• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.324-327
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• 2002

For a next generation PET that realizes high sensitivity and high resolution, we proposed a design of a depth of interaction detector. A unit of the detector is constructed of four stages rectangular blocks of 2 by 2 Gd$_2$SiO$\sub$5/: Ce (GSO) crystal array optically coupled to position sensitive photomultiplier tube (PS-PMT). The 256ch flat panel PS-PMT is under development by Hamamatsu Photonics K.K., JAPAN. It has large cathode area, 51.7 by 51.7 mm$^2$, and the ratio of the effective area to external size is about 90%. The feature will contribute high packing fraction, accordingly high sensitivity. The 256 anodes are arranged in 16 by 16 at intervals of 3.0 mm. So as to evaluate the detector capability for identifying crystal of interaction, we got positioning image histograms with coupling a 16 by 5 array of GSO crystals, 2.9 by 2.9 by 7.5 mm$^3$, to the PS-PMT by irradiating a gamma ray uniformly from a point source. Flat panel PS-PMT is a new promising device for PET. We need to evaluate it if its performance is sufficiency. The performance was compared to the one with a 16ch PS-PMT.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권2호
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• pp.312-317
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• 2015

In this paper, the RF characteristics of multi-finger MOSFETs were improved by decreasing the parasitic capacitance in spite of increased gate resistance in a 90-nm CMOS technology. Two types of device structures were designed to compare the parasitic capacitance in the gate-to-source ($C_{gs}$) and gate-to-drain ($C_{gd}$) configurations. The radio frequency (RF) performance of multi-finger MOSFETs, such as cut-off frequency ($f_T$) and maximum-oscillation frequency ($f_{max}$) improved by approximately 10% by reducing the parasitic capacitance about 8.2% while maintaining the DC performance.

• BMB Reports
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• 제34권4호
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• pp.371-378
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• 2001

The Glycoprotein D (gD) gene of the HSV-1 strain F was cloned, sequenced, recombinated into the HcNPV (Hyphantria cunea nuclear polyhedrosis virus) expression vector and expressed in insect cells. The gD gene was located in the 6.43 kb BamHI fragment of the strainF. The open reading frame (ORF) of the gD gene was 1,185 by and codes 394 amino acid residues. Recombinant baculoviruses, GD-HcNPVs, expressing the gD protein were constructed. Spodoptera frugiperda cells, infected with the recombinant virus, synthesized a matured gX-gD fusion protein with an approximate molecular weight of 54 kDa and secreted the gD proteins into the culture media by an immunoprecipitation assay The fusion gD protein was localized on the membrane of the insect cells, seen by using an immunofluorescence assay The deduced amino acid sequence presents additional characteristics compatible with the structure of a viral glycoprotein: signal peptide, putative glycosylation sites and a long C-terminal transmembrane sequence. These results indicate the utility of the HcNPV-insect cell system for producing and characterizing eukaryotic proteins.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
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• pp.45-45
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• 2003

To evaluate remodeling of infarcted myocardium with contrast-enhanced MRI (co-MRI) at true end-diastole (ED) MRI was performed with a Gyroscan Intera (1.5 Tesla, Philips, Netherlands) in 13 patients with acute subendocardial myocardial infarction. The First exam was done 0-15 days (mean 5.2days) after symptom onset and the second exam 28-88days (mean 49 days) after the first exam. Ce-MRI encompassing the entire left ventricle was performed with a multi-shot, turbo-field-echo, breath-hold sequence and a non-selective, inversion prepulse 10 minutes after the intravenous injection of Gd-DTPA at a dose of 0.2 mmol/kg body weight. To allow the long TD, ECG synchronization should use two RR-intervals for one acquisition of a segment of k-space by setting the heart rate to half that of the true heart rate. Trigger delay time (TD) was adjusted to the RR-interval for true end-diastolic imaging. The other typical parameters were TR=5.4ms, TE=1.6ms, voxel size=1.37${\times}$1.37${\times}$10mm, k-space data segmented into 8 segments with 32 lines of segment per two cycles over 16 cardiac circles. The thickness of hyperenhanced myocardium and epicardially nonenhanced myocardium were followed.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
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• pp.92-92
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• 2003

To evaluate remodeling of infarcted myocardium with contrast-enhanced MRI (co-MRI) at true end-diastole (ED) MRI was performed with a Gyroscan Intera (1.5 Tesla, Philips, Netherlands) in 13 patients with acute subendocardial myocardial infarction. The First exam was done 0-15 days (mean 5.2days) after symptom onset and the second exam 28-88days (mean 49 days) after the first exam. Ce-MRI encompassing the entire left ventricle was peformed with a multi-shot, turbo-field-echo, breath-hold sequence and a non-selective, inversion prepulse 10 minutes after the intravenous injection of Gd-DTPA at a dose of 0.2 mmol/kg body weight. To allow the long TD, ECG synchronization should use two RR-intervals for one acquisition of a segment of k-space by setting the heart rate to half that of the true heart rate. Trigger delay time (TD) was adjusted to the RR-interval for true end-diastolic imaging. The other typical parameters were TR=5.4ms, TE=1.6ms, voxel size=1.37$\times$1.37$\times$10mm, k-space data segmented into 8 segments with 32 lines of segment per two cycles over 16 cardiac cycles. The thickness of hyperenhanced myocardium and epicardially nonenhanced myocardium were followed.

• Journal of Korean Neurosurgical Society
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• 제46권2호
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• pp.161-164
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• 2009

Plasma cell granuloma is a tumor-like disease characterized by non-neoplastic polyclonal proliferation of plasma cells and other mononuclear cells. This disease occurs most frequently in the lung and upper respiratory tract, while the involvement of the central nervous system is very rare. A 44-year-old female patient presented with nausea and progressive visual disturbance. Brain magnetic resonance imaging (MRI) revealed the mass along the right tentorium with low signal intensity in the T2 weighted image (T2WI) and fluid-attenuated inversion recovery (FLAIR) sequence, and an isosignal intensity in T1 weighted image (T1WI), the latter of which was enhanced after administration of gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA). The thickest portion of the tentorium was partially excised via the combined suboccipital and infratentorial approach. The histopathological examination indicated a diagnosis of plasma cell granuloma. Postoperative steroid therapy was administered for remnant tumor control. Although a follow up MRI scan taken 20 months after the operation showed a slight decrease in tumor size, the lesion had extended to the falx and left frontal convexity along with parenchymal edema at 32 months after the operation and the clinical status was aggravated. The mass was removed from the left frontal convexity. Radiation therapy was given, together with steroid administration.

• 대한의생명과학회지
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• 제11권2호
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• pp.221-225
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• 2005

To investigate the spectroscopic findings of embolized lesions induced with a fat-emulsion technique with magnetic resonance images (MRI). A fat emulsion was made with 0.1 ml of triolein and 20 ml of normal saline. In 12 cats, the internal carotid artery was infused with the fat emulsion. Contrast-enhanced T1-weighted MRI and multivoxel spectroscopy were obtained at 1 hour, 1 and 4 days, and 1 week after embolization. NAA (N-acetylaspartate), Cr (creatine) and Cho (choline) were evaluated on the spectroscopy. Statitistical analysis wsperformed at the embolized and contralateral normal hemisphere in the integral and amplitude of NAA, Cr and Nho in time course. Also NAA/Cr and Cho/Cr were compared in both hemisphere and in time course. The emboli zed lesions showed contrast enhance ments on Gd-enhanced Tl-weighted i~ages at 1 hour. This contrast enhancement was decreased at day 1, and id not appear agter day 4. In spectroscopy, the embolized hemisphere showed no statistical difference to the normal contralateral side at 1 hour and in time course. NAA/Cr and Cho/Cr were not significantly different in both hemispheres at 1 hour and in time course. Cerebral-fat embolism induced by a triolein emulsion in cats revealed no statistical difference on MR spectroscopy. Triolein-emulsion can be used in the study of blood-brain barrier.

• 한국약용작물학회지
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• 제21권3호
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• pp.220-228
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• 2013

This study was conducted to assess the genetic diversity and population structure of 70 amaranth accessions collected from South and Southeast Asia using 14 simple sequence repeat (SSR) markers. In total, 67 alleles were detected, with an average of 4.79 per locus. Rare alleles comprised a large portion (46.3%) of the detected alleles, and 29 unique alleles associated with rice accessions were also discovered. The mean major allele frequency (MAF), genetic diversity (GD) and polymorphic information content (PIC) of the 14 SSR loci were 0.77, 0.36, and 0.34, respectively. A model-based structural analysis revealed the presence of three subpopulations. The genetic relationships revealed by the neighbor-joining tree method were fairly consistent with the structure-based membership assignments for most of the accessions. All 70 accessions showed a clear relationship to each cluster without any admixtures. We observed a relatively low extent of genetic exchange within or among amaranth species from South and Southeast Asia. The genetic diversity results could be used to identify amaranth germplasms and so facilitate their use for crop improvement.

• Design & Manufacturing
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• 제13권4호
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• pp.51-56
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• 2019

Due to industrial development, the importance of GD&T tolerance is growing day by day. Roundness measurement means the size deviated from the ideal circle. Roundness evaluation methods include LSCI, MZCI, MCCI, and MICI. Generally, A is used a lot at industrial evaluation. In this experiment, we studied the variations in table velocity, filter values, and detector angles, which can cause errors in roundness measurements. The measurement conditions were table speeds of 10, 30 and 60 mm/s, probe angles of 10, 20 and 30 degrees and frequency filter settings of 15, 150 and 500 upr and The number of experiments was measured 30 and the average value was chosen as a representative value. The hypothesis test showed that the p-value for the frequency filter was greater than 0.05, and the experiment rejected the null hypothesis and adopted the alternative hypothesis.

• 대한방사선기술학회지:방사선기술과학
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• 제42권6호
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• pp.483-489
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• 2019

This paper obtained and compared these dose values by setting and comparing the X-ray imaging conditions (tube voltage 60 kVp, 70 kVp, 80 kVp, tube current 10 mAs, 16 mAs and X-ray field size are 10 × 10 cm, 15 × 15 cm). Each dose value was measure 10 times and represented as an average value. The purpose of this experiment is to serve as a reference for the X-ray exposure of diagnostic areas according to the type of dosimeter and to help with another dose measurement. The results of the experiment showed very little difference between the glass dosimeter(GD) and semiconductor dosimeter values due to changes in tube voltage of 60, 70, 80 kVp, regardless of field sized, but for dose area product(DAP), the difference in dose value was significant according to field size.