• Research in Plant Disease
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• v.7 no.3
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• pp.155-163
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• 2001

Two attenuated Cucumber mosaic virus (CMV) isolates, Paf-CMV and Rs2-CMV that had been selected from CMV isolates associated with satellite RNA (satRNA) were tested for cross-protection effect in pepper plants. The viruses selected as attenuated strains appeared to be identical serologically and physically to the challenge virus (Mf-CMV), but they were lower in the dilution end-point of infectivity of crude sap than Mf-CMV When symptoms were observed in several indicator plants after inoculation, Paf-CMV and Rs2-CMV were symptomless or showed mild mosaic symptoms while another satRNA isolate Ap-CMV developed severe mosaic symptoms on the leaves as Mf-CMV. The nucleotide sequences of the satRNAs were determined by sequencing full-length cDNA clones. Paf-, Rs2- and Ap-satRNAs were 386, 335, and 347 nucleotides long, respectively, The sequences were then compared with the other known Y-satRNA, revealing that nucleotide sequences of the satRNAs consisted of 5'- and 3'-terminal conserved regions. However variations occurred on the middle regions of the sequences, especially those related to symptom interference, showing significant differences between Paf-satRNA and other isolates. Infectious transcripts of Paf-satRNA and Rs2-satRNA induced mild mosaic symptoms in pepper plants when supported by genomic RNAs of Mf-CMV. Under greenhouse conditions, Paf-CMV and Rs2-CMV were tested for cross-protection effect in pepper and tobacco (Nicotiana tabacum cv, Xanthi nc) plants against Mf-CMV. No symptoms were developed on the plants vaccinated with Paf-CMV until 3 weeks after inoculation with the virulent strain; however another attenuated isolate, Rs2-CMV, showed less effectiveness in cross-protection. Depending on the concentration of the challenged virus, symptoms sometimes appeared later in the upper leaves. However, in plants challenged with low concentrations (below 0.2 mg/ml) of the challenge inoculum, symptoms caused by the virulent strain did not develop on the plants vaccinated with Paf-CMV. In the field experiments, the number of pepper plants with severe mosaic symptoms in the control plots was progressively increased after transplanting and reached approximately 50% after 50 days. On the other hand, the incidence of mosaic disease appeared very low on the plants that had received the protective inoculation with Paf-CMV.

• Korean Journal of Psychosomatic Medicine
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• v.26 no.2
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• pp.77-85
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• 2018

Objectives : This study aimed to investigate the level of distress using the distress thermometer (DT) and the factors associated with distress in postoperative breast cancer (BC) patients. Methods : DT and WHOQOL-BREF (World Health Organization Quality of Life Scale Abbreviated Version) along with sociodemographic variables were assessed in patients undergoing surgery for their first treatment of BC within one week postoperatively. The distress group consisted of participants with a DT score ${\geq}4$. The prevalence and associative factors of distress were examined by descriptive, univariable, and logistic regression analysis. Results : Three hundred seven women were recruited, and 264 subjects were finally analyzed. A total of 173 (65.5%) were classified into the distress group. The distress group showed significantly younger age (p=0.045), living without a spouse (p=0.032), and worse quality of life (QOL) as measured by overall QOL (p=0.009), general health (p=0.005), physical health domain (p<0.000), and psychological health domain (p=0.002). The logistic regression analysis showed that patients aged 40-49 years were more likely to experience distress than those aged ${\geq}60years$ (Odds ratios [OR]=2.992, 95% confidence interval [CI] 1.241-7.215). Moreover, the WHOQOL-BREF physical health domain was a predictive factor of distress (OR=0.777, 95% CI 0.692-0.873). Conclusions : A substantial proportion of patients are experiencing significant distress after BC surgery. It would be expected that distress management, especially in the middle-aged patients and in the domain of physical QOL (e.g., pain, insomnia, fatigue), from the early BC treatment stage might reduce chronic distress.

• The Journal of Internal Korean Medicine
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• v.30 no.3
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• pp.510-524
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• 2009

Objective : This study was designed to find the correlation between Sasang Constitution and heart rate variability(HRV). Method : There were 665 subjects (280 men and 385 women), between 39 and 72 years old. in a rural community. Sasang Constitution was diagnosed by a Sasang constitutional specialist using PSSC (Phonetic System for Sasang Constitution), face and tongue photo and checkup-list. A structured-questionnaire was used to assess the general characteristics. HRV was recorded using SA-2000 (medi-core). HRV was assessed by time domain and by frequency domain analysis. Metabolic syndrome was defined on the basis of clustering of risk factors, when three or more of the following cardiovascular risk factors were included : blood pressure, fasting blood sugar, triglyceride HDL-cholesterol, and abdominal obesity (waist). Because of the skewness of the data, logarithmic transformation was performed on the absolute units of the spectral components of HRV, and the resulting logarithmic values and normalized units were compared between the groups by a logistic regression. The 95% confidence interval (CI) of the odds ratio was used and calculated from the data laid out for a cross sectional study. Results : 1. Odds ratios of Taeeumin and Soeumin in female adults below 60 years old were significantly lower than that of Soyangin in LF norm and LF/HF ratio. Odds ratios of Taeeumin and Soeumin in female adults below 60 years old were significantly higher than that of Soyangin in HF norm. 2. There was no significant correlation between HRV and Sasang Constitution in female adults from 60 years old and over. 3. There was no significant correlation between HRV and Sasang Constitution in male adults. Conclusion : There is a statistically significant correlation between the HRV and Sasang Constitution. There is a tendency of increase in the sympathetic activity in Soyangin. There is a tendency of decrease in the parasympathetic activity in Taeeumin and Soeumin.

• Journal of the Korean Society of School Health
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• v.17 no.1
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• pp.85-95
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• 2004

Objectives : The aim of this study was to identify the trend of school health research by analyzing articles related to school health for the last 10 years. this information can be used to guide research direction for the future. Methods : This study is a descriptive study that analyzed annual data. using an objective frame of evaluation about the methodology and research domain in each paper, all the papers included in the journals concerning school health from January 1993 to December 2000 were analyzed. The data was processed statistically by frequency and percentage. Results : 455 papers in 9 journals related to school health were published. The Journal of the Korean Society of School Health had 204 articles, the highest number of any journal. most of the articles were descriptive, but the number of experimental studies increased over time. the most common research subjects were students were the greatest ones, but the trend to study both parents and teachers increased near the end of the sampling period. the most common selection of subjects appeared to be based on convenience, but probability sampling gradually increasing annually. the most common research instrument was the questionnaire and the reliability and the validity of instruments were described in approximately half of the studies. The survey was the most commonly used method of data collection. The papers that met ethical issue in data collection were less than those that did not. In addition, the papers that provided the rationale for the calculation of sample size were less than those that did not. parametric statistics were the main methods of data analysis, but some advanced statistics were used more often than simple descriptive statistics in the latter part of the sampling period. In general, limit of the studies were not frequently mentioned but more recommendations were made. regarding the characteristics of the research area, the assesment domain was remarkable. The rate of school health problem assesment was the highest among research subjects. Sex- related subjects were the highest in detail research subjects. Conclusions : The research of school health has increased quantitatively, but it is difficult to ascertain its qualitative development. Therefore, on the basis of the research completed up until now, more school-based intervention studies and longitudinal studies need to be another target for the evaluation of the effects of the school health service. as well, policy suggestion through international and cross-sectional comparison studies are needed to assist in the establishment of the long term direction of school health.

• Geophysics and Geophysical Exploration
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• v.9 no.1
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• pp.102-107
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• 2006

Recently, rapid developments in computer hardware have enabled reverse-time migration to be applied to various production imaging problems. As a wave-equation technique using the two-way wave equation, reverse-time migration can handle not only multi-path arrivals but also steep dips and overturned reflections. However, reverse-time migration causes unwanted artefacts, which arise from the two-way characteristics of the hyperbolic wave equation. Zero-lag cross correlation with diving waves, head waves and back-scattered waves result in spurious artefacts. These strong artefacts have the common feature that the correlating forward and backward wavefields propagate in almost the opposite direction to each other at each correlation point. This is because the ray paths of the forward and backward wavefields are almost identical. In this paper, we present several tactics to avoid artefacts in shot-domain reverse-time migration. Simple muting of a shot gather before migration, or wavefront migration which performs correlation only within a time window following first arriving travel times, are useful in suppressing artefacts. Calculating the wave propagation direction from the Poynting vector gives rise to a new imaging condition, which can eliminate strong artefacts and can produce common image gathers in the reflection angle domain.

• Journal of agricultural medicine and community health
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• v.40 no.4
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• pp.221-227
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• 2015

Objective: This study assessed whether both physical disability and perceived dependence relate to depression or whether perceived dependence in personal care activities, household activities, community mobility and recreational activities is an intermediate step in the relationship between physical disability and depressive symptoms. Methods: Data come from a cross-sectional survey of 209 women, aged 55 or older, with osteoarthritis (OA). Mediation analyses occurred in four step and included logistic regression analyses as outlined by Baron & Kenny. Results: The results from step 1 showed that greater difficulty with each domain of physical disabilities was significantly related to greater perceived dependence. In step 2, greater perceived dependence was significantly associated with greater depressive symptoms in all domains. Step 3 analyses showed that greater physical disabilities in each domain were significantly associated with depression. The final step testing mediation indicated that personal care activities, household activities and community mobility were fully mediated by perceived dependence. That was, once dependence was taken into account, the relationship between physical disabilities and depression was no longer significant. Partial mediation was found for dependence and recreational activity limitations. Conclusion: It is important to take into account the experience of perceived dependence as a mediator in understanding the relationship between disability and depression in the domains of personal care, household, and community mobility. To conclude, these findings point to the importance of taking into account an individual's reaction to their disability rather than just focusing on the severity of disability.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.3
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• pp.199-206
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• 2014

In this paper, a scheme to evaluate the response variability for functionally graded material (FGM) beam with varying sectional area is presented. The randomness is assumed to appear in a spatial domain along the beam axis in the elastic modulus. The functionally graded material categorized as composite materials, however without the drawbacks of delamination and occurrence of cracks due to abrupt change in material properties between layers in the conventional composite materials. The functionally graded material is produced by the gradual solidification through thickness direction, which endows continuous variation of material properties, which makes this material performs in a smooth way. However, due to difficulties in tailoring the gradients, to have uncertainty in material properties is unavoidable. The elastic modulus at the center section is assumed to be random in the spatial domain along the beam axis. Introducing random variables, defined in terms of stochastic integration, the first and second moments of responses are evaluated. The proposed scheme is verified by using the Monte Carlo simulation based on the random samples generated employing the spectral representation scheme. The response variability as a function of correlation distance, the effects of material and geometrical parameters on the response variability are investigated in detail. The efficiency of the proposed scheme is also addressed by comparing the analysis time of the proposed scheme and MCS.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.4
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• pp.428-435
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• 2004

With the rapid and wide-spread use of cellular telephones much attention has been focussed on propagation in the urban area crowed with buildings and houses. It is often surrounded by hills, forests, and mountains. The importance of surface scattering intereference between transmitters and receivers on the rough surfaces has been interested and investigated. Therefore, a prediction method is necessary to estimate the influence of rough surfaces on microwave radio propagation. Moreover, most of the mobile communications are performed based on the digital communication system rather than the analog one. In this case, we must pay more careful attention to the signal delay caused by the phase delay due to the multi-path propagation. In this paper we have analyzed numerically scattering of electromagnetic waves from building walls by using FVTD(Finite Volume Time Domain) method. We consider three different types of rough surfaces such as periodic, random, and composite structures. We calculate the bistatic normalized radar cross section (NRCS) for horizontal and vertical polarization, and we take account of the conventional optical reflection which corresponds to the n-th Bragg reflection for periodic structures. In addition, we investigated what conditions are needed in order to be able to ignore the higher order Bragg reflection for the periodic structures.

• Journal of Platform Technology
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• v.9 no.3
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• pp.52-62
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• 2021

Quality control is critical at manufacturing sites and is key to predicting the risk of quality defect before manufacturing. However, the reliability of manual quality control methods is affected by human and physical limitations because manufacturing processes vary across industries. These limitations become particularly obvious in domain areas with numerous manufacturing processes, such as the manufacture of major nuclear equipment. This study proposed a novel method for predicting the risk of quality defects by using natural language processing and machine learning. In this study, production data collected over 6 years at a factory that manufactures main equipment that is installed in nuclear power plants were used. In the preprocessing stage of text data, a mapping method was applied to the word dictionary so that domain knowledge could be appropriately reflected, and a hybrid algorithm, which combined n-gram, Term Frequency-Inverse Document Frequency, and Singular Value Decomposition, was constructed for sentence vectorization. Next, in the experiment to classify the risky processes resulting in poor quality, k-fold cross-validation was applied to categorize cases from Unigram to cumulative Trigram. Furthermore, for achieving objective experimental results, Naive Bayes and Support Vector Machine were used as classification algorithms and the maximum accuracy and F1-score of 0.7685 and 0.8641, respectively, were achieved. Thus, the proposed method is effective. The performance of the proposed method were compared and with votes of field engineers, and the results revealed that the proposed method outperformed field engineers. Thus, the method can be implemented for quality control at manufacturing sites.

• Geophysics and Geophysical Exploration
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• v.2 no.2
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• pp.86-95
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• 1999

This paper presents an efficient three-dimensional (3-D) modeling algorithm using the extended approximation to an electric field integral equation. Numerical evaluations of Green's tensor integral are performed in the spatial wavenumber domain. This approach makes it possible to reduce computing time, to handle smoothly varying conductivity model and to remove singularity problems encountered in the integration of Green's tensor at a source point. The responses obtained by 3-D modeling algorithm developed in this study are compared with those by the full integral equation for a thin-sheet EM scattering. The extensive analyses on the performance of modeling algorithm are made with the conductivity contrasts and source frequencies. These results show that the modeling algorithm are accurate up to the conductivity contrast of 1:16 and the frequency range of 100 Hz-100 kHz. The extended Born approximation, however, may produce inaccurate results for some source and model configurations in which the electric field is discontinuous across the conductivity boundary. We performed the modeling of a composite model of which conductivity varies continuously and this shows the modeling algorithm developed in this study is efficient for 3-D EM modeling. For a cross-hole source-receiver configuration a composite model of which conductivity varies continuously can be successfully simulated using this algorithm.