Function Of Complexity Research Articles

Artificial neural networks for positioning of gamma interactions in monolithic PET detectors

To detect gamma rays with good spatial, timing and energy resolution while maintaining high sensitivity we need accurate and efficient algorithms to estimate the first gamma interaction position from the measured light distribution. Furthermore, monolithic detectors are investigated as an alternative to pixelated detectors due to increased sensitivity, resolution and intrinsic DOI encoding. Monolithic detectors, however, are challenging because of complicated calibration setups and edge effects. In this work, we evaluate the use of neural networks to estimate the 3D first (Compton or photoelectric) interaction position. Using optical simulation data of a 50 × 50 × 16 mm3 LYSO crystal, performance is evaluated as a function of network complexity (two to five hidden layers with 64 to 1024 neurons) and amount of training data (1000−8000 training events per calibration position). We identify and address the potential pitfall of overfitting on the training grid through evaluation on intermediate positions that are not in the training set. Additionally, the performance of neural networks is directly compared with nearest neighbour positioning. Optimal performance was achieved with a network containing three hidden layers of 256 neurons trained on 1000 events/position. For more complex networks, the performance degrades at intermediate positions and overfitting starts to occur. A median 3D positioning error of 0.77 mm and a 2D FWHM of 0.46 mm is obtained. This is a 17% improvement in terms of FWHM compared to the nearest neighbour algorithm. Evaluation only on events that are not Compton scattered results in a 3D positioning error of 0.40 mm and 2D FWHM of 0.42 mm. This reveals that Compton scatter results in a considerable increase of 93% in positioning error. This study demonstrates that very good spatial resolutions can be achieved with neural networks, superior to nearest neighbour positioning. However, potential overfitting on the training grid should be carefully evaluated.

A Graph-Theoretic Approach for Spatial Filtering and Its Impact on Mixed-Type Spatial Pattern Recognition in Wafer Bin Maps

Statistical quality control in semiconductor manufacturing hinges on effective diagnostics of wafer bin maps, wherein a key challenge is to detect how defective chips tend to spatially cluster on a wafer--a problem known as spatial pattern recognition. Recently, there has been a growing interest in mixed-type spatial pattern recognition--when multiple defect patterns, of different shapes, co-exist on the same wafer. Mixed-type spatial pattern recognition entails two central tasks: (1) spatial filtering, to distinguish systematic patterns from random noises; and (2) spatial clustering, to group filtered patterns into distinct defect types. Observing that spatial filtering is instrumental to high-quality mixed-type pattern recognition, we propose to use a graph-theoretic method, called adjacency-clustering, which leverages spatial dependence among adjacent defective chips to effectively filter the raw wafer maps. Tested on real-world data and compared against a state-of the-art approach, our proposed method achieves at least 46% gain in terms of internal cluster validation quality (i.e., validation without external class labels), and about ~5% gain in terms of Normalized Mutual Information--an external cluster validation metric based on external class labels. Interestingly, the margin of improvement appears to be a function of the pattern complexity, with larger gains achieved for more complex-shaped patterns.

Lip and Perioral Trauma: Principles of Aesthetic and Functional Reconstruction.

Successful management of lip and perioral trauma requires a nuanced understanding of anatomy and surgical techniques. Surgical correction is particularly challenging in instances of tissue loss, due to a narrow tolerance for aesthetic deformity and highly specialized functions of the perioral region, including facial expression, communication, and oral competence. Restoring continuity of the orbicularis oris musculature is critical for dynamic sphincter function of the upper and lower lips. Lip and perioral tissue symmetry are also critical for aesthetic balance, and failure to restore a natural appearance can adversely affect personal identity, with attendant psychological trauma. This discussion of lip and perioral trauma management encompasses lip and perioral anatomy, evaluation of injuries, reconstructive techniques, and prevention and management of complications. Perioral injuries are classified by size, depth, and extent of injury, and the corresponding reconstructive approaches are a function of complexity. These approaches proceed sequentially up rungs of the reconstructive ladder including primary repair, local flaps, grafting, regional flaps, as well as microvascular free tissue transfers. Procedures may be single stage or require multiple stages or subsequent refinement. Regardless of the defect size or location, the guiding principle of repair in the perioral region is restoring natural function and aesthetic appearance. This still-evolving area of facial plastic and reconstructive surgery lends itself to artistry and technical precision, offering opportunities for further innovation to improve the outcomes of patients with lip and perioral trauma.

Impact of BMPs on water quality: a case study in Big Sunflower River watershed, Mississippi

ABSTRACT Impact of Best Management Practices (BMPs) can be evaluated using hydrologic and water quality models. Although numerous models with diverse function, capability and degree of complexity are available, suitable model for each watershed should be determined. The Soil and Water Assessment Tool (SWAT) and Hydrologic Simulation Program-Fortran (HSPF) models were applied to the Big Sunflower River Watershed (BSRW) and their performances in simulating hydrology and water quality were evaluated. Both the models simulated streamflow, sediment, and nutrient concentrations with model efficiency greater than 50%. The SWAT model simulated streamflow and sediment concentration more accurately than HSPF whereas, for total nitrogen (TN) and total phosphorous (TP) concentrations, the HSPF model simulated equally good as SWAT. Models evaluated effect of two BMPs: vegetative filter strip (VFS) and tailwater recovery pond (TRP) in reduction of streamflow, sediment, TN, and TP concentrations. Average reduction of streamflow due to the implementation of both BMPs in SWAT and HSPF were less than 1% but average reduction of sediment concentration by VFS in SWAT was 26% and in HSPF was 38%. Average reduction of sediment concentration by TRP in SWAT and HSPF were 21% and 30% respectively. VFS reduced TN concentration by 51% in SWAT and by 25% in HSPF, while average reduction of TN concentration by TRP in SWAT and HSPF were 7% and 2% respectively. Similarly, average reduction of TP concentration by VFS in SWAT and HSPF were 56% and 31% respectively and that by TRP in SWAT and HSPF were 2% and 1% respectively. Differences in simulation results based on application of two models were mainly attributed by the modelling mechanism and equations used. The results from this study will provide a broader idea to other modellers and end-users in selecting appropriate model according to their need and type of watershed.

Application and Practice of Computer BIM in Cost Management Control and Cost Coordination Management

At present, the scale of China’s construction projects is gradually expanding, which has greatly promoted the rapid development of China’s economy. Construction engineering is an organic system, which has the function of complexity and variability. Therefore, we must do a good job in cost management control, which can reduce the overall budget of the project. At the same time, we must do a good job in cost management, which can strictly control the consistency between cost and budget. Therefore, through computer BIM, we can control cost management and coordinate cost management, which will improve the management and control of complex projects. First of all, this paper analyzes the difference between project cost management control and project cost management. Then, this paper constructs the collaborative management mode of cost management control and project cost. Finally, some suggestions are put forward.

Ostrowski-automatic sequences: Theory and applications

We extend the notion of k-automatic sequences to Ostrowski-automatic sequences, and develop a procedure to computationally decide certain combinatorial and enumeration questions about such sequences that can be expressed as predicates in first-order logic. Our primary contribution is the design and implementation of an adder recognizing addition in a generalized Ostrowski numeration system. We also provide applications of our work to several topics in combinatorics on words, including repetitions and pattern avoidance. We partially resolve a previous conjecture about balanced words by Rampersad et al., and make the first progress on an open problem on rich words by Vesti. We also prove some known results about Lucas words using only machine computation.

Multiplicative analogue of Markoff-Lagrange spectrum and Pisot numbers

Markoff-Lagrange spectrum uncovers exotic topological properties of Diophantine approximation. We investigate asymptotic properties of geometric progressions modulo one and observe significantly analogous results on the setL(α)={lim supn→∞‖ξαn‖|ξ∈R}, where ‖x‖ is the distance from x to the nearest integer. First, we show that L(α) is closed in [0,1/2] for any Pisot number α.Then we consider the case where α is an integer with α≥2, or a quadratic unit with α≥3. We show that L(α) contains a proper interval when α is quadratic but it does not when α is an integer. We also determine the minimum limit point and all isolated points beneath this point. In the course of the proof, we revisit a property studied by Markoff which characterizes bi-infinite balanced words and sturmian words.

Timing, Distribution, and Relationship Between Nonpsychotic and Subthreshold Psychotic Symptoms Prior to Emergence of a First Episode of Psychosis.

Prospective population studies suggest that psychotic syndromes may be an emergent phenomenon-a function of severity and complexity of more common mental health presentations and their nonpsychotic symptoms. Examining the relationship between nonpsychotic and subthreshold psychotic symptoms in individuals who later developed the ultimate outcome of interest, a first episode of psychosis (FEP), could provide valuable data to support or refute this conceptualization of how psychosis develops. We therefore conducted a detailed follow-back study consisting of semistructured interviews with 430 patients and families supplemented by chart reviews in a catchment-based sample of affective and nonaffective FEP. The onset and sequence of 27 pre-onset nonpsychotic (NPS) or subthreshold psychotic (STPS) symptoms was systematically characterized. Differences in proportions were analyzed with z-tests, and correlations were assessed with negative binomial regressions. Both the first psychiatric symptom (86.24% NPS) and the first prodromal symptom (66.51% NPS) were more likely to be NPS than STPS. Patients reporting pre-onset STPS had proportionally more of each NPS than did those without pre-onset STPS. Finally, there was a strong positive correlation between NPS counts (reflecting complexity) and STPS counts (β = 0.34, 95% CI [0.31, 0.38], P < 2 e-16). Prior to a FEP, NPS precede STPS, and greater complexity of NPS is associated with the presence and frequency of STPS. These findings complement recent arguments that the emergence of psychotic illness is better conceptualized as part of a continuum-with implications for understanding pluripotential developmental trajectories and strengthening early intervention paradigms.

On sets of indefinitely desubstitutable words

The stable set associated to a given set S of nonerasing endomorphisms or substitutions is the set of all right infinite words that can be indefinitely desubstituted over S. This notion generalizes the notion of sets of fixed points of morphisms. It is linked to S-adicity and to property preserving morphisms. Two main questions are considered. Which known sets of infinite words are stable sets? Which ones are stable sets of a finite set of substitutions? While bringing answers to the previous questions, some new characterizations of several well-known sets of words such as the set of binary balanced words or the set of episturmian words are presented. A characterization of the set of nonerasing endomorphisms that preserve episturmian words is also provided.

Abstract 16774: Adverse Childhood Experiences Reported by Adults With Congenital Heart Disease

Introduction: Adverse childhood experiences (ACEs), such as witnessing domestic abuse or experiencing physical/sexual abuse, are associated with poorer long-term health outcomes, including acquired cardiovascular disease. This study offers the first investigation of ACEs in adults with congenital heart disease (CHD). Methods: In this cross-sectional study, adult CHD outpatients completed the ACE Questionnaire, the Relationship Scales Questionnaire, the Perceived Stress Scale, and a 0 - 100 linear analogue scale of quality of life. Total scores on the ACE Questionnaire range from 0 - 10 (a point for each ACE reported) and scores ≥ 4 are associated with poorest health outcomes. We performed correlations, t-tests, and analyses of variance to explore relationships between ACE Questionnaire scores and demographics, medical variables, and other survey scores. Results: A total of 100 patients were enrolled in the study (40 ± 13 years; 60% female). Ninety percent had defects of moderate or great complexity and 79% were categorized as American Heart Association anatomy + physiology stage B, C or D (i.e., some degree of symptoms and/or functional impairment). Total scores on the ACE Questionnaire ranged from 0 - 9, with a mean of 2.6 ± 2.5; 30% reported ≥ 4 ACEs. The most frequently reported ACEs were parental divorce (46%), emotional abuse (42%), and parental substance abuse problem (32%). ACE Questionnaire scores did not differ as a function of age, sex, defect complexity, or anatomy + physiology stage. However, total ACE score was significantly correlated with all 4 relationship styles (secure, preoccupied, dismissive and fearful; p-values &lt; 0.05). Quality of life scores were lower among those with elevated ACEs, although this did not reach statistical significance (69 vs. 76, p = 0.07). Conclusion: It is well accepted that adults with CHD face many health-related challenges throughout their lives. This study serves as an important reminder to providers that many patients will also experience other significant (and potentially traumatic) stressors in childhood. Further research is needed to determine whether the impact of ACEs on adults with CHD extends beyond relationship and stress outcomes and also includes cardiac morbidity and mortality.

UAV-Aided Information and Energy Transmissions for Cognitive and Sustainable 5G Networks

To develop sustainable fifth generation (5G) wireless networks and utilize the unused spectrum, this paper focuses on cognitive radio (CR) based wireless information and energy transmissions from an unmanned aerial vehicle (UAV) to multiple low-power ground terminals (GTs). By practically considering the location-dependent air-to-ground (A2G) channel states and the non-linear energy harvesting (EH), we propose a dynamic fly-hover-transmit scheme, where the UAV successively flies between GTs, and hovers close to each GT for efficient wireless energy transfer (WET) or wireless information transfer (WIT) when the primary user (PU) is idle. By causally and optimally determining the UAV’s mobility and transmit power for each selected transmission mode (WIT, WET, or being silent), we formulate the UAV’s sum-throughput maximization over all GTs as a constrained Markov decision process (MDP) problem with battery energy constraints at all GTs and the UAV. Due to the infinitely large MDP system state space, this problem is difficult to solve. We then decompose this problem into two subproblems, by first deciding the UAV’s transmission mode and power above a given GT, and then optimizing the UAV movement policy over multiple GTs. In the first subproblem, we propose an approximate to the complicated MDP value function of low complexity in closed-form, and then analytically derive the threshold-based suboptimal transmission policies. In the second subproblem, we optimally solve a simple-but-fundamental two-GT case, and then extend the general location-dependent GT weight design to an efficient suboptimal UAV movement policy. Simulation results show the significantly improved system performance under the proposed suboptimal policies over various benchmarks in dynamic networks.

The Effect of Background Noise on Immediate Free Recall of Words in Younger and Older Listeners with Hearing Loss.

Auditory working memory is a crucial factor for complex cognitive tasks such as speech-in-noise understanding because speech communication in noise engages multiple auditory and cognitive capacities to encode, store, and retrieve information. An immediate free recall task of words has been used frequently as a measure of auditory working memory capacity. The present study investigated performance on the immediate free recall of words in quiet and noisy conditions for hearing-impaired listeners. Fifty hearing-impaired listeners (30 younger and 20 older) participated in this study. Lists of 10 phonetically and lexically balanced words were presented with a fixed presentation rate in quiet and noise conditions. Target words were presented at an individually determined most comfortable level (MCL). Participants were required to recall as many of the words in an arbitrary order immediately after the end of the list. Serial position curves were determined from the accuracy of free recall as a function of the word position in the sequence. Three-way analyses of variance with repeated measures were conducted on the percent-correct word recall scores, with two independent within-group factors (serial position and listening condition) and a between-group factor (younger, older). A traditional serial position curve was found in hearing-impaired listeners, yet the serial position effects depended on the listening condition. In quiet, the listeners with hearing loss were likely to recall more words from the initial and final positions compared with the middle-position words. In multi-talker babble noise, more difficulties were observed when recalling the words in the initial position compared with the words in the final position. Without a noise, a traditional U-shaped serial position curve consisting of primacy and recency effects was observed from hearing-impaired listeners, in accord with previous findings from normal-hearing listeners. The adverse impact of background noise was more pronounced in the primacy effect than in the recency effect.

Development of a secured optical code-division multiple access system by implementing hybrid 2D-modified Walsh code

We present the development of a multi-user cross-layer security network implemented on the optical code-division multiple access (OCDMA) with newly designed hybrid 2D-modified Walsh code (MWC) along with an algorithmic approach in cryptography domain. Minimum BER value is evaluated on the order of 10 − 50 using our designed MWC, which is comparatively lower than other existing codes. The security performance of the network was analyzed using the probability detection parameter, which was found to be superior apart from few other available existing codes. The enhancement of the quality and grade of security in this network eavesdropper can intercept the designed optical code of OCDMA in the physical layer. It compels one to break the security in the data-layer to access the original code. We also calculated the probability of successful data interception as a function of time complexity. Furthermore, we presented the simulation of the hybrid system using the OptiSystem simulator.

Encoding Labelled p-Riordan Graphs by Words and Pattern-Avoiding Permutations

The notion of a p-Riordan graph generalizes that of a Riordan graph, which, in turn, generalizes the notions of a Pascal graph and a Toeplitz graph. In this paper we introduce the notion of a p-Riordan word, and show how to encode p-Riordan graphs by p-Riordan words. For special important cases of Riordan graphs (the case $$p=2$$ ) and oriented Riordan graphs (the case $$p=3$$ ) we provide alternative encodings in terms of pattern-avoiding permutations and certain balanced words, respectively. As a bi-product of our studies, we provide an alternative proof of a known enumerative result on closed walks in the cube.

Hierarchical Epidemic Risk Modeling of Spreading New COVID-19 Coronavirus

The subject of the research are a multi-level study of the territorial characteristics of emergency situations, analysis of operational information, and risk management of various origins. A topic model of the current COVID-19 coronavirus epidemic process have been developed in terms of reliability theory. The model is based on the methods of parametric hierarchical and variational modeling, which takes into account the similarity of exponential functions of the relationship between the parameters of the situation at different organizational levels.The objective of the work is to identify the characteristics of the reaction of the population of different countries to anti-epidemic measures of public risk management.The research methods are based on information technology for designing and approximating curves and surfaces with functions of various complexity, which is implemented by means of fractal parametric modeling of spatial objects and allows you to create new graphical confi gurations by varying the parameters and functions of their connections. Calculations are performed in variables that are biased relative to the environmental values, which makes it possible to take into account the territorial specifi cs of managing the parameters of the failure rate (risk of disease). In comparative statistical analysis, the advantage of this modeling is related to the relativity of reliability indicators, which makes it possible to eliminate country-specific features of epidemiological data collection. The complexity of hierarchical models is expressed in the multiplicity of embedding (superposition) of exponential functions. The model of the epidemic does not regulate the intensity of infection (disease risk), but reduces the acceptable risk of infection by organizational pressure on the magnitude of this risk. The effectiveness of the impact is assessed by the values of stable manageability indicators, which is individual for each territory. The Chinese authorities demonstrated high manageability of the population's behavior in the conditions of the beginning of the epidemic. The average manageability level is typical for Western countries with similar trends in the development of the pandemic. Russian society has shown low manageability with a high degree of state readiness to fight the pandemic.

Tobacco Harm Reduction: in pursuit of awareness and training for health care professionals

Cigarette smoking harms as to morbidity and mortality and relative costs constitute a real plague. It concerns not just health care providers but is also a function of the intrinsic complexity of tobacco addiction.

A network model for stemflow solute transport

While the role of stemflow in directing and concentrating water and nutrients at the tree base is rarely in dispute, its mathematical representation remains a subject of inquiry and research. A network model that seeks to estimate stemflow solute concentration and leaching is proposed. The model accommodates the physico-chemical properties of individual furrows embedded within the tree bark and their interconnections. The within-furrow equations for water and solute transport that include leaching are first developed and integrated along a rough-bark network topology to describe solute concentration and fluxes out of the network. The model is parameterized using published data on stemflow, field measurements of bark geometry, and laboratory experiments on bark leaching for potassium, magnesium, and calcium. The parameterization is intended to impose plausibility constraints and not to test model predictions at a particular site, a single event, or an individual experiment. The outflow concentration is then analyzed as a function of the network complexity that includes asymmetry in the lengths or subpaths connecting network nodes. For a symmetric network, an effective ’channel-flow’ analogy may be used to represent solute concentration at the outflow. However, as the asymmetry increases in subpath lengths, the efficiency of the bark network at moving solutes diminishes for the same rainfall input onto the stem. The network representation featured here is by no means offering a ’finality’ to the stemflow mathematical representation. It must be viewed as an embryonic step that opens up the possibility of using modern advances in network theories to link rainfall properties to stemflow water and solute input from a variety of tree species with differing bark microrelief configurations into the soil.

Risk Of Running-related Injury Associated With Center Of Mass Acceleration Complexity

Dynamical systems theory suggests that examining the complexity of biological signals may be more sensitive in differentiating between groups of varying health status, including predicting who may develop a running-related overuse injury (RROI). This theory has yet to be tested in prospective running studies. PURPOSE: To evaluate if changes in complexity, quantified by mean control entropy, of center of mass (COM) resultant acceleration during running is associatedwith RROI development. METHODS: 30 collegiate runners wore an ActiGraph GTX3+ during ‘easy’ training runs throughout a cross-country season. Clinician-diagnosed RROI were reported via an online survey. Complexity was calculated on the resultant acceleration time series from each run. Cox proportional hazards analysis assessed injury risk as a function of the mean complexity for each runner across the season and the change in complexity per week. RESULTS: Seven runners sustained an injury. Across all 30 participants over the season, the mean ± 1SD complexity was 0.623 ± 0.086 units. The mean change in complexity over the course of the cross country season was -0.0014 ± 0.0043 units per week. Although not statistically significant, each 0.1-unit increase in complexity was associated with a 1.65-fold increase in injury rate (95% CI 0.70-3.89, p=0.30) and a 0.01-unit increase in complexity per week was associated with a 1.50-fold increase in injury rate (95% CI 0.06-35.5, p = 0.80). CONCLUSION: These preliminary findings suggest that COM complexity could at least contribute to RROI detection strategies in cross-country runners. Given these preliminary results, additional prospective studies with larger sample sizes are necessary to further assess relationships between baseline complexity and changes in complexity during running training that can be monitored with wearable technology.

Modified Gaussian models applied to the description and deconvolution of peaks in chiral liquid chromatography

The description of the profiles of chromatographic peaks has been studied extensively, with a large number of proposed mathematical functions. Among them, the accuracy achieved with modified Gaussian models that describe the deviation of an ideal Gaussian peak as a change in the peak variance or standard deviation over time, has been highlighted. These models are, in fact, a family of functions of different complexity with great flexibility to adjust chromatographic peaks over a wide range of asymmetries and shapes. However, an uncontrolled behaviour of the signal may occur outside the region being fitted, forcing the use of different strategies to overcome this problem. In this work, the performance of the LMG (Linear Modified Gaussian), PVMG (Parabolic Variance Modified Gaussian), and PLMG (Parabolic-Lorentzian Modified Gaussian) models is compared with variants obtained by combination of the modified Gaussian models with an equation that adds an exponential tail and with other functions that limit the growth of the independent variable. The behaviour of the approaches is checked through the simultaneous fitting of enantiomeric peaks showing a wide range of characteristics, obtained in the separation of drugs with chiral activity by liquid chromatography using enantioselective columns. The study is also carried out with the purpose of performing the deconvolution of the peaks of the enantiomers, when these are not completely resolved, in order to evaluate the enantiomeric fraction.

WCE polyp detection based on novel feature descriptor with normalized variance locality-constrained linear coding.

Wireless capsule endoscopy (WCE) has become an effective facility to detect digestive tract diseases. To further improve the accuracy and efficiency of computer-aided diagnosis system in the detection of intestine polyps, a novel algorithm is proposed for WCE polyp detection in this paper. First, by considering the rich color information of endoscopic images, a novel local color texture feature called histogram of local color difference (LCDH) is proposed for describing endoscopic images. A codebook acquisition method which is based upon positive samples is also proposed, generating more balanced visual words with the LCDH features. Furthermore, based on locality-constrained linear coding (LLC) algorithm, a normalized variance regular term is introduced as NVLLC algorithm, which considers the dispersion degree between k nearest visual words and features in the approximate coding phase. The final image representations are obtained from using the spatial matching pyramid model. Finally, the support vector machine is employed to classify the polyp images. The WCE dataset including 500 polyp and 500 normal images is adopted for evaluating the proposed method. Experimental results indicate that the classification accuracy, sensitivity and specificity have reached 96.00%, 95.80% and 96.20%, which performances better than traditional ways. A novel method for WCE polyp detection is developed using LCDH feature descriptor and NVLLC coding scheme, which achieves a promising performance and can be implemented in clinical-assisted diagnosis of intestinal diseases.