Resource Management in Civil Construction Using RFID Technologies

Abstract Large amount of construction resources and their scattered locations in a civil construction site make it extremely difficult for project managers to effectively utilize the resources. In order to manage construction resource effectively, a Radio Frequency Identification (RFID) technology was used in this research. RFID tags for metallic objects were attached to structural components used in a cable-stayed bridge. The RFID reader and antennas were installed at the construction site for tracking the structural components and the acquired data were transferred to the head office via Local Area Network (LAN). The proposed RFID system enabled real-time monitoring of the construction materials in the civil construction site

Multilayered Composites with Modulus Gradient for Enhanced Pressure???Temperature Sensing Performance

Highly sensitive and flexible composite sensors with pressure and temperature sensing abilities are of great importance in human motion monitoring, robotic skins, and automobile seats when checking the boarding status. Several studies have been conducted to improve the temperature-pressure sensitivity; however, they require a complex fabrication process for micro-nanostructures, which are material-dependent. Therefore, there is a need to develop the structural designs to improve the sensing abilities. Herein, we demonstrate a flexible composite with an enhanced pressure and temperature sensing performance. Its structural design consists of a multilayered composite construction with an elastic modulus gradient. Controlled stress concentration and distribution induced by a micropatterned structure between the layers improves its pressure and temperature sensing performance. The proposed composite sensor can monitor a wide range of pressure and temperature stimuli and also has potential applications as an automotive seat sensor for simultaneous human temperature detection and occupant weight sensing

Recent Development of Mechanical Stimuli Detectable Sensors, Their Future, and Challenges: A Review

By virtue of their wide applications in transportation, healthcare, smart home, and security, development of sensors detecting mechanical stimuli, which are many force types (pressure, shear, bending, tensile, and flexure) is an attractive research direction for promoting the advancement of science and technology. Sensing capabilities of various force types based on structural design, which combine unique structure and materials, have emerged as a highly promising field due to their various industrial applications in wearable devices, artificial skin, and Internet of Things (IoT). In this review, we focus on various sensors detecting one or two mechanical stimuli and their structure, materials, and applications. In addition, for multiforce sensing, sensing mechanism are discussed regarding responses in external stimuli such as piezoresistive, piezoelectric, and capacitance phenomena. Lastly, the prospects and challenges of sensors for multiforce sensing are discussed and summarized, along with research that has emerged

A Reflection Self-Canceling Design Technique for Multidrop Memory Interfaces

We propose a reflection self-canceling design technique for multidrop memory interfaces. In this technique, lengths of branch lines are designed, so that dominant multiple reflections become self-canceling. As a result, reflective intersymbol interferences (ISIs) can be greatly reduced to increase the bandwidth without utilizing serial resistor insertion, reflection compensation lines (RCLs), or advanced circuits, such as equalization circuits. Using the proposed and the conventional techniques, two eight-drop channels were designed with 50- $\Omega$ microstrip lines on FR-4 printed circuit board (PCB) and tested with the pseudo-random binary sequence (PRBS) 31 pattern for comparison. At 10.5 Gb/s, the worst eye height was measured 28.0 mV in the proposed design, while the worst eye diagram of the conventional design was closed. The proposed design achieved the maximum data rate of 12.5 Gb/s and achieved the worst eye height of 10.0 mV. The achieved data rate of 12.5 Gb/s is 95.3% faster than the prior art measured with an eight-drop channel without equalization circuits. © 2011-2012 IEEE.11Nsciescopu

A Fast Eye Size Evaluation Method for High Speed Signal

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Evaluation of the Impact of Activated Biochar-Manure Compost Pellet Fertilizer on Volatile Organic Compound Emissions and Heavy Metal Saturation

For this experiment, pelletized activated biochar made of rice hullsor palm bark with swine manure compost was prepared to demonstrate the significant benefits of applying activated biochar-manure compost pellet fertilizer (ABMCP) inmitigating volatile organic compounds (VOCs), odor emission, and heavy metal saturation. Morphology and surface area analysis indicated that the activated rice hull biochar-manure compost pellet (ARP) had a significantly lower surface area, porous volume, and Fe content the activated palm biochar-manure compost pellet (APP). However, the ARP presented great potential to mitigate VOCs and odorant emissions. Our results indicated that the ARP reduced total reduced sulfur (TRS) and volatile fatty acids (VFAs) emissions by 69% and 93%, respectively. Heavy metals such as Pb, As, and Cd were not detected in the leachates fromthe ARP, APP, and swine manure compost. These results suggest that ABMCP can be a potential adsorbent to control VOCs and odorant emissions andpromote sustainable swine manure management and agricultural application

Colorimetric Sensor Based on Hydroxypropyl Cellulose for Wide Temperature Sensing Range

Recently, temperature monitoring with practical colorimetric sensors has been highlighted because they can directly visualize the temperature of surfaces without any power sources or electrical transducing systems. Accordingly, several colorimetric sensors that convert the temperature change into visible color alteration through various physical and chemical mechanisms have been proposed. However, the colorimetric temperature sensors that can be used at subzero temperatures and detect a wide range of temperatures have not been sufficiently explored. Here, we present a colorimetric sensory system that can detect and visualize a wide range of temperatures, even at a temperature below 0 degrees C. This system was developed with easily affordable materials via a simple fabrication method. The sensory system is mainly fabricated using hydroxypropyl cellulose (HPC) and ethylene glycol as the coolant. In this system, HPC can self-assemble into a temperature-responsive cholesteric liquid crystalline mesophase, and ethylene glycol can prevent the mesophase from freezing at low temperatures. The colorimetric sensory system can quantitatively visualize the temperature and show repeatability in the temperature change from -20 to 25 degrees C. This simple and reliable sensory system has great potential as a temperature-monitoring system for structures exposed to real environments

Interfacial enhancements between a three-dimensionally printed Honeycomb-Truss core and woven carbon fiber/polyamide-6 facesheets in sandwich-structured composites

A novel sandwich-structured composite comprising a three-dimensionally (3D) printed core and a woven carbon fiber/polyamide-6 facesheet was fabricated and characterized. By using selective laser sintering, which is a 3D printing technology, a structurally reinforced honeycomb-truss hybrid core was produced, which had superior compressive stiffness in various directions compared with conventional honeycomb cores. The interface between the core and the facesheet was enhanced by laser power control during the sintering as well as plasma surface treatment. The sandwich composite was produced by the reactive thermoplastic resin transfer molding (T-RTM) technique using anionic polymerization of epsilon-caprolactam, which has an ultra-low viscosity in the molten state. This in-situ polymerization not only enabled manufacturing process simplification by combining fabrication and bonding processes of the facesheet, but also provided excellent resin impregnation into the fiber fabrics and core surface. Therefore, the 3D printing technology, interfacial strengthening techniques, and T-RTM process induced synergistic effects on mechanical properties of the sandwich composite by forming structural reinforcement and strong mechanical and chemical interactions. The edgewise compressive properties of the hybrid core were significantly better than those of a normal honeycomb core. In addition, the interlaminar fracture toughness, impact energy absorption, and penetration limit of the sandwich composite consisting of the structurally and interfacially strengthened hybrid core increased by 76, 77, and 125%, respectively, compared to those of a nonreinforced sandwich composite

Application of pseudo-3D Chirp sub-bottom profiler survey: a case study of ancient wooden shipwreck site, west coast of Korea

Chirp sub-bottom profilers (SBP) provide centi-to-decimetre resolution, seismic data with applications for various geophysical and geological purposes. To verify the field application of imaging of a buried target with a cost-effective and easy-to-apply pseudo-3D Chirp SBP survey, we explored the buried site of an ancient wooden shipwreck off the west coast of Korea before underwater excavations. The survey was conducted using a commercial 2D Chirp SBP system with a newly devised recording system that preserved the true polarity of the chirp signal. To produce high-resolution 3D Chirp SBP data from 2D Chirp SBP datasets recorded by the novel system, an optimal data processing sequence, consisting of a first phase of 2D data processing and a second phase of 3D data processing was designed. The first, 2D phase, included the estimation of a source sweep signature, cross-correlation, and deconvolution using an inverse filter. The resulting resolution of the 2D Chirp SBP data was better than that of the enveloped data provided by the commercial acquisition system. The second phase of 3D data processing included gathering 3D datasets, redistributing of ping positions, and static correction. To improve the consistency of the seismic events and reduce the repetitive corrections (swell, tidal, tie, and residual corrections), a static correction was based on multi-beam echo sounder data. The amplitude variation near the shipwreck was clearly apparent in the time slice from the final pseudo-3D Chirp SBP dataset with a bin size of 2.0 m (crossline) × 0.6 m (inline). Through 3D rendering, the buried ancient shipwreck with dimensions of 5 m (width) × 12 m (length) × 2 m (depth) was imaged successfully