Chinese immigrant entrepreneurs in New England area

Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management, 2008.More and more Chinese immigrants came to the U.S. to start a whole new life. Some of them became entrepreneurs. This study focused on Chinese new immigrant entrepreneurs in New England area, and analyzed what factors have the most effective impact of the Chinese new immigrants to become an entrepreneur. This is first survey to study the career choice and entrepreneurship experience of Chinese immigrants in the New England area. From 190 complete responses, 66 of them are entrepreneurs. In this survey study, we have gained valuable information of the well-educated Chinese immigrants in the New England area. Also, we studied the specific characteristics of these Chinese entrepreneurs, and tried to identify some features that are helpful to becoming a successful entrepreneur. Based on the survey result, (1) working in a small company, (2) having responsibilities relating to greater China, (3) holding a position in general management or sales and marketing, and (4) attending social activity at least once per month are positive factors contributing to Chinese immigrant entrepreneurs.by Joe Xiongwei Zhou.M.B.A

How much should I invest? The influence of reputable investors and platform investors in online lending

This paper draws on signaling theory to examine the joint effects of platform investment and investment of reputable investors on the investment behavior of ordinary investors in online lending. We tested our hypotheses with a dataset of 2,276,380 bidding records pertaining to 46,140 loans posted on an online lending platform. Our results show that (1) The investment of reputable investors as a quality signal can increase the investment amount of subsequent investors. (2) Platform investment signal and reputable investment signal are complementary. In the loan projects with platform investment (compared to those without), investment of reputable investors exerts greater influence on the investment amount of subsequent investors. (3) Focusing on loan projects with platform investment, the investment of reputable investors has greater impact on the investment amount of subsequent investors after the platform investment. This paper offers important theoretical and practical implications

Noise reduction optimization of sound sensor based on a Conditional Generation Adversarial Network

To address the problems in the traditional speech signal noise elimination methods, such as the residual noise, poor real-time performance and narrow applications a new method is proposed to eliminate network voice noise based on deep learning of conditional generation adversarial network. In terms of the perceptual evaluation of speech quality (PESQ) and shorttime objective intelligibility measure (STOI) functions used as the loss function in the neural network, which were used as the loss function in the neural network, the flexibility of the whole network was optimized, and the training process of the model simplified. The experimental results indicate that, under the noisy environment, especially in a restaurant, the proposed noise reduction scheme improves the STOI score by 26.23% and PESQ score by 17.18%, respectively, compared with the traditional Wiener noise reduction algorithm. Therefore, the sound sensor\u27s noise reduction scheme through our approach has achieved a remarkable noise reduction effect, more useful information transmission, and stronger practicability

A New Derivation and Recursive Algorithm Based on Wronskian Matrix for Vandermonde Inverse Matrix

For an analytical expression of Vandermonde inverse matrix, a new derivation process based on Wronskian matrix and Lagrange interpolation polynomial basis is presented. Recursive formula and implementation cases for the direct formula of Vandermonde inverse matrix are given based on deriving the unified formula of Wronskian inverse matrix. For the calculation of symbol-type Vandermonde inverse matrix, the direct formula and recursive method are verified to be more efficient than Mathematica which is good at symbolic computation by comparing the computing time in Mathematica. The process and steps of recursive algorithm are relatively simple. The derivation process and idea both have very important values in theory and practice of Vandermonde and generalized Vandermonde inverse matrix

All-optical format conversion-based flexible optical interconnection using nonlinear MZI with nested-pump assisted NOLM

An all-optical format conversion (AOFC) scheme of star-m-ary quadrature amplitude modulation (star-mQAM) based on a nonlinear Mach-Zehnder interferometer (MZI) with nested-pump assisted nonlinear optical loop mirror (nested-PA-NOLM) is proposed and numerically simulated. In this scheme, input multi-Gbps star-8QAM signals can be converted into three quadrature phase shift keying (QPSK) signals (namely QPSK-A, -B and -C) through the PA-NOLM under different input power of the signal and the pump. The nonlinear MZI is formed by two PA-NOLMs of the upper and the lower arms, the former and the latter 3-dB optical couplers (OCs), a directional variable optical attenuator (VOA) in the upper arm and a directional variable phase shifter (VPS) in the lower arm. A VOA and a VPS are used to adjust the power ratio (PR) and relative phase shift (RPS) between any two of QPSK-A, -B and -C. When any two adjusted signals in QPSK-A, -B and -C are coherently superposed, the aggregated star-8QAM signal can be extracted again. Furthermore, the proposed scheme can also be used to convert the 20 Gbps bipolar 4-ary pulse amplitude modulation (PAM4) signal into two 10 Gbps BPSK signals and a 20 Gbps QPSK signal. When the proposed scheme is combined with the phase-sensitive amplification (PSA), it can also be used to convert one 16QAM into two QPSK signals. The scheme performance is analyzed via constellation diagrams, power waveforms, the error vector magnitude (EVM) and the bit error rate (BER) of the optical signals. The scheme can not only be deployed in optical gateways to connect optical networks using different modulation formats, but also has a potential applied advantage in security information transmission between different optical networks

CHD7 and Runx1 interaction provides a braking mechanism for hematopoietic differentiation.

Hematopoietic stem and progenitor cell (HSPC) formation and lineage differentiation involve gene expression programs orchestrated by transcription factors and epigenetic regulators. Genetic disruption of the chromatin remodeler chromodomain-helicase-DNA-binding protein 7 (CHD7) expanded phenotypic HSPCs, erythroid, and myeloid lineages in zebrafish and mouse embryos. CHD7 acts to suppress hematopoietic differentiation. Binding motifs for RUNX and other hematopoietic transcription factors are enriched at sites occupied by CHD7, and decreased RUNX1 occupancy correlated with loss of CHD7 localization. CHD7 physically interacts with RUNX1 and suppresses RUNX1-induced expansion of HSPCs during development through modulation of RUNX1 activity. Consequently, the RUNX1:CHD7 axis provides proper timing and function of HSPCs as they emerge during hematopoietic development or mature in adults, representing a distinct and evolutionarily conserved control mechanism to ensure accurate hematopoietic lineage differentiation.Bloodwise, CRUK, MRC, Wellcome Trust, NIH, Leukemia and Lymphoma Societ

Numerical simulation on the interaction of longitudinal guided waves with double defects in pipes

In guided-wave based pipeline non-destructive inspection, it is inevitable that guided waves will interact with multiple defects, which makes damage identification more challenging. In this study, a numerical simulation was conducted to investigate the interaction of longitudinal guided waves with double notches in pipes. Firstly, a three-dimensional finite element model was established to simulate guided wave propagating in a pipe with a single notch. Then the established model was validated by comparing with existing experiments results. Based on the validated model, the guided wave reflection characteristics of two equal-sized notches of various relative positions were discussed systematically. The results show that, the relative circumferential positions of the two notches have little influence on the overall reflection, and the reflection coefficient rarely varies with the circumferential distance. However, the overall reflection of the two notches at the same circumferential location mainly depends on their axial positions, and the reflection coefficient varies periodically with the axial distance of the two notches. Moreover, the reflection coefficients of multiple notches within some axial range follow superposition principle approximately, which is very helpful for group corrosion detection

Estimation of DBH at Forest Stand Level Based on Multi-Parameters and Generalized Regression Neural Network

The diameter at breast height (DBH) is an important factor used to estimate important forestry indices like forest growing stock, basal area, biomass, and carbon stock. The traditional DBH ground surveys are time-consuming, labor-intensive, and expensive. To reduce the traditional ground surveys, this study focused on the prediction of unknown DBH in forest stands using existing measured data. As a comparison, the tree age was first used as the only independent variable in establishing 13 kinds of empirical models to fit the relationship between the age and DBH of the forest subcompartments and predict DBH growth. Second, the initial independent variables were extended to 19 parameters, including 8 ecological and biological factors and 11 remote sensing factors. By introducing the Spearman correlation analysis, the independent variable parameters were dimension-reduced to satisfy very significant conditions (p ≤ 0.01) and a relatively large correlation coefficient (r ≥ 0.1). Finally, the remaining independent variables were involved in the modeling and prediction of DBH using a multivariate linear regression (MLR) model and generalized regression neural network (GRNN) model. The (root-mean-squared errors) RMSEs of MLR and GRNN were 1.9976 cm and 1.9655 cm, respectively, and the R2 were 0.6459 and 0.6574 respectively, which were much better than the values for the 13 traditional empirical age–DBH models. The use of comprehensive factors is beneficial to improving the prediction accuracy of both the MLR and GRNN models. Regardless of whether remote sensing image factors were included, the experimental results produced by GRNN were better than MLR. By synthetically introducing ecological, biological, and remote sensing factors, GRNN produced the best results with 1.4688 cm in mean absolute error (MAE), 13.78% in MAPE, 1.9655 cm for the RMSE, 0.6574 for the R2, and 0.0810 for the Theil’s inequality coefficient (TIC), respectively. For modeling and prediction based on more complex tree species and a wider range of samples, GRNN is a desirable model with strong generalizability