bluuebunny/crossref_metadata_2025 huggingface dataset:
A Geometric Framework for Optimal Surface Design
Authors: Park Frank C.
Published: March 2021

We present a Riemannian geometric framework for variational approaches to geometric design. Optimal surface design is regarded as a special case of the more general problem of finding a minimum distortion mapping between Riemannian manifolds. This geometric approach emphasizes the coordinate-invariant aspects of the problem, and engineering constraints are naturally embedded by selecting a suitable metric in the physical space. In this context we also present an engineering application of the theory of harmonic maps.
Use of Piezoceramic Actuation for Automotive Active Suspension Mechanisms: A Feasibility Study
Authors: Thirupathi Sridhar R. , Naganathan Nagi G.
Published: March 2021

Active suspension for automobiles involves an active control of wheel motions. This work investigates the possibility of realizing controlled wheel motion for an active suspension using piezoceramic actuation. The proposed concept deviates significantly from conventional practice of using heavier, hydraulic actuators. Rather than accomplising the wheel motion using the direct stroke of an actuator, the motion is to be realized by actively modifying the stiffness of the suspension system using piezoceramic sensing and actuation. Preliminary analysis and experimentation are performed to test the above concept. Two candidate designs are presented for composite piezoceramic suspension elements. It is shown that it is possible to control suspension system deflections through sufficient motion ranges necessary for this application.
Computer Aided Design of Robot Work Cell
Authors: Neogy C. , Mohan S. , Soni A. H.
Published: March 2021

The extensive use of robots in flexible manufacturing systems and other engineered systems has created the need for developing a design tool for workcells in which robots are used. In current practice, the location of a robot within a workcell is determined by evaluating reachability and mobility criteria. Using reachability and mobility criteria, the robot can be located in a wide area within a workcell. In this paper, a computer aided design procedure that addresses the issues of minimum cycle time of the robot, optimum location of the robot within the cell and location of the workstations for time optimal motion, is provided. Significant results for three, four and six workstation cases are presented along with a design procedure for using these results.
A Synthesis Algorithm of Three-Revolute Manipulators by Means of the Workspace Contour Algebraic Formulation
Authors: Ceccarelli Marco
Published: March 2021

A synthesis algorithm of general three-revolute open chain manipulators is proposed making use of an algebraic formulation of the workspace contour, which has been deduced in a previous paper. The algebraic form of the synthesis model allows to formulate some algebraic design equations and to discuss the number and the type of the multiple solutions.
Singularity-Free Evolution From One Configuration to Another in Serial and Fully-Parallel Manipulators
Authors: Innocenti C. , Parenti-Castelli V.
Published: March 2021

Among the several ways adopted for the characterization of manipulator performances is identification of the typologies of maneuvers allowed by the manipulator kinematic arrangement. The multiplicity of configurations corresponding to a given hand position for serial manipulators, or to a given set of input values for fully-parallel manipulators, makes one wonder whether a manipulator can perform the maneuver of changing its configuration without meeting singularities. The paper shows that singularity-free configuration change is possible both for general-geometry serial and fully-parallel architectures. Results are reported that shed light on potential performances of manipulators and allow, in perspective, a deeper exploitation of their structural peculiarities.
Predicting Force Redistributions on Walking Robots for Reliable Locomotion: Modeling and Experiments
Authors: Nagy Peter V. , Desa Subhas , Whittaker William L.
Published: March 2021

A large number of walking robots walk with a statically-stable gait. A statically-stable walker has at least three feet that are in ground contact at any time. If there are more than three feet in ground contact, the normal (vertical) forces exerted by the ground on the feet of the walker are indeterminate, unless they are measured. Some walking robots may walk with more than three legs in ground contact in order to achieve greater stability. To ensure this stability it is desirable to predict how vertical forces passively redistribute underneath the feet during walker motions. Predictions of future foot forces can be used as a basis for accepting or rejecting any planned walker motion. Two methods — the least-squares method and the compliance method — for predicting this redistribution of forces in the face of static indeterminacy are presented in this work. Both methods are computationally efficient, and give reasonably accurate predictions, as verified by experiments on a walking robot.
Design of Articulated Manipulators Based on Kinematic and Dynamic Criteria
Authors: Dwarakanath A. , Ghosal A. , Shrinivasa U.
Published: March 2021

This paper deals with the design of articulated manipulators with joint motion constraints. The aim is to design smaller and lighter robots by taking into account kinematic and dynamic criteria and the application. Painting and welding of large areas are the applications considered for which the end effector carrying the necessary tool should move at a uniform velocity in the work area. Further entire work area and the area required for acceleration and deceleration, must also lie inside the workspace of the manipulator. From kinematic consideration, link dimensions, joint rotation ranges and mean positions are obtained such that the required work area lies inside the workspace. The cross-sectional dimensions of the links are chosen such that the tip deflection under the worst loading conditions is less than a given minimum. The worst loading is obtained by considering the static loads due to weights of payloads, links, actuators and transmission elements and the dynamic loads due to the motion of the links. The torque requirements for a specified process velocity and acceleration depend on the loading and also on the kinematic parameters such as link lengths, joint ranges and mean positions. Hence the link dimensions, joint ranges and mean positions are optimized for minimum torque and the results are compared with those found from purely kinematic considerations.
Link-Centre and Indexes of a Kinematic Chain
Authors: Agrawal V. P. , Yadav J. N. , Pratap C. R.
Published: March 2021

A new graph theoretic concept of link-centre of a kinematic chain is introduced. The link-centre of a kinematic chain is defined as a subset of set of links of the kinematic chain using a hierarchy of criteria based on distance concept. A number of structural invariants are defined for a kinematic chain which may be used for identification and classification of kinematic chains and mechanisms. An algorithm is developed on the basis of the concept of distance and the link-centre for optimum selection of input, output and fixed links in a multi-degree-of-freedom function generator.
Generalized Synthesis of Adjustable Mechanisms
Authors: Chuenchom Tushchai , Kota Sridhar
Published: March 2021

Conventional mechanisms (cams, gears, and linkage-based that are typically single degree of freedom) are being increasingly replaced by multi-degree of freedom multi-actuators integrated with logic controllers. This new trend in sophistication although provides greatly enhanced flexibility, there are many instances where the flexibility needs are exaggerated and the associated complexity is unnecessary. On the other hand, the conventional mechanisms cannot fulfill multi-task requirements due to lack methods to design-in flexibility. Adjustable mechanisms or “programmable” mechanisms provide a cost-effective middle ground between hard automation and overly flexible expensive robots; especially for tasks that demand only limited flexibility. This paper presents a generalized synthesis procedure for designing adjustable robotic mechanisms for path generation. The goal is to develop a methodology to synthesize a single mechanism that can trace a given set of three-dimensional trajectories by simply adjusting one of the mechanism parameters; say the length of a particular link. The synthesis procedure presented in this paper entails coupler curve classification and pattern recognition techniques, eleven precision-point (Burmester theory) synthesis of geared five-bar mechanisms, multi-objective optimization and statistical analysis.
Geometric Construction of Bézier Type Motion Interpolants
Authors: Ge Q. J. , Ravani B.
Published: March 2021

This paper deals with discrete computational geometry of motions and develops geometric construction algorithms for interpolating in-between rigid displacements. It combines concepts from the fields of kinematics and computational geometry and develops a computational framework for constructing motion interpolants useful in mechanical systems animation, robot trajectory planning and key framing in computer graphics.

A de Casteljau type algorithm is presented for constructing Bézier and rational Bézier motion interpolants. In addition, the problem of achieving higher order of continuity in piecing together motion interpolants is studied. A geometric construction algorithm is presented for designing C2 continuous motion interpolants.
Theory on Joint Specifications in the Design of Deployable Truss Structures
Authors: Warnaar D. B. , Chew M. , Olariu S.
Published: March 2021

The inter-connectivity and type selection of joints in a mechanism can be represented by a graph. In this article a technique is presented for the generation of such a graph for a (spatial) deployable truss structure. First a fundamental graph is constructed which reveals all possible joint connections in a deployable structure. This graph, which can be derived from the geometry of a deployable structure, is then reduced to the graph of the kinematic structure (revealing the joint inter-connectivity) by applying a set of rules. The process of joint specification is completed by assigning joint types to edges in the graph such that the required mobility of the deployable structure it represents is ensured. Procedures are provided that incorperate the techniques introduced in this article and which can be used to generate all possible joint assignments for a given deployable structure.
A Method for Detecting Isomorphism in Graphs Using Vertex Degree Correspondence With Partitioning
Authors: Warnaar D. B. , Chew M. , Olariu S.
Published: March 2021

An efficient and accurate procedure is presented for testing pairs of graphs for isomorphism. The procedure determines isomorphism conclusively by partitioning the graphs into sets of vertices of the same degree. Subsequently, isomorphism is proven or disproven through a comparison of the inter-connectivity of the vertices within each set and a comparison of the inter-connectivity between each set. The procedure is tested on large sets of graphs generated using a (novel) technique also introduced in this article. The procedure has shown to be more efficient than previous methods, without compromising its accuracy.
Development of a Standard Code for Colored Graphs and its Application to Kinematic Chains
Authors: Shin Jae Kyun , Krishnamurty Sundar
Published: March 2021

The development of an efficient solution procedure for the detection of isomorphism and canonical numbering of vertices of colored graphs is introduced. This computer based algorithm for colored graphs is formed by extending the standard code approach earlier developed for the canonical numbering of simple noncolored graphs, which fully utilizes the capabilities of symmetry analysis of such noncolored graphs. Its application to various kinematic chains and mechanisms is investigated with the aid of examples. The method never failed to produce unique codes, and is also found to be robust and efficient. Using this method, every kinematic chain and mechanism, as well as path generators and function generators, will have their own unique codes and a corresponding canonical numbering of their respective links. Thus, based on its efficiency and applicability, this method can be used as a universal standard code for identifying isomorphisms, as well as for enumerating nonisomorphic kinematic chains and mechanisms.
An Efficient Method for the Kinematics of Multibody Systems That Works in Singular Positions
Authors: Avello A. , Bayo E.
Published: March 2021

When a multibody system reaches a singular position, one or more degrees of freedom appear instantaneously and the jacobian matrix of the constraint equations becomes rank-deficient. The classical kinematic formulation is based on the factorization of the jacobian and, therefore, fails in singular positions. In this paper we develop an efficient method, which uses a penalty and an augmented Lagrangian formulation, and successfully handles singular positions. This formulation automatically copes with redundant incompatible constraints and guarantees the stability of the constraints during numerical integration. Critical numerical examples are shown which corroborate these findings.
Signal Flow Graphs for Spatial Gear Trains
Authors: Ma R. , Gupta Krishna C.
Published: March 2021

Signal flow graphs (SFG) have been applied in many areas such as circuit analysis, controls, mechanical vibrations, statistics and operations research. They have also been applied to the analysis of planetary gear trains which are planar, i.e. all of the gear axes are parallel. In this paper, signal flow graphs are applied to the spatial planetary gear trains. Some additional terminology and rules which are needed for this important application are developed in this paper and illustrated by examples.
Automated Welding Process Fixture Planning Using Features
Authors: Straus R. J. , Liou F. W.
Published: March 2021

Flexible robotic welding cells have been established as an integral part of manufacturing. In order to plan the entire welding process in the design stage, mathematical modeling of the planning procedure has become very important. Both the geometric and non-geometric representations, such as the geometric description of workpieces, fixtures, and end-effectors and the planning of the welding process, are the key elements to success. Emphasis in this paper is fixture planning, in which an automated fixturing approach is examined to greatly increase workcell flexibility. A feature-based modeling approach is proposed to simulate the fixturing process in an automated welding cell.
Implications of Ergonomic and User Considerations on Manufacturing Consumer Products
Authors: Allada Venkat , Kopardekar Parimal , Anand S. , Mital Anil
Published: March 2021

Most designers do not consider ergonomic guidelines in designing consumer products. Also, very little attention is generally paid to user needs and preferences. It is imperative that consumer products be designed keeping in mind the human capabilities and limitations. Such considerations in the product design process are necessary since the market is becoming competitive and users more picky. The purpose of this paper is to consider the implications of ergonomic design guidelines on consumer product design, its manufacturing, and associated costs. A Linear Programming model is also developed to assist designers in the product design process.
User-Oriented Intelligent Indexing and Retrieval in a Design Documentation System
Authors: Ruecker Lukas , Seering Warren P.
Published: March 2021

This paper presents results of our research in design documentation. We have focused on capturing design knowledge and experience generated in the product development process and on providing computational services that facilitate its use and re-use in concurrent and subsequent design activity. For this purpose we have developed a task- and domain-specific representation for semi-formal dialectical and qualitative reasoning in design. Here we will describe the types of retrieval operations possible within a documentation system, outline the epistemological foundation and the main ideas behind our representation, offer a preliminary analysis of the tradeoffs among expressiveness, computational power, tractability, and human usability in the framework we propose, and explain why we believe that our approach will indeed offer a significant improvement over current methods without a corresponding increase in cost.
Managing Design Structure Data in a Concurrent Engineering Design Environment
Authors: Lindeman Dennis , Wijaya Lissy
Published: March 2021

The ability to productively share design data among concurrent engineering team members is critical to successfully implementing a concurrent engineering methodology. In the concurrent process, the product structure is the focal point for all design deliverables. This paper focuses on the need to share and manipulate the product’s design structure and its associated parametric data throughout the course of detailed design. It is based on our experiences at Texas Instruments as we worked to implement concurrent engineering practices into our design environment and came to realize the criticality of managing the product structure throughout the process.

This paper provides the reader with a brief overview of a concurrent engineering methodology, a description of a concurrent engineering data structure (CEDS) and its life cycle, the benefits of maintaining and sharing a common structure (and format) throughout the design process, and proposed requirements for a CEDS management tool. In addition, we describe how we initially implemented CEDS within TI and some thoughts on future implementation possibilities.
Large-scale synthesis of atomically thin ultrawide bandgap β-Ga2O3 using a liquid gallium squeezing technique
Authors: Park Hyunik , Choi Yongha , Yang Sujung , Bae Jinho , Kim Jihyun
Published: March 2021

β-Ga2O3, an emerging ultrawide bandgap (UWBG) semiconductor, offers promising properties for next-generation power electronics, chemical sensors, and solar-blind optoelectronics. Scaling down of β-Ga2O3 to the atomic level affords the advantages of two-dimensional (2D) materials, while maintaining the inherent properties of the parent bulk counterpart. Here, we demonstrate a simple approach to synthesize ultrathin millimeter-size β-Ga2O3 sheets using a liquid gallium squeezing technique. The GaOx nanolayer produced by stamping liquid gallium under the Cabrera–Mott oxidation was converted into few-atom-thick β-Ga2O3 via thermal annealing under atmospheric conditions. This approach was also applied to various substrates such as SiO2, Si, graphene, quartz, and sapphire to heteroepitaxially synthesize 2D β-Ga2O3 on a target substrate. Finally, we propose a patterning strategy combining the squeezing technique with conventional lithography to obtain a β-Ga2O3 layer with a controllable thickness and shape. Our synthetic method has the potential to overcome the limitations of conventional β-Ga2O3 growth methods, paving a path for applications in UWBG-based (opto-)electronics with a high throughput in a cost-effective manner.
Time Spent Near V˙O2max During Different Cycling Self-Paced Interval Training Protocols
Authors: Dall’ Agnol Cristiano , Turnes Tiago , De Lucas Ricardo Dantas
Published: March 2021

Purpose: Cyclists may increase exercise intensity by prolonging exercise duration and/or shortening the recovery period during self-paced interval training, which could impact the time spent near . Thus, the main objective of this study was to compare the time spent near during 4 different self-paced interval training sessions. Methods: After an incremental test, 11 cyclists (mean [SD]: age = 34.4 [6.2] y; ) performed in a randomized order 4 self-paced interval training sessions characterized by a work–recovery ratio of 4:1 or 2:1. Sessions comprised 4 repetitions of 4 minutes of cycling with 1 minute (4/1) or 2 minutes (4/2) of active recovery or 8 minutes of cycling with 2 minutes (8/2) or 4 minutes (8/4) of active recovery. Time spent at 90% to 94% (), ≥95% (), and 90% to 100% () was analyzed in absolute terms and relative to the total work duration. Power output, heart rate, blood lactate, and rating of perceived exertion were compared. Results: The 8/4 session provided higher absolute and than 8/2 (P = .015 and .029) and 4/1 (P = .002 and .047). The 4/2 protocol elicited higher relative (47.7% [26.9%]) and (23.5% [22.7%]) than 4/1 (P = .015 and .028) and 8/2 (P < .01). Session 4/2 (275 [23] W) elicited greater mean power output (P < .01) than 4/1 (261 [27] W), 8/4 (250 [25] W), and 8/2 (234 [23] W). Conclusions: Self-paced interval training composed of 4-minute and 8-minute work periods efficiently elicit , but protocols with a work–recovery ratio of 2:1 (ie, 4/2 and 8/4) could be prioritized to maximize .
A cryo–electron tomography workflow reveals protrusion-mediated shedding on injured plasma membrane
Authors: Mageswaran Shrawan Kumar , Yang Wei Yuan , Chakrabarty Yogaditya , Oikonomou Catherine M. , Jensen Grant J.
Published: March 2021

Cryo-ET of photodamaged plasma membrane reveals shedding from protrusions that depends on F-actin dynamics, Myo1a, and Vps4B.
Predicting the severity of the grass pollen season and the effect of climate change in Northwest Europe
Authors: Kurganskiy Alexander , Creer Simon , de Vere Natasha , Griffith Gareth W. , Osborne Nicholas J. , Wheeler Benedict W. , McInnes Rachel N. , Clewlow Yolanda , Barber Adam , Brennan Georgina L. , Hanlon Helen M. , Hegarty Matthew , Potter Caitlin , Rowney Francis , Adams-Groom Beverley , Petch Geoff M. , Pashley Catherine H. , Satchwell Jack , de Weger Letty A. , Rasmussen Karen , Oliver Gilles , Sindt Charlotte , Bruffaerts Nicolas ,   The PollerGEN Consortium, Skjøth Carsten A.
Published: March 2021

Hay fever patients can be helped in managing their symptoms by predicting the severity of the upcoming grass pollen seasons.
Ancient genomic time transect from the Central Asian Steppe unravels the history of the Scythians
Authors: Gnecchi-Ruscone Guido Alberto , Khussainova Elmira , Kahbatkyzy Nurzhibek , Musralina Lyazzat , Spyrou Maria A. , Bianco Raffaela A. , Radzeviciute Rita , Martins Nuno Filipe Gomes , Freund Caecilia , Iksan Olzhas , Garshin Alexander , Zhaniyazov Zhassulan , Bekmanov Bakhytzhan , Kitov Egor , Samashev Zainolla , Beisenov Arman , Berezina Natalia , Berezin Yakov , Bíró András Zsolt , Évinger Sándor , Bissembaev Arman , Akhatov Gaziz , Mamedov Aslan , Onggaruly Akhan , Voyakin Dmitriy , Chotbayev Aidos , Kariyev Yeldos , Buzhilova Alexandra , Djansugurova Leyla , Jeong Choongwon , Krause Johannes
Published: March 2021

Ancient genomic time-transect across the Central Asian Steppe sheds new light onto the origins and demise of the Scythians.
Erosion of global functional diversity across the tree of life
Authors: Carmona Carlos P. , Tamme Riin , Pärtel Meelis , de Bello Francesco , Brosse Sébastien , Capdevila Pol , González-M. Roy , González-Suárez Manuela , Salguero-Gómez Roberto , Vásquez-Valderrama Maribel , Toussaint Aurèle
Published: March 2021

Among plants and vertebrates, extinction risk is universally higher for the largest species with slower paces of life.
Ambient air pollution, lung function and COPD: cross-sectional analysis from the WHO Study of AGEing and adult health wave 1
Authors: Elbarbary Mona , Oganesyan Artem , Honda Trenton , Kelly Patrick , Zhang Ying , Guo Yuming , Morgan Geoffrey , Guo Yanfei , Negin Joel
Published: March 2021

Background

Long-term exposure to ambient air pollution leads to respiratory morbidity and mortality; however, the evidence of the effect on lung function and chronic obstructive pulmonary disease (COPD) in older adult populations is inconsistent.

Objective

To address this knowledge gap, we investigated the associations between particulate matter (PM), nitrogen dioxide (NO2) exposure and lung function, as well as COPD prevalence, in older Chinese adults.

Methods

We used data from the WHO Study on global AGEing and adult health (SAGE) China Wave 1, which includes 11, 693 participants from 64 townships in China. A cross-sectional analysis explored the association between satellite-based air pollution exposure estimates (PM with an aerodynamic diameter of ≤10 µm [PM10], ≤2.5 µm [PM2.5] and NO2) and forced expiratory volume in one second (FEV1), forced vital capacity (FVC), the FEV1/FVC ratio and COPD (defined as post-bronchodilator FEV1/FVC <70%). Data on lung function changes were further stratified by COPD status.

Results

Higher exposure to each pollutant was associated with lower lung function. An IQR (26.1 µg/m3) increase in PM2.5was associated with lower FEV1(−71.88 mL, 95% CI –92.13 to –51.64) and FEV1/FVC (−2.81, 95% CI −3.37 to –2.25). For NO2, an IQR increment of 26.8 µg/m3was associated with decreases in FEV1(−60.12 mL, 95% CI –84.00 to –36.23) and FVC (−32.33 mL, 95% CI –56.35 to –8.32). A 31.2 µg/m3IQR increase in PM10was linked to reduced FEV1(−8.86 mL, 95% CI −5.40 to 23.11) and FEV1/FVC (−1.85, 95% CI −2.24 to –1.46). These associations were stronger for participants with COPD. Also, COPD prevalence was linked to higher levels of PM2.5(POR 1.35, 95% CI 1.26 to 1.43), PM10(POR 1.24, 95% CI 1.18 to 1.29) and NO2(POR 1.04, 95% CI 0.98 to 1.11).

Conclusion

Ambient air pollution was associated with lower lung function, especially in individuals with COPD, and increased COPD prevalence in older Chinese adults.
Real-world retrospective observational study exploring the effectiveness and safety of antifibrotics in idiopathic pulmonary fibrosis
Authors: Wright William Alexander , Crowley Louise E , Parekh Dhruv , Crawshaw Anjali , Dosanjh Davinder P , Nightingale Peter , Thickett David R
Published: March 2021

Background

Pirfenidone and nintedanib are the only disease-modifying treatments available for idiopathic pulmonary fibrosis (IPF). Our aim was to test their effectiveness and safety in clinical practice.

Methods

This is a single-centre retrospective observational study undertaken at a specialised interstitial lung disease centre in England. Data including progression-free survival (PFS), mortality and drug tolerability were compared between patients with IPF on antifibrotic therapies and an untreated control group who had a forced vital capacity percentage (FVC %) predicted within the licensed antifibrotic treatment range.

Results

104 patients received antifibrotic therapies and 64 control patients were identified. PFS at 6 months was significantly greater in the antifibrotic group (75.0%) compared with the control group (56.3%) (p=0.012). PFS was not significant at 12 or 18 months when comparing the antifibrotic group with the control group. The 12-month post-treatment mean decline in FVC % predicted (−4.6±6.2%) was significantly less than the 12-month pretreatment decline (−10.4±11.8%) (p=0.039). The 12-month mortality rate was not significantly different between the antifibrotic group (25.3%) and the control group (35.5%) (p=0.132). Baseline Body Mass Index of≤25, baseline diffusion capacity for carbon monoxide percentage predicted of ≤35 and antifibrotic discontinuation within 3 months were independent predictors of 12-month mortality. Antifibrotic discontinuation was significantly higher by 3 and 6 months for patients on pirfenidone than those on nintedanib (p=0.006 and p=0.044, respectively). Discontinuation at 12 months was not significantly different (p=0.381).

Conclusions

This real-world study revealed that antifibrotics are having promising effects on PFS, lung function and mortality. These findings may favour commencement of nintedanib as first-line antifibrotic therapy, given the lower rates of early treatment discontinuation, although further studies are required to investigate this.
High-dimensional analysis of the adenosine pathway in high-grade serous ovarian cancer
Authors: Bareche Yacine , Pommey Sandra , Carneiro Mayra , Buisseret Laurence , Cousineau Isabelle , Thebault Pamela , Chrobak Pavel , Communal Laudine , Allard David , Robson Simon C , Mes-Masson Anne-Marie , Provencher Diane , Lapointe Rejean , Stagg John
Published: March 2021

Background

Hydrolysis of extracellular ATP to adenosine (eADO) is an important immune checkpoint in cancer immunology. We here investigated the impact of the eADO pathway in high-grade serous ovarian cancer (HGSC) using multiparametric platforms.

Methods

We performed a transcriptomic meta-analysis of eADO-producing CD39 and CD73, an eADO signaling gene signature, immune gene signatures and clinical outcomes in approximately 1200 patients with HGSC. Protein expression, localization and prognostic impact of CD39, CD73 and CD8 were then performed on approximately 1000 cases on tissue microarray, and tumor-infiltrating lymphocytes (TILs) were analyzed by flow cytometry and single-cell RNA sequencing on a subset of patients.

Results

Concomitant CD39 and CD73 gene expression, as well as high levels of an eADO gene signature, were associated with worse prognosis in patients with HGSC, notably in the immunoregulatory molecular subtype, characterized by an immune-active microenvironment. CD39 was further associated with primary chemorefractory and chemoresistant human HGSC and platinum-based chemotherapy of murine HGSC was significantly more effective in CD39-deficient mice. At protein level, CD39 and CD73 were predominantly expressed by cancer-associated fibroblasts, and CD39 was expressed on severely exhausted, clonally expanded and putative tissue-resident memory TILs.

Conclusions

Our study revealed the clinical, immunological, subtype-specific impacts of eADO signaling in HGSC, unveiled the chemoprotective effect of CD39 and supports the evaluation of eADO-targeting agents in patients with ovarian cancer.
Effects of Funneliformis mosseae on the utilization of organic phosphorus in Camellia oleifera Abel
Authors: Wu Fei , Li Zhengyun , Lin Yulan , Zhang Linping
Published: March 2021

Arbuscular mycorrhizal (AM) fungi play an important role in the acquisition of phosphorus (P) by plants. The external hyphae of AM fungi function as an extension of plant roots and may downregulate related functions in the roots. It is not clear whether the ability of AM fungi to mineralize organic P affects root phosphatase activities. A pot experiment was conducted to investigate the effect of Funneliformis mosseae on soil organic P mineralization under phytate application and to explore root phosphatase activities, P uptake, and growth in Camellia oleifera Abel. The plants and their growth substrates were harvested 4 and 8 months after planting. The results showed that organic P application had no effect on the total dry mass of nonmycorrhizal plants, but differences in dry mass under P application were observed in mycorrhizal plants in both harvests. Inoculation with F. mosseae increased soil acid phosphatase, phytase, and alkaline phosphatase activities and reduced the soil organic P content. Mycorrhizal plants had higher root activity, shoot and root P contents and root acid phosphatase and phytase activities than nonmycorrhizal plants irrespective of organic P application. In conclusion, AM fungi enhanced the mineralization of soil organic P and positively affect root phosphatase activities.
Vanishing of the first-order cohomology on Olshanski spherical pairs
Authors: Rabaoui Marouane
Published: March 2021

In this paper, we study the first-order cohomology space of countable direct limit groups related to Olshanski spherical pairs, relatively to unitary representations which do not have almost invariant vectors. In particular, we prove a variant of Delorme’s vanishing result of the first-order cohomology space for spherical representations of Olshanski spherical pairs.
LIFE SATISFACTION, PRO-ACTIVITY AND EMPLOYMENT
Authors: AKAY ALPASLAN , KARABULUT GOKHAN , YILMAZ LEVENT
Published: March 2021

Using longitudinal data from the German Socio-Economic Panel (GSOEP), this paper investigates how pro-active time-use (e.g., in sports/arts/socializing) relates to subjective well-being of the unemployed and their probability of finding a new job. Allowing for a variety of socio-demographic and -economic observed characteristics, we find that pro-activity is negatively associated with the well-being loss upon unemployment. That is, the negative unemployment shock on their well-being is mitigated through various stress-reducing activities including, in particular, art participation, socializing, going on trips and visiting a church. We also find that the probability of returning to the labor market later is positively associated with pro-activity during the unemployment period. The results are robust to various checks including estimators, measures and individual personality characteristics which can correlate with time-use activities.
A Time–Cost Tradeoff Problem with Multiple Assessments and Release Times on a Chain Precedence Graph
Authors: Park Myoung-Ju , Choi Byung-Cheon , Chung Jibok
Published: March 2021

We consider two variants of a time–cost tradeoff problem with multiple assessments on a chain precedence graph. Furthermore, each job can only be started after a release time, and a penalty cost is incurred when a job is not finished before its due date. The motivation is from the project such that a project owner can control the duration of each job and the support level of each project partner to avoid the penalty cost from the tardy jobs. We describe the penalty costs of the first and the second variants as the total weighted number of tardy jobs and the total weighted tardiness, respectively. These can be avoided by compressing the processing times or advancing the release times, which incurs a compression cost or release cost according to the linear and the piecewise constant functions, respectively. The objective is to minimize the total penalty, compression cost and release cost. In this paper, we propose the procedure based on the reduction to a shortest path problem, and show that the procedure can solve two variants in strongly polynomial time.
Four-agent bidirectional quantum controlled teleportation via quantum entanglement swapping
Authors: Zhang Wanbin , Li Baosheng
Published: March 2021

A total of seven qubits are in a maximally entangled state. Using such an entangled state as quantum channel is based on the construction requirements of quantum long-distance communication [Pan et al., Nature 488, 185 (2012)]. Multi-party quantum channel (QC) should be studied. We put forward three deterministic bidirectional quantum controlled teleportation (BQCT) schemes. To be specific, BQCT can be realized between any two parties in a deterministic manner with another as the control. Alternatively, the BQCT capacity of such state in the given qubit distribution is thus essentially revealed by virtue of the schemes.
Simulation study of the traffic circle system with adaptive traffic lights
Authors: Ez-Zahar A. , Ez-Zahraouy H. , Bentaleb K. , Khallouk A. , Lakouari N.
Published: March 2021

In this paper, we propose a cellular automaton model to investigate the traffic flow characteristics in the traffic circle system with adaptive traffic lights control. The traffic flow in the circulating lane was evaluated and depending on it the traffic lights lit red in the entry lanes to reduce the coming traffic. The density and the satisfaction rate were used as feedback to control the traffic flow in the circulating lane. It is found that both parameters (i.e. the density and the satisfaction rate in the circulating lane), if they are used as a criterion to control the coming traffic from entry lanes, promote the throughput in the traffic circle system. Traffic flow for the traffic circle system without using the traffic lights was investigated. In this case, we find that the traffic flow in the system is characterized by three phases, namely, gridlock, congestion, and free flow. The gridlock phase is predominant over the other phases. Furthermore, with the use of the adaptive traffic lights, the gridlock phase has vanished and the maximum current, jammed, and congestion phases take place. The density criterion shows good performance as compared with the satisfaction rate criterion in terms of the lengths of the red cycle. The capacity is also investigated. The space-time configurations were given to understand the microscopic interaction between vehicles.
Error analysis of initial phase estimation for X-ray pulsar navigation system
Authors: Li Wei , Ruan Ning-Juan , Liu Xun , Yan Feng
Published: March 2021

In this paper, a nonlinear least squares estimator based on the extending cost function is derived, and its performance is analyzed in a Monte-Carlo simulation. Numerical results show that estimation error of the pulse time of arrival satisfies the normal distribution, the relation between the variance and the number of X-ray photon obtained by our simulation is compared with the analytical model. In addition, the effect of time bin size on the statically behavior of estimation error is also studied. This work holds great promise for designing the parameters of X-ray camera adopted in the pulsar navigation system.
Experimental Investigation on the Performance of Signal Processing Tools for the Analysis of Mechanical Vibrations in Rotor Rubbing
Authors: Rubio Eduardo , Chávez-Olivares César , Cervantes-Herrera Alejandro
Published: March 2021

Rubbing is an important problem in machinery industry which occurs when a rotating element hits a stationary part. This rotor-to-stator rub may result in the catastrophic breakdown of the machine. In this work, the phenomenon of rotor rubbing is analyzed from the perspective that the signal analysis tools that are in use today to detect this defect emphasize or highlight particular aspects of the studied phenomenon. So, sometimes it is necessary to use more than one tool to deepen the understanding of the problem. For this purpose, laboratory tests were performed on a rotor system with a rubbing mechanism, while mechanical vibrations were measured with an accelerometer and a data acquisition system. Experiments were carried out for fixed rotor speed, and for run-up and run-down rotor speed conditions. The analysis approach included various processing tools to study their capabilities in rubbing detection: Root Mean Square (RMS), Fourier transform, Wavelet transform and Hurst exponent. Fixed rubbing conditions show similar results for RMS and Hurst exponent on the information obtained. For variable run-up and run-down rotor speed conditions, the Hurst exponent shows predictability, a fact that can be used for rub detection. However, the Wavelet and Fourier Transforms operated in a very distinct way. Although both transforms give frequency information, Fourier transform results in a more detailed frequency analysis, while the Wavelet transform can give time localization of the rubbing phenomenon.
Processes of sand entrainment and emplacement in sand injection complexes of the Viking Graben
Authors: Wild John L.
Published: March 2021

The Balder Field reservoir sandstone has been interpreted as remobilized from a Mesozoic parent bed. This paper seeks to address the questions raised about this unusual origin. Research and broadly analogous processes are reviewed, leading to the proposal that the parent beds may have been fluidized by bedding-parallel retrogressive entrainment of Statfjord Formation sands by a connected larger source of overpressured fluids. These fluids are identified as most likely derived by lateral migration from the Viking Graben, initiated in response to early Eocene basin inversion related to North Atlantic rifting. The event probably involved breaching of the topseal in multiple places over a large section of the Utsira High. The geometry of large sills formed from small breach points and the internal differentiation seen may show that the sills inflated by lateral accretion from a medial active flowing zone of turbulent, transitional or laminar flowing suspension. It is suggested that sequence-stratigraphic and structural context should be considered as additional criteria to discriminate between depositional and intruded sands.
UNIQ
Authors: Baskin Chaim , Liss Natan , Schwartz Eli , Zheltonozhskii Evgenii , Giryes Raja , Bronstein Alex M. , Mendelson Avi
Published: March 2021

We present a novel method for neural network quantization. Our method, named
UNIQ
, emulates a non-uniform
k
-quantile quantizer and adapts the model to perform well with quantized weights by injecting noise to the weights at training time. As a by-product of injecting noise to weights, we find that activations can also be quantized to as low as 8-bit with only a minor accuracy degradation. Our non-uniform quantization approach provides a novel alternative to the existing uniform quantization techniques for neural networks. We further propose a novel complexity metric of number of bit operations performed (BOPs), and we show that this metric has a linear relation with logic utilization and power. We suggest evaluating the trade-off of accuracy vs. complexity (BOPs). The proposed method, when evaluated on ResNet18/34/50 and MobileNet on ImageNet, outperforms the prior state of the art both in the low-complexity regime and the high accuracy regime. We demonstrate the practical applicability of this approach, by implementing our non-uniformly quantized CNN on FPGA.
Efficient External Sorting for Memory-Constrained Embedded Devices with Flash Memory
Authors: Jackson Riley , Gresl Jonathan , Lawrence Ramon
Published: March 2021

Embedded devices are ubiquitous in areas of industrial and environmental monitoring, health and safety, and consumer appliances. A common use case is data collection, processing, and performing actions based on data analysis. Although many Internet of Things (IoT) applications use the embedded device simply for data collection, there are benefits to having more data processing done closer to data collection to reduce network transmissions and power usage and provide faster response. This work implements and evaluates algorithms for sorting data on embedded devices with specific focus on the smallest memory devices. In devices with less than 4 KB of available RAM, the standard external merge sort algorithm has limited application as it requires a minimum of three memory buffers and is not flash-aware. The contribution is a memory-optimized external sorting algorithm called no output buffer sort (NOBsort) that reduces the minimum memory required for sorting, has excellent performance for sorted or near-sorted data, and sorts on external memory such as SD cards or raw flash chips. When sorting large datasets, no output buffer sort reduces I/O and execution time by between 20% to 35% compared to standard external merge sort.
Tough Double Network Hydrogel and Its Biomedical Applications
Authors: Nonoyama Takayuki , Gong Jian Ping
Published: March 2021

Soft and wet hydrogels have many similarities to biological tissues, though their mechanical fragility had been one of the biggest obstacles in biomedical applications. Studies and developments in double network (DN) hydrogels have elucidated how to create tough gels universally based on sacrificial bond principles and opened a path for biomedical application of hydrogels in regenerative medicine and artificial soft connective tissues, such as cartilage, tendon, and ligament, which endure high tension and compression. This review explores a universal toughening mechanism for and biomedical studies of DN hydrogels. Moreover, because the term sacrificial bonds has been mentioned often in studies of bone tissues, consisting of biomacromolecules and biominerals, recent studies of gel–biomineral composites to understand early-stage osteogenesis and to simulate bony sacrificial bonds are also summarized.
The Influence of Current Density on Transport of Vanadium Cations through Membranes with Different Charges
Authors: Darling Robert M. , Saraidaridis James D. , Shovlin Christopher , Fortin Michael , Murdock Laura A. , Benicewicz Brian C.
Published: March 2021

Fluxes of the four vanadium cations V2+, V3+, VO2+and VO2+through three archetypal membranes were measured as functions of current density. The membranes include a cation-exchange membrane, an anion-exchange membrane, and an initially uncharged membrane. Comprehensive data sets including mass and vanadium sorption, in-plane and through-plane conductivity, diffusive permeability, and transference number were collected to help interpret vanadium fluxes. Conductivity, diffusion coefficient, and transference number appear to be inter-related as predicted by Nernst-Planck theory for the cation-exchange membrane Nafion. The properties do not appear to be as compellingly connected for the anion-exchange membrane FAPQ-330 or polybenzimidazole. The Nernst-Planck formalism, with the Nernst-Einstein approximation, predicts a larger influence of current density on vanadium flux than is observed experimentally for these membranes. Possible explanations for these disparate findings are investigated and discussed.
Au/Cdot-Nanohybrid Electrocatalyst Synthesized by Rice-Straw-Derived Carbon Dots as a Reducing Agent for Improved Hydrogen Evolution Reactions
Authors: Nguyen Ngoc-Anh , Le Thi-Hien , Trinh Van-Huy , Ngo Quang-Tung , Nguyen Van-Toan , Lee Gilhwan , Choi Ho-Suk , Chen Guangliang
Published: March 2021

We report a facile method by which to synthesize Au/Cdot nanohybrids using carbon dots (Cdots) obtained from rice straw as a direct reducing agent as well as a stabilizer. Rice-straw-derived Cdots possess oxygen-containing functional groups that act as an electron-donating source to reduce Au3+ to Au0 without the use of chemical reagents for the reduction of Au precursors. Additionally, the strong Au-carbon interaction promotes a high electron transfer of the Au/Cdot nanohybrid electrocatalyst, resulting in enhanced performance of the hydrogen evolution reaction (HER). The overpotential is 150 mV at a current density of 10 mA·cm−2 and the TOF value is 0.06·s−1, representing the most outstanding HER performance among Au-based catalysts as a non-Pt HER electrocatalyst. The HER activity is stably maintained for 2000 cycles as well as for 48 h. The synthesis of Cdots, the hybridization of Au/Cdot electrocatalyst, and the production of clean hydrogen fuel using Au/Cdots are zero CO2 emission strategies, not only preventing the emission of pollutants but also satisfying the energy needs of humankind.
Newman and Balsara on Electrochemical Systems Fourth Edition
Authors: Chaves Frances
Published: March 2021

The long-awaited fourth edition of Electrochemical Systems by John Newman and Nitash P. Balsara is now available. This classic serves as a textbook and dependable resource for students and seasoned scientists alike. The authors update all of the chapters, add content on lithium battery electrolyte characterization and polymer electrolytes, and include a new chapter on impedance spectroscopy. Make room on your bookshelf for the fourth edition.
The ECS Community on Adapting, Advancing, and Overcoming the Pandemic
Authors: Chaves Frances
Published: March 2021

Here we are, over a year into a global pandemic, the likes of which has not been seen in a century. The Society continues to actively monitor the pandemic to prepare for potential impact on programming—and to support our community. When we spoke with members last spring about COVID-19’s impact on their lives and work, it was clear that engagement with an active community was vital to maintain mental health. Everyone was convinced that electrochemistry and solid state science would play a critical role in overcoming the current crisis. Today we see that research, collaboration, teaching, and learning are continuing in new ways. The ECS community is responding to the pandemic with resilience and creativity rather than despondence. Here’s how.