A Robust Beamformer Based on Weighted Sparse Constraint

Applying a sparse constraint on the beam pattern has been suggested to suppress the sidelobe level of a minimum variance distortionless response (MVDR) beamformer. In this letter, we introduce a weighted sparse constraint in the beamformer design to provide a lower sidelobe level and deeper nulls for interference avoidance, as compared with a conventional MVDR beamformer. The proposed beamformer also shows improved robustness against the mismatch between the steering angle and the direction of arrival (DOA) of the desired signal, caused by imperfect estimation of DOA.Comment: 4 pages, 2 figure

Ambient Light Independent Depth Acquisition Using Switchable IR filter

Devices such as smartphones, tablets, etc. are equipped with cameras that have depth-sensing capabilities. The quality of depth acquisition in such devices is often limited by the cost, available physical space for depth-sensing hardware, and by the ambient light conditions in which an image is captured. This disclosure describes a depth-sensing camera system that utilizes a switchable infrared filter. In an IR-cut mode, used when ambient light is of sufficient quality, the filter allows visible light to pass through and cuts off IR. In an IR-pass mode, used in low light conditions, the filter allows IR to pass through while cutting off visible light. The camera system enables high resolution depth acquisition in arbitrary light conditions at low cost and with compact hardware

The Impact of Impression Management on Purchase Intentions in Online Auctions: The Moderating Effects of Relationship Norms

The IT-mediated nature of e-commerce creates the uncertainty in online buyer-seller relationships where online buyers are difficult to personally scrutinize sellers, leading to many challenges for online sellers to win buyers’ trust. In order to overcome this problem, according to impression management theory and relationship theory, this research proposes a research framework for understanding how impression management tactics can be used by sellers to create a positive impression in the minds of buyers, affect buyers’ trust in the sellers, and subsequently purchase from them. This research further examines the moderating role of relationship norms on the relationship between impression management tactics and trust. A Web-based survey is then conducted in Yahoo! Taiwan auction to validate our proposed framework. Our research is expected to contribute to the theories by first examining the impression management theory and relationship theory in the context of online auctions. We also expect to contribute to the practice by illustrating that sellers should adjust their impression management tactics to suit buyers’ relationship norms. Specifically, self-focused tactics are more useful for buyers in an exchange relationship; other-focused tactics are more effective for buyers in a communal relationship

Power-Efficient Ultra-Wideband Waveform Design Considering Radio Channel Effects

This paper presents a power-efficient mask-constrained ultra-wideband (UWB) waveform design with radio channel effects taken into consideration. Based on a finite impulse response (FIR) filter, we develop a convex optimization model with respect to the autocorrelation of the filter coefficients to optimize the transmitted signal power spectrum, subject to a regulatory emission mask. To improve power efficiency, effects of transmitter radio frequency (RF) components are included in the optimization of the transmitter-output waveform, and radio propagation effects are considered for optimizing at the receiver. Optimum coefficients of the FIR filter are obtained through spectral factorization of their autocorrelations. Simulation results show that the proposed method is able to maximize the transmitted UWB signal power under mask constraints set by regulatory authorities, while mitigating the power loss caused by channel attenuations.Comment: 14 pages, 2 figures, 1 tabl

Topological Phase Separation In Trapped Ultracold Fermionic Gases

We investigate the harmonically trapped 2D fermionic systems with a effective spin-orbit coupling and intrinsic s-wave superfluidity under the local density approximation, and find that there is a critical value for Zeeman field. When the Zeeman field larger than the critical value, the topological superfluid phases emerge and coexist with the normal superfluid phase, topological phase separation, in the trapped region. Otherwise, the superfluid phase is topologically trivial.Comment: 6 pages, 3 figure

Local false discovery rate facilitates comparison of different microarray experiments

The local false discovery rate (LFDR) estimates the probability of falsely identifying specific genes with changes in expression. In computer simulations, LFDR <10% successfully identified genes with changes in expression, while LFDR >90% identified genes without changes. We used LFDR to compare different microarray experiments quantitatively: (i) Venn diagrams of genes with and without changes in expression, (ii) scatter plots of the genes, (iii) correlation coefficients in the scatter plots and (iv) distributions of gene function. To illustrate, we compared three methods for pre-processing microarray data. Correlations between methods were high (r = 0.84–0.92). However, responses were often different in magnitude, and sometimes discordant, even though the methods used the same raw data. LFDR complements functional assessments like gene set enrichment analysis. To illustrate, we compared responses to ultraviolet radiation (UV), ionizing radiation (IR) and tobacco smoke. Compared to unresponsive genes, genes responsive to both UV and IR were enriched for cell cycle, mitosis, and DNA repair functions. Genes responsive to UV but not IR were depleted for cell adhesion functions. Genes responsive to tobacco smoke were enriched for detoxification functions. Thus, LFDR reveals differences and similarities among experiments

Diagnostic challenges in a case of B cell lymphoma unclassifiable with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma

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Perceived similarity of other customers on service experience

This study aims to examine how a mere appearance of other similar customers will influence the perceived service quality of a potential customer. This research involves two experimental studies. Findings shows that if potential customers perceive other customers to be similar (vs. dissimilar) in a hospitality setting with regard to age, they will have more favorable perceptions toward the service quality and have a higher purchase intention. However, the positive impact of the similarity in age cohort can override the negative impact of dissimilarity in ethnicity on one\u27s perceived service quality and purchase intentions. The results provide implications for hospitality managers