UWB-assisted real-time localization in wireless sensor networks

A safety monitoring and accident warning system for underground construction site has been designed in our previous work based on wireless sensor networks (WSNs). Real-time localization of mobile targets is crucial for tracking the related incidents. However, the current RSSI-based localization approach struggles to achieve the required performance. This is due to the limited ranging accuracy of RSSI devices. In this paper, we investigate various ways of improving the localization accuracy and propose our solution of a hybrid UWB-assisted approach. We argue that a hybrid UWB-assisted RSSI ranging has the best overall performance for our application. We show with both mathematical analysis and demonstration system that, instead of implementing a full UWB network, our approach can improve the accuracy to our desired level with only a small number of additional UWB anchor nodes. © 2013 IEEE

An integrated information management model for proactive prevention of struck-by-falling-object accidents on construction sites

The construction industry is one of the most hazardous industries in many countries. Struck-by-falling-object accidents are not given adequate attention even though they are of great importance on construction sites. The objective of this paper is to analyze the proactively preventive information requirement of struck-by-falling-object accidents and propose an integrated information management model using a ZigBee RFID sensor network to fulfill these requirements. First, the frequency of particular type of objects is analyzed based on vast historical accident cases. Next, this paper analyzes the proactively preventive information requirement of struck-by-falling-object accidents and brought forth an integrated information management model. Furthermore, considering the crucial and controllable objects, an integrated information management model is proposed. This study would provide a possible approach for tracking struck-by-falling-object accidents based on real-time information for proactive prevention and could serve as a foundation for further study. © 2012 Elsevier B.V. All rights reserved

Cp*Ir-Catalyzed Acceptorless Dehydrogenation of Carbon–Carbon Single Bonds

Pentamethylcyclopentadienyl (Cp*) iridium­(III) chloride catalyzed acceptorless dehydrogenation of α-tetralone is reported. Cp* iridium chloride showed higher activity in comparison to other Cp* iridium complexes having bromide, iodide, or hydride or complexes without a Cp ring. The desired product, naphthol, was obtained in up to 71% yield from α-tetralone. The dehydrogenation by Cp* iridium catalyst could be applied to not only α-tetralone but also dihydrocoumarin, dihydroquinolinone, dimethylcyclohexanone, dihydrobenzofuran and 1-isochromanone, although the conversion stayed moderate. The catalytic turnover was not limited by the increased concentration of the product but by catalyst decomposition

Design and implementation of an identification system in construction site safety for proactive accident prevention

Identifying accident precursors using real-time identity information has great potential to improve safety performance in construction industry, which is still suffering from day to day records of accident fatality and injury. Based on the requirements analysis for identifying precursor and the discussion of enabling technology solutions for acquiring and sharing real-time automatic identification information on construction site, this paper proposes an identification system design for proactive accident prevention to improve construction site safety. Firstly, a case study is conducted to analyze the automatic identification requirements for identifying accident precursors in construction site. Results show that it mainly consists of three aspects, namely access control, training and inspection information and operation authority. The system is then designed to fulfill these requirements based on ZigBee enabled wireless sensor network (WSN), radio frequency identification (RFID) technology and an integrated ZigBee RFID sensor network structure. At the same time, an information database is also designed and implemented, which includes 15 tables, 54 queries and several reports and forms. In the end, a demonstration system based on the proposed system design is developed as a proof of concept prototype. The contributions of this study include the requirement analysis and technical design of a real-time identity information tracking solution for proactive accident prevention on construction sites. The technical solution proposed in this paper has a significant importance in improving safety performance on construction sites. Moreover, this study can serve as a reference design for future system integrations where more functions, such as environment monitoring and location tracking, can be added

Transfer Hydrogenation of Aldehydes, Allylic Alcohols, Ketones, and Imines Using Molybdenum Cyclopentadienone Complexes

The molybdenum tetraphenylcyclopentadienone complex (C₅Ph₄O)­Mo­(CO)₃­(CH₃CN) <b>1a</b> is an effective precatalyst for the transfer hydrogenation of aldehydes, allylic alcohols, ketones, and imines under mild conditions with either 2-propanol or formic acid as reducing reagent. Mechanistic studies suggest that these molybdenum cyclopentadienone complexes can be reduced to the corresponding hydroxycyclopentadienyl Mo hydrides. These complexes, by virtue of the hydroxyl group on the cyclopentadienyl ligand, are more reactive and chemoselective than the analogous cyclopentadienyl molybdenum complexes for the reduction of ketones, aldehydes, and imines

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Supplementary Table S

RawData_mgf.tar

Raw data with mass spectrometry (MS/MS) spectra information for the iTRAQ analysis of soybean cell wall proteins

Lead Zirconate Titanate Nanowire Textile Nanogenerator for Wearable Energy-Harvesting and Self-Powered Devices

Wearable nanogenerators are of vital importance to portable energy-harvesting and personal electronics. Here we report a method to synthesize a lead zirconate titanate textile in which nanowires are parallel with each other and a procedure to make it into flexible and wearable nanogenerators. The nanogenerator can generate 6 V output voltage and 45 nA output current, which are large enough to power a liquid crystal display and a UV sensor

Magnetic Force Driven Nanogenerators as a Noncontact Energy Harvester and Sensor

Nanogenerator has been a very important energy harvesting technology through directly deforming piezoelectric material. Here, we report a new magnetic force driven contactless nanogenerator (CLNG), which avoids the direct contact between nanogenerator and mechanical movement source. The CLNG can harvest the mechanical movement energy in a noncontact mode to generate electricity. Their output voltage and current can be as large as 3.2 V and 50 nA, respectively, which is large enough to power up a liquid crystal display. We also demonstrate a means by which a magnetic sensor can be built