130,624 research outputs found

    Overload protection system for power inverter

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    An overload protection system for a power inverter utilized a first circuit for monitoring current to the load from the power inverter to detect an overload and a control circuit to shut off the power inverter, when an overload condition was detected. At the same time, a monitoring current inverter was turned on to deliver current to the load at a very low power level. A second circuit monitored current to the load, from the monitoring current inverter, to hold the power inverter off through the control circuit, until the overload condition was cleared so that the control circuit may be deactivated in order for the power inverter to be restored after the monitoring current inverter is turned off completely

    Cognitive demands of face monitoring: Evidence for visuospatial overload

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    Young children perform difficult communication tasks better face to face than when they cannot see one another (e.g., Doherty-Sneddon & Kent, 1996). However, in recent studies, it was found that children aged 6 and 10 years, describing abstract shapes, showed evidence of face-to-face interference rather than facilitation. For some communication tasks, access to visual signals (such as facial expression and eye gaze) may hinder rather than help children’s communication. In new research we have pursued this interference effect. Five studies are described with adults and 10- and 6-year-old participants. It was found that looking at a face interfered with children’s abilities to listen to descriptions of abstract shapes. Children also performed visuospatial memory tasks worse when they looked at someone’s face prior to responding than when they looked at a visuospatial pattern or at the floor. It was concluded that performance on certain tasks was hindered by monitoring another person’s face. It is suggested that processing of visual communication signals shares certain processing resources with the processing of other visuospatial information

    Pemantauan Intake Output Cairan Pada Pasien Gagal Ginjal Kronik Dapat Mencegah Overload Cairan

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    Fluid Intake Output Monitoring of Chronic Renal Failure Patients can Prevent Fluid Overload. Unhealthy diet in urban society as one of risk factor noncommunicable disease, such as Diabetes and Hypertension. Both of them is leading causes of kidney disease and it can be End Stage Renal Disease stage (ESRS). ESRD patient often experience fluid overload state, that can cause another health problem even it can be cause of death. That\u27s way, it is important to make effective and efficient fluid restriction program to prevent the complication, one other thing is fluid intake output monitoring. This scientific paper use case study method to describe analysis of clinical practice in fluid intake output monitoring by using fluid intake output chart. Monitoring is proven effective to treat fluid overload, it is shown by decreasing of patient\u27s fluid overload clinical manifestatio

    Attention focussing and anomaly detection in real-time systems monitoring

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    In real-time monitoring situations, more information is not necessarily better. When faced with complex emergency situations, operators can experience information overload and a compromising of their ability to react quickly and correctly. We describe an approach to focusing operator attention in real-time systems monitoring based on a set of empirical and model-based measures for determining the relative importance of sensor data

    Cognitive barriers during monitoring-based commissioning of buildings

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    Monitoring-based commissioning (MBCx) is a continuous building energy management process used to optimize energy performance in buildings. Although monitoring-based commissioning (MBCx) can reduce energy waste by up to 20%, many buildings still underperform due to issues such as unnoticed system faults and inefficient operational procedures. While there are technical barriers that impede the MBCx process, such as data quality, the focuses of this paper are the non-technical, behavioral and organizational, barriers that contribute to issues initiating and implementing MBCx. In particular, this paper discusses cognitive biases, which can lead to suboptimal outcomes in energy efficiency decisions, resulting in missed opportunities for energy savings. This paper provides evidence of cognitive biases in decisions during the MBCx process using qualitative data from over 40 public and private sector organizations. The results describe barriers resulting from cognitive biases, listed in descending order of occurrence, including: risk aversion, social norms, choice overload, status quo bias, information overload, professional bias, and temporal discounting. Building practitioners can use these results to better understand potential cognitive biases, in turn allowing them to establish best practices and make more informed decisions. Researchers can use these results to empirically test specific decision interventions and facilitate more energy efficient decisions

    Balancing stress and recovery in sports

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    To reach elite level in sports, athletes have to start their intensive and time-consuming training at an early stage. The road to the top is a stressful one, not only due to the physiological stress of training, but also caused by psychological and social stress. In order to improve performance athletes continuously challenge their personal boundaries. This may lead to a local or general overload of the human body that results into injuries, illnesses and overtraining. Overtraining is characterized by an unexplained decrement in sport-specific performance and is often coupled with symptoms such as increased fatigue, poor concentration, disturbed mood, and altered eating and sleeping patterns. Full recovery may take months to years. Monitoring stress and recovery may help to optimize performance and prevent a local or general overload. Clinical measurements showed that mood state and hormonal responses to a double maximal exercise protocol provided valuable information to confirm the diagnosis of overtraining.

    Clinical and molecular characterization of a cardiac ryanodine receptor founder mutation causing catecholaminergic polymorphic ventricular tachycardia

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    Background Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a difficult-to-diagnose cause of sudden cardiac death (SCD). We identified a family of 1400 individuals with multiple cases of CPVT, including 36 SCDs during youth. Objectives We sought to identify the genetic cause of CPVT in this family, to preventively treat and clinically characterize the mutation-positive individuals, and to functionally characterize the pathogenic mechanisms of the mutation. Methods Genetic testing was performed for 1404 relatives. Mutation-positive individuals were preventively treated with β-blockers and clinically characterized with a serial exercise treadmill test (ETT) and Holter monitoring. In vitro functional studies included caffeine sensitivity and store overload–induced calcium release activity of the mutant channel in HEK293 cells. Results We identified the p.G357S_RyR2 mutation, in the cardiac ryanodine receptor, in 179 family members and in 6 SCD cases. No SCD was observed among treated mutation-positive individuals over a median follow-up of 37 months; however, 3 relatives who had refused genetic testing (confirmed mutation-positive individuals) experienced SCD. Holter monitoring did not provide relevant information for CPVT diagnosis. One single ETT was unable to detect complex cardiac arrhythmias in 72% of mutation-positive individuals, though the serial ETT improved the accuracy. Functional studies showed that the G357S mutation increased caffeine sensitivity and store overload–induced calcium release activity under conditions that mimic catecholaminergic stress. Conclusion Our study supports the use of genetic testing to identify individuals at risk of SCD to undertake prophylactic interventions. We also show that the pathogenic mechanisms of p.G357S_RyR2 appear to depend on β-adrenergic stimulation

    prototipe Repeater untuk Sistem Monitoring Trafo Distribusi Tenaga Listrik Melalui Link PLC (Powerline Communication) pada Tegangan Rendah Berbasis Cenelec-C

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    ABSTRAKSI: Trafo Distribusi adalah merupakan suatu komponen yang sangat penting dalam penyaluran tenaga listrik dari gardu distribusi ke konsumen. Kerusakan pada Trafo Distribusi akan menyebabkan kontiniutas pelayanan terhadap konsumen terganggu sehingga terjadi pemutusan aliran listrik atau pemadaman. Salah satu penyebab kerusakan trafo distribusi yaitu overload dan beban tidak seimbang. Overload terjadi karena beban yang terpasang pada trafo melebihi kapasitas maksimum dari trafo dimana arus beban melebihi arus beban penuh dari trafo. Trafo juga dapat mengalami overload walaupun arus beban belum melebihi arus beban penuh dikarenakan suhu trafo sudah melebihi batas yang diijinkan. Oleh karena itu dibutuhkan sistem monitoring terhadap trafo tersebut agar dapat diketahui performansi dan kondisi dari trafo. Akan tetapi karena jarak antara Trafo Distribusi dengan lokasi monitoring cukup jauh dibutuhkan suatu repeater untuk mentransmisikan kembali data yang diterima dari transmitter sehingga dapat diterima dengan baik oleh receiver.Dalam Tugas Akhir ini dibuat prototipe repeater sistem monitoring Trafo Distribusi Tenaga Listrik melalui link PLC Tegangan Rendah berbasis CENELEC-C, yang akan digunakan untuk memantau performansi kondisi arus dan suhu pada Trafo Distribusi. Pada sistem ini data dari transmitter diterima kemudian diproses untuk selanjutnya ditransmisikan kembali ke receiver untuk ditampilkan melalui kanal PLC (Powerline Communication).Dari tugas akhir ini, sistem repeater ini dapat diimplementasikan pada sistem monitoring trafo distribusi tenaga listrik. Dengan frekuensi kerja 125-140 kHz yang merupakan standar CENELEC-C. Idealnya sistem ini dapat ditempatkan dengan jarak 45 meter dari transmitter.Kata Kunci : Trafo Distribusi, overload, PLC, repeater, sensor arus, sensor suhu,ABSTRACT: The distribution transformer is a very important component in the distribution of electricity from distribution substations to consumers. Damage to the distribution transformer will cause the service to consumers troubled kontiniutas causing power outages or blackouts. One cause of damage to distribution transformers are overloaded and unbalanced load. Overload occurs because the load is mounted on the transformer exceeds the maximum capacity of the transformer when the load current exceeds the full load current of the transformer. Transformer can also be experienced even if the load current overload do not exceed the full load current transformer due to the temperature has exceeded the allowable limit. It is therefore necessary to transformer monitoring system in order to know the performance and condition of the transformer. However, because the distance between the distribution transformer monitoring location is far enough to need a repeater retransmits data received from the transmitter so well received by the receiver.In this final project proposal a prototype repeater monitoring system Electrical Power Distribution Transformers through the link-based PLC Low Voltage CENELEC-C, which will be used to monitor the performance of current conditions and temperature on distribution transformers. In this system the data from the transmitter is received then further processed to be transmitted back to the receiver for display through the canal PLC (Powerline Communication).Of this final task, this repeater system can be implemented in the monitoring system of power distribution transformers. With a working frequency of 125-140 kHz which is the standard CENELEC-C. Ideally, this system can be placed with a distance of 45 meters from the transmitter.Keyword: Distribution transformers, overload, PLC, repeater, flow sensors, temperatur

    Load shedding in network monitoring applications

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    Monitoring and mining real-time network data streams are crucial operations for managing and operating data networks. The information that network operators desire to extract from the network traffic is of different size, granularity and accuracy depending on the measurement task (e.g., relevant data for capacity planning and intrusion detection are very different). To satisfy these different demands, a new class of monitoring systems is emerging to handle multiple and arbitrary monitoring applications. Such systems must inevitably cope with the effects of continuous overload situations due to the large volumes, high data rates and bursty nature of the network traffic. These overload situations can severely compromise the accuracy and effectiveness of monitoring systems, when their results are most valuable to network operators. In this thesis, we propose a technique called load shedding as an effective and low-cost alternative to over-provisioning in network monitoring systems. It allows these systems to handle efficiently overload situations in the presence of multiple, arbitrary and competing monitoring applications. We present the design and evaluation of a predictive load shedding scheme that can shed excess load in front of extreme traffic conditions and maintain the accuracy of the monitoring applications within bounds defined by end users, while assuring a fair allocation of computing resources to non-cooperative applications. The main novelty of our scheme is that it considers monitoring applications as black boxes, with arbitrary (and highly variable) input traffic and processing cost. Without any explicit knowledge of the application internals, the proposed scheme extracts a set of features from the traffic streams to build an on-line prediction model of the resource requirements of each monitoring application, which is used to anticipate overload situations and control the overall resource usage by sampling the input packet streams. This way, the monitoring system preserves a high degree of flexibility, increasing the range of applications and network scenarios where it can be used. Since not all monitoring applications are robust against sampling, we then extend our load shedding scheme to support custom load shedding methods defined by end users, in order to provide a generic solution for arbitrary monitoring applications. Our scheme allows the monitoring system to safely delegate the task of shedding excess load to the applications and still guarantee fairness of service with non-cooperative users. We implemented our load shedding scheme in an existing network monitoring system and deployed it in a research ISP network. We present experimental evidence of the performance and robustness of our system with several concurrent monitoring applications during long-lived executions and using real-world traffic traces.Postprint (published version
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