• Korean Journal of Materials Research
• /
• v.12 no.6
• /
• pp.458-463
• /
• 2002

Carbon nanotubes were synthesized at various conditions using Ni-catalytic thermal chemical vapor deposition method and their characteristic properties were investigated by SEM, TEM and Raman spectroscopy. Carbon nanotubes were formed on very fine Ni-catalytic particles. The carbon nanotubes synthesized by thermal decomposition of acetylene at $700^{\circ}C$ had a coiled shape, while those synthesized at $850^{\circ}C$ showed a curved and Y-shape having a bamboo-like morphology. It was found that the carbon nanotube was also made on the fine Ni-catalytic particles formed on the surface of 100~400nm sized large ones after pretreatment with $NH_3$.ber composites show the high dielectric constant and large conduction loss which is increased with anisotropy of fiber arrangement. It is, therefore, proposed that the glass and carbon fiber composites can be used as the impedance transformer (surface layer) and microwave reflector, respectively. By inserting the foam core or honeycomb core (which can be treated as an air layer) between glass and carbon fiber composites, microwave absorption above 10 dB (90% absorbance) in 4-12 GHz can be obtained. The proposed fiber composites laminates with sandwitch structure have high potential as lightweight and high strength microwave absorbers.

• Journal of the East Asian Society of Dietary Life
• /
• v.6 no.2
• /
• pp.277-284
• /
• 1996

The objective of this study was to screen the antimutagenicity of yam enzymatic browning reaction product (YEBRP), mucopolysaccharide and dietary fiber from yam to the mutagen of sodium azide and 2-aminoflourene (2-AF). Antimutagenicity of YEBRP on the mutagenicity of sodium azide showed no difference compared to control without YEBRP but that of 2-AF was high In all substrate. (P＜0.01) On the mutagenicity of sodium azide and 2-AF, antimutagenicity of mucopolysaccharide and dietary fiber were high (p＜0.01) in $\alpha$-cellulose and hemicellulose, Antimutagenicity of u-cellulose on the mutagenicity of 2-AF was high at 5 hours reaction time but that was decreased as the reaction time increased.

• Journal of Korean Society for Geospatial Information Science
• /
• v.13 no.2 s.32
• /
• pp.71-77
• /
• 2005

Digital maps that art the primitive components for GIS has been increasingly used for various applications. Although their production processes has been noticeably improved, particularly, the geographic survey and structural editing processes still depends on the traditional process depending on maps printed on papers. This study thus proposes a new efficient method employing a computerized filed survey system into these processes. We applied this method to producing a digital map ver 2.0 and compare the results nth those based on the existing method. From this comparison analysis, it is shown that the proposed method saves about 5% from the overall cost by reducing the man power and processing steps required for digital map production.

• Journal of Korean Society for Geospatial Information Science
• /
• v.13 no.1 s.31
• /
• pp.37-43
• /
• 2005

GPS has been increasingly used in high precision positioning thanks to rapid advances of GPS technology. In order to acquire precise coordinates from GPS, it is important to solve accurately integer ambiguity inherent in GPS signals. The previous methods to solve this ambiguity were mostly based on multi-epoch data but recently a method based on single-epoch data has been developed. In this study, we selected three sets of software based on these methods, applied them to GPS baseline processing, and analyzed the experimental results. From these analyses, we have also verified the potential of their uses in real time precision positioning.

• Journal of Powder Materials
• /
• v.9 no.1
• /
• pp.19-24
• /
• 2002

This paper reports the results of an investigation into the effect of Cu additions upon the nano-crystallization behaviour of an Al-Y-Ni alloy. 1 at.% Cu was added to a base alloy of Al/sub 88/Y₄Ni/sub 8/ either by substitution for Al to form Al/sub 87/Y₄Ni/sub 8/Cu₁, or by substitution for Ni to form Al/sub 88/Y₄Ni/sub 7/Cu₁. Consistent with previous findings in the literature, the substitution of Cu for Al was found to increase the thermal stability of the amorphous phase whereas the substitution of Cu for Ni was found to decrease its thermal stability. Comparing the microstructures of these alloys after heat treatment to produce equivalent volume fractions of Al nanocrystals showed average grain sizes of 14 nm, 12 nm and 9 nm for the alloys Al/sub 88/Y₄Ni/sub 8/, Al/sub 87/Y₄Ni/sub 8/Cu₁respectively. The effect of Cu in refining the size of the nanocrystals was attributed to enhanced nucleation increasing the number density of the nanocrystals, rather than diffusion limited or interface limited growth.

• Korean Journal of Remote Sensing
• /
• v.31 no.2
• /
• pp.171-182
• /
• 2015

We propose a camera system to acquire indoor stereo omni-directional images and its calibration method. These images can be utilized for indoor precise mapping and sophisticated imagebased services. The proposed system is configured with a rotating stereo line camera system, providing stereo omni-directional images appropriate to stable stereoscopy and precise derivation of object point coordinates. Based on the projection model, we derive a mathematical model for the system calibration. After performing the system calibration, we can estimate object points with an accuracy of less than ${\pm}16cm$ in indoor space. The proposed system and calibration method will be applied to indoor precise 3D modeling.

• Korean Journal of Remote Sensing
• /
• v.32 no.5
• /
• pp.511-527
• /
• 2016

We propose a rotating stereo frame camera system to acquire indoor images with a low cost. For experiments, we selected a test site and acquired images using the proposed system and control points using a total station. Using these data, we generated various indoor 3D models using commercial photogrammetric software, PhotoScan. We then performed qualitative and quantitative analysis of the generated indoor 3D models to investigate the possibility of the indoor modeling using the proposed system. From the results, it is confirmed that the generated indoor models using the proposed system can be applicable to the services not inquiring high accuracy.

• Journal of Wetlands Research
• /
• v.13 no.2
• /
• pp.307-317
• /
• 2011

Recently, we have a growing interest in the washland construction for the function of flood control. Therefore this study analyzed flood reduction effect of washland using hydraulic experiment. We used open-channel unit for flood reduction effect of washland. And we used side weir to lateral structure. The result of hydraulic experiment showed a decrease of the average velocity and discharge according to the installation location of side weir. Also, we compared the results of HEC-RAS model and hydraulic experiment for the review of the result of hydraulic experiment. As the result, hydraulic experiment and HEC-RAS model have showed the similar results.

• Journal of Korean Society for Geospatial Information Science
• /
• v.18 no.2
• /
• pp.119-129
• /
• 2010

Many algorithms for processing LIDAR data have been developed for diverse applications not limited to patch segmentation, bare-earth filtering and building extraction. However, since we cannot exactly know the true locations of individual LIDAR points, it is difficult to assess the performance of a LIDAR data processing algorithm. In this paper, we thus attempted the performance assessment of the segmentation algorithm developed by Lee (2006) using the LIDAR data generated through simulation based on sensor modelling. Consequently, based on simulation, we can perform the performance assessment of a LIDAR processing algorithm more objectively and quantitatively with an automatic procedure.

• The Korean Journal of Rehabilitation Nursing
• /
• v.20 no.1
• /
• pp.69-78
• /
• 2017

Purpose: This study aimed to identify the relationship among conflict management style, communication competence and nurse-physician collaboration in hospital nurses and physicians. Methods: This is a descriptive study. Using a questionnaire, data were collected from 230 nurses and 107 physicians at a university hospital in D city. With SPSS/WIN 22.0 program, data were analyzed by t-test, ANOVA, $Scheff{\acute{e}}$ test, and Pearson's correlation coefficient. Results: Physicians scored the highest for communication competence in nurse-physician relationship and the lowest in medical decision making, while nurses scored the highest in patient information sharing and the lowest in nurse-physician relationship. Physicians with problem solving tendency scored higher in communication competence than those with avoiding tendency. Among the nurses, those with avoiding tendency scored the lowest. For both physicians and nurses, communication competence showed a significant negative correlation with avoidance. For nurses there was also a significant positive correlation with compromising tendency. Finally, there was a significant correlation between nurse-physician collaboration and communication competence in both groups. Conclusion: This study demonstrates that nurse-physician collaboration and communication competence are correlated with conflict management style. We suggest educational programs at more hospitals in various locations to improve nurse-physician collaboration reflecting conflict management style.