• Journal of Korean Elementary Science Education
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• v.42 no.4
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• pp.497-512
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• 2023

While scientific explanation is a fundamental component of science, teachers often lack familiarity with the formal structure of scientific explanations and the criteria for assessing their quality. Consequently, this study aims to clarify the concept of scientific explanation and proposes a tool for constructing scientific explanations. The primary objective is to explore the tool's impact on enhancing the explanatory skills of pre-service teachers when it comes to the phenomenon of condensation. The research findings indicate that many pre-service teachers initially operated at a description level during the pre-test. However, the implementation of the tool enabled them to advance their explanatory skills beyond the associative level. Notably, the tool was analyzed for its ability to provide pre-service teachers with a conceptual framework for explaining phenomena and guiding logical explanations and micro-level interpretations. This study holds significance in demonstrating that pre-service teachers can comprehend the formalities and criteria of scientific explanations and apply them to enhance their own explanatory abilities. Moving forward, efforts should be made to enhance the scientific explanation level among pre-service teachers across various topics and subject areas. Furthermore, pre-service teachers need classroom experiences that foster the construction of scientific explanations in authentic contexts.

• Journal of East-West Nursing Research
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• v.8 no.1
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• pp.113-125
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• 2003

This study is a descriptive investigation into the image of nurses, and attempted to help to advance the profession of nursing and to provide basic data for developing strategies to improve the image of nurses. The Subject of this study was a group of 380 persons from a K Medical Centre in Seoul, including the hospital patients and their guardians, as well as the doctors, assistants and hospital administrative staff. The data have been collected from the 10th to the 30th of May, 2003. We have developed a research tool of 40 questions divided into three categories using a tool developed by Kim, H.J and KIm, H.O.(2001) verifying its construct validity. The reliability of the tool was Cronbache's ${\alpha}=.97$, and by categories, Cronbach's ${\alpha}=.86$ for service image, Cronbach's ${\alpha}=.96$ for professional image and Cronbache's ${\alpha}=.90$ for social image. The collected data have been analysed according to the purpose of this study using SPSS WIN 11.0 for real number, percentage, factors analysis, multiple regression analysis, ANOVA and $x^2$-test, and the results are as follows: 1) There was a significant difference in the image of nurses by job series of the subjects; from patients and guardians for 4.01 to doctors 3.62, assistants 3.54 and staff members 3.41 (F=36.14, p=.000). As well, there was a significant difference in service, professional and social image categories according to the position of the subjects ($F=20.36{\sim}42.35$, p=.000). 2) The main factors that affect on formation the nurse's imaging came by direct experiences with nurses at hospitals for 81.3%, by looking at the every life of the nurses that the subjects personally know for 15.5%, by mass media for 1.6% and by the accounts from the others for 1.6%. 3) 78.4% of the subjects considered that the image of nurses on mass media is described better than for real, 8.2% believed that the image is described worse than for real, and only 13.2% of the subjects perceived that the image of nurses on mass media corresponds the image of nurses in actual life. 4) 74.5% of the subjects said that they got a better image of nurses after their hospitalization while 2% got a worse one and 23.5% said to have had no changes, and the period of hospitalization had no relevance to the image of nurses (X2=5.04, P=.489). However, while 16.8% of the subjects who spent less than one week in hospital said that they got a better image of nurses, 27.5% of those who spent longer than four weeks got a better image of nurses. 5) There was a significant difference in the total image points of nurses by the patients and their guardians according to the period of hospitalization; 4.14 for 1 to 2 weeks, 4.07 for 2 to 4 weeks, 4.02 for 4 weeks and longer and 3.80 for less than a week (F=3.40, P=.019). Upon the results stated above, I should like to propose as below: 1) An investigative enquiry is needed to improve the image of nurses as though being a nurse is very hard and difficult. 2) A continuous monitoring in mass media is needed to create a positive image of nurses.

• The Journal of Korean Society for Radiation Therapy
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• v.21 no.2
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• pp.89-95
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• 2009

Purpose: The purpose is to evaluate efficiency of the CT simulator QA phantom manufactured for daily QA. Materials and Methods: We made holes ($1{\times}100{\times}1\;mm$) to verify accuracy between image and real measurement in polystyrene phantom and made 1 mm holes to verify table movement accuracy at superior and inferior 100 mm to the center of the phantom and inserted radiopacity material. To evaluate laser alignment, we made cross mark on the right and left side at phantom and to evaluate CT number accuracy we made 3 cylindrical holes and inserted equivalence material of bone, water, air in them. After CT scanning the phantom, We evaluated accuracy between image and real measurement, accuracy of table movement, laser, and CT number using exposed image. Results: It was measured that the accuracy between image and real measurement was ${\pm}0.3\;mm$, table movement accuracy was ${\pm}0.3\;mm$, laser accuracy was ${\pm}0.5\;mm$ from 7th January to 7th March in 2008 as within the reference point ${\pm}1\;mm$. In the CT number accuracy of bone was ${\pm}10\;HU$, air was ${\pm}5\;HU$, water was ${\pm}5\;HU$ as within the reference point is ${\pm}10\;HU$. Conclusion: We was able to perform CT simulator QA and laser equipment QA more conveniently and fast using manufactured phantom at the same time. We will be able to make more accurate treatment plan that added to QA procedures using images at previous daily QA.

• Radiation Oncology Journal
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• v.13 no.3
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• pp.205-214
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• 1995

Purpose : To investigate the effect of Ginkgo biloba extract (GBE) on hypoxic cell fraction and metabolic status in fibrosarcoma (FSa II) of C3H mouse. Materials and Methods : Fibrosarcoma (FSa II) 6 mm in diameter, growing in the right hindleg muscle of C3H mouse was used for estimation of hypoxic cell fraction using comparison of $TCD_{50}$. Radiation was given one hour after administration of GBE (100 mg/kg. i.p.) with or without priming dose of GBE (100 mg/kg, i.p.) given 24 hours earlier. Radiation was also given under air breathing condition or clamp hypoxia without GBE as controls. $^{31}p$ NMR spectroscopy was performed before and one hour after administration of GBE with or without priming dose of GBE. Results : $TCD_{50/120's}$ were 81.7 (77.7-86.0) Gy when irradiated under clamped hypoxia 69.6 (66.8-72.5) Gy under air breathing condition. 67.5 (64.1-71.1) Gy with a single dose of GBE (100 mg/kg) given one hour before irradiation, and 62.2 (59.1-65.5) Gy with two doses of GBE given at 25 hours and one hour before irradiation. The hypoxic cell fractions, estimated from $TCD_{50/120's}$, were $10.6{\%}$ under air breathing condition, $7.2{\%}$ after a single dose of GBE, and $2.7{\%}$ after two doses of GBE. The results of $^{31}P$ NMR spectroscopy were as follow. PCr/Pi ratio was $0.27{\pm}0.04$ and $0.40{\pm}0.04$ before and one hour after a single dose of GBE (p<0.05), respectively, without priming dose and $0.30{\pm}0.02$ and $0.71{\pm}0.04$, respectively, with priming dose (p<0.01). These findings indicate that the metabolic status is slightly improved after a single dose and markedly after repeated administrations. Conclusion : GBE decreases the hypoxic cell fraction and imprvoes the meta bolic status of tumor, probably by increasing the blood flow and delivery of oxygen and nutrients, resulting in increased radiosensitivity of tumor.

• The Korean Journal of Nuclear Medicine
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• v.34 no.4
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• pp.353-359
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• 2000

Purpose: Although ${\alpha}$-fetoprotein is one of the most commonly used tumor markers in Korea, most of the radioimmunoassay kits for ${\alpha}$-fetoprotein have been imported from foreign countries. The purpose of this study was to evaluate the performance of a recently developed domestic immunoradiometric kit for ${\alpha}$-fetoprotein (Riakey AFP IRMA $CT^R$, Sin-Jin Medics, Seoul, Korea). Materials and Methods: We evaluated intra- and inter-assay precision, recovery rate, parallelism, and sensitivity of serum ${\alpha}$-fetoprotein measurement using Riakey AFP IRMA $CT^R$ kit. The values of ${\alpha}$-fetoprotein measured by Riakey AFP IRMA $CT^R$ kit were compared with those measured by two foreign commercial kits (${\alpha}$-fetoproteina of Radim and ${\alpha}$-feto.riabead of Abbott). Results: Intra-assay coefficients of variation on three different levels were 5.3% for 18.9 ng/ml, 3.4% for 133 ng/ml and 1.6% for 330 ng/ml. Inter-assay coefficients of variation were 9.7% for 20.9 ng/ml, 3.2% for 137 ng/ml and 4.1% for 330 ng/ml respectively. Recovery rate tests on all three different levels showed within $100{\pm}10%$. Parallelism was also good and the sensitivity was 0.63 ng/ml. There was strong correlation between the measurement of ${\alpha}$-fetoprotein by Riakey AFP IRMA $CT^R$ and that by two foreign commercial kits(r=0.98). Conclusion: The first Korean domestic immunoradiometric kit for ${\alpha}$-fetoprotein, Riakey AFP IRMA $CT^R$, performed well for clinical use.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.1
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• pp.1-8
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• 2008

The objectives of this study were to compare nutrient natural input between thinned and unthinned natural hardwood stands at Mt. Joongwang, Pyongchang-gun, Gangwon-do. Throughfall, stemflow, A-layer and B-layer soil water as well as litterfall were sampled at two-week intervals during the period of June to October from 2002 to 2004. The amount of rainfall interception in thinned and unthinned natural hardwood stands was as 12% and 18%, respectively. The results indicated that there was no difference in annual nutrient input by rainfall between thinned and unthinned stands. $Na^+$, $Cl^-$ and $SO_4{^{2-}}$ concentrations of A-layer soil water in the unthinned stand were higher than those in the thinned stand. In the B-layer soil water, $Ca^{2+}$, $Cl^-$, $NO_3{^-}$ and $SO_4{^{2-}}$ concentrations in the unthinned stand were higher than those in thinned stand. Mean annual litterfall input was $2,706kg\;ha^{-1}$ in unthinned stand and $2,589kg\;ha^{-1}$ in thinned stand. Total-N input from litterfall was $50.28kg\;ha^{-1}yr^{-1}$ in the unthinned stand and $36.81kg\;ha^{-1}yr^{-1}$ in the thinned stand, while there was no difference in exchangeable cation input from litterfall between thinned and unthinned stands. Thus, the difference in nutrient inputs except for N by throughfall, stemflow and litterfall between the two stands was not influenced by thinning.

• Research in Plant Disease
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• v.28 no.4
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• pp.221-230
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• 2022

The fire blight caused by Erwinia amylovora (Ea) was first reported in 2015 in Korea, and the disease has rapidly spread to 22 regions until 2021. In Korea, all host plants in the apple and pear orchards where fire blight occurred should be eliminated and buried by the Plant Protection Act. To prevent the spread of the disease, all burial sites were prohibited from planting the new host plants for the next three years. To confirm the eradication efficiency of Ea and the reoccurrence of fire blight, the surveillance facilities were established on three burial sites from 2019 to 2020 in Anseong-si, Gyeonggi-do, and Chungju-si, Chungcheongbuk-do. As host plants, five apple trees of fire blight-susceptible cultivar 'Fuji', were planted in each facility. All facilities were enclosed with fences and nets and equipped with two CCTVs, motion sensors, and several other sensors for recording weather conditions to monitor the environment of the sentinel plants in real-time. The sentinel plants were checked for the reoccurrence of fire blight routinely. Suspicious plant parts were collected and analyzed for Ea detection by loop-mediated isothermal amplification polymerase chain reaction and conventional polymerase chain reaction. Until November 2022, Ea has not been detected in all sentinel plants. These results might support that the burial control of infected plants in soil works efficiently to remove Ea and support the possibility to shorten the prohibition period of host plant establishment in the burial sites.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.10 no.2
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• pp.163-170
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• 2003

Purpose: This study was done to identify stress, fatigue, and self efficacy in patients on dialysis and identify their effect on quality of life. Method: The participants (n=149) who agreed to participate in the research were selected from among those who were on dialysis treatment at C University Medical Centers in Seoul and Inchon, and at C University Medical Center in Jeju. The data were collected from July, 2001 to March, 2002 using interviews. Data analysis was done with t-test, ANOVA, and multiple stepwise regression using the SAS program. Result: Quality of life was significantly different according to economic status, and type of dialysis. Quality of life for the group with higher economic status was better than for the group with lower economic status, and the group on peritoneal dialysis had higher quality of lift scores than the group on hemodialysis. As for self-efficacy, there were significant difference according to duration of disease, type of dialysis, and duration of dialysis. Stress was significantly different according to marital status. Quality of life was significantly predicted by stress (40.02%) and fatigue (3.85%). Conclusion: To improve quality of life for people on dialysis, their stress should be treated positively, also multi-dimensional nursing interventions to provide emotional support and nursing interventions to diminish fatigue are required.

• Korean Journal of Materials Research
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• v.24 no.9
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• pp.502-507
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• 2014

Recently, improvement in the conversion efficiency of silicon-based solar cells has been achieved by decreasing emitter doping concentration, because the lightly doped emitter can effectively prevent the recombination of electrons and holes generated by solar light irradiation. This type of emitter is very thin due to the low doping concentration, thus conductive materials (i.e., silver) used for front electrodes can easily penetrate the emitter during a firing process because of their large diffusivity in silicon. This results in junction leakage currents which might reduce cell efficiencies. In this study, $Al_2O_3$-coated Ag powders were synthesized by an ultrasonic spray pyrolysis method and applied to the conductive materials of the front electrode to control the junction leakage current. The $Al_2O_3$ shell obstructs the Ag diffusion into the emitter during the firing process. The powder is spherical with a core-shell structure and the thickness of the $Al_2O_3$ shell is tens of nanometers. Solar cells were fabricated using pure Ag powders or the $Al_2O_3$-coated Ag powder as front electrode materials, and the conversion efficiency and junction leakage current were compared to investigate the role of the $Al_2O_3$ shell during the firing processes.

• The Korean Journal of Health Service Management
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• v.9 no.3
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• pp.175-185
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• 2015

Objectives : This study was did a meta-analysis of emergency room visits decreased effectiveness of self management education interventions in asthma among adult patients with asthma. Methods : A search of the database PubMed resulted in identifying 8,619 studies done between January 1990 and November 2012. STATA version 10.0 was used to analyze the effect size, explore possible causes of heterogeneity, and determine publication bias with a funnel plot. Results : We included 7 cases on emergency room visits decreased effectiveness of self management and education. Asthmatic patients experienced fewer attacks (summary effect size, 0.75; 95% confidence interval [CI], 0.65-0.95). We found that emergency room visits decreased effectiveness of self management and education were associated with statistically significant effects. Conclusions : Based on these finding, self management and education on interventions are necessary to prevent asthmatic attacks in patients and to reduce the severity of the attacks, and self management and education programs are needed in Korea.