Search results for: restricted three body problem
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 11257

Search results for: restricted three body problem

9607 Prominent Lipid Parameters Correlated with Trunk-to-Leg and Appendicular Fat Ratios in Severe Pediatric Obesity

Authors: Mustafa M. Donma, Orkide Donma

Abstract:

The examination of both serum lipid fractions and body’s lipid composition are quite informative during the evaluation of obesity stages. Within this context, alterations in lipid parameters are commonly observed. The variations in the fat distribution of the body are also noteworthy. Total cholesterol (TC), triglycerides (TRG), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C) are considered as the basic lipid fractions. Fat deposited in trunk and extremities may give considerable amount of information and different messages during discrete health states. Ratios are also derived from distinct fat distribution in these areas. Trunk-to-leg fat ratio (TLFR) and trunk-to-appendicular fat ratio (TAFR) are the most recently introduced ratios. In this study, lipid fractions and TLFR, as well as TAFR, were evaluated, and the distinctions among healthy, obese (OB), and morbid obese (MO) groups were investigated. Three groups [normal body mass index (N-BMI), OB, MO] were constituted from a population aged 6 to 18 years. Ages and sexes of the groups were matched. The study protocol was approved by the Non-interventional Ethics Committee of Tekirdag Namik Kemal University. Written informed consent forms were obtained from the parents of the participants. Anthropometric measurements (height, weight, waist circumference, hip circumference, head circumference, neck circumference) were obtained and recorded during the physical examination. Body mass index values were calculated. Total, trunk, leg, and arm fat mass values were obtained by TANITA Bioelectrical Impedance Analysis. These values were used to calculate TLFR and TAFR. Systolic (SBP) and diastolic blood pressures (DBP) were measured. Routine biochemical tests including TC, TRG, LDL-C, HDL-C, and insulin were performed. Data were evaluated using SPSS software. p value smaller than 0.05 was accepted as statistically significant. There was no difference among the age values and gender ratios of the groups. Any statistically significant difference was not observed in terms of DBP, TLFR as well as serum lipid fractions. Higher SBP values were measured both in OB and MO children than those with N-BMI. TAFR showed a significant difference between N-BMI and OB groups. Statistically significant increases were detected between insulin values of N-BMI group and OB as well as MO groups. There were bivariate correlations between LDL and TLFR (r=0.396; p=0.037) as well as TAFR values (r=0.413; p=0.029) in MO group. When adjusted for SBP and DBP, partial correlations were calculated as (r=0.421; p=0.032) and (r=0.438; p=0.025) for LDL-TLFR as well as LDL-TAFR, respectively. Much stronger partial correlations were obtained for the same couples (r=0.475; p=0.019 and r=0.473; p=0.020, respectively) upon controlling for TRG and HDL-C. Much stronger partial correlations observed in MO children emphasize the potential transition from morbid obesity to metabolic syndrome. These findings have concluded that LDL-C may be suggested as a discriminating parameter between OB and MO children.

Keywords: children, lipid parameters, obesity, trunk-to-leg fat ratio, trunk-to-appendicular fat ratio

Procedia PDF Downloads 111
9606 Optimum Design of Hybrid (Metal-Composite) Mechanical Power Transmission System under Uncertainty by Convex Modelling

Authors: Sfiso Radebe

Abstract:

The design models dealing with flawless composite structures are in abundance, where the mechanical properties of composite structures are assumed to be known a priori. However, if the worst case scenario is assumed, where material defects combined with processing anomalies in composite structures are expected, a different solution is attained. Furthermore, if the system being designed combines in series hybrid elements, individually affected by material constant variations, it implies that a different approach needs to be taken. In the body of literature, there is a compendium of research that investigates different modes of failure affecting hybrid metal-composite structures. It covers areas pertaining to the failure of the hybrid joints, structural deformation, transverse displacement, the suppression of vibration and noise. In the present study a system employing a combination of two or more hybrid power transmitting elements will be explored for the least favourable dynamic loads as well as weight minimization, subject to uncertain material properties. Elastic constants are assumed to be uncertain-but-bounded quantities varying slightly around their nominal values where the solution is determined using convex models of uncertainty. Convex analysis of the problem leads to the computation of the least favourable solution and ultimately to a robust design. This approach contrasts with a deterministic analysis where the average values of elastic constants are employed in the calculations, neglecting the variations in the material properties.

Keywords: convex modelling, hybrid, metal-composite, robust design

Procedia PDF Downloads 211
9605 A Stochastic Vehicle Routing Problem with Ordered Customers and Collection of Two Similar Products

Authors: Epaminondas G. Kyriakidis, Theodosis D. Dimitrakos, Constantinos C. Karamatsoukis

Abstract:

The vehicle routing problem (VRP) is a well-known problem in Operations Research and has been widely studied during the last fifty-five years. The context of the VRP is that of delivering or collecting products to or from customers who are scattered in a geographical area and have placed orders for these products. A vehicle or a fleet of vehicles start their routes from a depot and visit the customers in order to satisfy their demands. Special attention has been given to the capacitated VRP in which the vehicles have limited carrying capacity for the goods that are delivered or collected. In the present work, we present a specific capacitated stochastic vehicle routing problem which has many realistic applications. We develop and analyze a mathematical model for a specific vehicle routing problem in which a vehicle starts its route from a depot and visits N customers according to a particular sequence in order to collect from them two similar but not identical products. We name these products, product 1 and product 2. Each customer possesses items either of product 1 or product 2 with known probabilities. The number of the items of product 1 or product 2 that each customer possesses is a discrete random variable with known distribution. The actual quantity and the actual type of product that each customer possesses are revealed only when the vehicle arrives at the customer’s site. It is assumed that the vehicle has two compartments. We name these compartments, compartment 1 and compartment 2. It is assumed that compartment 1 is suitable for loading product 1 and compartment 2 is suitable for loading product 2. However, it is permitted to load items of product 1 into compartment 2 and items of product 2 into compartment 1. These actions cause costs that are due to extra labor. The vehicle is allowed during its route to return to the depot to unload the items of both products. The travel costs between consecutive customers and the travel costs between the customers and the depot are known. The objective is to find the optimal routing strategy, i.e. the routing strategy that minimizes the total expected cost among all possible strategies for servicing all customers. It is possible to develop a suitable dynamic programming algorithm for the determination of the optimal routing strategy. It is also possible to prove that the optimal routing strategy has a specific threshold-type strategy. Specifically, it is shown that for each customer the optimal actions are characterized by some critical integers. This structural result enables us to design a special-purpose dynamic programming algorithm that operates only over these strategies having this structural property. Extensive numerical results provide strong evidence that the special-purpose dynamic programming algorithm is considerably more efficient than the initial dynamic programming algorithm. Furthermore, if we consider the same problem without the assumption that the customers are ordered, numerical experiments indicate that the optimal routing strategy can be computed if N is smaller or equal to eight.

Keywords: dynamic programming, similar products, stochastic demands, stochastic preferences, vehicle routing problem

Procedia PDF Downloads 257
9604 Detection of Alzheimer's Protein on Nano Designed Polymer Surfaces in Water and Artificial Saliva

Authors: Sevde Altuntas, Fatih Buyukserin

Abstract:

Alzheimer’s disease is responsible for irreversible neural damage of brain parts. One of the disease markers is Amyloid-β 1-42 protein that accumulates in the brain in the form plaques. The basic problem for detection of the protein is the low amount of protein that cannot be detected properly in body liquids such as blood, saliva or urine. To solve this problem, tests like ELISA or PCR are proposed which are expensive, require specialized personnel and can contain complex protocols. Therefore, Surface-enhanced Raman Spectroscopy (SERS) a good candidate for detection of Amyloid-β 1-42 protein. Because the spectroscopic technique can potentially allow even single molecule detection from liquid and solid surfaces. Besides SERS signal can be improved by using nanopattern surface and also is specific to molecules. In this context, our study proposes to fabricate diagnostic test models that utilize Au-coated nanopatterned polycarbonate (PC) surfaces modified with Thioflavin - T to detect low concentrations of Amyloid-β 1-42 protein in water and artificial saliva medium by the enhancement of protein SERS signal. The nanopatterned PC surface that was used to enhance SERS signal was fabricated by using Anodic Alumina Membranes (AAM) as a template. It is possible to produce AAMs with different column structures and varying thicknesses depending on voltage and anodization time. After fabrication process, the pore diameter of AAMs can be arranged with dilute acid solution treatment. In this study, two different columns structures were prepared. After a surface modification to decrease their surface energy, AAMs were treated with PC solution. Following the solvent evaporation, nanopatterned PC films with tunable pillared structures were peeled off from the membrane surface. The PC film was then modified with Au and Thioflavin-T for the detection of Amyloid-β 1-42 protein. The protein detection studies were conducted first in water via this biosensor platform. Same measurements were conducted in artificial saliva to detect the presence of Amyloid Amyloid-β 1-42 protein. SEM, SERS and contact angle measurements were carried out for the characterization of different surfaces and further demonstration of the protein attachment. SERS enhancement factor calculations were also completed via experimental results. As a result, our research group fabricated diagnostic test models that utilize Au-coated nanopatterned polycarbonate (PC) surfaces modified with Thioflavin-T to detect low concentrations of Alzheimer’s Amiloid – β protein in water and artificial saliva medium. This work was supported by The Scientific and Technological Research Council of Turkey (TUBITAK) Grant No: 214Z167.

Keywords: alzheimer, anodic aluminum oxide, nanotopography, surface enhanced Raman spectroscopy

Procedia PDF Downloads 291
9603 Effect of Microencapsulated Butyric Acid Supplementation on Growth Performance, Ileal Digestibility of Protein, Gut Health and Immunity in Broilers

Authors: Saeed Ahmed, Muhammad Imran, Yasir Allah Ditta, Shahid Mehmood, Zahid Rasool

Abstract:

A study was conducted to investigate the effect of different levels of microencapsulated butyric (MEB) on growth performance, gut health and immunity in commercial broiler chickens. In total, 336 day-old Hubbard classic broilers chicks were randomly assigned to 4 dietary treatments (Control, 0.25, 0.35 and 0.45g/kg of butyric acid) under completely randomized design. Each treatment was replicated 3 times with 28 birds in each replicate. Feed intake, body weight gain, feed conversion ratio, intestinal morphology, apparent ileal digestibility of protein and immunity parameters were evaluated. At the end of the experiment (35-d) 3 birds/replicate in each group were randomly selected and slaughtered to collect blood, duodenal samples and ileal digesta. The data were analyzed by using ANOVA technique. The results indicated improved body weight gain (P = 0.0222), feed conversion ratio (P = 0.0056), duodenal villus height (P = 0.0512), AID (P = 0.0098) antibody titer against Newcastle disease improved (P = 0.0326). Treatments remained unresponsive with respect to feed intake (P = 0.9685).

Keywords: butyric acid, broilers, gut health, ileal digestibility

Procedia PDF Downloads 324
9602 Multi-Objective Discrete Optimization of External Thermal Insulation Composite Systems in Terms of Thermal and Embodied Energy Performance

Authors: Berfin Yildiz

Abstract:

These days, increasing global warming effects, limited amount of energy resources, etc., necessitates the awareness that must be present in every profession group. The architecture and construction sectors are responsible for both the embodied and operational energy of the materials. This responsibility has led designers to seek alternative solutions for energy-efficient material selection. The choice of energy-efficient material requires consideration of the entire life cycle, including the building's production, use, and disposal energy. The aim of this study is to investigate the method of material selection of external thermal insulation composite systems (ETICS). Embodied and in-use energy values of material alternatives were used for the evaluation in this study. The operational energy is calculated according to the u-value calculation method defined in the TS 825 (Thermal Insulation Requirements) standard for Turkey, and the embodied energy is calculated based on the manufacturer's Energy Performance Declaration (EPD). ETICS consists of a wall, adhesive, insulation, lining, mechanical, mesh, and exterior finishing materials. In this study, lining, mechanical, and mesh materials were ignored because EPD documents could not be obtained. The material selection problem is designed as a hypothetical volume area (5x5x3m) and defined as a multi-objective discrete optimization problem for external thermal insulation composite systems. Defining the problem as a discrete optimization problem is important in order to choose between materials of various thicknesses and sizes. Since production and use energy values, which are determined as optimization objectives in the study, are often conflicting values, material selection is defined as a multi-objective optimization problem, and it is aimed to obtain many solution alternatives by using Hypervolume (HypE) algorithm. The enrollment process started with 100 individuals and continued for 50 generations. According to the obtained results, it was observed that autoclaved aerated concrete and Ponce block as wall material, glass wool, as insulation material gave better results.

Keywords: embodied energy, multi-objective discrete optimization, performative design, thermal insulation

Procedia PDF Downloads 141
9601 Kinaesthetic Method in Apprenticeship Training: Support for Finnish Learning in Vocational Education and Training

Authors: Inkeri Jaaskelainen

Abstract:

The purpose of this study is to shed light on what it is like to study in apprenticeship training using Finnish as a second language. This study examines the stories and experiences of apprenticeship students learning and studying Finnish as part of their vocational studies. Also, this pilot study examines the effects of learning to pronounce Finnish through body motions and gestures. Many foreign students choose apprenticeships and start vocational training too early, while their language skills in Finnish are still very weak. Both duties at work and school assignments require reasonably good general language skills (B1.1), and, especially at work, language skills are also a safety issue. At work, students should be able to simultaneously learn Finnish and do vocational studies in a noisy, demanding, and stressful environment. Learning and understanding new things is very challenging under these circumstances and sometimes students get exhausted and experience a lot of stress - which makes learning even more difficult. Students are different from each other and so are their ways to learn. Thereafter, one of the most important features of apprenticeship training and second language learning is a good understanding of adult learners and their needs. Kinaesthetic methods are an effective way to support adult students’ cognitive skills and make learning more relaxing and fun. Empirical findings show that language learning can indeed be supported in physical ways, by body motions and gestures. The method used here, named TFFL (Touch and Feel Foreign Languages), was designed to support adult language learning, to correct or prevent language fossilization, and to help the student to manage emotions. Finnish is considered as a difficult language to learn, mostly because it is so different from nearly all other languages. Many learners complain that they are lost or confused and there is a need to find a way to simultaneously learn the language and to handle negative emotion that comes from the Finnish language and the learning process itself. Due to the nature of the Finnish language, good pronunciation skills are needed just to understand the way the language work. Movements (body movements etc.) are a natural part of many cultures, but not Finnish. In Finland, students have traditionally been expected to stay still, and that is not a natural way for many foreign students. However, the kinaesthetic TFFL method proved out to be a useful way to help some L2 students to feel phonemes, rhythm, and intonation, to improve their Finnish, and, thereby, also to successfully complete their vocational studies.

Keywords: Finnish, fossilization, interference, kinaesthetic method

Procedia PDF Downloads 139
9600 Combating Domestic Violence in Malaysia: Issues and Challenges

Authors: Aspalella A. Rahman

Abstract:

Domestic violence is not an uncommon phenomenon throughout the world. Malaysia is no exception. However, the exact prevalence of domestic violence in Malaysia is difficult to capture due to cultural understanding and sensitivity of the issues existing in the society. This paper aims to examine the issues and problems with the law of domestic violence in Malaysia. As such, it will mainly rely on statutes as its primary sources of information. It will analyse the scope and provisions of the Penal Code as well as the Domestic Violence Act 1994. Any shortcomings and gaps in the laws will be highlighted. It is submitted that domestic violence remains a problem in Malaysia. Although many strategies and plans have been implemented in attempting to combat this social problem, it remains unresolved. This is due to the inefficient implementation of the law. Although much has been done, there is still more to be done by the Malaysian government to combat domestic violence more effectively. For this reason, significant cooperation between the law enforcement authorities, NGOs, and the community must be established.

Keywords: challenges, domestic violence, issues, Malaysia

Procedia PDF Downloads 302
9599 Implementing Urban Rainwater Harvesting Systems: Between Policy and Practice

Authors: Natàlia Garcia Soler, Timothy Moss

Abstract:

Despite the multiple benefits of sustainable urban drainage, as demonstrated in numerous case studies across the world, urban rainwater harvesting techniques are generally restricted to isolated model projects. The leap from niche to mainstream has, in most cities, proved an elusive goal. Why policies promoting rainwater harvesting are limited in their widespread implementation has seldom been subjected to systematic analysis. Much of the literature on the policy, planning and institutional contexts of these techniques focus either on their potential benefits or on project design, but very rarely on a critical-constructive analysis of past experiences of implementation. Moreover, the vast majority of these contributions are restricted to single-case studies. There is a dearth of knowledge with respect to, firstly, policy implementation processes and, secondly, multi-case analysis. Insights from both, the authors argue, are essential to inform more effective rainwater harvesting in cities in the future. This paper presents preliminary findings from a research project on rainwater harvesting in cities from a social science perspective that is funded by the Swedish Research Foundation (Formas). This project – UrbanRain – is examining the challenges and opportunities of mainstreaming rainwater harvesting in three European cities. The paper addresses two research questions: firstly, what lessons can be learned on suitable policy incentives and planning instruments for rainwater harvesting from a meta-analysis of the relevant international literature and, secondly, how far these lessons are reflected in a study of past and ongoing rainwater harvesting projects in a European forerunner city. This two-tier approach frames the structure of the paper. We present, first, the results of the literature analysis on policy and planning issues of urban rainwater harvesting. Here, we analyze quantitatively and qualitatively the literature of the past 15 years on this topic in terms of thematic focus, issues addressed and key findings and draw conclusions on research gaps, highlighting the need for more studies on implementation factors, actor interests, institutional adaptation and multi-level governance. In a second step we focus in on the experiences of rainwater harvesting in Berlin and present the results of a mapping exercise on a wide variety of projects implemented there over the last 30 years. Here, we develop a typology to characterize the rainwater harvesting projects in terms of policy issues (what problems and goals are targeted), project design (which kind of solutions are envisaged), project implementation (how and when they were implemented), location (whether they are in new or existing urban developments) and actors (which stakeholders are involved and how), paying particular attention to the shifting institutional framework in Berlin. Mapping and categorizing these projects is based on a combination of document analysis and expert interviews. The paper concludes by synthesizing the findings, identifying how far the goals, governance structures and instruments applied in the Berlin projects studied reflect the findings emerging from the meta-analysis of the international literature on policy and planning issues of rainwater harvesting and what implications these findings have for mainstreaming such techniques in future practice.

Keywords: institutional framework, planning, policy, project implementation, urban rainwater management

Procedia PDF Downloads 287
9598 Using Econometric Methods to Explore Obesity Stigma and Avoidance of Breast and Cervical Cancer Screening

Authors: Stephanie A. Schauder, Gosia Sylwestrzak

Abstract:

Overweight and obese women report avoiding preventive care due to fear of weight-related bias from medical professionals. Gynecological exams, due to their sensitive and personally invasive nature, are especially susceptible to avoidance. This research investigates the association between body mass index (BMI) and screening rates for breast and cervical cancer using claims data from 1.3 million members of a large health insurance company. Because obesity is associated with increased cancer risk, screenings for these cancers should increase as BMI increases. However, this paper finds that the distribution of cancer screening rates by BMI take an inverted U-shape with underweight and obese members having the lowest screening rates. For cervical cancer screening, those in the target population with a BMI of 23 have the highest screening rate at 68%, while Obese Class III members have a screening rate of 50%. Those in the underweight category have a screening rate of 58%. This relationship persists even after controlling for health and demographic covariates in regression analysis. Interestingly, there is no association between BMI and BRCA (BReast CAncer gene) genetic testing. This is consistent with the narrative that stigma causes avoidance because genetic testing does not involve any assessment of a person’s body. More work must be done to determine how to increase cancer screening rates in those who may feel stigmatized due to their weight.

Keywords: cancer screening, cervical cancer, breast cancer, weight stigma, avoidance of care

Procedia PDF Downloads 202
9597 Addressing the Oracle Problem: Decentralized Authentication in Blockchain-Based Green Hydrogen Certification

Authors: Volker Wannack

Abstract:

The aim of this paper is to present a concept for addressing the Oracle Problem in the context of hydrogen production using renewable energy sources. The proposed approach relies on the authentication of the electricity used for hydrogen production by multiple surrounding actors with similar electricity generation facilities, which attest to the authenticity of the electricity production. The concept introduces an Authenticity Score assigned to each certificate, as well as a Trust Score assigned to each witness. Each certificate must be attested by different actors with a sufficient Trust Score to achieve an Authenticity Score above a predefined threshold, thereby demonstrating that the produced hydrogen is indeed "green."

Keywords: hydrogen, blockchain, sustainability, structural change

Procedia PDF Downloads 64
9596 Extra Skin Removal Surgery and Its Effects: A Comprehensive Review

Authors: Rebin Mzhda Mohammed, Hoshmand Ali Hama Agha

Abstract:

Excess skin, often consequential to substantial weight loss or the aging process, introduces physical discomfort, obstructs daily activities, and undermines an individual's self-esteem. As these challenges become increasingly prevalent, the need to explore viable solutions grows in significance. Extra skin removal surgery, colloquially known as body contouring surgery, has emerged as a compelling intervention to ameliorate the physical and psychological burdens of excess skin. This study undertakes a comprehensive review to illuminate the intricacies of extra skin removal surgery, encompassing its diverse procedures, associated risks, benefits, and psychological implications on patients. The methodological approach adopted involves a systematic and exhaustive review of pertinent scholarly literature sourced from reputable databases, including PubMed, Google Scholar, and specialized cosmetic surgery journals. Articles are meticulously curated based on their relevance, credibility, and recency. Subsequently, data from these sources are synthesized and categorized, facilitating a comprehensive understanding of the subject matter. Qualitative analysis serves to unravel the nuanced psychological effects, while quantitative data, where available, are harnessed to underpin the study's conclusions. In terms of major findings, the research underscores the manifold advantages of extra skin removal surgery. Patients experience a notable improvement in physical comfort, amplified mobility, enhanced self-confidence, and a newfound ability to don clothing comfortably. Nonetheless, the benefits are juxtaposed with potential risks, encompassing infection, scarring, hematoma, delayed healing, and the challenge of achieving symmetry. A salient discovery is the profound psychological impact of the surgery, as patients consistently report elevated body image satisfaction, heightened self-esteem, and a substantial enhancement in overall quality of life. In summation, this research accentuates the pivotal role of extra skin removal surgery in ameliorating the intricate interplay of physical and psychological difficulties posed by excess skin. By elucidating the diverse procedures, associated risks, and psychological outcomes, the study contributes to a comprehensive and informed comprehension of the surgery's multifaceted effects. Therefore, individuals contemplating this transformative surgical option are equipped with comprehensive insights, ultimately fostering informed decision-making, guided by the expertise of medical professionals.

Keywords: extra skin removal surgery, body contouring, abdominoplasty, brachioplasty, thigh lift, body lift, benefits, risks, psychological effects

Procedia PDF Downloads 66
9595 Seat Assignment Model for Student Admissions Process at Saudi Higher Education Institutions

Authors: Mohammed Salem Alzahrani

Abstract:

In this paper, student admission process is studied to optimize the assignment of vacant seats with three main objectives. Utilizing all vacant seats, satisfying all program of study admission requirements and maintaining fairness among all candidates are the three main objectives of the optimization model. Seat Assignment Method (SAM) is used to build the model and solve the optimization problem with help of Northwest Coroner Method and Least Cost Method. A closed formula is derived for applying the priority of assigning seat to candidate based on SAM.

Keywords: admission process model, assignment problem, Hungarian Method, Least Cost Method, Northwest Corner Method, SAM

Procedia PDF Downloads 498
9594 Microalgae Applied to the Reduction of Biowaste Produced by Fruit Fly Drosophila melanogaster

Authors: Shuang Qiu, Zhipeng Chen, Lingfeng Wang, Shijian Ge

Abstract:

Biowastes are a concern due to the large amounts of commercial food required for model animals during the biomedical research. Searching for sustainable food alternatives with negligible physiological effects on animals is critical to solving or reducing this challenge. Microalgae have been demonstrated as suitable for both human consumption and animal feed in addition to biofuel and bioenergy applications. In this study, the possibility of using Chlorella vulgaris and Senedesmus obliquus as a feed replacement to Drosophila melanogaster, one of the fly models commonly used in biomedical studies, was investigated to assess the fly locomotor activity, motor pattern, lifespan, and body weight. Compared to control, flies fed on 60% or 80% (w/w) microalgae exhibited varied walking performance including travel distance and apparent step size, and flies treated with 40% microalgae had shorter lifespans and decreased body weight. However, the 20% microalgae treatment showed no statistical differences in all parameters tested with respect to the control. When partially including 20% microalgae in the standard food, it can annually reduce the food waste (~ 202 kg) by 22.7 % and save $ 7,200 of the food cost, offering an environmentally superior and cost-effective food alternative without compromising physiological performance.

Keywords: animal feed, Chlorella vulgaris, Drosophila melanogaster, food waste, microalgae

Procedia PDF Downloads 166
9593 Effect of Resistance Exercise on Hypothalamic-Pituitary-Gonadal Axis

Authors: Alireza Barari, Saeed Shirali, Ahmad Abdi

Abstract:

Abstract: Introduction: Physical activity may be related to male reproductive function by affecting on thehypothalamic-pituitary-gonadal(HPG) axis. Our aim was to determine the effects of 6 weeks resistance exercise on reproductive hormones, HPG axis. The hypothalamic-pituitary-gonadal (HPG) axis refers tothe effects of endocrine glands in three-level including (i) the hypothalamic releasing hormone GnRH, which is synthesized in in a small heterogenous neuronal population and released in a pulsatile fashion, (ii) the anterior pituitary hormones, follicle-stimulating hormone(FSH) and luteinizing hormone (LH) and (iii) the gonadal hormones, which include both steroid such as testosterone (T), estradiol and progesterone and peptide hormones (such as inhibin). Hormonal changes that create a more anabolic environment have been suggested to contribute to the adaptation to strength exercise. Physical activity has an extensive impact on male reproductive function depending upon the intensity and duration of the exercise and the fitness level of the individual. However, strenuous exercise represents a physical stress and inflammation changed that challenges homeostasis. Materials and methods: Sixteen male volunteered were included in a 6-week control period followed by 6 weeks of resistance training (leg press, lat pull, chest press, squat, seatedrow, abdominal crunch, shoulder press, biceps curl and triceps press down) four times per week. intensity of training loading was 60%-75% of one maximum repetition. Participants performed 3 sets of 10 repetitions. Rest periods were two min between exercises and sets. Start with warm up exercises include: The muscles relax and stretch the body, which was for 10 minutes. Body composition, VO2max and the circulating level of free testosterone (fT), luteinizing hormone (LH), follicle-stimulating hormone (FSH), sex hormone binding globulin (SHBG) and inhibin B measured prior and post 6-week intervention. The hormonal levels of each serum sample were measured using commercially available ELISA kits. Analysis of anthropometrical data and hormonal level were compared using the independent samples t- test in both groups and using SPSS (version 19). P ≤ 0.05 was considered statistically significant. Results: For muscle strength, both lower- and upper-body strength were increased significantly. Aerobic fitness level improved in trained participant from 39.4 ± 5.6 to 41.9 ± 5.3 (P = 0.002). fT concentration rise progressively in the trained group and was significantly greater than those in the control group (P = 0.000). By the end of the 6-week resistance training, serum SHBG significantly increased in the trained group compared with the control group (P = 0.013). In response to resistance training, LH, FSH and inhibin B were not significantly changed. Discussion: According to our finfings, 6 weeks of resistance training induce fat loss without any changes in body weight and BMI. A decline of 25.3% in percentage of body fat with statiscally same weight was due to increase in muscle mass that happened during resistance exercise periods . Six weeks of resistance training resulted in significant improvement in BF%, VO2max and increasing strength and the level of fT and SHBG.

Keywords: resistance, hypothalamic, pituitary, gonadal axis

Procedia PDF Downloads 399
9592 Standardized Black Ginseng Extract Improving a Suppressed Immunomodulatory Effect Induced by Heat Stress

Authors: Byung Wook Yang, Jong Dae Park, Wang Soo Shin, Ji-Hyeon Song, Seo-Yun Choi, Boo-Yong Lee, Young Tae Hahm

Abstract:

Korean ginseng (Panax ginseng C. A. Meyer) is frequently taken orally as a traditional herbal medicine with ginsenosides as the main pharmacological component in Asian countries, and its use is increasing worldwide. Recently, the increase in global temperature has been reported to cause various kinds of biological disorders induced by heat stress in human. The standardized black ginseng extract (SBGE; KGR-BG1) was developed in our biological screening experiment on the thermo-regulation, whose chemical characteristics were evaluated as ginsenoside Rg1, Rb1, Rg3(S), as well as Re, Rf, Rg2(S), Rh1(S), Rh2(S), and Rg5+Rk1. Heat stress responses such as body weight, food intake, water consumption have been measured when treated with Standardized Black Ginseng Extract (SBGE) in the animal experiment and also, biomarkers. SBGE treated group has been found to inhibit a decrease in body weight, a decrease in food intake and an increase in the water consumption when compared with non-treated group against environmental heat stress. These results suggest that SBGE might have a protective effect against environmental heat stress. And also, the several factors of stress response on the immune system need to be done for further studies and its evaluation is in progress.

Keywords: ginseng, ginsenoside, standardization, heat stress, immunomodulatory effect

Procedia PDF Downloads 297
9591 Comparative Effects of Homoplastic and Synthetic Pituitary Extracts on Induced Breeding of Heterobranchus longifilis (Valenciennes, 1840) in Indoor Hatchery Tanks in Owerri South East Nigeria

Authors: I. R. Keke, C. S. Nwigwe, O. S. Nwanjo, A. S. Egeruoh

Abstract:

An experiment was carried out at Urban Farm and Fisheries Nigeria Ltd, Owerri Imo State South East Nigeria between February and June 2014 to induce Brood stock of Heterobranchus longifilis (mean wt 1.3kg) in concrete tanks (1.0 x 2.0 x 1.5m) in dimension using a synthetic hormone (Ovaprim) and pituitary extract from Heterobranchus longifilis. Brood stock males were selected as pituitary donors and their weights matched those of females to be injected at 1ml/kg body weight of Fish. Ovaprim, was injected at 0.5ml/kg body weight of female fish. A latency period of 12 hours was allowed after injection of the Brood stock females before stripping the egg and incubation at 23 °C. While incubating the eggs, samples were drawn and the rate of fertilization was determined. Hatching occurred within 33 hours and hatchability rate (%) was determined by counting the active hatchings. The result showed that Ovaprim injected Brood stock eggs fertilized up to 80% while the pituitary from the Heterobranchus longifilis had low fertilization and hatching success 20%. Ovaprim is imported and costly, so more effort is required to enhance the procedures for homoplastic hypophysation.

Keywords: heterobranchus longifilis, ovaprim, hypophysation, latency period, pituitary

Procedia PDF Downloads 215
9590 An Output Oriented Super-Efficiency Model for Considering Time Lag Effect

Authors: Yanshuang Zhang, Byungho Jeong

Abstract:

There exists some time lag between the consumption of inputs and the production of outputs. This time lag effect should be considered in calculating efficiency of decision making units (DMU). Recently, a couple of DEA models were developed for considering time lag effect in efficiency evaluation of research activities. However, these models can’t discriminate efficient DMUs because of the nature of basic DEA model in which efficiency scores are limited to ‘1’. This problem can be resolved a super-efficiency model. However, a super efficiency model sometimes causes infeasibility problem. This paper suggests an output oriented super-efficiency model for efficiency evaluation under the consideration of time lag effect. A case example using a long term research project is given to compare the suggested model with the MpO model

Keywords: DEA, Super-efficiency, Time Lag, research activities

Procedia PDF Downloads 658
9589 Modifying Assessment Modes in the Science Classroom as a Solution to Examination Malpractice

Authors: Catherine Omole

Abstract:

Examination malpractice includes acts that temper with collecting accurate results during the conduct of an examination, thereby giving undue advantage to a student over his colleagues. Even though examination malpractice has been a lingering problem, examinations may not be easy to do away with completely as it is an important feedback tool in the learning process with several other functions e.g for the purpose of selection, placement, certification and promotion. Examination malpractice has created a lot of problems such as a relying on a weak work force based on false assessment results. The question is why is this problem still persisting, despite measures that have been taken to curb this ugly trend over the years? This opinion paper has identified modifications that could help relieve the student of the examination stress and thus increase the student’s effort towards effective learning and discourage examination malpractice in the long run.

Keywords: assessment, examination malpractice, learning, science classroom

Procedia PDF Downloads 260
9588 Health and Disease, Sickness and Well Being: Depictions in the Vinaya Pitaka and Jataka Narratives

Authors: Abhimanyu Kumar

Abstract:

The relationship between religion and medicine is much evident in the context of Buddhism. This paper is an attempt to look at the processes of social and cultural evolution of scientific creativity in the field of medicine and institutionalization of medical practices. The objective of the paper is to understand the Buddhist responses towards health as understood from the Vinaya Piṭaka and the Jātaka. This work is a result of the analysis of two important Buddhist texts: the Vinaya Piṭaka and the Jātaka. Broadly the Vinaya Piṭaka is concerned with the growth of Buddhist monasticism. The Vinaya Piṭaka is considered one of the most important sacred texts of the Buddhists, and contains rules for monastic life. These rules deal with such aspects as formal meetings of the saṃgha (monastery), expiation, confession, training, and legal questions. The Jātaka stories, on the other hand, are in the form of folk narratives, and provide a major source of medical consultation for all classes. These texts help us to ascertain the ‘proficiency and perceptions’ of the prevailing medical traditions. The Jātakas are a collection of 547 stories about the past lives of the Buddha, who is represented in anthropomorphic and animal form. The Jātaka connects itself between existing cognitive environments related to ethics and Buddhist didacticism. These stories are a reflection of the connection between the past and contemporary times (in the sense of time of creation of the story) as well. This is visible through the narrative strategy of the text, where every story is sub-divided into the story of the past and story of the present, and there is a significant identification element or connection that established at the end of each story. The minimal presence of philosophical content and the adoption of a narrative strategy make it possible for more of everyday life. This study gives me an opportunity to raise questions about how far were the body and mind closely interrelated in the Buddhist perceptions, and also did the society act like a laboratory for the Buddhists to practice healing activities? How far did religious responses to afflictions, be they leprosy or plague or anger, influence medical care; what impact did medical practitioners, religious authorities and the regulation of medical activity and practice have on healing the body and the mind; and, how has the healing environment been viewed. This paper is working with the idea that medical science in early India was not only for the curative purpose of diseases, but it fulfilled a greater cause of promoting, maintaining and restoring human health. In this regard, studying these texts gives an insight regarding religious responses to epidemics, from leprosy to plague, as well as to behavioral disorder such as anger. In other words, it deals with the idea about healing the body and healing the soul from a religious perspective.

Keywords: food for health, folk narratives, human body, materia medica, social sickness

Procedia PDF Downloads 277
9587 Verification of Low-Dose Diagnostic X-Ray as a Tool for Relating Vital Internal Organ Structures to External Body Armour Coverage

Authors: Natalie A. Sterk, Bernard van Vuuren, Petrie Marais, Bongani Mthombeni

Abstract:

Injuries to the internal structures of the thorax and abdomen remain a leading cause of death among soldiers. Body armour is a standard issue piece of military equipment designed to protect the vital organs against ballistic and stab threats. When configured for maximum protection, the excessive weight and size of the armour may limit soldier mobility and increase physical fatigue and discomfort. Providing soldiers with more armour than necessary may, therefore, hinder their ability to react rapidly in life-threatening situations. The capability to determine the optimal trade-off between the amount of essential anatomical coverage and hindrance on soldier performance may significantly enhance the design of armour systems. The current study aimed to develop and pilot a methodology for relating internal anatomical structures with actual armour plate coverage in real-time using low-dose diagnostic X-ray scanning. Several pilot scanning sessions were held at Lodox Systems (Pty) Ltd head-office in South Africa. Testing involved using the Lodox eXero-dr to scan dummy trunk rigs at various degrees and heights of measurement; as well as human participants, wearing correctly fitted body armour while positioned in supine, prone shooting, seated and kneeling shooting postures. The verification of sizing and metrics obtained from the Lodox eXero-dr were then confirmed through a verification board with known dimensions. Results indicated that the low-dose diagnostic X-ray has the capability to clearly identify the vital internal structures of the aortic arch, heart, and lungs in relation to the position of the external armour plates. Further testing is still required in order to fully and accurately identify the inferior liver boundary, inferior vena cava, and spleen. The scans produced in the supine, prone, and seated postures provided superior image quality over the kneeling posture. The X-ray-source and-detector distance from the object must be standardised to control for possible magnification changes and for comparison purposes. To account for this, specific scanning heights and angles were identified to allow for parallel scanning of relevant areas. The low-dose diagnostic X-ray provides a non-invasive, safe, and rapid technique for relating vital internal structures with external structures. This capability can be used for the re-evaluation of anatomical coverage required for essential protection while optimising armour design and fit for soldier performance.

Keywords: body armour, low-dose diagnostic X-ray, scanning, vital organ coverage

Procedia PDF Downloads 122
9586 Decrease of Aerobic Capacity in Twenty Years in Lithuanian 11–18 Years-Old Youth

Authors: Arunas Emeljanovas, Brigita Mieziene, Tomas Venckunas

Abstract:

Background statement: Level of aerobic capacity in school age children provides important information about the current and future cardiovascular, skeletal and mental health. It is widely recognised that risk factors for modern chronic diseases of the adults have their origins in childhood and adolescence. The aim of the study was to analyse the trends of aerobic capacity across decades within groups of gender and age. Methods. The research included data of participants from the three nationally representative cohort studies performed in Lithuania in the years 1992, 2002 and 2012 among 11 to 18-years-old school children. Total of 18,294 school children were recruited for testing. Only those who had their body weight and height measured and completed 20 m shuttle endurance test were included in the analysis. The total number of students included in the analyses was 15,213 (7608 boys and 7605 girls). The permission to conduct the study was obtained from the Lithuanian Bioethics Committee (permission number BE-2-45). Major findings: Results are performed across gender and age groups. The comparison of shuttle endurance test, controlling for body mass index, indicated that in general there is a constant decrease of aerobic capacity across decades in both genders and age groups. The deterioration in aerobic capacity in boys accounted for 17 to 43 percent across age groups within decades. The biggest decrease was in 14 years-old boys. The deterioration in girls accounted for 19 to 37 percent across age groups with the highest decrease in 11 years-old girls. Though, girls had lower levels of aerobic capacity through all age groups and across three decades. Body mass index, as a covariate, accounted for up to six percent in deterioration of aerobic capacity. Final statement: The detected relationships may reflect the level and pattern of engagement in physical activity and sports where increased activity associates with superior performance in the tests because of the upregulated physiological function and instigated competitive/motivational level. The significance of the decade indirectly supports the importance of the recently changed activity among schoolchildren for this relationship.

Keywords: aerobic capacity, cardiovascular health, endurance, school age children

Procedia PDF Downloads 185
9585 Free Will and Compatibilism in Decision Theory: A Solution to Newcomb’s Paradox

Authors: Sally Heyeon Hwang

Abstract:

Within decision theory, there are normative principles that dictate how one should act in addition to empirical theories of actual behavior. As a normative guide to one’s actual behavior, evidential or causal decision-theoretic equations allow one to identify outcomes with maximal utility values. The choice that each person makes, however, will, of course, differ according to varying assignments of weight and probability values. Regarding these different choices, it remains a subject of considerable philosophical controversy whether individual subjects have the capacity to exercise free will with respect to the assignment of probabilities, or whether instead the assignment is in some way constrained. A version of this question is given a precise form in Richard Jeffrey’s assumption that free will is necessary for Newcomb’s paradox to count as a decision problem. This paper will argue, against Jeffrey, that decision theory does not require the assumption of libertarian freedom. One of the hallmarks of decision-making is its application across a wide variety of contexts; the implications of a background assumption of free will is similarly varied. One constant across the contexts of decision is that there are always at least two levels of choice for a given agent, depending on the degree of prior constraint. Within the context of Newcomb’s problem, when the predictor is attempting to guess the choice the agent will make, he or she is analyzing the determined aspects of the agent such as past characteristics, experiences, and knowledge. On the other hand, as David Lewis’ backtracking argument concerning the relationship between past and present events brings to light, there are similarly varied ways in which the past can actually be dependent on the present. One implication of this argument is that even in deterministic settings, an agent can have more free will than it may seem. This paper will thus argue against the view that a stable background assumption of free will or determinism in decision theory is necessary, arguing instead for a compatibilist decision theory yielding a novel treatment of Newcomb’s problem.

Keywords: decision theory, compatibilism, free will, Newcomb’s problem

Procedia PDF Downloads 321
9584 Assessing the Prevalence of Accidental Iatrogenic Paracetamol Overdose in Adult Hospital Patients Weighing <50kg: A Quality Improvement Project

Authors: Elisavet Arsenaki

Abstract:

Paracetamol overdose is associated with significant and possibly permanent consequences including hepatotoxicity, acute and chronic liver failure, and death. This quality improvement project explores the prevalence of accidental iatrogenic paracetamol overdose in hospital patients with a low body weight, defined as <50kg and assesses the impact of educational posters in trying to reduce it. The study included all adult inpatients on the admissions ward, a short stay ward for patients requiring 12-72 hour treatment, and consisted of three cycles. Each cycle consisted of 3 days of data collection in a given month (data collection for cycle 1 occurred in January 2022, February 2022 for cycle 2 and March 2022 for cycle 3). All patients given paracetamol had their prescribed dose checked against their charted weight to identify the percentage of adult inpatients <50kg who were prescribed 1g of paracetamol instead of 500mg. In the first cycle of the audit, data were collected from 83 patients who were prescribed paracetamol on the admissions ward. Subsequently, four A4 educational posters were displayed across the ward, on two separate occasions and with a one-month interval in between each poster display. The aim of this was to remind prescribing doctors of their responsibility to check patient body weight prior to prescribing paracetamol. Data were collected again one week after each round of poster display, from 72 and 70 patients respectively. Over the 3 cycles with a cumulative 225 patients, 15 weighed <50kg (6.67%) and of those, 5 were incorrectly prescribed 1g of paracetamol, yielding a 33.3% prevalence of accidental iatrogenic paracetamol overdose in adult inpatients. In cycle 1 of the project, 3 out of 6 adult patients weighing <50kg were overdosed on paracetamol, meaning that 50% of low weight patients were prescribed the wrong dose of paracetamol for their weight. In the second data collection cycle, 1 out of 5 <50kg patients were overdosed (20%) and in the third cycle, 1 out of 4 (25%). The use of educational posters resulted in a lower prevalence of accidental iatrogenic paracetamol overdose in low body weight adult inpatients. However, the differences observed were statistically insignificant (p value 0.993 and 0.995 respectively). Educational posters did not induce a significant decrease in the prevalence of accidental iatrogenic paracetamol overdose. More robust strategies need to be employed to further decrease paracetamol overdose in patients weighing <50kg.

Keywords: iatrogenic, overdose, paracetamol, patient, safety

Procedia PDF Downloads 112
9583 Strategic Mine Planning: A SWOT Analysis Applied to KOV Open Pit Mine in the Democratic Republic of Congo

Authors: Patrick May Mukonki

Abstract:

KOV pit (Kamoto Oliveira Virgule) is located 10 km from Kolwezi town, one of the mineral rich town in the Lualaba province of the Democratic Republic of Congo. The KOV pit is currently operating under the Katanga Mining Limited (KML), a Glencore-Gecamines (a State Owned Company) join venture. Recently, the mine optimization process provided a life of mine of approximately 10 years withnice pushbacks using the Datamine NPV Scheduler software. In previous KOV pit studies, we recently outlined the impact of the accuracy of the geological information on a long-term mine plan for a big copper mine such as KOV pit. The approach taken, discussed three main scenarios and outlined some weaknesses on the geological information side, and now, in this paper that we are going to develop here, we are going to highlight, as an overview, those weaknesses, strengths and opportunities, in a global SWOT analysis. The approach we are taking here is essentially descriptive in terms of steps taken to optimize KOV pit and, at every step, we categorized the challenges we faced to have a better tradeoff between what we called strengths and what we called weaknesses. The same logic is applied in terms of the opportunities and threats. The SWOT analysis conducted in this paper demonstrates that, despite a general poor ore body definition, and very rude ground water conditions, there is room for improvement for such high grade ore body.

Keywords: mine planning, mine optimization, mine scheduling, SWOT analysis

Procedia PDF Downloads 225
9582 The Concept of Art: A Redefinition or Reconstruction

Authors: Patricia Agboro

Abstract:

The definition of a concept is quite important in any philosophical discourse as it serves as a guide in the analysis of that concept. In the sciences, arriving at a consensus regarding concepts is quite easily achievable due to the nature of the discipline. Problem arises when one delves into the realm of the humanities. Discourses in the humanities are largely perspectival because the question of values come into play. Defining the concept of Art is no different as it has yielded unresolved and problematic issues arising from attempts at definition. A major problem arising from such attempt is that of exclusion of other art forms. In this paper therefore, we call for the rejection of an attempt at providing a comprehensive definition for Art since it is clear that the collection of definitions provided so far, has failed in capturing the nuances and intricacies of the infinite varieties of the art forms that there are. Rather, a more fruitful approach to philosophical discourses on Art is not to construe the theories of Art per-se but to reconstruct them as a collection of criteria for determining artistic excellence.

Keywords: art, creativity, definition, reconstruction

Procedia PDF Downloads 175
9581 A Fuzzy Inference Tool for Assessing Cancer Risk from Radiation Exposure

Authors: Bouharati Lokman, Bouharati Imen, Bouharati Khaoula, Bouharati Oussama, Bouharati Saddek

Abstract:

Ionizing radiation exposure is an established cancer risk factor. Compared to other common environmental carcinogens, it is relatively easy to determine organ-specific radiation dose and, as a result, radiation dose-response relationships tend to be highly quantified. Nevertheless, there can be considerable uncertainty about questions of radiation-related cancer risk as they apply to risk protection and public policy, and the interpretations of interested parties can differ from one person to another. Examples of tools used in the analysis of the risk of developing cancer due to radiation are characterized by uncertainty. These uncertainties are related to the history of exposure and different assumptions involved in the calculation. We believe that the results of statistical calculations are characterized by uncertainty and imprecision. Having regard to the physiological variation from one person to another. In this study, we develop a tool based on fuzzy logic inference. As fuzzy logic deals with imprecise and uncertain, its application in this area is adequate. We propose a fuzzy system with three input variables (age, sex and body attainable cancer). The output variable expresses the risk of infringement rate of each organ. A base rule is established from recorded actual data. After successful simulation, this will instantly predict the risk of infringement rate of each body following chronic exposure to 0.1 Gy.

Keywords: radiation exposure, cancer, modeling, fuzzy logic

Procedia PDF Downloads 311
9580 Enhanced Tensor Tomographic Reconstruction: Integrating Absorption, Refraction and Temporal Effects

Authors: Lukas Vierus, Thomas Schuster

Abstract:

A general framework is examined for dynamic tensor field tomography within an inhomogeneous medium characterized by refraction and absorption, treated as an inverse source problem concerning the associated transport equation. Guided by Fermat’s principle, the Riemannian metric within the specified domain is determined by the medium's refractive index. While considerable literature exists on the inverse problem of reconstructing a tensor field from its longitudinal ray transform within a static Euclidean environment, limited inversion formulas and algorithms are available for general Riemannian metrics and time-varying tensor fields. It is established that tensor field tomography, akin to an inverse source problem for a transport equation, persists in dynamic scenarios. Framing dynamic tensor tomography as an inverse source problem embodies a comprehensive perspective within this domain. Ensuring well-defined forward mappings necessitates establishing existence and uniqueness for the underlying transport equations. However, the bilinear forms of the associated weak formulations fail to meet the coercivity condition. Consequently, recourse to viscosity solutions is taken, demonstrating their unique existence within suitable Sobolev spaces (in the static case) and Sobolev-Bochner spaces (in the dynamic case), under a specific assumption restricting variations in the refractive index. Notably, the adjoint problem can also be reformulated as a transport equation, with analogous results regarding uniqueness. Analytical solutions are expressed as integrals over geodesics, facilitating more efficient evaluation of forward and adjoint operators compared to solving partial differential equations. Certainly, here's the revised sentence in English: Numerical experiments are conducted using a Nesterov-accelerated Landweber method, encompassing various fields, absorption coefficients, and refractive indices, thereby illustrating the enhanced reconstruction achieved through this holistic modeling approach.

Keywords: attenuated refractive dynamic ray transform of tensor fields, geodesics, transport equation, viscosity solutions

Procedia PDF Downloads 51
9579 On Estimating the Headcount Index by Using the Logistic Regression Estimator

Authors: Encarnación Álvarez, Rosa M. García-Fernández, Juan F. Muñoz, Francisco J. Blanco-Encomienda

Abstract:

The problem of estimating a proportion has important applications in the field of economics, and in general, in many areas such as social sciences. A common application in economics is the estimation of the headcount index. In this paper, we define the general headcount index as a proportion. Furthermore, we introduce a new quantitative method for estimating the headcount index. In particular, we suggest to use the logistic regression estimator for the problem of estimating the headcount index. Assuming a real data set, results derived from Monte Carlo simulation studies indicate that the logistic regression estimator can be more accurate than the traditional estimator of the headcount index.

Keywords: poverty line, poor, risk of poverty, Monte Carlo simulations, sample

Procedia PDF Downloads 423
9578 A Novel Exploration/Exploitation Policy Accelerating Learning In Both Stationary And Non Stationary Environment Navigation Tasks

Authors: Wiem Zemzem, Moncef Tagina

Abstract:

In this work, we are addressing the problem of an autonomous mobile robot navigating in a large, unknown and dynamic environment using reinforcement learning abilities. This problem is principally related to the exploration/exploitation dilemma, especially the need to find a solution letting the robot detect the environmental change and also learn in order to adapt to the new environmental form without ignoring knowledge already acquired. Firstly, a new action selection strategy, called ε-greedy-MPA (the ε-greedy policy favoring the most promising actions) is proposed. Unlike existing exploration/exploitation policies (EEPs) such as ε-greedy and Boltzmann, the new EEP doesn’t only rely on the information of the actual state but also uses those of the eventual next states. Secondly, as the environment is large, an exploration favoring least recently visited states is added to the proposed EEP in order to accelerate learning. Finally, various simulations with ball-catching problem have been conducted to evaluate the ε-greedy-MPA policy. The results of simulated experiments show that combining this policy with the Qlearning method is more effective and efficient compared with the ε-greedy policy in stationary environments and the utility-based reinforcement learning approach in non stationary environments.

Keywords: autonomous mobile robot, exploration/ exploitation policy, large, dynamic environment, reinforcement learning

Procedia PDF Downloads 417