• Title/Summary/Keyword: Golden ratio

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The Meaning of 'Golden Hour' in Prehospital Time for Abdominal Trauma Victims with Emergency Laparotomy (복부외상으로 응급개복술을 시행한 환자에서 병원전단계 황금시간의 의의)

  • Jang, Tae-Chang;Lee, Kyung-Won
    • Journal of Trauma and Injury
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    • v.23 no.2
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    • pp.180-187
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    • 2010
  • Purpose: The "golden hour" concept in trauma is pervasive despite little evidence to support it. This study addressed the association between prehospital time and in-hospital mortality in seriously injured abdominal trauma victims. Methods: A retrospective study was conducted over a three-year period from 2006 to 2008. We analyzed trauma victims with abdominal injuries who underwent an emergency laparotomy in a local emergency center located in a city with a population of 2,500,000. According to the 'golden hour' oncept, we separated the trauma victims into two groups (Gourp 1: prehospital time ${\leq}$ 1 hour, Group 2: prehospital time > 1hour) and investigated several factors, such as time, process, and outcome. Results: During the period from January 2006 to December 2008 139 trauma victims underwent an emergency laparotomy, and 89 of them were enrolled in this study. Between the two groups, emergency department (ED) access, transportation, and injury mechanism showed statistically meaningful differences, but no statistically meaningful differences were observed in various measures of the outcome, such as length of hospital stay, length of Intensive Care Unit stay, and mortality. In a univariate logistic regression study, age (odds ratio [OR]: 1.101; 95% confidence interval [CI]: 1.026 to 1.182), Revised Trauma Score (RTS) (OR: 0.444; 95% CI 0.278 to 0.710), hemoglobin (OR: 0.749; 95% CI: 0.585 to 0.960), and creatinine (OR: 24.584; 95% CI: 2.019 to 299.364) were significant prognostic factors, but prehospital time was not. In a multivariate logistic regression study, age and RTS were significant associated with mortality. Conclusion: In this study, we found no association between prehospital time and mortality among abdominal trauma patient who underwent an emergency laparotomy. We suggest that in our current out-of-hospital and emergency care system, until arrival at the hospital time may be less crucial for trauma victims than once thought.

A Study on the TiN Thin Film by Sol-Gel Method (졸-겔 방법으로 제조한 TiN 박막에 관한 연구)

  • 김왕섭;선효님;김경용;김병호
    • Journal of the Korean Ceramic Society
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    • v.29 no.4
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    • pp.328-334
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    • 1992
  • TiO2 sols were prepared by hydrolysis and polymerization of titanium tetra-isopropoxide (TTIP) in the presence of diethanolamine (DEA). The optimal mole ratio of water to TTIP is 2 and the concentration of the TiO2 sol 0.7 M. Golden TiN films without cracks were obtained by dipping Si(110) wafers into the TiO2 sol and followed by nitridation in NH3 at 1100$^{\circ}C$ for 5 h. The TiN films were studied by an optical microscope, DTA, TGA and X-ray analysis.

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유클리드 기하학과 그리스의 미술

  • 계영희
    • Journal for History of Mathematics
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    • v.16 no.2
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    • pp.23-34
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    • 2003
  • In this paper, we consider relationship between the mathematics and the fine arts. The former is one of the advanced sciences, the latter is one of the arts. But there is correlation between the mathematics and the arts. Here, we concern with the ancient greek mathematics, Euclidean geometry and the ancient greek arts. The ancient greek arts is classified with Geometric Style, Archaic Style, Classical Style and Hellenistic Style. The Geometric Style, Classical Style and Hellenistic Style are very effected by Euclidean geometry. Because the greek artists as keep the geometric proportion as the Euclidean's 5th postulates. The artist's cannon in just golden ratio 1:(1+$\sqrt{5}$)/2.

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사영기하학과 르네상스 미술

  • 계영희
    • Journal for History of Mathematics
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    • v.16 no.4
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    • pp.59-68
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    • 2003
  • Mathematics and arts are reflection of the spirit of the ages, since they have human inner parallel vision. Therefore, in ancient Greek ages, the artists' cannon was actually geometric ratio, golden section. However, in middle ages, the Euclidean Geometry was disappeared according to the Monastic Mathematics, then the art was divided two categories, one was holy Christian arts and the other was secular arts. In this research, we take notice of Renaissance Painting and Perspective Geometry, since Perspective Geometry was influenced by Renaissance notorious painter, Massccio, Leonardo and Raphael, etc. They drew and painted works by mathematical principles, at last, reformed the paradigm of arts. If we can say Euclidean Geometry is tactile geometry, the Perspective Geometry can be called by visual geometry.

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Cognitive analysis and mathmatical application of emotivity information (감성정보의 인지과학적 해석과 수리적 적응)

  • 김홍재
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1999.11a
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    • pp.256-261
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    • 1999
  • 본 연구는 감성의 정보적 측면 즉 감성정보를 인지과학적 관점에서 유도하였다. 감성정보는 인간행동의 내부와 외부의 변환과정을 주도하는 감성의 정보적 측면이라 할 수 있다. 이 감성정보와 인지과학의 인터페이스를 근간으로 하여 감성정보의 고유기능특성을 고찰하여 해석하고자 한다. 나아가 인간의 감성정보를 황금비(Golden section ratio)와 유비(Analogy)시켜 수리적 적응을 도모하고자 한다. 이러한 적응은 인간 감성이 미치는 제 대상에 새로운 방안을 제공하므로서 응용폭의 확대를 기대할 수 있다고 사료된다.

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A Study on Numerical Optimization Method for Aerodynamic Design (공력설계를 위한 수치최적설계기법의 연구)

  • Jin, Xue-Song;Choi, Jae-Ho;Kim, Kwang-Yong
    • The KSFM Journal of Fluid Machinery
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    • v.2 no.1 s.2
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    • pp.29-34
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    • 1999
  • To develop the efficient numerical optimization method for the design of an airfoil, an evaluation of various methods coupled with two-dimensional Naviev-Stokes analysis is presented. Simplex method and Hook-Jeeves method we used as direct search methods, and steepest descent method, conjugate gradient method and DFP method are used as indirect search methods and are tested to determine the search direction. To determine the moving distance, the golden section method and cubic interpolation method are tested. The finite volume method is used to discretize two-dimensional Navier-Stokes equations, and SIMPLEC algorithm is used for a velocity-pressure correction method. For the optimal design of two-dimensional airfoil, maximum thickness, maximum ordinate of camber line and chordwise position of maximum ordinate are chosen as design variables, and the ratio of drag coefficient to lift coefficient is selected as an objective function. From the results, it is found that conjugate gradient method and cubic interpolation method are the most efficient for the determination of search direction and the moving distance, respectively.

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Recovery of Golden yellow and Cibacron LSG dyes from aqueous solution by bulk liquid membrane technique

  • Muthuraman, G;Ali, P. Jahfar
    • Membrane and Water Treatment
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    • v.3 no.4
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    • pp.243-252
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    • 2012
  • Tri-n-butyl phosphate (TBP) was used as carrier for the transport of Golden yellow and Cibacron LSG dyes through a hexane bulk liquid membrane. The transport efficiency of dyes by TBP was investigated under various experimental conditions such as pH of the feed phase (dyes solution), concentration of the receiving phase (NaOH solution), concentration of TBP in membrane, rate of stirring, effect of transport time, type of solvent, dye concentration in feed phase, effect of temperature.. The maximum transport dyes occurs at ratio of 1:1 TBP-hexane At pH 3.0 0.1 (feed phase) the transport dyes decreased. At high stirring speed (300 rpm) the dyes transport from the feed phase to the strip phase was completed within 60 minutes at $27^{\circ}C$. Under optimum conditions: Feed phase 100 mg/L dyes solution at pH 1.0 0.1, receiving phase 0.1 mol/L NaOH solution, membrane phase 1:1 TBP-hexane , Stirring speed 300 rpm and temperature $27^{\circ}C$, the proposed liquid membrane was applied to recover the textile effluent.

Nutrition composition differences among steamed and freeze-dried mature silkworm larval powders made from 3 Bombyx mori varieties weaving different colored cocoons

  • Ji, Sang-Deok;Kim, Nam-Suk;Kweon, HaeYong;Choi, Bo Hye;Kim, Kee-Young;Koh, Young Ho
    • International Journal of Industrial Entomology and Biomaterials
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    • v.33 no.1
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    • pp.6-14
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    • 2016
  • The mulberry silkworm, Bombyx mori has been one of the most important domestic animals which have provided with silk fibers for weaving fabrics and a food for a protein and lipid source. In addition, various health improvement effects of diverse silkworm larval powders were reported. Recently we found that steamed and freeze-dried mature silkworm larval powder (SMSP) generated using white-jade (also known as Backokjam) silkworm variety extended healthspan and increased resistance to Parkinson's disease in animal models. Because the colors of cocoons in silkworm varieties were caused by altered signal transduction pathways transporting phytochemicals from intestinal lumens to silk glands, we performed the proximate, amino acid, mineral, carbohydrates, fatty acid, and cholesterol composition analyses of SMSPs of 3 silkworm varieties which were weaving light yellow, golden, and red cocoons. Although most of nutrient compositions among 3 SMSPs were similar, there were significant differences in certain amino acids, minerals, and fatty acid compositions. Red silk silkworm (RS)-SMSP had higher contents of crude proteins and total amino acids than other SMSPs. In addition, the ratio of n-3/n-6 unsaturated fatty acids were higher than the other SMSPs. In contrast Golden silk silkworm (GS)-SMSP had higher ratio of potassium/sodium than the other SMSPs. These nutrient analysis results suggested that 3 SMSPs might have common and unique health improvement effects. Thus, further studies in the functionalities of the 3 SMSPs will reveal unknown their health improvements effects.

A Study on Generalized Fibonacci Sequence (피보나치 수열의 일반화에 관한 고찰)

  • Yang, Young-Oh;Kim, Tae-Ho
    • Journal for History of Mathematics
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    • v.21 no.4
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    • pp.87-104
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    • 2008
  • In this paper we investigate several properties and characteristics of the generalized Fibonacci sequence $\{g_n\}$={a, b, a+b, a+2b, 2a+3b, 3a+5b,...}. This concept is a generalization of the famous Fibonacci sequence. In particular we find the identities of sums and the nth term $g_n$ in detail. Also we find the generalizations of the Catalan's identity and A. Tagiuri's identity about the Fibonacci sequence, and investigate the relation between $g_n$ and Pascal's triangle, and how fast $g_n$ increases. Furthermore, we show that $g_n$ and $g_{n+1}$ are relatively prime if a b are relatively prime, and that the sequence $\{\frac{g_{n+1}}{g_n}\}$ of the ratios of consecutive terms converges to the golden ratio $\frac{1+\sqrt5}2$.

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Analysis of esthetic factors and evaluation of esthetic perception for maxillary anteriors of dental students (치과대학생의 상악 전치부의 심미적 요소 분석 및 인식도 평가)

  • Kim, Seon-Kyung;Kim, Ok-Su
    • The Journal of Korean Academy of Prosthodontics
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    • v.57 no.2
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    • pp.118-126
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    • 2019
  • Purpose: This research is to investigate factors that affect dental aesthetics and analyze whether individual perception affects and difference of genders affects the esthetic factors. Materials and methods: Seventy dental students of Chonnam University aged from 25 to 35 years old without periodontal problems were included. Maxillary dental cast for participants were made, and standardized photo was taken with a digital camera. Maximum visual width and the position of gingival zenith of maxillary anterior teeth and maximum height of the maxillary central incisors were measured by a measurement program and the shape of central incisor was categorized. Questionnaire was conducted to evaluate esthetic perception. SPSS program was used to perform statistical analysis. Results: The average visual width ratio of right maxillary anteriors was 1.38:1:0.78 and 1.41:1:0.81 for the left which differ from the golden ratio. The width to height ratio for right and left central incisor was 0.84 and 0.83 respectively. The gingival zenith position was determined to be: mostly, central incisors and canines were located in the distal side, lateral incisors were located in the center. The visual width ratio of right maxillary anterior teeth, ratio of width to height of central incisor, gingival zenith position, crown morphology and amounts of gingival exposure upon smiling were not significantly different between genders, and facial patterns and these dental esthetic factors were not related to aesthetic perception. Conclusion: Even though participants had the visual width ratio of maxillary anteriors or ideal width to ideal height of central incisors that did not agree with the golden ratio, they had high satisfaction for dental esthetics. Esthetic perception depends more on subjective judgements of participants than objective indices.