Evaluation of in-service smartphone battery drainage profile for video calling feature in major apps.

Video calling is one of the most energy-intensive features in apps requiring the simultaneous operation of the mobile camera, display screen, audio speaker, and internet services. This feature impacts a smartphone battery's runtime and lifetime. This paper is the first of its kind experimental study, which quantifies the operating profile (discharge current, temperature, and terminal voltage) of video call feature in multiple widely used social media apps, which include WhatsApp, Facebook Messenger, Zoom, Skype, WeChat, Google Hangouts, Imo and Viber. One smartphone each of Vivo and Motorola has been evaluated as the manufacturer-provided application programming interface (API) allowed real-time measurement of the operating profile. Results indicate that the video calling feature for Facebook Messenger and Imo is the most energy efficient. In contrast, Google Hangouts is up to 35% more energy-intensive for video calling than other apps. Measurements also show that Vivo's in-service battery temperature is lower than Motorola due to its efficient chipset. For instance, during active Google Hangouts operation for 1 h, Vivo temperature is limited to 46 °C, whereas Motorola temperature rises to 52 °C. Finally, the influence of app algorithms and codecs on energy efficiency is also discussed with regard to operating performance.

Wetting Kinetics and Microstructure Analysis of BNi2 Filler Metal over Selective Laser Melted Ti-6Al-4V Substrate.

The wetting kinetics of nickel-based filler metal (BNi2) over selective laser-melted Ti-6Al-4V (SLMed TC4) titanium alloy in a protective argon atmosphere is experimentally investigated using a real-time in situ hot stage equipped with an optical microscope. The spreading processes at different temperatures are similar, and the overall wetting/spreading process can be roughly divided into three stages: (i) an initial stage, (ii) a rapid spreading stage, and (iii) an asymptotic stage. Moreover, the wetting kinetics of the BNi2/SLMed TC4 system can be expressed by empirical power exponential function Rn~t with n = ~1. In the process of spreading, Ti-based solid solution (Ti(ss)) and intermetallic compound (Ti2Ni and TiB2) were formed at the interface within the reaction domain, and the phase transition of α' martensitic to α-Ti and ß-Ti also took place. The influence of elevated temperature on the spreading and wetting kinetics of the BNi2/SLMed TC4 system was studied, and the results show that the increase of temperature has a slightly promoting effect on the spreading, but a limited impact on the value of n. In addition, the spreading and wetting kinetics of BNi2/SLMed TC4 system are similar to those of BNi2 on conventional forged TC4 substrate.

Degradation Monitoring of Insulation Systems Used in Low-Voltage Electromagnetic Coils under Thermal Loading Conditions from a Creep Point of View.

Electromagnetic coils are a key component in a variety of systems and are widely used in many industries. Because their insulation usually fails suddenly and can have catastrophic effects, degradation monitoring of coil insulation systems plays a vital role in avoiding unexpected machine shutdown. The existing insulation degradation monitoring methods are based on assessing the change of coil high-frequency electrical parameter response, whereas the effects of the insulation failure mechanisms are not considered, which leads to inconsistency between experimental results. Therefore, this paper investigates degradation monitoring of coil insulation systems under thermal loading conditions from a creep point of view. Inter-turn insulation creep deformation is identified as a quantitative index to manifest insulation degradation changes at the micro level. A method is developed to map coil high-frequency electrical monitoring parameters to inter-turn insulation creep deformation in order to bridge the gap between the micro-level and macro-level changes during the incipient insulation degradation process. Thermally accelerated tests are performed to validate the developed method. The mapping method helps to determine the physical meaning of coil electrical monitoring parameters and presents opportunities for predictive maintenance of machines that incorporate electromagnetic coils.

Maximizing Network Resilience against Malicious Attacks.

The threat of a malicious attack is one of the major security problems in complex networks. Resilience is the system-level self-adjusting ability of a complex network to retain its basic functionality and recover rapidly from major disruptions. Despite numerous heuristic enhancement methods, there is a research gap in maximizing network resilience: current heuristic methods are designed to immunize vital nodes or modify a network to a specific onion-like structure and cannot maximize resilience theoretically via network structure. Here we map complex networks onto a physical elastic system to introduce indices of network resilience, and propose a unified theoretical framework and general approach, which can address the optimal problem of network resilience by slightly modifying network structures (i.e., by adding a set of structural edges). We demonstrate the high efficiency of this approach on three realistic networks as well as two artificial random networks. Case studies show that the proposed approach can maximize the resilience of complex networks while maintaining their topological functionality. This approach helps to unveil hitherto hidden functions of some inconspicuous components, which in turn, can be used to guide the design of resilient systems, offer an effective and efficient approach for mitigating malicious attacks, and furnish self-healing to reconstruct failed infrastructure systems.

Autonomous health management for PMSM rail vehicles through demagnetization monitoring and prognosis control.

Autonomous vehicles are playing an increasingly importance in support of a wide variety of critical events. This paper presents a novel autonomous health management scheme on rail vehicles driven by permanent magnet synchronous motors (PMSMs). Firstly, the PMSMs are modeled based on first principle to deduce the initial profile of pneumatic braking (p-braking) force, then which is utilized for real-time demagnetization monitoring and degradation prognosis through similarity-based theory and generate prognosis-enhanced p-braking force strategy for final optimal control. A case study is conducted to demonstrate the feasibility and benefit of using the real-time prognostics and health management (PHM) information in vehicle 'drive-brake' control automatically. The results show that accurate demagnetization monitoring, degradation prognosis, and real-time capability for control optimization can be obtained, which can effectively relieve brake shoe wear.

Color Shift Failure Prediction for Phosphor-Converted White LEDs by Modeling Features of Spectral Power Distribution with a Nonlinear Filter Approach.

With the expanding application of light-emitting diodes (LEDs), the color quality of white LEDs has attracted much attention in several color-sensitive application fields, such as museum lighting, healthcare lighting and displays. Reliability concerns for white LEDs are changing from the luminous efficiency to color quality. However, most of the current available research on the reliability of LEDs is still focused on luminous flux depreciation rather than color shift failure. The spectral power distribution (SPD), defined as the radiant power distribution emitted by a light source at a range of visible wavelength, contains the most fundamental luminescence mechanisms of a light source. SPD is used as the quantitative inference of an LED's optical characteristics, including color coordinates that are widely used to represent the color shift process. Thus, to model the color shift failure of white LEDs during aging, this paper first extracts the features of an SPD, representing the characteristics of blue LED chips and phosphors, by multi-peak curve-fitting and modeling them with statistical functions. Then, because the shift processes of extracted features in aged LEDs are always nonlinear, a nonlinear state-space model is then developed to predict the color shift failure time within a self-adaptive particle filter framework. The results show that: (1) the failure mechanisms of LEDs can be identified by analyzing the extracted features of SPD with statistical curve-fitting and (2) the developed method can dynamically and accurately predict the color coordinates, correlated color temperatures (CCTs), and color rendering indexes (CRIs) of phosphor-converted (pc)-white LEDs, and also can estimate the residual color life.

Position and enforcement practice of the People's Republic of China's pharmaceutical data exclusivity protection.

The concept of pharmaceutical data exclusivity protection comes from the West. The Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) establishes the basic rules for pharmaceutical data exclusivity protection. People's Republic of China's domestic law is consistent with the TRIPS agreement. In the drug registration approval process of the People's Republic of China's Drug Supervision Department, pharmaceutical data exclusivity protection has encountered some problems, including data authentication, exclusive rights to data, number of drugs requiring data to be submitted, and drug costs. In view of the long-term interests of the People's Republic of China's pharmaceutical industry and intellectual property protection trends, there are a lot of difficulties in the enforcement of pharmaceutical data exclusivity protection law that need to be overcome. Some measures can be taken, such as establishing a shorter data exclusivity protection period, only protecting the data submitted and relied on in the People's Republic of China, only protecting the drugs that use new chemical components, allowing application and necessary research before the expiry of pharmaceutical data exclusivity protection period of generic drugs.

Conflict Minerals in Electronic Systems: An Overview and Critique of Legal Initiatives.

The Democratic Republic of Congo has vast natural resources, many of which are regularly exploited by the electronics industry. Unfortunately, in addition to these resources, there are widespread human rights abuses committed by armed groups entrenched in the eastern part of the Democratic Republic of Congo. These armed groups are using profits from these minerals as a source of funding. Their human rights abuses have led to a growing humanitarian interest in the region and prompted the international community to action. This paper explores the conflicts in the Democratic Republic of Congo, provides an understanding of the link between human rights abuses and conflict minerals, and interprets and critiques the legal actions of the international community.

New Minimum Relative Humidity Requirements Are Expected to Lead to More Medical Device Failures.

In 2010, the Addendum D to ASHRAE Standard 170, "Ventilation of healthcare facilities," lowered the minimum relative humidity (RH) requirement of anesthetizing locations (including operating rooms, operating/surgical cystoscopic rooms, delivery rooms (Caesarean), recovery rooms, critical and intensive care, newborn intensive care, treatment rooms, trauma rooms (crisis or shock), laser eye rooms, newborn nursery suites, and endoscopy rooms) from 30 % to 20 %. The new minimum limit was adopted based on the results of a review paper that suggested that lowering humidity levels will have little or no impact on providing a safe environment for patients, staff, or medical equipment. That review paper reached this conclusion by assuming that there were no medical device failures due to electrostatic discharge (ESD). However, in an examination of the FDA's MAUDE database of reported defects and recalls, we identified numerous medical device failures explicitly due to ESD. This paper presents technical reliability and safety concerns regarding the new guidelines and recommends that such changes should not be implemented and that the guidelines should be revoked.

Effect of Temperature on the Aging rate of Li Ion Battery Operating above Room Temperature.

Temperature is known to have a significant impact on the performance, safety, and cycle lifetime of lithium-ion batteries (LiB). However, the comprehensive effects of temperature on the cyclic aging rate of LiB have yet to be found. We use an electrochemistry-based model (ECBE) here to measure the effects on the aging behavior of cycled LiB operating within the temperature range of 25 °C to 55 °C. The increasing degradation rate of the maximum charge storage of LiB during cycling at elevated temperature is found to relate mainly to the degradations at the electrodes, and that the degradation of LCO cathode is larger than graphite anode at elevated temperature. In particular, the formation and modification of the surface films on the electrodes as well as structural/phase changes of the LCO electrode, as reported in the literatures, are found to be the main contributors to the increasing degradation rate of the maximum charge storage of LiB with temperature for the specific operating temperature range. Larger increases in the Warburg elements and cell impedance are also found with cycling at higher temperature, but they do not seriously affect the state of health (SoH) of LiB as shown in this work.

Field Reliability Estimation for Cochlear Implants.

Cochlear implants are electronic devices used to provide useful hearing sensations to patients with severe to profound hearing loss. Safety and reliability are considered by patients and clinicians when selecting among the different models of cochlear implants. However, comparing reliability estimates from different manufacturers is difficult because of the lack of a standardized approach for classifying and quantifying failure data. This paper develops a classification scheme for cochlear implant failures wherein each failure report is categorized based on the failure site, cause, mode, and mechanism obtained through failure modes, mechanisms, and effects analysis. Failure parameters based on the Weibull distribution are used to quantify the following reliability metrics: B1, B5, B10, and B50 lives. The developed reporting scheme provides clear and quantitative information on failure causes and failure sites for a given implant. This method provides a consistent reporting format for communicating field reliability to regulatory units, clinicians, and patients.

Point-of-care biosensor system.

Point-of-care biosensor systems can potentially improve patient care through real-time and remote health monitoring. Over the past few decades, research has been conducted in the field of biosensors to detect patterns of biomarkers and provide information on their concentration in biological samples for robust diagnosis. In future point-of-care applications, requirements such as rapid label-free detection, miniaturized sensor size, and portability will limit the types of biosensors that can be used. This paper reviews label-free detection techniques using Biological MicroElectroMechanical Systems as a potential candidate for point-of-care biosensing applications. Furthermore, detailed surveys have been carried out on wireless networking schemes applicable for a point-of-care environment and on prognostic techniques that will enable decision-support services. This paper concludes by providing a list of challenges that must be resolved before realizing biosensor systems for next-generation point-of-care applications.

Health assessment of cooling fan bearings using wavelet-based filtering.

As commonly used forced convection air cooling devices in electronics, cooling fans are crucial for guaranteeing the reliability of electronic systems. In a cooling fan assembly, fan bearing failure is a major failure mode that causes excessive vibration, noise, reduction in rotation speed, locked rotor, failure to start, and other problems; therefore, it is necessary to conduct research on the health assessment of cooling fan bearings. This paper presents a vibration-based fan bearing health evaluation method using comblet filtering and exponentially weighted moving average. A new health condition indicator (HCI) for fan bearing degradation assessment is proposed. In order to collect the vibration data for validation of the proposed method, a cooling fan accelerated life test was conducted to simulate the lubricant starvation of fan bearings. A comparison between the proposed method and methods in previous studies (i.e., root mean square, kurtosis, and fault growth parameter) was carried out to assess the performance of the HCI. The analysis results suggest that the HCI can identify incipient fan bearing failures and describe the bearing degradation process. Overall, the work presented in this paper provides a promising method for fan bearing health evaluation and prognosis.

Reduction of motion artifacts in electrocardiogram monitoring using an optical sensor.

The effectiveness of electrocardiogram (ECG) monitors can be significantly impaired by motion artifacts, which can trigger false alarms, cause misdiagnoses, and lead to inappropriate treatment decisions. Skin stretch associated with patient motion is the most significant source of motion artifacts in current ECG monitoring. In this study, motion artifacts are adaptively filtered by using skin strain as the reference variable, measured noninvasively using an optical sensor incorporated into an ECG electrode. The results demonstrate that this new device and method can significantly reduce motion induced ECG artifacts in continuous ambulatory ECG monitoring.

Sensor systems for prognostics and health management.

Prognostics and health management (PHM) is an enabling discipline consisting of technologies and methods to assess the reliability of a product in its actual life cycle conditions to determine the advent of failure and mitigate system risk. Sensor systems are needed for PHM to monitor environmental, operational, and performance-related characteristics. The gathered data can be analyzed to assess product health and predict remaining life. In this paper, the considerations for sensor system selection for PHM applications, including the parameters to be measured, the performance needs, the electrical and physical attributes, reliability, and cost of the sensor system, are discussed. The state-of-the-art sensor systems for PHM and the emerging trends in technologies of sensor systems for PHM are presented.

Developments in ambulatory electrocardiography.

Cardiovascular disease (CVD) is the leading cause of death in many developed countries. There is a need for cardiovascular monitoring devices that can supplement traditional medical and clinical care by enabling the diagnosis of conditions with infrequent symptoms, the timely detection of critical signs that are precursors to sudden cardiac death, and the long-term management of chronic conditions through monitoring of symptoms, risk factors, and the effects of therapy. This paper provides an overview of ambulatory electrocardiogram (ECG) monitors, which are one of the most widely prescribed diagnostic procedures for cardiovascular disease. The engineering challenges associated with ambulatory electrocardiography are discussed, and technological improvement areas that are the focus of current research effort are reviewed.

Reduction of skin stretch induced motion artifacts in electrocardiogram monitoring using adaptive filtering.

The effectiveness of electrocardiogram (ECG) monitors can be significantly impaired by motion artifacts which can cause misdiagnoses, lead to inappropriate treatment decisions, and trigger false alarms. Skin stretch associated with patient motion is a significant source of motion artifacts in current ECG monitoring. In this study, motion artifacts are adaptively filtered by using skin strain as the reference variable. Skin strain is measured non-invasively using a light emitting diode (LED) and an optical sensor incorporated in an ECG electrode. The results demonstrate that this device and method can significantly reduce skin strain induced ECG artifacts.