• Journal of Environmental Science International
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• v.16 no.4
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• pp.495-503
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• 2007

In this study, we took the geometrical character of the river channel junction and hydrologic conditions as independent variables, and hydraulic behavior characteristics as an independent variable. The result, after multiple analysis was carried out, proved that, except for the generating area of the accelerating zone of velocity the accelerating zone and both the main channel and the tributary zone of stagnation the stagnation zone, there was correlation of over 90%. Also, derived presumed expression of the hydraulic characteristics of the junction was applied to the real natural channel - the river channel of the Guem-ho main channel(the A-yang bridge to the Guem-ho bridge). As the result, it proved that it represented hydraulic characteristics relatively well.

• Korean Institute of Interior Design Journal
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• no.26
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• pp.95-103
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• 2001

This study was performed to search for the geometrical principles in modern architecture and design based on Frobel's educational idea and Kindergarten system. Especially, it studies on the geometrical principles of Froebel's building gifts and it's types, and then illustrates applied examples in modern architecture and design. As the architectural scope, the architecture and design theory of Frank Lloyd Wright and Bauhaus in early 20th century is analyzed. The conclusions of this study that starts these purpose are as follows. First, Froebel's educational theory is based on principles and rules which are perceived through the observation of nature, and Froebel's Kindergarten system consists of geometrical building gifts and categories of geometrical forms. Second, the characteristics of Froebel's building gifts are mathematical size, proportion, symmetry and the rules of spatial relation. Third, the influence of Froebel's kindergarten system on Bauhaus is that it based on the rational rules of $\bigtriangleup\square\bigcirc$ organized by geometrical basic forms as like Froebel's educational idea. And the influence of Froebel's Kindergarten system on Frank Lloyd Wright is that he used unit system, unity of space and structure and modular system as like the Froebel's building gifts.

• The korean journal of orthodontics
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• v.44 no.4
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• pp.177-183
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• 2014

Objective: To determine the unique contribution of geometrical design characteristics of orthodontic mini-implants on maximum insertion torque while controlling for the influence of cortical bone thickness. Methods: Total number of 100 cylindrical orthodontic mini-implants was used. Geometrical design characteristics of ten specimens of ten types of cylindrical self-drilling orthodontic mini-implants (Ortho Easy$^{(R)}$, Aarhus, and Dual Top$^{TM}$) with diameters ranging from 1.4 to 2.0 mm and lengths of 6 and 8 mm were measured. Maximum insertion torque was recorded during manual insertion of mini-implants into bone samples. Cortical bone thickness was measured. Retrieved data were analyzed in a multiple regression model. Results: Significant predictors for higher maximum insertion torque included larger outer diameter of implant, higher lead angle of thread, and thicker cortical bone, and their unique contribution to maximum insertion torque was 12.3%, 10.7%, and 24.7%, respectively. Conclusions: The maximum insertion torque values are best controlled by choosing an implant diameter and lead angle according to the assessed thickness of cortical bone.

• Bulletin of the Korean Chemical Society
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• v.29 no.3
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• pp.627-640
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• 2008

The geometrical structures, atomic charges, and relative energies of tetracoordinated Pd complexes [PdCl3Z (Z = Cl-, Br-, OH?-, H2O, NH3, PH3), PdCl2Z2 (Z = Br-, OH?-, H2O, NH3, PH3), PdZ?2X (Z = Cl-, OH?-, H2O, NH3, PH3; X = oxalate, O2-?CCO2-), and PdZ2Y (Z = Cl?-, OH?-, H2O, NH3, PH3; Y = succinate, CO2-?CHCHCO2-?)] and the ligand exchange reactions of the Pd complexes were investigated using the ab initio second order Mller-Plesset perturbation (MP2) and Density Functional Theory (DFT) methods. The geometrical characteristics of the tetracoordinated Pd(II) complexes with mono- and bidentate ligands, the effects of the atomic charges for the charged and uncharged ligands, the (dz2-p ) interactions between the dz2-orbital of Pd(II) and the p -orbital of bidentates, and the relative stabilities between the isomers of PdCl2Z2 and PdZ2Y were investigated in detail. The potential energy surfaces for the ligand exchange reactions used for the conversions of {[PdCl2(NH3)2] + H2O} to {[PdCl(NH3)2(H2O)]+ + Cl?-?} and {[PdCl2(PH3)2] + H2O} to {[PdCl(PH3)2(H2O)]+ + Cl?-?]} were investigated. The geometrical structure variations, molecular orbital variations (HOMO and LUMO), and relative stabilities for the ligand exchange processes were also examined quantitatively.

• School Mathematics
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• v.11 no.1
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• pp.147-164
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• 2009

This study investigated the development of geometrical thinking levels of the under achievers at mathematics through supplementary classes according to van Hiele's learning process by stages using mathematical journal writing. We selected five under achievers at mathematics among the fourth graders. We examined their geometrical thinking levels in advance and interviewed them to collect basic data related to their family backgrounds and their attitude toward mathematics and their characteristics. Supplementary classes for the under achievers were conducted a couple of times a week during 12 weeks. Each class was conducted through five learning stages of van Hiele and journal writing was applied to the last consolidating stage. After 12th class had been finished, posttest on geometrical thinking levels was conducted and the journals written by the pupils were analyzed to find out changes in their geometrical thinking levels. The result is that three out of five under achievers showed one or two level-up in their geometrical thinking levels, though the other two pupils remained at the same level as the results by the pretest. Moreover we found that mathematical journal writing could provide the pupils with opportunities to restructure the content which they study through their class.

• 전기의세계
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• v.14 no.1
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• pp.5-12
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• 1965

In the designs of the sensitive electronic devices such as phase sensitive detector, X-ray diffractometer, and neutron diffractometers, we must take into account the geometrical factors in a coil systems and extraneous stray fields. Input wave forms in such a sensitive electronic devices are often altered by the influence of these factors. Since the magnitude of the stray fields is generally very small, this affection may be removed by applying a good shielding but it is not ease to remove the affection from a geometrical factor. This affection must be however calculated by the theoretical methods and analytical solution in the equation of these factors. The fundamental purpose of this paper lie in the theoretical calculations and practical measurements of the geometrical factor in the coil systems, finite solenoid, and four point prove. In the heoretical calculations, the geometrical factors in the coil systems were calculated by applying the elliptic functions and in the contact points were calculated by applying the elliptic functions and in the contact points were calculated by applying the eigen functions and the infinite series. The measurements were carried out by using the sensitive electronic device made from author's design, as shown in the Fig. 9. The result of this work has verified the essential correctness of theoretical investigations and measuring techniques of geometrical factors on the design of sensitive electronic devices. It also has several advantages such that: (1) all the data obtained may give effective data to designer to work on the field of sensitive electronic devices or microelectronic devices, (2) it has evidently explained the characteristics of electrical investigations and physical definition, and has removed the conventional error of geometrical factors in the coil systems and contact points.

• Journal of Korean Society of Steel Construction
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• v.9 no.3 s.32
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• pp.323-332
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• 1997

This study is aimed at investigating the buckling characteristics of single layer latticed domes with triangular network pattern under the partially concentrated equipment loading in the cases of both having a geometrical imperfection and not having.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.23-26
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• 2002

In ceramic systems using LTCC, many components including embedded passives and TRL's are used for composition of 3-dimensional circuit. So the exact analysis on this components must be performed. As for the TRL's, material properties including electrical conductivity of metal, loss factor and effective dielectric constant of dielectric material and geometrical factors like roughness of surface, vias, dimension of TRL structure have a large effect on the characteristics of transmission lines. Such properties of materials have different values in each system with ideal ones presented in text book. In this research, the effective material properties in each system are examined and the effect of material properties and geometrical factors on the characteristics of TRL's are analyzed and quantified by simulation and measurement.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.05a
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• pp.69-73
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• 2002

In ceramic systems, many components including embedded passives and TRL(transmission line) are used for composition of 3-dimensional circuit. So the exact analysis on this components, As for the TRL's, material properties including electrical conductivity of metal, loss factor and effective dielectric constant of dielectric material and geometrical factors like roughness of surface, vias, dimension of stripline structure have a large effect on the charactersistics of transmission lines. In this research, of effect of material and geometrical factors on the characteristics of stripline structure is analyzed and quantified by simulation and measurement.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.5 no.2
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• pp.39-51
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• 2001

This paper shows how boundary element method can be used to calculate torsion geometrical stiffness of cross-sections of various beams and airfoil profiles. Using the BEM direct formulation, the technique for determining bending and torsional geometrical characteristics of arbitrary multiply connected cross-sections is presented. The application limits of several well-known formulae on some test problems have been demonstrated and discused.