Early detection of health changes in the elderly using in-home multi-sensor data streams

The rapid aging of the population worldwide requires increased attention from health care providers and the entire society. For the elderly to live independently, many health issues related to old age, such as frailty and risk of falling, need increased attention and monitoring. When monitoring daily routines for older adults, it is desirable to detect the early signs of health changes before serious health events, such as hospitalizations, happen, so that timely and adequate preventive care may be provided. By deploying multi-sensor systems in homes of the elderly, we can track trajectories of daily behaviors in a feature space defined using the sensor data. In this work, we investigate a methodology for learning data distribution from streaming data and tracking the evolution of the behavior trajectories over long periods (years) using high dimensional streaming clustering and provide very early indicators of changes in health. If we assume that habitual behaviors correspond to clusters in feature space and diseases produce a change in behavior, albeit not highly specific, tracking trajectory deviations can provide hints of early illness. Retrospectively, we visualize the streaming clustering results and track how the behavior clusters evolve in feature space with the help of two dimension-reduction algorithms, Principal Component Analysis (PCA) and t-distributed Stochastic Neighbor Embedding (t-SNE). Moreover, our tracking algorithm in the original high dimensional feature space generates early health warning alerts if a negative trend is detected in the behavior trajectory. We validated our algorithm on synthetic data, real-world data and tested it on a pilot dataset of four TigerPlace residents monitored with a collection of motion, bed, and depth sensors over ten years. We used the TigerPlace electronic health records (EHR) to understand the residents' behavior patterns and to evaluate and explain the health warnings generated by our algorithm. The results obtained on the TigerPlace dataset show that most of the warnings produced by our algorithm can be linked to health events documented in the EHR, providing strong support for a prospective deployment of the approach.Includes bibliographical references

Therapeutic potential of a combination of recombinant human growth hormone (r-hGH) and vitamin D in children with idiopathic short stature

Purpose: To study the effectiveness and clinical significance of recombinant human growth hormone (rhGH) in combination with vitamin D in the treatment of idiopathic short-stature children.Methods: A total of 90 idiopathic short-stature children admitted at Children Health Care Center of Shiyan Maternal and Child Health Care Hospital, Shiyan between March 2017 and March 2020 were assigned to three groups: A, B and C, based on dose of r-hGH given. Group A received r-hGH at a dose of 0.26 mg/kg/week, while groups B and C received r-hGH at doses of 0.35 and 0.42mg/kg/week, respectively. All the patients were given vitamin D along with the r-hGH doses administered. Height, growth rate, bone age, height standard deviation score, fasting blood glucose, thyroid function and treatment effectiveness were determined and compared among the three groups before treatment, and one year after treatment.Results: Significantly higher height standard deviation score, growth rate, bone age, and height were observed in the three groups of patients after one year of treatment than before treatment, with group A < group B < group C (p < 0.05). Fasting blood glucose and thyroid function were not significantly different amongst the three groups after treatment (p < 0.05). Group C showed the highest treatment effectiveness, followed by group B, and then group A (p < 0.05).Conclusion: The use of a combination of r-hGH and vitamin D produces a favorable treatment effectiveness in idiopathic short-stature children. However, further clinical trials are required to validate this treatment strategy

Exploring diastereoselectivity mechanism of L-threonine aldolase

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Price competition model in decentralized and centralized supply chains with demand disruption

Purpose: The paper studies the price competition of a supply chain with one supplier and two competing retailers under occasional demand disruption. Design/methodology/approach: The supply chain is either decentralized or centralized. The demand disruption for two retailers occurs with different probability. We analyze the effect of occurrence probability of demand disruption on the optimal prices of the supplier and two retailers. Findings: We find that the profits of supplier, retailers and supply chain are decreasing with the occurrence probability of demand disruption. Originality/value: It is helpful for supply chain members to adjust the original contracts to demand disruption.Peer Reviewe

Unlocking the flexibility of combined heat and power for frequency response by coordinative control with batteries

Owners of combined heat and power (CHP), e.g., industrial manufacturers, are motivated to provide frequency response to power grids due to clear financial benefits. Yet, the slow response speed of CHP limits its capability in providing such services. Moreover, frequent adjustments would cause a faster lifetime reduction of CHP and rapid pressure fluctuation in the gas network. To further unlock the flexibility of CHP, this paper integrates a battery unit with CHP via a power electronic interface. A filter-based coordinative controller is designed for smoothing short-term fluctuations in CHP outputs. Based on the filter parameters and frequency response requirements, the minimum required capacity of the battery is identified. The results show that the proposed system enhances the capability of CHP for frequency response and mitigates the associated adverse effects on the gas network. The required capacity of the battery is economically feasible considering the benefit it brings to the CHP

A four-leg buck inverter for three-phase four-wire systems with the function of reducing DC-bus ripples

Three-phase four-wire inverters are usually used to feed unbalanced three-phase loads with neutral currents. The unbalanced three-phase loads also bring to second-order ripples in the DC bus, which should be mitigated by bulky DC-bus capacitors to improve the system performance. In this case, the DC capacitance is designed for the second-order ripple frequency instead of the switching frequency, so it can not be reduced even when SiC MOSFETs are adopted to achieve high switching frequency. Although various topologies of three-phase four-wire inverters has been proposed to provide the path for neutral currents, they cannot handle the second-order ripples. Also, some active power decoupling solutions can be adopted, but they require additional active swithes and components, which increases the cost of the system. In this paper, a four-leg buck inverter is proposed, which consists of four DC-DC buck converters. Each buck converter is independently controlled. This topology can not only provide neutral currents, but also reduce the second-order ripples in the DC bus with active power decoupling control. The proposed topology doesn't require any additional active switches comparing to the conventional topologies with neutral legs. The effectiveness of proposed topology is verified by the simulation in MATLAB/Simulink

State-of-the-art analysis and perspectives for peer-to-peer energy trading

As a promising solution to address the “energy trilemma” confronting human society, peer-to-peer (P2P) energy trading has emerged and rapidly developed in recent years. When carrying out P2P energy trading, customers with distributed energy resources (DERs) are able to directly trade and share energy with each other. This paper summarizes and analyzes the global development of P2P energy trading based on a comprehensive review of related academic papers, research projects, and industrial practice. Key aspects in P2P energy trading are identified and discussed, including market design, trading platforms, physical infrastructure and information and communication technology (ICT) infrastructure, social science perspectives, and policy. For each key aspect, existing research and practice are critically reviewed and insights for future development are presented. Comprehensive concluding remarks are provided at the end, summarizing the major findings and perspectives of this paper. P2P energy trading is a growing field with great potential and opportunities for both academia and industry across the world

A SiC-based neutral leg for the three-phase four-wire inverter

SiC-based inverters can operate at high switching frequency with high efficiency, which can reduce the size of passive components and heat sinks to achieve high power density. However, in three-phase four-wire inverters supplying unblanced loads, the second-order ripples in the DC bus need to be mitigated by large DC capacitance, which increases the size of the converter. The conventional neutral leg is widely used in three-phase four-wire inverters to provide neutral currents for the unbalanced loads. In this paper, an improved neutral leg is proposed, which can provide neutral currents and reduce the second-order ripples in the DC bus simultaneously. The DC bus ripples can be reduced without adding any hardware components. Furthermore, the proposed neutral leg can save 50% DC capacitance comparing to the conventional neutral leg. The proposed neutral leg was built with SiC MOSFETs and tested with a three-phase four-wire inverter in the laboratory. The experimental results verified the effectiveness of the proposed neutral leg