92 research outputs found
Design and Investigation of RGB-type LED Visible Light Communication System
This paper examines the feasibility of a Red Green Blue (RGB)-type Light Emitting Diode (LED) Visible Light Communication (VLC) system based on wavelength division multiplexing (WDM). Each color in the RGB-LED is individually modulated to increase the data rate by three times as compared to the single channel modulation approach used in conventional VLC system. Color filters are employed to detect separately the RGB signals at the receiver side. The proposed system utilized a reflector to improve the performance and the system is lens-free. In this work, an approach of approximated WDM testing is adopted due to the incapability of multiplexing by the microcontroller at higher data rate. The proposed system is demonstrated to transmit and receive data at a maximum distance of 1.4m, with total data transmission speed of 345.6 kbps using standard WDM, while a total speed of 1.5 Mbps up to maximum distance of 1.2m and 3 Mbps up to maximum distance of 0.7m is achieved by the approach of approximated WDM testing
Efficiently Embedding Dynamic Knowledge Graphs
Knowledge graph (KG) embedding encodes the entities and relations from a KG
into low-dimensional vector spaces to support various applications such as KG
completion, question answering, and recommender systems. In real world,
knowledge graphs (KGs) are dynamic and evolve over time with addition or
deletion of triples. However, most existing models focus on embedding static
KGs while neglecting dynamics. To adapt to the changes in a KG, these models
need to be re-trained on the whole KG with a high time cost.
In this paper, to tackle the aforementioned problem, we propose a new
context-aware Dynamic Knowledge Graph Embedding (DKGE) method which supports
the embedding learning in an online fashion. DKGE introduces two different
representations (i.e., knowledge embedding and contextual element embedding)
for each entity and each relation, in the joint modeling of entities and
relations as well as their contexts, by employing two attentive graph
convolutional networks, a gate strategy, and translation operations. This
effectively helps limit the impacts of a KG update in certain regions, not in
the entire graph, so that DKGE can rapidly acquire the updated KG embedding by
a proposed online learning algorithm. Furthermore, DKGE can also learn KG
embedding from scratch. Experiments on the tasks of link prediction and
question answering in a dynamic environment demonstrate the effectiveness and
efficiency of DKGE.Comment: 14 page
Ultrasonographic Findings of Medullary Thyroid Carcinoma: a Comparison with Papillary Thyroid Carcinoma
Higher Doses of Subcutaneous IgG Reduce Resource Utilization in Patients with Primary Immunodeficiency
The recommended dose of IgG in primary immunodeficiency (PID) has been increasing since its first use. This study aimed to determine if higher subcutaneous IgG doses resulted in improved patient outcomes by comparing results from two parallel clinical studies with similar design. One patient cohort received subcutaneous IgG doses that were 1.5 times higher than their previous intravenous doses (mean 213 mg/kg/week), whereas the other cohort received doses identical to previous subcutaneous or intravenous doses (mean 120 mg/kg/week). While neither cohort had any serious infections, the cohort maintained on higher mean IgG dose had significantly lower rates of non-serious infections (2.76 vs. 5.18 episodes/year, P < 0.0001), hospitalization (0.20 vs. 3.48 days/year, P < 0.0001), antibiotic use (48.50 vs. 72.75 days/year, P < 0.001), and missed work/school activity (2.10 vs. 8.00 days/year, P < 0.001). The higher-dose cohort had lower health care utilization and improved indices of well being compared to the cohort treated with traditional IgG doses
Quaternary Organic Solar Cells Enhanced by Cocrystalline Squaraines with Power Conversion Efficiencies >10%
The incorporation of multiple donors into the bulk-heterojunction layer of organic polymer solar cells (PSCs) has been demonstrated as a practical and elegant strategy to improve photovoltaics performance. However, it is challenging to successfully design and blend multiple donors, while minimizing unfavorable interactions (e.g., morphological traps, recombination centers, etc.). Here, a new Förster resonance energy transfer-based design is shown utilizing the synergistic nature of three light active donors (two small molecules and a high-performance donor–acceptor polymer) with a fullerene acceptor to create highly efficient quaternary PSCs with power conversion efficiencies (PCEs) of up to 10.7%. Within this quaternary architecture, it is revealed that the addition of small molecules in low concentrations broadens the absorption bandwidth, induces cocrystalline molecular conformations, and promotes rapid (picosecond) energy transfer processes. These results provide guidance for the design of multiple-donor systems using simple processing techniques to realize single-junction PSC designs with unprecedented PCEs
Quaternary Organic Solar Cells Enhanced by Cocrystalline Squaraines with Power Conversion Efficiencies >10%
The incorporation of multiple donors into the bulk-heterojunction layer of organic polymer solar cells (PSCs) has been demonstrated as a practical and elegant strategy to improve photovoltaics performance. However, it is challenging to successfully design and blend multiple donors, while minimizing unfavorable interactions (e.g., morphological traps, recombination centers, etc.). Here, a new Förster resonance energy transfer-based design is shown utilizing the synergistic nature of three light active donors (two small molecules and a high-performance donor–acceptor polymer) with a fullerene acceptor to create highly efficient quaternary PSCs with power conversion efficiencies (PCEs) of up to 10.7%. Within this quaternary architecture, it is revealed that the addition of small molecules in low concentrations broadens the absorption bandwidth, induces cocrystalline molecular conformations, and promotes rapid (picosecond) energy transfer processes. These results provide guidance for the design of multiple-donor systems using simple processing techniques to realize single-junction PSC designs with unprecedented PCEs
International Recommendations on Reirradiation by Intensity Modulated Radiation Therapy for Locally Recurrent Nasopharyngeal Carcinoma
Purpose: Reirradiation for locally recurrent nasopharyngeal carcinoma (NPC) is challenging because prior radiation dose delivered in the first course is often close to the tolerance limit of surrounding normal structures. A delicate balance between achieving local salvage and minimizing treatment toxicities is needed. However, high-level evidence is lacking because available reports are mostly retrospective studies on small series of patients. Pragmatic consensus guidelines, based on an extensive literature search and the pooling of opinions by leading specialists, will provide a useful reference to assist decision-making for these difficult decisions. Methods and Materials: A thorough review of available literature on recurrent NPC was conducted. A set of questions and preliminary draft guideline was circulated to a panel of international specialists with extensive experience in this field for voting on controversial areas and comments. A refined second proposal, based on a summary of the initial voting and different opinions expressed, was recirculated to the whole panel for review and reconsideration. The current guideline was based on majority voting after repeated iteration for final agreement. Results: The initial round of questions showed variations in clinical practice even among the specialists, reflecting the lack of high-quality supporting data and the difficulties in formulating clinical decisions. Through exchange of comments and iterative revisions, recommendations with high-to-moderate agreement were formulated on general treatment strategies and details of reirradiation (including patient selection, targets contouring, dose prescription, and constraints). Conclusion: This paper provides useful reference on radical salvage treatment strategies for recurrent NPC and optimization of reirradiation through review of published evidence and consensus building. However, the final decision by the attending clinician must include full consideration of an individual patient's condition, understanding of the delicate balance between risk and benefits, and acceptance of risk of complications. (C) 2021 Elsevier Inc. All rights reserved
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