• Journal of the Korean Society of Earth Science Education
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• v.5 no.1
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• pp.60-67
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• 2012

The purpose of this study is to find out the effect of hypothesis formulations using abduction on science processing skills and the creative thinking activities. As the subject, 2 classes in the $6^{th}$ grade of B elementary school located in Busan were selected. Through the pre/post inspection design between experiment and comparison class, the units of science courses in the second semester of $6^{th}$ grade '1. A change in the weather' and '2. Various gases' were applied. The results were as follows: Firstly, the test on science processing skills showed that there was not statistic meaningful differences between the two groups. And, in the sub-parts, there was not statistic meaningful differences between the two groups. Secondly, it was observed that it would have a meaningful effect to improve the creative thinking activities of students who performed hypothesis formulation using abduction. Especially, through this, the experimental class gave a positive effect on the 'Fluency' and 'Elaboration', one of lower categories of the creative activities. The results of 'Flexibility' and 'Originality' in the experimental class were higher than those of students in the comparative class. However, according to statistical analysis, this result is meaningless. Thirdly, on the survey about the hypothesis formulation using abduction, many students thought that this learning method was very interesting and helpful to study science. In addition, it was observed that the ability to use abduct thinking was improved more than ever before.

• Tribology and Lubricants
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• v.16 no.1
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• pp.39-45
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• 2000

In this paper, the effects of shaft and bearing flexibilities are investigated for the accurate modeling of a shaft-bearing system supported by ball bearings. Generally, rolling bearings are modeled by simple rigid pin-joint in the mechanical design. However, they can no longer be modeled by ideal boundary conditions in the advanced applications because the rigid pin-joint model cannot satisfy the current trends of mechanical design decreasing mass and reducing volume. Consequently the flexible support model of ball bearing is investigated using the static analysis module developed by A .B. Jones and T. A. Harris. A simple two-bearing system, supported by two deep groove ball bearings and radially loaded on the shaft midway between the bearings, is utilized to validate the coupled model of shaft-bearing system. Numerical computations using the model indicate that the shaft span length, locating/floating bearing arrangements and applied bearing size are significant factors in determining the mechanical behaviors. The flexible support model of ball bearing can be escaped to over-estimate in the bearing fatigue life. The proposed simple design formulation obtained by numerical simulations can approximately predict a rate of bearing life reduction as a function of shaft span length/shaft diameter (L/d).

• KSBB Journal
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• v.31 no.4
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• pp.291-299
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• 2016

In this study, Indomethacin, the poorly water soluble drug, was selected and prepared dispersing oral disintegrating films according to the molecular weight of polyethylene glycol (PEG) which are sort of dispersing agents. Also the molecular weight and content of PEG were evaluated effect on the degree of dispersion, physical property and dissolution when making oral dispersing film containing indomethacin to find appropriate condition and suggested guidelines of making oral dispersing film. The appropriate dispersing ratio of the amount of surfactants and dispersing agent were 1% and 4%, also the stability dropped in the PEG molecular weight of 4000 or more. Drying time of oral dispersing film was $90^{\circ}C$ for 10 minutes to 12 minutes that dispersing film's property about flexibility, detachability were very good. The oral dispersion film's content used PEG 400 was $98.6{\pm}0.5%$ and the most uniform. As the molecular weight of PEG increased, dissolution time also increased. On the basis of evaluation parameter, PEG with 400~600 of molecular weight was selected as good dispersing agent in oral dispersing film. Therefore, it can be suggested guideline of preparation application study in oral dispersing film.

• Computational Structural Engineering
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• v.7 no.1
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• pp.117-124
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• 1994

Multi-level Multi-objective optimization(MLMO) for reinforced concrete framed structure is performed, and compared with the results of single-level single-objective optimization. MLMO method allows flexibility to meet the design needs such as deflection and cost of structures using weighting factors. Using Multi-level formulation, the numbers of constraints and variables are reduced at each levels, and the optimization formulation becomes simplified. The force approximation method is used to reflect the variation in design variables between the substructures, and thus coupling is maintained. And the linear approximated constraints and objective function are used to reduce the number of structural analysis in optimization process. It is shown that the developed algorithm with move limit can converge effectively to optimal solution.

• Steel and Composite Structures
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• v.4 no.6
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• pp.489-507
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• 2004

The flexibility of the connection between steel and concrete largely influences the global behaviour of the composite beam. Therefore the way the connection is modelled is the key issue in its structural analysis. Here we present a new strain-based finite element formulation in which we consider non-linear material and contact models. The computational efficiency and accuracy of the formulation is proved with the comparison of our numerical results with the experimental results of Abdel Aziz (1986) obtained in a full-scale laboratory test. The shear connectors are assumed to follow a non-linear load-slip relationship proposed by Ollgaard et al. (1971). We introduce the notion of the generalized slip, which offers a better physical interpretation of the behaviour of the contact and gives an additional material slip parameter. An excellent agreement of experimental and numerical results is obtained, using only a few finite elements. This demonstrates that the present numerical approach is appropriate for the evaluation of behaviour of planar composite beams and perfect for practical calculations.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.27 no.4
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• pp.313-320
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• 1991

The paper describes the formulation for the analysis of the flexural free vibration of rectangular plate structure by the transfer influence coefficient method, which was developed on the base of the concept of the successive transmission of dynamic influence coefficients. For the analysis of rectangular plate which two opposite sides are simply-supported edge condition, the results of simple numerical examples demonstrate the validity of the present method, that is, the numerical high accuracy, the high speed and the flexibility for programming, compared with results of the transfer matrix method and exact solution or Leissa's method.

• Journal of Korean Library and Information Science Society
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• v.8
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• pp.127-154
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• 1981

Today's complicated society with a rapid change needs more objective and accurate data for the better managerical decisions and the prospect for the future other than the intuition or subjective experience by men themselves. These data can't be extracted without the analysis of actual data by a n.0, pplying any of mathematical techniques. One of these mathematical techniques, called bibliometrics has been newly developed in the field of library and information science to extract the objective data for the better services through the library operations. The Beadford's Law, one important law in bibliometrics has provided rather scientific and objective basis on the more valid building of library collection within the constraints of budget. The purpose of the study is to investigate the theory of the Bradford's Law, to clarify the possible areas of its a n.0, pplication, and to discern some problems in doing so. The results of the study can be summarized as follows; (1) There is certain difference between the graphical formulation and verbal formulation of Bradford's Law. But this law is very useful for the field of library and information science, owing to the flexibility of the a n.0, pplication of the law in the field. (2) The minimal nucleus can consist of a single periodical only if j, the number of relevant papers in the most productive journals is greater than Z/2. On the other hand, if j is less than or equal to Z/2, then the minimal nucleus will consist of 2 or more periodicals. (3) It is possible to design the most compact selection of scientific periodicals covering any specified percentage P among the total periodicals by using the formulation, log n=Plog N+(1-P)logs, or Nlog N/s=P center dot N log N/s. (4) If there is need to provide all the articles needed by users the given budget, the library can purchase the proper number of journals, by using the formulation, f center dot AN=An+PN (log N/s-logn/s). (5) In the building of the library collection based on the decreasing ratio of use, the library can subscribe to the proper number of journals according to the satisfactory degree of the need, by using the formulation, f=Nu+uNlogN/S-uNlogn/s / nNlogN/s = 1+logN/m /logN/s (6) If the order of valuable journals is decided according to the frequency of being cited, the order can't always represent the value. (7) The evaluation criteria for the journals with high value, but less cited should be made a further study.

• Journal of the Korean Chemical Society
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• v.51 no.2
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• pp.171-177
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• 2007

Polymer-based electrically conductive pastes have been used to make the conductive paths between voltage sources and devices. The pastes used for these applications consist of two main components: a polymer binder and a conductive filler. Having both low viscosity and good metal-encapsulating properties, cellulose acetate butyrate (CAB) was regarded to be a good candidate as a binder for the conductive paste. We have prepared a formulation for a novel conductive paste based on CAB. Preliminary studies showed that this conductive paste revealed stable conductivity, together with uniform coating and flexibility.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.473-480
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• 2005

Geometrical non-linearity due to the flexibility of cables must be considered efficiently in the dynamic analysis of cable structures. In this paper, formulation of tangent stiffness matrix of elastic catenary cable is derived by using relative nodal displacements, self-weight and unstressed cable length. Free vibration analysis of simply supported cable using elastic catenary cable elements is conducted and compared with that using truss elements. The result shows that elastic catenary cable elements are more compatible than truss elements in the case of analysis of cable structures. Furthermore, the characteristic of dynamic behaviors of cable structures by temporary unstability phenomenon is confirmed.

• Steel and Composite Structures
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• v.26 no.2
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• pp.171-182
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• 2018

This paper presents an isogeometric discretization of Kirchhoff-Love thin shells using truncated hierarchical B-splines (THB-splines). It is demonstrated that the underlying basis functions are ideally appropriate for adaptive refinement of the so-called thin shell structures in the framework of isogeometric analysis. The proposed approach provides sufficient flexibility for refining basis functions independent of their order. The main advantage of local THB-spline evaluation is that it provides higher degree analysis on tight meshes of arbitrary geometry which makes it well suited for discretizing the Kirchhoff-Love shell formulation. Numerical results show the versatility and high accuracy of the present method. This study is a part of the efforts by the authors to bridge the gap between CAD and CAE.