Search results for: result oriented product-service system

Authors: Mwafak Shakoor

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The purpose of this study was to reduce patient waiting times, improve system throughput and improve resources utilization in radiology department. A discrete event simulation model was developed using Arena simulation software to investigate different alternatives to improve the overall system delivery based on adding resource scenarios due to the linkage between patient waiting times and resource availability. The study revealed that there is no addition investment need to procure additional scanner but hospital management deploy managerial tactics to enhance machine utilization and reduce the long waiting time in the department.

Keywords: discrete event simulation, radiology department, arena, waiting time, healthcare modeling, computed tomography

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Authors: N. Kaewpraek, W. Assawinchaichote

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This paper considers an H_∞ TS fuzzy state-derivative feedback controller for a class of nonlinear dynamical systems. A Takagi-Sugeno (TS) fuzzy model is used to approximate a class of nonlinear dynamical systems. Then, based on a linear matrix inequality (LMI) approach, we design an H_∞ TS fuzzy state-derivative feedback control law which guarantees L₂-gain of the mapping from the exogenous input noise to the regulated output to be less or equal to a prescribed value. We derive a sufficient condition such that the system with the fuzzy controller is asymptotically stable and H_∞ performance is satisfied. Finally, we provide and simulate a numerical example is provided to illustrate the stability and the effectiveness of the proposed controller.

Keywords: h-infinity fuzzy control, an LMI approach, Takagi-Sugano (TS) fuzzy system, the photovoltaic systems

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Authors: Yuan-Ching Chiang, Chien-Yeh Hsu, Chen Chih-Hao, Sih-Li Chen

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The p-n junction temperature of LEDs directly influences their operating life and luminous efficiency. An excessively high p-n junction temperature minimizes the output flux of LEDs, decreasing their brightness and influencing the photon wavelength; consequently, the operating life of LEDs decreases and their luminous output changes. The maximum limit of the p-n junction temperature of LEDs is approximately 120 °C. The purpose of this research was to devise an approach for dissipating heat generated in a confined space when LEDs operate at low temperatures to reduce light decay. The cooling mode of existing commercial LED lights can be divided into natural- and forced convection cooling. In natural convection cooling, the volume of LED encapsulants must be increased by adding more fins to increase the cooling area. However, this causes difficulties in achieving efficient LED lighting at high power. Compared with forced convection cooling, heat transfer through water convection is associated with a higher heat transfer coefficient per unit area; therefore, we dissipated heat by using a closed loop water cooling system. Nevertheless, cooling water exposed to air can be easily influenced by environmental factors. Thus, we incorporated a ground heat exchanger into the water cooling system to minimize the influence of air on cooling water and then observed the relationship between the amounts of heat dissipated through the ground and LED efficiency.

Keywords: helical ground heat exchanger, high power LED, ground source cooling system, heat dissipation

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Authors: Chul Ho Han, Kyoung Hoon Kim

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This paper carries out a performance analysis based on the first and second laws of thermodynamics for heat recovery vapor generator (HRVG) of ammonia-water mixture when the heat source is low-temperature energy in the form of sensible heat. In the analysis, effects of the ammonia mass concentration and mass flow ratio of the binary mixture are investigated on the system performance including the effectiveness of heat transfer, entropy generation, and exergy efficiency. The results show that the ammonia concentration and the mass flow ratio of the mixture have significant effects on the system performance of HRVG.

Keywords: entropy, exergy, ammonia-water mixture, heat exchanger

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Authors: Cajethan U. Ugwuoke

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Agriculture is taught in secondary schools to develop skills in students which will empower them to contribute to national economic development. Unfortunately, our educational system emphasizes the application of conventional teaching methods in delivering instructions, which fails to produce students competent enough to carry out agricultural production. This study was therefore aimed at examining the application of digital technologies as tools for transformative instructional delivery. Four specific purposes, research questions and hypotheses guided the study. The study adopted a descriptive survey research design where 80 subjects representing 64 teachers of agriculture and 16 principals in the Udenu local government area of Enugu State, Nigeria, participated in the study. A structured questionnaire was used to collect data. The assumption of normality was ascertained by subjecting the data collected to a normality test. Data collected were later subjected to mean, Pearson product-moment correlation, ANOVA and t-test to answer the research questions and test the hypotheses at a 5% significant level. The result shows that the application of digital technologies helps to reduce learners’ boredom (3.52.75), improves learners’ performance (3.63.51), and is used as a visual aid for learners (3.56.61), among others. There was a positive, strong and significant relationship between the application of digital technologies and effective instructional delivery (+.895, p=.001<.05, F=17.73), competency of teachers to the application of digital technologies and effective instructional delivery (+998, p=.001<0.5, F=16263.45), and frequency of the application of digital technologies and effective instructional delivery (+.999, p=.001<.05, F=31436.14). There was no evidence of autocorrelation and multicollinearity in the regression models between the application of digital technologies and effective instructional delivery (2.03, Tolerance=1.00, VIF=1.00), competency of teachers in the application of digital technologies and effective instructional delivery (2.38, Tolerance=1.00, VIF=1.00) and frequency of the application of digital technologies and effective instructional delivery (2.00, Tolerance=1.00, VIF=1.00). Digital technologies should be therefore applied in teaching to facilitate effective instructional delivery in agriculture.

Keywords: agricultural science, digital technologies, instructional delivery, learning

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Authors: Simiso Fisokuhle Nyandeni

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The environment is one of the major components of intergenerational equity under sustainability; however, this component has been facing a lot of issues/crises, which include those that are caused by natural systems due to the actions of humans. Although some of those environmental issues may occur from natural causes, however, climate change effects have shown to increase rapidly due to human behavior, which led to the increase in greenhouse emissions and the over-exploitation of natural resources that maintain an ecological balance in our environment. Based on the recent projections, the growing population tends to outstrip the environmental resources, and as a result, the rapid depletion of natural resources that maintain ecological balance within the environment has resulted in such environmental issues. This paper has adopted desktop analysis to address the main objective, which seeks to address the effects of population dynamics on environmental issues and what needs to be done to maintain the ecological balance between the growing population and the limited resources that are available; thus, the collective data sources were used to justify the literature in order to get adequate results to influence the potential findings. The major findings postulate that there is an ecological imbalance between limited resources available and the growing population; as a result, the environment is taking action against humanity through climate change impacts. Hence findings further outline that in order to prevent such impacts, there should be drastic interventions by the governments (all stakeholders should be involved in decision-making; Governmental or non-governmental institutions, scientists, researchers, etc.) around the world to maintain this ecological balance and also to prioritize the adaptation measures. Therefore, this paper seeks to examine the implications of population dynamics on the environmental issues and what needs to be done in order to maintain this ecological balance between the growing population and environmental resources; hence, this review will be based on the climate change context.

Keywords: population dynamics, climate change, environment, sustainability

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Authors: G. Quiroga-Cubides, M. Cruz, E. Grijalba, J. Sanabria, A. Ceballos, L. García, M. Gómez

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Beauveria sp. has been used as an entomopathogenic microorganism for biological control of various plant pests such as whitefly, thrips, aphids and chrysomelidaes (including Cerotoma tingomariana species), which affect soybean crops in Colombia´s Altillanura region. Therefore, a biopesticide prototype based on B. bassiana strain Bv060 was developed at Corpoica laboratories. For the production of B. bassiana conidia, a baseline fermentation was performed at laboratory in a solid medium using broken rice as a substrate, a temperature of 25±2 °C and a relative humidity of 60±10%. The experimental design was completely randomized, with a three-time repetition. These culture conditions resulted in an average conidial concentration of 1.48x10^10 conidia/g, a yield of 13.07 g/kg dry substrate and a productivity of 8.83x10^7 conidia/g*h were achieved. Consequently, the objective of this study was to evaluate the influence of the particle size reduction of rice (<1 mm) and the addition of a complex nitrogen source over conidia production and efficiency parameters in a solid-state fermentation, in a completely randomized experiment with a three-time repetition. For this aim, baseline fermentation conditions of temperature and humidity were employed in a semisolid culture medium with powdered rice (10%) and a complex nitrogen source (8%). As a result, it was possible to increase conidial concentration until 9.87x10^10 conidia/g, yield to 87.07 g/g dry substrate and productivity to 3.43x10^8 conidia/g*h. This suggested that conidial concentration and yield in semisolid fermentation increased almost 7 times compared with baseline while the productivity increased 4 times. Finally, the designed system for semisolid-state fermentation allowed to achieve an easy conidia recovery, which means reduction in time and costs of the production process.

Keywords: Beauveria bassiana, biopesticide, solid state fermentation, semisolid medium culture

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Authors: Fatai O. Oladoyinbo, Felix O. Sanni, Akinwunmi Fatai, Kamoli A. Amusa, Saheed A. Ganiyu, Wasiu B. Ayinde, Tajudeen A. Afolabi, Enock O. Dare

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Silver (Ag) and silica (SiO2) nanoparticles were synthesized using the chemical reduction method from silver nitrate and sodium silicate, respectively. X-ray Diffraction (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), Scanning Electron Microscopy (SEM), Uv-Visible spectroscopy, Energy Dispersive X-ray (EDX) spectroscopy and N2 adsorption-desorption techniques were utilized to characterize the composition and structure of the samples. The crystallinity pattern of Ag nanoparticles was indexed as (111), (200), (220) and (311), which allowed reflections from face-centered cubic silver. XRD of SiO2 showed good porosity with a broad-spectrum band at Bragg’s angle 2θ of 22° while that of Ag-SiO2 showed distinct peaks at 2θ values of 39°, 43°, 66° and 79°. The XRD result agreed perfectly with the SEM and HRTEM images which showed Ag-SiO2 isotropic and anisotropic under the varying concentration of reactants. The elemental composition of Ag-SiO2, as displayed by EDX, confirmed Ag enrichment in the Ag-SiO2 heterostructure. The Uv-Visible peak at 421 nm confirmed the Surface Plasmon Resonance absorption peak of silver nanoparticles. N2 adsorption-desorption result showed a broad band of Ag-SiO2 from 3 to 8 nm, which indicated relatively narrow pore size distributions. Humidity sensing measurements performed in a controlled humidity chamber showed very high sensitivity with a sensitivity factor (SF) of 4.63 and high linearity with a steady decrease in resistance to humidity from 880 Ω at 10% RH to 190 Ω at 100% RH, indicating that Ag-SiO2 nanocomposite is a good sensing material with high sensitivity and linearity.

Keywords: silver, silica, nanocomposite, synthesis, heterostructure, core shell

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Authors: Jaroslav Frantík, Jan Najser

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This article deals with increasing the energy efficiency of a plant in terms of optimizing the process. The European Union is striving to achieve the climate-energy package in the area increasing of energy efficiency. The goal of energy efficiency is to reduce primary energy consumption by 20% within the EU until 2020. The objective of saving energy consumption in the Czech Republic was set at 47.84 PJ (13.29 TWh). For reducing electricity consumption, it is possible to choose: a) mandatory increasing of energy efficiency, b) alternative scheme, c) combination of both actions. The Czech Republic has chosen for reducing electricity consumption using-alternative scheme. The presentation is focused on the proposal of a technological unit dealing with the gasification process of processing of biomass with an increase of power in the output. The synthesis gas after gasification of biomass is used as fuel in a cogeneration process of reciprocating internal combustion engine with the classic production of heat and electricity. Subsequently, there is an explanation of the ORC system dealing with the conversion of waste heat to electricity with the using closed cycle of the steam process with organic medium. The arising electricity is distributed to the power grid as a further energy source, or it is used for needs of the partial coverage of the technological unit. Furthermore, there is a presented schematic description of the technology with the identification of energy flows starting from the biomass treatment by drying, through its conversion to gaseous fuel, producing of electricity and utilize of thermal energy with minimizing losses. It has been found that using of ORC system increased the efficiency of the produced electricity by 7.5%.

Keywords: biomass, efficiency, gasification, ORC system

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Authors: Vijayalaxmi Khopade

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The Prima facie caste system is intrinsic to Indian society. It is an ancient system of intense social stratification based upon birth and enjoying religious sanction. The uppermost strata and privileges are ascribed and enjoyed by brahmins (priestly class), while the lowest strata are occupied by Dalits who are not ascribed with any privileges. The caste system is inherently hierarchical, patriarchal, and systematic and thrives solely on exploitation justified through means of the Brahminical system of hegemony based singularly on birth. The caste system has extended its tentacles to other religions like Christianity, Buddhism, Jainism, and Islam in South Asia. Term Dalit is colloquially used to categorize persons belonging to lower strata in the caste hierarchy. However, this category is heterogenous and highly stratified, following practices like untouchability and exclusion amongst themselves. The modern Indian legal system acknowledges the existence of Caste and its perils. Therefore, by virtue of the Indian Constitution, provisions for affirmative action for the protection and development of Dalits are made. Courts in India have liberally interpreted laws to benefit Dalits. However, the modern system of governance is not immune from Caste based biases. These biases are reflected in the implementation of governance, including the dispensation of justice. The economic reforms of the 1990s gave a huge boost to the Indian diaspora. Persons of Indian origin are now seen making great strides in almost every sector and enjoying positions of power globally. As one peels off the layer of ethnic Indian origin, a deep seated layer of Caste and Caste based patriarchy is clearly visible. Indian diaspora enjoying positions of power essentially belongs to upper castes and carry Caste based biases with them. These castes have long enjoyed the benefits of education; therefore, they were the first ones to benefit from LPG (Liberalization, Privatization, Globalization) model adopted in the 1990s. Dalits, however, had little formal education until recently. The western legal system, to the best of our knowledge, does not recognize Caste and, therefore, cannot afford protection for Dalits, wherein discrimination and exploitation take place solely on the basis of Caste. Therefore, Dalits are left with no legal remedy outside domestic jurisdiction. Countries like the UK have made an attempt to include Caste in their Equality Bill 2010. This has met with tough resistance from Upper caste Hindus who shy away from recognizing their caste privileges and, therefore, the existence of Caste. In this paper, an attempt for comparative analysis is made between various legal protections accorded to Dalits in India vis-à-vis international human rights as protected by the United Nations under its declaration of Universal Human rights. An attempt has been made to mark a distinction between race and Caste and to establish a position of women in Caste based hierarchy. The paper also makes an argument for the inclusion of atrocities committed against Dalits as a violation of international human rights, their protection by the United Nations, and the trial of their violations by International Courts. The paper puts into perspective the need for an external agency like the United Nations and International courts to interfere in rights guaranteed by the Indian Constitution, even with the existence of a modern legal system in a sovereign democratic country.

Keywords: atrocity, caste, diaspora, legal framework

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Authors: Samaneh Nabavi, Hadi Shirzad, Somayeh Khanjani, Shirin Jalili

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Quantum dots (QDs) are semiconductor nanocrystals that exhibit intrinsic optical and electrical properties that are size dependent due to the quantum confinement effect. Quantum confinement is brought about by the fact that in bulk semiconductor material the electronic structure consists of continuous bands, and that as the size of the semiconductor material decreases its radius becomes less than the Bohr exciton radius (the distance between the electron and electron-hole) and discrete energy levels result. As a result QDs have a broad absorption range and a narrow emission which correlates to the band gap energy (E), and hence QD size. QDs can thus be tuned to give the desired wavelength of fluorescence emission.Due to their unique properties, QDs have attracted considerable attention in different scientific areas. Also, they have been considered for forensic applications in recent years. The ability of QDs to fluoresce up to 20 times brighter than available fluorescent dyes makes them an attractive nanomaterial for enhancing the visualization of latent fingermarks, or poorly developed fingermarks. Furthermore, the potential applications of QDs in the detection of nitroaromatic explosives, such as TNT, based on directive fluorescence quenching of QDs, electron transfer quenching process or fluorescence resonance energy transfer have been paid to attention. DNA analysis is associated tightly with forensic applications in molecular diagnostics. The amount of DNA acquired at a criminal site is inherently limited. This limited amount of human DNA has to be quantified accurately after the process of DNA extraction. Accordingly, highly sensitive detection of human genomic DNA is an essential issue for forensic study. QDs have also a variety of advantages as an emission probe in forensic DNA quantification.

Keywords: forensic science, quantum dots, DNA typing, explosive sensor, fingermark analysis

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Authors: Adriana Pereira Arteaga

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In many Latin American countries the transition towards legal pluralism - has developed as part of what is called Latin-American-Constitutionalism over the last thirty years. The aim of this paper is to discuss how legal pluralism in its current form in Bolivia may produce exclusion and violence. Legal sources and discourse analysis - as an approach to examine written language on discourse documentation- will be used to develop this paper. With the constitution of 2009, Bolivia was symbolically "re-founded" into a multi-nation state. This shift goes hand in hand with the "indigenista" and "decolonisation" ideologies developing since the early 20th century. Discourses based on these ideologies reflect the rejection of liberal and western premises on which the Bolivian republic was originally built after independence. According to the "indigenista" movements, the liberal nation-state generates institutions corresponding to a homogenous society. These liberal institutions not only ignore the Bolivian multi-nation reality, but also maintain the social structures originating form the colony times, based on prejudices against the indigenous. The described statements were elaborated through the image: the indigenous people humiliated by a cruel western system as highlighted by the constitution's preamble. This narrative had a considerable impact on the sensitivity of people and received great social support. Therefore the proposal for changing structures of the nation-state, is charged with an emancipatory message of restoring even the pre-Columbian order. An order at times romantically described as the perfect order. Legally this connotes a rejection of the positivistic national legal system based on individual rights and the promotion of constitutional recognition of indigenous justice administration. The pluralistic Constitution is supposed to promote tolerance and a peaceful coexistence among nations, so that the unity and integrity of the country could be maintained. In its current form, legal pluralism in Bolivia is justified on pre-existing rights contained for example in the International - Labour - Organization - Convention 169, but it is more developed on the described discursive constructions. Over time these discursive constructions created inconsistencies in terms of putting indigenous justice administration into practice: First, because legal pluralism has been more developed on level of political discourse, so a real interaction between the national and the indigenous jurisdiction cannot be observed. There are no clear coordination and cooperation mechanisms. Second, since the recently reformed constitution is based on deep sensitive experiences, little is said about the general legal principles on which a pluralistic administration of justice in Bolivia should be based. Third, basic rights, liberties, and constitutional guarantees are also affected by the antagonized image of the national justice administration. As a result, fundamental rights could be violated on a large scale because many indigenous justice administration practices run counter to these constitutional rules. These problems are not merely Bolivian but may also be encountered in other regional countries with similar backgrounds, like Ecuador.

Keywords: discourse, indigenous justice, legal pluralism, multi-nation

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Authors: Luana N. Cardozo, Debora A. S. Coutinho, Fabiola Lagher, Bruno J. G. Silva, Ivonilce Venture, Mainara Tesser, Graciela Venera

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Ostrich oil is used as food in Brazil, and it has been the subject of scientific research because it contains essential fatty acids (Omega 3, 6, 7, and 9), which provide benefits to human health. Alkylglycerols are lipid ethers consisted of a saturated or unsaturated hydrocarbon chain joined by ether-type bonding to one of the glycerol hydroxyls. It is known that supplementation with alkylglycerols can act significantly on the functioning of immune system cells, both in pathological situations and in homeostasis. Objective: Analyze the presence of alkylglycerols in ostrich oil. Methods: The ostrich oil was bought from an industry that manufactures the product for sale as food, located in Mirante da Serra, northern Brazil. The samples were sent for analysis to the chemistry department of the Federal University of Paraná, where they were analyzed by the gas chromatography method. Results: The analysis of the ostrich oil presented alkylglycerols in area 514505154. Comparison, it is possible to observe that shark liver oil contains the area 26190196, and the difference between both is highly significant. Conclusion: The importance of alkylglycerol supplementation for the immune system is known. The analysis of the results made it possible to verify the presence of alkylglycerols in the ostrich oil, which is five times higher than in the shark liver oil, that would be the largest source food, but was surpassed by the ostrich oil until the present time. The present study emphasizes that ostrich oil can be considered a food source of alkylglycerols and may play a promising role in the immune system because it contains such substance, but further studies are needed to prove its performance in the body.

Keywords: ostrich oil, nutritional composition, alkylglycerols, food

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Authors: Changho Han, Jaemin Lee, Li Hua, Seokkwon Jeong

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Design of membership function ranges in fuzzy logic control (FLC) is presented for robust control of a variable speed refrigeration system (VSRS). The criterion values of the membership function ranges can be carried out from the static experimental data, and two different values are offered to compare control performance. Some simulations and real experiments for the VSRS were conducted to verify the validity of the designed membership functions. The experimental results showed good agreement with the simulation results, and the error change rate and its sampling time strongly affected the control performance at transient state of the VSRS.

Keywords: variable speed refrigeration system, fuzzy logic control, membership function range, control performance

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Authors: Simmi Chopra

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In the last few years, there has been a surge of Autoimmune diseases that have become more like an epidemic all over the world. The reasons vary from stress, insufficient sleep, smoking, genetics, environmental pollution, adulterated foods, and a diet full of “the deadly white,” which is white sugar and white flour. Most of the people diagnosed with these diseases are given steroids, opioids, supplements, or elimination diets to manage their lives, but most of them continue suffering to varying degrees. On the other hand, Ayurveda can help manage autoimmune problems effectively. Ayurveda is a 5000 years old holistic medical system from India that has an individualistic approach where health problems are looked at from the lens of balancing body and mind and by targeting the root cause of the problem. A combination of diet and lifestyle according to Ayurvedic principles, Ayurvedic herbal formulations and Ayurvedic therapies can help in the management of autoimmune and other chronic diseases. Panchkarma, which is an intense six weeks detox method, helps balance our body and mind, and has been very effective in managing autoimmune problems. The paper will introduce the basic concepts of Ayurveda and describe the terminologies- doshas, agni and ama. The paper will discuss the importance of diet and lifestyle according to the individual’s imbalance in the three functional parameters - doshas, which govern every aspect of our body and mind, our cells and tissues. The significance of agni, which can be correlated to digestive strength and ama, which can be correlated to toxins that are formed in our body leading to health problems, will be outlined. The Ayurvedic pathophysiology of autoimmune diseases will be discussed with emphasis on Rheumatoid arthritis, Multiple sclerosis and Psoriasis. Ayurvedic management will be discussed for these autoimmune conditions. As Ayurveda is an individualistic system, one protocol will not work for everyone. Therefore, case studies with Ayurvedic protocols for the above autoimmune disease will be presented. Conclusion: Ayurveda can help in managing as well as arresting the progression of autoimmune problems. Ayurveda is an ancient medical system, is much more needed today than ever. It is a tried and tested holistic system which has been practiced for the past many generations in India.

Keywords: ayurveda, autoimmune, diseases, nutrition

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Authors: Jieh-Jiuh Wang

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Disasters happen frequently due to the global climate changes today. The cultural heritage conservation should be considered from the perspectives of surrounding environments and large-scale disasters. Most current thoughts about the disaster prevention of cultural heritages in Taiwan are single-point thoughts emphasizing firefighting, decay prevention, and construction reinforcement and ignoring the whole concept of the environment. The traditional conservation cannot defend against more and more tremendous and frequent natural disasters caused by climate changes. More and more cultural heritages are confronting the high risk of disasters. This study adopts the perspective of risk identification and takes flood as the main disaster category. It analyzes the amount and categories of cultural heritages that might suffer from disasters with the geographic information system integrating the latest flooding potential data from National Fire Agency and Water Resources Agency and the basic data of cultural heritages. It examines the actual risk of cultural heritages confronting floods and serves as the accordance for future considerations of risk measures and preparation for reducing disasters. The result of the study finds the positive relationship between the disaster affected situation of national cultural heritages and the rainfall intensity. The order of impacted level by floods is historical buildings, historical sites indicated by municipalities and counties, and national historical sites and relics. However, traditional settlements and cultural landscapes are not impacted. It might be related to the taboo space in the traditional culture of site selection (concepts of disaster avoidance). As for the regional distribution on the other hand, cultural heritages in central and northern Taiwan suffer from more shocking floods, while the heritages in northern and eastern Taiwan suffer from more serious flooding depth.

Keywords: cultural heritage, flood, preventive conservation, risk management

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Authors: Daniel Panario, Daniel Santana de Freitas, Brett Stevens

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Almost Perfect Nonlinear (APN) permutations with optimal resistance against differential cryptanalysis can be found in several domains. The permutation used in the standard for symmetric cryptography (the AES), for example, is based on a special kind of inversion in GF(28). Although very close to APN (2-uniform), this permutation still contains one number 4 in its differential spectrum, which means that, rigorously, it must be classified as 4-uniform. This fact motivates the search for fully APN permutations in other domains of definition. The extremely high complexity associated to this kind of problem precludes an exhaustive search for an APN permutation with 256 elements to be performed without the support of a suitable mathematical structure. On the other hand, in principle, there is nothing to indicate which mathematically structured domains can effectively help the search, and it is necessary to test several domains. In this work, the search for APN permutations in rings ℤ2×ℤ2k is investigated. After a full, exhaustive search with k=2 and k=3, all possible APN permutations in those rings were recorded, together with their differential profiles. Some very promising heuristics in these cases were collected so that, when used as a basis to prune backtracking for the same search in ℤ2×ℤ8 (search space with size 16! ≅244), just a few tenths of a second were enough to produce an APN permutation in a single CPU. Those heuristics were empirically extrapolated so that they could be applied to a backtracking search for APNs over ℤ2×ℤ16 (search space with size 32! ≅2117). The best permutations found in this search were further refined through Simulated Annealing, with a definition of neighbors suitable to this domain. The best result produced with this scheme was a 3-uniform permutation over ℤ2×ℤ16 with only 24 values equal to 3 in the differential spectrum (all the other 968 values were less than or equal 2, as it should be the case for an APN permutation). Although far from being fully APN, this result is technically better than a 4-uniform permutation and demanded only a few seconds in a single CPU. This is a strong indication that the use of mathematically structured domains, like the rings described in this work, together with heuristics based on smaller cases, can lead to dramatic cuts in the computational resources involved in the complexity of the search for APN permutations in extremely large domains.

Keywords: APN permutations, heuristic searches, symmetric cryptography, S-box design

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Authors: Gizem Kodak, Alper Unal, Birsen Koldemir, Tayfun Acarer

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Turkish Straits System which consists of Istanbul Strait (Bosphorus), Canakkale Strait (Dardanelles) and the Marmara Sea has a strategical location on international maritime as it is a unique waterway between the Mediterranean Sea, Black Sea and the Aegean Sea. Thus, this area has great importance since it is the only waterway between Black Sea countries and the rest of the World. Turkish Straits System has dangerous environmental factors hosts more vessel every day through developing World trade and this situation results in expanding accident risks day by day. Today, a lot of precautions have been taken to ensure safe navigation and to prevent maritime accidents, and international standards are followed to avoid maritime accidents. Despite this, the environmental factors that affect this area, trigger the maritime accidents and threaten the vessels with new accidents risks in different months with different hazards. This descriptive study consists of temporal and spatial analyses of environmental factors causing maritime accidents. This study also aims at contributing to safety navigation including monthly and regionally characteristics of variables. In this context, two different data sets are created consisting of environmental factors and accidents. This descriptive study on the accidents between 2001 and 2017 the mentioned region also studies the months and places of the accidents with environmental factor variables. Environmental factor variables are categorized as dynamic and static factors. Dynamic factors are appointed as meteorological and oceanographical while static factors are appointed as geological factors that threaten safety navigation with geometrical restricts. The variables that form dynamic factors are approached meteorological as wind direction, wind speed, wave altitude and visibility. The circulations and properties of the water mass on the system are studied as oceanographical properties. At the end of the study, the efficient meteorological and oceanographical parameters on the region are presented monthly and regionally. By this way, we acquired the monthly, seasonal and regional distributions of the accidents. Upon the analyses that are done; The Turkish Straits System that connects the Black Sea countries with the other countries and which is one of the most important parts of the world trade; is analyzed on temporal and spatial dimensions on the reasons of the accidents and have been presented as environmental factor dynamics causing maritime accidents.

Keywords: descriptive study, environmental factors, maritime accidents, statistics

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Authors: Arunkumar Thirugnanasambantham, Velraj Ramalingam

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An experimental attempt has been made to study the effect of system integration by two different concentrator assisted desalting systems. The compound parabolic concentrator (CPC) and compound conical concentrator (CCC) are used in this research work. Two solar desalination systems, the single slope solar still (SSSS) and pyramid solar still (PSS), have been integrated with a CCC and compound parabolic concentrator-concentric circular tubular solar still (CPC-CCTSS). To study the effect of system integration, a thick cloth prevents the entry of sunlight into the solar still top. Additionally, the concentrator assisted desalting systems are equipped with phase change material (PCM) for enhancement. In CCC-SSSS, PCM has been filled inside copper balls and placed on the SSSS basin. The PCM is loaded in the specially designed circular trough of the tubular solar still. Here, the used concentrators and distillers are not the same. Two methodologies are followed here to produce the fresh water even while the distillers are blocked from the sunlight. They are (1) thermosyphon effect in CCC-SSSS and (2) waste heat recovery from CPC-CCTSS. The results showed that the productivity of CCC-SSSS, CCC-SSSS with PCM and CCC-SSSS (PCM) top cover shaded were found as 2680 ml / m² / day, 3240 ml / m² / day, and 1646 ml / m² / day. Similarly, the productivity of the CPC-CCTSS-PSS, CPC-CCTSS (PCM)-PSS and CPC-CCTSS (PCM)-PSS top cover shaded were found as 7160 ml / m² / day, 7346 ml / m² / day, and ml / m² / day. The productivity of the CCC-SSSS and CPC-CCTSS-PSS is examined, and conclusions are drawn such as the solar radiation blocked distillers productivity did not drop to zero.

Keywords: compound conical concentrator, compound parabolic concentrator, desalination, system integration

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Authors: Miroslav Gutten, Daniel Korenciak, Milan Simko, Milan Chupac

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Ensure the reliable and correct function of transformers is the main essence of on-line non-destructive diagnostic tool, which allows the accurately track of the status parameters. Devices for on-line diagnostics are very costly. However, there are devices, whose price is relatively low and when used correctly, they can be executed a complex diagnostics. One of these devices is sensor HYDRAN M2, which is used to detect the moisture and gas content in the insulation oil. Using the sensor HYDRAN M2 in combination with temperature, load measurement, and physicochemical analysis can be made the economically inexpensive diagnostic system, which use is not restricted to distribution transformers. This system was tested in educational laboratory environment at measured oil transformer 22/0.4 kV. From the conclusions referred in article is possible to determine, which kind of fault was occurred in the transformer and how was an impact on the temperature, evolution of gases and water content.

Keywords: transformer, diagnostics, gas and moisture sensor, monitoring

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Authors: Ahmad Forouzantabar, Mohammad Azadi, Alireza Alesaadi

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This paper describes a sliding mode controller for autonomous underwater vehicles (AUVs). The dynamic of AUV model is highly nonlinear because of many factors, such as hydrodynamic drag, damping, and lift forces, Coriolis and centripetal forces, gravity and buoyancy forces, as well as forces from thruster. To address these difficulties, a nonlinear sliding mode controller is designed to approximate the nonlinear dynamics of AUV and improve trajectory tracking. Moreover, the proposed controller can profoundly attenuate the effects of uncertainties and external disturbances in the closed-loop system. Using the Lyapunov theory the boundedness of AUV tracking errors and the stability of the proposed control system are also guaranteed. Numerical simulation studies of an AUV are included to illustrate the effectiveness of the presented approach.

Keywords: lyapunov stability, autonomous underwater vehicle, sliding mode controller, electronics engineering

Procedia PDF Downloads 594

Authors: Jorge Anibal Restrepo Morales, Sonia Martín Gómez

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A model based on a logical framework was developed to quantify SMEs' internationalization capacity. To do so, linguistic variables, such as human talent, infrastructure, innovation strategies, FTAs, marketing strategies, finance, etc. were integrated. It is argued that a company’s management of international markets depends on internal factors, especially capabilities and resources available. This study considers internal factors as the biggest business challenge because they force companies to develop an adequate set of capabilities. At this stage, importance and strategic relevance have to be defined in order to build competitive advantages. A fuzzy inference system is proposed to model the resources, skills, and capabilities that determine the success of internationalization. Data: 157 linguistic variables were used. These variables were defined by international trade entrepreneurs, experts, consultants, and researchers. Using expert judgment, the variables were condensed into18 factors that explain SMEs’ export capacity. The proposed model is applied by means of a case study of the textile and clothing cluster in Medellin, Colombia. In the model implementation, a general index of 28.2 was obtained for internationalization capabilities. The result confirms that the sector’s current capabilities and resources are not sufficient for a successful integration into the international market. The model specifies the factors and variables, which need to be worked on in order to improve export capability. In the case of textile companies, the lack of a continuous recording of information stands out. Likewise, there are very few studies directed towards developing long-term plans, and., there is little consistency in exports criteria. This method emerges as an innovative management tool linked to internal organizational spheres and their different abilities.

Keywords: business strategy, exports, internationalization, fuzzy set methods

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Authors: Mohammad Aminnia, Mahmood Hosseini

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Environmental and functional conditions sometimes necessitate the architectural plan of the building to be asymmetric, and this result in an asymmetric structure. In such cases, finding an optimal pattern for locating the components of the lateral load bearing system, including shear walls, in the building’s plan is desired. In case of shear walls, in addition to the location, the shape of the wall cross-section is also an effective factor. Various types of shear wall and their proper layout might come effective in better stiffness distribution and more appropriate seismic response of the building. Several studies have been conducted in the context of analysis and design of shear walls; however, few studies have been performed on making decisions for the location and form of shear walls in multi-story buildings, especially those with irregular plan. In this study, an attempt has been made to obtain the most reliable seismic behavior of multi-story reinforced concrete vertically chamfered buildings by using more appropriate shear walls form and arrangement in 7-, 10-, 12-, and 15-story buildings. The considered forms and arrangements include common rectangular walls and L-, T-, U- and Z-shaped plan, located as the core or in the outer frames of the building structure. Comparison of seismic behaviors of the buildings, including maximum roof displacement, and particularly the formation of plastic hinges and their distribution in the buildings’ structures, have been done based on the results of a series of nonlinear time history analyses by using a set of selected earthquake records. Results show that shear walls with U-shaped cross-section, placed as the building central core, and also walls with Z-shaped cross-section, placed at the corners give the building more reliable seismic behavior.

Keywords: vertically chamfered buildings, non-linear time history analyses, l-, t-, u- and z-shaped plan walls

Procedia PDF Downloads 246

Authors: Han-Bin Park, Taesam Kang, SunKi Hong, Jeong Hoi Gu

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The piezoelectric material is being used widely for actuators due to its large power density with simple structure. It can generate a larger force than the conventional actuators with the same size. Furthermore, the response time of piezoelectric actuators is very short, and thus, it can be used for very fast system applications with compact size. To control the piezoelectric actuator, we need analog signal conditioning circuits as well as digital microcontrollers. Conventional microcontrollers are not equipped with analog parts and thus the control system becomes bulky compared with the small size of the piezoelectric devices. To overcome these weaknesses, we are developing one-chip micro controller that can handle analog and digital signals simultaneously using mixed signal FPGA technology. We used the SmartFusion™ FPGA device that integrates ARM®Cortex-M3, analog interface and FPGA fabric in a single chip and offering full customization. It gives more flexibility than traditional fixed-function microcontrollers with the excessive cost of soft processor cores on traditional FPGAs. In this paper we introduce the design of single chip controller using mixed signal FPGA, SmartFusion™[1] device. To demonstrate its performance, we implemented a PI controller for power driving circuit and a 5th order H-infinity controller for the system with piezoelectric actuator in the FPGA fabric. We also demonstrated the regulation of a power output and the operation speed of a 5th order H-infinity controller.

Keywords: mixed signal FPGA, PI control, piezoelectric actuator, SmartFusion™

Procedia PDF Downloads 511

Authors: Kwaku Damoah

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This paper presents a methodology and software application (App) designed to empower users in accessing, retrieving, and comparatively exploring data within the hierarchical network framework of the Government Finance Statistics (GFS) system. It explores the ease of navigating the GFS system and identifies the gaps filled by the new methodology and App. The GFS, embodies a complex Hierarchical Network Classification (HNC) structure, encapsulating institutional units, revenues, expenses, assets, liabilities, and economic activities. Navigating this structure demands specialized knowledge, experience, and skill, posing a significant challenge for effective analytics and fiscal policy decision-making. Many professionals encounter difficulties deciphering these classifications, hindering confident utilization of the system. This accessibility barrier obstructs a vast number of professionals, students, policymakers, and the public from leveraging the abundant data and information within the GFS. Leveraging R programming language, Data Science Analytics and Machine Learning, an efficient methodology enabling users to access, navigate, and conduct exploratory comparisons was developed. The machine learning Fiscal Analytics App (FLOWZZ) democratizes access to advanced analytics through its user-friendly interface, breaking down expertise barriers.

Keywords: data science, data wrangling, drilldown analytics, government finance statistics, hierarchical network classification, machine learning, web application.

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Authors: Ana Hol

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Digital systems are in the cognitive wave of the eTransformations and are now extensively aimed at meeting the individuals’ demands, both those of customers requiring services and those of service providers. It is also apparent that successful future systems will not just simply open doors to the traditional owners/users to offer and receive services such as Uber for example does today, but will in the future require more customized and cognitively enabled infrastructures that will be responsive to the system user’s needs. To be able to identify what is required for such systems, this research reviews the historical and the current effects of the eTransformation process by studying: 1. eTransitions of company websites and mobile applications, 2. Emergence of new sheared economy business models as Uber and, 3. New requirements for demand driven, cognitive systems capable of learning and just in time decision making. Based on the analysis, this study proposes a Cognitive eTransformation Framework capable of guiding implementations of new responsive and user aware systems.

Keywords: system implementations, AI supported systems, cognitive systems, eTransformation

Procedia PDF Downloads 226

Authors: Glaoui Hachemi

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Wind has been proven as a cost effective and reliable energy source. Technological advancements over the last years have placed wind energy in a firm position to compete with conventional power generation technologies. Algeria has a vast uninhabited land area where the south (desert) represents the greatest part with considerable wind regime. In this paper, an analysis of wind energy utilization as a viable energy substitute in six selected sites widely distributed all over the south of Algeria is presented. In this presentation, wind speed frequency distributions data obtained from the Algerian Meteorological Office are used to calculate the average wind speed and the available wind power. The annual energy produced by the Fuhrlander FL 30 wind machine is obtained using two methods. The analysis shows that in the southern Algeria, at 10 m height, the available wind power was found to vary between 160 and 280 W/m2, except for Tamanrasset. The highest potential wind power was found at Adrar, with 88 % of the time the wind speed is above 3 m/s. Besides, it is found that the annual wind energy generated by that machine lie between 33 and 61 MWh, except for Tamanrasset, with only 17 MWh. Since the wind turbines are usually installed at a height greater than 10 m, an increased output of wind energy can be expected. However, the wind resource appears to be suitable for power production on the south and it could provide a viable substitute to diesel oil for irrigation pumps and electricity generation. In this paper, a model of the wind turbine (WT) with permanent magnet generator (PMSG) and its associated controllers is presented. The increase of wind power penetration in power systems has meant that conventional power plants are gradually being replaced by wind farms. In fact, today wind farms are required to actively participate in power system operation in the same way as conventional power plants. In fact, power system operators have revised the grid connection requirements for wind turbines and wind farms, and now demand that these installations be able to carry out more or less the same control tasks as conventional power plants. For dynamic power system simulations, the PMSG wind turbine model includes an aerodynamic rotor model, a lumped mass representation of the drive train system and generator model. In this paper, we propose a model with an implementation in MATLAB / Simulink, each of the system components off-grid small wind turbines.

Keywords: windgenerator systems, permanent magnet synchronous generator (PMSG), wind turbine (WT) modeling, MATLAB simulink environment

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Authors: Slimane Souag, Amel Graa, Farid Benhamida

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In this paper we present a new method for solving the secured power flow problem by the economic dispatch using DC power flow method and Generation Shift Distribution Factor (GSDF), in this work we create a graphical interface in LabVIEW as a virtual instrument. Hence the dc power flow reduces the power flow problem to a set of linear equations, which make the iterative calculation very fast and the GSFD matrix present the effects of single and multiple generator MW change on the transmission line. The effectiveness of the method developed is identified through its application to an IEEE-14 bus test system. The calculation results show excellent performance of the proposed method, in regard to computation time and quality of results.

Keywords: electrical power system security, economic dispatch, sensitivity matrix, labview

Procedia PDF Downloads 475

Authors: Abdellah Boualouch, Ahmed Essadki, Tamou Nasser, Ali Boukhriss, Abdellatif Frigui

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This paper presents a power control for a Doubly Fed Induction Generator (DFIG) using in Wind Energy Conversion System (WECS) connected to the grid. The proposed control strategy employs two nonlinear controllers, Backstipping (BSC) and sliding-mode controller (SMC) scheme to directly calculate the required rotor control voltage so as to eliminate the instantaneous errors of active and reactive powers. In this paper the advantages of BSC and SMC are presented, the performance and robustness of this two controller’s strategy are compared between them. First, we present a model of wind turbine and DFIG machine, then a synthesis of the controllers and their application in the DFIG power control. Simulation results on a 1.5MW grid-connected DFIG system are provided by MATLAB/Simulink.

Keywords: backstipping, DFIG, power control, sliding-mode, WESC

Procedia PDF Downloads 583

Authors: Srinivasan Chandrasekaran, Shihas A. Khader

Abstract:

Motion response of floating structures is of great concern in marine engineering. Nonlinearity is an inherent property of any floating bodies subjected to irregular waves. These floating structures are continuously subjected to environmental loadings from wave, current, wind etc. This can result in undesirable motions of the vessel which may challenge the operability. For a floating body to remain in its position, it should be able to induce a restoring force when displaced. Mooring is provided to enable this restoring force. This paper discuss the hydrodynamic performance and motion characteristics of an 8 point spread mooring system applied to a pipe laying barge operating in the West African sea. The modelling of the barge is done using a computer aided-design (CAD) software RHINOCEROS. Irregular waves are generated using a suitable wave spectrum. Both frequency domain and time domain analysis is done. Numerical simulations based on potential theory are carried out to find the responses and hydrodynamic performance of the barge in both free floating as well as moored conditions. Initially, potential flow frequency domain analysis is done to obtain the Response Amplitude Operator (RAO) which gives an idea about the structural motion in free floating state. RAOs for different wave headings are analyzed. In the following step, a time domain analysis is carried out to obtain the responses of the structure in the moored condition. In this study, wave induced motions are only taken into consideration. Wind and current loads are ruled out and shall be included in future studies. For the current study, 5000 seconds simulation is taken. The results represent wave-induced motion responses, mooring line tensions and identifies critical mooring lines.

Keywords: irregular wave, moored barge, time domain analysis, numerical simulation

Procedia PDF Downloads 241