Simple Link Research Articles

An improved semi-supervised segmentation of the retinal vasculature using curvelet-based contrast adjustment and generalized linear model

Diagnosis of most ophthalmic conditions, such as diabetic retinopathy, generally relies on an effective analysis of retinal blood vessels. Techniques that depend solely on the visual observation of clinicians can be tedious and prone to numerous errors. In this article, we propose a semi-supervised automated approach for segmenting blood vessels in retinal color images. Our method effectively combines some classical filters with a Generalized Linear Model (GLM). We first apply the Curvelet Transform along with the Contrast-Limited Histogram Adaptive Equalization (CLAHE) technique to significantly enhance the contrast of vessels in the retinal image during the preprocessing phase. We then use Gabor transform to extract features from the enhanced image. For retinal vasculature identification, we use a GLM learning model with a simple link identity function. Binarization is then performed using an automatic optimal threshold based on the maximum Youden index. A morphological cleaning operation is applied to remove isolated or unwanted segments from the final segmented image. The proposed model is evaluated using statistical parameters on images from three publicly available databases. We achieve average accuracies of 0.9593, 0.9553 and 0.9643, with Receiver Operating Characteristic (ROC) analysis yielding Area Under Curve (AUC) values of 0.9722, 0.9682 and 0.9767 for the CHASE_DB1, STARE and DRIVE databases, respectively. Compared to some of the best results from similar approaches published recently, our results exceed their performance on several datasets.

ПОСИЛЕННЯ РОЛІ ПРЕССЛУЖБ У РЕАЛІЗАЦІЇ КОМУНІКАТИВНОЇ ПОЛІТИКИ ОРГАНІВ МІСЦЕВОГО САМОВРЯДУВАННЯ В УКРАЇНІ

The communicative policy of local self-government bodies in Ukraine began to undergo significant transformations during the years of the global COVID-19 pandemic and actively continued to change already in the conditions of a full-scale Russian-Ukrainian war. External challenges led to a transition from one-sided coverage of information in the «government-citizen» format to a two-way process of interaction, which in some territorial communities reached a more or less stable partnership. Among all the factors that had a significant impact on the mentioned changes, it is worth highlighting the active development of strategies for the development of territorial communities in Ukraine and communication strategies, as their components, and the appearance of press services and press secretaries in the structure of local self-government bodies. The latter replaced divisions and individual specialists, for whom the performance of communicative functions was often far from the main area of responsibility. The main task of the press services of local self-government bodies is to create a friendly attitude of the population towards state, socio-political, economic and other institutions of society (informative and representative functions), as well as functions related to processing information and requests from citizens and monitoring functions public sentiments. However, provided that their ability to influence the implementation of the communication policy of local self-government bodies is strengthened, they can become a full-fledged subject of information policy. The activities of press services of local self-government bodies in Ukraine are regulated by a relatively large number of normative legal acts (from the Constitution of Ukraine to the relatively new Law of Ukraine «On Media»), which together form a solid legal basis for their implementation of the communication policy of local self-government bodies. Attention is drawn to the fact that local normative legal acts can expand the competence of press services and, depending on the specifics of the communication policy of one or another community, supplement their functions. And under the condition of forming a communicative strategy in the community in addition to the development strategy, the list of functions of press services can be supplemented with the following: communicative function, organizational function, ideological function, educational function, monitoring function. The performance of such a wide range of functions requires the press services of local self-government bodies to carefully plan their activities, which is a natural task after the adoption of the community's communication strategy. Such planning can be strategic and ongoing. Strengthening the role of the press service in the implementation of the communication policy of local self-government is ensured by the development of the ability to manage crisis communications, which is one of the priority goals of the communication strategies of all territorial communities of Ukraine without exception, regardless of their distance from the front line. Key steps in crisis management are prevention, preparedness and response, and recovery. An equally important factor in strengthening the communication policy of local self-government is the introduction of measurable indicators of the efficiency and effectiveness of communication. These indicators are conditionally divided into quantitative and qualitative. The role of press services is, on the one hand, to assist in the development of these indicators, and on the other hand, to monitor their implementation. It was concluded that the implementation of modern communication policy is impossible without the effective work of press services of local self-government bodies, which very quickly went from a simple communication link between the authorities and citizens to a subject of information policy. Therefore, the ways outlined in the study to strengthen their ability to implement communication policy have important theoretical and practical significance both for individual local self-government bodies and for the entire system of public administration of Ukraine.

The Einstein–Hilbert action for entropically dominant causal sets

In the path integral formulation of causal set quantum gravity, the quantum partition function is a phase-weighted sum over locally finite partially ordered sets, which are viewed as discrete quantum spacetimes. It is known, however, that the number of ‘layered’ sets—a class of causal sets that look nothing like spacetime manifolds—grows superexponentially with the cardinality n, giving an entropic contribution that can potentially dominate that of the action. We show here that in any dimension, the discrete Einstein–Hilbert action for a typical K-layered causal set reduces to the simple link action to leading order in n. Combined with earlier work, this completes the proof that the layered sets, although entropically dominant, are very strongly suppressed in the path sum of causal set quantum gravity whenever the discreteness scale is greater than or equal to a (mildly dimension-dependent) order one multiple of the Planck scale.

حول بعد التقسيم وهيمنة الرسم البياني لعابد - وحيد 〖(AW)〗_r^4

يحتوي الرسم البياني H المرتبط ببساطة على مجموعة رؤوس بالنظر إلى الرسم البياني، فإن المجموعة المسيطرة S هي مجموعة فرعية من مجموعة الرؤوس V بحيث يكون أي رأس خارج S قريبًا من رأس واحد على الأقل داخل S. أصغر حجم من H هو المسيطر على المجموعات هو المعروف برقم سيطرة الرسم البياني. عندما يكون للرسم البياني H رأس x ومجموعة فرعية من الرأس V (H) ، يكون الفصل. فيما يتعلق بالقسم k المرتب من V (H) ، فإن الرسم التوضيحي لـ x بالنسبة إلى Π هو المتجهفي هذا البحث ، قمنا بدراسة بعض النتائج على رقم الهيمنة ورقم السيطرة المستقل والمقيد والمشار إليه بـ على التوالي في الرسوم البيانية Abid-Waheed والعلاقة بين رقم الهيمنة ورقم الهيمنة المستقلة والمقيدة. كما أن الهدف من هذه الورقة هو إنشاء أبعاد التقسيم لـ

A simple and efficient resonant DC link inverter with low current stress on main switch

This paper proposes a simple and efficient resonant DC link inverter topology with low current stress on main switches. The inverter has a straightforward structure and is readily controllable, avoids the auxiliary resonant current passing through the main switches of the inverter, and the current passing through the main switches remains consistently equivalent to the load current, thus reducing the current stress and the switching loss of the main switches, thereby the inverter’s efficiency is increased. The proposed inverter’s operating principle is examined and contrasted with the inverter described in the literature. Ultimately, the validity of the resonant DC link inverter is demonstrated through simulation.

Cretaceous stratigraphy of Antarctica and its global significance

Abstract The Cretaceous Period is particularly well represented by a thick sequence of clastic sedimentary rocks exposed in the Antarctic Peninsula region of western Antarctica. This was an active margin throughout the Late Mesozoic, and in total some 7 km+ of Cretaceous sedimentary rocks accumulated in a series of fore-, intra- and back-arc basins. The Fossil Bluff Group of eastern Alexander Island can be traced from the Jurassic–Cretaceous boundary into the Upper Albian and represents a broad-scale shallowing-upward sequence from deep marine to a prominent Upper Albian fluvial interval in which high-density forests developed at a palaeolatitude of 75° S. The Cretaceous sequence exposed in the James Ross Island group continues right through the Upper Cretaceous to the Cretaceous–Paleogene boundary. The Campanian–Maastrichtian succession in particular is over 2 km in total thickness and richly fossiliferous. The improved Cretaceous stratigraphy of Antarctica is an invaluable terrestrial record of climatic change at a high palaeolatitude. This includes a gradual increase in temperature to the Cretaceous Thermal Maximum, and then a decline to the Cretaceous–Paleogene boundary. There may be no simple link between these palaeotemperature changes and Cretaceous patterns of biotic radiation and extinction.

Can we use heavy nuclei to detect relic neutrinos?

Recent analysis of the viability of solid state-based relic neutrino detectors has revealed the fundamental necessity for the use of heavy, A>100, beta -decayers as neutrino targets. Of all heavy isotopes, and stand out for their sufficiently low decay energies, reasonable half-life times and stable daughter nuclei. However, the crucial bit of information, that is the soft neutrino capture cross-section is missing for both isotopes. The main reason for that is a particular type of beta -decay, which precludes a simple link between the isotope’s half-life time and the neutrino capture rate. In light of the necessity for a reliable estimate of the capture rate – unimpeded by potentially devastating theoretical uncertainties – prior to using the isotope in a full-scale experiment, we propose an experimental method to bypass this difficulty and obtain the capture cross-section of a soft neutrino by a given isotope from the isotope’s beta -spectrum.

Quantifying Charge Extraction and Recombination Using the Rise and Decay of the Transient Photovoltage of Perovskite Solar Cells.

The extraction of photogenerated charge carriers and the generation of a photovoltage belong to the fundamental functionalities of any solar cell. These processes happen not instantaneously but rather come with finite time constants, e.g., a time constant related to the rise of the externally measured open circuit voltage following a short light pulse. Herein, a new method to analyze transient photovoltage measurements at different bias light intensities combining rise and decay times of the photovoltage. The approach uses a linearized version of a system of two coupled differential equations that are solved analytically by determining the eigenvalues of a 2×2 matrix. By comparison between the eigenvalues and the measured rise and decay times during a transient photovoltage measurement, the rates of carrier recombination and extraction as a function of bias voltage are determined, and establish a simple link between their ratio and the efficiency losses in the perovskite solar cell.

Simple polarization-insensitive coherent RoF link with increased capacity.

A simple polarization-insensitive coherent radio-over-fiber (RoF) link with increased spectrum efficiency and transmission capacity is proposed and demonstrated. Instead of using two polarization splitters (PBSs), two 90° hybrids, and four pairs of balanced photodetectors (PDs) in a conventional polarization-diversity coherent receiver (PDCR), a simplified PDCR with only one PBS, one optical coupler (OC), and two PDs is employed in the coherent RoF link. At the simplified receiver, a novel, to the best of our knowledge, digital signal processing (DSP) algorithm is proposed to achieve polarization-insensitive detection and demultiplexing of two spectrally overlapping microwave vector signals as well as the elimination of the joint phase noise originating from the transmitter and the local oscillator (LO) laser sources. An experiment is performed. The transmission and detection of two independent 16QAM microwave vector signals at identical microwave carrier frequencies of 3 GHz with a symbol rate of 0.5 GSym/s over a 25-km single-mode fiber (SMF) is demonstrated. Thanks to the spectrum superposition of the two microwave vector signals, the spectral efficiency as well as the data transmission capacity is increased.

Dynamical Quantum Phase Transitions from Quantum Optics Perspective

It is shown that dynamical quantum phase transitions observed as singularities in the Loschmidt rate singularities bear close resemblance to standard Rabi oscillations known from dynamics of two-level systems. For some many-body systems this analogy may go even further and the behaviour observed for e.g. transverse Ising chain can be directly mapped to such simple dynamics. It is explained why A simple link between Loschmidt echo singularities and quantum scars is suggested.

Productivity, Economic Dynamism and the “Failure of Competition” Narrative*

Productivity growth has declined in Australia and other developed countries over the past two decades. It has been argued that reduced dynamism and the failure of competition at an economy‐wide level is to blame, leading to calls for broad competition policy reforms. In this paper we consider the theoretical and empirical evidence to support this “failure of competition” narrative. We find that the evidence, at best, is ambiguous. Competition failures in some areas support the need for reform, but the competition landscape across Australia is complex and there is no simple link between indicators of competition, such as concentration levels; indicators of reduced dynamism, such as falling business investment, and falling productivity growth.

Middle to Late Pennsylvanian tetrapod evolution: the Kasimovian bottleneck

Abstract The Late Pennsylvanian was a critical juncture in tetrapod evolution when many terrestrially adapted taxa first appeared. The Middle Pennsylvanian (Moscovian) tetrapod record reflects a taphonomic megabias that favoured preservation, discovery and collection of aquatic tetrapods that lived in wetland palaeoenvironments (‘coal swamps’). The Kasimovian tetrapod record is limited to seven localities, all but one in the USA, and two of which are singleton records, so it is less abundant, diverse or widespread than earlier Moscovian and later Gzhelian tetrapod records. This ‘Kasimovian bottleneck’ hinders interpretation of tetrapod evolutionary events across the Middle–Late Pennsylvanian boundary. Significant changes did take place across that boundary, but they were spread out over Moscovian through Gzhelian time. Many of the perceived changes in tetrapods across the Middle–Late Pennsylvanian boundary are largely artefacts of facies changes and the Moscovian tetrapod taphonomic megabias and of the limited fossil record of Kasimovian tetrapods. Therefore, there is no simple link between Late Pennsylvanian tetrapod evolutionary events and changes in climate and vegetation.

Are narcissists more creative? Only if we believe it: How narcissism can relate to creativity.

The relationship between narcissism and creativity has inspired interesting debates for decades. Drawing on a new perspective, the current study tried to explain how narcissism influences others' creativity evaluation in the organizational context. Based on the theory of impression management, we suggested that narcissism and creativity may have a more complex relationship rather than a simple linear link. To test this relationship, we conducted a survey of 596 subordinates and 60 leaders in three high-technology companies. The result showed that there was an inverted U-shaped relationship between narcissism and creativity evaluation. Moreover, personal reputation mediated this curvilinear relationship and this relationship was significant only when narcissists were low in political skill. Theoretical and practical implications, limitations and future directions have also been discussed.

Special invited paper: The SCORE normalization, especially for heterogeneous network and text data

SCORE was introduced as a spectral approach to network community detection. Since many networks have severe degree heterogeneity, the ordinary spectral clustering (OSC) approach to community detection may perform unsatisfactorily. SCORE alleviates the effect of degree heterogeneity by introducing a new normalization idea in the spectral domain and makes OSC more effective. SCORE is easy to use and computationally fast. It adapts easily to new directions and sees an increasing interest in practice. In this paper, we review the basics of SCORE, the adaption of SCORE to network mixed membership estimation and topic modeling, and the application of SCORE in real data, including two datasets on the publications of statisticians. We also review the theoretical “ideology” underlying SCORE. We show that in the spectral domain, SCORE converts a simplicial cone to a simplex and provides a simple and direct link between the simplex and network memberships. SCORE attains an exponential rate and a sharp phase transition in community detection, and achieves optimal rates in mixed membership estimation and topic modeling.

Environment manipulation mechanism with free adaptability using a simple parallel link structure made of flexible materials

Environment manipulation mechanism with free adaptability using a simple parallel link structure made of flexible materials

Why Is Seasonal Density Stratification in Shelf Seas Expected to Increase Under Future Climate Change?

AbstractCoastal and shelf seas provide a diverse range of ecosystem services, which are often mediated by seasonal density stratification through its control on biogeochemical cycles. These seas are highly vulnerable to climate change and downscaling studies consistently project an increase in seasonal stratification over the next century, but without a clear explanation. Here we revisit a well‐established theory of coastal ocean mixing and demonstrate with a new ensemble of downscaled simulations for the Northwest European continental shelf seas to 2100 that the increase of expansivity with temperature is sufficient to consistently increase the seasonal stratification. Where there is a closed balance between buoyancy input and mixing, small changes in expansivity are amplified to a large relative change in stratification. This simple link between global heating and stratification substantially reduces uncertainty in projections of this key parameter in seas around the world.

A Decade of Telemedicine for Facial Plastic Surgery: Tips and Techniques from 2000 Consultations before the COVID Pandemic.

Many practices now offer telemedicine.1,2 Reports have reviewed telemedicine for follow-up care but not for initial consultation.3,4 This article reviews initial video consultations for aesthetic surgery done by Dr. Spiegel between 2012 and 2020. Before 2012, video consultations were performed but the information was not readily available. In 2012, 62 persons had a video consultation; by 2013, that number had more than doubled to 134. In 2014, possibly because of the increased availability of video conferencing software, the number of video consultations increased by 63% to 219. Between 2014 and 2019, the number of initial video consultations done by our practice stabilized, with an average of 232 per year over this period. In 2020, there were 437 video consultations, up 88% (Fig. 1). A total of 2024 initial video consultations were performed during this 9-year period.Fig. 1.: Video consults by year.There are advantages to this approach. For all participants, the costs of consultation are reduced, reflecting monetary as well as time savings. The prospective patient can work until the consultation starts from their own home or office and costs related to transportation to the office are eliminated. For the doctor, savings are realized in terms of reducing the need for room cleaning and preparation and patient amenities (ie, coffee, water, brochures). Typical new patient consultations only take 10 to 15 minutes, although some consultations may exceed this time frame. There are disadvantages as well. Successful aesthetic surgery practices design their offices to highlight the competence of the surgeon and the practice. With a video consultation, the patient remains in his or her own environment, so this ability is lost. In addition, some patients lack familiarity with the required technology. They may not know their username for programs such as Skype (Microsoft), may not understand that Apple devices are required for FaceTime, or may be unfamiliar with how to access Zoom. Some newer telehealth software programs ameliorate these problems by providing a simple emailed link. Possible issues also include camera malfunctions, speaker malfunctions, poor internet access, and bulky headphones obstructing the patient’s face. Lighting issues are common, and patients often sit in front of bright windows, where backlighting obscures their face. Patients are often unable to determine the proper degree of rotation from the camera to show their profile and may have a camera that is off to the side of their screen so the practitioner cannot see them face on. In addition, laptop cameras aim upward toward the face, so it can be difficult to get a proper view of the patient. In a video consultation, it is not possible to see inside the nose or mouth clearly or to feel tissues; it is necessary to communicate these limitations clearly to the patient. Patients often appear unprepared for the consultation. They may be driving, partially dressed, in bed, or in a public place with a lack of privacy. Patient privacy is an important consideration, but one that in a video consultation largely falls to the patient, who selects his or her own environment for the consultation. Some patients multitask during the consultation or ask the doctor to wait as they finish another task. The practitioner must keep in mind that there may be other people present out of the camera view. Video conferencing provides a net advantage for the medical practice and its availability is expected by patients. Our experience performing more than 1200 surgical procedures solely based on video consultation reinforces the reports of others that video consultations result in high levels of patient satisfaction.5 There are steps the surgeon can take for a successful video consultation. One must create a professional environment in which to perform telehealth services. Good lighting and a suitable background reinforce the proper image (Fig. 2). The telephone must be muted and a sign hung on the office door to prevent anyone from knocking or entering during these consultations.Fig. 2.: Office configuration for video consultations. Walls and backdrops are set to create a professional environment.Performing video consultations well takes practice. The doctor should look directly at the camera to reflect his or her engagement with the patient. To watch for patient reactions, it is helpful to position the camera close to the spot on the screen where the patient appears. Patients should be sent instructions before the consultation regarding lighting, hair position, cosmetics limitations, and equipment testing. In conclusion, our experience with more than 2000 video consultations reflects that this format can be successfully employed in facial plastic surgery consultations. High-quality experiences require physical preparation of the office environment and new communication protocols. Software and technology will continue to evolve to facilitate the process and permit more enhanced consultations opportunities as telemedicine consultations increase in frequency. DISCLOSURE The authors have no financial interest to declare in relation to the content of this article.

Dual structures for the additive DEA model

We show that the weighted additive DEA score (WA) for the additive DEA model is simultaneously the (dual) support function for a translation of the DEA technology and the gauge of the dual polar set of the translated technology. Those results are used: to show that WA and the indicator function for the translated technology form a dual conjugate pair; to show that WA and the translated technology’s gauge function form a dual polar pair; to develop a simple but exact link between WA and the profit function for the DEA technology; to show that WA and the directional distance function form a dual polar pair; and to develop an exact decomposition of profit inefficiency that extends the Cooper, Pastor, Aparicio, and Borras (2011) and Aparicio et al. (2016) decomposition.

The inverse association of state cannabis vaping prevalence with the e-cigarette or vaping product-use associated lung injury.

The e-cigarette or vaping product-use-associated lung injury (EVALI) epidemic was primarily associated with the use of e-cigarettes containing tetrahydrocannabinol (THC)- the principal psychoactive substance in cannabis, and vitamin-E-acetate- an additive sometimes used in informally sourced THC-containing e-liquids. EVALI case burden varied across states, but it is unclear whether this was associated with state-level cannabis vaping prevalence. We, therefore, used linear regression models to assess the cross-sectional association between state-level cannabis vaping prevalence (obtained from the 2019 behavioral Risk Factor Surveillance System) and EVALI case burden (obtained from the Centers for Disease Control and Prevention) adjusted for state cannabis policies. Cannabis vaping prevalence ranged from 1.14%(95%CI, 0.61%-2.12%) in Wyoming to 3.11%(95%CI, 2.16%-4.44%) in New Hampshire. EVALI cases per million population ranged from 1.90(0.38-3.42) in Oklahoma to 59.10(19.70-96.53) in North Dakota. There was no significant positive association but an inverse association between state cannabis vaping prevalence and EVALI case burden (Coefficient, -18.6; 95%CI, -37.5-0.4; p-value, 0.05). Thus, state-level cannabis vaping prevalence was not positively associated with EVALI prevalence, suggesting that there may not be a simple direct link between state cannabis vaping prevalence and EVALI cases, but rather the relationship is likely more nuanced and possibly reflective of access to informal sources of THC-containing e-cigarettes.

A new approach for the prediction of fatigue life in rolling bearings based on damage accumulation theory considering residual stresses

Today, the service life calculation of rolling bearings is standardized in ISO 281, based on the theory of Lundberg and Palmgren. In the standard calculation method, material properties such as fatigue limit stress were taken into account by introducing the fatigue limit stress proposed by Ioannides and Harris. This standard calculation method provides a reasonable range of fatigue life in good agreement with experimental results under ideal test conditions such as constant external load. However, complex operating conditions of bearings such as varying loads and oscillating motion are not considered. Therefore, there is a need for a new analytical calculation model that can predict the fatigue life of rolling bearings operating under these complex conditions. This makes it possible to advance the application of rolling bearings and optimize their use in machines such as wind turbines. In the proposed approach, the fatigue life is determined based on the Palmgren-Miner linear damage rule, evaluating the subsurface stresses below the rolling contact using the S-N curve according to the fatigue criterion proposed by Lundberg and Palmgren. All rolling contacts that occur in an internal stress cycle due to the internal dynamic behavior during rotating operations are evaluated individually and referred to as partial damage risks. The partial damage risks are accumulated linearly according to the Palmgren-Miner theory to obtain the load cycle to failure. At this time, the loaded volume is assessed along the depth from the contact area to the core of the bearing ring, which makes it possible to indicate the depth position of fatigue occurrence in terms of crack initiation. The material properties such as the fatigue limit stress and the probability of failure are taken from the S-N curve itself. To consider the residual stress, a simple link concept is suggested by using the ratio of the maximum contact pressure to the yield criteria. The proposed approach can be extended to calculate oscillating fatigue life regarding the number of rolling contacts at a given oscillation amplitude. In this study, it can be confirmed that the analytically determined fatigue lifetime according to ISO 281 is still close to the bearing life test result. In addition, it shows that the results obtained using the proposed approach agree well with the calculation results obtained using ISO 281.