• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9B
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• pp.1616-1623
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• 1999

This paper describes error resilient coding scheme is added in WLL system and its application for robust low-bit rate still image transmission over power controlled W-CDA system Rayleigh fading channels. The baseline JPEG compressing methods are uses in image coding over wireless channel. The channel uses Reed-Solomon(RS) outer codes concatenated with convolutional inner codes, and truncated type I hybrid ARQ protocol based on the selective repeat strategy and the RS error detection capability. Simulation results are proved for the statistics of the frame-error bursts of the proposed system in comparison with conventional WLL system. it gains the 2 dB of the Eb/No in same BER.

• Journal of the Korean Chemical Society
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• v.65 no.1
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• pp.9-14
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• 2021

In this study, the DFT calculation was performed using the B3LYP/6-31G(d,p) basis sets for the reaction process in which phenanthrene decomposes due to the chain reaction of two OH radicals on phenanthrene in the gaseous state of 298 K at 1 atm. As a result of the calculation, even when two OH radicals act on phenanthrene in a chain, the reaction for producing phenanthren-9-ol is predicted to be more advantageous than the reaction for producing phenanthren-1-ol. On the other hand, it was predicted that the OH addition process at room temperature would be advantageous for the priority of the OH addition and H abstraction process.

• Geophysics and Geophysical Exploration
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• v.25 no.4
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• pp.242-251
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• 2022

Automatic differentiation automatically calculates the derivatives of a function using the chain rule once the forward operation of a function is defined. Given the recent development of computing libraries that support automatic differentiation, many researchers have adopted automatic differentiation techniques to solve geophysical inverse problems. We analyzed the advantages, disadvantages, and performances of automatic differentiation techniques using the gradient calculations of seismic full waveform inversion objective functions. The gradients of objective functions can be expressed as multiplications of the derivatives of the model parameters, wavefields, and objective functions using the chain rule. Using numerical examples, we demonstrated the speed of analytic differentiation and the convenience of complex gradient calculations for automatic differentiation. We calculated derivatives of model parameters and objective functions using automatic differentiation and derivatives of wavefields using analytic differentiation.

• Investigative Magnetic Resonance Imaging
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• v.17 no.2
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• pp.133-143
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• 2013

Purpose : To evaluate and compare the accuracy of magnetic resonance imaging (MRI) and ultrasound (US) for detection and estimation of invasion depth of colorectal carcinoma (CRC) by correlation with histopathologic findings in vitro, and to find out the best MR pulse sequence for accurate delineation of tumor from surrounding normal tissue. Materials and Methods: Resected specimens of CRC from 45 patients were examined about tumor detectability and invasion depth of US using high frequency (5-17 MHz) linear transducer in a tube filled with normal saline and MRI in a 8-channel quadrate head coil. The institutional review board approved this study and informed consent was waived. MRI with seven pulse sequences of in- and out-of-phases gradient echo T1 weighted images, fast spin echo T2 weighted image and its fat suppression image, fast imaging employing steady-state acquisition (FIESTA) and its fat suppression image, and diffusion weighted image (DWI) were performed. In each case, both imaging findings of MRI and US were evaluated independently for detection and estimation of invasion depth of tumor by consensus of two radiologists and were compared about diagnostic accuracy according to the histopathologic findings as reference standard. Seven MR pulse sequences were evaluated on the point of accurate delineation of tumor from surrounding normal tissue in each specimen. Results: In specimens of CRC, both imaging modalities of MRI (91.1%) and US (86.7%) showed relatively high diagnostic accuracy to detect tumor and evaluate invasion depth of tumor. In early CRC, diagnostic accuracy of US was 87.5% and that of MRI was 75.0%. There was no statistically significant difference between two imaging modalities (p > 0.05). The best pulse sequence among seven MR sequences for accurate delineation of tumor from surrounding normal tissue in each specimen of CRC was fast spin echo T2 weighted image. Conclusion: MRI and US show relatively high diagnostic accuracy to detect tumor and evaluate invasion depth of resected specimen of CRC. The most excellent pulse sequence of MRI for accurate delineation of tumor from surrounding normal tissue in CRC is fast spin echo T2 weighted image.

• Clinical and Experimental Pediatrics
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• v.45 no.8
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• pp.973-979
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• 2002

Purpose : Recently, a number of rapid antigen detection tests have been available to diagnose group A streptococcal pharyngotonsillitis. The purpose of this study was to determine the sensitivity, specificity and consistency of the two rapid antigen detection tests. Methods : Among the patients who visited our clinic from November 2001 to February 2002, 61 patients who had clinical findings of pharyngeal erythema or edema, pharyngeal exudates and soft palatine petechiae were enrolled in our study. A total of 61 patients were tested with rapid antigen detection tests and throat culture. BD $LINK2^{TM}$ Strep A(Becton, Dickinson & Company, U.S.A.) and $QuickVue^{(R)}$ $In-Line^{TM}$(Quidel Corporation, U.S.A.) were selected for rapid antigen detection tests. Results : Of the 61 patients tested, 22 patients were confirmed as group A streptococcal pharyngotonsillitis by throat culture. The BD $LINK2^{TM}$ Strep A had a sensitivity of 81.8% and a specificity 89.7%. The positive and negative predictive values were 81.8% and 89.7%, respectively. The $QuickVue^{(R)}$ $In-Line^{TM}$ had a sensitivity of 77.3% and a specificity of 100%. The positive and negative predictive values were 100% and 88.6%, respectively. The kappa values of BD $LINK2^{TM}$ Strep A and $QuickVue^{(R)}$ $In-Line^{TM}$ were 0.72 and 0.81, respectively. Conclusion : In addition to high sensitivity, specificity and consistency, both kits are easy to use and simple to interpret, and therefore have the potential to be used with backup throat culture for diagnosis of acute pharyngotonsillitis.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1979.05a
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• pp.4.4-5
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• 1979

The degree of hearing impairment of chronic otitis media will indicate the nature and severity of middle ear pathology especially condition of ossicular chain, size of ear drum perforation and location of granulation tissue in the middle ear cavity. The subjects were 189 ears of tympanoplasty for chronic otitis media and divided into four groups as follows: Normal ossicular chain with only ear drum perforation (group I), normal ossicular chain with granulation tissue only around the ossicles regardless of any other region (group II), ossicular ankylosis or fixation of handle of malleus to promontory with or without granulation tissue around the ossicle (group III) and ossicular interruption by partial or complete destruction(groupf IV). The results were concluded as follows: 1) The average hearing threshold of chronic otitis media was 44.6 dB and hearing threshold was closely related to the condition of ossicular chain. Hearing threshold became greater in order of normal ossicular chain, ankylosis and interruption. 2) The average hearing threshold of ossicular interrupted group was 49.1 dB and it was greater in the cases of total destruction than that of partial destruction. 3) The hearing loss in the cases of normal ossicular chain with only tympanic membrane perforation was within 45 dB and this level was presumed to represent normal ossicular function. The degree of hearing loss was in proportion to the size of ear drum perforation and when over 45 dB, other middle ear pathology was suggested. 4) In the cases of small ear drum perforation with normal ossicular function, the hearing threshold was within 30 dB. 5) In the type of audiogram, flat type was 30.2% and ascending type 35.4%. Descending type was more frequent in the cases of normal ossicular mobility with granulation tissue around the ossicle and flat type was observed frequently in the cases of ossicular ankylosis. 6) Carhart's notch was seen in 14 cases (7.4%) and observed mainly in ossicular ankylosis. 7) There was no relation between hearing threshold and histopathological type of granulation tissue in chronic otitis media. However the degree of hearing impairment was related to the location of granulation tissue in the middle ear cavity. 8) Authors recognized the granulation tissue compensated the function of interrupted ossicular chain.

• Korean Security Journal
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• no.29
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• pp.139-162
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• 2011

The purpose of this study is to compare with the general and behavioral characteristics between simple and serial arsonists using the data derived from Scientific Crime Analysis System, Criminal Filing Search System, and Crime Information Management System. The analysis and findings reported here are derived from data extracted from 160 arsonists arrested by police officer. The independent variables included such socio-economic characteristic as arsonists' gender, age, occupation, education level, and previous criminal records of arsonists, and finally the general characteristics of the scene of fire settings. The dependent variable is whether or not serial fire setter. To achieve the purpose, the analysis of frequencies and cross-tab were conducted. According to frequence and cross-tab analysis, there are great differences of the general and behavior characteristics between two groups. In the comparison of simple and serial arsonists, serial arsonists are more likely to have previous criminal records, low socio-economic status, unmarried and no cohabitants than simple arsonists. furthermore, serial arsonists are more likely to use garbage papers for fire setting in the scene of the crime, to have mental or psychological problems, and to get involved in fire setting for the psychological pleasure than simple arsonists do. The present research has some obvious limitations. First, the analysis is based only on arsonists arrested by police officers. These may be considerable differences in arsonists arrested by police officers and fire setters not arrested by them. Additional research is needed to assess the extent to which these findings would apply to fire setters not arrested by police officer in Korea. Secondly, the data in this study are cross-sectional and simple cross-tab analysis are used. Potential limitation of cross-sectional data concerns the inability to specify the changes in measures as arsonists behavioral characteristics. Therefore, further studies need to use longitudinal data and more complicate statistical techniques such as correlation analysis, multiple regression analysis, or LISREL models to specify the casual relationships between dependent and independent variables for fire settings. Even if this study has some limitations, it is meaningful in which it first investigated the comparison of simple and serial arsonists focusing on the general and behavioral characteristics between two groups in Korea.

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.123-129
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• 1999

Purpose: Acute poststreptococcal glomerulonephritis(APSGN) is a renal disease which is characterized by glomerular proliferation and inflammatory changes due to immune reaction. Although the 95% of patients with APSGN seems to recover fully and present as benign course, the remaining patients show poor prognosis. Therefore comparative retrograde study between APSGN with and without nephrotic syndrome was done to find out the any prognostic indicator to predict the outcome in patients with APSGN. Methods: We had retrospectively analyzed seventy-one patients who were diagnosed as APSGN clinically from Mar.1989 to Feb.1999 in Yonsei university medical center. Sixty-four of the patients was APSGN without nephrotic syndrome(Group A) and seven patients were in APSGN with nephrotic syndrome(Group B). Results: Patients who were diagnosed as APSGN with nephrotic syndrome were seven(9.9%) out of seventy-one. In the comparative study, sex ratio was 1:1 in group A and 1.9: 1 in group B, onset mean age was $8.9{\pm}2.6$ in group A and $8.8{\pm}2.6$ in group B. Following clinical profiles were compared but there were no significant difference between these two groups: WBC count($9413{\pm}2964\;vs\;9368{\pm}2650(/mm^3)$), hemoglobin($10.6{\pm}1.2\;vs\;10.0{\pm}0.9(gm/dL)$), ASO($746.1{\pm}640.7\;vs\;614.9{\pm}475.9(IU/ml)$), $C_3(20.1{\pm}17.0\;vs\;16.9{\pm}13.1(mg/dL)$), $C_4(22.8{\pm}9.5\;vs\;22.6{\pm}6.9(mg/dL)$), BUN($25.8{\pm}26.1\;vs\;28.1{\pm}14.5(mg/dL)$), creatinin($0.8{\pm}0.3\;vs\;0.8{\pm}0.3(mg/dL)$), $C_{cr}(80.6{\pm}28.8{\pm}62.4{\pm}31.4(ml/min/1.73\;m^2$)), the duration of edma, gross hematuria, and hypertension. However, we found that there were a significant difference in the duration of proteinuria($1.95{\pm}2.27\;vs\;13.3{\pm}21.1(months)$)(P<0.05), decreased $C_3$ duration($1.9{\pm}2.9\;vs\;7.3{\pm}5.0(weeks)$)(P<0.05) and especially it was proloned according to the amount of early urine protein excretion. Conclusion: Our study showed markedly prolonged duration of proteinuria and decreased $C_3$ duration in patients with APSGN with nephrotic syndrome. We were not able to find the definite prognostic factor that will guide the outcome of patients with APSGN accompaning nephrotic syndrome, but above findings seemed to represent as a relative indication of the outcome of the disease. All patients recovered completely and we did not experience any cases that progressed into the renal failure.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.2
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• pp.135-140
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• 2017

Polymerase chain reaction (PCR) was used to detect cattle material from processed meat products. Seventy-eight different commercial processed meat products were purchased from several big food marts. Among them, 17 products contained cattle material (10 samples contained only cattle, 5 samples mixed with cattle and porcine, 2 samples mixed with cattle, porcine and chicken). The genomic DNA was extracted directly from the processed meat products, and strain-specific primer targeting the 16S ribosomal RNA mitochondrial gene was used. All PCR products were cloned into the pGEM-T easy vector and sequenced. Consequently, the PCR products were amplified from 10 processed meat products, which contained only cattle material in our conditions. Furthermore, PCR reactions showed the same results at mixed samples. The DNA sequence obtained from pGEM-T easy/PCR products showed more than 95% identity with Bos taurus 16S rRNA gene using homology analysis. In conclusion, we suggest that the method using PCR, as performed in this study, could be useful in detecting cattle material in processed meat products. Moreover, our system could be applicable in inspection procedures to improve the verification of correct labeling for import and export processed meat products.

• The korean journal of orthodontics
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• v.35 no.4 s.111
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• pp.312-319
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• 2005

Streptococcus mutans and Streptococcus sobrinus are major etiological agents in enamel demineralization around orthodontic appliances. This study was designed to examine the prevalence of these streptococci on orthodontic brackets in vivo using polymerase chain reaction. Four incisor brackets in the upper and lower arches were removed and collected from 80 patients at the time of debonding. The genomic DMA of adhered bacteria was extracted and each dextranase gene of S. mutans and S. sobrinus was amplified using the specific oligonucleotide primers. The results showed that the maxillary incisor brackets were colonized by both cariogenic streptococci to a somewhat higher degree than that taken from the mandible. The prevalence of S. mutans was $50.0\%$ on the maxillary incisor brackets and $33.8\%$ on the mandibular incisor brackets, and that of S. sobrinus was $17.5\%$ and $15.0\%$, respectively. Both species were detected on the maxillary incisor brackets of 7 patients $(8.8\%)$ and the mandibular incisor brackets of 5 patients $(6.3\%)$. These results suggest that cariogenic streptococci can adhere to the incisor brackets and may be resident species on the incisor brackets.