• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.363-363
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• 2008

The development of dry etching process for sapphire wafer with plasma has been key issues for the opto-electric devices. The challenges are increasing control and obtaining low plasma induced-damage because an unwanted scattering of radiation is caused by the spatial disorder of pattern and variation of surface roughness. The plasma-induced damages during plasma etching process can be classified as impurity contamination of residual etch products or bonding disruption in lattice due to charged particle bombardment. Therefor, fine pattern technology with low damaged etching process and high etch rate are urgently needed. Until now, there are a lot of reports on the etching of sapphire wafer with using $Cl_2$/Ar, $BCl_3$/Ar, HBr/Ar and so on [1]. However, the etch behavior of sapphire wafer have investigated with variation of only one parameter while other parameters are fixed. In this study, we investigated the effect of pressure and other parameters on the etch rate and the selectivity. We selected $BCl_3$ as an etch ant because $BCl_3$ plasmas are widely used in etching process of oxide materials. In plasma, the $BCl_3$ molecule can be dissociated into B radical, $B^+$ ion, Cl radical and $Cl^+$ ion. However, the $BCl_3$ molecule can be dissociated into B radical or $B^+$ ion easier than Cl radical or $Cl^+$ ion. First, we evaluated the etch behaviors of sapphire wafer in $BCl_3$/additive gases (Ar, $N_2,Cl_2$) gases. The behavior of etch rate of sapphire substrate was monitored as a function of additive gas ratio to $BCl_3$ based plasma, total flow rate, r.f. power, d.c. bias under different pressures of 5 mTorr, 10 mTorr, 20 mTorr and 30 mTorr. The etch rates of sapphire wafer, $SiO_2$ and PR were measured with using alpha step surface profiler. In order to understand the changes of radicals, volume density of Cl, B radical and BCl molecule were investigated with optical emission spectroscopy (OES). The chemical states of $Al_2O_3$ thin films were studied with energy dispersive X-ray (EDX) and depth profile anlysis of auger electron spectroscopy (AES). The enhancement of sapphire substrate can be explained by the reactive ion etching mechanism with the competition of the formation of volatile $AlCl_3$, $Al_2Cl_6$ or $BOCl_3$ and the sputter effect by energetic ions.

• Journal of the Korea Concrete Institute
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• v.25 no.1
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• pp.115-123
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• 2013

The steel industry, a representative industry that significantly consumes raw materials and energy, produces steel as well as a large amount of by-product steel slag through the production process. The vast habitat foundation of marine life has been destroyed due to recent reckless marine development and environment pollution, resulting in intensification of the decline of marine resources, and a solution to this issue is imperative. In order to propose a method to recycle large amounts of by-product slag into a material that can serve as an alternative to natural aggregate, the engineering properties and applicability for each mixing factor of environment friendly porous concrete as a material for the composition of marine ranches were evaluated in this study. The test results for percentage of voids per mixing ratio revealed that the margin of error for all conditions was within 2.5%. The compressive strength test results showed that the most outstanding environmental friendly porous concrete can be manufactured when mixing 30% slag aggregate and 10% specially treated granular fertilizer for the optimum volume fraction. As concrete for marine applications, the best seawater resistance was obtained with mixing conditions for high compression strength. An assessment of the ability to provide a marine life habitat foundation of environmentally friendly porous concrete showed that a greater percentage of voids facilitated implantation and inhabitation of marine life, and the mixing of specially treated granular fertilizer led to active initial implantation and activation of inhabitation. The evaluation of harmfulness to marine life depending on the mixture of slag aggregate and specially treated granular fertilizer revealed that the stability of fish is secured.

• Journal of Radiation Protection and Research
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• v.37 no.1
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• pp.41-49
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• 2012

The objective of this study is for development of the reference Korean female phantom, HDRK-Woman. The phantom was constructed by adjusting a Korean woman voxel phantom to the Reference Korean data. The Korean woman phantom had been developed based on the high-resolution color slice images obtained from an adult Korean female cadaver. There were a total of 39 organs including the 27 organs specified in ICRP 103 for effective dose calculation. The voxel resolution of the phantom was $1.976{\times}1.976{\times}2.0619\;mm^3$ and the voxel array size is $261{\times}109{\times}825$ in the x, y and z directions. Then, the voxel resolution was changed to $2.0351{\times}2.0351{\times}2.0747\;mm^3$ for adjustment of the height and total bone mass of the phantom to the Reference Korean data. Finally, the internal organs and tissue were adjusted using in-house software program developed for 3D volume adjustment of the organs and tissue. The effective dose values of HDRK phantoms were calculated for broad parallel photon beams using MCNPX Monte Carlo code and compared with those of ICRP phantoms.

• Journal of Aquaculture
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• v.11 no.1
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• pp.99-103
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• 1998

Artemia often observed as a co-existing organism in the mass culture tank of marine rotifer. The rotifer and Atremia are commonly used as food organisms in the marine fish larvae rearing. In this study, interspecific relation between the rotifer Brachionus rotundiformis (formely called S-type) and anostracan Artemia of the two developmental stages (0 and 19 day old after hatching) were investigated in the larboratory. The population growth of B. rotundiformis and one of the stage (nauplius or adult) of Artemia in mixed culture was compared with that of each single species culture. Culture period was 16 days. Every two days, the number of organisms in each species was counted and transferred to a fresh medium containing $7{\times}10^5$cells/ml of food Nannochloropsis oculata. Culture volume, temperature, salinity and photoperiod were set at 40ml, $25^{\circ}C.$, 22ppt and 24h all dark except to observation time, respectively. The rotifer population growth was greatly decreased by co-existence with Artemia. The coexisting Artemia suppressed the rotifer population growth due to it's high filtering speed for food (N. oculata). This study suggested that contamination by Artemia must be prevented for the stable rotifer production in the rotifer mass culture tank.

• Culinary science and hospitality research
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• v.19 no.4
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• pp.119-135
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• 2013

This study investigates waxy barley powder substituted for wheat flour in bread recipes with the amounts of 0%(control), 5%, 10%, 15% and 20%. Waxy barley powder consisted of 8.33% of moisture content, 10.47% of crude protein, 1.63% of crude fat, and 2.97% of crude ash. Sedimentation value and pelshenke value have decreased as the waxy barley powder content increased. The farinograph measurement result of the bread made with waxy barley powder showed that consistency, water absorption, development time, stability and time breakdown have increased as the waxy barley powder content increased. The amylograph measurement result of the bread made with waxy barley powder showed that T have increased as the waxy barley powder content increased. Their P, H and P-H have decreased as the ingredient contents increased. Baking loss and specific loaf volume have decreased as the waxy barley powder content increased. The chromaticity measurement result of the bread made with waxy barley powder showed no significant difference as the waxy barley powder content increased. The texture measurement result showed that the hardness and gumminess of bread have increased as the waxy barley powder content increased. Their cohesiveness, springiness and chewiness have decreased as the ingredient contents increased. Overall preference scores showed a high acceptability for the bread made with 10% waxy barley powder.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.4
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• pp.307-311
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• 2007

Purpose: The aim of this study was simply assessing linear measurements in the lateral and medial approach, respectively, for bone harvesting using anatomic and three-dimensional(3D) computed tomographic(CT) analyses on a dried cadaveric proximal tibia. In addition, the availability of the three-dimensional computed tomographic(3D-CT) analysis was also estimated. Materials and methods: Ten dried proximal tibia were obtained from five Korean cadavers. Four the reference points, the SM(superior-medial), IM(inferior-medial), SL(superior-lateral), and IL(inferior-lateral) were marked around the tibial tuberosity. The PM(posterior-medial) and PL(posterior-lateral) points were randomly marked at points farthest from the lateral and medial reference points, respectively, in the posterior border of the superior articular surface of both condyles. All measurements were obtained on the dried proximal tibia. After computed tomography had been performed, the three dimensional images were reconstructed using V works $4.0^{TM}$(Cybermed Inc., Seoul, Korea), and the length between the reference points were measured three dimensionally using the method described above. The error between the mean actual and mean 3D-CT measurements was calculated in order to determine the availability of the three dimensional computed tomographic analysis. Results: The length between the reference points was greatest at the IL-PM, which averaged $65.39mm{\pm}10.35$. This was followed by the SL-PM with $63.24mm{\pm}8.10$, the IM-PL with $58.09mm{\pm}10.02$, and the SM-PL with $51.99mm{\pm}9.06$. The differences between the IL-PM and SM-PL were 13.4 mm. The mean values were 55.04 mm in the medial approach and 64.32 mm in the lateral approach, and the differences between medial and lateral were 9.28 mm. The error between the mean actual and mean 3D-CT measurements was 0.31% and the standard deviation was 0.28%. Conclusion: The anatomical and three dimensional computed tomographic analysis indicates that there was only a 9.28 mm linear difference between the lateral and medial approach. This is consistent with previous studies, which showed that there was little difference between the two approaches in terms of the bone volume. In addition, the error(0.31%) and the standard deviation(0.28%) were considered low, demonstrating high accuracy of 3D-CT. Therefore it can be used in preoperative treatment planning.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.12
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• pp.1583-1588
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• 2007

PC-camera based automatic titration was executed in the acidity analyses of vinegar, milk and Takju. The average hue value (Havg) of 144 pixels in the image of the sample solution being titrated was computed and followed up at regular time intervals during titration in order to detect the titration end point. The Havg increase of 5 degrees from the first Havg was regarded as reaching at the end point in the cases of vinegar and milk. The Havg increase set up to detect the end point was 70 degrees in the case of Takju. In the case of vinegar, the volume of added titrant (0.1 N NaOH) was $21.409{\pm}0.066mL$ in manual titration and $21.403{\pm}0.055mL$ in automatic titration (p=0.841). In the case of milk, it was $1.390{\pm}0.025mL$ in manual titration and $1.388{\pm}0.027mL$ in automatic titration (p=0.907). In the case of Takju, it was $4.738{\pm}0.028mL$ in manual titration and $4.752{\pm}0.037mL$ in automatic titration (p=0.518). The high p values suggested that there were good agreements between manual and automatic titration data in all three food samples. The automatic method proposed in this article was considered to be applicable not only to acidity titrations but also to most titrations in which the end points can be detected by color change.

• Journal of Korean Society of Forest Science
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• v.99 no.1
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• pp.131-135
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• 2010

This study was carried out to establish a proper cultivation condition and diagnose the drought-tolerance of three wild edible greens belonging to genus of Ligularia by using pressure-volume curves methods. The result of the original bulk osmotic pressure at maximum turgor ${\Psi}_{\circ}{^{sat}}$ was -0.8 MPa in Ligularia fischeri and L. stenocephala, which was somewhat lower than the value, -0.7 MPa, in L. fischeri var. spiciformis. In addition, the values of the osmotic pressure at incipient plasmolysis ${\Psi}_{\circ}{^{tlp}}$ in L. fischeri and L. stenocephala, both of which were -0.9 MPa, These were slightly lower than that of -0.8 MPa in L. fischeri var. spiciformis. On the other hand, it appeared that the values of maximum bulk modulus of elasticity $E_{max}$ of L. fischeri and L. stenocephala were approximately two times higher than that of L. fischeri var. spiciformis. However, There was a distinct difference between the values of the relative water contents in these three species. Therefore, Ligularia spp, occurring incipient plasmolysis in the high water contents, have a relatively low property of drought-tolerance, suggesting that growth of those Ligularia spp. are appropriate for relative moisture forest.

• Journal of Korean Society for Geospatial Information Science
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• v.25 no.1
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• pp.47-54
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• 2017

Recently, there are many studies related aerial mapping project and 3 dimensional shape and model reconstruction using UAV(unmanned aerial vehicle) system and images. In this study, we create 3D reconstruction point data using image matching technology of the UAV overlap images, detect shape change of structure and perform accuracy assessment of area($m^2$) and volume($m^3$) value. First, we build the test structure model data and capturing its images of shape change Before and After. Second, for post-processing the Before dataset is convert the form of raster format image to ensure the compare with all 3D point clouds of the After dataset. The result shows high accuracy in the shape change of more than 30 centimeters, but less is still it becomes difficult to apply because of image matching technology has its own limits. But proposed methodology seems very useful to detect illegal any structures and the quantitative analysis of the structure's a certain amount of damage and management.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.5
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• pp.361-366
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• 2017

As the recent development of computing architecture and application software technology, real world simulation, which is the ultimate destination of computer simulation, is emerging as a practical issue in several research sectors. In this paper, metal plate motion in a square shock tube for small time interval was calculated using a supercomputing-based fluid-structure-combustion multi-physics simulation tool called Illinois Rocstar, developed in a US national R amp; D program at the University of Illinois. Afterwards, the simulation results were compared with those from experiments. The coupled solvers for unsteady compressible fluid dynamics and for structural analysis were based on the finite volume structured grid system and the large deformation linear elastic model, respectively. In addition, a strong correlation between calculation and experiment was shown, probably because of the predictor-corrector time-integration scheme framework. In the future, additional validation studies and code improvements for higher accuracy will be conducted to obtain a reliable open-source software research tool.