• Journal of Power System Engineering
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• v.18 no.2
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• pp.50-56
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• 2014

Friction welding is a very useful joining process to weld metals which have axially symmetric cross section. In this paper, for the friction welding with tube-to-tube shape, the feasibility of industry application was determined using analyzing mechanical properties of weld and optimized welding variables was suggested. In order to accomplish this object, rotating speed, friction heating pressure, and friction heating time were selected as the major process variables and the experiment was performed in three levels of each parameter. Weld characteristic was investigated in terms of weld shape and metal loss, and 7mm of metal loss was regarded as the optimal metal loss. By tensile test, tensile strength and yielding strength was measured and fracture was occurred at base metal. In order to optimize the welding condition, fitness function was defined with respect to metal loss and yielding strength and the fitness values for each welding condition could be calculated in experimental range. Consequently, we set the optimal welding condition as the point which had maximum value of fitness function. As the result of this paper the optimal welding variables could be suggested as rotating speed was 1300 rpm, friction heating pressure was 15 MPa, and friction heating time was 10 sec.

• International Journal of Contents
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• v.11 no.2
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• pp.15-19
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• 2015

In this paper, we propose an efficient document layout analysis algorithm that includes table detection. Typical methods of document layout analysis use the height and gap between words or columns. To correspond to the various styles and sizes of documents, we propose an algorithm that uses the mean value of the distance transform representing thickness and compare with components in the local area. With this algorithm, we combine a table detection algorithm using the same feature as that of the text classifier. Table candidates, separators, and big components are isolated from the image using Connected Component Analysis (CCA) and distance transform. The key idea of text classification is that the characteristics of the text parallel components that have a similar thickness and height. In order to estimate local similarity, we detect a text region using an adaptive searching window size. An improved adaptive run-length smoothing algorithm (ARLSA) was proposed to create the proper boundary of a text zone and non-text zone. Results from experiments on the ICDAR2009 page segmentation competition test set and our dataset demonstrate the superiority of our dataset through f-measure comparison with other algorithms.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.6
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• pp.909-915
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• 2010

In order to determine the most effective ratio of black soybean powder as an ingredient in cake, black soybean power was added at ratio of 10, 20, 30, and 40% versus wheat flour set as 0(control). Black soybean powder consisted of moisture(8.44%), crude protein(31.34%), crude fat(6.64%), crude ash(3.88%) and carbohydrates(49.70%). The specific gravity, spreadability, and baking loss increased according to the amount of black soybean powder, although specific volume decreased. The chromaticity 'L' and 'b' values of sponge cake with black soybean powder showed an reducing trend while the 'a' value displayed an increasing trend with an increase in black soybean powder. The texture properties of sponge cake with added black soybean powder showed an increasing trend in hardness and stiffness when the cake contained more black soybean powder. The sensory test for sponge cake with added black soybean powder showed high preference for 20% added black soybean powder to sponge cake.

• Journal of Korean Medicine Rehabilitation
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• v.25 no.4
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• pp.75-81
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• 2015

Objectives To investigate the relationship between cervical intervertebral space narrowing in the X-ray and HIVD level of cervical spine in the CT image. Methods We studied 101 subjects who were taken cervical spine X-ray and CT. Intervertebral space were measured at the anterior, middle and posterior portion of each cervical disc in the X-ray. Considering individual difference, intervertebral space was set as value divided by upper width of lower vertebral body. We analyzed statistically adjusted intervertebral space of normal group and herniated disc group using student' t t-test. Results Intervertebral space of cervical spine was narrowed in the herniated disc group. But there was no significant difference at C2~C3. Conclusions We found that narrowing intervertebral space of cervical spine is associated with herniated disc. Further clinical observation is needed.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.7
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• pp.53-61
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• 1998

In this paper, we propose an efficient multi-view images coding algorithm to find the optimal depth and texture from the set of multi-view images. The proposed algorithm consists of two consecutive steps, i) the depth estraction step, and ii) the texture extraction step, comparedwith the traditional algorithem which finds the depth and texture concurrently. The X-Y plane of the normalized object space is divided into traingular paatches and the Z value of the node is determined in the first step and then the texture of the each patch is extracted in the second step. In the depth extraction step, the depth of the node is determined by applying the block based disparity compensation method to the windowed area centered at the node. In the second step, the texture of the traingular patches is extracted from the multi-view images by applying the affine transformation based disparity compensation method to the traingular pateches with the depth extracted from the first step. Experimental results show that the SNR(Singnal-to- Noise Ratio) of images enconded by our algorithm is better than that of images encoded by the traditional algorithm by the amount about 4dB for for the test sets of multi-view images called dragon, kid, city and santa.

• Hwankyungkyoyuk
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• v.17 no.2
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• pp.26-37
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• 2004

The goal of this paper is to develop a regional environmental education program using a regional environment of dam, and to set up a regional education for sustainable development with applying that program to the students. This environmental education program is based on Hungerford's project, which consists of 4 subjects. They are good and bad influences of dam environment which students can experience easily in daily life. Through the volunteering activities such as discussion, search and observation, pre- and post-test, study of value, presentation and game, students can decide which is a favorable strategy for preserving dam facilities well. And they are encouraged to take part in environmental preservation and practice what they learn everyday in the community. The following are the outcomes of this environmental education program: First, students are much more interested in regional and general environmental problems than before and participate in conservation activities voluntarily. Second, students express their willingness for the prevention of water pollution in Hapcheon Dam by collecting garbages and reducing synthetic detergent. Third, students demand some measures which connect the school program to citizen groups for the prevention of water pollution in Hapcheon Dam.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.56 no.1
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• pp.45-50
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• 2007

In this paper, this paper discusses how to improve the power control system of cold and hot water purifiers, in particular, system protecting device against abnormal voltage. The existing power supply control system came with a protecting device composed of varistor device only for impulse-type surges. Even though the existing system senses surge other than impulse-type, the system can not be protected. Accordingly, a new type of power control system was designed to protect the system from surge and ultimately prevent electricity accidents. The power control system suggested in this paper will be designed to protect the system by sensing input voltage and discontinuing power supply by means of SSR if voltage exceeding set value is sensed. To test the designed system, surge was imposed on the existing system and processes of system failure were experimented before safety of the designed power control system was simulated via P-spice program developed by Orcad in order to examine safety and reliability of the system.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1759-1768
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• 2018

The energy density, power density and ohm resistance of battery change significantly as results of battery aging, which lead to decrease in the accuracy of the equivalent model. A parameter identification method of the equivale6nt circuit model with 3 R-C branches based on the test database of battery life cycle is proposed in this paper. This database is built on the basis of experiments such as updating of available capacity, charging and discharging tests at different rates and relaxation characteristics tests. It can realize regular update and calibration of key parameters like SOH, so as to ensure the reliability of parameters identified. Taking SOH, SOC and T as independent variables, lookup table method is adopted to set initial value for the parameter matrix. Meanwhile, in order to ensure the validity of the model, the least square method based on variable forgetting factor is adopted for optimizing to complete the identification of equivalent model parameters. By comparing the simulation data with measured data for charging and discharging experiments of Li-ion battery, the effectiveness of the full life cycle database and the model are verified.

• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.329-332
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• 2005

In this paper, we describe implementation of personal media gateway (PMG) for applications over BcN networks. PMG is a TV based set-top terminal, which enables transmission of Full D1 high quality video and audio at the speed of maximum 2Mbps. It supports SIP protocol and QoS for the BcN networks. The hardware of the PMG consists of host module, audio/video codec processing module, DTMF module, and remote control I/O module. H.263 and MPEG4 software are implemented in DSP as codec for hi-directional communication and streaming, respectively. G.711 and Ogg-Vorbis are implemented as audio codec. We examined the quality of video using the Video Quality Test Equpment, which was developed by KT Convergence Lab. The experimental results show the video quality of MOS 4.1 and audio quality of MOS 4.3. We expect that PMG will be prospective business models, and create new customer value.

• Korean Journal of Metals and Materials
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• v.50 no.4
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• pp.263-270
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• 2012

This study investigates the effect of heat treatment on the mechanical properties of a forged Ni-based superalloy called Nimonic 80A. Nimonic 80A ingot samples were fabricated by vacuum spray casting to achieve a fine and homogenized microstructure. The ingot samples were subsequently hot-forged with the diameter of 220 mm at 1373 K. From the center to the surface of the forged Nimonic 80A, its average grain size decreased and its micro-Vickers hardness increased slightly. Solution treatment was carried out at 1353 K with 8 hours of air cooling followed by aging treatment, which was carried out in the range of 873-1073 K with various times from 0.5 to 256 hours. To set the optimum aging conditions, micro-Vickers hardness tests were performed. The maximum hardness value of 388.0 Hv was obtained by aging at 973 K for 32 hours. Also, tensile tests were performed for optimum aging conditions at room temperature and 873 K. The results can be used effectively to perform reasonable heat treatment of Nimonic 80A superalloy.