Dependence Index Research Articles

The dependence index based on martingale difference correlation: An efficient tool to distinguish different complex systems

For the study of complex systems, the existing correlation measures suffer from deficiencies and may lead to the loss of information and inefficient characterizations of complex systems. We aim to capture detailed dynamical characteristics from complex systems effectively, including periodical features, chaotic features, and mixed features. Our objectives also include discriminating different complex systems and performing clustering of complex data with higher efficiency. So in this paper, we propose the dependence index (DI) based on the martingale difference correlation (MDC), the synchronization index, and the phase space reconstruction. Through simulation experiments, we demonstrate that our proposed method is effective in detecting different and subtle dynamical features, including periodic, chaotic, and mixed behaviors. For applications, we apply our method to analyze real-world data, including heartbeat signals, stock indices, bearing fault data, image outline data, CBF data, and food spectrum data. To achieve our objectives and demonstrate the applicability of our method, the DI is applied to multidimensional scaling (MDS) to cluster reality-based data with better performance when compared with the MDS based on other measures. We affirm that our method can distinguish different complex systems more effectively and obtain detailed information.

The dependence measurements based on martingale difference correlation and distance correlation: Efficient tools to distinguish different complex systems

The study of the relationships between time series is the basis of nonlinear dynamics and especially plays an important role in revealing the dynamical relationships between different systems. So in this work, we use the volatility martingale difference divergence matrix (VMDDM) to construct the dependence index (DI) from the perspective of the martingale difference correlation (MDC) and the phase space reconstruction. The dependence measure (DM) is also structured based on the phase space reconstruction and the refined version of distance correlation (RDC), which involves a modified distance dependence statistic. Through simulation experiments, it is demonstrated that our proposed methods are efficient in discovering various subtle dynamical characteristics. For applications, data from the real world are used, containing human heartbeat data, stocks indices series, data of complex image outlines, artificial CBF data, and data of food (coffee) spectrum. We are sure that the proposed approaches can obtain information with more specifics when compared with the state-of-the-art cross-sample entropy (CSE) and the frequently used synchrony measuring technique, the synchronization index (SI). Moreover, for complex systems, we construct the DM-tr(VMDDM) plane to achieve distinct and reasonable results of clustering.

Rehabilitation Nursing Program in Oncological Surgery of the Head and Neck: A Retrospective Cohort Study

Background: Head and neck cancer (HNC) has a considerable mortality and morbidity rate. Surgery is one of the most effective treatments; however, it may compromise the independence of patients after its performance. Early start rehabilitation is essential for the recovery of these patients, preventing functional capacity limitations. Objective: The objective of this study was to compare the independence between hospitalized patients who underwent rehabilitation nurse (RN) intervention versus general health care after HNC surgery. Methods: Patients submitted to different types of HNC surgery were divided into two groups intervention by the RN versus general health care, the outcome was the independence categorized as dichotomic to assess the patient independence at discharge and their differences calculated by statistical analysis. To analyze the effect of the RN intervention on independence, a Poisson regression model was used, adjusting the confounding factors initial Barthel Index and age in the variable Barthel Index independence. Results: Independence at discharge (p = 0.01) improved significantly in the RN intervention group compared to the general health care group. The intervention of the RN after surgery had a positive effect on the independence of the patients, after adjusting the confounding factors (RR: 1.47; 95% CI: [1.02; 2.12]). In the middle/late postoperative period, in the group with RN intervention (n = 79), the hospitalization time was reduced by 4.29 days versus general health care (n = 72). Conclusion: The RN intervention is an added value in the independence of the patient submitted to HNC surgery. It is an innovative study in patients after diagnosis of HNC, showing that the intervention of RN through rehabilitation programs allows independence after his surgery.

A Novel Optimization Method for a Multi-Year Planning Scheme of an Active Distribution Network in a Large Planning Zone

Electric power distribution networks plays a significant role in providing continuous electrical energy to different categories of customers. In the context of the present advancements, future load expansion in the active distribution networks (ADNs) poses the key challenge of planning to be derived as a multi-stage optimization task, including the optimal expansion planning scheme optimization (EPSO). The planning scheme optimization is a multi-attribute decision-making issue with high complexity and solving difficulty, especially when it involves a large-scale planning zone. This paper proposes a novel approach of a multi-year planning scheme for the effective solution of the EPSO problem in large planning zones. The proposed approach comprises three key parts, where the first part covers two essential aspects, i.e., (i) suggesting a project condition set that considers the elements directly related to a group of specific conditions and requirements (collectively referred to as conditions) to ADN planning projects; and (ii) Developing a condition scoring system to evaluate planning projects. The second part of our proposed scheme is a quantization method of correlativity among projects based on two new concepts: contribution index (CI) and dependence index (DI). Finally, considering the multi-year rolling optimization, a detailed mathematical model of condition evaluation and spatiotemporal optimization sequencing of ADN planning projects is developed, where the evaluation and optimization are updated annually. The proposed model has been successfully validated on a practical distribution network located in Xiantao, China. The investigated case study and comparisons verify the various advantages, suitability, and effectiveness of the proposed planning scheme, consequently saving more than 10% of the investment compared with the existing implemented scheme.

A multi-criteria comprehensive evaluation method for distributed energy system

As the evaluation of distributed energy system (DES) is a complex problem, multi-criteria is necessary to fully evaluate the performance for different systems. In this paper, a novel multi-criteria evaluation method was established to assess the comprehensive performance of DES from economic, energy and environment criterions. Before constructing a multi-level indexes system, index correlation analysis was carried out to ensure the independence of indexes. Considering the advantages and disadvantages of subjective and objective methods, AHP-entropy method was proposed by integrating analytic hierarchy process (AHP) and information entropy method together to assign weights to the indexes. Finally, the technique for order preference by similarity to ideal solution (TOPSIS) method was applied to determine the optimal DES scheme. The case study indicated that the evaluation results of this method were in accordance with the reality, which could provide a reference for the selection of DES solutions.

Effects of a 12-Week Aerobic Exercise Program Combined with Music Therapy and Memory Exercises on Cognitive and Functional Ability in People with Middle Type of Alzheimer's Disease

Background: The Alzheimer's disease is the most common form of dementia and represents 60% of its cases. The disease is characterized by cognitive, non-cognitive and functional deficits and it’s incurable. The main of this study was to examine the effects of the aerobic exercise in combination with the music therapy and memory exercises in functional and cognitive ability on a patient with that have been affected by middle type (Second stage) of Alzheimer's disease.Methods: Thirty patients from Chronic Diseases Center, with Alzheimer's disease, divided between an intervention and a control group, participated in this randomized controlled study. (Thirty patients with Alzheimer's were chosen from chronic disease center, and are divided into an intervention and a control group). The intervention requires 30 minutes of aerobic exercise, 10 minutes of memory games and music therapy, three times a week, for the duration of 12 weeks. The outcome measures the “Mini Mental State Examination” (MMSE) scale and the “Alzheimer's Disease Assessment Scale cognitive test” (ADAS) for the cognitive ability, “Katz Index Independence in Activities of Daily Living” (ADL), “Get up and Go test” and “One leg standing balance test” (OLST) for the functionality. A three-way analysis of variance designs was applied to compare changes in each outcome measure before and after the intervention between the groups.Results: The MMSE score decrease significantly for the control group (males: 16.00 ± 4.04 to 15.14 ± 4.01 and for females: 16.00 ± 1.85 to 15.25 ± 1.98 before and after intervention) but not for the intervention group (p > 0.05) (males: 16.25 ± 2.71 to 16.12 ± 2.94 and females: 12.85 ± 2.67 to 12.57 ± 2.93). The ADAS score on intervention experimental therapy group was significantly low (males: 39.00 ± 7.98 to 37.50 ± 8.12 and females: 49.85 ± 6.54 to 48.28 ± 6.79). In the Get up and Go test (males: 18.87 ± 5.24 to 17.87 ± 4.15 and females: 19.85 ± 4.94 to 18.57 ± 4.64) and in the OLST(males: 4.57 ± 3.10 to 6.00 ± 2.77 and females: 4.00 ± 3.26 to 5.28 ± 3.40) there was a sign of progress in the results, while in the ADL no difference was observed in any group. (experimental group males: 3.50 ± 1.19 to 3.50 ± 1.19 and females: 2.57 ± 1.13 to 2.57 ± 1.13, control group males: 3.57 ± 1.51 to 3.57 ± 1.51 and females: 3.50 ± 0.75 to 3.50 ± 0.75).Conclusion: The aerobic exercise combined with the music therapy and the memory tests offer some improvement in cognitive and functional ability and contribute to the deteriorating delay of the symptoms of patients that suffer from Alzheimer and are hospitalized.

Influence of Kenyan Youth’s Perception towards Agriculture and Necessary Interventions; a Review

Approximately 64% of unemployed persons in Kenya are youth, most of which live in rural areas and lacks formal education and vocational or professional skills. In spite of this, youth participation in agriculture has been relatively low in the country. This may be partly attributed to, among other factors, the poor perception of the youth on agriculture . Agriculture which is basically a rural oriented sector remains the backbone of the Kenya’s economy co ntributing over 30% of GDP. The sector provides over 80% of employment opportunities in the country but remains unattractive to the youth. This implies that most of the Kenyan youth are not fully engaged in productive economic activities which put their de pendency index quite high. If the perception of youth towards agriculture

Phylogenetic community structure: temporal variation in fish assemblage.

Hypotheses about phylogenetic relationships among species allow inferences about the mechanisms that affect species coexistence. Nevertheless, most studies assume that phylogenetic patterns identified are stable over time. We used data on monthly samples of fish from a single lake over 10 years to show that the structure in phylogenetic assemblages varies over time and conclusions depend heavily on the time scale investigated. The data set was organized in guild structures and temporal scales (grouped at three temporal scales). Phylogenetic distance was measured as the mean pairwise distances (MPD) and as mean nearest-neighbor distance (MNTD). Both distances were based on counts of nodes. We compared the observed values of MPD and MNTD with values that were generated randomly using null model independent swap. A serial runs test was used to assess the temporal independence of indices over time. The phylogenetic pattern in the whole assemblage and the functional groups varied widely over time. Conclusions about phylogenetic clustering or dispersion depended on the temporal scales. Conclusions about the frequency with which biotic processes and environmental filters affect the local assembly do not depend only on taxonomic grouping and spatial scales. While these analyzes allow the assertion that all proposed patterns apply to the fish assemblages in the floodplain, the assessment of the relative importance of these processes, and how they vary depending on the temporal scale and functional group studied, cannot be determined with the effort commonly used. It appears that, at least in the system that we studied, the assemblages are forming and breaking continuously, resulting in various phylogeny-related structures that makes summarizing difficult.

The allocation of patients in an intensity-of-care based Internal Medicine ward: the ADOIT Tri-Co (Triage in the Corridor) study

BACKGROUND Early warning scores based on simple physiological variables were originally derived to recognize the impending patients' clinical deterioration and to prevent in-hospital deaths. However, they can also be used to allocate patients on admission. The hypothesis of a previously validated model, the Modified Early Warning Score (MEWS) was tested. It could be used as a stratifying tool to identify medical patients whose baseline physiological measures predict a worse outcome, in order to assign them to an appropriate care level (e.g., High Dependence Units, special areas etc.). METHODS We considered all patients admitted to Internal Medicine wards over a week period, without any exclusion criteria. On admission, we calculated the MEWS and a 28-variables original Dependence Index (DI). The main outcomes of the study were: in-hospital mortality and a composite of mortality and admission to a higher care level (namely, transfer to ICU, Coronary Care Unit, CCU, or Emergency Medicine). A secondary end-point was the length of stay for discharged patients. RESULTS 22 Internal Medicine wards participated in the study. 597 patients were admitted, 329 females (55.4%; 95% CI 51.3-59.4) and 265 males (44.6%; 95% CI 40.6-48.7; female to male ratio was 1.24; p < 0.05). Women were older (mean age 76.2 years) than men (73.3 years); a large proportion of patients (509/597 or the 85.2%) were 65 or older. 522 patients were discharged, 44 died and 31 were transferred. The MEWS on admission predicted both death (Chi2 for trend 59.391, p < 0.00001) and the death and transfer composite end-point (Chi2 for trend 55.339; p < 0.00001); the DI worked well, too (risk of death, Chi2 for trend 53.052; p < 0.00001; risk of death or transfer, Chi2 for trend 66.030; p < 0.00001). These results were not influenced by either the wards dimensions or the hospitals complexity. CONCLUSIONS In this multicentric study we have confirmed that the MEWS, even when calculated once on admission, is a simple but highly useful tool to predict a worse in-hospital outcome.

Incorporating message weights in UML-based analysis of behavioral dependencies in distributed systems

Behavioral dependency analysis (BDA) and the visualization of dependency information have been identified as a high priority in industrial software systems (in specific, distributed systems). BDA determines the extent to which the functionality of one system entity (e.g., an object or a node) depends on other entities. Among many uses, a BDA is used to perform risk analysis and assessment, load planning, fault tolerance and redundancy provisions in distributed systems. Traditionally, most BDA techniques are based on source code or execution traces of a system. However, as model-driven development is gaining more popularity, there is a need for model-based BDA techniques. To address this need, we proposed in a previous work a metric, referred to as dependency index (DI), for the BDA of distributed objects and nodes based on UML behavioral models (sequence diagrams). However, in our previous BDA work, for simplicity, it was assumed that all messages are equivalent in terms of the dependencies they entail. However, to perform a more realistic BDA on real-world systems, messages must be weighted, e.g., certain messages may be more critical (or important) than others, and thus entail more intensive dependency. To address the above need, we define in this article a family of new BDA metrics, as extensions to our basic DI metric, based on different weighting mechanisms. Through an example application of the proposed metrics, we show that they can be used to predict more realistic dependency information. Furthermore, we derive interesting observations from our dependency analysis that would influence, in practice, practical decisions, which could not have been easily derived without it, e.g., we come up with a suggestion to install more reliable data-transmission network links between two nodes to ensure a reliable communication on links with intensive dependencies.

Improving and Extending Home Range and Habitat Analysis by Integration with a Geographic Information System

The minimum convex polygon and fixed kernel techniques for analysing animal home range (HR), and the Schoener index independence test, are integrated as functions into the ArcView GIS. The ArcView Spatial Analyst, 3DAnalyst, SmartImage, Movement and Xtools extensions are used, as is the Avenue customization language. HR is calculated in surface area and presented over a virtual model of the landscape. The efficiency of HR analysis, interpretation and understanding is greatly improved within a GIS, eliminating the need to engage in the traditional multi‐procedural approach using external packages. A case study is undertaken using observational data from four eastern grey kangaroos (Macropus giganteus). The GIS, through use of query and partitioning functionality, enables a deeper understanding of the parameters influencing each HR estimate. Geo‐referenced multiple data overlay is shown to significantly enhance comparison of estimates of more than one animal and the identification of error.

Quality of paediatric care: application and validation of an instrument for measuring parent satisfaction with hospital care.

To apply and validate an adapted version of an existing adult patient questionnaire in a study of parental satisfaction with paediatric care in a university hospital. A cross-sectional, anonymous questionnaire study. A total of 912 questionnaires were distributed to parents by hospital staff during a 2-week period. A university children's hospital in Stockholm, Sweden. Six hundred and twenty-four parents whose children were receiving care at the hospital during a 2-week period in April of 1999. The 63-item questionnaire uses eight main measurement indices and an overall quality rating to define parental satisfaction with paediatric care. Measures of the instrument's reliability and validity were established by comparison with results of a pilot study conducted 1 year earlier on the paediatric departments of two regional Swedish hospitals. All measures were compared to reliability and validity estimates in the original patient questionnaire. A total of 624 questionnaires were returned, a response rate of 68%. The instrument demonstrated good reliability and validity. Reliability estimates for all eight indices were greater than 0.70 and consistent over time. Inter-index correlations were generally lower than 0.60, indicating index independence. Of the nine parameters measured, parents were most satisfied with staff attitudes, care processes and medical treatment. Parents' ratings were lowest for accessibility and staff work environment. This study presents a valid and reliable questionnaire instrument for measuring parental views of paediatric hospital care. The instrument measures the quality of paediatric care from a broader perspective than previously existing parent questionnaires.

Prospective study of factors influencing the development of craving associated with smoking cessation

There have been few prospective studies of craving following smoking cessation. This paper presents findings from a prospective examination of factors associated with craving over an 8-week treatment period. Two findings merit attention: (1) dependence, as measured by the Dependence Index (DI), was associated with craving at 48 h, 4 and 8 weeks post-cessation. The magnitude of the association between the DI and short-term craving was, at the least, comparable to that previously reported among several biochemical measures of smoke intake; (2) a measure of craving obtained 48 h after smoking cessation was associated with treatment outcome. Forty-three per cent of participants with low initial craving scores were abstinent at a 2-month follow-up compared to only 26% of those with high craving scores. The DI was also associated with participants' status at follow-up. This result is interesting because evidence that craving or other abstinence effects are prospectively associated with outcome has been lacking.