• Journal for History of Mathematics
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• v.16 no.1
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• pp.25-44
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• 2003

In this paper, we deal with the ‘dearithmetization’ of algebra. Historically, the origin of algebra comes from arithmetic. Also school algebra is related to arithmetic in general. However, we have many difficulties in teaching school algebra, and there is many problems for students to learn algebra from elementary arithmetic knowledges. This paper supposed that the solution of these problem may be founded in the ‘dearithmetization’ of algebra. And we supposed that the ‘dearithmetization’ of algebra may be developed by three historical achievements - the completion of symbolic algebra, the principle of permanence of form, and the expansion of number concepts. In order to justify these supposition, we investigate Peacock's ideas, i.e. ‘symbolic algebra’, ‘the principle of permanence of form’, and consider how the integer is introduced in modern mathematics. And we analyze various textbooks, and investigate the ‘dearithmetization’ of school algebra which has been progressed in the three fields - symbolic algebra, the principle of permanence of form, and the expansion of number concepts.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.5
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• pp.2338-2356
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• 2019

Vehicular ad-hoc network (VANET) is the name of technology, which uses 'mobile internet' to facilitate communication between vehicles. The aim is to ensure road safety and achieve secure communication. Therefore, the reliability of this type of networks is a serious concern. The reliability of VANET is dependent upon proper communication between vehicles within a given amount of time. Therefore a new formula is introduced, the terms of the new formula correspond 1 by 1 to a class special ST route (SRORT). The new formula terms are much lesser than the Inclusion-Exclusion principle. An algorithm for the Source-to-Terminal reliability was presented, the algorithm produced Source-to-Terminal reliability or computed a Source-to-Terminal reliability expression by calculating a class of special networks of the given network. Since the architecture of this class of networks which need to be computed was comparatively trivial, the performance of the new algorithm was superior to the Inclusion-Exclusion principle. Also, we introduce a mobility metric called universal speed factor (USF) which is the extension of the existing speed factor, that suppose same speed of all vehicles at every time. The USF describes an exact relation between the relative speed of consecutive vehicles and the headway distance. The connectivity of vehicles in different mobile situations is analyzed using USF i.e., slow mobility connectivity, static connectivity, and high mobility connectivity. It is observed that $p_c$ probability of connectivity is directly proportional to the mean speed ${\mu}_{\nu}$ till specified threshold ${\mu}_{\tau}$, and decreases after ${\mu}_{\tau}$. Finally, the congested network is connected strongly as compared to the sparse network as shown in the simulation results.

• The Journal of Korean Philosophical History
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• no.31
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• pp.7-32
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• 2011

Cheng Yi(程?, 1033~1107) understood that nature is full of "changes(易)". And he noted that human being as part of nature also exists only in a series of changes, i.e. birth, growth, extinction and death. All things including human being arise from the same principle, or "Heavenly Principle." Hence human being can fundamentally be one with all other beings, or nature. It is called "Unity of all things(萬物一體)" and "Unity of heaven and human(天人合一)." This philosophical perspective cannot be regarded as being unique to Cheng only; neo-Confucian predecessors called "the five masters of the Northern Song(北宋五子)" anticipated Cheng's vision already. Nevertheless, Cheng elaborated on the shared vision, revealing his philosophical uniqueness. Cheng maintains that only human being receives the principle in the unstained form, and thereby is capable of being one with nature. The one who realizes her/his potential to be one with nature is a sage(聖人); for Cheng, the order and pattern found in nature is nothing other than moral principle that human beings have to live up to and vice versa. Cheng's idea on the principle which human being receives from Heaven no doubt relates to Mencian notion of the innate goodness of human nature(性善); the innate goodness of human nature is no other than Heavenly Principle, and to become a sage depends on whether one can realize her/his potential - human nature, i.e. Heavenly Principle in her/himself. For Cheng, human nature tantamount to Heavenly Principle has no evil quality; all the evil in the world comes from imperfect "physical endowment(氣質)," or "capacity(才)" which is various from person to person, making various personalities. Accordingly, the task of moral cultivation in Cheng's theory can translate into the matter of rectification of one's physical endowment.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.378-381
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• 2015

To produce low cost and efficient photovoltaic cells, inorganic-organic lead halide perovskite materials appear promising for most suitable solar cells owing to their high power conversion efficiency. Most recent research showes that formamidinium lead iodide ($FAPbI_3$) with methylammonium lead bromide ($MAPbBr_3$) improves the power conversion efficiency of the solar cell to more than 18 per cent under a standard illumination because incorporated $MAPbBr_3$ makes $FAPbI_3$-relatively unstable but comparatively narrow band gap-more stable composition. In respect to first principle study, we investigated band gap of $MAPbI_3$, $FAPbI_3$, $MAPbBr_3$, $(FAPbI_3)_{0.89}-(MAPbBr_3)_{0.11}$ and 0.615(eV), 0.466, 1.197, 0.518 respectively through EDISON DFT software. These results emphasize enhancing structure stability is important factor as well as finding narrow band gap.

• Steel and Composite Structures
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• v.23 no.5
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• pp.597-610
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• 2017

This paper presents a mathematical model for fixed-end moments of I-sections with straight haunches for the general case (symmetrical and/or non-symmetrical) subjected to a concentrated load localized anywhere on beam taking into account the bending deformations and shear, which is the novelty of this research. The properties of the cross section of the beam vary along its axis "x", i.e., the flange width "b", the flange thickness "t", the web thickness "e" are constant and the height "d" varies along of the beam, this variation is linear type. The compatibility equations and equilibrium are used to solve such problems, and the deformations anywhere of beam are found by the virtual work principle through exact integrations using the software "Derive" to obtain some results. The traditional model takes into account only bending deformations, and others authors present tables considering the bending deformations and shear, but are restricted. A comparison between the traditional model and the proposed model is made to observe differences, and an example of structural analysis of a continuous highway bridge under live load is resolved. Besides the effectiveness and accuracy of the developed models, a significant advantage is that fixed-end moments are calculated for any cross section of the beam "I" using the mathematical formulas.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.1
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• pp.85-91
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• 2008

A Boost Power Factor Correction (PFC) Converter employing Zero Voltage Switching (ZVS) based Compound Active Clamping (CAC) technique is presented in this paper. An Electro Magnetic Interference (EMI) Filer is connected at the line side of the proposed converter to suppress Electro Magnetic Interference. The proposed converter can effectively reduce the losses caused by diode reverse recovery. Both the main switch and the auxiliary switch can achieve soft switching i.e. ZVS under certain condition. The parasitic oscillation caused by the parasitic capacitance of the boost diode is eliminated. The voltage on the main switch, the auxiliary switch and the boost diode are clamped. The principle of operation, design and simulation results are presented here. A prototype of the proposed converter is built and tested for low input voltage i.e. 15V AC supply and the experimental results are obtained. The power factor at the line side of the converter and the converter efficiency are improved using the proposed technique.

• Language and Information
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• v.1
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• pp.137-179
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• 1997

This paper discusses several basic issues of the 'focus' phenomenon. One of them is the issue of the nature of focus, i.e., what constituent of the sentences gets focused. Another is the issue of to what aspect of meaning the focus contributes. The other is the issue of the functions of focus-sensitive operators. As for the first issue, it is observed that the basic function of focus is to mark all and only the new information of the sentence. But for the cases in which this principle is not observed, it is proposed that the focus in these cases in general plays a secondary function of triggering an additional emphatic scalar meaning. And yet, in these cases, the state of the matter is different between free focus and bound focus. It is also shown that contrary to the general belief that free focus contributes to the meaning semantically. Concerning focus-sensitive operators, we classify them into two groups, i.e., quantificational and scalar operators, and try to formalize their meaning in the framework of Pulman's(1997) 'higher order unification theory'.

• Journal of Surface Science and Engineering
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• v.29 no.5
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• pp.314-324
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• 1996

Scanning probe microscopes (SPMs) such as the scanning tunneling microscope (STM) and the atomic force microscope (AFM) were used for surface modification tools at the nanometer scale. Material surfaces, i. e., titanium, hydrogen-terminated silicon and trimethylsilyl organosilane monolayer on silicon, were locally oxidized with the best lateral spatial resolution of 20nm. The principle behind this proximal probe oxidation method is scanning probe anodization, that is, the SPM tip-sample junction connected through a water column acting as a minute electrochemical cell. An SPM-nanolithogrphy process was demonstrated using the organosilane monolayer as a resist. Area-selective chemical modifications, i. e., etching, electroless plating with gold, monolayer deposition and immobilization of latex nanoparticles; were achieved in nano-scale resolution. The area-selectivity was based on the differences in chemical properties between the SPM-modified and unmodified regions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.183-192
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• 1999

The derivative equation measured of a ${\Delta}MV=Kp*{(EVn-EVn-1)+\frac{1}{Ki/S}* EVn+(Kd/S)*(2PVn-1-PVn-PVn-1)}$ is used on the machine apparatus of industrial field, but this par doesn\`t able to educate now, because we didn\`t have the implementation device of PID module, so the principle implementation system of the PID Module is manufactured and developed. Through this system, the implementation system of PID Module is practiced with that the SV and the set of P, I, D is set on the derivative equation measured of PID. A things to be known of this experiment result is flow. 1)PID module is known that had to be used with the module of A/D and D/A. 2) In process of PV is approached to the SV to follow Kp, Ti and Td to cause a constant of set value on the $MVp=Kp*EV, MV=\frac{1}{Ki}{\int}EVdt, MVd=Td\frac{d}{dt}EV$, the variable rate of E and Kp, Td, Ti in that table 1 is analysed, is same as flow. (1)If Kp is high, PV is near fast to the SV, but Kp is small, PV is near slowly to the SV. (2)If Ki is shot, PV is close fast to the SV, but Ti is high, PV is close slowly to the SV (3)If Td is high, the variable rate of E press hardly when because it doesn\`t increase, but Td is small, the variable rate of E press not hardly, upper with 1), 2), PID module is supposed that be able to do the A/S and an implementation of that apparatus, and getting a success of aim that an engineer want, on control of temperature, tension, velocity, amount of flow, power of wind end so on, to get the principle of automatic implementation in industrial field with cooperation of A/D and D/A module.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.4
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• pp.381-387
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• 2016

In this paper, the methodology applied to the improvement of stress analyses is extended to free vibration and buckling analyses. The essence of the methodology is the Saint-Venant's principle that is applicable to beam and plate models. The principle allows one to dimensionally reduce three-dimensional elasticity problems. Thus the methodology can be employed to vibration and buckling as well as stress analysis. First, the principle is briefly revisited, and then the formations of classical beam theories are presented. To improve the predictions, the perturbed terms (unknowns) are introduced together with the warping functions that are calculated by stress equilibrium equations. The unknowns are then calculated by applying the equivalence of stress resultants (i.e., Saint-Venant's principle). As numerical examples, cantilever and simply supported beams are analytically solved. The results obtained are compared with those of the classical beam theories. It is shown that the methodology can be used to improve the predictions without introducing shear correction factors.