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Manzo, Mario, i Simone Pellino. "Bag of ARSRG Words (BoAW)". Machine Learning and Knowledge Extraction 1, nr 3 (5.08.2019): 871–82. http://dx.doi.org/10.3390/make1030050.
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In recent years researchers have worked to understand image contents in computer vision. In particular, the bag of visual words (BoVW) model, which describes images in terms of a frequency histogram of visual words, is the most adopted paradigm. The main drawback is the lack of information about location and the relationships between features. For this purpose, we propose a new paradigm called bag of ARSRG (attributed relational SIFT (scale-invariant feature transform) regions graph) words (BoAW). A digital image is described as a vector in terms of a frequency histogram of graphs. Adopting a set of steps, the images are mapped into a vector space passing through a graph transformation. BoAW is evaluated in an image classification context on standard datasets and its effectiveness is demonstrated through experimental results compared with well-known competitors.
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Toman, Inka, Jonathan Loree, Alex Klimowicz, Nizar J. Bahlis, Raymond Lai, Andrew Belch, Linda M. Pilarski i Tony Reiman. "High Oct-2 Protein Expression Is Associated with Decreased Overall Survival, While High Bob-1 Protein Expression Is Associated with Improved Overall Survival in Myeloma Patients." Blood 114, nr 22 (20.11.2009): 2822. http://dx.doi.org/10.1182/blood.v114.22.2822.2822.
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Abstract Abstract 2822 Poster Board II-798 Background: Oct-2 and Bob1 are B-lymphoid lineage specific transcription factors which drive the expression of genes involved in B-lymphocyte and plasma cell development and differentiation, including the immunoglobulin heavy chain (IgH) genes and many others. It is also thought that these transcription factors drive the overexpression of oncogenes involved in IgH translocations through upregulation of the IgH enhancers. We sought to evaluate the expression of Oct-2 and Bob1 in multiple myeloma, a malignancy of the B cell/plasmacyte lineage, in order to determine their potential biological significance as determinants of disease behaviour/prognosis and as potential therapeutic targets. Methods: A tissue microarray containing triplicate samples from 220 myeloma patient samples was generated. Samples were collected at the time of diagnosis between 1993 and 2008. To measure Oct-2 and Bob-1 protein expression in the CD138+ plasma cells of each sample, fluorescent immunohistochemistry was used to stain the samples and the HistoRx PM-2000 platformTM was used to generate an AQUA score for each patient. Oct-2 AQUA scores were available for 169 patient samples and Bob-1 AQUA scores were available for 169 patient samples. The analysis was repeated using conventional immunohistochemistry and visual scoring of staining intensity. Results: The Oct-2 and Bob-1 AQUA scores were continuously distributed over the patient cohort; thus, subsequent analyses were done by dividing the patient cohort by the median Oct-2 or Bob-1 AQUA score and comparing the group with high AQUA scores to the group with low AQUA scores. The patient group with high Oct-2 AQUA scores had an OS of 52.8 months compared to 73.1 months in the group with low Oct-2 AQUA scores (hazard ratio [HR]=1.74, 95% confidence interval [CI]=1.11-2.73, p=0.0164). The patient group with high Bob-1 AQUA scores had an OS of 70.5 months compared with 38.3 months in the group with low Bob-1 AQUA scores (HR=0.46, 95% CI=0.29-0.71, p=0.0008). In a Cox regression proportional hazards model including autologous stem cell transplant (ASCT) status, serum albumin, serum β2-microglobulin and Oct-2 or Bob-1 AQUA scores, only ASCT status was independently predictive of OS. The patient group with low Oct-2 AQUA scores had a significantly higher proportion of ASCT recipients than the group with high Oct-2 AQUA scores. Conversely, the patient group with high Bob-1 AQUA scores had a significantly higher proportion of ASCT recipients than the group with low Bob-1 AQUA scores. Results were similar but not statistically significant when analyzing the TMA with conventional immunohistochemistry and visual scoring of staining intensity. Discussion: In this retrospective study high Oct-2 expression was found to be associated with decreased OS, while high Bob-1 protein expression was associated with increased OS. These results suggest that Oct-2 is a negative prognostic factor in myeloma, while Bob-1 is a favorable prognostic factor, and demonstrates the applicability of the HistoRx platform to myeloma bone marrow TMA analysis. Since this was a small, exploratory study these results must be interpreted with caution and must be confirmed in a larger, prospective analysis. Disclosures: No relevant conflicts of interest to declare.
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Sun, Huadong, Xu Zhang, Xiaowei Han, Xuesong Jin i Zhijie Zhao. "Commodity Image Classification Based on Improved Bag-of-Visual-Words Model". Complexity 2021 (17.03.2021): 1–10. http://dx.doi.org/10.1155/2021/5556899.
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With the increasing scale of e-commerce, the complexity of image content makes commodity image classification face great challenges. Image feature extraction often determines the quality of the final classification results. At present, the image feature extraction part mainly includes the underlying visual feature and the intermediate semantic feature. The intermediate semantics of the image acts as a bridge between the underlying features and the advanced semantics of the image, which can make up for the semantic gap to a certain extent and has strong robustness. As a typical intermediate semantic representation method, the bag-of-visual-words (BoVW) model has received extensive attention in image classification. However, the traditional BoVW model loses the location information of local features, and its local feature descriptors mainly focus on the texture shape information of local regions but lack the expression of color information. Therefore, in this paper, the improved bag-of-visual-words model is presented, which contains three aspects of improvement: (1) multiscale local region extraction; (2) local feature description by speeded up robust features (SURF) and color vector angle histogram (CVAH); and (3) diagonal concentric rectangular pattern. Experimental results show that the three aspects of improvement to the BoVW model are complementary, while compared with the traditional BoVW and the BoVW adopting SURF + SPM, the classification accuracy of the improved BoVW is increased by 3.60% and 2.33%, respectively.
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Kotova, Galina, Mikhail Verigin, Tamash Gomboshi i Konstantin Kabin. "ANALYTICAL MODEL OF THE PLANETARY BOW SHOCK FOR VARIOUS MAGNETIC FIELD DIRECTIONS BASED ON MHD CALCULATIONS". Solar-Terrestrial Physics 6, nr 4 (22.12.2020): 44–49. http://dx.doi.org/10.12737/stp-64202007.
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Study of physical processes in plasma near planets often requires knowledge of the position and shape of the planetary bow shock. Empirical models are usually used since theoretical MHD and kinetic models consume too much computer time and cannot be used to track fast processes. M.I. Verigin proposed a semi-empirical approach based on the use of exact theoretical expressions with a small number of parameters, which have a clear physical meaning. These parameters are estimated by fitting experimental data or detailed MHD calculations. A model of the bow shock near an arbitrary-shaped obstacle has previously been developed for a gas-dynamic flow. This model can be applied to any sonic Mach numbers and large values of the Alfven Mach number. In addition, the asymptotic Mach cone — the angle of inclination of the shock wave at an infinite distance from the planet — has been calculated analytically in the MHD approximation. In this paper, we propose a model of the bow shock for any direction of the magnetic field with respect to the upcoming flow and for any Mach numbers. Parameters of the model are the distance of the nose point from the obstacle, radius of curvature and bluntness of the bow shock at the nose point, a parameter related to the transition to the asymptotic downstream slope of the shock, and a skewing angle appearing when the interplanetary magnetic field is directed at an angle to the solar wind velocity.
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N. Sultani, Zainab, i Ban N. Dhannoon. "Modified Bag of Visual Words Model for Image Classification". Al-Nahrain Journal of Science 24, nr 2 (1.06.2021): 78–86. http://dx.doi.org/10.22401/anjs.24.2.11.
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Image classification is acknowledged as one of the most critical and challenging tasks in computer vision. The bag of visual words (BoVW) model has proven to be very efficient for image classification tasks since it can effectively represent distinctive image features in vector space. In this paper, BoVW using Scale-Invariant Feature Transform (SIFT) and Oriented Fast and Rotated BRIEF(ORB) descriptors are adapted for image classification. We propose a novel image classification system using image local feature information obtained from both SIFT and ORB local feature descriptors. As a result, the constructed SO-BoVW model presents highly discriminative features, enhancing the classification performance. Experiments on Caltech-101 and flowers dataset prove the effectiveness of the proposed method.
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Tőkés, László. "Hatvanhat éves a Solow-Swan modell = The Solow-Swan model just turned 66". Köz-gazdaság 17, nr 2 (2.08.2022): 149–80. http://dx.doi.org/10.14267/retp2022.02.08.
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„Pontosan a növekedéselmélet az, amelyről beszélni akarok: önmagáért, az eredményeiért, a lyukakért, amelyeket még be kell tömni … .” – mondta Robert M. Solow 1987-ben, Nobel-díjas előadása elején, és ez a motivációja ennek a tanulmánynak is. A modern növekedéselmélet úttörőinek tekinthető Bob Solow és Trevor Swan alapvető tanulmányai 66 évvel ezelőtt, 1956-ban jelentek meg. A növekedési irodalom azóta elképesztően bővült. Ez az inkább tájékoztató, mint tudományos jellegű írás rövid áttekintést ad a főbb kutatási területekről, az empirikus eredményekre összpontosítva. = “Growth theory is exactly what I want to talk about: for itself, for its achievements, for the gaps that remain to be filled […]” – said Robert M. Solow in 1987, at the beginning of his Nobel Prize Lecture, and this is also the motivation of this paper. The seminal papers of Bob Solow and Trevor Swan, who can be considered the pioneers of modern growth theory, were published 66 years ago, in 1956. The growth literature has been expanding astonishingly since then. This more informative than scientific paper gives a brief survey of the main research areas, focusing on empirical results.
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Haroon, Muhammad, Junaid Baber, Ihsan Ullah, Sher Muhammad Daudpota, Maheen Bakhtyar i Varsha Devi. "Video Scene Detection Using Compact Bag of Visual Word Models". Advances in Multimedia 2018 (8.11.2018): 1–9. http://dx.doi.org/10.1155/2018/2564963.
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Video segmentation into shots is the first step for video indexing and searching. Videos shots are mostly very small in duration and do not give meaningful insight of the visual contents. However, grouping of shots based on similar visual contents gives a better understanding of the video scene; grouping of similar shots is known as scene boundary detection or video segmentation into scenes. In this paper, we propose a model for video segmentation into visual scenes using bag of visual word (BoVW) model. Initially, the video is divided into the shots which are later represented by a set of key frames. Key frames are further represented by BoVW feature vectors which are quite short and compact compared to classical BoVW model implementations. Two variations of BoVW model are used: (1) classical BoVW model and (2) Vector of Linearly Aggregated Descriptors (VLAD) which is an extension of classical BoVW model. The similarity of the shots is computed by the distances between their key frames feature vectors within the sliding window of length L, rather comparing each shot with very long lists of shots which has been previously practiced, and the value of L is 4. Experiments on cinematic and drama videos show the effectiveness of our proposed framework. The BoVW is 25000-dimensional vector and VLAD is only 2048-dimensional vector in the proposed model. The BoVW achieves 0.90 segmentation accuracy, whereas VLAD achieves 0.83.
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Xu, Wang Ming, Hang Yang, Kang Ling Fang i Xin Hai Liu. "A Generalized BoVW Model for Content-Based Image Retrieval". Applied Mechanics and Materials 496-500 (styczeń 2014): 1817–20. http://dx.doi.org/10.4028/www.scientific.net/amm.496-500.1817.
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BoVW (Bag of Visual Words) Model has attracted much attention for many computer vision applications in which an image is represented by a histogram of visual words. Two of its critical steps are to construct a visual dictionary and to quantize each local feature to its nearest visual word in the dictionary. In this paper, we present the framework of a generalized BoVW (GBoVW) Model in which feature quantization can be replaced by sparse coding based feature encoding. We also propose to use spectral clustering to construct a visual dictionary to overcome the shortcomings of K-Means based clustering algorithms. Image retrieval experiments on ZuBud database indicate that GBoVW Model improves BoVW Model and the visual dictionary generated by spectral clustering achieves better performance than that by K-Means based clustering methods.
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Gustafsson, M., T. Ravkilde, L. E. Kristensen, S. Cabrit, D. Field i G. Pineau des Forêts. "3D model of bow shocks". Astronomy and Astrophysics 513 (kwiecień 2010): A5. http://dx.doi.org/10.1051/0004-6361/200912977.
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Soleti, Raffaella, Marine Coué, Charlotte Trenteseaux, Gregory Hilairet, Lionel Fizanne, Fatima Kasbi-Chadli, Patricia Mallegol i in. "Carrot Supplementation Improves Blood Pressure and Reduces Aortic Root Lesions in an Atherosclerosis-Prone Genetic Mouse Model". Nutrients 13, nr 4 (2.04.2021): 1181. http://dx.doi.org/10.3390/nu13041181.
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Epidemiological studies have shown that carrot consumption may be associated with a lower risk of developing several metabolic dysfunctions. Our group previously determined that the Bolero (Bo) carrot variety exhibited vascular and hepatic tropism using cellular models of cardiometabolic diseases. The present study evaluated the potential metabolic and cardiovascular protective effect of Bo, grown under two conditions (standard and biotic stress conditions (BoBS)), in apolipoprotein E-knockout (ApoE−/−) mice fed with high fat diet (HFD). Effects on metabolic/hemodynamic parameters and on atherosclerotic lesions have been assessed. Both Bo and BoBS decreased plasma triglyceride and expression levels of genes implicated in hepatic de novo lipogenesis and lipid oxidation. BoBS supplementation decreased body weight gain, secretion of very-low-density lipoprotein, and increased cecal propionate content. Interestingly, Bo and BoBS supplementation improved hemodynamic parameters by decreasing systolic, diastolic, and mean blood pressure. Moreover, Bo improved cardiac output. Finally, Bo and BoBS substantially reduced the aortic root lesion area. These results showed that Bo and BoBS enriched diets corrected most of the metabolic and cardiovascular disorders in an atherosclerosis-prone genetic mouse model and may therefore represent an interesting nutritional approach for the prevention of cardiovascular diseases.
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Obreja, Dan. "Experimental model tests to improve a tanker resistance performance". Analele Universităţii "Dunărea de Jos" din Galaţi Fascicula XI Construcţii navale/ Annals of "Dunărea de Jos" of Galati Fascicle XI Shipbuilding 44 (3.12.2021): 11–14. http://dx.doi.org/10.35219/annugalshipbuilding/2021.44.02.
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The ship resistance is one of the most important hydrodynamics performances, being related to the contractual ship speed. The experimental model tests can be used to measure and improve the resistance performance. In this paper, the possibility of using the experimental techniques in order to improve a tanker model resistance is demonstrated, based on a bulbous bow modelling solution. In this context, the results obtained in the Towing Tank of the Naval Architecture Faculty of “Dunarea de Jos” University of Galati, related to a tanker model resistance with and without bulbous bow are presented. The bulbous bow form was realised based on the hydrodynamics principles adapted to the bow forms of the tanker. In the case of the bulbous bow solution, a significant reduction of over 8% of the tanker model resistance was obtained, in the design speed domain.
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Khansa, Parmila. "STRATEGI PEMASARAN USAHA BUNATY DENGAN MODEL 7C DAN PENERAPANNYA PADA BUSINESS MODEL CANVAS". Jurnal Bioindustri 3, nr 1 (20.11.2020): 487–502. http://dx.doi.org/10.31326/jbio.v3i1.709.
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This research is about marketing strategies for Bunaty's ready to drink beverage business which is derived from dragon fruit peel with strawberry popping boba innovation. Dragon fruit peels in Bunaty products contain natural antioxidants that can nourish the body. The purpose of this study is to analyze the conditions of the internal environment and external environmental conditions, identify marketing strategies with the 7C model to improve the efficiency of marketing functions and be able to deal with competitors outside, and analyze the application of the business model of the canvas in the Bunaty business. The analytical method used is IFAS and EFAS, SWOT analysis, marketing strategy of 7C model, and business model canvas. The results of this study are the results of the calculation of internal factors obtained a total score of 2.64, where this value indicates strength in the internal position that can overcome weaknesses. The results of the analysis of external factors in the matrix get a total score of 3.26, where this value shows the opportunities for external factors that can minimize threats. To face competition in the alternative business strategy market through a SWOT matrix that is incorporated into the marketing strategy of the 7C model and applied to the business model canvas by the company. Keywords: business model canvas, dragonskin, marketing 7C model, ready to drink beverages, SWOT analysis.
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Dong, Zhikui, Chenpu Zhang, Ziliang Liu, Yanheng Zhao, Ke Xing i Wenming Guo. "A Wire Bow Model of Diamond Wire Sawing with Asymmetric Arc Hypothesis". Micromachines 14, nr 5 (6.05.2023): 1004. http://dx.doi.org/10.3390/mi14051004.
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Diamond wire sawing is the main processing method for hard and brittle materials, but the unreasonable matching of process parameters will reduce its cutting ability and stability. In this paper, the asymmetric arc hypothesis of a wire bow model is proposed. Based on this hypothesis, an analytical model of the wire bow between the process parameters and the wire bow parameters was established and verified with a single-wire cutting experiment. The model considers the asymmetry of the wire bow in diamond wire sawing. The tension at both ends of the wire bow is called the endpoint tension; by calculating the difference in tension between the two ends, a reference for the cutting stability and a tension range for the selection of the diamond wire were provided. The model was used to calculate the wire bow deflection and the cutting force, providing theoretical guidance for the matching of process parameters. Based on the theoretical analysis of the cutting force, endpoint tension and wire bow deflection, the cutting ability, cutting stability, and the risk of wire cutting were predicted.
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Stern, F., J. Longo, Z. J. Zhang i A. K. Subramani. "Detailed Bow-Flow Data and CFD for a Series 60 CB = 0.6 Ship Model for Froude Number 0.316". Journal of Ship Research 40, nr 03 (1.09.1996): 193–99. http://dx.doi.org/10.5957/jsr.1996.40.3.193.
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The bow flow of the Series 60 CB = 0.6 ship model is reinvestigated using both experiments and computational fluid dynamics (CFD). More detailed bow-flow data are obtained by taking measurements of the wave elevation with a point gauge very near the bow. In the CFD, the bow flow is resolved in more detail by using the real bow geometry instead of the simplified vertical zero-thickness bow used in previous studies, which requires a much finer grid in the bow region. The experiments and CFD are briefly described; results are presented; and discussions are made concerning comparisons of the new and old CFD solutions with the extended data regarding the wave profile and elevation at the bow, the thin film and beads (i.e. attached spray sheet and bow vortices), and the stagnation effects.
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梁, 景盛. "Traffic Accident Analysis Based on Bow-Tie Model". Modeling and Simulation 11, nr 04 (2022): 1151–60. http://dx.doi.org/10.12677/mos.2022.114105.
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Xu, Qingwei, Kaili Xu, Li Li i Xiwen Yao. "Safety assessment of petrochemical enterprise using the cloud model, PHA–LOPA and the bow-tie model". Royal Society Open Science 5, nr 7 (lipiec 2018): 180212. http://dx.doi.org/10.1098/rsos.180212.
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Safe production is the foundation of the normal operations of petrochemical enterprises, and it helps maintain social stability. The main purpose of this study is to prevent petrochemical enterprise accidents by proposing a composite safety assessment approach based on the cloud model, preliminary hazard analysis–layer of protection analysis (PHA–LOPA) and the bow-tie model. First, the petrochemical enterprise and its relevant indicators were evaluated based on the cloud model. Second, the quantitative effect of the uncertainty transformation on the evaluation result of the cloud model was further analysed. This mainly includes the error analysis of the numerical characteristics under the conditions of few samples and small values. Third, the critical indicators such as shock and noise can be weakened and prevented by corresponding safety measures based on PHA–LOPA and the bow-tie model. After adopting two independent protection layers, the risk levels of shock and noise decrease from 3 to 2. Then, shock and noise were analysed in depth with the bow-tie model, and the causes and consequences were identified. Moreover, corresponding safety measures were taken to prevent accidents. The case study validated the validity and feasibility of the composite safety assessment approach proposed here.
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Turc, L., D. Fontaine, P. Savoini i E. K. J. Kilpua. "A model of the magnetosheath magnetic field during magnetic clouds". Annales Geophysicae 32, nr 2 (21.02.2014): 157–73. http://dx.doi.org/10.5194/angeo-32-157-2014.
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Abstract. Magnetic clouds (MCs) are huge interplanetary structures which originate from the Sun and have a paramount importance in driving magnetospheric storms. Before reaching the magnetosphere, MCs interact with the Earth's bow shock. This may alter their structure and therefore modify their expected geoeffectivity. We develop a simple 3-D model of the magnetosheath adapted to MCs conditions. This model is the first to describe the interaction of MCs with the bow shock and their propagation inside the magnetosheath. We find that when the MC encounters the Earth centrally and with its axis perpendicular to the Sun–Earth line, the MC's magnetic structure remains mostly unchanged from the solar wind to the magnetosheath. In this case, the entire dayside magnetosheath is located downstream of a quasi-perpendicular bow shock. When the MC is encountered far from its centre, or when its axis has a large tilt towards the ecliptic plane, the MC's structure downstream of the bow shock differs significantly from that upstream. Moreover, the MC's structure also differs from one region of the magnetosheath to another and these differences vary with time and space as the MC passes by. In these cases, the bow shock configuration is mainly quasi-parallel. Strong magnetic field asymmetries arise in the magnetosheath; the sign of the magnetic field north–south component may change from the solar wind to some parts of the magnetosheath. We stress the importance of the Bx component. We estimate the regions where the magnetosheath and magnetospheric magnetic fields are anti-parallel at the magnetopause (i.e. favourable to reconnection). We find that the location of anti-parallel fields varies with time as the MCs move past Earth's environment, and that they may be situated near the subsolar region even for an initially northward magnetic field upstream of the bow shock. Our results point out the major role played by the bow shock configuration in modifying or keeping the structure of the MCs unchanged. Note that this model is not restricted to MCs, it can be used to describe the magnetosheath magnetic field under an arbitrary slowly varying interplanetary magnetic field.
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Qin, Lifeng. "Category Related BoW Model for Image Classification". Journal of Information and Computational Science 12, nr 9 (10.06.2015): 3547–54. http://dx.doi.org/10.12733/jics20106109.
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Ulutas, Guzin, Beste Ustubioglu, Mustafa Ulutas i Vasif V. Nabiyev. "Frame duplication detection based on BoW model". Multimedia Systems 24, nr 5 (15.12.2017): 549–67. http://dx.doi.org/10.1007/s00530-017-0581-6.
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Li, Zhen Wei, Jing Zhang, Xin Liu i Li Zhuo. "Creating the Bag-of-Words with Spatial Context Information for Image Retrieval". Applied Mechanics and Materials 556-562 (maj 2014): 4788–91. http://dx.doi.org/10.4028/www.scientific.net/amm.556-562.4788.
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Recently bag-of-words (BoW) model as image feature has been widely used in content-based image retrieval. Most of existing approaches of creating BoW ignore the spatial context information. In order to better describe the image content, the BoW with spatial context information is created in this paper. Firstly, image’s regions of interest are detected and the focus of attention shift is produced through visual attention model. The color and SIFT features are extracted from the region of interest and BoW is created through cluster analysis method. Secondly, the spatial context information among objects in an image is generated by using the spatial coding method based on the focus of attention shift. Then the image is represented as the model of BoW with spatial context. Finally, the model of spatial context BoW is applied into image retrieval to evaluate the performance of the proposed method. Experimental results show the proposed method can effectively improve the accuracy of the image retrieval.
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Liang, Yulong. "Research on the Shape Optimization of Three-Dimensional Bow". Highlights in Science, Engineering and Technology 37 (18.03.2023): 318–23. http://dx.doi.org/10.54097/hset.v37i.6087.
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Boat is mainly composed of hull, ship frame, deck, cabin and ship deck building. When people are designing the boat, one key consideration is the shape of the bow in order to decrease the resistance and fuel-consumption. In this paper, theoretical analysis of resistance to bow and the optimization aimed for lower resistance were produced by using COMSOL Multiphysics 6.0. Firstly, a simple and ordinary model of bow is presented. Then, the mathematical and physical model are established by COMSOL. Afterwards, after I exam whether the computational model is effective enough for the further optimization, the calculating results are worked out and I compare them with the common bow’s experimental data, with the purpose of the optimization, the lower resistance, in different conditions such as different ship speed and draft. The polynomial expression of several important section is used to construct the basic outline of the three-dimensional bow with different width, bow length, angle of bow top and the possible maximum and its position. Then, I choose the bow length, angle of bow top and the possible maximum and its position as the optimization parameter. Finally, I reach the conclusion of a better-performing bow design for newer high-speed boat requirements and future studies are discussed.
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DONG, RONALD R., JOSEPH KATZ i THOMAS T. HUANG. "On the structure of bow waves on a ship model". Journal of Fluid Mechanics 346 (10.09.1997): 77–115. http://dx.doi.org/10.1017/s0022112097005946.
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Particle image velocitmetry (PIV) measurements and free-surface visualizations around a ship model focus on the flow within the attached liquid sheet, upstream of the point at which the bow wave separates from the model, the origin and structure of the bow wave and the flow downstream of the wave crest. The measurements are performed at Reynolds numbers ranging between 2.8×106 and 7.4×106 and Froude numbers between 0.17 and 0.45 (both are based on ship length L). Representative velocity and vorticity distributions at FrL=0.28 and FrL=0.45 demonstrate the characteristic structure of mild and steep waves, respectively. Very close to the bow the attached sheet is thin and quite unsteady. With increasing distance from the nose the sheet becomes thicker and its development involves considerable vorticity production. In the mild case this vorticity is originated at the free surface, whereas in the steep wave case, boundary layer separation occurs on the model, which also transports vorticity into the sheet. This vorticity and its associated induced lateral flow remain near the model downstream of the bow wave. By calculating the acceleration component tangent to the free surface of the sheet it is shown that the peaks in the near-surface vorticity appear in regions with high viscous flux of vorticity from the surface. Formation of a bow wave also involves considerable production of vorticity. Similar to two-dimensional breakers, the primary origin of this vorticity is at the toe of the breaker. However, unlike the two-dimensional cases, the region containing vorticity in the ship wave does not appear as an extended shear layer. Instead, this vorticity is convected out of the plane of the laser sheet in a series of distinct vortex filaments. The ship wave also has powerful counter-rotating vorticity concentrated near the wave crest that has been observed in two-dimensional waves, but not of the same strength. Breaking becomes weaker, i.e. there is less vorticity production, with increasing distance from the model, but it persists even at the ‘tail’ of the bow wave. The sites of vorticity entrainment of both signs are consistent with the computed near-surface acceleration. Estimates of the three-dimensional velocity distribution and head losses within the wave are also provided.
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Feng, Jiangfan, Yuanyuan Liu i Lin Wu. "Bag of Visual Words Model with Deep Spatial Features for Geographical Scene Classification". Computational Intelligence and Neuroscience 2017 (2017): 1–14. http://dx.doi.org/10.1155/2017/5169675.
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With the popular use of geotagging images, more and more research efforts have been placed on geographical scene classification. In geographical scene classification, valid spatial feature selection can significantly boost the final performance. Bag of visual words (BoVW) can do well in selecting feature in geographical scene classification; nevertheless, it works effectively only if the provided feature extractor is well-matched. In this paper, we use convolutional neural networks (CNNs) for optimizing proposed feature extractor, so that it can learn more suitable visual vocabularies from the geotagging images. Our approach achieves better performance than BoVW as a tool for geographical scene classification, respectively, in three datasets which contain a variety of scene categories.
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Shabani, Babak, Jason Lavroff, Damien S. Holloway, Michael R. Davis i Giles A. Thomas. "The influence of the centre bow and wet-deck geometry on motions of wave-piercing catamarans". Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 233, nr 2 (1.02.2018): 474–87. http://dx.doi.org/10.1177/1475090217753761.
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The effects of tunnel height and centre bow length on the motions of a 112-m wave-piercer catamaran with an above-water centre bow were investigated through model tests. Five alternative centre bow configurations were considered, and multiple series of model tests were conducted in regular head sea waves. The results showed that both heave and pitch increased over a wide range of wave encounter frequency as the wet-deck height of the catamaran model increased. However, increasing the length of the centre bow showed an increase in the pitch but a decrease in the heave for a limited range of wave encounter frequency near the heave and pitch resonance frequencies of the catamaran model. The positions of minimum vertical displacement were found to be aft of the longitudinal centre of gravity, between 20% and 38% of the overall length from the transom. Increase in the wet-deck height and consequently the archway clearance between the main hulls and centre bow also resulted in an increase in the vertical displacement relative to the undisturbed water surface in the centre bow area. The results also indicated the vulnerability to wet-deck slamming for the different bow and wet-deck designs.
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Tomka, Steve A. "The Adoption of the Bow and Arrow: A Model Based on Experimental Performance Characteristics". American Antiquity 78, nr 3 (lipiec 2013): 553–69. http://dx.doi.org/10.7183/0002-7316.78.3.553.
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AbstractThe timing of the arrival of the bow and arrow in the New World and reasons for its adoption have long been discussed by archaeologists. It typically has been assumed that the bow and arrow provided mechanical and physical advantages over the atlatl and dart, particularly in long-range killing power. This experimental study examines the effectiveness of traditional bows and arrows to deliver lethal wounds to prey species of different sizes. The results suggest that the bow and arrow was effective in hunting prey species such as antelope and deer but ineffective in bringing down larger animals unless changes in hunting strategies were adopted. In contrast, the atlatl and dart would have excelled in large game hunting. It is proposed that the adoption of the bow and arrow and the abandonment of the atlatl and dart were conditioned by their distinct performance advantages and changes in the game species targeted over time.
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Stepanenko, Olga V., Denis O. Roginskii, Olesya V. Stepanenko, Irina M. Kuznetsova, Vladimir N. Uversky i Konstantin K. Turoverov. "Structure and stability of recombinant bovine odorant-binding protein: III. Peculiarities of the wild type bOBP unfolding in crowded milieu". PeerJ 4 (18.04.2016): e1642. http://dx.doi.org/10.7717/peerj.1642.
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Contrary to the majority of the members of the lipocalin family, which are stable monomers with the specific OBP fold (a β-barrel consisting of a 8-stranded anti-parallel β-sheet followed by a short α-helical segment, a ninth β-strand, and a disordered C-terminal tail) and a conserved disulfide bond, bovine odorant-binding protein (bOBP) does not have such a disulfide bond and forms a domain-swapped dimer that involves crossing the α-helical region from each monomer over the β-barrel of the other monomer. Furthermore, although natural bOBP isolated from bovine tissues exists as a stable domain-swapped dimer, recombinant bOBP has decreased dimerization potential and therefore exists as a mixture of monomeric and dimeric variants. In this article, we investigated the effect model crowding agents of similar chemical nature but different molecular mass on conformational stability of the recombinant bOBP. These experiments were conducted in order to shed light on the potential influence of model crowded environment on the unfolding-refolding equilibrium. To this end, we looked at the influence of PEG-600, PEG-4000, and PEG-12000 in concentrations of 80, 150, and 300 mg/mL on the equilibrium unfolding and refolding transitions induced in the recombinant bOBP by guanidine hydrochloride. We are showing here that the effect of crowding agents on the structure and conformational stability of the recombinant bOBP depends on the size of the crowder, with the smaller crowding agents being more effective in the stabilization of the bOBP native dimeric state against the guanidine hydrochloride denaturing action. This effect of the crowding agents is concentration dependent, with the high concentrations of the agents being more effective.
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Wei, Ping, Wenrong Yan, Shoufa Wang i Xin Yu. "Bow and Stern Control Surface’s Effectiveness and Influence on Supercavity". Journal of Sensors 2021 (3.12.2021): 1–9. http://dx.doi.org/10.1155/2021/2728928.
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The numerical model of supercavitating flow field was established based on multiphase model, cavitation model, and turbulence model. The model was employed to simulate the supercavitation flow for the supercavitating vehicle with two types of control surfaces: bow rudder and stern rudder. The influence of both control surfaces on the supercavity shape and rudder effectiveness is compared under the different rudder angles (0-12°), and the effectiveness and the influences on supercavities of bow rudder and stern rudder were explored according to the numerical research results. From the research results, the following conclusions can be drawn: (1) the bow rudders have stable rudder effectiveness and available rudder angle, and the bow rudders also have significant influence on supercavities’ shape. (2) By contrast with the bow rudder, stern rudders’ effectiveness is difficult to predict accurately, and the phenomenon of stalling will occur when stern rudders’ rudder angle exceeds 6°; however, there is almost no influence of stern rudders on supercavities. (3) The bow and stern rudders joint control mode must take the influence on supercavities’ shape and the accuracy of control force’s forecasting into account at the same time. The research is helpful to the optimizing of superhigh-speed vehicles and the design of control modes.
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He, Peishan, Xiaojun Xu, Hsinchen Yu, Xing Wang, Ming Wang, Qing Chang, Zilu Zhou, Lei Luo i Hui Li. "The Mercury’s Bow-shock Models Near Perihelion and Aphelion". Astronomical Journal 164, nr 6 (30.11.2022): 260. http://dx.doi.org/10.3847/1538-3881/ac9d89.
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Abstract When Mercury moves in its high-eccentricity orbit around the Sun, the background solar wind conditions are significantly changed. We investigated the effects of heliocentric distance and interplanetary magnetic field (IMF) orientation on the shape and location of Mercury’s bow shock. We fit empirical models to the bow shock crossings obtained from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging magnetometer observations under different conditions. Our results demonstrate that the bow shock moves antiplanetward when Mercury moves from perihelion to aphelion. However, this difference is not as significant as that of magnetopause due to the thickness variation of the magnetosheath. The IMF orientations show a weak influence on the bow shock shape and location, which implies that the southward magnetic field component is not the determinant factor that drives reconnection at the low-β magnetopause of Mercury.
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Cabrit, Sylvie, Alex Raga i Frederic Gueth. "Models of Bipolar Molecular Outflows". Symposium - International Astronomical Union 182 (1997): 163–80. http://dx.doi.org/10.1017/s0074180900061635.
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This paper reviews various hydrodynamical models proposed for explaining bipolar molecular outflows from young stars. The different possibilities discussed are : wind-driven molecular shells, steady state filled flows, and jet-driven bow shocks. Particular emphasis is placed on comparisons between model predictions and observations of molecular flows. While it appears that jet-driven bow shocks are at the present time the most popular mechanism for explaining molecular outflows, other models have interesting characteristics that might be relevant for at least some objects.
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YOSHIMURA, Yasuo. "Simple Prediction Model of Bow Squat in Shallow Water". Journal of Japan Institute of Navigation 121 (2009): 185–90. http://dx.doi.org/10.9749/jin.121.185.
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Lee, Jaehoon, Dong-Min Park i Yonghwan Kim. "Experimental investigation on the added resistance of modified KVLCC2 hull forms with different bow shapes". Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 231, nr 2 (28.04.2016): 395–410. http://dx.doi.org/10.1177/1475090216643981.
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The effect of different bow shapes on the added resistance in waves was observed through a series of model tests. To this end, three different hull forms of KRISO Very Large Crude Carrier 2 were considered: an original hull form and two modified hulls with different bow shapes, called ax-bow and leadge-bow. The model tests were conducted for a wide range of wavelengths with two wave amplitudes in a regular head-sea condition at the design speed. Each test condition was imposed at least twice in order to check the repeatability of measurement, considering the uncertainties in model test and the nonlinear nature of the added resistance. This article introduces a preliminary study on the effects of surge motion, amplitude of incident wave, and green-water allowance around bow region. This article briefly includes the uncertainty analysis of recent study regarding the performance of the original hull. Based on the results of the experimental study for three different bow shapes, the parameters which influence the added resistance and motion responses are discussed.
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Dai, Jie Tao, i Qing Dong Zhang. "Mechanism of Cross Bow in Single-Roll Transmission Temper Mill". Advanced Materials Research 145 (październik 2010): 216–22. http://dx.doi.org/10.4028/www.scientific.net/amr.145.216.
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In a 1220mm temper mill, the cross bow was serious, which seriously affected the unit’s output and efficiency. In order to solve this problem, the mechanism of cross bow is studied in rolling of single-roll transmission temper mill. First, established the FEM of the single-roll drive temper mill rolling, analyzed the distribution factors of vertical extension in thickness. Second, used the method of symplectic elasticity to establish the analytical calculation model to study the relationship between the cross bow with the uneven vertical extension, explained the mechanism of cross bow. Then, used ANSYS to establish finite element model which further analyzed the cross bow under different distribution of extension in width direction. On the basis of analyzed the mechanism, proposed measures to reduce the value of cross bow. These measures have been applied in production; the effect of application was obvious.
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Wang, Qiang, Pengyao Yu, Boran Zhang i Guangzhao Li. "Experimental Study and Numerical Simulation of the Water Entry of a Ship-Like Symmetry Section with an Obvious Bulbous Bow". Polish Maritime Research 28, nr 3 (1.09.2021): 16–34. http://dx.doi.org/10.2478/pomr-2021-0031.
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Abstract A bulbous bow is a typical ship structure. Due to the influence of the bulbous bow, complex flow separation and gas capture phenomena may appear during the water entry of ship-like sections. In this paper, experimental and numerical studies on the water entry of a ship-like section with an obvious bulbous bow are carried out. Two thin plates are installed at both ends of the test model to ensure that the flow field during the impact process is approximately two-dimensional. The free-fall drop test is carried out in the test rig equipped with guide rails. By changing drop heights, impact pressure on the model surface with different initial impact velocities is measured. A numerical model for simulating the water entry of the ship-like section is established by using the Computational Fluid Dynamics (CFD) method, based on the Navier-Stokes equations. Reasonable time steps and mesh size are determined by convergence analysis. Four different flow models are used in the numerical analysis. It is found that the K-Epsilon turbulence model can present the most reasonable numerical prediction by comparing numerical results with the experimental data. Furthermore, the influence of the bulbous bow on the impact loads is numerically studied by using the validated numerical model. It suggests that the bulbous bow has little effect on the impact force acting on the bow-flared area but, in the position near the bulbous bow, the pressure will be affected by the second slamming and the air cushion.
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Bash, Eleanor A., i Shawn J. Marshall. "Estimation of glacial melt contributions to the Bow River, Alberta, Canada, using a radiation-temperature melt model". Annals of Glaciology 55, nr 66 (2014): 138–52. http://dx.doi.org/10.3189/2014aog66a226.
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AbstractAlberta’s Bow River has its headwaters in the glaciated eastern slopes of the Canadian Rockies and is a major source of water in southern Alberta. Glacial retreat, declining snowpacks and increased water demand are all expected in the coming century, yet there are relatively few studies focusing on quantifying glacial meltwater in the Bow River. We develop a new radiation-temperature melt model for modelling distributed glacier mass balance and runoff in the Bow River basin. The model reflects physical processes through the incorporation of near-surface air temperature and absorbed radiation, while avoiding problems of collinearity through the use of a radiation-decorrelated temperature index. The model is calibrated at Haig Glacier in the southern portion of the basin and validated at Haig and Peyto Glaciers. Application of the model to the entire Bow River basin for 2000-09 shows glacier ice melt is equivalent to 3% of annual discharge in Calgary on average. Modelled ice melt in August is equal to 8-20% of the August Bow River discharge in Calgary. This emphasizes the importance of glacier runoff to late-summer streamflow in the region, particularly in warm, dry years.
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ZHOU Yue, LÜ Jianyong, WANG Ming i YUAN Huanzhi. "Comparative Study of Bow Shock Models". Chinese Journal of Space Science 40, nr 6 (2020): 990. http://dx.doi.org/10.11728/cjss2020.06.990.
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Ustyuzhanin, Anton, Karl-Heinz Dammer, Antje Giebel, Cornelia Weltzien i Michael Schirrmann. "Discrimination of Common Ragweed (Ambrosia artemisiifolia) and Mugwort (Artemisia vulgaris) Based on Bag of Visual Words Model". Weed Technology 31, nr 2 (marzec 2017): 310–19. http://dx.doi.org/10.1614/wt-d-16-00068.1.
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Common ragweed is a plant species causing allergic and asthmatic symptoms in humans. To control its propagation, an early identification system is needed. However, due to its similar appearance with mugwort, proper differentiation between these two weed species is important. Therefore, we propose a method to discriminate common ragweed and mugwort leaves based on digital images using bag of visual words (BoVW). BoVW is an object-based image classification that has gained acceptance in many areas of science. We compared speeded-up robust features (SURF) and grid sampling for keypoint selection. The image vocabulary was built using K-means clustering. The image classifier was trained using support vector machines. To check the robustness of the classifier, specific model runs were conducted with and without damaged leaves in the trainings dataset. The results showed that the BoVW model allows the discrimination between common ragweed and mugwort leaves with high accuracy. Based on SURF keypoints with 50% of 788 images in total as training data, we achieved a 100% correct recognition of the two plant species. The grid sampling resulted in slightly less recognition accuracy (98 to 99%). In addition, the classification based on SURF was up to 31 times faster.
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Zhou, Yaming, Bin Meng, Nan Wang, Shoujing Yin, Aiping Feng, Huan Zhao, Li Zhu i Rong Zhang. "Study of Identification and Classification Models of Urban Black and Odorous Water Based on Field Measurements of Spectral Data". Water 14, nr 8 (13.04.2022): 1254. http://dx.doi.org/10.3390/w14081254.
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Urban Black and Odorous Water (BOW) has become an environmental problem in many cities in China. The use of satellite remote sensing technology to identify BOW is still in its infancy, and there are many problems that need further solutions. In order to monitor BOW by satellite, between 2016 and 2017, the reflectance of remote sensing and some other parameters of 173 samples were collected from multiple field water experiments first. The samples were located at the major BOW in the urban areas of four Chinese cities, and the differences in remote sensing reflectance of severe BOW (SBOW), moderate BOW (MBOW), and general water (GW) were analyzed. Based on field measurements of spectral data, six remote sensing classification or identification models of BOW were compared in terms of their correct identification rate and reliability. The results show that compared with the GW in the study area, the urban BOW has the lowest reflectance. The peaks and valleys were not obvious in the visible band, especially the remote sensing reflectance of heavy BOW, which fluctuated very little in the visible band. Compared with the other five models, the H Index model had the best identification correctness and reliability.
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Bennett, L., M. G. Kivelson, K. K. Khurana, L. A. Frank i W. R. Paterson. "A model of the Earth's distant bow shock". Journal of Geophysical Research: Space Physics 102, A12 (1.12.1997): 26927–41. http://dx.doi.org/10.1029/97ja01906.
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Markowski, Adam S., i Agata Kotynia. "“Bow-tie” model in layer of protection analysis". Process Safety and Environmental Protection 89, nr 4 (lipiec 2011): 205–13. http://dx.doi.org/10.1016/j.psep.2011.04.005.
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Sawade, Caleb, Stephen Turnock, Alexander Forrester i Martin Toward. "Assessment of an Empirical Bob-skeleton Steering Model". Procedia Engineering 72 (2014): 447–52. http://dx.doi.org/10.1016/j.proeng.2014.06.078.
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Freitas, A., i R. S. Nishizaki. "Model Test of an Ice Class Bulk Carrier With the Thyssen/Waas Bow Form". Journal of Energy Resources Technology 108, nr 2 (1.06.1986): 168–72. http://dx.doi.org/10.1115/1.3231257.
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Alternative bow forms have been investigated for the “M. V. Arctic” in a test program sponsored by the German Ministry for Research and Technology and the Transportation Development Centre of Transport Canada. The “M. V. Arctic” is a Canadian Arctic Class 2 bulk carrier of 28000 dwt which operates between the Northwest Territories and Europe during the summer and fall months. The tests were conducted at the Hamburg Ship Model Basin using a 1/30th scale model fitted with three different forebody forms. These included the Thyssen/Waas design, a new design by Melville Shipping Ltd., Calgary, and the existing bow form. The tests were performed in ice, still water and irregular seaway. The Thyssen/Waas icebreaker system includes a novel bow form and employs an unconventional icebreaking technique. The system has been successfully tested in model and demonstrated in full scale with the modified icebreaker “Max Waldeck”. The Melville design uses a conventional form incorporating the latest technology. This paper describes the model tests and discusses the relative performance as indicated by the test results. The investigation has shown the potential for the use of the Thyssen/Waas bow form on icebreaking cargoships such as the “M.V. Arctic”.
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Simanjuntak, Frans, Samuel Samuel, Parlindungan Manik, Eko Sasmito Hadi i Willma Amiruddin. "Analisis Pengaruh Pengunaan Ulstein X-Bow pada Kapal Perintis Type 750 DWT Terhadap Nilai Hambatan dengan Metode Computational Fluid Dynamics". Jurnal Rekayasa Hijau 5, nr 3 (14.03.2022): 248–66. http://dx.doi.org/10.26760/jrh.v5i3.248-266.
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ABSTRAKHambatan merupakan aspek penting yang perlu diperhatikan dalam mendesain sebuah kapal. Salah satu upaya untuk mengurangi hambatan adalah memodifikasi bentuk haluan kapal dengan menggunakan Ulstein X-Bow. Penelitian ini bertujuan untuk mengetahui efektifitas penggunaan Ulstein X-Bow serta mencari nilai hambatan, trim dan sinkage terkecil dengan menggunakan metode CFD (Computational Fluid Dynamics) dengan teknik overset mesh. Penerapan variasi Froude Number, Stem Angle, Flare Bow, serta kondisi perairan (deep water dan medium shallow water) dilakukan untuk mendapatkan bentuk desain yang paling optimal. Hasil penelitian ini menunjukan bahwa Kapal Perintis 750 DWT dengan penggunaan Ulstein X-Bow pada kondisi perairan dalam (deep water) h/t = 19.3, dapat mengurangai nilai hambatan sebesar 4.85%, trim sebesar 2.32% dan sinkage sebesar 0.40% yang terdapat pada Model 4 dibandingkan dengan Model 1 pada Froude Number (Fn = 0.24), sedangkan pada kondisi perairan medium (medium shallow water) h/t = 4.0, nilai hambatan, trim dan sinkage terkecil terjadi pada Kapal Perintis 750 DWT tanpa penggunaan Ulstein X-Bow pada Froude Number (Fn = 0.24).Kata kunci: Hambatan, Ulstein X-Bow, Kapal Perintis 750 DWT, Computational Fluid Dynamics ABSTRACTResistance is an important aspect that needs to be considered when designing a ship. One of the ways to reduce the resistance value is to modify the shape of the ship's bow using the Ulstein X-Bow. The main objective of this research is to find out the Effectiveness of using Ulstein X-Bow and to find the smallest resistance, trim and sinkage values using the CFD (Computational Fluid Dynamics) method with mesh overset techniques. The application of variations in Froude Number, Stem Angle, Flare Bow, and water conditions (deep water and medium shallow water) is done to get the most optimal design shape.The results of this study showed that in deep water conditions (h/t = 19.3), Perintis 750 DWT using Ulstein X-Bow can reduce the resistance value by 4.85%, trim by 2.32% and sinkage by 0.40% that can be found in model 4 compared to model 1 on Froude Number (Fn = 0.24). while in medium shallow water conditions h/t = 4.0, the smallest resistance, trim and sinkage values occur on the Perintis 750 DWT ship without using Ulstein X-Bow at Froude Number (Fn = 0.24).Keywords: Resistance, Ulstein X-Bow, Perintis 750 DWT Ship, Computational Fluid Dynamic
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Yamada, Yasuhira, i Hisayoshi Endo. "Experimental and Numerical Study on the Collapse Strength of the Bulbous Bow Structure in Oblique Collision". Marine Technology and SNAME News 45, nr 01 (1.01.2008): 42–53. http://dx.doi.org/10.5957/mt1.2008.45.1.42.
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The purpose of this paper is to investigate the collapse strength and the mechanism of the bulbous bow structure in case of an oblique collision. In this study, quasi-static experiments were conducted using two types of large-scale bulbous bow models using the scenario that a ship collides with another ship at oblique angle. One of the models is a prototype buffer bow adopting a transverse stiffening system, and the other model is a standard bow adopting a longitudinal stiffening system. Each model was collapsed by a thrusting rigid board while being subject to the combined action of compressive force and bending moment. Collapse mechanism, load-displacement curve, and energy absorption capability of the buffer bow structure were investigated as compared with those of standard bow structure. Nonlinear finite element analysis (FEA) corresponding to the experiments was also conducted, and fairly good agreement was achieved between FEA and the experiments. It is also found from these investigations that the buffer bow structure is expected to be efficient in reducing the risk of an oil spill, especially in case of oblique collision.
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Chayangkoon, Narongsak, i Anongnart Srivihok. "Text classification model for methamphetamine-related tweets in Southeast Asia using dual data preprocessing techniques". International Journal of Electrical and Computer Engineering (IJECE) 11, nr 4 (1.08.2021): 3617. http://dx.doi.org/10.11591/ijece.v11i4.pp3617-3628.
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<span>Methamphetamine addiction is a prominent problem in Southeast Asia. Drug addicts often discuss illegal activities on popular social networking services. These individuals spread messages on social media as a means of both buying and selling drugs online. This paper proposes a model, the “text classification model of methamphetamine tweets in Southeast Asia” (TMTA), to identify whether a tweet from Southeast Asia is related to methamphetamine abuse. The research addresses the weakness of bag of words (BoW) by introducing BoW and Word2Vec feature selection (BWF) techniques. A domain-based feature selection method was performed using the BoW dataset and Word2Vec. The BWF dataset provided a smaller number of features than the BoW and TF–IDF dataset. We experimented with three candidate classifiers: Support vector machine (SVM), decision tree (J48) and naive bayes (NB). We found that the J48 classifier with the BWF dataset provided the best performance for the TMTA in terms of accuracy (0.815), F-measure (0.818), Kappa (0.528), Matthews correlation coefficient (0.529) and high area under the ROC Curve (0.763). Moreover, TMTA provided the lowest runtime (3.480 seconds) using the J48 with the BWF dataset.</span>
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Sclafani, Robert A., Marianne Tecklenburg i Angela Pierce. "The mcm5-bob1 Bypass of Cdc7p/Dbf4p in DNA Replication Depends on Both Cdk1-Independent and Cdk1-Dependent Steps in Saccharomyces cerevisiae". Genetics 161, nr 1 (1.05.2002): 47–57. http://dx.doi.org/10.1093/genetics/161.1.47.
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Abstract The roles in DNA replication of two distinct protein kinases, Cdc7p/Dbf4p and Cdk1p/Clb (B-type cyclin), were studied. This was accomplished through a genetic and molecular analysis of the mechanism by which the mcm5-bob1 mutation bypasses the function of the Cdc7p/Dbf4p kinase. Genetic experiments revealed that loss of either Clb5p or Clb2p cyclins suppresses the mcm5-bob1 mutation and prevents bypass. These two cyclins have distinct roles in bypass and presumably in DNA replication as overexpression of one could not complement the loss of the other. Furthermore, the ectopic expression of CLB2 in G1 phase cannot substitute for CLB5 function in bypass of Cdc7p/Dbf4p by mcm5-bob1. Molecular experiments revealed that the mcm5-bob1 mutation allows for constitutive loading of Cdc45p at early origins in arrested G1 phase cells when both kinases are inactive. A model is proposed in which the Mcm5-bob1 protein assumes a unique molecular conformation without prior action by either kinase. This conformation allows for stable binding of Cdc45p to the origin. However, DNA replication still cannot occur without the combined action of Cdk1p/Clb5p and Cdk1p/Clb2p. Thus Cdc7p and Cdk1p kinases catalyze the initiation of DNA replication at several distinct steps, of which only a subset is bypassed by the mcm5-bob1 mutation.
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Tátrallyay, M., G. Erdös, Z. Németh, M. I. Verigin i S. Vennerstrom. "Multispacecraft observations of the terrestrial bow shock and magnetopause during extreme solar wind disturbances". Annales Geophysicae 30, nr 12 (12.12.2012): 1675–92. http://dx.doi.org/10.5194/angeo-30-1675-2012.
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Abstract. Three events are discussed from the declining phase of the last solar cycle when the magnetopause and/or the bow shock were observed unusually close to the Earth due to major interplanetary disturbances. The observed extreme locations of the discontinuities are compared with the predictions of three magnetopause and four bow shock models which describe them in considerably different ways using statistical methods based on observations. A new 2-D magnetopause model is introduced (based on Verigin et al., 2009) which takes into account the pressure of the compressed magnetosheath field raised by the interplanetary magnetic field (IMF) component transverse to the solar wind flow. The observed magnetopause crossings could be predicted with a reasonable accuracy (0.1–0.2 RE) by one of the presented models at least. For geosynchronous magnetopause crossings observed by the GOES satellites, (1) the new model provided the best predictions when the IMF was extremely large having a large negative Bz component, and (2) the predictions of the model of Shue et al. (1998) agreed best with the observations when the solar wind dynamic pressure was extremely large. The magnetopause crossings close to the cusp observed by the Cluster spacecraft were best predicted by the 3-D model of Lin et al. (2010). The applied empirical bow shock models and the 3-D semi-empiric bow shock model combined with magnetohydrodynamic (MHD) solution proved to be insufficient for predicting the observed unusual bow shock locations during large interplanetary disturbances. The results of a global 3-D MHD model were in good agreement with the Cluster observations on 17 January 2005, but they did not predict the bow shock crossings on 31 October 2003.
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Burakovskiy, Pavel. "Experimental study of hydrodynamic forces acting on ship bow during wave capture". Transactions of the Krylov State Research Centre, SPECIAL ISSUE 1 (16.04.2019): 146–52. http://dx.doi.org/10.24937/2542-2324-2019-1-s-i-146-152.
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This paper studies behavior of ship in head waves, when her bow dips under water, which leads to hydrodynamic forces and moments to be assessed. This paper presents model test data obtained in the test tank on the model of ship bow (hydrodynamic loads on forecastle deck during wave capture) as well as updates the coefficient of flow around the bow. The study also shows that bulwark has negative effect upon safety in these conditions because it significantly increases hydrodynamic loads on the deck.
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Raga, A. C., K. H. Böhm i M. Mateo. "Bow shock models of Herbig-Haro objects". Symposium - International Astronomical Union 122 (1987): 185–86. http://dx.doi.org/10.1017/s0074180900156360.
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It has recently been found that models of a radiating bow shock can explain qualitatively the strange emission line profiles observed in some Herbig-Haro (H-H) objects. It is also possible to compare directly the emission line intensity maps predicted from these models with CCD images of H-H objects. Such a comparison between our models and observations of HH 46/47 is presented, showing that the condensation HH 47A may tentatively be identified with a bow shock formed at the “head” of a jet.
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Chatterjee, Shami, i James M. Cordes. "Bow Shocks from Radio Pulsars: Observations of the Guitar Nebula". International Astronomical Union Colloquium 177 (2000): 517–18. http://dx.doi.org/10.1017/s0252921100060474.
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AbstractWe present optical observations and radio non-detections of the bow shock nebula associated with the pulsar B2224+65 (the “Guitar Nebula”), and fit an analytic model to the observed bow shock to estimate its inclination and constrain other parameters (distance, pulsar velocity, ISM density). We also test scaling laws for bow shock parameters.
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Ngoc, Vo Truong Nhu, Agwu Chinedu Agwu, Le Hoang Son, Tran Manh Tuan, Cu Nguyen Giap, Mai Thi Giang Thanh, Hoang Bao Duy i Tran Thi Ngan. "The Combination of Adaptive Convolutional Neural Network and Bag of Visual Words in Automatic Diagnosis of Third Molar Complications on Dental X-Ray Images". Diagnostics 10, nr 4 (9.04.2020): 209. http://dx.doi.org/10.3390/diagnostics10040209.
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In dental diagnosis, recognizing tooth complications quickly from radiology (e.g., X-rays) takes highly experienced medical professionals. By using object detection models and algorithms, this work is much easier and needs less experienced medical practitioners to clear their doubts while diagnosing a medical case. In this paper, we propose a dental defect recognition model by the integration of Adaptive Convolution Neural Network and Bag of Visual Word (BoVW). In this model, BoVW is used to save the features extracted from images. After that, a designed Convolutional Neural Network (CNN) model is used to make quality prediction. To evaluate the proposed model, we collected a dataset of radiography images of 447 patients in Hanoi Medical Hospital, Vietnam, with third molar complications. The results of the model suggest accuracy of 84% ± 4%. This accuracy is comparable to that of experienced dentists and radiologists.