There are three types of power lines in the 10 kV distribution network in China, i.e., copper power cables, overhead power conductors and aluminum alloy power cables. It is necessary to give a comprehensive evaluation to choose the type of power line in some delicate practical engineering. This paper presents a life cycle cost (LCC)-based analysis method for the three types of power lines. An LCC model of the power line in the 10 kV distribution network is established, which considers four parts: investment cost, operation and maintenance cost, failure cost and discard cost. A detailed calculation model for the four parts is presented, and to calculate the failure cost, the Monte Carlo algorithm is employed to simulate the values of expected energy not supplied (EENS). Two practical 10 kV power line projects in Fujian Province in China were analyzed based on the proposed LLC model and corresponding developed software, which has helped the power company select the appropriate power line successfully. Full article

This study proposes a long period fiber grating (LPFG) with a zinc oxide (ZnO) nanoparticle layer for use as a carbon dioxide (CO₂) gas sensor. Inductively coupled plasma (ICP) etching, corona treatment, and electrostatic spraying were used to fabricate this ZnO nanoparticle-coated LPFG CO₂ gas sensor. Repeated gas sensor tests showed that, when a 15% CO₂ mixture was injected (0.2 L/min) into a closed chamber into which the sensor had been placed, the CO₂ gas was absorbed by the ZnO nanoparticle-coated LPFG sensor. In these tests, the transmission loss gradually decreased, and the maximum transmission loss was 2.039 dB. The concentration test results showed that as the concentration of CO₂ introduced into the chamber was increased, the rate of the transmission loss change was increased in direct proportion. In addition, the sensitivity was 0.0513 dB/%. The results confirm that this low-cost ZnO nanoparticle-coated LPFG gas sensor was successfully applied to the measurement of CO₂ gas. Therefore, the proposed ZnO nanoparticle-coated LPFG can be used to measure CO₂ gas. Full article

During recent years, optimal electrification of isolated offshore systems has become increasingly important and received extensive attention from the maritime industry. Especially with the introduction of electric propulsion, which has led to a total electrification of shipboard power systems known as all-electric ships (AESs), the need for more cost-effective and emission-aware solutions is augmented. Such onboard systems are prone to sudden load variations due to the changing weather conditions as well as mission profile, thus they require effective power management systems (PMSs) to operate optimally under different working conditions. In this paper, coordinated optimal power management at the supply/demand side of a given AES is studied with regard to different objectives and related technical/environmental constraints. The optimal power management problem is formulated as a mixed-integer nonlinear programming (MINLP) model and is solved using a metaheuristic algorithm. To show the effectiveness and applicability of the proposed PMS, several test scenarios are implemented and related simulation results are analyzed and compared to those from conventional methods. Full article

This invention relates to a wireless bus information management system, which includes bus stop and vehicle management subsystems. The management signals are transmittable between bus stops and the vehicle. Based on vehicle management signals, the bus stop management subsystem can obtain information about the bus route identification, the number of unoccupied seats, the intention to stop or not, etc. Similarly, with the bus stop management signals, the vehicle management subsystem can make the decision of stopping. Accordingly, when a passenger wants to get off the vehicle or there are unoccupied seats, the vehicle management subsystem will inform the bus stop management subsystem such that the passengers waiting at the bus stop may flexibly schedule their travel plan. The proposed distributed wireless system is detailed by a prototype implementation and a simulation analysis, which is shown to be feasible and scalable. Full article

Although theoretically the patent system is meant to bolster innovation, the current United States Patent and Trademark Office (USPTO) is cumbersome and involves a significant time investment to locate inactive patents less than 20 years old. This article reports on the development of an open source database to find these public domain ideas. First, a search strategy is explained. Then the operation and use of free and open source software are detailed to meet the needs of open hardware innovators. Finally, a case study is presented to demonstrate the utility of the approach with 3-D printing. The results showed how the Free Inactive Patent Search enables users to search using plain language text to find public domain concepts and then provides a hyperlinked list of ideas that takes users to the USPTO database for the patent for more information. All of the source code to operate the search and the website are open source themselves and provided in the public domain for free. In the case study on 3-D printing the time to identify public domain patents was cut by a factor of more than 1500. This tool has the potential for accelerating the development of open hardware technologies to create high value for the public. Full article

Recent developments in smartphone technology have increased user demand for indoors applications. The Global Navigation Satellite System (GNSS) and the Inertial Navigation System (INS) are the two advanced systems for navigation technology. However, it is still difficult for GNSS to provide an accurate and practical navigation solution, especially in environments with little or no signal availability. These failings should be easy to overcome; because of their portability and multiple embedded hardware sensors, smartphones seem well positioned to make pedestrian navigation easy and convenient in any environment. Pedestrian Dead Reckoning (PDR) is one of the most commonly used technologies used for pedestrian navigation, but it is not always accurate because its positioning errors tend to accumulate over time. Therefore, this research introduces a new tool to overcome this failing; a Bluetooth Low-Energy (BLE) beacon can maintain and improve the accuracy of PDR. Moreover, a BLE beacon can be initialized from any user position in an indoor environment. The random and unpredictable positions of pedestrians inevitably result in the degradation of navigation guidance systems’ data. To rectify this problem, we have implemented activity recognition technology to notify the proposed system so as to provide a more accurate heading estimate. This study proposes a Personal Navigation System (PNS) based on this technology; it can estimate navigation solutions in real time and combines the advantages of PDR and Bluetooth positioning technology. A series of experiments were conducted to evaluate the accuracy of the system and the efficacy of our proposed algorithms. Preliminary results show the average relative precision of PDR to be about 2.5%, when using a mobile hand-held device. The error of initial position from 2-D beacon positioning is less than two meters. The proposed system works well without post-processing, and the multi-sensor activity recognition system can determine the placement of the device when it is being carried or used by someone with close to 100% accuracy. Full article

Titanium dioxide nanoparticles (nTiO₂) show biocidal activity when exposed to UV illumination. Modification of their physical properties can expand their photoresponse region toward visible light. In this study, such modification was made through a sol-gel synthesis followed by calcination at a range of temperatures (250–900 °C), generating a series of nTiO₂ particles with different crystal phases, sizes, porosities, zeta potentials, and BET surface areas. The unique properties of nTiO₂ were linked to their toxicity to the marine bacterium, Vibrio fischeri. A modified “Flash” high-through put assay was used to test the viability of these marine organisms after short term (15–60 min) exposure under visible light only to the individual groups of nTiO₂ (500–2000 μg/mL). Linear regression analysis indicated that across all concentrations and time points, high biocidal activity correlated with the amorphous and anatase crystal phases, high BET surface area, high pore volume and small crystal size. The linkage between physicochemistry and nanotoxicity would be helpful for future design of more efficient and sustainable nTiO₂. Full article