• Investigative Magnetic Resonance Imaging
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• v.4 no.2
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• pp.128-135
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• 2000

Purpose : The aim of this study is to develope the Magnetic Resonance Spectroscopy(MRS) data processing S/W which plays an important role as a diagnostic tool in clinical field. Materials and methods : Post-processing software of MRS based on graphical user interface(GUI) under windows operating system of personal computer(PC) was developed using MATLAB(Mathwork, U.S.A.). This tool contains many functions to increase the quality of spectrum data such as DC correction, zero filling, line broadening, Gauss-Lorentzian filtering, phase correction, etc. And we obtained the normal human brain $^1H$ MRS data from parietal white matter, basal ganglia and occipital grey matter region using 1.5T Gyroscan ACS-NT R6 (philips, Amsterdam, Netherland) MRS package. The analysis of the MRS peaks were performed by obtaining the ratio of peak area. Results : The peak ratios of NAA/Cr, Cho/Cr, MI/Cr for the different MRS machines have a little different values. But these peak ratios were not significantly different between different echo time MRS peak ratios in the same machine (p<0.05). Conclusion : MRS post-processing S/W based on GUI using PC was developed and applied to the analysis of normal human brain $^1H$ MRS. This independent MRS processing job increases the performance and throughput of patient scan of main console. Finally, we suggest that the database for normal in-yivo human MRS data should be obtained before clinical applications.

• Journal of Veterinary Clinics
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• v.11 no.2
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• pp.529-537
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• 1994

Sector scanner which has a conical end is used to image through the intercostal space because heart is protected by the ribs. Cardiac data published all around the world were also obtained by sector scanner. Although scanners being used in every small animal practice and animal hospital at college in Korea include convex ape and linear type, linear type is not appropriate f3r cardiac scan because of a wide contact surface. The purpose of this study is to establish ultrasonographic images of normal cardiac structures by measuring shape, size of reflectable cardiac structure according to restraint position in scanning normal heart of the puppies with 6.5 MHz convex scanner(SonoAce 4500, Medison, Korea) used in our veterinary teaching hospital, Seoul national university. Seventeen male and female puppies considered having healthy hear by X-ray and clinical examination are used feom April to July 1994. Scanning point selection of probe head and the distinction of imaged cardiac structures were accomplished by necropsy and cardiac scanning performed through thoracotomy under general anesthesia. At 10 o'clock position of transducer(at an angle of 30$^{\circ}$ between imaginary line from elbow joint to 3rd sternum and probe head, 60$^{\circ}$ from body surface, 4th intercostal space of right thorax) with the marker of scanner toward the head of dogs right atrium, left atrium and left ventricle were observed in 2, 3, 4, 5 intercostal space(2cm from the sternum) of experimental dog positioned ventrodorsally under general anesthesia. Under these conditions, the numerical values of imaged diastolic hear are as follows : the distance from skin to apex(mean$\pm$S.D) 47.53$\pm$6.94mm, thickness of left ventricular wall 6.00$\pm$1.60mm, length of left ventricle 16.27$\pm$5.31mm, width of left ventricle 15,33$\pm$4.25mm, length of left atrium 12.33$\pm$3.82mm, width of left atrium 11. 33$\pm$3.94mm, length of right atrium 1.00$\pm$2.41mm, width of right atrium 11.21$\pm$2.76mm and the area of left ventricle 270.92$\pm$109.81mm$^2$, area of left atrium 98.00$\pm$41.08mm$^2$, area of right atrium 62.75$\pm$21.04mm$^2$.

• Korean Journal of Remote Sensing
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• v.31 no.2
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• pp.85-99
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• 2015

TDI CCD sensors are being used for most of the electro-optical camera mounted on the low earth orbit satellite to meet high performance requirements such as SNR and MTF. However, the CMOS sensors which have a lot of implementation advantages over the CCD, are being upgraded to have the TDI function. A few methods for improving the issue of motion blur which is apparent in the CMOS sensor than the CCD sensor, are being introduced. Each pixel can be divided into a few sub-pixels to be read more than once as is the same case with three or four phased CCDs. The fill factor can be reduced intentionally or even a kind of mask can also be implemented at the edge of pixels to reduce the blur. The motion blur can also be reduced in the TDI CMOS sensor by reducing the integration time from the full line scan time. Because the integration time can be controlled easily by the versatile control electronics, one of two performance parameters, MTF and SNR, can be concentrated dynamically depending on the aim of target imaging. MATLAB simulation has been performed and the results are presented in this paper. The goal of the simulation is to compare dynamic MTFs affected by the different methods for reducing the motion blur in the TDI CMOS sensor.

• Journal of the Korean Wood Science and Technology
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• v.37 no.1
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• pp.37-47
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• 2009

For the inspection of wood, machine vision is the most common automated inspection method used at present. It is required to sort wood products by grade and to locate surface defects prior to cut-up. Many different sensing methods have been applied to inspection of wood including optical, ultrasonic, X-ray sensing in the wood industry. Nowadays the scanning system mainly employs CCD line-scan camera to meet the needs of accurate detection of lumber defects and real-time image processing. But this system needs exact feeding system and low deviation of lumber thickness. In this study low cost CCD area sensor was used for the development of image processing system for lumber being fed. When domestic red pine being fed on the conveyer belt, lumber images of irregular term of captured area were acquired because belt conveyor slipped between belt and roller. To overcome incorrect image merging by the unstable feeding speed of belt conveyor, it was applied template matching algorithm which was a measure of the similarity between the pattern of current image and the next one. Feeding the lumber over 13.8 m/min, general area sensor generates unreadable image pattern by the motion blur. The red channel of RGB filter showed a good performance for removing background of the green conveyor belt from merged image. Threshold value reduction method that was a image-based thresholding algorithm performed well for knot detection.

• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.295-304
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• 2001

Characterization of quantitative trait loci (QTL) was investigated in the experimental crosses between Berkshire and Yorkshire breed. A total of 525 F$_2$ progenies from 65 matting of F$_1$ Parents were produced. Phenotypic measurements included average daily gain (ADG), average back fat thickness (ABF), and loin eye area (LEA). To identify the presence of QTL for reproductive performance, birth weight (BWT) and body weight at 16 days (16DAY) were included as indirect trait. QTL segregation was deduced using 8 markers assigned to chromosome 2 (SSC2). Quantitative trait locus analyses were performed using interval mapping by regression under line-cross model. Presence of imprinting was tested under the statistical model that separated the expression of paternally and maternally inherited alleles. To set the evidence of QTL presence, significance thresholds were derived by permutation following statistical tests, respectively. Genome scan revealed significant evidence for three quantitative trait loci (QTL) affecting growth and body compositions, of which two were identified to be QTL with imprinting expression mode near the ICF II gene region. For average back fat thickness (ABF), a paternally expressed QTL was found on chromosome 2 (SSC2). A paternally expressed QTL affecting loin eye area (LEA) was found in the region of SSC2 where evidence of imprinted QTL was found for average back fat thickness (ABF). For average daily gain (ADG), QTL expressed with Mendelian mode was found on chromosome 2 (SS2). Also, QTL affecting average daily gain (ADC), was identified to be expressed with Mendelian express mode.

• Korean Journal of Optics and Photonics
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• v.16 no.3
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• pp.287-294
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• 2005

In this paper, an optical true time-delay (TTD) for two-dimensional (2-D) phased array antennas (PAAs), composed of a multi-wavelength optical source and a fiber optic delay line matrix consisting of $2\times2$ optical switches with optical fiber connected between cross ports, has been proposed. A 2-bit $\times4-bit$ optical TTD for 10-GHz 2-D PAAs has been implemented by cascading a wavelength dependent TTD (WD-TTD) and a wavelength independent TTD (WI-TTD). The unit time delay for WD-TTD and WI-TTD have been chosen as ${\Delta}T=12ps$ and $\Delta\tau=6ps$, respectively. Time delay have been measured at all radiation angles. The maximum delay error for WD-TTD was measured to be 3 ps due to jitter incurred from gain switching. For the case of WI-TTD, error was within ${\pm}\;1\;ps$. The proposed optical TTD for a 2-D PAA has the following advantages: 1) higher gain compared to one-dimensional linear PAAs, 2) stabilization of optical power and wavelength by using a multi-wavelength optical source, and 3) fast beam scan and simple operation due to electronic control of the $2\times2$ optical switches matrix on a column-by-column basis.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.1
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• pp.9-18
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• 2004

This paper presents an efficient image compression method for memory reduction in multimedia processor which can be simply implemented in hardware and provides high performance. The multimedia processor, which includes processing of high-resolution images and videos, requires large memories: they are external frame memories to store frames and internal line memories for implementing some linear filters. If we can reduce those memories by adopting a simple compression method in multimedia processor, it will strengthen its cost competitiveness. There exist many standards for efficiently compressing images and videos. However, those standards are too complex for our purpose and most of them are 2-D block-based methods, which do not support raster scanned input and output. In this paper, we propose a low-complexity compression method which has good performance, can be implemented with simple hardware logic, and supports raster scan. We have adopted 1${\times}$8 Hadamard transform for simple implementation in hardware and compression efficiency. After analyzing the coefficients, we applied an adaptive thresholding and quantization. We provide some simulation results to analyze its performance and compare with the existing methods. We also provide its hardware implementation results and discuss about cost reduction effects when applied in implementing a multimedia processor.

• Journal of the Korean Magnetics Society
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• v.13 no.4
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• pp.155-159
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• 2003

We report on the annealing effect and ferromagnetic characteristics of Zn$_{0.7}$Mn$_{0.3}$O film prepared by sol-gel method on the silicon (100) substrate using field emission-scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), X-ray diffractometry (XRD) and superconducting quantum interference device (SQUID) magnetometry. Magnetic measurements show thatZn$_{0.7}$Mn$_{0.3}$O films exhibit ferromagnetism at 5 K revealing the coercive field of ∼110 Oe for as grown sample and 360, 1035 Oe for samples annealed at 700, 800 $^{\circ}C$, respectively. Our experimental evidence suggests that ferromagnetic precipitates of a manganese oxide may be responsible for the observed ferromagnetic behaviors of the film.he film.

• The Journal of Engineering Geology
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• v.24 no.1
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• pp.39-52
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• 2014

Limestone caves that consist of main passages and branches are formed by a variety of processes, and have the characteristic of developing with a preferred orientation controlled by discontinuities such as bedding, joints, and faults around the cave. However, it is difficult to analyze a representative orientation from various orientations. To interpret the overall development orientation of limestone caves, this study proposes new development orientation analysis methods, termed the Average Span Ratio Method (ASRM) and the Individual Development Ratio Method (IDRM), using the weighting of persistence. Nine limestone caves in Korea were randomly selected for testing the new methods. The methods show a stronger development orientation for limestone caves than that obtained by traditional methods, which consider only the distribution of development orientations. Based on an analysis of the relationship between the average span and the dip angle of bedding, it is confirmed that shallowly dipping bedding is a major contributor to the expansion of span in limestone caves. In addition, using scan-line survey data acquired in the field, we perform an RMR analysis of stability of the ground around limestone caves.

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.481-484
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• 2010

Purpose: Congenital dermoid cysts develop during the fusion of the embryo when the ectodermal tissue gets trapped in the line of fusion. Dermoid cysts of the head are rare lesions comprised of epidermal and mesodermal elements. Furthermore, dermoid cysts in the occipital area are extremely rare. Only a few cases of dermoid cysts in the posterior scalp have been reported. Especially, A bilateral, synchronous presentation in this location has not been reported previously in the literature. Methods: All 5 cases had a gradually enlarging mass of the posterior aspect of the scalp. The cysts were mobile, noncompressible, and non-tender, without evidence of an associated sinus tract, skin dimpling, discoloration, or communication with adjacent structures. The CT scan displayed a hypodense cystic lesions about -87 to +24 HU (Housefield units, average +3.2 HU) with hypodense capsule and no postcontrast enhancement. All tumors were found just under the skin, and were well encapsulated, so they were completely removed the mass with adjacent periosteum. Results: On gross findings, all tumors were oval-or round-shaped, and when the cystic tumor was cut open it presented a greasy and caseous substance. Histologically, all specimens contain desquamated squamous epithelium and keratin in the lumen and are encapsulated and lined by keratinized stratified squamous epithelium. And, all cases of posterior mass are the presence of adnexal structures. Conclusion: Appropriate diagnosis requires not only an index of suspicion for this rare tumor a very careful history and search for skin changes. Especially, CT can reveal the exact location of the cyst, its relationship with the adjacent structures. We think that occipital dermoids divide into superficial and deep type. In our cases, because they did not have intra-cranial involvement or fistula formation, they are superficial type. This report describes the clinical and operative aspects of the superficial dermoid cysts and provides a review of the literatures.