Departure Time Research Articles

[Development of a carbamazepine determination method based on high-performance liquid chromatography with diode array].

Carbamazepine is used in the treatment of convulsive disorders, trigeminal neuralgia and mental illnesses such as bipolar disorder and pain syndromes. It has been found in clinical applications that carbamazepine causes many serious adverse drug reactions, which are associated with drug concentration in blood and dosage in clinical use. Due to its pharmacological properties, carbamazepine can be life-threatening in an overdosage, making the therapeutic drug control of carbamazepine important in any clinical settings. Creation of a method for carbamazepine quantification in biological objects during forensic chemical examinations is an urgent problem. A method of high-performance liquid chromatography with diode array detection is proposed for carbamazepine quantitation. The stability of proposed conditions for carbamazepine analysis has been proved in the modifying study conditions (flow rate of eluent, its composition, pH of buffer, column oven temperature). The relative standard deviation of retention time and areas of chromatographic peaks of carbamazepine did not exceed 0.5%.

In situ growth of imine-based covalent organic framework as stationary phase for open-tubular capillary electrochromatographic separation.

Designing advanced stationary phases to improve separation efficiency is essential in capillary electrochromatography. Due to their outstanding performance, covalent organic frameworks have recently demonstrated considerable promise in the field of separation science. Herein, an open-tubular capillary electrochromatography method was reported using porous imine-based covalent organic framework with sufficiently available interaction sites as stationary phase. The imine-based covalent organic framework coated capillary was easily prepared via an in situ growth method at room temperature, and its separation performance was evaluated, indicating the high separation efficiency for three types of analytes, including herbicides, polybrominated dibenzofurans, and bisphenols. Moreover, the imine-based covalent organic framework coated capillary showed good reproducibility and stability, with intraday (n=3), interday (n=3), and column-to-column (n=3) relative standard deviations of retention time and peak areas of less than 5%. The separation efficiency of the coated capillary remained unchanged even after 200 runs and the maximum theoretical plates reached up to 85595 N/m for 4,4'-ethylidenebisphenol. It was predicted that the imine-based covalent organic framework stationary phase would be a strong contender for chromatographic separation with high efficiency.

Artificial Intelligence and Deep Learning-based Model for Indoor Environment: with Virtual Reference Tag Allocation

By the evolution of context-aware application, indoor location positioning gains much more attention worldwide. Radio Frequency Identification (RFID) is one such wireless positioning technology adopted widely. Moreover, enhancing the tracking accuracy and thus reducing the tracking error remains a challenging task in RFID based indoor environment. So as to overcome this aspect, a localization and tracking method depending on virtual reference tag (VRT) is employed in the indoor environment. This research work includes four modules like (i) data collection and Received Signal Strength Indication (RSSI) estimation;(ii) Optimal allocation of VRT using Spider Monkey Optimization (SMO) at which the allocation of VRT is made by considering number of tags, environmental factors (humidity and temperature), and SNR. Based on this data, the RFID reader allocates VRT for each grid so as to increase the tracking accuracy; (iii) Artificial Neural Network (ANN) module-based localization at which the localization of unknown tags is made; and (iv) tracking of moving target tag is carried based on Aquila Swarm Optimization-Long short-term memory (ASO-LSTM) approach. The optimization at this stage is employed to choose optimal position which enhances the accuracy of tracking. Thus, finally the location estimation is carried by this approach. The simulation is carried in NS3.26 network simulator and the performance are estimated in terms of SNR, tracking error, mean error, tracking accuracy, mean time, and standard deviation. The performance value is then compared with traditional models to show the enhancement of proposed mode over the other conventional techniques.

Optimization of Train Timetables in High-Speed Railway Corridors Considering Passenger Departure Time and Price Preferences

Optimization of Train Timetables in High-Speed Railway Corridors Considering Passenger Departure Time and Price Preferences

The test bench for simulation impact of core saturation on the current transformer on coordination of inverse relay protection

When the measurement-type Current Transformer (CT) is used for protection schemes, this condition causes problems related to the operation of the protection relay. This performance can provide the right output to be captured by the relay when using the CT type of protection system, and measurement CT will be appropriately used as a measurement instrument. When the primary current is greater, the denser the flux flowing in the iron core, and when a certain primary current value is reached, the iron core is unable to accommodate the flux that must be flowed. As a result, the value Es is unable to rise again, so the error ratio begins to rise, and the secondary current output is distorted. This research aims to design a tool that can display the distortion that occurs in the secondary current, and this research will evaluate its impact on the characteristics of the inverse-type overcurrent relay. The research method is R&D (Research & Development) by configuring a prototype analog test table so that saturation occurs on the CT connected to the protection relay. The results of the research Simulation of protection coordination failure due to core saturation can be shown, and the design of core saturation test equipment can be demonstrated. The root cause of core failure can be traced from the disconnection time deviation that occurs at the protection relay. The design of core saturation test equipment can be implemented to display protection failures due to core saturation and show the correlation between the voltage excitation curve and relay disconnection time. Testing CT ratio 30/5 with a burden of 1.5 VA, the operating limit is 183.3% of the primary rated rating, meaning that for CT with a primary rated current of 30 amperes, testing up to 60 amperes shows the results have not occurred core saturation.

An Adaptive Dynamic Scheduling Policy for the Integrated Optimization Problem in Automated Transshipment Hubs

This study considers the multi-period dynamic integrated optimization problem in automated transshipment hubs, which includes berth allocation, quay crane assignment, and yard assignment problems. The planner needs to determine the berth and storage schedule in real-time. In the previous literature, the scholars always assume that all of the required information, especially the arrival time and operation time of vessels, is accessible prior to making any design decisions, and formulate the problem into an integrated model. However, the information of vessels is updated dynamically and changed frequently. Therefore, we consider a problem in a dynamic setting that decisions are made in each period and the scenario at each period depends on the decisions in previous periods. We formulate the problem into a multi-objective model, which aims to maximize total revenue, saved time deviation, saved transportation distance, and service quality. An efficient adaptive dynamic scheduling policy is developed, which adaptively balances the trade-offs between multiple objectives. Through numerical experiments, we demonstrate that our approach presents solutions with a delicate balance between multiple objectives and brings value to the automated container terminals compared to benchmark policies. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —Automated technologies have brought great opportunities for container terminals. While the construction of an automated container terminal requires enormous investment. Utilizing the resources of container terminals reasonably and efficiently can improve the operation efficiency and economic performance of automated container terminals. In practice, the scheduling of resources in container terminals always encounters uncertain factors. Therefore, this study proposes a dynamic integrated optimization policy for resources in automated container terminals to balance the trade-offs between multiple objectives given any pre-determined target in a dynamic environment.

Rapid and in-situ preparation COFs coated capillary by adsorption method for the separation and determination of phthalate ester using CEC

As a novel class of stationary phase materials, covalent organic frameworks (COFs) have shown great promise in open-tubular capillary electrochromatography. However, the current preparation of COFs coating capillaries heavily relies on tedious and time-consuming covalent bond methods. In this work, a novel, simple and rapid adsorption method was developed for fabrication of TPB-DMTP COF (fabricated from 1,3,5-tris(4-aminophenyl)benzene (TPB) and 2,5-dimethoxyterephthalaldehyde (DMTP)) coated capillary. Due to the crystallization process of the COF is greatly shortened because pre-modification capillary does not require silane coupling agent, this method enables the rapid preparation of COFs-coated capillaries. The organic molecular building units only need 25 min to form a stable COFs coating on the inner wall of a capillary by this method. To our knowledge, this is the shortest method for preparing COFs coated capillary up to now. The performance of the TPB-DMTP COF coated capillary was evaluated by using phthalate esters as model analytes. The results demonstrated that the TPB-DMTP COF coated capillary has excellent repeatability and stability. The relative standard deviations (RSDs) of the analyte's retention time of intra-day, inter-day and column-to-column were in the range of 0.05 %–0.27 %, 0.31 %–0.63 % and 0.31 %–0.88 %, respectively. And, no significant changes were observed in separation efficiency and retention time after over 200 runs. Finally, the TPB-DMTP COF coated capillary was applied for the determination of phthalates in marketed plastic bag and the recovery ranged from 88.0 % to 114.0 %.

Stochastic-priority-integrated signal coordination considering connected bus operation uncertainties

Multimodal arterial signal coordination for buses and passenger vehicles can improve arterial travel smoothness and efficiency. However, uncertainty in bus operations requires signal priority at intersections, which impacts coordination and increases stop times for other traffic types. Therefore, this study proposes a stochastic priority-integrated signal coordination (SPIC) method. It includes an offline stochastic programme to determine the arterial signal coordination, i.e. cycle length and offsets, considering the stochastic signal priority, and an online mixed-integer nonlinear programme to determine the signal priority together with the bus arrival and departure times at and from stops and intersections in a connected vehicle environment. A scenario-based heuristic algorithm is proposed to solve the SPIC efficiently. Numerical studies have validated that SPIC can improve the efficiency of buses and passenger vehicles. Sensitivity analyses show that the SPIC effectively reduces delays with fluctuations in the bus travel time, dwell time, and passenger vehicle demands.

Impact of Particle Size on the Setting Behavior of Tricalcium Silicate: A Comparative Study Using ISO 6876 Indentation Testing and Isothermal Induction Calorimetry.

This study examines the impact of particle size on the setting behavior of tricalcium silicate powders. The setting behavior was evaluated using ISO 6876 indentation testing and isothermal induction calorimetry techniques. The objective was to compare the outcomes obtained from these methods and establish a correlation between particle size and setting characteristics. The cement pastes were manually mixed with a water-to-solid ratio of 0.66 for conducting indentation tests according to ISO 6876, while calorimetry measurements were performed using isothermal (conduction) calorimetry at room temperature. The findings demonstrate a significant influence of smaller particle sizes on accelerating the hydration process of cement pastes, resulting in a reduction of setting time by up to 24%. Moreover, the final setting times obtained through the indentation method closely approximate the inflection points of the acceleration curves acquired by calorimetry, with time deviations of less than 12% regardless of particle size.

Itaconic Acid-Based Organic-Polymer Monolithic Column for Hydrophilic Capillary Electrochromatography and Its Application in Pharmaceutical Analysis.

Itaconic acid is an excellent hydrophilic monomer owing to the dicarboxylic group possessing strong polarity. This study reports on the preparation of a new organic-polymer monolithic column poly(itaconic acid-co-3-(acryloyloxy)-2-hydroxypropyl methacrylate) (poly(IA-co-AHM)) featuring excellent hydrophilic chromatography ability and its application in pharmaceutical analysis. The monolithic column was successfully synthesized by using the monomer itaconic acid and the cross-linker AHM through an in situ copolymerization method. Optical microscopy, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were employed for the characterization of the poly(IA-co-AHM) monolithic column, and all of these demonstrated that the prepared itaconic acid-based monolithic column exhibited satisfactory permeability and a homogeneous porous structure. Owing to the carboxylic groups of itaconic acid, a cathodic electroosmotic flow (EOF) was generated on the itaconic acid-based monolithic column among the pH ranges of the mobile phase from 4.0 to 9.0. Depending on the powerful hydrophilic interactions, different kinds of polar substances, including thioureas, nucleoside drugs, sulfonamides, and polypeptides, were separated efficiently by the itaconic acid-based monoliths poly(IA-co-AHM). The separations of polar compounds were successfully realized, even at a lower level of 50% acetonitrile content on this monolithic column. The highest column efficiencies corresponding to N,N'-dimethylthiourea and idoxuridine were 102 720 and 124 267 N/m, respectively. The poly(IA-co-AHM) monolithic column displayed excellent repeatability, whose relative standard deviations (RSDs) of the retention time and peak area were both lower than 5.0%. All experimental results demonstrated that the new itaconic acid-functionalized monolithic column was greatly appropriate to separate the polar compounds under the HILIC mode.

An exact algorithm for maximum electric vehicle flow coverage problem with heterogeneous chargers, nonlinear charging time and route deviations

Typical electric vehicles (EVs) should be recharged multiple times to reach a long distance due to the limited travel ranges. The EV flow covering problem determines the locations of charging stations to maximize the “covered” OD flows, respecting a given budget for the new charging stations. This paper proposes an exact algorithm for solving the problem by considering the heterogeneous EV chargers, nonlinear charging time, and route deviations from the shortest distance paths. We develop an exact Benders decomposition-based algorithm, in which the Benders subproblem utilizes a nested cut-generation via a customized labeling algorithm. Two methods for solving the Benders subproblem are developed, which are combined to accelerate the Benders cut generation. In addition, we present a heuristic algorithm based on the proposed exact algorithm for the larger-sized problems. The computational results show that the proposed algorithm could solve real-life problems. Especially, the heuristic algorithm could solve problems up to 339 nodes and 500 km of the EV’s travel range. The extensive computational study shows that addressing the multiple charger types, the charging time, and the deviation routes can be crucial to provide realistic charging infrastructure for EVs.

Untangling Complexity in ASEAN Air Traffic Management through Time-Varying Queuing Models

Free route airspace allows airspace users to freely plan a route in en-route airspaces within certain restrictions. It is anticipated to offer the benefit of fuel saving and operational flexibility. Regarding its efficient implementation into the ASEAN airspace, the key challenge would be reducing hotspots with clusters of potential conflicts. This paper designed a time-varying queuing network model, which contributed to untangle trajectory complexity in the most congested hotspot area. A series of fast-time simulation experiments were conducted to identify hotspots in en-route airspace in Singapore FIR. The application of departure time control using time-varying queuing networks successfully reduced up to 45% of potential conflicts. This was achieved within an average delay of 30 min by controlling time of less than 60% of candidate flights. The original contribution of this paper is to develop a novel modeling and simulation framework for composing ideal air traffic patterns. Lastly, we discussed the extension of this study toward a generalized application of the proposed approach in future air traffic management.

Passengers Flow Analysis of Public Transit Service in Pokhara

The motive of the study is to evaluate the existing public transportation system and propose recommendations for Pokhara public transportation to enhance its efficiency and effectiveness. In urban locations, a well-managed public transportation system is unquestionably required. According to the previous study, passengers faced various issues on their journey, such as delays in reaching their destination, bus congestion, an inappropriate time of departure, lane stoppage, and more. (Duwadi, et al., 2019) The primary and secondary data collected from fieldwork and the Yatayat Bibhag, respectively, were used in the research for the analysis. The volumes of passenger flows on ten different routes were analyzed. Mapping and modeling were done using GIS and CAD. Results show that the service frequency did not match the actual swings in consumer demand, resulting in increased time delays. It is recommended that well-managed loading areas be needed in areas with the highest person capacity of more than 3000 per stop per hour, such as Chipledhunga, Mahendrapool, Srijanachowk, and more. A practical operation schedule and service frequency, including 10% for backup and maintenance, were recommended. Demand for passengers on various routes and the number of years the capacity can fulfill the demand is calculated.

Time deviation analysis of the baseline plan on the case study: Implementation of reinforced concrete works on a school construction project in the Republic of Croatia

Time deviation analysis of the baseline plan on the case study: Implementation of reinforced concrete works on a school construction project in the Republic of Croatia

Construction of MOFs@COFs composite material as stationary phase for efficient separation of diverse organic compounds

BackgroundThe development of efficent chromatographic stationary phases (SP) with mixed-mode or multiple interactions in high-performance liquid chromatography (HPLC) for the separation of complex samples is a challenging task. Metal organic frameworks (MOFs)-based SP can provide desired multiple interactions and enable the separation of a diverse range of solutes, but have limitations of low column efficiency and poor stability. ResultsHerein, the hybrid MOFs@Covalent organic frameworks (COFs) materials were used as SP in HPLC due to their synergistic structural features. The SiO2@NH2-UiO-66@CTF SP was synthesized by integration of NH2-UiO-66 and covalent triazine framework (CTF) onto silica surface. Due to the unique structure of SiO2@NH2-UiO-66@CTF with hierarchical-pores, this column showed higher column efficiency (up to 49,369 plates m−1 for alkylbenzenes) than the reported columns packed with MOFs-based SP. Owing to the Zr4+-N coordination bonding between CTF and NH2-UiO-66, the structural stability of SiO2@NH2-UiO-66@CTF can be improved. Furthermore, this new column exhibited remarkable column stability with relative standard deviation of retention time of <0.40% after 400 injections. With the combined advantages of multifunctional properties, high column efficiency, and good stability, SiO2@NH2-UiO-66@CTF SP showed excellent selectivity for the separation of a variety of hydrophobic, aromatic, heteroatomic, and hydrophilic analytes. Significance and noveltyThis work not only offers a promising SP with multiple retention mechanisms for HPLC, but also provides an efficient strategy for development of high column efficiency MOFs-based SP with good stability. Moreover, the MOFs@COFs hybrid materials were expanded in application area through this study, and the research results can also afford the foundation for further explore its structural characteristics.

Study on Optimization of Departure Interval of Pure Electric Bus in Airport Area

As a zero-emission, pollution-free and pure green public transport, pure electric bus has received more and more attention from society and enterprises. At present, most urban public transport lines in China have basically realized pure electric bus. With the popularization of pure electric bus, the operation and management of pure electric bus in specific areas are required. How to reasonably set the departure time interval, configure the number of vehicles and reduce the charging cost while meeting the travel needs of passengers and the enterprise cost as low as possible has become a hot issue in the research of pure electric bus operation management. In this paper, from the perspective of system cost, a pure electric bus departure interval optimization model is constructed, which considers the comprehensive cost of passengers and enterprises to be minimum. The load factor constraint and departure interval are considered as the main constraints, and the optimal departure interval is obtained.

Clock synchronizing radio access networks to picosecond precision using optical clock distribution and clock phase caching

Performing positioning of future mobile devices using trilateration through radio access networks would provide a robust alternative to currently used global navigation satellite systems. However, the positioning accuracy is strongly dependent on the time synchronization accuracy of the antennas used as location reference points. Consequently, achieving sub-30 cm positioning accuracies requires the synchronization of radio access network antennas to sub-nanosecond accuracy. Here we show a clock phase synchronization and optical clock signal distribution approach to clock synchronization in radio access networks that achieves 0.98-ps root-mean-square precision clock synchronization, in a real-time field-trial demonstration on 37.6-km dark fiber, with optical clock frequency synchronization and clock phase caching operating using 25.6-Gb/s commercial transceivers. We quantify the clock synchronization performance of our approach using standard metrics, including time deviation (TDEV) and mean time interval error (MTIE). Furthermore, we estimate the impact of varying the phase update rate used in clock phase caching on the clock synchronization performance of our approach. Through our two combined approaches, we explore a route towards achieving sub-nanosecond clock synchronization in radio access networks.

A comparative study on the accuracy of an automated multi-parameter high-dose-rate brachytherapy quality assurance system

This study aims to explore the measuring accuracy of an automated high-dose-rate brachytherapy (HDR BT) quality assurance system (hereinafter referred to as OriQA system) that could provide simultaneous measurements of dwell position, dwell time and source strength in a single test. Elekta-Flexitron was selected as the HDR BT afterloader, and measured the farthest transmission distance by source position simulator. Within the effective distance, we set dwell positions in two groups, specifically, plan_1 with an interval of 2.00 cm: 106.00 cm, 108.00 cm, 110.00 cm, 102.00 cm, 104.00 cm, 106.00 cm, 108.00 cm, and plan_2 with an interval of 0.20 cm: 111.40 cm, 111.60 cm, 111.80 cm, 112.00 cm, 112.20 cm, 112.40 cm, 112.60 cm. The measured values collected from OriQA device were compared with the data from traditional HDR BT QA tool (source position check ruler). Three groups of dwell time were set, specifically, plan_1: with fixed dwell time 2.00 s, plan_3 with interval 0.10 s: 3.70 s, 3.80 s, 3.90 s, 4.00 s, 4.10 s, 4.20 s, 4.30 s, and plan_4: fixed dwell time 5.00 s. Source strength was also measured continuously for a period of 10 weeks, and compared with the data collected from the well-chamber. The OriQA system showed reliable performance in the evaluation of measuring accuracy. The adjusted farthest transmission distance was 119.33 cm. And according to the time-position graph, the maximum deviation of dwell position between the measured and planned data was 0.34 mm, which was smaller than that between the ruler and planed data (0.75 mm). The maximum deviation of dwell time between the measured and planned data was 0.05 s. Fitting analysis revealed linear relationship between source strength Sk and the intensity detector response, with R2 = 0.9877, and intensity deviation fluctuated between 1.14% and 2.19%. Compared with the traditional QA tool, the OriQA device provided improved measuring accuracy and efficiency QA procedure for HDR BT.

Research on Teaching Resource Management in Colleges and Universities Based on Multiple Data Chain Networks

Abstract In this paper, we first take the datalink network as the entry point and construct a university teaching resource management model based on a multivariate datalink network. A Link-22 data chain time synchronization algorithm with KF-RTPT is proposed to address the actual existence and unavoidable time deviation based on accuracy and timestamp acquisition errors. Meanwhile, a time slot allocation and optimization algorithm designed to maximize message transmission benefits is being developed to optimize the allocation of node time slot requirements. Finally, the constructed teaching resource management model is empirically analyzed from three perspectives: error optimization, dynamic time slot allocation, and model application effect. According to the findings, the KF-RTPT algorithm increases motion error efficiency by 3.83 in low-speed motion states and 8.16 in high-speed motion states when compared to the conventional RTT method. This effectively eliminates motion error and boosts the effectiveness of teaching and managing resources in colleges and universities.

A general variable neighborhood search for the traveling salesman problem with time windows under various objectives

The traveling salesman problem with time windows (TSPTW) has wide practical applications in transportation and scheduling operations. We study the TSPTW in the deterministic case as well as under travel time uncertainty. We consider the three classical TSPTW variants with the objectives of minimizing cost, completion time, and tour duration. In addition, a new TSPTW variant that maximizes the minimum slack of a tour, i.e., the smallest time buffer between the arrival time and the end of the time window over all nodes visited on the tour, is introduced. We further address a variant of the TSPTW in which the arc travel times are uncertain. This problem is modeled by means of an uncertainty set, and the goal is to determine a tour that remains feasible in the worst case within a budget stipulating the sum of all travel time deviations from their nominal values. To solve all targeted problem variants, we develop a two-phase general variable neighborhood search (GVNS) that applies an efficient move evaluation approach within the local search. Extensive numerical experiments on benchmark instances from the literature show that our GVNS finds high-quality solutions that are competitive with those obtained by the state-of-the-art heuristics for all problem variants.