• Journal of Korean Elementary Science Education
• /
• v.34 no.4
• /
• pp.419-433
• /
• 2015

Analogical reasoning is a central component of human cognition and contributes to scientific discovery and to develop science education. In this study, we investigated the process features of lower elementary school students' analogical reasoning to explain mixture concept. The subjects are 24 lower elementary students. And the research design includes three phases instruction to investigate the features of students' self generated analogy. Phase 1 is the introduction of analogy in which student learn to use analogy. Phase 2 is a POE class about mixture conception. Piaget and Inhelder studied the conception of mixing among children in relation to cognitive development. In phase 2, we taught the student with Piaget and Inhelder's the experiment and observed the features of learning process about mixture conception. Phase 3 is students' generation of analogy (self generated analogy) for the experienced phenomena in phase 2. We analyzed the students' responses through the three phases in the view of Gentner's Structure Mapping Theory. The results showed that many lower elementary school students even before formal operation stage understood the mixture conception and made well their self generated analogy to explain the mixture conception in spite of the difficulty of making self generated analogy.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.401-404
• /
• 2008

This study exploited the design of mixture proportion for the high strength concrete to establish the method of the quality control and high strength ready-mixed concrete for the application to the construction filed systematically how to output the estimated formula which could forecast mixture proportion for the high strength concrete classed 40${\sim}$60MPa through a experiment. It might contribute for systematic establishment of the method of the quality control and high strength ready-mixed concrete because it was possessed of the function of common data though a server, preservation and output of data, and estimation for the design of mixture proportion for the high strength concrete due to the experimental result, and Visual Basic, MS-SQL were used. Simply, it was produced corresponding to the condition of a laboratory, so it could be fundamental data for the design of mixture proportion for the high strength concrete. If upgrade is enforced with mixture proportion data of the each factory after then, it may contribute to the stability on quality and manufacture of high strength ready-mixed concrete to agree with the properties of each factory.

• Speech Sciences
• /
• v.10 no.2
• /
• pp.35-43
• /
• 2003

General speaker verification systems improve their recognition performances by normalizing log likelihood ratio, using a speaker model and its background speaker model that are required to be verified. So these systems rely heavily on the availability of much speaker independent databases for background speaker model design. This constraint, however, may be a burden in practical and portable devices such as palm-top computers or wireless handsets which place a premium on computations and memory. In this paper, new approach for the GMM-based background model design used in portable speaker verification system is presented when the enrollment data is available. This approach is to modify three parameters of GMM speaker model such as mixture weights, means and covariances along with reduced mixture order. According to the experiment on a 20 speaker population from YOHO database, we found that this method had a promise of effective use in a portable speaker verification system.

• The Korean Journal of Applied Statistics
• /
• v.20 no.2
• /
• pp.267-280
• /
• 2007

Various single-valued design optimality criteria such as D-, G-, and V-optimality are used often in constructing optimal experimental designs for mixture experiments in a constrained region R where lower and upper bound constraints are imposed on the ingredients proportions. Even though they are optimal in the strict sense of particular optimality criterion used, it is known that their performance is unsatisfactory with respect to the prediction capability over a constrained region. (Vining et at., 1993; Khuri et at., 1999) We assume the quadratic polynomial model as the mixture response surface model and are interested in finding efficient designs in the constrained design space for a mixture. In this paper, we make an expanded list of candidate design points by adding interior points to the extreme vertices, edge midpoints, constrained face centroids and the overall centroid. Then, we want to propose a robust design with respect to D-optimality, G-optimality, V-optimality and distance-based U-optimality. Comparing scaled prediction variance quantile plots (SPVQP) of robust designs with that of recommended designs in Khuri et al. (1999) and Vining et al. (1993) in the well-known examples of a four-component fertilizer experiment as well as McLean and Anderson's Railroad Flare Experiment, robust designs turned out to be superior to those recommended designs.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.10 no.3
• /
• pp.133-142
• /
• 2006

The purpose of this study is to predict the fracture energy in accordance with the combination variables by applying the mix design nomogram in ready mixed concrete products. In terms of the experiment for drawing up Mix Design Nomogram, the beam is manufactured based on the mixture table described in the specifications of ready mixed concrete manufacturing company and a three-point bending test suggested in RILEM 50-FMC Committee is performed. As a result, this study makes sure the possibility to apply the mix design nomogram that is possible to predict the fracture energy in ready mixed concrete products and enables one to achieve the automation of the design of mixture for the production of ready mixed concrete products with the development of program using it.

• Journal of Korean Society for Quality Management
• /
• v.42 no.4
• /
• pp.757-768
• /
• 2014

Purpose: In this paper we present a case study of developing fast curing adhesives for insulation material of LNG carriers using an extreme vertices design with four mixture components. Three material properties are considered - shear strength, viscosity, and tensile strength. In the optimization experiment, we used hardness instead of tensile strength due to shortage of specimens. Methods: We employ four-factor extreme vertices design with 19 runs and desirability function approach for simultaneously optimizing three responses. After selecting optimal condition of the mixture components, we do confirmation experiments to verify the reproducibility of the optimal condition under manufacturing circumstance. Results: Simultaneous optimal condition for the three responses, that is, shear strength, viscosity, and harness is obtained. At the optimal condition, confirmation experiments are executed in manufacturing circumstance. The variation for the shear strength is not satisfactory, which is due to the variation of the humidity. Conclusion: At the optimal condition three material properties are satisfactory. To reduce the variability for the shear strength, robust design is needed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.25 no.6
• /
• pp.426-430
• /
• 2012

The properties of green sheet were investigated in order to understanding an effects of organic solvent mixture ratio for solid oxide fuel cells fabrication. The purpose of this work is to optimize the slurry condition using the design of experiment to improve green sheet properties. The elongation increased with increasing amount of binder and solvent. With increasing amount of solvent, the air permeability increased but the tensile strength decreased. The best properties of the green sheet appeared amount of the binder 17 wt%, solvent 35 wt% and powder 48 wt%. The optimum condition of green and sintered density for solid oxide fuel cells fabrication was obtained in the sample pressured at 800 $kgf/cm^2$.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.33 no.1
• /
• pp.1-9
• /
• 2010

Quality design methodologies have received constituent attention from a number of researchers and practitioners for more than twenty years. Specially, the quality design for drug products must be carefully considered because of the hazards involved in the pharmaceutical industry. Conventional pharmaceutical formulation design problems with mixture experiments have been typically studied under the assumption of an unconstrained experimental region with a single quality characteristic. However, real-world pharmaceutical industrial situations have many physical limitations. We are often faced with multiple quality characteristics with constrained experimental regions. ln order to address these issues, the main objective of this paper is to propose a robust desirability function (RDF) model using a desirability function (DF) and mean square error (MSE) to simultaneously consider a number of multiple quality characteristics. This paper then present L-pseudocomponents and U-pseudocomponents to handle physical constraints. Finally, a numerical example shows that the proposed RDF can efficiently be applied to a pharmaceutical process design.

• Ocean and Polar Research
• /
• v.26 no.2
• /
• pp.333-339
• /
• 2004

This paper is concerned with an experimental investigation about tractive performance of a tracked vehicle on extremely soft soil. A tracked vehicle model with principal dimensions of $0.9\;m(L)\;{\times}\;0.75\;m(B)\;{\times}\;0.4\;m(H)$ and the weight of 167 kg was constructed with a pair of driving chain links driven by two AC-servo motors. The tracks are configured with detachable grousers with variable span. Deep seabed was simulated by means of bentonite-water mixture in a soil bin of $6.0\;m(L)\;{\times}\;3.7\;m(B)\;{\times}\;0.7\;m(H)$. Slip of vehicle and driving torque of motor were measured with respect to experimental variables; grouser span, grouser chevron angle, driving speed, drawbar-pull weight, position of center-of-gravity and weight. $L_8$ orthogonal array is adopted for DOE (Design Of Experiment). The effects of experiment variables on traction performance are evaluated.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2005.05a
• /
• pp.990-997
• /
• 2005

Many products, such as gasoline, polymer plastics, alloys, and ceramics are manufactured by mixing two or more ingredients or components. When we are to develop new mixture products, we must deal with a long list of potentially important component variables. This paper introduces some design methods for many mixture variables and some analysis tools for screening important variables out of the many candidate variables. The results of this paper will be helpful to engineers who work in the research and development sector of chemical, polymer, alloys, and electro-material industries.