Periodicals
Linking plant phenology to conservation biology
[no abstract]
Architecture & Planning• 2016• Elsevier BV
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in Architecture & Planning
Periodicals
Multisystem inflammatory syndrome in children and COVID-19 are distinct presentations of SARS–CoV-2
BACKGROUNDInitial reports from the severe acute respiratory coronavirus 2 (SARS-CoV-2) pandemic described children as being less susceptible to coronavirus disease 2019 (COVID-19) than adults. Subsequently, a severe and novel pediatric disorder termed multisystem inflammatory syndrome in children (MIS-C) emerged. We report on unique hematologic and immunologic parameters that distinguish between COVID-19 and MIS-C and provide insight into pathophysiology.METHODSWe prospectively enrolled hospitalized patients with evidence of SARS-CoV-2 infection and classified them as having MIS-C or COVID-19. Patients with COVID-19 were classified as having either minimal or severe disease. Cytokine profiles, viral cycle thresholds (Cts), blood smears, and soluble C5b-9 values were analyzed with clinical data.RESULTSTwenty patients were enrolled (9 severe COVID-19, 5 minimal COVID-19, and 6 MIS-C). Five cytokines (IFN-γ, IL-10, IL-6, IL-8, and TNF-α) contributed to the analysis. TNF-α and IL-10 discriminated between patients with MIS-C and severe COVID-19. The presence of burr cells on blood smears, as well as Cts, differentiated between patients with severe COVID-19 and those with MIS-C.CONCLUSIONPediatric patients with SARS-CoV-2 are at risk for critical illness with severe COVID-19 and MIS-C. Cytokine profiling and examination of peripheral blood smears may distinguish between patients with MIS-C and those with severe COVID-19.FUNDINGFinancial support for this project was provided by CHOP Frontiers Program Immune Dysregulation Team; National Institute of Allergy and Infectious Diseases; National Cancer Institute; the Leukemia and Lymphoma Society; Cookies for Kids Cancer; Alex's Lemonade Stand Foundation for Childhood Cancer; Children's Oncology Group; Stand UP 2 Cancer; Team Connor; the Kate Amato Foundations; Burroughs Wellcome Fund CAMS; the Clinical Immunology Society; the American Academy of Allergy, Asthma, and Immunology; and the Institute for Translational Medicine and Therapeutics.
Architecture & Planning• 2020• American Society for Clinical Investigation
Periodicals
Localizing and segmenting text in images and videos
Many images, especially those used for page design on Web pages, as well as videos contain visible text. If these text occurrences could be detected, segmented, and recognized automatically, they would be a valuable source of high-level semantics for indexing and retrieval. We propose a novel method for localizing and segmenting text in complex images and videos. Text lines are identified by using a complex-valued multilayer feed-forward network trained to detect text at a fixed scale and position. The network's output at all scales and positions is integrated into a single text-saliency map, serving as a starting point for candidate text lines. In the case of video, these candidate text lines are refined by exploiting the temporal redundancy of text in video. Localized text lines are then scaled to a fixed height of 100 pixels and segmented into a binary image with black characters on white background. For videos, temporal redundancy is exploited to improve segmentation performance. Input images and videos can be of any size due to a true multiresolution approach. Moreover, the system is not only able to locate and segment text occurrences into large binary images, but is also able to track each text line with sub-pixel accuracy over the entire occurrence in a video, so that one text bitmap is created for all instances of that text line. Therefore, our text segmentation results can also be used for object-based video encoding such as that enabled by MPEG-4.
Architecture & Planning• 2002• Institute of Electrical and Electronics Engineers
Periodicals
"It Takes a Village to Raise a Child": The Role of Social Capital in Promoting Academic Success for African American Men at a Black College
Historically Black colleges and universities (HBCUs) were created to provide educational opportunities for African Americans when other higher education venues restricted their participation. HBCUs are credited with nurturing and producing leaders who embraced W. E. B. Du Bois's concept of the "Talented Tenth," and exhibiting fortitude in advancing social equality for all. Over the years, as legalized segregation was overturned and efforts were made to expand opportunities for African Americans, some have questioned the continuing need for HBCUs. A study of 11 African American men attending a public, urban HBCU, indicated that the university's rich supply of social capital (a direct consequence of its mission and history) makes it a unique fixture in the landscape of higher education, one whose special features have not been replicated by historically White institutions.
Architecture & Planning• 2008• Johns Hopkins University Press
Periodicals
Report on cardiovascular health and diseases in China 2021: an updated summary
In 2019, cardiovascular disease (CVD) accounted for 46.74% and 44.26% of all deaths in rural and urban areas, respectively. Two out of every five deaths were attributed to CVD. It is estimated that approximately 330 million individuals in China are affected by CVD. Among them, there are 13 million cases of stroke, 11.4 million cases of coronary heart disease, 5 million cases of pulmonary heart disease, 8.9 million cases of heart failure, 4.9 million cases of atrial fibrillation, 2.5 million cases of rheumatic heart disease, 2 million cases of congenital heart disease, 45.3 million cases of lower extremity artery disease, and 245 million cases of hypertension. With the dual challenges of population aging and a steady increase in the prevalence of metabolic risk factors, the burden of CVD in China is expected to continue rising. Consequently, new demands arise for CVD prevention, treatment, and the allocation of medical resources. Emphasizing primary prevention to reduce disease prevalence, increasing the allocation of medical resources for CVD emergency and critical care, and providing rehabilitation services and secondary prevention to reduce the risk of recurrence, rehospitalization, and disability among CVD survivors are of paramount importance. Hypertension, dyslipidemia, and diabetes affect millions of individuals in China. Since blood pressure, blood lipids, and blood sugar levels often rise insidiously, vascular disease and serious events such as myocardial infarction and stroke occur by the time they are detected in this population. Therefore, it is crucial to implement strategies and measures to prevent risk factors such as hypertension, dyslipidemia, diabetes, obesity, and smoking. Furthermore, greater efforts should be directed towards assessing cardiovascular health status and conducting research on early pathological changes to enhance prevention, treatment, and understanding of CVD.
Architecture & Planning• 2023
Periodicals
The Technological Dimension of a Massive Open Online Course: The Case of the CCK08 Course Tools
In 2008, a new term emerged in the already crowded e-learning landscape: MOOC, or massive open online course. Lifelong learners can now use various tools to build and manage their own learning networks, and MOOCs may provide opportunities to test such networks. This paper focuses on the technological aspects of one MOOC, the Connectivism and Connective Knowledge (CCK08) course, in order to investigate lifelong learners’ attitudes towards learning network technologies. The research framework is represented by three perspectives: (a) lifelong learning in relation to open education, with a focus on the effective use of learning tools; (b) the more recent personal knowledge management (PKM) skills approach; and (c) the usability of web-based learning tools. Findings from a survey of CCK08 participants show that the course attracted mainly adult, informal learners, who were unconcerned about course completion and who cited a lack of time as the main reason for incompletion. Time constraints, language barriers, and ICT skills affected the participants’ choice of tools; for example, learners favoured the passive, filtered mailing list over interactive but time-consuming discussion forums and blogs. Some recommendations for future MOOCs include highlighting the pedagogical purpose of the tools offered (e.g., learning network skill-building) and stating clearly that the learners can choose which tools they prefer to use. Further research on sustainability and instructor workload issues should be conducted to determine the cost and effectiveness of MOOCs. Investigation is also necessary to understand whether such terms as <i>course</i>, <i>drop-out</i>, and <i>attrition</i> are appropriate in relation to MOOCs.
Architecture & Planning• 2009• Athabasca University Press
Periodicals
Antimicrobial Peptides Targeting Gram-Positive Bacteria
Antimicrobial peptides (AMPs) have remarkably different structures as well as biological activity profiles, whereupon most of these peptides are supposed to kill bacteria via membrane damage. In order to understand their molecular mechanism and target cell specificity for Gram-positive bacteria, it is essential to consider the architecture of their cell envelopes. Before AMPs can interact with the cytoplasmic membrane of Gram-positive bacteria, they have to traverse the cell wall composed of wall- and lipoteichoic acids and peptidoglycan. While interaction of AMPs with peptidoglycan might rather facilitate penetration, interaction with anionic teichoic acids may act as either a trap for AMPs or a ladder for a route to the cytoplasmic membrane. Interaction with the cytoplasmic membrane frequently leads to lipid segregation affecting membrane domain organization, which affects membrane permeability, inhibits cell division processes or leads to delocalization of essential peripheral membrane proteins. Further, precursors of cell wall components, especially the highly conserved lipid II, are directly targeted by AMPs. Thereby, the peptides do not inhibit peptidoglycan synthesis via binding to proteins like common antibiotics, but form a complex with the precursor molecule, which in addition can promote pore formation and membrane disruption. Thus, the multifaceted mode of actions will make AMPs superior to antibiotics that act only on one specific target.
Architecture & Planning• 2016• Multidisciplinary Digital Publishing Institute
Periodicals
Humanities Approaches to Graphical Display
As digital humanists have adopted visualization tools in their work, they have borrowed methods developed for the graphical display of information in the natural and social sciences. These tools carry with them assumptions of knowledge as observer-independent and certain, rather than observer co-dependent and interpretative. This paper argues that we need a humanities approach to the graphical expression of interpretation. To begin, the concept of data as a given has to be rethought through a humanistic lens and characterized as capta, taken and constructed. Next, the forms for graphical expression of capta need to be more nuanced to show ambiguity and complexity. Finally, the use of a humanistic approach, rooted in a co-dependent relation between observer and experience, needs to be expressed according to graphics built from interpretative models. In summary: all data have to be understood as capta and the conventions created to express observer-independent models of knowledge need to be radically reworked to express humanistic interpretation.
Architecture & Planning• 2011• Alliance of Digital Humanities Organizations
Periodicals
Exascale computing and big data
Scientific discovery and engineering innovation requires unifying traditionally separated high-performance computing and big data analytics.
Architecture & Planning• 2015• Association for Computing Machinery
Periodicals
Artificial intelligence for natural product drug discovery
[no abstract]
Architecture & Planning• 2023• Nature Portfolio
Periodicals
Genome-wide association study identifies a variant in HDAC9 associated with large vessel ischemic stroke
[no abstract]
Architecture & Planning• 2012• Nature Portfolio
Periodicals
Leaf Morphology, Taxonomy and Geometric Morphometrics: A Simplified Protocol for Beginners
Taxonomy relies greatly on morphology to discriminate groups. Computerized geometric morphometric methods for quantitative shape analysis measure, test and visualize differences in form in a highly effective, reproducible, accurate and statistically powerful way. Plant leaves are commonly used in taxonomic analyses and are particularly suitable to landmark based geometric morphometrics. However, botanists do not yet seem to have taken advantage of this set of methods in their studies as much as zoologists have done. Using free software and an example dataset from two geographical populations of sessile oak leaves, we describe in detailed but simple terms how to: a) compute size and shape variables using Procrustes methods; b) test measurement error and the main levels of variation (population and trees) using a hierachical design; c) estimate the accuracy of group discrimination; d) repeat this estimate after controlling for the effect of size differences on shape (i.e., allometry). Measurement error was completely negligible; individual variation in leaf morphology was large and differences between trees were generally bigger than within trees; differences between the two geographic populations were small in both size and shape; despite a weak allometric trend, controlling for the effect of size on shape slighly increased discrimination accuracy. Procrustes based methods for the analysis of landmarks were highly efficient in measuring the hierarchical structure of differences in leaves and in revealing very small-scale variation. In taxonomy and many other fields of botany and biology, the application of geometric morphometrics contributes to increase scientific rigour in the description of important aspects of the phenotypic dimension of biodiversity. Easy to follow but detailed step by step example studies can promote a more extensive use of these numerical methods, as they provide an introduction to the discipline which, for many biologists, is less intimidating than the often inaccessible specialistic literature.
Architecture & Planning• 2011• Public Library of Science
Periodicals
Mechanisms of Guided Bone Regeneration: A Review
Post-extraction crestal bone resorption is common and unavoidable which can lead to significant ridge dimensional changes. To regenerate enough bone for successful implant placement, Guided Bone Regeneration (GBR) is often required. GBR is a surgical procedure that uses barrier membranes with or without particulate bone grafts or/and bone substitutes. There are two approaches of GBR in implant therapy: GBR at implant placement (simultaneous approach) and GBR before implant placement to increase the alveolar ridge or improve ridge morphology (staged approach). Angiogenesis and ample blood supply play a critical role in promoting bone regeneration.
Architecture & Planning• 2014• Bentham Science Publishers
Periodicals
Spatial and Temporal Heterogeneity in High-Grade Serous Ovarian Cancer: A Phylogenetic Analysis
BACKGROUND: The major clinical challenge in the treatment of high-grade serous ovarian cancer (HGSOC) is the development of progressive resistance to platinum-based chemotherapy. The objective of this study was to determine whether intra-tumour genetic heterogeneity resulting from clonal evolution and the emergence of subclonal tumour populations in HGSOC was associated with the development of resistant disease. METHODS AND FINDINGS: Evolutionary inference and phylogenetic quantification of heterogeneity was performed using the MEDICC algorithm on high-resolution whole genome copy number profiles and selected genome-wide sequencing of 135 spatially and temporally separated samples from 14 patients with HGSOC who received platinum-based chemotherapy. Samples were obtained from the clinical CTCR-OV03/04 studies, and patients were enrolled between 20 July 2007 and 22 October 2009. Median follow-up of the cohort was 31 mo (interquartile range 22-46 mo), censored after 26 October 2013. Outcome measures were overall survival (OS) and progression-free survival (PFS). There were marked differences in the degree of clonal expansion (CE) between patients (median 0.74, interquartile range 0.66-1.15), and dichotimization by median CE showed worse survival in CE-high cases (PFS 12.7 versus 10.1 mo, p = 0.009; OS 42.6 versus 23.5 mo, p = 0.003). Bootstrap analysis with resampling showed that the 95% confidence intervals for the hazard ratios for PFS and OS in the CE-high group were greater than 1.0. These data support a relationship between heterogeneity and survival but do not precisely determine its effect size. Relapsed tissue was available for two patients in the CE-high group, and phylogenetic analysis showed that the prevalent clonal population at clinical recurrence arose from early divergence events. A subclonal population marked by a NF1 deletion showed a progressive increase in tumour allele fraction during chemotherapy. CONCLUSIONS: This study demonstrates that quantitative measures of intra-tumour heterogeneity may have predictive value for survival after chemotherapy treatment in HGSOC. Subclonal tumour populations are present in pre-treatment biopsies in HGSOC and can undergo expansion during chemotherapy, causing clinical relapse.
Architecture & Planning• 2015• Public Library of Science
Periodicals
RoboEarth
Humans can use the Internet to share knowledge and to help each other accomplish complex tasks. Until now, robots have not taken advantage of this opportunity. Sharing knowledge between robots requires methods to effectively encode, exchange, and reuse data. In this article, we present the design and first implementation of a system for sharing knowledge between robots.
Architecture & Planning• 2011• Institute of Electrical and Electronics Engineers
Periodicals
Multi-Factor Authentication: A Survey
Today, digitalization decisively penetrates all the sides of the modern society. One of the key enablers to maintain this process secure is authentication. It covers many different areas of a hyper-connected world, including online payments, communications, access right management, etc. This work sheds light on the evolution of authentication systems towards Multi-Factor Authentication (MFA) starting from Single-Factor Authentication (SFA) and through Two-Factor Authentication (2FA). Particularly, MFA is expected to be utilized for human-to-everything interactions by enabling fast, user-friendly, and reliable authentication when accessing a service. This paper surveys the already available and emerging sensors (factor providers) that allow for authenticating a user with the system directly or by involving the cloud. The corresponding challenges from the user as well as the service provider perspective are also reviewed. The MFA system based on reversed Lagrange polynomial within Shamir’s Secret Sharing (SSS) scheme is further proposed to enable more flexible authentication. This solution covers the cases of authenticating the user even if some of the factors are mismatched or absent. Our framework allows for qualifying the missing factors by authenticating the user without disclosing sensitive biometric data to the verification entity. Finally, a vision of the future trends in MFA is discussed.
Architecture & Planning• 2018• Multidisciplinary Digital Publishing Institute
Periodicals
Comprehensive Evidence-Based Guidelines forInterventional Techniques in the Managementof Chronic Spinal Pain
Background: Comprehensive, evidence-based guidelines for interventional techniques in the management of chronic spinal pain are described here to provide recommendations for clinicians. Objective: To develop evidence-based clinical practice guidelines for interventional techniques in the diagnosis and treatment of chronic spinal pain. Design: Systematic assessment of the literature. Methods: Strength of evidence was assessed by the U.S. Preventive Services Task Force (USPSTF) criteria utilizing 5 levels of evidence ranging from Level I to III with 3 subcategories in Level II. Outcomes: Short-term pain relief was defined as relief lasting at least 6 months and longterm relief was defined as longer than 6 months, except for intradiscal therapies, mechanical disc decompression, spinal cord stimulation and intrathecal infusion systems, wherein up to one year relief was considered as short-term. Results: The indicated evidence for accuracy of diagnostic facet joint nerve blocks is Level I or II1 in the diagnosis of lumbar, thoracic, and cervical facet joint pain. The evidence for lumbar and cervical provocation discography and sacroiliac joint injections is Level II-2, whereas it is Level II-3 for thoracic provocation discography. The indicated evidence for therapeutic interventions is Level I for caudal epidural steroid injections in managing disc herniation or radiculitis, and discogenic pain without disc herniation or radiculitis. The evidence is Level II-1 or II-2 for therapeutic cervical, thoracic, and lumbar facet joint nerve blocks; for caudal epidural injections in managing pain of post-lumbar surgery syndrome, and lumbar spinal stenosis, for cervical interlaminar epidural injections in managing cervical pain; for lumbar transforaminal epidural injections; for percutaneous adhesiolysis in management of pain secondary to post-lumbar surgery syndrome; and spinal cord stimulation for post-lumbar surgery syndrome. The indicated evidence for intradiscal electrothermal therapy (IDET), mechanical disc decompression with automated percutaneous lumbar discectomy (APLD), and percutaneous lumbar laser discectomy (PLDD) is Level II-2. Limitations: The limitations of these guidelines include a continued paucity of the literature, lack of updates, and conflicts in preparation of systematic reviews and guidelines by various organizations. Conclusion: The indicated evidence for diagnostic and therapeutic inverventions is variable from Level I to III. These guidelines include the evaluation of evidence for diagnostic and therapeutic procedures in managing chronic spinal pain and recommendations for managing spinal pain. However, these guidelines do not constitute inflexible treatment recommendations. Further, these guidelines also do not represent “standard of care.” Key words: Interventional techniques , chronic spinal pain, diagnostic blocks, therapeutic interventions, facet joint interventions, epidural injections, epidural adhesiolysis, discography, radiofrequency, disc decompression, spinal cord stimulation, intrathecal implantable systems
Architecture & Planning• 2009• American Society of Interventional Pain Physicians
Periodicals
In-Memory Big Data Management and Processing: A Survey
Growing main memory capacity has fueled the development of in-memory big data management and processing. By eliminating disk I/O bottleneck, it is now possible to support interactive data analytics. However, in-memory systems are much more sensitive to other sources of overhead that do not matter in traditional I/O-bounded disk-based systems. Some issues such as fault-tolerance and consistency are also more challenging to handle in in-memory environment. We are witnessing a revolution in the design of database systems that exploits main memory as its data storage layer. Many of these researches have focused along several dimensions: modern CPU and memory hierarchy utilization, time/space efficiency, parallelism, and concurrency control. In this survey, we aim to provide a thorough review of a wide range of in-memory data management and processing proposals and systems, including both data storage systems and data processing frameworks. We also give a comprehensive presentation of important technology in memory management, and some key factors that need to be considered in order to achieve efficient in-memory data management and processing.
Architecture & Planning• 2015• IEEE Computer Society
Periodicals
IoT-Based Healthcare-Monitoring System towards Improving Quality of Life: A Review
The Internet of Things (IoT) is essential in innovative applications such as smart cities, smart homes, education, healthcare, transportation, and defense operations. IoT applications are particularly beneficial for providing healthcare because they enable secure and real-time remote patient monitoring to improve the quality of people's lives. This review paper explores the latest trends in healthcare-monitoring systems by implementing the role of the IoT. The work discusses the benefits of IoT-based healthcare systems with regard to their significance, and the benefits of IoT healthcare. We provide a systematic review on recent studies of IoT-based healthcare-monitoring systems through literature review. The literature review compares various systems' effectiveness, efficiency, data protection, privacy, security, and monitoring. The paper also explores wireless- and wearable-sensor-based IoT monitoring systems and provides a classification of healthcare-monitoring sensors. We also elaborate, in detail, on the challenges and open issues regarding healthcare security and privacy, and QoS. Finally, suggestions and recommendations for IoT healthcare applications are laid down at the end of the study along with future directions related to various recent technology trends.
Architecture & Planning• 2022• Multidisciplinary Digital Publishing Institute
Periodicals
A Review of Indoor Localization Techniques and Wireless Technologies
Abstract This paper introduces a review article on indoor localization techniques and technologies. The paper starts with current localization systems and summarizes comparisons between these systems in terms of accuracy, cost, advantages, and disadvantages. Also, the paper presents different detection techniques and compare them in terms of accuracy and cost. Finally, localization methods and algorithms, including angle of arrival (AOA), time of arrival (TOA), and recived signal strength (RSS) are introduced. The study contains concepts, requirements, and specifications for each category of methods presents pros and cons for investigated methods, and conducts comparisons between them.
Architecture & Planning• 2021• Springer Science+Business Media
Periodicals
Genome-Wide Association Analyses in 128,266 Individuals Identifies New Morningness and Sleep Duration Loci
Disrupted circadian rhythms and reduced sleep duration are associated with several human diseases, particularly obesity and type 2 diabetes, but until recently, little was known about the genetic factors influencing these heritable traits. We performed genome-wide association studies of self-reported chronotype (morning/evening person) and self-reported sleep duration in 128,266 white British individuals from the UK Biobank study. Sixteen variants were associated with chronotype (P<5x10-8), including variants near the known circadian rhythm genes RGS16 (1.21 odds of morningness, 95% CI [1.15, 1.27], P = 3x10-12) and PER2 (1.09 odds of morningness, 95% CI [1.06, 1.12], P = 4x10-10). The PER2 signal has previously been associated with iris function. We sought replication using self-reported data from 89,283 23andMe participants; thirteen of the chronotype signals remained associated at P<5x10-8 on meta-analysis and eleven of these reached P<0.05 in the same direction in the 23andMe study. We also replicated 9 additional variants identified when the 23andMe study was used as a discovery GWAS of chronotype (all P<0.05 and meta-analysis P<5x10-8). For sleep duration, we replicated one known signal in PAX8 (2.6 minutes per allele, 95% CI [1.9, 3.2], P = 5.7x10-16) and identified and replicated two novel associations at VRK2 (2.0 minutes per allele, 95% CI [1.3, 2.7], P = 1.2x10-9; and 1.6 minutes per allele, 95% CI [1.1, 2.2], P = 7.6x10-9). Although we found genetic correlation between chronotype and BMI (rG = 0.056, P = 0.05); undersleeping and BMI (rG = 0.147, P = 1x10-5) and oversleeping and BMI (rG = 0.097, P = 0.04), Mendelian Randomisation analyses, with limited power, provided no consistent evidence of causal associations between BMI or type 2 diabetes and chronotype or sleep duration. Our study brings the total number of loci associated with chronotype to 22 and with sleep duration to three, and provides new insights into the biology of sleep and circadian rhythms in humans.
Architecture & Planning• 2016• Public Library of Science
Periodicals
Spatial deconvolution of HER2-positive breast cancer delineates tumor-associated cell type interactions
In the past decades, transcriptomic studies have revolutionized cancer treatment and diagnosis. However, tumor sequencing strategies typically result in loss of spatial information, critical to understand cell interactions and their functional relevance. To address this, we investigate spatial gene expression in HER2-positive breast tumors using Spatial Transcriptomics technology. We show that expression-based clustering enables data-driven tumor annotation and assessment of intra- and interpatient heterogeneity; from which we discover shared gene signatures for immune and tumor processes. By integration with single cell data, we spatially map tumor-associated cell types to find tertiary lymphoid-like structures, and a type I interferon response overlapping with regions of T-cell and macrophage subset colocalization. We construct a predictive model to infer presence of tertiary lymphoid-like structures, applicable across tissue types and technical platforms. Taken together, we combine different data modalities to define a high resolution map of cellular interactions in tumors and provide tools generalizing across tissues and diseases.
Architecture & Planning• 2021• Nature Portfolio
Periodicals
Electric Vehicle Charging Station Placement: Formulation, Complexity, and Solutions
To enhance environmental sustainability, many countries will electrify their transportation systems in their future smart city plans, so the number of electric vehicles (EVs) running in a city will grow significantly. There are many ways to recharge EVs' batteries and charging stations will be considered as the main source of energy. The locations of charging stations are critical; they should not only be pervasive enough such that an EV anywhere can easily access a charging station within its driving range, but also widely spread so that EVs can cruise around the whole city upon being recharged. Based on these new perspectives, we formulate the EV charging station placement problem (EVCSPP) in this paper. We prove that the problem is nondeterministic polynomial-time hard. We also propose four solution methods to tackle EVCSPP, and evaluate their performance on various artificial and practical cases. As verified by the simulation results, the methods have their own characteristics and they are suitable for different situations depending on the requirements for solution quality, algorithmic efficiency, problem size, nature of the algorithm, and existence of system prerequisite.
Architecture & Planning• 2014• Institute of Electrical and Electronics Engineers
Periodicals
Flow Monitoring Explained: From Packet Capture to Data Analysis With NetFlow and IPFIX
Flow monitoring has become a prevalent method for monitoring traffic in high-speed networks. By focusing on the analysis of flows, rather than individual packets, it is often said to be more scalable than traditional packet-based traffic analysis. Flow monitoring embraces the complete chain of packet observation, flow export using protocols such as NetFlow and IPFIX, data collection, and data analysis. In contrast to what is often assumed, all stages of flow monitoring are closely intertwined. Each of these stages therefore has to be thoroughly understood, before being able to perform sound flow measurements. Otherwise, flow data artifacts and data loss can be the consequence, potentially without being observed. This paper is the first of its kind to provide an integrated tutorial on all stages of a flow monitoring setup. As shown throughout this paper, flow monitoring has evolved from the early 1990s into a powerful tool, and additional functionality will certainly be added in the future. We show, for example, how the previously opposing approaches of deep packet inspection and flow monitoring have been united into novel monitoring approaches.
Architecture & Planning• 2014• Institute of Electrical and Electronics Engineers