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To increase the acceptability of exoskeletons, there is growing attention toward finding an alternative soft actuator that can safely perform at close vicinity of the human body. In this study, we investigated the capability of the dielectric elastomer actuators (DEAs), for muscle-like actuation of rehabilitation robots. First, an artificial skeletal muscle was configured using commercially available stacked DEAs arranged in a 3x4 array of three parallel fibers consisting of four DEAs connected in series. The shortening and force generation capabilities of this artificial muscle were then measured. An alternate 3x5 version of this muscle was mounted on the forearm of an upper extremity phantom model to actuate its elbow joint. The actuation capability of this muscle was then tested under various tensile loads, 1 N to 4 N, placed at the center of mass of the forearm+hand of the phantom model. The active range of motion and angular velocity of the phantom model's tip of the hand were measured using a motion capture system. The 3×4 artificial muscle produced 30.47 N of force and 5.3 mm of maximum shortening. The 3x5 artificial muscle was capable of actuating the elbow flexion 19.5º with 16.2 º/s angular velocity in the sagittal plane, under a 1 N tensile load. The active range of motion was substantially reduced as the tensile loads increased, which limits the capability of these muscles in the current upper extremity exoskeleton design.

Hospital provided drugs kit with individual packaging and information. The reminder use QR code to set administrative dosage and the timetable. The app prompts the elder through text and voice. Prototype utilizes Arduino platform, switch, and LED and Bluetooth module. The sensed user activities transfer to App of the mobile phone through the Bluetooth connection. The 3D printed prototype model and circuit work well with App during user's evaluation.

In December 2015, three hydrophones were moored at the east side of Drygalski Ice Tongue (DIT), seaward of the Nansen Ice Shelf (NIS). On 7 April 2016, the front of the NIS calved into two medium-sized icebergs, presenting a rare opportunity to measure the temporal variation of acoustic signals produced by a large scale ice shelf fracturing event. The acoustic data indicates there are hundreds of short duration, broadband (10–400 Hz) signals throughout the 4-month hydrophone record. We interpret these signals as cryogenic, caused by the cracking of the ice shelves and impacts of nearby sea-ice. The majority of these ice-cracking signals occur during the 21 January to 21 March time frame, two months to two weeks prior to the shelf fracturing observed by satellite on 7 April. Meteorological records of barometric pressure, air temperature, and wind speed show that the day the two icebergs drifted from the NIS coincided with the largest low pressure storm system recorded in the previous 7 months. Our interpretation is the NIS leading edge broke free during the January–March high acoustic energy time period, but the iceberg remained grounded on the seafloor until the low pressure event. The combination of low atmospheric pressure, high winds and high ocean tide, freed the iceberg keel from the seafloor. Strong bio-acoustic signals were also observed on the hydrophones, where the vocalizations of blue whales and leopard seals dominate certain time periods and frequency bands of the long-term acoustic record.

The earlier result of his research showed that most Taiwanese SME designers were frustrated in innovations since it takes hard evidences to persuade their managements, but they are in lack of resources. Thus, this research proposed the SSFD model with ready templates to help them. This paper focused on the third stage of the SSFD Model, i.e. "The Stage of Strategy Formulation". It will help SME designers to prepare design strategies easier with very limited resources.

In this paper, we discuss the principles of operating the electric spring (ES) as a reactive power compensator and as a power factor corrector. The theory on electric springs with capacitors for voltage stabilization is reviewed to present a general idea on the behavior of ES. Further discussion focuses on the principle of ES with batteries to cover its eight possible operating modes and their usefulness in providing line current regulation. An input current control scheme is designed for ES with batteries to validate its capability in power factor correction. A low-voltage single-phase power system with different types of loads has been built for verifying the feasibility of proposed theory of ES with batteries. Experimental results show that the ES is capable of performing the eight operating modes when changing the power consumption of the non-critical load, and that with the proposed input current control, the ES can achieve power factor correction for both RL and RC loads.

In this work, we present a single-chip design for the three-phase brushless DC motors (BDCM) system, and which is implemented by a 0.35 ㎛ 3.3 V CMOS process. A mixed-signal IC will be accomplished by the implementation of analog circuit and digital circuit in the same chip. Eventually, this chip system includes an analog circuit (Hall signal amplifier), a digital circuit (logic process block), and a frequency voltage converter (FVC) to complete the control & driving circuits. Meanwhile, experimental results are included to verify the proposed scheme and the real measurement fit theoretical analysis well.

This paper describes a patent-pending method that can be used to estimate the speed and position of surface-mounted permanent magnet synchronous motors (SMPMSM) with cylindrical rotor structure and sinusoidal back emf. The concept involves the use of the power inverter's switching actions and switching current to provide instantaneous real-time information for extracting the speed information. The theory and algorithm are included to explain the proposed concept, which has been verified by simulations on a SMPMSM drive under the control of a sensorless speed control scheme.

Epidemic control becomes more difficult and challenging than ever due to increased population density and close social interactions. In this paper, we introduce a new information system named EPIC to predict epidemic conditions based on the continually collected vital signs of individuals from body sensor networks in a community and their social network. The core of EPIC is a critical network that models health conditions and social interactions of individuals. Facilitated by critical network, our prediction algorithms can cost-effectively determine quarantine strategies. The effectiveness of EPIC is evaluated through simulation.

Database-generated dynamic web pages (db-pages, in short), whose contents are created on the fly by web applications and databases, are now prominent in the web. However, many of them cannot be searched by existing search engines. Accordingly, we develop a novel search engine named Dash, which stands for Db-pAge Search, to support db-page search. Dash determines db-pages possibly generated by a target web application and its database through exploring the application code and the related database content and supports keyword search on those db-pages. In this paper, we present its system design and focus on the efficiency issue. To minimize costs incurred for collecting, maintaining, indexing and searching a massive number of db-pages that possibly have overlapped contents, Dash derives and indexes db-page fragments in place of db-pages. Each db-page fragment carries a disjointed part of a db-page. To efficiently compute and index db-page fragments from huge datasets, Dash is equipped with MapReduce based algorithms for database crawling and db-page fragment indexing. Besides, Dash has a top-k search algorithm that can efficiently assemble db-page fragments into db-pages relevant to search keywords and return the k most relevant ones. The performance of Dash is evaluated via extensive experimentation.

Directions search returns the shortest path from a source to a destination on a road network. However, the search interests of users may be exposed to the service providers, thus raising privacy concerns. For instance, a path query that finds a path from a resident address to a clinic may lead to a deduction about "who is related to what disease". To protect user privacy from accessing directions search services, we introduce the OPAQUE system, which consists of two major components: (1) an obfuscator that formulates obfuscated path queries by mixing true and fake sources/destinations; and (2) an obfuscated path query processor installed in the server for obfuscated path query processing. OPAQUE reduces the likelihood of path queries being revealed and allows retrieval of requested paths. We propose two types of obfuscated path queries, namely, independently obfuscated path query and shared obfuscated path query to strike a balance between privacy protection strength and query processing overhead, and to enhance privacy protection against collusion attacks.

In distance-based location update schemes with a predefined distance threshold d, an object reports its location to the location server, whenever it is located more than a distance of d away from the location expected of by the server. Adopting a small threshold can keep locations maintained in the location server close to exact object locations, but that incurs high location update costs. In this paper, we address the important issue of finding an optimal distance threshold. Our approach exploits a costfunction that takes into account location update and query processing costs, the two key performance costs, based on which an optimal threshold that minimizes the overall cost is derived. In dynamic environments, costs may vary over time, so a threshold good at one moment could become bad at another. To determine an optimal threshold adaptively, we propose two optimization algorithms, namely, conjectural algorithm and progressive algorithm. Conjectural optimization algorithm " guesses" the current system conditions, based on which it directly determines the most probable optimal value. Progressive optimization algorithm starts with a certain threshold value and adjusts it gradually towards the optimal point. To evaluate our proposed algorithms, various simulation studies are conducted and significant performance gain is observed with our algorithms.

Children with cerebral palsy (CP) expend up to three times the energy required for ambulation as compared to typically developed children of the same age. Measuring the metabolic energy required to execute a task is an intuitively appealing way to quantify task efficiency. Task energy demand is often quantified through pulmonary tests that measure oxygen consumption. Although providing an accepted measure of energy demand, these tests are technically demanding and staff intensive. For this reason, we sought a measure of gait efficiency based on spatiotemporal and kinematic parameters that would be reflective of the energy cost during ambulation in children with cerebral palsy. Gait data from 18 subjects with CP over 30 separate data collection sessions was used. Statistical analysis showed oxygen cost highly correlates to several kinematic variables, most notably, pelvic tilt, walking speed, landing angle and the biomechanical efficiency quotient (BEQ). The results of the work support the development of a computational model that would capture gait energy efficiency.

This paper presents a system framework to support continuous nearest surrounder (NS) queries in moving object environments. NS query finds the nearest objects at individual distinct angles from a query point. This query distinguishes itself from other conventional spatial queries such as range queries and nearest neighbor queries by considering both distance and angular aspects of objects with respect to a query point. One of NS query applications is to monitor the nearest objects around an observation point. In our framework, a centralized server is dedicated to collect object location updates, to determine affected NS queries of each object location update, to compute the incremental result change of affected queries and to deliver result updates to corresponding interested users/applications that initiate the queries. In particular, we propose algorithms namely, safe region formation and partial query evaluation, that can significantly improve the system performance. Through simulations, we validate our proposed algorithms over a wide range of settings

In this paper, we present a new type of spatial queries called Nearest Surrounder (NS) queries. An NS query determines the nearest polygon-shaped spatial objects (referred to as nearest surrounder objects) and their orientations with respect to a query point from an object set. Besides, we derive two NS query variants, namely, multitier NS (m-NS) queries and angle-constrained NS (ANS) queries. An m-NS query searches multiple layers of NS objects for the same range of angles from a query point. An ANS query searches for NS objects within a specified range of angles. To evaluate NS queries and their variants, we explore angle-based and distance-based bound properties of polygons, and devise two efficient algorithms, namely, Sweep and Ripple, based on R-tree. The algorithms access objects in an order according to their orientations and distances with respect to a given query point, respectively. They are efficient as they can finish a search with one index lookup. Besides, they can progressively deliver a query result. Through empirical studies, we evaluate the proposed algorithms and report their performance for both synthetic and real object sets.

This study tested our mathematical model's ability to predict isometric forces for children with spinal cord injuries. The model accounted more than 95% of the variance in the experimental forces produced by stimulation trains with mean frequencies from 12.5 to 100 Hz for both non-fatigued and fatigued muscles. The ability of the model to predict forces suggests its use for the identification of optimal activation patterns during functional electrical stimulation.

The performance of real-time network routing (RTNR) in a dynamic class-of-service network is discussed. Three motivations for developing the RTNR network are to support multiple classes-of-service, to move towards a robust routing strategy for self-healing networks, and to simplify operations support functions. RTNR network performance results for high-day traffic loads, for peak day traffic loads, for unexpected network overloads, and for network failure are presented. >

A 2.5 V, 72 Mbit packet protocol based SDRAM (PSDRAM) achieving a peak bandwidth of 2.0 GByte/s has been developed with a 0.23 /spl mu/m twin-well, 4-poly, 2-metal CMOS process. An internal Vcc of 2.0 V and V/sub term/ of 1.8 V with 0.8 V signal swing are used in the array to reduce the sensing power and I/O switching power, respectively. The total maximum chip power consumption of 1.80 W, including the average I/O switching power of 0.25 W, has been achieved when internal 16 banks are interleavingly operated with 20 ns interval commands at 2.0 GByte/s, Vcc=2.7 V, and T=25/spl deg/C.