• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.10A
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• pp.1223-1229
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• 2004

A variable-gain low-voltage low noise amplifier MMIC operating at 5GHz frequency band is designed and implemented using the ETRI 0.5$\mu\textrm{m}$ GaAs MESFET library process. This low noise amplifier is designed to have the variable gain for adaptive antenna array combined in HIPERLAN/2. The feedback circuit of a resistor and channel resistance controlled by the gate voltage of enhancement MESFET is proposed for the variable-gain low noise amplifier consisted of cascaded two stages. The fabricated variable gain amplifier exhibits 5.5GHz center frequency, 14.7dB small signal gain, 10.6dB input return loss, 10.7dB output return loss, 14.4dB variable gain, and 2.98dB noise figure at V$\_$DD/=1.5V, V$\_$GGl/=0.4V, and V$\_$GG2/=0.5V. This low noise amplifier also shows-19.7dBm input PldB, -10dBm IIP3, 52.6dB SFDR, and 9.5mW power consumption.

• Journal of Microbiology
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• v.43 no.4
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• pp.345-353
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• 2005

The complex ecosystem of intestinal micro flora is estimated to harbor approximately 400 different microbial species, mostly bacteria. However, studies on bacterial colonization have mostly been based on culturing methods, which only detect a small fraction of the whole microbiotic ecosystem of the gut. To clarify the initial acquisition and subsequent colonization of bacteria in an infant within the few days after birth, phylogenetic analysis was performed using 16S rDNA sequences from the DNA iso-lated from feces on the 1st, 3rd, and 6th day. 16S rDNA libraries were constructed with the amplicons of PCR conditions at 30 cycles and $50^{\circ}C$ annealing temperature. Nine independent libraries were produced by the application of three sets of primers (set A, set B, and set C) combined with three fecal samples for day 1, day 3, and day 6 of life. Approximately 220 clones ($76.7\%$) of all 325 isolated clones were characterized as known species, while other 105 clones ($32.3\%$) were characterized as unknown species. The library clone with set A universal primers amplifying 350 bp displayed increased diversity by days. Thus, set A primers were better suited for this type of molecular ecological analysis. On the first day of the life of the infant, Enterobacter, Lactococcus lactis, Leuconostoc citreum, and Streptococcus mitis were present. The largest taxonomic group was L. lactis. On the third day of the life of the infant, Enterobacter, Enterococcus faecalis, Escherichia coli, S. mitis, and Streptococcus salivarius were present. On the sixth day of the life of the infant, Citrobacter, Clostridium difficile, Enterobacter sp., Enterobacter cloacae, and E. coli were present. The largest taxonomic group was E. coli. These results showed that microbiotic diversity changes very rapidly in the few days after birth, and the acquisition of unculturable bacteria expanded rapidly after the third day.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.851-856
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• 2005

Although valuable microbes have been isolated from the soil for the various productions of useful components, the microbes which can be cultivated in the laboratory are only $0.1-1\%$ of all microbes. To solve this problem, the study has recently been tried for making the valuable components from the environment by directly separating unculturable micrbial DNA in the soil. But it is known that humic acid originated from the soil interrupts various restriction enzymes and molecular biological process. Thus, in order to prevent these problems, this study modified the method separated soil DNA with phenol, CTAB and PEG. In order to compare the degree of purity for each DNA and the molecular biological application process, $A_{260}/A_{280}$ ratio, restriction enzymes, and PCR were performed. In case of DNA by the modified method, total yield of DNA was lower but $A_{260}/A_{280}$ ratio was higher than the previously reported methods. It was confirmed that the degree of purity is improved by the modified method. But it was not cut off by all kinds of tested restriction enzymes because of the operation of a very small amount of interrupting substances. When PCR was operated with each diluted DNA in different concentrations and GAPDH primer, the DNA by the modified method could be processed for PCR in the concentration of 100 times higher than by the previously reported separation method. Therefore, this experiment can find out the possibility of utilization for the unknown substances by effectively removing the harmful materials including humic acid and help establishing metagenomic DNA library from the soil DNA having the high degree of purity.

• Journal of Biomedical Engineering Research
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• v.27 no.5
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• pp.203-209
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• 2006

The aim of this study is to investigate the feasibility of ex vivo MR diffusion tensor imaging technique in order to observe the diffusion-contrast characteristics of human gastric tissues. On normal and pathologic gastric tissues, which have been fixed in a polycarbonate plastic tube filled with 10% formalin solution, laboratory made 3D diffusion tensor Turbo FLASH pulse sequence was used to obtain high resolution MR images with voxel size of $0.5{\times}0.5{\times}0.5mm^3\;using\;64{\times}32{\times}32mm^3$ field of view in conjunction with an acquisition matrix of $128{\times}64{\times}64$. Diffusion weighted- gradient pulses were employed with b values of 0 and $600s/mm^2$ in 6 orientations. The sequence was implemented on a clinical 3.0-T MRI scanner(Siemens, Erlangen, Germany) with a home-made quadrature-typed birdcage Tx/Rx rf coil for small specimen. Diffusion tensor values in each pixel were calculated using linear algebra and singular value decomposition(SVD) algorithm. Apparent diffusion coefficient(ADC) and fractional anisotropy(FA) map were also obtained from diffusion tensor data to compare pixel intensities between normal and abnormal gastric tissues. The processing software was developed by authors using Visual C++(Microsoft, WA, U.S.A.) and mathematical/statistical library of GNUwin32(Free Software Foundation). This study shows that 3D diffusion tensor Turbo FLASH sequence is useful to resolve fine micro-structures of gastric tissue and both ADC and FA values in normal gastric tissue are higher than those in abnormal tissue. Authors expect that this study also represents another possibility of gastric carcinoma detection by visualizing diffusion characteristics of proton spins in the gastric tissues.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.9
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• pp.918-926
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• 2010

A widget is a small application running by the users' favorite services, so they are provided with web contents without explicitly visiting the web site. Although widgets can be easily implemented with Open APIs, only a few web sites provide them because of refactoring the structures of web resource to supply Open APIs to the widget developers. This paper presents an Open API Proxy Server System for widget services. The system consists of two components: an Open API Source Code Generator and an Open API Proxy Server. The Open API Source Code Generator provides a Graphical User Interface (GUI) for users to generate the Open APIs of user's choice and sends the Open API source code generation request to the Open API Proxy Server. The Open API Proxy Server using the HTML Table Processing Library receives the HTML web page from web site and extracts useful information from the target HTML table. The proxy server converts the extracted data into the corresponding XML document which becomes available through the Open API. We verify the operation of the proposed system through experiments with the HTML tables in the example web sites.

• Journal of the Institute of Convergence Signal Processing
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• v.16 no.4
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• pp.175-181
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• 2015

In this paper, we propose a design method for a digital filter using software in order to analyze the radio astronomy observation data. Recently the analysis method for radio astronomy observing system is transferring from hardware to software by developing of state-of-the-art of computer system. The existing hardware system is not able to easily change the specification because it is implemented to meet special requirements and it takes a high cost and time. In case of software, however, it has an advantage to implement with small cost if open software is used, and flexibly changes to satisfy the desired specification. But, in order to analyze the massive data like radio astronomy with software, the good performance system is needed for computer. Therefore, this paper proposes a digital filter design method using software with the same performance as that of digital filter implemented with hardware in observation system which is operated by the KVN(Korean VLBI Network). To design a digital filter, the proposed method is performed with standard C language and the simulation is conducted with GNU(GNU's Not Unix) Octave and investigated to show its effectiveness. In addition, for the high speed operation of the designed digital filter, the SSE(Streaming SIMD Extensions) library is adopted for available parallel operation. By the proposed digital filter, the digital filtering is performed for the wide band observation data in the KVN observation mode, the filtering result of narrow band observation has no ripple inside of stop band, and confirmed the effectiveness of the proposed method.

• Journal of Dental Anesthesia and Pain Medicine
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• v.21 no.5
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• pp.413-429
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• 2021

Background: Migraine headaches are the second leading cause of disability worldwide and are responsible for significant morbidity, reduction in the quality of life, and loss of productivity on a global scale. The purpose of this systematic review and meta-analysis was to evaluate the efficacy of ketamine on migraines and other primary headache disorders compared to placebo and other active interventions, such as midazolam, metoclopramide/diphenhydramine, and prochlorperazine/diphenhydramine. Methods: An electronic search of databases published up to February 2021, including Medline via PubMed, EMBASE, Web of Science, and Cochrane Library, a hand search of the bibliographies of the included studies, as well as literature and systematic reviews found through the search was conducted to identify randomized controlled trials (RCTs) investigating ketamine in the treatment of migraine/headache disorders compared to the placebo. The authors assessed the risk of bias according to the Cochrane Handbook guidelines. Results: The initial search strategy yielded 398 unduplicated references, which were independently assessed by three review authors. After evaluation, this number was reduced to five RCTs (two unclear risk of bias and three high risk of bias). The total number of patients in all the studies was 193. Due to the high risk of bias, small sample size, heterogeneity of the outcomes reported, and heterogeneity of the comparison groups, the quality of the evidence was very low. One RCT reported that intranasal ketamine was superior to intranasal midazolam in improving the aura attack severity, but not duration, while another reported that intranasal ketamine was not superior to metoclopramide and diphenhydramine in reducing the headache severity. In one trial, subcutaneous ketamine was superior to saline in migraine severity reduction; however, intravenous (I.V.) ketamine was inferior to I.V. prochlorperazine and diphenhydramine in another study. Conclusion: Further double-blind controlled studies are needed to assess the efficacy of ketamine in treating acute and chronic refractory migraines and other primary headaches using intranasal and subcutaneous routes. These studies should include a long-term follow-up and different ketamine dosages in diagnosed patients following international standards for diagnosing headache/migraine.

• Journal of the Korean Society for information Management
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• v.38 no.3
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• pp.311-334
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• 2021

The purpose of this study is to present the theoretical basis and quantified objective standards for the establishment of collection management policy. The study results are summarized as follows. Most of the study books were in the form of periodicals as a steady seller. Most of the steady sellers were textbooks which published periodically. As a modern novel, a steady seller was able to confirm the phenomenon of dependence on a specific author. Bestsellers were investigated to be influenced by publishers and authors. Books of publishers that publish comics and children's textbooks had a significant correlation with the selection of bestsellers. The average number of recommended books borrowed per recommended book was 14,871. The average number of loans per book selected as a bestseller was 53,531. Based on the loan data, about 80-82% of all top-tier loans were covered by 90%, and about 27-29% of all top-ranked loans were covered by 50%. This shows that the Pareto Principle can be firmly applied to public library lending patterns. Loans in the field of literature accounted for 50.6% of the total loans. Among literature, Korean literature accounted for 51.3% of the total. The natural sciences were generating more loans with a relatively small pool of literature compared to other subject fields.

• The Korean Journal of Archival Studies
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• no.7
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• pp.37-74
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• 2003

An Old document(Diploma) is a historical and unique record, so it must be collected, arranged, and preserved for research as soon as possible. Especially, for the effective use of the Old Document(Diploma), it is needed to arrange and describe the material systematically on the ground of modern archival theory. The Kyujanggak Archives in the Seoul National University has published 23 volumes of Old document(Diploma) material Old Document(Diploma). But they seem to cause the readers inconvenience, because the materials are classified and gathered only by genre, the titles or the orders of the materials are not standardized, and there is no description about the content of each Old document(Diploma). Jangseo-gak Library in The Academy of Korean Studies has also published the series of Old document(Diploma) material Old Document(Diploma) Collection. However the case is not different, since they are all mixed up with materials classified and gathered by genre, family, academy, or local school. And a great part of the materials have no titles and no description about the content of each Old document(Diploma), either. About the arrangement and description of the records, European and American archival science has established the theory of l)the principle of provenance, 2)the principle of original order, 3)levels of control, 4)collective description. These theories are valuable for the effective use of Old document(Diploma). On the viewpoint of the principle of provenance, Old document(Diploma) materials should not be classified by subject and genre, but by family and person. Then, the Old document(Diploma) materials, after collected by the unit of family or person on the viewpoint of the principle of provenance, should be arranged in their original order for more detailed arrangement and furthermore, for the work to find their relationship. This is so called the principle of original order. The hierarchical management of the Old document(Diploma) materials, for example, classifying by record group, sub-group, series, item and so on, is the concept of the levels of control, and comprehensive description of the each hierarchical structure is the concept of the collective description. Let's apply these archival theories to 34 pieces of the Chung, Man-Seok's material in the series of Old document(Diploma) material Old Document(Diploma). First, collect the Old document(Diploma) materials into Chung, Man-Seok's collection(the principle of provenance), which were scattered in the series classified by genre. Secondly, rearrange them chronologically(the principle of original order), and then we can find the comprehensive information about Chung, Man-Seok. For the hierarchical management of the Old document(Diploma) materials, we should establish a few concepts from the general, large group to specific, small item. The concepts can be organized as following; l)record group(Chung, Man-Seok record group) - 2)sub-group(personnel document, property document, family document, social activity document, political activity document, etc) - 3)series(gyoji-series, gyoseo-series, yuji-series etc. in the personnel document) - 4)folder(document with additions) - 5)item(one document). According to the the theory of the collective description, in the level of record group, there should be a collective description of Chung, Man-Seok's biography or a summary of record group. Similarly, there should be a collective description of a summary of sub-group in the level of sub-group and a summary of series in the level of series.

• Journal of Dental Anesthesia and Pain Medicine
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• v.21 no.3
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• pp.183-205
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• 2021

This systematic review and meta-analysis aimed to analyze the effectiveness of maxillary stabilization splint (SS) therapy to reduce headache (HA) intensity and HA frequency in patients with temporomandibular disorders (TMD)-HA comorbidity. Randomized controlled trials (RCTs) using full-arch coverage, hard resin, and maxillary SS therapy were included. Electronic databases, including Cochrane Library, MEDLINE through PubMed, Web of Science, and EMBASE, were searched. The risk of bias was analyzed based on Cochrane's handbook. The search yielded 247 references up to January 28, 2020. Nine RCTs were included at a high risk of bias. The comparison groups included other splints, counseling, jaw exercises, medications, neurologic treatment, and occlusal equilibration. Four studies reported a statistically significant reduction in HA intensity, and five studies reported significant improvement in HA frequency from baseline at 2-12 months in patients with TMD-HA comorbidity treated with a full-arch hard maxillary SS. HA frequency in tension-type HA (TTH) comorbid with TMD diagnoses of myofascial pain (MFP) or capsulitis/synovitis improved significantly with SS than that with full-arch maxillary non-occluding splint (NOS) in two studies. Comparison groups receiving hard partial-arch maxillary splint nociceptive trigeminal inhibition (NTI) showed statistically significant improvements in HA intensity in patients with mixed TMD phenotypes of MFP and disc displacement comorbid with "general HA." Comparison groups receiving partial-arch maxillary resilient/soft splint (Relax) showed significant improvements in both HA intensity and frequency in patients with HA concomitant with MFP. The meta-analysis showed no statistically significant difference in the improvement of pain intensity at 2-3 months with comparison of the splints (partial-arch soft [Relax], hard [NTI], and full-arch NOS) or splint use compliance at 6-12 months with comparison of the splints (partial-arch Relax and full-arch NOS) versus the SS groups in patients with various TMD-HA comorbidities. In conclusion, although SS therapy showed a statistically significant decrease in HA intensity and HA frequency when reported, the evidence quality was low due to the high bias risk and small sample size. Therefore, further studies are required.