• The Journal of Korean Academy of Prosthodontics
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• v.40 no.2
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• pp.131-139
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• 2002

There have been many studies about marginal discrepancy of single restorations made by various systems and materials. But many of statistical inferences are not definite because of sample size, measurement number, measuring instruments. etc. The purpose of this study was to compare the marginal adaptations of the anterior single restorations made by different systems and to consider more desirable statistical methods in analysing the marginal fit. The in vitro marginal discrepancies of three different all-ceramic crown systems (Celay In-Ceram. Conventional In-Ceram. IPS Empress 2 layering technique) and one control group (PFM) were evaluated and compared. The crowns were made from one extracted maxillary central incisor prepared with a 1mm shoulder margin and $6^{\circ}$ taper walls by milling machine. 10 crowns per each system were fabricated. Measurements or a crown were recorded at 50 points that were randomly selected for marginal gap evaluation. Non-parametric statistical analysis was performed for the results. Within the limits of this study, the following conclusions were drawn: 1 Mean gap dimensions and standard deviations at the marginal opening for the maxillary incisor crowns were $98.2{\pm}40.6{\mu}m$ for PFM, $83.5{\pm}18.7{\mu}m$ for Celay In-Ceram, $104.9{\pm}44.1{\mu}m$ for conventional In-Ceram, and $45.5{\pm}11.5{\mu}m$ for IPS Empress 2 layering technique. The IPS Empress 2 system showed the smallest marginal gap (P<0.05). The marginal openings of the other three groups were not significantly different (P<0.05). 2 The marginal discrepancies found in this study were all within clinically acceptable standards ($100\sim150{\mu}m$). 3. When the variable is so controlled that the system may be the only one, mean value is interpreted to be the marginal discrepancy of a restoration which is made by each system and standard deviation is to be technique-sensitivity of each one. 4. From the standard deviations. the copy-milling technique (Celay/In-Ceram) was not considered to be technique-sensitive in comparison with other methods. 5. Parametric analysis is more reliable than non-parametric one in interpretation of the mean and standard deviation. The sample size of each group has to be more than 30 to use parametric statistics. The level of clinically acceptable marginal fit has not been established. Further studies are needed.

• Journal of Korea Water Resources Association
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• v.31 no.6
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• pp.821-832
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• 1998

This study investigates the prediction of daily water supply, which is a necessary for the efficient management of water distribution system. Fuzzy neuron, namely artificial intelligence, is a neural network into which fuzzy information is inputted and then processed. In this study, daily water supply was predicted through an adaptive learning method by which a membership function and fuzzy rules were adapted for daily water supply prediction. This study was investigated methods for predicting water supply based on data about the amount of water supplied to the city of Kwangju. For variables choice, four analyses of input data were conducted: correlation analysis, autocorrelation analysis, partial autocorrelation analysis, and cross-correlation analysis. Input variables were (a) the amount of water supplied (b) the mean temperature, and (c)the population of the area supplied with water. Variables were combined in an integrated model. Data of the amount of daily water supply only was modelled and its validity was verified in the case that the meteorological office of weather forecast is not always reliable. Proposed models include accidental cases such as a suspension of water supply. The maximum error rate between the estimation of the model and the actual measurement was 18.35% and the average error was lower than 2.36%. The model is expected to be a real-time estimation of the operational control of water works and water/drain pipes.

• 한국균학회소식:학술대회논문집
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• 2015.11a
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• pp.41-41
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• 2015

Oomycetes belong to the kingdom Straminipila, a remarkably diverse group which includes brown algae and planktonic diatoms, although they have previously been classified under the kingdom Fungi. These organisms have evolved both saprophytic and pathogenic lifestyles, and more than 60% of the known species are pathogens on plants, the majority of which are classified into the order Peronosporales (includes downy mildews, Phytophthora, and Pythium). Recent phylogenetic investigations based on DNA sequences have revealed that the diversity of oomycetes has been largely underestimated. Although morphology is the most valuable criterion for their identification and diversity, morphological species identification is time-consuming and in some groups very difficult, especially for non-taxonomists. DNA barcoding is a fast and reliable tool for identification of species, enabling us to unravel the diversity and distribution of oomycetes. Accurate species determination of plant pathogens is a prerequisite for their control and quarantine, and further for assessing their potential threat to crops. The mitochondrial cox2 gene has been widely used for identification, taxonomy and phylogeny of various oomycete groups. However, recently the cox1 gene was proposed as a DNA barcode marker instead, together with ITS rDNA. To determine which out of cox1 or cox2 is best suited as universal oomycete barcode, we compared these two genes in terms of (1) PCR efficiency for 31 representative genera, as well as for historic herbarium specimens, and (2) in terms of sequence polymorphism, intra- and interspecific divergence. The primer sets for cox2 successfully amplified all oomycete genera tested, while cox1 failed to amplify three genera. In addition, cox2 exhibited higher PCR efficiency for historic herbarium specimens, providing easier access to barcoding type material. In addition, cox2 yielded higher species identification success, with higher interspecific and lower intraspecific divergences than cox1. Therefore, cox2 is suggested as a partner DNA barcode along with ITS rDNA instead of cox1. Including the two barcoding markers, ITS rDNA and cox2 mtDNA, the multi-locus phylogenetic analyses were performed to resolve two complex clades, Bremia lactucae (lettuce downy mildew) and Peronospora effuse (spinach downy mildew) at the species level and to infer evolutionary relationships within them. The approaches discriminated all currently accepted species and revealed several previously unrecognized lineages, which are specific to a host genus or species. The sequence polymorphisms were useful to develop a real-time quantitative PCR (qPCR) assay for detection of airborne inoculum of B. lactucae and P. effusa. Specificity tests revealed that the qPCR assay is specific for detection of each species. This assay is sensitive, enabling detection of very low levels of inoculum that may be present in the field. Early detection of the pathogen, coupled with knowledge of other factors that favor downy mildew outbreaks, may enable disease forecasting for judicious timing of fungicide applications.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.2
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• pp.157-163
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• 2017

The aim of the study is to examine the reliability and validity of UFOV, which is a visual driving evaluation tool that has been proven to be reliable and valid in western countries, for the purpose of adapting the tool in a systematic manner to the South Korean population. Two evaluator assessed 23 healthy and 19 stroke patients with UFOV, Trail Making Test A & B(TMT A & B) and Motor Free Visual Perception Test(MVPT) from 7 October 2014 to 25 November, 2014. The researcher analyzed inter-rater reliability, correlation between raters of UFOV with Intraclass correlation coefficient, test-retest reliablility, UFOV with spearman correlation coefficient, concurrent validity, UFOV, TMT A & B and MVPT with spearman correlation coefficient, and discriminative validity, comparison mean scores of UFOV between groups, healthy and stroke with Mann-Whitney U test. UFOV score of participants with stroke had lower compared to the healthy control group. The inter-rater reliability(p<.001), test-retest reliability(p<.01) and concurrent validity(p<.01) was statistically significant. Also discriminant validity was statistically significant(p<.001). Based on this study, Use of UFOV for drivers at risk is essential to prevent future traffic accidents and support driving rehabilitation.

• Clean Technology
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• v.13 no.3
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• pp.195-200
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• 2007

This study investigated the flow rate changes of the heterogeneous rectangular microchannels which have different hydrophilic property on the bottom surface. The heterogeneous rectangular microchannel has three native PDMS (poly-dimethyl siloxane) surfaces which were patterned by the soft lithography. PDMS bottom surface was treated by the argon plasma and coated by the allyl alcohol (99%). The channel length was 10, 20 and 30 mm and the channel width was 100, 200 and $300\;{\mu}m$, respectively. Several external voltages were applied to make the fluid flow by the electroosmosis in the microchannel. For the same electric field strength and hydrophilicity of the bottom surface, the flow rate is almost same. This result is matched to the theoretical expectation and confirms that the experimental system is reliable. With increasing the channel width, the flow rate increased for the same hydrophilicity of the bottom surface. The flow rate of the microchannel of higher hydrophilicity was larger than that of the microchannel of lower hydrophilicity. This result implies that the hydrophilicity change of the bottom surface could be applied to control the flow rate in the microchannel.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.7
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• pp.39-47
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• 2012

The combination of the broadband property and the wide area coverage of satellite communications enables high speed transmission. Every user in the region under the satellite beam coverage can tranceiver and one can simultaneously communicate with multiple users. For these reasons, it is one of commendable telecommunication networks for information transfer. Since the satellite communications use open channels, it is likely to cause jamming with unwanted interference signals. In the thesis, APSK (Amplitude Phase Shift Keying) is employed, which is recommended for DVB-S2 due to high-speed transmission and excellent bandwidth efficiency. For obtaining reliable communication under the jamming environments, the communication satellite transponder rests on the polyphase filter bank structure, which enables switching among the subchannels and gain control on each subchannel, resulting in effectively eliminating jamming. Furthermore, the nulling scheme, one of the various anti-jamming approaches, is investigated, in which unwanted jamming signals are eliminated in the frequency domain after passing through the analysis part of the polyphase filter bank. The performance of the nulling scheme is evaluated for tone jamming and partial band jamming in terms of BER and EVM. The simulation results indicate that the nulling scheme improve the BER and EVM performance over the case without any anti-jamming approach.

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.199-208
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• 2010

In order to substitute FRP bar for steel bar in new structures, it is necessary to establish a reliable design code. But relatively little research has been conducted on the material in Korea. So, a total of 22 beam specimens (18 GFRP reinforced concrete and 4 conventional steel reinforced concrete) were constructed and tested. In the first phase of the experiment, it was carried out to observe flexural behavior, and collect deflection and crack data. In order to eliminate of the uncertainty by the shear reinforcements and induce flexural failure mode, any stirrup were not used and only shear span-depth ratio were adjusted. However, almost beams were broken by shear and the ACI 440.1R, CSA S806, which were used to design test beams, showed considerable deviation between prediction and test results of shear strengths. Therefore in the second phase of the study, shear failure modes and behavior were observed. A standard specimen had dimensions of 3,300 mm long ${\times}$ 800 mm wide ${\times}$ 200 mm effective depth. Clear span and shear span were 2,800 mm, 1,200 mm respectively. Control shear span-depth ratio was 6.0. Four-point bending test over simple support was conducted. Variables of the specimens were concrete compressive strength, type and elastic modulus of reinforcement, shear span-depth ratio, effective reinforcement ratio, the effect of bundle placing method and cover thickness.

• Journal of Korean Academy of Nursing
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• v.26 no.3
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• pp.709-729
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• 1996

This study was done to analyze the trends of research on coping in Korea, to suggest future direction, for research on coping, and ultimately to contribute to an increase in explanation of adaptation. This article reviewed 79 nursing research papers on coping done since 1978 by examining them according to the period of publication or presentation, research design, type of subjects, measurement instruments, research for a degree or not, range of reliability, and association of coping and related variables. The results are as follows : The number of studies on coping increased rapidly from the mid-1980's and decreased slowly from the mid-1990's. The maority of the studies were surveys, comparative studies, or correlational studies. The subects of the 46 studies were healthy people, while those in the remaining studies were patients with a variety of illnesses. Thirth-eight studies on coping were done for master's thesis, three for dissertion, and 38 were not degrees. The Bell and Jalowiec coping scales have not been used since the early 1990's. In contrast, Lazarus and Folkman's W.C.C.L. has been used increasingly since that time. The reliabilities of the coping scale were reported in 37 cases and the Cronbach's alpha coefficients were .71 to .86. All subjects reported using more problem-oriented coping than emotion-oriented coping in short-term or emotion-oriented coping and healthy groups did more long-term coping. It was difficult to describe consistently the relationship between stress and coping according to the type of coping scale or research subjects, but generally moderate relationships were found. This was due to instrumental problems and no consideration of situational context. The subject group who used more short-term coping and less long-term coping reported poorer mental status, and higher scores in burnout and state anxiey than others. That is, the relationship between stress and adaptation increased the power of explanation with intervening the mediating effect of coping. The association of locus of control, mastery, social support, and self-concept with coping showed positive relationships : those of uncertainty and severity in illness with coping showed negativerelationships ; those of state anxiety and depression with short-term coping were positive, and those of self-esteem with long-term coping or problem-oriented coping were negative. There were significant differences in the scores of types of coping according to religion, level of education, and socio-economic status. That is, Presbyterians and Catholics, those with higher education levels and higher socio-economic status used more long-term or problem-oriented coping. On the basis of the above findings the following recommendations are made : 1. There is a need to test the mediating effect of coping variable in order to clarify the concept. 2. Longitudinal studies are needed to determine the patterns of change in coping strategies when stressful events are encountered. 3. It's necessary to develop a reliable and variable measurement tool for coping. 4. There is a need to identify subscales of coping to increase explanation of variance 5. It's necessary to consider personal, situational, and antecedent variables : the characteristics of subject populations, the natures of illness and treatment situations. 6. The power of explanation of studies designed to identify the stress-adaptation process should be increased using the combination model of process-oriented coping and cognitive-structural model.

• Tuberculosis and Respiratory Diseases
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• v.72 no.1
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• pp.15-23
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• 2012

Background: The survival of non-small cell lung cancer (NSCLC) patients with brain metastases is reported to be 3~6 months even with aggressive treatment. Some patients have very short survival after aggressive treatment and reliable prognostic scoring systems for patients with cancer have a strong correlation with outcome, often supporting decision making and treatment recommendations. Methods: A total of one hundred twenty two NSCLC patients with brain metastases who received gamma knife radiosurgery (GKRS) were analyzed. Survival analysis was calculated in all patients for thirteen available prognostic factors and four prognostic scoring systems: score index for radiosurgery (SIR), recursive partitioning analysis (RPA), graded prognostic assessment (GPA), and basic score for brain metastases (BSBM). Results: Age, Karnofsky performance status, largest brain lesion volume, systemic chemotherapy, primary tumor control, and medication of epidermal growth factor receptor tyrosine kinase inhibitor were statistically independent prognostic factors for survival. A multivariate model of SIR and RPA identified significant differences between each group of scores. We found that three-tiered indices such as SIR and RPA are more useful than four-tiered scoring systems (GPA and BSBM). Conclusion: There is little value of RPA class III (most unfavorable group) for the same results of 6-month and 1-year survival rate. Thus, SIR is the most useful index to sort out patients with poorer prognosis. Further prospective trials should be performed to develop a new molecular- and gene-based prognostic index model.

• Journal of IKEEE
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• v.24 no.1
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• pp.33-39
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• 2020

In this paper, we propose the design technique of the vehicle's load weight measuring system using tire pressure, which is one of the physical elements of tires. The proposed technique consists of four processes: noise correction by load and vibration, gas flow correction, data mixer and weight conversion. Noise correction by load and vibration eliminates noise that increases the tire's internal pressure due to external shocks and vibrations produced by the vehicle while it is in motion. In the gas flow correction process, the noise of the internal pressure of the tire is increased due to the temperature rise of the ground with respect to the data obtained through the noise correction process due to the load and vibration. In the data mixer process, the load and pressure on the tolerances the empty, median and the full load are classified according to the change in pressure of the tire that is delivered perpendicular to the tire in the event of cargo. In the weight conversion process, weight is expressed by weight through weight conversion algorithms using noise correction results by load and vibration and gas flow correction. The weight conversion algorithm calculates the weight conversion factor, which is the slope of the linear function with respect to the load and pressure change, and converts the weight. In order to evaluate the accuracy of the loading weight measurement system of the vehicle using the tire pneumatic system technique proposed in this paper, we propose the design technique of the vehicle's load weight measuring system using tire pressure, which is one of the physical elements of tires.. Noise correction results by load and vibration and gas flow data correction results showed reliable results. In addition, repeated weight precision test showed better weight accuracy than the standard value of 90% of domestic companies.