scholarly journals Conceptual Design of Urban E-Bus Systems with Special Focus on Battery Technology

2019 ◽  
Vol 1 (1) ◽  
pp. 2823-2832 ◽  
Author(s):  
Dietmar Göhlich ◽  
Tu-Anh Fay ◽  
Sangyoung Park
Keyword(s):  
Conceptual Design ◽  
Design Space ◽  
Transformation Process ◽  
Special Focus ◽  
Electric Bus ◽  
Battery Capacity ◽  
System Solution ◽  
Depth Analysis ◽  
Battery Technology ◽  
Suitable System

AbstractMany cities have announced ambitious plans to introduce zero-emission electric bus systems. The transformation process to electric bus systems opens up a vast design space as different charging strategies, charging technologies and battery types are available. Therefore, a profound assessment strategy is necessary to find a “most suitable system solution” under given strategic and operational requirements.In this study, we present a new methodology for conceptual design of urban electric bus systems. First, the available e-bus technologies are analysed with a special focus on charging systems, battery technology and aging. Relational functional analysis is used to derive a suitable simulation model. Based on the operational requirements, an energetic simulation of the e-bus is carried out, and the required battery capacity is obtained. Subsequently, the design space is reduced by applying a qualitative cost- technology compatibility matrix taking cost and battery aging into account. The applicability of the model is shown for an exemplary realistic operational scenario to identify three most expedient concepts, which are finally validated with an in-depth analysis.

scholarly journals Design of urban electric bus systems

2018 ◽  
Vol 4 ◽  
Author(s):  
Dietmar Göhlich ◽  
Tu-Anh Fay ◽  
Dominic Jefferies ◽  
Enrico Lauth ◽  
Alexander Kunith ◽  
...  
Keyword(s):  
Stochastic Modelling ◽  
Pilot Project ◽  
Transformation Process ◽  
Technology Selection ◽  
Cost Of Ownership ◽  
Electric Bus ◽  
System Solution ◽  
Vehicle Technologies ◽  
Suitable System ◽  
Operational Aspects

Many public transport authorities have a great interest in introducing zero-emission electric buses. However, the transformation process from diesel to electric bus systems opens up a vast design space which seems prohibitive for a systematic decision making process. We present a holistic design methodology to identify the ‘most suitable system solution’ under given strategic and operational requirements. The relevant vehicle technologies and charging systems are analysed and structured using a morphological matrix. A modular simulation model is introduced which takes technical and operational aspects into account. The model can be used to determine a feasible electric bus system. The technology selection is based on a detailed economic analysis which is conducted by means of a total cost of ownership (TCO) model. To cope with uncertainties in forecasting, a stochastic modelling of critical input parameters is applied and three different future scenarios are evaluated. The applicability of the model was verified in a pilot project in Berlin and the methodology was applied to a realistic operational scenario. Our results indicate that electric bus systems are technically feasible and can become economically competitive from the year 2025 under the conditions examined.

scholarly journals Configuration Study of Electric Helicopters for Urban Air Mobility

Aerospace ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 54
Author(s):  
Julia A. Cole ◽  
Lauren Rajauski ◽  
Andrew Loughran ◽  
Alexander Karpowicz ◽  
Stefanie Salinger
Keyword(s):  
Conceptual Design ◽  
Urban Areas ◽  
Design Space ◽  
Design Method ◽  
Urban Air ◽  
Main Rotor ◽  
Potential Benefits ◽  
Compound Helicopter ◽  
Configuration Changes

There is currently interest in the design of small electric vertical take-off and landing aircraft to alleviate ground traffic and congestion in major urban areas. To support progress in this area, a conceptual design method for single-main-rotor and lift-augmented compound electric helicopters has been developed. The design method was used to investigate the feasible design space for electric helicopters based on varying mission profiles and technology assumptions. Within the feasible design space, it was found that a crossover boundary exists as a function of cruise distance and hover time where the most efficient configuration changes from a single-main-rotor helicopter to a lift-augmented compound helicopter. In general, for longer cruise distances and shorter hover times, the lift-augmented compound helicopter is the more efficient configuration. An additional study was conducted to investigate the potential benefits of decoupling the main rotor from the tail rotor. This study showed that decoupling the main rotor and tail rotor has the potential to reduce the total mission energy required in all cases, allowing for increases in mission distances and hover times on the order of 5% for a given battery size.

Adoption and Success of e-HRM in a Cloud Computing Environment

2019 ◽  
Vol 9 (2) ◽  
pp. 1-27 ◽  
Author(s):  
Robert-Christian Ziebell ◽  
Jose Albors-Garrigos ◽  
Klaus-Peter Schoeneberg ◽  
Maria Rosario Perello Marin
Keyword(s):  
Success Factors ◽  
New Technology ◽  
Digital Transformation ◽  
Special Focus ◽  
Computing Environment ◽  
Extensive Experience ◽  
Cloud Computing Environment ◽  
Software Adoption ◽  
Operational Level ◽  
Depth Analysis

This qualitative study examines the digitisation of HRM in a cloud-based environment. The influencing factors for the transformation from conventional HRM to eHRM are examined with a special focus on the success factors from a strategic to the operational level. Additionally, an in-depth analysis of the currently existing and new HR metrics which emerge during the transformation takes place. The study is based on interviews with HR experts with extensive experience in transforming and working with the new technology. Active participation of the HR department is relevant for the success of the digital transformation HRM project. HR metrics have not been applied extensively so far and are used less for controlling and optimizing HR processes. New metrics would increase the acceptance of the new technology and thus the success of the overall HR transformation. The main contribution is related to the field of HR software adoption of cloud-based solutions.

scholarly journals A GRASP Approach for Solving Large-Scale Electric Bus Scheduling Problems

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6610
Author(s):  
Raka Jovanovic ◽  
Islam Safak Bayram ◽  
Sertac Bayhan ◽  
Stefan Voß
Keyword(s):  
Public Transport ◽  
High Speed ◽  
Large Scale ◽  
Integer Program ◽  
Mixed Integer ◽  
Transport Systems ◽  
Mixed Integer Program ◽  
Scheduling Problems ◽  
Electric Bus ◽  
Battery Capacity

Electrifying public bus transportation is a critical step in reaching net-zero goals. In this paper, the focus is on the problem of optimal scheduling of an electric bus (EB) fleet to cover a public transport timetable. The problem is modelled using a mixed integer program (MIP) in which the charging time of an EB is pertinent to the battery’s state-of-charge level. To be able to solve large problem instances corresponding to real-world applications of the model, a metaheuristic approach is investigated. To be more precise, a greedy randomized adaptive search procedure (GRASP) algorithm is developed and its performance is evaluated against optimal solutions acquired using the MIP. The GRASP algorithm is used for case studies on several public transport systems having various properties and sizes. The analysis focuses on the relation between EB ranges (battery capacity) and required charging rates (in kW) on the size of the fleet needed to cover a public transport timetable. The results of the conducted computational experiments indicate that an increase in infrastructure investment through high speed chargers can significantly decrease the size of the necessary fleets. The results also show that high speed chargers have a more significant impact than an increase in battery sizes of the EBs.

Adoption and Success of e-HRM in a Cloud Computing Environment

2022 ◽  
pp. 1990-2021
Author(s):  
Robert-Christian Ziebell ◽  
Jose Albors-Garrigos ◽  
Klaus-Peter Schoeneberg ◽  
Maria Rosario Perello Marin
Keyword(s):  
Cloud Computing ◽  
Qualitative Study ◽  
Success Factors ◽  
New Technology ◽  
Digital Transformation ◽  
Special Focus ◽  
Extensive Experience ◽  
Cloud Computing Environment ◽  
Software Adoption ◽  
Depth Analysis

This qualitative study examines the digitisation of HRM in a cloud-based environment. The influencing factors for the transformation from conventional HRM to eHRM are examined with a special focus on the success factors from a strategic to the operational level. Additionally, an in-depth analysis of the currently existing and new HR metrics which emerge during the transformation takes place. The study is based on interviews with HR experts with extensive experience in transforming and working with the new technology. Active participation of the HR department is relevant for the success of the digital transformation HRM project. HR metrics have not been applied extensively so far and are used less for controlling and optimizing HR processes. New metrics would increase the acceptance of the new technology and thus the success of the overall HR transformation. The main contribution is related to the field of HR software adoption of cloud-based solutions.

scholarly journals On the way to continuous cover forest at middle elevations – the question of forest structure and specific site characteristics

2013 ◽  
Vol 59 (No. 10) ◽  
pp. 391-397 ◽  
Author(s):  
L. Bílek ◽  
J. Remeš ◽  
O. Švec ◽  
D. Zahradník
Keyword(s):  
Species Diversity ◽  
Gini Index ◽  
Structural Diversity ◽  
Transformation Process ◽  
Special Focus ◽  
Simpson Index ◽  
Forest Stands ◽  
Site Characteristics ◽  
Evenness Index ◽  
Diameter Differentiation

The transformation process of even-aged forest stands to irregular forest stands on waterlogged sites after 20 years effort was analysed. Data from two 1-ha PRP was analysed with special focus on structural (Shannon Evenness Index, Simpson Index and Gini Index) and species (Shannon Evenness Index and Simpson Index) diversity. Different development on study plots confirmed that the highest structural diversity is not often compatible with the concept of species diversity. On PRP 1 high diameter differentiation has led to lower values of species diversity, while on PRP 2 rather moderate diameter differentiation supported higher species diversity in lower DBH classes. The Gini Index was confirmed to be the best indicator for monitoring the diameter differentiation in the course of stand transformation.

Transforming the service idea – a communication and learning process

2014 ◽  
Vol 6 (1) ◽  
pp. 2-16 ◽  
Author(s):  
Patrik Gottfridsson ◽  
Anna Stålhammar
Keyword(s):  
Turning Points ◽  
Service Innovation ◽  
Innovation Process ◽  
Transformation Process ◽  
Content Type ◽  
Knowledge Transformation ◽  
The Public ◽  
System Solution ◽  
Innovation Processes

Purpose – This paper is about service innovation processes and especially about how an idea about a new service proposition is realized and gradually transformed during the process. The purpose of this paper is to describe and explain the process by which the idea of what should be developed is formed. Design/methodology/approach – Empirically this study is built on two case studies from the public transport context. The cases studied are long-term and involves a number of different actors from different organizations put together to deliver a new system solution regarding information- and ticketing systems. Findings – The findings indicate that the service ideas gradually develop throughout the service innovation process; some of the changes are that distinct that they could be described as turning points. The reasons for the changes of the ideas are sometimes the renewed awareness that the involved actors get from communicating and learning from each other's, other times the turning points occur as a result form confrontation with the outside world, and what is their perceived as necessary and possible to do. Originality/value – The study is novel in several respects: the notion of the transformation of the service idea during a service innovation process is introduced; it provides an empirical analysis of the knowledge transformation process during a service innovation process, and it applies traditional innovation perspective in a new context.

Coupling Failure for Torsional Fatigue: A Multi-Disciplinary Root Cause Analysis Approach

2011 ◽  
Author(s):  
Valerio Rossi ◽  
Marco Romanelli ◽  
Lorenzo Naldi ◽  
Luca Antonelli ◽  
Marco Manetti ◽  
...  
Keyword(s):  
Field Measurements ◽  
Root Cause Analysis ◽  
Fatigue Tests ◽  
Special Focus ◽  
Model Calculations ◽  
Cause Analysis ◽  
Root Cause ◽  
Data Matching ◽  
System Solution ◽  
First Occurrence

The successful growth of an EHS culture, focus on equipment availability and reliability, as well as continuous pressure on increased production is causing a higher demand for improvements in Root Cause Analysis (RCA) quality and speed of completion. Root causes investigations need to be driven to a strong level of understanding and resolution to guarantee safe operation, to optimize production and to reduce costs. RCA processes are many times based on different disciplines to investigate the most challenging failures having the following characteristics: - Top Critical: potential impact on safety and production; - First occurrence: no similar cases investigated before; - Lack of information: no operation data and only fragmented information available. In these cases only a multi disciplinary approach allows studying various aspects of the failure and validating the results as an overall system solution. In this paper the authors present a recent study where finite element stress model calculations, metallurgical laboratory analysis (fractography examination, mechanical testing, fracture mechanics), dynamic analysis, fatigue tests and field measurements were used to investigate causes of coupling failure and determinate corrective actions. Results of each study are presented with special focus on comparative analysis and data matching.

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