this study, fire extinguishing equipment and automatic fire extinguishing equipment to be added for each sub-use application are proved to have fire extinguishing performance of Class A, Class B, and Class C, respectively. In view of the fact that, in overseas standards, all space except containing such materials as Deep fire, metal fire and peroxide, can be installed with fire fighting equipment, a legal system for specifying the capacity units of fire fighting apparatus by application is, in this study, proposed.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2008.05a
• /
• pp.281-284
• /
• 2008

Inundation of substation and ground power equipment breaks out every summer season in low-lying downtown and low-lying shore by localized heavy rain, typhoon and tidal wave. In case inundation excluding the exchanging cost of equipment, it occurs a great economic and social loss owing to recovery time and events of electric shock occur by inundation electrical equipment(Pad-mounted Transformer and Switch). In case of installing the power equipment at flood danger territory, we are necessary to the product development, the product is that water does not come in the inside the power equipment. Product of pressure maintaining are established on the basic frame and sensor operates at the flooding occurrence and is maintained a shutting tightly structure and it is a method. The product which is produced the reliability of the product it confirmed a flooding yes or no from the condition which puts in the water tank and it verified. We estimate that loss cost which is caused by with flooding and the power failure will be diminished if it is addition to advances the reliability evaluation and a security of the flood protection product.

• Journal of Korea Foundry Society
• /
• v.18 no.4
• /
• pp.383-388
• /
• 1998

Effects of $CaCN_2$ addition on the grain refinement in the AM60 magnesium ingots were investigated. The effects of the $CaCN_2$ are estimated with different inoculation temperatures, inoculation contents, and holding time to find out the optimum condition. AM60 alloy was melted in the low carbon steel crucible by cylindrical electric furnace under an argon atmosphere. The melting and casting apparatus is specially designed for magnesium alloys. The grain size of AM60 magnesium alloy decreased significantly with an increase in $CaCN_2$ content and, at 0.8 wt% $CaCN_2$ or more, grain size becomes constant at about $85 {\mu}m$. The optimum condition was obtained in the 0.8 wt% $CaCN_2$ for holding molten metal of 30 min. at the temperature of $710^{\circ}C$. The tensile properties of AM60 magnesium alloys were improved due to grain refinement by addition of $CaCN_2$. In the optimum condition, the yield strength, tensile strength and elongation were ${\sigma}_{0.2}=107 MPa$, ${\sigma}_{T.S}=234 MPa$ and e=14.2%. The variation of stress with strain obeyed the relationship of the ${\sigma}=K{\varepsilon}^n$. The strain-hardening exponent, n and strength coefficient, K obtained in the 0.8 wt% $CaCN_2$ added AM 60 magnesium alloy were n=0.21 and K=390 MPa.

• Korean Journal of Acupuncture
• /
• v.21 no.2
• /
• pp.1-28
• /
• 2004

Objectives : Human physiological changes in the state of qigong has been measured using EEG(Electroencephalography), functional MRI(functional Magnetic Resonance Image), EAV(Electro-Acupuncture according to Voll) and SQUID(Superconducting Quantum Interference Device) measurements. Methods & Results : EEGs were measured to study the differences between Qigong masters and Qi receiver on the changes of EEG. During Qigong, an alpha waves were increased. The power spectra indicate that the peak frequency of alpha waves increased during Qigong. Qi receiver's EEG signals seemed to affected by the state of himself. Brain activation did not observed when qigong master concentrates the Qi at Laogong(P8). But a localization of fMRI signal in the sensory cortex was observed by electric acupuncture stimulation at Laogong(P8). Five phase deviation of EAV were clearly changed in the both cases of Qigong master and Qi receiver. When a Qigong master concentrates the Qi at Yintang, Laogong(P8), Qihai(CV6) meridian points during Qigong state, the change of magnetic field around acupoints Yintang, Laogong points has been measured using 40-Channel DROS-SQUID apparatus. After smoothing process of the continuously measured magnetic signal around acupoints for a few minutes, we could observe that a series of peaks, magnitude of -1.0~2.5pT appeared. But there was no significant difference in changes of magnetic signal around acupoints. Physical signals of magnetocardiogram has been measured by using 2-Channel DROS SQUID(Magnetocardiogram). Physical signals of magnetocardiogram were clealy changed at the ST segments after S-wave when qigong master concentrates the Qi.

• Journal of the Korean Society of Safety
• /
• v.19 no.3 s.67
• /
• pp.32-39
• /
• 2004

This papers describes on the experimental consideration for the intrinsically-safe explosion-proof capability of rechargeable battery's body about main item rechargeable battery and cellular phone battery which is selling in domestic that IEC(International Electrotechnical Commission) recommend the measurement of ignition limit by short circuit of rechargeable battery and temperature increase test to use a explosion grade Group IIC type of explosion-proof type apparatus test an object of hydrogen gas. Because of that there are many different results for existence or nonexistence for ignition by different company and different types. It is concluded that the maximum of self temperature increasing by spark circuit of rechargeable battery is $180^{\circ}C$ in case of Nickel-Hydrogen and $110^{\circ}C$ in case of Nickel-Cadmium. The reaction of cellular battery for external temperature have following processes. It is confirmed that the temperature of reaction is rise slantly as the ambient temperature rising, then exterior shape of one is swell up and change when the temperature of ambient reach to about $130\~140^{\circ}C$, and when reach to about $160^{\circ}C$ the battery is blown up. Therefore, it is considered that have to be in considering selection of rechargeable battery using in itself due to different ignition limits of various rechargeable battery when the portable electric containing rechargeable battery are designed, produced and used, the characteristics and the proper safety factors of devices.

• Journal of the Korean Solar Energy Society
• /
• v.27 no.2
• /
• pp.71-78
• /
• 2007

The heat transfer characteristics of solar tower receivers are experimentally investigated with receiver shapes. Generally, these become different according to the shapes and materials of the volumetric air receiver. In order to study these effects, the apparatus adopting laminated mesh and honeycombs as the volumetric air receiver is proposed. The receiver consists of laminated mesh (diameter; 100 mm, thickness; 1 mm), honeycombs (diameter; 100 mm, thickness; 30 mm) inserted into ceramic tube (inside diameter; 100 mm, outside diameter; 120 mm, length: 1000 mm). To apply heat to the receiver, an electric heater is used. To find out the heat transfer characteristics of the laminated mesh, the air temperatures are obtained by installing 3 thermocouples on each layer, dividing ceramic tube into 4 layers. Also, a radiative shield is installed to measure the only air temperature. The data for laminated mesh and honeycomb thickness of 30, 60, 90 mm are obtained. The results show that the temperature of layer 3 is higher than those of layer 2 and layer 1.

• The Journal of Korean Medicine
• /
• v.17 no.1 s.31
• /
• pp.222-233
• /
• 1996

In order to understand the stimulation quality of Artemisine Vulgaris Folium(Bong), Mori Ramulus(Sangi) and Persicae Ramulus(Dogi) combustion, and get the basic data for the development of electric moxibustion apparatus, the average temperature, peak temperature, average gradient temperature, maximum gradient temperature and combustion time of heating period on the three moxa materials were measured. 1. The average combustion temperature was high in order of Dogi, Sangi and Bong, and these were acknowledged to have a significant difference each other in the average temperature. 2. The peak combustion temperature among those was high in order of Dogi, Sangi and Bong, and Bong was acknowledged to have significant differences with Dogi and Sangi. Sangi and Dogi however were not acknowledged to have difference each other. 3. The average gradient temperature among those was high in order of Dogi, Sangi and Bong, and Bong was proved to have significant differences with Dogi and Sangi. Sangi and Dogi however were not proved to have difference each other. 4. The maximum temperature among those was high in order of Dogi, Sangi and Bong, bong was acknowledged to have signigicant differences with Dogi and Sangi, but Sangi and Dogi were not proved to have difference each other. 5. The combustion time was short in order of Dogi, Sangi and Bong. Bong was acknowledged to have significant differences with Dogi and Sangi, but Sangi and Dogi were not. In order to understand well the characteristics of combustion, it is required to have a quantitative interpretation of combustion calory, and, in the future, we expect it is required to have a consistent study for the clinical effectiveness and the mutual relationship according to the combustion characteristics.

• International Journal of Precision Engineering and Manufacturing
• /
• v.8 no.2
• /
• pp.44-48
• /
• 2007

In recent years, the size of plane substrates and semiconductor wafers has increased. As conventional contact transportation systems composed of, for example, carrier rollers, belt conveyers, and robot hands carry these longer and wider substrates, the increased weight results in increased potential for fracture. A noncontact transportation system is required to solve this problem. We propose a new noncontact transportation system combining acoustic viscous and aerostatic forces to provide damage-free transport. In this system, substrates are supported by aerostatic force and transported by acoustic viscous streaming induced by traveling wave deformation of a disk-type stator. A ring-type piezoelectric transducer bonded on the stator excites vibration. A stator with a high Q piezoelectric transducer can generate traveling vibrations with amplitude of $3.2{\mu}m$. Prior to constructing a carrying road for substrates, we clarified the basic properties of this technique and stator vibration characteristics experimentally. We constructed the experimental equipment using a rotational disk with a 95-mm diameter. Electric power was 70 W at an input voltage of 200 Vpp. A rotational torque of $8.5\times10^{-5}Nm$ was obtained when clearance between the stator and disk was $120{\mu}m$. Finally, we constructed a noncontact transport apparatus for polycrystalline silicon wafers $(150(W)\times150(L)\times0.3(t))$, producing a carrying speed of 59.2 mm/s at a clearance of 0.3 mm between the stator and wafer. The carrying force when four stators acted on the wafer was $2\times10^{-3}N$. Thus, the new noncontact transportation system was demonstrated to be effective.