• Clean Technology
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• v.26 no.3
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• pp.161-167
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• 2020

For the design of the prevention and mitigation measures in process industries involving flammable substances, reliable safety data are required. An important property used to estimate the risk of fire and explosion for a flammable liquid is the flash point. Flammability is an important factor to consider when developing safe methods for storing and handling solids and liquids. In this study, the flash point data were measured for the binary systems {2-butanol + 2,2,4-trimethylpentane}, {2-butanol + methylcyclohexane} and {2-butanol + toluene} at 101.3 kPa. Experiments were performed according to the standard test method (ASTM D 3278) using a Stanhope-Seta closed cup flash point tester. A minimum flash point behavior was observed in the binary systems as in the many cases for the hydrocarbon and alcohol mixture that were observed. The measured flash points were compared with the predicted values calculated via the following activity coefficient (GE) models: Wilson, Non-Random Two-Liquid (NRTL), and UNIversal QUAsiChemical (UNIQUAC) models. The predicted data were only adequate for the data determined by the closed-cup test method and may not be appropriate for the data obtained from the open-cup test method because of its deviation from the vapor liquid equilibrium. The predicted results of this work can be used to design safe petrochemical processes, such as the identification of safe storage conditions for non-ideal solutions containing flammable components.

• Korean Journal of Materials Research
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• v.4 no.6
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• pp.626-637
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• 1994

The relationship between microstructures and tensile properties depending on various solution treatment temperature and cooling rate of Ti-6A1-4V alloy have been investigated. The complex and random edge shaped $\alpha$ phases were formed after the 1st solution treatment at $\beta$ region and the 2nd solution treatment at $900^{\circ}C$, which was followed by furnace cooled. When the specimen was subjected to the 2nd solution treated at $950^{\circ}C$, and furnace cooled, $\alpha$ phase changed its morphology to equiaxed structure. The aspect ratio showing the appreciation basis of microstructual refinement decreases with the temperature of 1st and 2nd solution treatment. The slightly decrease in strength were observed in the Widmanstltten structures than in the bimodal structures. Also, ductility of the Widmanstatten structures was considerable lower than that of bimodal structures. The tensile-fractured surface of the Widmanstatten structures appears to be quasi-cleavage and dimple fracture, while that of the bimodal structures was the type of ductile fracture. The tensile fracture surface of the bimodal structures can easily be separated into cental crack areas lying generally perpendicular to the tensile axis and shear lip areas lying at angles of high shear(around 45 deg.) to the tensile axis.

• Journal of Elementary Mathematics Education in Korea
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• v.11 no.2
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• pp.117-136
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• 2007

The purpose of this study was to analyze the effects of mathematics learning through tessellation activities on the improvement of spatial sense and to find out a better mathematics teaching method that could further develop spatial sense. For this purpose, the following questions were attempted; Can mathematics learning using tessellation activities develop spatial sense? In odor to test this hypothesis, twenty-four fifth graders of a class were selected at random. And the experimental group was divided into four groups according to gender and academic performance. The groups were protested and post-tested to determine results based on the quasi-experimental design(i.e. one-group pretest-post test design). The process of this study was checking spatial sense for a common evaluation of experimental group. In this study, tangram, pattern block, and GSP was used for mathematics learning through tessellation activities during each independent-study, discretion-activity, and math class. The instrument used in this study was a spatial sense test and pretest and post-test were implemented with the same instrument(i.e. K-WISC-III Activity Test). In conclusion, mathematics learning through tessellation activities with tangram, pattern block, and GSP is an effective teaching and learning method for the improvement of the spatial sense.

• Korean Journal of Adult Nursing
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• v.12 no.1
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• pp.122-133
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• 2000

The purpose of this study was to identify the effect of body positioning on $PaO_2$, $SpO_2$, systolic blood pressure, diastolic blood pressure, pulse, and respiration(above all defined physiologic index), of patients with unilateral lung disease. The subjects for this study were eleven patients admitted to I.C.U. of K.H.M.C. with a diagnosis of unilateral lung disease confirmed by chest X-ray and the attending doctor, from January 30th. to April 20th. 1999. A quasi-experimental repeated-measures cross-over design was used to compare three body positions(semi-Fowler's, lateral decubitus with good lung dependent, and lateral decubitus with diseased lung dependent). Each subject spent 30 minutes in semi-Fowler's position and 2 hours in good lung dependent position and diseased lung dependent position. Starting in the semi-Fowler's position, then in the lateral position with the good lung dependent or the diseased lung dependent as assigned in random order. Thirty minutes after each positioning, arterial blood sample was analyzed. Measurements of all physiologic index were recorded at the specified intervals(0, 30, 60 90, and 120 minutes) in good lung dependent and diseased lung dependent position. Statistical comparison of $PaO_2$ value was done using the Wilcoxon Signed Rank Test, and Multivariate repeated-measures analysis of variance was performed to analyse the within-subject effect of two dependent position for 2 hours on the five dependent variables: (1) $PaO_2$ (2) $SpO_2$ (3) systolic blood pressure (4) diastolic blood pressure (5) pulse. The results obtained were as follows: 1. The $PaO_2$ value in the good lung dependent position was significantly higher than the $PaO_2$ value in the diseased lung dependent position(Z=-2.8451, p=.002). 2. The $PaO_2$ value in the good lung dependent position was significantly higher than the $PaO_2$ value in the semi-Fowler's position (Z=-2.6673, p=.003). 3. The difference between the $PaO_2$ value in the semi-Fowler's position and the $PaO_2$ value in the diseased lung dependent position was not significant(Z=-1.2448, p=.10). 4. There were no statistically significance in the trends of physiologic index in the good lung dependent position and the diseased lung dependent position. From the results, it may be concluded that the good lung dependent position is the most effective position for patients with unilateral lung disease that improve oxygenation. Identification of positioning over time may be need further studies.

• Journal of Gifted/Talented Education
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• v.21 no.2
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• pp.287-307
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• 2011

The purpose of this study is to investigate levels of mathematically gifted students' understanding of statistical samples through comparison with non-gifted students. For this purpose, rubric for understanding of samples was developed based on the students' responses to tasks: no recognition of a part of population (level 0), consideration of samples as subsets of population (level 1), consideration of samples as a quasi-proportional, small-scale version of population (level 2), recognition of the importance of unbiased samples (level 3), and recognition of the effect of random sampling (level 4). Based on the rubric, levels of each student's understanding of samples were identified. t tests were conducted to test for statistically significant differences between mathematically gifted students and non-gifted students. For both of elementary and middle school graders, the t tests show that there is a statistically significant difference between mathematically gifted students and non-gifted students. Table of frequencies of each level, however, shows that levels of mathematically gifted students' understanding of samples were not distributed at the high levels but were overlapped with levels of non-gifted students' understanding of samples.

• Journal of Home Health Care Nursing
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• v.13 no.1
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• pp.54-60
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• 2006

This study, a quasi-experimental study using a nonequivalent control group pretest-posttest design. conducted a survey on 30 patients test group and control group of IS patients sampling an adjacent population at random - who are operated on the breast cancer and are in the A University Hospital located in Suwon, to examine into the effects of foot reflex zone massage on their pain and sleep satisfaction through the nursing interventions. It gave them a foot reflex zone massage for the total 30 minutes-basic massage 10 minutes and reflex massage 20 minutes required to alleviate their pain day in day out covering a two-month period from the first of July to the first of September 2004. for the purpose of collecting data. It launched into a two-round foot reflex zone massage at 6 and 24 hours since mastectomy through a direct visit at the hospital room to measure pain intensity, physiological index(pulse and blood pressure) and sleep satisfaction of them. The results are as follows. First, it showed that there is all the difference between pain intensity of test group and that of control group. In result, the first hypothesis, pain of test group. which measure at 6(p=.000) and 24 hours(p=.001) since mastectomies, will be bigger than that of control group, was established. Second, it showed that there is all the difference between physiological index of test group and that of control group. In result. the second hypothesis, pulse(p= .025, p= .002), systolic blood pressure(p= .004, p=.012) and diastolic blood pressure(p=.004. p= .003) of test group, which investigate at 6 and 24 hours since mastectomies, will be bigger than that of control group, was established. Third, it showed that there is a significant difference between sleep satisfaction of test group and that of control group(p=.000). In result, the fourth hypothesis, sleep satisfaction of test group. which examine in the morning after mastectomies, will be bigger than that of control group, was established. In the result. a foot reflex zone massage is seen to be effective in the pain reduction and sleep promotion of patients who are operated on breast cancer, and in providing them with more qualitative care by improving confidence between them and nurses through a physical touch. Also, it can be applied to a clinical examination through an independent nursing intervention.

• Journal of KIISE:Information Networking
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• v.30 no.1
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• pp.24-29
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• 2003

In this paper, a new method for the mixed image separation is presented using the independent component analysis, the innovation process, and the expectation-maximization. In general, the independent component analysis (ICA) is one of the widely used statistical signal processing schemes, which represents the information from observations as a set of random variables in the from of linear combinations of another statistically independent component variables. In various useful applications, ICA provides a more meaningful representation of the data than the principal component analysis through the transformation of the data to be quasi-orthogonal to each other. which can be utilized in linear projection.. However, it has been known that ICA does not establish good performance in source separation by itself. Thus, in order to overcome this limitation, there have been many techniques that are designed to reinforce the good properties of ICA, which improves the mixed image separation. Unfortunately, the innovation process still needs to be studied since it yields inconsistent innovation process that is attached to the ICA, the expectation and maximization process is added. The results presented in this paper show that the proposed improves the image separation as presented in experiments.

• Clean Technology
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• v.25 no.2
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• pp.140-146
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• 2019

Flammable substances, such as organic solvents, are commonly used in laboratories and industrial processes. The flash point of flammable liquid mixtures is a very important parameter for characterizing the ignition and explosion hazards, and the flash points of mixtures of $C_2{\sim}C_3$ alcohols and 2,2,4-trimethylpentane were measured in the present study. The 2,2,4-trimethylpentane is an important component of gasoline and is frequently used in the petroleum industry as a solvent. Lower flash point data were measured for the binary systems {ethanol + 2,2,4-trimethylpentane}, {1-propanol + 2,2,4-trimethylpentane}, and {2-propanol + 2,2,4-trimethylpentane}. The flash point measurements were carried out according to the standard test method (ASTM D3278) using a Stanhope-Seta closed cup flash point tester. The measured flash points were compared with the predicted values calculated using Raoult's law and also following $G^E$ models: Wilson, Non-Random Two Liquid (NRTL) and UNIversal QUAsiChemical (UNIQUAC). These models were able to predict the experimental flash points for different compositions of {$C_2{\sim}C_3$ alcohols + 2,2,4-trimethylpentane} mixtures with minimal deviations. The average absolute deviation between the predicted and measured lower flash point was less than 1.28 K. A minimum flash point behaviour was observed in all of the systems as in the many observed cases for the hydrocarbon and alcohol mixtures.

• Journal of Korean Academy of Nursing
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• v.12 no.2
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• pp.1-26
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• 1982

The main purpose of this study was to test the effect of the structured information on the sleep amount of the patients undergoing open heart surgery. This study has specifically addressed to the Following two basic research questions: (1) Would the structed in formation influence in the reduction of sleep disturbance related to anxiety and Physical stress before and after the operation? and (2) that would be the effects of the structured information on the level of preoperative state anxiety, the hormonal change, and the degree of behavioral change in the patients undergoing an open heart surgery? A Quasi-experimental research was designed to answer these questions with one experimental group and one control group. Subjects in both groups were matched as closely as possible to avoid the effect of the differences inherent to the group characteristics, Baseline data were also. collected on both groups for 7 days prior to the experiment and found that subjects in both groups had comparable sleep patterns, trait anxiety, hormonal levels and behavioral level. A structured information as an experimental input was given to the subjects in the experimental group only. Data were collected and compared between the experimental group and the control group on the sleep amount of the consecutive pre and post operative days, on preoperative state anxiety level, and on hormonal and behavioral changes. To test the effectiveness of the structured information, two main hypotheses and three sub-hypotheses were formulated as follows; Main hypothesis 1: Experimental group which received structured information will have more sleep amount than control group without structured information in the night before the open heart surgery. Main hypothesis 2: Experimental group with structured information will have more sleep, amount than control group without structured information during the week following the open heart surgery Sub-hypothesis 1: Experimental group with structured information will be lower in the level of State anxiety than control group without structured information in the night before the open heart surgery. Sub-hypothesis 2 : Experimental group with structured information will have lower hormonal level than control group without stuctured information on the 5th day after the open heart surgery Sub-hypothesis 3: Experimental group with structured information will be lower in the behavioral change level than control group without structured information during the week after the open heart surgery. The research was conducted in a national university hospital in Seoul, Korea. The 53 Subjects who participated in the study were systematically divided into experimental group and control group which was decided by random sampling method. Among 53 subjects, 26 were placed in the experimental group and 27 in the control group. Instruments; (1) Structed information: Structured information as an independent variable was constructed by the researcher on the basis of Roy's adaptation model consisting of physiologic needs, self-concept, role function and interdependence needs as related to the sleep and of operational procedures. (2) Sleep amount measure: Sleep amount as main dependent variable was measured by trained nurses through observation on the basis of the established criteria, such as closed or open eyes, regular or irregular respiration, body movement, posture, responses to the light and question, facial expressions and self report after sleep. (3) State anxiety measure: State Anxiety as a sub-dependent variable was measured by Spi-elberger's STAI Anxiety scale, (4) Hormornal change measure: Hormone as a sub-dependent variable was measured by the cortisol level in plasma. (5) Behavior change measure: Behavior as a sub-dependent variable was measured by the Behavior and Mood Rating Scale by Wyatt. The data were collected over a period of four months, from June to October 1981, after the pretest period of two months. For the analysis of the data and test for the hypotheses, the t-test with mean differences and analysis of covariance was used. The result of the test for instruments show as follows: (1) STAI measurement for trait and state anxiety as analyzed by Cronbachs alpha coefficient analysis for item analysis and reliability showed the reliability level at r= .90 r= .91 respectively. (2) Behavior and Mood Rating Scale measurement was analyzed by means of Principal Component Analysis technique. Seven factors retained were anger, anxiety, hyperactivity, depression, bizarre behavior, suspicious behavior and emotional withdrawal. Cumulative percentage of each factor was 71.3%. The result of the test for hypotheses show as follows; (1) Main hypothesis, was not supported. The experimental group has 282 minutes of sleep as compared to the 255 minutes of sleep by the control group. Thus the sleep amount was higher in experimental group than in control group, however, the difference was not statistically significant at .05 level. (2) Main hypothesis 2 was not supported. The mean sleep amount of the experimental group and control group were 297 minutes and 278 minutes respectively Therefore, the experimental group had more sleep amount as compared to the control group, however, the difference was not statistically significant at .05 level. Thus, the main hypothesis 2 was not supported. (3) Sub-hypothesis 1 was not supported. The mean state anxiety of the experimental group and control group were 42.3, 43.9 in scores. Thus, the experimental group had slightly lower state anxiety level than control group, howe-ver, the difference was not statistically significant at .05 level. (4) Sub-hypothesis 2 was not supported. . The mean hormonal level of the experimental group and control group were 338 ㎍ and 440 ㎍ respectively. Thus, the experimental group showed decreased hormonal level than the control group, however, the difference was not statistically significant at .05 level. (5) Sub-hypothesis 3 was supported. The mean behavioral level of the experimental group and control group were 29.60 and 32.00 respectively in score. Thus, the experimental group showed lower behavioral change level than the control group. The difference was statistically significant at .05 level. In summary, the structured information did not influence the sleep amount, state anxiety or hormonal level of the subjects undergoing an open heart surgery at a statistically significant level, however, it showed a definite trends in their relationships, not least to mention its significant effect shown on behavioral change level. It can further be speculated that a great degree of individual differences in the variables such as sleep amount, state anxiety and fluctuation in hormonal level may partly be responsible for the statistical insensitivity to the experimentation.