• Journal of Educational Research in Mathematics
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• v.8 no.1
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• pp.381-403
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• 1998

As a researcher engaged in the mathematical education, mathematics teachers are interested in instructional methods. While it is unlikely that the viewpoints of individual mathematics teachers are reflected in making decisions on instructional purposes and instructional contents, a good many parts of instructional methods on mathematical facts are decided by individual teachers. This means that the role of mathematics teachers is given much weight in the mathematical education. Therefore, the mathematics teachers must not be excluded in all parts of the study of mathematical education. We studied the instructional methods of function concept, a central topic in school mathematics from the following perspectives. First, we examined the characteristics of the three(correspondence-centered, middle, dependence centered) viewpoints about the essence of function concept. And we should that which of them should be the viewpoint of instruction of function concept in school mathematics. Second, we investigated the questions regarding the process of function instruction in school mathematics and presented alternative instruction methods of function concept to solve the questions. Third, we postulated the importance of polynomial function, relating college mathematics in order to present the reason why the polynomial function is importantly treated in functional instruction of school mathematics.

• Korean Journal of Construction Engineering and Management
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• v.13 no.4
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• pp.33-47
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• 2012

548 thousand apartment houses of Seoul has been used over 15 years and remodeling is available. It is 42% of the overall apartment houses currently and it is assumed to increase to 800 thousand in 2015. The maintenance work is divided to reconstruction and remodeling. Due to the regulations of the government, expansion remodelling has been the most considered alternative. However, 75% of the extension remodelling, yet, are in the preliminary phases. Thus, this study suggests factors hampering the vitalization of extension remodelling and solutions for each factor by means of Delphi analysis method.

• Food Science of Animal Resources
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• v.36 no.3
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• pp.421-426
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• 2016

Polylactic acid (PLA) is a biodegradable and renewable polymer, which represents a valuable alternative to plastic packaging films, often associated with environmental problems. In this study, we tested the suitability of PLA as a biodegradable packaging film and assessed the antimicrobial activity of lemongrass oil (LO), incorporated into the PLA film in different concentrations. To obtain the optimal physical properties for PLA films, tensile strength, elongation at break, and water vapor permeability were measured under different preparation conditions. In addition, the antimicrobial activity of the LO contained in the PLA film against Listeria monocytogenes was investigated by disc diffusion and viable cell count. Among all concentrations tested, 2% LO was the most suitable in terms of antimicrobial activity and physical properties of the PLA film. Based on these results, we used the PLA film containing 2% LO to pack pork sausages; after 12 d of storage at 4℃, the population of inoculated L. monocytogenes in the sausage samples wrapped with the PLA film containing 2% LO was reduced by 1.47 Log CFU/g compared with the control samples. Our data indicate that PLA films containing 2% LO represent a valuable means for antimicrobial sausage packaging.

• Smart Structures and Systems
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• v.11 no.5
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• pp.435-451
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• 2013

High-rise buildings are a common feature of urban cities around the world. These flexible structures frequently exhibit large vibration due to strong winds and earthquakes. Structural control has been employed as an effective means to mitigate excessive responses; however, structural control mechanisms that can be used in tall buildings are limited primarily to mass and liquid dampers. An attractive alternative can be found in outrigger damping systems, where the bending deformation of the building is transformed into shear deformation across dampers placed between the outrigger and the perimeter columns. The outrigger system provides additional damping that can reduce structural responses, such as the floor displacements and accelerations. This paper investigates the potential of using smart dampers, specifically magnetorheological (MR) fluid dampers, in the outrigger system. First, a high-rise building is modeled to portray the St. Francis Shangri-La Place in Philippines. The optimal performance of the outrigger damping system for mitigation of seismic responses in terms of damper size and location also is subsequently evaluated. The efficacy of the semi-active damped outrigger system is finally verified through numerical simulation.

• Korean Institute of Interior Design Journal
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• v.20 no.6
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• pp.79-87
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• 2011

Spatial perception and spatial structure that focus on psychological effects produce a real force through the medium of space that can control human actions, even their psychology. The job of understanding the characteristics and effects of architectural spaces that recognize the relationship between architecture and human beings, including the psychological dimension, is an alternative search for quality spaces that can increase the mutual relationship between space and human beings. This paper introduces two propositions called "space" and "psychology" in order to discover a meta-pattern connecting space and the human mind with the aim of systematizing that internal network and establishing a new architectural system concerning space and human beings. This paper also proposes a method of accessing physical spaces that can affect psychological states through a conceptual substitution called "extension," with the aim of discovering the implications inherent in such extensive relationships and proposing a methodology of organizing psychological spaces based on the characteristics of that extensive connection. The means of extensively connecting psychological spaces were classified into the three categories of memory system, sensory system, and motor system, and their corresponding extensive connection characteristics called "simultaneous relativity," "non-mediated immediacy," and "purification process" were also derived. These characteristics accelerate the changes in psychological intensity and function as principles that organize psychological space.

• New & Renewable Energy
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• v.7 no.4
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• pp.18-29
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• 2011

Biofuls are considered as an option to reduce greenhouse gases emission, increase energy supply diversity and security of supply, as well as an opportunity for job creation and rural development. First of all, biofuls technologies have been promoted as a means for reducing the carbon intensity of the transport sector. Hence, in the last decade biofuels production has been driven by governmental policies. The key instruments widely adopted to foster production and increase consumption have been mandatory blending targets, tax exemptions and sibsidies. As one of the most powerful instruments, biofuel mandates require fuel producers to produce a pre-defined amount (or share) of biofuels and blend them with petroleum fuel. National biofuels mandates are in place 35 countries and partially in place in 6 countries. In this study, we reviewed status of global biofuels policies to reduce greenhouse gases in the European Union, United States and other countires worldwide. Especially, we discussed representative biofuels mandates policies same as Renewable Fuel Standard (RFS, US), Renewable Transport Fules Obligation (RTFO, UK) in transport sector.

• Fire Science and Engineering
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• v.15 no.4
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• pp.49-56
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• 2001

There have been the current controversy over effectiveness of the pressurized smoke control systems, which are installed within escape shaft to provide 'smoke-free' access for escaping peoples. Therefore, many effective measures were given in this paper by means of the production of a design guide for various types of escape routes used in domestic buildings. The solutions were established on basis of both an investigating current door closing device application in existing facilities and global standardization for pressurized smoke control system, especially in British Standard. Finally, the design guidance for open door air velocity with introduction to three door protection clauses was presented on the basis of consideration of the safety and economical factor,

• Korean Journal of Computational Design and Engineering
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• v.18 no.4
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• pp.275-282
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• 2013

This paper proposes a method for human identification using teeth contours extracted from dental images that are captured from the frontal views of subjects each of who opens his or her mouth slightly. Each dental image has a black-colored region containing the subject's teeth contours which are usually different from subject to subject. This means that this black-colored region has bio-mimetic information useful for human identification. The basic idea of the method is to extract the upper and lower teeth contours from the dental image of each subject and to encode their geometric patterns using a back-propagation neural network model. After acquiring 400 teeth images form 10 university students, we used 300 images for the training data of the neural network model and 100 images for its verification. Experimental results have shown that the proposed neural network-based method can be used as an alternative solution for identification among a small group of humans with a low cost and simple setup.

• Journal of Arbitration Studies
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• v.27 no.1
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• pp.131-160
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• 2017

When any investment dispute arises, the investor has to exhaust the local remedies available in the host state, and according to the agreement between the parties, the investor is filed to the ICSID arbitral tribunal to seek arbitral awards. At this time, if the arbitral tribunal decides that the investment agreement has been violated, it normally demands the host state to provide financial compensations to the investor for economic loss. According to the rules of the investment agreement, the host state is supposed to fulfill the arbitral awards voluntarily. If it is unwilling to provide financial compensations according to the arbitral awards, however, the investor may ask the domestic court of the host state for the recognition and enforcement of arbitral awards. In addition, if the host state is unwilling to fulfill arbitral awards on account of state immunity, the investor may ask his own country (state of nationality) for diplomatic protection and urge it to demand the fulfillment of arbitral awards. Effectiveness for pecuniary damages, a means to solve problems arising in the enforcement of investment arbitral awards, is found to be rather ineffective. For such cases, this study suggests an alternative to demand either a restitution of property or a corrections of violated measures subject to arbitral awards.

• KSBB Journal
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• v.29 no.5
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• pp.307-315
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• 2014

Recently seaweed polysaccharides have been extensively studied for alternative energy application. Because their producing cost is high and efficiency low, their industrial applications have been limited. The main component of cell wall of red algae represented by Gelidiales and Gracilariales is agar. Red-algae agar or galactan, consisting of D-galactose and 3, 6-anhydro-L-galactose, is suitable for bio-product application if hydrolyzed to monomer unit. For the hydrolysis of algae, chemical or enzymatic treatment can be used. A chemical process using a strong acid is simple and efficient, but it generates together with target sugar and toxic compounds. In an enzymatic hydrolysis process, target sugar without toxic compounds generation. The objective of this review is to summary the recent data of saccharification by chemical and enzymatic means from red seaweed for especially focused on automobile industry.