bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of antecedent drying events on structure, composition and functional traits of invertebrate assemblages and leaf‐litter breakdown in a former perennial river of Central Apennines (Aterno River, Abruzzo, Central Italy)
Authors: Di Sabatino Antonio , Coscieme Luca , Cristiano Giovanni
Published: September 2021

Because of global change and increasing anthropogenic pressures, non‐perennial rivers and streams are predicted to drastically increase in the European‐Mediterranean region. Some river basins already subject to reduced levels of available superficial flow may present a further reduction, with a significant increase in intermittence phenomena and complete drought of former perennial rivers. In this context, a sound knowledge of the ecological effects of increasing drying events on these watercourses may help to better predict impacts of the altered flow regime on structure and functions of freshwater ecosystems. In this paper, we assessed the long‐term response of invertebrate assemblages and ecosystems processes to antecedent drying events (drying memory) in a Central Apennine river (Italy). We demonstrated that compared to the perennial reach, the 7‐km downstream intermittent site, after more than 1 year from a complete superficial flow resumption, still conserved the ‘memory’ of past disturbance with marked differences in structure, composition and functional traits of assemblages which, in turn, negatively influenced the leaf‐litter breakdown process. Despite total abundance and taxa richness were on average higher at the intermittent site, antecedent droughts determined a decline of shredders and scrapers and an increase of collectors. In addition, some more sensible, semivoltine and rheophile taxa were replaced by generalist, multivoltine and more resistant taxa. Our findings confirm and extend the ‘drying memory’ hypothesis and suggest that irregular drying events in former perennial Apennine rivers may have dramatic long‐term effects on both structure and functions of lotic ecosystems.
Using coverage‐based rarefaction to infer non‐random species distributions
Authors: Engel Thore , Blowes Shane A. , McGlinn Daniel J. , May Felix , Gotelli Nicholas J. , McGill Brian J. , Chase Jonathan M.
Published: September 2021

Understanding how species are non‐randomly distributed in space and how the resulting spatial structure responds to ecological, biogeographic, and anthropogenic drivers is a critical piece of the biodiversity puzzle. However, most metrics that quantify the spatial structure of diversity (i.e., community differentiation), such as Whittaker’s β‐diversity, depend on sampling effort and are influenced by species pool size, species abundance distributions, and numbers of individuals. Null models are useful for identifying the degree of differentiation among communities due to spatial structuring relative to that expected from sampling effects, but do not accommodate the influence of sample completeness (i.e., the proportion of the species pool in a given sample). Here, we develop an approach that makes use of individual‐ and coverage‐based rarefaction and extrapolation, to derive a metric, βC, which captures changes in intraspecific aggregation independently of changes in the species pool size. We illustrate the metric using spatially explicit simulations and two case studies: (1) a re‐analysis of the “Gentry” plot data set consisting of small forest plots spanning a latitudinal gradient from North to South America and (2) comparing a large plot in high diversity tropical forests of Barro Colorado Island, Panama, with a plot in a lower diversity temperate forest in Harvard Forest, Massachusetts, USA. We find no evidence for systematic changes in spatial structure with latitude in these data sets. As it is rooted in biodiversity sampling theory and explicitly controls for sample completeness, our approach represents an important advance over existing null models for spatial aggregation. Potential applications range from better descriptors of biogeographic diversity patterns to the consolidation of local and regional diversity trends in the current biodiversity crisis.
Mini‐pillar Based Multi‐channel Electrochemical Platform for Studying the Multifactor Silver Electrodeposition
Authors: Li Zehua , Song Yongchao , Fan Chuan , Xu Tailin , Zhang Xueji
Published: September 2021

Here, we demonstrated a mini‐pillar based multi‐channel electrochemical platform that can efficiently adjust multiple electrochemical deposition parameters in the microdroplet arrays to control and predict the final structures of silver nanomaterials. Each mini‐pillar is capable of anchoring microdroplet to form a separate microreactor, and the electrodes are integrated to achieve a multi‐channel electrochemical electrodeposition platform. We systematically investigated the multiple deposition parameters of silver nanostructures and summarized the relevant experience of electrochemical silver deposition to guide silver nanostructure preparation. Such the mini‐pillar based microdroplet platform provides an approach for further high‐throughput and intelligent nanomaterial fabrication.
Multiscale evaluation method of the drag effect on shallow water flow through coastal forests based on 3D numerical simulations
Authors: Nomura Reika , Takase Shinsuke , Moriguchi Shuji , Terada Kenjiro , LeVeque Randall J.
Published: September 2021

This study presents a method for determining the drag parameter in the 2D shallow water (SW) equation for flows through a coastal forest by conducting a series of 3D numerical simulations (3D NSs). Following the theory of multiscale modeling, an evaluation method procedure is proposed. We first prepare a local test domain that contains a sufficient number of trees to constitute part of a coastal forest. Then, 3D NSs are conducted in this test domain with various inflow conditions. Based on the corresponding results, the momentum losses over the test domain are converted into the drag parameter of the global SW equation. A response surface of the drag parameter is constructed as a function of the flow conditions. The stabilized finite element method is employed for both the local and the global NSs, and the phase‐field method is utilized to represent 3D free surfaces. Comparisons between the 2D SW calculation results and the 3D NS results are also performed to verify the validity of the proposed method.
Iron production in Ptolemaic Egypt: From the Abu Gerida specular hematite mines to the Hamama smelting workshop
Authors: Abd El‐Rahman Yasser , Serneels Vincent
Published: September 2021

Although ancient Egypt has a firmly established record of mining and metallurgy of gold and copper, iron production in ancient Egypt is less well documented. Evidence of ancient iron manufacture in Egypt is to be found in the burnt plant remains, slag fragments, and a furnace‐like structure discovered in the Hamama workshop in the Eastern Desert of Egypt. The iron ore required for iron production was delivered from the nearby specular hematite mines of the Abu Gerida area. This Egyptian specularite is geochemically distinguished from other Mediterranean varieties of specularite such as those in Elba, Tuscany, and Seriphos Island. The bloomery iron smelting process in the Hamama workshop produced two types of slags: furnace slags and tapping slags. These two types show different petrographic features and geochemical signatures. Some of the geochemical signatures of the slags, such as their high calcium contents, were derived from charcoal, while others were related to the ore used during the smelting process. Radiocarbon dating of the charred plant remains from the Hamama workshop suggests that the iron smelting activities took place in the early Ptolemaic era. Iron production was seasonal and was conducted by locals who most likely had dynamic socioeconomic ties with the urban centers of the Nile valley.
Breeding custom‐designed crops for improved drought adaptation
Authors: Varshney Rajeev K. , Barmukh Rutwik , Roorkiwal Manish , Qi Yiping , Kholova Jana , Tuberosa Roberto , Reynolds Matthew P. , Tardieu Francois , Siddique Kadambot H. M.
Published: September 2021

The current pace of crop improvement is inadequate to feed the burgeoning human population by 2050. Higher, more stable, and sustainable crop production is required against a backdrop of drought stress, which causes significant losses in crop yields. Tailoring crops for drought adaptation may hold the key to address these challenges and provide resilient production systems for future harvests. Understanding the genetic and molecular landscape of the functionality of alleles associated with adaptive traits will make designer crop breeding the prospective approach for crop improvement. Here, we highlight the potential of genomics technologies combined with crop physiology for high‐throughput identification of the genetic architecture of key drought‐adaptive traits and explore innovative genomic breeding strategies for designing future crops.
A method to remove the influence of fixative concentration on postmortem T2 maps using a kinetic tensor model
Authors: Tendler Benjamin C. , Qi Feng , Foxley Sean , Pallebage‐Gamarallage Menuka , Menke Ricarda A. L. , Ansorge Olaf , Hurley Samuel A. , Miller Karla L.
Published: September 2021

Formalin fixation has been shown to substantially reduce T2 estimates, primarily driven by the presence of fixative in tissue. Prior to scanning, post‐mortem samples are often placed into a fluid that has more favourable imaging properties. This study investigates whether there is evidence for a change in T2 in regions close to the tissue surface due to fixative outflux into this surrounding fluid. Furthermore, we investigate whether a simulated spatial map of fixative concentration can be used as a confound regressor to reduce T2 inhomogeneity. To achieve this, T2 maps and diffusion tensor estimates were obtained in 14 whole, formalin‐fixed post‐mortem brains placed in Fluorinert approximately 48 hr prior to scanning. Seven brains were fixed with 10% formalin and seven brains were fixed with 10% neutral buffered formalin (NBF). Fixative outflux was modelled using a proposed kinetic tensor (KT) model, which incorporates voxelwise diffusion tensor estimates to account for diffusion anisotropy and tissue‐specific diffusion coefficients. Brains fixed with 10% NBF revealed a spatial T2 pattern consistent with modelled fixative outflux. Confound regression of fixative concentration reduced T2 inhomogeneity across both white and grey matter, with the greatest reduction attributed to the KT model versus simpler models of fixative outflux. No such effect was observed in brains fixed with 10% formalin. Correlations between the transverse relaxation rate R2 and ferritin/myelin proteolipid protein (PLP) histology lead to an increased similarity for the relationship between R2 and PLP for the two fixative types after KT correction.
Mental health of people of diverse genders and sexualities in Aotearoa/New Zealand: Findings from the New Zealand Mental Health Monitor
Authors: Tan Kyle K. H. , Wilson Adelaide B. , Flett Jayde A. M. , Stevenson Brendan S. , Veale Jaimie F.
Published: September 2021

Issues addressed

To examine the mental health inequities, and social exclusion and isolation and protective factor differences between people of diverse genders and sexualities (lesbian/gay, bisexual, gender diverse and takatāpui) and cisgender and heterosexual people in Aotearoa/New Zealand.

Methods

We employed data from the pooled probability sample of 2016 and 2018 New Zealand Mental Health Monitor. The sample comprised of 2938 people at least 15 years old, of which 93 had diverse gender and sexuality identities. Generalised linear models were used to test for differences in mental health (current and lifetime mental distress, depression, anxiety, self‐harm and suicide), social exclusion and isolation, and friend and family support for people of diverse genders and sexualities. We also conducted exploratory linear regression analyses to examine whether mental health difficulties were associated with social exclusion and isolation and friend/family support.

Results

People of diverse genders and sexualities had high rates of mental health difficulties across all variables we examined. For example, people identifying as diverse genders and sexualities had three times the risk of considering self‐harm and suicide than their cisgender and heterosexual counterparts (22% vs 5%; RR = 3.12). People of diverse genders and sexualities also scored an average of 6.08 points higher on the 27‐point PHQ‐9 depression scale when they had experienced social isolation, and 4.01 points higher when they experienced social exclusion.

Conclusion

Our results are consistent with current literature on the large mental health inequities faced by people of diverse genders and sexualities.

So what?

Policy makers and health care providers in Aotearoa/New Zealand should consider the negative mental health consequences of social exclusion and isolation for people of diverse genders and sexualities.
Hybrid nanofluid (MoS2–SiO2/water) flow with viscous dissipation and Ohmic heating on an irregular variably thick convex/concave‐shaped sheet in a porous medium
Authors: Yaseen Moh , Rawat Sawan K. , Kumar Manoj
Published: September 2021

The objective of the present investigation is to find the convex and concave shape effects on radiative hybrid nanofluid (MoS2–SiO2/water) flow. Moreover, the surface is assumed to be permeable in an attempt to achieve the suction/injection of hybrid nanofluid through the surface of a stretching/shrinking sheet. As a novelty, the flow is studied under the influence of space‐ and temperature‐reliant heat source/sink, viscous dissipation, Ohmic heating on stretching/shrinking surface embedded in a porous medium. First, similarity transformations are used to transcribe the momentum and thermal equations in nondimensional form, and then Runge–Kutta–Fehlberg method is used to solve the hybrid nanofluid flow problem numerically. Effects of the convex and concave shape of the sheet with nanoparticles volume fraction, Eckert number, space‐ and temperature‐dependent heat source/sink, thermal radiation parameter, and suction/injection parameter on the temperature and velocity profiles are studied. Results reveal that the convex‐shaped stretching/shrinking sheet assists both flow and thermal distribution of hybrid nanofluid (MoS2–SiO2/water) flow in comparison to the concave‐shaped sheet. The role of Eckert number and both heat source parameters is to increase the temperature of the hybrid nanofluid (MoS2–SiO2/water) flow as well as heat transfer rate at the surface of the sheet. When the volume fraction of SiO2 nanoparticles is increased from 1% to 5%, the heat transfer coefficient also increases by 15.47% and 14.28%, for flow over the convex‐ and concave‐shaped sheets, respectively.
Joule–Thomson effect investigations on a cryogenic three‐fluid–three thermal communication heat exchanger
Authors: Chodankar Vishnudas Alias Vipul L. , Aswatha  , Krishna V. , Seetharamu K. N.
Published: September 2021

The present study investigates the Joule–Thomson (JT) effect due to pressure drop on three‐fluid heat exchangers (HXs) with three thermal communications. The increased miniaturization of cryogenic HXs has led to the introduction of the JT effect. The present study investigates JT effects on a three‐fluid HX with three communications presenting different JT effects, which leads to a rise or drop in effectiveness values. The study is carried out using finite element analysis and MATLAB, considering seven nondimensional parameters of which one is JT pressure drop. The highest effectiveness is achieved for the positive JT effect at the hot stream. This improved effectiveness at hot fluid is achieved by maintaining the size (number of transfer units) of the HX more than 3.1, along with the ratio of the cold fluid heat capacity to the hot fluid heat capacity above 0.8 and the intermediate fluid temperature above 0.7.
Numerical investigation into flow and solidification behavior of billet continuous casting with and without mold electromagnetic stirring
Authors: Gupta Vipul Kumar , Jha Pradeep Kumar , Jain Pramod Kumar
Published: September 2021

Mold electromagnetic stirring (M‐EMS) in the continuous casting process improves the metallurgical quality of the caster as it acts as a dendrite breaker and increases the heat transfer. In this study, a numerical model of molten steel flow and solidification of continuous casting billet caster is developed. Further, this model is coupled with M‐EMS to investigate the influence of stirring on molten steel flow dynamics and solidification in the mold. The magnetic field calculations are performed in ANSYS Maxwell and computational fluid dynamics solver Fluent is used for flow field and heat transfer calculations. The fluid flow, temperature field, and solidification are investigated and compared with without M‐EMS case. The results indicate that the application of M‐EMS significantly changes flow dynamics in the mold. Strong swirl flow is dominant and a significant increment in tangential velocity is observed in the presence of M‐EMS. High intense rotational flow about the strand center gives rise to the superheat transfer near the solidification front, which further enhances the temperature in this region and thereby decreases the solidification thickness in the M‐EMS‐affected zone
Renal effects of long‐term lithium therapy, revisited
Authors: Yazıcı M. Kâzım , Özçelik Eroğlu Elçin , Ertuğrul Aygün , Anıl Yağcıoğlu A. Elif , Ağaoğlu Esen , Karahan Sevilay , Eni Nurhayat , Sağlam Aykut Demet , Kavak Özlem , Erdem Yunus
Published: September 2021

Objective

The aim of this study was to investigate the effect of lithium treatment on renal function and to determine influencing factors. In addition, the utility of spot urine protein/creatinine ratio in detection of lithium induced nephropathy was also investigated.

Methods

Serum concentrations of lithium, blood urea nitrogen (BUN), creatinine, estimated glomerular filtration rate (eGFR), and urinalysis including protein/creatinine ratio were measured in 375 patients using lithium.

Results

Patients taking lithium for ≥8 years had higher BUN, creatinine levels, percentage of proteinuria, percentages of stage 2 and 3 chronic kidney disease (CKD); lower urine density and eGFR compared to patients taking lithium <8 years. Urine density was lower in groups with >0.8 and 0.6–0.8 mmol/L lithium level than <0.6 mmol/L. Predictors of CKD were serum level of lithium, dose of lithium, cumulative duration of lithium use, age at onset of illness, and caffeine consumption.

Conclusions

Detrimental effects of lithium on renal functions were detected after lithium use for ≥8 years. Proteinuria measured by spot urine protein/creatinine ratio can be detected even when eGFR is >90 ml/min/1.73 m2. Spot urine protein/creatinine ratio, which is a cost‐effective and practical laboratory test, can be used to monitor lithium‐treated patients.
Duloxetine attenuates pain in association with downregulation of platelet serotonin transporter in patients with burning mouth syndrome and atypical odontalgia
Authors: Nakamura Mariko , Yoshimi Akira , Mouri Akihiro , Tokura Tatsuya , Kimura Hiroyuki , Kishi Shinichi , Miyauchi Tomoya , Iwamoto Kunihiro , Ito Mikiko , Sato‐Boku Aiji , Ozaki Norio , Nabeshima Toshitaka , Noda Yukihiro
Published: September 2021

Objective

The aim of this study was evaluation of the association between severity of pain and expression of total or ubiquitinated serotonin transporter (SERT) protein in patients with burning mouth syndrome and atypical odontalgia (BMS/AO), who were treated by duloxetine.

Methods

Patients with BMS/AO were assessed for severity of pain using the visual analog scale (VAS), and expression of total and ubiquitinated SERT protein in platelets before (baseline) and 12 weeks after duloxetine‐treatment.

Results

The expression of total and ubiquitinated SERT protein at baseline in all patients (n = 33) were higher and lower, respectively, compared to those in healthy controls. 12 weeks after duloxetine‐treatment, there was no difference in the total SERT protein levels between patients (n = 21) and healthy controls. In the 16 patients who could be measured, mean VAS scores and total SERT protein levels were significantly decreased after the treatment, compared to those at baseline. There was tendency for a positive correlation between total SERT protein levels and VAS scores in these patients.

Conclusions

Our findings indicate that duloxetine relieves pain in association with downregulation of platelet SERT expression in patients with BMS/AO.
Randomly initialized convolutional neural network for the recognition of COVID‐19 using X‐ray images
Authors: Ben Atitallah Safa , Driss Maha , Boulila Wadii , Ben Ghézala Henda
Published: September 2021

By the start of 2020, the novel coronavirus (COVID‐19) had been declared a worldwide pandemic, and because of its infectiousness and severity, several strands of research have focused on combatting its ongoing spread. One potential solution to detecting COVID‐19 rapidly and effectively is by analyzing chest X‐ray images using Deep Learning (DL) models. Convolutional Neural Networks (CNNs) have been presented as particularly efficient techniques for early diagnosis, but most still include limitations. In this study, we propose a novel randomly initialized CNN (RND‐CNN) architecture for the recognition of COVID‐19. This network consists of a set of differently‐sized hidden layers all created from scratch. The performance of this RND‐CNN is evaluated using two public datasets: the COVIDx and the enhanced COVID‐19 datasets. Each of these datasets consists of medical images (X‐rays) in one of three different classes: chests with COVID‐19, with pneumonia, or in a normal state. The proposed RND‐CNN model yields encouraging results for its accuracy in detecting COVID‐19 results, achieving 94% accuracy for the COVIDx dataset and 99% accuracy on the enhanced COVID‐19 dataset.
Aspect‐Oriented Architecting Using Architecture Frameworks
Authors: Martin James N.
Published: September 2021

In the early days of systems engineering, we had a few tried and true methods for depicting the structure and behavior of a system, such as functional flow diagrams, control flow diagrams, state transition diagrams, schematic block diagrams, and system breakdown structure. Nowadays we have a wider variety of choices when it comes to the creation of architecture views. The Unified Architecture Framework, for example, defines 71 possible architecture views that can be created. An easy and intuitive way to navigate the many available offerings was needed. Hence, most architecture frameworks have adopted a “grid” approach to help organize the various views. One of the key dimensions of this organizing approach is the use of architecture aspects. This paper will examine the various frameworks to determine how they organize their views and how they address the different aspects and perspectives of the architecture being described. These concepts were used as the basis for an aspect‐oriented architecting approach reflected in the recently revised version of the ISO 42010 standard on architecture description.
Developing a Topic Network of Published Systems Engineering Research
Authors: Oosthuizen Rudolph
Published: September 2021

This paper investigates past systems engineering research structure by developing a network of research topics from an extensive corpus of publications. The bibliometric data analysis from the published research articles provides valuable information on past progress and future scientific discipline opportunities. Topic modelling, a form of unsupervised machine‐learning‐based natural language processing, is applied to extract the main topics from the titles and abstracts of a wide range of papers published about systems engineering. The co‐occurrence of research topics in these papers provides the data for generating network diagrams. A visual and quantitative network analysis of these topics revealed several cliques and clusters of research topics in systems engineering. Systems engineering researchers should consider these relationships between these research topics to plan a systems engineering research project.
Framework for Formal Verification of Machine Learning Based Complex System‐of‐System
Authors: Raman Ramakrishnan , Gupta Nikhil , Jeppu Yogananda
Published: September 2021

A complex system is characterized by emergence of global properties which are very difficult, if not impossible, to anticipate just from complete knowledge of component behaviors. Emergence, hierarchical organization and numerosity are some of the characteristics of complex systems. Recently, there has been an exponential increase on the adoption of various neural network‐based machine learning models to govern the functionality and behavior of systems. With this increasing system complexity, achieving confidence in systems becomes even more difficult. Further, ease of interconnectivity among systems is permeating numerous system‐of‐systems, wherein multiple independent systems are expected to interact and collaborate to achieve unparalleled levels of functionality. Traditional verification and validation approaches are often inadequate to bring in the nuances of potential emergent behavior in a system‐of‐system, which may be positive or negative. This paper describes a novel approach towards application of machine learning based classifiers and formal methods for analyzing and evaluating emergent behavior of complex system‐of‐systems that comprise a hybrid of constituent systems governed by conventional models and machine learning models. The proposed approach involves developing a machine learning classifier model that learns on potential negative and positive emergent behaviors, and predicts the behavior exhibited. A formal verification model is then developed to assert negative emergent behavior. The approach is illustrated through the case of a swarm of autonomous UAVs flying in a formation, and dynamically changing the shape of the formation, to support varying mission scenarios. The effectiveness and performance of the approach are quantified.
Demonstrating the Value of Systems Engineering as the Professional Standard of Care
Authors: Hoehne Oliver
Published: September 2021

One of the most difficult challenges systems engineers face when attempting to introduce or expand the application of systems engineering (SE) is the demonstration of the systems engineering value. As SE is an upfront investment that may not pay dividends before sometime in the possibly distant future, business leaders unfamiliar with the process can be skeptical about the value of SE, especially in industries where SE is still an emerging discipline without a proven track record.

Sometimes, however, the value of systems engineering can be demonstrated by the increased risk of NOT applying systems engineering, for example the Central Artery/Tunnel Project (CA/T), commonly known as the Big‐Dig. Designed and built between 1982 and 2007, it was the most expensive highway project in the US at the time (approx. $21 billion in 2020 dollars), and was plagued by thousands of water leaks, design flaws, charges of poor execution, use of substandard materials and other issues, which eventually led to the death of a motorist and criminal arrests (Wiki, 2020, NTSB, 2006). The project managing consortium agreed to pay $407 million in restitution and several smaller companies agreed to pay a combined sum of approximately $51 million (AP, 2008). The settlement agreement included a statement of facts as the basis for liability, specifically addressing several areas of construction management oversight failures, including the use of non‐specified material, the use of substandard materials, as well as ignored observations of failing epoxy bolt load tests (AP, 2008). The consortium was paid more than $2 billion in fees (AP, 2008) that would have resulted in approximately $160M in profit (applying an 8% profit target). Looking at this project purely from an ROI perspective, however, the consortium not only lost all profit, but faced an additional $247M ($407M ‐ $160M) in losses.

The issues identified above are typically addressed in construction specifications describing in detail the scope of work, materials, installation, and quality of workmanship. The Big Dig example should provide a cautionary tale of the risks associated with managing and overseeing construction projects, such as infrastructure, transportation, water, energy, or other projects.

This paper describes the application of systems engineering principles to construction specifications in a large infrastructure project using a case study approach. The paper demonstrates the systematic exercise of a reasonable level of care, diligence, and skill, commonly described as the professional standard of care, thereby demonstrating the value of systems engineering as a successful liability protection and risk mitigation strategy.
Opportunities and Challenges of Sociotechnical Systems Engineering
Authors: Gill John , Zonnenshain Avigdor , Lamoureux Danielle
Published: September 2021

The authors propose a Sociotechnical Systems Engineering (STSE) framework that elevates the requirements and concerns of external/global stakeholders to be on par with those of traditional system users and counters the argument that profit motivation should be the dominant factor when deciding which systems we should build. STSE offers a more complete perspective on what it means to deliver a balanced solution. The authors distill unique elements of Sociotechnical Systems Engineering (STSE) and an integrated framework. The framework serves as the foundation for ongoing discussion of opportunities and challenges associated with our evolving practice of SE. Traditional SE framework, practices and processes remain intact. STSE emphasizes the importance of accounting for societal considerations and hidden costs excluded from our current decision‐making consideration. Post‐deployment societal outcomes we experience may not lie in our ability to perform SE/STSE, but in the governing motivations as we do so.
Evaluation of Requirements Management Processes Utilizing System Modeling Language (SysML) Executable Models
Authors: Katz Tami
Published: September 2021

Like many project processes, requirements management can be time consuming and costly if not well planned. The fundamentals of the process steps can be obtained through literature search, however the variation of application can lead to program cost challenges if not tailored for the project's risk posture and budget scope. This paper investigates various published requirements management processes, presents a fundamental process model, demonstrates a method to capture the process steps using a Systems Modeling Language (SysML), and shows the results of a simulation of the process steps enabling a comparison of outcomes for a project. This method investigates an option of using duration constraints to calculate labor hours based on process steps, and uses inputs from the project's requirement data to provide a method of calculating systems engineering labor hours utilizing the Constructive Systems Engineering Cost Model (COSYSMO) in a SysML model. This work is intended to show how SysML can be used to support development and refinement of project processes in general, with specific focus on how this method can enable implementation of requirements management in a way that provides insight into potential cost and schedule impacts to the project.
The risk maturity model: a new tool for improved risk management and feedback
Authors: Aas‐Haug Brede , Haskins Cecilia
Published: September 2021

Norwegian governmental institutions use their risk management regulations to acquire and manage projects and assess the institutional practices. After many years documenting a positive trend, the audit authority noticed a stagnation in process improvement across the organization. A literature review of the use of risk management maturity models from other industries suggested a method for achieving continuous improvement. A corresponding maturity model has been developed and tested with positive results.

This research developed a risk maturity model based on compliance requirements for the Norwegian defense sector. The intended use of this model is as the foundation for conducting assessments through audits and provide explicit guidance toward given requirements that facilitate extensive improvement in application of the risk management system. Use of the model in performing maturity assessments of organizational elements within the defense sector showed that the model supports the subsequent improvement activities through providing better understanding of the existing situation, and explicit visual feedback on areas that are satisfactory and areas in need of improvement. A maturity model provides a stepwise path showing the next level of improvement on the way to achieve required performance.
Measuring performance and identifying metrics of machine protection systems for particle accelerators
Authors: Kövecses Szandra , Nordt Annika , Bergsjö Dag Henrik
Published: September 2021

Machine protection systems are used at high power particle accelerators in order to prevent long downtimes due to equipment damage. No systematic way to measure their success at reaching this goal exists (the performance of machine protection systems). This paper briefly goes through the history of particle accelerators and gives an introduction to machine protection for particle accelerators. Two metrics to measure the performance of machine protection systems are suggested and discussed. This paper is part of the work to define the problem from the perspective of a recently initiated PhD‐student project.
Network Rail's Systems Integration for Delivery (SI4D) Framework
Authors: Price Derek A
Published: September 2021

In the United Kingdom Network Rail delivers hundreds of infrastructure projects every year to enhance and renew the national rail network. This forms a capital delivery portfolio measured in Billions of pounds per year, from platform extensions to large scale regionwide upgrades.

This paper presents a case study of the development and implementation of Network Rail's System Integration (SI) for Delivery framework. The focus here is on

Drivers for a new framework,

Implementation embedded with existing management systems,

Language and terminology used to communicate the new framework.

The framework is designed to be flexible in terms of effort relative to complexity and benefit and aims to optimise the performance of new infrastructure delivered by Network Rail.

The framework consists of a suite of competence management, training, processes, products and tools that have been embedded within existing management systems to support a consistent and cohesive approach to delivery of capital projects
Using Models and simulation for concept analysis of Electric Roads
Authors: Kihlström Lars‐Olof , Hause Matthew , Kihlström Andreas , Karlsson Ida , Chen Bilin
Published: September 2021

Using electricity to directly power moving vehicles has been used for a long time as evidenced by trains, trams, and electrical buses. Providing electricity to move heavy transport trucks on roads Therefore does not represent a huge innovation. Since heavy haulage traffic on roads represents a significant part of carbon dioxide emissions, electric roads (ERs) that can provide engine power to heavy road haulage is seen as significant by the Swedish government (Bateman et al, 2018SP04EN). Several Swedish government authorities as well as private companies are actively testing equipment both for trucks as well as roads. Once they have been deployed, ERs will also provide benefits as regards air quality and traffic noise. This paper describes a concept analysis project that uses models and simulation to analyze electric road scenarios. Electric road enabled trucks of different types run along an electric road and are subjected to different road conditions, speed restrictions as well as queues over a defined amount of time. The ability to analyze both management and energy consumption of an electric road is of paramount importance in determining its ability to accomplish the desired carbon‐dioxide emission reductions.
Investigation of Remote Work for Aerospace Systems Engineers
Authors: van Velzen Eric , Olechowski Alison
Published: September 2021

In many industries, remote work is becoming increasingly common. The global COVID‐19 pandemic has accelerated this shift, which poses a particular challenge to aerospace systems engineers (ASEs). ASE work is complex, consisting of a number of tasks that are traditionally largely conducted in‐person. Little literature exists to establish a basic understanding of remote work in the context of aerospace systems engineering development projects.

This paper presents the results of an interview study, where hypotheses are explored to provide initial understanding of remote work in this context, and to motivate future studies. Analysis revealed: Design reviews experienced both challenges and benefits; Remote work has complicated collaborative work with artifacts; Assembly, Integration and Testing activities experienced significant challenges; Solutions have been thought of or implemented by ASEs, in particular the use of Slack and strategies managers may use to support their team members. Several additional research questions are motivated.
A Method to Visualize the Relationship between Regulations and Architectural Constraints
Authors: Ohno Yoshiko , Shirasaka Seiko
Published: September 2021

The increasing influence of technologies like IoT and AI has made “regulation by architecture” an important discussion point. While system architecture needs to address legal regulations, it also acts as a constraint on stakeholders. Architectural constraints do not require the subject to be aware of them and automatically enforce by preempting behavior. This feature leads to efficient governance, but previous research pointed out concerns caused by the “Unnecessity of Awareness” of architecture. This concern should be avoided by visualizing architectural constraints. However, a concrete visualization method has not been proposed.

We propose a method to visualize the relationship between regulations and architectural constraints in accordance with ISO/IEC/IEEE42010:2011. System engineers use this method to reveal the constraints faced by users owing to the architecture and verify that there is no deviation from the regulations.

We interviewed legal and engineering experts and concluded that the proposed method is effective under certain conditions.
Idea Development Method, Applying Systems Design Thinking in a Very Small Entity
Authors: Langen Tommy , Syverud Elisabet
Published: September 2021

Very Small Entities (VSE) delivers a substantial percentage of the world's product and services. These agile and innovative companies approach their market in a flexible, informal, and human‐centered approach. Their transformation from startup phase to an established company can be problematic. As they grow, the VSE must put more emphasis on incorporating formal organizational structure and processes to cope with the increased size and complexity. Failure in adapting often results in a negative market effect. Systems Design Thinking (SDT) is a combination of Systems Engineering, Systems Thinking, and Design Thinking. There is an increased awareness that the perspectives of SDT bring value to organizations. However, the advantage of SDT is not well understood for VSEs that are in the maturing phase. In this work, the researchers explore the value of SDT for very small enterprises transitioning from infancy to adolescence. The article presents a new method for idea development based on SDT principles and tailored to the needs of a VSE. Case‐based research is applied in a small company to understand the needs and verify the desirability, feasibility, and viability of our proposed method. The results suggest that an SDT approach improves the company's ability to capture and develop ideas and can help grow the company.
THE BENEFITS OF ENHANCED CONTACT TRACING AND QUARANTINE TO RESUME AND MAINTAIN COLLEGE‐CAMPUS OPERATIONS: AN AGENT‐BASED PROABLISTIC SIMULATION ANALYSIS
Authors: Bashatah Jomana A. , Sherry Lance , Roess Amira
Published: September 2021

Universities, K‐12 schools, sports programs, and businesses are operating (and generating revenue) during the COVID‐19 pandemic. The key to operating safely is to manage the risk of infectious events that lead to an outbreak and require excess costs and/or lead to a complete shutdown of the enterprise. To operate through a pandemic, organizations must plan to accommodate the quarantine of exposed individuals and isolation of infected individuals (e.g. accommodations and food). To prevent or slow infections, organizations can implement mitigation options to: (1) reduce peer‐to‐peer transmission in operations (e.g. social distancing and protective equipment), (2) identify and quarantine individuals who have been exposed (e.g. daily symptom and exposure screening, randomized surveillance testing, timely contact tracing), and (3) test and/or isolate individuals who are infected (asymptomatic as well as symptomatic). Mitigation option #1 prevents individuals from becoming infected. Mitigation options #2 and #3 remove people who are infected from circulation, preventing them from infecting others. The efficacy of mitigations #2 and #3 have a non‐linear impact due to the amplifying effect of circulating asymptomatic/symptomatic individuals.

An agent‐based, probabilistic model measured the efficacy of contact tracing and quarantine on infection counts and lost productivity (i.e. total days in quarantine and isolation). Two modes of operations were evaluated: Cohort with no interaction with the community (i.e. hermetically sealed “bubble” with one undetected infection at start), Cohort with limited interaction with community (e.g. attending classes, take‐out food court). For the No Community Interaction cohort, a contact tracing and quarantine with only 25% efficacy and compliance reduced the infection count from 60% to 6%. This yielded a reduction in total lost productivity days of 94%. In contrast, the Limited Community Interaction cohort required more than 75% efficacy and compliance in contact tracing and quarantine to reduce the infection count from 80% to 30%. This yielded a reduction in total lost productivity days of 30%.

These results highlight the role interaction with the general community has on a cohort's health. Further, the results emphasize the utility of contact tracing and quarantine within a cohort to mitigate community‐wide practices that are not under jurisdiction of managers of the enterprise. The implications of these results and limitations of the model are discussed.
Application of T‐shaped engineering skills in complex multidisciplinary projects
Authors: Trogstad Ida Kristin , Kokkula Satyanarayana , van der Aker Joris
Published: September 2021

In this research, we study the application of T‐shaped engineering profile skills in complex multidisciplinary projects. Literature survey revealed a relation between the systems engineers and technical experts; we explore this relation further here. Data collection was through a survey with practicing engineers, technical managers, and academics with industrial experience. Research findings revealed that the ‘systems engineering discipline’ shall be used as a common language between systems engineers and technical experts in projects. We identified a gap between the design and production lifecycle stages. Questionnaire respondents confirmed this gap during validation and mentioned the lack of ‘operational context’ as a challenge in the system development process. There is a clear interest in acquiring T‐shaped skills through training. To achieve this, the technical experts shall use training programs within their organization, by focusing on the ‘systems engineering discipline’ and ‘system's domain & operational context’ proficiencies.
Analyzing Standard Operating Procedures Using Model‐Based Systems Engineering Diagrams
Authors: Bashatah Jomana A. , Sherry Lance , Dam Steve , Flenniken Lauren , Hartmann Patrick , Harold Tom
Published: September 2021

Standard Operating Procedures (SOPs) are critical for the safe operations of complex, hazard‐sensitive systems. The SOPs are particularity important for dealing with non‐normal operations in which the human operator must intervene and/or provide instructions to the automation. Under these rare circumstances, the appropriate human operator actions are defined by SOPs. The SOPs must be completed within an Allowable Operational Time Window (AOTW) to avert a hazardous outcome. In many cases, the AOTW is not fixed, but exhibits variance due to complex non‐linear, plant dynamics. The Time on Procedure (ToP) is also subject to variability due to human factors such as experience, proficiency, fatigue, and the efficacy of the SOPs and the supporting automation user‐interface. For this reason, it is critical to evaluate the dynamic performance of the SOP in the context of the operations and determine the likelihood of the ToP exceeding the AOTW.

This paper describes how to model SOPs and perform SOP analysis using LML/SysML Action/Activity Diagrams that can be found in most Model‐based System Engineering (MBSE) tools. The method enables the SOP designer to assess the performance of the SOP by accounting for human factors and operation dynamics. The ability to test the procedures in a MBSE tool can inform the system design and verify the procedure design early in the development life‐cycle. The implications and limitations of this approach are discussed.
Automated trade study analysis based on dynamic requirements verification in the model‐based system engineering
Authors: Bankauskaite Jovita , Strolia Zilvinas , Morkevicius Aurelijus
Published: September 2021

In this complex world, where evolving systems communicate independently to achieve a common goal, the ability for an engineer to develop systems with traceability to requirements, using one integrated architecture model that enables all types of automated analysis (e.g., impact analysis, gap analysis, trade study analysis, and simulation) is becoming more and more vital. Today, the core enabler for automated analysis is the application of model‐based systems engineering practices. Model‐based systems engineering is used to capture system or systems of systems architecture as descriptive and analytical system models, which relate text‐based requirements to the architecture and provide an infrastructure to support trade study analysis. One of the core techniques to perform such analysis is requirements verification. This paper proposes an approach for an automated trade study analysis based on dynamic requirements verification in the model‐based systems engineering environment, with a goal to support trade of analysis both in the system of systems and systems engineering domains.