• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1408-1409
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• 2011

Carbon nanotubes (CNTs) were grown on conical tip substrates by using various methods such as electrophoretic deposition, dip-coating, and spray. The scanning electron microscope measurement showed that the spray method ascertained the most uniform deposition of CNTs. The CNT-emitter that was fabricated by the spray method revealed the lowest turn on voltage of electron emission and the highest emission current. In addition, the spray-produced CNT emitter showed the most stable long-term emission characteristics.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.559-561
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• 2011

송전선로 건설시 적용해 왔던 이도측정 방식에 대하여 정확성이나 효율성면에서 기존의 방식보다 우수한 측량방법을 개발하여 현장에 적용할 필요가 있으며, 그 대안으로 광파기를 활용한 이도측정방법이다. 신공법 적용에 따른 여러 가지 문제점도 발생하고 있어 현장에서 개선방안을 도출하였으며 모터가 부착된 측량기내에 프로그램을 내장하여 누구나 쉽게 현장에서 이도를 측정 할수 있게 되었다.

• Journal of IKEEE
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• v.11 no.2
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• pp.77-82
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• 2007

This paper decribess the strain and temperature sensor using fiber optic surface plasmon resonance sensor. The sensor head is 3-layered, Cr, Ag, Au and we showed feasibility to use this sensor to measure strain and temperature.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.6
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• pp.948-954
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• 2008

Now, but task for stringing trolley wire is worked manually by a measurement of dip, we need to development the automatic control system for a safety and effective tasks. In this paper, in works of stringing trolley wire by a mobile of robot, a method is proposed tension control for the stringing trolley wire. On the basics of a wire model with hard nonlinear, ac servo motor model for torque generating and stringing wire tension, the tension control scheme is design and implemented with a detected wire tension by a load cell. We experimentally show that the performance of the tension response are satisfactory to regulator tension. The proposed system is simulated and experimented, results is verified the utilities.

• Environmental Engineering Research
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• v.10 no.2
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• pp.71-78
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• 2005

A series of column experiments was conducted to develop a monitoring system for in-situ and realtime measurement of ozone transport in unsaturated porous media using a fiber optic sensor. The calibration of the fiber optic transflection dip probe (FOTDP) system was successfully carried out at various ozone concentrations using a column with length of 30 cm and diameter of 5 cm packed with glass beads, which don't react with gaseous ozone. The breakthrough curves (BTCs) of ozone were obtained by converting the normalized intensity into ozone concentration. The FOTDP system worked well for in-situ monitoring of gas phase ozone at various water saturations and in presence of soil organic matter (SOM). However, the FOTDP system did not measure the ozone concentration at more than 70% water saturation.

• Journal of the Korean institute of surface engineering
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• v.33 no.4
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• pp.233-240
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• 2000

A novel electrostatic spraying method to solidify molten zinc coating layer was studied by SEM and measurement of sample's temperature. The sprayed droplets also served as nucleation sites in the solidification reaction of molten zinc but might leave the pitting mark by impinging on its surface especially at high spray pressure. Our experimental results showed that electric field could change the sprayed particle trajectories and assist the fine droplets to attach on the surface. Thus, by reducing the spray pressure and by applying the electric voltage higher than -20 KV to charge the droplets electrostatically, we could produce the spangle free galvanized coating layer without pitting.

• The Journal of Engineering Geology
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• v.15 no.2 s.42
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• pp.201-212
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• 2005

A photogrammetric camera system and a software have been built for capturing planned stereo images. To evaluate the system,25 planar data from a constructed rock slope were measured using both geological compass and photo system. Comparison of the data groups from both system showed matching relationship that falls within the error range of $5.25\pm4.53$ in strike and $3.18\pm3.17$ in dip angles, when the 2 standard deviation error distributions were considered. To evaluate the errors of the Photo matching and non planarity of the surface, orientations of the same plane were repeatedly measured 20times. These measurements showed error ranges of $8.2\pm3.4$in strike and $6.6\pm3.4$ in dip angle, considering the same error distributions. Measured strikes and dips were compared with the corresponding compass measurements in 5 constructed. slopes to test the system. Stereonet plots showed that the photo system measured data coincided well with the compass measurements. With these evaluations, the photo system can measure the planar structure in inaccessible locations with reliable accuracy at the same time reducing the data gathering period therefore resulting to an efficient geological survey.

• Journal of Astronomy and Space Sciences
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• v.19 no.2
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• pp.123-132
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• 2002

The electron density and temperature in the topside ionosphere are observed by the ionosphere Measurement Sensor (IMS) onboard the KOMPSAT-1, which has the sun-synchronous orbit of the altitude of 685 km and the orbital inclination of $98^{\circ}$ with a descending node at 22:50LT. Observations have been analyzed to determine the seasonal variations of the electron density and temperature in the low-latitude region. Only the night-time (22:50LT) behavior on magnetically quiet days (Kp < 4) has been examined. Observations show a strong longitudinal and seasonal variation. Generally, in the dip equator the density increases and the temperature decreases. In equinox the latitudinal distributions of the electron density and temperature are quite symmetric about the dip equator. However, the local maximum of the density and the local minimum of the temperature shift toward the Northern hemisphere in summer solstice but the Southern hemisphere in winter solstice. Such variations are due to the influences of field-aligned plasma transport induced by F region neutral wind. Compared with the IRI95 model, the observed electron density and temperature show significant differences from those predicted by the IRI95 model.

• Journal of Korea Water Resources Association
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• v.38 no.11
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• pp.917-925
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• 2005

LSIV (Large Scale Image Velcocimetry) Is one of the image-based velocity measurement techniques. Since it measures surface velocities, it gives simple and inexpensive way to measure velocity, compared to other methods. Because of these advantages, there have been many studies to apply LSIV to the river discharge measurement in the field. Measuring the discharge by using LSIV requires a method which converts a surface velocity to a mean velocity In the present study, experiments and analysis of vortical velocity profile of open-channel flow in various conditions were performed to develop methods which estimate a mean velocity from a surface velocity. The result of this experiment reveals that velocity-dip phenomena occur at free-surface layer in open channel flow and Froude number affects more than bed roughness does. Two methods for estimating the mean velocity were proposed. One is to correct the wake law's profiles by using the difference of surface velocity from the mean velocity, and the other is to use the ratio of mean and surface velocities. The result of applying these methods in an experiment shows that they are quite accurate having an error of approximately $6\%$ only.

• Tunnel and Underground Space
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• v.17 no.2 s.67
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• pp.139-151
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• 2007

Stereophotogrammetry is a method to extract information of an interested area by constructing a stereo-image from two or more photos. In this study, the stereophotogrammetry was adopted to obtain the joint orientation and trace length from a sampling window and its measurements were compared with the result by a clinocompass and measuring tape to evaluate the applicability of the stereophotogrammetry to rock joint survey. A commercial stereophotogrammetry program, ShapeMetriX 3D, was used for this purpose. Firstly, the accuracy of the measuring method using ShpaeMetrix 3D was evaluated by a model test. Secondly, joint orientations on a rock slope and tunnel were obtained by using ShapeMetriX 3D and compared with the measurement by a clinocompass. Finally. the effect of base-depth ratio in photographing was evaluated by comparing images with various base-depth ratios, and the usefulness of closed-up photographing on a rock exposure to increase the measurement accuracy was tested. The dip and dip direction of each model plane obtained by ShapeMetriX 3D showed an error ranged between $-5^{\circ}\;and\; 5^{\circ}$ on the basis of the results by the measuring tape. Base-depth ratio proved not to influence the analysis result by ShapeMetriX 3D if all the images were taken without any hidden area. The close-up photographing turned out useful to obtain the detailed images and therefore precise result when ShapeMetriX 3D was adopted.