Boundary Extension Research Articles

Small stream catchments in a developing city context: The importance of land cover changes on the ecological status of streams and the possibilities for providing ecosystem services

Urban expansion and the transformation of rural areas into suburban areas along with increasing human pressure can cause major changes in the environment. Typical effects of urbanization include degradation of aquatic ecosystems. However, urban expansion is often accompanied by an effort to provide residents with some contact with nature in the city. Natural waterbodies are the elements of the environment predestined to ensure appropriate conditions for recreation and other ecosystem services key to human well-being. In this study, the changes in the forms of development of a submontane stream catchment area (Carpathians, Poland) against the background of the gradual extension of city boundaries were analysed. In addition, the impact of urbanization on the ecological conditions of the urban stream, and therefore the potential ecosystem to provide ecosystem services, was assessed. Although the extension of the city entailed the development of settlements, it was accompanied by the expansion of the municipal sewage infrastructure, thus improving sewage management. The disappearance of arable lands from the stream catchment due to the decline in agricultural activities initiated the spontaneous process of buffer restoration along the stream. All the biotic indices such as Shannon diversity index, Margalef species richness index and BMWP-PL index, based on macroinvertebrate communities increased, and the fish were more numerous in the late stage of city development compared with the early (rural) stage. Surprisingly, the system has rehabilitated well with no revitalisation actions. It is necessary, however, to improve morphological in-stream conditions, and to make further efforts to improve water quality for the system to develop a semi-natural state. Only reaching full ecological potential can lead to an increase in the ecosystem capacity to provide ecosystem services. The studied ecosystem may provide many different services simultaneously, but their availability depends on the protection of the ecosystem's functioning as a whole.

Li1.4Al0.4Ge0.4Ti1.4(PO4)3 promising NASICON-structured glass-ceramic electrolyte for all-solid-state Li-based batteries: Unravelling the effect of diboron trioxide

Li-ion batteries (LIBs) are the ubiquitous technology to power portable electronics; however, for the next-generation of high-performing electrochemical energy storage systems for electric vehicles and smart grid facilities, breakthroughs are needed, particularly in the development of solid-state electrolytes, which may allow for enhanced energy density while enabling lithium metal anodes, combined with unrivalled safety and operative reliability. In this respect, here we present the successful synthesis of a glass-ceramic Li1.4Al0.4Ge0.4Ti1.4(PO4)3 NASICON-type solid-state electrolyte (SSE) through a melt-casting technique. Being grain boundaries crucial for the total ionic conductivity of SSEs, the effect of the addition of diboron trioxide (B2O3, 0.05 wt.%) to promote their liquefaction and restructuring is investigated, along with the effects on the resulting microstructures and ionic conductivities. By the thorough combination of structural-morphological and electrochemical techniques, we demonstrate that bulk materials show improved performance compared to their powder sintered counterpart, achieving remarkable ion mobility (> 0.1 mS cm–1 at –10 °C) and anodic oxidation stability (> 4.8 V vs Li+/Li). The addition of B2O3 positively affects the grain cohesion and growth, thus reducing the extension of the grain boundaries (and the related grain/grain interface resistance) and, therefore, increasing the overall ion mobility. In addition, B2O3 is seen to contrast the microcracks formation in the LAGTP system under study which, overall, shows very promising prospects as SSE for the next-generation of high-energy density, safe lithium-based batteries.

Systematic transition from boundary extension to contraction along an object-scene continuum

After viewing a picture of a scene, our memory of it typically extends beyond what was presented—a phenomenon called boundary extension (Intraub et al, 1992). However, recent work has found evidence for boundary contraction as well (Bainbridge & Baker, 2020), proposing different outcomes for object-focused and scene-focused images. In naturalistic visual experience, there is a continuum of views that naturally transition between scene-focused and object-focused, e.g., as an observer enters an indoor environment and moves toward an object. Here, we examined how memory for a view of an environment changes along this object-scene continuum. We constructed 3D indoor environments using a virtual-reality game engine, allowing for tight control of their spatial dimensions and object content, and captured a series of images at systematic distances from a center object within each environment. We found continuous progression from boundary-extension in close-up views to boundary-contraction in distant views, with a consistent transition point across environments, and a clear relationship between the magnitude of the memory distortion and the position along the continuum. In a series of subsequent experiments, by manipulating the number of objects in the environment, we found that the memory transition point is not linked to a specific depicted distance per se, e.g., the transition between reachable and non-reachable space. Rather, the position at which boundary extension transitions to boundary contraction seems to track with the views that “looked best,” as judged by independent observers. Taken together, these results demonstrate that there is indeed a systematic link between the direction of memory distortion and the depicted scale of the space, but where object content has a clear influencing role. Further, the correspondence between the best view and the transition point suggests a common underlying mechanism, providing new empirical inroads for articulating the mechanisms of visual scene encoding.

Boundary extension and contraction are predicted by the natural statistics of images

Boundary extension and contraction are predicted by the natural statistics of images

Effects of phonological and visual-spatial working memory load on Boundary Extension.

Effects of phonological and visual-spatial working memory load on Boundary Extension.

Effect of abdominal compression on target movement and extension of the external boundary of peripheral lung tumours treated with stereotactic radiotherapy based on four-dimensional computed tomography

BackgroundThis study aimed to investigate the effect of abdominal compression on tumour motion and target volume and to determine suitable planning target volume (PTV) margins for patients treated with lung stereotactic body radiotherapy (SBRT) based on four-dimensional computed tomography (4DCT).MethodsTwenty-three patients diagnosed to have a peripheral pulmonary tumour were selected and divided into an all lesions group (group A), an upper middle lobe lesions group (group B), and a lower lobe lesions group (group C). Two 4DCT scans were performed in each patient, one with and one without abdominal compression. Cone beam computed tomography (CBCT) was performed before starting treatment. The gross target volumes (GTVs) were delineated and internal gross target volumes (IGTVs) were defined. IGTVs were generated using two methods: (1) the maximum intensity projections (MIPs) based on the 4DCT were reconstructed to form a single volume and defined as the IGTVMIP and (2) GTVs from all 10 phases were combined to form a single volume and defined as the IGTV10. A 5-mm, 4-mm, and 3-mm margin was added in all directions on the IGTVMIP and the volume was constructed as PTVMIP5mm, PTVMIP4mm, and PTVMIP3mm.ResultsThere was no significant difference in the amplitude of tumour motion in the left–right, anterior–posterior, or superior-inferior direction according to whether or not abdominal compression was applied (group A, p = 0.43, 0.27, and 0.29, respectively; group B, p = 0.46, 0.15, and 0.45; group C, p = 0.79, 0.86, and 0.37; Wilcoxon test). However, the median IGTVMIP without abdominal compression was 33.67% higher than that with compression (p = 0.00), and the median IGTV10 without compression was 16.08% higher than that with compression (p = 0.00). The median proportion of the degree of inclusion of the IGTVCBCT in PTVMIP5mm, PTVMIP4mm, and PTVMIP3mm ≥ 95% was 100%, 100%, and 83.33%, respectively.ConclusionsAbdominal compression was useful for reducing the size of the IGTVMIP and IGTV10 and for decreasing the PTV margins based on 4DCT. In IGTVMIP with abdominal compression, adding a 4-mm margin to account for respiration is feasible in SBRT based on 4DCT.

Rotating boson stars using finite differences and global Newton methods

We study rotating boson star data for numerical relativity using a 3 + 1 decomposition adapted to a curvilinear axisymmetric spacetime with regularization at the rotation axis. The Einstein–Klein–Gordon equations result in a system of six coupled, elliptic, nonlinear equations with an added unknown for the scalar field’s frequency ω. Utilizing a Cartesian two-dimensional grid, fourth-order finite differences, and global Newton methods, we generated seven data sets characterized by a rotation azimuthal integer l ∈ [0, 6]. Our numerical implementation is shown to correctly converge both with respect to the resolution size and boundary extension. Thus, global parameters such as the Komar masses and angular momenta can be precisely calculated to characterize these spacetimes. Furthermore, analyzing each family at fixed rotation integer l produces maximum masses and minimum rotation frequencies. Our results coincide with previous results in literature for l ∈ [0, 2] [as in references (Yoshida and Eriguchi 1997 Phys. Rev. D 56 6370; Lai 2004 PhD Thesis; Grandclément, et al 2014 Phys. Rev. D 90 024068; Liebling and Palenzuela 2017 Living Rev. Relativ. 20)], and are new for l > 2. In particular, the study of high-amplitude and localized scalar fields in axial symmetry is revealed to be only possible by adding the sixth regularization variable, thus reaffirming previous work on the importance of regularization in curvilinear-based numerical relativity. These results also provide the groundwork for extending this research to other self-gravitating systems, such as rotating boson stars with nonlinear self-interactions, or the case of massive vector fields.

The effect of biomass pyrolysis temperature on the performance of biochar-fed molten hydroxide direct carbon fuel cells

Biomass derived biochar is a promising fuel for direct carbon fuel cells, and the pyrolysis process to produce biochar has significant influence on the performance of said biochar-fed cells. In the present study, pine pellets were utilized as the fuel feedstock, and by using a molten hydroxide direct carbon fuel cell, the effect of the pyrolysis temperature on the fuel performance of pine biochar pellets obtained from fast pyrolysis was explored. The results revealed high pyrolysis temperature was beneficial to the fuel performance of pine biochar pellets in terms of peak power density and electrochemical impedance spectroscopy. To illustrate the observed results, a mechanism was proposed based on the physical and chemical characterizations. The proposed mechanism indicated that high pyrolysis temperature would result in high carbonization degree, amorphous microstructure, and smooth surface morphology of the pine biochar pellets, as well as high reactivity of carbon fuel in the cell operating conditions, which in turn would be conducive to the extension of triple phase boundaries and the improvement of charge transfer at/near triple phase boundaries. According to the results, the cells fed with the pine biochar pellets produced at 800 °C achieved the highest peak power density of 76.6 mW/cm2 at 400 °C.

Functional Context Affects Scene Processing.

Rapid visual perception is often viewed as a bottom-up process. Category-preferred neural regions are often characterized as automatic, default processing mechanisms for visual inputs of their categorical preference. To explore the sensitivity of such regions to top-down information, we examined three scene-preferring brain regions, the occipital place area (OPA), the parahippocampal place area (PPA), and the retrosplenial complex (RSC), and tested whether the processing of outdoor scenes is influenced by the functional contexts in which they are seen. Context was manipulated by presenting real-world landscape images as if being viewed through a window or within a picture frame-manipulations that do not affect scene content but do affect one's functional knowledge regarding the scene. This manipulation influences neural scene processing (as measured by fMRI): The OPA and the PPA exhibited greater neural activity when participants viewed images as if through a window as compared with within a picture frame, whereas the RSC did not show this difference. In a separate behavioral experiment, functional context affected scene memory in predictable directions (boundary extension). Our interpretation is that the window context denotes three-dimensionality, therefore rendering the perceptual experience of viewing landscapes as more realistic. Conversely, the frame context denotes a 2-D image. As such, more spatially biased scene representations in the OPA and the PPA are influenced by differences in top-down, perceptual expectations generated from context. In contrast, more semantically biased scene representations in the RSC are likely to be less affected by top-down signals that carry information about the physical layout of a scene.

Economic efficiency of spectrum allocation

Spectrum demand is rapidly expanding, driven by the developments of incumbent radio systems, as well as with the requirements of new technologies and market players to get spectrum access. In this regard, one of the fundamental functions of the state spectrum regulator is to create an enabling administrative and legal environment to ensure efficient spectrum use and to mitigate scarcity of this valuable natural resource. This paper analyses the economic value of spectrum use and suggests an extension of the spectrum's traditional technical boundaries, in order to take into consideration energy, environmental, sanitary and bio-geotechnical limits. The study reviews the phenomena of increasing transaction costs and negative externalities of spectrum access requiring economic criteria and assessment to achieve optimum resource allocation with a spectrum's demand growth. Results develop an input-output matrix as an allocation instrument to achieve spectrum efficiency and optimum equilibrium based on analysis of the economic effects from different band utilization scenarios, supplemented by currently used technical criteria. Practical application of proposed economic methods should improve the existing spectrum management system.

Exact Monte Carlo calculation method for K-eigenvalue change using perturbation source method

ABSTRACT The ‘perturbation source method’ (PSM) is a Monte Carlo perturbation method that calculates an exact k-eigenvalue change caused by cross-section changes. Although the PSM, which can consider the effect of fission source perturbation, was proposed long ago, it has garnered minimal interest as a Monte Carlo perturbation method. The applicability of the PSM has not been thoroughly elucidated hitherto. This study revisits the PSM and reviews the associated Monte Carlo algorithm. Some improvements have been made to improve the efficiency. The PSM is applied to some numerical tests that involve the replacement of a fuel material with light water, a density change in a water hole, an interface shift between a fuel and reflector, and an external boundary extension. The performance of the PSM for these tests is compared with that of another exact Monte Carlo perturbation method, which is the correlated sampling method. The PSM can yield an accurate k-eigenvalue change even for large cross-section changes such as the replacement of a material with another material. The PSM used in this study is the exact method except for the approximation related to the spatial discretization for fission source perturbation. Furthermore, it exhibits superiority in terms of accuracy and computational efficiency, particularly for large perturbations added in a small region.

Boundary extension as a tool for detection of cognitive change among individuals with mild cognitive impairment: A preliminary study

ObjectivesRecent neuropathological research suggests that recognition memory supported by familiarity rather than recollection may be the earliest cognitive change in course of Alzheimer's disease (AD). Nonetheless, the findings on the issue of familiarity capacity in the prodromal AD remain inconsistent. Boundary extension (BE), in which the view recollected by the subject covers a wider angle than was actually observed, is a form of false memory. Given that BE occurs implicitly and automatically, it may be a candidate for assessing familiarity functioning in cases of AD. This was the issue explored in the current study. Methods: One-hundred and six participants comprising a younger adult group (YA, n = 40), a healthy older adult group (OA, n = 40), and a group of patients with mild cognitive impairment (MCI, n = 26) underwent testing for BE and neuropsychological functions. Parts of OA and MCI underwent analysis for plasma tau levels. Receiver-operating characteristic analysis was used to assess memory associated with familiarity and recollection among participants. Results: The OA and MCI groups could be differentiated by the degree of familiarity associated with BE, wherein the latter group displayed minimal familiarity. Among OAs, familiarity was positively associated with education level. We observed a correlation between plasma tau levels and various neuropsychological functions. Most of the associations between plasma tau levels and neuropsychological functions were mediated by education level. Conclusions: Our findings indicate that BE could detect early decline in familiarity and assess preserved cognitive functions in aging

Numerical investigation on combustion system optimization of stoichiometric operation natural gas engine based on knocking boundary extension

In this work, a computational fluid dynamic model is established based on a natural gas engine and experimental results, and the combustion system of stoichiometric operation natural gas engine (intake manifolds and combustion chambers) is optimized based on knocking boundary extension under high load condition. In addition, the effects of Miller cycle and EGR on the combustion and knocking boundary extension are also explored. Results reveal that the intensity and distribution of in-cylinder turbulent kinetic energy will significantly affect the flame development and combustion characteristics. The combination of spiral intake manifold + K15 chamber shows better performance in antiknock because of the enhanced in-cylinder airflow motion and flame development. In addition, the Miller cycle with the late intake valve close timing of 20 °CA can effectively extend the antiknock performance of the engine under the current operating operation. EGR has limited effect on turbulent kinetic energy, and the primary affective mechanism of EGR on knocking is mainly achieved by changing the in-cylinder temperature during the combustion process. It is found that with tangential and spiral intake manifold + K15 chamber, combined with late intake valve closing (20 °CA) and EGR (30%), the indicated mean effective pressure (IMEP) can be increased by 5.21% within the knocking boundary compared to that of the original combustion system.

Application of supplier collaborative management in a Cuban commercial chain

Abstract: Suppliers´ management is an international practice which focuses on the interrelation between a supplier and a customer; therefore, the need for collaboration arises due to the extension of business boundaries. In this regard, this article aims to apply a procedure that facilitates the management of suppliers collaboratively within a Cuban commercial chain. This begins with the study of the commercial chain and its suppliers, respectively. Then, the business diagnosis continues with the evaluation of the suppliers based on a criteria matrix and concludes with a collaborative proposal. A collaborative supplier procedure adjusted to the conditions of the Cuban market is designed. This research presents a practical - methodological value because of the praxis of collaborative supplier management within a Cuban commercial chain.

The Impact of E-Commerce Development on an Example of Jingdong Company

E-commerce is not only changing the way people transact». This article takes Jingdong Mall as an example to review the development trajectory of China’s e-commerce in the past two decades. Research shows that: the development of e-commerce is promoting the extension of industrial boundaries; driving the reform of the express delivery industry and even the logistics industry; reshaping the supply chain and the optimization process of supply chain management. At the same time, the development of e-commerce requires the support of more public infrastructures and puts forward higher requirements on the government’s market supervision capabilities.

On Boundary Extension of Sobolev Classes with Critical Exponent by Prime Ends

This article is devoted to the study of mappings with bounded and finite distortion, as well as the Sobolev classes that have been actively studied recently. We study the homeomorphisms of the Sobolev classes $$W^{1,p}_{\textrm{loc}}$$ for the case when $$p=n-1$$ , where $$n$$ is the corresponding dimension of space. For these classes, we prove the estimate of the distortion of the modulus of families of curves under mapping. As an application, we obtain results on the boundary extension of homeomorphisms of the indicated class in terms of prime ends.

Episodic and semantic memory processes in the boundary extension effect: An investigation using the remember/know paradigm

BackgroundBoundary extension (BE) is a phenomenon where participants report from memory that they have experienced more information of a scene than was initially presented. The goal of the current study was to investigate whether BE is fully based on episodic memory or also involves semantic scheme knowledge. MethodsThe study incorporated the remember/know paradigm into a BE task. Scenes were first learned incidentally, with participants later indicating whether they remembered or knew that they had seen the scene before. Next, they had to rate 3 views - zoomed in, zoomed out or unchanged - of the original picture on similarity in closeness in order to measure BE. ResultsThe results showed a systematic BE pattern, but no difference in the amount of BE for episodic (‘remember’) and semantic (‘know’) memory. Additionally, the remember/know paradigm used in this study showed good sensitivity for both the remember and know responses. DiscussionThe results suggest that BE might not critically depend on the contextual information provided by episodic memory, but rather depends on schematic knowledge shared by episodic and semantic memory. Schematic knowledge might be involved in BE by providing an expectation of what likely lies beyond the boundaries of the scene based on semantic guidance. GEL classification2343 learning & memory

Esophageal Tumor Identification by Deep Learning on Treatment Planning CT Images

Esophageal tumor delineation on CT is difficult due to poor visibility of the tumor extension and lack of clear boundary between tumor and normal esophagus. Since CT is the standard image for RT planning. It is critical to identify tumor on CT image. Here, we want to distinguish the esophageal tumor on CT slices by deep learning method. Three hundred sixty-one esophageal squamous cell carcinoma patient’s treatment planning CT were enrolled in this study. The total slice number was 23794. This dataset was randomly divided into training (80%, 297 patients) and validation (20%, 64 patients) datasets. Each slice of the CT images was labeled as tumor, normal esophagus and others by one physician. A 128x128 pixels patch was cropped from the center of the CT image. A resnet-18 based convolution network was used to distinguish between tumors, normal esophagus and others. A data augmentation, which perturb the image shape and image brightness, was performed to increase data sample. The learning rate was 1e-4. The training process was run 2000 epochs. The total accuracy, tumor precision and tumor recall rate for training dataset was 97.9%, 98.5% and 97.5%. The total accuracy tumor precision and tumor recall rate for validation dataset was 84.9%, 84.5% and 86.4%. Deep learning-based single CT slice classification have the potential to distinguish between tumors and normal esophageal for esophageal squamous cell carcinoma. This method may help radiation oncology esophageal delineation.

Rethinking boundary extension as a universal phenomenon of visual memory

Rethinking boundary extension as a universal phenomenon of visual memory

An SVDD-based post-processing approach for vibration risk assessment of the hydro-turbine-generator in a large hydropower station

Due to the frequently occurred adverse vibration of hydraulic structures, vibration risk assessment is significant for the water energy efficiency of hydropower station and the safety of people and structures. Recently, the abnormal vibration of hydro-turbine-generator in a large hydropower station occurred and the main influencing factors of vibration are analyzed based on the prototype data and engineering experience. Different from the deterministic variable features in traditional support vector domain description (SVDD) algorithms, the feature of vibration amplitude is actually a random variable so that the different target objects will be obtained at different confidence levels. In order to assess the vibration range and excessive vibration probability, the original SVDD boundary at relatively low confidence level is firstly calculated. Then, the boundary extension operation with detailed theoretical deduction is performed and the extended boundary is further optimized inspired by path planning problem. The advantage of proposed approach is that it can improve the data fitting performance for single dimension (i.e. vibration amplitude) without leading to complex boundary which cannot be used for vibration risk assessment. By applying this approach to the practical vibration problem, the quantitative and slightly conservative assessment results are conveniently obtained, which indicate that this approach is reasonable and cost-effective.