• Journal of the Korean Chemical Society
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• v.52 no.5
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• pp.550-560
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• 2008

• Journal of the Korean Chemical Society
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• v.65 no.5
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• pp.333-346
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• 2021

In this study, we developed education materials using history of science related to the experiment of 'Boyle's air pump' and the Boyle and Hobbs' debate of vacuum to find out the perceptions of NOS by pre-service chemistry teachers. For the study, 29 pre-service chemistry teachers at a college of education in Chungcheongbuk-do were selected. As RFN items that were related to the contextual situation developed in this study, items in the categories of 'Aims and Values', 'Scientific practices', 'Scientific Methods among Educational Applications' and 'Social-Institutional Aspects among Educational Applications' were selected. Through the items of RFN, the perceptions of pre-service teachers in non-contextual situations were investigated. Then we presented the pre-service teachers with the situation related to Boyle's experiment on air pump and Boyle and Hobbes' debate over vacuum. In addition, their perception of NOS was examined in contextual situations related to RFN items. Responses to the items, experimental results related to Boyle's Law, group discussion, and interview data were collected as data. As a result of the study, it was found that pre-service teachers had informed perceptions in most of the items, but cases with naive views or mixed views were found in context experimental situations. This study can contribute to the NOS education for pre-service chemistry teachers by development of context situation education materials related to NOS and by finding out their perceptions in the non-contextual and contextual situation.

• Journal of the Korean Society of Safety
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• v.23 no.4
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• pp.79-84
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• 2008

Auto injector grouting method as low pressure injected by using epoxy and Boyle's law is very excellent method in economical efficiency and construction work because injected process can be dealt with collectively. For estimation of filling capacity purpose of this study compared the Auto injector method with the piston injector method. In this study, the tests allow for width of crack, injected angle of epoxy resin and injected method were performed using concrete block specimen making artificial crack. The results of test, tilling et1iciency of epoxy by Auto Injector grouting method verify to better than the piston injector method and uniaxial strength increased about 11% than standard specimen.

• Water for future
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• v.26 no.1
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• pp.71-79
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• 1993

Nonlinear characteristics of air pressure variation and wave transformation of a fixed air-chamber structure are discussed theoretically and experimentally. Two analytical methods(method I and II) based on the perturbation method and Green's formula are employed in order to evaluate nonlinearities by the submerged and semi-submerged air-chamber structure. Moreover, an air compression model is newly developed to estimate the dynamic air pressure in the air-chamber inside the structure, assuming the Boyle-Charles's law with adiabatic process in the air pressure variation. Theoretical values of the method I considering evanescent mode waves at an fictious boundary, are in good agreement with those of method II employing the fictious boundary which is not affected by evanescent mode waves. Both theoretical values are shown to agree well with experimental values.

• Journal of the Korean Vacuum Society
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• v.22 no.5
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• pp.231-237
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• 2013

New method of volume measurement for reference weights of a pressure balance using a gas pycnometer is proposed. The result of volume measurement of proposed method shows the uncertainties of approximately 0.2% at the level of confidence of 95% for reference weights in the ranges of 1 kg, 2 kg, and 5 kg. This measuring system consists of a sample chamber, an expansion chamber, a precision pressure gage, a precison thermometer, a vacuum pump, and helium as a medium gas. The measurement principle of this proposed method is based on Boyle's law. This method will contribute a reliability of the volume measurements of reference weights for a pressure balance to the national measurement standard.

• Journal of the Korean Chemical Society
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• v.55 no.6
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• pp.1042-1055
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• 2011

The purpose of this study was to compare the conceptual and algorithmic problem solving ability on Boyle's law and Charles's law according to cognitive levels and characteristics of students in middle school 1st grade students. For this study, questionnaire items of conceptual and algorithmic problem solving ability were developed. and the problem solving ability according to cognitive levels and characteristics of students was compared. The long-term memory effect in conceptual and algorithmic problem solving ability according to cognitive levels was investigated, and problem solving process were analyzed by questionnaire items. In the results of this study, conceptual problem solving ability was higher than algorithmic problem solving ability in all cognitive levels. There was statistically significant difference in concrete operational period and transitional period students. In comparison of the long-term memory effect in conceptual and algorithmic problem solving ability, formal operational period students had the long-term memory effect. There was no statistically significant difference in the conceptual and algorithmic problem solving ability according to private education among the characteristics of students. But there was statistically significant difference in the problem solving ability according to experiences of the scientific activities and hopes to related scientific careers. From results of analysis of problem solving process, it is known that the students had a tendency to just remember macroscopic phenomena and to solve the problems without understanding the concepts. Therefore, teaching and learning strategy is necessary to replace unscientific concepts by the scientific concepts through identifying students's unscientific concepts in advance.

• Journal of Advanced Navigation Technology
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• v.21 no.3
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• pp.230-242
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• 2017

A significant rise in product-liability cost is expected due to the newly passed product liability amendment Bill approved during the assembly plenary session on March 30, 2017. Korean government legal service(KGLS) filed a damage suit against Korea aerospace industries, Ltd.(KAI) and Hanwha Techwin Co., Ltd., the manufactures of the KUH-1 Surion helicopter crashed. KGLS alleged claims under the product liability Act, the warrant liability Act and the non-performance of contract act. The accountability limits of military aircraft manufacturers was a highly divisive issue among related scholars and legal practitioners. The bottom line was that military aircraft manufacturers had no product-liability insurance available. The United States courts have, therefore, developed the government contractor defense(GCD) and it was recognized by the U.S. Supreme Court in Boyle v. United Technologies corporation(1988). product liability insurances for military aircraft manufacturers are excessively expensive and it cannot be added onto the military procurement cost accounting. However, having an aircraft accident without one can be ruinously expensive. Therefore, the manufacturers should promptly set up appropriate risk management measures. This thesis will first review the advance GCD theory, and then find a way to either reform government contract related regulations.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.611-620
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• 2010

The purpose of this study was to explore the structure and content of chemistry teacher's explanations from the perspective of 'persuasion'. Especially, this study was to explore how the argument structure and the conceptual change constructs in chemistry teachers' explanations were established and interacted. Data were collected from chemistryI classes considering the gas unit which includes kinetic theory of gas, Graham's law, Boyle's law, and Charles' law. The classes were vediotaped and transcribed. The transcriptions were analyzed with Toulmin's argument frame and the two constructs of conceptual change model; the conceptual ecology and the status of a conception to interpret the persuasive structure and content of the teacher's explanations. As the results of this study, four explanatory discourses which show various persuasive explanations in chemistry classes. Based on this results, discussion and implications for effective teachers' explanations in chemistry classes were presented.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1244-1249
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• 2002

In this study, the physical characteristics of steel-wire sound absorbing materials with different thickness and bulk density is experimentally obtained in terms of the porosity and specific flow resistivity. Based on the experimental results, the following conclusions can be made. The porosities of steel-wire sound absorbing materials are smaller than those of general absorbing materials, which are inversely proportional to the volume densities. For the porosity measurement with a good accuracy, the dynamic correction based on the system compliance should be involved in porosity measurement. In addition, the flow condition for the precise measurement of the specific flow resistivity of steel-wire sound absorbing materials should be limited in the laminar flow region.

• Journal of the Korean Chemical Society
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• v.68 no.2
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• pp.107-116
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• 2024

The purpose of this study is to analyze changes in pre-service chemistry teachers' cognition of the nature of model in the evaluation and modification process of model using technology. Changes in cognition of the nature of model were analyzed focusing on the 'Abstraction' and 'Simplification' of the 'Representational aspect', 'Interpretation', 'Reasoning', 'Explanation' and 'Quantification' of the 'Explanatory aspect' that were deemed insufficient for pre-chemistry teachers in previous study. For this purpose, 19 third-year pre-service chemistry teachers at a teacher's college in Chungcheongbuk-do were asked to evaluate the model related to Boyle's law developed using technology, revise the model based on the evaluation results, and make a final evaluation. As a result of the study, it was confirmed that pre-service chemistry teachers' cognition of 'Simplification' of the 'Representational aspect' and 'Interpretation', 'Explanation', and 'Quantification' of the 'Explanatory aspect' changed positively through the evaluation and modification process of the model. Therefore, it was found that the evaluation and modification process of the model plays a key role in changing the cognition of the nature of model. However, there was little change in cognition of 'Abstraction' of the 'Representational aspect' and 'Reasoning' of the 'Explanatory aspect'. The cognition of these factors can be seen as more difficult to change than the cognition of other factors. To solve this problem, more sophisticated educational design for pre-service chemistry teachers is needed.