546 research outputs found

    Optimum Remedial Operation of Permanent Magnet Synchronous Motor

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    In critical systems, the reliability of the drive is very important. The faults are unwanted. The faults may be lead to loss of the human life and capital. This paper is addressed this problem and suggested two models to solve it. The first model doesn’t contain any special tools to improve the torque ripple and THD. The second model contains 2PI current controllers to improvement the performance at fault and remedial operation. One is for the torque and the other is for the flux. The first PI controller is feeding from the torque error between the reference and estimated torques to get new q-axis current component representing modifier current arises from uncertain things inside the machine and drive system such as temperature and parameters variations. This current will add to reference q-axis current to get robust new q-axis current to satisfy the drive requirement and solve the torque problem (ripple torque). With robust current, the total harmonic distortion is a decrease but doesn’t reach the best value so the other PI controller is used to adjust the THD. In this PI controller, the d-axis flux is compared to rotor permanent magnet flux to solve this problem arises from non-sinusoidal of the magnetic flux. The output of the PI controller is introduced to the reference d-axis current. The new d-axis current will reach the best value of THD. The simulation of the second controller is compared to the simulation of first controller to show if the second controller strong or weak. Matlab simulink is used to simulate the drive system.DOI:http://dx.doi.org/10.11591/ijece.v2i5.72

    Smart Detection Of Arm Muscle Strength For Post Stroke Patient Therapy

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    Kelumpuhan otot merupakan fenomena yang sering terjadi di masyarakat khususnya pada pasien pasca stroke dan spinal cord injury (SCI). Kelumpuhan dapat terjadi karena adanya kerusakan atau stimulasi saraf ke otot baik yang disebabkan karena kerusakan saraf pusat maupun saraf perifer misalnya pada pasien pasca stroke dan spinal cord injury.  lektromiografi (EMG) adalah suatu teknik untuk mengevaluasi dan merekam sinyal aktivitas otot. Teknik ini mendeteksi potensial aksi dari sel-sel otot saat sel-sel berkontraksi dan relaksasi dengan menggunakan elektroda yang ditempel di atas jaringan otot. Pemeriksaan ini dapat membantu untuk membedakan antara masalah-masalah yang berasal dari otot itu sendiri atau dari gangguan syaraf. Sistem ini didesain untuk menyimpan dan menampilkan hasil monitoring nilai skala kekuatan otot pada smartphone android untuk multi-channel secara realtime. Sinyal dari instrumentasi elektromiograf Akan diolah pada Raspberry Pi melalui ADC kemudian dikirim ke database firebase melalui koneksi internet. Data yang telah dikirim kemudian ditampilkan pada smartphone android. Pada pengujian keseluruhan, sistem mampu mendeteksi nilai skala otot 0 sampai 5. Rata-rata waktu yang dibutuhkan untuk pengiriman data dari instrumentasi menuju aplikasi adalah 1 detik

    Exploiting the Synergy Between Gossiping and Structured Overlays

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    In this position paper we argue for exploiting the synergy between gossip-based algorithms and structured overlay networks (SON). These two strands of research have both aimed at building fault-tolerant, dynamic, self-managing, and large-scale distributed systems. Despite the common goals, the two areas have, however, been relatively isolated. We focus on three problem domains where there is an untapped potential of using gossiping combined with SONs. We argue for applying gossip-based membership for ring-based SONs---such as Chord and Bamboo---to make them handle partition mergers and loopy networks. We argue that small world SONs---such as Accordion and Mercury---are specifically well-suited for gossip-based membership management. The benefits would be better graph-theoretic properties. Finally, we argue that gossip-based algorithms could use the overlay constructed by SONs. For example, many unreliable broadcast algorithms for SONs could be augmented with anti-entropy protocols. Similarly, gossip-based aggregation could be used in SONs for network size estimation and load-balancing purposes

    Cardiac Disease in Adolescents With Delayed Diagnosis of Vertically Acquired HIV Infection

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    Background. At least one-third of human immunodeficiency virus (HIV)–infected infants survive to adolescence even without antiretroviral therapy (ART), but are at high risk of complications including cardiac disease. We investigated the characteristics of cardiac disease among adolescents with HIV infection diagnosed in late childhood who were receiving ambulatory HIV care in Harare, Zimbabwe. / Methods. Consecutive adolescents with vertically acquired HIV attending 2 HIV outpatient treatment clinics were studied. Assessment included clinical history and examination, and 2-dimensional, M-mode, pulsed- and continuous-wave Doppler echocardiography. / Results. Of 110 participants (47% male; median age, 15 years; interquartile range, 12–17 years), 78 (71%) were taking ART. Exertional dyspnea, chest pain, palpitations, and ankle swelling were reported by 47 (43%), 43 (39%), 10 (9%), and 7 (6%), respectively. The New York Heart Association score was ≥2 in 41 participants (37%). Echocardiography showed that 74 participants (67%) had left ventricular (LV; septal and/or free wall) hypertrophy and 27 (24%) had evidence of impaired LV relaxation or restrictive LV physiology. The estimated pulmonary artery systolic pressure (ePASP) was >30 mm Hg in 4 participants (3.6%); of these 2 also had right ventricular (RV) dilatation. Another 32 participants (29%), without elevated ePASP, had isolated RV dilatation. / Conclusions. A significant burden of cardiac disease was seen among adolescents with vertically acquired HIV infection. More than half were asymptomatic yet had significant echocardiographic abnormalities. These findings highlight the need to screen this population in order to better define the geography, natural history, etiopathogenic mechanisms, and management (including the timing and choice of optimal therapeutic ART and cardiac drug interventions) to prevent development and/or progression of HIV-associated cardiac disease

    Evaluation of energy dissipation in flexure for two stage concrete

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    Concrete is a multiphase material and the energy dissipation in concrete is considered as the index to measure the capability of its ingredients to resist cyclic loading during its service life. This paper presents the results from an investigation conducted on the behaviour of two stage concrete (TSC) subjected to constant and gradual cyclic loading. A total of 128 samples were cast and tested at 28 days of normal curing, using mixes having water/cement ratio (w/c) of 0.55, 0.65, 0.75 and 0.80 and sand/cement ratio (s/c) of 1, 1.25, 1.5 and 2.0. Empirical approach namely ratio of energy dissipation (Rn) has been used to assess the results. In general, the results are comparable either in constant or gradual cyclic loading system regardless of the variation in w/c and s/c. It seems, however, that the rate of energy dissipation was slightly higher in the samples subjected to gradual cyclic loading

    Towards Extending CityGML for Property Valuation: Property Valuation ADE

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    This paper introduces Property Valuation Application Domain Extension (ADE) within CityGML 3.0, aiming to integrate relevant indoor and outdoor 3D variables (cost estimation, view quality, etc.) for accurate property valuation. Current models lack the necessary features for this specific application. Leveraging IFC data for indoor elements, this ADE extends CityGML, addressing the existing gap. This paper identifies and categorizes data requirements, leading to the conceptualization and development of the model. By enriching CityGML 3.0 with IFC data, the approach introduces new features like the "Property Unit" to ensure adaptability across diverse valuation scenarios. Despite encountering data integrability challenges, we here commit to refining the model and overcoming these obstacles. A preliminary implementation using CityJSON demonstrates successful integration and paves the way for future implementation. These include developing an API platform and establishing an official repository to facilitate practical usability and scalability. This research significantly contributes to advancing property valuation processes by providing accurate valuations for stakeholders and promoting the use of 3D urban data in domain-specific extensions

    Impact of biostimulants based amino acids and irrigation frequency on agro-physiological characteristics and productivity of broccoli plants

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    Abstract scientists are concerned about the utilizing of biostimulants-based amino acids in plant feeding and mitigating negative effects of water stress. As a result, two-year field experiments were conducted at Faculty of Agriculture's experimental station at Cairo University to study the effectiveness of liquid yeast waste (CMS) and Cargo amino acids (AAs) on the agro-physiological features of broccoli plants with different irrigation frequencies (every 5, 10, and 15 days). Compared with control plants, the foliar application of AAs and CMS significantly increased plant height, photosynthesis pigments, head weight, head diameter, head height, plant yield, and quality at different irrigation frequencies. Likewise, both treatments (CMS and AAs) significantly improved ascorbic acids by 16.65% and 15.95% and increased total phenol content by 24.10% and 36.60%, respectively, compared to control plants. Accordingly, the highest productivity was achieved for broccoli grown under irrigation every five days with the CMS bio-stimulant, where it was 3111.17 kg ha-1, while the lowest productivity was achieved for the control treatment in which no biostimulants were added and irrigation frequency every 15 days, and the productivity was 1376.22 kg ha-1. Plants irrigated every 15 days produced the highest levels of abscisic acid (ABA) and superoxide dismutase (SOD), followed by plants irrigated every 10 days and every 5 days. Exogenous application of amino acids bio-stimulants could be suggested to improve vegetative growth, biochemical characteristics, productivity, and nutritional value as well as to mitigate negative effects of water scarcity.

    Enriching lower LoD 3D city models with semantic data computed by the voxelisation of BIM sources

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    The role and adoption of 3D city models have been changing from a data endpoint to a centralised data source that is used for a variety of different analyses in different sectors. This change has not yet been fully completed and the transition process is still very noticeable at certain places. For example, data required for city-scale analyses are often missing, incorrect, or not stored in a standard way. A subset of these data (E.g. shell volume, shell area & footprint area) can be approximated from lower LoD shapes (LoD2.2 or lower) in the 3D city models. However, these models frequently simplify reality and therefore these approximations are not accurate. This paper proposes computing these data by voxelising Building Information Modelling (BIM) models representing the same buildings as the 3D city model. It is shown that a subset of these approximations (shell volume & footprint area) are more accurate than values computed from lower LoD shapes. Storing these data as attributes of the building models in 3D city models can improve the ease of use and the outcome of city-scale analyses. The computed values from BIM models can also be assigned to outputs of BIM to Geo conversions. This overturns the accuracy loss of the geometry caused by the conversion in which geometry is significantly generalised and simplified
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