bluuebunny/crossref_metadata_2025 huggingface dataset:
Quality of learning experience, student satisfaction and perceived overall experience in the COVID-19 context
Authors: Gantasala Venugopal Prabhakar , Gantasala Swapna Bhargavi , Al Tawil Tareq Na'el , Prasad Prerana
Published: February 2021

Purpose

The intention for this study was to explore any relationship that might exist between quality of learning experience (QLE), the second construct student satisfaction (SS) and the third construct perceived overall experience (POE) among undergraduate students within the higher education context. This study also attempts to explain the path direction between QLE, SS and POE.

Design/methodology/approach

The researchers utilized structural equation modeling to analyze the variables considered for this study – QLE, SS and POE and for hypotheses testing. Respondents for this study were medical students' coordinators of the undergraduate level of medical colleges in the 28 states of India. Data collected for the study were possible by utilizing a questionnaire that was emailed to these student coordinators. The emailing effort returned 198 (n) filled questionnaires (complete) representing 198 institutions offering undergraduate-level medical programs out of a total of 542 institutions that offer undergraduate medical programs.

Findings

Findings from this study confirm the relationship between QLE with SS, and PLE. Interestingly, the findings established a significant relationship between SS and POE.

Practical implications

Decision-makers and administrators of higher education institutions (HEIs) can utilize the findings from this study to focus on strengthening important elements of QLE in ways that positively impact SS and POE of students taking online courses and program offerings. The study reiterates the importance of course content, course structure, lecture-delivery quality, instructor mentoring and student-instructor interactions on SS and POE. The role of SS in reinforcing confirmation, perceived usefulness, perceived openness of the online courses and the perceived reputation was established. This relationship is key to administrators while they focus on improving SS and building on the institutions' reputation in addition to their efforts to support marketing and enrollments during the pandemic.

Originality/value

Researchers in the past have examined the relationships between QLE and another construct of this study – SS. Past research has also examined the relationship between QLE and POE. However, there is not enough research exploring the relationship between SS and POE. This study establishes the relationship between SS and POE that benefits decision-makers in higher education.
Knowledge management processes and organizational culture in the higher educational technical institutions
Authors: Nanjundeswaraswamy T.S , Swamy D.R
Published: February 2021

Purpose

The rationale of this study is to explore the stages of knowledge management, types of organizational culture and their relationship in higher educational technical institutions (HETIs) in India.

Design/methodology/approach

A survey instrument has been designed to evaluate knowledge management, organizational culture and their relationship. Further, the instrument has been tested and validated using structural equation modelling. The data have been collected from the faculty working in HETIs.

Findings

Empirical pieces of evidence support that knowledge management in the HETIs is still in the growth stage. Clan-type organization culture is dominating, and there is a significant and positive relationship between knowledge management and organization culture.

Research limitations/implications

The study has been conducted in the HETIs of India. Therefore, the outcome of the research cannot be generalized to the other sectors. In addition to this, the data have been limited to 233 faculty from the eight HETIs located in Bangalore.

Practical implications

HETIs are trying hard to improve the employability of the students by enhancing their skill sets, knowledge, attitude and innovativeness to meet global challenges. In such an environment, this study provides insight into the stages of knowledge management and the type of organizational culture in HETIs, which will help build a strategic plan and improve students' attributes for better employability and innovations.

Originality/value

A positive relationship exists between the knowledge management process and organizational culture in HETIs.
An approach to cost-benefit analysis by competitive advantages with stochastic data
Authors: Khodabakhshi Mohammad , Ahmadi Mehdi
Published: February 2021

Purpose

The paper aims to present an approach to cost-benefit analysis with stochastic data. Determining the type and the values of alternative’s factors are probably the most important issue in this approach. Therefore, in the proposed approach, a competitive advantage model was built to measure the values of alternative’s factors. Then, a satisfactory cost-benefit analysis model with random data was proposed to evaluate the alternatives. The cost-benefit analysis of each alternative was carried out to obtain the real and satisfactory cost-benefit of the decision-maker.

Design/methodology/approach

This paper is orientationally expressed as a mathematical problem in which the optimization problem needs to analyze the approach. This paper is written based on uncertainty linear optimization. Optimization under uncertainty refers to this branch of optimization where there are uncertainties involved in the data or the model and is popularly known as stochastic optimization problems.

Findings

As was seen in the purpose part, in this paper, an approach is presented to cost-benefit analysis by the use of competitive advantage with stochastic data. In this regards, a stochastic optimization problem to assess competitive advantage is proposed. This optimization problem recognizes the values of alternative’s factors which is the most important step in cost-benefit analysis. An optimization problem is proposed to cost benefit analysis, as well.

Practical implications

To investigate different aspects of the proposed approach, a case study with random data of 21 economic projects was considered.

Originality/value

Cost–benefit analysis is a systematic approach to estimating the strengths and weaknesses of alternatives used to determine options which provide the best approach to achieving benefits while preserving savings. Cost–benefit analysis is related to cost-effectiveness analysis. Benefits and costs are expressed in monetary terms and are adjusted for the time value of money; all flows of benefits and costs over time are expressed on a common basis in terms of their net present value, regardless of whether they are incurred at different times. As seen the paper using competitive advantage tries to determine the values of alternative’s factor. As competitive advantage model analyze the advantages and disadvantages of alternatives, this paper by the use of this idea tries to determine the costs and benefits. Two stochastic optimization problems in the middle of this approach are proposed, which assess competitive advantage and cost–benefit analysis, respectively.
How electronic word of mouth (e-WOM) triggers intention to visit through destination image, trust and satisfaction: the perception of a potential tourist in Japan and Indonesia
Authors: Setiawan Putu Yudi , Purbadharmaja Ida Bagus Putu , Widanta Anak Agung Bagus Putu , Hayashi Toshikatsu
Published: February 2021

Purpose

The purpose of the paper is to analyze the different results between the effects of electronic word of mouth (e-WOM) on the perception of potential tourist in Japan and Indonesia regarding destination image, destination trust, satisfaction and their intention to visit.

Design/methodology/approach

This research method is a structural model. Based on the existing literature review, several variables were obtained which were then analyzed by WarpPLS 6.0 software. The sampling method applied in this study is the purposive sampling technique. Samples of 200 potential tourists were collected in Indonesia and 100 potential tourists were collected in Japan. The population in this study was a potential tourist in Indonesia and Japan, with the following criteria: An Indonesian citizen, age between 19 and 60 years, who has never visited Japan and a Japanese citizen who has never visited Indonesia and have ever read or conduct online discussions regarding Japan and Indonesia as a tourist destination.

Findings

The results of the analysis of the two respondents in Japan and Indonesia prove that e-WOM has a positive effect on the image of the destination and intention to visit but not on the confidence of the destination. Destination image was also proven to significantly mediate the influence of e-WOM on intention to visit. These findings bring important implications for the theory and practice of tourism marketing.

Originality/value

Theoretically, the result could be used as a reference for further research about the comparison between the effect e-WOM on destination image, destination trust and intention to visit of potential tourist in developed countries and developing countries. Practically, the result could be used as a consideration for the tourism industry and authority in both countries when formulating the destination marketing strategy.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/OIR-03-2019-0111
Appreciative inquiry's potential in program evaluation and research
Authors: Griggs Dana M. , Crain-Dorough Mindy
Published: February 2021

Purpose

The purposes of this paper are to provide a description of AI and to document and compare two applications of AI, one in program evaluation and another in an applied research study.

Design/methodology/approach

Focus groups, interviews and observations were used to gather rich qualitative data which was used to detail Appreciative Inquiry's value in evaluation and research.

Findings

AI aided the researcher in connecting with the participants and valuing what they shared. In both studies, the use of AI amassed information that answered the research questions, provided a rich description of the context and findings, and led to data saturation. The authors describe and compare experiences with two applications of AI: program evaluation and a research study. This paper contributes further understanding of the use of AI in public education institutions. The researchers also explore the efficacy of using AI in qualitative research and recommend its use for multiple purposes.

Research limitations/implications

Limitations occurred in the AI-Design Stage by using a positive viewpoint and because both program and partnership studied were new with limited data to use for designing a better future. So, the authors recommend a revisit of both studies through the same 4D Model.

Practical implications

This manuscript shows that AI is useful for evaluation and research. It amplifies the participants' voices through favorite stories and successes. AI has many undiscovered uses.

Social implications

Through the use of AI the authors can: improve theoretical perspectives; conduct research that yields more authentic data; enable participants to deeply reflect on their practice and feel empowered; and ultimately impact and improve the world.

Originality/value

AI is presented as an evaluation tool for a high-school program and as a research approach identifying strengths and perceptions of an educational partnership. In both studies, AI crumbled the walls that are often erected by interviewees when expecting to justify or defend decisions and actions. This paper contributes further understanding of the use of AI in public education institutions.
Process parameter optimization for porosity and compressive strength of calcium sulfate based 3D printed porous bone scaffolds
Authors: Modi Yashwant Kumar , Sahu Kiran Kumar
Published: February 2021

Purpose

This study aims to optimize the process parameters of ZPrinter® 450 for measured porosity (MP) and compressive strength (CS) of calcium sulfate-based porous bone scaffold using Taguchi approach.

Design/methodology/approach

Initially, a porous scaffold with smallest pore size that can be de-powdered completely is identified through a pilot study. Five printing parameters, namely, layer thickness (LT), build orientation (BO), build position (BP), delay time (DT) and binder saturation (BS), each at three levels have been optimized for MP and CS of the fabricated scaffolds using L27 orthogonal array (OA), signal-to-noise ratio and analysis of variance (ANOVA).

Findings

The scaffolds with 600 µm pores could be de-powdered completely. Optimum levels of parameters are LT2, BO1, BP2, DT1 and BS1 for MP and LT1, BO1, BP2, DT1 and BS2 for CS. The ANOVA reveals that the BS (49.12%) is the most and BP (8.34%) is the least significant parameter for MP. LT (50.84%) is the most, BO (33.79%) is second most and DT (2.59%) is the least significant parameter for CS. Taguchi confirmation test and linear regression models indicate a good agreement between predicted and experimental values of MP and CS. The experimental values of MP and CS at the optimum levels of parameters are found 38.12% and 1.29 MPa, respectively.

Originality/value

The paper presents effect of process parameters of ZPrinter® 450 on MP and CS of calcium sulfate-based porous scaffolds. Results may be used as guideline for powder bed binder jetting three-dimensional printing of ceramic scaffolds.
Advances in additive manufacturing of shape memory polymer composites
Authors: Garces Irina Tatiana , Ayranci Cagri
Published: February 2021

Purpose

A review on additive manufacturing (AM) of shape memory polymer composites (SMPCs) is put forward to highlight the progress made up to date, conduct a critical review and show the limitations and possible improvements in the different research areas within the different AM techniques. The purpose of this study is to identify academic and industrial opportunities.

Design/methodology/approach

This paper introduces the reader to three-dimensional (3 D) and four-dimensional printing of shape memory polymers (SMPs). Specifically, this review centres on manufacturing technologies based on material extrusion, photopolymerization, powder-based and lamination manufacturing processes. AM of SMPC was classified according to the nature of the filler material: particle dispersed, i.e. carbon, metallic and ceramic and long fibre reinforced materials, i.e. carbon fibres. This paper makes a distinction for multi-material printing with SMPs, as multi-functionality and exciting applications can be proposed through this method. Manufacturing strategies and technologies for SMPC are addressed in this review and opportunities in the research are highlighted.

Findings

This paper denotes the existing limitations in the current AM technologies and proposes several directions that will contribute to better use and improvements in the production of additive manufactured SMPC. With advances in AM technologies, gradient changes in material properties can open diverse applications of SMPC. Because of multi-material printing, co-manufacturing sensors to 3D printed smart structures can bring this technology a step closer to obtain full control of the shape memory effect and its characteristics. This paper discusses the novel developments in device and functional part design using SMPC, which should be aided with simple first stage design models followed by complex simulations for iterative and optimized design. A change in paradigm for designing complex structures is still to be made from engineers to exploit the full potential of additive manufactured SMPC structures.

Originality/value

Advances in AM have opened the gateway to the potential design and fabrication of functional parts with SMPs and their composites. There have been many publications and reviews conducted in this area; yet, many mainly focus on SMPs and reserve a small section to SMPC. This paper presents a comprehensive review directed solely on the AM of SMPC while highlighting the research opportunities.
Barriers for implementing solar energy initiatives in Nigeria: an empirical study
Authors: Abdullahi Dahiru , Renukappa Suresh , Suresh Subashini , Oloke David
Published: February 2021

Purpose

Despite the abundant renewable energy potential in the Nigeria, the power-sector stakeholder has not paid attention to the prospect of the natural resources that can be accrued when it is properly harnessed. Although a very negligible fraction of the population has invested in solar photovoltaics (PVs) for home solution, the initiative was only made public commercialised under the public-private partnership (PPP) and the objectives of the Power Sector Reform Act. 2005. It is, therefore, aimed to investigate the causes and insight of the barriers that are responsible for the slow implementation of the solar energy initiative in the Nigeria.

Design/methodology/approach

An empirical study was performed in the Nigeria. The study was conducted qualitatively, through semi-structured face-to-face interviews of 25 participants. The interviews were recorded, transcribed, interpreted, coded, categorised into themes and analysed by content analysis.

Findings

The study reveals technological, financial, political and social barriers have been the reason for slowing down solar energy development in Nigeria. While the technical barrier is a challenge to the solar energy implementation, socio-cultural issues have also been an obstacle to the implementation process. It is suggested that, the stakeholders of the initiative endeavour to proffer sustainable policies to enable public and private promoters to be able to generate and distribute electricity through solar PV and to complement the inadequate conventional electricity sources from the grids.

Originality/value

The paper provides a richer insight into the understanding and awareness of barriers for implementing solar energy strategies in Nigeria.
Underpinnings of social contributions: conceptualizing behavioral patterns among socially contributive leaders in India
Authors: Bhumika Bhumika , Priya Kumar Ravi , Sinha Arvind Kumar
Published: February 2021

Purpose

This study aims to explore how some organizational leaders are making successful attempts toward making “social contributions” toward the underprivileged or needy stakeholders in the society. This study suggests empirical themes about behavioral patterns of such organizational leaders and illustrates the need to transcend erstwhile “avoid harm” socially responsible leadership.

Design/methodology/approach

Data were collected on 52 Indian organizational leaders and were analyzed following the guidelines of constructionist grounded theory.

Findings

Findings suggested that organizational leaders who facilitated some form of social contributions in the life of different stakeholders had “unconditional adherence to social contributions,” they were “pertinacious about going the extra mile” to facilitate social contributions and at times their “existence as an enthusiastically innovative change agent” also facilitated social contributions to the lives of different stakeholders.

Social implications

This study might initiate discussion around the behavioral patterns of organizational leaders who are attempting to make society a better place by leading or facilitating social contributions. Identified exemplary behavioral patterns might encourage more exploratory studies directed toward the identification of other forms of socially contributive leadership attributes.

Originality/value

Emphasis on investigating corporate social responsibility (CSR) from individual-level perspective advocated the importance of the psychological foundation of CSR. This study empirically identifies behavioral patterns that characterize organizational leaders who had a strong commitment to make social contributions to society. Patterns identified corresponded to cognitive and behavioral approaches of organizational leaders that were instrumental in actualizing social contributions to the Indian society.
Dietary antioxidants reduce damage and rescue sperm viability and fertility following oxidative stress in Drosophila melanogaster
Authors: Lang Weily , Gertner Daniel , Radhakrishnan Preethi
Published: February 2021

Reactive oxygen species (ROS) in large amounts have been shown to cause peroxidative damage to tissues, thereby influencing life‐history trade‐offs such as between reproduction and survival. Reactive oxygen species production is heightened in stressful environments, such as after exposure to toxins. Our study analyzes the effects of antioxidants in reducing the damaging effects of ROS to rescue pre‐ and post‐copulatory reproductive efforts in Drosophila melanogaster Meigen (Diptera: Drosophilidae). We hypothesized that if male fruit flies were fed antioxidant‐enriched diets prior to environmental stress, then the antioxidants would quench the ROS. This would then reduce the lipid peroxidative damage to male sperm, resulting in increased pre‐ and post‐copula reproductive efforts. Two groups of fruit flies were fed antioxidant‐rich diets of lipoic acid (2.15 mM) or melatonin (0.43 mM). Males from all treatments were then fed an herbicide, paraquat (10 mM), which functions as an environmental stressor to shock their immune systems and increase ROS production. All males were then mated to virgin females and copula behavior, sperm viability, male fertility, and total antioxidant capacity were assessed. Our results showed significantly longer mating latencies, higher levels of viable sperm, and more offspring sired in antioxidant‐fed treatments compared to controls. Antioxidant assays reveal that post‐paraquat challenge, males up‐regulate the amount of antioxidants produced. These results draw light on the basis of life‐history trade‐offs such as between reproduction and survival under the context of the molecular mechanisms that govern them, such as pre‐ and post‐copulatory behavior, ROS production, fertility, and sperm viability.
Thermomechanical and thermochemical stability of HfSiO4 for environmental barrier coating applications
Authors: Ridley Mackenzie J. , Opila Elizabeth J.
Published: February 2021

Thermomechanical and thermochemical stability of hafnon (HfSiO4) was evaluated for application as an environmental barrier coating (EBC) candidate for SiC/SiC CMCs. High‐temperature X‐ray diffraction (XRD) analysis showed that hafnon has an excellent coefficient of thermal expansion (CTE) match with SiC as well as minimal CTE anisotropy, which supports hafnon as an EBC candidate. Alternatively, high‐velocity water vapor testing at 1,200‐1,400°C showed large amounts of silica depletion from chemical reaction at all velocities and excessive material erosion at steam velocities greater than 190 m/s. HfSiO4 is therefore not suitable as an EBC for turbine applications due to insufficient thermochemical stability in water vapor‐containing combustion environments.
For Richer, for Poorer: Bankers' Liability and Bank Risk in New England, 1867 to 1880
Authors: KOUDIJS PETER , SALISBURY LAURA , SRAN GURPAL
Published: February 2021

We study whether banks are riskier if managers have less liability. We focus on New England between 1867 and 1880 and consider the introduction of marital property laws that limited liability for newly wedded bankers. We find that banks with managers who married after a law had higher leverage, delayed loss recognition, made more risky and fraudulent loans, and lost more capital and deposits in the Long Depression of 1873 to 1878. These effects were most pronounced for bankers with the largest reduction in liability. We find no evidence that limiting liability increased firm investment at the county level.
Capabilities, capacity, and consent: sexual intimacy in the Court of Protection
Authors: LINDSEY JAIME , HARDING ROSIE
Published: February 2021

This article uses original data from research at the Court of Protection to explore capacity to consent to sex in practice. It argues that the approach under the Mental Capacity Act 2005 fails to place appropriate focus on consent as central to understanding sexual capacity. The capabilities approach to justice is then used to demonstrate the limitations of the existing legal approach to capacity to consent to sex, and to argue that the protective focus of the legal test would be better centred on the social risks resulting from non‐consensual sex and exploitation. Finally, the article argues that, rather than focusing on a medicalized approach to understanding sexual intimacy, an analysis based on capabilities theory provides conceptual tools to support arguments for additional resources to help disabled people to realize their rights to sexual intimacy.
Harnessing the potential of bacterial oxidative folding to aid protein production
Authors: Slater Sabrina L. , Mavridou Despoina A.I.
Published: February 2021

Protein folding is central to both biological function and recombinant protein production. In bacterial expression systems, which are easy to use and offer high protein yields, production of the protein of interest in its native fold can be hampered by the limitations of endogenous posttranslational modification systems. Disulfide bond formation, entailing the covalent linkage of proximal cysteine amino acids, is a fundamental posttranslational modification reaction that often underpins protein stability, especially in extracytoplasmic environments. When these bonds are not formed correctly, the yield and activity of the resultant protein are dramatically decreased. Although the mechanism of oxidative protein folding is well understood, unwanted or incorrect disulfide bond formation often presents a stumbling block for the expression of cysteine‐containing proteins in bacteria. It is therefore important to consider the biochemistry of prokaryotic disulfide bond formation systems in the context of protein production, in order to take advantage of the full potential of such pathways in biotechnology applications. Here, we provide a critical overview of the use of bacterial oxidative folding in protein production so far, and propose a practical decision‐making workflow for exploiting disulfide bond formation for the expression of any given protein of interest.
Nonparametric detection of changes over time in image data from fluorescence microscopy of living cells
Authors: Bissantz Kathrin , Bissantz Nicolai , Proksch Katharina
Published: February 2021

The question whether structural changes in time‐resolved images are of statistical significance or merely emerge from random noise is of great relevance in many practical applications such as live cell fluorescence microscopy, where intracellular diffusion processes are investigated. Using bootstrap‐methods, we construct nonparametric confidence bands for time‐resolved images from fluorescence microscopy and use these to detect and visualize temporal changes between individual frames in imaging of living cells. We model the images frames as two‐dimensional fields of Poisson random variables and provide a strong approximation result for independent and standardized but not necessarily identically distributed Poisson random variables. The latter result is used to derive a limit result for the maximal difference between the reconstructed and the true image. This provides the theoretical foundation of our method. We apply regularization techniques to cope with the ill‐posedness of the convolution problem induced by the imaging system. Our approach provides a criterion to assess time‐resolved small scale structural changes, for example, in the nanometer range. It can also be adopted for use in other imaging systems. Moreover, a data‐driven selection method for the regularization parameter based on statistical multiscale methods is discussed.
Black Politics and the 2020 Election in Hindsight
Authors: Sekou Bilal Dabir
Published: February 2021

This article reviews predictions made in an earlier piece entitled “The Limits of Black Politics in the Post–Civil Rights Era” (Sekou 2020).
Highly efficient multiplex editing: one‐shot generation of 8× Nicotiana benthamiana and 12× Arabidopsis mutants
Authors: Stuttmann Johannes , Barthel Karen , Martin Patrick , Ordon Jana , Erickson Jessica L. , Herr Rosalie , Ferik Filiz , Kretschmer Carola , Berner Thomas , Keilwagen Jens , Marillonnet Sylvestre , Bonas Ulla
Published: February 2021

Genome editing by RNA‐guided nucleases, such as SpCas9, has been used in numerous different plant species. However, to what extent multiple independent loci can be targeted simultaneously by multiplexing has not been well documented. Here, we developed a toolkit, based on a highly intron‐optimized zCas9i gene, which allows assembly of nuclease constructs expressing up to 32 single guide RNAs (sgRNAs). We used this toolkit to explore the limits of multiplexing in two major model species, and report on the isolation of transgene‐free octuple (8×) Nicotiana benthamiana and duodecuple (12×) Arabidopsis thaliana mutant lines in a single generation (T1 and T2, respectively). We developed novel counter‐selection markers for N. benthamiana, most importantly Sl‐FAST2, comparable to the well‐established Arabidopsis seed fluorescence marker, and FCY‐UPP, based on the production of toxic 5‐fluorouracil in the presence of a precursor. Targeting eight genes with an array of nine different sgRNAs and relying on FCY‐UPP for selection of non‐transgenic T1, we identified N. benthamiana mutant lines with astonishingly high efficiencies: All analyzed plants carried mutations in all genes (approximately 112/116 target sites edited). Furthermore, we targeted 12 genes by an array of 24 sgRNAs in A. thaliana. Efficiency was significantly lower in A. thaliana, and our results indicate Cas9 availability is the limiting factor in such higher‐order multiplexing applications. We identified a duodecuple mutant line by a combination of phenotypic screening and amplicon sequencing. The resources and results presented provide new perspectives for how multiplexing can be used to generate complex genotypes or to functionally interrogate groups of candidate genes.
MADEsmart: An Integrated Design Environment
Authors: Barrett Tom , Coen Gary , Hirsh Joel , Obrst Leo , Spering Judith , Trainer Asa
Published: February 2021

Technology is within reach today to significantly improve the design/build environment for large scale engineering efforts such as those undertaken by the aerospace industry and defense contractors. On large and possibly geographically distributed teams, strong task management and easy information distribution is required to minimize the time necessary to develop designs. Broadening the scope of design constraints to include producibility issues, particularly with respect to design optimization, can significantly improve the quality of the designs and reduce the number of times they must be adjusted. Further, the ability to automatically evaluate designs with respect to requirements documentation can contribute additional improvements in quality and reductions in rework. The MADEsmart1 distributed concurrent engineering environment addresses these needs by providing task coordination and easy access to needed information. It will also provide integration of a number of multidisciplinary tools for design optimization and the ability to automatically evaluate designs with respect to existing, textually specified, requirements.
A Tuning Mechanism for Feature Recognition
Authors: De Martino Teresa , Falcidieno Bianca
Published: February 2021

In this paper a flexible feature recognition mechanism that can be tuned by the user in order to meet the specific application requirements, is presented. The recognition process is performed at different levels of detail and is based on topological, morphological and geometric reasoning. Invariant shape characteristics are studied and used for defining shape equivalence relations among features, on which the tuning mechanism provided to the user is based. The system supports the recognition of both classes and specific instances of features.
Using Spreadsheet Modules to Augment the Design and Analysis of Journal Bearings
Authors: Shoup Terry E.
Published: February 2021

This paper presents three easy-to-use spreadsheet modules in Microsoft Excel ’97 for solving the load and friction problems associated with the design of journal bearings. The modules make use of numerical approximations to data from the literature, and contain numerical interpolation procedures that are highly accurate. These modules allow designs that are more accurate than was possible with previous, graphical methods.
Non-Linear FE Approach for Flexible Multibody Simulation of Mechanism Dynamics
Authors: Sivertsen Ole Ivar
Published: February 2021

The simulation approach presented in this paper is based on a nonlinear Finite Element (FE) formulation for modelling of multibody systems (MBS). This formulation is developed to include a comprehensive library of MBS elements as links, joints, springs, dampers and external forces. The links are modelled as FE substructures and reduced to super elements by component mode synthesis (CMS). Super nodes are used for modelling of the mechanism elements referred to above.
Assessing the Effectiveness of Traditional and Virtual Reality Interfaces in Spherical Mechanism Design
Authors: Evans Paul T. , Vance Judy M. , Dark Veronica J.
Published: February 2021

Virtual reality (VR) interfaces have the potential to enhance the engineering design process, but before industry embraces them, the benefits must be understood and documented. The current research compared two software applications, one which uses a traditional human-computer interface (HCI) and one which uses a virtual reality HCI, that were developed to aid engineers in designing complex three-dimensional spherical mechanisms. Participants used each system to design a spherical mechanism and then evaluated the different interfaces. Participants rated their ability to interact with the computer images, their feelings about each interface, and their preferences for which interface device to use for certain tasks. The results indicated that participants preferred a traditional interface for interaction tasks and a VR interface for visual tasks. These results provide information about how to improve implementation of VR technology, specifically for complex three-dimensional design applications.
Development and Application of Design Concept Ontologies for Contextual Conceptualization
Authors: Horváth Imre , Vergeest Joris S. M. , Kuczogi György
Published: February 2021

This study focuses on two specific problems of knowledge intensive computer aided design: (a) how can design concepts be modeled and represented in a form that is understandable for human beings and can be processed by computers, (b) how can they be arranged in structures that enables a computer-based functional design of products. First, a methodology for definition of very high level modeling entities based on the ontology theory is presented. It formalizes design concepts in terms of all concerned entities, phenomena and situations and describes them by attributes, parameters and descriptors, respectively. Validity and interactions of design concepts are governed by constraints. The very high level modeling entities are arranged into domain oriented design ontologies based on their contents and semantic relationships. The formalism used for logical specification of design ontologies is based on a library of declarative expressions called ACN-Code. A design ontology lends itself to a specific knowledge base called associative concept network (ACN). The inference engine that works on an application oriented ACN selects the appropriate design concepts against a set of user specified functional requirements. Due to the pre-defined associations incomplete functional specifications can be completed to result in a fully functional design solution. The paper also presents an application example.
PEDAL: A Knowledge-Based Design Assistant for Automotive PEDAL Packaging
Authors: Lomangino Paul , Wang Nanxin
Published: February 2021

Pedal packaging is a complex and tedious design process involving trade-offs among many related activities, including driver placement and engine compartment layout. Pedal layout design requires checks of candidate designs against large libraries of standards. Designers of pedal assemblies must carefully follow these regulations and standards, and manually come up with the pedal layout design. Differences in interpretation of the regulations result in inconsistent designs. A knowledge-based design assistant, named PEDAL, has been designed and developed to help automotive package designers overcome these problems. This paper reviews the needs of the pedal package designer in the framework of the abilities of knowledge-based engineering. PEDAL’s prototype implementation and its combined knowledge base of design standards are described.
Influence of Imperfections in the Working Media on Diesel Engine Indicator Process: Part 2 — Results
Authors: Danov Stanislav N. , Gupta Ashwani K.
Published: February 2021

In the companion Part 1 of this two-part series paper several improvements to the mathematical model of the energy conversion processes, taking place in a diesel engine cylinder, have been proposed. Analytical mathematical dependencies between thermal parameters (pressure, temperature, volume) and caloric parameters (internal energy, enthalpy, specific heat capacities) have been obtained. These equations have been used to provide an improved mathematical model of diesel engine indicator process. The model is based on the first law of thermodynamics, by taking into account imperfections in the working media which appear when working under high pressures and temperatures. The numerical solution of the simultaneous differential equations is obtained by Runge-Kutta type method. The results show that there are significant differences between the values calculated by equations for ideal gas and real gas under conditions of high pressures and temperatures. These equations are then used to solve the desired practical problem in two different two-stroke turbo-charged engines (8DKRN 74/160 and Sulzer-RLB66). The numerical experiments show that if the pressure is above 8 to 9 MPa, the working medium imperfections must be taken into consideration. The mathematical model presented here can also be used to model combustion process of other thermal engines, such as advanced gas turbine engines and rockets.
Automatic Tolerance Assignment Using Fuzzy Logic
Authors: Srikanth K. , Liou F. W. , Balakrishnan S. N.
Published: February 2021

Tolerance design is interdisciplinary in nature and requires input from various stages of product development such as design, manufacturing, and assembly. The factors involved, such as equipment and labor costs, process information, and required rate of successful assembly, are highly uncertain, especially in the early design stage. This paper presents a fuzzy logic approach to model all uncertain parameters in the process for automatic optimal tolerance assignment. A method based on fuzzy logic to evaluate assembly rate is proposed, and the comparison between the fuzzy logic approach and the statistical method is discussed. It is found that using fuzzy logic, a relatively smaller sample size is needed to estimate the assembly rate with reasonable accuracy. Two cases studies are used to demonstrate the process of integrating cost, manufacturing processes, and assembly rates and their uncertainties using fuzzy logic.
A Tunneling Based Method for Mixed-Discrete Constrained Nonlinear Optimization
Authors: Kott Gregory J. , Gabriele Gary A.
Published: February 2021

This paper describes the development of a new method to solve mixed-discrete optimization problems. The method is a two phase approach similar to Tunnel Methods developed for global optimization of continuous problems. It uses a SQP optimization solver in the first phase and an efficient rounding procedure to find discrete solutions in the second phase. All components utilized in this heuristic method are implemented with an emphasis on efficiency. The method was implemented in MATLAB and the solutions of three classical design problems are given. The results show the new method is very robust in finding high quality solutions which are consistently as good or better than past published results.
A Relaxed Lexicographic Pattern Search Method for Solving Design Problems With Nondifferentiable Constraints and Goals
Authors: Bauer Matthew D. , Rosen David W.
Published: February 2021

In engineering design, many design problems have multiple constraints and objectives, which may be nondifferentiable. For this problem type, only zero-order solution methods are applicable. In this paper, we present a relaxed lexicographic pattern search method for solving this design problem type, where the objectives are preferenced in either an Archimedean or preemptive formulation. The Hooke-Jeeves (HJ) pattern search method is the basis of this method, which is implemented as the MORPS (Multi-Objective Randomized Pattern Search) algorithm. The HJ pattern search method is used because it requires only function values and has an intuitive graphical interpretation through which to gain insight into the nature of complex design spaces. A relatively new class of simultaneous product/process design problem utilizing virtual prototypes to support design for disassembly is introduced to motivate the need for the MORPS algorithm. An example, based on the design of an automotive center console for disassembly, illustrates the application of the MORPS algorithm.
The Datum Flow Chain: A Systematic Approach to Assembly Design and Modeling
Authors: Mantripragada R. , Whitney D. E.
Published: February 2021

In order to be able to lay out, analyze, outsource, assemble, and debug complex assemblies, we need ways to capture their fundamental structure in a top-down design process, including the designer’s strategy for kinematically constraining and locating the parts accurately with respect to each other. We describe a concept called the “Datum Flow Chain” to capture this logic. The DFC relates the datum logic explicitly to the product’s key characteristics, assembly sequences, and choice of mating features, and provides the information needed for tolerance analyses. Two types of assemblies are addressed: Type-1 where the assembly process puts parts together at their prefabricated mating features, and Type-2 where the assembly process can incorporate in-process adjustments to redistribute variation. Two types of assembly joints are defined: mates that pass dimensional constraint from part to part, and contacts that merely provide support. The scope of DFC in assembly planning is presented using several examples. Analysis tools to evaluate different DFCs and select the ones of interest are also presented.
Thermo-Geometrical Design Models for Solid Freeform Fabrication With Material Transfer
Authors: Doumanidis Charalabos , Kwak Yong-Min
Published: February 2021

In thermal solid freeform fabrication of layered products, simultaneous quality assurance of the part geometry and material structure requires concurrent design of the process conditions with the product features. For a heat transfer analysis yielding the material structure, an analytical, distributed-parameter quasi-linear thermal model is developed and tested in scan welding. This is based on Green’s field, identified in-process by infrared temperature sensing to reflect thermal nonlinearities. Similarly, a mass transfer model of the layer surface geometry is established on an analogous concept of the material deposition field, approximated by an ellipsoidal shape and identified in-process by Laser 3D scanning of the part topology in fused deposition modeling tests. The invertibility and computational efficiency of both models provide a basis for design of adaptive feedback control strategies for the thermogeometrical characteristics of rapid prototypes.
Fixture-Based Usefulness Measures for Hybrid Process Planning
Authors: Balasubramanian Sundar , Elinson Alexei , Herrmann Jeffrey W. , Nau Dana S.
Published: February 2021

This paper describes a usefulness measure that supports ongoing work on a hybrid process planning approach that combines the best characteristics of both variant and generative process planning while avoiding their worst limitations. To specify the fixtures needed by a process plan for a new design, the hybrid approach must identify existing designs and process plans that have fixtures that can hold the new design. Because traditional geometric similarity measures are inadequate, we have developed a new fixture-based usefulness measure.
Design for Optimal Welding Orientation
Authors: Yao Z. , Bradley H. D. , Maropoulos P. G.
Published: February 2021

The process time and cost of a weld product depend largely on the decisions to select the weld orientation and relevant fixtures. Such decisions must be made at the early stages of the design process so that necessary design changes can easily be made to achieve an optimal design solution. However, traditional CAD and CAPP systems cannot support weld product design and welding process planning unless detailed design information is available.

The present paper describes a “Design for Orientation” method which can be applied in the early stages of weld product design. The method is based on CAPABLE/Welding, which is an aggregate process planning system for weld products. By utilizing a feature-based aggregate product model in a concurrent engineering environment, feasible welding orientations can automatically be generated. Computer algorithms have been developed for evaluating the orientations of a weld feature, generating welding orientation options for a fabrication and processing the equipment constraints. The results can be used in the design process to reduce the number of set-ups, increase the efficiency of welding processes and reduce the cost of fixtures.
A Geometric Theory for Form, Profile and Orientation Tolerances: Evaluation Algorithms and Simulation Results
Authors: Gou J. B. , Chu Y. X. , Li Z. X.
Published: February 2021

Using the geometric theory for formulation of form, profile and orientation tolerances, we develop a simple geometric algorithm, called the Symmetric Minimum Zone (SMZ) algorithm, to unify the computation of form, profile and orientation tolerances. First, using a technique of numerical analysis, we transform the non-differentiable minimization problem into a differentiable minimization problem over an extended configuration space. Then, we solve the latter problem by computing the solutions of a sequence of linear programming problems which can be easily derived using the geometric properties of SE(3)/G0. The SMZ algorithm is incorporated into a software package called GTPack for tolerance verification. Numerous simulation experiments show that the SMZ algorithm has several important features which could lead to its rapid acceptance in the industry: (1) consistency with the Y14.5M standard, (2) computational efficiency, (3) robustness with respect to variations in initial conditions; and (4) implementational simplicity. We also give extensive simulation results comparing the performances of the SMZ algorithm against the best known algorithms in the literature.
Collision Detection for Assembly Planning Using Solid Modelling
Authors: Golabi Sa’id , Abhary Kazem
Published: February 2021

Details of a method for detecting collision of two parts when one is moved along a direction are discussed in this paper. Reduced number of grid points and the rays emit from these points to detect the intersection of a moving part with a fixed part, is the main advantage of this method comparing with the previous works in the literature. The intersection of rays, sent from a plane considerably far from both parts, with the faces of moving and fixed part are detected in this methods. If any ray intersects the moving part before intersecting the fixed part, the moving part will collide with the fixed part in that direction. Determining the starting point of the rays and detecting intersection of rays with the parts are also discussed in this paper.