bluuebunny/crossref_metadata_2025 huggingface dataset:
Interventions to Improve the Willingness to Work Among Health care Professionals in Times of Disaster: A Scoping Review
Authors: Karimi Dehkordi Negin , Abbasi Amir Farhang , Radmard Lord Mostafa , Soleimanpour Samira , Goharinezhad Salime
Published: December 2021

The critical role of the health workforce in the function of the health care system is undeniable. In times of disaster and public health emergency, the importance of this valuable resource for the organization multiplies. This scoping review was conducted to identify, analyze, and categorize interventions to improve willingness to work in times of disaster as well as the existing knowledge gaps in the topic. For this purpose, four databases were searched. These included Scopus, PubMed, WOS, and World Health Organization observatory, and they were searched for papers published from July 2000 to September 2020. Studies of the English language that described strategies to improve human resources for health willingness to work during times of disaster/public health emergency were included. Full-text papers were screened by authors and data extraction was done according to self-designed form. Framework analysis identified key interventions based on human resources for health action framework. From 6246 search results, 52 articles were included, a great portion of which was published in 2020 probably due to the COVID-19 pandemic. Northern America was the region with most studies. From 52 included studies, 21 papers have reported the interventions to improve willingness to work and 31 papers have explored factors that affected a willingness to work. The interventions used in the studies were categorized into five themes as Leadership, Partnership, Financing, Education, and Organizational policies. The most and least interventions were financial and partnership respectively. The review identified a wide range of feasible strategies and interventions to improve human resources for health’s willingness to work at times of disaster that are expected to be effective. Organizations should let the staff know these decisions and as a necessary step in every organizational intervention remember to evaluate the impacts.
Social Media Use and Adolescents’ Well-Being: Developing a Typology of Person-Specific Effect Patterns
Authors: Beyens Ine , Pouwels J. Loes , van Driel Irene I. , Keijsers Loes , Valkenburg Patti M.
Published: December 2021

This study investigated the effects of active private, passive private, and passive public social media use on adolescents’ affective well-being. Intensive longitudinal data (34,930 assessments in total) were collected through a preregistered three-week experience sampling method study among 387 adolescents. N = 1 time series were investigated, using Dynamic Structural Equation Modeling. Findings showed that different types of social media use very rarely yielded different effects within one and the same adolescent: 45% of adolescents experienced no changes in well-being due to any of the three types of social media use, 28% only experienced declines in well-being, and 26% only experienced increases in well-being. Only one adolescent experienced the theoretically expected effect pattern of a positive effect of active private and passive private use and negative effect of passive public use. Together, the findings suggest that the active–passive use dichotomy in social media research is less clear-cut than it might seem.
Postverbal subjects in child Italian: Argument structure, discourse and the definiteness effect
Authors: Cairncross Alex , Dal Pozzo Lena
Published: December 2021

While previous work on postverbal subjects in Italian has shown that young children are sensitive to the effects of argument structure and definiteness, little is known about the acquisition of postverbal subjects at the VP-periphery. In response, the present study investigated such subjects under new-information focus by monolingual Italian children (6;1 – 7;4). For this, we employed an elicitation task and a forced-choice task. The results indicated that the children use postverbal subjects at the VP-periphery felicitously, although they do not perform at ceiling. Unexpectedly, the results also suggested possible remnant difficulty with the definiteness effect. However, after comparison with adult data we argue that this is not a developmental issue and instead may suggest that our children were aware that the definiteness effect is not about definiteness per se.
Three Cases of Parotid Hemangiomas in Adults
Authors: Huang Yi-Ting , Ou Chun-Yen , Lee Wei-Ting , Hsu Heng-Jui
Published: December 2021

Hemangiomas account for only 0.4% to 0.6% of all parotid tumors, making them extremely rare in adults. Unlike pediatric parotid hemangiomas, those in adults typically present as asymptomatic swellings of the parotid, have no skin discoloration, and usually do not regress spontaneously. Therefore, an accurate diagnosis of parotid hemangiomas in adults before surgical excision is generally challenging. Herein, we present 3 cases of adult parotid hemangiomas. The patients all received parotidectomies with tumor resection. Histopathological analysis of the resected specimens revealed numerous dilated, thin- or thick-walled (small, large, or variably sized) vessels lined with flattened endothelial cells. A diagnosis of cavernous hemangioma of the parotid gland was established only after the histopathological analysis. Parotid cavernous hemangiomas in adults are rare and often misdiagnosed before surgical resection. Clinical presentation and imaging features on ultrasonography, computed tomography, magnetic resonance imaging, and angiography may support an accurate preoperative diagnosis. Surgical resection proved a suitable treatment approach for our 3 cases.
Pregnancy and Fertility Trends Among Female Otolaryngologists
Authors: Huguet Makenzie , Beliveau Angela , Taylor Sandra L. , Aizenberg Debbie A.
Published: December 2021

Objective

This study sought to determine childbearing patterns and decision making among female otolaryngologists.

Study Design

Anonymous survey.

Setting

An anonymous survey was sent in 2020 to female otolaryngologists identified through their membership with the American Academy of Otolaryngology–Head and Neck Surgery.

Methods

Data were analyzed concerning individual fertility and childbearing history, reflections regarding decision making, perceptions of workplace support, and estimations of objective childbearing potential.

Results

There were 398 responses. The mean age at first pregnancy was 32.3 years. Almost one‐third of respondents who attempted to conceive (30.4%) were diagnosed with infertility. Of those who had their first pregnancy during training, 55% reported having substantial workplace support, as opposed to 70% of those whose first pregnancies followed completion of training (P =. 01). When asked what they would do differently in retrospect, most women with infertility (65.0%) would have attempted conception earlier; 41 (41.0%) would have used cryopreservation to extend fertility; and 14 (14.0%) would have gone into a different specialty.

Conclusion

Female otolaryngologist respondents have children later in life than the general population, and a substantial proportion face infertility or have regrets about family planning decisions and career decision making. Increased awareness, further investigation, and targeted programs are needed to support the growing number of female otolaryngologists who desire both a career and a family.
Cochlear Implantation and Risk of Falls in Older Adults
Authors: Grimm David R. , Fakurnejad Shayan , Alyono Jennifer C.
Published: December 2021

Objective

To examine whether cochlear implantation (CI) increases the risk of clinically significant falls in older adults.

Study Design

Retrospective analysis of deidentified administrative claims from a US commercial insurance database.

Setting

Nationwide deidentified private insurance claims database (Clinformatics Data Mart; Optum).

Methods

Patients undergoing CI were identified through Current Procedural Terminology codes. Number of days with falls resulting in health care expenditure were counted 1 year pre‐ and post‐CI. Generalized estimating equation Poisson regression was used to determine medical and sociodemographic predictors for fall days, including age, sex, race, and income, with pre‐ vs post‐CI status.

Results

Between 2003 and 2019, 3773 patients aged >50 years underwent CI. An overall 139 (3.68%) patients recorded at least 1 fall diagnosis a year pre‐CI, and 142 (3.76%) recorded at least 1 fall diagnosis post‐CI. The average number of days with fall diagnoses per patient with a recorded fall was 3.12 pre‐CI and 2.04 post‐CI. In bivariate analysis, age (P <. 0001) and Charlson Comorbidity Index (P <. 0001) were predictive of falls, but sex (P <. 10), race (P <. 72), and income (P <. 51) were not. Poisson regression demonstrated a statistically significant association between Charlson Comorbidity Index and days with fall diagnoses (risk ratio, 1.39 [95% CI, 1.30‐1.49]; P <. 0001]). No statistically significant difference in falls was seen pre‐ vs post‐CI (risk ratio, 0.67 [95% CI, 0.34‐1.33]; P <. 25]). Age also was not predictive of falls in multivariate analysis.

Conclusions

CI does not appear to increase the risk of falls in older adults. Patient comorbidities correlate most strongly with fall risk and should be considered in patient selection for CI.
COVID‐19 Disparities and Vaccine Hesitancy in Black Americans: What Ethical Lessons Can Be Learned?
Authors: Restrepo Nicolas , Krouse Helene J.
Published: December 2021

Objective

This state of the art review focuses on bioethical questions and considerations from research findings and methodological issues, including design and recruitment of participants, in studies related to COVID‐19 vaccine hesitation in Black individuals. Ethical concerns identified were applied to otolaryngology with recommendations for improving health inequities within subspecialties.

Data Sources

An internet search through PubMed, CINAHL, and socINDEX was conducted to identify articles on COVID‐19 vaccine hesitation among the Black population between 2020 and 2021.

Review Methods

A systematic review approach was taken to search and analyze the research on this topic, which was coupled with expert analysis in identifying and classifying vital ethical considerations.

Conclusions

The most common COVID‐19 vaccine hesitation factors were related to the development of the vaccine, mistrust toward government agencies, and misconceptions about safety and side effects. These findings raised bioethical concerns around mistrust of information, low health literacy, insufficient numbers of Black participants in medical research, and the unique positions of health professionals as trusted sources. These bioethical considerations can be applied in otolaryngology and other health‐related areas to aid the public in making informed medical decisions regarding treatments, which may reduce health inequalities among Black Americans and other racial and ethnic minority groups.

Implications for Practice

Addressing ethical questions by decreasing mistrust, tailoring information for specific populations, increasing minority representation in research, and using health professionals as primary sources for communicating health information and recommendations may improve relationships with Black communities and increase acceptance of new knowledge and therapies such as COVID‐19 vaccination.
Effectiveness and safety of povidone iodine for prolonged lung air-leak after lung surgery
Authors: Chaari Zied , Hentati Abdessalem , Ben Ayed Aimen , Abid Walid , Frikha Imed
Published: December 2021

Background

Pulmonary surgery is often associated with postoperative prolonged parenchymal air-leak. The purpose of this study was to determine efficacy and safety of povidone iodine as treatment of prolonged parenchymal air-leak following all-types of lung surgery.

Methods

This prospective trial was conducted from June 2019 to December 2020, and designed under PanAfrican Clinical Trials Registry requirements. Patients having prolonged parenchymal air-leak were randomly allocated to povidone iodine protocol (Group A) or surveillance without povidone iodine (Group B). We collected the number of povidone iodine injections required before bubbling stopped, total drainage period, tolerance after injection, complications and side-effects. Comparative study was performed to evaluate povidone iodine efficacy.

Results

Following randomization, Group A included 19 patients, and Group B 21. Both groups were comparable. The mean drainage period was 9.21 days in Group A (6–14 days) and 15.62 days in Group B (7–31 days) ( p = 0.001). The mean hospitalization period was 11.05 days in Group A (7–16 days) and 18.9 days in Group B (9–38 days) ( p < 0.0001). The mean follow-up period was 6.8 months (3–18 months). No deaths were noted in either groups. Four side-effects were reported in Group A (21%) and four serious complications were noticed in Group B (19%). No recurrences were reported in Group A versus one recurrence of homolateral pneumothorax in Group B (4.76%).

Conclusions

Povidone iodine is an effective and safe solution for pleurodesis. It is associated with a low complication rate that remains acceptable, and could be proposed as treatment of prolonged parenchymal air-leak after lung resections.
The meaning of misinformation and those who correct it: An extension of relational dialectics theory
Authors: Malhotra Pranav , Scharp Kristina , Thomas Lindsey
Published: December 2021

What misinformation means and what it means to be someone who corrects it is socially contested, especially in interpersonal contexts where politeness expectations complicate correction. Given this flux in meaning, we analyze posts about misinformation correction in interpersonal contexts from the AmItheAsshole subreddit through a relational dialectics theory (RDT) lens. Findings revealed that discourses of misinformation as harmful and as innocuous and potentially helpful constituted the meaning of misinformation, while discourses of misinformation correctors as inconsiderate and as communal guardians constituted the meaning of misinformation correctors. The latter meaning was dependent on the meaning of misinformation and the adjacent ideology of politeness. Thus, we extend RDT by elucidating how the meaning of a semantic object is predicated on a web of larger intertextual meaning.
Practice review: Evidence-based and effective management of fatigue in patients with advanced cancer
Authors: Chapman Emma J , Martino Erica Di , Edwards Zoe , Black Kathryn , Maddocks Matthew , Bennett Michael I
Published: December 2021

Background:

Fatigue affects most patients living with advanced cancer and is a symptom that healthcare professionals can find difficult to manage.

Aim:

To provide healthcare professionals with a pragmatic overview of approaches to management of fatigue in patients with advanced cancer that are commonly recommended by guidelines and to evaluate evidence underpinning them.

Design:

Scoping review methodology was used to determine the strength of evidence supporting use of interventions recommended in management of fatigue in patients with advanced cancer.

Data sources:

National or international guidelines were examined if they described the management of fatigue in adult cancer patients and were written within the last 6 years (2015–2021) in English. The Cochrane Database of Systematic Reviews (January 2011–December 2021) was searched for ‘cancer’ AND ‘fatigue’ in title, abstract or keywords. A PubMed search was also made.

Results:

Evidence indicates physical exercise interventions are effective and patients may benefit from energy conservation tactics. Evidence does not support use of psychostimulants such as methylphenidate. Limited data were found on efficacy of corticosteroids, psychological interventions, nutritional intervention, sleep optimization or complementary therapies for management of fatigue in advanced cancer.

Conclusion:

We recommend regular assessment, review and acknowledgement of the impact of fatigue. Exercise and energy conservation should be considered. Pharmacological interventions are not endorsed as a routine approach. Many interventions currently recommended by guidelines are not supported by a robust evidence base and further research on their efficacy is required.
Multi-echo Dixon and breath-hold T2-corrected multi-echo single-voxel MRS for quantifying hepatic iron overload in rabbits
Authors: Zhao Fanyu , Chen Yidi , Zhang Huiting , Li Chenhui , Long Liling
Published: December 2021

Background

Three-dimensional (3D) multi-echo-Dixon (ME-Dixon) and breath-hold T2-corrected multi-echo single-voxel MR spectroscopy (HISTO) can simultaneously quantify liver fat and liver iron. However, their diagnostic efficacy and application scope for quantitative iron in co-existing fatty liver have not been adequately evaluated.

Purpose

To evaluate the accuracy of ME-Dixon and HISTO for quantitative analysis of hepatic iron in rabbits with iron deposition and fatty liver using liver–iron concentration (LIC) as a reference standard.

Material and Methods

ME-Dixon, HISTO, and conventional two-dimensional multi-echo gradient echo (GRE) sequences were performed on 42 rabbits. The following parameters were calculated: R2* from ME-Dixon and GRE; proton density fat fraction (PDFF) from the ME-Dixon, HISTO (normal TE range), and HISTO-H (extended TE range); and R2_water from HISTO and HISTO-H. The LIC and liver–fat concentration (LFC) were measured through chemical analysis, and their relationship with the MRI parameters were assessed. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were used to evaluate the diagnostic efficiency.

Results

LIC was significantly correlated with R2_HISTO-H, R2*_Dixon, and R2*_GRE ( r = 0.858, 0.910, 0.931, respectively; P < 0.001) and weakly with R2_HISTO ( r = 0.424; P = 0.008). A strong correlation was also observed between the LFC and PDFF obtained from HISTO, HISTO-H, and ME-Dixon ( r = 0.776, 0.811, 0.888, respectively; P < 0.001). ME-Dixon showed the best performance with moderate iron overload (AUC = 0.983).

Conclusion

3D ME-Dixon is useful for quantifying the LIC, especially with co-existing fatty liver. Its diagnostic performance is also superior to that of the HISTO sequence.
Experimental study on an airfoil equipped with an active flow control element
Authors: Hochhäusler Dominik , Erfort Gareth
Published: December 2021

This paper addresses the torque ripple problem of vertical axis wind turbines (VAWT) by applying an oscillating bump which was previously optimised with a numerical model. Since the element primarily affects the drag of an airfoil, a low-speed wind-tunnel experiment using the wake survey method was conducted in order to highlight the effect on the drag of a symmetrical airfoil. Measurements were taken along the centreline of the foil to compare with numerically simulated results on a 2D foil. This study provides an experimental data set for an active flow control device. When the stationary results were compared against numerical simulation they showed an overall good agreement. The moving bump increased the drag coefficient for higher frequencies of oscillation and induced less drag compared to the steady maximum distortion. Uncertainties in the experiments were primarily caused by fluctuations in the test section and the data reduction error. Future work should include the measurement of lift in order to determine the influence of the element on the torque.
Designing the Ideal Patient Navigation Program for Older Adults with Complex Needs: A Qualitative Exploration of the Preferences of Key Informants
Authors: Kokorelias Kristina M. , DasGupta Tracey , Hitzig Sander L.
Published: December 2021

Navigating the healthcare system is complex. Many older adults and their family members report sub-optimal outcomes when transitioning from hospital to home. Patient navigation has been introduced as a model of care to help improve hospital to home transitions and to better integrate care across care environments. There are no best-practice guidelines for designing a patient navigation program for older adults with complex needs. This qualitative descriptive study interviewed 38 healthcare professionals to determine key characteristics of the “ideal” patient navigator program. Thematic analysis revealed four themes describing key components of an ideal patient navigator program for older adults with complex needs: (1) Easy accessibility and open communication amongst staff; (2) flexible eligibility requirements; (3) characteristics of the patient navigator; and (4) appropriate program size and duration. We suggest directions for future research, program design, and implementation considers to improve patient navigation for older adults and their family caregivers.
Adaptation and Validation of a Chinese Online Self-Regulated Learning Questionnaire
Authors: Lau Kit-Ling
Published: December 2021

This study aimed to adapt and validate a Chinese version of the online self-regulated learning questionnaire (COSLQ) with Chinese junior secondary students in Hong Kong. A total of 716 students from six schools participated voluntarily in the study. Overall, the findings of this study supported the COSLQ’s psychometric quality. The COSLQ subscales all demonstrated high internal consistency. Different measurement models were tested using confirmatory factor analysis. The results indicated that a 7-factor model best fit the data, suggesting that the participants could distinguish seven types of online self-regulatory strategies: goal setting, environment structuring, time management, effort regulation, cognitive/monitoring strategies, help seeking, and self-evaluation.
Ethnography, Tactical Responsivity and Political Utility
Authors: Nichols Naomi , Guay Emanuel
Published: December 2021

In this article, we address issues of attribution, utility, and accountability in ethnographic research. We examine the two main analytical approaches that have structured the debate on data collection and theorization in ethnography over the last five decades: an inductivist approach, with grounded theory as its main analytic strategy; and a deductivist stance, which uses field sites to explore empirical anomalies that enable an ethnographer to test and build upon pre-existing theories. We engage recent reformulations of this classical debate, with a specific focus on abductive and reflexive approaches in ethnography, and then weigh into these debates, ourselves. drawing on our own experiences producing and using research in non-academic settings. In so doing, we highlight the importance of strategy and accountability in one’s ethnographic practices and accounts, advocating for an approach to ethnographic research that is reflexive and overtly responsive to the knowledge needs and change goals articulated by non-academic collaborators. Ultimately, we argue for a research stance that we describe as tactical responsivity, whereby researchers work with key collaborators and stakeholders to identify the strategic aims and audiences for their research, and develop ethnographic, analytic, and communicative practices that enable them to generate and mobilize the knowledge required to actualize their shared aims.
What Moves Physicians to Work in Rural Areas? An In-Depth Examination of Physician Practice Location Decisions
Authors: Hu Xiaochu , Dill Michael J. , Conrad Sarah S.
Published: December 2021

This study contributes to the current understanding of what drives physicians to practice in rural areas by analyzing new, comprehensive survey data of practicing physicians in the United States. This research confirmed that rural origin is a powerful and reliable predictor for rural practice and revealed that new and experienced physicians have different priorities regarding location choice. Physicians choosing rural practice locations are more likely to be motivated by compensation, the resemblance of the environment to the one they grew up in, patient needs, and prenegotiated service obligations or visa/immigration status. They are less likely to attribute their location choice to social network proximity. These findings have important implications for salary incentives and policy initiatives aimed at increasing the rural physician workforce. The results of this study will help decrypt the difficulties rural areas face in attracting and retaining medical and other professionals and inform policy development.
Design and implementation of human driving data-based lane-keeping assistance system for electric bus
Authors: Lim Hyeongho , Kim Changhee , Yi Kyongsu , Jeon Kwangki
Published: December 2021

This paper describes design, implementation, and evaluation of human driving data-based Lane Keeping Assistance System (LKAS) for electric bus equipped with a hybrid electric power steering system. The hybrid electric-power steering system used in this study means a steering system in which an Electric Power Steering (EPS) system and an Electro-Hydraulic Power Steering (EHPS) system are integrated into a ball-nut. A dynamic model of hybrid EPS system including EHPS system and EPS system has been developed to generate EPS torque and EHPS force corresponding to the input torque. In order to determine proper timing of LKAS intervention, driving data of electric bus drivers were collected and driving patterns were analyzed using a 2-D normal distribution probability density function. Lane information necessary for the lane-keeping assistance system is obtained from a vision camera mounted on the electric bus. Sliding mode control is used to get a Steering Wheel Angle (SWA) required for LKAS. A Proportional–Integral (PI) control is used to obtain an overlay torque required to track the target SWA. A proposed DLC threshold has been validated using vehicle simulation software, TruckSim, and MATLAB/Simulink. It is shown that the proposed DLC threshold shows good performance in both cases of slow lane departure and fast lane departure. The proposed algorithm has been successfully implemented on the electric bus and evaluated via real-world driving tests. Test scenario setting and the evaluation of performance were carried out by ISO 11270 criteria. It is shown that the algorithm successfully prevented the electric bus from unintended lane departure satisfying ISO 11270 criteria.
Study on the safety speed of vehicle turning with considering the driving safety evaluation
Authors: Xian Qu , Feng Yu , Jinlong Zhang , Jun Xie
Published: December 2021

Safety speeds estimation, as an indispensable link in the development of the aided or automatic drive, receives wide attention recently. Due to uncertain disturbances of vehicle driving, it is a challenging task to estimate the safety speed credibly. This work proposes a modified estimation approach to predict the turning safety speed by combining the static drive safety evaluation with the dynamic vehicle speed calculation. First, the driving safety state is evaluated considering the coupling of driver-vehicle-road-environment, where a comprehensive evaluation is obtained by combing the analytic hierarchy process and entropy weight analysis method. Then, a turning critical speed is calculated based on the vehicle driving dynamics considering both sideslip and rollover. The estimation of turning safety speed is achieved by modifying the critical speed with a safety correction factor obtained from the driving safety state evaluation. Finally, cases discussion on driving safety states evaluation, as well as the critical speed verification and safety speed analysis, are carried out. The results verify the validity of the driving safety state evaluation and critical speed calculation. The safety speeds have a reasonable safety margin according to the driving safety state evaluation. The maximum differences between the safety speeds and critical speeds are about 26.45% for buses and 26.39% for cars under low adhesion conditions, showing sufficient reliability for safety speed estimation.
Vibrational health risk assessment for truck operators in mining using artificial neural network
Authors: Rahimdel Mohammad Javad , Mirzaei Mehdi , Sattarvand Javad
Published: December 2021

Operators of mining vehicles are frequently exposed to harmful levels of whole-body vibration (WBV). Long time exposure to WBV causes backache and has non-ergonomic effects on the human body. Exposure levels of the WBV have already been evaluated for different vehicles. Among these vehicles, mining trucks usually operate at the various working phases and also in different haul road conditions. This paper aims to develop a simultaneous integrated model to predict the WBV exposure for mining truck drivers. Considering the effect of the speed level, weight and geometry of load on the WBV exposure for the mining truck drivers are limited. There is not much research to predict the vibrational health risk level in conditions with no or missing data, as well. The root mean squire (RMS) of the vertical vibration of the seat and cabin floor was obtained during different operational conditions of an open pit mine in Iran. Then an artificial neural network was designed for the prediction of the vibrational health risk level. Regarding the results of this study, haul road quality, speed level, and load profile had a significant effect on vibration exposure. The average of the RMS values were 0.942 and 1.176 m/s2 for the good and poor road conditions, respectively that are in the high health risk levels. However, there was no significant relationship between the payloads, in the range of 20 to 30 tons, in the RMS values. At speeds higher than 30 km/h, the vibrational health risk was at high level for all conditions. Moreover, there were 93.83% correlation between the measured and simulated RMS values was found in the application of the neural network. This paper helps the mine managers to predict the unsafe conditions and consider the practical approach for the WBV risk reduction.
A planning framework of environment detection for unmanned ground vehicle in unknown off-road environment
Authors: Guan Haijie , Wu Shaobin , Xu Shaohang , Gong Jianwei , Zhou Wenkai
Published: December 2021

This paper describes a planning framework of environment detection for unmanned ground vehicle (UGV) in the completely unknown off-road environment, which is able to quickly guide the UGV with nonholonomic constraints to detect the environmental information as much as possible. The contributions of this paper contain four fold. First, due to the sensor characteristics of camera and lidar, we present a two-layer combined detection map which can accurately represent the detected and undetected area. Second a frontier extraction algorithm based on RRT considering information acquisition and nonholonomic constraints of UGV is used to extract the target pose. Third, we use a search path planning method based on motion primitive which is able to handle obstacle constraints of environment, nonholonomic constraints of UGV. Fourth the heuristic fusion is proposed to guide the extension of motion primitives to generate a kinodynamically feasible and collision-free trajectory in real-time. And it works well in both simulation and real scene.
Synthesis of multi-input multi-degree-of-freedom fixed shaft gear transmission configuration for vehicles
Authors: Li Xueliang , Wu Zhihang , Yang Shujun , Hu Jibin , Peng Zengxiong
Published: December 2021

The rapid development of dual-clutch transmission (DCT) and hybrid and purely electric vehicles stimulate the researches on multi-input fixed shaft gear transmission mechanisms. The multiple degree-of-freedom (DOF) transmission mechanism can achieve a wider range of speed ratio adjustment and more modes under certain space and weight constraints, which is an ideal choice for multi gear transmission. In this paper, a synthesis method of fixed shaft gear transmission configuration is proposed. Based on the established graph theory model, kinematic characteristics of the fixed shaft gear transmission configuration are studied and the shift sequence is determined. Using these characteristics, a derivation method from the basic configuration to the comprehensive gears and shafts configuration is proposed. Multiple parameters such as the synchronizer arrangement and speed ratios are optimized. Finally, the proposed method is vigorously verified by a seven-speed DCT with four DOFs. This method is comprehensive and systematic in designing fixed shaft gear transmission configurations, which can be applied to DCT, transmissions for parallel hybrid electric vehicles, and to some novel multi-input transmissions.
Investigation on surface roughness, tool wear and cutting power in MQL turning of bio-medical Ti-6Al-4V ELI alloy with sustainability
Authors: Rajan K M , Kumar Sahoo Ashok , Chandra Routara Bharat , Kumar Ramanuj
Published: December 2021

Ti-6Al-4V ELI (Grade 23) is highly recommended for bio-materials and due to its low thermal conductivity and chemically reactive properties, machinability is poor. Thus the current work emphasized on the selection of appropriate cooling technique and optimal cutting parameters for machining of Ti-6Al-4V ELI alloy with sustainability analysis for surface roughness, flank wear and cutting power. Initially, the cutting performances under dry, flood and MQL environments are compared and MQL is observed to better performed. At lower speed (70 m/min), MQL exhibited 26.38% and 19.69% lesser surface roughness relative to dry and flood cooling individually. At the same cutting condition, MQL assisted cutting resulted in lower flank wear relative to dry (157. 33%) and flood cooling (40%). Further, a detailed investigation has been made under MQL through Taguchi L18 design of experiments. The major mechanisms for flank wear are found to be abrasion, chipping and notch wear. Optimal data set through Grey relational analysis is found to be v1 (70 m/min), f1 (0.1 mm/rev) and d1 (0.1 mm) and improved. Quadratic regression model is found to be significant for prediction of responses. Sustainability Pugh matrix assessment revealed that MQL environment enhanced the economical, technological as well as environmental and operator health aspects. Reduction of energy consumption by 53.96% and savings of carbon footprints by 68.46 kg of CO2 observed under MQL at optimal conditions and thus saves manufacturing cost.
The behavior of cambered belts transiting cylindrical rollers
Authors: Shi Jinxin , Pan Sheng , Markum Ron E. , Good James K.
Published: December 2021

The lateral deformations of webs in roll-to-roll process machines can affect the quality of the manufactured products. Webs with simple nonuniform length variation across their width (camber) will steer toward the long side, leading to the steady state lateral deformation and hence registration. Most previous studies have focused on a cambered web in a free span between two rollers. These studies assume some displacement and slope boundary conditions are known and seek the remaining conditions that would dictate the steady state lateral deformation of the web. This article focuses on the lateral behavior of a cambered web belt transiting between two aligned rollers as the simplest case of multiple span cambered web. Dynamic simulation has been conducted to better understand the response of a cambered web under tension that has been witnessed in tests. There are no boundary conditions enforced and no steady state deformation of the cambered webs. Thus there is no closed-form solution to the lateral movement of a cambered web transits over multiple rollers. This explained why the previous research focused more on the experimental exploration without few theoretical validations. The web travels toward the long side continually from one span to the next until a web guide attempts to return the web to an acceptable lateral location in the process machine.
Modeling the abrasive wear behavior of in-situ synthesized magnesium RZ5/TiB2 metal matrix composites
Authors: Meher Arabinda , Mahapatra Manas Mohan , Samal Priyaranjan , Vundavilli Pandu R.
Published: December 2021

In the present study, the statistical analysis on tribological behavior of RZ5/TiB2 magnesium-based metal matrix composites is carried out using Taguchi design and analysis of variance (ANOVA) technique. Taguchi analysis using signal-to-noise ratio indicates that the sliding distance and wt.% TiB2 are the most significant factors in evaluating weight loss and coefficient of friction, respectively. The regression equation is formulated utilizing the ANOVA technique to study the output responses based on the input abrasive wear test experimental results. The regression equation is validated through a comprehensive study taking a series of abrasive wear tests and indicates the percentage deviation of regression modeling is in the range of ± 10%. The individual and combined effect of wear parameters on tribological behavior are investigated through the main effect plots and response surface plots. The micrograph of the worn surface of RZ5/TiB2 composites is studied using field emission scanning electron microscope (FESEM), indicating the formation of an oxide layer on the worn surface.
Effect of polygon-shaped wheels on fatigue fracture of fastener clips in high-speed railway lines
Authors: Kang Xi , Chen Guangxiong , Zhu Qi , Ren Wenjuan , Dai Huanyun
Published: December 2021

This paper studies the effect of wheel polygonalization and material properties on the fatigue failure of fastener clips in high-speed railway lines and puts forward the corresponding inhibition measures. Vibration frequencies excited by 24th-order wheel out-of-roundness (OOR) were analysed by on-site tests of the axle box vertical vibration acceleration. A finite element modelling method of polygon-shaped wheels was proposed, which was verified by comparing the field measurement with the dynamic simulation. The dynamic response of the fastener clip was simulated by using a rigid–flexible coupled model of the wheelset-track system. The effect of amplitudes as well as typical wavelengths of wheel OOR on the fracture of the clip was analysed based on the Miner fatigue damage accumulation ruler. The results show that when the wheelset ran at 237 km/h on the track, the 24th-order wheel OOR had no obvious effect on the Mises equivalent stress of the clip. When the amplitude of the 24th-order wheel OOR reached 0.225 mm and above, excited vibrations of about 1172 Hz were transmitted from the wheelset-rail system to the fastener systems, thus reducing the safe operating life of the clips. This phenomenon can be inhibited by setting a reasonable amplitude threshold for wheel re-profiling. Wheel eccentric wear (first-order OOR) and 12th-order OOR had lesser effects on the fatigue failure of the clip. The decrease of Poisson’s ratio or the increase of Young’s modulus of the material could cause the maximum Mises equivalent stress at the clip to increase, which might induce cracks, thus leading to the fracture of the clip. Therefore, during the production process, the Poisson’s ratio and Young’s modulus of fastener clips should be strictly controlled to ensure that they are within the permitted range.
Kinematic control of a cable-driven snake-like manipulator for deep-water based on fuzzy PID controller
Authors: Xue Fufeng , Fan Zhimin
Published: December 2021

The traditional deep-water manipulators have several problems to work in confined spaces, such as large volume, complex structure, and inability. To solve these problems, a novel cable-driven snake-like manipulator robot for deep-water is proposed. In this study, the structure design of the cable-driven snake-like manipulator robot is first introduced. Then, we establish the kinematics model of the proposed cable-driven snake-like manipulator robot, which includes three parts: motor-cable kinematics, cable-joint kinematics, and joint-end kinematics. Especially, a tip-following algorithm (Supplemental Material) is presented to fit the confined and complicated underwater scenarios. Furthermore, a kinematics control strategy based on fuzzy PID controller is presented to reduce the tracking error caused by transmission mechanism, and the simulation of the cable-driven snake-like manipulator is carried out based on the MATLAB. The results demonstrate that the tracking error is less than 0.04 mm, which shows the proposed control strategy is effective.
Modeling treatment effect modification in multidrug-resistant tuberculosis in an individual patientdata meta-analysis
Authors: Liu Yan , Schnitzer Mireille E , Wang Guanbo , Kennedy Edward , Viiklepp Piret , Vargas Mario H , Sotgiu Giovanni , Menzies Dick , Benedetti Andrea
Published: December 2021

Effect modification occurs while the effect of the treatment is not homogeneous across the different strata of patient characteristics. When the effect of treatment may vary from individual to individual, precision medicine can be improved by identifying patient covariates to estimate the size and direction of the effect at the individual level. However, this task is statistically challenging and typically requires large amounts of data. Investigators may be interested in using the individual patient data from multiple studies to estimate these treatment effect models. Our data arise from a systematic review of observational studies contrasting different treatments for multidrug-resistant tuberculosis, where multiple antimicrobial agents are taken concurrently to cure the infection. We propose a marginal structural model for effect modification by different patient characteristics and co-medications in a meta-analysis of observational individual patient data. We develop, evaluate, and apply a targeted maximum likelihood estimator for the doubly robust estimation of the parameters of the proposed marginal structural model in this context. In particular, we allow for differential availability of treatments across studies, measured confounding within and across studies, and random effects by study.
Leveraging historical data to optimize the number of covariates and their explained variance in the analysis of randomized clinical trials.
Authors: Branders Samuel , Pereira Alvaro , Bernard Guillaume , Ernst Marie , Dananberg Jamie , Albert Adelin
Published: December 2021

The amount of data collected from patients involved in clinical trials is continuously growing. All baseline patient characteristics are potential covariates that could be used to improve clinical trial analysis and power. However, the limited number of patients in phases I and II studies restricts the possible number of covariates included in the analyses. In this paper, we investigate the cost/benefit ratio of including covariates in the analysis of clinical trials with a continuous outcome. Within this context, we address the long-running question “What is the optimum number of covariates to include in a clinical trial?” To further improve the benefit/cost ratio of covariates, historical data can be leveraged to pre-specify the covariate weights, which can be viewed as the definition of a new composite covariate. Here we analyze the use of a composite covariate to improve the estimated treatment effect in small clinical trials. A composite covariate limits the loss of degrees of freedom and the risk of overfitting.
The City as Fac¸ade in Velha Goa: Recognising Enduring Forms of Urbanism in the Early Modern Konkan
Authors: Wilson Brian C.
Published: December 2021

What do we know of early modern colonial urbanisms in South Asia? Rich archival sources provide meta-narratives of the ‘rise and fall’ of colonial outposts and their spatial projects. This article revisits these histories through the results of an archaeological project conducted at Portuguese Goa. In settings such as Velha Goa, histories of the city are unavoidably structured by elite, top-down understandings of social processes, principally owing to the limits of the colonial archives themselves. Quotidian material transformations, essential to urban process, remain largely unconsidered. In Goa, the archaeological data suggest the dominant historical narratives that characterise this capital of empire as the ̒Rome of the East’ work to substantiate a vision of the city that erases other socialities. The archaeological data allow us to productively think of the colonial early modern urban landscape as both a physical and conceptual façade. Historical tropes of ruination mask rich and varied archaeological evidence of enduring forms of urbanism. The idea of the city as façade allows at once a characterisation of the concealed failures of colonial urban governance and its legacies in perpetuating certain ideals and understandings of urbanism, and it questions narratives of urban decline that still resonate today.
Politics Beyond Imperial Cores: Spatial Production in the Peripheries of Medieval South India
Authors: Fanthome Eduard
Published: December 2021

Current scholarship on medieval South India has developed a comprehensive account of the ways in which political claims were constituted by dynasts and their subordinates in a range of contexts, from imperial courts to provinces. It has elaborated the modalities of political claim-making through instantiations of politico-cultural traditions or ‘cosmopolises’, and the integrative processes and social changes associated with them. However, this scholarship largely focused on imperial capitals and secondary urban settlements, which constituted nodes in the political networks of polities and loci of contestation and integration within them. Regions in which cosmopolitan traditions did not inform political practice remain opaque to this historiography.

This article investigates one such contest- the ‘contested’ Raichur Doab. It explores the politics of the production of a settlement- MARP-30 and the ways they were negotiated to constitute relations of inclusion and exclusion.MARP-30 is part of the multi-component site at Maski that during the period of MARP-30’s occupation does not evince evidence of cosmopolitan practices. Examining the constitution of socio-political relations in this context will expand our understanding of political practice in medieval South India to include practices inaccessible through texts and under-explored archaeologically, and yet typical of medieval South India given the political and social dynamism that characterize the medieval period.