Performance comparison between iSCSI and other hardware and software solutions

We report on our investigations on some technologies that can be used to build disk servers and networks of disk servers using commodity hardware and software solutions. It focuses on the performance that can be achieved by these systems and gives measured figures for different configurations. It is divided into two parts : iSCSI and other technologies and hardware and software RAID solutions. The first part studies different technologies that can be used by clients to access disk servers using a gigabit ethernet network. It covers block access technologies (iSCSI, hyperSCSI, ENBD). Experimental figures are given for different numbers of clients and servers. The second part compares a system based on 3ware hardware RAID controllers, a system using linux software RAID and IDE cards and a system mixing both hardware RAID and software RAID. Performance measurements for reading and writing are given for different RAID levels.Comment: Paper associated to a poster from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 4 pages, LaTeX. PSN TUDP00

Modeling, Fabrication and Characterization of Scalable Electroless Gold Plated Nanostructures for Enhanced Surface Plasmon Resonance

The scientific and industrial demand for controllable thin gold (Au) film and Au nanostructures is increasing in many fields including opto-electronics, photovoltaics, MEMS devices, diagnostics, bio-molecular sensors, spectro-/microscopic surfaces and probes. In this study, a novel continuous flow electroless (CF-EL) Au plating method is developed to fabricate uniform Au thin films in ambient condition. The enhanced local mass transfer rate and continuous deposition resulting from CF-EL plating improved physical uniformity of deposited Au films and thermally transformed nanoparticles (NPs). Au films and NPs exhibited improved optical photoluminescence (PL) and surface plasmon resonance (SPR), respectively, relative to batch immersion EL (BI-EL) plating. Suggested mass transfer models of Au mole deposition are consistent with optical feature of CF-EL and BI-EL films. The prototype CF-EL plating system is upgraded an automated scalable CF-EL plating system with real-time transmission UV-vis (T-UV) spectroscopy which provides the advantage of CF-EL plating, such as more uniform surface morphology, and overcomes the disadvantages of conventional EL plating, such as no continuous process and low deposition rate, using continuous process and controllable deposition rate. Throughout this work, dynamic morphological and chemical transitions during redox-driven self-assembly of Ag and Au film on silica surfaces under kinetic and equilibrium conditions are distinguished by correlating real-time T-UV spectroscopy with X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) measurements. The characterization suggests that four previously unrecognized time-dependent physicochemical regimes occur during consecutive EL deposition of silver (Ag) and Au onto tin-sensitized silica surfaces: self-limiting Ag activation; transitory Ag NP formation; transitional Au-Ag alloy formation during galvanic replacement of Ag by Au; and uniform morphology formation under controlled hydraulic conditions. A method to achieve the time-resolved optical profile of EL Au plating was devised and provided a new transitional EL Au film growth model which validated mass transfer model prediction of the deposited thickness of ¡Ü100 nm thin films. As a part of the project, validation of mass transfer model, a spectrophotometric method for quantitative analysis of metal ion is developed that improves the limit of detection comparable to conventional instrumental analysis. The present work suggests that modeling, fabrication and characterization of this novel CF-EL plating method is performed to achieve an ultimate purpose: developing a reliable, inexpensive wet chemical process for controlled metal thin film and nanostructure fabrication

Sharp Rejection Techniques in High Frequency Active-RC LPF for UWB Applications

This paper describes a sharp-rejection technique in designing active-RC LPF for MB-OFDM UWB applications. Sharp rejection is attributed to the combination of different AC characteristic of three Biquads in series. A simple operational amplifier (Op-amp) is adopted to ensure high frequency and high linear performance for the designed filter. The cutoff frequency is 264MHz, with 13dB rejection at 290MHz and about 50dB at twice bandwith. the LPF is designed in 0.13um IBM CMOS process with pass-band ripple of less that 1dB, IIP3 is 23dBm while cnsuming 8.4mA from 1.5V supply

9.1 dBm IIP3 36 dB Gain Controllable LNA for WCDMA in 0.13-m CMOS

This article presents a low-power, high-linearity cascodetype low noise amplifier (LNA) with 36 dB of variable gain for the WIDE Code Division Multiple Access systems. By enhancing the substrate resistance of a common gate transistor along with adopting multiple-gate technique, the linearity is significantly improved. Shunt-current steering is adopted for smooth gain control. Step gain mode is used to further increase the gain control range. The main common source transistor is disabled in attenuation mode, saving unwanted power consumption. Measurements show maximum gain of 12.3 dB with S11 of 19.5 dB, and S22 of 14 dB. The total gain control range is 36 dB. NF is measured as 2 dB and two-tone test shows 9.1 dBm of IIP3. Implemented in 0.13-m CMOS technology, the LNA consumes only 1.6 mA at maximum gain mode and only 0.2 mA in attenuation mode from 1.2 V supply. Its die size is 0.3 mm2. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1385–1388, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop. 2432

Sharp Rejection Techniques in High Frequency Active-RC LPF for UWB Applications

This paper describes a sharp-rejection technique in designing active-RC LPF for MB-OFDM UWB applications. Sharp rejection is attributed to the combination of different AC characteristic of three Biquads in series. A simple operational amplifier (Op-amp) is adopted to ensure high frequency and high linear performance for the designed filter. The cutoff frequency is 264MHz, with 13dB rejection at 290MHz and about 50dB at twice bandwith. the LPF is designed in 0.13um IBM CMOS process with pass-band ripple of less that 1dB, IIP3 is 23dBm while cnsuming 8.4mA from 1.5V supply

380 MHz Low-Power Sharp-Rejection Active-RC LPF for IEEE 802.15.4a UWB WPAN

This paper describes a wide-band sharp-rejection active-RC low pass filter (LPF) for pulse-based UWB IEEE 802.15.4a WPA, applications. Sharp rejection is attributed to the combination of different AC characteristic of three biquads in series. A simple operational amplifier (Op-amp) is adopted to ensure high frequency performance for the designed filter. The LPF is designed in 0.13μm TSMC CMOS process. The cutoff frequency is 380MHz with about 50% of the tuning range from 300-500MHz. The rejection is 40 dB at 600 MHz. The passband ripple is less than 1.5dB and the filter consumes 4.6mA from 1.2V supply. Core chip size is 580 x 700μm2

Attitudes and Intentions of Business Master Students towards Sustainable Tourism and Entrepreneurship

Sustainable development has become in the last three decades an issue of high importance, both from theoretical view and from the public policies’ view. Nevertheless, sustainable development can be generated only by sustainable enterprises and businesses, which should take into consideration not only the economic aspects, but also the social and environmental ones, i.e. businesses striving to meet the ”triple bottom line”. This paper aims at investigating master students in Business Administration, i.e. future business people, are actually prepared for creating and running businesses in sustainable tourism and which is the profile of future “sustainable entrepreneur”. In order to answer this question, a surveybased research was conducted among master students in Business administration, concerning aspects such as: what is the understanding of business master students on ”sustainability” issues and which are their sustainability-related habits, attitudes and behaviour as consumers. We used factorial analysis, resulting in a four factors model, to investigate attitudes related to: importance to run a sustainable business, the use of renewable energy resources, recycling used products, employing local labour force, promoting the use of local resources etc. The paper presents the main findings in the context of previous researches in the literature, drawing conclusions and proper recommendations

380 MHz Low-Power Sharp-Rejection Active-RC LPF for IEEE 802.15.4a UWB WPAN

This paper describes a wide-band sharp-rejection active-RC low pass filter (LPF) for pulse-based UWB IEEE 802.15.4a WPA, applications. Sharp rejection is attributed to the combination of different AC characteristic of three biquads in series. A simple operational amplifier (Op-amp) is adopted to ensure high frequency performance for the designed filter. The LPF is designed in 0.13μm TSMC CMOS process. The cutoff frequency is 380MHz with about 50% of the tuning range from 300-500MHz. The rejection is 40 dB at 600 MHz. The passband ripple is less than 1.5dB and the filter consumes 4.6mA from 1.2V supply. Core chip size is 580 x 700μm2