• Journal of Environmental Health Sciences
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• v.47 no.3
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• pp.193-204
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• 2021

Objectives: In January 2021, the former heads of the manufacturer SK Chemical and the vendor Aekyung were acquitted for manufacturing and selling humidifier disinfectant (HD) containing 5-chloro-2-methylisothiazol-3(2H)-one/2-methylisothiazol-3(2H)-one (CMIT/MIT). In this article, we analyzed the rationale used in this judgement in the light of scientific consideration. Methods: The sentencing document for the judgements was obtained from the Korea Supreme Court Service. In particular, the judgements made by the court related to the toxicological and individual association with HD perspectives were discussed based on scientific evidence. Results: The ruling stated that the necessary conditions for causality between CMIT/MIT and such diseases were not met based on the fact that asthma and lung damage were not found in the inhalation exposure animal experiments. The judgment overlooked the inevitable limitations of using animal experiments for verifying health effects in humans, which are often inconsistent with the observations in animals. Among 11 governmentaffirmed lung injury cases with CMIT/MIT usage, three patients' humidifier disinfectant-associated lung injury (HDLI) pathology proved that CMIT/MIT could cause lung injury similar to that caused by PHMG and PGH. In addition, five children showed decreased lung function related to damage caused by humidifier disinfectant exposure. Conclusions: We conclude that there is sufficient evidence supporting the assertion that HDs containing CMIT/MIT cause lung injuries, including asthma, contrary to the court's decision.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.11
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• pp.1624-1628
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• 2008

Experiments were conducted to evaluate the nutritional value of yellow-seeded rapeseed meal (YRSM). In the first experiment nutrient retention was recorded by 48 Arbor Acres-broiler chickens (28-d old) to determine AMEn (nitrogen-corrected apparent metabolizable energy), coefficient of apparent protein digestibility based on ileal digesta nitrogen, excreta nitrogen and uric acid nitrogen. The second experiment was carried out with 304 Arbor Acres-broiler chickens to compare effects of SBM (soybean meal) and YRSM on performance, carcass and digestive tract status. In the control treatment, SBM was replaced by graded levels of YRSM at 15, 22.5 and 30% of diet. Digestibility of YRSM protein was significantly lower (p<0.001) than SBM protein. The protein digestibility based on ileal measurement was significantly higher (p<0.001) than protein digestibility from excreta samples. There was no significant difference (p>0.001) between ileal and excreta digestibility of protein based on uric acid. AMEn as a fraction of gross energy was 0.54 in SBM and 0.45 in YRSM. With the exception of 30% YRSM, other YRSM treatments resulted in major effects on length and weight of the gastrointestinal tract. The results of this study have shown no adverse effect on performance as well as protein digestibility and energy value in response to replacement of SBM by YRSM with the exception of 22.5 and 30% YRSM.

• Journal of Korean Elementary Science Education
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• v.30 no.3
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• pp.340-352
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• 2011

The purpose of this study was to analyze effects of teaching materials for elementary science gifted conception about object recognition. Elementary science gifted have misconceptions that they can see in lightness. They can not explain how a shadow is made. This paper reports in-depth investigation on elementary science gifted's understanding of object recognition focusing on process of light. A program is developed to elementary science gifted in the subject matter. The tutorial emphasizing the process of light consists of pre-test, worksheet, and post-test. The Tutorial has 4 steps; darkness and light, light on things, light reached eyes, structure of the eyes. Each steps has 2~4 experiments. Through the tutorial, we expect their misconceptions can be changed into scientific conceptions. For the research and analysis, a questionnaire is posed to 39 elementary science gifted at M Elementary School in D Metropolitan City. The first method of product analysis makes a comparative study of pre-test, post-test score, and hake gain each test. As a result, total score of all student was raised. And hake gain of pre-test(II) is 0.6, hake gain of post-test is 0.68. It is Medium gain. Also, elementary science gifted could understand how we see through the tutorial emphasizing process of light. And their misconceptions can be changed into scientific conceptions.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.4
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• pp.382-390
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• 2018

The history of the pregnancy test started in ancient Egypt with a germination test using wheat and barley. Since then, unscientific methods have been used from the days of Hippocrates and Galen to the Middle Ages when uroscopy was used, even until the early 1800s. On the other hand, since the mid-1800s, scientific methods and evidence have begun to emerge, which led to scientific research on the physiological characteristics of pregnancy. The first attempt to utilize these scientific findings was initiated with the bioassay by Aschheim and Zondek using rats and mice in 1927, and then developed into experiments using rabbits and frogs. The immunoassay method, which started in the 1960s, contributed greatly to the generalization of the pregnancy tests while improving the problems of the bioassay. In 1976, a pregnancy test kit was introduced that can be used at home, contributing to the popularization of pregnancy tests. Since the 1980s, technological advances in diagnostic tests have also been applied to pregnancy tests to further improve the reliability of the diagnosis of pregnancy. In the 2000s, the accuracy and ease of use of the pregnancy test kits for home use have improved drastically. This study examined the history and scientific development of the pregnancy test.

• KNOM Review
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• v.21 no.2
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• pp.46-52
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• 2018

For data-intensive scientific workflow application experiments that leverage the cloud computing environment, large amounts of data can be distributed across multiple data centers in the cloud. The generated intermediate data can also be transmitted through access between different data centers. When the application is executed, the execution result is changed according to the location of the data since the intermediate data generated is used. However, existing data placement strategies do not consider the characteristics of scientific applications. In this paper, we define a data-intensive tasks and propose runtime data placement in that interval. Through the proposed data placement scheme, we analyze the scenarios considering the number of times in the data intensive tasks defined in this study and derive the results. In addition, performance was compared by analyzing runtime data placement times and runtime data placement overhead.

• Journal of The Korean Association For Science Education
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• v.42 no.2
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• pp.253-264
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• 2022

The purpose of this study is to examine the practice of scientists from the perspective of Ian Hacking's 'creation of phenomena'. Scientific phenomena, according to Hacking, are regular and do not exist in nature without the intervention of scientists or experimental tools. This study tries to derive scientific educational meaning by analyzing the thoughts and episodes of the 'Sontanda (inter-individual variability)' phenomenon experienced by four life scientists. The Sontanda phenomenon is a common term used by scientists to describe phenomena in which findings do not appear consistently even when studies are carried out using the same experimental procedure and materials. The following four educational implications were discovered as a result of the research. First, we confirmed the importance of embodied knowledge, or non-verbal knowledge, which solves issues by making appropriate judgments and reactions at all times, rather than simply becoming accustomed to the experimental method. This argues that propositional knowledge and non-verbal knowledge should be handled equally in order to provide students with a practical scientific inquiry. Second, we tried to reconsider the picture of the experiment. The phenomenon revealed in the interviews of scientists is rare, and it takes a long time to stabilize the phenomenon. On the other hand, the image of school experiments is always positive and consistent, necessitating a shift in perspective. Third, the precise meaning of scientific practice could be confirmed. This study confirms that scientists use their knowledge effectively in line with the circumstances, and we examined strategies to apply scientific practice to school instruction based on this. Finally, by provoking uncertainty, the Sontanda phenomena may give students with an opportunity to engage in meaningful scientific involvement. By breaking away from the cookbook experiment, this study expects school experimental education to help in efforts to experience scientific practice.

• Journal of the Korean Chemical Society
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• v.50 no.6
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• pp.506-514
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• 2006

purpose of this work was to study the applied effects of out-of-class Chemical Experience Learning (CEL) Programs on scientific process skills and science-related attitude for middle school students. The out-of-class CEL Programs which were developed to make the funny out-of-class chemistry and the exciting science class', included the nature-friendly chemical experiments suitable for natural environment and composed of real life-centered experiences. The out-of-class CEL programs were applied to natural environment through all-day improvement activity. The science club students in D middle school in Busan were selected as the objects of the study consisting of one experiment group and one control group. The out-of-class CEL programs were applied to the experiment group and traditional class method was applied to the control group. The change of scientific process skills and science-related attitudes between two groups were compared and analyzed. And students reaction on the out-of-class CEL programs was investigated. As a result, out-of-class nature-friendly chemical experiments were improved scientific process skills and science-related attitudes of middle school students. Also, more than 70% of students in the experimental group gave positive feedbacks to the out-of-class CEL programs and increased attention, interest, and degree of self-participation in science.

• Journal of The Korean Association For Science Education
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• v.28 no.1
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• pp.75-88
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• 2008

The purpose of this study was to understand the factors affecting interactions as well as the students' learning process in small group activities. For this purpose, the changes and characteristics of students' interactions in scientific inquiry experiments were analyzed. This study focused on 2 homogeneous small groups of eighth graders. Students were involved in 13 inquiry experiments for one year and students' interactions in each experiments were observed and recorded using video/audio and the data recorded were transcribed. The analysis of data was based on the method of making a note by looking on and listening to the data repeatedly. Changes in the interactions of the two homogeneous groups differ remarkably. In small group A, owing to the conflicts of students' emotions, learning through social interactions became to be impossible. On the other hand, the interactions in small group B became more active. It seems that this changes are affected largely by the existence of peers who are able to mediate different opinions or feelings among group members. In general, middle school students were poor at receiving peers' opinion, cared a lot about writing reports. The less able students tended to be placed at a disadvantageous position in experiment lessons emphasizing social interactions. Four factors that affected the change of interactions were identified: Is the aim of experiments the understanding or completion of report? Is there any attitude towards peers' suggestions? Is there a disposition to care about peers? Is there any peer to mediate on peers' opinions or feelings? Educational implications of the progression of activities emphasizing interactions and the organization of grouping were drawn.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.03a
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• pp.134-137
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• 1998

Caliber design in bar and rod rolling depends on the designer's experience, which in general is acquired through costly trial-and-error process. As a prerequisite for developing a scientific approach to caliber design, we present a finite element model to simulate 3-D deformation of bars and rods occurring in multi-pass sequence. The results are compared with measurements obtained from POSCO for to assess the solution accuracy. The comparison shows that the simulation results agree well experiments.

• Journal of the Korean Society of Visualization
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• v.7 no.1
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• pp.21-28
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• 2009

The study of swirling flow is of technical and scientific interest because it has an internal recirculation field, and its tangential velocity is related to the curvature of streamline. The fluid flow for tubes and elbow of heat exchangers has been studied largely through experiments and numerical methods, but studies about swirling flow have been insufficient. Using the particle image velocimetry(PTV) method, this study found the time averaged velocity distribution with swirl and without swirl along longitude sections and the results appear to be physically reasonable. In addition, streamwise mean velocity distribution was compares with that of other. Furthermore, other experimental investigation was performed to study the characteristics of turbulent water flow in a horizontal circular tube by using liquid crystal. 2D PIV technique is employed for velocity measurement and liquid crystal is used for heat transfer experiments in water. Temperature visualization was made quantitatively by calibrating the colour of the liquid crystal versus temperature using various approaches.