scholarly journals Mixed Scheduling Model for Limited-Stop and Normal Bus Service with Fleet Size Constraint

Information ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 400
Author(s):  
Xiaohong Jiang ◽  
Jianxiao Ma
Keyword(s):  
Flow Distribution ◽  
Significant Saving ◽  
Fleet Size ◽  
Total Cost ◽  
Scheduling Model ◽  
Proposed Model ◽  
Depth Analysis ◽  
Bus Service ◽  
The Cost ◽  
The Relationship

Limited-stop service is useful to increase operation efficiency where the demand is unbalanced at different stops and unidirectional. A mixed scheduling model for limited-stop buses and normal buses is proposed considering the fleet size constraint. This model can optimize the total cost in terms of waiting time, in-vehicle time and operation cost by simultaneously adjusting the frequencies of limited-stop buses and normal buses. The feasibility and validity of the proposed model is shown by applying it to one bus route in the city of Zhenjiang, China. The results indicate that the mixed scheduling service can reduce the total cost and travel time compared with the single scheduling service in the case of unbalanced passenger flow distribution and fleet constraints. With a larger fleet, the mixed scheduling service is superior. There is an optimal fleet allocation that minimizes the cost for the system, and a significant saving could be attained by the mixed scheduling service. This study contributed to the depth analysis of the relationship among the influencing factors of mixed scheduling, such as fleet size constraint, departure interval and cost.

scholarly journals Potential Field Cellular Automata Model for Pedestrian Evacuation in a Domain with a Ramp

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Xiao-Xia Jian ◽  
Xiaoning Zhang
Keyword(s):  
Cellular Automata ◽  
Potential Field ◽  
Empty Space ◽  
Domino Effect ◽  
Cellular Automata Model ◽  
Pedestrian Evacuation ◽  
Crowd Density ◽  
Proposed Model ◽  
The Cost ◽  
The Relationship

We propose a potential field cellular automata model with a pushing force field to simulate the pedestrian evacuation in a domain with a ramp. We construct a cost potential depending on the ramp angle and introduce a function to evaluate the pushing force, which is related to the cost and the desired direction of pedestrian. With increase of crowd density, there is no empty space for pedestrian moving forward; pedestrian will purposefully push another pedestrian on her or his desired location to arrive the destination quickly. We analyse the relationship between the slope of ramp and the pushing force and investigate the changing of injured situations with the changing of the slope of ramp. When the number of pedestrians and the ramp angle arrive at certain critical points, the Domino effect will be simulated by this proposed model.

Capacities, competences and capabilities as knowledge structures to build relational capital

Kybernetes ◽  
2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Juan Gabriel Cegarra-Navarro ◽  
Eva Martínez Caro ◽  
Aurora Martínez-Martínez ◽  
Maria Dolores Aledo-Ruiz ◽  
Eusebio Martínez-Conesa
Keyword(s):  
Structural Equation ◽  
Knowledge Structures ◽  
Educational Institutions ◽  
Relational Capital ◽  
Community Members ◽  
Content Type ◽  
Proposed Model ◽  
Depth Analysis ◽  
Additional Value ◽  
The Relationship

Purpose This paper aims to investigate the relationship between relational capital produced by universities and knowledge structures, which include both the capacities and competencies that students have learned and the capabilities they have put into practice. Design/methodology/approach To analyse research data and test the proposed model, partial least squares structural equation modelling (SmartPLS 3.2.9) is used on a sample of 125 students of a Spanish university. Findings The results of the study demonstrate that the creation of relational capital by universities will depend largely on how students’ capacity is supplemented and merged with students’ competency to develop synergies that increase the students’ capability to give an additional value to the community members. Originality/value This study allows an in-depth analysis of the cause and effect link between the knowledge structures and support the members of higher educational institutions to understand how to achieve relational capital in universities.

MODELING AND SIMULATION OF THE PRODUCTION OF HYDROGEN USING HYDROELECTRICITY IN VENEZUELA

2018 ◽  
pp. 88-95 ◽  
Author(s):  
A. Contrerasa ◽  
F. Possob ◽  
Т. N. Veziroglu
Keyword(s):  
Mathematical Model ◽  
Hydrogen Production ◽  
Modeling And Simulation ◽  
Regression Models ◽  
Low Cost ◽  
Total Cost ◽  
Time Horizons ◽  
Proposed Model ◽  
Production Of Hydrogen ◽  
The Cost

The purpose of this work is to develop and evaluate a mathematical model for the process of hydrogen production in Venezuela, via electrolysis and using hydroelectricity, with a view to using it as an energy vector in rural sectors of the country. Regression models were prepared to estimate the fluctuation of the main variables involved in the process: the production of hydrogen, the efficiency of energy conversion, the cost of hydroelectricity and the cost of the electrolyser. Finally, the proposed model was applied to various different time-horizons and populations, obtaining the cost of hydrogen production in each case. The results obtained are well below those mentioned in the references, owing largely to the low cost of the electricity used, which accounts for around 45% of the total cost of the system.

A MEMBERSHIP FUNCTION APPROACH FOR COST-RELIABILITY TRADE-OFF OF COTS SELECTION IN FUZZY ENVIRONMENT

2011 ◽  
Vol 18 (06) ◽  
pp. 573-595 ◽  
Author(s):  
PANKAJ GUPTA ◽  
SHILPI VERMA ◽  
MUKESH KUMAR MEHLAWAT
Keyword(s):  
Real World ◽  
Fuzzy Optimization ◽  
Delivery Time ◽  
Minimum Threshold ◽  
Trade Off ◽  
Total Cost ◽  
Fuzzy Environment ◽  
Proposed Model ◽  
The Cost ◽  
Cots Selection

The optimization techniques used in commercial-off-the-shelf (COTS) selection process faces challenges to deal with uncertainty in many important selection parameters, for example, cost, reliability and delivery time. In this paper, we propose a fuzzy optimization model for selecting the best COTS product among the available alternatives for each module in the development of modular software systems. The proposed model minimizes the total cost of the software system satisfying the constraints of minimum threshold on system reliability, maximum threshold on the delivery time of the software, and incompatibility among COTS products. In order to deal with uncertainty in real-world applications of COTS selection, the coefficients of the cost objective function, delivery time constraints and minimum threshold on reliability are considered fuzzy numbers. The fuzzy optimization model is converted into a pair of mathematical programming problems parameterized by possibility (feasibility) level α using Zadeh's extension principle. The solutions of the resultant problems at different α-cuts provide lower and upper bounds of the fuzzy minimum total cost which helps in constructing the membership function of the cost objective function. The solution approach provide fuzzy solutions instead of a single crisp solution thereby giving decision maker enough flexibility in maintaining cost-reliability trade-off of COTS selection besides meeting other important system requirements. A real-world case study is discussed to demonstrate the effectiveness of the proposed model in fuzzy environment.

scholarly journals APPLICATION OF THE EXPONENTIAL GREY MODEL ON THE MAINTENANCE COST PREDICTION FOR A LARGE SCALE HOSPITAL / EKSPONENTINIO PILKOJO MODELIO TAIKYMAS PROGNOZUOJANT DIDELĖS LIGONINĖS EKSPLOATACINES SĄNAUDAS

2012 ◽  
Vol 15 (4) ◽  
pp. 379-392
Author(s):  
Tzu-Ping Lo ◽  
Sy-Jye Guo ◽  
Chin-Te Chen
Keyword(s):  
Large Scale ◽  
Grey Model ◽  
Maintenance Cost ◽  
Exponential Series ◽  
Limited Budget ◽  
Proposed Model ◽  
Cost Distribution ◽  
Hospital Building ◽  
The Cost ◽  
The Relationship

Realizing the maintenance cost distribution and predicting the future tendency are important for facility managers to efficiently arrange the limited budget. This paper collects 16,228 maintenance records of a representative hospital in Taiwan and further analyzes the cost distribution. Besides, by calculating the maintenance cost of per square meter of floor area per year (dollar/m2/year) and comparing with the previous studies, this paper also points out the relationship between maintenance cost and the operation ages. moreover, this paper establishes a hybrid grey model termed as EGM(1,1), which adopting exponential series to identify the residual error series resulted from grey model, to predict the maintenance cost. The repair cost of hospital building from 1998 to 2006 is adopted to demonstrate the applicability and practicability of EGM(1,1). Results show that the proposed model can predict the tendency precisely. Santrauka Norint efektyviai išdėstyti ribotą biudžetą, pastatų ūkio valdytojai turi suprasti eksploatacijos sąnaudų pasiskirstymą ir sudaryti ateities tendencijų prognozes. Šiame darbe surinkti 16 228 įrašai apie reprezentacinės Taivano ligoninės eksploataciją ir jais remiantis analizuojamas sąnaudų pasiskirstymas. Apskaičiavus metines eksploatacijos sąnaudas vienam kvadratiniam metrui (doleriai/m2/metus) ir palyginus jas su ankstesniais tyrimais, darbe taip pat parodomas ryšys tarp eksploatacijos sąnaudų ir objekto amžiaus. Be to, darbe sudaromas hibridinis pilkasis modelis, pavadintas EGM(1,1), kuriame naudojant eksponentines eilutes nustatomos liktinės paklaidų eilutės, gautos pilkajame modelyje, taip siekiant prognozuoti eksploatacines sąnaudas. Naudojant 1998–2006 m. ligoninės pastato remontui išleistą sumą pristatomas EGM(1,1) taikymas ir praktiškumas. Rezultatai rodo, kad pasiūlytas modelis tendencijas gali prognozuoti tiksliai.

Thermoeconomic Optimization of a Combined Heating and Humidification Coil for HVAC Systems

2016 ◽  
Vol 41 (3) ◽  
Author(s):  
Liliana Teodoros ◽  
Bjarne Andresen
Keyword(s):  
Minimum Cost ◽  
Total Cost Of Ownership ◽  
Total Cost ◽  
Air Handling Unit ◽  
Operation Costs ◽  
Cost Of Ownership ◽  
Optimization Function ◽  
Length Width ◽  
The Cost ◽  
The Relationship

AbstractThe total cost of ownership is calculated for a combined heating and humidification coil of an air-handling unit taking into account investment and operation costs simultaneously. This total cost represents the optimization function for which the minimum is sought. The parameters for the cost dependencies are the physical dimensions of the coil: length, width and height. The term “coil” is used generically since in this setup it generates heating as well as humidification in a single unit. The first part of the paper deals with the constructive optimization and finds the relationship between the dimensions for a minimum cost. The second part of the paper takes the results of the constructive optimization further and, based on the data derived in our previous papers, analyzes the minimum total cost for the humidification coil while balancing the amount of water used to humidify the air and modify its temperature.

scholarly journals A Numerical Study on the Effects of Trust in Supplier Development

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 300
Author(s):  
Haniyeh Dastyar ◽  
Daniel Rippel ◽  
Jürgen Pannek ◽  
Klaus-Dieter Thoben ◽  
Michael Freitag
Keyword(s):  
Numerical Study ◽  
Investment Decisions ◽  
Supply Chain Performance ◽  
Automotive Sector ◽  
Supplier Development ◽  
Development Programs ◽  
Proposed Model ◽  
Cost Development ◽  
The Cost ◽  
The Relationship

Supplier development constitutes one of the current tools to enhance supply chain performance. While most literature in this context focuses on the relationship between manufacturers and suppliers, supplier development also provides an opportunity for distinct manufacturers to collaborate in enhancing a joint supplier. This article proposes a model for the optimization of such joint supplier development programs, which incorporates the effects of trust in the manufacturer-to-manufacturer relationship. This article uses a model-predictive formulation to obtain optimal supplier development investment decisions to consider the strong dynamics of the markets. Thereby, the model is designed to be highly customizable to the needs and requirements of different companies. We analyzed the price development related to Mercedes’ A-Class cars and the cost development in the automotive sector over the last ten years in Germany. According to the obtained result, the proposed model shows a sensible behavior in including trust and its effects in supplier development, even when just applying a set of generalized rules. Moreover, the numeric experiments showed that aiming for a balanced mix of optimizing revenue and trust results in the highest revenue obtained by each partner.

scholarly journals Optimization of Static and Dynamic Charging Infrastructure for Electric Buses

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3516
Author(s):  
Bálint Csonka
Keyword(s):  
Minimum Cost ◽  
Careful Planning ◽  
Charging Infrastructure ◽  
Dynamic Charging ◽  
Urban Bus ◽  
Bus Service ◽  
The Cost ◽  
Service Data ◽  
The Relationship

The adoption of electric buses in public transport requires careful planning for the bus fleet and charging infrastructure. A mathematical model of an urban bus service was developed to support the deployment of charging infrastructure. The novelty of the model is that it incorporates infrastructure elements for both static and dynamic charging technologies at the same time. The model supports the electrification of the bus lines without route and schedule adjustments. The volume of charged energy at charging units is considered as a variable in the objective function to determine the location of charging units at minimum cost. The model was verified by a case study based on actual bus service data. It was found that the use of static chargers is more favorable if the cost of a static charging unit is less than the cost of a dynamic charger with a length of 1600 m and the charging power of static chargers is three times greater than the charging power of dynamic chargers. The relationship between charging power and the length of the dynamic charging unit was analyzed. It was noted that the use of charging power higher than 162.5 kW at dynamic charging units is not necessary.

scholarly journals Routing cross-docking depots, considering the time windows and pricing routes (case study: container transportation of Chabahar port)

2020 ◽  
Vol 33 (02) ◽  
pp. 409-422
Author(s):  
Farhad Bavar ◽  
Majid Sabzehparvar ◽  
Mona Ahmadi Rad
Keyword(s):  
High Efficiency ◽  
Programming Model ◽  
Time Windows ◽  
Container Transportation ◽  
Total Cost ◽  
Cross Docking ◽  
Proposed Model ◽  
Nonlinear Programming Model ◽  
Implementation Time ◽  
The Cost

In this study, we develop a model for routing cross-docking centers considering time windows and pricing routs. In this model picking and delivery in several times is permitted and each knot can be serviced by more than one vehicle. Every truck can transport one or more product, in other words, we consider compatibility between product and vehicle. This model includes two goals: reducing the total cost and reducing the cost of carrying goods (freight fare). The total cost includes the cost required to traverse between the points, the cost of traversing the routes between the central cross-docking center and the first points after moving, and the cost to traverse the routes between the last points in each route and the depots that must be minimized. In general, the purpose of the model is to obtain the number of cross-docking center, the number of vehicles and the best route in the distribution network. We present a nonlinear programming model for this problem. We have solved the proposed model by GAMS. As the dimensions of the problem increase, the implementation time of the program increases progressively. So, in order to solve the model in medium and large scales, we proposed a genetic meta-heuristic algorithm. The results of examining different issues by the meta-heuristic approach show the very high efficiency of the developed algorithms in terms of the solution time and the answer of the problem.

scholarly journals Charging power optimisation for electric buses at terminals

2021 ◽  
Author(s):  
Bálint Csonka
Keyword(s):  
Public Transportation ◽  
Mixed Integer Linear Programming ◽  
Lower Number ◽  
Operating Costs ◽  
Mixed Integer ◽  
Charging Infrastructure ◽  
Total Cost ◽  
Network Characteristics ◽  
Bus Service ◽  
The Relationship

Charging infrastructure has a key role in the operation of electric buses in public transportation. In this paper, mixed-integer linear programming was used to model the bus service and capture the relationship among the network characteristics, vehicles, and charging unit attributes. The model supports the charging power optimisation at terminals to reduce the total operating costs of electric buses and charging units. The model was applied for the bus network of Kőbánya, Budapest. It was found that despite using more expensive high-power chargers, the total cost is lower because of the lower number of electric buses. It was also found that higher charging power does not affect the total cost significantly if it is higher than 350kW.

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