62 research outputs found
Measuring Pants
We investigate the terms arising in an identity for hyperbolic surfaces proved by Luo and Tan, namely showing that they vary monotonically in terms of lengths and that they verify certain convexity properties. Using these properties, we deduce two results. As a first application, we show how to deduce a theorem of Thurston which states, in particular for closed hyperbolic surfaces, that if a simple length spectrum "dominates" another, then in fact the two surfaces are isometric. As a second application, we show how to find upper bounds on the number of pairs of pants of bounded length that only depend on the boundary length and the topology of the surface.
A Novel Wideband Bandpass Filter using H-shaped DGS
This paper presents a novel compact wide-band bandpass filter (BPF) having good selectivity. It is designed using a dual-plane structure which consists of a parallel-coupled microstrip line on the upper surface and three H-shape defected ground structures (DGS) on the ground plane. By adding three H-shape DGS units on the ground plane, then properly adjusting their dimensions and position, the bandwidth and selectivity of the designed filter can be significantly improved. A compact prototype of wide-band microstrip bandpass filter has been designed, fabricated and measured for the wireless systems applications. The filter exhibits a center frequency at 4.8 GHz, passband from 2.8 GHz to 6.8 GHz with best insertion loss and return loss of 0.8 dB and 40 dB, respectively. The measured results agrees well with the theoretical expectations validating the proposed design
MEASURING PANTS
peer reviewedWe investigate the terms arising in an identity for hyperbolic surfaces proved by Luo and Tan, namely showing that they vary monotonically in terms of lengths and that they verify certain convexity properties. Using these properties, we deduce two results. As a first application, we show how to deduce a theorem of Thurston which states, in particular for closed hyperbolic surfaces, that if a simple length spectrum “dominates” another, then in fact the two surfaces are isometric. As a second application, we show how to find upper bounds on the number of pairs of pants of bounded length that only depend on the boundary length and the topology of the surface
LBMT team at VLSP2022-Abmusu: Hybrid method with text correlation and generative models for Vietnamese multi-document summarization
Multi-document summarization is challenging because the summaries should not
only describe the most important information from all documents but also
provide a coherent interpretation of the documents. This paper proposes a
method for multi-document summarization based on cluster similarity. In the
extractive method we use hybrid model based on a modified version of the
PageRank algorithm and a text correlation considerations mechanism. After
generating summaries by selecting the most important sentences from each
cluster, we apply BARTpho and ViT5 to construct the abstractive models. Both
extractive and abstractive approaches were considered in this study. The
proposed method achieves competitive results in VLSP 2022 competition.Comment: In Proceedings of the 9th International Workshop on Vietnamese
Language and Speech Processing (VLSP 2022
SYSTEM THEORY BASED MULTIPLE BEAMFORMING
In this paper, the problem of analysis and design of large-scale multiple beamforming system is considered by system theory approach. We consider the response of system parameters by set of objective functions in a critical condition, which is unable to access measurement data or the data size is large. The reduced-order model is built and the robust solution is found for a multiple beamforming system. The Monte Carlo simulation results show that the proposed multiple beamforming system yields significant performance against over existing methods
When Intervention Becomes Imperative: A Case Report of Spontaneous Vulvar Edema During Pregnancy
Spontaneous idiopathic vulvar edema during the second trimester is a rare condition. The approach to managing this condition involves relieving symptoms, identifying underlying causes, and implementing appropriate treatment. Managing such cases during pregnancy is challenging because of concerns for potential adverse fetal outcomes. Conservative management expects the condition to be relieved spontaneously postpartum, whereas invasive treatment offers a more rapid resolution. Treatment choices are controversial because each method has its pros and cons and influences the delivery process to a certain extent. Surgical drainage becomes a viable option when patients are not responsive to medications. We report a case of spontaneous massive vulvar edema in a 22-year-old primigravida in her 23rd week of pregnancy. After ruling out other notable causes of vulvar edema, we decided to intervene using an invasive procedure because she complained of progressive symptoms and discomfort. Subsequently, the edema subsided postprocedure, and the patient experienced successful labor with no complications. This report aims to alert clinicians that drainage attempts should be considered in pregnant patients with worsening symptoms
Isolation and characterization of Rhizobium spp. and Bradyrhizobium spp. from legume nodules
Rhizobia topic has been re-focused in recent years because of new findings on their traits not only as nitrogen-fixing bacteria but also as plant growth-promoting rhizobacteria. When combing rhizobial strains with novel biological carriers (e.g., biochar) for inoculant production, it brings great potential for improving soil health in long-term. Appreciating this trend, this study is designed to isolate and characterize local rhizobial strains from legume fields using the conventional method with some modifications to increase efficiency in rhizobial identification. As a result, 17 rhizobial strains were isolated and classified biochemically that genetic identification outcome confirmed 10 strains belong to 07 different Rhizobium species as R. mayense, R. paknamense, R. pusense, R. miluonense, R. tropici, R. phaseoli, and R. multihospitium while the rest belong to 06 various Bradyrhizobium species as B. elkanii, B. centrosematis, B. guangxiense, B. liaoningense, B. yuanmingense, and B. arachidis. Thermal and saline tolerant tests together with seed germination tests also performed on these rhizobial strains to gain data on their responses to abiotic stresses. By comparing rice and mung bean GI values, we can assess the effectiveness of each rhizobial strains to help seeds at their early germination
THỰC VẬT PHÙ DU VÙNG BIỂN VEN BỜ ĐÀ NẴNG
Phytoplankton, especially community characteristics, in coastal waters of Da Nang have not been well studied. This present study analyzed data of phytoplankton for diversity and abundance from surveys from 2002 to 2016 at 44 stations in the coastal Da Nang waters. A total of 316 taxa from 9 classes were identified: Dinophyceae (134 taxa), Mediophyceae (77 taxa), Coscinodiscophyceae (44 taxa), Bacillariophyceae (36 taxa), Cyanophyceae (3 taxa), Dictyochophyceae (2 taxa), Bacillariophyta classis incertae sedis (1 taxon), Conjugatophyceae (1 taxon) and Thecofilosea (1 taxon). A list of 36 species of potentially harmful microalgae was recorded in coastal waters of Da Nang. In which, Pseudo-nitzschia spp. often had higher cell densities in some locations during the northeast monsoon. Analyzing diversity indices in different locations showed that there were significance differences of Margalef and Shannon indices, low in estuarine area (CS) and higher in the south of Son Tra peninsula (NST). Meanwhile no strong differences of Pielou and Simpson indices were found among the locations. However, there were strong differences of Margalef, Simpson and Pielou indices, which were found over the three studied years (2004, 2005, and 2006), mainly in NST, the northeast of Son Tra peninsula (DBST) and Da Nang bay (VDN). Analysis of species accumulation curves indicated that only 56–95% of species was found compared to maximal expected species richness in all studied locations. DMS analysis showed that there was year-based similarity among the years (ca. 50% of similarity) of phytoplankton communities. Among the studied years, average phytoplankton cell densities in Da Nang bay and the northeast of Son Tra were higher than those in other years and locations. This present study on species richness, expected species richness and variation in phytoplankton abundance suggested that there is a need of increasing sampling efforts, especially in riverine area and DBST for better understanding of characteristics of phytoplankton communities in coastal Da Nang waters.Thực vật phù du là đối tượng ít được nghiên cứu ở vùng biển ven bờ Đà Nẵng, nhất là những đặc trưng về thành phần loài và cấu trúc quần xã. Trong bài báo này, chúng tôi phân tích số liệu về đa dạng loài và sự phong phú của thực vật phù du thu thập được trong các chuyến khảo sát từ năm 2002 đến năm 2016 ở 44 trạm trong vùng biển ven bờ Đà Nẵng. Kết quả phân tích đã xác định được 316 loài và dưới loài thuộc 9 lớp tảo khác nhau. Trong các loài thực vật phù du ghi nhận được, có 36 loài tảo có khả năng gây hại, trong đó mật độ của Pseudo-nitzschia spp. cao hơn tại một số khu vực trong thời kỳ gió mùa Đông Bắc. Phân tích các chỉ số theo từng khu vực, có thể thấy chỉ số giàu có loài Margalef và chỉ số đa dạng Shannon khác nhau đáng kể giữa các khu vực, thấp ở cửa sông trong vịnh Đà Nẵng và cao ở nam bán đảo Sơn Trà. Trong khi các chỉ số cân bằng Pielou và đa dạng Simpson lại không khác biệt giữa các khu vực. Tuy nhiên, sự đa dạng và độ giàu có loài lại có sự khác biệt giữa các năm 2004, 2005 và 2016, chủ yếu ở nam bán đảo Sơn Trà, đông bắc bán đảo Sơn Trà và vịnh Đà Nẵng. Phân tích độ giàu có loài cho thấy hầu hết các khu vực đều chỉ ghi nhận được từ 56% đến 95% số loài mong đợi. Phân tích cấu trúc quần xã thực vật phù du thu thể hiện sự biến động giữa các năm nghiên cứu với mức độ tương đồng trong năm xấp xỉ 50%. So sánh trung bình mật độ thực vật phù du thu của từng khu vực cho thấy mật độ vào năm 2005 cao hơn hẳn so với các năm khác ở vịnh Đà Nẵng và đông bắc Sơn Trà. Các phân tích về độ giàu có loài, loài mong đợi và biến động mật độ thực vật phù du thu cho thấy dù vùng biển nghiên cứu được ghi nhận thành phần loài thực vật phù du thu cao, nhưng số lượng trạm và thời gian thu mẫu ở vùng biển Đà nẵng nhất là khu vực cửa sông cần được thu thập nhiều hơn, vẫn cần thu thập thêm vật mẫu ở tất cả các khu vực, nhất là vùng cửa sông trong vịnh Đà Nẵng và đông bắc bán đảo Sơn Trà
Global, regional, and national burden of hepatitis B, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019
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