• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.4
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• pp.161-164
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• 2006

In this thesis we designed the vision system to inspect the defect of a back light unit of plat panel display device. The vision system is divided into hardware and inspection algorithm of defect. Hardware components consist of illumination part, robot-arm controller part and image-acquisition part. Illumination part is made of acrylic panel for light diffusion and five 36W FPL's(Fluorescent Parallel Lamp) and electronic ballast with low frequency harmonics. The CCD(Charge-Coupled Device) camera of image-acquisition part is able to acquire the bright image by the light coming from lamp. The image-acquisition part is composed of CCD camera and frame grabber. The robot-arm controller part has a role to let the CCD camera move to the desired position. To take inspections of surface images of a flat panel display it can be controlled and located every nook and comer. Images obtained by robot-arm and image-acquisition board are saved on the hard-disk through windows programming and are tested whether there are defects by using the image processing algorithms.

• Conservation Science in Museum
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• v.12
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• pp.71-76
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• 2011

This study examined characteristics and structure of earthen Janggu that were excavated from Jeollabuk-do and other regions, and it described conservation process of earthen Janggu that were excavated from Samsanyujeok Jeonju. Earthen Janggu that were excavated from Samsanyujeok were destroyed and lost by more than one third, and they were thought to make use of them at living lives. We take an x-ray of center of the Janggu for inspect production technique and, destroyed area of the Janggu was recovered by making recovery frame made by plaster and using epoxy series CDK-520. After recovery, acrylic paint was used to do color matching and to get rid of sense of difference of the area that was recovered and remained.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.6
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• pp.555-562
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• 2019

This paper presents soil deformation measurement in model chamber based on photogrammetry. We created an aluminum framed acrylic model chamber with soil inside and applied photogrammetry to measure soil deformation caused by loading tests. The soil consists of 40% black and 60% regular sand to create image contrast in soil images. In preprocessing, the self camera calibration was carried out for IOPs (Interior Orientation Parameters), followed by the space resection to estimate EOPs (Exterior Orientation Parameters) using control points located along the aluminum frame. Image matching was applied to measure the soil displacement. We tested different matching window sizes and the effect of image smoothing. Experimental results showed that 65x65 pixels of window size produced better soil deformation map and the image smoothing was useful to suppress the matching outliers. In conclusion, photogrammetry was able to efficiently generated soil deformation map.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.354-354
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• 2009

We have developed the prototypes of superconducting magnetic separation system with high temperature superconductor wire. This separation filter system consist of magnetized matrix SUS430 wire and acrylic frame. This study introduced rolled steel process coolant wastewater applied superconductor HGMS(High Gradient Magnetic Separation). HGMS treatment have acted high efficient method for various wastewater. We have surveyed superconducting magnetic separation technology and reviewed the status of related industries using applied superconductivity. In our basic preliminary experiment using HGMS, it was made clear that the fine para-magnetic particles in the wastewater obtained from rolling process of steel can be separated with high efficiency. We investigated the ability of magnetic flock formation, which used inorganic materials and polymer coagulants. We had a purpose to remove SS of coolant at steel factory. Maximum coagulation remove rate of SS 98%. Removing ratio of $Fe_3O_4$ fine particles in wastewater showed over than 99% in the wastewater containing magnetic fines after four times of repetition of separation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.2
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• pp.173-180
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• 2013

In this paper, we studied on measurement of soil deformation around the tip of model pile by close-range photogrammetry. The rigorous bundle adjustment method was utilized to monitor the soil deformation in the laboratory model pile-load test as function of incremental penetration of the pile. Control points were installed on the frame of the laboratory model box case and more than 150 target points were inserted inside the soil around the model pile and on the surface. Four overlapping images including three horizontal and one vertical image were acquired by a non-metric camera for each penetration step. The images were processed to automatically locate the control and target points in the images for the self-calibration and the bundle adjustment. During the bundle adjustment, the refraction index of the acrylic case of the laboratory model was accounted for accurate measurement. The experiment showed the proposed approach enabled the automated photogrammetric monitoring of soil deformation around the tip of model pile.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.12
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• pp.921-925
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• 2015

The number of people suffering from renal disease increases every year. One of the most common treatments (clinical care options) for renal diseases is hemodialysis. However it takes a long time and has a high cost. Therefore, the importance of artificial kidney research has risen. Filtering creatinine from blood is one of the prime renal functions. Thus, we designed a novel two channel microfluidic chip focused on that function. In order to bond the individual polydimethylsiloxane layers, we have developed a housing system using acrylic plastic frame. This method has significant advantages in changing filter membranes. We use anodic aluminum oxide for the filter membrane. We analyzed the difference in the absorbance values for various creatinine concentrations using the Jaffe reaction. For the purpose of acquiring a standard equation to quantify the creatinine concentration, we interpolated the measured data and confirmed the concentration of the filtered solution. Through this experiment, we determined how the filtration efficiency depended on the flow rate and creatinine concentration.

• Journal of People, Plants, and Environment
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• v.24 no.6
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• pp.595-608
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• 2021

Background and objective: For effective horticultural education, it is required to develop kits for practice. In this study, we developed a horticultural kit for germination that introduces storytelling, characterization, and assembly, and investigated the educational effects of using it to study its educational differentiation and usefulness. Methods: First, we developed a seed germination kit for learning. It consists of three components: the kit main frame for hydroponics, the activity sheet for storytelling, and the instruction manual. It is made into an acrylic assembly in consideration of the ease of delivery for contactless learning. Second, we developed two programs, each using a germination kit for horticultural education (experimental group) and a general germination kit program (control group). At this time, the class consists of pre-questionnaire, the 1st and 2nd classes, observation log writing (total six times for two weeks), the 3rd class, and post-questionnaire. The experimental group and control group were separately executed. Third, the application results were compared and analyzed before and after class. As a quantification questionnaire, the effects before and after class were compared through t-test with a questionnaire on program satisfaction and attitude change toward plants. The quantitative results were analyzed through observation activity sheets and effects before and after the class were analyzed through t-test with quantification and language coding. Results: The effect of horticulture education using the developed kit was estimated by a quantification questionnaire. Both the program satisfaction and the change in attitude toward plants showed high in the experimental group, and this difference was statistically significant (p < .05). As a result of analyzing the observation paper with a qualitative questionnaire, various cognitive and affective expressions appeared in the experimental group as well as the contents of the observation paper. The number of syllables and various qualitative expressions appeared, and these differences were also statistically significant (p < .05). Conclusion: Compared to general germination activities, it was found that the germination activities using storytelling-based horticultural kits would be effective for contactless classes in the post-COVID-19 era and in increasing the educational effect of horticultural activities.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.5
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• pp.611-621
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• 2005

State of problem: Zirconia all-ceramic restoration fabricated with CAM system is on an increasing trend in dentistry. However, evaluation of the marginal and internal fits of zirconia bridge seldomly have been reported. Purpose: This study was to evaluate the at of margin and internal surface in posterior 3-unit zirconia bridge framework fabricated with CAM system(DeguDent, Germany). Material and Method: Preparations of secondary premolar and secondary molar on artificial resin model were performed for fabrication of 3-unit posterior bridge framework. Fits of 5 zirconia bridge framework were compared with 5 precious ceramo-metal alloy framework(V-GnathosPlus, Metalor, Switzerland), and prepared margins were designed to chamfer and shoulder finishing line. Each framework was cemented to epoxy resin model with reinforced glass ionomer(FujiCEM, GC Co., Japan), embedded in acrylic resin and sectioned in two planes, mesio-distal and buccolingual. Samples were divided into six pieces by sectioning and had two pieces of each surface(i.e mesial, distal, buccal and lingual surface) per abutment, so there were eight measuring points in each abutment. External gap was measured at the margin and internal gaps were measured at the margin, axial and occlusal surface. Gaps were observed under the measuring microscope(Compact measuring microscope STM5; Olympus, Japan) at a magnification of $\times100$. T-test were used to determine the statistic significance of the different gaps between zirconia and metal framework. Results and Conclusion: 1. External and internal marginal gaps of zirconia and metal framework were in clinically acceptable range. External marginal gaps were not different significantly between zirconia$(81.9{\mu}m)$ and metal $(81.3{\mu}m)$ framework and internal marginal gaps of zirconia $(44.6{\mu}m)$ were smaller than those of metal framework $(58.6{\mu}m)$. 2. Internal axial gaps of zirconia framework$(96.7{\mu}m)$ were larger than those of metal frame-work$(78.1{\mu}m)$ significantly and adversely, internal occlusal gaps of zirconia frame-work$(89.4{\mu}m)$ were smaller than those of metal framework $(104.9{\mu}m)$ significantly. 3. There were no significant differences in external and internal marginal gaps between chamfer and shoulder finish line when zirconia frameworks were fabricated.

• Journal of Korean Neurosurgical Society
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• v.62 no.4
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• pp.476-486
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• 2019

Objective : The functional information of $^{11}C$-methionine positron emission tomography (MET-PET) images can be applied for Gamma knife radiosurgery (GKR) and its image quality may affect defining the tumor. This study conducted the phantom-based evaluation for geometric accuracy and functional characteristic of diagnostic MET-PET image co-registered with stereotactic image in Leksell $GammaPlan^{(R)}$ (LGP) and also investigated clinical application of these images in metastatic brain tumors. Methods : Two types of cylindrical acrylic phantoms fabricated in-house were used for this study : the phantom with an array-shaped axial rod insert and the phantom with different sized tube indicators. The phantoms were mounted on the stereotactic frame and scanned using computed tomography (CT), magnetic resonance imaging (MRI), and PET system. Three-dimensional coordinate values on co-registered MET-PET images were compared with those on stereotactic CT image in LGP. MET uptake values of different sized indicators inside phantom were evaluated. We also evaluated the CT and MRI co-registered stereotactic MET-PET images with MR-enhancing volume and PET-metabolic tumor volume (MTV) in 14 metastatic brain tumors. Results : Imaging distortion of MET-PET was maintained stable at less than approximately 3% on mean value. There was no statistical difference in the geometric accuracy according to co-registered reference stereotactic images. In functional characteristic study for MET-PET image, the indicator on the lateral side of the phantom exhibited higher uptake than that on the medial side. This effect decreased as the size of the object increased. In 14 metastatic tumors, the median matching percentage between MR-enhancing volume and PET-MTV was 36.8% on PET/MR fusion images and 39.9% on PET/CT fusion images. Conclusion : The geometric accuracy of the diagnostic MET-PET co-registered with stereotactic MR in LGP is acceptable on phantom-based study. However, the MET-PET images could the limitations in providing exact stereotactic information in clinical study.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.5
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• pp.401-409
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• 2008

Purpose: Recently multi-modal imaging system has become widely adopted in molecular imaging. We tried to fabricate animal-specific positioning molds for PET/MR fusion imaging using easily available molding clay and rapid foam. The animal-specific positioning molds provide immobilization and reproducible positioning of small animal. Herein, we have compared fiber-based molding clay with rapid foam in fabricating the molds of experimental animal. Materials and Methods: The round bottomed-acrylic frame, which fitted into microPET gantry, was prepared at first. The experimental mice was anesthetized and placed on the mold for positioning. Rapid foam and fiber-based clay were used to fabricate the mold. In case of both rapid foam and the clay, the experimental animal needs to be pushed down smoothly into the mold for positioning. However, after the mouse was removed, the fabricated clay needed to be dried completely at $60^{\circ}C$ in oven overnight for hardening. Four sealed pipet tips containing $[^{18}F]FDG$ solution were used as fiduciary markers. After injection of $[^{18}F]FDG$ via tail vein, microPET scanning was performed. Successively, MRI scanning was followed in the same animal. Results: Animal-specific positioning molds were fabricated using rapid foam and fiber-based molding clay for multimodality imaging. Functional and anatomical images were obtained with microPET and MRI, respectively. The fused PET/MR images were obtained using freely available AMIDE program. Conclusion: Animal-specific molds were successfully prepared using easily available rapid foam, molding clay and disposable pipet tips. Thanks to animal-specific molds, fusion images of PET and MR were co-registered with negligible misalignment.