• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.4
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• pp.51-58
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• 2008

Unit costs for energy production in bioenergy facilities are dependent upon both fixed cost for facility construction and operational costs including biomass feedstock supply. With the increase of capacity, unit fixed cost could be decreased while supply cost tends to increase due to the longer transportation distance. It is desirable to take into account biomass availability in planning bioenergy facilities. A cumulative curve relationship was proposed to relate biomass availability and cumulative products of biomass amount and transportation distance. Optimum size of gasification facilities was affected by collection cost, biomass cumulative relationship. Based on biomass availability of Icheon-City, optimum sizes were about $400kW_{th}$ for gas production, and about $200kW_{el}$ for power generation. Unit cost of bioenergy production could be substantially reduced by reducing collection cost through supplying biomass from diverse sources including land development areas where significant amount of waste wood is generated. When planning bioenergy facilities, however, biomass availability and spatial distribution are key factors in determining the size of capacity.

• Journal of Environmental Science International
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• v.16 no.3
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• pp.255-260
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• 2007

The photocatalytic decolorization of Rhodamine B (RhB) was studied using packed-bed reactor and immobilized $TiO_2/UV$ System. The 20 W UV-A, UV-B and UV-C lamps were employed as the light source. The effect of shape and surface polishing extent of reflector, distance between the reactor and reflector, reactor material were investigated. The results showed that the order of the initial reaction constant with reflector shape was round > polygon > W > rhombus. The optimum distance between the reactor and reflector was 2 cm. The initial reaction constant of quartz reactor was 1.46 times higher than that of tile PVDF reactor.

• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.3
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• pp.124-130
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• 2005

In this paper, we designed a cylindrical type light source having an electromagnetic principle of inductively coupled plasma, and measured its electrical-optical properties. Using the transformer principle, an electrically equivalent circuit cylindrical type light source was analyzed. According to the parameters of electromagnetic induction, which were diameter of coil with cpO.3$\~$ 1.2mm, number of turns with 4$\~$ 12 turns, distance with 40$\~$ l20mm and RF power with 10$\~$ 150W, the electrical .md optical properties were measured. When the diameter of the coil was cp0.3mm, number of turns was 8 and distance was 40mm, and the maximum brightness of 29,730 cd/m$^{2}$ was shown with RF power l50W. The relationship between electromagnetic induction and plasma discharges was demonstrated using the mode transition from E-mode to H-mode

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.387-390
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• 1993

The most important technique for an indoor robot navigation is to find out the direction and the distance from the current location to the destination through the information achieved from the sensor. For this purpose, we suggest sensor-based local homing method which compares the destination sensory data with the current location. As for the sensors, we use the CCD camera and the ultrasonic sensor, and recorded entire 360 degree panoramic data. We match the features of the image data, and the distance and the direction of the matched point will be considered as fuzzy numbers. Through a simple fuzzy arithmetic, we infer the geometric relations between the current location and the destination location.

• Journal of the Korean Society of Safety
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• v.19 no.1
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• pp.88-93
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• 2004

This experimental study was carried out to evaluate effect of the radiation heat flux for the pool and spill fire in petroleum storage tanks, which were made form steel. Each of them had the capacity of 250, 2500 and 25000 liter, respectively. The effects of the radiation heat flux are as follows; 1) The intensity of radiation heat flux from a flame decreased exponentially with increasing distance from outside wall of tanks, and increased significantly with surface area of tank and dyke. 2) In the case of 25000L tank, the radiation heat flux was about max. 98.9kW/$m^2$ in 1m from wall of tank. 3) The distance, that was able to ignite wood or plastics by radiation heat flux of approximately 12.5kW/$m^2$, was about 3.14m from wall of 25000L tank.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.30 no.1
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• pp.87-95
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• 2016

Recently, the interests of the precise localization are rapidly increasing, which are linked to IoT(Internet of Things) sensors. The precise localization in indoor environment can be utilized in navigation, security, anti-collision, and various location based services etc. However, conventional positioning sensors, such as PIR, ultrasonic, microwave etc. are vulnerable to weather or insensitive to direction of subject movement or low precision performance. In this paper we implement a UWB-IR localization system for long distance and high-precision localization, which is not affected by temperature, light and weather. The proposed system was divided and designed by H/W, Antenna, S/W parts, each of which was designed based on an accurate analysis and simulation. As a result, we can implemented and verified UWB IR system with precise localization performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.392-395
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• 2006

In this paper, Maharanobis distance was used to distinguish defective motors from good motors. Maharanobis distance was calculated from the noise data of good motors and the test motor that were measured in 1/3 octave hand from 25 Hz to 20 kHz frequency range. The suggested method was applied to the detection of defective air-conditioner motors.

• Journal of the Korean Mathematical Society
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• v.41 no.4
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• pp.667-680
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• 2004

We generalize a theorem of W. Benz by proving the following result: Let $H_{\theta}$ be a half space of a real Hilbert space with dimension $\geq$ 3 and let Y be a real normed space which is strictly convex. If a distance $\rho$ > 0 is contractive and another distance N$\rho$ (N $\geq$ 2) is extensive by a mapping f : $H_{\theta}$ \longrightarrow Y, then the restriction f│$_{\theta}$ $H_{+}$$\rho$/2// is an isometry, where $H_{\theta}$＋$\rho$/2/ is also a half space which is a proper subset of $H_{\theta}$. Applying the above result, we also generalize a classical theorem of Beckman and Quarles.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.1
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• pp.11-16
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• 2006

To manipulate large video databases, effective video indexing and retrieval are required. A large number of video indexing and retrieval algorithms have been presented for frame-w]so user query or video content query whereas a relatively few video sequence matching algorithms have been proposed for video sequence query. In this paper, we propose an efficient algorithm to extract key frames using color histograms and to match the video sequences using edge features. To effectively match video sequences with low computational load, we make use of the key frames extracted by the cumulative measure and the distance between key frames, and compare two sets of key frames using the modified Hausdorff distance. Experimental results with several real sequences show that the proposed video retrieval algorithm using color and edge features yields the higher accuracy and performance than conventional methods such as histogram difference, Euclidean metric, Battachaya distance, and directed divergence methods.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.871-874
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• 1997

A new typed distance relaying scheme is proposed. Artificial neural networks are applied to the distance relaying system composed of pattern recognition based. The proposed distance relaying scheme have the two block of pattern recognition stages to estimate the fundamental frequency and to classify the fault types. The advantage of this approach is demonstrated by the random waves and the fault transient wave signals of EMTP(electromagnetic transients program) in power systems fault conditions. The proposed method is compared with the conventional method and the simulation results show the efficiency of the neural networks.