2,199 research outputs found
A passive control method of HAWT blade cyclical aerodynamic load induced by wind shear
Abstract: Modern wind turbines are mainly horizontal axis and operate in bottom atmospheric boundary layer driven by wind shear flow, therefore as the blades rotating the aerodynamic load vary cyclically, with horizontal axis wind turbine (HAWT) large-scaling the cyclical characteristic becomes more obvious, shortening blade life and increasing cost of wind turbine. As the development of wind turbine largescaling is the essential trend, load fluctuation control is more and more critical in HAWT design and manufacture. In common, individual pitch control is introduced to solve the problem, but cost much energy from electric net. In this paper, a concept of telescopic blade root is introduced to reduce fluctuate load induced by wind shear passively, and considering the blades as rigid assessment is operated, meanwhile aerodynamic model based on blade element method in order to analysis the aerodynamic load on NREL Phase VI reference based blade. The result shows that after introducing the equipment the blade fatigue load can be released, lengthening blade life
Segmenting Taipei’s Real Estate Data – A Cluster Analysis
Data mining has been widely used for knowledge discovery from large amount of data. In this paper, clustering analysis is applied to Taiwan government open data platform (DATA.GOV.TW), segmenting the real estate data so as to understand the real estate market structure in Taiwan. This paper use design science research methodology (DSRM) as research method. The result provides valuable insights into market structures in Taipei City that has limited addressed in past research and contributes to real estate agencies and practitioners an insight-seeking approach that they can follow to generate values from data
Using Header Session Messages to Filter-out Junk E-mails
Due to the popularity of Internet, e-mail use is the major activity when surfing Internet. However, in recent years, spam has become a major problem that is bothering the use of the e-mail. Many anti-spam filtering techniques have been implemented so far, such as RIPPER rule learning algorithm, NaĂ¯ve Bayesian classifier, Support Vector Machine, Centroid Based, Decision trees or Memory-base filter. Most existed anti-spamming techniques filter junk emails out according to e-mail subjects and body messages. Nevertheless, subjects and e-mail contents are not the only cues for spamming judgment. In this paper, we present a new idea of filtering junk e-mail by utilizing the header session messages. In message head session, besides sender\u27s mail address, receiver\u27s mail address and time etc, users are not interested in other information. This paper conducted two content analyses. The first content analysis adopted 10,024 Junk e-mails collected by Spam Archive (http://spamarchive.org) in a two-months period. The second content analysis adopted 3,482 emails contributed by three volunteers for a one week period. According to content analysis results, this result shows that at most 92.5% of junk e-mails would be filtered out using message-ID, mail user agent, sender and receiver addresses in the header session as cues. In addition, the idea this study proposed may induce zero over block errors rate. This characteristic of zero over block errors rate is an important advantage for the antispamming approach this study proposed. This proposed idea of using header session messages to filter-out junk e-mails may coexist with other anti-spamming approaches. Therefore, no conflict would be found between the proposed idea and existing anti-spamming approaches
Liposome encapsulation of fluorescent nanoparticles: Quantum dots and silica nanoparticles
Quantum dots (QDs) and silica nanoparticles (SNs) are relatively new classes of fluorescent probes that overcome the limitations encountered by organic fluorophores in bioassay and biological imaging applications. We encapsulated QDs and SNs in liposomes and separated nanoparticle-loaded liposomes from unencapsulated nanoparticles by size exclusion chromatography. Fluorescence correlation spectroscopy was used to measure the average number of nanoparticles inside each liposome. Results indicated that nanoparticle-loaded liposomes were formed and separated from unencapsulated nanoparticles by using a Sepharose gel. As expected, fluorescence self-quenching of nanoparticles inside liposomes was not observed. Each liposome encapsulated an average of three QDs. These studies demonstrated that nanoparticles could be successfully encapsulated into liposomes and provided a methodology to quantify the number of nanoparticles inside each liposome by fluorescence correlation spectroscop
Recommended from our members
Extracellular RNA in a single droplet of human serum reflects physiologic and disease states.
Extracellular RNAs (exRNAs) are present in human serum. It remains unclear to what extent these circulating exRNAs may reflect human physiologic and disease states. Here, we developed SILVER-seq (Small Input Liquid Volume Extracellular RNA Sequencing) to efficiently sequence both integral and fragmented exRNAs from a small droplet (5 μL to 7 μL) of liquid biopsy. We calibrated SILVER-seq in reference to other RNA sequencing methods based on milliliters of input serum and quantified droplet-to-droplet and donor-to-donor variations. We carried out SILVER-seq on more than 150 serum droplets from male and female donors ranging from 18 y to 48 y of age. SILVER-seq detected exRNAs from more than a quarter of the human genes, including small RNAs and fragments of mRNAs and long noncoding RNAs (lncRNAs). The detected exRNAs included those derived from genes with tissue (e.g., brain)-specific expression. The exRNA expression levels separated the male and female samples and were correlated with chronological age. Noncancer and breast cancer donors exhibited pronounced differences, whereas donors with or without cancer recurrence exhibited moderate differences in exRNA expression patterns. Even without using differentially expressed exRNAs as features, nearly all cancer and noncancer samples and a large portion of the recurrence and nonrecurrence samples could be correctly classified by exRNA expression values. These data suggest the potential of using exRNAs in a single droplet of serum for liquid biopsy-based diagnostics
Posterolateral Lumbar Spinal Fusion with Autogenous Bone Chips from Laminectomy Extended with OsteoSet®
BackgroundThis study was conducted to evaluate posterolateral lumbar fusion with autogenous corticocancellous bone chips from the laminae and spinous processes extended with OsteoSet® instead of cancellous bone from the iliac crest.MethodsA total of 124 patients who underwent posterior decompression and posterolateral fusion with instrumentation between May 2001 and December 2003 were analyzed retrospectively. The study population comprised 49 males and 75 females with a mean age of 66 ± 9.5 years. In all the patients, corticocancellous bone chips from laminectomy and OsteoSet® were used as the graft material. There was no cancellous bone harvested from the iliac crest. The follow-up period was 28 + 7.1 months.ResultsThe overall union rate was 91%, and the average union time was 3.9 months. There were 3 complications, including 2 patients with dura tear, and 1 with deep infection. At the final follow-up, the good and excellent results were up to 83.9%.ConclusionGraft material from laminae and spinous processes extended with OsteoSet® is reliable and effective enough to replace the graft from the posterior iliac crest
Identifying Users’ Behavior Purchasing Virtual Items
Virtual asset has become more important in the virtual worlds. A growing number of users involve in the virtual worlds has created a new business phenomena. An online transaction on virtual goods involves real money. This research mainly focus on finding out what are the factors influence customers’ behavior and how to predict it toward purchasing in virtual worlds. There are thirty eight participants from different countries involve in this study. An online questionnaire is design to get necessary information from the users. The correlation and regression analysis applied in order to predict customer behavior toward purchasing in virtual worlds
- …