• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2000.10a
• /
• pp.665-668
• /
• 2000

This paper presents development of a different substance monitoring system base reliable detection between the conveyer belt and hopper used lot materials transport line of steel company. Conventional detection method of a piece of iron separation system is losed the confidence, because of the place with bad surroundings of measurement so much that materials Production line are completely exposed to dust, moisture and vibration. For the solution of this problem, we developed a different substance detection system using the acoustic emittion sensor and one chip microprocessor which is available for bad surroundings and inexpensive. The reliability of the system was estimated by experiment.

• Journal of Satellite, Information and Communications
• /
• v.7 no.1
• /
• pp.102-107
• /
• 2012

In this paper, we presented interference scenarios and an evaluation methodology for the co-frequency radio interference between a multi-beam mobile satellite communication system and a mobile communication system in 2.1 GHz band. Radio interferences between these systems are calculated using a minimum coupling loss method and an assesment for minimum separation distances was conducted for coexistence of a mobile satellite system and a mobile system in the same geographical area.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.4 no.4
• /
• pp.803-808
• /
• 2000

This paper presents development of a different substance monitoring system base reliable detection between the conveyer belt and hopper used for materials transport line of steel company. Conventional detection method of a piece of iron separation system is losed the confidence, because of the place with bad surroundings of measurement so much that materials production line are completely exposed to dust, moisture and vibration. For the solution of this problem, we developed a different substance detection system using the acoustic emittion sensor and one chip microprocessor which is available for bad surroundings and inexpensive. The reliability of the system was estimated by experiment.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.17 no.4
• /
• pp.395-407
• /
• 1988

Transient flow in a cold-water supply system for cooling the inside of a coal mining pit was numerically simulated. Properly designed and presetted pressure reducing valves control the level of pressures of the piping system at normal or emergent conditions Quasi-steady relations to simulate the valve motion are obtained and the transient performance of the valve is investigated in the present paper. The present method reasonably simulate transient phenomena in the system including the pressure reducing valve. Excessive valve motion and column separation are simulated when the flow is abruptly reduced. A calculated example of the real system is also presented. The simulation can be used for the safety-check and the guidance for design and operation in emergent cases of the system.

• Progress in Superconductivity and Cryogenics
• /
• v.18 no.1
• /
• pp.23-27
• /
• 2016

The technologies using magnetic force control have been investigated toward application in various fields. Some of them have been put into practical use as the results of technological development. This paper introduces our technical development in the field of water processing, scale removal, magnetic drug delivery system, decontamination of radioactive substances and resources recycling.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.55 no.4
• /
• pp.213-216
• /
• 2006

The magnetic levitation effect a high Tc superconductor beneath the toroidal permanent magnet was examined by means of a improved magnetic seesaw method. Magnetic effects associated with penetration and pinning in superconductor. One of these was focussing of magnetic field by superconductor and the other was magnetic levitation. The existence of equilibrium was shown to be related to hysteresis observed in the force separation for a toroidal permanent magnet and superconductor. Obtained results indicate that magnetic levitation effect in the present case was mainly due to diamagnetic effect.

• Korean Journal of Pharmacognosy
• /
• v.24 no.4
• /
• pp.309-312
• /
• 1993

A new method for separation and quantitative determination of isoflavone glucosides in rhizomes of Belamcanda chinensis (Iridaceae) by high performance liquid chromatography was elaborated. A reverse-phase system with a Spheri-5 RP-18 column using MeOH:HOAc:$H_2O$(24 : 5 : 71) as a mobile phase was developed. The isoflavonoids were detected at 268 nm and the analysis was successfully carried out within 15 min.

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.276.1-276.1
• /
• 2003

This study describes a simple and sensitive semi-micro HPLC method with UV detection and direct deproteinization. The plasma protein was precipitated using perchloric acid (60％) and the supernatant was directly injected onto the semi-micro HPLC system. The separation was achieved on a C18 (25 mm ${\times}$ 2.0 mm I.D) analytical column with a mobile phase of sodium acetate buffer (pH 3.5, 50 mmol) - acetonitrile (60:40, V/V). (omitted)

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.22 no.11
• /
• pp.1047-1053
• /
• 2011

In this paper, we proposed an HF-band wireless power transfer system with adaptive frequency control circuit for efficiency enhancement in a short range. In general, a wireless power transfer system shows an impedance mismatching due to a reflected impedance, because a coupling coefficient is varied with respect to separation distance between two resonating loop antennas. The proposed method can compensate this impedance mismatching by varying input frequency of a voltage-controlled oscillator adaptively with respect to separation distance. Therefore, transmission efficiency is enhanced in a short distance, where large impedance mismatch occurs. The adaptive frequency circuit consists of a directional coupler, a detector, and a loop filter. In order to demonstrate the performance of the proposed system, a wireless power transfer system with adaptive frequency control circuits is designed and implemented, which has a pair of loop antennas with a dimension of 30${\times}$30 $cm^2$. From measured results, the proposed system shows enhanced efficiency performance than the case without adaptive frequency control.

• Journal of the HCI Society of Korea
• /
• v.3 no.2
• /
• pp.1-8
• /
• 2008

We introduce VRSMS(VR-based sensor management system) which is the visualization system of micro-scale air quality monitoring system Airscope[3]. By adopting VR-based visualization method, casual users can get insight of air quality data intuitively. Users can also manipulate sensors in VR space to get specific data they needed. For adaptive visualization, we separated visualization and interaction methods from air quality data. By separation, we can get consistent way for data access so new visualization and interaction methods are easily attached. As one of the adaptive visualization method, we constructed large display system which consists of several small displays. This system can provide accessibility for air quality data to people one public space.