Local Commutativity Research Articles

Business Model Canvas: Business Analytics on Gas stations with C-stores in United States

Today’s gas stations with convenience stores in the United States are not inclined to only selling gas and diesel, they are now offering more value propositions to their respective customers following their needs and choices. In the United States, people from every corner are now connected to gas stations and convenience stores for their daily needs. Therefore, any further improvements in this sector would benefit them even more. Gas stations with convenient stores can develop and maintain Business Model Canvas (BMC) for further improvement in their business and create even better value propositions for their customers. BMC will facilitate gas stations with better control of their business and help increase revenue streams. It also helps optimize the cost structure and fair pricing. Therefore, applying BMC model could facilitate gas stations with endless benefits by integrating all the nine segments of the model. In this research work, we designed our plan to explain the BMC model and analyze segments to the most relevant extent. Then we like to apply the model in a typical Gas station with C-store in the United States of America to see how a gas station can develop BMC in their business. In a typical gas station with C-store, we see, the customer segment composed of local consumers, commuters, travelers, and late-night shoppers. Gas stations are striving to extend their value propositions to attract more consumers and satisfy their growing needs. Value propositions include uninterrupted flow of gas/diesel supply, fresh produce, foods, merchandise items, friendly customer service, a wide range of products available in-store, ATM service, EV (Electric Vehicle) charging facility, car wash facility and more. Procurements of merchandise from various suppliers, building credit-worthy relationships with them, managing inventory/stocks are the key activities for this type of business. Key partners like banks, suppliers, delivery partners, and professional IT partners. A typical gas station with C-store may have multiple revenue streams. The cost structure of a typical gas station is classified as fixed costs and variable costs including suppliers’ pay, utilities pay, payroll, monthly rents, and maintenance costs.

Relativistic Consistency of Nonlocal Quantum Correlations.

What guarantees the "peaceful coexistence" of quantum nonlocality and special relativity? The tension arises because entanglement leads to locally inexplicable correlations between distant events that have no absolute temporal order in relativistic spacetime. This paper identifies a relativistic consistency condition that is weaker than Bell locality but stronger than the no-signaling condition meant to exclude superluminal communication. While justifications for the no-signaling condition often rely on anthropocentric arguments, relativistic consistency is simply the requirement that joint outcome distributions for spacelike separated measurements (or measurement-like processes) must be independent of their temporal order. This is necessary to obtain consistent statistical predictions across different Lorentz frames. We first consider ideal quantum measurements, derive the relevant consistency condition on the level of probability distributions, and show that it implies no-signaling (but not vice versa). We then extend the results to general quantum operations and derive corresponding operator conditions. This will allow us to clarify the relationships between relativistic consistency, no-signaling, and local commutativity. We argue that relativistic consistency is the basic physical principle that ensures the compatibility of quantum statistics and relativistic spacetime structure, while no-signaling and local commutativity can be justified on this basis.

Visualizing Travel Accessibility in a Congested City Center: A GIS-Based Isochrone Model and Trip Rate Analysis Considering Sustainable Transportation Solutions

Urban settlements often deal with the massive transportation problems caused by mixed land-use development and improper travel services. This situation propels travel accessibility issues within urban centers. This research is intended to focus on the 3rd largest city of Pakistan’s Sindh province, i.e., Sukkur, where residents were found struggling to reach their desired destinations. The study area has naturally grown without planning guidelines, generating traffic congestion and haphazard land-use patterns. This research aims to measure accessibility within the city center using trip rate analysis and a GIS-based isochrone model (1-km radius). In total, 234 household trips were randomly considered according to Morgan’s sampling standards. The results revealed that scattered locations caused heavy traffic volumes without public transport facilities. The ratio of traveling by bike for shopping was recorded at 17.24%. Commuting by car; home-based, health, and shopping trips were ranked 1st (5.52%), 2nd (2.76%), and 3rd (1.38%), respectively. The isochrone-based maps were delineated to clarify the temporal accessibility features. Only three shopping activities were found to be accessible within 6 min. Most of the banks were found to be highly accessible. None of the health facilities were located within a 0–6 minute isochronal boundary. Two entertainment sites were accessible within 0–6 min. The residential neighborhoods were not close to the city center. Only three parks and six religious facilities were accessible within 6–12 min. The study findings clarified mixed land use activities accessed through multiple travel modes in the city center. Executing traffic management implications is a need of the time to induce sustainable transportation guidelines. Besides, the results may contribute to SDG 11.2, i.e., “affordable and sustainable transport systems” available for local commuters. The findings of this study are also relevant to evaluating the progress of some cities on SDG 11.2 regarding accessing feasible transportation services.

Integrability in $$[d+1]$$ dimensions: combined local equations and commutativity of the transfer matrices

Integrability in $$[d+1]$$ dimensions: combined local equations and commutativity of the transfer matrices

Estimation of multi-infeed HVDC inter converter direct current interaction in close electric proximity

This paper aims at investigating the direct current interaction between various converters of High Voltage Direct Current (HVDC) system, which lie in close electric proximity within the multi-infeed configuration. The interaction between converters in multi-infeed DC system are highly possible events which need to be evaluated in order to avoid the adverse operational results. The various indices such as multi-infeed interaction factor (MIIF) considering AC busbar voltages, local and concurrent commutation failures (CF) in converter stations under different AC disturbances, influence of AC system’s strength on fault recovery time (FRT), transient over-voltage (TOV) under permanent DC faults, voltage and power stability of multi-infeed DC system are comprehensively illustrated in literatures. However, there is lack of literature regarding the investigation of current interaction in multi-infeed DC system. Therefore, in this paper, a power flow approach is adopted to estimate the inter converter direct current interaction. An index, multi-infeed current interaction factor (MICIF) is proposed that can effectively depicts the interaction between converters. The MICIF index is verified through electromagnetic transient simulations of dual infeed HVDC system developed in PSCAD/EMTDC. The results show that MICIF index can accurately assess the interaction between different converter stations of HVDC system under steady and transient states.

Suppression to concurrent commutation failure of UHVDC with hierarchical connection mode based on improved dc current prediction

AbstractFor the ultra high‐voltage dc (UHVDC) transmission with hierarchical connection mode (HCM) at the inverter side, local commutation failure (LCF) at one layer after the ac fault may cause concurrent commutation failure (CCF) at the non‐fault layer. The inter‐layer couplings at the ac and dc sides add the difficulty to suppress the CCF. The fault instant may decide the dc current variation during the commutation, which affects the suppression effect. This paper shows the mechanism of the CCF including the inter‐layer ac and dc coupling, and proposes a control method for the inverter at the fault and non‐fault layers. First, an analytical expression among the dc current, ac voltage, and extinction angle of both layers is newly derived to find the dominant factors to the CCF. Second, to improve the calculation accuracy, a three‐point sampling function using Newton interpolation is newly proposed to predict the dc current. Finally, a coordinated control strategy based on the constant extinction area, the overlap‐arc area, and the dominant factor of the CCF is proposed to adjust the firing angle and suppress the CCF. The simulation results using the PSCAD/EMTDC software are given to verify the control effect of the proposed method against the CCF.

Detection and Damage Evaluation of Hinge Joints in Hollow Slab Bridges Based on a Light-Load Field Test

The hollow slab bridge is a widely used bridge type for urban bridges. The slabs are prefabricated in a factory and are assembled on site, and then the hinge joints are poured on site. Shallow hinge joints have been used in most existing hollow slab bridges, which commonly bring inadequate connection to the adjacent slabs and probably result in bridge damage. Traditional detection and test methods for hinge joints interrupt traffic, which is inconvenient for local commuters. In the present study, a light-load field test method for hinge joints was proposed. The principles and procedures of the light-load test were concluded and provided based on the test results of 96 spans. The theoretical and measured lateral load distribution ratios were calculated and compared based on hinge joint plate theory. The damage evaluation method and damage classification for hinge joints were defined based on the test results of 1100 hinge joints. Furthermore, the accuracy of the proposed method was verified by a destructive experiment. The research results indicate that the light-load field test and the damage evaluation method for hinge joints are indeed convenient, reliable, and economical, and deserve practical spread and repetition in this area.

How does trip frequency distort time value to impact congestion charging schemes?

Abstract A notable feature of a city or region with close economic and social connections with its neighbours is its highly mixed local and external traffic, and in some cases the external traffic volume is almost as high as that of local traffic. Whilst local traffic volume may be largely made up of the same regular local commuters making frequent trips, external traffic from outside of the city (region) may not be the same people making regular trips to/from the city. However, from a large pool of people making infrequent trips to/from the city, the existence of external traffic is proven by data from the licence plate recognition system of road vehicles in Changde, China. The function of value of time correlated with the income/wage rate and trip frequency is exploited and verified statistically. The time value distorted by trip frequency is defined as perceived time value (PTV), which also influences the way travellers perceive any travel impedance such as congestion delay and toll charges. This paper analyses the price of anarchy (POA) when explicitly considering the travel frequency of the trip-makers and their PTV, and compares with previous analysis without considering travel frequency. We show that when travel frequency is considered, the optimal toll of congested road pricing schemes which converts road traffic flow from user equilibrium into system optimization is much lower than that without considering travel frequency. The cost of licence plate auction cannot be treated as a congestion toll, which is only a threshold of vehicle ownership. That travellers choose routes by PTV rather than TV (time value) is proven by an example of Heishipu Bridge in Changsha, Hunan Province, China.

Assessment of metal pollution and human health risks in road dust from mineral rich zone of East Singhbhum, India.

A detailed study of heavy metals in the road dust of a mineral rich zone of Jharkhand state, India is reported herein. Metal concentrations in the road dust exceeded the corresponding values in the average shale as well as world average of soil. Metal pollution due to the road dust and the possible health impact arising there from was appraised through a number of indices such as Geo-accumulation Index (Igeo), Pollution Load Index, Enrichment Factor (EF), Contamination Factor and US EPA Hazard Index and Cancer Risk. Cu contamination was highest as per EF and Igeo, followed by Pb and Zn. Aggravated heavy metal loading in the road dust was conspicuous in the proximity of copper mines and processing units. Both geogenic and anthropogenic sources were responsible for heavy metals in road dust according to principal component analysis. Hazard Quotient, Hazard Index and Cancer Risk were calculated to ascertain non-carcinogenic and carcinogenic health risks in adults and children. Local inhabitants, particularly children, were under appreciable cancer and non-cancer risk. Oral ingestion was the major pathway for risk to the local commuters followed by dermal pathway. Present study underscored the importance of regular heavy metal monitoring of road dust in this zone and administer proactive road dust management practices to reduce metal pollution.

Commutation Failure Analysis and Prevention of UHVDC System With Hierarchical Connection Considering Voltage Harmonics

Although the harmonics interaction plays a vital role in causing commutation failure (CF) in an ultra HVDC (UHVDC) system with hierarchical connection, it has not been sufficiently considered in previous work. In this paper, the electric interaction among the inverter valves of the UHVDC system with hierarchical connection during receiving system fault transient process is demonstrated. Moreover, the mechanism of CFs in UHVDC system with hierarchical connection is also investigated via the analysis of harmonics interaction. After the AC fault occurs, the appearance processes of the local commutation failure (LCF) and concurrent commutation failure (CCF) are divided into several stages and interpreted by schematic diagrams. And the characteristics of each stage are also concluded. In addition, a coordinated CF prevention scheme based on harmonics and DC current detection is proposed to mitigate the CFs in UHVDC system with hierarchical connection. Finally, the effectiveness of the proposed scheme is verified via a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm 1100$</tex-math></inline-formula> kV UHVDC transmission system under various short circuit ratio values and AC-side coupling strengths.

Commutators of local bilinear maximal operator with Sobolev symbols

In the present paper, we introduce the commutators of local bilinear maximal operator, local bilinear maximal commutators and their fractional variants. Under the conditions that the symbol function belongs to the first-order Sobolev spaces, the bounds for the above commutators on the Sobolev spaces are established. These results are based on several new pointwise estimates for the weak gradients of the above commutators.

Tropospheric and Surface Nitrogen Dioxide Changes in the Greater Toronto Area during the First Two Years of the COVID-19 Pandemic

We present tropospheric nitrogen dioxide (NO2) changes observed by the Canadian Pandora measurement program in the Greater Toronto Area (GTA), Canada, and compare the results with surface NO2 concentrations measured via in situ instruments to assess the local emission changes during the first two years of the COVID-19 pandemic. In the City of Toronto, the first lockdown period started on 15 March 2020, and continued until 24 June 2020. ECMWF Reanalysis v5 (ERA-5) wind information was used to facilitate the data analysis and reveal detailed local emission changes from different areas of the City of Toronto. Evaluating seven years of Pandora observations, a clear NO2 reduction was found, especially from the more polluted downtown Toronto and airport areas (e.g., declined by 35% to 40% in 2020 compared to the 5-year mean value from these areas) during the first two years of the pandemic. Compared to the sharp decline in NO2 emissions in 2020, the atmospheric NO2 levels in 2021 started to recover, but are still below the mean values in pre-pandemic time. For some sites, the pre-pandemic NO2 local morning rush hour peak has still not returned in 2021, indicating a change in local traffic and commuter patterns. The long-term (12 years) surface air quality record shows a statistically significant decline in NO2 with and without April to September 2020 observations (trend of −4.1%/yr and −3.9%/yr, respectively). Even considering this long-term negative trend in NO2, the observed NO2 reduction (from both Pandora and in situ) in the early stage of the pandemic is still statistically significant. By implementing the new wind-based validation method, the high-resolution satellite instrument (TROPOMI) can also capture the local NO2 emission pattern changes to a good level of agreement with the ground-based observations. The bias between ground-based and satellite observations during the pandemic was found to have a positive shift (5–12%) than the bias during the pre-pandemic period.

Stress and Adaptation Among Mumbai Local Train Commuters

Stress and Adaptation Among Mumbai Local Train Commuters

Abelian networks IV. Dynamics of nonhalting networks

An abelian network is a collection of communicating automata whose state transitions and message passing each satisfy a local commutativity condition. This paper is a continuation of the abelian networks series of Bond and Levine (2016), for which we extend the theory of abelian networks that halt on all inputs to networks that can run forever. A nonhalting abelian network can be realized as a discrete dynamical system in many different ways, depending on the update order. We show that certain features of the dynamics, such as minimal period length, have intrinsic definitions that do not require specifying an update order. We give an intrinsic definition of the torsion group of a finite irreducible (halting or nonhalting) abelian network, and show that it coincides with the critical group of Bond and Levine (2016) if the network is halting. We show that the torsion group acts freely on the set of invertible recurrent components of the trajectory digraph, and identify when this action is transitive. This perspective leads to new results even in the classical case of sinkless rotor networks (deterministic analogues of random walks). In Holroyd et. al (2008) it was shown that the recurrent configurations of a sinkless rotor network with just one chip are precisely the unicycles (spanning subgraphs with a unique oriented cycle, with the chip on the cycle). We generalize this result to abelian mobile agent networks with any number of chips. We give formulas for generating series such as \[ ∑ n ≥ 1 r n z n = det ( 1 1 − z D − A ) \sum _{n \geq 1} r_n z^n = \det (\frac {1}{1-z}D - A ) \] where r n r_n is the number of recurrent chip-and-rotor configurations with n n chips; D D is the diagonal matrix of outdegrees, and A A is the adjacency matrix. A consequence is that the sequence ( r n ) n ≥ 1 (r_n)_{n \geq 1} completely determines the spectrum of the simple random walk on the network.

Analytically Evaluating the Impact of Voltage Stability on Commutation Failure in Multi-Infeed LCC-HVDC Systems

Both the local and concurrent commutation failures (LCF and CCF) are concerned threats to the secure operation of multi-infeed LCC-HVDC (MIDC) systems, which will be largely impacted by the voltage stability. However, this impact has not been clearly revealed yet by earlier works due to the lack of the related analytical evaluation method. Thus in this paper, the analytical evaluation method related to the LCF and CCF with the voltage stability in MIDC systems is firstly proposed considering the complicated inter-inverter interactions. This is realized by deriving the analytical expressions of the LCF and CCF immunity indices (LCFII and CCFII) as the functions of the voltage stability factor (VSF) based on the system quasi-steady-state model. Moreover, the proposed method is used to clearly evaluate the impact of the voltage stability on the LCF and CCF by comprehensively conducting the parametric dependence analysis of the LCFII, CCFII, and VSF versus various system parameters and operation variables. The analysis results indicate that in some certain situations, increasing the voltage stability of MIDC systems however imposes an unexpected negative impact on the LCF and CCF. Finally, the simulation results of the PSCAD&#x002F;EMTDC program based on a tri-infeed LCC-HVDC system validate the theoretical developments.

Analysis on Local and Concurrent Commutation Failure of Multi-infeed HVDC Considering Inter-converter Interaction

This paper provides a comprehensive analysis of local and concurrent commutation failure (CF) of multi-infeed high-voltage direct current (HVDC) system considering multi-infeed interaction factor (MIIF). The literature indicates that the local CF is not influenced by MIIF, whereas this paper concludes that both the local CF and concurrent CF are influenced by MIIF. The ability of remote converter to work under reduced reactive power enables its feature to support local converter via inter-connection link. The MIIF measures the strength of electrical connectivity between converters. Higher MIIF gives a clearer path to remote converter to support local converter, but at the same time, it provides an easy path to local converter to disturb remote converter under local fault. The presence of nearby converter increases the local commutation failure immunity index (CFII) while reducing concurrent CFII. Higher MIIF causes reactive power support to flow from remote converter to local converter, which reduces the chances of CF. A mathematical approximation to calculate the increase in local CFII for multi-infeed HVDC configurations is also proposed. A power flow approach is used to model the relation between MIIF and reactive power support from remote end. The local and concurrent CFIIs are found to be inverse to each other over MIIF; therefore, it is recommended that there is an optimal value of MIIF for all converters in close electric proximity to maintain CFII at a certain level. The numerical results of established model are compared with PSCAD/EMTDCsimulations. The simulation results show the details of the influence of MIIF on local CF and concurrent CF of multi-infeed HVDC, which validates the analysis presented.

Drivers to Obesity-A Study of the Association between Time Spent Commuting Daily and Obesity in the Nepean Blue Mountains Area.

Obesity has become a public health challenge in every country on this planet, with a substantial contribution to global mortality and morbidity. Studies of the built environment have shown some promise in understanding the drivers of this obesity pandemic. This paper contributes to this knowledge, by focusing on one aspect of the urban environment and asking whether there is an association between commuting and obesity in residents of the Nepean Blue Mountains area on the fringes of Sydney. This is a cross-sectional study with obesity being the dependent variable, and commuting the independent variable, where 45 min or less was defined as local and distant commute was more than 45 min. In the sample of 158 respondents, the risk of obesity was twice as likely in the distant commuters than in the local commuters (OR 2.04, 95% CI 1.051 to 3.962, p = 0.034). Investigation of possible mediators of this association was limited by sample size; however, mode of transport was found to be a significant mediator. The results support the design of cities to provide health supporting environments for all residents, including equitable access to employment at a reasonable distance and effective public transport.

Evaluate the Understandability of Information Display Board Signs Using a Driving Simulator Experiment

ABSTRACT The main research question of this study was how to apply the design guidelines for traditional Changeable Message Signs (CMSs) to the design of the full-color and full-matrix LED Information Display Boards (IDBs). Three categories of messages were evaluated in this study, including (1) travel-time messages, (2) transit travel-time messages, and (3) Graphic Route Information Panels (GRIPs). A driving simulation program was developed based on real-world videos and used to evaluate the designed signs in terms of understandability and helpfulness for decision-making. A total of twenty-four local commuters participated in the driving simulator experiments. Results show that: (1) the perceived easiness of five-line travel-time message is significantly lower than the baseline three-line message, (2) the perceived helpfulness of the transit logo is significantly higher than the generic symbol, and (3) there is no significant difference between the drivers’ comprehension of the three-line message and the single-link GRIPs.

Local commutants and ultrainvariant subspaces

For an operator A on a complex Banach space X and a closed subspace M⊆X, the local commutant of A at M is the set C(A;M) of all operators T on X such that TAx=ATx for every x∈M. It is clear that C(A;M) is a closed linear space of operators, however it is not an algebra, in general. For a given A, we show that C(A;M) is an algebra if and only if the largest subspace MA of X such that C(A;M)=C(A;MA) is invariant for every operator in C(A;M). We say that a closed subspace M⊆X is ultrainvariant for A∈B(X) if it is invariant for every operator in C(A;M). For several types of operators we prove that they have non-trivial ultrainvariant subspaces. For a normal operator on a Hilbert space, every hyperinvariant subspace is ultrainvariant. On the other hand, the family of all ultrainvariant subspaces of a nilpotent operator can be a proper subset of the lattice of all hyperinvariant subspaces.

Operation and Challenges of Multi-Infeed LCC–HVDC System: Commutation Failure, AC/DC Power Flow, and Voltage Stability

This paper presents a detailed analysis of commutation failure, AC/DC power flow, and voltage stability of multi-infeed high-voltage direct current (HVDC). The use of HVDC power transmission technology has become common in modern power systems. During the past two decades, HVDC technology has been extensively used for long-distance bulk power transmission to remote areas. Throughout the world, the demand for power has drastically increased in recent years due to industrialization; such situations make HVDC an economic candidate because the distance between power generation plants and load areas is significantly very long. The line-commutated converter (LCC) technology-based HVDC system is well more mature than other available conversion schemes (i.e., voltage source converters), and it is widely used in high-power projects. China had approximately 50 HVDC–LCC links in 2020, and a single LCC-based link with the highest capacity is 12 GW. The installation of several HVDC links in an existing power network has led to a situation where two or more HVDC links terminate in the electric vicinity of each other’s AC network or even in same AC busbar. Such scenarios are termed multi-infeed HVDC system. Multi-infeed HVDC systems bring various challenges related to voltage stability, local and concurrent commutation failure, and AC/DC power flow. Here, the literature available on these phenomena of LCC-based HVDC is discussed for future research. The assumptions and drawbacks of various techniques used for investigating the mentioned phenomena are also highlighted.