Teaching the User By Learning From the User:Personalizing Movement Control in Physical Human-robot Interaction

This paper proposes a novel approach for physical human-robot interactions (pHRI), where a robot provides guidance forces to a user based on the user performance. This framework tunes the forces in regards to behavior of each user in coping with different tasks, where lower performance results in higher intervention from the robot. This personalized physical human-robot interaction (p2HRI) method incorporates adaptive modeling of the interaction between the human and the robot as well as learning from demonstration (LfD) techniques to adapt to the users' performance. This approach is based on model predictive control where the system optimizes the rendered forces by predicting the performance of the user. Moreover, continuous learning of the user behavior is added so that the models and personalized considerations are updated based on the change of user performance over time. Applying this framework to a field such as haptic guidance for skill improvement, allows a more personalized learning experience where the interaction between the robot as the intelligent tutor and the student as the user, is better adjusted based on the skill level of the individual and their gradual improvement. The results suggest that the precision of the model of the interaction is improved using this proposed method, and the addition of the considered personalized factors to a more adaptive strategy for rendering of guidance forces.      

Influence of Aluminum Content on Mechanical Properties and Cold Workability of Fe-33Ni-15Co Alloy

 The influence of 001% to 025% of Aluminum content (in mass percent) on the mechanical properties and cold workability of low thermal expansion Fe-33Ni-15Co sheets in the annealed and hot rolled condition was investigated. Addition of Al up to 015% resulted in the increase of ductility and toughness and improvement of workability. Besides, achievement of fine grain structure and increase in the amount of annealing twins caused ductility to improve. Addition of Al higher than 015% led to the increase in oxidation reaction during melting process and to refine under argon atmosphere. This caused the volume fraction of Al containing inclusions to increase and consequently the ductility and toughness to decrease.     

Directly silica bonded analytical reagents: synthesis of 2-mercaptobenzothiazole–silica gel and its application as a new sorbent for preconcentration and determination of silver ion using solid-phase extraction method

A new and efficient method is described for the easy synthesis of directly bonded 2-mercaptobenzothiazole–silica gel. This new bonded analytical reagent is used as an effective sorbent for the solid-phase extraction of silver ion from aqueous solutions. Conditions for effective adsorption of trace levels of silver ion concentration are optimized with respect to different experimental parameters in column process. Sodium thiosulfate solution could efficiently elute the adsorbed silver ion from the surface of the sorbent which then was determined by atomic absorption spectroscopy (AAS). Common coexisting ions did not interfere with the separation and determination. The preconcentration factor is 300 (1 ml elution volume) for a 300 ml sample volume. The sorbent exhibited excellent stability and its sorption capacity under optimum conditions has been found to be 343 μg of silver per gram of sorbent. The relative standard deviation under optimum conditions is 2.04% (n=7). Accuracy of the method was estimated by using test samples of natural water spiked with different amounts of silver ion. The method is simple and inexpensive.     

A robust noncoherent equalizer receiver for fading channels with short memory . II. Modified structure

For pt. I see ibid., vol.5, no.5, p.1040-54 (2002). In Part I, we introduced a robust noncoherent maximum likelihood sequence estimation (MLSE) equalizer receiver structure applicable to radio channels with impulse responses spanning less than two bit intervals. The distinct characteristic of this receiver was its robustness to carrier frequency offsets. However, due to the differential operation prior to the MLSE equalization, we observed some performance degradation, resulting in a delay spread range significantly smaller than an equivalent coherent MLSE equalizer. We propose techniques to significantly improve the performance of the noncoherent equalizer by using a second, complementary differential processor. The performance assessment of the new receiver is presented. In particular, using the Digital Enhanced Cordless Telecommunications system as an example, it is shown that the modified receiver's dispersive channel operation range is almost twice as much as the basic structure, with a multipath diversity gain comparable to a coherent equalizer receiver. On the other hand, unlike coherent structures, it retains low sensitivity to both frequency offsets and modulation index drifts. Finally, we introduce an approach to further extend the receiver's frequency offset tolerance to that of a standard differential detector receiver.     

Competitive advantage of enterprise resource planning vendors in Iran

Enterprise Resource Planning (ERP) has become one of the competitive advantages for companies around the globe and the dynamic force driving the process of global integration through information. Governmental organizations are increasing their adoption of these systems for various benefits such as integrated real-time information, better administration, and result-based management. Reaching the standard level of being a global company, organizations are concerned about this application and invest in this project for many years and, as a result, help the company reduce the cost and increase the efficiency and effectiveness. Iranian organizations, along with multi-national companies, attempt to be a good player in the flow of this change. The primary purpose of this study is to investigate and determine the competitive environment of ERP vendors implementing their product in Iranian context. The authors investigated the activities of both international and local ERP vendors established in the country and analyzed them by their advantages and potentials.     

Developing porous fibers by electrocentrifuge spinning system

In this study, polysulfone fibers with various surface morphologies were developed using electrocentrifuge spinning system. The effects of a number of parameters, including the solvent system, spinning system angular velocity, and relative humidity, on the fiber morphology were studied using field emission scanning electron microscopy, porosimetry [Brunauer–Emmett–Teller (BET)], and contact angle test. The results showed that the fibers prepared from the acetone/dimethylformamide (DMF) solvent system had higher micro/nano roughness than those fabricated from the tetrahydrofuran/DMF solvent system, that is to say, the higher the vapor pressure of the solvent, the higher the surface roughness. The acetone/DMF system created fibers that had internal porosity. Also, the relative humidity had a significant effect on providing micro/nano roughness, so that increasing the relative humidity led to an increase in the surface roughness. The increase in the angular velocity caused to stretch the micro/nano patterns and increase the fiber diameter. The results of the BET confirmed the microscopic observations. With the increase in the relative humidity and the use of the acetone/DMF system, porosity, and specific surface area of the fiber increased. X-ray diffraction analysis was also performed and it was found that the presence of moisture did not affect the crystallinity of the fibers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47513.     

Electrochemically deposited hybrid nickel–cobalt hexacyanoferrate nanostructures for electrochemical supercapacitors

This study describes the use of electrodeposited nanostructured hybrid nickel–cobalt hexacyanoferrate in electrochemical supercapacitors. Herein, various compositions of nickel and cobalt hexacyanoferrates (Ni/CoHCNFe) nanostructures are electrodeposited on an inexpensive stainless steel substrate using cyclic voltammetric (CV) method. The morphology of the electrodeposited nanostructures is studied using scanning electron microscopy, while their electrochemical characterizations are investigated using CV, galvanostatic charge and discharge and electrochemical impedance spectroscopy. The results show that the nanostructures of hybrid metal cyanoferrate, shows a much higher capacitance (765 F g⁻¹) than those obtained with just nickel hexacyanoferrate (379 F g⁻¹) or cobalt hexacyanoferrate (277 F g⁻¹). Electrochemical impedance spectroscopy results confirm the favorable capacitive behavior of the electrodeposited materials. The columbic efficiency is approximately 95% based on the charge and discharge experiments. Long cycle-life and excellent stability of the nanostructured materials are also demonstrated during 1000 cycles.     

Discovering hierarchical object models from captioned images

We address the problem of automatically learning the recurring associations between the visual structures in images and the words in their associated captions, yielding a set of named object models that can be used for subsequent image annotation. In previous work, we used language to drive the perceptual grouping of local features into configurations that capture small parts (patches) of an object. However, model scope was poor, leading to poor object localization during detection (annotation), and ambiguity was high when part detections were weak. We extend and significantly revise our previous framework by using language to drive the perceptual grouping of parts, each a configuration in the previous framework, into hierarchical configurations that offer greater spatial extent and flexibility. The resulting hierarchical multipart models remain scale, translation and rotation invariant, but are more reliable detectors and provide better localization. Moreover, unlike typical frameworks for learning object models, our approach requires no bounding boxes around the objects to be learned, can handle heavily cluttered training scenes, and is robust in the face of noisy captions, i.e., where objects in an image may not be named in the caption, and objects named in the caption may not appear in the image. We demonstrate improved precision and recall in annotation over the non-hierarchical technique and also show extended spatial coverage of detected objects.     

On CDMA with space-time codes over multipath fading channels

We explore code-division multiple-access systems with multiple transmitter and receiver antennas combined with algebraic constellations over a quasi-static multipath fading channel. We first propose a technique to obtain transmit diversity for a single user over quasi-static fading channels by combining algebraic constellations with full spatial diversity and spreading sequences with good cross-correlation properties. The proposed scheme is then generalized to a multiuser system using the same algebraic constellation and different spreading sequences. We also propose a linear multiuser detector based on the combination of linear decorrelation with respect to all users, and the application of the sphere decoder to decode each user separately. Finally, we consider the generalization to multipath fading channels where the additional diversity advantage due to multipath is exploited by the sphere decoder, and a method of blind channel estimation based on subspace decomposition is examined.