Search results for: HVDC power system

Authors: Tai Yuan Yu, Pei-Jen Wang

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Oil-free turbomachinery is considered one of the critical technologies for future green power generation systems as rotor machinery systems. Oil-free technology allows clean, compact, and maintenance-free working, and gas foil bearings, abbreviated as GFBs, are important for the technology. Since the first applications in the auxiliary power units and air cycle machines in the 1970s, obvious improvement has been created to the computational models for dynamic rotor behavior. However, many technical issues are still poorly understood or remain unsolved, and some of those are thermal management and the pattern of how pressure will be distributed in bearing clearance. This paper presents a three-dimensional, abbreviated as 3D, fluid-structure interaction model of single pad foil bearings and three pad foil bearings to predict bearing working behavior that researchers could compare characteristics of those. The coupling analysis model involves dynamic working characteristics applied to all the gas film and mechanical structures. Therefore, the elastic deformation of foil structure and the hydrodynamic pressure of gas film can both be calculated by a finite element method program. As a result, the temperature distribution pattern could also be iteratively solved by coupling analysis. In conclusion, the working fluid state in a gas film of various pad forms of bearings working characteristic at constant rotational speed for both can be solved for comparisons with the experimental results.

Keywords: fluid-structure interaction, multi-physics simulations, gas foil bearing, oil-free, transient thermo-hydrodynamic

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Authors: Gu Dongxing, Li Yuxuan, Nong Tengxiao, Burra Venkata Durga Kumar

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Since computers are widely used in business models, more and more companies choose to store important information in computers to improve productivity. However, this information can be compromised in many cases, such as when it is stored locally on the company's computers or when it is transferred between servers and clients. Of these important information leaks, source code leaks are probably the most costly. Because the source code often represents the core technology of the company, especially for the Internet companies, source code leakage may even lead to the company's core products lose market competitiveness, and then lead to the bankruptcy of the company. In recent years, such as Microsoft, AMD and other large companies have occurred source code leakage events, suffered a huge loss. This reveals to us the importance and necessity of preventing source code leakage. This paper aims to find ways to prevent source code leakage based on the direction of operating system, and based on the fact that most companies use Linux or Linux-like system to realize the interconnection between server and client, to discuss how to reduce the possibility of source code leakage during data transmission.

Keywords: data transmission, Linux, source code, operating system

Procedia PDF Downloads 237

Authors: Mutadi

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Pipes laying on an unstable slope of soft soil are prone to movement. Pipelines that are buried in unstable slope areas will move due to lateral loads from soil movement, which can cause damage to the pipeline. A small-scale laboratory model of the reinforcement system of piles supported by retaining walls was conducted to investigate the effect of lateral load on the reinforcement. In this experiment, the lateral forces of 0.3 kN, 0.35 kN, and 0.4 kN and vertical force of 0.05 kN, 0.1 kN, and 0.15 kN were used. Lateral load from the electric jack is equipped with load cell and vertical load using the cement-steel box. To validate the experimental result, a finite element program named 2-D Plaxis was used. The experimental results showed that with an increase in lateral loading, the displacement of the reinforcement system increased. For a Vertical Load, 0.1 kN and versus a lateral load of 0.3 kN causes a horizontal displacement of 0.35 mm and an increase of 2.94% for loading of 0.35 kN and an increase of 8.82% for loading 0.4 kN. The pattern is the same in the finite element method analysis, where there was a 6.52% increase for 0.35 kN loading and an increase to 23.91 % for 0.4 kN loading. In the same Load, the Reinforcement System is reliable, as shown in Safety Factor on dry conditions were 3.3, 2.824 and 2.474, and on wet conditions were 2.98, 2.522 and 2.235.

Keywords: soft soil, deflection, wall, pipeline

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Authors: Nosheen Fatima Warraich

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One of the most often used models in information system (IS) research is the technology acceptance model (TAM). This meta-analysis aims to measure the relationship between TAM variables, Perceived Ease of Use (PEOU), and Perceived Usefulness (PU) with users’ attitudes and behavioral intention (BI) in mobile and digital libraries context. It also examines the relationship of external variables (information quality and system quality) with TAM variables (PEOU and PU) in digital libraries settings. This meta-analysis was performed through PRISMA-P guidelines. Four databases (Google Scholar, Web of Science, Scopus, and LISTA) were utilized for searching, and the search was conducted according to defined criteria. The findings of this study revealed a large effect size of PU and PEOU with BI. There was also a large effect size of PU and PEOU with attitude. A medium effect size was found between SysQ -> PU, InfoQ-> PU, and SysQ -> PEOU. However, there was a small effect size between InfoQ and PEOU. It fills the literature gap and also confirms that TAM is a valid model for the acceptance and use of technology in mobile and digital libraries context. Thus, its findings would be helpful for developers and designers in designing and developing mobile library apps. It will also be beneficial for library authorities and system librarians in designing and developing digital libraries in academic settings.

Keywords: technology acceptance model (tam), perceived ease of use, perceived usefulness, information quality, system quality, meta-analysis, systematic review, digital libraries, and mobile library apps.

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Authors: Collins Nkapnwo Formella

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The democratic wave of the 1980s and 1990s brought a lot of hopes to the politics of African states as many nation-states adopted ‘democracy.’ The end of the Cold War ushered in, with a lot of rush, pro-democracy movements, which led to multi-party politics, following constitutional reviews. For the very first time since independence, Africans revolted against personalized dictatorship and adopted the idea of limited office terms for the presidents. This paper dives deep into the history of Africa post-independence with the aim of allowing the readers to understand the nature of the differences in the political setups that currently govern the continent and the central region in particular. Time has proven the euphoria that characterized post-Cold War African politics at least for many countries short-lived, as their leaders were unable to re-design the institutions of governance from the compromise and interest-oriented structures handed down after independence. The result has been that politics in many of the countries have been tailored down along the lines of winner takes all approach, with the accumulation of state power being the sole objective of the leaders. The paper contends that 21ˢᵗ Century African politics is exactly the politics of inclusion/exclusion based on ethnic and interest groups, leading to the flourishing of patrimonial authoritarian regimes. It also puts to the test, whether authoritarian responses to delivering growth (economic, political, social) and peace as has been the model adopted by many leaders is superior compared to democracy. This paper then concludes by adding that the practice of democracy in the Central African region in its current form is inherently flawed from its foundations, thus incapable of rooting out the crises faced in the region.

Keywords: authoritarianism, democracy, development, power, institutions

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Authors: Danika Tynes

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Telehealth is a promising advancement in health care, though there are certain conditions under which telehealth has a greater chance of success. This research sought to further the understanding of what conditions compel the success of telehealth adoption at the systems level applying Diffusion of Innovations (DoI) theory (Rogers, 1962). System-level indicators were selected to represent four components of DoI theory (relative advantage, compatibility, complexity, and observability) and regressed on 5 types of telehealth (teleradiology, teledermatology, telepathology, telepsychology, and remote monitoring) using multiple logistic regression. The analyses supported relative advantage and compatibility as the strongest influencers of telehealth adoption, remote monitoring in particular. These findings help to quantitatively clarify the factors influencing the adoption of innovation and advance the ability to make recommendations on the viability of state telehealth adoption. In addition, results indicate when DoI theory is most applicable to the understanding of telehealth diffusion. Ultimately, this research may contribute to more focused allocation of scarce health care resources through consideration of existing state conditions available foster innovation.

Keywords: adoption, diffusion of innovation theory, remote monitoring, system-level indicators

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Authors: Nimet Yildirim Tirgil, Ahmed Busnaina, April Z. Gu

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Environmental waters are monitored worldwide to protect people from infectious diseases primarily caused by enteric pathogens. All long, Escherichia coli (E. coli) is a good indicator for potential enteric pathogens in waters. Thus, a rapid and simple detection method for E. coli is very important to predict the pathogen contamination. In this study, to the best of our knowledge, as the first time we developed a rapid, direct and reusable SWCNTs (single walled carbon nanotubes) based biosensor system for sensitive and selective E. coli detection in water samples. We use a novel and newly developed flexible biosensor device which was fabricated by high-rate nanoscale offset printing process using directed assembly and transfer of SWCNTs. By simple directed assembly and non-covalent functionalization, aptamer (biorecognition element that specifically distinguish the E. coli O157:H7 strain from other pathogens) based SWCNTs biosensor system was designed and was further evaluated for environmental applications with simple and cost-effective steps. The two gold electrode terminals and SWCNTs-bridge between them allow continuous resistance response monitoring for the E. coli detection. The detection procedure is based on competitive mode detection. A known concentration of aptamer and E. coli cells were mixed and after a certain time filtered. The rest of free aptamers injected to the system. With hybridization of the free aptamers and their SWCNTs surface immobilized probe DNA (complementary-DNA for E. coli aptamer), we can monitor the resistance difference which is proportional to the amount of the E. coli. Thus, we can detect the E. coli without injecting it directly onto the sensing surface, and we could protect the electrode surface from the aggregation of target bacteria or other pollutants that may come from real wastewater samples. After optimization experiments, the linear detection range was determined from 2 cfu/ml to 10⁵ cfu/ml with higher than 0.98 R² value. The system was regenerated successfully with 5 % SDS solution over 100 times without any significant deterioration of the sensor performance. The developed system had high specificity towards E. coli (less than 20 % signal with other pathogens), and it could be applied to real water samples with 86 to 101 % recovery and 3 to 18 % cv values (n=3).

Keywords: aptamer, E. coli, environmental detection, nanobiosensor, SWCTs

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Authors: Matthias Banholzer, Hagen Müller, Michael Pfitzner

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Gas internal combustion engines are widely used as propulsion systems or in power plants to generate heat and electricity. While there are different types of injection methods including the manifold port fuel injection and the direct injection, the latter has more potential to increase the specific power by avoiding air displacement in the intake and to reduce combustion anomalies such as backfire or pre-ignition. During the opening process of the injector, multiple flow regimes occur: subsonic, transonic and supersonic. To cover the wide range of Mach numbers a compressible pressure-based solver is used. While the standard Pressure Implicit with Splitting of Operators (PISO) method is used for the coupling between velocity and pressure, a high-resolution non-oscillatory central scheme established by Kurganov and Tadmor calculates the convective fluxes. A blending function based on the local Mach- and CFL-number switches between the compressible and incompressible regimes of the developed model. As the considered operating points are well above the critical state of the used fluids, the ideal gas assumption is not valid anymore. For the real gas thermodynamics, the models based on the Soave-Redlich-Kwong equation of state were implemented. The caloric properties are corrected using a departure formalism, for the viscosity and the thermal conductivity the empirical correlation of Chung is used. For the injector geometry, the dimensions of a diesel injector were adapted. Simulations were performed using different nozzle and needle geometries and opening curves. It can be clearly seen that there is a significant influence of all three parameters.

Keywords: high pressure gas injection, hybrid solver, hydrogen injection, needle opening process, real-gas thermodynamics

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Authors: Mansour Hadji Hosseinlou, Alireza Mahdavi

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Transportation is one of any society's needs which have developed after improving economically and socially and is one of civilization symbols today. Although it is so useful for human, it leads to many serious harms and injuries. The development of communication system and building new roads has resulted in increasing the rate of accidents; therefore, in practice, this increasing rate has decreased the advantages of transportation. Traffic accidents are one of the causes of death, serious financial and bodily harms and its significant social, economic and cultural consequences threatens the societies seriously. Iran's ground transportation system is one of the most eventful transportation systems in the world and mortality rate and financial harms cost too much for the country in national aspect. Therefore, we have presented a data collection by referring to recorded statistics of the accidents occurred in freeways from 2013 to 2015. These statistics are recorded in different related databases, generally police and road transportation system. The data is separated and arranged in tables and after preparing, processing and prioritizing the factors, the achieved collection is presented to the departments, managers and researchers to help them suggest practical solutions.

Keywords: freeways’ accidents, humane causes, death, tiredness, drowsiness

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Authors: Miria Gambardella

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The influence of solidarity demonstrations towards the Zapatista National Liberation Army has been constantly present over the years, both locally and internationally, guaranteeing visibility to the cause, shaping the movement’s choices, and influencing its hopes of impact worldwide. Most of the coffee produced by the autonomous cooperatives from Chiapas is exported, therefore making coffee trade the main income from international solidarity networks. The question arises about the implications of the relations established between the communities in resistance in Southeastern Mexico and international solidarity movements, specifically on the strategies adopted to conciliate army's demands for autonomy and economic asymmetries between Zapatista cooperatives producing coffee and European collectives who hold purchasing power. In order to deepen the inquiry on those topics, a year-long multi-site investigation was carried out. The first six months of fieldwork were based in Barcelona, where Zapatista coffee was first traded in Spain and where one of the historical and most important European solidarity groups can be found. The last six months of fieldwork were carried out directly in Chiapas, in contact with coffee producers, Zapatista political authorities, international activists as well as vendors, and the rest of the network implicated in coffee production, roasting, and sale. The investigation was based on qualitative research methods, including participatory observation, focus groups, and semi-structured interviews. The analysis did not only focus on retracing the steps of the market chain as if it could be considered a linear and unilateral process, but it rather aimed at exploring actors’ reciprocal perceptions, roles, and dynamics of power. Demonstrations of solidarity and the money circulation they imply aim at changing the system in place and building alternatives, among other things, on the economic level. This work analyzes the formulation of discourse and the organization of solidarity activities that aim at building opportunities for action within a highly politicized economic sphere to which access must be regularly legitimized. The meaning conveyed by coffee is constructed on a symbolic level by the attribution of moral criteria to transactions. The latter participate in the construction of imaginaries that circulate through solidarity movements with the Zapatista rebellion. Commercial exchanges linked to solidarity networks turned out to represent much more than monetary transactions. The social, cultural, and political spheres are invested by ethics, which penetrates all aspects of militant action. It is at this level that the boundaries of different collective actors connect, contaminating each other: merely following the money flow would have been limiting in order to account for a reality within which imaginary is one of the main currencies. The notions of “trust”, “dignity” and “reciprocity” are repeatedly mobilized to negotiate discontinuous and multidirectional flows in the attempt to balance and justify commercial relations in a politicized context that characterizes its own identity through demonizing “market economy” and its dehumanizing powers.

Keywords: coffee trade, economic anthropology, international cooperation, Zapatista National Liberation Army

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Authors: Miled Amel, Ben Maad Hatem, Askri Faouzi, Ben Nasrallah Sassi

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Metal hydride water pumping system uses hydrogen as working fluid to pump water for low head and high discharge. The principal operation of this pump is based on the desorption of hydrogen at high pressure and its absorption at low pressure by a metal hydride. This work is devoted to study a concept of the dynamic behavior of a metal hydride pump using unsteady model and LaNi5 as hydriding alloy. This study shows that with MHP, it is possible to pump 340l/kg-cycle of water in 15 000s using 1 Kg of LaNi5 at a desorption temperature of 360 K, a pumping head equal to 5 m and a desorption gear ratio equal to 33. This study reveals also that the error given by the steady model, using LaNi5 is about 2%.A dimensional mathematical model and the governing equations of the pump were presented to predict the coupled heat and mass transfer within the MHP. Then, a numerical simulation is carried out to present the time evolution of the specific water discharge and to test the effect of different parameters (desorption temperature, absorption temperature, desorption gear ratio) on the performance of the water pumping system (specific water discharge, pumping efficiency and pumping time). In addition, a comparison between results obtained with steady and unsteady model is performed with different hydride mass. Finally, a geometric configuration of the reactor is simulated to optimize the pumping time.

Keywords: dynamic behavior, LaNi5, performance of water pumping system, unsteady model

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Authors: Dalila Oulhaci, Mehdi Benlarbi, Mohammed Zahaf

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The irrigation method is fundamental for maintaining a wet bulb around the roots of the crop. This is the case with localized irrigation, where soil moisture can be maintained permanently around the root system between the two water content extremes. Also, one of the oldest methods used since Roman times throughout North Africa and the Near East is based on the frequent dumping of water into porous pottery vases buried in the ground. In this context, these two techniques have been combined by replacing the pottery vase with plastic bottles filled with sand that discharge water through their perforated walls into the surrounding soil. The first objective of this work is the theoretical determination using CLIMWAT and CROPWAT software of the irrigation doses of some crops (palm, wheat, and onion) and experimental by measuring the humidity of the soil before and after watering. The second objective is to determine the purifying power of the sand filter in the bottle. Based on the CROPWAT software results, the date palm needs 18.5 mm in the third decade of December, 57.2 mm in January, and 73.7 mm in February, whereas the doses received by experimentally determined by means of soil moisture before and after irrigation are 19.5 mm respectively, 79.66 mm and 95.66 mm. The onion needs 14.3 mm in the third decade of December of, 59.1 mm in January, and 80 mm in February, whereas the experimental dose received is 15.07 mm, respectively, 64.54 and 86.8 mm. The total requirements for the vegetative period are estimated at 1642.6 mm for date palms, 277.4 mm for wheat, and 193.5 mm for onions. The removal rate of the majority of pollutants from the bottle is 80%. This work covers, on the one hand, the context of water conservation, sustainable development, and protection of the environment, and on the other, the agricultural field.

Keywords: irrigation, sand, filter, humidity, bottle

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Authors: R. Hocine, A. Boudjemai, A. Amrani, K. Belkacemi

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Temperature rising is a negative factor in almost all systems. It could cause by self heating or ambient temperature. In solar photovoltaic cells this temperature rising affects on the behavior of cells. The ability of a PV module to withstand the effects of periodic hot-spot heating that occurs when cells are operated under reverse biased conditions is closely related to the properties of the cell semi-conductor material. In addition, the thermal effect also influences the estimation of the maximum power point (MPP) and electrical parameters for the PV modules, such as maximum output power, maximum conversion efficiency, internal efficiency, reliability, and lifetime. The cells junction temperature is a critical parameter that significantly affects the electrical characteristics of PV modules. For practical applications of PV modules, it is very important to accurately estimate the junction temperature of PV modules and analyze the thermal characteristics of the PV modules. Once the temperature variation is taken into account, we can then acquire a more accurate MPP for the PV modules, and the maximum utilization efficiency of the PV modules can also be further achieved. In this paper, the three-Dimensional Transmission Line Matrix (3D-TLM) method was used to map the surface temperature distribution of solar cells while in the reverse bias mode. It was observed that some cells exhibited an inhomogeneity of the surface temperature resulting in localized heating (hot-spot). This hot-spot heating causes irreversible destruction of the solar cell structure. Hot spots can have a deleterious impact on the total solar modules if individual solar cells are heated. So, the results show clearly that the solar cells are capable of self-generating considerable amounts of heat that should be dissipated very quickly to increase PV module's lifetime.

Keywords: thermal effect, conduction, heat dissipation, thermal conductivity, solar cell, PV module, nodes, 3D-TLM

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Authors: R. T. Aggangan

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Woodfuels continue to be a major component of the energy supply mix of the Philippines due to increasing demand for energy that are not adequately met by decreasing supply and increasing prices of fuel oil such as liquefied petroleum gas (LPG) and kerosene. The Development Academy of the Philippines projects the demand of woodfuels in 2016 as 28.3 million metric tons in the household sector and about 105.4 million metric tons combined supply potentials of both forest and non-forest lands. However, the Revised Master Plan for Forestry Development projects a demand of about 50 million cu meters of fuelwood in 2016 but the capability to supply from local sources is only about 28 million cu meters indicating a 44 % deficiency. Household demand constitutes 82% while industries demand is 18%. Domestic household demand for energy is for cooking needs while the industrial demand is for steam power generation, curing barns of tobacco: brick, ceramics and pot making; bakery; lime production; and small scale food processing. Factors that favour increased use of wood-based energy include the relatively low prices (increasing oil-based fuel prices), availability of efficient wood-based energy utilization technology, increasing supply, and increasing population that cannot afford conventional fuels. Moreover, innovations in combustion technology and cogeneration of heat and power from biomass for modern applications favour biomass energy development. This paper recommends policies and strategic directions for the development of the woodfuel industry with the twin goals of sustainably supplying the energy requirements of households and industry.

Keywords: biomass energy development, fuelwood, households and industry, innovations in combustion technology, supply and demand

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Authors: Sultan Ahmad Azizi, Gaurang J. Joshi

Abstract:

Urban transportation has come to lime light in recent times due to deteriorating travel quality. The economic growth of India has boosted significant rise in private vehicle ownership in cities, whereas public transport systems have largely been ignored in metropolitan cities. Even though there is latent demand for public transport systems like organized bus services, most of the metropolitan cities have unsustainably low share of public transport. Unfortunately, Indian metropolitan cities have failed to maintain balance in mode share of various travel modes in absence of timely introduction of mass transit system of required capacity and quality. As a result, personalized travel modes like two wheelers have become principal modes of travel, which cause significant environmental, safety and health hazard to the citizens. Of late, the policy makers have realized the need to improve public transport system in metro cities for sustaining the development. However, the challenge to the transit planning authorities is to design a transit system for cities that may attract people to switch over from their existing and rather convenient mode of travel to the transit system under the influence of household socio-economic characteristics and the given travel pattern. In this context, the fast-growing industrial city of Surat is taken up as a case for the study of likely shift to bus transit. Deterioration of public transport system of bus after 1998, has led to tremendous growth in two-wheeler traffic on city roads. The inadequate and poor service quality of present bus transit has failed to attract the riders and correct the mode use balance in the city. The disaggregate travel behavior for trip generations and the travel mode choice has been studied for the West Adajan residential sector of city. Mode specific utility functions are calibrated under multi-nominal logit environment for two-wheeler, cars and auto rickshaws with respect to bus transit using SPSS. Estimation of shift to bus transit is carried indicate an average 30% of auto rickshaw users and nearly 5% of 2W users are likely to shift to bus transit if service quality is improved. However, car users are not expected to shift to bus transit system.

Keywords: bus transit, disaggregate travel nehavior, mode choice Behavior, public transport

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Authors: Mohammad S. Islam

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Elections in Bangladesh are always controversial, and sometimes it becomes a violent affair when state power is combined with politics. Despite the commitment of the ruling party- the polling government to ensure free, fair, and credible elections, the participants of opposition parties and the general voters became very disappointed, terribly frustrated, and severely shocked. It happened when numerous claims of serious irregularities of vote rigging and violence came out in broad daylight during the election. This paper addresses the issues of how the ruling party created frightening and a horror situation to make people silent over electoral fraud and violent incidents, including gang rape. It also seeks to demonstrate that election-2018 was simply the deceptive action of the ruling party to legitimate their power, but not to provide a minimum opportunity for voters to exercise their fundamental right to vote. The fundamental freedom and the rule of law seemed to be ignored completely in this election process and afterwards. With the help of state machinery, the government of the ruling party violated human rights, restricted fundamental freedoms, and humiliated social protection & dignity. The contestant’s views as witnessed and relevant literatures are cited first for conceptual understanding. Then, the paper will examine how a new dimension of circumstantial social measures related to sustained protection can reduce all kinds of violence against humanity towards establishing a peaceful democratic society. Finally, this paper interprets the key findings and considers wider implications.

Keywords: electoral fraud, human rights, sustained protection, social measures, vote rigging

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Authors: Dwi Arisandi Wijaya, Ernawati Arifin Giri-Rachman, Neni Nurainy

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Typhoid fever disease can be prevented by using a polysaccharide-based vaccine Vi which is a virulence factor of S.typhi. To produce high yield Vi polysaccharide from bacteria, it is important to know the biosynthesis of Vi polysaccharide and the regulators involved. In the In vivo condition, S. typhi faces different osmolarity, and the bacterial two-component system OmpR-EnvZ, regulate by up and down Capsular Vi polysaccharide biosynthesis. A high yielded Vi Polysaccharide strain, S. typhi strain C6524 used to study the effect of media osmolarity on Vi polysaccharide biosynthesis and the osmoregulation pattern of S. typhi strain C6524. The methods were performed by grown S. typhi strain C6524 grown on medium with 50 mM, 100 mM, and 150 mM osmolarity with the batch system. Vi polysaccharide concentration was measured by ELISA method. For further investigation of the osmoregulation pattern of strain C6524, the osmoregulator gene, OmpR, has been isolated and sequenced using the specific primer of the OmpR gene. Nucleotide sequence analysis is done with BLAST and Lallign. Amino Acid sequence analysis is done with Prosite and Multiple Sequence Alignment. The results of cultivation showed the average content of polysaccharide Vi for 50 mM, 100 mM, and 150 mM osmolarities 11.49 μg/mL, 12.06 μg/mL, and 14.53 μg/mL respectively. Analysis using Anova stated that the osmolarity treatment of 150 mM significantly affects Vi content. Analysis of nucleotide sequences shows 100% identity between S. typhi strain C6524 and Ty2. Analysis of amino acid sequences shows that the OmpR response regulator protein of the C6524 strain also has a α4-β5-α5 motif which is important for the regulatory activation system when phosphorylation occurs by domain kinase. This indicates that the regulator osmolarity response of S. typhi strain C6524 has no difference with the response regulator owned by S. typhi strain Ty2. A high Vi response rate in the 150 mM osmolarity treatment requires further research for RcsB-RcsC, another two-component system involved in Vi Biosynthesis.

Keywords: osmoregulator, OmpR, Salmonella, Vi polysaccharide

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Authors: Niina Meriläinen

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Digital platforms are arenas for dialogue, various kinds of political debates, information and news gathering, policymaking, and social change processes. Human rights serve as examples of social and political issues that are universally noted as principles and yet often violated on digital platforms as well as in the analog world. Digital platforms in this study are different Internet sites, blogs, discussion platforms, social media apps, and gaming. Various actors, from human rights activists and non-governmental organizations to individual people, governments, and corporations, use digital platforms along with analog arenas to discuss and defend human rights, while violators can find new victims and continue violating rights on the same platforms. Digital platforms create opportunities for various women and minorities to empower themselves and others and to be active in various arenas of society and policymaking. At the same time, digital platforms pose threats to human rights globally, especially to women, girls, and minorities. The results of this meta-study of n=120 academic case studies indicate that more research is needed to determine the framework of human rights and human rights on digital platforms. A broad discussion must be had on what human rights require in the digital realm and how ICTs may enhance or threaten our ability to respect, protect, and fulfill a wide variety of human rights while various digital platforms pose multiple threats to human rights. This relates to the willingness of political decision-makers to act upon various crimes committed on and with online platforms. More research is needed to determine the framework of digital human rights and human rights on digital platforms in relation to political communication and decision-making. It is important to develop a framework in which these are defined. It must be discussed who participates in this process: those whose rights are violated, companies that profit by selling our personal data, activists, governments, and some unknown actors. In the end, the question comes back to who has the power to define what we talk about, when, and where. This use of power plays a big role. Digital platforms illustrate the darker side of technological progress, which, on the one hand, has given various people the possibility to engage in society, empower themselves, and take ownership of their rights globally. At the same time, the platforms enable others to use the same platforms to find victims, abuse them, and exploit them. Bullying, harassment, and violence are rampant on various digital platforms, where minorities and people with limited support are victims. There is indeed a need for a discussion of normative values in the era of fake news, the power of influencers, Trumpism, and institutionalized disregard for human rights, gender equality, and the elimination of gender-based violence online. Attention and obligations must be placed on politicians and internet architecture, such as corporations, and their roles in human rights and their violations online.

Keywords: human rights, digital platforms, violations, internet, social media

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Authors: Lakhoua Najeh

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Introduction: In most situations, an industrial system already existing, conditioned by its history, its culture and its context are in difficulty facing the necessity to restructure itself in an organizational and technological environment in perpetual evolution. This is why all operations of restructuring first of all require a diagnosis based on a functional analysis. After a presentation of the functionality of a supervisory system for complex processes, we present the concepts of industrial automation and supervisory control and data acquisition (SCADA). Methods: This global analysis exploits the various available documents on the one hand and takes on the other hand in consideration the various testimonies through investigations, the interviews or the collective workshops; otherwise, it also takes observations through visits as a basis and even of the specific operations. The exploitation of this diagnosis enables us to elaborate the project of restructuring thereafter. Leaving from the system analysis for the restructuring of industrial systems, and after a technical diagnosis based on visits, an analysis of the various technical documents and management as well as on targeted interviews, a focusing retailing the various levels of analysis has been done according a general methodology. Results: The methodology adopted in order to contribute to the restructuring of industrial systems by its participative and systemic character and leaning on a large consultation a lot of human resources that of the documentary resources, various innovating actions has been proposed. These actions appear in the setting of the TQM gait requiring applicable parameter quantification and a treatment valorising some information. The new management environment will enable us to institute an information and communication system possibility of migration toward an ERP system. Conclusion: Technological advancements in process monitoring, control and industrial automation over the past decades have contributed greatly to improve the productivity of virtually all industrial systems throughout the world. This paper tries to identify the principles characteristics of a process monitoring, control and industrial automation in order to provide tools to help in the decision-making process.

Keywords: automation, supervision, SCADA, TQM

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Authors: Rubin Dan, Xingcai Wang, Ziyang Chen

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A chaotic time series noise reduction method based on the fusion of the local projection method, wavelet transform, and particle swarm algorithm (referred to as the LW-PSO method) is proposed to address the problem of false recognition due to noise in the recognition process of chaotic time series containing noise. The method first uses phase space reconstruction to recover the original dynamical system characteristics and removes the noise subspace by selecting the neighborhood radius; then it uses wavelet transform to remove D1-D3 high-frequency components to maximize the retention of signal information while least-squares optimization is performed by the particle swarm algorithm. The Lorenz system containing 30% Gaussian white noise is simulated and verified, and the phase space, SNR value, RMSE value, and K value of the 0-1 test method before and after noise reduction of the Schreiber method, local projection method, wavelet transform method, and LW-PSO method are compared and analyzed, which proves that the LW-PSO method has a better noise reduction effect compared with the other three common methods. The method is also applied to the classical system to evaluate the noise reduction effect of the four methods and the original system identification effect, which further verifies the superiority of the LW-PSO method. Finally, it is applied to the Chengdu rainfall chaotic sequence for research, and the results prove that the LW-PSO method can effectively reduce the noise and improve the chaos recognition rate.

Keywords: Schreiber noise reduction, wavelet transform, particle swarm optimization, 0-1 test method, chaotic sequence denoising

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Authors: John R Evans, Sook-Ying Ho, Rey Chin

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This paper describes the research investigations orientated to the starting and propelling of a solid fuel rocket engine which operates as combined cycle propulsion system using three thrust pulses. The vehicle has been designed to minimise the cost of launching small number of Nano/Cube satellites into low earth orbits (LEO). A technology described in this paper is a ground-based launch propulsion system which starts the rocket vertical motion immediately causing air flow to enter the ramjet’s intake. Current technology has a ramjet operation predicted to be able to start high subsonic speed of 280 m/s using a liquid fuel ramjet (LFRJ). The combined cycle engine configuration is in many ways fundamentally different from the LFRJ. A much lower subsonic start speed is highly desirable since the use of a mortar to obtain the latter speed for rocket means a shorter launcher length can be utilized. This paper examines the means and has some performance calculations, including Computational Fluid Dynamics analysis of air-intake at suitable operational conditions, 3-DOF point mass trajectory analysis of multi-pulse propulsion system (where pulse ignition time and thrust magnitude can be controlled), etc. of getting a combined cycle rocket engine use in a single stage vehicle.

Keywords: combine cycle propulsion system, low earth orbit launch vehicle, computational fluid dynamics analysis, 3dof trajectory analysis

Procedia PDF Downloads 176

Authors: Jiwon Lee, Yeong-Ju Go, Jong-Soo Choi

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Drones were first developed for military use and were used in World War 1. But recently drones have been used in a variety of fields. Several companies actively utilize drone technology to strengthen their services, and in agriculture, drones are used for crop monitoring and sowing. Other people use drones for hobby activities such as photography. However, as the range of use of drones expands rapidly, problems caused by drones such as improperly flying, privacy and terrorism are also increasing. As the need for monitoring and tracking of drones increases, researches are progressing accordingly. The drone detection system estimates the position of the drone using the physical phenomena that occur when the drones fly. The drone detection system measures being developed utilize many approaches, such as radar, infrared camera, and acoustic detection systems. Among the various drone detection system, the acoustic detection system is advantageous in that the microphone array system is small, inexpensive, and easy to operate than other systems. In this paper, the acoustic signal is acquired by using minimum microphone when drone is flying, and direction of drone is estimated. When estimating the Direction of Arrival(DOA), there is a method of calculating the DOA based on the Time Difference of Arrival(TDOA) and a method of calculating the DOA based on the beamforming. The TDOA technique requires less number of microphones than the beamforming technique, but is weak in noisy environments and can only estimate the DOA of a single source. The beamforming technique requires more microphones than the TDOA technique. However, it is strong against the noisy environment and it is possible to simultaneously estimate the DOA of several drones. When estimating the DOA using acoustic signals emitted from the drone, it is impossible to measure the position of the drone, and only the direction can be estimated. To overcome this problem, in this work we show how to estimate the position of drones by arranging multiple microphone arrays. The microphone array used in the experiments was four tetrahedral microphones. We simulated the performance of each DOA algorithm and demonstrated the simulation results through experiments.

Keywords: acoustic sensing, direction of arrival, drone detection, microphone array

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Authors: S. Kaymakçı, D. Gündoğdu, H. Özçelik

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The truck park of a warehouse for a chain of supermarket was going to be constructed on a poor ground. Rather than using a piled foundation, the client was convinced that a ground improvement using a reinforced foundation raft also known as “basal reinforcement” shall work. The retaining structures supporting the truck park area were designed using a hybrid structure made up of the Terramesh® Wall System and MacGrid™ high strength geogrids. The total wall surface area is nearly 2740 sq.m , reaching a maximum height of 13.00 meters. The area is located in the first degree seismic zone of Turkey and the design seismic acceleration is high. The design of walls has been carried out using pseudo-static method (limit equilibrium) taking into consideration different loading conditions using Eurocode 7. For each standard approach stability analysis in seismic condition were performed. The paper presents the detailed design of the reinforced soil structure, basal reinforcement and the construction methods; advantages of using such system for the project are discussed.

Keywords: basal reinforcement, geogrid, reinforced soil raft, reinforced soil wall, soil reinforcement

Procedia PDF Downloads 283

Authors: Alexander de Tomás, Miquel Sierra, Stefan Pfenninger, Francesco Lombardi, Ines Campos, Cristina Madrid

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Environmental parameters are key in the definition of sustainable energy systems yet excluded from most energy system optimization models. Still, decision-making may be misleading without considering them. Environmental analyses of the energy transition are a key part of industrial ecology but often are performed without any input from the users of the information. This work assesses the systemic impacts of energy transition pathways in Portugal. Using the Calliope energy modeling framework, 250+ optimized energy system pathways are generated. A Delphi study helps to identify the relevant criteria for the stakeholders as regards the environmental assessment, which is performed with ENBIOS, a python package that integrates life cycle assessment (LCA) with a metabolic analysis based on complex relations. Furthermore, this study focuses on how the uncertainty propagates through the model’s consortium. With the aim of doing so, a soft link between the Calliope/ENBIOS cascade and Brightway’s data capabilities is built to perform Monte Carlo simulations. These findings highlight the relevance of including uncertainty analysis as a range of values rather than informing energy transition results with a single value.

Keywords: energy transition, energy modeling, uncertainty, sustainability

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Authors: Mohammad Saleh Vahdatpour, Yanqing Zhang

Abstract:

Understanding the neural mechanisms underlying motion detection in the human visual system has long been a fascinating challenge in neuroscience and artificial intelligence. This paper presents a spiking neural network model inspired by the processing of motion information in the primate visual system, particularly focusing on the Middle Temporal (MT) area. In our study, we propose a multi-layer spiking neural network model to perform motion detection tasks, leveraging the idea that synaptic delays in neuronal communication are pivotal in motion perception. Synaptic delay, determined by factors like axon length and myelin insulation, affects the temporal order of input spikes, thereby encoding motion direction and speed. Overall, our spiking neural network model demonstrates the feasibility of capturing motion detection principles observed in the primate visual system. The combination of synaptic delays, learning mechanisms, and shared weights and delays in SMD provides a promising framework for motion perception in artificial systems, with potential applications in computer vision and robotics.

Keywords: neural network, motion detection, signature detection, convolutional neural network

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Authors: Ayelet Siman-Tov, Shlomo Kaniel

Abstract:

Objectives: The research validates a multivariate model that predicts parental adjustment to coping successfully with an autistic child. The model comprises four elements: parental stress, parental resources, parental adjustment and the child's autism symptoms. Background and aims: The purpose of the current study is the construction and validation of a model for the adjustment of parents and a child with autism. The suggested model is based on theoretical views on stress and links personal resources, stress, perception, parental mental health and quality of marriage and child adjustment with autism. The family stress approach focuses on the family as a system made up of a dynamic interaction between its members, who constitute interdependent parts of the system, and thus, a change in one family member brings about changes in the processes of the entire family system. From this perspective, a rise of new demands in the family and stress in the role of one family member affects the family system as a whole. Materials and methods: 176 parents of children aged between 6 to 16 diagnosed with ASD answered several questionnaires measuring parental stress, personal resources (sense of coherence, locus of control, social support), adjustment (mental health and marriage quality) and the child's autism symptoms. Results: Path analysis showed that a sense of coherence, internal locus of control, social support and quality of marriage increase the ability to cope with the stress of parenting an autistic child. Directions for further research are suggested.

Keywords: stress, adjustment, resources, Autism, parents, coherence

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Authors: L. K. Karimova, K. I. Shariukova, A. A. Kirpichnikova, E. A. Razuvalova

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This article deals with technology of virtual reconstruction of Kazan Imperial University of XIX - early XX centuries. The paper describes technologies of 3D-visualization of high-resolution models of objects of university space, creation of multi-agent system and connected with these objects organized database of historical sources, variants of use of technologies of immersion into the virtual environment.

Keywords: 3D-reconstruction, multi-agent system, database, university space, virtual reconstruction, virtual heritage

Procedia PDF Downloads 248

Authors: Adel Nikfarjam, Hamed Tayebi, Sadoullah Ebrahimnejad

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This paper considers a two-echelon inventory system with a number of warehouses and a single retailer. The retailer replenishes its required items from warehouses, and assembles them into a single final product. We assume that each warehouse supplies only one kind of the raw material for the retailer. The demand process of the final product is assumed to be Poissson, and unsatisfied demand of the final product will be lost. The retailer applies one-for-one-period ordering policy which is also known as (1, T) ordering policy. In this policy the retailer orders to each warehouse a fixed quantity of each item at fixed time intervals, which the fixed quantity is equal to the utilization of the item in the final product. Since, this policy eliminates all demand uncertainties at the upstream echelon, the standard lot sizing model can be applied at all warehouses. In this paper, we calculate the total cost function of the inventory system. Then, based on this function, we present a procedure to obtain the optimal time interval between two consecutive order placements from retailer to the warehouses, and the optimal order quantities of warehouses (assuming that there are positive ordering costs at warehouses). Finally, we present some numerical examples, and conduct numerical sensitivity analysis for cost parameters.

Keywords: two-echelon supply chain, multi-vendor-single-buyer inventory system, lost sales, Poisson demand, one-for-one-period policy, lot sizing model

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Authors: M. Kamel El-Sayed

Abstract:

The process of determining the degree of membership for an element to an uncertain concept has been found in many ways, using equivalence and symmetry relations in information systems. In the case of similarity, these methods did not take into account the degree of symmetry between elements. In this paper, we use a new definition for finding the membership based on the degree of symmetry. We provide an example to clarify the suggested methods and compare it with previous methods. This method opens the door to more accurate decisions in information systems.

Keywords: information system, uncertain concept, membership function, similarity relation, degree of similarity

Procedia PDF Downloads 199

Authors: Péter Restás, Andrea Czibor, Zsolt Péter Szabó

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Purpose: This article aims to rethink the phenomena of employee behavior as a product of a system. Both organizational culture and Complex Adaptive Systems (CAS) theory emphasize that individual behavior depends on the specific system and the unique organizational culture. These two major theories are both represented in the field of organizational studies; however, they are rarely used together for the comprehensive understanding of workplace behavior. Methodology: By reviewing the literature we use key concepts stemming from organizational culture and CAS theory in order to show the similarities between these theories and create an enriched understanding of employee behavior. Findings: a) Workplace behavior is defined here as social cognition issue. b) Organizations are discussed here as complex systems, and cultures which drive and dictate the cognitive processes of agents in the system. c) Culture gives CAS theory a context which lets us see organizations not just as ever-changing and unpredictable, but as such systems that aim to create and maintain stability by recurring behavior. Conclusion: Applying the knowledge from culture and CAS theory sheds light on our present understanding of employee behavior, also emphasizes the importance of novel ways in organizational research and management.

Keywords: complex adaptive systems theory, employee behavior, organizational culture, stability

Procedia PDF Downloads 393