Subjective Perception Of Quality Research Articles

A Superpixel-Wise Just Noticeable Distortion Model

The just noticeable distortion (JND) model reveals the visibility limitation. Human eyes hold different attention and sensitivity to different regions owing to different contributions to the perceptual quality. In this paper, a superpixel-wise JND model based on region (RJND) is proposed. First, an image is segmented into superpixels by the simple linear iterative clustering (SLIC). Then, region color contrast is calculated for each region and foveation regions are selected for the image. Based on the human visual perception, a region weighting model is established by incorporating region color contrast and foveation regions modulation. Considering the contrast masking (CM) effect is not perfect, we introduce the texture coarseness combined with CM effect for a more accurate visual masking effect. Finally, a new region JND model is established by combining the region weighting model and the coarseness modulation. The experimental results demonstrate the proposed RJND model can decrease PSNR more efficiently compared with some existing JND models when achieving nearly the same subjective perceptual quality. It can remove much more visual redundancy.

A Hybrid QoS-QoE Estimation System for IPTV Service

The internet protocol television service (IPTV) has become a key product for internet service providers (ISP), offering several benefits to both ISP and end-users. Because packet networks based on internet protocol have not been prepared for time-sensitive services, such as voice or video, packet networks have had to adopt several mechanisms to secure minimal transmission standards in the form of data stream prioritization. There are two commonly used approaches for video quality assessment. The first approach needs an original source for comparison (full-reference objective metrics), and the second one requires observers for subjective evaluation of video quality. Both approaches are impractical in real-time transmission because it is difficult to transform an objective score into a subjective quality perception, and on the other hand, subjective tests are not able to be performed immediately. Since many countries worldwide put IPTV on the same level as other broadcasting systems (e.g., terrestrial, cable, or satellite), IPTV services are subject to regulation by the national regulation authority. This results in the need to prepare service qualitative criteria and monitoring tools capable of measuring end-user satisfaction levels. Our proposed model combines the principles of both assessment approaches, which results in an effective monitoring solution. Therefore, the main contribution of the created system is to offer a monitoring tool able to analyze the features extracted from the video sequence and transmission system and promptly translate their impact into a subjective point of view.

Consumer perception of plant-based proteins: The value of source transparency for alternative protein ingredients

Consumers in the ‘clean label’ trend are increasingly interested in knowing the ingredients of their food. There is also an emerging demand for more and diverse protein products as well as a trend towards plant-based foods. Food manufacturers consider reformulation of the ingredient lists of their products or innovation of new food products answering to these trends. However, they need to know how consumers perceive new alternative ingredients, such as alternative proteins, and how the exchange of ingredients affects overall product and subjective quality perception. An experimental quantitative and qualitative survey study among 495 consumers in Denmark explored how consumer ingredient perception carries over to product perception as well as how differences in one protein ingredient affects attitude and subjective quality perception for plant-based products containing protein. Results confirm the favourable view on protein as an ingredient. Among consumers who have experience with or an interest in plant-based food, specifying the protein origin leads to more favourable perception of the product. Potato protein emerges as particularly favourable in a number of subjective quality dimension, is freely associated with starch and well understood as providing texture. Findings suggest food manufacturers can improve product perception among the target market when highlighting the precise protein type in the ingredient list. Potato protein can be a worthwhile alternative protein to use as it leads to favourable consumer perception.

Research on assessment method of network quality performance for a private data network

These authors focuses on an assessment method of network quality performance research for a private data network which can be made up of either leased lines or IP-Virtual Private Network (IP/VPN). It is the very difficult to obtain real-time monitoring assessment information for leased lines in a point-to-point network from the traditional network evaluation methods; the reason for this is that a variety of network infrastructures and traffic are applied in this kind of network. The typical parameters measured for network performance assessment include packet loss, delay, throughput, and so on. These are difficult to interpret in terms of excellent, good, fair, poor, or bad for a network performance. Moreover, judge the quality of network by customers is always based on the subjective perception of quality which is a less objective assessment in practical cases. However, the network providers need a comprehensive and quantized method for network performance monitoring and evaluation, and need to satisfy the commitment of Service Level Agreement (SLA) for customers. This paper proposed a comprehensive multiple indexes assessment method based on the Dempster–Shafer (D–S) evidence structure for comprehensive service assessment or specific service assessment, such as data transmission service evaluation as well as voice and video service evaluation. The real testing data is used to verify the viability of this method. Based on the proposed method, the relative software was produced and has been tested in a real network. The testing results show that this method can offer the real-time and objective service performance assessments for users and the network providers under the full-service operation.

Impacts of internal HMD playback processing on subjective quality perception

Impacts of internal HMD playback processing on subjective quality perception

Wheelchair basketball: fitness and quality of life

Abstract: The study aimed to assess the physical activity (PA) level, subjective perception of quality of life (QOL), muscle strength, flexibility, and agility in wheelchair basketball (WB) players from Pelotas/RS. The sample consisted of 10 WB amateur athletes. For muscle strength, it was applied three isometric handgrip tests - maximum handgrip test (MIHS in kgf), sub-maximum handgrip test (to assess strength endurance at 70% of MIHS (70MIHS in s) and scapular isometric test (SIS), - and two isotonic tests to measure strength endurance (maximum repetitions in 1 min) in: i) elbow flexor muscles (EFS) and ii) shoulder abductors (SAS). To evaluate agility, it was conducted adapted 20-m Shuttle Run (SR). For flexibility, it was adopted Apley’s and Back Stretch tests. Physical activity and QOL were measured by IPAQ and WHOQOL–bref, respectively. After that, descriptive statistics and t test were used with significance level at 5%. The performance in MIHS, 70MIHS, SIS, EFS, SAS and Apley’s test was, respectively, 46.17±5.06 kgf, 49.31±15.75 s, 28.44±11.53 kgf, 37.10±9.89 reps, 28.30±6.56 reps and 12.70±10.94 to right side and 47.51±8.98 kgf, 45.41±11.28 s, 30.75±12.64 kgf, 40.40±7.79 reps, 29.80±5.55 reps and 13.35±5.06 cm to left side. The athletes reached 93.00±10.92 cm in the Back Stretch (cm) test and 16.23±1.93 s in the SR. They showed 736±120 min/week of moderate and 467±191.4 min/week of vigorous PA, and the WHOQOL-bref overall score was 67.62±5.45 au. The WB players exhibited QOL near from reference values and superior performance in agility test when compared with people with physical disabilities from other sports.

The quality of care questionnaire: development of a valid measure for persons with inflammatory bowel disease

Background and aims: Quality of care is important in lifelong illnesses such as inflammatory bowel disease (IBD). Valid, reliable and short questionnaires to measure quality of care among persons with IBD are needed. The aim of this study was to develop a patient-derived questionnaire measuring quality of care in persons with IBD.Methods and results: The development of the questionnaire The Quality of Care -Questionnaire (QoC-Q) was based on a literature review of studies measuring quality of care, and the results of two qualitative studies aiming to identify the knowledge need and perception of health care among persons with IBD. Further development and evaluation was done by focus groups, individual testing and cognitive interviews with persons with IBD, as well as evaluation by a group of professionals. After the development, the questionnaire was tested for validity and test–retest reliability in 294 persons with IBD.Conclusions: The QoC-Q is showing promising validity and reliability for measuring the subjective perception of quality of care. Further testing in clinical practice is suggested to assess if the QoC-Q can be used to evaluate care and areas of improvement in health care for persons living with IBD.

Predicting perceptual quality of images in realistic scenario using deep filter banks

Classical image perceptual quality assessment models usually resort to natural scene statistic methods, which are based on an assumption that certain reliable statistical regularities hold on undistorted images and will be corrupted by introduced distortions. However, these models usually fail to accurately predict degradation severity of images in realistic scenarios since complex, multiple, and interactive authentic distortions usually appear on them. We propose a quality prediction model based on convolutional neural network. Quality-aware features extracted from filter banks of multiple convolutional layers are aggregated into the image representation. Furthermore, an easy-to-implement and effective feature selection strategy is used to further refine the image representation and finally a linear support vector regression model is trained to map image representation into images’ subjective perceptual quality scores. The experimental results on benchmark databases present the effectiveness and generalizability of the proposed model.

What you pay is what you get?

Complementing the current paradigm change from QoS to QoE, we address fundamental QoE charging issues for Internet services from an end user perspective. Here, key issues arise from gaps of different information contexts involved, which have to be managed when introducing a QoE product. Hence, this paper analyzes the double role of prices for quality perception as well as the impact of QoE on user demand with the help of a fixed point model. Our model is consistent with real-world user behavior that we have observed during comprehensive user trials on quality perception for video on demand services. Based on these results, we propose a simple approach for convergence-based user classification, and discuss the complementarity of willingness-to-pay vs. subjective quality perception in service purchasing situations.

A QoC‐based model for performance and QoE trade‐off in distributed systems

SummaryThis paper proposes a quality of context (QoC)–based model to enhance trade‐off between system performance and users quality of experience (QoE) in distributed systems. The QoE considers the users subjective perceptions of quality on technology services and depends on context attributes related to the users expectations. In addition, context information can be used to improve performance in context‐aware systems. Therefore, the QoC‐based model proposed in this paper aims to establish performance and QoE trade‐off for resource allocation in distributed systems. With the massive data growth over the past years, the demand for computing capacity has been notably growing in a proportional way. In view of that, the demand for distributed systems has also increased significantly due to the advantages of distributed computing such as cost‐benefit gains, large processing capacity, and an extensive capability for resources sharing. In this sense, the large‐scale utilization of distributed systems has generated problems concerning resource allocation because of the heterogeneous characteristics and continuous evolution of distributed computational devices, resulting in several challenges in terms of environment performance and users' satisfaction trade‐off. The model conceived in this paper provides for an experimental evaluation considering performance and QoE trade‐off by means of simulations. Simulations were performed in order to study complex distributed systems scenarios. Experimental results showed that the proposed QoC model policy has an enhanced performance in comparison with classical approaches.

Visual saliency-based fast intracoding algorithm for high efficiency video coding

Intraprediction has been significantly improved in high efficiency video coding over H.264/AVC with quad-tree-based coding unit (CU) structure from size 64×64 to 8×8 and more prediction modes. However, these techniques cause a dramatic increase in computational complexity. An intracoding algorithm is proposed that consists of perceptual fast CU size decision algorithm and fast intraprediction mode decision algorithm. First, based on the visual saliency detection, an adaptive and fast CU size decision method is proposed to alleviate intraencoding complexity. Furthermore, a fast intraprediction mode decision algorithm with step halving rough mode decision method and early modes pruning algorithm is presented to selectively check the potential modes and effectively reduce the complexity of computation. Experimental results show that our proposed fast method reduces the computational complexity of the current HM to about 57% in encoding time with only 0.37% increases in BD rate. Meanwhile, the proposed fast algorithm has reasonable peak signal-to-noise ratio losses and nearly the same subjective perceptual quality.

Patient self-reported concerns in inflammatory bowel diseases: A gender-specific subjective quality-of-life indicator

BackgroundPatient-reported disease perceptions are important components to be considered within a holistic model of quality of care. Gender may have an influence on these perceptions. We aimed to explore gender-specific concerns of patients included in a national bilingual inflammatory bowel disease cohort.MethodsFollowing a qualitative study, we built a questionnaire comprising 37 items of concern. Answers were collected on a visual analog scale ranging from 0 to 100. Principal axis factor analysis was used to explore concern domains. Linear multiple regressions were conducted to assess associations with patient characteristics.ResultsOf 1102 patients who replied to the survey, 54% were female and 54% had Crohn’s disease. We identified six domains of concern: socialization and stigmatization, disease-related constraints and uncertainty, symptoms and their impact on body and mind, loss of body control (including sexuality), disease transmission, and long-term impact of the disease. Cancer concerns were among the highest scored by all patients (median 61.8). Severity of symptoms was the only factor associated with concerns, unrelated to dimension and gender (p<0.015). In women, being >40 years decreased disease-related constraints and uncertainty concerns, and being at home or unemployed increased them. Treatments were associated with increased socialization and stigmatization and with increased disease-related constraints and uncertainty concerns in men. Overall, psychosomatic characteristics were highly associated with concerns for both men and women. Depending on the concern dimensions, increased levels of concern were associated with the highest signs of anxiety in women or depression in men, as well as lower health-related quality of life in men.ConclusionsPatients have numerous concerns related to their illness that need to be reassessed regularly. Concerns differ between men and women, suggesting that information and communication about the disease should take gender differences and subjective perceptions of quality of life into consideration.

More than I ever wanted or just good enough? User expectations and subjective quality perception in the context of networked multimedia services

This article addresses the overall relevance and the influence of user expectations in the context of perceptual quality evaluation of technical systems, and how information about individual expectations can be integrated into research on Quality of Experience (QoE). Based on a literature survey on expectations in the fields of psychology, service quality and consumer satisfaction theory, an existing conceptual QoE perception model is extended by explicitly including desired and adequate expectations in the quality perception process. A direct expectation assessment paradigm is proposed that uses dedicated questionnaires. Further, it is shown how expectation-related knowledge can be used to increase the accuracy of quality prediction models. In addition, experimental setups are presented that enable controlled triggering of expectations in user studies. It is discussed how the role of expectations for QoE can be investigated in future research as well as how to further validate the proposed methods.

Evaluation of Quality of Life, Clinical Parameters, and Psychological Distress after Bariatric Surgery: Comparison of the Laparoscopic Sleeve Gastrectomy and Laparoscopic Greater Curvature Plication

Objectives: The aim of this prospective study was to compare the effect of two surgical methods, Laparoscopic Sleeve Gastrectomy (LSG) and Laparoscopic Greater Curvature Plication (LGCP), weight loss, and clinical parameters (fat, lean body mass [LBM], glycemia) on subjective perception of quality of life (QoL) regarding health and on anxiety and depression in obese patients during 12 months after the procedure. Further aim was to ascertain which clinical parameters contribute to a positive QoL after bariatric surgery. Methods: The research set consisted of 68 patients undergoing bariatric treatment (LSG and LGCP). QoL data were collected by means of the WHOQOL-BREF questionnaire, and the Hospital Anxiety and Depression Scale (HADS) was used to evaluate anxiety and depression. Patients filled the questionnaire before the planned surgery and later 3, 6, and 12 months after the planned surgery. Results: Body mass index (BMI) and body weight decreased, all monitored clinical parameters improved, and QoL, namely physical and psychological health, improved as early as 3 months after bariatric surgery (p < 0.01). No statistically significant differences in monitored parameters were found between the surgery types. Regarding physical and psychological health, an association was determined between changes in QoL and changes in BMI and circumference of the hips. Conclusion: QoL improvement experienced after bariatric surgery is associated particularly with weight reduction and lower levels of anxiety and depression, but not with other clinical parameters.

Ambulatório de mindfulness e promoção da saúde: relato de experiência

The aim of this study was to describe the experience and the profile of users of an outpatient clinic of Mindfulness and health promotion from a public University in Brazil. The profile of the participants was obtained from the application of different psychometric scales (BDI, SUBI, MAAS and EUROQOL 5 D), as well as socio‐demographic and health information. The description of the experience of the clinic was held from the SWOT technique. In this sample, the profile found was predominantly female, with health insurance and medical care. Despite the problems reported, the subjective perception of quality of life was above average. Belong to a public University, rely on multidisciplinary team and facilitators of different configurations in mindfulness, plus easily accessible location are strengths of this clinic, as well as the high prevalence of anxiety and depression, which can enhance the expansion of this activity.

Subjektives Qualitätsverständnis von Vertragszahnärzten im Umgang mit Qualitätsmanagement – Ergebnisse eines bundesweiten Surveys

Statutory health insurance dentists working in private practice have a duty to maintain and improve the quality of dental care. An individual practice's approach to quality management (QM) can be made to reflect the practice's philosophy on quality and standards and can be adapted to the specific requirements of the practice setting they are meant to serve. This study set out to collect data on the subjective perceptions of quality that exist among German dentists, and to canvass their views on the process and benefits of implementing QM systems. In doing so, this study aimed to identify the incentives and obstacles that currently exist in relation to the implementation and further development of practice-based QM systems. As part of a nationally representative cross-sectional study, a random sample of 2,084 dentists was asked to complete a questionnaire on perceptions of quality and QM. The response rate was 40.3% (n=838). The study's primary end point was defined as the surveyed dentists' interpretative description of quality. The study's secondary end point was defined as the dentists' subjective evaluations of the benefits of QM in the day-to-day management of their own practices. Responses to open-ended questions were analysed using content analysis, while quantitative questions were analysed using descriptive univariate analysis. When analysing respondents' subjective perceptions of quality (primary end point), the following dimensions were revealed as highly significant: patient (mentioned by 31.4% of the responders), quality of treatment (29.5%) and staff (14.8%). As far as the benefits of QM in the day-to-day management of the respondent's own practices (secondary end point) were concerned, these appeared to be linked to the ease of implementation of the organizational tools offered by QM systems: managing emergencies, team meetings and procedural check lists were ranked as "can be implemented to a reasonable degree" and "can be fully implemented" by 82.3%, 80.2% and 79.9% of respondents, respectively. There appeared to be a disconnect between the respondents' subjective perceptions of quality and the benefits of QM as part of day-to-day practice management, with QM systems failing to reflect the respondents' subjective views on quality. The perceptions of QM among German statutory health insurance dentists are generally positive but marked by a disconnect between aspects of quality currently measured by QM systems and the dentists' views on what is required in order to assess quality standards in relation to the dimensions "patient", "quality of treatment" and "staff". A targeted review of the tools offered by QM systems may lead to improved ease of implementation. If QM is to form an integral part of clinical practice, all future developments need to consider the dentists' subjective perceptions of quality and their attitudes towards QM.

Evaluation of the impact on quality of life of patients with temporomandibular disorders

BACKGROUND AND OBJECTIVES: Chronic pain, such as temporomandibular disorder, often leads to significant changes in quality of life. This study aimed at evaluating the influence of temporomandibular disorders in the subjective perception of quality of life by means of the Oral Health Impact Profile-14. METHODS: Participated in the study 80 patients diagnosed with temporomandibular disorders by means of the Research Diagnostic Criteria for Temporomandibular Disorders, aged between 18 and 60 years (32.71±1.1), who were submitted to the Oral Health Impact Profile-14 questionnaire. Non parametric Mann-Whitney statistics, Pearson Correlation test, Analysis of Variance and Tukey test were used with significance level of 5%. RESULTS: There has been no statistically significant difference in the perception of the impact on quality of life between genders; patients with association of signs and symptoms of the three groups of the Research Diagnostic Criteria for Temporomandibular Disorders had further impact on quality of life, as well as the most severe the temporomandibular disorder the highest the reported impact (p=0.05), and the age group with the highest impact on quality of life was between 18 and 30 years (p<0.01). CONCLUSION: Increased age, severity and the association of diagnoses have exacerbated the impact of temporomandibular disorders on quality of life. Variables analyzed in this study were related to temporomandibular disorder chronicity, stressing the importance of early intervention strategies to minimize the impact on quality of life.

Quality of life assessment in women after cervicosacropexy with polypropylene mesh for pelvic organ prolapse: a preliminary study.

Aim of the studyAim of the study was to assess the changes in the subjective perception of quality of life in patients who underwent abdominal cervicosacropexy for pelvic organ prolapse.Material and methodsForty patients with diagnosed pelvic organ prolapse (Pelvic Organ Prolapse – Quantification [POPQ] stage IV or IIIC) underwent abdominal supracervical hysterectomy and cervicosacropexy. The questionnaire concerning the quality of life was filled in before and 6 months after the surgery.ResultsIn all patients, an accurate prolapse correction was achieved. In 42% of patients, stress urinary incontinence (SUI) was diagnosed prior to surgery, while after the surgery in 38.24% (p > 0.05). In 50% of women, symptoms of overactive bladder (OAB) occurred pre-surgery. These symptoms were reported by 17.65% of patients postoperatively (p < 0.05). Urinary retention was observed in 32.36% before and in 2.5% after the surgery (p < 0.05). The average score of the quality of sexual life was 5.75 (SD 2.52, 95% CI: 4.41-7.1) before and increased to 7.93 (SD 1.77, 95% CI: 6.9-8.95) after the procedure (p < 0.05). The mean score of the overall quality of life in relation to POP before and after the procedure was 2.77 (SD 2.39, 95% CI: 1.87-8.64) and 9.03 (SD 1.08, 95% CI: 8.66-9.43), respectively (p < 0.001).ConclusionsThese results show a highly significant improvement of the quality of life in patients who underwent abdominal cervicosacropexy for POP. The change in quality of their sexual life, reduced OAB and urinary retention rates, as well as improvement of the esthetic self-perception may have contributed to this positive effect.

Factors related to the quality of life of the elderly in programs for senior citizens

Population aging is a social phenomenon that demands the attention of health professionals. This article seeks to analyze the influence of possible intervening factors on the quality of life of the elderly. It was a cross-sectional, quantitative, descriptive and exploratory study, in which 182 elderly of both genders participated. They were aged ≥ 60 years and were enrolled in programs for senior citizens from three universities located in the cities of Sao Paulo, Sao Caetano do Sul and Mogi das Cruzes. To evaluate the subjective perception of quality of life, the World Health Organization Quality of Life questionnaire (WHOQOL-Bref) was used. Multiple linear regression analysis was performed on the dependent and independent variables. A significance level of 5% was adopted. The results showed that the absence of disease positively influenced the quality of life on the four domains evaluated. In the environmental domain, full tertiary education, old age, the absence of disease and being a resident in Sao Caetano do Sul positively influenced the quality of life of the elderly. The factors associated with better quality of life were: full tertiary education, old age, the absence of disease and being a resident in Sao Caetano do Sul, in that order of importance.

Effectiveness of osteotropic materials in an experiment and data for evaluation of quality of life in patients with generalized periodontitis III severity level.

Background. The theoretical basis of osteoplasty, fully supported by clinical observations, is that violations occur in periodontitis of correlation between tooth and the surrounding tissues, including the microcirculation. However, complex morphological and clinical analysis of effectiveness of the material held EasyGraft was not. Objective. The aim was experimental evaluation of tissue alterations in bone implant materials Easy-Graft® and tricalcium phosphate®, as well as determining the life quality after use in the surgical treatment of patients with generalized periodontitis ІII severity level. Methods. The comparative analysis a quantitative morphological estimation of regenerative processes in osteal tissue in model of osteal defect is carried out at implantation of material EasyGraft and amor­p­hous calcium phosphate at this work. It was investigated dynamics of life quality indicators at patients after used materials by specialised questionnaire OHІР-14 (Oral Health Impact Profile) during 1 year. Results and Conclusion. We found out that EasyGraft and amorphous calcium phosphate undergo resorbtion and thus optimize bone regeneration. Regeneration is accompanied by decreased specific area of the particles implanted and increased integration index and specific density of trabeculae within the reaction zone. Highest intensity of these processes was ob-served in the period from 15th fill the 30th day after implantation. EasyGraft is more preferable for implantation than amorphous calcium phosphate. Adapted Ukrainian language and Russian language version of the OHIP-14 questionnaire is valid and accurate tool for assessing the quality of life of patients with chronic generalized periodontitis by which demonstrated the influence of the intensity of inflammatory and destructive changes periodontal severity of the pathological process, the presence of complete occlusion and methods of correction applied to the subjective perception of quality of life. The use of material EasyGraft compared with tricalcium phosphate improves the life quality of patients by 18-22%.