994 resultados para Akademik Sergey Vavilov
(Table 1) Major element oxides of basalts obtained during R/V Akademik Nikolaj Strakhov cruise ANS25
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Oxygen isotope records, radiocarbon AMS data, carbonate and opal stratigraphy, sediment magnetic susceptibility, tephrachronology, and paleontological results were used to obtain detailed sediment stratigraphy and an age model for the studied cores. For studying sea-ice sedimentation an analysis of lithogenic grain number in >0.15 mm grain size fraction of bottom sediments was carried out. For quantitative estimation of intensity ice-rafting debris sedimentation number of IRD particles per sq cm per ka was calculated. Obtained results allowed to plot IRD AR distribution for the first oxygen isotope stage (0-12.5 14C ka, 14C) and for the second stage (12.5-24 14C ka). The first stage was subdivided into the latest deglaciation and the beginning of Holocene (6-12.5 14C ka) (transitive period), when the sea level was changing significantly, and the second part of Holocene (0-6 14C ka), when climate conditions and the sea level were similar to modern estimates. Data clearly show strong increase in ice formation in the glacial Sea of Okhotsk and its extent in the middle part of the sea. Average annual duration of ice coverage during glaciation was longer than that for interglaciation. However the sea ice cover was not continuous all the year round and disappeared in summer time except the far northwestern part of the sea.
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Written in a Church Slavonic variant of the Moldavian cyrillic alphabet.
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On the base of data on benthic foraminifera and sediment biogeochemistry (contents of total organic carbon, calcium carbonate and biogenic opal) in two cores (1265 and 1312 m water depth) from the southeastern Sakhalin slope and one core (839 m water depth) from the southwestern Kamchatka slope variations of the oxygen minimum zone during the last 50 ka in the Okhotsk Sea are reconstructed. The oxygen minimum zone was less pronounced during cooling in the MIS 2 that is suggested to be caused by maximal expansion of the sea ice cover, decrease of marine productivity and increase of production of oxygenated Okhotsk Sea Intermediate Water (OSIW). Two-step-like strengthening of oxygen minimum zone during warmings in the Terminations 1a and 1b was combined with (1) enhanced oxygen consumption due to decomposition of large amount of organic matter in the water column and bottom sediments due to increased marine productivity and supply of terrigenous material from submerged northern shelves; (2) sea ice cover retreat and reduction of OSIW production; (3) freely inflow of the oxygen-depleted intermediate water mass from the North Pacific.
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Research indicates attributes and practices for mentor teachers that can be used for effective mentoring. Universities provide guidelines for preservice teacher (mentee) engagement in schools generally from anecdotal evidence, however, what are desirable attributes and practices for mentees? This qualitative study gathers data from 25 mentor teachers through extended response questionnaire and audio-recorded focus group discussions about attributes and practices for mentees. Findings showed that desirable attributes for mentees included: enthusiasm, being personable, commitment to children, lifelong learning/love of learning, open/reflective to feedback, develop resilience, and taking responsibility for their learning, while desirable practices included: planned and preparation for teaching, reflective practices, understanding school and university policies, knowing students for differentiated learning, and building a teaching repertoire (e.g. teaching strategies, behaviour management, content knowledge, and questioning skills). Preservice teachers need to consider teachers’ suggestions on desirable attributes and practices that can help them achieve positive teaching experiences.
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Purpose The LUX-Lung 3 study investigated the efficacy of chemotherapy compared with afatinib, a selective, orally bioavailable ErbB family blocker that irreversibly blocks signaling from epidermal growth factor receptor (EGFR/ErbB1), human epidermal growth factor receptor 2 (HER2/ErbB2), and ErbB4 and has wide-spectrum preclinical activity against EGFR mutations. A phase II study of afatinib in EGFR mutation-positive lung adenocarcinoma demonstrated high response rates and progression-free survival (PFS). Patients and Methods In this phase III study, eligible patients with stage IIIB/IV lung adenocarcinoma were screened for EGFR mutations. Mutation-positive patients were stratified by mutation type (exon 19 deletion, L858R, or other) and race (Asian or non-Asian) before two-to-one random assignment to 40 mg afatinib per day or up to six cycles of cisplatin plus pemetrexed chemotherapy at standard doses every 21 days. The primary end point was PFS by independent review. Secondary end points included tumor response, overall survival, adverse events, and patient-reported outcomes (PROs). Results A total of 1,269 patients were screened, and 345 were randomly assigned to treatment. Median PFS was 11.1 months for afatinib and 6.9 months for chemotherapy (hazard ratio [HR], 0.58; 95% CI, 0.43 to 0.78; P = .001). Median PFS among those with exon 19 deletions and L858R EGFR mutations (n = 308) was 13.6 months for afatinib and 6.9 months for chemotherapy (HR, 0.47; 95% CI, 0.34 to 0.65; P = .001). The most common treatmentrelated adverse events were diarrhea, rash/acne, and stomatitis for afatinib and nausea, fatigue, and decreased appetite for chemotherapy. PROs favored afatinib, with better control of cough, dyspnea, and pain. Conclusion Afatinib is associated with prolongation of PFS when compared with standard doublet chemotherapy in patients with advanced lung adenocarcinoma and EGFR mutations.
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In order to execute, study, or improve operating procedures, companies document them as business process models. Often, business process analysts capture every single exception handling or alternative task handling scenario within a model. Such a tendency results in large process specifications. The core process logic becomes hidden in numerous modeling constructs. To fulfill different tasks, companies develop several model variants of the same business process at different abstraction levels. Afterwards, maintenance of such model groups involves a lot of synchronization effort and is erroneous. We propose an abstraction technique that allows generalization of process models. Business process model abstraction assumes a detailed model of a process to be available and derives coarse-grained models from it. The task of abstraction is to tell significant model elements from insignificant ones and to reduce the latter. We propose to learn insignificant process elements from supplementary model information, e.g., task execution time or frequency of task occurrence. Finally, we discuss a mechanism for user control of the model abstraction level – an abstraction slider.
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Real world business process models may consist of hundreds of elements and have sophisticated structure. Although there are tasks where such models are valuable and appreciated, in general complexity has a negative influence on model comprehension and analysis. Thus, means for managing the complexity of process models are needed. One approach is abstraction of business process models-creation of a process model which preserves the main features of the initial elaborate process model, but leaves out insignificant details. In this paper we study the structural aspects of process model abstraction and introduce an abstraction approach based on process structure trees (PST). The developed approach assures that the abstracted process model preserves the ordering constraints of the initial model. It surpasses pattern-based process model abstraction approaches, allowing to handle graph-structured process models of arbitrary structure. We also provide an evaluation of the proposed approach.
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Companies use business process models to represent their working procedures in order to deploy services to markets, to analyze them, and to improve upon them. Competitive markets necessitate complex procedures, which lead to large process specifications with sophisticated structures. Real world process models can often incorporate hundreds of modeling constructs. While a large degree of detail complicates the comprehension of the processes, it is essential to many analysis tasks. This paper presents a technique to abstract, i.e., to simplify process models. Given a detailed model, we introduce abstraction rules which generalize process fragments in order to bring the model to a higher abstraction level. The approach is suited for the abstraction of large process specifications in order to aid model comprehension as well as decomposing problems of process model analysis. The work is based on process structure trees that have recently been introduced to the field of business process management.
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Process models provide companies efficient means for managing their business processes. Tasks where process models are employed are different by nature and require models of various abstraction levels. However, maintaining several models of one business process involves a lot of synchronization effort and is erroneous. Business process model abstraction assumes a detailed model of a process to be available and derives coarse grained models from it. The task of abstraction is to tell significant model elements from insignificant ones and to reduce the latter. In this paper we argue that process model abstraction can be driven by different abstraction criteria. Criterion choice depends on a task which abstraction facilitates. We propose an abstraction slider - a mechanism that allows user control of the model abstraction level. We discuss examples of combining the slider with different abstraction criteria and sets of process model transformation rules.
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Business processes are an important instrument for understanding and improving how companies provide goods and services to customers. Therefore, many companies have documented their business processes well, often in the Event-driven Process Chains (EPC). Unfortunately, in many cases the resulting EPCs are rather complex, so that the overall process logic is hidden in low level process details. This paper proposes abstraction mechanisms for process models that aim to reduce their complexity, while keeping the overall process structure. We assume that functions are marked with efforts and splits are marked with probabilities. This information is used to separate important process parts from less important ones. Real world process models are used to validate the approach.
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Современный этап развития комплексов автоматического управления и навигации малогабаритными БЛА многократного применения предъявляет высокие требования к автономности, точности и миниатюрности данных систем. Противоречивость требований диктует использование функционального и алгоритмического объединения нескольких разнотипных источников навигационной информации в едином вычислительном процессе на основе методов оптимальной фильтрации. Получили широкое развитие бесплатформенные инерциальные навигационные системы (БИНС) на основе комплексирования данных микромеханических датчиков инерциальной информации и датчиков параметров движения в воздушном потоке с данными спутниковых навигационных систем (СНС). Однако в современных условиях такой подход не в полной мере реализует требования к помехозащищённости, автономности и точности получаемой навигационной информации. Одновременно с этим достигли значительного прогресса навигационные системы, использующие принципы корреляционно экстремальной навигации по оптическим ориентирам и цифровым картам местности. Предлагается схема построения автономной автоматической навигационной системы (АНС) для БЛА многоразового применения на основе объединения алгоритмов БИНС, спутниковой навигационной системы и оптической навигационной системы. The modern stage of automatic control and guidance systems development for small unmanned aerial vehicles (UAV) is determined by advanced requirements for autonomy, accuracy and size of the systems. The contradictory of the requirements dictates novel functional and algorithmic tight coupling of several different onboard sensors into one computational process, which is based on methods of optimal filtering. Nowadays, data fusion of micro-electro mechanical sensors of inertial measurement units, barometric pressure sensors, and signals of global navigation satellite systems (GNSS) receivers is widely used in numerous strap down inertial navigation systems (INS). However, the systems do not fully comply with such requirements as jamming immunity, fault tolerance, autonomy, and accuracy of navigation. At the same time, the significant progress has been recently demonstrated by the navigation systems, which use the correlation extremal principle applied for optical data flow and digital maps. This article proposes a new architecture of automatic navigation management system (ANMS) for small UAV, which combines algorithms of strap down INS, satellite navigation and optical navigation system.
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We report the catalyst-free synthesis of the arrays of core–shell, ultrathin, size-uniform SiC/AlSiC nanowires on the top of a periodic anodic aluminum oxide template. The nanowires were grown using an environmentally friendly, silane-free process by exposing the silicon supported porous alumina template to CH4 + H2 plasmas. High-resolution scanning and transmission electron microscopy studies revealed that the nanowires have a single-crystalline core with a diameter of about 10 nm and a thin (1–2 nm) amorphous AlSiC shell. Because of their remarkable length, high aspect ratio, and very high surface area-to-volume ratio, these unique structures are promising for nanoelectronic and nanophotonic applications that require efficient electron emission, light scattering, etc. A mechanism for nanowire growth is proposed based upon the reduction of the alumina template to nanosized metallic aluminum droplets forming between nanopores. The subsequent incorporation of silicon and carbon atoms from the plasma leads to nucleation and growth from the top of the alumina template.