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A step-down wireless power transfer converter with center-tapped pickup windings is proposed in this article. The pickup winding is split into two sections and only one is connected to the load. This topology is more suitable for low-voltage level applications, such as consumer electronic products. Like the conventional series–parallel compensation technique, the circuit does not induce high circulation current at the transmitter coil under light load operation. The loosely coupled coils are analyzed with mutual inductance model; in addition, the input impedance and voltage gain are derived. The input impedance is proportional to the load impedance, and the voltage gain is less sensitive to the load variation. The proposed topology performs better than the conventional one at higher load conditions, especially when the coupling is poor. The efficiency of a laboratory circuit reaches 88.8% at best condition and it is higher than 63% ranging from 10- to 100-W load at 10- or 60-mm coil separation.

Competition between one-way car-sharing operators is currently increasing. Fleet relocation as a means to compensate demand imbalances constitutes a major cost factor in a business with low profit margins. Existing decision support models have so far ignored the aspect of a competitor when the fleet is rebalanced for better availability. We present mixed-integer linear programming formulations for a pickup and delivery orienteering problem under different business models with multiple (competing) operators. Structural solution properties, including existence of equilibria and bounds on losses as a result of competition, of the competitive pickup and delivery problem under the restrictions of unit-demand stations, homogeneous payoffs, and indifferent customers based on results for congestion games are derived. Two algorithms to find a Nash equilibrium for real-life instances are proposed. One can find equilibria in the most general case; the other can only be applied if the game can be represented as a congestion game, that is, under the restrictions of homogeneous payoffs, unit-demand stations, and indifferent customers. In a numerical study, we compare different business models for car-sharing operations, including a merger between operators and outsourcing relocation operations to a common service provider (coopetition). Gross profit improvements achieved by explicitly incorporating competitor decisions are substantial, and the presence of competition decreases gross profits for all operators (compared with a merger). Using a Munich, Germany, case study, we quantify the gross profit gains resulting from considering competition as approximately 35% (over assuming absence of competition) and 12% (over assuming that the competitor is omnipresence) and the losses because of the presence of competition to be approximately 10%.

An airport serves as an interface between ground and air transportation; the efficient processing of ground transportation arrivals and departures is, therefore, an important part of airport operations. At many airports, the current pickup and dropoff locations for taxis and other passenger cars are along the terminal curb or in existing parking facilities, and many of these pickup and dropoff facilities suffer from excessive congestion. In addition, in recent years there has been growth in the use of on-demand ground transportation to and from airports, with the increased adoption of ride-hailing services, resulting in increased congestion. Since most airports are severely space constrained, there is a need to consider pickup and dropoff facilities that are more efficient (in vehicle throughput per unit space) than terminal curbs. In this paper we compare the throughput capacities of different pickup and dropoff facility layouts. We take into account the effect of the facility layout and operational rules on conflicts between the movements of different vehicles, the resulting delays in the movements of vehicles, as well as the spatial requirements of different layouts. We demonstrate the impact of mean service times, variability in service times and vehicle movement times, and operational rules on the relative throughput capacities of different facility layouts.

As an online and offline integrated service of refund, replacement, and after-sales service, omnichannel is placing itself as a major service used in the online shopping market, as efficiency and an integrated operation system develop according to channel integration due to ICT development. Centered on young people who have recently put importance on in-store experience and direct experience, offline pickup service is reinforced beyond online delivery. This study aims to analyze the effects of a distribution company’s brand factors on customer consumption value and satisfaction targeting the omnichannel-based pickup service. The research model was designed to find out whether brand image, identity, attachment, and trust factors affect consumption satisfaction factors through the intervention of emotional and functional consumption value factors. This study targeted 324 consumers using Korea’s omnichannel-based pickup service and carried out a questionnaire survey. According to the analysis result, the brand image and brand identity had a positive (+) effect on the emotional value and functional value. Brand attachment and brand trust positively affected emotional value but the hypothesis on functional value was rejected. Hence, brand factors were confirmed to work on improving a consumer’s emotional value effectively.

This study addresses a capacitated vehicle routing problem with time windows and simultaneous pickup and delivery (VRPTWPD) for scheduling bus-type taxis formerly served by regular buses. The effec...

Over the past decade, electric vehicles (EVs) have been considered in a growing number of models and methods for vehicle routing problems (VRPs). This study presents a comprehensive survey of EV routing problems and their many variants. We only consider the problems in which each vehicle may visit multiple vertices and be recharged during the trip. The related literature can be roughly divided into nine classes: Electric traveling salesman problem, green VRP, electric VRP, mixed electric VRP, electric location routing problem, hybrid electric VRP, electric dial-a-ride problem, electric two-echelon VRP, and electric pickup and delivery problem. For each of these nine classes, we focus on reviewing the settings of problem variants and the algorithms used to obtain their solutions.

Designs of hodoscopes of nuclear fragments based on quartz and scintillation plates with light pickup by silicon avalanche photodiodes are described. Hodoscopes are planned for use in the BM@N experiment for registration of heavy nuclear fragments near the axis of the heavy ion beam. The results of measurements of light yields in detector elements based on quartz and scintillation plates on the electron beam of the synchrotron "Pakhra" (LPI) are presented. The measured nonuniformity of the light collection shows that readout from both sides of hodoscope detector elements is needed.

An increasing number of micro/nano-components with complex structures have emerged in recent years. Different kinds of feature sizes usually exist in a single component and require the use of instruments with nanometer-level accuracy. The traditional types of equipment cannot meet the current demands because of their lack of function and effectiveness. In this study, a multifunctional probe is designed by combining the interference and focusing principles. The Linnik principle is adopted in the interferometry module for its high vertical resolution and large horizontal range and its ability to measure surface topography. The focusing module modified from a Blue-ray DVD pickup head has a high horizontal resolution and a large vertical range suitable for measuring step height and line/groove width. The two modules share a polarizing beam splitter and an objective lens to reduce probe size. Then, the probe is manufactured, calibrated, and verified by measuring the surface topography with a reference height of 100 nm, a step height of approximately $4~\mu \text{m}$ , and a diameter of approximately $25~\mu \text{m}$ . The proposed probe has a high resolution and large range in 3D and can measure high-precision components with multiple features.

This paper proposes a new operation method for an image pickup tube under high-temperature conditions. The landing energy of an electron beam is set at a value for the secondary electron yield above 1.0. The mesh electrode, which is located in front of the image plate, can act as a potential barrier and control the surface potential of the image plate in the balanced state, where secondary electron yield is 1.0. The polarity of signal charges can be also selected with the proposed method. These effects can suppress image degradation caused at high temperatures. We successfully demonstrated imaging operation around 100 °C.

In the application of the magnetic nanoparticle (MNP) imaging technique, which uses a large ac magnetic field and detects harmonic signals, it is important to attenuate the fundamental signal generated by the magnetic field used for excitation. In this article, we propose a method to reduce this fundamental signal using a compensation circuit with a digital-to-analog (D/A) converter, which can be interpreted as an electrical bridge. We apply the proposed method to an MNP imaging system. The system contains one excitation coil that generates an ac magnetic field and 16 pickup coils that detect the third-harmonic signals from the MNP samples. The position of an MNP sample containing $100~\mu \text{g}$ of Fe was estimated using this system via an inverse problem analysis. The results demonstrate that the fundamental signal is suppressed successfully and also show that the distance between the estimated and actual positions of the MNP sample is less than 10 mm at a depth of 50 mm.

The coils in a three-axis fluxgate magnetometer have been investigated to enhance the noise and power performance for the use in geomagnetic stations. The turn number of the excitation and pickup coils in the fluxgate sensors is carefully optimized by measuring the equivalent magnetic noise spectral density of the magnetometers. Correspondingly, the values of the tuning and demodulation capacitors are delicately designed to match the optimized coils. The noise of the fluxgate magnetometer is 6 pT/ $\surd $ Hz at 1 Hz with a power consumption lower than 360 mW. The size of the packaged magnetometer is $30 \times 30 \times 113$ mm3, and its weight is less than 80 g (without cable). The features of the fluxgate magnetometer make it a suitable instrument for geomagnetic stations and other applications.

Regular inspections of steam generator tubes (SGTs) to evaluate structure degradation and sludge deposition are essential for maintaining safety and efficiency of power plants. However, with the interference of complex structures such as tube support plates (TSPs), simultaneously detecting multiple objects is still a challenging problem. This article proposes a novel integrated versatile probe for multiobject inspection. The probe consists of a low-frequency operating region (LFOR) with tunnel magnetoresistance (TMR) array sensors and a high-frequency operating region (HFOR) that uses array coils as the pickup sensors. After frequency optimization and image calibration, the signals of three types of objects are concentrated in three different modalities of the probe’s output. Then, features for position of TSP, profile, and location of sludges are extracted from the image of LFOR. A feature extraction algorithm based on convolution and pattern search is developed to extract defects’ features from the quadrature component image of HFOR. Finally, a hierarchical independent decision-level data fusion scheme is adopted to integrate and visualize the recognition and discrimination of multiple objects in an RGB image. Combinations of machined defects, sludges, and TSP mockup on an SGT are experimentally tested by the probe. Experimental results show that the TSP and sludges are detected accurately. Most of the defects, including the defect embedded under the TSP, can be identified and localized with a high intersection of union (IoU) of 0.92. The TSP, sludges, and defects are clearly visualized in the fused image. For complex scenarios with multiple objects superimposed, the fused image shows each type of objects clearly.

This paper addresses a variant of the known selective pickup and delivery problem with time windows. In this problem, a fleet composed of several vehicles with a given capacity should satisfy a set of customers requests consisting in transporting goods from a supplier (pickup location) to a customer (delivery location). The selective aspect consists in choosing the customers to be served on the basis of the profit collected for the service. Motivated by urban settings, wherein road congestion is an important issue, in this paper, we address the profitable pickup and delivery problem with time windows with uncertain travel times. The problem under this assumption, becomes much more involved. The goal is to find the solution that maximizes the net profit, expressed as the difference between the collected revenue, the route cost and the cost associated to the violation the time windows. This study introduces the problem and develops a solution approach to solve it. Very preliminary tests are performed in order to show the efficiency of developed method to cope with the problem at hand.

This paper undertakes the design, modeling and simulation of the suspension system for a Formula Student Vehicle. Suspension systems are the most integral part of a vehicle. This system is responsible for smoothing out the disturbances of a ride caused by uneven tracks while also maintaining optimum contact with the track surface at all times. The study takes place in three phases. The first phase includes the determination of ideal inboard and outboard pickup points for the suspension system of a Formula Student vehicle according to the identified design constraints. The second phase includes the determination of spring stiffness & optimum geometric set-ups for pushrod-actuated double-wishbone suspension systems using Motion Ratio Calculators devised to calculate the spring travel at defined intervals of wheel travel of the suspension system. This phase concludes in increasing motion ratios with an average of 1.20 and 1.01 for front and rear suspension set-ups, respectively. The third phase includes the material selection, design, simulation and optimization of bell-cranks. This phase concludes in safe bell-crank designs with factors of safety 4.88 and 3.3 and weight reduction of 79.4% and 74% for front and rear bell-cranks, respectively with AISI 1018 as the chosen material. The bell-cranks are modeled using SolidWorks® and their Finite Element Analysis is performed using ANSYS® Workbench.

The active introduction and modern technologies application in the transport market greatly affect all transport branches and the ways of their business. Availability and mass usage of the internet and Web services create a new ambiance of trade through online sales and e-commerce. The increase in internet sales has a direct effect on the business of courier companies. The number of shipments in the B2C (Business-to-Consumer) segment is growing and putting an increasing pressure on costs for companies that perform pickup and delivery. Companies are trying to adapt their business to the new challenges and conditions that prevail in the transport market through different cost management models. One way to manage costs is to outsource costs. This paper proposes a model cost calculation in outsourcing services for pickup and delivery shipments based on the number of stops.

This paper investigates the potential benefits of collaboration among less than truckload (LTL) carriers in fulfilling pickup and delivery jobs. It adopts the commonly used centralized collaborativ...

As an emerging research topic, wireless power transfer (WPT) with a single transmitter for multiple pickups (STMP) shows salient advantages of reducing the number of power inverters, increasing the power density, and so on, which has profound implications for various applications, such as wireless charging for electric vehicles (EVs) and smart homes. First, this article introduces the concept of STMP-WPT and three critical issues, namely, misaligned transmission, resonance shifting, and energy security. Then, the corresponding solutions are elaborated from the perspectives of the magnetic and electric fields, respectively. Finally, the technical challenges for STMP-WPT systems are discussed.

This article addresses the one-commodity pickup and delivery traveling salesman problem (1-PDTSP), which is a generalization of the well-known traveling salesman problem. The 1-PDTSP aims to find a Hamiltonian tour in which a set of supply points (pickup locations), demand points (delivery locations) are visited and, the total traveled distance is minimized. We propose a hybrid metaheuristic based on multi-start evolutionary local search and variable neighborhood descent to solve the 1-PDTSP. To test the performance of our algorithm, we solve instances with up to 500 nodes available in the literature and we demonstrate that our approach is able to provide competitive results when comparing to other existing strategies. Since a direct application of the 1-PDTSP arises as the bicycle repositioning problem, we also use our metaheuristic algorithm to solve a set of real-case instances based on EnCicla, the bicycle sharing system in the Aburra Valley (Antioquia, Colombia).

This research addresses a vehicle routing problem with simultaneous pickup and delivery with time windows from multiple depots (MVRPSPDTW) over a time horizon in the B2C e-commerce logistics system...

This article proposes and implements a continuously adjustable capacitor for multiple-pickup wireless power transfer (WPT), aiming to enhance the energy security performance under single-power-induced energy field. With the accelerated development and commercialization of WPT, the energy security issue shows the increasing significance for multiple-pickup WPT systems, where the induced open radial electromagnetic field facilitates all involved pickup coils to access the wirelessly transferred energy. If utilizing no appropriate protection strategy, the energy privacy is inevitably jeopardized, especially for the single-power-induced energy field where the auxiliary technique, such as the radio-frequency identification, cannot identify the multiple pickups. Accordingly, this article proposes a continuously adjustable capacitor that enhances the security/transmission performance for multiple-pickup WPT systems. Differing from impedance adjusting schemes reported in previous studies, the continuously adjustable capacitor can continuously adjust the impedance to match the encrypted switching frequency dynamically and continuously. In such ways, it can effectively enhance the flexibility of the WPT hardware platform for the cryptographic algorithm, thus significantly reduce the possibility of power being hacked. Finally, the simulated and experimental results are provided to verify the feasibility of the proposed continuously adjustable capacitor for the energy encryption of multiple-pickup WPT systems.

The pickup characteristics of lump non-spherical particles in an oscillating airflow were numerically studied on the basis of experimental verification. Five typical shapes of lump coal particles w...

The online pickup and delivery problem is motivated by the takeaway order delivery on crowdsourcing delivery platform, which is a newly emerged online to offline business model based on sharing economy. Considering the features of crowdsourcing delivery, an online pickup and delivery problem with constrained capacity is proposed, whose objective is to route a delivery man with constrained capacity to serve requests released over time so as to minimize the total latency. We consider online point-to-point requests with single pickup location where each request has to be picked up at the single pickup location and delivered to its destination, and each request become available at its release time, which is not known in advance. The lower bound of this problem for various capacities is proved. Two online algorithms WR and WI are presented, the competitive ratios on a half line and on general metric space are proved respectively. Further, a computational study is conducted to compare the performance of these two online algorithms on random instances of general metric space. The result shows algorithm WR performs better than WI in random cases but not in the worst case.

In dynamic pickup and delivery problems with time windows (PDPTWs), potentially urgent request information is released over time. This gradual data availability means the decision-making process must be continuously repeated. These decisions are therefore likely to deteriorate in quality as new information becomes available. It is still believed that the state of the art for this problem remains far from reaching maturity due to the distinct absence of algorithms and tools for obtaining high-quality solutions within reasonable computational runtimes. This paper proposes a periodic approach to the dynamic PDPTW based on buffering, more specifically a two-step scheduling heuristic which consists of the cheapest insertion followed by a local search. The heuristic’s performance is assessed by comparing its results against those obtained by a mixed integer linear programming model which operates under the assumption that all information is available in advance. Results illustrate how the performance is impacted by urgency levels, the degree of dynamism associated with request arrivals and re-optimization frequency. The findings indicate that increases in dynamism improve solution quality, whereas increases in urgency have the opposite effect. In addition, the proposed approach’s performance is only slightly affected by re-optimization frequency when changing these two characteristics.

This paper proposes a quadrature-shaped pickup coil, which can realize an angular-misalignment insensitive omnidirectional wireless charging system. Recently, the three-dimensional wireless charging has shown promising prospects for removing the performance deterioration caused by the positional misalignment, which can transfer power to arbitrary spatial objectives. In the conventional design, the strength and the direction of the induced magnetic field can be adjusted by controlling the excitation currents of transmitting coils. However, the existence of angular misalignment caused by the self-rotation of the pickup unit still can result in a sharp decrease of the transmitted power. Accordingly, this paper proposes and implements a novel pickup coil topology to compensate such huge fluctuations in power transfer, which aims to ensure an angular misalignment insensitive omnidirectional wireless charging. Simulated and experimental results are both given to verify the feasibility of the proposed quadrature-shaped topology.

Acharge pickup detector was developed at the University of Colorado for use in classroom demonstrations and in the dust accelerator at the Institute for Modeling Plasma, Atmospheres and Cosmic Dust (IMPACT). The detector can be used in a physics classroom to help high school and introductory-level physics students connect electromagnetic phenomena with measurement techniques that are common to experimental physics and in electronics courses to demonstrate the use of a charge-sensitive amplifier (CSA). Construction of a similar detector would develop students’ basic machining and electronics skills, which are crucial in most undergraduate experimental physics opportunities. The detector is designed to nondestructively determine the velocity and charge of particles. The detector is compact (8.6 cm x 5.4 cm x 4.1 cm), simple, and lightweight. It is built with off-the-shelf components with simple machining, resulting in a low-cost (∼$100) detector that maintains the high sensitivity (0.2 fC) necessary for characterization of most hypervelocity dust particles, as well as a wide variety of other applications accessible to introductory-level physics students such as charged particles in a dust storm, pith balls, or charged raindrops. This paper focuses on both characterization of the detector using the accelerator at IMPACT and the basics of the undergraduate-level physics principles, electronics principles, mechanical design, and lab applications.

Publisher Summary The standard piping detail is a drawing that depicts an item or items that are used with such frequency and having consistency in their installation procedure that a single drawing can be created and duplicated for use to represent their installation in almost every situation. This chapter discusses the methods and devices used for the support, anchoring, guiding, and spacing of pipes. Arrangement and positioning are important factors in the layout of a piping facility. Therefore, proper spacing and arrangement of pipes in a pipe rack require special attention. A pipe rack has a defined width; therefore, working within the allotted space makes spacing crucial. Pipes should be arranged to take up a minimum amount of space, and allowances should be made for any pipes that might be added in the future. A major concern when arranging pipes in a rack is the amount of expansion and, to an extent, contraction that occurs when a cold pipe is heated to its normal operating temperature. Expansion is not the only force that can alter the alignment of a pipe. Vibration, commodity turbulence, and other external forces—such as wind—cause a pipe to move.

Extreme events such as faults, cyber-physical attacks, and natural disasters have a widespread impact on the electrical system infrastructure, leading to extensive power outages or blackouts. These events can cause temporary or permanent damages to the power systems and seriously compromise the system’s resiliency. A quick restoration strategy for the systems’ critical loads after extreme events is crucial to ensure resilient operation. This paper presents a fast load restoration (LR) approach for multi-agent-system-based networked DC microgrid systems with distributed energy resources. The overall restoration problem is designed with a weighted sum optimization technique that consists of operational costs, load pickup costs, and optimum power-flow-related costs. It was solved in a distributed manner by applying Alternating Direction Method of Multipliers (ADMM) algorithm through multi-agent communications. The effectiveness of the developed LR technique is verified by applying it to a networked MG system of 4 single-bus DC MGs.

Logistics is one of the primary areas of operation within cutting-edge supply chain operations. In the e-commerce supply chain also logistics operations play a vital part. The logistics operations must be controlled effectively and efficiently since they deal with the high-cost besides environmental impacts. In e-commerce logistics operations, first-mile and last-mile delivery operations are considered as the operations with the highest costs incurred. So, e-commerce service providers are interested in optimizing their first-mile and last-mile delivery operations. Though it is known that the integration of first-mile pickup and last-mile deliveries will minimize the cost of transportation, there are more practical concerns to be taken into account when combining the first-mile pickup and last-mile delivery operations. Capacitated Vehicle Routing Problem (CVRP) is discussed in the literature as a solution approach for this kind of problems. The objective of this study is to provide a comprehensive overview of the current CVRP related literature, including models, algorithmic solution approaches, objectives, and industrial applications, with a focus of identifying interesting study paths for the future to improve distribution in e-commerce logistics networks by combining first-mile pickup and last-mile delivery operations. The findings of the study have demonstrated that constraints and features of Vehicle Routing Problem with Backhauls are very attractive with today's e-commerce operations, and the majority of the cited publications employed approximation methods rather than precise algorithms to solve these types of models.

Electromagnetic eddy current sensors are commonly used to identify and quantify the surface notches of metals. However, the unintentional tilt of eddy current sensors affects results of size profiling, particularly for the depth profiling. In this paper, based on the eddy current thin-skin regime, a revised algorithm has been proposed for the analytical voltage or impedance of a tilted driver–pickup eddy current sensor scanning across a long ideal notch. Considering the resolution of the measurement, the bespoke driver–pickup, also termed as transmitter–receiver (T-R) sensor is designed with a small mean radius of 1 mm. In addition, the T-R sensor is connected to the electromagnetic instrument and controlled by a scanning stage with high spatial travel resolution, with a limit of 0.2 μm and selected as 0.25 mm. Experiments were conducted for imaging of an aluminium sheet with seven machined long notches of different depths using T-R sensor under different tilt angles. By fitting the measured voltage (both real and imaginary part) with proposed analytical algorithms, the depth profiling of notches is less affected by the tilt angle of sensors. From the results, the depth of notches can be retrieved within a deviation of 10% for tilt angles up to 60 degrees.

Micro-transfer printing is a powerful methodology for the manufacturing of 3D heterogeneously integrated micro-systems. This paper explores an active elastomeric composite dense array stamp which improves throughput while enabling local monitoring and control of the process. This dense array stamp is a scalable 4x4 geometry design with a multiplexed interconnection scheme, ensuring a small footprint. It consists of 16 individual stamps, each with a Lead Zirconate Titanate (PZT) actuator and a strain gauge sensor. Actuation and sensing characterization and closed-loop feedback control were established, and the dense array stamp performance was validated using selective pickup and place micro-transfer printing experiments.

Limited available methods for the generation of an elemental image array (EIA) may be the most severe bottleneck for the promotion and application of integral imaging. To obtain rich information of three dimensional (3D) real scene at a relatively low cost, and solve the pseudoscopic problem in real display mode, we propose an EIA generation method based on convergent camera array through establishing the optical mapping model between the proposed method and the classical computer virtual generation method. We expound the basic principle of solving the pseudoscopic problem by changing the relative position of object and center of the convergent camera array in this paper. The experimental results indicate that the generated EIA can be displayed without the pseudoscopic problem in real display mode, relative position relationships of the objects in 3D real scene can also be accurately restored. Both preliminary optical experiments and the optical analysis are conducted to prove the feasibility and validity of the proposed method.

In this paper, we analyze the route efficiency trade-offs that emerge from combining first-mile pickup and last-mile delivery operations in an urban distribution system. We build on the extant literature on continuum approximation of optimal route distances and propose adjustment factors that account for the effects of integrated pickup and delivery operations. By means of comprehensive numerical experiments and regression analysis, we further propose a set of closed-form adjustment factors that improve existing continuum approximation-based route length estimations. These adjustment factors incorporate some non-trivial route efficiency trade-offs emerging from first-mile and last-mile integration that cannot easily be captured through continuum approximation. The proposed extensions are particularly relevant for the optimal strategic design and operational planning of large-scale, high-density last-mile distribution systems that are gaining in importance in light of e-commerce and omni-channel retailing. Our analyses suggest that the efficiency gains emerging from integrating first-mile pickup and last-mile delivery operations can be as high as 30%. However, the effective efficiency gains are sensitive to vehicle capacity constraints and other factors complicating the optimal stop sequence in integrated routes. We apply our proposed method to a real-world case study informed by operational data from one of India’s largest e-commerce platforms for the city of Bengaluru. We find that by properly integrating its first-mile and last-mile operations, the company could reduce its urban traffic and emissions impact by up to 16%, while increasing the asset utilization and reducing the cost of operations of its vehicle fleet.

A self-healing power grid can mitigate the impact of power outages and recover the affected area swiftly. To properly size the optimal amount and location of de-energized loads in the presence of both conventional and renewable sources, a precise optimization-based load recovery tool is proposed in this paper. The steady-state and transient behaviors of loads have been taken into account. The proposed tool contains three separate problems that interact with each other during the restoration period. The first-level problem determines the dispatching of generation units. The second-level problem comprises the non-linear algebraic equations, whose task is to provide the initial conditions for the third-level problem. Finally, the third-level problem intends to determine the optimal location and amount of load pickup through modeling the governor of generators as well as loads’ dynamic behaviors. To examine the effectiveness of the proposed tool, a modified IEEE 39-system under a partial blackout condition has been tested. The results are verified by a commercial time-domain simulation software (PSS/E) to demonstrate the accuracy of the proposed approach. Ultimately, the impact of wind turbine frequency control on the load recovery process has been studied under different penetration levels.

Rate-of-change-of-frequency (ROCOF) relay is commonly used in distributed generation (DG) to detect islanding conditions. According to the field tripping records of an investigated ROCOF relay in a biomass power plant in Ontario, most of the false trips were caused by frequency oscillations. In this paper, the impact of relay parameters on the ROCOF relay nuisance trips caused by frequency oscillation disturbances is investigated. These parameters include the trip level, the measuring time window, the pickup time delay, and the trend of frequency change. The investigation was conducted using the simulation and field recorded data. In addition, the impact of DG parameters and status on the ROCOF relay performance is also studied. Finally, a set of principles is proposed to guide ROCOF relay settings to reduce the nuisance trips from frequency oscillation disturbances.

We present a novel formulation and a matheuristic for a rich humanitarian logistic problem that is motivated by the daily operation of food banks. The problem consists of collecting food donations from suppliers in the food industry and delivering them to food relief agencies that serve individuals in need. This setting requires simultaneous vehicle routing and resource allocation decisions, with the aim of balancing two possibly colliding goals: maximizing the total amount distributed and achieving equity in the allocation. The proposed formulation is based on certain properties satisfied by the optimal solution to the problem and is used within a framework of a broader solution method, which is shown to provide better performance than previously suggested methods. We demonstrate how the new approach can also be extended to the multivehicle counterpart, both with and without time windows.

We present measurements on high-temperature superconducting (HTS) superconducting cables using a NbTi-wound, 3-T dipole ac magnetometer. Our goal is to measure the magnetization properties of the cables for use in accelerator magnet field error calculations. YBCO-wound CORCTM and Roebel cables were measured in pool boiling helium with no epoxy impregnation. The Roebel cable was a 9–5.6 style, while the CORCTM sample had 16 tapes, and was 3.21 mm OD. For measurement, the samples were inserted in a G-10 holder with pickup and compensation coils, and subjected to a ramping dipole field. The signals were read from a set of nanovoltmeters using data aquisition (DAQ) to monitor the pickup coils, and the data were imported into a LabVIEW software program. The Roebel and CORCTM cable measurements were compared to one another and to the tapes they were made with. Maximum cable magnetization was 1000 kA/m for the CORC and 2200 kA/m for the Roebel when normalizing to total cable volume. These values increased to 2860 and 2640 kA/m, respectively, when normalizing to tape volume.

We have developed a new type of magnetometer using a high-critical-temperature superconductor (HTS) coil. This magnetometer consists of pickup and input coils made from HTS tape. The two coils are connected with very low joint resistance, and the signal flux that is collected by the pickup coil is transferred to the input coil. The signal at the input coil is then read out using a newly developed inductance-modulation scheme. The inductance of the input coil is modulated over time using a magnetic wire that is inserted into the input coil, and the magnetic flux is converted into a signal voltage using this time-dependent inductance. It is demonstrated that this magnetometer can measure low-frequency signal fields down to 0.03 Hz without any reduction in responsivity. The noise level was measured to be 0.85 pT/Hz 1/2 at frequencies above 25 Hz and reached 11 pT/Hz 1/2 at 1 Hz when using a pickup coil with 50 turns and an average diameter of 25 mm.

A stable, reliable and well-calibrated beam position monitor (BPM) system is essential for a safe and reproducible operation of accelerators. The BPM system enables the measurement of important machine and beam parameters, such as the Twiss parameters, and helps to avoid damage to accelerator components by high-energy particle beams or radiation. In this paper, we discuss a new BPM calibration scheme tested at the Taiwan Photon Source (TPS). By altering the current in a single horizontal or vertical corrector magnet, we generate an orbit distortion with respect to the nominal reference orbit. The difference orbit is measured by observing the change of the beam position at each BPM pickup location as a function of the corrector current. The analog BPM signals are digitized by analog-to-digital converters (ADC), giving raw, non-calibrated beam position data for each BPM. By comparison of the beam orbit response in terms of raw ADC data from each BPM with the expected beam displacement we can calibrate the beam position monitors. Moreover, because of limited setup time available after a long shutdown, this new procedure acts as a fast, easy way to calibrate the BPM system.

When wirelessly supplying electric power to movable devices using capacitive power transfer (CPT) technology, the sudden move in and move out of the pickup will cause a sudden change to the system structure. As a result, the current and voltage of the inverter may increase dramatically, which may destroy the semiconductor switches or other circuit components, and the system may consume a lot of power after the pickup is removed. To address the issues, this paper proposes an F-type compensated CPT system based on the characteristics of the inductor–capacitor–inductor resonant network. A steady-state model of the proposed CPT system is established, and a set of design equations is provided. The feasibility and validity of the proposed topology and its parameter design method have been verified by the simulation and experimental results. It has demonstrated experimentally that the CPT prototype can be self-protected and automatically enter standby mode after the pickup is removed, and restore to deliver the required power (>25 W) to the load at a high power efficiency (>80%) after the pickup is moved back to the primary circuit, which are the inherent features of the proposed system rather than relying on any additional detection and control.

The current state-of-the-art surgical robotic systems use only a single endoscope to view the surgical field. Research has been conducted to introduce additional cameras to the surgical system, giving rise to new camera angles that cannot be achieved using the endoscope alone. While this additional visualization certainly aids in surgical performance, current systems lack visual-motor compatibility with respect to the additional camera views. We propose a new system that overcomes this limitation. In this paper, we introduce a novel design of an additional “pickup” camera that can be integrated into the da Vinci Surgical System. We also introduce a solution to work comfortably in the various arbitrary views this camera provides by eliminating visual-motor misalignment. This is done by changing the working frame of the surgical instruments to work with respect to the coordinate system at the “pickup” camera instead of the endoscope. Human user trials ( $$N=14$$ ) were conducted to evaluate the effect of visual-motor alignment with respect to the “pickup” camera on surgical performance. An inanimate surgical peg transfer task from the validated Fundamentals of Laparoscopic Surgery (FLS) Training Curriculum was used, and an improvement of 73% in task completion time and 80% in accuracy was observed with the visual-motor alignment over the case without it. Our study shows that there is a requirement to achieve visual-motor alignment when utilizing views from external cameras in current clinical surgical robotics setups. We introduce a complete system that provides additional camera views with visual-motor aligned control. Such a system would be useful in existing surgical procedures and could also impact surgical planning and navigation.

More mobile devices such as mobile phones and robots are wirelessly charged for convenience, simplicity, and safety, and it would be desirable to achieve three-dimensional (3D) wireless charging with high spatial freedom and long range. This paper proposes a 3D wireless charging cube with three orthogonal coils and supporting magnetic cores to enhance the magnetic flux outside the cube. The proposed system is simulated by Ansoft Maxwell and implemented by a downsized prototype. Both simulation and experimental results show that the magnetic cores can strengthen the magnitude of B-field outside the cube. The final prototype demonstrates that the power transfer distance outside the cube for getting the same induced electromotive force in the receiver coil is extended approximately by 50 mm using magnetic cores with a permeability of 2800. It is found that the magnitude of B-field outside the cube can be increased by increasing the width and the permeability of the magnetic cores. The measured results show that when the permeability of the magnetic cores is fixed, the induced electromotive force in the receiver coil at a point 300 mm away from the center of the cube is increased by about 2V when the width of the magnetic cores is increased from 50 to 100 mm. The increase in the induced electromotive force at an extended point implies a greater potential of wireless power transfer capability to the power pickup.

Suppression of beam losses is essential for successful operation of high-intensity linac. Historically, the values of the field amplitudes and phases of the side-coupled, 805-MHz LANSCE linac modules are maintained using a well-known delta-t tuning procedure. Transverse matching of the beam with accelerator is performed through adjustments of beam ellipses in 4D phase space with accelerator lattice using matching quadrupoles. Control of the beam-energy ramp along the length of a proton linear accelerator is required to improve tune of accelerator and decrease beam losses. Time-of-flight measurements of the H − beam energy are now being used to confirm and improve the overall control of the energy ramp along the linac. The time-of-flight method utilizes absolute measurements of beam energy using direct signals from beam at an oscilloscope, as well as the difference in RF phases measured as the beam passes installed delta-t pickup loops. A newly developed BPPM data acquisition system is used. Beam energy measurement along accelerator together with phase scans, klystrons output power control, and delta-t method, allow tuning of accelerator much more close to original design and reduce losses generated by linac. Details of the upgraded tuning procedure and results of tuning and operation are presented.

To reduce the airflow velocity and improve the pneumatic conveying performance of lump coal particle, the pickup process and pickup prediction of lump coal particles with 5–15 mm diameters are firstly studied in this paper. The pickup velocity of lump coal particles were determined by the weight loss method and observed by a high speed camera. The results show that the pickup mechanism, the pickup process, and the variation in the weight loss curve of the lump coal particle are similar to the results of Geldart D particles and Geldart B particles. Notably, two observations are worth highlighting: (1) the pickup of lump coal particles is determined by the critical motion, namely, initial shaking and rolling, which are mainly affected by the disturbance of airflow, the disturbance of particle impact, and the disturbance of unstable-support; and (2) the K & R model has a favorable adaptability to large lump coal particles, and an exponential equation, based on the foundation of the K & R model and taking the dimensionless particle size into account, is employed to predict the pickup velocity of lump coal particles. The prediction deviations agree well with the experimental results.