• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.4
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• pp.88-96
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• 1994

In this paper, we propose a subband pyramid image coding scheme that uses ECVQ (ntropy Constrained Vector Quantizer). In subband pyramid image coding, each subband can be encoded with a coder matched to the statistics of that particular subband, and available versions of the original image at different resolution are easily obtained. ECVQ, aiming at the minimization of the distortion for a fixed entropy of the quantizer output, is well combined with the subband pyramid image coding which yields high compression ratio and good image quality. The optimum bit allocation to each subbands corresponds to the points where the individual distortion rate curves are of particular slope, weighted to the number of samples in that subband, in designing ECVQ.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1760-1769
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• 2007

The cut slope sliding which has been frequently encountered in Pohang area has been reported due to the rapid reduction of shear strength in mudstone after being exposed to the air. Mudstone has characteristics that it has high enough strength and stiffness in a dry condition, but the strength and stiffness decrease in a wet condition with groundwater infiltration. The case study in this paper shows that mudstone which had enough strength in a boring stage has lost the strength after installing PRD steel pipe pile inducing an insufficient bearing capacity, which has been ascertained by the static load test. Test construction has been performed to investigate the most favorable method for increasing a pile bearing capacity in mudstone with various methods such as MSG (Micro Silica Grouting) around the tip and side of a pile, the perimeter grouting combined with Micro pile reinforcement, and concrete filling after tip reinforcing grouting. From the test construction, MSG has been turned out to be the most favorable method for increasing a pile bearing capacity in mudstone, which has been confirmed by the static load test.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1010-1015
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• 2003

Bubble growth on microheater has been experimentally investigated in this study. The experiment was performed using platinum microheaters having dimensions of 300 ${\mu}m$ or 50 ${\mu}m$ in length, 20 ${\mu}m$ or 5 ${\mu}m$ in width, and $0.2{\pm}0.01$ ${\mu}m$ in thickness. A high speed video camera was used to observe bubble growth at 2,000 frames per second. Microheater temperature was measured at the rate of 300 Hz. with a data acquisition system. Bubble nucleation frequency increased with working fluid temperature. Although the slope of temperature drop was similar in all cases, the magnitude of temperature drop was different. The temperature profiles and the high speed camera images were combined to explain temperature drop.

• Journal of Biomedical Engineering Research
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• v.30 no.6
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• pp.510-515
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• 2009

In this paper, variable characteristic ratio algorithm based on oscillometric method is proposed to enhance the accuracy of blood pressure measurement. We combined the slope-based approach and fuzzy inference technique to change the characteristic ratios of height-based method. The proposed algorithm was assessed on 255 measurements from 85 subjects and compared with the conventional height-based algorithm. The testing results showed that the developed algorithm achieved an overall grade A for both systolic and diastolic blood pressures according to the BHS protocol. And, mean standard deviation between the observers and the developed algorithm were 5.71mmHg and 6.29mmHg for systolic and diastolic pressures respectively, which also fulfilled the AAMI criteria. In conclusion, this algorithm was successfully developed and recommended for further clinical trials with the wider adult population.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.863-864
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• 2006

The aim of this study is to acquire useful information of lower urinary tract symptom(LUTS) diagnosis through urophonogaphy signal as noninvasive method. The system was implemented to measure urophonography signal, urinary volume and uroflow. The slope of the log-log plot of power spectrum density changed rapidly from $2.01{\sim}2.07$ to over 3.32 when the occlusion rate was 2 mm to 3.8 mm. This information combined with the uroflow parameters could give a useful prediction of lower urinary tract symptoms.

• Structural Engineering and Mechanics
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• v.19 no.6
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• pp.749-755
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• 2005

In this work, thermo-elastic stability behavior of laminated cross-ply elliptical cylindrical shells subjected to uniform temperature rise is studied employing the finite element approach based on higher-order theory that accounts for the transverse shear and transverse normal deformations, and nonlinear in-plane displacement approximations through the thickness with slope discontinuity at the layer interfaces. The combined influence of higher-order shear deformation, shell geometry and non-circularity on the prebuckling thermal stress distribution and critical temperature parameter of laminated elliptical cylindrical shells is examined.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.3
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• pp.414-418
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• 2010

Due to the increasing demand for carious methodologies to improve the quality of products were introduced. A Brush the most frequently used type of grinding process is one of the deburring. in order to produce consistent burr shape, various machining conditions have been combined and applied to disk grinding process. Between the workpiece and the grinding disc to earn depends on the angle of the slope has been observed. Drastic increase of tool wear has been also observed along the inclination angle variation. Various burr shapes have been captured and analyzed using image processing technique.

• Korean Journal of Remote Sensing
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• v.8 no.1
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• pp.45-58
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• 1992

The study is aimed at extraction of the groundwater potential area using the Geographic Information System. The study was to develop techniques of the thematic mapping such as slope map, geologic map, soil map and suitability mapping for grotential area. There thematic maps were combined and weightages were given to produce suitability map for groundwater potential area. The results of this study are as follows. 1) The 78% of cased wells have releation to lineament coincided with the appraisement point of the suitability map. 2) The 9 sites of 18 test sites produced over than 200 m$^3$/day. The with the highest appraisement point of the suitability map. 3) Suitability map is effective to extract groundwater potential area which can not be extracted from the remotely sensed data. The developed suitability mapping techniques are expected to do as an important tool for exploration and development of the newable and unnewable resources such as groundwater, petroleum etc.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.1
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• pp.47-56
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• 2010

The main objectives of this comparative study were 1) to quantify the potential contribution of wood chips to revegetation on the cut slope in a constructed area, 2) to compare the floristic similarity of species composition whether existing of wood chips in the soil media or not. Wood chips were combined with soil media in the ratio of 30%. The thin layer (1 cm, 3 cm) soil media revegetation methods and the thick layer (10 cm) soil media revegetation method were constructed on the cut slopes by machineries respectively. Also, comparative experiments the existence of wood chips in the soil media were conducted to evaluate the effects of wood chips on revegetation works. The total size of quadrat was $300m^2$ ($100m^2{\times}3$). The results of monitoring for 3 years on cut slopes were as follows: 1) All the quadrat existed in the proper range for vegetation. 2) Species richness of quadrat including wood chips was 10% more than those of commercial soil medias. 3) The coverage rates of quadrat including wood chips were similar or superior to those of conventional methods. It can be concluded that the use of wood chips would be effective to promote establishment of diverse landscape and vegetation. However, it behooves to continue monitoring on succession of vegetation for ecological restoration. Finally, adequate wood chips deposit and gathering methods should be studied properly.

• Journal of Korean Society on Water Environment
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• v.25 no.1
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• pp.102-111
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• 2009

Turbid storm runoff from intensive highland agriculture area has emerged as the major problem of water quality deterioration in the upstream region of the Han River. High slope of the upland combined with high rate of fertilization and intensive plowing causes high rate of soil erosion, and subsequently high suspended sediment and phosphorus content in the runoff water. The variations of water quality during rain spells were surveyed for two years (2005 and 2006) in the Jawoon Stream that is one of hot spots of intensive horticulture discharging turbid storm runoff. SS and TP showed large increase according to the increase of flow rate, whereas TN and BOD showed less fluctuations. Mean EMCs of SS and TP measured for nine rain events were as high as $207mgSS{\cdot}L^{-1}$ and $0.27mgP{\cdot}L^{-1}$, respectively. The export coefficient of SS and TP per area of cultivated field were calculated as $11,912kgSS{\cdot}yr^{-1}{\cdot}km^{-2}$ and $785kgP{\cdot}yr^{-1}{\cdot}km^{-2}$, repectively, which are significantly higher than reports of other area. It can be concluded that SS and TP in the runoffs were high enough to impose major threat to aquatic habitats, and the highland agriculture should be the main target of water quality management or habitat conservation in the study area.