Dispatch Center Research Articles

Private vehicle-based crowdshipping for intercity express transportation: Feasibility assessment

To support urban sustainable development, cities need innovative green logistics solutions to meet the needs of economic development. Crowdshipping is regarded as a promising sustainable freight solution. This article aims to assess the feasibility of implementing intercity express crowdshipping using private vehicle traveling. The crowdshipping carrier, who drives his or her private vehicle and travels on the intercity route, carries out the express delivery task between the regional cargo center and the dispatch center along the route. The feasibility assessment covers three parts. First, face-to-face interview and stated preference survey are used to investigate the willingness and preferences of express companies and car owners to participate in crowdshipping activities, respectively. Then, it calculates the environmental benefit and economic benefit brought by the crowdshipping mode in comparison with the traditional mode. The results show that the express companies are willing to pay 30 yuan for each car participating in the crowdshipping activities, and there are considerable numbers of car owners to support this crowdshipping activity, and this crowdshipping activity could bring positive impacts on environment as well as corporate economics. It is hoped that the research could enrich the knowledge of the development of green logistics.

The architecture and key technology of fault inversion systemfor Hybrid UHV AC/DC power system

The architecture and key technology of fault inversion system for Hybrid UHV AC/DC power system are introduced in this paper. The complete and accurate fault inversion model of power grid is formed by integrating the off-line model of Power System Data Base(PSDB) with the real-time online model of Smart Grid Dispatching and Control System(D5000). This model not only solves the problem that the real-time online model lacks transient parameter, but also overcomes the difficulty that the off-line model cannot reflect the real-time operation condition of the power grid, Therefore, this model meets the requirements of timeliness and accuracy of fault inversion calculation. Based on this model, the simulation calculation and analysis of power grid are carried out, and the changes of electricity volume in the process of power grid fault are simulated accurately. The system has been installed successfully and put into use in the simulation centre of the State Grid. The fault inversion analysis is carried out for State Grid Dispatch Centre and East China power grid. Besides, the scientific validity of the proposed scheme is verified.

Hierarchically-Coordinated Voltage/VAR Control of Distribution Networks Using PV Inverters

Photovoltaic (PV) inverters can provide fast and flexible reactive power support for voltage regulation and power loss reduction in distribution networks. Conventionally, central and local voltage/VAR control (VVC) strategies are separately determined, lacking a cross-hierarchy coordination. This paper proposes a novel hierarchically-coordinated VVC (HC-VVC) method where central hierarchy dispatches the inverter reactive power output to minimize network power loss and local hierarchy responds to real-time voltage deviation through a linear droop controller. The proposed method simultaneously optimizes inverter reactive power output setpoints for the central dispatch and droop functions for the local control so that the two control hierarchies are optimally coordinated under stochastic PV power generation and load variations. The coordination model is solved by a scenario-based stochastic optimization approach with probabilistic uncertainty modeling where real-time variations of the uncertainties are fully addressed. Simulation results show that, compared with existing methods, the proposed HC-VVC method is overall superior in minimizing power loss and voltage deviation.

Wind power integration and emission reduction via coal power retrofits in China's quota-based dispatch system: a case study of Jilin Province.

As China expands the renewable share in its power system, coal power is regulated to balance load by adjusting output to meet system demand at all times. In 2016, the Chinese government required existing coal fleets to conduct flexibility retrofits to accommodate more renewable power. We conduct this study to evaluate how coal power retrofits could affect wind integration and emissions at a system level. By constructing a balancing model that respects China's unique quota-based dispatch rules, we use real data from provincial dispatch center of Jilin Province to compare wind power integration and system emissions before and after coal power retrofits. We find that coal power retrofits can significantly reduce wind curtailment from 31 to 7% in our base simulation model. However, emission reductions achieved from coal power retrofits are subject to diminishing marginal returns. We suggest policy efforts to proceed with the strategy of coal power retrofits but carefully evaluate both economic and environmental costs associated with different technologies to reduce pollution and implement from the least expensive ones.

Improving telephone CPR time interval at Hamad Medical Corporation Ambulance Service

Background: Hamad Medical Corporation Ambulance Service (HMCAS) Emergency Medical Dispatch Center uses protocols and processes ensuring early recognition and early telephone CPR (T-CPR) for Sudden Cardiac Arrest (SCA) reported by the public through 999 emergency lines. An audit of random sampling cases indicated that the average time to start bystander hands-on CPR varies from 5 to 7 minutes. Consequently, a quality improvement plan was designed and launched in the Emergency Dispatch Center of HMCAS for the aim of improving the average time interval from when the call is answered by an Emergency Medical Dispatcher until the caller starts hands-on CPR. The project aimed to improve the average telephone-CPR time initiation from 5 minutes in January 2018 to 3 minutes by July 2019. Methods: We adopted the American Heart Association Telephone Cardiopulmonary Resuscitation Time standards and performance benchmarks. A cardiac registry was implemented, audio recordings of confirmed Out of Hospital Cardiac Arrests (OHCA) received at 999 Emergency Dispatch Center were reviewed using a standardized time-stamp methodology linked with the Ambulance Service outcome data. All call takers went through training and continuous measurement of their performance levels with timely feedback. Results: Out of 214,220 received emergency calls in 2018 a total of 697 OHCA cases were audited, 332 cases received T-CPR, 231 cases met the criteria for inclusion. By July 2019, there was a reduction in Average telephone-CPR time interval from 5:38 minutes to 3:33 minutes (). Conclusion: The implementation of T-CPR time standards and staff training was associated with improvements in the provision and timeliness of T-CPR.

Optimal escort dispatch for airport travelers with reduced mobility

An important component of airport landside operations involves providing assistance to passengers with reduced mobility. These operations are typically managed by third-party contractors, which leverage a team of escorts and a set of wheelchairs to provide mobility assistance services. The performance of these systems relies critically on the dispatch of escorts and wheelchairs to serve each traveler request. Sub-optimal dispatch can lead to negative individual and system-wide implications, such as long passenger wait times, customer dissatisfaction or added delays in flight departures. This paper reports the outcomes of a collaboration with the Pittsburgh International Airport that involved three steps. First, the collection and digitization of data provided visibility into demand for mobility assistance services and historical performance of the system. Second, we propose an original integer programming model to optimize and support the assignment of escorts to traveler requests, and we develop an efficient solution approach based on a rolling algorithm to enable the implementation of the model with realistic problem sizes. We verify that the model’s outputs are consistent with insights obtained from the historical records of operations, and identify opportunities to enhance the level of service without increasing system capacity. In particular, the results suggest that improvements in information flows and in communication between airlines, the central dispatcher and passenger escorts can result in significant dispatch improvements. Third, we leveraged these insights by developing a tablet application to provide real-time visibility into traveler requests, dispatch recommendations, and data visualizations for continued performance assessment and enhancement.

Emergency medical dispatch services across Pan-Asian countries: a web-based survey

BackgroundDispatch services (DS’s) form an integral part of emergency medical service (EMS) systems. The role of a dispatcher has also evolved into a crucial link in patient care delivery, particularly in dispatcher assisted cardio-pulmonary resuscitation (DACPR) during out-of-hospital cardiac arrest (OHCA). Yet, there has been a paucity of research into the emerging area of dispatch science in Asia. This paper compares the characteristics of DS’s, and state of implementation of DACPR within the Pan-Asian Resuscitation Outcomes (PAROS) network.MethodsA cross-sectional descriptive survey addressing population characteristics, DS structures and levels of service, state of DACPR implementation (including protocols and quality improvement programs) among PAROS DS’s.Results9 DS’s responded, representing a total of 23 dispatch centres from 9 countries that serve over 80 million people. Most PAROS DS’s operate a tiered dispatch response, have implemented medical oversight, and tend to be staffed by dispatchers with a predominantly medical background. Almost all PAROS DS’s have begun tracking key EMS indicators. 77.8% (n = 7) of PAROS DS’s have introduced DACPR. Of the DS’s that have rolled out DACPR, 71.4% (n = 5) provided instructions in over one language. All DS’s that implemented DACPR and provided feedback to dispatchers offered feedback on missed OHCA recognition. The majority of DS’s (83.3%; n = 5) that offered DACPR and provided feedback to dispatchers also implemented corrective feedback, while 66.7% (n = 4) offered positive feedback. Compression-only CPR was the standard instruction for PAROS DS’s. OHCA recognition sensitivity varied widely in PAROS DS’s, ranging from 32.6% (95% CI: 29.9–35.5%) to 79.2% (95% CI: 72.9–84.4%). Median time to first compression ranged from 120 s to 220 s.ConclusionsWe found notable variations in characteristics and state of DACPR implementation between PAROS DS’s. These findings will lay the groundwork for future DS and DACPR studies in the PAROS network.

Intelligent decision - making support on the level of encryption of information transmitted in the UMV information exchange channels

The paper considers the solution of the interdisciplinary fundamental scientific problem of ensuring the reliability and high throughput of information exchange channels (IEX) between unmanned vehicles (UMV) located in different environments and dispatch centers (DC) of the “smart city”. The solution of the management problem of providing a reliable and high-bandwidth IEX between UMV and DC in different environments requires the development of an intelligent decision support system to select the level of encryption of information transmitted over open communication channels, under conditions of uncertainty.

Research on Block-Chain-Based Intelligent Transaction and Collaborative Scheduling Strategies for Large Grid

In view of the problems of large-grid-level centralized transactions and dispatch centers with information asymmetry and high processing costs, a completely decentralized transaction architecture and a weak centralized scheduling strategy based on block-chain are proposed. Firstly, the concepts of transaction decentralization and scheduling decentralization are defined, and the reliability of distributed transaction communication is studied. Built a blockchain transaction risk control model based on the communication credit consensus mechanism. Secondly, under the weakly centralized scheduling architecture based on the autonomous chain of substations, security checks are performed, and temporary central nodes are set up to perform scheduling tasks. Finally, an improved evolutionary game algorithm is used to solve the above model, and the optimal solution is obtained by dynamically updating the credibility.

A Linear Integer Programming Model for Fault Diagnosis in Active Distribution Systems With Bi-Directional Fault Monitoring Devices Installed

With the extensive installation of intelligent electronic devices with bi-directional fault monitoring capabilities, richer fault direction information can be collected and utilized to achieve an accurate fault diagnosis. In this paper, we consider the fault diagnosis problem in active distribution systems with distributed generators connected, such as rotating electrical machine power sources and centralized inverter interfaced renewable energy resources. The fault diagnosis problem is modeled as a linear integer programming problem with an objective to minimize the numbers of fault zones and false alarms. A novel functional form is derived to capture the expected alarms sent by bi-directional fault monitoring devices to be compared with the actual alarms received by the dispatch center. Uncertainties in both the monitoring and communication stages are considered in the model by formulating the numbers of false alarms in the objective function. Three types of suspected false alarms can be detected: “missing alarms”, “distorted alarms”, and “reverse alarms”. By solving the developed optimization model for fault diagnosis, false alarms and suspected fault zones can be found. Case studies in a modified IEEE 33-bus system and a 55-bus system in Guangzhou, China are carried out in several different scenarios with multiple faults to demonstrate the performance of the proposed model. Numerical tests show that the proposed approach is superior in computational time such that it can be used for real-time fault diagnosis in active distribution systems.

Importance of "Telephone Cardiopulmonary Resuscitation" in out-of-Hospital Cardiac Arrest in India.

Background:Out-of-hospital cardiac arrest (OHCA) is a major cause of mortality in developing countries such as India. Most cardiac arrests happen outside the hospital and are associated with poor survival rates due to delay in recognition and in performing early cardiopulmonary resuscitation (CPR). Community CPR training and telephone CPR (T-CPR) in the dispatch centers have been shown to increase bystander CPR rates and survival.Objectives:The aim of this study is to identify the significance of T-CPR in OHCA and to discuss its implementation in the health system to improve OHCA outcomes in India.Materials and Methods:A descriptive research study methodology was adopted following a literature search.Results:The search criterion “Cardiovascular diseases” resulted in 162, “Out-side hospital cardiac arrest” in 50; For a comprehensive overview, these publications were evaluated looking for data on T-CPR incidence, criteria for detecting OHCA by emergency medical dispatchers, sensitivity and specificity, and BCPR.Conclusion:This current research stresses the scale and seriousness of the implementation of T-CPR in OHCA in India.

Non-Iterative estimation of the AC overhead line state by relinearization method

Information about the current mode of the electric power system (EPS) is received by the dispatch control centers in the form of telemetry and tele-signals by the SCADA complexes, and from phasor measurement units (PMU) devices. Tele-measurements include information about the mode parameters, and the state of the switching equipment. Since the system of equation of state is nonlinear, the problem of state estimation is traditionally solved using iterative methods. This article presents the results of solving the state estimation problem using a method based on the Kipnis-Shamir re-linearization method, which allows solving it by non-iterative method. The results of the solution are given on the example of a power transmission line with 500 kV voltage.

Distributed energy management of integrated electricity-thermal systems for high-speed railway traction grids and stations

This paper proposes an integrated electricity-thermal energy management system (EMS) for high-speed railways. First, an operational model is built for the integrated electricity-thermal system, including a train operation EMS (TO-EMS) model and station operation EMS (SO-EMS) model. In the TO-EMS model, traction grids (TGs) are formulated with a solvable second-order cone programming problem. In the SO-EMS model, station indoor thermal systems are taken into account, and the building heat exchange process and solar radiation influence upon station indoor temperature are also included. Then the TO-EMS and the SO-EMS are coordinated with an alternating direction method of the multipliers-based (ADMM-based) algorithm, protecting the privacy and interests both for the train dispatch center and stations. To demonstrate the effectiveness of the proposed railway EMS, a modified realistic high-speed railway segment with six stations in North China with summer and winter scenarios is studied.

2019 American Heart Association Focused Update on Pediatric Basic Life Support: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.

This 2019 focused update to the American Heart Association pediatric basic life support guidelines follows the 2019 systematic review of the effects of dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) on survival of infants and children with out-of-hospital cardiac arrest. This systematic review and the primary studies identified were analyzed by the Pediatric Task Force of the International Liaison Committee on Resuscitation. It aligns with the International Liaison Committee on Resuscitation's continuous evidence review process, with updates published when the International Liaison Committee on Resuscitation completes a literature review based on new published evidence. This update summarizes the available pediatric evidence supporting DA-CPR and provides treatment recommendations for DA-CPR for pediatric out-of-hospital cardiac arrest. Four new pediatric studies were reviewed. A systematic review of this data identified the association of a significant improvement in the rates of bystander CPR and in survival 1 month after cardiac arrest with DA-CPR. The writing group recommends that emergency medical dispatch centers offer DA-CPR for presumed pediatric cardiac arrest, especially when no bystander CPR is in progress. No recommendation could be made for or against DA-CPR instructions when bystander CPR is already in progress.

Application of natural language understanding in Chinese power dispatching centre

It is difficult for computer to understand the texts in unstructured Chinese language, which becomes an obstacle for further application of artificial intelligence in the power dispatch center. Understanding of the orders from human dispatchers is the premise for the collaboration of machine and human being in power system operation. Towards understanding of dispatching texts, this paper proposes a textual semantic analysis framework with active learning of the semantic structure knowledge. Firstly, the words are vectorized by the Skip-gram models. And the hierarchical clustering algorithm is designed to detect the sentence patterns. Then the knowledge base is set up by converting the sentence structure to their regular expressions. In application, define a proprietary semantic framework to extract important device information and to parse the semantic slot using dependency syntax. Application shows that the Chinese texts describing the operation mode switching process can be understood accurately by the computer program.

A new class of polyphase pseudo-random sequences with a nonlinear generation algorithm for secure radio communication link between unmanned vehicles and dispatch centers of the "smart city"

The article discusses an algorithm for generating a new class of polyphase pseudo-random sequences with a nonlinear generation algorithm for use in secure communication systems with spread spectrum technology. In particular, the proposed sequences are relevant to use for generating signals in a secure command radio link between unmanned vehicles located in different environments, and dispatch centers of the "smart city". An analysis of the existing ensembles and an assessment of their main characteristics are carried out. Namely, the size of the ensemble, which affects the security of the communication system, and the level of maximum emissions of the cross-correlation function. The existing ensembles of polyphase pseudo-random sequences do not simultaneously have satisfactory values of the considered indicators. Therefore, an urgent task is to develop an ensemble that finds a compromise between these two characteristics and has a nonlinear generation algorithm. The essence of the algorithm for the formation of the proposed new class of polyphase pseudo-random sequences is to expand the classical polyphase sequences, for example, Frank, Chu, or Milewski, which have good correlation properties, de Bruijn sequences with a large ensemble and a nonlinear formation algorithm. Comparative analysis of the proposed method for forming a class of polyphase sequences shows the advantage of its use. In particular, an improvement in cross-correlation characteristics and a significant increase in the size of the ensemble of new sequences compared to the original sequences are shown. These properties can be used to increase the structural secrecy of command radio links.

ON APPLICATION OF PIPES FROM POLYMER MATERIALS FOR FIELD PIPELINES

According to the Federal State Budgetary Institution «Central Dispatch Office of the Fuel and Energy Complex» for 2018, in Russia 92 % of incidents and accidents with oil spills occurred due to corrosion. At the same time, about 45 % of pipelines are operated in aggressive soils, 30 % - in slightly aggressive environments, and only 10 % do not need active anti-corrosion protection. According to Rostechnadzor, the total length of the field pipelines reaches 300 thousand km. At the same time, the deterioration of the main stock of production pipes reaches 70 %. Since the most used material for the construction of pipelines is steel, the main problem in the transportation of hydrocarbons is external and internal corrosion of pipelines. In this regard, one of the key points is the replacement of metal pipelines with reinforced polymer pipes that combine corrosion resistance, low moisture absorption, and high dielectric performance. The aim of this work is to analyze the use of pipes made of polymeric materials for field pipelines used to transport hydrocarbons in Russia and abroad. Tasks: - analysis of the operating experience of reinforced polyethylene pipes used for the transportation of hydrocarbons in Russia and abroad; - consideration of the main problems arising during the operation of composite pipelines; - comparison of the characteristics of pipes used in different countries. In the course of the study, the regulatory documents on foreign and domestic polymer pipelines were studied and a generalized analysis of these pipes was carried out. The problems faced by the oil and gas industry in the transportation of hydrocarbons are identified. The history of Western and domestic use of polymer pipelines is considered, on the basis of which the relevance of the use of composite pipelines based on polyethylene is substantiated.

Load Balancing Guardrails

Load balancing systems, comprising a central dispatcher and a scheduling policy at each server, are widely used in practice, and their response time has been extensively studied in the theoretical literature. While much is known about the scenario where the scheduling at the servers is First-Come-First-Served (FCFS), to minimize mean response time we must use Shortest-Remaining- Processing-Time (SRPT) scheduling at the servers. Much less is known about dispatching polices when SRPT scheduling is used. Unfortunately, traditional dispatching policies that are used in practice in systems with FCFS servers often have poor performance in systems with SRPT servers. In this paper, we devise a simple fix that can be applied to any dispatching policy. This fix, called guardrails, ensures that the dispatching policy yields optimal mean response time under heavy traffic when used in a system with SRPT servers. Any dispatching policy, when augmented with guardrails, becomes heavy-traffic optimal. Our results yield the first analytical bounds on mean response time for load balancing systems with SRPT scheduling at the servers.

A validation of machine learning-based risk scores in the prehospital setting.

The triage of patients in prehospital care is a difficult task, and improved risk assessment tools are needed both at the dispatch center and on the ambulance to differentiate between low- and high-risk patients. This study validates a machine learning-based approach to generating risk scores based on hospital outcomes using routinely collected prehospital data. Dispatch, ambulance, and hospital data were collected in one Swedish region from 2016-2017. Dispatch center and ambulance records were used to develop gradient boosting models predicting hospital admission, critical care (defined as admission to an intensive care unit or in-hospital mortality), and two-day mortality. Composite risk scores were generated based on the models and compared to National Early Warning Scores (NEWS) and actual dispatched priorities in a prospectively gathered dataset from 2018. A total of 38203 patients were included from 2016-2018. Concordance indexes (or areas under the receiver operating characteristics curve) for dispatched priorities ranged from 0.51-0.66, while those for NEWS ranged from 0.66-0.85. Concordance ranged from 0.70-0.79 for risk scores based only on dispatch data, and 0.79-0.89 for risk scores including ambulance data. Dispatch data-based risk scores consistently outperformed dispatched priorities in predicting hospital outcomes, while models including ambulance data also consistently outperformed NEWS. Model performance in the prospective test dataset was similar to that found using cross-validation, and calibration was comparable to that of NEWS. Machine learning-based risk scores outperformed a widely-used rule-based triage algorithm and human prioritization decisions in predicting hospital outcomes. Performance was robust in a prospectively gathered dataset, and scores demonstrated adequate calibration. Future research should explore the robustness of these methods when applied to other settings, establish appropriate outcome measures for use in determining the need for prehospital care, and investigate the clinical impact of interventions based on these methods.

Comparison of the effects of audio-instructed and video-instructed dispatcher-assisted cardiopulmonary resuscitation on resuscitation outcomes after out-of-hospital cardiac arrest

BackgroundThis study compared the real-world effects of audio-instructed dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) and video-instructed DA-CPR on resuscitation outcomes after out-of-hospital cardiac arrest (OHCA). MethodsA retrospective cohort study was conducted among adult OHCA patients in whom resuscitation was attempted in 2017 in Seoul, Korea. The dispatch center of Seoul introduced video-instructed DA-CPR in 2017, whereas audio-instructed DA-CPR was first implemented in 2010. When more than two bystanders were at the scene and could handle a video-call, the dispatcher call back a video-call and provided CPR instructions. In other situations, standard audio-instructed DA-CPR was provided. The primary outcome was survival to discharge. The secondary outcome was good neurological outcome at hospital discharge. The tertiary outcome was early instruction time interval (ITI, time from call to the initiation of CPR instruction ≤90 s). The study outcomes of audio-instructed DA-CPR (audio group) and video-instructed DA-CPR (video group) were compared. The propensity score matching (PSM) method was used to increase the comparability of the two groups and the logistic regression was performed for the PSM cohort. ResultsA total of 1720 eligible OHCA patients (1489 and 231 in the audio and video groups, respectively) were evaluated. The median ITI was 136 s in the audio group and 122 s in the video group (p = 0.12). The survival to discharge rates were 8.9% in the audio group and 14.3% in the video groups (p < 0.01). Good neurological outcome occurred in 5.8% and 10.4% in the audio and video groups, respectively (p < 0.01). Compared to the audio group, the AORs (95% CIs) for survival to discharge, good neurological outcome and early ITI of the video group were 1.20 (0.74–1.94), 1.28 (0.73–2.26) and 1.00 (0.70–1.43), respectively. The PSM population showed similar results as those of the original cohort. ConclusionCompared to audio-instructed DA-CPR, video-instructed DA-CPR was not associated with survival improvement in this observational study conducted in one metropolitan city. Randomized controlled trials are needed to compare the effects of video- and audio-instructed DA-CPR.