• The Journal of Korean Academy of Prosthodontics
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• v.58 no.3
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• pp.207-216
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• 2020

Purpose: To compare the polishing characteristics and their influence on Candida albicans adhesion to the recently introduced polyetherketoneketone (PEKK) and the conventional polymethylmethacrylate (PMMA) denture resin material. Materials and methods: Specimens from PEKK (Group E) and PMMA (Group M) were made in dimensions of 8 mm in diameter and 2 mm in thickness. The specimens were further divided into sub-groups according to the extent of polishing (ER, MR: rough; EP, MP: polished, N = 12 each). The specimens were polished using polishing machine and SiC foil. ER and MR group specimens were polished with 600 grit SiC foil only. EP and MP groups were further polished with 800, 1,000, 1,200 grit SiC foils sequentially. To measure the surface roughness values (Sa) of specimens, atomic force microscope (AFM) was used and scanning electron microscope (SEM) observation under 1,000, and 20,000 magnifications was performed to investigate surface topography. The polished specimens were soaked in C. albicans suspension for 2 hours with shaking to promote adhesion. The attached C. albicans were detached from the surface with 10 times of pipetting. The suspension of detached C. albicans was performed by serial dilution to 10³ times, and the diluted suspensions were inoculated on Sabouraud dextrose agar plates using spread plate method. After incubating the plate for 48 hours, colony forming unit (CFU)/plate of C. albicans was counted. Statistical analysis was performed using one-way ANOVA and Tukey HSD test to confirm significant difference between the groups (α=.05). Results: Average Sa value was significantly higher in MR group compared to other groups (P<.05), meaning that additional polishing steps reduced surface roughness effectively only in the PMMA specimens. There was no significant difference in Sa values between MP and EP groups. In SEM images, PEKK specimens showed numerous spikes of abraded material protruding from the surface and this phenomenon was more significant in EP group. The mean CFU/plate value was the highest in EP group and this was significant when it was compared to MP group (P<.05) which was the lowest. Conclusion: Polishing PEKK using serial SiC abrasive foil may result in higher adhesion of C. albicans. In clinic, this should be considered carefully.

• Journal of Radiation Protection and Research
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• v.32 no.2
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• pp.89-96
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• 2007

Radiation safety managements in medical institutions are needed to protect certain radiation damages as a part of National Coalition. This study investigates the characteristics of self-efficacy that become the major factor on the knowledge, attitude, and behavior on the radiation safety management of radiation workers as an approach of educational aspects and analyzes the relationship between such factors to provide basic materials for improving the activity level of radiation safety managements. In order to implement the goal or this study, a survey was performed for 1,200 workers who were engaged in radiation treatments in medical centers, such as general hospital, university hospital, private hospital, and public health center for 42 days from July 23,2006. Then, the results of the analysis can be summarized as follows: 1. Average scores on knowledge, attitude, and behavior in the radiation safety management were presented as $75.76{\pm}11.20$, $90.55{\pm}8.59$, $80.58{\pm}11.70$, respectively. Also, the average score of self-efficacy was recorded as $73.55{\pm}9.82$. 2. Knowledge levels in the radiation safety management showed significant differences according to the sex, age, marriage, education, and experience. Also, males of married, older, highly educated, and largely experienced represented high knowledge levels. Attitude levels in the radiation safety management showed certain significant differences according to the type of medical centers in which private hospitals showed a relatively low level compared to that of high levels in university hospitals. Behavior levels in the radiation safety management also represented significant differences according to the age, marriage, education, experience, and types of medical centers. Factors in married, general hospital, older, highly educated, and largely experienced showed high behavior levels. In addition, the self-efficacy showed certain differences according to the marriage and types of medical centers. Factors in married and general hospital demonstrated high self-efficacy levels. 3. Relationship between knowledge, attitude, behavior, and self-efficacy on the radiation safety management showed statistical differences according to the relationship between the knowledge and the attitude, the knowledge and the behavior, the attitude and the behavior, the attitude and the self-efficacy, and the behavior and the self-efficacy. The relationship between the behavior and the self-efficacy was represented as r = 0.482, which was the strongest relationship in such factors. Also, the knowledge and self-efficacy didn't show certain relationships.

• Child Health Nursing Research
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• v.2 no.2
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• pp.45-57
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• 1996

A serious disease in a family influences the entire family member given the fact that the members closely interact with each other. Especially in terms of pediatric nursing, study on family gains importance as the need to care of families whose children with developmental disabilities and chronic disease This study was done based on The Resiliency Model of Family Adjustment and Adaptation(McCubbin, 1991) is intended to examine the stress of parents whose children suffer from cleft lip or /and cleft palate. It also helps them to cope with the stress and analyze the relationship between the stress and coping This study used Family Inventory of Life Events and Changes (FILE) and Coping Health Inventory for Parents(CHIP) for measuring family stress and coping. The two instruments are revised to fit the social and cultural environment of Korean culture. Data collection was done from April 18, 1996 to May 18, 1996 at 8 University medical centers located in Seoul. Those who answered questionnaires were 84 parents whose children have cleft lip or /and cleft palate. SPSS PC+ was used to analyze the data collotted. Programs used for data analysis were t-test, ANOVA, Pearson correlation coefficient. The study is summarized as follows .1. The average score of family stress is 10.46(percentage of the full score 24.90) and 'finance and business strains'(3.25), and 'intrafamily strains'(2.65) ranked the highest. The average score of family's coping is 1.93, which is close to the answer of' moderately helpful' and they are measured to put their utmost efforts to' intergration and cooperation of family and optimistic definition on the situation'. 2. There is no significant statistical correlation between the family stress and coping. 3. Mothers show more stress than fathers in the parts of 'illness and family care strains' and 'losses'(t〓-2.34, t〓-2.32, p<.05). 4. Fathers show more willingness to cope with the stress than mothers do in the parts of' seeking social support','self-esteem','emotional comfort' 5. Mothers are more stress than fathers in the parts of family stress and its coping with it by usual traits(t〓-2.78, p<.05). Parents with religion are measured to cope more willingly than those who are not 6. Income of a family shows positive correlationship with family coping (r〓.28, p<.05). The study shows that gender difference is significant variable in studying on family stress and coping. Mothers get more stress than fathers, which has much to do with the fact that they are in charge of raising children and keeping houseworks. Accordingly, managing family crisis and its survival can be induced by giving support for the mothers, studying fathers including the rest of the family members and giving nursing care and arbitration ; religious background is also considered to be one of the important factors in family stress , judging from the relationship between family income and family's coping, caring given to suffering children is needed on societal levels. The above considerations bring up the need to have a longitudinal study of children with congenital anomaly including cleft lip or /and cleft palate and their families about family stress and coping. Resiliency programs on family system and their effectiveness and the relationship between the enlarged families with social and cultural values reflecting Korean tradition are also needed to be studied.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.4
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• pp.285-291
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• 2007

Objective: To evaluate the outcomes of in vitro fertilization and embryo transfer (IVF-ET) in women over 40 years of age. Methods: A total of 170 patients (271 cycles) over 40 years of age who underwent IVF-ET at Seoul Women's Hospital (Incheon, Korea) were analyzed in this study retrospectively. The patients were grouped into the women <44 years old group and the women $\geq$44 years old group. Statistical analysis was performed using Student's t-test and Fisher's exact test as appropriate. Results: An overall clinical pregnancy rate per retrieval was 11% (30/271). Of these, clinical miscarriage rate were 33% (10/30) and the overall delivery rate was 7.4% (20/271) per retrieval, respectively. The women $\geq$44 years old group had significantly higher cancellation rate (13% vs. 25%), lower number of retrieved oocytes (6.17$\times$4.62 vs. 4.13$\times$4.07), decreased number of 2PN (4.83$\times$3.61 vs. 3.46$\times$3.12), and reduced embryos for transfer (3.52$\times$1.72 vs. 2.81$\times$1.83) than the women <44 years old group. We found significantly lower clinical pregnancy rate (13.0% vs. 2.1%) and live birth rate (9.0% vs. 0.0%) in the women $\geq$44 years old group than the women <44 years old group. Conclusion: The present study has shown that IVF outcome is seriously impaired in the women $\geq$44 years old.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.4
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• pp.305-312
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• 2007

Objective: To evaluate the efficacy of split insemination method in treatments for non-male factor infertility. Method: Laboratory and clinical data were collected from 505 cycles of split insemination during 2002$\sim$2005 in our center. The subjects were non-male factor infertility such as endometriosis, tubal, uterine, PCOS and idiopathic infertility without any sperm defects. Retrieved oocytes were randomly divided, and inseminated by conventional IVF or ICSI. Fertilized zygotes were cultured for 2$\sim$5 days to ET date, and surplus zygotes and embryos were frozen for subsequent frozen-thawed ET cycles. Clinical outcomes according to insemination method were compared by statistical analysis. Results: The overall fertilization per retrieved oocytes was significantly higher in ICSI than that of conventional IVF in sibling oocytes (62.5$\pm$22.3% vs 52.9$\pm$28.0%, p<0.01). Total fertilization failure occurred only in 2 of 505 cycles (0.4%) in split insemination cycles. Incidence of fertilization failure and poor fertilization rate less than 30% by ICSI were significantly lower than those of conventional IVF (1.1% and 7.5% vs 8.5% and 22.0%, p<0.01). Delivery rates after transfer of fresh and thawed embryos from split insemination cycles were 40.0% (185/462) and 35.0% (55/157), respectively. There was no significant difference in the implantation and delivery rates of ET with embryos from conventional IVF or ICSI. Conclusion: Taken together, the split insemination method improves poor fertilization rates resulting in successful clinical outcomes and thus could be used for non-male factor infertile couples in human ART program.

• The Journal of the Petrological Society of Korea
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• v.20 no.1
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• pp.23-37
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• 2011

The scaling properties on the length distribution of microcrack populations from Tertiary crystalline tuff are investigated. From the distribution charts showing length range with 15 directional angles and five groups(I~V), a systematic variation appears in the mean length with microcrack orientation. The distribution charts are distinguished by the bilaterally symmetrical pattern to nearly N-S direction. The whole domain of the length-cumulative frequency diagram for microcrack populations can be divided into three sections in terms of phases of the distribution of related curves. Especially, the linear middle section of each diagram of five groups represents a power-law distribution. The frequency ratio of linear middle sections of five groups ranges from 46.6% to 67.8%. Meanwhile, the slope of linear middle section of each group shows the order: group V($N60{\sim}90^{\circ}E$, -2.02) > group IV($N20{\sim}60^{\circ}E$, -1.55) > group I($N60{\sim}90^{\circ}W$, -1.48), group II($N10{\sim}60^{\circ}W$, -1.48) > group III($N10^{\circ}W{\sim}N20^{\circ}E$, -1.06). Five sub-populations(five groups) that closely follow the power-law length distribution show a wide range in exponents( -1.06 - -2.02). These differences in exponent among live groups emphasizes the importance of orientation effect. In addition, breaks in slope in the lower parts of the related curves represent the abrupt development of longer lengths, which is reflected in the decrease in the power-law exponent. Especially, such a distribution pattern can be seen from the diagram with $N10{\sim}20^{\circ}E,\;N10{\sim}20^{\circ}W$ and $N60{\sim}70^{\circ}W$ directional angles. These three directional angles correspond with main directions of faults developed around the study area. The distribution chart showing the individual characteristics of the length-cumulative frequency diagrams for 15 directional angles were made. By arraying above diagrams according to the categories of three groups(A, B and C), the differences in length-frequency distributions among these groups can be easily derived. The distribution chart illustrates the importance of analysing microcrack sets separately. From the related chart, the occurrence frequency of shorter microcracks shows the order: group A > group B > group C. These three types of distribution patterns could reveal important information on the processes occurred during microcrack growth.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1983.05a
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• pp.6.4-7
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• 1983

Hoarseness is the most common and early symptom in laryngeal diseases. A clinico - statistical analysis was performed on 228 cases with chief complaint of hoarseness at the department of otolaryngology, Jeonbug National University during the past 3 years from January 1980 to December 1980. 1) The number of the patient with hoarseness were 228 cases (2.3 %) among total outpatient of 10110 cases. 2) Among the 228 cases with hoarseness, male were 115 cases and female were 113 cases, so sex ratio was nearly same. 3) The underlying diseases causing hoarseness in order of frequency were acute laryngitis 43 cases (18.9 %), chronic laryngitis 36 cases (15.8 %), vocal nodule 30 cases(13.2 %), vocal polyp 30 cases (13.2 %), vocal cord paralysis 26 cases (11.4 %), laryngeal carcinoma 18 cases (7.9 %) and laryngeal tuberculosis 15 cases (6.6 %). There were other diseases of larynx in 30 cases (13.2 %). 4) The incidence of age distribution in order of frequency were 4th decade (26.8 % ), 3rd decade (18.9%), 5th decade (17.1 %), 2nd decade (15.8 %) and 6th decade (9.6 %). 5) The duration from onset to consultation in order of frequency were 11 days-1 month (22.8 %), 1 month-3 months(19.7%), 3 months -6 months (18.9 %), within 10 days (13.6 %), 6 months-l year (13.2 % ), 1 year -3 years(7. 9 %) and 3 years over. 6) The duration from onset to consultation for underlying diseases were as follows ; acute laryngitis was within 10 days, chronic laryngitis was 3 months - 6 months, vocal nodule was 1 month-3 months, vocal polyp was 3 months -1 year, vocal cord paralysis was 11 days -1 month. 7) Associated symptoms with hoarseness in order of frequency were sore throat (25 %), sputum (8.8 %), swallowing difficulty (7.9 %) and dyspnea (6.1 %). But 84 cases (36.8 %), there were no other symptoms except hoarseness.

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.174-180
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• 2000

This work was carried out to investigate the effects of mashing proportion of meju(as wet weight basis of raw soybean) to 20% salt brine on the chemical compositions and sensory characteristics of kanjang. By increasing the salt brine proportion in the kanjang mash, total nitrogen, TCA soluble nitrogen and total free amino acid content in kanjang were decreased accordingly, but although pH values and organic acids content were not different noticeably, the major organic acids in kanjang, lactic acid, pyroglutamic acid and acetic acid were increased up to the mashing proportion of 1:2 from 1:1 and pH values decreased up to that of 1:2.5. Residual sugar content in 1:1 kanjang was exceptionally high. The major free amino acids in kanjang were glutamic acid, lysine, alanine and leucine. The acceptability scores of kanjang tested by sensory evaluation were decreased in inverse proportion to the salt brine proportion of kanjang mash, but those of kanjang samples with $1:1{\sim}1:2.5$ mashing proportions were not significantly different but that of 1:3 different from 1:1 statistically at 5% level. The major chemical compositions, significantly effective to the acceptability of kanjang, were found to be glutamic acid and free amino acid by statistical analysis.

• Education of Primary School Mathematics
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• v.16 no.2
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• pp.123-145
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• 2013

This study was expected to yield the meaningful conclusions from the experimental group who took lessons based on inductive activities using GeoGebra at the beginning of proof learning and the comparison one who took traditional expository lessons based on deductive activities. The purpose of this study is to give some helpful suggestions for teaching proof to mathematically gifted elementary students. To attain the purpose, two research questions are established as follows. 1. Is there a significant difference in proof abilities between the experimental group who took inductive lessons using GeoGebra and comparison one who took traditional expository lessons? 2. Is there a significant difference in proof attitudes between the experimental group who took inductive lessons using GeoGebra and comparison one who took traditional expository lessons? To solve the above two research questions, they were divided into two groups, an experimental group of 10 students and a comparison group of 10 students, considering the results of gift and aptitude test, and the computer literacy among 20 elementary students that took lessons at some education institute for the gifted students located in K province after being selected in the mathematics. Special lesson based on the researcher's own lesson plan was treated to the experimental group while explanation-centered class based on the usual 8th grader's textbook was put into the comparison one. Four kinds of tests were used such as previous proof ability test, previous proof attitude test, subsequent proof ability test, and subsequent proof attitude test. One questionnaire survey was used only for experimental group. In the case of attitude toward proof test, the score of questions was calculated by 5-point Likert scale, and in the case of proof ability test was calculated by proper rating standard. The analysis of materials were performed with t-test using the SPSS V.18 statistical program. The following results have been drawn. First, experimental group who took proof lessons of inductive activities using GeoGebra as precedent activity before proving had better achievement in proof ability than the comparison group who took traditional proof lessons. Second, experimental group who took proof lessons of inductive activities using GeoGebra as precedent activity before proving had better achievement in the belief and attitude toward proof than the comparison group who took traditional proof lessons. Third, the survey about 'the effect of inductive activities using GeoGebra on the proof' shows that 100% of the students said that the activities were helpful for proof learning and that 60% of the reasons were 'because GeoGebra can help verify processes visually'. That means it gives positive effects on proof learning that students research constant character and make proposition by themselves justifying assumption and conclusion by changing figures through the function of estimation and drag in investigative software GeoGebra. In conclusion, this study may provide helpful suggestions in improving geometry education, through leading students to learn positive and active proof, connecting the learning processes such as induction based on activity using GeoGebra, simple deduction from induction(i.e. creating a proposition to distinguish between assumptions and conclusions), and formal deduction(i.e. proving).

• Journal of the Mineralogical Society of Korea
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• v.22 no.4
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• pp.313-324
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• 2009

We explore the effect of particle shape and size on 3-dimensional (3D) network and pore structure of porous earth materials composed of glass beads and silica gel using NMR micro-imaging in order to gain better insights into relationship between structure and the corresponding hydrologic and seismological properties. The 3D micro-imaging data for the model porous networks show that the specific surface area, porosity, and permeability range from 2.5 to $9.6\;mm^2/mm^3$, from 0.21 to 0.38, and from 11.6 to 892.3 D (Darcy), respectively, which are typical values for unconsolidated sands. The relationships among specific surface area, porosity, and permeability of the porous media are relatively well explained with the Kozeny equation. Cube counting fractal dimension analysis shows that fractal dimension increases from ~2.5－2.6 to 3.0 with increasing specific surface area from 2.5 to $9.6\;mm^2/mm^3$, with the data also suggesting the effect of porosity. Specific surface area, porosity, permeability, and cube counting fractal dimension for the natural mongolian sandstone are $0.33\;mm^2/mm^3$, 0.017, 30.9 mD, and 1.59, respectively. The current results highlight that NMR micro-imaging, together with detailed statistical analyses can be useful to characterize 3D pore structures of various porous earth materials and be potentially effective in accounting for transport properties and seismic wave velocity and attenuation of diverse porous media in earth crust and interiors.