Approximate expressions for modulation speed and threshold for performance optimization of biaxially compressive strain quantum-well lasers

Simple analytical expressions for transparency, threshold, and relaxation oscillation corner frequency are derived for biaxial strain quantum-well lasers. An optimal operating point loss for high speed operation (in the absence of nonlinear gain) is established which varies as the square root of the number of quantum wells. The corresponding relaxation oscillation frequency is found to depend only on fundamental quantities. Its power dependence is [vR(max) = (87 GHz õm^3/mW) (Powerout/Vmode)^1/2) where Vmode is the mode volume

Estimates of genetic parameters from a selection experiment for growth and reproductive success in Tribolium castaneum by using different statistical methods

The general problem of estimating breeding values of animals in a population under selection to improve performance for growth and reproductive success is addressed. Genetic and environmental (co)variances for correlated traits must be estimated from the data if they are unknown or expected to have changed due to the type of selection. The data were a set of four lines, one selected for increased pupa weight, another for increased family size, the third based on an index combining pupa weight and family size, and a randombred control. The analysis of genetic responses over 16 generations in these four selection lines derived from a common base population present some interesting phenomena likely to be encountered in the analysis of other populations under selection. Changes in genetic and environmental (co)variances associated with selection for pupa weight were found to have a profound effect on estimates of (co)variance components within and between generations. New insight is provided on ways to interpret restricted maximum likelihood estimates of genetic parameters. Base populations and control lines with 16 generations of data from two replicated experiments were used to show how insufficient data, misidentification of major fixed effect when combining data across experiments, and confounding of random effects can lead to widely different estimates of parameters for the same data. Gibbs sampling techniques were used to implement a full Bayesian analysis of the data. All (co)variance components in the model were not estimated with equal information from the data. Extensive use was made of the 95% central interval of the posterior distribution to graphically show the effect of different assumptions about prior knowledge or belief in the realized values of random variables. Even a small amount of weight on prior knowledge about parameters can overcome problems associated with the belief that all information must come entirely from the data. A multiple trait heterogeneous mixed model is proposed to adjust for the effects of genotype by environment interaction. It is argued that this model overcomes several deficiencies of other models proposed to account for heterogeneous (co)variances

Direct determination of the ambipolar diffusion length in strained InxGa1−xAs/InP quantum wells by cathodoluminescence

The ambipolar diffusion length is measured in strained InxGa1−xAs/InP quantum wells for several mole fractions in the interval 0.3<x<0.8 by cathodoluminescence. The ambipolar diffusion length is found to have a significantly higher value in the lower indium mole fraction samples corresponding to tensile-strained wells. This longer diffusion length for the tensile samples is consistent with results of carrier lifetime experiments by M. C. Wang, K. Kash, C. E. Zah, R. Bhat, and S. L. Chuang [Appl. Phys. Lett. 62, 166 (1993)]

Online Self-Concordant and Relatively Smooth Minimization, With Applications to Online Portfolio Selection and Learning Quantum States

Consider an online convex optimization problem where the loss functions are self-concordant barriers, smooth relative to a convex function $h$, and possibly non-Lipschitz. We analyze the regret of online mirror descent with $h$. Then, based on the result, we prove the following in a unified manner. Denote by $T$ the time horizon and $d$ the parameter dimension. 1. For online portfolio selection, the regret of $\widetilde{\text{EG}}$, a variant of exponentiated gradient due to Helmbold et al., is $\tilde{O} ( T^{2/3} d^{1/3} )$ when $T > 4 d / \log d$. This improves on the original $\tilde{O} ( T^{3/4} d^{1/2} )$ regret bound for $\widetilde{\text{EG}}$. 2. For online portfolio selection, the regret of online mirror descent with the logarithmic barrier is $\tilde{O}(\sqrt{T d})$. The regret bound is the same as that of Soft-Bayes due to Orseau et al. up to logarithmic terms. 3. For online learning quantum states with the logarithmic loss, the regret of online mirror descent with the log-determinant function is also $\tilde{O} ( \sqrt{T d} )$. Its per-iteration time is shorter than all existing algorithms we know.Comment: 19 pages, 1 figur

Bolstering the pipeline for primary care: a proposal from stakeholders in medical education

The Association of American Medical Colleges reports an impending shortage of over 90,000 primary care physicians by the year 2025. An aging and increasingly insured population demands a larger provider workforce. Unfortunately, the supply of US-trained medical students entering primary care residencies is also dwindling, and without a redesign in this country’s undergraduate and graduate medical education structure, there will be significant problems in the coming decades. As an institution producing fewer and fewer trainees in primary care for one of the poorest states in the United States, we propose this curriculum to tackle the issue of the national primary care physician shortage. The aim is to promote more recruitment of medical students into family medicine through an integrated 3-year medical school education and a direct entry into a local or state primary care residency without compromising clinical experience. Using the national primary care deficit figures, we calculated that each state medical school should reserve 20–30 primary care (family medicine) residency spots, allowing students to bypass the traditional match after successfully completing a series of rigorous externships, pre-internships, core clerkships, and board exams. Robust support, advising, and personal mentoring are also incorporated to ensure adequate preparation of students. The nation’s health is at risk. With full implementation in allopathic medical schools in 50 states, we propose a long-term solution that will serve to provide more than 1,000–2,700 new primary care providers annually. Ultimately, we will produce happy, experienced, and empathetic doctors to advance our nation’s primary care system

Ethnic Identity and Local Government Responsiveness in Taiwan

Countless studies have shown that local officials are less responsive to ethnic minority citizens. Surprisingly, we find no similar pattern of discrimination by Taiwanese local officials. In an online contacting experiment, we send citizen service requests to the websites of 358 township and district chiefs, randomly varying the name of the putative citizen to reflect an indigenous or an ethnically Chinese identity and collecting data on officials\u27 responses. We find that officials are equally responsive to both identities. Drawing on in-depth interviews and nonparticipant observation in government service centers, we attribute this surprising finding to institutional elements of Taiwan\u27s local bureaucracy that limit the impact of individual-level bias. However, our research provides preliminary evidence that local governments are generally less responsive in indigenous areas. While clearly defined procedures may prevent discrimination against indigenous individuals, interregional differences in local state capacity can nonetheless produce unequal experiences with local governance

Ketofol for monitored anesthesia care in shoulder arthroscopy and labral repair: a case report

A 21-year-old male (body mass index: 28.3) with a history of asthma and reactive airway disease since childhood underwent left shoulder arthroscopy and labral repair surgery under monitored anesthesia care. Because the procedure was performed in the beach chair position, access to the patient’s airway was limited throughout. To avoid general anesthesia and to limit potential complications associated with monitored anesthesia care, a ketofol admixture was used. This case demonstrates that, in conjunction with regional anesthesia, ketofol may be an acceptable alternative to propofol for maintenance in outpatient orthopedic procedures

COMPARISON OF EMG ACTIVITY WITH DYNAMIC MOVEMENT AND STATIC POSTURE ON VIBRATION PLATFORM

The aim of this study is to investigate the difference among dynamic movement and static posture on vibration platform as well as no vibration. For this purpose, six healthy male subjects were recruited in this study. Each subject was instructed to maintain four situations: dynamic movement with vibration (frequency: 40 Hz, amplitude: 1 mm), and no-vibration; static posture with vibration (frequency: 40 Hz, amplitude: 1 mm), and novibration. Result showed statistically significant increase at EMG rms of whole body vibration treatment and EMG rms value of dynamic movement was significantly larger than that of static posture (

A systematic architecting approach for supply chains

Thesis (S.M. in Engineering and Management)--Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, June 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 76-81).Over the past two decades, the advent of information and communication technology has broken physical distance limits and enabled seamless collaboration models, real-time planning, and quick responses among participants in supply chain systems. Globalization, specification, and the use of technologies that pursue low costs with high services have been dominating the supply chain design for years. Since 9/11 in 2001, however, supply chain designs have shifted from concentrating on cost-competitive advantages to security, collaboration, robustness, and flexibility. After 2008, worldwide events such as fluctuating gasoline prices, increased labor costs in developing countries, volatile demand as a result of the economic recession, and environmental regulations and agreements have resulted in renewed scrutiny of supply chain design paradigms. These challenges not only have had an impact on supply chain operations, but also on its architecture: in the aspects of organization, culture, geography, and information. Obviously, expanding globalization has made it difficult to consider a system locally and closely. The interactions between internal and external stimulus, multiple stakeholders' goals, along with corporate bottom lines: sociality, plant, and profits have conducted a supply chain a complex system. In order to resolve this complexity, to understand the supply chain holistically, and to avoid applying a complex solution on a complex supply chain system, a supply chain architecting framework, derived from Systems Engineering and System Architecture, is proposed in this research to simplify the supply chain architecting process into steps: modeling, mapping, and linking operational and architectural improvements. In summary, the goals of this study are: (1) Eliminate the gaps between corporate (supply chain) strategy, design, and implementation; (2) Propose a framework consisting of previous research and best practices; (3) Develop a simple, easy-to-understand, planning modeling methodology that carries sufficient information for supply chains. The contributions of this study aligned with these three goals are: (1) Supply chain architecting framework, including the fulfillment and value chains and the three improvement cycles; and (2) Architecting methodology, including concept, form, and function, as well as three layers of views from which to represent a supply chain.by Chung-En (Conrad) Kao.S.M.in Engineering and Managemen