• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.5
• /
• pp.1102-1107
• /
• 2004

Fingerprint Recognition System is made up of Off-line treatment and On-line treatment; the one is registering all the information of there trieving features which are retrieved in the digitalized fingerprint getting out of the analog fingerprint through the fingerprint acquisition device and the other is the treatment making the decision whether the users are approved to be accessed to the system or not with matching them with the fingerprint features which are retrieved and database from the input fingerprint when the users are approaching the system to use. In matching between On-line and Off-line treatment, the most important thing is which features we are going to use as the standard. Therefore, we have been using “Delta” and “Core” as this standard until now, but there might have been some deficits not to exist in every person when we set them up as the standards. In order to handle the users who do not have those features, we are still using the matching method which enables us to make up of the spanning tree or the triangulation with the relations of the spanned feature. However, there are some overheads of the time on these methods and it is not sure whether they make the correct matching or not. Therefore, I would like to represent the more correct matching algorism in this paper which has not only better matching rate but also lower mismatching rate compared to the present matching algorism by selecting the line segment connecting two minutiae on the same ridge and furrow structures as the reference point.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.19 no.7
• /
• pp.771-777
• /
• 2008

In this paper, a frequency doubler using modified time-delay technique is proposed. A voltage controlled delay line (VCDL) in the proposed frequency doubler compensates the group delay time mismatching between input and delayed signal. With the group delay time matching and waveform shaping using the adjustable Schmitt triggers, the unwanted fundamental component($f_0$) and the higher order harmonics such as third and fourth are diminished excellently. In result, only the doubled frequency component($2f_0$) appears dominantly at the output port. The frequency doubler is designed at 1.15 GHz of $f_0$ and fabricated with TSMC $0.18\;{\mu}m$ CMOS process. The measured output power at $2f_0$ is 2.67 dBm when the input power is 0 dBm. The obtained suppression ratio of $f_0,\;3f_0$, and $4f_0$ to $2f_0$ are 43.65, 38.65 and 35.59 dB, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.26 no.1
• /
• pp.39-46
• /
• 2015

In this paper, a gas sensor using a modified $90^{\circ}$ hybrid coupler structure with conducting polymer which operates at 2.4 GHz is represented. Conducting polymers are used to the gas sensing material in proposed sensors. The conducting polymer varies its electrical property, such as work function and conductivity corresponding to the certain gas. To verify this variation of electrical property of conducting polymer at microwave frequencies, the conducting polymer is incorporated with the $90^{\circ}$ hybrid coupler structure, and this proposed sensor operates as reflection type variable attenuator and variable phase shifter. The conducting polymer is employed as impedence-variable transmission lines that cause a impedance mismatching between the general transmission line and conducting polymer. The experiment was conducted with 100 ppm ethanol gas at temperature of $28^{\circ}C$ and relative humidity of 85 %. As a result, the amplitude deviation of $S_{21}$ is 0.13 dB and the frequency satisfying ${\angle}S_{21}=360^{\circ}$ is shifted about 2.875 MHz.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.25 no.5
• /
• pp.502-508
• /
• 2015

Stereo images have an advantage of calculating depth(distance) values which can not analyze from 2-D images. However, depth information obtained by stereo images has due to following reasons: it can be obtained by computation process; mismatching occurs when stereo matching is processing in occlusion which has an effect on accuracy of calculating depth information. Also, if global method is used for stereo matching, it needs a lot of computation. Therefore, this paper proposes the method obtaining disparity map which can reduce computation time and has higher accuracy than established method. Edge extraction which is image segmentation based on feature is used for improving accuracy and reducing computation time. Color K-Means method which is image segmentation based on color estimates correlation of objects in an image. And it extracts region of interest for applying Loopy Belief Propagation(LBP). For this, disparity map can be compensated by considering correlation of objects in the image. And it can reduce computation time because of calculating region of interest not all pixels. As a result, disparity map has more accurate and the proposed method reduces computation time.

• Journal of Technologic Dentistry
• /
• v.33 no.1
• /
• pp.37-45
• /
• 2011

Purpose: Heat pressed ceramics, used for all ceramic restorations, have the additional advantage of being technically less change through using of the lost-wax technique. Conceptually, combining the ceramic with the clinically proven reinforcing ability of a metal framework would be advantageous; however, cause of mismatching of fusion between ceramics and metal frameworks which from differences of casting temperature and coefficient of thermal expansion, pressed ceramics could not be used with a metal framework. The purpose of this study was to compare shear bond strength of press-to metal ceramic to porcelain fused non precious metal and feldspatic porcelain fused non precious metal. Methods: The 30 metal specimens were casted in a porcelain fused non precious metal nickel-chromium alloy. They were divided into 3 groups by surface treatment and applied ceramic: $125{\mu}m$ aluminium oxide sandblasting and veneered feldspatic porcelain (group FP), $125{\mu}m$ aluminium oxide sandblasting and had press-to-metal ceramic applied (group PC), porcelain bonder (gold bonder) fused on surface of metal specimens and had press-to-metal ceramic applied (group PCG). In each group 10 metal specimens were used. The press-to-metal ceramic applied 20 specimens had ash-free wax pattern applied, the metal-wax complexes invested, and were pressed with heat press ceramic. All specimens were subjected to shear bond strength test at a crosshead speed of 1.0 mm/min. Results: The results of measured in Mean SD and data were analyzed by one-way AVOVA (p= .05) and Tukey HSD test (p= .05).: group FP $16.090{\pm}1.841$ MPa, group PC $12.620{\pm}1.8256$ MPa, group PCG $10.920{\pm}0.9283$, significant differences between all groups (p < .05). Significant differences were found in each between group FP and group PC, group FP and group PCG (p < .05). Conclusion: The shear bond strength of press-to-metal ceramic to porcelain fused non precious metal was described higher in unused gold bonder group than used gold bonder groups.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.05a
• /
• pp.487-489
• /
• 2016

In this paper, quad copter provides a method for preventing the possibility of accident in the air during a formation flight. The existing studies had a few studies upon the falls because quad copter formation flight was generally implemented indoors. Therefore, in this paper, we provide a self-diagnosis system to prevent a secondary accident for mismatching the Proportional-Integral-Derivative(PID) and detecting an abnormal communication modules each others in formation flying system. Scheme to be proposed, a system is that when one of the node meets a problem, the header node is sending the information of the current state to the server in the first and making a diagnosis itself in order to avoid the problems caused by dropping from the air. Therefore, if the difference between PID value of header node and slave node is greater than specified values or if it detects a defective sensors and communication modules, the proposed system is set to provide for moving toward a safe place. As a result, we expect that this proposed system is possible to minimize additional incidents by self adjusting the height through a self-diagnosis discovering flawed the acceleration sensor, gyro sensor and various attached sensors.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.54 no.2
• /
• pp.92-98
• /
• 2017

Generally, image contains geometrical and radiometric errors. Census transform can solve the stereo mismatching problem caused by the radiometric distortion. Since the general census transform compares center of window pixel value with neighbor pixel value, it is hard to obtain an accurate matching result when the difference of pixel value is not large. To solve that problem, we propose a census transform method that applies different 4-step weight for each pixel value difference by applying an assistance window inside the window kernel. If the current pixel value is larger than the average of assistance window pixel value, a high weight value is given. Otherwise, a low weight value is assigned to perform a differential census transform. After generating an initial disparity map using a weighted census transform and input images, the gradient information is additionally used to model a cost function for generating a final disparity map. In order to find an optimal cost value, we use guided filtering. Since the filtering is performed using the input image and the disparity image, the object boundary region can be preserved. From the experimental results, we confirm that the performance of the proposed stereo matching method is improved compare to the conventional method.

• Journal of the Korean institute of surface engineering
• /
• v.49 no.3
• /
• pp.316-321
• /
• 2016

To study emission characteristics for dual-emission tandem organic light emitting display (OLED), we fabricated blue fluorescent OLED according to thickness variation of $MoO_x$ as charge generation layer and Al as cathode. The bottom emission characteristics of OLED with $MoO_x$ 2, 3, 5 nm thickness showed threshold voltage of 9, 7, 9 V, maximum current emission efficiency of 19.32, 23.18, 15.44 cd/A and luminance of $1,000cd/m^2$ at applied voltage of 17.6, 13.2, 16.5 V, respectively. The top emission characteristics of OLED with $MoO_x$ 2, 3, 5 nm thickness indicated threshold voltage of 13, 10, 13 V, maximum current emission efficiency of 0.17, 0.23, 0.16 cd/A and luminance of $50cd/m^2$ at applied voltage of 22.6, 16.5, 20.1 V, respectively. In case of thicker or thinner than $MoO_x$ of 3 nm, the emission characteristics were decreased because of mismatching of electron and hole in emission layer. The bottom emission characteristics of OLED with Al 15, 20, 25 nm thickness showed threshold voltage of 8, 8, 7 V, maximum current emission efficiency of 18.42, 22.98, 23.18 cd/A and luminance of $1000cd/m^2$ at applied voltage of 16.2, 13.9, 13.2 V, respectively. The reduction of threshold voltage and increase of maximum current emission efficiency are caused by the increase of current injection according to increase of Al cathode thickness. The top emission characteristics of OLED with Al 15, 20, 25 nm thickness indicated threshold voltage of 7, 7, 8 V, maximum emission luminance of 371, 211, $170cd/m^2$, respectively. The top emission OLED of Al cathode with 15 nm thickness showed maximum luminance and it decreased at thickness of 20 nm. These phenomena are caused by the decrease of intensity of emitted light by reduction of optical transmittance according to increase of Al cathode thickness.

• Journal of Veterinary Science
• /
• v.22 no.5
• /
• pp.63.1-63.14
• /
• 2021

Background: Recently, mesenchymal stem cells therapy has been performed in dogs, although the outcome is not always favorable. Objectives: To investigate the therapeutic efficacy of mesenchymal stem cells (MSCs) using dog leukocyte antigen (DLA) matching between the donor and recipient in vitro. Methods: Canine adipose-derived MSCs (cA-MSCs) isolated from the subcutaneous tissue of Dog 1 underwent characterization. For major DLA genotyping (DQA1, DQB1, and DRB1), peripheral blood mononuclear cells (PBMCs) from two dogs (Dogs 1 and 2) were analyzed by direct sequencing of polymerase chain reaction (PCR) products. The cA-MSCs were co-cultured at a 1:10 ratio with activated PBMCs (DLA matching or mismatching) for 3 days and analyzed for immunosuppressive (IDO, PTGS2, and PTGES), inflammatory (IL6 and IL10), and apoptotic genes (CASP8, BAX, TP53, and BCL2) by quantitative real-time reverse transcriptase-PCR. Results: cA-MSCs were expressed cell surface markers such as CD90⁺/44⁺/29⁺/45^- and differentiated into osteocytes, chondrocytes, and adipocytes in vitro. According to the Immuno Polymorphism Database, DLA genotyping comparisons of Dogs 1 and 2 revealed complete differences in genes DQA1, DQB1, and DRB1. In the co-culturing of cA-MSCs and PBMCs, DLA mismatch between the two cell types induced a significant increase in the expression of immunosuppressive (IDO/PTGS2) and apoptotic (CASP8/BAX) genes. Conclusions: The administration of cA-MSCs matching the recipient DLA type can alleviate the need to regulate excessive immunosuppressive responses associated with genes, such as IDO and PTGES. Furthermore, easy and reliable DLA genotyping technology is required because of the high degree of genetic polymorphisms of DQA1, DQB1, and DRB1 and the low readability of DLA 88.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.6
• /
• pp.14-18
• /
• 2019

The conductivity of a semiconductor is primarily determined by the carriers. To achieve higher conductivity, the number of carriers should be high, and an energy trap level is created so that the carriers can cross the forbidden zone with low energy. Carriers have a crystalline binding structure, and interfacial mismatching tends to make them less conductive. In general, high-concentration doping is typically used to increase mobility. However, higher conductivity is also observed in non-orthogonal conjugation structures. In this study, the phenomena of higher conductivity and higher mobility were observed with space charge limiting current due to tunneling phenomena, which are different from trapping phenomena. In an atypical structure, the number of carriers is low, the resistance is high, and the on/off characteristics of capacitances are improved, thus increasing the mobility. ZTO thin film improved the on/off characteristics of capacitances after heat treating at $150^{\circ}C$. In charging and discharging tests, there was a time difference in the charge and discharging shapes, there was no distinction between n and p type, and the bonding structure was amorphous, such as in the depletion layer. The amorphous bonding structure can be seen as a potential barrier, which is also a source of space charge limiting current and causes conduction as a result of tunneling. Thus, increased mobility was observed in the non-structured configuration, and the conductivity increased despite the reduction of carriers.