bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent advances in exploring the neural underpinnings of auditory scene perception
Authors: Snyder Joel S. , Elhilali Mounya
Published: February 2017

Studies of auditory scene analysis have traditionally relied on paradigms using artificial sounds—and conventional behavioral techniques—to elucidate how we perceptually segregate auditory objects or streams from each other. In the past few decades, however, there has been growing interest in uncovering the neural underpinnings of auditory segregation using human and animal neuroscience techniques, as well as computational modeling. This largely reflects the growth in the fields of cognitive neuroscience and computational neuroscience and has led to new theories of how the auditory system segregates sounds in complex arrays. The current review focuses on neural and computational studies of auditory scene perception published in the last few years. Following the progress that has been made in these studies, we describe (1) theoretical advances in our understanding of the most well‐studied aspects of auditory scene perception, namely segregation of sequential patterns of sounds and concurrently presented sounds; (2) the diversification of topics and paradigms that have been investigated; and (3) how new neuroscience techniques (including invasive neurophysiology in awake humans, genotyping, and brain stimulation) have been used in this field.
Dysbiosis of oral buccal mucosa microbiota in patients with oral lichen planus
Authors: He Y , Gong D , Shi C , Shao F , Shi J , Fei J
Published: February 2017

Objective

The bacterial community structure of buccal mucosa in patients with oral lichen planus was evaluated and compared with healthy control.

Subjects and Methods

Buccal scraping samples have been taken on 43 oral lichen planus patients (21 erosive and 22 non‐erosive) and 21 mucosal healthy volunteers. The V3 hypervariable 16S rDNA region was amplified and sequenced by high‐throughput 454 pyrosequencing.

Results

94.26% of the total buccal bacteria were classified into 15 abundant genera. Eight of these abundant genera could be detected in all cases, namely Streptococcus, Prevotella, Haemophilu, Neisseria, Fusobacterium, Leptotrichia, Veillonella and Actinomyces. Four abundant bacteria showed significantly different prevalence at the genus level: Streptococcus was more abundant (P < 0.01) in healthy control group, while Fusobacterium (P < 0.01), Leptotrichia (P < 0.001) and Lautropia (P < 0.001) showed higher abundance in OLP group. Few differences can be found between erosive and non‐erosive OLP. In general, 19 ‘core’ OTUs at three levels were defined to be OLP specific, comparing with healthy control group.

Conclusions

These results suggest that OLP is associated with dysbiosis of the oral microbiome. Further studies should be taken to elucidate the inner relationship between these observed changes and OLP development.
Comparison of the analgesic efficacy of ultrasound‐guided rectus sheath block and local anesthetic infiltration for laparoscopic percutaneous extraperitoneal closure in children
Authors: Uchinami Yuka , Sakuraya Fumika , Tanaka Nobuhiro , Hoshino Koji , Mikami Eri , Ishikawa Taro , Fujii Hitomi , Ishikawa Takehiko , Morimoto Yuji
Published: February 2017

Background

Ultrasound‐guided rectus sheath block and local anesthetic infiltration are the standard options to improve postoperative pain for children undergoing surgery with a midline incision. However, there is no study comparing the effect of ultrasound‐guided rectus sheath block with local anesthetic infiltration for children undergoing laparoscopic surgery.

Aims

The aim of this trial was to compare the onset of ultrasound‐guided rectus sheath block with that of local anesthetic infiltration for laparoscopic percutaneous extraperitoneal closure in children.

Methods

We performed an observer‐blinded, randomized, prospective trial. Enrolled patients were assigned to either an ultrasound‐guided rectus sheath block group or a local anesthetic infiltration group. The ultrasound‐guided rectus sheath block group (n = 17) received ultrasound‐guided rectus sheath block with 0.2 ml·kg−1 of 0.375% ropivacaine per side in the posterior rectus sheath compartment. The local anesthetic infiltration group (n = 17) received local anesthetic infiltration with 0.2 ml·kg−1 of 0.75% ropivacaine. The Face, Legs, Activity, Cry, and Consolability (FLACC) pain scores were recorded at 0, 30, 60 min after arrival at the postanesthesia care unit.

Results

Of the 37 patients enrolled in this study, 34 completed the study protocol. A significant difference in the pain scale between the ultrasound‐guided rectus sheath block group and local anesthetic infiltration group was found at 0 min (median: 0, interquartile range [IQR]: 0–1.5, vs median: 1, IQR 0–5, confidence interval of median [95% CI]: 0–3, P = 0.048), but no significant difference was found at 30 min (median: 1, IQR: 0–4 vs median: 6, IQR: 0–7, 95% CI: 0–5, P = 0.061), or 60 min (median: 0, IQR: 0–2 vs median: 1, IQR: 0–3, 95% CI: −1 to 1, P = 0.310). No significant difference was found in anesthesia time between the ultrasound‐guided rectus sheath block and local anesthetic infiltration groups. No procedure‐related complications were observed in either group.

Conclusion

Ultrasound‐guided rectus sheath block is a quicker way to control postoperative pain for pediatric patients undergoing laparoscopic extraperitoneal closure than local anesthetic infiltration, and thus may provide a clinical benefit.
Social independence of adult congenital heart disease patients in Japan
Authors: Ochiai Ryota , Ikeda Yukitaka , Kato Hitoshi , Shiraishi Isao ,   Parents' Association of Heart Disease Children
Published: February 2017

Background

As treatment outcomes for congenital heart disease (CHD) have improved, the social independence of adult CHD patients has become a key goal. The aims of this study were therefore to (i) determine the relationship between social independence and psychological profile, and (ii) identify patient anxieties, difficulties, and demands related to life in society.

Methods

A total of 143 patients aged ≥15 years with physical disability certificates were selected using a questionnaire distributed by a patients' association. Each participant was asked about employment status, income, and receipt of disability pension as a social independence index, and about financial and psychological distress as a psychological status index. Furthermore, each participant was asked to freely describe his or her difficulties, anxieties, and needs pertaining to life in society.

Results

The subjects were 15–73 years old. Seventy‐one (50%) were female, and 94 (66%) had a grade 1 physical disability certificate. Fifty‐nine subjects (41%) were employed, 37 (26%) were unemployed, and 45 (31%) were students. Of those employed, 34 subjects (58%) reported annual individual income ≤2 million yen. Frequent hospital visits, low total household income, low individual annual income, work dissatisfaction, and receipt of a disability pension were associated with poorer psychological profile. In an open description section, subjects expressed desires for better pension systems, support for medical fees, and employment support.

Conclusions

Because financial issues can adversely affect the psychological profiles of adult CHD patients, enhancement of social welfare and employment support may improve their social independence.
Hume's Internalist Epistemology inEHU 12
Authors: Qu Hsueh
Published: February 2017

Much has been written about Kemp Smith's (1941) famous problem regarding the tension between Hume's naturalism and his scepticism. However, most commentators have focused their attention on theTreatise; those who address theEnquiryoften take it to express essentially the same message as theTreatise. When Hume's scepticism in theEnquiryhas been investigated in its own right, commentators have tended to focus on Hume's inductive scepticism in Sections 4 and 5. All in all, it seems that Section 12 has been unduly neglected. This paper seeks to address Kemp Smith's problem from the standpoint of Hume's treatment of scepticism inEHU12, and finds an interesting internalist account that makes sense both of Hume's discussion inEHU12, and his aims in theEnquiryas a whole. Moreover, it is one that is of substantive philosophical interest, having intriguing parallels to contemporary epistemological accounts.
TruthsquaGrounds
Authors: Guigon Ghislain
Published: February 2017

A number of philosophers have recently found it congenial to talk in terms of grounding. Grounding discourse features grounding sentences that are answers to questions about what grounds what. The goal of this article is to explore and defend a counterpart‐theoretic interpretation of grounding discourse. We are familiar with David Lewis's applications of the method of counterpart theory tode remodal discourse. Counterpart‐theoretic interpretations ofde remodal idioms and grounding sentences share similar motivations, mechanisms, and applications. I shall explain my motivations and describe two applications of a counterpart theory for grounding discourse. But, in this article, my main focus is on counterpart‐theoretic mechanisms.
The Unique Groundability of Temporal Facts
Authors: Cusbert John , Miller Kristie
Published: February 2017

The A‐theory and the B‐theory advance competing claims about how time is grounded. The A‐theory says that A‐facts are more fundamental in grounding time than are B‐facts, and the B‐theory says the reverse. We argue thatwhichevertheory is true of the actual world is also true of all possible worlds containing time. We do this by arguing that time is uniquely groundable: however time is actually grounded, it is necessarily grounded in that way. It follows that if either the A‐theory or the B‐theory is actually false, then it is necessarily false.
The Transition Experiences of British Military Veterans
Authors: Binks Eve , Cambridge Siobhan
Published: February 2017

The aim of the current research was to investigate the transition experiences of British military veterans upon exiting the military and rejoining civilian society, asking the specific research question: What effect does the transition from military to civilian life have on the individual's identity? Interpretative Phenomenological Analysis was employed and seven semistructured interviews were carried out with ex‐military personnel. Analysis of the data revealed three superordinate themes: (1) Several Selves: Identity; (2) Soldier and Society: Separation, and (3) Transition Time: Personal Perspective. Current findings suggest that transition from the military back to civilian life is often problematic, with identity complications, feelings of loss, and disconnection both from the military and from society in general. Individuals with a more salient military identity had more difficult transition experiences. Findings are discussed with reference to theories of identity formation, maintenance, and salience and recommendations for future research are made.
Response of photosynthesis and chlorophyll a fluorescence in leaf scald‐infected rice under influence of rhizobacteria and silicon fertilizer
Authors: Bueno A. C. S. O. , Castro G. L. S. , Silva Junior D. D. , Pinheiro H. A. , Filippi M. C. C. , Silva G. B.
Published: February 2017

Leaf scald caused by Monographella albescens reduces the photosynthetic area, causing yield losses in rice. This study investigated the efficacy of the rhizobacteria Burkholderia pyrrocinia (BRM‐32113) and Pseudomonas fluorescens (BRM‐32111), combined with silicon (Si) fertilization, to reduce lesion size and the area under the disease progress curve (AUDPC), as well as to minimize the negative effects on gas exchange, chlorophyll a fluorescence, chlorophyll content and the activity of oxidative stress enzymes. The experiment used a completely randomized design with four replications and seven treatments. Compared with plants only fertilized with Si, plants fertilized with Si and treated with BRM‐32113 showed reductions of 22% in scald lesion expansion and 37% in AUDPC, a 27% increase in the rate of CO2 assimilation (A), a 33% decrease in the internal CO2 concentration (Ci), and a 40% increase in ascorbate peroxidase activity. It was therefore concluded that the combination of BRM‐32113 with Si fertilization reduces the severity of leaf scald, protecting the photosynthetic apparatus, thus representing a sustainable method of reducing the loss of income caused by leaf scald in rice.
Genetic diversity and population structure among cultivars of Saccharina japonica currently farmed in northern China
Authors: Li Xia , Pang Shao J. , Shan Ti F.
Published: February 2017

Close to 50% of the annual production of the brown alga Saccharina japonica, about 2 million tons (fresh weight), is produced through farming in Shandong province, China, principally around Rongcheng. Under artificial selection for phenotypic traits (e.g. color, blade length) cultivated strains (cultivars) face the problems of inbreeding depression, which can be caused by the close relationships of the parental plants. Hence, in an attempt to evaluate genetic variations and relationships among cultivars, 15 major farmed cultivars were selected and sampled from seven major hatcheries and analyzed using 15 microsatellite markers. A total of 94 alleles were found across all samples, with allele numbers ranging from three to 17 per locus. All of the cultivars exhibited relatively high levels of genetic diversity, with mean Nei's genetic diversity (H) and the Shannon's information index (I) of 0.466 and 0.862, respectively. A UPGMA dendrogram grouped all cultivars into three main clusters. However, two of the most commonly farmed cultivars (DB and BN) from different hatcheries failed to cluster together. Instead, differently named cultivars from the same hatchery tended to group together, implying that their high similarities is partly due to the presence of genetic mixing among cultivars within a hatchery or misuse of cultivar's names. Genetic analysis performed by Bayesian model‐based clustering revealed clear differentiation of three major subgroups (LJ‐202 and LJ‐205; LJ‐C033; XS‐2 and XS‐BN) and one admixed group (the remaining ten cultivars). Our results revealed ambiguous genetic relationships among certain cultivars of S. japonica farmed in northern China. A more stringent and prudent regulation should be applied during breeding and production process in the future.
AGER gene polymorphisms and soluble receptor for advanced glycation end product in patients with idiopathic pulmonary fibrosis
Authors: Yamaguchi Kakuhiro , Iwamoto Hiroshi , Horimasu Yasushi , Ohshimo Shinichiro , Fujitaka Kazunori , Hamada Hironobu , Mazur Witold , Kohno Nobuoki , Hattori Noboru
Published: February 2017

Background and objective

The receptor for advanced glycation end product (RAGE) is a multiligand cell‐surface receptor abundantly expressed in the lung. RAGE/ligand interaction has been postulated to participate in the pathogenesis of inflammatory diseases, while soluble RAGE (sRAGE) might act as a decoy receptor. A functional polymorphism rs2070600 in the gene coding RAGE (AGER) might modulate its receptor function. The aim of this study was to investigate the association of AGER polymorphisms and circulatory sRAGE with the development and progression of idiopathic pulmonary fibrosis (IPF).

Methods

This study comprised 87 Japanese patients with IPF and 303 healthy controls. Seven tag polymorphisms in AGER were genotyped and their distributions were compared. We also measured serum sRAGE levels, and evaluated the correlations of sRAGE levels with AGER polymorphisms and the prognosis of the patients with IPF.

Results

The frequency of AGER rs2070600 genotype with minor allele was significantly higher in patients with IPF (OR = 1.84, 95% CI = 1.08–3.10). Additionally, the carriage of the rs2070600 minor allele and the presence of IPF were independently associated with reduced serum levels of sRAGE. Moreover, reduced sRAGE (≤471.8 pg/mL) was related to acute exacerbation of IPF and was an independent predictor of 5‐year survival in patients with the disease (hazard ratio (HR) = 7.956, 95% CI = 1.575–53.34).

Conclusion

These results suggest a possible association between a functional polymorphism in AGER and IPF disease susceptibility, and indicate a potential prognostic value of circulatory sRAGE.
Making Everyday Microaggressions: An Exploratory Experimental Vignette Study on the Presence and Power of Racial Microaggressions
Authors: Hughey Matthew W. , Rees Jordan , Goss Devon R. , Rosino Michael L. , Lesser Emma
Published: February 2017

The term “microaggression” has experienced a lively existence in the field of psychology since its introduction in 1970s. Sociology has recently come to study microaggressions, yet serious gaps remain in the study of microaggressions. In particular, sociological analysis has not taken into account how exposure to microaggressive interactions may affect racial attitudes, how variations in microaggressive interactions have different effects, and what racial and gender positions render one more or less likely to engage in, or fail to oppose, microaggressions. Based on a GSS‐based survey and an experimental vignette design, we address the following two questions: First, how might the presence of racial microaggressions affect racial attitudes? Second, what is the power of specific types of interactional microaggression? Results indicate that both exposure to microaggressions and the type of microaggressions are correlated with changes in specific racial attitudes associated with the marginalization, problematization, and symbolic and physical repression of people of color.
Intersecting Disadvantages: Race, Gender, and Age Discrimination Among Attorneys*
Authors: Collins Todd A. , Dumas Tao L. , Moyer Laura P.
Published: February 2017

Objective

This article explores the impact of race, gender, age, and intersectionality on attorneys' perceptions of unfair treatment by other lawyers and on satisfaction with their legal careers.

Method

Using an original survey of over 2,000 attorneys, ordered logit is utilized to analyze attorneys’ perceptions of disparate treatment based on race, gender, and age and to test whether minority female attorneys face unique barriers within their professional relationships.

Results

We find that minority women are more likely than others to perceive unfair treatment based on race, gender, and age. This also contributes to lower career satisfaction for attorneys who are women of color than for other groups.

Conclusion

The findings have important implications for understanding attorney relationships and potential barriers for minority groups within a profession's culture. These obstacles not only impact attorneys, but could also influence attorney choice for citizens and the prospects for a representative judiciary.
Haemoglobin responses to transfusion in severe iron deficiency anaemia: potential impact of gastrointestinal disorders
Authors: Bosch X. , Montori E. , Guerra‐García M. , Costa‐Rodríguez J. , Quintanilla M. H. , Tolosa‐Chapasian P. E. , Moreno P. , Guasch N. , López‐Soto A.
Published: February 2017

Background and Objectives

Red blood cell (RBC) transfusion may be justified in iron deficiency anaemia (IDA) when an increase in oxygen delivery is needed, as sometimes occurs in subjects with haemoglobin <8·0 mg/dL, serious comorbidities or at risk of cardiovascular instability. Earlier investigations showed that some patients with severe IDA requiring transfusion had lower than expected post‐transfusion haemoglobin levels with poorer clinical outcomes than other patients. After hypothesizing that haemoglobin responses to transfusion were different and that the underlying gastrointestinal (GI) disorders causing IDA could be a confounder explaining this association, these responses were analysed in a prospective cohort of IDA adults referred for outpatient GI investigation.

Materials and Methods

Transfused patients with proven IDA, baseline haemoglobin at referral <9·0 g/dL and no extraintestinal bleeding were eligible. To assess a homogeneous population, only GI disorders known to cause occult bleeding were considered. Haemoglobin increments per 100 mL of RBCs were investigated.

Results

In total, 2818 patients were enrolled over 10·5 years. On multivariable regression, diffuse angiodysplasias and GI cancer independently predicted for reduced increments in post‐transfusion haemoglobin [adjusted regression coefficients: −0·082 (95% confidence interval, −0·093 to −0·072) and −0·073 (95% confidence interval, −0·081 to −0·066), respectively, P < 0·001 in both]. Haemoglobin responses in the remaining bleeding disorders were adequate and agreed with the principle that one RBC unit increases the haemoglobin an average of 1 g/dL.

Conclusion

The potential differential impact of GI disorders on changes in haemoglobin levels after RBC transfusion could be useful for transfusing physicians, especially for diagnostic purposes.
Vision, Challenges and Solutions in the Development of Professional Social Work in Vietnam: Perceptions of Key Stakeholders
Authors: Nguyen Huong , Nguyen Trang Thu , Farber Naomi
Published: February 2017

It was not until 2010 that social work was officially recognized as a profession in Vietnam when the government approved a national master blueprint to develop social work. This blueprint identified seven strategic objectives including: creating a foundational labor force, developing laws and policies, and raising awareness about social work. This exploratory study examines the degree to which key stakeholders in Vietnam have shared vision and perceptions about the challenges and solutions necessary to make this ambitious plan for Vietnamese social work succeed. An anonymous survey was conducted with 65 policy makers, educators, service providers, and practitioners. The survey revealed that key stakeholders in held a shared vision about Vietnamese social work, focusing on making it a genuine profession. They identified the top challenges for Vietnamese social work as lack of national policy and regulations, lack of public awareness about the profession, and lack of resources to develop high quality social work education. Key stakeholders considered social work to be an integral function of the government and, as such, depend upon the government to lay the foundation for, provide direction to, and make available the resources necessary for the profession to grow. In other words, there would not be a Vietnamese social work profession outside of and without the Vietnamese government, unlike how the social work profession has developed in many Western countries.
Analysis of a Novel Technique for Temperature Rise Abatement in Liquid Piston Compressors–External Gas Injection
Authors: Bhaskaran Hari Subramaniam , Ro Paul , Park Joong-Kyoo , Ramakrishnan Kishore Ranganath
Published: February 2017

This paper analyses a novel heat transfer enhancement technique that can be used in compressors to limit the temperature rise during compression. This technique is based on the injection of external high-pressure gas into the chamber during the compression process. The impact of different factors on the effectiveness of this technique has been studied using experimental and computational methods. In the first set of trials, the location and angle of injection of the external air was varied. It was observed that the heat transfer coefficient governing the heat transfer rate from the chamber varied greatly with change in location and angle of injection. In the second set of experiments, the source pressure of the injected gas was varied from 100.66 kPa to 551.58 kPa. It was observed that the temperature rise of air in the chamber was reduced with an increase in source pressure. Additionally, the increase in chamber pressure was steeper in the higher source pressure cases. In the third set of experiments, the injection profile of the injected gas was varied. This parameter did not greatly impact the effectiveness of external gas injection. In the last set of experiments, the time of initiation of injection was varied. Earlier injection had a positive impact on reducing the temperature rise in the chamber. However, the pressure in the chamber was seen to increase more rapidly in the runs with early injection. Considering that these factors could have a positive/negative impact on the temperature and pressure in the chamber (work required for compression), it may be required to optimize the injection of external high-pressure gas depending on the application.
Influence of a Commercial Antithrombotic Filter on the Caval Blood Flow During Neutra and Valsalva Maneuver
Authors: Nicolás M. , Lucea B. , Laborda A. , Peña E. , De Gregorio M. A. , Martínez M. A. , Malvè M.
Published: February 2017

Anticoagulants are the treatment of choice for pulmonary embolism. When these fail or are contraindicated, vena cava filters are effective devices for preventing clots from the legs from migrating to the lung. Many uncertainties exist when a filter is inserted, especially during physiological activity such as normal breathing and the Valsalva maneuver. These activities are often connected with filter migration and vena cava damage due to the various related vein geometrical configurations. In this work, we analyzed the response of the vena cava during normal breathing and Valsalva maneuver, for a healthy vena cava and after insertion of a commercial Günther-Tulip® filter. Validated computational fluid dynamics (CFD) and patient specific data are used for analyzing blood flow inside the vena cava during these maneuvers. While during normal breathing, the vena cava flow can be considered almost stationary with a very low pressure gradient, during Valsalva the extravascular pressure compresses the vena cava resulting in a drastic reduction of the vein section, a global flow decrease through the cava but increasing the velocity magnitude. This change in the section is altered by the presence of the filter which forces the section of the vena cava before the renal veins to keep open. The effect of the presence of the filter is investigated during these maneuvers showing changes in wall shear stress and velocity patterns.
Type Synthesis of a Special Family of Remote Center-of-Motion Parallel Manipulators With Fixed Linear Actuators for Minimally Invasive Surgery
Authors: Li Qinchuan , Marie Hervé Jacques , Huang Pengcheng
Published: February 2017

Remote center-of-motion (RCM) parallel manipulators (PMs) are fit for robotized minimally invasive surgery (MIS). RCM PMs with fixed linear actuators have the advantages of high stiffness, reduced moving mass, and higher rigidity and load capacity. However, there are very few available architectures of these types of PMs. Using the Lie group algebraic properties of the set of rigid-body displacements, this paper proposes a new family of RCM PMs with fixed linear actuators for MIS. The general motion with a remote center has four degrees-of-freedom (DOF) and is produced by the in-series concatenation of a spherical S pair and a prismatic P pair and, therefore, is said to be SP equivalent. The SP-equivalent PMs can be used in minimally invasive surgery. First, the kinematic bonds of limb chains and their mechanical generators for SP-equivalent RCM PMs are presented. Limb chains with fixed linear actuators are then derived using the closure of products in subgroups. Structural conditions for constructing an SP-equivalent RCM PM with linear fixed actuators are revealed. Helical pairs are introduced to remove a local rotation and yield a 360-deg-rotation capability of the moving platform. Numerous new architectures with practical potential are presented.
Design and Kinematic Optimization of a Two Degrees-of-Freedom Planar Remote Center of Motion Mechanism for Minimally Invasive Surgery Manipulators
Authors: Nisar Sajid , Endo Takahiro , Matsuno Fumitoshi
Published: February 2017

Minimally invasive surgery (MIS) requires four degrees-of-freedom (DOFs) (pitch, translation, yaw, and roll) at the incision point, but the widely used planar remote center of motion (RCM) mechanisms only provide one degree-of-freedom. The remaining three DOFs are achieved through external means (such as cable-pulleys or actuators mounted directly on the distal-end) which adversely affect the performance and design complexity of a surgical manipulator. This paper presents a new RCM mechanism which provides the two most important DOFs (pitch and translation) by virtue of its mechanical design. Kinematics of the new mechanism is developed and its singularities are analyzed. To achieve maximum performance in the desired workspace region, an optimal configuration is also evaluated. The design is optimized to yield maximum manipulability and tool translation with smallest size of the mechanism. Unlike the traditional planar RCM mechanisms, the proposed design does not rely on external means to achieve translation DOF, and therefore, offers potential advantages. The mechanism can be a suitable choice for surgical applications demanding a compact distal-end or requiring multiple manipulators to operate in close proximity.
Cluster Analysis and Switching Control: A Post-Processing of Multi-Objective Optimal Designs
Authors: Qin Zhi-Chang , Sun Jian-Qiao
Published: February 2017

The multi-objective optimal control design usually generates hundreds or thousands of Pareto optimal solutions. How to assist an user to select an appropriate controller to implement is a post-processing issue. In this paper, we develop a method of cluster analysis of the Pareto optimal designs to discover the similarity of the optimal controllers. After we identify the clusters of optimal controllers, we then develop a switching strategy to select controls from different clusters to improve the performance. Numerical results show that the switching control algorithm is quite promising.
Automated Scene Generation for High Fidelity Robotics Simulations
Authors: Greenberg Rebecca A. , Dawkins Jeremy J.
Published: February 2017

This paper presents a methodology for automatically generating a scene to be used in high fidelity robotic simulators. Modeling and simulation play an important role in the development and testing of robotic motion planning algorithms. Virtual Robotic Experimentation Platform (V-REP) is a robotic simulator that can be used to test state of the art robotics algorithms in environments called scenes. V-REP contains a remote application programming interface (API) for Matlab that allows for control of the simulation from the external application. Using this functionality, an algorithm was developed to automatically create simulation environments. Given the dimensions of the space, the desired total number of rooms, and a room configuration type, the algorithm organizes the layout of the space into a set of rooms and hallways. Using the remote capabilities provided by the Matlab V-REP API, the scene is opened, each of the models is loaded, and the models are put into the appropriate location. The result is a saved V-REP scene file that can be used for testing of any relevant mobile robotic applications. Ultimately this tool can play an important role in running parametric studies and Monte Carlo simulations to test the performance of various motion planning and coordination algorithms.
Heterogeneous Bi-Directional Cooperative Unmanned Vehicles for Obstacle Avoidance
Authors: Lwowski Jonathan , Sun Liang , Pack Daniel
Published: February 2017

In this paper, we present a novel bi-directional cooperative obstacle avoidance system of heterogeneous unmanned vehicles, consisting of an unmanned ground vehicle (UGV) and a microaerial vehicle (MAV), equipped with cameras, operating in an indoor environment without Global Positioning System (GPS) signals. The system demonstrates the synergistic relationship between the two platforms by sharing different perspectives and information collected independently using their on-board sensors in performing a navigation task in an indoor environment, including avoiding obstacles and entering narrow pathways. The MAV uses an aerial view of the environment to develop an obstacle free path for the UGV using the A* algorithm. The UGV deploys the planned path in conjunction with information gathered from its own front facing camera to navigate through a cluttered environment using a Lyapunov stable sliding mode controller. The UGV is responsible for detecting low and narrow pathways and to guide the MAV to move through them. The bidirectional cooperation has been tested in hardware as well as in simulation, showing the system’s effectiveness.
Energy-Harvesting Shock Absorbers With Ride Comfort Controller on Vehicle
Authors: Chen Chien-An , Ngo Khai D. T. , Zuo Lei
Published: February 2017

In order to achieve higher fuel efficiency and better ride comfort, this paper introduces a shock absorber system including Mechanical-Motion-Rectifier (MMR), power converter and its current/force tracking (ICFT) controller.

MMR based shock absorbers has the benefit of higher efficiency and better mechanical reliability than conventional regenerative shock absorbers. However, the one-way clutches and inertia in MMR induce disengagement between input shaft and generator. This nonlinear behavior makes the input current/force of MMR uncontrollable with conventional feedback controller design. To solve this problem, this paper presents an input current/force tracking (ICFT) controller for MMR based suspension system. By adding additional control laws to the conventional controller, ICFT controller successfully solves the nonlinearity problem during MMR control. This ICFT controller is tested by tracking the reference force from skyhook control to improve ride comfort. The vehicle body displacement is simulated under specified speedbump.

By using this ICFT controller, the simulation result show displacement error between skyhook and ICFT-MMR is within 5% and its total harvested energy is 56 joules, as 56 W of average input power. Equivalent circuits used for circuit simulation are proved to have identical performances as mechanical models.
Complex Non-Minimum Phase Zeros in the Dynamics of Double Parallelogram Flexure Module Based Flexure Mechanisms
Authors: Cui Leqing , Okwudire Chinedum , Awtar Shorya
Published: February 2017

This paper presents a model to explain complex non-minimum phase (CNMP) zeros seen in the non-collocated frequency response of a large displacement XY flexure mechanism, which employs multiple double parallelogram flexure modules (DPFM) as building-blocks. Geometric non-linearities associated with large displacement along with the kinematic under-constraint in the DPFM, lead to a coupling between the X and Y direction displacements. Via a lumped-parameter model that captures the most relevant geometric non-linearity, it is shown that specific combinations of the operating point (i.e. flexure displacement) and mass asymmetry (due to manufacturing tolerances) give rise to CNMP zeros. This model demonstrates the merit of an intentionally asymmetric design over an intuitively symmetric design in avoiding CNMP zeros. Furthermore, a study of how the eigenvalues and eigenvectors of the flexure mechanism vary with the operating point and mass asymmetry indicates the presence of curve veering when the system transitions from minimum phase to CNMP. Based on this, the hypothesis of an inherent correlation between CNMP zeros and curve veering is proposed.
Validation of an Instrumented Walkway Designed for Estimation of the Ankle Impedance in Sagittal and Frontal Planes
Authors: Ficanha Evandro M. , Ribeiro Guilherme , Rastgaar Aagaah Mohammad
Published: February 2017

Recently, the authors designed and fabricated an Instrumented Walkway for the estimation of the ankle mechanical impedance in the sagittal and frontal planes during walking in arbitrary directions [1]. It consists of a powered platform; therefore, the users do not need to wear or carry any measurement device or actuation system other than reflective markers used to record the ankle kinematics with a motion capture camera system. This paper describes the continuous development of the Instrumented Walkway and presents an experimental preliminary validation of its capability to estimate the impedance of a system with time-varying dynamics. To validate the system, a mockup with mechanical characteristics similar to a human lower-leg and controllable time-varying stiffness was used. The stiffness of the mockup was estimated with fixed and time-varying stiffness. With fixed stiffness, a stochastic system identification method was used to estimate the mockup’s impedance. When the mockup presented a time-varying stiffness, a second order parametric model was used. The RMS error between the two methods was 2.81 Nm/rad (maximum 4.12 Nm/rad and minimum of −3.41 Nm/rad). The results show that the proposed approach can estimate the stiffness of systems with time-varying dynamics or static dynamics with similar accuracy. Since the setup was already validated for systems with time-invariant dynamics, it concluded the system’s applicability for time-varying systems such as the human ankle-foot during the stance phase.
Individually Controlled Magnetic Cilia for Mixing Inspired by the Blinking Vortex
Authors: Banka Nathan , Ng Yau Luen , Devasia Santosh
Published: February 2017

This paper introduces a new design for individually-controlled magnetic artificial cilia for use in microfluidic devices. The design has been implemented using a low-cost prototype that can be fabricated using polydimethylsiloxane (PDMS) and off-the-shelf parts, and achieves large cilium deflections (59% of the cilium length). Experimental results show that exploiting the individual control leads to faster mixing (38% reduction in mixing time) than when operating the device in a simultaneous-actuation mode with the same average cilium beat frequency.
On Vibrational Stabilization of a Horizontal Pendulum
Authors: Tahmasian Sevak , Jafari Farid , Woolsey Craig A.
Published: February 2017

This paper describes control design and stability analysis for a horizontal pendulum using translational control of the pivot. The system is a one-link mechanism subject to linear damping and moving in the horizontal plane. The goal is to drive the system to a desired configuration such that the system oscillates in an arbitrarily small neighborhood of that desired configuration. We consider two cases: prescribed displacement inputs and prescribed force inputs. The proposed control law has two parts, a proportional-derivative part for control of actuated coordinates, and a high-frequency, high-amplitude oscillatory forcing to control the motion of unactuated coordinate. The control system is a high-frequency, time-periodic system. Therefore we use averaging techniques to determine the necessary input amplitudes and control gains. We show that using a certain oscillatory input, the amplitudes of that input must follow a constraint equation. We discuss the geometric interpretation of constraint equation and stability conditions of the system. We also discuss the effects of damping and relative phase of the oscillatory inputs on the system and their physical and geometric interpretation.
Dynamic Modelling and Controller Design of Combustion Phasing for an RCCI Engine
Authors: Khodadadi Sadabadi Kaveh , Shahbakhti Mahdi
Published: February 2017

Reactivity controlled compression ignition (RCCI) is an advanced low temperature combustion strategy introduced to achieve near-zero NOx and soot emissions while maintaining diesel-like efficiencies. Precise control of RCCI combustion phasing is necessary in realizing high fuel conversion efficiency as well as meeting stringent emission standards. Model-based control of combustion phasing provides a powerful tool for real-time control during transient operation of the RCCI engine, which requires a computationally efficient combustion model that encompasses factors such as, injection timings, fuel blend composition and reactivity. In this work, physics-based models are developed to predict the combustion phasing of a 1.9-liter RCCI engine. A mean value control-oriented model (COM) of RCCI is developed by combining the auto-ignition model, the burn duration model, and a Wiebe function to predict combustion phasing. Development of a model-based controller requires a dynamic model which can predict engine operation, i.e., estimation of combustion phasing, on a cycle-to-cycle basis. Hence, the mean-value model is extended to encompass the full-cycle engine operation by including the expansion and exhaust strokes. In addition, the dynamics stemming from the thermal coupling between cycles are accounted for, that results in a dynamic RCCI control-oriented model capable of predicting the transient operation of the engine. This model is then simplified and linearized in order to develop a linear observer-based feedback controller to control the combustion phasing using the premixed ratio (the ratio of the port injected gasoline fuel to the total gasoline/diesel fuel injected). The designed controller depicts an accurate tracking performance of the desired combustion phasing and successfully rejects external disturbances in engine operating conditions.
On-Line Estimation of Wheelchair Tire Slip Utilizing an Instantaneous Center of Rotation Extended Kalman Filter
Authors: Wolkowicz Kelilah , Pentzer Jesse , Miller Christopher , Moore Jason Z. , Brennan Sean N.
Published: February 2017

There are over three million wheelchair users within the United States and that number is growing. This paper is concerned with improving the safety of wheelchair operation by the on-line estimation of tire slip. Wheelchair tire slip is a result of icy or low friction surfaces, often representative of dangerous conditions. In this research, wheel slip is detected by estimating the instantaneous center of rotation (ICR) locations of wheelchair wheels relative to the ground surface. Any departure of the estimated ICR positions from the wheel contact point indicates slippage is occurring.

An Extended Kalman Filter (EKF) algorithm uses inputs of position and orientation obtained via map-based localization to detect changes in wheelchair ICR location estimates. The ICR EKF algorithm is verified in simulation. A robotic wheelchair is used for testing the presented algorithms under conditions inducing tire slip. The results show that the ICR locations do not vary significantly when the wheelchair is operated under normal conditions, i.e. low slip surfaces; however, they change significantly under slip conditions. Implementing this method with electric wheelchairs can improve the prediction of wheelchair motion on slippery surfaces, enabling warning systems and safe operational modes that can enhance the safety of wheelchair users.
PID Sliding Mode Control of Prolate Flexible Pneumatic Actuators
Authors: Slightam Jonathon E. , Nagurka Mark L.
Published: February 2017

The inherent compliance, high power-density, and musclelike properties of soft actuators are especially attractive and useful in many applications, including robotics. In comparison to classical/modern control approaches, model-based control techniques, e.g., sliding mode control (SMC), applied to flexible fluidic actuators (FFAs) offer significant performance advantages and are considered to be state-of-the-art. Improvements in position tracking are possible using nonlinear control approaches that offer enhanced performance for common applications such as tracking of sinusoidal trajectories at high frequencies.

This paper introduces a SMC approach that increases the tracking capabilities of prolate flexible pneumatic actuators (PF-PAs). A model-based proportional, integral, derivative sliding mode control (PIDSMC) approach designed for position control of PFPAs is proposed. SMC and PIDSMC systems are implemented on low-cost open-source controls hardware and tested for tracking sinusoidal trajectories at frequencies of 0.5 Hz and 1.0 Hz with an amplitude of 8.255 mm and an offset of 12.7 mm. The PIDSMC approach reduced the maximum tracking error by 20.0%, mean error by 18.6%, and root-mean-square error by 10.5% for a 1 Hz sinusoidal trajectory and by 8.7%, 14.7%, and 3.8%, respectively, for a 0.5 Hz sinusoidal trajectory. These reductions in tracking errors demonstrate performance advantages of the PIDSMC over conventional sliding mode position controllers.
Towards an Optimal Learning for Robust Iterative-Based Intelligent PID
Authors: Madadi Elmira , Söffker Dirk
Published: February 2017

This contribution considers a model-free control method based on an optimal iterative learning control framework to design a suitable controller. Using this framework, the controller requires neither the information about the systems dynamical structure nor the knowledge about system physical behaviors. The task is solved using only the system outputs and inputs, which are assumed as measurable. The structure of the proposed method consists of three parts. The first part is implemented through an intelligent PID controller on the system. In the second part, a robust second order differentiator via sliding mode is applied in order to estimate accurately the evolution of the state function. In the third part, an optimal iterative learning control is chosen to improve the performance. Numerical examples are shown to demonstrate the successful application and performance of the method.
Reduced Order Model on DC Bias Effect on the Frequency Response of Electrostatically Actuated Biosensor Microplates
Authors: Caruntu Dumitru I. , Reyes Christian
Published: February 2017

This paper investigates the frequency response of microplates under electrostatic actuation. The microplate is parallel to a fixed ground plate. The electrostatic force that actuates the system is given by both Alternate Current (AC) and Direct Current (DC) voltages. The AC frequency is set to be near half natural frequency of the structure. Damping influence is also investigated in this paper. The method of investigation is Reduced Order Model. The effects of various parameters on the response of the structure are reported.
Model-Based Fault Detection Among Freeway Loop Sensors
Authors: Phegley Brian , Horowitz Roberto , Gomes Gabriel
Published: February 2017

Loop detectors are installed along many of the freeways across the state of California to provide real-time and historical traffic data. These data are used by Caltrans for traffic management operations, such as freeway ramp metering, and to evaluate the performance of freeway corridor traffic management systems. These data are also being used to calibrate traffic flow models and to perform model-based predictions of freeway corridor congestion and traffic throughput performance. However, such detection is prone to contain errors and inconsistencies, which can pose problems in further use of the data, and is also of such large quantities that identification of errors can be tedious. This paper proposes a fault detection algorithm associating loop detector data to the cell transmission model to identify significant errors among such detectors. It discusses how such an algorithm would apply to loop detection along the mainline freeway, as well as extends the algorithm to determine errors along on and off ramp detectors. It also gives a real-life example with appropriate identification of detectors in error.
Combining Gait Trainers and Partial Weight Bearing Lifters: A Dynamic Analysis of Seat-to-Stand Transition
Authors: Piovesan Davide , Yagiela Michael , Johnson Richard , Schmitz Anne
Published: February 2017

We analyzed a new class of passive devices that can help individuals regain their independence. A new walker design has been commercialized under the name of UP’N FREE®1. This new design can lift the user from a seated posture to a standing position through the employment of a four bar mechanism and gas piston. When the user is standing, the mechanism can provide partial compensation from gravity to help the user regain mobility. By using this system, users can sit and stand without another person’s assistance and can also compensate for gravity loads during walking both indoor and outdoor. This paper illustrates two examples of how to implement the dynamic lifting support and discusses the pros and cons of different system configuratons of a a gas spring cylinder as a passive actuator.