• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3
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• pp.402-407
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• 2013

In this paper, the image processing for flexible disk grinding and the effect of the grinding conditions on the flat zone length of a workpiece are investigated, with the purpose of automating the grinding process. To accomplish this, three issues should be carefully studied. The first is finding the relationship between the flat zone length and the grinding conditions such as the cutting speed and feeding speed. The second is developing a neural network algorithm to predict the flat zone. The third is developing an image processing algorithm to measure the flat zone length of a workpiece. Slope analysis is used to determine straight and curved sections during the image processing. For verification, the estimated length and the length from the image processing are compared with the length measured by a projector. There is a minimum difference of 1.7% between the predicted and measured values. The results of this paper will be useful in compiling a database for process automation.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.2
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• pp.19-26
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• 2011

SATEEC ArcView GIS system was developed using the Universal Soil Loss Equation (USLE) and sediment delivery ratio (SDR) modules. In addition, time-variant R and C modules and $R_5$ module were developed and integrated into the SATEEC system in recent years. The SATEEC ArcView GIS 2.1 system is a simple-to-use system which can estimate soil erosion and sediment yield spatially and temporarily using only USLE input data, DEM, and daily rainfall dataset. In this study, the SATEEC 2.1 system was used to evaluate the effects of USLE LS input data considering slope length segmentation on soil erosion and sediment yield estimation. Use of USLE LS with slope length segmentation due to roads in the watershed, soil erosion estimation decreased by 24.70 %. However, the estimated sediment yield using SATEEC GA-SDR matched measured sediment values in both scenarios (EI values of 0.650 and EI 0.651 w/o and w/flow segmentation). This is because the SATEEC GA-SDR module estimates lower SDR in case of greater soil erosion estimation (without flow length segmentation) and greater SDR in case of lower soil erosion estimation (with flow length segmentation). This indicates that the SATEEC soil erosion need to be estimated with care for accurate estimation of SDR at a watershed scale and for accurate evaluation of BMPs in the watershed.

• Korean Journal of Environmental Agriculture
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• v.26 no.4
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• pp.343-350
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• 2007

Three different experiments were carried out to investigate the runoff and erosion losses of endosulfan from sloped-field by rainfall. The mobility of endosulfan and which phase it was transported by were examined in adsorption study, the influence of rainfall pattern and slope degree on the pesticide loss were evaluated in simulated rainfall study, and the pesticide losses from soybean-grown field comparing with bare soil were measured in field lysimeter study. Adsorption parameter (K) of endosulfan ranged from 77 to 131 by adsorption method and K values by the desorption method were higher than those by the adsorption method. By the SSLRC's classification for pesticide mobility endosulfan was classified as non-mobile class ($K_{oc}>4,000$). Runoff and erosion loss of endosulfan by three rainfall scenarios ranged from 3.4 to 5.6%and from 4.4 to 15.6%of the amount treated. Endosulfan residues were mainly remained at the top 5 cm of soil depth after the simulated rainfall study. Pesticide loss in case of 30%-slope degree ranged from 0.6 to 0.9 times higher than those in case of 10%-slope degree. The difference of pesticide runoff loss was related with its concentration in runoff water and the difference of pesticide erosion loss would related closely with the quantity of soil eroded. Endosulfan losses from a series of lysimeter plots in sloped land by rainfall ranged from 5 to 35% of the amount treated. The erosion rate of endosulfan from soybean-plots was 66% of that from bare soil plots. The effect of slope conditions was not great for runoff loss, but was great for erosion loss as increasing to maximum $4{\sim}12$ times with slope degree and slope length. The peak runoff concentration of endosulfan in soybean-plots and bare soil plots ranged from 8 to 10 and from 7 to $9{\mu}gL^{-1}$ on nine plots with different slope degree and slope length. Therefore the difference of the peak runoff concentrations between bare soil plots and soybean-plots were not great.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.6
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• pp.119-124
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• 2009

In this study, the characteristics of estimating methodology for RUSLE factors such as soil erodibility factor, slope length-steepness factor, and cover management factor were reviewed and then the relative error according to each methodology was analyzed. RUSLE was applied to experimental watershed for 42 storm events and their results were compared with measured sediment yield to examine the applicability of RUSLE. As a result, this paper found that it should be necessary to consider vegetation effect for forest application of RUSLE as cover management was the most sensitive factor. Also, soil erodbility factor was calculated from data of soil series by National Academy of Agricultural Science caused sediment yield to be overestimated because there were big differences between the soil series and on-site soil texture. The 22.7% of maximum relative error was shown according to selecting the rain energy equation. In addition, it will be necessary to verify the RUSLE factors with more data in order to improve their accuracy.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.1
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• pp.26-32
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• 2003

Then-channel poly-Si thin-film transistors (poly-Si TFT's) formed by solid phase crystallization (SPC) method on glass were measured to obtain the electrical parameters such as of I-V characteristics, mobility, leakage current, threshold voltage, and subthreshold slope. Then, devices were analyzed to obtain the reliability and appliability on TFT-LCD with large-size and high density. In n-channel poly-Si TFT with 5$\mu\textrm{m}$/2$\mu\textrm{m}$, 8$\mu\textrm{m}$, 30$\mu\textrm{m}$ devices of channel width/length, the field effect mobilities are 111, 116, 125 $\textrm{cm}^2$/V-s and leakage currents are 0.6, 0.1, and 0.02 pA/$\mu\textrm{m}$, respectively. Low threshold voltage and subthreshold slope, and good ON-OFF ratio are shown, as well. Thus. the poly-Si TFT's used by SPC are expected to be applied on TFT-LCD with large-size and high density, which can integrate the display panel and peripheral circuit on a targe glass substrate.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.1
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• pp.86-95
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• 1986

A study on film water flow on steep open channel has been seldom found up to date. Therefore, this paper dealed with the depth variation of film thickness of water (city supply normal water) flowing on steep open channel. For this purpose, Experimental apparatus (made of a normal glass with 160cm of length and 15cm of width) was made and the depths of the water flowing on the channel were measured experimentally, changing the channel slope angle from 30 to 80 degree (5 steps) and the flow rate from 0.25 to 10CPM (11 steps). The results obtained, some characteristics of the film flow on the channel are as follows. (1) When thin film water flowed on steep open channel, the depths of flow tended to increase after decreasing and was kept nearly constant in its downstream in case of laminar and transitional flow region. The turining point of the depths of flow from decrease to increase tended to move downward with the increase of Reynolds number. In turbulent flow region, the depths of flow showed reapid decrease in its upper stream, gradual decrease in its midstream and were kept nearly constant in its downstream. (2) While the differences between the depths of flow along the channel slope got small in its upper stream and got large in its downstream in case of laminar flow region, they got very large in its upper stream and were kept nearly constant in its downstream in case of transitional and turbulent flow region. And the move flow rate increases, the more the differences between the depths of flow along the channel slope got large in its upper stream.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.11
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• pp.1666-1671
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• 1989

A novel switched-capacitor circuit for interfacing capacitive microtransducers with a digital system is developed based on the dual-slope integration. It consists of a differential integrator and a comparator. Driven by the teo phase clock, the circuit first senses the capacitance difference between the transducer and the reference capacitor in the form of charge, and accumulates it into the feedback capabitor of the integrator for a fixed period of time. The resulant accumulated charge is next extracted by the known reference charge until the integrator output voltage refurns to zero. The length of time required for the integrator output to return to zero, as measured by the number of clock cycle gated into a counter is proportional to the capacitance difference, averaged over the integration period. The whole operation is insensitive to the reference voltage and the capacitor values involved in the circuit, Thus the proposed circuit permits an accurate differental capacitance measurement. An error analysis has showh that the resolution as high as 8 bits can be expected by realizing the circuit in a monolithic MOS IC form. Besides the accuracy, it features the small device count integrable onto a small chip area. The circuit is thus particularly suitadble for the on-chip interface.

• Journal of Magnetics
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• v.12 no.2
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• pp.89-92
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• 2007

The authors propose a magnetic actuator for use as a navigation system for capsule endoscopes. The actuator is composed of a capsule dummy, a permanent magnet inside the capsule, and an external spiral structure. The device rotates and propels wirelessly when exposed to an external rotational magnetic field. In this study we measured the effect of the spiral shape on the velocity and thrust force properties. According to our experimental results, the actuator obtained a maximum velocity and thrust force when the spiral angle was set at 45 degrees, the number of spirals was set at 4, and the spiral-height was set at 1-mmf. We also conducted a motion test in the large intestine of a pig placed on a 30 degrees slope. The actuator passed through a 700 mm length of the intestine in about 300 s. The device also managed to travel up and down the 30 degrees slope with no difficulty whatsoever. Our results demonstrate the great potential of this actuator for use as a navigation system for capsule endoscopes.

• Journal of Power System Engineering
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• v.1 no.1
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• pp.80-90
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• 1997

The purpose of this study is to evaluate the validity examination of the J-R curve characteristics for the nuclear reactor pressure vessel steels and Al alloys by the load ratio analysis. The results of the load ratio analysis are compared with those of the J-R curve which are obtained by the ASTM unloading compliance method. The crack length calculated by the load ratio analysis is agree well with the measured final crack length. The slope of the exponential J-R curve estimated by the load ratio analysis is slightly smaller than that by the ASTM unloading compliance method. The J-R curve obtained by the ASTM unloading compliance method is over-predicted and should be offsetted due to the initial negative crack. On the other hand, the load ratio analysis method can evaluate the J-R curve by only load-displacement curve without particular crack measurement equipment.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3A
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• pp.555-563
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• 2006

Recently, many bridges become not only functionally obsolete of bridge deck due to inadequate width but also structurally deficient of substructure due to erosion. In these cases, widening is almost always more economical than complete replacement, and therefore there is a need to make available the results of research and field experience pertaining to the widening of bridge substructure. But, an experimental study for the guarantee of unification between existing and new substructure with adhesive anchor is so insufficient that the development of adhesive anchor system for the unification should be settled promptly. The purpose of the present study is to explore pull out and shear characteristics of adhesive anchor system. For this purpose, several series of concrete specimens have been tested. Major test variables were the bonded length, anchor diameter and anchor slope. The pull out strength, bond stress and shear strength of adhesive faces were measured for the specimens. The present study indicates that the pull out strength increased with more bonded length and more anchor diameter, and that the bond stress decreased with more bonded length and more anchor diameter. The pull out strength and the bond stress increases with more anchor slope and it is considered that the slope of $5^{\circ}$ was more efficient. From the shear tests, it is supposed that anchor diameters more than D19 was proper to the adhesive anchor. Finally, it is expected that both experimental data in these tests and further study including mock-up tests will contribute to the establishment of the unification between existing and new substructure with adhesive anchor.