bluuebunny/crossref_metadata_2025 huggingface dataset:
Is Kawasaki disease an infectious disorder?
Authors: Rowley Anne H.
Published: November 2017

Although the etiology of Kawasaki disease (KD) is largely unknown, a large body of clinical, epidemiologic, immunologic, pathologic and ultrastructural evidence suggests that an infectious agent triggers a cascade that causes the illness. However, this elusive infectious agent remains unidentified at present. Increasingly sensitive molecular methods for identifying microbial nucleic acids and proteins in tissue samples continue to rapidly emerge, and these methods should be utilized in studies on KD etiology as they become available. Identifying the etiology of this enigmatic disease remains the single most important research goal in the field, and accomplishing this goal is the best means to improve diagnosis, treatment and prevention of this potentially fatal childhood disease.
Analysis of food demand in Vietnam and short‐term impacts of market shocks on quantity and calorie consumption
Authors: Hoang Hoa K.
Published: November 2017

A complete demand system for Vietnam was estimated using household survey data. Results showed that demand for rice with respect to prices and expenditure is relatively inelastic compared to other foods. Demand for food in general tends to be less elastic at higher levels of income and for urban households. In the short term, a market shock such as a 10% decrease in income or a 30% increase in rice prices forces households to spend a larger portion of their expenditure on rice at the expense of other foods. Low‐income households face a higher risk of undernourishment as their daily calorie intake is more negatively affected by the shocks than high‐income households. The results suggest the importance of policies that provide necessary safety net programs for the poor.
Regulation of oxygen saturation in retinal blood vessels in response to dynamic exercise
Authors: Heitmar Rebekka , Vekria Pravin , Cubbidge Robert P.
Published: November 2017

Purpose

To evaluate the impact of dynamic exercise on retinal vessel oxygen saturation in healthy individuals.

Methods

Twenty‐six healthy participants underwent moderate dynamic exercise (modified Master's two‐step exercise). In all subjects, intraocular pressures (IOP), systolic and diastolic blood pressures (SBP and DBP), retinal vessel calibres and retinal arterial and venous oxygen saturation were measured at baseline, immediately following exercise and 15 min postexercise.

Results

Moderate dynamic exercise increased SBP and DBP immediately postexercise (SBP: 116 (±13) mmHg to 150 (±21) mmHg; p < 0.001 and DBP: 69 (±10) mmHg to 74 (±10); p < 0.001), while IOP decreased by an average of 2 mmHg (baseline: 13 (±3) mmHg)) immediately postexercise (11 (±2) mmHg). Oxygen saturation in retinal arteries remained unchanged (baseline = 93 ± 8%; immediately postexercise = 94 ± 9% and 15 min postexercise = 96 ± 8%; p = 0.069), but increased in retinal veins immediately postexercise and did not return to baseline values within 15 min postexercise (baseline = 54 ± 12%; immediately postexercise = 56 ± 15%; 15 min postexercise=57 ± 12%; p = 0.036).

Conclusion

There is a mild increase in retinal venous oxygen saturation and there is a trend towards an increase in arterial saturation in otherwise healthy individuals following dynamic exercise.
Editorial: therapeutic drug monitoring for anti‐TNF agents—has it all been said?
Authors: Domènech E. , Cañete F. , Mañosa M.
Published: November 2017

Linked Content

This article is linked to Nakase and Nakase et al papers. To view these articles visit https://doi.org/10.1111/apt.14365 and https://doi.org/10.1111/apt.14318.
Letter: reproducible evidence shows that exclusive enteral nutrition significantly reduces faecal calprotectin concentrations in children with active Crohn's disease
Authors: Logan M. , Ijaz U. Z. , Hansen R. , Gerasimidis K. , Russell R. K.
Published: November 2017

Linked Content

This article is linked to Swaminath et al and Feathers et al papers. To view these articles visit https://doi.org/10.1111/apt.14253 and https://doi.org/10.1111/apt.14360.
Editorial: ribavirin continues to play a role in treatment with direct‐acting antivirals for hepatitis C virus‐infected patients with decompensated cirrhosis
Authors: Waldenström J. , Lagging M.
Published: November 2017

Linked Content

This article is linked to van Tilborg et al paper. To view this article visit https://doi.org/10.1111/apt.14288.
Editorial: therapeutic drug monitoring for anti‐TNF agents—has it all been said? Author's reply
Authors: Nakase H.
Published: November 2017

Linked Content

This article is linked to Nakase et al and Domenèch et al papers. To view these articles visit https://doi.org/10.1111/apt.14318 and https://doi.org/10.1111/apt.14350.
Encountering Work: Intergenerational Informality, Child Labor, and Malnutrition in Urban Ecuador
Authors: Hinrichsen Megan B.
Published: November 2017

This article examines the interconnections among informality, child labor, and child malnutrition in households at the bottom of the socioeconomic pyramid in urban Ecuador. Through qualitative interviews with 120 adult informal laborers, mostly street vendors, I elicited stories that not only revealed current labor conditions but also reflected upon whole lives engaged in informal work. Interviews uncovered lifelong structural conditions that perpetuate the social and economic inheritances of intergenerational work in the informal sector and intergenerational patterns of a broader, more inclusive form of child labor termed “encountering work.” Social, political, and economic factors related to informality and child labor maintain structural vulnerabilities that contribute to the emergence and exacerbation of syndemic health conditions, most notably through multiple forms of child malnutrition. The children of these 120 informal sector workers, especially those that encounter work in a variety of ways alongside their parents, demonstrate profound childhood nutritional failures that will likely impact them throughout their lives. The challenges related to intergenerational informality, child labor as encountering work, and child malnutrition can only be understood in the context of pervasive, intergenerational poverty. Encountering work is a survival strategy that allows families to subsist in an unequal society that can simultaneously perpetuate vulnerabilities and inequalities in health and opportunity.
Relation of Nodal expression to the specification of the dorsal‐ventral axis and tissue patterning in the starfish Patiria pectinifera
Authors: Sasaki Hiroki , Kominami Tetsuya
Published: November 2017

In this study, we attempted to reveal fundamental aspects of starfish embryogenesis, particularly embryonic axis specification or determination, in Patiria pectinifera. We first cloned PpNodal, which is known to play an important role in the specification of the embryonic axis in a wide range of animals, and studied its expression profile. PpNodal expression was first detected at the mid‐blastula stage and showed a single peak around the onset of gastrulation. These features of Nodal expression were shifted to later stages by several hours, compared with those of sea urchin embryos. After the gastrulation started, the expression level became gradually lowered up to the early bipinnaria stage, while the expression level became drastically lowered in sea urchin embryos during gastrulation. The localized Nodal expression in the presumptive oral region was not observed in starfish embryos, unlike in sea urchin embryos. Furthermore, SB431542, an inhibitor of Nodal receptor, did not affect the formation of the DV axis, although it caused the loss of left‐right asymmetry. In contrast to this, SB525334, a specific inhibitor of TGF‐beta receptor, caused the complete loss of the DV axis. Thus, the usage of signaling molecules during early embryogenesis likely varies among echinoderm classes.
Social Support and Life‐Domain Interactions among Assigned and Self‐Initiated Expatriates
Authors: Ballesteros Leiva Felix , Poilpot‐Rocaboy Gwénaëlle , St‐Onge Sylvie
Published: November 2017

Based upon conservation of resources theory, this study is the first to explore (1) the relations between life‐domain support received by internationally mobile employees (IMEs) from their organization, supervisors, coworkers, and family and friends and their life‐domain conflicts and enrichments in two directions: work life → personal life (WL → PL) and personal life → work life (PL → WL) and (2) whether these links are different between assigned expatriates (AEs) and self‐initiated expatriates (SIEs). The questionnaire data were collected from 182 SIEs and 102 AEs. Results from multivariate analyses show that (1) the more IMEs perceive receiving life‐domain support from their family and friends and their organization, the less they report life‐domain conflicts and (2) the more IMEs perceive receiving life‐domain support from their coworkers, the more they report life‐domain enrichments. Finally, it appears that AEs' perceived life‐domain organizational support is positively related to their perceived WL → PL enrichments and that SIEs' perceived life‐domain coworker support is negatively related to their life‐domain conflicts in both directions.
Seizure outcomes in patients with anti‐NMDARencephalitis: A follow‐up study
Authors: Liu Xu , Yan Bo , Wang Rui , Li Chen , Chen Chu , Zhou Dong , Hong Zhen
Published: November 2017

Objective

To evaluate the long‐term seizure outcome and potential factors associated with seizure outcome in patients with anti‐N‐methyl‐d‐aspartate receptor (anti‐NMDAR) encephalitis.

Methods

In the setting of a prospective, single‐center, longitudinal cohort study, 109 patients were evaluated with ongoing follow‐up. Patients underwent clinical evaluation every 3 months. Seizure outcomes and the potential risk factors were assessed with a median follow‐up of 24 months (6–60 months).

Results

Of 109 patients (47 men; 62 women) with anti‐NMDARencephalitis, 88 patients (80.7%) had reported seizures at acute phase, including single seizure (17/88, 19.3%), repetitive seizures (27/88, 30.7%), nonrefractory status epilepticus (22/88, 25%), refractory status epilepticus (SE; 13/88, 14.8%), and super refractory status epilepticus (9/88, 10.2%). Seizure was more likely to recur in patients with tumor presence, status epilepticus (SE) development, coma, orintensive care unit (ICU) admission in the acute phase (p < 0.05). Seizure freedom was achieved within 2 years in all patients. More than 80% of the whole cohort with acute seizures had their last seizure within 6 months of disease onset.

Significance

Seizure is a common feature in the acute stage of anti‐NMDARencephalitis but not thereafter. The presence of tumor,SE, coma, and/orICUadmission in the acute phase predicts early seizure occurrence after the acute phase. Seizure freedom was typically achieved in our follow‐up, and long‐term use of antiepileptic drugs may not be necessary.
Cannabinoid receptor 1/2 double‐knockout mice develop epilepsy
Authors: Rowley Shane , Sun Xiaofei , Lima Isabel V. , Tavenier Alexandra , de Oliveira Antonio Carlos Pinheiro , Dey Sudhansu K. , Danzer Steve C.
Published: November 2017

The endocannabinoid system has gained attention as an important modulator of activity in the central nervous system. Initial studies focused on cannabinoid receptor 1 (CB1), which is widely expressed in the brain, but recent work also implicates cannabinoid receptor 2 (CB2) in modulating neuronal activity. Both receptors are capable of reducing neuronal activity, generating interest in cannabinoid receptor agonists as potential anticonvulsants. CB1 (Cnr1) and CB2 (Cnr2) single‐knockout mice have been generated, with the former showing heightened seizure sensitivity, but not overt seizures. Given overlapping and complementary functions of CB1 and CB2 receptors, we queried whether double‐knockout mice would show an exacerbated neurological phenotype. Strikingly, 30% of double‐knockout mice exhibited provoked behavioral seizures, and 80% were found to be epileptic following 24/7 video‐electroencephalographic monitoring. Single‐knockout animals did not exhibit seizures. These findings highlight the importance of the endocannabinoid system for maintaining network stability.
The mixed vs the integrated approach to style investing: Much ado about nothing?
Authors: Leippold Markus , Rueegg Roger
Published: November 2017

We study the difference between the returns to the integrated approach to style investing and those to the mixed approach. Unlike the mixed approach, the integrated approach aggregates factor characteristics at security level. Recent literature finds that the integrated approach dominates the mixed approach. Using statistical tools for robust performance testing, we demystify these findings as a statistical fluke. We do not find any evidence favouring the integrated approach. What we do find is that the integrated approach exhibits a higher sensitivity to the low‐risk anomaly. However, this reduction in risk does not lead to an improvement in performance.
Hemobilia immediately after transcatheter arterial chemoembolization using drug‐eluting beads for hepatocellular carcinoma with intrahepatic bile duct invasion
Authors: Nishi Maiko , Saeki Issei , Yamasaki Takahiro , Maeda Masaki , Hisanaga Takuro , Iwamoto Takuya , Matsumoto Toshihiko , Hidaka Isao , Ishikawa Tsuyoshi , Takami Taro , Sakaida Isao
Published: November 2017

Transcatheter arterial chemoembolization (TACE) is used as a palliative treatment for unresectable hepatocellular carcinoma (HCC) worldwide. Recently, a novel drug delivery–embolic agent, the drug‐eluting bead (DEB), was introduced for TACE. There are a few reports of tumor hemorrhage after TACE using DEB (DEB‐TACE) for HCC. However, there have not been any reports of hemobilia immediately after DEB‐TACE for HCC with intrahepatic bile duct invasion. Here, the first such case is reported. A 71‐year‐old woman was admitted to our hospital to undergo DEB‐TACE for multiple HCCs with worsening left intrahepatic bile duct dilatation. She was diagnosed with HCC that extensively invaded the left hepatic duct. After DEB‐TACE through the left hepatic artery, a hepatic arteriogram showed extra flow of the contrast agent to the left hepatic and common bile ducts. Therefore, transcatheter arterial embolization (TAE) of the responsible vessel was carried out using coils, and no extra flow of the contrast agent was identified. The patient was discharged 14 days after TAE without deterioration of liver function. Although hemobilia immediately after DEB‐TACE is rare, there may be increased potential for hemobilia when DEB‐TACE is carried out for HCC with extensive bile duct invasion. We suggest that DEB‐TACE may be contraindicated for such cases.
A min–max solution to optimise planned lead time in a remanufacturing system
Authors: Liu Biyu , Chen Weida , Segerstedt Anders , Yang Haidong , Zhang Qinhong
Published: November 2017

Determining a rational planned lead time (PLT) is a critical and difficult problem in production planning, especially for a remanufacturing system. This paper considers an optimisation problem of the PLT in a make‐to‐order remanufacturing system to coordinate disassembly–remanufacturing–reassembly and to improve performance. This optimisation model is designed to determine the PLT that minimises the inventory holding and shortage costs. Given the unknown distribution of remanufacturing time but with known first and second moments, this model is solved by a min–max approach, which can capture distributions with the same first and second moments. How the PLT and total cost are affected by yield rate with different first and second moments, unit holding cost, unit shortage cost and purchasing lead time are also investigated through numerical examples in this paper. The results of this study are shown to be consistent with practice and can be a support to decision‐making in production planning and scheduling for remanufacturing.
Clues for early detection of autoimmune Addison's disease – myths and realities
Authors: Sævik Å. B. , Åkerman A.‐K. , Grønning K. , Nermoen I. , Valland S. F. , Finnes T. E. , Isaksson M. , Dahlqvist P. , Bergthorsdottir R. , Ekwall O. , Skov J. , Nedrebø B. G. , Hulting A.‐L. , Wahlberg J. , Svartberg J. , Höybye C. , Bleskestad I. H. , Jørgensen A. P. , Kämpe O. , Øksnes M. , Bensing S. , Husebye E. S.
Published: November 2017

Background

Early detection of autoimmune Addison's disease (AAD) is important as delay in diagnosis may result in a life‐threatening adrenal crisis and death. The classical clinical picture of untreated AAD is well‐described, but methodical investigations are scarce.

Objective

Perform a retrospective audit of patient records with the aim of identifying biochemical markers for early diagnosis of AAD.

Material and Methods

A multicentre retrospective study including 272 patients diagnosed with AAD at hospitals in Norway and Sweden during 1978–2016. Scrutiny of medical records provided patient data and laboratory values.

Results

Low sodium occurred in 207 of 247 (84%), but only one‐third had elevated potassium. Other common nonendocrine tests were largely normal. TSH was elevated in 79 of 153 patients, and hypoglycaemia was found in 10%. Thirty‐three per cent were diagnosed subsequent to adrenal crisis, in whom electrolyte disturbances were significantly more pronounced (P < 0.001). Serum cortisol was consistently decreased (median 62 nmol L−1 [1–668]) and significantly lower in individuals with adrenal crisis (38 nmol L−1 [2–442]) than in those without (81 nmol L−1 [1–668], P < 0.001).

Conclusion

The most consistent biochemical finding of untreated AAD was low sodium independent of the degree of glucocorticoid deficiency. Half of the patients had elevated TSH levels. Only a minority presented with marked hyperkalaemia or other nonhormonal abnormalities. Thus, unexplained low sodium and/or elevated TSH should prompt consideration of an undiagnosed AAD, and on clinical suspicion bring about assay of cortisol and ACTH. Presence of 21‐hydroxylase autoantibodies confirms autoimmune aetiology. Anticipating additional abnormalities in routine blood tests may delay diagnosis.
Semantics or Sustainability: Socio‐legal Research in Family Law, or Sociology of Law and Family Justice
Authors: Maclean Mavis
Published: November 2017

This article first addresses the question of semantics in the rapidly developing field of law and society in the United Kingdom, and suggests that the various terminologies (sociology of law, socio‐legal studies, empirical legal studies, and more) indicate lively development rather than confusion, and should be a source of congratulation not concern. The second part of the article takes the development of the study of family justice as an example in addressing the issue of sustainability through methodological development and methods of communication which may provide the key to an ongoing contribution to the understanding of law in society.
Prosthodontic Management of a Patient with Moebius Syndrome: A Clinical Report
Authors: Mahrous Ahmed , Thalji Ghadeer
Published: November 2017

Moebius/Mӧbius Syndrome (MS) is an extremely rare congenital disorder characterized by uni‐ or bilateral palsy of the abducens (VI) and the facial (VII) nerves, causing facial paralysis. Dysfunction of cranial nerves III through XII is common, most often the glossopharyngeal (IX) and hypoglossus (XII). Afflicted individuals seeking prosthodontic care, particularly removable prosthetics, present multiple challenges related to inherent facial and tongue muscle weakness and microstomia. Other extraoral anomalies may include congenital multiple arthrogryposis and malformations of the upper and lower limbs. This clinical report describes the rehabilitation of a patient with Moebius Syndrome using a maxillary 2‐implant retained overdenture and mandibular partial removable denture prosthesis.
Chronostratigraphic framework and depositional environments in the organic‐rich, mudstone‐dominated Eagle Ford Group, Texas, USA
Authors: Minisini Daniel , Eldrett James , Bergman Steven C. , Forkner Rob
Published: November 2017

Since the beginning of the century, several authors have hypothesized and documented the presence of bottom currents during the deposition of mudstones, including mudstones rich in organic matter, challenging the assumption that persistent low‐energy conditions are necessary prerequisites for deposition of such sediments. More processes responsible for transport and deposition of mudstones mean also more processes acting contemporaneously in different parts of a basin. Without a precise and robust chronostratigraphic framework, however, it is not possible to characterize these differences. The new data reported here provide a profoundly different understanding of the controls on sedimentation in distal continental shelf platforms. To enhance the understanding of the different coeval environments of deposition coexisting in a muddy system, the Upper Cretaceous Eagle Ford Group, deposited on the Comanche carbonate platform, has been investigated by integrating sedimentology, mineralogy, geochemistry and palaeoecology, and creating age models in different physiographic sectors using biostratigraphy and geochronology. Data from two cores and 41 outcrops were analysed with a telescopic approach, from grain scale to basin scale. Nine temporal stages over a ca 8 Myr interval (ca 98 to 90 Ma) were defined in an area that spans 75 000 km2. Finally, the different environments of deposition recorded within each of the nine stages were interpreted. The construction of the chronostratigraphic framework also allowed: measuring the duration of a basin‐wide gradational increase in energy in the water column (ca 1 Myr) and a hiatus confined into the shallower water sector (ca 2 Myr); determining the mean eruption frequency of volcanoes (ca 9 kyr); and the time of inundation of the Western Interior Seaway (97·5 to 97·1 Ma). The context, the outcrops–cores–logs correlations, the large data set (Appendix S1), the high‐precision and well‐calibrated constraints represent an unprecedented contribution for future regional facies models of organic‐rich units and for improvements of key aspects in the industry of unconventional resources.
From Adult Finger Tapping to Fetal Heart Beating: Retracing the Role of Coordination in Constituting Agency
Authors: Solfo Alessandro , van Leeuwen Cees
Published: November 2017

Sense of agency can be defined as the self‐awareness of bodily movement, whereas extended agency as the self‐awareness of affecting, through movement, events concomitant with movement. As a distinctive manifestation of agency, we review Spizzo's effect. This effect arises when agents coordinate their rhythmic movements with visual pulses. Once coordination is established, agents feel controlling the onset or the offset of the pulses through their movements. Spizzo's effect, therefore, constitutes a manifest case of extended agency, in which agents are aware of controlling, through movement, the pulses temporally concomitant with movement. We propose that sense of agency requires continuity of kinesthesia, which in turn requires the continuity of selfhood. The continuity of kinesthesia is necessarily deduced from the consistent kinematics observed in movements, whereas the continuity of selfhood may stem from the patterns of rhythmic coordination that humans encounter ever since intrauterine life. The primacy of these patterns in adults is in accordance with phenomena such as Spizzo's effect, which require coordination to be induced. We, therefore, propose coordination as the fundamental interaction from which selfhood, kinesthesia, and agency arise.
Smart Multimode Transmission for Automobiles
Authors: Srinath Nitin , Kumar Ashwin , Joladarashi Sharnappa
Published: November 2017

There are two basic types of transmissions — manual and automatic. While manual transmissions have greater transmission efficiency and better overall driving experience, it is difficult and not as easy to handle as automatic transmissions. Automatic transmissions make life a lot easier for the driver but are less efficient and laggard. So, the aim of this project is to take the best of both worlds and combine it in one, i.e. a transmission system that is capable of working as both a manual and an automatic transmission. For this, we plan to automate a regular manual transmission with a manual override option on both the clutch and the gearbox systems. Motors will be used to control the clutch and the changing of gears in the gearbox. In the manual mode, the motors will be operated by user input switches (clutch pedal and stick shift). In the automatic mode, the same motors will be controlled by a control algorithm based on various inputs like weight of the car, inclination, speed of the engine and the car etc.
Computational Design and Additive Manufacturing of Conformal Metasurfaces by Combining Topology Optimization With Riemann Mapping Theorem
Authors: Vogiatzis Panagiotis , Ma Ming , Chen Shikui , Gu Xianfeng David
Published: November 2017

In this paper, we present a computational framework for computational design and additive manufacturing of spatial free-form periodic metasurfaces. The proposed scheme rests on the level-set based topology approach and the conformal mapping theory. A 2D unit cell of metamaterial with tailored effective properties is created using the level-set based topology optimization method. The achieved unit cell is further mapped to the 3D quad meshes on a free-form surface by applying the conformal mapping method which can preserve the local shape and angle when mapping the 2D design to a 3D surface. The proposed level-set based optimization methods not only can act as a motivator for design synthesis, but also can be seamlessly hooked with additive manufacturing with no need of CAD reconstructions. The proposed computational framework provides a solution to increasing applications involving innovative metamaterial designs on free-form surfaces in different fields of interest. The performance of the proposed scheme is illustrated through a benchmark example where a negative-Poisson’s-ratio unit cell pattern is mapped to a 3D human face and fabricated through additive manufacturing.
Higher-Order Local Analysis of Kinematic Singularities of Lower Pair Linkages
Authors: Müller Andreas
Published: November 2017

Kinematic singularities of linkages are configurations where the differential mobility changes. Constraint singularities are critical points of the constraint mapping defining the loop closure constraints. Configuration space (c-space) singularities are points where the c-space ceases to be a smooth manifold. These singularity types are not identical. C-space singularities are reflected by the c-space geometry. Identifying kinematic singularities amounts to locally analyze the set of critical points. The local geometry of the set of critical points is best approximated by its tangent cone (an algebraic variety). The latter is defined in this paper in a form that allows for its computational determination using the Jacobian minors. An explicit closed form expression for the derivatives of the minors is presented in terms of Lie brackets of joint screws. A computational method is proposed to determine a polynomial system defining the tangent cone. This finally allows for identifying c-space and kinematic singularities.
Research of Permanent Magnet Synchronous Motor Sensorless Control Based on Fractional Order PLL
Authors: Li Changhong , Bian Dangwei , Chen Chaobo , Gao Song
Published: November 2017

For those surface mounted permanent magnet synchronous motors (PMSM), a fractional order phase lock loop (FO-PLL) sensorless control method is proposed. On the basis of PMSM model in stationary coordinate, a rotor flux linkage observer is constructed. By designing the modified integrator and introducing the high pass filter, output saturation distortion or numeric overflow caused by integrator zero drift are solved. The observing results have no DC component. Moreover, a fractional order PLL is designed to estimate the PMSM rotor angle and speed. Parameters of FO-PLL controller are tuned and optimized via ITAE criterion. System indiscrimination degree is improved effectively. By using Oustaloup recursive filter, high order integer order approximation to fractional order integrator is realized. Last, the effectiveness and engineering application of the proposed method are verified on a MATLAB based PMSM control simulation platform.
Mathematical Modeling and Dynamic Contact Analysis of Beveloid Gear Pairs in Marine Gearbox With Small Shaft Angle
Authors: Lin Tengjiao , Li Hang , Liu Wen , Zhao Jun
Published: November 2017

The research objective of this study is involute beveloid gears in marine gearbox with small shaft angle. Based on the theory of gear geometry and the generation mechanism, the mathematical models of beveloid gear pairs are derived according to the tooth surface equations of the imaginary counterpart rack. Then a parametric modeling programs of beveloid gears are developed to automatically generate exact model of tooth surface, so as to establish gear solid models. Subsequently, the assembly models are established according to the spatial geometry relation of beveloid gear pairs with intersected axis and crossed axis respectively. On this basis, the finite element models of beveloid gear pairs with intersected axis and crossed axis are established, and the dynamic contact force, dynamic stress distribution and dynamic transmission error are obtained by dynamic contact finite element analysis.
Hypoid Gear Design Beyond Conventional Approach
Authors: Wang J. C. , Kuan Scott , Hirao W. Yukio
Published: November 2017

Conventional hypoid gear design approach utilizes specific commercial programs provided by gear machine providers. Those programs typically have a set of assumptions as the starting point for the hypoid gear design. That type of approach works well when the overall system performance matches the assumptions.

The gearing systems have been evolving significantly to reach ever-higher customer demands. The condition challenges the engineering community to go beyond the conventional wisdom. As the breakthrough ideas come into the system concept, the conventional hypoid gear design assumptions might not be sufficient to represent the actual performance. Unexpected failure modes and reliability of the products could cause serious consequences. Hypoid gear design based on system concept becomes a more effective approach under such conditions.

This paper presents examples of how system approach helped analyzing and designing hypoid gears for modern powertrain systems in heavy vehicle applications. The effectiveness of such approach makes those systems realistic and reliable to meet extremely strict customer demands.

Conventional hypoid gear design tools require the system to be sufficiently rigid to duplicate the actual gear tooth contacts as observed on the gear tester. Typical relationship between the gear set is represented by E, P, G, and α, which represents three linear displacements and one angle displacement as shown in Figure 1 [1]. This approach works well if the system performance meets all the assumptions defined by the tools.

As the complexity of the system increases, more considerations for hypoid gear design become critical. Analytical tools that take into consideration other components beyond the gear set provide an effective way to understand the hypoid gear performance in different conditions closer to the reality. Figure 2 is an example analytical model of a heavy vehicle carrier [2].

Gear performance could be predicted in advanced engineering stage and compared to experimental results at a later stage of the product development. This approach provides insight into potential risks earlier in a product development cycle and cuts the product development cycle time significantly. Another advantage of this type of approach is the possibility to understand the gear set performance under different operating conditions. Conventional hypoid gear design tools focus primarily on vehicle driving condition. The heavy vehicle industry faces more diversified operating conditions based on customer needs. Figure 3 is one example showing the analysis results of one testing condition where ring gear concave side drives pinion convex side (coast mode).
Solutions of Interval Systems for Under-Constrained and Redundant Parallel Manipulators
Authors: Notash Leila
Published: November 2017

For under-constrained and redundant parallel manipulators, the actuator inputs are studied with bounded variations in parameters and data. Problem is formulated within the context of force analysis. Discrete and analytical methods for interval linear systems are presented, categorized and implemented to identify the solution set, as well as the minimum 2-norm least square solution set. The notions of parameter dependency and solution subsets are considered. The hyperplanes that bound the solution in each orthant characterize the solution set of manipulators. While the parameterized form of the interval entries of the Jacobian matrix and wrench produce the minimum 2-norm least square solution for the under-constrained and over-constrained systems of real matrices and vectors within the interval Jacobian matrix and wrench vector, respectively. Example manipulators are used to present the application of methods for identifying the solution and minimum norm solution sets for actuator forces/torques.
On Performance Analysis of General Observers for Uncertain Systems
Authors: Bai Wenyan , Sen Chen , Huang Yi , Xue Wenchao , Liu Ping
Published: November 2017

This paper aims to rigorously study the observer for general uncertain systems. The proposed observer is shown to be the general form of extended state observer (ESO), disturbance observer (DO), generalized extended state observer (GESO) and extended high gain observer (EHGO). The properties of this general observer is discussed by analyzing the estimation error. The paper illustrates that the output of the proposed general observers may not performs as the estimation the real state and uncertainty. We prove that this observer gives the estimations for the group of states and uncertainties whose exact form is given in the paper. Finally, numerical simulations for a typical example validate the theoretical analysis.
Nonlinear Vibration of a Rotor-Active Magnetic Bearing System With 16-Pole Legs
Authors: Wu Ruiqin , Zhang Wei , Yao Ming Hui
Published: November 2017

In this paper, the nonlinear dynamics of a rotor-active magnetic bearing system with 16-pole legs and the time varying stiffness is investigated. The magnetic forces are obtained through an electromagnetic theory. The motion governing equation is derived by using Newton law. The resulting dimensionless equation of motion for the rotor-AMB system with 16-pole legs and the time varying stiffness is presented with the two-degree-of-freedom system including parametric excitation, the quadratic and cubic nonlinearities. The averaged equations of the rotor-AMB system are obtained by using the method of multiple scales under the case of the primary parametric resonance and 1/2 sub-harmonic resonance. The numerical results show that there exist the periodic, quasi-periodic and chaotic motions in the rotor-active magnetic bearing system. Since the weight of the rotor effect the system, it is also found that there are the different shapes of motion on the two directions of the rotor-AMB system. The parametric excitation, or the time-varying stiffness produced by the PD controller has great impact on the system. Thus, the complicated dynamical response in the rotor-AMB system can be controlled through adjusting the parametric excitation.
Linear Active Disturbance Rejection Control for Grid-Connected Inverter With LCL Filter
Authors: Ling Yuchang , Dong Junyi , Yang Hongbo , Xue Yali , Zeng Jiang , Li Donghai
Published: November 2017

This paper proposes a linear active disturbance rejection control (LADRC) for gird-connected inverter with LCL filter to deal with parameters variation, internal coupling and external disturbance. Relative degree of plant is used to design LADRC and on the basis of relationship between LADRCs parameters and bandwidth, the parameters tuning are sum up in several guidable points. It is demonstrated that LADRC presents a good dynamic performances, high disturbance rejection and extremely robust to parameters variation in Matlab/Simulink.
Vibration Characteristics Analysis of the Rotating Blade Based on a Polynomial Aerodynamic Force
Authors: Yao Ming Hui , Ma Li , Zhang Ming Ming , Zhang Wei
Published: November 2017

In this paper, aerodynamic expressions in forms of the series and the polynomial for a blade with low speed in low pressure compressor are deduced by numerical simulation. Considering shear deformation and cross-section warping effect, the blade is simplified as a pre-twist, pre-setting rotating cantilever plate, which subjected to the aerodynamic force and the centrifugal force. Based on the first-order shear deformation theory and von-Karman nonlinear geometric relationship, nonlinear partial differential dynamic equation of the rotating blade is derived by using Hamilton principle. Equations of motion are converted into a series of ordinary differential equations using Galerkin method. The dynamic frequency and the dynamic deformation of the blade are explored and contrasted with results obtained by finite element method. Effects of parameters on vibration characteristics of the blade under different rotation speed are analyzed. Results show that the explicit expression of the aerodynamic force for the blade has a good applicability.
Kinematics of a Particular 3T1R Parallel Manipulator of Type 2PRPU
Authors: Simas Henrique , Di Gregorio Raffaele
Published: November 2017

Schoenflies-motion generators (SMGs) are 4-degrees-of-freedom (dof) manipulators whose end effector can perform translations along three independent directions, and rotations around one fixed direction (Schoenflies motions). Such motions constitute the 4-dimensional (4-D) Schoenflies subgroup of the 6-D displacement group. The most known SMGs are the serial robots named SCARA. Pick-and-place tasks are typical industrial applications that SMGs can accomplish. In the literature, 3T1R parallel manipulators (PMs) have been also proposed as SMGs. Here, a somehow novel 3T1R PM is presented and studied. Its finite and instantaneous kinematics are analyzed in depth, and analytic and geometric tools that are useful for its design are presented. The proposed SMG has a single-loop not-overconstrained architecture with actuators on or near the base and can make the end effector perform a complete rotation.
Clearance-Induced Position Uncertainty of Planar Linkages and Parallel Manipulators
Authors: Ting Kwun-Lon , Hsu Kuan-Lun
Published: November 2017

The paper presents a simple and effective kinematic model and methodology, based on Ting’s N-bar rotatability laws [2629], to assess the extent of the position uncertainty caused by joint clearances for any linkage and manipulators connected with revolute or prismatic pairs. The model is derived and explained with geometric rigor based on Ting’s rotatability laws. The significant contribution includes (1) the clearance link model for P-joint that catches the translation and oscillation characteristics of the slider within the clearance and separates the geometric effect of clearance from the input error, (2) a simple uncertainty linkage model that features a deterministic instantaneous structure mounted on non-deterministic flexible legs, (3) the generality of the method, which is effective for multiloop linkages and parallel manipulators.

The discussion is carried out through symmetrically constructed planar eight-bar parallel robots. It is found that the uncertainty region of a three-leg parallel robot is enclosed by a hexagon, while that of its serial counterpart is enclosed by a circle inscribed by the hexagon. A numerical example is also presented. The finding and proof, though only based on three-leg planar 8-bar parallel robots, may have a wider implication suggesting that based on kinematics, parallel robots tends to inherit more position uncertainty than their serial counterparts. The use of more loops in parallel robots cannot fully offset the adverse effect on position uncertainty caused by the use of more joints.
Periodic Motions and Bifurcation Trees in a Parametric Duffing Oscillator
Authors: Luo Albert C. J. , Ma Haolin
Published: November 2017

This paper studies bifurcation trees of periodic motions in a parametric, damped Duffing oscillator. From the semi-analytic method, the corresponding differential equation is discretized to obtain the implicit mapping. From implicit mapping structure, the periodic nodes of periodic motions are computed, and the bifurcation trees of period-1 to period-4 motions are presented and the corresponding stability and bifurcation are carried out by eigenvalue analysis. From the analytical predictions, numerical simulations are completed, and the trajectory, harmonic amplitudes and phases of period-1 to period-4 motions are illustrated.
An Approach to Flexible-Robust Optimization of Large-Scale Systems
Authors: Biswas Arpan , Chen Yong , Hoyle Christopher
Published: November 2017

Though Robust Optimization has proven useful in solving many design problems with uncertainties, it is not suitable for certain problems which have sequential options in the decision making process. In this work, an integration of a Real Option model with the Robust Optimization technique is presented. This approach aims to eliminate the shortcomings of robust optimization for sequential decision making problems. We provide an example of applying this new integrated model to the operational control of a single reservoir of the Oregon-Washington Columbia River system by optimizing the flexibility of the system. Flexibility for an engineering system is the ease with which the system can respond to uncertainty in a manner to sustain or increase its value delivery through decision-making. In this paper, we define flexibility as the amount of water left in the storage reservoir to produce electricity after meeting demand. Real Option analysis is an economic tool which helps to value the multiple courses of actions in a decision: that is to either sell the flexibility or hold it for future use based upon the future value of flexibility. Selling flexibility causes one to lose some future value because one may be forced to repurchase that flexibility from the market at higher prices later due to shortages; Real Options analysis values future purchases to support decision-making. Robust optimization focuses on for selling the flexibility in a daily market and gives an optimal result by maximizing net revenue, considering all the physical and operational constraints of the reservoir to avoid floods or other environmental calamities. Net revenue is defined as cost of selling and cost of future purchase of the flexibility. We provide an optimization result of 27 random inflow scenarios which gives high, medium and low flexibility to allocate using the integrated model. We compare the optimal solutions given by the integrated model with that given by robust optimization. The integrated real option-robust optimization model improves the revenue from allocating flexibility as much as 40 percent over the robust optimization result.
Divergent Thinking Ability + Interest = Creative Ideas: Exploring the Relationships Between Cognitive Creativity Assessments and Product Design Idea Generation
Authors: Kwon Jieun , Bromback Luke , Kudrowitz Barry
Published: November 2017

The external validity of existing creativity tests was examined in the product-design field. To examine the external validity, this study adopted the Consensual Assessment Technique (CAT), by which industry leaders directly rate product ideas for their creativity. A simple correlation analysis showed that among three broadly used creativity tests (Remote Associations Test, Alternative Uses Test, and Torrance Test for Creative Thinking), only the Alternative Uses Test (AUT) was found to predict creativity in the product-design industry. In addition to the correlations analysis, two factors, product familiarity and level of interest, were tested for moderation. The results show that familiarity with the product lessens RAT-CAT (Remote Associations Test - Consensual Assessment Technique) correlation, whereas level of interest strengthens the correlation. Thus, the less familiar and more interested an individual is in the product, the more likely the individual’s divergent thinking skills will translate into an actual creative product idea.
A 3-Legged Parallel Robot for Long Bone Fracture Alignment
Authors: Abedinnasab Mohammad H. , Farahmand Farzam , Gallardo-Alvarado Jaime
Published: November 2017

The reduction of long bone fractures is traditionally an invasive procedure with drawbacks of intense force, soft tissue damage, and, both, rotational and longitudinal malalignment. To combat these drawbacks, we applied a novel, wide open, three-legged, 6-DOF parallel robot, to the current surgical procedure. This platform will balance the accuracy, payload, and workspace for the surgeon, resulting in more efficient, successful surgeries. The experimental tests on a phantom reveal that the mechanism is well capable of applying the desired reduction steps against the large muscular payloads with high accuracy.
Design and Gait Analysis of a Two-Legged Miniature Robot With Piezoelectric-Driven Four-Bar Linkage
Authors: Dharmawan Audelia G. , Hariri Hassan H. , Soh Gim Song , Foong Shaohui , Wood Kristin L.
Published: November 2017

This paper presents the design and development of a new type of piezoelectric-driven robot, which consists of a piezoelectric unimorph actuator integrated as part of the structure of a four-bar linkage to generate locomotion. The unimorph actuator replaces the input link of the four-bar linkage and motion is generated at the coupler link due to the actuator deflection. A dimensional synthesis approach is proposed for the design of four-bar linkage that amplifies the small displacement of the piezoelectric actuator at the coupler link. The robot consists of two such piezo-driven four-bar linkages and its gait cycle is described. The robot speed is derived through kinematic modelling and experimentally verified using a fabricated prototype. This result will be important for developing a motion planning control strategy for the robot locomotion, which will be part of future work.
Design and Analysis of Symmetrical, Monolithic Tip-Tilt-Piston Flexure Stages
Authors: Hao Guangbo
Published: November 2017

This paper mainly deals with the determinate design/synthesis of a class of symmetrical and monolithic flexure mechanisms. Each is composed of 6 identical in-plane wire beams with uniform square cross sections. These flexure stages can provide three out-of-plane tip-tilt-piston motions for applications in high-precision or miniaturisation environments. A generic symmetrical structure is proposed as first with a group of defined parameters considering constraint and non-interference conditions. Normalised static analytical compliance entries for the diagonal compliance matrix of a generic structure are derived and symbolically represented by the parameters. Comprehensive compliance analysis is then followed using the analytical results, and quick insights into effects of parameters on compliances in different directions are gained. Case studies without and with actuation consideration are finally discussed. As a second contribution, a physical prototype with three actuation legs is monolithically fabricated (using CNC milling machining), kinematically modelled and experimentally tested, which shows that the desired out-of-plane motion can be generated from the in-plane actuation.