bluuebunny/crossref_metadata_2025 huggingface dataset:
MRI abnormality of the bilateral middle cerebellar peduncles and long‐term follow‐up in hypoglycemic encephalopathy: A case report
Authors: Sugimoto Takamichi , Morikawa Yuria , Ishikawa Ruoyi , Abe Takafumi , Ohno Narumi , Giga Mayumi , Naito Hiroyuki , Kono Tomoyuki , Nomura Eiichi , Yamawaki Takemori
Published: November 2020

A 32‐year‐old woman had a medical history of a hypoglycemic attack. One year later, she had a second hypoglycemic attack. She could move her limbs after an intravenous glucose injection, but communication difficulty and cerebellar ataxia remained. We found brain MRI abnormalities in the bilateral middle cerebellar peduncles and internal capsule. The patient was diagnosed with insulinoma. High‐intensity MRI fluid‐attenuated inversion recovery at the bilateral middle cerebellar peduncles remained on the 45th day, but it disappeared after 1.7 years from the second attack. Consciousness improved, but cerebellar ataxia remained. The patient was able to walk without a cane following rehabilitation. There are few case reports of MRI abnormalities in the bilateral middle cerebellar peduncles in hypoglycemic encephalopathy. This case showed that infratentorial lesions, such as those in the middle cerebellar peduncles, might be observed on MRI in hypoglycemic encephalopathy that MRI abnormalities might disappear at long‐term follow‐up.
Connectivity at a cost: Economic dynamics of restoring habitat connectivity
Authors: Akpalu Wisdom , Stage Jesper
Published: November 2020

Both in the United States and in Europe there is ongoing work on reversing habitat fragmentation and the attendant loss in biodiversity in river systems caused by hydropower and other developments. Fish ladders and other measures are being introduced to restore the connectivity in river systems. In this paper, we set up a theoretical model to investigate what the conditions are for such an investment to be socially profitable. We find that, even in cases where it would have been socially preferable not to build hydropower installations in the first place, connectivity‐restoring measures affecting the installations are not necessarily socially beneficial. This is the case for a wide range of plausible assumptions about discount rates, investment costs and productivity losses.

Recommendations for Resource Managers:

Even in situations where it would have been socially preferable not to build hydropower plants in a river, carrying out measures now to reconnect different parts of the river and re‐establish ecological connectivity may not be socially desirable.

Any economic analysis of the value of re‐establishing ecological connectivity needs to consider the time lags involved until the river ecology is restored.

Reducing the time lags by actively resettling species does not necessarily improve the overall social profitability of reconnecting the different parts of the river.
A rare case of hypoplastic coronary sinus partially draining into right superior vena cava: A case report
Authors: Kumar Vivek , Kumar Viveka , Arora Vanita
Published: November 2020

Background

The hypoplastic coronary sinus (CS) is a rare anomaly of the cardiac venous system, wherein some of the tributaries fail to join the CS. These tributaries usually drain into atrial chambers through dilated thebesian channels. We report the first case where the tributaries are draining into the right superior vena cava (SVC).

Case summary

A case of ischemic cardiomyopathy with severe LV systolic dysfunction with NYHA class III symptoms was taken for CRTD implantation. CS venogram after direct cannulation from left subclavian access revealed a hypoplastic CS. The part of CS beyond the attachment of the oblique vein of the left atrium to CS (distal to the posterolateral vein) formed a common channel and was draining into the right‐sided SVC. The posterolateral vein was of sufficient caliber so that an left ventricle (LV) lead could be implanted, and the CRTD procedure could be completed.

Discussion

Hypoplastic CS though has no pathological significance in the normal population but for CRT it can become a significant limitation. Tributaries of CS draining into right SVC are the rarest of the finding, the channel draining most likely is a remnant of the splanchnic plexus around the embryonic foregut that usually has a temporary communication with cardinal veins during intrauterine growth. This communication somehow has persisted and resulted in a channel between coronary vein and the SVC, which may be referred to as coronary veno‐cardinal vein.
A fully assembled plastid‐encoded RNA polymerase complex detected in etioplasts and proplastids in Arabidopsis
Authors: Ji Yan , Lehotai Nóra , Zan Yanjun , Dubreuil Carole , Díaz Manuel Guinea , Strand Åsa
Published: November 2020

The plastid‐encoded genes of higher plants are transcribed by at least two types of RNA polymerases, the nuclear‐encoded RNA polymerase (NEP) and the plastid‐encoded RNA polymerase (PEP). In mature photosynthesizing leaves, the vast majority of the genes are transcribed by PEP. However, the regulatory mechanisms controlling plastid transcription during early light response is unclear. Chloroplast development is suggested to be associated with a shift in the usage of the primary RNA polymerase from NEP to PEP as the expression of the plastid‐encoded photosynthesis genes is induced upon light exposure. Assembly of the PEP complex has been suggested as a rate‐limiting step for full activation of plastid‐encoded photosynthesis gene expression. However, two sigma factor mutants, sig2 and sig6, with reduced PEP activity, showed significantly lower expression of the plastid‐encoded photosynthesis genes already in the dark and during the first hours of light exposure indicating that PEP activity is required for basal expression of plastid‐encoded photosynthesis genes in the dark and during early light response. Furthermore, in etioplasts and proplastids a fully assembled PEP complex was revealed on Blue Native PAGE. Our results indicate that a full assembly of the PEP complex is possible in the dark and that PEP drives basal transcriptional activity of plastid‐encoded photosynthesis genes in the dark. Assembly of the complex is most likely not a rate‐limiting step for full activation of plastid‐encoded photosynthesis gene expression which is rather achieved either by the abundance of the PEP complex or by some posttranslational regulation of the individual PEP components.
Nonparametric volatility change detection
Authors: Mohr Maria , Neumeyer Natalie
Published: November 2020

We consider a nonparametric heteroscedastic time series regression model and suggest testing procedures to detect changes in the conditional variance function. The tests are based on a sequential marked empirical process and thus combine classical CUSUM tests from change point analysis with marked empirical process approaches known from goodness‐of‐fit testing. The tests are consistent against general alternatives of a change in the conditional variance function, a feature that classical CUSUM tests are lacking. We derive a simple limiting distribution and in the case of univariate covariates even obtain asymptotically distribution‐free tests. We demonstrate the good performance of the tests in a simulation study and consider exchange rates as a real data application.
Body flexibility and incident hypertension: The Niigata wellness study
Authors: Gando Yuko , Sawada Susumu S. , Momma Haruki , Kawakami Ryoko , Miyachi Motohiko , Lee I‐Min , Blair Steven N. , Tashiro Minoru , Horikawa Chika , Matsubayashi Yasuhiro , Yamada Takaho , Fujihara Kazuya , Kato Kiminori , Sone Hirohito
Published: November 2020

A high level of physical fitness, especially cardiorespiratory fitness, is associated with lower incidence of hypertension. However, the relationship between flexibility, which is a component of physical fitness, and the incidence of hypertension is unknown. The purpose of this study was to investigate the relationship between flexibility and the incidence of hypertension in a cohort study. A total of 22,972 (14,805 men and 8167 women; median age 49 years) normotensive participants were included in this study. Between April 2001 and March 2002, flexibility (standing forward bending) was measured using a standing trunk flexion meter. The participants were divided into quartiles of flexibility by sex and age group. Hypertension was defined as systolic blood pressure ≥ 140 mm Hg, diastolic blood pressure ≥ 90 mm Hg, or a self‐reported history of previously diagnosed hypertension or current medication for hypertension at a health examination between April 2002 and March 2008. Hazard ratios and 95% confidence intervals (95% CI) for the incidence of hypertension were estimated using Cox proportional hazards models after adjusting for age, sex, body mass index, exercise habits, smoking status, and drinking status. During 102,948 person years of follow‐up (median 5.6 years), 4235 participants developed hypertension. Compared with the lowest flexibility (quartile 1), hazard ratios and 95% CI were 0.96 (0.88 − 1.04) for quartile 2, 0.94 (0.86 − 1.03) for quartile 3, and 0.83 (0.76 − 0.91) for quartile 4. A high level of flexibility was associated with lower incidence of hypertension, independent of other confounding factors.
Impact of exercise training and supplemental oxygen on submaximal exercise performance in patients with COPD
Authors: Neunhäuserer Daniel , Reich Bernhard , Mayr Barbara , Kaiser Bernhard , Lamprecht Bernd , Niederseer David , Ermolao Andrea , Studnicka Michael , Niebauer Josef
Published: November 2020

Functional impairment caused by chronic obstructive pulmonary disease (COPD) impacts on activities of daily living and quality of life. Indeed, patients’ submaximal exercise capacity is of crucial importance. It was the aim of this study to investigate the effects of an exercise training intervention with and without supplemental oxygen on submaximal exercise performance. This is a secondary analysis of a randomized, controlled, double‐blind, crossover trial. 29 COPD patients (63.5 ± 5.9 years; FEV1 46.4 ± 8.6%) completed two consecutive 6‐week periods of high‐intensity interval cycling and strength training, which was performed three times/week with either supplemental oxygen or medical air (10 L/min). Submaximal exercise capacity as well as the cardiocirculatory, ventilatory, and metabolic response were evaluated at isotime (point of termination in the shortest cardiopulmonary exercise test), at physical work capacity at 110 bpm of heart rate (PWC 110), at the anaerobic threshold (AT), and at the lactate‐2 mmol/L threshold. After 12 weeks of exercise training, patients improved in exercise tolerance, shown by decreased cardiocirculatory (heart rate, blood pressure) and metabolic (respiratory exchange ratio, lactate) effort at isotime; ventilatory response was not affected. Submaximal exercise capacity was improved at PWC 110, AT and the lactate‐2 mmol/L threshold, respectively. Although supplemental oxygen seems to affect patients’ work rate at AT and the lactate‐2 mmol/L threshold, no other significant effects were found. The improved submaximal exercise capacity and tolerance might counteract patients’ functional impairment. Although cardiovascular and metabolic training adaptations were shown, ventilatory efficiency remained essentially unchanged. The impact of supplemental oxygen seems less important on submaximal training effects.
Policing counter‐protest
Authors: Wood Lesley
Published: November 2020

In the Trump era, when clashes between right wing protesters and left counter protesters escalate, police disproportionately repress left wing activists. Explanations that rest solely on the conservative politics and culture of the police, or the ideological targeting of the left neglect the ways political systems, identities and organizations shape interactions between police and protesters. This study draws on the research on social movements, counter‐protest and protest policing in order to explain the patterns of policing of counter‐protest.
An Interactional Space of Permanent Observability: WeChat and Reinforcing the Power Hierarchy in Chinese Workplaces
Authors: Tian Xiaoli
Published: November 2020

Does digital media empower or disempower workers? In existing studies on how information and communication technologies influence work, researchers investigate work–life boundaries and how workers use digital media to obtain more control. This article focuses on how digital media influences daily interpersonal interactions in the workplace: how does social media use influence workplace hierarchies and power dynamics? Based on 56 in‐depth interviews with WeChat users in Chinese workplaces, I find that lower‐ranked individuals were compelled to constantly express loyalty and appreciation, and publicly submit to their superordinates by clicking “like” or commenting on their WeChat posts. They also had to provide immediate and polite responses to their superordinates in WeChat group chats after work hours or to non‐work‐related issues. The distinctive features of online interaction—lack of physical interaction spaces, recordability of past conversations, and n‐adic nature of online disclosures—created an environment where past encounters were omnipresent and accessible, and placed workers under permanent observability. This social interaction environment leaves little room for forms of resistance and, in response, employees retreat into cynical performances of submission. This study finds that, under certain circumstances, WeChat use actually intensifies workplace hierarchies and power dynamics, thereby sharpening social inequality, rather than eliminating it.
Asset Limits in Public Assistance and Savings Behavior Among Low‐Income Families
Authors: Hamilton Leah
Published: November 2020

Objectives

Low‐income families receiving public benefits in the United States are often subject to asset limits for eligibility, which some argue to be counterproductive to their long‐term economic stability. Previous research suggests that families were more likely to save when asset limits increased after welfare reform in 1996. The current study builds upon this work for the years before and after the Great Recession.

Methods

This study utilized data from the Panel Study of Income Dynamics. Assets and bank account ownership of low‐income female‐headed households were compared to multiple control groups for the years 2003–2013 using a difference‐in‐difference analytical approach.

Results

Results suggest that wealth is associated with race and income, but not with asset limit policies. Bank account ownership was similarly unaffected by Temporary Assistance to Needy Families (TANF) policy.

Conclusions

It is likely that TANF policies are only one of the many barriers to asset accumulation faced by low‐income families, especially in a period of recession.
Unexpected cryptic species diversity of parasites of the family Xenidae (Strepsiptera) with a constant diversification rate over time
Authors: Benda Daniel , Votýpková Kateřina , Nakase Yuta , Straka Jakub
Published: November 2020

Parasitism is one of the most successful and ancient strategies. Due to the specialized lifestyle of parasites, they are usually affected by reductions and changes in their body plan in comparison with nonparasitic sister groups. Extreme environmental conditions may impose restraints on behavioural or physiological adaptations to a specific host and limit morphological changes associated with speciation. Such morphological homogeneity has led to the diversity of parasites being underestimated in morphological studies. By contrast, the species concept has dramatically changed in many parasitic groups during recent decades of study using DNA sequence data. Here we tested the phenomenon of cryptic species diversity in the twisted‐wing parasite family Xenidae (Strepsiptera) using nuclear and mitochondrial DNA sequence data for a broad sample of Xenidae. We used three quantitative methods of species delimitation from the molecular phylogenetic data – one distance‐based (ABGD) and two tree‐based (GMYC, bPTP). We found 77–96 putative species in our data and suggested the number of Xenidae species to be more diverse than expected. We identified 67 hosts to species level and almost half of them were not previously known as hosts of Xenidae. The mean number of host species per putative species varied between 1.39 and 1.55. The constant rate in net diversification can be explained by the flexibility of this parasitic group, represented by their ability to colonize new host lineages combined with passive long‐range dispersal by hosts.
From a source of real data to a brief news report: Introducing first‐year preservice teachers to the basic cycle of learning from data
Authors: Ubilla Francisca M. , Gorgorió Núria
Published: November 2020

Statistical data is used in the media and on online platforms, often with an interpretation that serves some commercial or political purpose. Primary preservice teachers must be able to understand statistical data and analyze it critically. Only in this way will they be able to contribute as future teachers to the development of a critical spirit in the community. We present the process of construction on a teacher‐training program of an activity for first‐year students (aged 19) based on data published by Eurostat. The activity, structured around the basic cycle of learning from data, provided real data on different topics in the form of tables, graphs and infographics, and its final goal required students to generate a brief news report based on what they had learned from the data. Finally, we note that this activity can be used at various levels, from secondary education to the introductory tertiary.
Regional variations of context‐based association rules in OpenStreetMap
Authors: Ludwig Christina , Fendrich Sascha , Zipf Alexander
Published: November 2020

As a user‐generated map of the whole world, OpenStreetMap (OSM) provides valuable information about the natural and built environment. However, the spatial heterogeneity of the data due to cultural differences and the spatially varying mapping process makes the extraction of reliable information difficult. This study investigates the variability of association rules extracted from OSM across different geographic regions and depending on different context variables, such as the number of OSM mappers. The focus of this study is the spatial co‐occurrence of OSM tags mapped inside of parks within eight different cities. Without considering any context variable, most association rules were very region‐specific without any rule being valid across all cities. Limiting the association rule analysis to parks based on specific context variables increased the number of rules which are applicable across multiple cities. Furthermore, additional region‐specific association rules emerged. The most important context variables were found to be the number of features mapped inside the park, the number of tags and the park size. These results suggest that the mapping process has a significant influence on the emergence of association rules within user‐generated data. Therefore, this subject needs further investigation to enable effective usage of OSM data across different cultural realms.
Disagreement and Conflict: How Moral and Taste Judgements DoNotDiffer
Authors: Pietroiusti Giulio
Published: November 2020

Eriksson thinks that moral disagreements are intuitively faulty whereas disagreements about taste are intuitively faultless. He attempts to account for this difference by arguing, first, that moral judgements and taste judgements differ with regard to the presence of a disposition to challenge conflicting judgements and, second, that the intuition that a judgement is mistaken consists in the disposition to challenge it. In this article, I focus on the reasons given to support the first claim and argue that they are not sufficient. First, I assess the thesis that a taste judgement is only contingently connected with a disposition to challenge conflicting judgements. Second, I focus on the claim that a moral judgement is in part a disposition to challenge conflicting judgements. In both cases, I argue that the reasons given fail to disclose any substantial difference between the two domains.
In vitro iatrogenic hemolysis of canine packed red blood cells during various rapid transfusion techniques
Authors: Weeks Jessica M. , Motsinger‐Reif Alison A. , Reems Miryam M.
Published: November 2020

Objective

To evaluate which rapid blood administration technique causes the least iatrogenic hemolysis in canine packed red blood cells (pRBCs) as determined by plasma free hemoglobin (fHb) and percent hemolysis (% hemolysis).

Design

Prospective in vitro randomized study.

Setting

Private referral center.

Animals

None.

Interventions

Thirteen units of canine pRBCs were divided equally into 5 aliquots, resulting in 65 trials. The aliquots of each unit were subjected to the following administration techniques: gravity‐driven (control), an infusion pump at maximal rate, application of a pressure bag, manual compression, and syringe bolus. Plasma fHb and % hemolysis were recorded before and after each trial. Rate of administration (mL/s) was calculated for each method.

Measurements and main results

Compared to the control, there were no significant increases in % hemolysis or plasma fHb noted among any of the trial methods. The manual compression and syringe bolus methods resulted in the fastest transfusion rates, whereas the infusion pump was not faster than the gravity‐driven method. Despite a storage time of ≤14 days, 15% of pRBC units had unsuitable (>0.8%) hemolysis before even being subjected to the trials.

Conclusions

Commonly used rapid infusion techniques in small animal transfusion medicine do not cause significant iatrogenic hemolysis of canine pRBCs in vitro, although a significant risk is present in stored blood. This suggests that if an expedited transfusion is needed, any method described in this study could be considered, although stored pRBCs should be tested for unsuitable levels of hemolysis prior to transfusion.
Barriers and facilitators to oral health care utilization in culturally and linguistically diverse mothers: a mixed methods systematic review protocol
Authors: Marcus Kanchan , Balasubramanian Madhan , Short Stephanie , Sohn Woosung
Published: November 2020

Objective:

The objective of the review is to synthesize existing literature examining the barriers and facilitators to preventive oral health care utilization experienced by culturally and linguistically diverse mothers.

Introduction:

Preventive oral health care in the absence of pain is underutilized in culturally and linguistically diverse groups. Culturally and linguistically diverse mothers experience oral health care utilization barriers compared to their host country counterparts. Much of the current evidence is focused on oral health care knowledge, attitudes, and beliefs of culturally and linguistically diverse groups. To date, it remains unclear as to which barriers or facilitators impact preventive oral health care utilization in culturally and linguistically diverse mothers.

Inclusion criteria:

This review will consider studies that explore oral health care utilization in culturally and linguistically diverse mothers (with children younger than 18 years) who are either born in a different country or who have one parent born in a country that differs culturally and/or linguistically to the host population. Papers that explore barriers and facilitators to oral health care utilization will be included. Quantitative and qualitative studies will be included.

Methods:

A three-step search strategy will be conducted within the following databases: MEDLINE, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, ProQuest Central, and Scopus. The search will be supplemented with gray literature and reference searching from collected articles. No date limitation will be applied. Two reviewers will assess papers against the inclusion criteria. A convergent integrated approach using the JBI mixed methods methodology will be followed for critical appraisal, data extraction, and data synthesis and integration.
Couple- or family-oriented interventions and outcomes for preventing mental health problems and promoting mental health: a scoping review protocol
Authors: Kim Suk-Sun , Kim Daeun , Gil Minji , Lim Boram , Gagne Jennie C. De
Published: November 2020

Objective:

The objective of this scoping review is to map the literature describing couple- and family-oriented interventions and outcomes to prevent mental health problems and promote mental health.

Introduction:

Literature involving couple- and family-focused mental health interventions has gained increased attention over the past two decades, yet little is known about the efficacy of these interventions for promoting mental health and preventing mental disorders. Despite recognition that the most sustainable method for reducing the increasing burden of mental disorders is primary prevention, there has been no systematic investigation of relevant couple- and family-focused interventions.

Inclusion criteria:

This scoping review will consider studies that include couples or multiple family members who have participated in couple- and family-focused interventions aimed at primary prevention of mental disorders and promotion of mental health. This study will include experimental, quasi-experimental, and observational study designs, as well as qualitative studies. Conference abstracts, posters, editorials, commentaries, and opinion papers will be excluded.

Methods:

Multiple databases will be searched, including PubMed (MEDLINE), CINAHL, ERIC, PsycINFO (via EBSCO), Web of Science, Scopus, and Research Information Sharing Service (RISS). Trial registers and gray literature will also be searched. Two independent reviewers will screen the abstract/title of retrieved citations using inclusion and exclusion criteria. After screening titles and abstracts of identified citations, relevant studies will be retrieved in full. Using a data extraction instrument developed specifically for this review, eligible studies will be extracted and presented in diagrammatic or tabular form, accompanied by a narrative summary.
Soil–Structure–Wave Interaction of Gravity-Based Offshore Wind Turbines: An Analytical Model
Authors: Pavlou Dimitrios G.
Published: November 2020

The structural design of offshore wind turbines is based on the consideration of coupled dynamic phenomena. Wave loads cause the dynamic oscillation of the monopile, and the dynamic oscillation of the monopile affects the wave loads. The boundary conditions of the gravity-based foundation-monopile-turbine system are mostly affected by the flexural stiffness of the foundation plate, the elastic and creep behavior of the soil, and the inertia (translational and rotational) of the wind turbine mass. The design of the foundation should consider the dynamic response of the soil and the monopile, and the dynamic response of the soil and the monopile is affected by the design parameters of the foundation. The initial conditions of the system yield transient dynamic phenomena. A braking wave at t = 0 causes different dynamic response than the steady-state conditions due to a harmonic wave load. In the present work, an integrated analytical model simulating the above dynamic phenomena is proposed. With the aid of double integral transforms and generalized function properties, a solution of the corresponding differential equations for the monopile-soil-foundation system and the boundary and initial conditions is derived. A parametric study is carried out, and results of the effect of the design parameters and soil properties are presented and discussed.
Wave Motion Dynamic Analysis of Planar Frame Structures With Clearance Joints
Authors: Zhu Juntao , Li Tuanjie , Wang Zuowei , Dong Hangjia
Published: November 2020

Due to kinematic function requirements, deployable structures inevitably have many clearance joints. The existence of clearance joints not only reduces the structural stiffness but also leads to complex nonlinear dynamic characteristics. This paper proposed a general numerical method based on the wave motion theory, which is able to analyze these complex nonlinear dynamic characteristics of frame structures with clearance joints. The dynamic model of frame structures with clearance joints is derived on the basis of continuous wave equations. The clearance joint is modeling by combining Lankarani and Nikravesh contact model with the Ambrósio friction model. The established dynamic model of frame structures is solved by the finite difference time domain (FDTD) method. A triangular frame structure with two clearance joints is taken as the numerical example for the verification of the proposed numerical method. Numerical results show that the longitudinal wave affects the distribution direction of contact positions and the transverse wave mainly affects the distribution range of contact positions. It has been also found that the introduction of torsional springs with reasonable pretension torque is able to significantly improve the distribution of contact positions and reduce state uncertainties of clearance joints in structural vibrations.
Investigation of a Novel Tri-Stable Cantilever Beam With Two Magnets
Authors: Sun Shuailing , Leng Yonggang
Published: November 2020

The conventional non-linear tri-stable cantilever beams (TCBs) consisting of permanent magnets have the disadvantages of many magnets and complex parameters. In this paper, a novel TCB is proposed, which contains only two magnets, a ring magnet and a rectangular magnet. Through theoretical analysis and experimental verification of the magnetic force and the system potential function, it is proved that this TCB can have tri-stable characteristics, which provides an effective and simplified design approach for constructing a TCB. The dynamics analysis of this TCB with different structural parameters reveals the mechanism of excitation intensity, potential well depth and potential well spacing on the response of the system.
Toward a Theory of Systems Engineering
Authors: Hazelrigg George A. , Saari Donald G.
Published: November 2020

The derivation of a theory of systems engineering has long been complicated by the fact that there is little consensus within the systems engineering community regarding precisely what systems engineering is, what systems engineers do, and what might constitute reasonable systems engineering practices. To date, attempts at theories fail to accommodate even a sizable fraction of the current systems engineering community, and they fail to present a test of validity of systems theories, analytical methods, procedures or practices. This paper presents a more theoretical and more abstract approach to the derivation of a theory of systems engineering that has the potential to accommodate a broad segment of the systems engineering community and present a validity test. It is based on a simple preference statement: “I want the best system I can get.” From this statement, it is argued that a very rich theory can be obtained. Whereas most engineering disciplines are framed around a core set of widely accepted physical laws, to the authors’ knowledge, this is the first attempt to frame an engineering discipline around a preference.
LSTM-Based Ensemble Learning for Time-Dependent Reliability Analysis
Authors: Li Mingyang , Wang Zequn
Published: November 2020

This paper presents a long short-term memory (LSTM)-based ensemble learning framework for time-dependent reliability analysis. To deal with the time-dependent uncertainties, a LSTM network is first adopted to capture the system dynamics. As a result, time-dependent system responses for random realizations of stochastic processes can be accurately predicted by the LSTM. With realizations of the random variables and stochastic processes, multiple LSTMs are trained for generating a set of augmented data. Then a deep feedforward neural network (DFN) is employed to ensemble the knowledge extracted from LSTMs and generate a deep surrogate for the original time-dependent system responses. To improve the performance of DFN in terms of accuracy, the Gaussian process modeling technique is utilized for architecture design, where the number of neurons in the hidden layer is determined by minimizing the validation loss. With the DFN, the time-dependent system reliability can be directly approximated by using the Monte Carlo simulation. Two case studies are introduced to demonstrate the efficiency and accuracy of the proposed approach.
Architecting a Modular Battery Electric Truck
Authors: Williamsson David , Sellgren Ulf
Published: November 2020

Product architecting involves conceptual system design, module identification (clustering) and product layout design. In this paper, we propose a new extended version of the previously introduced Integrated Modularization Methodology (IMM) that integrates technical complexity and business strategic concerns into product architecture clustering. The extended IMM (eIMM) adds physical interference and implementation dependent behavior into architecture clustering. The proposed method is logically verified by an industrial case, where the architecture of a presently developed battery electric truck is used as a test bench for studying if and how the product architecture DSM and eIMM approaches may enable us to identify module candidates that are reasonable trade-offs between technical complexity, business strategies and physical interferences. The case study indicates that the eIMM is able to propose a modular product architecture with reasonable module candidates from a technical complexity point of view, and without conflicting business strategies or intra-modular physical interferences.
A Novel Iterative Method of Determining the Pose Error of Planar Clearance-Affected Flexible Parallel Mechanisms Under Loaded Mode
Authors: Zhao Qiangqiang , Guo Junkang , Hong Jun
Published: November 2020

Clearance and flexibility play an essential role in determining the accuracy of a planar parallel mechanism. However, previous accuracy prediction methods either considered only one of them or combined them in linear superposition. Therefore, this study proposes a novel iterative method for determining the pose error by considering clearance and flexibility simultaneously. First, the rigid-flexible model of the mechanism with clearances is developed based on the virtual joint method, in which the equilibrium conditions under the external load are established via the virtual work principle and differential forward kinematics. Then, using a Taylor series approximation, the “instant” stiffness matrix corresponding to a specific load is deduced. On this basis, an iterative scheme is explored to search for the final equilibrium pose, in which a child iterative scheme is constructed to determine the joint variables and suffered wrench of the single chain given a pose. Finally, the developed method is demonstrated by calculating the comparative pose errors of the planar five-bar mechanism and 3-RPR robot.
Reliability-Based Reinforcement Learning Under Uncertainty
Authors: Wang Zequn , Patwardhan Narendra
Published: November 2020

Despite the numerous advances, reinforcement learning remains away from widespread acceptance for autonomous controller design as compared to classical methods due to lack of ability to effectively tackle uncertainty. The reliance on absolute or deterministic reward as a metric for optimization process renders reinforcement learning highly susceptible to changes in problem dynamics. We introduce a novel framework that effectively quantify the uncertainty in the design space and induces robustness in controllers by switching to a reliability-based optimization routine. A model-based approach is used to improve the data efficiency of the method while predicting the system dynamics. We prove the stability of learned neuro-controllers in both static and dynamic environments on classical reinforcement learning tasks such as Cart Pole balancing and Inverted Pendulum.
Non-Enzymatic and Electrodeless Detection of Direct Bilirubin Using Metal Enhanced Fluorescence Effect
Authors: Li Cheng-Yi , Peng Chang-I , Hsu Sandy Huey-Jen , Chang Cheng-Chung , Wang Gou-Jen
Published: November 2020

In this study, a metal enhanced fluorescence (MEF) approach using the homemade Ag nanowires for enzyme free and electrodeless detection of direct bilirubin (d-BLR) was successfully developed. The average diameter and length of the fabricated Ag nanowires were measured to be around 80 nm and 25 μm, respectively. Solvent effect experiments found that EtOH is more suitable as the solvent for d-BLR. The experimental results found that the linear detection range is from 1 to 10 μM, which can be used for detecting abnormal d-BLR concentration from 5 to 10 μM. The MEF approach not only enhanced the bilirubin fluorescence, but also improved the linearity of the standard curve. Furthermore, we also found that the fluorescence intensity of the chip-based MEF is much higher than that of the solution-based MEF. It is believed that the proposed enzyme free and electrodeless d-BLR detection platform is highly feasible for clinical applications.
Assessing Global Needs When Identifying Potential Engineering for Global Development Projects
Authors: Mabey Christopher S. , Mattson Christopher A. , Dahlin Eric C.
Published: November 2020

With limited time and resources available to carry out Engineering for Global Development (EGD) projects, it can be difficult to know where those resources should be allocated to have great potential for meaningful impact. It is easy to assume that projects should occur in a particular location based upon personal experience or where other development projects are taking place. This can be a consideration, but it may not lead to the greatest social impact. Where to work on a project and what problem to work on are key questions at the outset of an EGD project. To aid in this process, this paper presents a method for assessing global needs to ensure thoughtful use of limited EGD resources. We introduce a method for identifying locations where there is human need, gaps in technological achievement, and what countries are favorable to do business in. Results of the method are compared to what countries receive the most foreign aid dollars per capita. Measures were calculated using principal component analysis (PCA) on data collected from the United Nations, World Bank, World Economic Forum, and AidData. These results can help practitioners in selecting where to undertake development projects with an eye toward targeting locations that may yield high levels of social impact.
HPC FEM Calculations for Damping Estimation of Bladed Disk With Dry-Friction Contacts
Authors: Pesek Ludek , Snabl Pavel , Bula Vitezslav
Published: November 2020

The experimental set-up for studying dynamical behaviour of the bladed wheel with pre-stressed dry-friction contacts in tie-bosses was built. The numerical solution of the turbine bladed wheel with tie-bosses based on 3D finite element method with surface to surface dry friction contact model is proposed. Comparison of experimental and numerical results of dynamical behaviour and damping estimation of our bladed wheel design yielded a reasonable agreement. Due to dry friction contacts and non-linear solution of 3D FE model it, however, leads to HPC computations and long computation times. The contribution deals with description of proposed computational strategy for damping evaluation and achieved results, too.
Computing Natural Frequencies and Mode Shapes of an Axially Moving Non-Uniform Beam
Authors: Sinha Alok
Published: November 2020

The partial differential equation of motion of an axially moving beam with spatially varying geometric, mass and material properties has been derived. Using the theory of linear time-varying systems, a general algorithm has been developed to compute natural frequencies, mode shapes, and the critical speed for stability. Numerical results from the new method are presented for beams with spatially varying rectangular cross sections with sinusoidal variation in thickness and sine-squared variation in width. They are also compared to those from the Galerkin method. It has been found that critical speed of the beam can be significantly reduced by non-uniformity in a beam’s cross section.
System Design Method of Complex Product Based on Heterogeneous Language Information Environment
Authors: Wang Guan , Liu Yusheng , Ye Xiaoping , Zhao Jianjun
Published: November 2020

In the product design process, early system design often plays an important role. Although the existing system design methods are very effective, the preference information of different stakeholders and the subjective uncertainty of their existence have not been processed well. Because different stakeholders have different backgrounds and different personalities, the language preferences are expressed differently. Therefore, it is difficult to select a system scheme that meets the performance requirements and is approved by various stakeholders. To solve this problem, this paper proposes a system design method based on heterogeneous language information environment. First, the theoretical system schemes set is constructed through the morphological matrix, and the multi-objective programming model is constructed through the performance indicators to select the system schemes set that optimizes each performance objective and meets the performance constraints. Then, a trapezoidal asymmetric cloud model is used as an intermediate for heterogeneous language information to integrate each stakeholder’s preference information expressed by their favorite linguistic term set to select the best system solution. The effectiveness of the method is verified by a system design example of a horizontal directional drilling machine (HDDM).
A Literature Review of Design Decision Making in Disruptive Technological Innovations of New Products
Authors: Nikolaev Mikhail Y. , Fortin Clement
Published: November 2020

This paper reviews the information available on specifics of the design decision-making process for the case of disruptive technological innovations associated with new products and systems. It defines the term “disruptive technological innovation,” provides with the explanation of decision-making methodology peculiarities for this type of innovation, and describes currently existing techniques and tools to support design decision making in case of disruptive technological innovations. The current paper relates to decision making in systems engineering and design, and therefore deals with the design decision making.

The terms “disruptive technologies” and “disruptive innovations” appeared at the end of the 1990s. Researchers frequently mention disruptive innovations and technologies in the description of technical products for different industries: aircraft, automotive, food, petroleum, etc. A disruptive technological innovation is defined as a combination of disruptive technology and disruptive innovation. A new product can be relatively a simple device like an unmanned aerial vehicle and a smartphone, or a complex system like a modern aerospace vehicle or a space information network. Being an innovative developed product, it possesses peculiarities influencing the product development phase of the product lifecycle design decision-making process and accompanying supporting techniques and tools.

This review investigates the specifics of design decision making of disruptive technologically innovative products that influence different stages of the product development phase in their product lifecycles. The paper combines aspects of systems engineering with innovation theory, key elements of the design of complex systems, and highlights the product development phase of the product lifecycle design decision-making process.
Comparing Student and Sponsor Perceptions of Interdisciplinary Teams’ Capstone Performance
Authors: Krishnakumar Sandeep , Berdanier Catherine , McComb Christopher , Parkinson Matthew , Menold Jessica
Published: November 2020

The purpose of this work is to investigate the relationship between the disciplinary diversity of capstone design teams and perceptions of success and engineering design abilities. Capstone design programs are effective environments for students to collaborate with industry sponsors on authentic design problems. They provide students with the opportunity to hone their technical and professional skills, often in teams. Previous work has demonstrated that interdisciplinary teams outperform within-discipline teams on complex open-ended tasks, but struggle to communicate across disciplinary boundaries. They also report lower levels of team cohesion and satisfaction with final outcomes. The results of the mixed-methods study conducted with 58 capstone design teams for this paper indicate that team diversity may be inversely related to students’ beliefs in their abilities to construct a prototype. Preliminary qualitative analysis suggests that students tend to divide prototyping tasks based on disciplinary background and struggle to integrate design efforts for complex systems, particularly during later stage design.
Detecting and Characterizing Archetypes of Unintended Consequences in Engineered Systems
Authors: Walsh Hannah S. , Dong Andy , Tumer Irem Y. , Brat Guillaume
Published: November 2020

When designing engineered systems, the potential for unintended consequences of design policies exists despite best intentions. The effect of risk factors for unintended consequences are often known only in hindsight. However, since historical knowledge is generally associated with a single event, it is difficult to uncover general trends in the formation and types of unintended consequences. In this research, archetypes of unintended consequences are learned from historical data. This research contributes toward the understanding of archetypes of unintended consequences by using machine learning over a large data set of lessons learned from adverse events at NASA. Sixty-six archetypes are identified because they share similar sets of risk factors such as complexity and human-machine interaction. To validate the learned archetypes, system dynamics representations of the archetypes are compared to known high-level archetypes of unintended consequences. The main contribution of the paper is a set of archetypes that apply to many engineered systems and a pattern of leading indicators that open a new path to manage unintended consequences and mitigate the magnitude of potentially adverse outcomes.
Milling Simulation-Based Method to Evaluate Manufacturability of Machine Parts
Authors: Inui Masatomo , Zhang Tong , Umezu Nobuyuki
Published: November 2020

The designers of mechanical products are generally not experts in machining. Therefore, they often design parts with inherent machining difficulties. Although various design for manufacturability tools have been developed to avoid such problems, their use in practice remains limited due to their lack of versatility. We develop a novel piece of software that can automatically detect difficult-to-machine shapes in a part. Using this software, the designer can determine which shapes are difficult to produce using conventional cutting by themselves, and can modify the shape on the spot. In the Internet-based part manufacturing business, the same software can be used to check whether the given part can be produced using the standard milling operations predetermined in a company. Our system is based on “milling simulation”. It detects any shapes that cannot be produced using the prepared cutting tools by executing the milling simulations with the tools, and then visualizing shapes that remain unmachined after all simulations. In this study, the acceleration of the processing is realized using graphics processing unit technology, and it is possible to extract difficult-to-machine shapes in several minutes using a standard PC.