A Hybrid Intelligent System for Stamping Process Planning in Progressive Die Design

This paper presents an intelligent, hybrid system for stamping process planning in progressive die design. The system combines the flexibility of blackboard architecture with case-based reasoning. The hybrid system has the advantage that it can use past knowledge and experience for case-based reasoning when it exists, and other reasoning approaches when it doesn’t exist. A prototype system has been implemented in CLIPS and interfaced with Solid Edge CAD system. An example is included to demonstrate the approach.Singapore-MIT Alliance (SMA

Functional Modeling in Conceptual Die Design

The use of function has been recognized as an important part of the design process over last two decades, especially at the conceptual design stage, due to its critical role in determining the final product’s functionality. Although there are now some general methodologies dealing with functions or reasoning about functions, virtually no commercial CAD system can support conceptual design process due to their focus on geometrical modeling but not functional modeling. This paper presents a functional modeling approach to guide conceptual die design through functional reasoning steps including functional decomposition, functional supportive synthesis and function-structure mapping. The formed functional model provides a good basis to generate various die structures at the conceptual design stage, because function is a higher level of abstraction than structure, and helps to capture the designer’s intent. The functional modeling process has been implemented in a computerized design environment to expedite the conceptual die design process.Singapore-MIT Alliance (SMA

Functional design of mechanical products based on behavior-driven function-environment-structure modeling framework

The relative significance of upstream design activity to downstream design activity is widely recognized, due to its critical role in determining the final product’s functionality. Although there are now some general methodologies dealing with functions or reasoning about functions, virtually no commercial CAD system can support functional design. In functional modeling, a design problem is represented in a hierarchy of functions and the behaviors that realize the functions. This paper presents a functional design methodology based on a behavior-driven function-environment-structure (B-FES) modeling framework to guide functional design through functional reasoning steps including causal behavioral reasoning (CBR) and functional decomposition. The proposed functional design starts from a set of design specifications including functional requirements and design constraints, and results in diverse behavioral schema corresponding to a set of design alternatives. A design example for functional design of a terminal cut-off unit in an automatic assembly system is used to provide a demonstration of the proposed functional design methodology.Singapore-MIT Alliance (SMA

Electron Spin Relaxation in a Semiconductor Quantum Well

A fully microscopic theory of electron spin relaxation by the D'yakonov-Perel' type spin-orbit coupling is developed for a semiconductor quantum well with a magnetic field applied in the growth direction of the well. We derive the Bloch equations for an electron spin in the well and define microscopic expressions for the spin relaxation times. The dependencies of the electron spin relaxation rate on the lowest quantum well subband energy, magnetic field and temperature are analyzed.Comment: Revised version as will appear in Physical Review

Carotenoid content and reflectance of yellow and red nuptial plumages in widowbirds (Euplectes spp.)

1. Ornamental carotenoid coloration is commonly based on several different pigments with different nutritional and metabolic constraints. The identification and quantification of carotenoid pigments is therefore crucial to the understanding of signal content and signal evolution. 2. In male widowbirds (Euplectes spp.), the striking yellow and red carotenoid colours have been measured by reflectance spectrometry and studied with respect to sexual selection through male contest competition, but their biochemical mechanisms have not been analysed. 3. Here we use reflectance analysis and high performance liquid chromatography (HPLC) to describe the species-specific colours and plumage carotenoids in three widowbird species: yellow-mantled widowbird (YMW) Euplectes macrourus, red-shouldered widowbird (RSW) E. axillaris and red-collared widowbird (RCW) E. ardens. 4. YMW yellow (‘hue’ colorimetric λR50 = 522 nm) derives from the two ‘dietary yellow’ xanthophylls lutein and zeaxanthin, together with small amounts of ‘derived yellow’ pigments (3′-dehydrolutein and canary xanthophylls). 5. RCW red (λR50 = 574 nm) is achieved by the addition of low concentrations of ‘derived red ’ 4-keto-carotenoids, notably α- and β-doradexanthin and canthaxanthin. 6. RSW red (λR50 = 589 nm) is, in contrast, created by high concentrations of ‘dietary yellow ’ pigments (lutein, zeaxanthin) and ‘derived yellow ’ anhydrolutein, the latter only recently described in birds. 7. The two different mechanisms of producing red plumage are compared with other bird species and discussed with regard to costs and signal ‘honesty’

История развития физической культуры и спорта на Урале в дореволюционный период

На сегодняшний день становится чрезвычайно актуальным рассмотрение феномена физической культуры и спорта сквозь призму принципа историзма. Существует еще много неизвестного в истории физической культуры, что требует переоценки событий, фактов с позиции современност

Model-independent search for CP violation in D0→K−K+π−π+ and D0→π−π+π+π− decays

A search for CP violation in the phase-space structures of D0 and View the MathML source decays to the final states K−K+π−π+ and π−π+π+π− is presented. The search is carried out with a data set corresponding to an integrated luminosity of 1.0 fb−1 collected in 2011 by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. For the K−K+π−π+ final state, the four-body phase space is divided into 32 bins, each bin with approximately 1800 decays. The p-value under the hypothesis of no CP violation is 9.1%, and in no bin is a CP asymmetry greater than 6.5% observed. The phase space of the π−π+π+π− final state is partitioned into 128 bins, each bin with approximately 2500 decays. The p-value under the hypothesis of no CP violation is 41%, and in no bin is a CP asymmetry greater than 5.5% observed. All results are consistent with the hypothesis of no CP violation at the current sensitivity

Measurement of the Bs0→J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction

The $B_s^0\to J/\psi K_S^0$ branching fraction is measured in a data sample corresponding to 0.41$fb^{-1}$ of integrated luminosity collected with the LHCb detector at the LHC. This channel is sensitive to the penguin contributions affecting the sin2$\beta$ measurement from $B^0\to J/\psi K_S^0$ The time-integrated branching fraction is measured to be $BF(B_s^0\to J/\psi K_S^0)=(1.83\pm0.28)\times10^{-5}$. This is the most precise measurement to date

Measurement of the CP-violating phase \phi s in Bs->J/\psi\pi+\pi- decays

Measurement of the mixing-induced CP-violating phase phi_s in Bs decays is of prime importance in probing new physics. Here 7421 +/- 105 signal events from the dominantly CP-odd final state J/\psi pi+ pi- are selected in 1/fb of pp collision data collected at sqrt{s} = 7 TeV with the LHCb detector. A time-dependent fit to the data yields a value of phi_s=-0.019^{+0.173+0.004}_{-0.174-0.003} rad, consistent with the Standard Model expectation. No evidence of direct CP violation is found.Comment: 15 pages, 10 figures; minor revisions on May 23, 201

The PHENIX Experiment at RHIC

The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix