bluuebunny/crossref_metadata_2025 huggingface dataset:
CEO personality and language use in CSR reporting
Authors: Mahmoudian Fereshteh , Nazari Jamal A. , Gordon Irene M. , Hrazdil Karel
Published: April 2021

We explore the relationship between chief executive officer (CEO) personality traits and corporate social responsibility (CSR) reporting. Upper echelons theory indicates that the values, experiences, and personalities of top organizational managers influence their organization's strategic decisions and effectiveness. We utilize IBM Watson Personality Insights software to infer CEOs’ personality traits based on their responses to questions raised by analysts during year‐end conference calls; we obtain CEOs’ Big Five personality traits—openness, conscientiousness, extraversion, agreeableness, and neuroticism—from which we compute a measure of their risk tolerance. Using a longitudinal dataset of Standard and Poor's 500 firms for 2008–2015, we document that high CEO risk tolerance is related to lower CSR report readability and smaller CSR disclosure volume. This finding indicates that executives who are comfortable with greater risk are more willing to supply stakeholders with reports that are shorter and require greater effort to understand. Exploration of the association between CEO Big Five personality traits and CSR report readability and disclosure volume allows key stakeholders to better comprehend CSR disclosures and connotations thereof. Overall, our results contribute to the debate on how CEO personality traits affect organizations’ CSR disclosure reporting strategies, and support upper echelons theory in the CSR setting.
Evolution of sexual dimorphism and polychromatism in a lineage of tiger moths (Lepidoptera: Erebidae): advancing knowledge of a taxonomically chaotic group
Authors: Moraes Simeão de Souza , Murillo‐Ramos Leidys , Duarte Marcelo
Published: April 2021

Pericopina is divided into 36 genera, with the greatest diversity recorded in the Neotropics. Studies on the taxonomy and systematics of pericopines are scarce, and one of the few phylogenetic hypotheses available in the literature places some Afro‐Indo‐Malayan lineages among the Neotropical representatives. Through a survey of adult morphological characters, we analyzed the phylogenetic relationships in Pericopina including Nyctemera and other Afro‐Indo‐Malayan genera as putative members of this subtribe. Additionally, we tested the monophyly of Dysschema, a key genus to understanding the evolutionary patterns of the extreme sexual dimorphism and polychromatism in Pericopina. Our cladistic analysis, based on 162 morphological characters, suggests that Pericopina is a polyphyletic group. Xenosoma is the only genus among the Neotropical pericopines related to the Afro‐Indo‐Malayan species; Scearctia is closely related to Lithosiini, and Pteroodes shows morphological similarities with Phaegopterina. Additionally, Seileria is a new junior subjective synonym of Thyrgis. The monophyly of Dysschema is supported only if the monotypic genera Myserla and Are are included. These are herein designated new synonyms of Dysschema. Our findings suggest that intersexual polychromatism and intersexual polymorphism for wing characters have arisen multiple times in the evolutionary history of Pericopina. Intersexual polychromatism is also widely distributed within Dysschema, perhaps representing a derived feature with multiple origins in the genus.
Marine reserves, fisheries ban, and 20 years of positive change in a coral reef ecosystem
Authors: Mumby Peter J. , Steneck Robert S. , Roff George , Paul Valerie J.
Published: April 2021

By 2004, Belize was exhibiting classic fishing down of the food web. Groupers (Serranidae) and snappers (Lutjanidae) were scarce and fisheries turned to parrotfishes (Scarinae), leading to a 41% decline in their biomass. Several policies were enacted in 2009–2010, including a moratorium on fishing parrotfish and a new marine park with no‐take areas. Using a 20‐year time series on reef fish and benthos, we evaluated the impact of these policies approximately 10 years after their implementation. Establishment of the Southwater Caye Marine Reserve led to a recovery of snapper at 2 out of 3 sites, but there was no evidence of recovery outside the reserve. Snapper populations in an older reserve continued to increase, implying that at least 9 years is required for their recovery. Despite concerns over the feasibility of banning parrotfish harvest once it has become a dominant fin fishery, parrotfishes returned and exceeded biomass levels prior to the fishery. The majority of these changes involved an increase in parrotfish density; species composition and adult body size generally exhibited little change. Recovery occurred equally well in reserves and areas open to other forms of fishing, implying strong compliance. Temporal trends in parrotfish grazing intensity were strongly negatively associated with the cover of macroalgae, which by 2018 had fallen to the lowest levels observed since measurements began in 1998. Coral populations remained resilient and continued to exhibit periods of net recovery after disturbance. We found that a moratorium on parrotfish harvesting is feasible and appears to help constrain macroalgae, which can otherwise impede coral resilience.
The utility of ThyroSeq® in the management of indeterminate thyroid nodules by fine‐needle aspiration
Authors: Li Wencheng , Justice‐Clark Tracy , Cohen Michael B.
Published: April 2021

Objective

We aim to evaluate the impact of ThyroSeq® in the management of indeterminate thyroid nodules (ITN), including Bethesda III and IV nodules.

Methods

ITNs that underwent ThyroSeq testing between 2016 and 2019 were retrospectively reviewed. A control cohort included ITNs without molecular testing. Cytological, molecular, and histological data were collected.

Results

We identified 202 ITNs that underwent molecular testing (128 in Bethesda III and 74 in Bethesda IV). Mutations were found in 58 nodules with mutation rates of 21.9% in Bethesda III and 40.5% in Bethesda IV. In this cohort, 49 cases had surgical resection with a resection rate of 24.3% (49/202, 15.6% in Bethesda III and 39.2% in Bethesda IV). Among the resected cases, 42 cases had positive molecular results. Thyroid cancer was diagnosed in 21 nodules with a malignancy detection rate of 10.4%. In the other cohort, we identified 236 ITNs (158 in Bethesda III and 78 in Bethesda IV). Surgical resection was performed in 127 cases, with a resection rate of 53.8% (127/236, 46.2% in Bethesda III and 69.2% in Bethesda IV). Thyroid cancer was diagnosed in 21 nodules, with a malignancy detection rate of 8.9%. The risk of malignancy (ROM) recalculated based on positive ThyroSeq results was significantly higher (21.4%‐35.5% in Bethesda III and 50%‐60% in Bethesda IV) than that without molecular testing (4.4%‐9.6% in Bethesda III and 17.9%‐25.9% in Bethesda IV).

Conclusion

We concluded that ThyroSeq significantly decreased the surgical resection rate (from 53.8% to 24.3%) without significantly affecting the malignancy detection rate in ITNs. Furthermore, positive molecular testing significantly increased ROM in ITNs. We believe that the recalculated ROM should be incorporated into the management of ITNs.
False positive cases in thyroid cytopathology – the experience of a single laboratory and a systematic review
Authors: Mezei Tibor , Kolcsár Melinda , Pașcanu Ionela , Vielh Philippe
Published: April 2021

Introduction

Fine needle aspiration (FNA) is fundamental in the pre‐operative assessment of thyroid nodules. However, the shining success of thyroid FNA is occasionally eclipsed by false positive (FP) cytological diagnoses. We describe our experience regarding FP cytological diagnoses and present a literature review concerning FP rates.

Materials and methods

We retrospectively analyzed 2031 consecutive cytology reports. FP was defined as a case with “suspicious for malignancy” or “malignant” cytology, whose surgical follow‐up failed to confirm the initial diagnosis of malignancy. We used the PubMed database for the literature review using specific search terms (“thyroid”, “cytology”, “false positive”).

Results

Out of 2031 FNA reports, 93 cases with “suspicious for malignancy” or “malignant” cytology underwent surgical excision. Histopathology did not confirm malignancy in 10 cases (0.6% FP rate). Nodules with FP cytology were significantly larger (P = 0.0024) than those with with TP (true positive) cytology. A review of 25 publications shows comparable results to ours with some slight differences. The majority of studies achieve a FP rate below 3%. Most FP cytological diagnoses turn out to be non‐neoplastic lesions (nodular hyperplasia, adenomatous nodule, lymphocytic thyroiditis), which combined account for 80.5% of all histological diagnoses.

Conclusions

Thyroid nodules with FP cytology were larger than nodules with TP cytology. Most studies manage to adhere to the recommended FP rates, or values close to them, with some outliers. Nevertheless, the mean FP rate values are very close to the value recommended by The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). The FP rate value depends on how one defines true negative cases, which can be either histologically proven benign cases, via a benign clinical course, or by assuming that cytologically benign cases remain as such.
Impact test behavior of aluminum alloys welded joints: Experimental and numerical analysis
Authors: Frutos Martínez José A. , Ambriz Ricardo R. , Naït‐Abdelaziz Moussa , Jaramillo David
Published: April 2021

The Charpy impact test behavior of base metal, weld metal, and heat‐affected zone for 6061‐T6 and 7075‐T651 aluminum alloy welds was analyzed. Force versus time curves of welded joints were obtained by means of an instrumented Charpy pendulum. An explicit finite element model was implemented to evaluate the performance of the Cowper–Symonds constitutive model. Parameters were obtained through a strain‐rate‐sensitivity analysis of base metals at high strain rates. Experimental results were compared with those computed by finite element method (FEM) by assuming the same physical and geometrical conditions of the dynamic‐experimental tests. ANSYS‐LS DYNA was used to achieve the FEM simulations. The comparison between experimental and FEM results in terms of force versus time data was evaluated. Higher accuracies were observed in Al 7075‐T651 alloy (roughly 98%). The 6061‐T6 alloy has shown an approximation of about 90%. Discrepancies are explained in terms of the effective plastic strain at fracture.
Audit firm transparency disclosures and audit quality
Authors: Johl Shireenjit K , Muttakin Mohammad Badrul , Mihret Dessalegn Getie , Cheung Samuel , Gioffre Nathan
Published: April 2021

This study examines whether audit firm transparency disclosures are associated with audit quality and explores the effect of audit firm size on this association. Using control and treatment samples of Australian audit firms pre‐ and post‐introduction of a disclosure requirement, we document that firms affected by the regulation display improvement in audit quality. We find that the extent of transparency disclosures is positively associated with audit quality, and audit firm size affects this association in a non‐linear manner. That is, the association is stronger for large non‐Big 4 than Big 4 firms and insignificant for medium and small non‐Big 4 firms. The results suggest that large non‐Big 4 firms (and Big 4 to a lesser extent) attempt to distinguish themselves through audit quality by providing extensive disclosures about their systems and practices. The incremental effect for Big 4 firms is smaller, as these firms have an already established reputation for quality in the audit market.
NIR‐I/III afterglow induced by energy transfers between Er and Cr codoped in ZGGO nanoparticles for potential bioimaging
Authors: Yang Jian , Jiang Rongyun , Meng Yangqi , Zhao Yangyang , Wang Mingwei , Zhu Hancheng , Yan Duanting , Liu Chunguang , Xu Changshan , Liu Yuxue
Published: April 2021

Herein, Cr3+ and Er3+ codoped zinc gallogermanate (ZGGO) nanoparticles with average size of ~60 nm was synthesized via a hydrothermal path. It was found that near infrared (NIR)‐III (~1540 nm) afterglow was realized in ZGGO:Cr3+,Er3+ nanoparticles based on the successive energy transfer (ET) from Cr3+ to Er3+ after the stoppage of low‐dose (60 mSv) X‐ray irradiation. Meanwhile, the upconverted afterglow at 696 nm was produced via the ET from Er3+ to Cr3+ under different NIR light (808, 980, and 1532 nm) irradiations. Our results demonstrated that an X‐ray pre‐irradiation and a subsequent 980‐nm light re‐excitation might be a good strategy for realizing potential bioimaging. In particular, local‐tissue NIR‐I afterglow imaging using Cr3+ and Er3+ codoped ZGGO nanoparticles can be easily acquired by one‐step 980‐nm laser radiation. Furthermore, NIR‐I/III afterglow mechanisms of ZGGO:Cr3+,Er3+ nanoparticles after stopping X‐ray or different NIR lights (808, 980, and 1532 nm) irradiations were given.
Hereditary palmoplantar keratoderma – phenotypes and mutations in 64 patients
Authors: Harjama L. , Karvonen V. , Kettunen K. , Elomaa O. , Einarsdottir E. , Heikkilä H. , Kivirikko S. , Ellonen P. , Saarela J. , Ranki A. , Kere J. , Hannula‐Jouppi K.
Published: April 2021

Background

Hereditary palmoplantar keratodermas (PPK) represent a heterogeneous group of rare skin disorders with epidermal hyperkeratosis of the palms and soles, with occasional additional manifestations in other tissues. Mutations in at least 69 genes have been implicated in PPK, but further novel candidate genes and mutations are still to be found.

Objectives

To identify mutations underlying PPK in a cohort of 64 patients.

Methods

DNA of 48 patients was analysed on a custom‐designed in‐house panel for 35 PPK genes, and 16 patients were investigated by a diagnostic genetic laboratory either by whole‐exome sequencing, gene panels or targeted single‐gene sequencing.

Results

Of the 64 PPK patients, 32 had diffuse (50%), 19 focal (30%) and 13 punctate (20%) PPK. None had striate PPK. Pathogenic mutations in altogether five genes were identified in 31 of 64 (48%) patients, the majority (22/31) with diffuse PPK. Of them, 11 had a mutation in AQP5, five in SERPINB7, four in KRT9 and two in SLURP1. AAGAB mutations were found in nine punctate PPK patients. New mutations were identified in KRT9 and AAGAB. No pathogenic mutations were detected in focal PPK. Variants of uncertain significance (VUS) in PPK‐associated and other genes were observed in 21 patients that might explain their PPK. No suggestive pathogenic variants were found for 12 patients.

Conclusions

Diffuse PPK was the most common (50%) and striate PPK was not observed. We identified pathogenic mutations in 48% of our PPK patients, mainly in five genes: AQP5, AAGAB, KRT9, SERPINB7 and SLURP1.
Description of a new perchlet, Chelidoperca formosa, from southwestern Taiwan (Peciformes: Serranidae)
Authors: Tang Chi‐Ngai , Ho Hsuan‐Ching
Published: April 2021

A new perchlet species is described on the basis of four specimens collected from southwestern Taiwan. It is similar to congeners with relatively few lateral‐line scales (35–38) and can be distinguished by having third to sixth dorsal‐fin spines notably long; eighth and ninth dorsal‐fin spines notably short; developed gill rakers 1 + 7–8; scale rows between lateral line and sixth dorsal‐fin spine 4 (the dorsalmost half‐sized); tip of upper corner of caudal fin reddish; four reddish bands midlaterally on body with groups of melanophores in these bands. DNA barcoding analysis reveals the new species is a distinct lineage and closest to Chelidoperca microdon. The average interspecific genetic distance calculated by the K2P model is 15.4%, whereas the mean distance from the new species to C. microdon is 18.3%. The inferred phylogenetic tree supports monophyly of Chelidoperca. Including the new species, six nominal species of Chelidoperca are recognized in Taiwanese waters.
Evaluation of the frequency and intensity of favipiravir‐associated yellow‐green fluorescence in lunulae, hair, and face
Authors: Turan Çağrı , Metin Nurcan , Utlu Zeynep , Yıldız Türkan Tuğba , Caferoğlu Sakat Selcen
Published: April 2021

Background

We detected yellow‐green fluorescence in the face, hair and lunulae of patients using favipiravir.

Aim

We evaluated the frequency and intensity of favipiravir‐associated fluorescence.

Patients/Methods.

The participants comprised patients who had taken at least a single dose of favipiravir and been examined no later than 30 days after the last dose. The gender, age, body mass index (BMI), Fitzpatrick's skin‐type, hair color, N‐acetylcysteine use, presence and the intensity of fluorescent reflection under Wood's light in the lunulae of the fingernails, hair, and the face were recorded.

Results

There were 275 patients, 144 (52.4%) of whom were women. 165 (57.9%) had used treatment for a maximum of 5 days, 99 (34.7%) for 6–10 days, and 21 (7.4%) for more than ten days. Using more than 22 tablets of favipiravir increased the probability of detecting fluorescence in the lunulae by 6.72 (2.61–17.23) times. Using more than 28 tablets increased the risk of fluorescence in hair and the T‐zone by 5.92 (2.43–14.71) and 2.88 (1.11–7.47) times, respectively. No relationship was found between the fluorescence intensity in any localization and the total dose. However, we determined a negative correlation between the elapsed time after the last dose and the fluorescence intensity in the lunulae and the T‐zone (p=0.036; p=0.031; respectively). It was noted that BMI negatively correlated with the fluorescence intensity in the lunulae (p=0.001). Skin type was related to intensity for all localizations (p<0.001). Fluorescence was found in the lunulae with significantly less frequency in patients using N‐acetylcysteine (p=0.040).

Conclusions

We must be aware of favipiravir‐induced phototoxicity.
Allelic polymorphism at foxo contributes to local adaptation in Drosophila melanogaster
Authors: Betancourt Nicolas J. , Rajpurohit Subhash , Durmaz Esra , Fabian Daniel K. , Kapun Martin , Flatt Thomas , Schmidt Paul
Published: April 2021

The insulin/insulin‐like growth factor signalling pathway has been hypothesized as a major determinant of life‐history profiles that vary adaptively in natural populations. In Drosophila melanogaster, multiple components of this pathway vary predictably with latitude; this includes foxo, a conserved gene that regulates insulin signalling and has pleiotropic effects on a variety of fitness‐associated traits. We hypothesized that allelic variation at foxo contributes to genetic variance for size‐related traits that vary adaptively with latitude. We first examined patterns of variation among natural populations along a latitudinal transect in the eastern United States and show that thorax length, wing area, wing loading, and starvation tolerance exhibit significant latitudinal clines for both males and females but that development time does not vary predictably with latitude. We then generated recombinant outbred populations and show that naturally occurring allelic variation at foxo, which exhibits stronger clinality than expected, is associated with the same traits that vary with latitude in the natural populations. Our results suggest that allelic variation at foxo contributes to adaptive patterns of life‐history variation in natural populations of this genetic model.
The association of soluble CD163, a novel biomarker of macrophage activation, with type 2 diabetes mellitus and its underlying physiological disorders: A systematic review
Authors: Semnani‐Azad Zhila , Blanco Mejia Sonia , Connelly Philip W. , Bazinet Richard P. , Retnakaran Ravi , Jenkins David J. A. , Harris Stewart B. , Hanley Anthony J.
Published: April 2021

This systematic review investigates the association of sCD163, a novel biomarker of macrophage activation, with type 2 diabetes mellitus (T2DM), insulin resistance, and beta‐cell dysfunction. Sixteen studies (seven cross‐sectional, two case–control, one nested case–control, three prospective cohort, and three experimental) were identified. Most studies demonstrated that elevated sCD163 concentrations were associated with increased insulin resistance. Cross‐sectional, case–control, and nested case–control studies showed higher sCD163 in subjects with T2DM compared with healthy individuals. An 18‐year follow‐up prospective cohort study showed that elevated baseline sCD163 was a strong predictor of T2DM incidence. Prospective cohort studies demonstrated that baseline measures and longitudinal changes in sCD163 were positively associated with insulin resistance; however, associations with beta‐cell function were inconsistent. Two experimental studies evaluated the relationship of sCD163 with T2DM and HOMA‐IR after weight‐reducing interventions. After very low‐calorie diet treatments, sCD163 concentration declined significantly in patients with T2DM but was not associated with insulin resistance. Bariatric surgery did not significantly impact sCD163 levels. In a double‐blind randomized controlled trial, resveratrol supplementation significantly reduced circulating sCD163 in T2DM patients. Current studies demonstrate the potential utility of sCD163 as an early biomarker of T2DM risk and highlight a potential mechanism linking obesity with T2DM onset.
SLCO4A1‐AS1 regulates laryngeal squamous cell carcinoma cell phenotypes via the Wnt pathway
Authors: Zhang Feng , Mao Dehong , He Zhongmei , Li Weichun , Zhang Xu , Li Linglong
Published: April 2021

Aim

Long non‐coding RNAs were widely reported to regulate laryngeal squamous cell carcinoma (LSCC), a prevalent tumor in the head and neck. We aimed to investigate the role of solute carrier organic anion transporter family member 4A1 antisense RNA 1 (SLCO4A1‐AS1) in LSCC.

Materials & methods

CCK‐8 and colony formation assays were conducted to examine the viability and proliferation of LSCC cells. The apoptosis of LSCC cells was evaluated using flow cytometry and TUNEL assays. The distribution of SLCO4A1‐AS1 in LSCC cells was detected by subcellular fractionation assay. The interaction between molecules was confirmed using luciferase reporter assay.

Results

SLCO4A1‐AS1 was overexpressed in LSCC tissues and cells. Furthermore, silenced SLCO4A1‐AS1 repressed the proliferation and facilitated apoptosis of LSCC cells. Mechanistical investigation revealed that SLCO4A1‐AS1 was a competing endogenous RNA (ceRNA) to upregulate SETD7 by binding with miR‐7855‐p. Additionally, SLCO4A1‐AS1 positively regulated the Wnt/β‐catenin signaling pathway by upregulating SETD7. Rescue experiments demonstrated that SLCO4A1‐AS1 promoted LSCC proliferation and inhibited LSCC apoptosis by upregulation of SETD7 and activation of the Wnt/β‐catenin pathway.

Conclusion

SLCO4A1‐AS1 promotes proliferation and inhibits apoptosis of LSCC cells by upregulation of SETD7 in a miR‐7855‐5p dependent way to activate the Wnt/β‐catenin pathway.
Working through the fog of a pandemic: Street‐level policy entrepreneurship in times of crises
Authors: Gofen Anat , Lotta Gabriela , Marchesini da Costa Marcelo
Published: April 2021

Imposing significant challenges for both street‐level implementation and policy (re)design, crises alter the environment for street‐level policy entrepreneurship (SLPE), wherein street‐level bureaucrats engage in policy formulation processes to secure future policy outcomes. Nevertheless, like street‐level implementation in general, SLPE is studied during ordinary times but rarely during crises. Focusing on community‐health workers in Brazil during the Covid‐19 crisis uncovered a defensive motivation for SLPE, which aimed to legitimize community healthcare as an integral part of pandemic treatment, reforming the government's hitherto neglectful approach to community health services. Moreover, the continuing crisis created an unusually prolonged window of opportunity for securing community healthcare provision. By utilizing collective efforts and drawing on powerful politicians' mobilization, SLPE during crisis shares similarities with, yet differs from, SLPE during ordinary times, while further closing the interstices between local, professional, and political perspectives in the formulation of policy decisions.
English in the United Arab Emirates
Authors: Thomas Suneeta
Published: April 2021

This paper provides a sociolinguistic profile of the United Arab Emirates (UAE) with a focus on the status and functions of English in contemporary UAE society. With less than a 12 per cent local population, the UAE presents a unique linguistic laboratory for the spread of English among an expanding foreign and a shrinking local demographic. Contributing to the current literature on English in Expanding Circle countries, I first present a sociohistorical review of foreign and English language presence in the UAE from the ninth century to the present day. By employing archival research, governmental artifacts, and first‐hand observations, I follow this with a description of contemporary users and the four functions of English in the UAE context. The paper then provides a summary of users’ attitudes towards English and Arabic and concludes with an evaluation of key findings and avenues for future research.
Implementation of Semi-Heuristic Reasoning for Boundedness Analysis of Design Optimization Models
Authors: Rao J. R. J. , Papalambros P. Y.
Published: April 2021

A production system performing global boundedness analysis of optimal design models has been implemented in the OPS5 programming environment. The system receives as input an initial model monotonicity table and derives global facts about boundedness and constraint activity using monotonicity principles. Additional facts may be discovered by heuristic search of implicit elimination sequences that examine boundedness of reduced models with active constraints eliminated. The global facts generated automatically by this reasoning system can be used either for a global solution, or for a combined local-global active set strategy.
Statistical Machine Learning for the Cognitive Selection of Nonlinear Programming Algorithms in Engineering Design Optimization
Authors: Hoeltzel D. A. , Chieng W. H.
Published: April 2021

In order to overcome the problem of lack of generality in nonlinear programming (NLP) test problem formulation and to introduce the concept of cognitive NLP method switching, statistical machine learning has been applied to a sample data base of nonlinear programming problems. Reasonable conclusions have been drawn about an optimization problem type and a corresponding sequence of NLP solution algorithms, using statistical pattern recognition applied to local (vs. global) design information. A program, referred to as OPTDEX-OLDM, with the capability of learning from statistical pattern recognition is discussed. The statistical aspects and algorithmic optimization of the nonlinear programming problem are emphasized in this discussion. A clustering process has been performed on attributes assigned to the NLP problem sample data base, and an example which describes this statistical clustering process is discussed.
The Complementary Roles of Symbolic Computing and Numerical Optimization in Engineering Design Software
Authors: Ellsworth R. , Parkinson A. , Cain F.
Published: April 2021

In many engineering design problems, the designer converges upon a good design by iteratively evaluating a mathematical model of the design problem. The trial-and-error method used by the designer to converge upon a solution may be complex and difficult to capture in an expert system. It is suggested that in many cases, the design rule base could be made significantly smaller and more maintainable by using numerical optimization methods to identify the best design. The expert system is then used to define the optimization problem and interpret the solution, as well as to apply the true heuristics to the problem.

An example of such an expert system is presented for the design of a valve anti-cavitation device. Because of the capabilities provided by the optimization software, the expert system has been able to outperform the expert in the test cases evaluated so far.
Nonlinear Goal Programming Techniques in the Synthesis of Mechanisms
Authors: Krishnamurty S. , Turcic D. A.
Published: April 2021

The development of an effective optimization approach for the solution of synthesis problems in mechanisms is presented. The optimization procedure is based on the technique of nonlinear goal programming. In this approach, the generalized variables describing the mechanism are determined by first prioritizing the various objectives of the problem and then by minimizing the value of the achievement function, which represents how closely the designed mechanism meets the specified set of requirements.

The following are the main advantages to such an optimization technique. The many conflicting objectives inherent in any design can be included directly in the optimization process. Such a treatment will avoid the need to introduce constraints artificially and/or to combine the objectives into a single objective. This will allow all feasible optimal solutions to be identified. This technique also requires only simple function evaluations and, hence, the optimization process will be both time and cost efficient.

Two synthesis examples of industrial type mechanisms are presented and the results are discussed. The proposed design technique produced accurate and acceptable solutions in both cases. This method was found to be computationally robust and effective in yielding optimal solutions to mechanism synthesis problems.
Mechanism Optimization Using Zero-Order Methods and Penalty Functions: A Comparison of Incremented Versus Nonincremented Penalty Parameter
Authors: Klatt M. A. , Reinholtz C. F.
Published: April 2021

This paper explores the use of two different penalty parameter strategies applied to mechanism optimization using zero-order methods. For the cases studied, a large, nonincremented value of the penalty parameter appears to be superior to the conventional sequential unconstrained minimization technique.
A Procedure for Comparative Evaluation of Design for Assembly Methodologies
Authors: Darlow M. S. , Avidar D. M. , Steiner M. W.
Published: April 2021

It has been generally agreed that it is necessary to include assembly considerations during product design in order to produce a cost-effective design. To this end, a number of design for assembly (DFA) methodologies have been proposed. This presents the designer with a choice of methodology and little or no criteria on which to base a decision. This paper presents a comparative evaluation procedure which has been developed as a tool to help the designer select the DFA methodology which is most appropriate for a particular situation. This tool is a step-by-step procedure for evaluating and selecting a DFA method from a group of alternatives by bringing together factors and criteria used to measure their characteristics and capabilities. This paper presents the details of this evaluation procedure and applies it to three DFA methodologies, to illustrate its use. The results of the evaluation presented herein are interesting, although the subjective nature of the criteria and the ratings limits their usefulness. Rather, the point of this paper is that the evaluation method described, modified for individual needs and tastes, can be used to provide useful results for that individual.
Optimal Control of a Flexible Assembly System
Authors: Pourbaba B.
Published: April 2021

The performance of a flexible assembly system consisting of a set of work stations linked by a set of transporter stations is modeled by a Markovian queueing network in steady state. Its optimal behavior is characterized such that the throughput rate from the system is maximized, while the probability of finding an arbitrary workpiece waiting inside either each work station or each transporter station in addition to an allowable lenght of time will be sufficiently close to zero.
Design and Implementation of an Intelligent CAD System
Authors: Jakiela M. J. , Papalambros P. Y.
Published: April 2021

System requirements and system design for integrating a production rule program and a computer aided design system are presented. An implementation using a commercially available graphics modeling system is described. A “suggestive mode” interface is programmed as an example with application to design for automated assembly. Initial use of the implementation indicates that encoding production rules is more difficult than with conventional text-only knowledge-based systems, but that this system is a more effective way to use artificial intelligence techniques in design.
NC Machining Algorithms for CSG Solids
Authors: Tan S. T. , Yuen M. F. , Sze W. S. , Wong W. Y.
Published: April 2021

This paper presents two algorithms for NC (Numerical Control) machining of engineering parts defined as a CSG (Constructive Solid Geometry) (1) model. The algorithms are respectively for automatically roughing out the approximate shape using octree and quadtree encoding techniques and for machining the final shape with fine cuts. In this paper, the two algorithms are referred to as rough machining and fine machining and form the Hong Kong University’s NC module for the PADL-2 solid modelling system developed by the Production Automation Project of Rochester University. The NC module with its own command language is embedded into PADL-2. Parts defined with the PADL-2 system can be machined using this module on a 3-axis machining centre via a hardwired link. Examples of the parts machined with this set-up are also illustrated in this paper.
Controlling Vibration in Remote Manipulators
Authors: Singer N. C. , Seering W. P.
Published: April 2021

Robotic manipulators for use in space have flexible structures and as a result have special control problems. These manipulators change their vibrational characteristics as they change in orientation. The Space Shuttle Remote Manipulator System (RMS) was chosen as a typical system and experiments were performed using the Draper Laboratory software model of the arm (DRS). First, the workspace of the manipulator was characterized in terms of the robot’s first two modes of vibration. Next, some feedforward experiments were performed on the computer model to show the promise of vibration reduction using feedforward control.
Reliability Analysis of Function Generating Mechanisms Through Monte Carlo Simulation
Authors: Crawford R. H. , Rao S. S.
Published: April 2021

Due to normal variations in dimensions inherent in the manufacture of the components of a mechanism, there is a small probability of not meeting the accuracy predicted by a deterministic representation of the mechanism. The reliability of a mechanism can be defined as the probability of deviation from its specified function. This paper presents a Monte Carlo simulation approach for the reliability analysis of function generating mechanisms. The approach is illustrated by considering the reliability analysis of a four-bar straight-line mechanism. The effect of the probability distribution of the random parameters on the overall reliability is also investigated. The Monte Carlo approach can be coupled with the known statistical properties of the production techniques to significantly increase the production yield of mechanisms that satisfy specified reliability requirements.
A Computer-Aided Design Technique for the Synthesis of Planar Four Bar Mechanisms Satisfying Specified Kinematic and Dynamic Conditions
Authors: Rigelman G. A. , Kramer S. N.
Published: April 2021

This paper presents a computer-aided design optimization method for synthesizing planar four bar mechanisms which satisfy specified kinematic and dynamic conditions. The method can be used for path, motion, and function generation as well as for combinations of these. The kinematic conditions consist of combinations of specifications on the position, velocity, and acceleration of the coupler point and the rotations of the coupler and follower links. The dynamic conditions consist of the minimization of the average power consumed by the mechanism as well as a limit on the maximum input torque. The external loads consist of variable forces and moments at the coupler point as well as variable torques on the follower link. The Selective Precision Synthesis (SPS) method is used to express each kinematic condition in terms of a specification plus an allowable deviation or tolerance from the specification. In this manner, the synthesis problem is converted into a nonlinear optimization problem which is solved by using the Generalized Reduced Gradient (GRG) method. In addition, two force balancing routines are included to help the dynamic performance of the mechanism. The mathematical formulation and derivation as well as numerical examples are presented in this paper.
Synthesis of Linkages to Generate Specified Histories of Forces and Torques: The Planar 4R Four-Bar Mechanism
Authors: Bagci C.
Published: April 2021

Analytical precision position and optimum synthesis methods for linkages to generate specified force and torque histories are presented and applied to the planar four-bar mechanism. Mechanical advantage method (MAM) and integration of power equilibrium method (IPEM) are used to develop design equations. MAM yields design equations to use when the torque multiplication factor is defined at discrete number of design positions, as well as in continuous forms. IPEM requires continuous forms, but it reduces the torque generation problem into a function generation problem. Design equations with one, two, three, and four unknowns are developed for precision position synthesis; and they are used to formulate optimum synthesis process using many design positions that requires no iteration. Generation of infinite torque multiplication factor and synthesis of quick-return four-bar mechanism to generate specified advance-to-return time ratio are also considered. The synthesized four-bar mechanisms replace circular and non-circular external and internal gear drives. Several industrial application examples are included. The second part of the article considers the slider-crank mechanism.
Quaternions, Hamilton Operators, and Kinematics of Mechanical Systems
Authors: Agrawal O. P.
Published: April 2021

In this paper, quaternions are briefly reviewed and their associated matrix algebra is developed. Two Hamilton operators are defined and some of their properties are studied. The properties of these operators are then applied to find kinematic relations of a body undergoing spatial rotation and to find a recursive relation for intermediate-axes. The formulation presented provides an easy approach to kinematic analysis of spatial mechanical systems.
Planetary-Gear-Type Second-Harmonic Balancers
Authors: Tasi L. W. , Maki E. R.
Published: April 2021

This paper describes several mechanical balancers, based on the planetary gear trains known as the hypotrochoid and epitrochoid trains, for reducing or eliminating second-order out-of-balance in mechanical systems. It is shown that by proper arrangement of the planetary gear trains, a balancer can be obtained for the elimination of second-order shaking forces or second-order shaking moments or a combination of both shaking forces and moments. The advantage of this type of balancer is that the carrier of the gear train needs only to run at the primary speed of the mechanical system to be balanced. Therefore, the balancer can be designed to be concentric with the primary rotating shaft of the machine using the primary shaft as the carrier. For example, for the balance of the second-order shaking force of an in-line four-cylinder four-stroke internal combustion piston engine, the balancer can be placed on the third main bearing or one on each of the second and fourth main bearings.
Constructive Solid Geometry of the Trihedron
Authors: Wilde D. J.
Published: April 2021

As a first step toward a Constructive Solid Geometry for designing general polyhedra, this paper develops the set theory of the trihedron, loosely speaking any set combination of three planar half spaces (monohedra). The trihedron can be decomposed precisely into its primitive monohedra and its CSG-tree of union or intersection operations with no designer topological input other than the convexity or concavity of each edge, giving a human-computer interface simpler than those for existing right-hand rule boundary representation methods. The somewhat visual trigonometric concepts of classical solid geometry are formulated in terms of vectors and matrices appropriate for numerical computation. This reorganization may be useful not only for designers of CAD systems, but also for educators seeking to strengthen and modernize the geometric education of engineering students wonting to make full use of CAD/CAM technology.
Single Domain Methods for Modeling Objects in the Round for Engineering and Manufacturing Applications
Authors: Cox J. J. , Ferguson H. , Kohkonen K.
Published: April 2021

Basic principles are presented for writing down global parametric equations for a broad class of bounded and closed surfaces embedded in three spatial dimensions. The paper focuses on the topological decomposition and identification of objects into appropriate domains and the development of single-valued maps which take these domains into images of the objects in 3-space. Several examples are presented showing the mapping functions and domains. Heuristics used in the identification of the domains and maps are also discussed. These methods are specifically applied to the engineering design process.
A Strategy for Reducing Turnaround Time in Design Optimization Using a Distributed Computer System
Authors: Young K. C. , Padula S. L. , Rogers J. L.
Published: April 2021

There is a need to explore methods for reducing lengthly computer turnaround or clock time associated with engineering design problems. Different strategies can be employed to reduce this turnaround time. One strategy is the use of a supercomputer, which can be costly in terms of hardware acquisition and software modification. Another strategy is to run validated analysis software on a network of existing smaller computers so that portions of the computation can be done in parallel. This paper focuses on the implementation of this second strategy using two types of problems. The first type is a traditional structural design optimization problem, which is characterized by a simple data flow and a complicated analysis. The second type of problem uses an existing computer program designed to study multilevel optimization techniques. This problem is characterized by complicated data flow and a simple analysis. The paper shows that distributed computing can be a viable means for reducing computational turnaround time for engineering design problems that lend themselves to decomposition. Parallel computing can be accomplished with a minimal cost in terms of hardware and software.
A Modified Game Theory Approach to Multiobjective Optimization
Authors: Freiheit T. I. , Rao S. S.
Published: April 2021

In todays competitive economy, it is no longer possible for the designer to find solutions to conflicting objective problems which are merely adequate. The designer must select the design variables such that there is a superior compromise between the objectives. To this end, a large number of methods have been developed for the solution of multiobjective optimization problems. The earliest reported in-depth work on the formulation of the multiobjective problem is that of Kuhn and Tucker [1]. Reviews of the progress in the field have been published by Hwang and Masud [2], Stadler [3], Evans [4], and Rastrigin and Eiduk [5]. The methods for optimizing multiple objectives may be categorized into two types, leaving the objectives in vector form and scalarizing the objectives into one equation.
Remarks on Sufficiency of Constraint-Bound Solutions in Optimal Design
Authors: Papalambros P. Y.
Published: April 2021

Solution strategies for optimal design problems in nonlinear programming formulations may require verification of optimality for constraint-bound points. These points are candidate solutions where the number of active constraints is equal to the number of design variables. Models leading to such solutions will typically offer little insight to design trade-offs and it would be desirable to identify them early, or exclude them in a strategy using active sets. Potential constrained-bound solutions are usually identified based on the principles of monotonicity analysis. This article discusses some cases where these points are in fact global or local optima.
Optimal Design of Complex Systems Using Decomposition Methods: An Example Application to Electromechanical Control
Authors: McLain T. W. , Free J. C. , Teng A.
Published: April 2021

The utility of the classical optimization and decomposition methods were examined with respect to actuator/control system design. A method of integrating actuator design with control system design to obtain optimal transient response was explored and found to be effective. A test problem consisting of an electromechanical actuator was decomposed and optimized following the strategy proposed by Sobieski [1,2]. A comparison of optimization results from decomposed and undecomposed actuator/control system models was made. The results from the sample problems showed decomposition to be a potentially valuable tool in the optimization of large scale dynamic systems. Methods of discrete optimization techniques to select catalog values for dc motors and gears were examined. In the problems tested, a variation of an exhaustive search was found to be the most reliable method for handling discrete variables since a relatively small number of combinations was involved. A sucessful method for evaluating and optimizing the time response characteristics of dynamic systems was also developed.
Sensitivity Analysis and Optimization of Mechanical System Design
Authors: Langner W. J.
Published: April 2021

The paper follows studies on simulation of three-dimensional mechanical dynamic systems with the help of sparse matrix and stiff integration numerical algorithms.

For sensitivity analyses and the application of numerical optimization procedures it is substantial to calculate the effect of design parameters on the system behaviour by means of derivatives of state variables with respect to the design parameters.

For static and quasi static analyses the computation of these derivatives from the governing equations leads to a linear equation system.

The matrix of this set of linear equations shows to be the Jacobian matrix required in the numerical integration process solving the system of governing equations for the mechanical system. Thus the factorization of the matrix perfomed by the numerical integration algorithm can be reused solving the linear equation system for the state variable sensitivities.

Some example demonstrate the simplicity of building the right hand sides of the linear equation system.

Also it is demonstrated that the procedure proposed neatly fits into a modular concept for simulation model building and analysis.
Sensitivity Analysis of Model Coordination Method of Decomposition in Nonlinear Programming
Authors: Torab H.
Published: April 2021

A methodology in sensitivity analysis of the Model Coordination Method (MCM) of Decomposition in Nonlinear Programming is discussed. Under the Model Coordination Method, the optimization of an engineering system is divided into two levels. In the first level, each component is analysed and optimized independently. This is done through separation of variables into two groups of local and coordinating variables. At the second level, the coordinating variables are determined so that the interaction between the components provides an optimal performance of the system. This study focuses on sensitivity analysis for the Model Coordination Method.