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Online e-commerce giants are continuously investigating innovative ways to improve their practices in last-mile deliveries. Inspired by the current practices at JD.com (the largest online retailer by revenue in China), we investigate a delivery problem that we call the traveling salesman problem with bike and robot (TSPBR), where a cargo bike is aided by a self-driving robot to deliver parcels to customers in urban areas. We present two mixed-integer linear programming models and describe a set of valid inequalities to strengthen their linear relaxation. We show that these models can yield optimal solutions of TSPBR instances with up to 60 nodes. To efficiently find heuristic solutions, we also present a genetic algorithm based on a dynamic programming recursion that efficiently explores large neighborhoods. We computationally assess this genetic algorithm on instances provided by JD.com and show that high-quality solutions can be found in a few minutes of computing time. Finally, we provide some managerial insights to assess the impact of deploying the bike-and-robot tandem to deliver parcels in the TSPBR setting. [ABSTRACT FROM AUTHOR]

A deeper understanding of the intricate relationship between the two components of the Asian summer monsoon (ASM)—the Indian summer monsoon (ISM) and the East Asian summer monsoon (EASM)—is crucial to improve the subseasonal forecasting of extreme precipitation events. Using an innovative complex network‐based approach, we identify two dominant synchronization pathways between ISM and EASM—a southern mode between the Arabian Sea and southeastern China occurring in June, and a northern mode between the core ISM zone and northern China which peaks in July—and their associated large‐scale atmospheric circulation patterns. Furthermore, we discover that certain phases of the Madden–Julian oscillation and the lower frequency mode of the boreal summer intraseasonal oscillation (BSISO) seem to favour the overall synchronization of extreme rainfall events between ISM and EASM while the higher‐frequency mode of the BSISO is likely to support the shifting between the modes of ISM–EASM connection. [ABSTRACT FROM AUTHOR]

To an extent, large‐scale circulation situations and moisture transport are responsible for extreme precipitation occurrence. The aim of our study is to investigate the possible modifications of circulation patterns (CPs) in driving extreme precipitation over the central‐eastern China (CEC). The self‐organizing map (SOM) and event synchronization methods are used to link the extreme precipitation events with CPs. Results show that 23% of rain gauges have a significant change point (at the 90% confidence level) in annual extreme precipitation from 1960 to 2015. Based on the identified change points, we classified the data into two periods, that is, 1960–1989 and 1990–2015. Overall, CPs characterized by obvious positive anomalies of 500 hPa geopotential height over the Eastern Eurasia continent and negative values over the surrounding oceans are highly synchronized with extreme precipitation events. During 1990–2015, the predominant CPs are more related to the extreme precipitation with enhanced event synchronization. We found that the CP changes produce an increase in extreme precipitation frequency from 1960–1989 to 1990–2015. [ABSTRACT FROM AUTHOR]

Based on the complex network method, this study reveals the temporal and spatial characteristics of the synchronization of extreme rainfall events in southwest China (SWC) during the main rainfall season (May–September). Our results show the significant synchronization pattern of extreme rainfall events in SWC, which is closely associated with the convergence of warm‐wet air and cold‐dry air and the corresponding occurrence of extreme rainfall in SWC. The network divergence indicates a dominated direction of the net influence of extreme rainfall from the Sichuan Basin to the Yunnan–Guizhou Plateau, implying the extreme rainfall synchronization moving from north to south in SWC is more frequent than the opposite direction. The development of the low vortex and the north wind system usually shows a movement from north to south, resulting in the evolution of extreme rainfall events more tend to present a southward movement. The low‐reinforced latitude cyclonic circulation leads to the strengthened transportation of water vapour from the tropical area to the north and converges with the anticyclonic circulation in the mid‐latitudes to form the movement of heavy rainfall events from the Yunnan–Guizhou Plateau to the Sichuan Basin. Therefore, the synchronization direction of extreme rainfall events in SWC has obvious asymmetry spatial feature due to the more frequent and stronger circulation system moving from north to south than the opposite. [ABSTRACT FROM AUTHOR]

Based on the GDP constant 2010 US$ from the World Bank, this paper uses the instantaneous quasi-correlation coefficient to measure the business cycle synchronization linkages among 53 Belt and Road Initiative (BRI) economies from 2000 to 2019, and empirically studies the topological characteristics of the Business Cycle Synchronization Network (BCSN) with the help of complex network analysis method. The main conclusions are as follows: First, the BCSN density and efficiency of BRI economies are still low, and it presents a topological feature of "small world". Second, the individual characteristics of the economies in the network are obviously different. Among them, China's relative influence is significantly increased, but its betweenness centrality level is still low. Third, since the inception of BRI, the topological characteristics of BCSN of BRI economies have undergone great changes, and their topological evolution has gradually reflected the characteristic of self-stability. [ABSTRACT FROM AUTHOR]

• A timetable synchronization problem of high-speed railway and air transportation systems with passenger routing is proposed. • Based on train unit circulation and aircraft rotation plan, the problem is transformed into a multi-commodity flow model. • Some real-world requirements including train overtaking, train headways, flight spacing requirements at airports and seat capacity are considered. • An ADMM decomposition approach on the problem is designed. • A real-world case study (Shijiazhuang-Zhengding Airport in China) with shuttle buses is conducted. The design of synchronized services is of great significance to the development of intermodal transportation. In the planning of Air and High-Speed Railway (HSR) integration services (AHIS), the operators aim to synchronize flight and train schedules and determine the possible transferring options for intermodal passengers. This paper attempts to design an intermodal timetable for train and flight services considering the time-dependent passenger demand. Different transferring modes are further considered in this paper including both shuttle and rapid walking services. The synchronization problem of "train unit flows", "aircraft flows", "shuttle flows" and "passenger flows" is formulated using a multi-commodity flow model in a time–space network. Based on the Lagrangian relaxation method, we first decompose the original problem into four types of routing subproblems associated with train units, aircrafts, shuttle buses and passengers, respectively. Then the coordination of the four different types of flows is achieved through both the pricing mechanism and Alternating Direction Method of Multipliers (ADMM) method. The proposed model and solution approach are validated using both hypothetical and real-world cases and the results show that the synchronized timetables are able to serve more intermodal passengers and shorten their travelling times. [ABSTRACT FROM AUTHOR]

• We analyze the time synchronization performance within the BDS-3 ISL system using real data (one month) • A two-way time synchronization method with error correction models is utilized. • The one-way ranging accuracy of BDS-3 ISLs is consistently better than 7 cm, and the calculated clock-free observables better than 5 cm. • Correcting various errors is crucial for improving synchronization to sub-ns levels. • The overall time synchronization accuracy between satellites achieved is better than 0.4 ns, with most BDS-3 satellites showing comprehensive synchronization accuracy of better than 0.3 ns. • The results verify the effectiveness of the BDS-3 ISL system for high-precision timekeeping. Time synchronization through inter-satellite link (ISL) observations is crucial for enabling autonomous navigation in global navigation satellite systems. This study investigates the time synchronization performance within China's BeiDou Navigation Satellite System (BDS) using ISL measurements from 29 BDS-3 constellation satellites. A dedicated two-way time synchronization method is detailed, emphasizing its uniqueness and precision in ensuring accurate time synchronization. The study also delves into the application of various error corrections, encompassing time delay induced by motion, relativistic effects, and hardware delays. Ranging results show accuracies around 7 cm for one-way ISLs. The impact of error corrections is quantified, with the time delay error caused by motion exhibiting the most significant influence on synchronization accuracy. Using one month of BDS-3 ISL data, time synchronization accuracies better than 0.4 ns are consistently achieved between all satellites after implementing comprehensive error mitigation. The results indicate the robust performance of the BDS-3 ISL system for high-precision timekeeping, supporting autonomous orbit determination and navigation without relying on ground monitoring. These findings demonstrate the effectiveness of using ISLs for GNSS satellites and provide valuable insights for advancing satellite navigation capabilities. [ABSTRACT FROM AUTHOR]

The Comprehensive Research Facility for Fusion Technology (CRAFT), National big science facility in China, is focused on exploring and building key technologies and prototype systems for Chinese Fusion Engineering Test Reactor (CFETR). The toroidal field (TF) coil is one of the most important parts of CRAFT, targeting at manufacturing a prototype TF coil for CFETR. The TF coil is gigantic “D” shape, consists of a winding pack (WP) enclosed in the coil case. The WP is composed of 3 sub-WPs, called low, medium, and high field WPs. Limited by the unit length of the conductor, each sub-WP contains 1–4 subwindings connected by joints. In this article, the layout of the winding line, function, and main features of each unit are introduced, followed by the calculation of the winding trajectory. Based on these results, the detail design of the winding line has been completed, all the winding machines are under manufacturing now. [ABSTRACT FROM AUTHOR]

Air and high-speed rail (AH) integration services are gaining ground with the development of the high-speed railway and airline industries. A well-designed feeder train timetable with good synchronization is of great significance in an AH integration service, because it can improve the connectivity at transfer nodes and offer more opportunities for intermodal passengers to travel. In this study, we propose a multi-objective model of a feeder railway timetable problem in an AH integration service to improve synchronization. The aims of the optimization model are to maximize the number of synchronizations and the coverage of synchronized flights, as well as to minimize the transfer penalties of passengers. We focus on a scenario of a partial subnetwork in which one direction of a two-direction railroad line with one transfer station is considered. The model is applied to Shijiazhuang Zhengding International Airport, China. The results illustrate the effectiveness of the approach developed in the paper. [ABSTRACT FROM AUTHOR]

In view of the problems of the uneven distribution of medical and surgical resources in many areas of China, especially in the Midwest, and the lack of immersion in the operating training platform based on the current virtual reality technology, a single way of interactively surgical platform is proposed to achieve remote guidance and cooperation. The superposition of virtual scene, interaction mode, data collection of patient’s operation, data transmission, and synchronization of virtual scene information are studied and mixed in the reality system. Finally, as an example, the virtual training and guidance is used in a knee arthroscopy to illustrate the remotely cooperative operation by multi persons on the mixed reality equipment. This platform is a new attempt to combine the mixed reality technology, remote cooperative technology and virtual operation training. It makes the doctor convenient and efficient to carry out remote telemedicine training and operation guidance. It will play a very good role in alleviating the shortage of medical and surgical resources in the central and western regions of China. [ABSTRACT FROM AUTHOR]

The synchronization of power generators is an important condition for the proper functioning of a power system, in which the fluctuations in frequency and the phase angle differences between the generators are sufficiently small when subjected to stochastic disturbances. Serious fluctuations can prompt desynchronization, which may lead to widespread power outages. Here, we model the stochastic disturbance by a Brownian motion process in the linearized system of the non-linear power systems and characterize the fluctuations by the variances of the frequency and the phase angle differences in the invariant probability distribution. We propose a method to calculate the variances of the frequency and the phase angle differences. For the system with uniform disturbance-damping ratio, we derive explicit formulas for the variance matrices of the frequency and the phase angle differences. It is shown that the fluctuation of the frequency at a node depends on the disturbance-damping ratio and the inertia at this node only, and the fluctuations of the phase angle differences in the lines are independent of the inertia. In particular, the synchronization stability is related to the cycle space of the network. We reveal the influences of constructing new lines and increasing capacities of lines on the fluctuations in the phase angle differences in the existing lines. The results are illustrated for the transmission system of Shandong Province of China. For the system with non-uniform disturbance-damping ratio, we further obtain bounds of the variance matrices. [ABSTRACT FROM AUTHOR]

The Sunflower Movement that took place in Taiwan in spring 2014 has been an epochal event for Taiwan, China, and East Asia. Many critics identified China as the most important factor for triggering the movement, while others emphasized the internal contradictions of economy, politics, and culture within Taiwan as reasons for its outburst. Although the Sunflower Movement has been treated as Taiwanese resistance to political and economic integration with China under the framework of free trade and the World Trade Organization, few have considered the discourses of neoliberalism surrounding and instigating it as the conditions of subjectivity in which Taiwanese youth apprehend their place and future. In the Sunflower Movement, neoliberalism is prominently associated with worries about the future, where college students on the verge of entering the job market feel ambivalent about their career prospects and life choices. These young people feel a sharp sense of deprivation and a strong anxiety about Chinese competition. How do we theorize such anxieties about the future in relation to neoliberalism as a structure of feeling, and such anxious subjects, in relation to Taiwan’s status? This article addresses these issues by conceptualizing the Sunflower Movement as an affective-political outburst of discontents that sits uncomfortably with the future of neoliberal globalization as the ontology of being. [ABSTRACT FROM AUTHOR]

This study investigated the effects of international anti-dumping events on the stock prices of the photovoltaic (PV) sector using sample data from China. Nine international anti-dumping events were tested using the event study methodology, and we found that most of them had significant impact on the stock returns of PV companies. Then, we chose a threshold value to construct stock networks for the different phases of the event development. We studied the changes in the scale and strength of the stock price synchronization, the evolution of the stock price co-movement and the stability of the co-movement between adjacent stocks by analyzing the changes in the topological structure of the stock networks. We found that the international anti-dumping events had different effects on the evolution of the synchronization and co-movement of the prices of Chinese PV stocks. In addition, the stock market of the PV sector exhibits high sensitivity to certain events. This study provides a novel approach that combines the event study methodology and stock-network analysis to help us to better understand the effects of anti-dumping on the PV stocks. [ABSTRACT FROM AUTHOR]

Synchronization is an important current frontier area of nonlinear sciences. In order to explore the spatio-temporal evolution of ore-forming elements in complex system at mesoscale, the principles, promises, methods and procedures of a spatio-temporal synchronization method were defined. Based on the phase conversion equation, the phase data and the phase difference were calculated in two directions, and the phase difference constant was set as 0.1 as a critical value to extract the plateau length in two directions. After the plateau length in both directions was superimposed, we got the synchronization threshold. Through its spatio-temporal extension, the synchronized space-time domain was determined. Then, we utilized geostatistics and Kriging method to generate the map of synchronized space-time domain, which includes ore formation, time and space. Applying the developed method and using local stream sediment geochemical data in Dajishan tungsten deposit (China), we have carried out the research on the synchronization of pairwise matching elements between ore-forming and ore-transporting elements in two directions at mesoscale, besides pairwise matching elements between ore-forming elements. Results indicate that the mineralization time-space domains of W, Sn, Mo, Bi, Cu, Pb, Zn, Au, Ag, and Be elements in the study area and their isoconcentration contours show a good coincident correspondence. For pairwise matching elements of ore-forming element matching with ore-transporting element, the high synchronization threshold area appears on the edge of the element mineralization center in the map of space-time domain for synchronization (or mineralization), which reveals the onset of ore formation; For pairwise matching elements between ore-forming elements, it reveals the mechanism of ore formation. Furthermore, this theory and method can be also applied to other fields of geochemistry, such as environmental geochemistry. • A method of spatiotemporal synchronization at mesoscale ore-forming system is proposed. • A method of superposition of synchronization values in two directions is adopted. • This work specifically discussed the synchronization between ore-forming elements. [ABSTRACT FROM AUTHOR]

In November 2012, an experiment demonstrating biological mimicry method for covert underwater acoustic communication (UAC) was conducted at Lianhua Lake in Heilongjiang China. Dolphin whistles were used for synchronization while dolphin clicks were used as information carrier. The time interval between dolphin clicks conveys the information bits. Channel estimates were obtained with matching pursuit (MP) algorithm, which is useful for sparse channel estimation. Adaptive RAKE Equalization was employed at the receiver. Bit error rates were less than 10-4 with 37 bits per second data rate in the lake trial. [ABSTRACT FROM AUTHOR]

Abstract: High-precision time synchronization between satellites and ground stations plays the vital role in satellite navigation system. Laser time transfer (LTT) technology is widely recognized as the highest accuracy way to achieve time synchronization derived from satellite laser ranging (SLR) technology. Onboard LTT payload has been designed and developed by Shanghai Astronomical Observatory, and successfully applied to Chinese Beidou navigation satellites. By using the SLR system, with strictly controlling laser firing time and developing LTT data processing system on ground, the high precise onboard laser time transfer experiment has been first performed for satellite navigation system in the world. The clock difference and relative frequency difference between the ground hydrogen maser and space rubidium clocks have been obtained, with the precision of approximately 300ps and relative frequency stability of 10E−14. This article describes the development of onboard LTT payload, introduces the principle, system composition, applications and LTT measuring results for Chinese satellite navigation system. [Copyright &y& Elsevier]

Abstract: The distributed timing and synchronization system (DTSS) plays an important role in Experimental Advanced Superconducting Tokamak (EAST), which is one of the national key fusion research facilities in China. This system synchronizes each subsystem of EAST by using reference clock and trigger. A prototype DTSS module has been developed based on PXI bus and RIO (reconfigurable I/O) devices. The DTSS can provide reference clock in frequency up to 80MHz. The trigger can be pre-defined from 1ms to 6872s with 10ns accuracy. In addition, this system can acquire, process signals, and send output or command to other systems. The DTSS has been successfully applied to 2010 fall EAST experiment, and the results confirmed its accuracy and reliability. After the analysis of system requirement, the architecture of the DTSS and the technical implementation based on PXI are presented in this paper. [Copyright &y& Elsevier]

Calibration systems with digital output are used to replace conventional calibration systems because of principle diversity and characteristics of digital output of electronic transformers. But precision and unpredictable stability limit their onsite application even development. So fully considering the factors influencing accuracy of calibration system and employing simple but reliable structure, an all-digital calibration system with digital output is proposed in this paper. In complicated calibration environments, precision and dynamic range are guaranteed by A/D converter with 24-bit resolution, synchronization error limit is nanosecond by using the novelty synchronization method. In addition, an error correction algorithm based on the differential method by using two-order Hanning convolution window has good inhibition of frequency fluctuation and inter-harmonics interference. To verify the effectiveness, error calibration was carried out in the State Grid Electric Power Research Institute of China and results show that the proposed system can reach the precision class up to 0.05. Actual onsite calibration shows that the system has high accuracy, and is easy to operate with satisfactory stability. [ABSTRACT FROM AUTHOR]

Synchronization is an important frontier in contemporary nonlinear science. It has been developed and applied widely in the late 20th century. However, it has limited applications in geological science, especially in the study of mineralization. The ore formation of fluids is a problem of propagation of chemical waves and the generation of their spatiotemporal structures. Geological processes and spatiotemporal structures are the essence and core of all geological phenomena. Taking these ideas as guides, giving a new definition for 'phase' in geochemical dynamics, and selecting the concentration data of 10 elements from stream-sediment samples on a 1: 50 000 scale, this article applies the synchronization theory to the study of the distribution of tungsten-polymetallic mineralization in the Qianlishan (千里山)-Qitianling (骑田岭) area in southern Hunan (湖南) which is one of the most important metallogenetic districts in the Nanling (南岭) region. The results show that there are large ore deposits in Shizhuyuan (柿竹园), Huangshaping (黄沙坪), Xianghualing (香花岭), Qitianling, and other areas, which verifies the present distribution of mineral resources in southern Hunan. Moreover, this article holds that the spatiotemporal synchronization of chemical waves plays an important role in the science of metallogenesis: it leads to the regional ore zoning centered at Qitianling, confirms that the Yanshan epoch is the chief ore-forming epoch in southern Hunan, and predicts other prospective areas of specific ores. [ABSTRACT FROM AUTHOR]

The ARGO-YBJ experiment has been in stable data taking since November 2007 at the YangBaJing Cosmic Ray Laboratory (Tibet, China, 4300 m a.s.l.). Its main fields of research are \gamma-astronomy with an energy threshold of a few hundred GeV and cosmic ray physics in the 1\div 1000~TeV energy range. The ARGO-YBJ detector consists of a single layer of RPCs operated in streamer mode, housed in a large building of about 11\thinspace000~m^2). Signals from each RPC are picked up with 80 readout strips 61.8 cm wide and 6.75 cm long (23~strips/m^2) that allow the shower front reconstruction with a high space-time resolution. In order to fully investigate the PeV region, where the previous (digital) readout saturates, an analog one has been implemented by instrumenting each RPC with two large size electrodes of dimension 1.39 \times 1.23~m^2. The 130 Clusters of the central carpet have been instrumented with the charge readout hardware and software since November 2009. In this paper we describe the hardware solution that implements the real-time charge readout in the ARGO-YBJ experiment, paying a special attention to the synchronization with the central data acquisition system, which is also described. [ABSTRACT FROM AUTHOR]

A new harmonic power standard has been developed at the National Institute of Metrology (NIM), Beijing, China, for the calibration of harmonic power analyzers under nonsinusoidal conditions at fundamental frequencies of 50 and 60 Hz. The standard is based on digital sampling techniques that do not require synchronization. A compensation algorithm is presented in this paper. A new definition of the uncertainty for harmonic measurement is proposed that is referred to the fundamental. A characterization signal and its application are introduced. Results have shown that over its operating range of up to 50 A, 500 V, and the sixtieth-order harmonic, the harmonic power standard has uncertainties (k = 2) of less than 30 μV/V, 36 μA/A, and 42 μW/VA for voltage, current, and power measurements, respectively. [ABSTRACT FROM AUTHOR]

Digital terrestrial multimedia/television broadcasting (DTMB), which is the recently released Chinese digital television terrestrial broadcasting (DTTB) standard, uses guard intervals padded with known pseudo-noise (PN) sequences for multi-carrier or single-carrier block transmission. Well designed synchronization algorithms are a prerequisite for achieving high-quality multimedia transmission. In this paper, a novel frame synchronization technique, which is robust to carrier frequency offset (CFO), is proposed for DTMB systems. This technique is derived through segmenting the local PN sequence into M contiguous blocks and performing multiple cross-correlations with the received signal. The metric for peak detection is defined as the non-coherent summation of the M cross-correlation magnitude outputs. Moreover, a low-complexity frame synchronizer based on segment-based full correlation for PN420 mode in DTMB system is proposed. It is shown through computer simulation that the proposed techniques generally outperform the conventional ones when CFO occurs, over both AWGN and frequency-selective fading channels. For a DTMB system using PN420 mode, the maximal allowed CFO to keep system still working normally of our proposed schemes are more than 3 times larger than that of the conventional method. [ABSTRACT FROM AUTHOR]

This essay examines the theme of monuments and monumentality in Hong Kong by focusing on the proliferation of images of the Star Ferry terminal and clocktower prior to its demolition and the circulation of these images via on-line image-sharing sites. I am especially interested in the act of photography under these circumstances and what it might mean for a consideration of participatory democracy in a postcolonial context. More generally there is the question of what role the image plays in constituting historical memory in an embodied sense - especially in a city that is characterized in many ways as image. My essay examines the extent to which historical memory of colonial experiences is still in part materially constitutive of Hong Kong's postcolonial consciousness - and this is registered in community activism around the preservation of sites marked for demolition. What this activism produces is what I will call a spectral monumentality, a bringing into existence of invisible monuments - in this case, the memories of demolished structures which survive in an embodied form, supported by miniature images in the digital photographs uploaded and shared on internet sites, and small, publicly available documentary movies posted on YouTube. To think in greater detail about the meaning of the 'spectral monument', I draw upon Wu Hung's discussion of 'political space', not simply as a conceptual sphere of public discourse or a physical space where public events occur, but rather as the architectonic embodiment of political ideology and a site for activating political action and expression. [ABSTRACT FROM AUTHOR]

Describes timing and synchronization considerations in the development of the third generation high-definition television encoder in China. Design of timing stamps; Characteristics of the timing and synchronization system; Experimental result.

Abstract: X-ray sources based on Thomson-scattering require strict synchronization between the laser pulse and the electron bunch. Jitter between the laser and the RF phase should be kept within a femtosecond scale to guarantee electron beam quality and the time of flight before impact with the terawatt laser pulse. A laser–RF synchronizer that uses the 36th harmonic of the laser repetition rate was built at Tsinghua University, and it has tested to have a less than 100-fs [10-Hz, 100-kHz] rms time jitter. An RF deflector cavity is used to verify the electron bunch pulse-to-pulse time jitter with respect to the RF accelerating phase in the same condition, and the result shows a 540-fs rms jitter. This paper discusses the synchronization experiment setup, as well as the time jitter measurements under different conditions. [Copyright &y& Elsevier]