In China, Factory Workers Allege Poisoning From iPhone Production

This document is part of a digital collection provided by the Martin P. Catherwood Library, ILR School, Cornell University, pertaining to the effects of globalization on the workplace worldwide. Special emphasis is placed on labor rights, working conditions, labor market changes, and union organizing.CLW_2011_Report_China_in_china.pdf: 79 downloads, before Oct. 1, 2020

Use of available storage to improve scheduling in an automobile assembly plant

The Final Assembly Plant at General Motors-Holden's Automotive Ltd converts painted body shells into drive-away vehicles. It encounters difficulties when processing certain sequences of vehicles with high work contents, so GMHAL wishes to schedule its input to reduce or eliminate such undesirable sequences. GMHAL has a set of empirical rules for delineating undesirability. The Painted Body Storage (PBS), which precedes Final Assembly, has 4 lanes that can be used to partially reschedule a vehicle sequence. Information on vehicle work content is available prior to arrival at the PBS, and GMHAL wants advice on using this data and the PBS to achieve a more satisfactory input to Final Assembly. The Study Group devised three approaches. 1. Use the rules to show which short sequences are desirable and devise input and output strategies for the PBS to achieve these consistently. Choice between the strategies requires further investigation. 2. Model Final Assembly to produce an optimality criterion for vehicle sequences and use combinatorial optimization methods to optimise it over possible PBS outputs. A characterization of these outputs was derived. 3. Suggest that the initial production be suitably scheduled, which may substantially reduce the difficulties at the PBS stage

Effect of Oocyte Vitrification Before and After in Vitro Maturation Towards Bcl-2, Bax and Bcl-2/Bax Ratio Expression

Objectives: to compare the expression of Bcl-2, Bax and Bcl-2/Bax ratio in cumulus cell and oocyte between vitrified oocyte pre and post in vitro maturation.Materials and Methods: Maturation was operated in medium TC 100 µl for 24 hours. Vitrification begins with washing oocyte in PBS basic medium supplemented of 20% serum for 1-2 minutes, followed by equilibration medium PBS + 20% serum + 10% ethylene glycol for 10-14 minutes, then transferred to 20% serum + PBS + 0.5 M sucrose + 15% ethylene glycol + PROH 15% for 25-30 seconds. Thawing is processed by submerging the oocytes in the media: 1). PBS + 20% serum + 0.5 M sucrose, 2). PBS + 20% serum + 0.25 M sucrose, and 3). PBS + 20% serum + 0.1 M sucrose. Imunocytochemistry observed the expression of Bcl-2, bax and Bcl-2/bax ratio.Results: Bcl-2 expression on oocyte in control group differed significantly with treatment group, Bcl-2 expression on cumulus in control group differed significantly with treatment 1 group. Bax expression on oocyte in control group differed significantly with treatment group. Bax expression on cumulus in control group differed significantly with treatment group. Bcl-2/Bax expression ratio on oocyte and cumulus did not differ significantly in all groupConclusion: No difference Bcl-2/Bax expression ratio on oocyte and cumulus between vitrified oocyte pre and post in vitro maturation

Intensity-Dependent Enhancement of Saturable Absorption in PbS-Au4 Nanohybrid Composites: Evidence for Resonant Energy Transfer by Auger Recombination

Intensity-dependent enhancement of saturable absorption in a film of PbS-Au4 nanohybrid composites has been observed by femtosecond time-resolved transient absorption measurement at 780 nm. The nonlinear absorption coefficient of saturable absorption in PbS-Au4 nanohybrid composites is found to be dependent on excitation irradiance and it is determined to be -2.9 cm/GW at 78 GW/cm2, an enhancement of nearly fourfold in comparison with that of pure PbS quantum dots (QDs). The enhancement is attributed to excitation of surface plasmon by resonant energy transfer between PbS QDs and Au nanoparticles through Auger recombination.Comment: 14 pages, 3 figures. Accepted in Appl. Phys. Lett. (2008

The effects of motivational climate interventions on psychobiosocial states in high school physical education

Purpose: The purpose of this study was to examine the effects of task- and ego-involving climate manipulations on students’ climate perception and psychobiosocial (PBS) states in a physical education setting. Method: Two subsamples of female students (N = 108, 14-15 years of age) participated for 12 lessons on either a task- or an ego-involving climate intervention as grounded in the TARGET model. Results: At the end of the treatment, the participants of the ego-involved group reported lower scores in perceived task-involving climate and higher scores in perceived ego-involving climate than their peers in the task-involved group. Lower scores in pleasant/functional PBS states and higher scores in unpleasant/dysfunctional PBS states were also observed in the ego-involved group as a consequence of the intervention. Conclusion(s): Findings suggested that teacher’s induced achievement motivational climates can influence students’ perceptions and prompt PBS states consistent with the motivational atmosphere

Wirelessly Powered Backscatter Communication Networks: Modeling, Coverage and Capacity

Future Internet-of-Things (IoT) will connect billions of small computing devices embedded in the environment and support their device-to-device (D2D) communication. Powering this massive number of embedded devices is a key challenge of designing IoT since batteries increase the devices' form factors and battery recharging/replacement is difficult. To tackle this challenge, we propose a novel network architecture that enables D2D communication between passive nodes by integrating wireless power transfer and backscatter communication, which is called a wirelessly powered backscatter communication (WP-BackCom) network. In the network, standalone power beacons (PBs) are deployed for wirelessly powering nodes by beaming unmodulated carrier signals to targeted nodes. Provisioned with a backscatter antenna, a node transmits data to an intended receiver by modulating and reflecting a fraction of a carrier signal. Such transmission by backscatter consumes orders-of-magnitude less power than a traditional radio. Thereby, the dense deployment of low-complexity PBs with high transmission power can power a large-scale IoT. In this paper, a WP-BackCom network is modeled as a random Poisson cluster process in the horizontal plane where PBs are Poisson distributed and active ad-hoc pairs of backscatter communication nodes with fixed separation distances form random clusters centered at PBs. The backscatter nodes can harvest energy from and backscatter carrier signals transmitted by PBs. Furthermore, the transmission power of each node depends on the distance from the associated PB. Applying stochastic geometry, the network coverage probability and transmission capacity are derived and optimized as functions of backscatter parameters, including backscatter duty cycle and reflection coefficient, as well as the PB density. The effects of the parameters on network performance are characterized.Comment: 28 pages, 11 figures, has been submitted to IEEE Trans. on Wireless Communicatio

Controlling the isothermal crystallization of isodimorphic PBS-ran-PCL random copolymers by varying composition and supercooling

In this work, we study for the first time, the isothermal crystallization behavior of isodimorphic random poly(butylene succinate)-ran-poly(e-caprolactone) copolyesters, PBS-ran-PCL, previously synthesized by us. We perform nucleation and spherulitic growth kinetics by polarized light optical microscopy (PLOM) and overall isothermal crystallization kinetics by differential scanning calorimetry (DSC). Selected samples were also studied by real-time wide angle X-ray diffraction (WAXS). Under isothermal conditions, only the PBS-rich phase or the PCL-rich phase could crystallize as long as the composition was away from the pseudo-eutectic point. In comparison with the parent homopolymers, as comonomer content increased, both PBS-rich and PCL-rich phases nucleated much faster, but their spherulitic growth rates were much slower. Therefore, the overall crystallization kinetics was a strong function of composition and supercooling. The only copolymer with the eutectic composition exhibited a remarkable behavior. By tuning the crystallization temperature, this copolyester could form either a single crystalline phase or both phases, with remarkably different thermal propertiesPeer ReviewedPostprint (published version

The Importance of the Loss Function in Option Pricing

Which loss function should be used when estimating and evaluating option pricing models? Many different fucntions have been suggested, but no standard has emerged. We do not promote a partidular function, but instead emphasize that consistency in the choice of loss functions is crucial. First, for any given model, the loss function used in parameter estimation and model evaluation should be identical, otherwise suboptimal parameter estimates will be obtained. Second, when comparing models, the estimation loss function should be identical across models, otherwise unfair comparisons will be made. We illustrate the importance of these issues in an application of the so-called Practitioner Black-Scholes (PBS) model to S&P500 index options. We find reductions of over 50 percent in the root mean squared error of the PBS model when the estimation and evaluation loss functions are aligned. We also find that the PBS model outperforms a benchmark structural model when the estimation loss functions are identical across models, but otherwise not. The new PBS model with aligned loss functions thus represents a much tougher benchmark against which future structural models can be compared. Quelle fonction de pertes devrait être utilisée pour l'estimation et l'évaluation des modèles d'évaluation d'options? Plusieurs fonctions différentes ont été suggérées,0501s aucune norme ne s'est imposée. Nous ne promouvons aucune fonction,0501s soutenons que la cohérence dans le choix des fonctions est cruciale. Premièrement, pour n'importe quel modèle donné, la fonction de pertes utilisée dans l'estimation des paramètres et dans l'évaluation du modèle devrait être la même, sinon on obtient des estimations de paramètres sous-optimales. Deuxièmement, lors de la comparaison de modèles, la fonction de pertes pour l'estimation devrait être la même pour chaque modèle, autrement les comparaisons sont injustes. Nous illustrons l'importance de ces questions dans une application du modèle appelé Black-Scholes du praticien (PBS) aux options de l'index S&P500. Nous trouvons des réductions de plus de 50 pourcent de la racine de l'erreur quadratique moyenne du modèle PBS lorsque les fonctions de pertes d'estimation et d'évaluation sont alignées. Nous trouvons également que le modèle PBS dépasse un modèle de benchmark structurel quand les fonctions de pertes d'estimation sont identiques pour tous les modèles,0501s pas dans les autres cas. Le nouveau modèle PBS à fonctions de pertes alignées représente dès lors un benchmark bien plus robuste auquel les futurs modèles structurels pourront être comparés.Option pricing, implied volatility, practitioner Black-Scholes approach, pricing errors, loss functions, out-of-sample forecasting, parameter stability, Évaluation des options, volatilité implicite, approche Black-Scholes du praticien, erreurs d'évaluation, fonctions de perte, prévisions hors-échantillon, stabilité des paramètres

Tunable beam displacer

We report the implementation of a tunable beam displacer, composed of a polarizing beam splitter (PBS) and two mirrors, that divides an initially polarized beam into two parallel beams whose separation can be continuously tuned. The two output beams are linearly polarized with either vertical or horizontal polarization and no optical path difference is introduced between them. The wavelength dependence of the device as well as the maximum separation between the beams achievable is limited mainly by the PBS characteristics.Comment: 3 pages, 2 figure