• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.12-12
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• 2010

By using scanning tunneling microscopy/spectroscopy (STM/S), we can make images of various physical properties in nanometer-scale spatial resolutions. Here, I demonstrate imaging of two electron-correlated subjects; screening and superconductivity by STM/S. The electrostatic potential around a charge is described with the Coulomb potential. When the charge is located in a metal, the potential is modified because of the free electrons in the host. The potential modification, called screening, is one of the fundamental phenomena in the condensed matter physics. Using low-temperature STM we have developed a method to measure electrostatic potential in high spatial and energy resolutions, and observed the potential around external charges screened by two-dimensional surface electronic states. Characteristic potential decay and the Friedel oscillation were clearly observed around the charges [1]. Superconductivity of nano-size materials, whose dimensions are comparable with the coherence length, is quite different from their bulk. We investigated superconductivity of ultra-thin Pb islands by directly measuring the superconducting gaps using STM. The obtained tunneling spectra exhibit a variation of zero bias conductance (ZBC) with a magnetic field, and spatial mappings of ZBC revealed the vortex formation [2]. Size dependence of the vortex formation will be discussed at the presentation.

• Educational Technology International
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• v.23 no.2
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• pp.157-181
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• 2022

Scale scores for cognitive domains have been used as an important indicator for both academic achievement and clinical diagnosis. For example, in education, Cognitive Abilities Test (CogAT) has been used to measure student's capability in academic learning. In a clinical setting, Cognitive Impairment Screening Test utilizes items measuring cognitive ability as a dementia screening test. We demonstrated a procedure of generating cognitive ability test items similar as in CogAT but the theory associated with the generation is totally different. When creating cognitive test items, we applied automatic item generation (AIG) that reduces errors in predictions of cognitive ability but attains higher reliability. We selected two cognitive ability test items, categorized as a time estimation item for measuring quantitative reasoning and a paper-folding item for measuring visualization. As CogAT has widely used as a cognitive measurement test, developing an AIG-based cognitive test items will greatly contribute to education field. Since CLASS is the only LMS including AIG technology, we used it for the AIG software to construct item models. The purpose of this study is to demonstrate the item generation process using AIG implemented within CLASS, along with proving quantitative and qualitative strengths of AIG. In result, we confirmed that more than 10,000 items could be made by a single item model in the quantitative aspect and the validity of items could be assured by the procedure based on ECD and AE in the qualitative aspect. This reliable item generation process based on item models would be the key of developing accurate cognitive measurement tests.

• Clinical Endoscopy
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• v.55 no.4
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• pp.489-495
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• 2022

An appropriate post-polypectomy surveillance program requires the effectiveness of reducing colorectal cancer and safety. In addition, the post-polypectomy surveillance program should consider the burden of limited medical resource capacity, cost-effectiveness, and patient adherence. In this sense, a risk-stratified surveillance program based on baseline colonoscopy results is ideal. Major international guidelines for post-polypectomy surveillance, such as those from the European Union and the United States, have recommended risk-stratified surveillance programs. Both guidelines have recently been updated to better differentiate between high- and low-risk individuals. In both updated guidelines, more individuals have been downgraded to lower-risk groups that require less frequent or no surveillance. Furthermore, increased attention has been paid to the surveillance of patients who undergo serrated polyp removal. Previous guidelines in Japan did not clearly outline the risk stratification in post-polypectomy surveillance. However, the new colonoscopy screening and surveillance guidelines presented by the Japan Gastroenterological Endoscopy Society include a risk-stratified post-polectomy surveillance program. Further discussion and analysis of unresolved issues in this field, such as the optimal follow-up after the first surveillance, the upper age limit for surveillance, and the ideal method for improving adherence to surveillance guidelines, are warranted.

• Korean Institute of Interior Design Journal
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• v.26 no.6
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• pp.180-190
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• 2017

The subway station is not only an effective means to solve urban traffic problems, but also a kind of representative city shelters with a variety of functions such as urban beauty and disaster prevention. At the same time, the subway station as public facilities need activate the urban functions and through the effective design schemes for a variety of the facade of underground entrance to improve users' awareness and reliability for the subway station as a city shelters. This study is conducted to purpose the design direction considering design and disaster preventing characteristics of the underground subway station entrance. In addition, it will provide a basic reference for the subway station in the renovation and construction. The study is composed of literature reviews and field survey. The literature reviews through papers and documents related to the city shelters, the components and characteristics of city shelters, and components and characteristics of facade design of underground entrance at subway station. Before the field survey through the online surveys with evacuation capabilities and screening only the subway station. And field survey is conducted on the site with careful observation and confirmation. Last cluster analysis were applied to the finally selected samples by the SPSS Win18.0

• Journal of Korean Dental Science
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• v.15 no.2
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• pp.101-111
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• 2022

The purpose of laboratory tests in the field of oral medicine can be divided into two categories: (1) medical evaluation of patients with systemic diseases that are planning to receive dental care and (2) diagnosis of patients with certain oral diseases. First, laboratory tests are commonly used to evaluate patients with systemic diseases who need dental management. A combination of multiple tests is usually prescribed as a test panel to diagnose and assess a specific disease. Test panels closely related to oral medicine include those for rheumatoid arthritis, connective tissue disease/lupus, liver function, thyroid screening, anemia, and bleeding disorders. Second, laboratory tests are used as auxiliary diagnostic methods for certain oral diseases. They often provide crucial diagnostic information for infectious diseases caused by bacteria, fungi, and viruses that are associated with pathology in the oral and maxillofacial regions. Laboratory tests for infectious diseases are composed of growth-dependent methods, immunologic assays, and molecular biology. As the field develops, further application of laboratory tests, including synovial fluid analysis in temporomandibular joint disorders, salivary diagnostics, and hematologic biomarkers associated with temporomandibular disorders and orofacial pain conditions, is currently under scrutiny for their reliability as diagnostic tools.

• Research in Plant Disease
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• v.28 no.2
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• pp.92-97
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• 2022

Apple stem grooving virus (ASGV) is a high-risk viral pathogen that infects many types of fruit trees, especially pear and apple, and causes serious economic losses across the globe. Thus, rapid and reliable detection assay is needed to identify ASGV infection and prevent its spread. A reliable reverse transcription loop-mediated isothermal amplification (RT-LAMP) was developed, optimize, and evaluated for the coding region of coat protein of ASGV in pear leaf. The developed RT-LAMP facilitated the simple screening of ASGV using visible fluorescence and electrophoresis. The optimized reaction conditions for the RT-LAMP were 63℃ for 50 min, and the results showed high specificity and 100-fold greater sensitivity than the reverse transcription polymerase chain reaction. In addition, the reliability of the RT-LAMP was validated using field-collected pear leaves. Furthermore, the potential application of paper-based RNA isolation, combined with RT-LAMP, was also evaluated for detecting ASGV from field-collected samples. These assays could be widely applied to ASGV detection in field conditions and to virus-free certification programs.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.9
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• pp.15-22
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• 2000

The effects of carrier transport and input power on the extinction ratio was theoretically analyzed in a 1.55${\mu}m$ InGaAsP/InGaAsP multiple-quantum-well(MQW) electroabsorption(EA) modulator. Poisson's equation, current continuity equations for electrons and holes, and optical field distribution were self-consistently solved by considering electric field dependent absorption coefficients. The field screening effect due to the carrier accumulation in heterointerface and the space-charge region occurred more seriously at the input side of modulator as input optical intensity increased. It was revealed that extinction ratio could be steeply degraded for modulator with the length of 200${\mu}m$ when an input power exceeds 10mW. A degradation of extinction ratio due to the field screening effect would be more significantly at high-performance devices such as a 1.55${\mu}m$DFB-LD/EA-modulator integrated source where optical coupling efficiency is almost complete or a very high-speed modulator with its length as short as a few tens ${\mu}m$.

• The Journal of the Korean Society for Microbiology
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• v.3 no.1
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• pp.15-23
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• 1968

For the effective control of Syphilis, many investigators have developed a more rapid, simple and economical screening serological test which is adequately sensitive and specific. To fulfill the requirements of a more rapid serologic test for syphlis, a substitute for the conventional serum specimen was needed since considerable time and labor are involved in the processing of blood to serum. Burdon suggested the use of plasma in the serologic tests for syphilis as a substitute for serum. He noticed that plasma was more sensitive than serum in the Kline and Kahn tests, and attributed this to the presence of more antibody-like substance, "reagin" in plasma than in serum. However, to make plasma sufficiently sensitive, it was necessary to inactivate plasma by heating at a temperature of $56^{\circ}C$ for about 30 minutes. Heating of plasma resulted in the precipitation of fibrinogen which made centrifugation necessary to obtain dear plasma. Since the chief disadvantage to the use of unheated plasma(or serum) was a reduction in sensitivity of results-which probably was due to a labile factor such as complement-Portnoy et al began to consider rapid chemical methods of inactivation of plasma(or serum). They experienced that choline chloirde was shown to be anticomplementary which suggested its use as an inactivating agent for unheated plasma(or serum). In 1959 Portnoy et al reported the Rapid Plasma Reagin(RPR) Test for syphilis which is a more rapid, economical and simple. But still this test has many disadvantages as a rapid performing, field and office procedure, because it requires the usual laboratory equipments such as centrifuge, rotating machine, microscope etc. To substitute these disadvantages of the RPR test, in 1962, Portnoy et al developed the Rapid Plasma Reagin(RPR) card test for syphilis, which has the following advantages: a) Simplicity and rapidity of performance, b) Requires no laboratory equipments, c) Stable antigen suspension, d) Adequate sensitivity and specificity. This RPR card test can be used as a rapidly performing and screening test in field investigation, outpatient clinics, small laboratories and hospitals doing limited syphilis serology, and predonor in blood bank. Private clinic which has limited laboratory equipment and technic for syphilis serology can also use this RPR card test as a tool in the rapid diagnosis of syphilis. It was thought that this RPR card test is a useful tool in Korea for private physician and mass survey for syphilis diagnosis. But Portnoy patented the reagents needed for the performing the RPR card test. Therefore authors developed newly the reagents and according to Portnoy's method evaluated the newly developed. RPR card test compared with the VDRL, Kolmer CF, and RPCF tests. The RPR card and VDRL tests were performed plasma and serum from the total 1,132 cases. Among these 1,131 cases, 521 were syphilis suspected laboratory specimens, and 611 were syphilis unsuspected healthy young men. After screening with these two tests, the RPR card and VDRL tests, reactive specimens to the above one or both tests were retested by the Kolmer CF and RPCF tests.

• Clinical and Experimental Pediatrics
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• v.45 no.12
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• pp.1546-1550
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• 2002

Purpose : The authors carried out this study to determine the relationship between vigabatrin (VGB) and visual field defect.. Methods : Seventy eight patients older than 8 years who had epilepsy which had developed and been diagnosed, and were receiving add-on therapy, were the subjects of this study. If suspicious results were obtained from the initial test with the Humphrey automatic perimeter, the patient was tested again with the Goldman perimeter. Follow-up examinations were performed on these patients after 6 months. Results : In this study, five of the 78 patients had suspicious primary test results, but upon the second examination they were all found to be normal. Thus there were no patients with visual field defects. Conclusion : VGB is a drug which may cause visual field defects, but in this study no patients presented with this symptom. Instead of limiting the use of VGB due to the adverse effect of visual field defect in the initial treatment of partial seizure and infantile spasm untreatable with other medication, if used with care it may not cause serious problems. Screening for visual defect is recommended, and in patients taking VGB regular examination is necessary.

• Journal of Industrial Technology
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• v.23 no.A
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• pp.149-156
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• 2003

The development and maintenance of a sound bond are essential requirements of concrete repair and replacement. The bond property of a overlay to its substrate concrete during the lifetime is one of the most important performance requirements which should be quantified. A standard or a verified bond strength measurement method is required at field for screening, selecting materials and quality control for overlay or repair materials, but no test method has been adopted as a standard. In this study, a concrete pull off bond strength measurement method for field application is proposed and evaluated. This study compares the splitting tensile test, slant shear test, nipple pipe direct tensile test, flexural adhesion test, briquette tensile test, jumbo nail pull-out test and core pull-off test with their test procedures. From these comparison and investigation, core pull-off test is selected as a main topic of this study because of it's suitability for in situ testing, simplicities in field application and clearness at interface boundary condition. Thus, the proposed core pull off test is evaluated to be the most appropriate method for field application in a simple manner. The fracture surface and fracture mode could be easily determined by visual observation of failure surface of the field specimen. The core pull off test was found to be sensitive to surface condition and latex contents at latex modified concrete.