Mitsubishi

About: Mitsubishi is a company organization based out in Tokyo, Japan. It is known for research contribution in the topics: Signal & Layer (electronics). The organization has 53115 authors who have published 54821 publications receiving 870150 citations. The organization is also known as: Mitsubishi Group of Companies & Mitsubishi Companies.

An impulse radio asynchronous transceiver for high data rates

Abstract: The purpose of this paper is to provide an operative way of achieving high data rates for impulse radio (IR) transmission based systems. Since applications targeted for ultra wide band (UWB) are liable to be low-cost, we especially focus on simple transceiver design. To that effect, we present an original demodulation scheme adapted to a multi-band ON-OFF keying modulation. From the receiver point of view, we impose relaxed channel estimation constraints and derive suitable signal processing schemes and simple hardware architectures. Indeed, we only consider the benefit from a limited a priori channel knowledge: approximative delay spread and energy level. The associated optimum demodulation turns out to be a non-trivial energetic threshold comparison whose precise theoretical computation admits an analytical solution proving its feasibility. Numerical results are eventually performed for IEEE 802.15.3a channel models and FCC requirements; they obviously demonstrate the potential of these techniques.

G-Protein-Coupled Receptor GPR49 is Up-regulated in Basal Cell Carcinoma and Promotes Cell Proliferation and Tumor Formation

Abstract: The significance of Hedgehog (HH) signaling in the development of basal cell carcinoma (BCC) has been established. Although several target genes of HH signaling have been described previously, their precise role in tumorigenesis and cell proliferation is not yet known. To identify genes responsible for tumor formation in BCC, we screened a DNA microarray database of human BCC cases; the orphan G-protein-coupled receptor GPR49 was found to be up-regulated in all cases. GPR49 is a novel gene reported to be a marker of follicular and other tissue stem cells. Using real-time quantitative RT-PCR analysis, significant expression of GPR49 mRNA was observed in 19 of 20 BCC cases (95%) compared with controls. Up-regulation of GPR49 was confirmed by in situ hybridization. Moreover, knockdown of mouse Gpr49 showed suppression of cell proliferation in a mouse BCC cell line, and overexpression of GPR49 in human immortalized keratinocyte HaCaT cells induced proliferation. Furthermore, HaCaT cells overexpressing GPR49 showed tumor formation when transplanted into immunodeficient mice. In addition, inhibition of the HH signaling pathway in a mouse BCC cell line down-regulated endogenous Gpr49, whereas activation of HH signaling in mouse NIH3T3 cells up-regulated endogenous GPR49. These results suggest that GPR49 is expressed downstream of HH signaling and promotes cell proliferation and tumor formation in cases of BCC.

Epitaxial all‐perovskite ferroelectric field effect transistor with a memory retention

Abstract: All‐perovskite ferroelectric field effect transistors (FET) are proposed, and switching behaviors of the prototype devices having a (Pb,La)(Zr,Ti)O3 as a gate insulator and a La1.99Sr0.01CuO4 as a channel layer were demonstrated. Marked improvements in device performances were obtained as compared with the previous ferroelectric FETs. Namely, the present device was written and erased at an operating voltage of 7 V with a pulse width of less than 1 ms, yielding resistance modulation up to about 10% and retaining its memory for more than 10 days at room temperature. Examinations show that the switching speed was limited by a delay constant and can therefore be improved up to 1 μs, and that the memory retention may not be limited by an intrinsic ferroelectric instability as previously suggested.

A Software-Defined Radio System for Backscatter Sensor Networks

Abstract: Backscatter radio is proposed for sensor networks. In that way, the transmitter for each sensor is simplified to a transistor connected to an antenna and therefore, the cost for each sensor's communicator becomes negligible, while energy used for wireless communication per sensor is minimized. A software-defined transceiver is built to transmit a carrier, receive the reflections from various sensors and extract their transmitted messages. This work presents a thorough model of the backscatter radio link, the system architecture and a set of data extraction techniques for each sensor's information, testing in practice a sensor communicating through backscatter at a range of approximately 15 meters indoors, with 5 milliwatt transmission power at 10 bits per second. This work highlights the idiosyncrasies of the backscatter channel and provides a new communication perspective in the fertile area of scalable sensor networks, especially when low bit-rate, ultra-low cost sensors are required.