• Journal for History of Mathematics
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• v.19 no.1
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• pp.43-54
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• 2006

The purpose of this paper, followed by 'Nature$\cdot$Human, and Golden Section I ', is to study aesthetic consciousness, mentality model and body proportion of human, and the golden section applied to architecture and hand axe of stone age. In particular, handaxes of one million years ago have shown that they had critical competency to the basis of art and mathematics in the future. Furthermore, without pen, paper and ruler, the existence of mentality model made fundamental conversion of mathematics possible. Different sizes of handaxes were made by maintaining the equal golden section. This was the first example in relation to the principle mentioned in 'Stoicheia' by Euclid which was published hundred thousands of years later.

• Journal of Environmental Science International
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• v.5 no.3
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• pp.265-275
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• 1996

Air pollution characteristics and the influence of sea breeze on surface ozone concentration were studied using the data measured at 7 air quality continuous monitoring stations from June to September using 3 years (1990, 1993, 1994) in Pusan coastal area. Among the 246 sea breeze days for research Period, there were approximately 89 sea breeze days (36%) from lune to September, And there were 120 the episode days (68%) of ozone greater than or equal to 60 ppb in summer season. In 89 sea breeze days, the episode day was highly marked as 56 days (63%). So, we knew that the sea breeze greatly affects the occurence of ozone episode day. the ozone concentration under the condition of the sea breeze increase about 40% in the daytime. Frequencies distribution of $O_3$ concentration for sea breeze moved toward high concentration class. The characteristics of ozone concentration in relation to meteorological conditions of sea breeze is significant because we can discover major weather factors for eastablishing an air pollution- weather forecast system. For further. study about meterological approach method for photochemical air pollution, it is necessary to explain the characteristics of atmosphere below 1, 000 m, especially concerning the formation mechanism of inversion layers. And finally, we will study the relationships to synoptic weather conditions and vertical structure and diurnal variation of local wind systems including sea breeze, and the vertical movements of atmosphere in the city.

• Journal of the Korea Concrete Institute
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• v.11 no.5
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• pp.89-98
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• 1999

This paper evaluates nonlinear response characteristics of precast concrete frame buildings. where plastics hinging occurs in the precast connection. Designs were developed for buildings of 5, 10 and 15 stories in hight for moderate seismic risk regions of the U. S. The responses of the buildings were analyzed using DRAIN-2DX and following Nonlinear static analysis procedure of ATC 19. The main variables of the analyses were the strength and stiffness of the connection. Also, for the analysis, the bi-linear response model, developed and inserted into the DRAIN-2DX program by Shan Shi and D. Fouch, was used. With the results of analysis, the deformation demands of the connection of precast concrete frame buildings are proposed by using equal-dissipated energy capacity. It was shown that the strength of the buildings as well as their displacement capacities decreased with the decrease of either the strength or stiffness in the connections. Therefore such changes also require reductions in the response modification factors for such buildings. However, if the precast concrete frame building has plastic hinging in the connection, and has a more ductile connection than the monolithic frame building, then no reduction in R may be necessary. The deformation demand required of the connection to achieve that condition is evaluated and a simple relation is suggested in the paper.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.746-749
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• 2004

A new-type of FRP-concrete composite bridge deck system is proposed and its behaviors are experimentally studied. The new-typedeck consists of FRP as a permanent form and main tension resisting member and concrete as a compression resisting member. A suitable bonding method such as silica coating is applied to the interface between FRP and concrete to ensure composite behavior. The proposed deck system uses the box-shape FRP member, while a typical FRP-concrete composite deck uses the I-shape FRP member. Theproposed deck system has inherent advantages of a FRP-concrete composite deck like corrosion free and easy construction. The new-type deck shows the equal performances compared to a previous one, and has the advantage of reducing self-weight. In this study, the static tests on 3-span FRP-concrete decks in full scale are carried out, so that load-displacement relation, stress distribution, failure mode and design criteria are analyzed. The test results show that the deflection design criterion (L/800, L: span length) is satisfied at the service load state. No concrete tensile crack occurs in the negative moment region above the main girder, regardless of no tensile reinforcement at upper concrete portion.

• Journal of the Korean School Mathematics Society
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• v.12 no.3
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• pp.267-289
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• 2009

Students have difficulties in solving linear equation problems with a variable on the right side rather than linear equation problems a variable on the left side of the sign of equality. In order for students to overcome such difficulties, opportunities to experience many types of basic linear equation problems would have to be provided. Also, it is necessary to examine the process of students' problem solving process by constructing various types of evaluation item and test them in instruction and learning of linear equations, or grasp students' studying statues through individual interview and based on theses, error correction through feedbacks have to be achieved.

• Journal of the Korean Data and Information Science Society
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• v.25 no.4
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• pp.697-703
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• 2014

Deal-or-No-Deal game is a famous TV show program of NBC, USA, which is composed of 10 stages at most. At each stage from the first and the ninth, a banker suggests a deal price to participants. In this paper, we intend to reveal the banker's deal price model using a constrained linear model and quadratic program. As results, we provide a linear model in relation to the deal price at each stage and then show using simulation data that the deal price is equal to the nearest integer of the value to be obtained by the provided linear model.

• Journal of the Korean Society for Precision Engineering
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• v.9 no.3
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• pp.140-148
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• 1992

The effect of mechanical, properties in the plastic zone near the crack-tip was investigated, under various controlled loading conditions, i.e., ${\Delta}K$ increasing, ${\Delta}K$ decreasing, and single overload test. For both ${\Delta}K$ decreasing test and ${\Delta}K$ increasing test with constant stress ratio, it is found that the ratio of material constant m'( ${\Delta}K$ decreasing test) to material constant m( ${\Delta}K$ increasing test) is larger than 1 for n<0.1, and it is equal to 1 for 0.10.2. A modified crack growth rate equation based on Forman's equation which applied stable region of fatigue crack propagation in ${\Delta}K$ decreasing test is proposed. Within the limit of this single overload test, an empirical relation between among the retardation ratio (Nd/ $N^{*}$), the strain hardening exponent (n) and the percent peak load (%PL) has been established.established.

• Journal of architectural history
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• v.14 no.1 s.41
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• pp.7-19
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• 2005

The purpose of this paper is the study on the piazza plan of basilica S. Pietro. The results of study are as follows: 1. The piazza of the basilica S. Pietro was planned in relation to building-piazza-symbol of interior piazza-street as city planning characteristic of Baroque and architectural characteristic of elliptical piazza form. 2. The function of piazza of basilica S. Pietro was planned for religious meeting of a grand scale than a piazza for the common run of people. 3. In general, the disposition, ground, elevation and section plan of the piazza of basilica S. Pietro was planned by principle of spatial and formal composition, according to axis, symmetry, proportion, division and contrast. 4. The location, scale, shape of piazza for disposition and ground plan of the piazza of basilica S. Pietro was basically decided by not only elements of Basilica building, Vatican Palace, Street and Walls of surroundings with axis of the Basilica building, but Fountain and Obelisk as existing constituent elements. 5. The elevation of the piazza of basilica S. Pietro was composed of boundary that was enclosed from wall of trapezoid piazza and gallery of elliptical piazza with equal height as symmetry. And the section plan was planned to approach into the Basilica through slope and stairs of gentle angle, utilizing of existing land form.

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.3
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• pp.273-278
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• 1995

This study is to estimate the ventilation volume by the traffic that originated from driving automobiles for two tunnels (Kugi tunnel and Kumhwa tunnel) that adopted natural ventilation system among tunnels of Seoul, and on the basis of which, we estimated the ventilation velume at various conditions. With the result of the estimation, we will present the basic method that can be operated with the optimum condition for the ventilation system. Estimating the predicted ventilation volume in the tennel by the pollutant concentration, we used traffic volume and CO emission data by the automobile speed and CO concentration in the tunnel. And, when we estimated the traffic ventilation volume by natural and traffic ventilation force, we used traffic volume, automobile speed, tunnel area, automobile area data and so on. As the result of simple regression between predicted ventilation volume and traffic ventilation volume, we attained the regression coefficient 0.88, and achieved the relation form that predicted ventilation volume equal 0.12x traffic ventilation volume-92, 000. Using this equation, we estimated the ventilation volume to satisfy the enviromnental standards of several space, and calculated the required volume for mechanical ventilation. Incase of Kumhwa Tunnel, there is a need of mechanical ventilation all day long to satisfy air quality standard 9 ppm for 8 hours average and 10 ppm for the indoor air quality standard of public facilities.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.5
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• pp.332-339
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• 1986

This paper proposes a new method for the normalization of shape pattern based on Gaussian probability density function to increase automatic recognition rate of hand-written Hangul pattern. The sizes of hand-written Hangul pattern are detected from the input images, and pattern sizes are normalized by two variables interpolation. The pattrn shapes are noralized by letting correlation coefficients equal to zero. It is analyzed theoretically and verified through computer simulation for the relation between input image and normaized shape pattern. It is confirmed that this method is effective and reasonable for deformed hand-written Hangul pattern. Experimental resu results show that the declination. size and stroke width of hand-written Hangul patterns are mych improved.