• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.576-580
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• 2000

This paper describes about the field test of IGBT VVVF inverter for the propulsion system. The 1650kV class IGBT VVVF inverter has been developed. Therefore the field test is performed in SMG 6 Line to confirm its the reliability and performance. The train consists of 4M4T and the electrical equipment for field test are as follows : VVVF inverter 4 sets 16 traction motors and 3 SIVs The propulsion system which have the excellent acceleration/deceleration and the jerk chracteristics as well as starting ability on slope are taken through the field test.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.62-67
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• 2005

A new picking algorithm has been developed on real-time basis for finding the onset of P wave as well as discriminating the micro seismic signal from artificial noise. Unlike the previous methods which have used the STA/LTA ratio for discriminating the P arrivals, we have adopted the slope discrimination methods for identifying the P onset. As result, this algorithm has been turned out to be efficient in both accuracy and computation in on-line system.

• Journal of the Korean Society of Safety
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• v.15 no.1
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• pp.146-152
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• 2000

To estimate the behavior of reinforced and unreinforced embankment constructed on a impermeable foundation ground, a laboratory model test was performed for two types of soils and water level increasing velocity of a flood period. The experiment models were constructed with slopes of water level is 1.25cm/min, 2.5cm/min each. From model test results, as the slope of reinforced and unreinforced embankment was the slower, the more seepage line rised. In the unreinforced embankment, the rising velocity of water level was the faster, the larger the embankment failure was. And the reinforced embankment with geotextile was the more safe than the unreinforced embankment for seepage force.

• YAKHAK HOEJI
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• v.30 no.2
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• pp.100-103
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• 1986

The second derivative absorption spectra of acetaminophen in commercial tablet forms were measured without prior separation from other pharmaceutical adjuvants. The second derivative spectra of acetaminophen were found to have no influence on the characteristic absorbance band of it. A plot of 25 sets of the ordinate (Z) values with various acetaminophen concentrations mixed in other additives gave a straight line (correlation coefficient, 0.9999) and the slope was 2.901${\times}10^{-2}Z$ value/($\mu\textrm{g}$/ml). The procedures were sufficiently sensitive, precise and economical for the assay of tablets of acetaminophen.

• Magazine of the Korean Society of Agricultural Engineers
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• v.16 no.4
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• pp.3585-3593
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• 1974

This thesis a result of theoretical and experimental studies on the shape of seepage line and seepage quantities in various inclined core walls. The value of this determination was examined and compared with the values of calculation acquaired to be based on Fukutas, Jin's and author's approximate equation of the theory. Thus the writer of this paper confirms that the seepage quantity can be decreased by changing the types of the inclined core wall and it's change of the slope.

• Restorative Dentistry and Endodontics
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• v.44 no.1
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• pp.11.1-11.8
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• 2019

In the previous sections, simple linear regression (SLR) 1 and 2, we developed a SLR model and evaluated its predictability. To obtain the best fitted line the intercept and slope were calculated by using the least square method. Predictability of the model was assessed by the proportion of the explained variability among the total variation of the response variable. In this session, we will discuss four basic assumptions of regression models for justification of the estimated regression model and residual analysis to check them.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.1
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• pp.45-57
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• 2015

Soil moisture is critical for understanding the spatial-temporal variability of hydrologic processes. The distributions of soil moisture have been explored along transect line in hillslope hydrology. In this study, we measured several soil moistures along transect lines during ten-month period at a hillslope located the Cheong-mi catchment. The soil moisture properties were expressed by simple statistical methods (average, standard deviation, and recession slope) and analyzed in terms of soil depths and transects from the seasonal context. Supplementary studies were also performed about the effect of location, topography and soil texture to the soil moisture responses. The spatial distributions of average soil moisture at deep soil layer were distinguished from those at near surface due to the possibility of expected factors such as subsurface lateral flow from upslope, preferential flow and existence of bedrock. The soil moistures in combined line affected from significant contribution of upper transect line were relatively higher(wetter), low variability compared to those in other transect lines and seemed to be under stabilization process. There are confirmed heterogeneity of soil moisture variation related with preferential flow and significant influence of soil texture for soil moisture properties in upslope.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.185-185
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• 2011

Mapping of artificial levee lines, one of major tasks in river zone mapping, is critical to prevention of river flood, protection of environments and eco systems in river zones. Thus, mapping of artificial levee lines is essential for management and development of river zones. Coastal mapping including river zone mapping has been historically carried out using surveying technologies. Photogrammetry, one of the surveying technologies, is recently used technology for national river zone mapping in Korea. Airborne laser scanning has been used in most advanced countries for coastal mapping due to its ability to penetrate shallow water and its high vertical accuracy. Due to these advantages, use of LiDAR data in coastal mapping is efficient for monitoring and predicting significant topographic change in river zones. This paper introduces a method for construction of a 3D artificial levee line using a set of LiDAR points that uses normal vectors. Multiple steps are involved in this method. First, a 2.5-dimensional Delaunay triangle mesh is generated based on three nearest-neighbor points in the LiDAR data. Second, a median filtering is applied to minimize noise. Third, edge selection algorithms are applied to extract break edges from a Delaunay triangle mesh using two normal vectors. In this research, two methods for edge selection algorithms using hypothesis testing are used to extract break edges. Fourth, intersection edges which are extracted using both methods at the same range are selected as the intersection edge group. Fifth, among intersection edge group, some linear feature edges which are not suitable to compose a levee line are removed as much as possible considering vertical distance, slope and connectivity of an edge. Sixth, with all line segments which are suitable to constitute a levee line, one river levee line segment is connected to another river levee line segment with the end points of both river levee line segments located nearest horizontally and vertically to each other. After linkage of all the river levee line segments, the initial river levee line is generated. Since the initial river levee line consists of the LiDAR points, the pattern of the initial river levee line is being zigzag along the river levee. Thus, for the last step, a algorithm for smoothing the initial river levee line is applied to fit the initial river levee line into the reference line, and the final 3D river levee line is constructed. After the algorithm is completed, the proposed algorithm is applied to construct the 3D river levee line in Zng-San levee nearby Ham-Ahn Bo in Nak-Dong river. Statistical results show that the constructed river levee line generated using a proposed method has high accuracy in comparison to the ground truth. This paper shows that use of LiDAR data for construction of the 3D river levee line for river zone mapping is useful and efficient; and, as a result, it can be replaced with ground surveying method for construction of the 3D river levee line.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.27 no.2
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• pp.91-103
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• 1997

The purpose of this study was to aid in the prediction of tumor cell tolerance to radiotherapy and/or chemotherapy. For this study, cell surviving curves were obtained for human epidermoid carcinoma A-253 cell line using semiautomated MTT assay. 2,4,6,8,10 Gy were irradiated at a dose rate of 210 cGy/min using /sup 60/Co Irradiator ALDORADO 8. After irradiation, A-253 cell lines(2×10⁴cells/mil were exposed to bleomycin or cisplatin for 1 hour. The viable cells were determined for each radiation dose with/without 2 /lg/mi of drug at the 3rd day. And they were compared to control values. The results were obtained as follows : 1. The surviving curve with gentle slope was obtained after irradiation of 2, 4, 6, 8, 10 Gy on A-253 cell line. 2. The cytotoxicity of bleomycin or cisplatin at the concentration of 2㎍/ml was great on A-253 cell line. But, there was no significant difference between the cytotoxicity of bleomycin and that of cisplatin. 3. There were significant differences of surviving fractions after irradiation with 2㎍/mi of bleomycin compared with irradiation only on A-253 cell line. 4. There were significant differences of surviving fractions after irradiation with 2㎍/ml of cisplatin compared with irradiation only on A-253 cell line. 5. There were no significant differences of surviving fractions between the groups of irradiation with bleomycin and the groups of irradiation with cisplatin on A-253 cell line.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.2
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• pp.227-232
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• 2018

In a Hough transform that is a representative algorithm for the straight line detection, a great number of edge pixels generated from noisy or complex images cause enormous amount of computation and pseudo straight lines. This paper proposes a two step straight line detection algorithm to improve the conventional Hough transform. In the first step, the proposed algorithm divides an image into non-overlapping blocks and detects the information related to the straight line of the edge pixels in the block using a principal component analysis (PCA). In the second step, it detects the straight lines by performing the Hough transform limited slope area to the pixels associated with the straight line. Simulation results show that the proposed algorithm reduces average of ${\rho}$ computation by 94.6% and prevents the pseudo straight lines although some additional computation is needed.