Dynamic Test Environment Research Articles

A City Logistics Living Lab: A Methodological Approach

The field of city logistics can be characterized by its many local demonstrations and trials, that are quite often not lasting longer than the trial period. The number of demonstrations that continued and were implemented in daily practice is limited. Freight partnerships proved to be a good first step to engage stakeholders. This contribution proposes a new way to develop a more action-driven form of these partnerships that follows from a solution approach, which has proved successful worldwide in fostering innovation deployment, but has not yet been applied explicitly in the domain of City Logistics: Living Labs. The living lab approach ensures that the stakeholders are involved much earlier in the in planning and implementation processes, and that the proposed city logistics implementation is revised and continuously improved to meet stakeholder needs and obtain maximum impact for a long time. This contribution summarizes the steps that have to be taken to set-up and work in a city logistics living lab (CLLL). A CLLL can be defined as a dynamic test environment where complex city logistics innovations can be implemented, following a cyclical approach, where several solutions can be experimented and re-adjusted or improved to fit the real-life city challenges. In the Horizon 2020 project CITYLAB, we developed practical guidelines for establishing and running a city logistics living lab based on several living lab- and field test methodologies that enables stakeholders to set-up and run a CLLL. This contribution discusses the most important CLLL phases, roles, and characteristics, as well as the tools that are available. Next, this contribution shows the first results of cities in which CLLLs are actually set up, or already running.

A permutation-based dual genetic algorithm for dynamic optimization problems

Adaptation to dynamic optimization problems is currently receiving growing interest as one of the most important applications of genetic algorithms. Inspired by dualism and dominance in nature, genetic algorithms with the dualism mechanism have been applied for several dynamic problems with binary encoding. This paper investigates the idea of dualism for combinatorial optimization problems in dynamic environments, which are also extensively implemented in the real-world. A new variation of the GA, called the permutation-based dual genetic algorithm (PBDGA), is presented. Within this GA, two schemes based on the characters of the permutation in group theory are introduced: a partial-dualism scheme motivated by a new multi-attribute dualism mechanism and a learning scheme. Based on the dynamic test environments constructed by stationary benchmark problems, experiments are carried out to validate the proposed PBDGA. The experimental results show the efficiency of PBDGA in dynamic environments.

Model-based development for an electric power steering system

A model-based development method for electric power steering (EPS) system has been explored. A practicable model for the EPS system has been established in a full vehicle mechanical system environment. The performance of the electric control system of the EPS system has been evaluated in this static analysis environment. The model has then been used in a dynamic test environment based on dSPACE hardware and software, including Software-in-the-Loop and Hardware-in-the-Loop. The test result validates the simulation model, and shows that this development method can be used to evaluate the conceptual design of the EPS system as well as the control software design and testing.

Study on the establishment of dynamic performance test environment for the digital protective relay using RTDS

A performance test of digital protective relay is divided into three parts; a static test, a dynamic test, a EMC test. Among these, a dynamic test is increasingly important, but it is not easy to diffuse a technique for dynamic test because of the intricate approach to real time digital simulator. In order to solve these problems, KEPRI(Korea Electric Power Research Institute) has established environments for performance test, which consist of a system model and a performance test procedure for the dynamic test.

Computer-based Assessment of Problem Solving Competence

Problem solving competence cannot be described as a unidimensional construct. At least analytical and dynamic aspects of problem solving competence have to be distinguished if all aspects of problem solving are to be covered. Analytical problem solving abilities are needed to structure, represent and integrate information. Dynamic problem solving includes aspects of self-regulated learning as well as the ability to adapt the problem solving process to a changing environment by continuously processing feedback information. The assessment of dynamic aspects of problem solving competence requires dynamic test environments. As a German national option of PISA 2000, the analytical and dynamic problem solving competencies of 15-year-old students were tested using paper-and-pencil tests as well as computer-based assessments. Results show that analytical aspects of problem solving competence are strongly correlated with reasoning, while dynamic problem solving reflects a specific dimension of self-regulated exploration and control that can be identified across computer-simulated domains.

Analysis of airbag depowering and related parameters in out of position environment

Although airbags have proven to be effective in high severity crashes, they can cause unintended injuries in certain deployment scenarios in low severity crashes. Most airbag-induced injuries occur while airbag is still inflating, particularly, for unbelted occupants who may be closer to the airbag at the time of deployment. Many factors in airbag deployment affect the severity of injuries that need to be analyzed. In this paper the effect of occupant position and airbag inflation parameters on driver injury measures is investigated using finite element simulation models of a vehicle, airbag, and Hybrid III dummy. The influence of steering column characteristics as well as the relative velocity (ΔV) between the dummy and vehicle interior is also investigated. Simulations are conducted at both static and dynamic test environments for two different critical dummy vertical positions and for two additional horizontal alignments. Airbag deployment is considered for three different mass flow rate curves. The results indicate that the vertical and horizontal positions of the dummy are extremely important variables. The results also indicate that the presence of a ΔV increases the values of critical injury but the influence of steering column stiffness is greater.