• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.6
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• pp.9-15
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• 2012

Vibrational film has been more employed in ear-phones or small type of speakers along with a wide use of portable multi-media equipments such as MP3 and MP4. However, the current hand work production process of diaphragms is inefficient. In this study, a die-and-mold and a single production forming machine are developed, and they result in a multi-production forming machine. The multi-production forming machine consists primarily of a film feeding unit and an unwinding unit. A vacuum suction device provides the film feeding unit, while the unwinding unit is obtained using an appropriate damper. The advantage of the developed single production forming machine is shown according to a proper voice test.

• Journal of Korea Multimedia Society
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• v.8 no.1
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• pp.46-55
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• 2005

In this paper, we realize the panoramic infrared warning system to detect the small threaten object and propose the infrared image enhancement method to improve the warning ability of this system. This system composes of the sense head unit, the signal processing unit, and so on. In the proposed system, the sense head unit acquires the panoramic IR image with 360 degree field of view(FOV) by rotating the thermal sensor. The signal processing unit divides panoramic image into four sub-images with 90 degree FOV and computes the adaptive plateau value by using statistical characteristics of each subimage. Then the histogram equalization is performed for each subimage by using the adaptive plateau value. We realize the signal Processing unit by using the DSP and FPGA to perform the proposed method in real time. Experimental results show that the proposed method has better discrimination and lower false alarm rate than the conventional methods in this warning system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1390-1395
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• 2014

The objective of this study is to offer a basic data for the establishment of marketing strategies such as fixing price of a new product and creation of the development direction of the product through estimating consumers value by attributes of the newly developed university made multi cream. The Choice Experiment was used for analysis, and conditional logit model was estimated to derive the marginal willingness to pay(MWTP) of each attributes of the multi cream. Brand, container type, functionality, price were included as the attributes. As a result, MWTP were estimated at 21,754 Won/unit for large company product, 11,033 Won/unit for small company product and 16,178 Won/unit for university product, 7,476 Won/unit for enriched moisturizing, 12,107 Won/unit for enriched improvements in wrinkles. Consumers have a preference for university brand over small company brand, therefore, if university and small company cooperate and proceed a joint-venture, it will strengthen the competitive power in the low price brand market. Also, it is essential to develop products with enriched functionalities such as moisturizing and improvements in wrinkles.

• Water for future
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• v.25 no.1
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• pp.93-100
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• 1992

A study on the Derivation of the Unit Hydrograph using Multiple Regression Moe이. The purpose of this study is to deriver an optimal unit hydrograph suing the multiple regression model, particularly when only small amount of data is available. The presence of multicollinearity among the input data can cause serious oscillations in the derivation of the unit hydrograph. In this case, the oscillations in the unit hydrograph ordinate are eliminated by combining the data. The data used in this study are based upon the collection and arrangement of rainfall-runoff data(1977-1989) at the Soyang-river Dam site. When the matrix X is the rainfall series, the condition number and the reciprocal of the minimum eigenvalue of XTX are calculated by the Jacobi an method, and are compared with the oscillation in the unit hydrograph. The optimal unit hydrograph is derived by combining the numerous rainfall-runoff data. The conclusions are as follows; 1)The oscillations in the derived unit hydrograph are reduced by combining the data from each flood event. 2) The reciprocals of the minimum eigen\value of XTX, 1/k and the condition number CN are increased when the oscillations are active in the derived unit hydrograph. 3)The parameter estimates are validated by extending the model to the Soyang river Dam site with elimination of the autocorrelation in the disturbances. Finally, this paper illustrates the application of the multiple regression model to drive an optimal unit hydrograph dealing with the multicollinearity and the autocorrelation which cause some problems.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.420-422
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• 2005

This paper introduces a new paradigm for energy supply system in near future which produces electric and district heat cogeneration with dispersed power grid with small nuclear power units. Recently, in nuclear field, a lot of effort has been done in nuclear major countries to develop small and medium reactor for enhancement of nuclear peaceful use as like in district heating, electric power generation, seawater desalination or hydrogen generation.

• Proceedings of the Korea Concrete Institute Conference
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• 1991.04a
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• pp.99-104
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• 1991

It is necessary to generalize the use for structural ALA Concrete in our country, as increasing in the need for the development of ALA and the use of ALA Concrete which is related with the diminution of the self load and foundation section of structure responding to the realistic requirement against the decrease of natural aggregate and the high-rising and large-sizing of structures. This little study, therefore intended to help in the mixing design of concrete by considering the fundamental properties of ALA Concrete used with expanded clay, which is considered by acopting the experimental factors such as unit cement content, water cement ratio and the rate of fine aggregate. By considering the results of this experiment, it has difficulty in getting expected slump with the unit water content of normal concrete because of the large absorption of lightweight aggregate, and because the weight of unit volume and specific gravity ALA Concrete are small it appears that the strength and Elastic Modulus of that are small too and that it is more ductile than normal concrete.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.166-167
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• 2014

Recently, in according to increase cognizance of energy and resources exhaustion, renewable energy system is received attention. In particular, ground heat pump system(GSHP) utilizing annually stable ground temperature for energy saving have been attracted in many buildings. However, GSHP system have disadvantage due to increase of initial installation and boring cost. In this study, in order to reduce the initial cost and to supply ground heat pump system into small scale house, an unit-type ground heat exchanger was developed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.10
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• pp.670-675
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• 2015

Degradation diagnosis of cable is one of major issues for operation and maintenance in overhead distribution power lines. The diagnostic system for overhead power lines is composed of three parts in functional aspect - a travelling unit, a sensing unit and a communication unit. Among them, sensor detects the defects such as corrosion and disconnecting of power lines. Performance of sensor is very important, and besides, the size and structure of sensor is restricted for installation to small and lightweight diagnostic system. This paper suggests an optimal eddy current sensor best suit for small and lightweight diagnostic system in consideration of detecting performance, size and ease of installation and so on. Proposed sensor has been designed by Drum core structure and can be applied to the all domestic overhead power lines regardless of the cross-sectional areas. Also, it is showed that results of mock environmental test are satisfied.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.87-88
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• 2008

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.3
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• pp.731-740
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• 2015

In the recent days, interests in machine-to-machine communication schemes in small-scale networks has been increasing with growing demands. TDMA(Time Division Multiple Access) can be used as a multiple access method in small-scale networks. However, time synchronization for TDMA is complicated or needs additional equipments. Such a large cost is not suitable for small-scale networks. We propose, BC-DESYNC, a efficient time synchronization for small-scale networks by extending DESYNC(DESYNChronization). DESYNC takes a long time to complete synchronization and doesn't guarantee the synchronization delay. BC-DESYNC uses CU(Central Unit) that performs a centralized control to achieve the 2-hop communication and guarantees the synchronization completion time by using Mimic firing and C-DESYNC scheme.