Multiple-Criteria-Based Electric Vehicle Charging Infrastructure Design Problem

The article presents the issue of designing a network of electric vehicle charging stations (EVCSs) for servicing passenger and commercial vehicles and taking into account the already existing locations. The authors propose a five-stage multicriteria- and GIS-based EVCS location methodology (5MAGISEV) for designing the EVCS network that includes defining potential EVCS locations (stage 1), constructing a family of evaluation criteria (stage 2), generating alternatives (stage 3), selecting an appropriate multiple criteria decision aid method (stage 4) and conducting a multicriteria evaluation of alternatives (stage 5). The methodology was verified by its experimental application for solving the problem of EVCS location in Poznan, Poland. As a result of its application, a set of over 155,000 alternatives was generated in view of different EVCS location determination policies. A family of eight criteria with subcriteria was proposed to assess the solutions, including the evaluation of the degree of integration of the considered EVCSs with such issues as public transport (C1); urbanized areas (C2); main road network (C3); industrial areas (C4); and the location with respect to transport areas (C5), shops of various types (C6), address points (C7) and DYI stores (C8). Based on the selected method of multiple criteria decision aid (LBS), a solution was selected that constitutes a compromise design of the EVCS network.

A New Compromise Design Plan for Accelerated Failure Time Models with Temperature as an Acceleration Factor

An accelerated life test of a product or material consists of the observation of its failure time when it is subjected to conditions that stress the usual ones. The purpose is to obtain the parameters of the distribution of the time-to-failure for usual conditions through the observed failure times. A widely used method to provoke an early failure in a mechanism is to modify the temperature at which it is used. In this paper, the statistically optimal plan for Accelerated Failure Time (AFT) models, when the accelerated failure process is described making use of Arrhenius or Eyring equations, was calculated. The result was a design that had only two stress levels, as is common in other AFT models and that is not always practical. A new compromise plan was presented as an alternative to the widely used “4:2:1 plan”. The three-point mixture design proposed specified a support point in the interval that was optimal for the estimation of the parameters in AFT models, rather than simply the middle point. It was studied in comparison to different commonly used designs, and it proved to have a higher D-efficiency than the others.

Effect of Different Tool Geometries on the Mechanical Properties of Al-Al Clinch Joints

The use of clinch joints, e.g. vehicle structures, is determined by the reliability of the joint and its strength properties - in particular the fatigue strength. Clinch connections offer the advantage over form-closure and force-closure processes that they can also be used for hybrid material combinations. In order to be able to evaluate the influence of the geometry parameters such as e.g. undercut, neck thickness or also base thickness on the fatigue behavior, three clinch connections (in optimum and compromise design) with different tool parameters were designed and examined using the example of a joining task with aluminum sheet material. For this purpose, fatigue curves (F-N curves) in the range of high to very high numbers of load cycles (N = 105 to 107) were determined. In this load cycle range, a so-called "neck fracture" is mainly to be expected as the type of failure, whereas for quasi-static tests, a “buckling” is more likely to occur. The tests were carried out on single-cut overlapping shear tensile specimens. Metallographic and scanning electron microscopic examinations of the joints and the fracture surfaces served to identify the crack initiation site and to clarify the respective type of failure. Significant differences in the damage behaviour of the three clinching variants could be shown. This observation enables one step into the direction of fully understanding the relationship along the causal chain "joint requirements - joining process - fatigue strength". Thus the adaptability of the clinching process can be improved.

Approach to dyspnoea in pregnancy in the COVID-19 era

Importance: Dyspnoea and hypoxia in pregnant women during the COVID-19 pandemic may be due to causes other than SARS Co-V-2 infection which should not be ignored. Shared decision-making regarding early delivery is paramount. Objective: To highlight and discuss the differential diagnoses of dyspnoea and hypoxia in pregnant women and to discuss the risks versus benefit of delivery for maternal compromise. Design, setting and participants: Case series of two pregnant women who presented with dyspnoea and hypoxia during the COVID-19 pandemic. Results: Two pregnant women presented with dyspnoea and hypoxia. The first case had COVID-19 infection in the 3rd trimester. The second case had an exacerbation of asthma without concurrent COVID-19. Only the first case required intubation and delivery. Both recovered and were discharged home. Conclusion and relevance: Our two cases highlight the importance of making the correct diagnosis and timely decision-making to consider if delivery for maternal compromise is warranted. Whilst COVID-19 is a current healthcare concern other differential diagnoses must still be considered when pregnant women present with dyspnoea and hypoxia.

Contemporary free-form pavilions with the Delaunay gridshell patterns

The design of unique gridshell forms has become a key factor in effective interdisciplinary designing solutions, both architecturally aesthetic and structurally efficient. Modern bionic tendencies allow designers to implement organic shapes through proportion and mimicking the biological, developmental process by understanding the logic of the structural forms occurring in Nature. The improvement of digital tools based on algorithmic codes has enabled architects to implement their bold designs based on Nature’s technologies’ logic. The purpose of the research was to identify how the mathematical algorithms found in Nature collaborate with parametric designing influence structural optimization of the free-form structures. The Delaunay divisions used in the gridshells form-finding were obtained through various generative modeling algorithms. The case studies demonstrate how mathematical algorithms, such as structural dynamic relaxation, can support architectural aesthetic and structural optimization processes. The paper concludes that proper generative algorithmic design can compromise design diversity and search for efficiency.

The Unfinished Web

Early in the twentieth century, Los Angeles’s regional interurban electric railway, the Pacific Electric (PE), developed serious operational problems because the PE had been assembled from separate railroads that hadn’t been designed to fit together, and because Los Angeles’s explosive population growth overtaxed its facilities. The PE wanted to speed its trains and unify its system with a crosstown subway, but in 1923 the Los Angeles City1 Council blocked the PE’s plan and instead commissioned engineers and professional transit planners to devise comprehensive regional transit plans to be operated for the public good, not for private profit. These plans all focused on bringing lots of people downtown quickly, something irrelevant in a decentralizing city. Part I concludes with two seemingly propitious developments: the PE’s opening of its own mile-long but isolated Hollywood Subway, a compromise design but still impressive; and the unveiling of the most detailed and elaborate of the transit plans, as required by the new city charter. Part II, in the next issue, will describe why that comprehensive plan failed, then trace how political, economic, and demographic changes in the 1920s and 30s affected transit planning and why a plan to locate rail rapid transit in freeway medians failed. Part II will end with an examination of the PE’s financial condition as a refutation of a common explanation of the PE’s long decline.

Performance Analysis of a Three-Stream Adaptive Cycle Engine during Throttling

One advantage of the adaptive cycle engine (ACE) is its ability of throttling with constant airflow by the combined control of variable geometries, resulting in an improvement of spillage drag. However, the improvement is achieved at risk of a complex technical solution and control. This article investigates the selection scheme of variable geometries and engine configuration. It focuses on the performance of a three-stream ACE during throttling, whose configuration and control schedule are simpler than other types of ACEs. Five variable geometries are selected from seven available options through comparison analysis. The uninstalled thrust decreases from 100% to 60.36% during the subsonic throttling and to 59.81% during the supersonic throttling. Benefitting from the decreased spillage drag, the installed performance of the three-stream ACE is improved to some degree during throttling. This improvement is less than the result of a three-bypass ACE, whose configuration and control schedule are more complex. Thus, the three-stream ACE is a compromise design considering the technical risk and variable cycle characteristic, which is a better platform to verify the component technology and control schedule for the further research on a more complex type of ACE.

Robust Optimal Trailing-Edge Flaps for Helicopter Vibration Reduction for Various Flying Conditions

This paper aims to find a robust optimal design for twin trailing-edge flap for helicopter vibration reduction for various flying conditions with minimum flap power requirement. The objective is to find the optimum length and locations of twin trailing-edge flaps to minimize hub vibration in the helicopter with minimum flap power requirement and to evaluate the robustness of these optimum at various flying conditions such as advance ratio and thrust to solidity ratio. Polynomial response surface metamodels is used to approximate the hub vibration and flap power objective functions for optimization. Firstly, a single objective optimization minimizing hub vibration alone is carried out without considering the flap power requirement. A multi-objective optimization minimizing vibration and flap power is also carried out to explore the possibility of a compromise design of trailing-edge flaps. This optimization finds the robust optimal length and locations of twin trailing-edge flaps with the objective of minimizing hub vibration for various flying conditions. Result shows that a flap length of 9 percentage of the rotor is the optimum giving 55 percentage reduction in hub vibration compared to the baseline values. The corresponding inboard and outboard flap positions are 0.61R and 0.87R respectively. The robustness of these design solution with flying conditions such as advance ratio and thrust to solidity ratio are also explored.

Phase II clinical trial of six mercaptopurine (6MP) and methotrexate in patients with BRCA-defective tumors.

TPS5615 Background: BRCA1 and BRCA2 genes are critical in homologous recombination DNA repair and have been implicated in familial breast and ovarian cancer tumorigenesis. Tumor cells with these mutations demonstrate increased sensitivity to cisplatin and poly(ADP-ribose) polymerase (PARP) inhibitors. 6MP was identified in a screen for novel drugs and found to selectively kill BRCA-defective cells in a xenograft model as effectively as the PARP inhibitor, AGO14699, even after these cells had acquired resistance to a PARP inhibitor or cisplatin (Issaeva 2010). Exploiting the genetic basis of these tumours enables us to develop a more tailored approach to therapy for patients with BRCA mutated cancers. This multi-center phase II single arm trial was set up to investigate the activity and safety of 6MP with methotrexate in patients with breast or ovarian cancer who are known to have a BRCA mutation. Methods: Two-stage Simon compromise design (Jung 2001, Jung 2004) with α=0.20, power=90% to detect an increase in activity from 10 to 20%. 1st stage: if ≤ 3/30 evaluable patients respond at 8 weeks the trial will be stopped for futility; 2nd stage: if ≥9/65 evaluable patients respond at 8 weeks the treatment will be regarded as potentially effective and a phase III trial will be considered if the treatment appears safe and well-tolerated. 65 patients with BRCA defective cancer progressing after at least one prior chemotherapy or relapsed platinum resistant ovarian cancer, ECOG performance status 0-2 will be recruited and treated with daily 6MP (75mg/m2 ) and weekly methotrexate (20mg/m2) until progression. The starting dose was later reduced by 25% due to excess of expected toxicity. Patients with low TPMT activity or a low/low genotype are excluded due to the risk of increased toxicity. Prior treatment with a PARP inhibitor is permissible. Primary outcome: objective response at 8 weeks: complete, partial response or stable disease defined by RECIST 1.1. Secondary outcomes include safety, PFS, OS and quality of life. Of the 46 patients screened for TMPT activity between 15 Jun2009 and 05Dec 2012 from 12 UK sites, 31 patients were recruited. The pre-specified activity goal for the 1st stage was met and accrual into the 2nd stage continues. Clinical trial information: 2009-016846-16.