828 research outputs found
Minimalisasi Distorsi Dari Segmentasi Citra Metode Otsu Menggunakan Fuzzy Clustering
Segmentasi citra merupakan bagian dari proses pengolahan citra yang memiliki kegunaan dalam pengambilan sebuah informasi dari citra seperti pencarian bagian mesin, pencarian manusia dan pencarian citra yang serupa. Secara umum, pendekatan segmentasi citra yang sering digunakan adalah melalui pendekatan intensitas, pendekatan warna dan pendekatan bentuk. Pada penelitian ini dilakukan peningkatan hasil segmentasi citra berupa pengurangan distorsi hasil segmentasi dengan menggunakan metode Otsu dan Fuzzy Clustering agar diperoleh citra yang lebih baik. Hasil pengujian segmentasi citra diperoleh nilai MSE yang terbaik adalah pada metode Otsu dengan nilai rata-rata MSE yaitu 2295,80 dan PSNR adalah 14,11 sedangkan untuk metode Fuzzy C Means 2313,23 dan nilai PSNR sebesar 13.70
Evidence of displacement of lanternfish larvae associated with surface water movement: Case studies from Southern Africa
The paper is based on larval distribution data from five lanternfish species outside the spawning grounds of the adult populations. Using hydrographic information collected with the larvae, the effect of surface currentson the observed patterns of distribution is discussed. In the South-East Atlantic, adjacent to the Benguela upwelling system, larvae of the pseudoceanic Lampanyctodes hectoris were found farther offshore (250 – 450 km) than usual. The general flow of the current is parallel to the coast, but upwelling filaments extend offshore. The size distributions of the L. hectoris larvae found, together with the rather low temperature at two of the oceanic stations sampled, indicate that they had been displaced by a filament. In the South-West Indian Ocean, the distribution of larvae of highly oceanic species of lanternfish over the shelf is related to onshore intrusions of the Agulhas Current. The size distributions of Hygophum hygomii and Scopelopsis multipunctatus indicate southward transport of larvae. The presence of larvae of Myctophum selenops and Benthosema pterotum, which have not been documented as adults in the region, indicates not only transport to the area, but also that spawning could be taking place closer to the area than previously reported
Circulación marina en la plataforma continental del Ebro determinada a partir de la distribución de masas de agua y los microcontaminantes orgánicos en el sedimento
XI Congreso Español de Sedimentología, celebrado del 15 al 18 de septiembre de 1986 en Barcelona.-- 7 pages, 6 figures[ES] El análisis hidrográfico de las masas de agua en la plataforma continental del Ebro y las concentraciones de diversos microcontaminantes orgánicos en los sedimentos en las proximidades del delta, permiten aportar conclusiones sobre el régimen de circulación marina. Las aguas del río son frenadas por la corriente procedente del NE, ocasionando que parte del material en suspensión sedimente en el centro de un giro anticiclónico que se forma cerca de la desembocadura. El resto del material particulado es arrastrado hacia el S y desplazado progresivamente hacia la costa[EN] The continental margin of Ebro River delta lays in the region of the general southwestwards circulation of the Northwestern Mediterranean. South of paralle141° N the continental shelf widens suddenly and causes a deflection of 90" in the direction of the isobaths. The continental slope becomes then a barrier for the progression of
the main current. The important discharge of Ebro river waters also
influences the circulation on the continental shelfPeer reviewe
Circulación marina en la plataforma continental del Ebro determinada a partir de la distribución de masas de agua y los microcontaminantes orgánicos en el sedimento
El análisis hidrográfico de las masas de agua en la plataforma continental del Ebro y las concentraciones de diversos microcontaminantes orgánicos en los sedimentos en las proximidades del delta, permiten aportar conclusiones sobre el régimen de circulación marina. Las aguas del río son frenadas por la corriente procedente del NE, ocasionando que parte del material en suspensión sedimente en el centro de un giro anticiclónico que se forma cerca de la desembocadura. El resto del material particulado es arrastrado hacia el S y desplazado progresivamentehacia la costa
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The Relationship between Cortical Blood Flow and Sub-Cortical White-Matter Health across the Adult Age Span
Degeneration of cerebral white matter is commonly observed in aging, and the associated degradation in neural connectivity contributes to cognitive decline in older adults. Vascular dysfunction has been implicated as a potential mechanism for general age-related neural tissue deterioration; however, no prior study has examined the direct relationship between cortical vascular health and subcortical white-matter integrity. In this work, we aimed to determine whether blood supply to the brain is associated with microstructural integrity of connective tissue, and whether such associations are regionally specific and mainly accounted for by aging. We examined the association between cerebral blood flow (CBF) in the cortical mantle, measured using arterial spin labeling (ASL), and subcortical white-matter integrity, measured using diffusion tensor imaging (DTI), in a group of healthy adults spanning early to late adulthood. We found cortical CBF to be significantly associated with white-matter integrity throughout the brain. In addition, these associations were only partially tied to aging, as they remained even when statistically controlling for age, and when restricting the analyses to a young subset of the sample. Furthermore, vascular risk was not a prominent determinant of these effects. These findings suggest that the overall blood supply to the brain is an important indicator of white-matter health in the normal range of variations amongst adults, and that the decline in CBF with advancing age may potentially exacerbate deterioration of the connective anatomy of the brain
The Bone Regenerative Capacity of Canine Mesenchymal Stem Cells is Regulated by Site-Specific Multilineage Differentiation
Objectives Mesenchymal stem cells (MSCs) offer a promising therapy in dentistry because of their multipotent properties. Selecting donor MSCs is crucial because Beagle dogs (canines) commonly used in preclinical studies have shown variable outcomes, and it is unclear whether canine MSCs (cMSCs) are skeletal site specific. This study tested whether jaw and long bone cMSCs have disparate in vitro and in vivo multilineage differentiation capabilities. Study Design Primary cMSCs were isolated from the mandible (M-cMSCs) and femur (F-cMSCs) of four healthy Beagle dogs. The femur served as the non-oral control. Clonogenic and proliferative abilities were assessed. In vitro osteogenic, chondrogenic, adipogenic, and neural multilineage differentiation were correlated with in vivo bone regeneration and potential for clinical applications. Results M-cMSCs displayed two-fold increase in clonogenic and proliferative capacities relative to F-cMSCs (P = .006). M-cMSCs in vitro osteogenesis based on alkaline phosphatase (P = .04), bone sialoprotein (P = .05), and osteocalcin (P = .03), as well as adipogenesis (P = .007) and chondrogenesis (P = .009), were relatively higher and correlated with enhanced M-cMSC bone regenerative capacity. Neural expression markers, nestin and βIII-tubulin, were not significantly different. Conclusions The enhanced differentiation and bone regenerative capacity of mandible MSCs may make them favorable donor graft materials for site-specific jaw bone regeneration
Atypical Western Mediterranean deep water formation during winter 2005
The meteorological conditions in winter 2005, with anomalously low precipitation and unusual persistency of northerlies over the NW Mediterranean, caused a large extension both in time and space of deep convection processes. As a consequence, where convection typically gives rise to the Western Intermediate Waters (WIW) a New Western Mediterranean Deep Water (N-WMDW) was produced, slightly denser (+0.01kg m−3), warmer (+0.05ºC) and saltier (+0.03) than the usual WMDW. Moreover, near the continental slope, a cascading of colder and even denser water was found (-0.1ºC and +0.025 kg m−3), formed over the shelf (C-WMDW). In both cases it appears the high surface salinity as a responsible for the excess of density. The origin of this higher surface salinity is discusse
A simple model of a water column applied to the deep water formation in the Northern Catalan Sea
In this paper an attempt to reproduce the evolution of the thermal structure of water columns by a simple one-dimensional model is presented. The model is based on the heat balance between the sea and the atmosphere and it is specially sensitive to air temperature and wind speed. The model is used to study the influence of these atmospheric forcings on the deep water formation process in the Northern Catalan Sea. It is applied using meteorological and oceanographic data collected during the ALPEX Special Observation Period (SOP) and the results are compared to temperature profiles obtained during the CARON 82 cruise (MEDALPEX)Publicado
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