• Title/Summary/Keyword: Goal-Direction

Search Result 568, Processing Time 0.027 seconds

Finite Element Analysis on the Shaft Fitting to Inner Raceway of Radial Ball Bearing (레이디얼 볼베어링의 내륜 끼워맞춤에 관한 유한요소해석)

  • Ko, Byung-Du;Lee, Ha-Sung
    • Design & Manufacturing
    • /
    • v.6 no.1
    • /
    • pp.45-51
    • /
    • 2012
  • The main goal of this paper is to establish an interference tolerance for determining optimal amount of clearance in the shaft-bearing system supported by radial ball bearings. The 2-D frictional contact model was employed for the FE analysis between the shaft and the inner raceway. Several examples were simulated using different material properties for the solid shaft. Efforts were focused on the deformation applied in the radial direction to select suitable bearings. The analysis results showed that the initial axial preload applied on the bearings plays a significant role to reduce bearing fatigue life. The proposed design parameters obtained by numerical simulations can approximately predict a rate of bearing life reduction as a function of shaft diameter ratio. This analysis can also be used to calculate the optimal initial radial clearance in order to obtain a shaft-bearing system design for high accuracy and long life.

  • PDF

Mathematical Giftedness and the Need of Mathematics Specialists in Elementary Grades

  • Pandelieva, Valeria
    • Research in Mathematical Education
    • /
    • v.12 no.4
    • /
    • pp.259-270
    • /
    • 2008
  • The change of the developed countries to highly technological societies continuously requires that they nurture and use the full potential of mathematically and scientifically talented people. As this is a process that should start early in order to be efficient, the main responsibility of identifying and addressing the specific needs of these people is assigned to public school systems and, in particular, to elementary teachers. In this regard, three significant areas of concern arise and are discussed in this paper: (a) The complexity in identifying mathematically promising and mathematically talented elementary students; (b) The highly responsible and difficult task for elementary teachers to differentiate and serve the mathematically promising students within an inclusive classroom; and (c) The need of teachers with specialized training and mathematics knowledge in pre-high school grades. The last one should be considered predominantly as a logical consequence of the first two. The main goal and, hence, the purpose of the paper is to promote understanding of this crucial necessity of mathematics specialists and to advocate for a change in this direction.

  • PDF

A Numerical Study on Steam Flow and Beat Transfer of Pannier-arrangement Condensers

  • Hou Pingli;Yu Maozheng
    • Journal of Energy Engineering
    • /
    • v.14 no.2 s.42
    • /
    • pp.98-104
    • /
    • 2005
  • Pannier-arrangement condensers are usually adopted in the turbine generator units of combined cycle power plants. Optimization of operating performance and economy is an important goal, which requires accurate understanding of flow and heat transfer effects in the condenser. The tube bundle arrangement and steam flow behaviors of pannier-arrangement condensers are very different from those of common condensers. The physical model for existing numerical simulation program of condenser is refined by constructing the correlations for flow resistance and condensation heat exchange coefficient in which the influences of steam flow direction are considered according to available experimental data. The adaptability of the developed physical model and simulation program of pannier-arrangement condenser is verified with available experimental data.

Investigation of Deep Drawability and Product Qualities of Ultra Thin Beryllium Copper Sheet Metal (베릴륨동 극박판의 드로잉 성형성과 품질특성 연구)

  • Park, S.S.;Hwang, K.B.;Kim, J.B.;Kim, J.H.
    • Transactions of Materials Processing
    • /
    • v.19 no.3
    • /
    • pp.179-184
    • /
    • 2010
  • The present study is focused on the deep drawability and product qualities of ultra thin beryllium copper sheet metal. The goal of this research is to investigate the limit drawing ratio in deep drawing of ultra thin beryllium copper metal. For the experiment, beryllium copper(C1720, $50{\mu}m$ in thickness) is used. Tensile test are also carried out to find out the material properties. Deep drawing experiments are carried out in Universal Testing Machine(UTM) to obtain limit drawing ratio. Deep drawing tests are carried out for various specimen sizes. Teflon film is used as a lubricant and constant blank holding force is imposed. Sheet thickness and surface hardness are measured along radial direction after deep drawing. Thickness is measured using optical microscope. For beryllium copper(C1720), the maximum LDR of 2.4 is obtained when the die shoulder radius is 20 or 30 times of sheet thickness.

One-dimensional modeling of flat sheet casting or rectangular Fiber spinning process and the effect of normal stresses

  • Kwon, Youngdon
    • Korea-Australia Rheology Journal
    • /
    • v.11 no.3
    • /
    • pp.225-232
    • /
    • 1999
  • This study presents 1-dimensional simple model for sheet casting or rectangular fiber spinning process. In order to achieve this goal, we introduce the concept of force flux balance at the die exit, which assigns for the extensional flow outside the die the initial condition containing the information of shear flow history inside the die. With the Leonov constitutive equation that predicts non-vanishing second normal stress difference in shear flow, we are able to describe the anisotropic swelling behavior of the extrudate at least qualitatively. In other words, the negative value of the second normal stress difference causes thickness swelling much higher than width of extrudate. This result implies the importance of choosing the rheological model in the analysis of polymer processing operations, since the constitutive equation with the vanishing second normal stress difference is shown to exhibit the characteristic of isotropic swelling, that is, the thickness swell ratio always equal to the ratio in width direction.

  • PDF

Protein-protein Interaction Networks: from Interactions to Networks

  • Cho, Sa-Yeon;Park, Sung-Goo;Lee, Do-Hee;Park, Byoung-Chul
    • BMB Reports
    • /
    • v.37 no.1
    • /
    • pp.45-52
    • /
    • 2004
  • The goal of interaction proteomics that studies the protein-protein interactions of all expressed proteins is to understand biological processes that are strictly regulated by these interactions. The availability of entire genome sequences of many organisms and high-throughput analysis tools has led scientists to study the entire proteome (Pandey and Mann, 2000). There are various high-throughput methods for detecting protein interactions such as yeast two-hybrid approach and mass spectrometry to produce vast amounts of data that can be utilized to decipher protein functions in complicated biological networks. In this review, we discuss recent developments in analytical methods for large-scale protein interactions and the future direction of interaction proteomics.

A Study on the Characteristics of Transferred Element in Composition of Architectural Spaces -Focusing on Path and Stairs (공간구성에 있어서 전이적 요소의 특성에 관한 연구 -통로와 계단을 중심으로 -)

  • 이승우;윤도근
    • Korean Institute of Interior Design Journal
    • /
    • no.7
    • /
    • pp.79-86
    • /
    • 1996
  • This study is searching the characteristics of transferred element in composition of architectural spaces ; it is ultimate goal that frame of reference is arranged system about path of horizontal direction is two-dimension and stairs of vertical in three-dimension as transferred element in Architectural plan. With the exception of stylized discussion or rhetorical analysis about these, it is analysed as element in physical order of a whole architecture in relation to another elements in composition of architecture spaces. And one who is perceptible and cognitive through spaces is the subject. Consequently , these elements are classified concept of location and circulation. And it can't think that the formal is divided the latter for accept behavior of pedestrican and thinking system to consider verticality and time property is absolutely conceptual elements in space of architectural plan.

  • PDF

Remodeling Plan for K-Headquarters Building Office Space (K-본사사옥 사무공간 리모델링 계획)

  • Lee, Chang-No
    • Proceedings of the Korean Institute of Interior Design Conference
    • /
    • 2006.05a
    • /
    • pp.87-90
    • /
    • 2006
  • The purpose of this project is to greatly elevate the image of a high-technology wireless communication company by improving its office space environment through remodeling techniques. In order to accomplish this goal, the design concept was established in the direction of harmonious beauty with maximized functionality and aesthetics. Specifically, an efficient traffic line was planned in consideration of the connectivity between mutual spaces, and smooth yet strong formal aesthetics was given to such things as planes, frontal surfaces, and ceiling design, so as to do away with the existing authoritarian atmosphere and create an image of a futuristic company.

  • PDF

Performance analysis of symbiotic evolutionary algorithms according to partner selection strategies (공생 파트너 선택전략에 따른 공생진화 알고리듬의 성능 분석)

  • 김재윤;김여근;곽재승;김동묵
    • Proceedings of the Korean Operations and Management Science Society Conference
    • /
    • 2000.04a
    • /
    • pp.239-242
    • /
    • 2000
  • Symbiotic evolutionary algorithms are stochastic search algorithms that imitate the biological coevolution process through symbiotic interactions. In the algorithms, the fitness evaluation of an individual requires first selecting symbiotic partners of the individual. The symbiotic partner effects the change of individual's fitness and search direction. In this study we are to analyze how much partnering strategies can influence the performance of the algorithms. For this goal extensive experiments are carried out to compare the performance of partnering strategies. The NKC model and the binary string covering problem are used as the test-bed problems. The experimental results indicate that there does not exist statistically significant difference in their performance.

  • PDF

A Study on the Scientific Phase of Industrial Design (산업DESIGN의 학문적 위상정립을 위한 고찰)

  • 전성수
    • Archives of design research
    • /
    • v.5 no.1
    • /
    • pp.69-76
    • /
    • 1992
  • INDUSTRIAL DESIGN(1.D) has been recognized as an independent subject for 30 years 10 KOREA and 70 years in the worldwide. Though the beginning of the 1.D is extended to the commercialization of the art, history of 1.D is still 150 years, and very short compared to the those of other subject. The scientific identity of 1.D has to be established to prepare the role of 1.0 for the information society and industrial society of the 21 century. 1.D contains the essence such as integrated and $$\mu$titude character and two lineaments( Analytic science and Synthetic science-objective and subjective) 1.D has undergone confusion and fallacy in society and educational system. To develop achieve the goal of design education and to the competItIve design country in the world market, the scientific status of I.O has to be established as a integrated and independent subject. This study generally reviewed 1.0 to find the essence and scientific status of subject to determine the direction foward the next century in the view of intellectual structure and system.

  • PDF