Search results for: space velocity
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5177

Search results for: space velocity

3917 Laboratory and Numerical Hydraulic Modelling of Annular Pipe Electrocoagulation Reactors

Authors: Alejandra Martin-Dominguez, Javier Canto-Rios, Velitchko Tzatchkov

Abstract:

Electrocoagulation is a water treatment technology that consists of generating coagulant species in situ by electrolytic oxidation of sacrificial anode materials triggered by electric current. It removes suspended solids, heavy metals, emulsified oils, bacteria, colloidal solids and particles, soluble inorganic pollutants and other contaminants from water, offering an alternative to the use of metal salts or polymers and polyelectrolyte addition for breaking stable emulsions and suspensions. The method essentially consists of passing the water being treated through pairs of consumable conductive metal plates in parallel, which act as monopolar electrodes, commonly known as ‘sacrificial electrodes’. Physicochemical, electrochemical and hydraulic processes are involved in the efficiency of this type of treatment. While the physicochemical and electrochemical aspects of the technology have been extensively studied, little is known about the influence of the hydraulics. However, the hydraulic process is fundamental for the reactions that take place at the electrode boundary layers and for the coagulant mixing. Electrocoagulation reactors can be open (with free water surface) and closed (pressurized). Independently of the type of rector, hydraulic head loss is an important factor for its design. The present work focuses on the study of the total hydraulic head loss and flow velocity and pressure distribution in electrocoagulation reactors with single or multiple concentric annular cross sections. An analysis of the head loss produced by hydraulic wall shear friction and accessories (minor head losses) is presented, and compared to the head loss measured on a semi-pilot scale laboratory model for different flow rates through the reactor. The tests included laminar, transitional and turbulent flow. The observed head loss was compared also to the head loss predicted by several known conceptual theoretical and empirical equations, specific for flow in concentric annular pipes. Four single concentric annular cross section and one multiple concentric annular cross section reactor configuration were studied. The theoretical head loss resulted higher than the observed in the laboratory model in some of the tests, and lower in others of them, depending also on the assumed value for the wall roughness. Most of the theoretical models assume that the fluid elements in all annular sections have the same velocity, and that flow is steady, uniform and one-dimensional, with the same pressure and velocity profiles in all reactor sections. To check the validity of such assumptions, a computational fluid dynamics (CFD) model of the concentric annular pipe reactor was implemented using the ANSYS Fluent software, demonstrating that pressure and flow velocity distribution inside the reactor actually is not uniform. Based on the analysis, the equations that predict better the head loss in single and multiple annular sections were obtained. Other factors that may impact the head loss, such as the generation of coagulants and gases during the electrochemical reaction, the accumulation of hydroxides inside the reactor, and the change of the electrode material with time, are also discussed. The results can be used as tools for design and scale-up of electrocoagulation reactors, to be integrated into new or existing water treatment plants.

Keywords: electrocoagulation reactors, hydraulic head loss, concentric annular pipes, computational fluid dynamics model

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3916 Establishing Taiwan's Marine Space Planning System

Authors: Wen-Yan Chiau

Abstract:

Taiwan passed the 'Basic Ocean Act' in November 2019, and in accordance with Article 4 of its provisions, the government should draft a decree on ocean space planning (MSP). In the past few years, although Taiwan has passed the 'Coastal Zone Management Act' and the 'Spatial Planning Act', in the face of multiple use of marine areas, it still lacks a comprehensive marine area use blueprint and a fundamental mechanism for multi-purpose use planning management. In particular, Taiwan's active development of offshore wind power is facing this problem, and it is impossible to fully reconcile the use of each domain and the public welfare through a holistic system, highlighting the urgency of the establishment of MSP system. Therefore, this article will review relevant Taiwan laws and regulations, refer to important international initiatives and experiences, and participate in the exchange of practical experience in international conference(s), and propose adequate framework, principles, procedures, and promotion strategies on MSP. Possible solutions to promote sustainable and wise use in Taiwan's waters will also be suggested for comments.

Keywords: basic ocean act, coastal zone management act, marine spatial planning, spatial planning act, Taiwan

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3915 Fashion as a Tool of Modernity and Female Empowerment in the Nineteenth-Century Zenana

Authors: Ira Solomatina

Abstract:

This paper looks at the role of fashion and clothes in the context of the late nineteenth-century Indian zenana. It suggests that fashion and clothes served as tools for self-assertion and empowerment among the zenana women, allowing them to negotiate between tradition and modernity and establish themselves as modern subjects. In pre-Independence India and in upper-class Indians households, zenana was women's part of the house, where women lived separately from men and in seclusion (purdah). To male colonial scholars and officials, zenana remained impenetrable, inviting speculations about the position of the zenana women. In the colonial imagination, the Indian woman was not only the helpless victim, oppressed by the Indian man but also the agent of deviant sexuality. Consequently, in the colonial British scholarship, zenana was portrayed as a space of idleness, perverse sexuality, ignorance, and illness. Contrary to the dominating ideas about zenana, some Western women writers presented more varied accounts of the zenana life, noting on the good education, dignified manners, and sophisticated fashion choices of the women in the zenana. Contemporary research by postcolonial scholars shows that zenana women in purdah travelled, had access to education and political power. The history of India has examples of women rulers in purdah and more than enough instances of zenana women influencing politics and culture. Zenana, in short, was not an ahistorical, dark realm of idleness but the space of culture and a space impacted by modernity. The paper proves that in the context of zenana, clothes, and fashion provided a visual vocabulary for the women to establish themselves as modern subjects and negotiate between modernity and tradition. To do so, it relies on photographs of zenana women and written accounts about and from the nineteenth-century zenana.

Keywords: woman's fashion, colonial India, modernity, zenana

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3914 Behaviour of RC Columns at Elevated Temperatures by NDT Techniques

Authors: D. Jagath Kumari, K. Srinivasa Rao

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Reinforced concrete column is an important structural element in a building. Concrete usually performs well in building fires. However, when it is subjected to prolonged fire exposure or unusually high temperatures, and then it will suffer significant distress. Because concrete pre-fire compressive strength generally exceeds design requirements, therefore an average strength reduction can be tolerated. However high temperature reduces the compressive strength of concrete so much that the concrete retains no useful structural strength. Therefore the residual strength and its performance of structure can be assed by NDT testing. In this paper, rebound hammer test and the ultrasonic pulse velocity (UPV) are used to evaluate the residual compressive strength and material integrity of post-fire-curing concrete subjected to elevated temperatures. Also considering the large availability of fly ash in most of the countries, an attempt was made to study the effect of high volume fly ash concrete exposed to elevated temperatures. 32 RC column specimens were made with a M20 grade concrete mix. Out of 32 column specimens 16 column specimens were made with OPC concrete and other 16 column specimens were made with HVFA concrete. All specimens having similar cross-section details. Columns were exposed to fire for temperatures from 100oC to 800o C with increments of 100o C for duration of 3 hours. Then the specimens allowed cooling to room temperature by two methods natural air cooling method and immediate water quenching method. All the specimens were tested identically, for the compressive strengths and material integrity by rebound hammer and ultrasonic pulse velocity meter respectively for study. These two tests were carried out on preheating and post heating of the column specimens. The percentage variation of compressive strengths of RCC columns with the increase in temperature has been studied and compared the results for both OPC and HVFA concretes. Physical observations of the heated columns were observed.

Keywords: HVFA concrete, NDT testing, residual strength

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3913 Engineering Properties of Different Lithological Varieties of a Singapore Granite

Authors: Louis Ngai Yuen Wong, Varun Maruvanchery

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The Bukit Timah Granite, which is a major rock formation in Singapore, encompasses different rock types such as granite, adamellite, and granodiorite with various hybrid rocks. The present study focuses on the Central Singapore Granite found in the Mandai area. Even within this small aerial extent, lithological variations with respect to the composition, texture as well as the grain size have been recognized in this igneous body. Over the years, the research effort on the Bukit Timah Granite has been focused on achieving a better understanding of its engineering properties in association with civil engineering projects. To our best understanding, a few types of research attempted to systematically investigate the influence of grain size, mineral composition, texture etc. on the strength of Bukit Timah Granite rocks in a comprehensive manner. In typical local industry practices, the different lithological varieties are not differentiated, but all are grouped under Bukit Timah Granite during core logging and the subsequent determination of engineering properties. To address such a major gap in the local engineering geological practice, a preliminary study is conducted on the variations of uniaxial compressive strength (UCS) in seven distinctly different lithological varieties found in the Bukit Timah Granite. Other physical properties including Young’s modulus, P-wave velocity and dry density determined from laboratory testing will also be discussed. The study is supplemented by a petrographical thin section examination. In addition, the specimen failure mode is classified and further correlated with the lithological varieties by carefully observing the details of crack initiation, propagation and coalescence processes in the specimens undergoing loading tests using a high-speed camera. The outcome of this research, which is the first of its type in Singapore, will have a direct implication on the sampling and design practices in the field of civil engineering and particularly underground space development in Singapore.

Keywords: Bukit Timah Granite, lithological variety, thin section study, high speed video, failure mode

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3912 Intersections and Cultural Landscape Interpretation, in the Case of Ancient Messene in the Peloponnese

Authors: E. Maistrou, P. Themelis, D. Kosmopoulos, K. Boulougoura, A. M. Konidi, K. Moretti

Abstract:

InterArch is an ongoing research project that is running since September 2020 and aims to propose a digital application for the enhancement of the cultural landscape, which emphasizes the contribution of physical space and time in digital data organization. The research case study refers to Ancient Messene in the Peloponnese, one of the most important archaeological sites in Greece. The project integrates an interactive approach to the natural environment, aiming at a manifold sensory experience. It combines the physical space of the archaeological site with the digital space of archaeological and cultural data while, at the same time, it embraces storytelling processes by engaging an interdisciplinary approach that familiarizes the user to multiple semantic interpretations. The research project is co‐financed by the European Union and Greek national funds, through the Operational Program Competitiveness, Entrepreneurship, and Innovation, under the call RESEARCH - CREATE – INNOVATE (project code: Τ2ΕΔΚ-01659). It involves mutual collaboration between academic and cultural institutions and the contribution of an IT applications development company. New technologies and the integration of digital data enable the implementation of non‐linear narratives related to the representational characteristics of the art of collage. Various images (photographs, drawings, etc.) and sounds (narrations, music, soundscapes, audio signs, etc.) could be presented according to our proposal through new semiotics of augmented and virtual reality technologies applied in touch screens and smartphones. Despite the fragmentation of tangible or intangible references, material landscape formations, including archaeological remains, constitute the common ground that can inspire cultural narratives in a process that unfolds personal perceptions and collective imaginaries. It is in this context that cultural landscape may be considered an indication of space and historical continuity. It is in this context that history could emerge, according to our proposal, not solely as a previous inscription but also as an actual happening. As a rhythm of occurrences suggesting mnemonic references and, moreover, evolving history projected on the contemporary ongoing cultural landscape.

Keywords: cultural heritage, digital data, landscape, archaeological sites, visitors’ itineraries

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3911 Failure Statistics Analysis of China’s Spacecraft in Full-Life

Authors: Xin-Yan Ji

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The historical failures data of the spacecraft is very useful to improve the spacecraft design and the test philosophies and reduce the spacecraft flight risk. A study of spacecraft failures data was performed, which is the most comprehensive statistics of spacecrafts in China. 2593 on-orbit failures data and 1298 ground data that occurred on 150 spacecraft launched from 2000 to 2016 were identified and collected, which covered the navigation satellites, communication satellites, remote sensing deep space exploration manned spaceflight platforms. In this paper, the failures were analyzed to compare different spacecraft subsystem and estimate their impact on the mission, then the development of spacecraft in China was evaluated from design, software, workmanship, management, parts, and materials. Finally, the lessons learned from the past years show that electrical and mechanical failures are responsible for the largest parts, and the key solution to reduce in-orbit failures is improving design technology, enough redundancy, adequate space environment protection measures, and adequate ground testing.

Keywords: spacecraft anomalies, anomalies mechanism, failure cause, spacecraft testing

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3910 A Computational Study of the Electron Transport in HgCdTe Bulk Semiconductor

Authors: N. Dahbi, M. Daoudi

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This paper deals with the use of computational method based on Monte Carlo simulation in order to investigate the transport phenomena of the electron in HgCdTe narrow band gap semiconductor. Via this method we can evaluate the time dependence of the transport parameters: velocity, energy and mobility of electrons through matter (HgCdTe).

Keywords: Monte Carlo, transport parameters, HgCdTe, computational mechanics

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3909 Monocular 3D Person Tracking AIA Demographic Classification and Projective Image Processing

Authors: McClain Thiel

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Object detection and localization has historically required two or more sensors due to the loss of information from 3D to 2D space, however, most surveillance systems currently in use in the real world only have one sensor per location. Generally, this consists of a single low-resolution camera positioned above the area under observation (mall, jewelry store, traffic camera). This is not sufficient for robust 3D tracking for applications such as security or more recent relevance, contract tracing. This paper proposes a lightweight system for 3D person tracking that requires no additional hardware, based on compressed object detection convolutional-nets, facial landmark detection, and projective geometry. This approach involves classifying the target into a demographic category and then making assumptions about the relative locations of facial landmarks from the demographic information, and from there using simple projective geometry and known constants to find the target's location in 3D space. Preliminary testing, although severely lacking, suggests reasonable success in 3D tracking under ideal conditions.

Keywords: monocular distancing, computer vision, facial analysis, 3D localization

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3908 Universe at Zero Second and the Creation Process of the First Particle from the Absolute Void

Authors: Shivan Sirdy

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In this study, we discuss the properties of absolute void space or the universe at zero seconds, and how these properties play a vital role in creating a mechanism in which the very first particle gets created simultaneously everywhere. We find the limit in which when the absolute void volume reaches will lead to the collapse that leads to the creation of the first particle. This discussion is made following the elementary dimensions theory study that was peer-reviewed at the end of 2020; everything in the universe is made from four elementary dimensions, these dimensions are the three spatial dimensions (X, Y, and Z) and the Void resistance as the factor of change among the four. Time itself was not considered as the fourth dimension. Rather time corresponds to a factor of change, and during the research, it was found out that the Void resistance is the factor of change in the absolute Void space, where time is a hypothetical concept that represents changes during certain events compared to a constant change rate event. Therefore, time does exist, but as a factor of change as the Void resistance: Time= factor of change= Void resistance.

Keywords: elementary dimensions, absolute void, time alternative, early universe, universe at zero second, Void resistant, Hydrogen atom, Hadron field, Lepton field

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3907 Nimbus Radiance Gate Project: Media Architecture in Sacred Space

Authors: Jorge Duarte de Sá

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The project presented in this investigation is part of the multidisciplinary field of Architecture and explores an experience in media architecture, integrated in Arts, Science and Technology. The objective of this work is to create a visual experience comprehending Architecture, Media and Art. It is intended to specifically explore the sacred spaces that are losing social, cultural or religious dynamics and insert new Media technologies to create a new generate momentum, testing tools, techniques and methods of implementation. Given an architectural project methodology, it seems essential that 'the location' should be the starting point for the development of this technological apparatus: the church of Santa Clara in Santarém, Portugal emerged as an experimental space for apparatus, presenting itself as both temple and museum. We also aim to address the concept of rehabilitation through media technologies, directed at interventions that may have an impact on energizing spaces. The idea is emphasized on the rehabilitation of spaces that, one way or another, may gain new dynamics after a media intervention. Thus, we intend to affect the play with a sensitive and spiritual character which endemically, sacred spaces have, by exploring a sensitive aspect of the subject and drawing up new ideas for meditation and spiritual reflection. The work is designed primarily as a visual experience that encompasses the space, the object and the subject. It is a media project supported by a dual structure with two transparent screens operating in a holographic screen which will be projecting two images that complement the translucent overlay film, thus making the merger of two projections. The digitally created content reacts to the presence of observers through infrared cameras, placed strategically. The object revives the memory of the altarpiece as an architectural surface, promoting the expansion of messages through the media technologies.

Keywords: architecture, media, sacred, technology

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3906 Performance Analysis of a Hybrid DF-AF Hybrid RF/FSO System under Gamma Gamma Atmospheric Turbulence Channel Using MPPM Modulation

Authors: Hechmi Saidi, Noureddine Hamdi

Abstract:

The performance of hybrid amplify and forward - decode and forward (AF-DF) hybrid radio frequency/free space optical (RF/FSO) communication system, that adopts M-ary pulse position modulation (MPPM) techniques, is analyzed. Both exact and approximate symbol-error rates (SERs) are derived. The random variations of the received optical irradiance, produced by the atmospheric turbulence, is modeled by the gamma-gamma (GG) statistical distribution. A closed-form expression for the probability density function (PDF) is derived for the whole above system is obtained. Thanks to the use of hybrid AF-DF hybrid RF/FSO configuration and MPPM, the effects of atmospheric turbulence is mitigated; hence the capacity of combating atmospheric turbulence and the transmissitted signal quality are improved.

Keywords: free space optical, gamma gamma channel, radio frequency, decode and forward, error pointing, M-ary pulse position modulation, symbol error rate

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3905 In vivo Wound Healing Activity and Phytochemical Screening of the Crude Extract and Various Fractions of Kalanchoe petitiana A. Rich (Crassulaceae) Leaves in Mice

Authors: Awol Mekonnen, Temesgen Sidamo, Epherm Engdawork, Kaleab Asresb

Abstract:

Ethnopharmacological Relevance: The leaves of Kalanchoe petitiana A. Rich (Crassulaceae) are used in Ethiopian folk medicine for treatment of evil eye, fractured surface for bone setting and several skin disorders including for the treatment of sores, boils, and malignant wounds. Aim of the Study: In order to scientifically prove the claimed utilization of the plant, the effects of the extracts and the fractions were investigated using in vivo excision, incision and dead space wound models. Materials and Method: Mice were used for wound healing study, while rats and rabbit were used for skin irritation test. For studying healing activity, 80% methanolic extract and the fractions were formulated in strength of 5% and 10%, either as ointment (hydroalcoholic extract, aqueous and methanol fractions) or gel (chloroform fraction). Oral administration of the crude extract was used for dead space model. Negative controls were treated either with simple ointment or sodium carboxyl methyl cellulose xerogel, while positive controls were treated with nitrofurazone (0.2 w/v) skin ointment. Negative controls for dead space model were treated with 1% carboxy methyl cellulose. Parameters, including rate of wound contraction, period of complete epithelializtion, hydroxyproline contents and skin breaking strength were evaluated. Results: Significant wound healing activity was observed with ointment formulated from the crude extract at both 5% and 10% concentration (p<0.01) compared to controls in both excision and incision models. In dead space model, 600 mg/kg (p<0.01), but not 300 mg/kg, significantly increased hydroxyproline content. Fractions showed variable effect, with the chloroform fraction lacking any significant effect. Both 5% and 10% formulations of the aqueous and methanolic fractions significantly increased wound contraction, decreased epithelializtion time and increased hydroxyproline content in excision wound model (p<0.05) as compared to controls. These fractions were also endowed with higher skin breaking strength in incision wound model (p<0.01). Conclusions: The present study provided evidence that the leaves of Kalanchoe petitiana A. Rich possess remarkable wound healing activities supporting the folkloric assertion of the plant. Fractionation revealed that polar or semi-polar compound may play vital role, as both aqueous and methanolic fractions were endowed with wound healing activity.

Keywords: wound healing, Kalanchoae petitiana, excision wound, incision wound, dead space model

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3904 Spatiotemporal Modeling of Under-Five Mortality and Associated Risk Factors in Ethiopia

Authors: Melkamu A. Zeru, Aweke A. Mitiku, Endashaw Amuka

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Background: Under-five mortality is the likelihood that a baby will pass away before turning exactly 5 years old, represented as a percentage per 1,000 live births. Exploring the spatial distribution and identifying the temporal pattern is important to reducing under-five child mortality globally, including in Ethiopia. Thus, this study aimed to identify the risk factors of under-five mortality and the spatiotemporal variation in Ethiopian administrative zones. Method: This study used the 2000-2016 Ethiopian Demographic and Health Survey (EDHS) data, which were collected using a two-stage sampling method. A total of 43,029 (10,873 in 2000, 9,861 in 2005, 11,654 in 2011, and 10,641 in 2016) weighted sample under-five child mortality was used. The space-time dynamic model was employed to account for spatial and time effects in 65 administrative zones in Ethiopia. Results: From the result of a general nesting spatial-temporal dynamic model, there was a significant space-time interaction effect [γ = -0.1444, 95 % CI (-0.6680, -0.1355)] for under-five mortality. The increase in the percentages of mothers illiteracy [𝛽 = 0.4501, 95% CI (0.2442, 0.6559)], not vaccinated[𝛽= 0.7681, 95% CI (0.5683, 0.9678)], unimproved water[𝛽= 0.5801, CI (0.3793, 0.7808)] were increased death rates for under five children while increased percentage of contraceptive use [𝛽= -0.6609, 95% CI (-0.8636, -0.4582)] and ANC visit > 4 times [𝛽= -0.1585, 95% CI(-0.1812, -0.1357)] were contributed to the decreased under-five mortality rate at the zone in Ethiopia. Conclusions: Even though the mortality rate for children under five has decreased over time, still there is still higher in different zones of Ethiopia. There exists spatial and temporal variation in under-five mortality among zones. Therefore, it is very important to consider spatial neighbourhoods and temporal context when aiming to avoid under-five mortality.

Keywords: under-five children mortality, space-time dynamic, spatiotemporal, Ethiopia

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3903 Evaluation of Solid-Gas Separation Efficiency in Natural Gas Cyclones

Authors: W. I. Mazyan, A. Ahmadi, M. Hoorfar

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Objectives/Scope: This paper proposes a mathematical model for calculating the solid-gas separation efficiency in cyclones. This model provides better agreement with experimental results compared to existing mathematical models. Methods: The separation ratio efficiency, ϵsp, is evaluated by calculating the outlet to inlet count ratio. Similar to mathematical derivations in the literature, the inlet and outlet particle count were evaluated based on Eulerian approach. The model also includes the external forces acting on the particle (i.e., centrifugal and drag forces). In addition, the proposed model evaluates the exact length that the particle travels inside the cyclone for the evaluation of number of turns inside the cyclone. The separation efficiency model derivation using Stoke’s law considers the effect of the inlet tangential velocity on the separation performance. In cyclones, the inlet velocity is a very important factor in determining the performance of the cyclone separation. Therefore, the proposed model provides accurate estimation of actual cyclone separation efficiency. Results/Observations/Conclusion: The separation ratio efficiency, ϵsp, is studied to evaluate the performance of the cyclone for particles ranging from 1 microns to 10 microns. The proposed model is compared with the results in the literature. It is shown that the proposed mathematical model indicates an error of 7% between its efficiency and the efficiency obtained from the experimental results for 1 micron particles. At the same time, the proposed model gives the user the flexibility to analyze the separation efficiency at different inlet velocities. Additive Information: The proposed model determines the separation efficiency accurately and could also be used to optimize the separation efficiency of cyclones at low cost through trial and error testing, through dimensional changes to enhance separation and through increasing the particle centrifugal forces. Ultimately, the proposed model provides a powerful tool to optimize and enhance existing cyclones at low cost.

Keywords: cyclone efficiency, solid-gas separation, mathematical model, models error comparison

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3902 Spatial Data Mining by Decision Trees

Authors: Sihem Oujdi, Hafida Belbachir

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Existing methods of data mining cannot be applied on spatial data because they require spatial specificity consideration, as spatial relationships. This paper focuses on the classification with decision trees, which are one of the data mining techniques. We propose an extension of the C4.5 algorithm for spatial data, based on two different approaches Join materialization and Querying on the fly the different tables. Similar works have been done on these two main approaches, the first - Join materialization - favors the processing time in spite of memory space, whereas the second - Querying on the fly different tables- promotes memory space despite of the processing time. The modified C4.5 algorithm requires three entries tables: a target table, a neighbor table, and a spatial index join that contains the possible spatial relationship among the objects in the target table and those in the neighbor table. Thus, the proposed algorithms are applied to a spatial data pattern in the accidentology domain. A comparative study of our approach with other works of classification by spatial decision trees will be detailed.

Keywords: C4.5 algorithm, decision trees, S-CART, spatial data mining

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3901 Nadler's Fixed Point Theorem on Partial Metric Spaces and its Application to a Homotopy Result

Authors: Hemant Kumar Pathak

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In 1994, Matthews (S.G. Matthews, Partial metric topology, in: Proc. 8th Summer Conference on General Topology and Applications, in: Ann. New York Acad. Sci., vol. 728, 1994, pp. 183-197) introduced the concept of a partial metric as a part of the study of denotational semantics of data flow networks. He gave a modified version of the Banach contraction principle, more suitable in this context. In fact, (complete) partial metric spaces constitute a suitable framework to model several distinguished examples of the theory of computation and also to model metric spaces via domain theory. In this paper, we introduce the concept of almost partial Hausdorff metric. We prove a fixed point theorem for multi-valued mappings on partial metric space using the concept of almost partial Hausdorff metric and prove an analogous to the well-known Nadler’s fixed point theorem. In the sequel, we derive a homotopy result as an application of our main result.

Keywords: fixed point, partial metric space, homotopy, physical sciences

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3900 Fusing Mentorship, Leadership and Empowerment Among Young Women In STEM

Authors: Anne Bubriski

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Despite improvements in gender inequalities, women and girls continue to face glass ceilings, underrepresentation, and harmful stereotypes that can limit their aspirations and opportunities in STEM. While girls are taking similar high school math and science classes, boys are more likely to take physics and six times more likely to take an engineering course. The gap becomes even larger for minority or low-income girls. This gender gap is not due to biology; rather, it is due to cultural, social, and institutional forces. As girls get older, these forces often ‘teach’ them ‘STEM is more for boys’. The STEM gender gap widens in college, with only 20% of engineering degrees being awarded to women, and by the time women enter the workforce, they only occupy about 13% of engineering jobs. At the University of Central Florida, the Women’s and Gender Studies Program has developed a unique mentoring program to address these issues, Science Leadership and Mentoring (SLAM). What is unique about the approach of SLAM is that we look to address this problem through leadership and STEM. We look to help girls make connections between leadership and STEM—that young women can be leaders as scientists and that scientists are leaders making a change. This is particularly needed and relevant to our community because while there are mentoring programs to our knowledge, SLAM is one of the only, if not only, mentoring programs pairing college women and 7th-grade girls that includes a focus both on STEM and leadership in the United States. SLAM is a curriculum-based mentoring program pairing one 7th-grade girl with one UCF undergraduate STEM major. SLAM empowers young women to be assertive, brave, confident, independent, inquisitive and proud leaders in STEM. SLAM seeks to promote young women’s inspiration and excitement into STEM fields and careers while also building leadership abilities such as problem-solving, teamwork and cooperation, cultural identity and ethnic pride, advocacy for positive change, and goals for the future. SLAM serves about fifteen 7th-grade girls for the academic year and about 20 UCF students. SLAM holds weekly mentoring meetings lasting about 90 minutes, covering topics on leadership, STEM majors and careers, and STEM leadership. This past year, SLAM received a Community Action Grant from the American Association of University Women (AAUW) to run a sub-program, SLAM-Space. SLAM-Space focused on exposing SLAM participants to aerospace engineering and other space-related STEM fields, such as physics and astronomy, through guest speakers, workshops and field trips, including the Kenndy Space Center. The proposed paper presentation will present an overview of SLAM-Space and the data findings from pre and post-surveys, in-depth interviews and focus groups from the SLAM participants' experiences in the program.

Keywords: gender, leadership, STEM, empowerment

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3899 A Study on the Current Challenges Hindering Urban Park Development in Ulaanbaatar City, Mongolia

Authors: Bayarmaa Enkhbold, Kenichi Matsui

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Urban parks are important assets to every community in terms of providing space for health, cultural and leisure activities. However, Ulaanbaatar, the capital of Mongolia, faces a shortage of green spaces, particularly urban parks, due to overpopulation and haphazard growth. Therefore, in order to increase green space per person, the city government has planned to increase green space per person up to 20m² by 2020 and 30m² by 2030 by establishing more urban parks throughout the city. But this plan was estimated that it is highly unlikely to reach those goals according to the analysis of the present status of plan implementation because the current amount of green space per person is still 4m². In the past studies globally, city planners and scientists agree that it is highly improbable to develop urban parks and keep maintenance sustainably without reflecting community perceptions and their involvement in the park establishment. Therefore, this research aims to find the challenges which stymie urban park development in Ulaanbaatar city and recommend dealing with the problems. In order to reach the goal, communities’ perceptions about the current challenges and their necessity for urban parks were identified and determined whether they differentiated depending on two different types of residential areas (urban and suburban areas). It also attempted to investigate international good practices on how they deal with similar problems. The research methodology was based on a questionnaire survey among city residents, a document review regarding the involvement of stakeholders, and a literature review of relevant past studies. According to the residents’ perceptions, the biggest challenge was a lack of land availability and followed by a lack of proper policy, planning, management, and maintenance out of seven key challenges identified. The biggest community demand from the urban park was a playground for children and followed by recreation and relaxation out of six types of needs. Based on research findings, the study proposed several recommendations for enhancements as institutional and legal framework, park plan and management, supportive environment and monitoring, evaluation, and reporting.

Keywords: challenges of urban park planning and maintenance, community-based urban park establishment, community perceptions and participation, urban parks in Ulaanbaatar, Mongolia

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3898 Queer Anti-Urbanism: An Exploration of Queer Space Through Design

Authors: William Creighton, Jan Smitheram

Abstract:

Queer discourse has been tied to a middle-class, urban-centric, white approach to the discussion of queerness. In doing so, the multilayeredness of queer existence has been washed away in favour of palatable queer occupation. This paper uses design to explore a queer anti-urbanist approach to facilitate a more egalitarian architectural occupancy. Scott Herring’s work on queer anti-urbanism is key to this approach. Herring redeploys anti-urbanism from its historical understanding of open hostility, rejection and desire to destroy the city towards a mode of queer critique that counters normative ideals of homonormative metronormative gay lifestyles. He questions how queer identity has been closed down into a more diminutive frame where those who do not fit within this frame are subjected to persecution or silenced through their absence. We extend these ideas through design to ask how a queer anti-urbanist approach facilitates a more egalitarian architectural occupancy. Following a “design as research” methodology, the design outputs allow a vehicle to ask how we might live, otherwise, in architectural space. A design as research methodologically is a process of questioning, designing and reflecting – in a non-linear, iterative approach – establishes itself through three projects, each increasing in scale and complexity. Each of the three scales tackled a different body relationship. The project began exploring the relations between body to body, body to known others, and body to unknown others. Moving through increasing scales was not to privilege the objective, the public and the large scale; instead, ‘intra-scaling’ acts as a tool to re-think how scale reproduces normative ideas of the identity of space. There was a queering of scale. Through this approach, the results were an installation that brings two people together to co-author space where the installation distorts the sensory experience and forces a more intimate and interconnected experience challenging our socialized proxemics: knees might touch. To queer the home, the installation was used as a drawing device, a tool to study and challenge spatial perception, drawing convention, and as a way to process practical information about the site and existing house – the device became a tool to embrace the spontaneous. The final design proposal operates as a multi-scalar boundary-crossing through “private” and “public” to support kinship through communal labour, queer relationality and mooring. The resulting design works to set adrift bodies in a sea of sensations through a mix of pleasure programmes. To conclude, through three design proposals, this design research creates a relationship between queer anti-urbanism and design. It asserts that queering the design process and outcome allows a more inclusive way to consider place, space and belonging. The projects lend to a queer relationality and interdependence by making spaces that support the unsettled, out-of-place, but is it queer enough?

Keywords: queer, queer anti-urbanism, design as research, design

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3897 Energy Efficient Shading Strategies for Windows of Hospital ICUs in the Desert

Authors: A. Sherif, A. El Zafarany, R. Arafa

Abstract:

Hospitals, everywhere, are considered heavy energy consumers. Hospital Intensive Care Unit spaces pose a special challenge, where design guidelines requires the provision of external windows for day-lighting and external view. Window protection strategies could be employed to reduce energy loads without detriment effect on comfort or health care. This paper addresses the effectiveness of using various window strategies on the annual cooling, heating and lighting energy use of a typical Hospital Intensive Unit space. Series of experiments were performed using the EnergyPlus simulation software for a typical Intensive Care Unit (ICU) space in Cairo, located in the Egyptian desert. This study concluded that the use of shading systems is more effective in conserving energy in comparison with glazing of different types, in the Cairo ICUs. The highest energy savings in the West and South orientations were accomplished by external perforated solar screens, followed by overhangs positioned at a protection angle of 45°.

Keywords: energy, hospital, intensive care units, shading

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3896 Sustaining the Social Memory in a Historic Neighborhood: The Case Study of Uch Dukkan Neighborhood in Ardabil City in Azerbaijani Region of Iran

Authors: Yousef Daneshvar Rouyandozagh, Ece. K. Açikgöz

Abstract:

Conservation of historical urban patterns in the traditional neighborhoods is a part of creating integrated urban environments that are socially more sustainable. Urbanization reflects on life conditions and social, physical, economical characteristics of the society. In this regard, historical zones and traditional regions are affected by dramatic interventions on these characteristics. This article focuses on the Uch Dukkan neighborhood located in Ardabil City in Azarbaijani region of Iran, which has been up to such interventions that leaded its transformation from the past to the present. After introducing a brief inventory of the main elements of the historical zone and the neighborhood; this study explores the changes and transformations in different periods; and their impacts on the quality of the environment and its social sustainability. The survey conducted in the neighborhood as part of this research study revealed that the Uch Dukkan neighborhood and the unique architectural heritage that it possesses have become more inactive physically and functionally in a decade. This condition requires an exploration and comparison of the present and the expected transformations of the meaning of social space from the most private unit to the urban scale. From this token, it is argued that an architectural point of view that is based on space order; use and meaning of space as a social and cultural image, should not be ignored. Based on the interplay between social sustainability, collective memory, and the urban environment, study aims to make the invisible portion of ignorance clear, that ends up with a weakness in defining the collective meaning of the neighborhood as a historic urban district. It reveals that the spatial possessions of the neighborhood are valuable not only for their historical and physical characteristics, but also for their social memory that is to be remembered and constructed further.

Keywords: urban integrity, social sustainability, collective memory, social decay

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3895 Mathematical Modeling and Analysis of Forced Vibrations in Micro-Scale Microstretch Thermoelastic Simply Supported Beam

Authors: Geeta Partap, Nitika Chugh

Abstract:

The present paper deals with the flexural vibrations of homogeneous, isotropic, generalized micropolar microstretch thermoelastic thin Euler-Bernoulli beam resonators, due to Exponential time varying load. Both the axial ends of the beam are assumed to be at simply supported conditions. The governing equations have been solved analytically by using Laplace transforms technique twice with respect to time and space variables respectively. The inversion of Laplace transform in time domain has been performed by using the calculus of residues to obtain deflection.The analytical results have been numerically analyzed with the help of MATLAB software for magnesium like material. The graphical representations and interpretations have been discussed for Deflection of beam under Simply Supported boundary condition and for distinct considered values of time and space as well. The obtained results are easy to implement for engineering analysis and designs of resonators (sensors), modulators, actuators.

Keywords: microstretch, deflection, exponential load, Laplace transforms, residue theorem, simply supported

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3894 The Impact of Speech Style on the Production of Spanish Vowels by Spanish-English Bilinguals and Spanish Monolinguals

Authors: Vivian Franco

Abstract:

There has been a great deal of research about vowel production of second language learners of Spanish, vowel variation across Spanish dialects, and more recently, research related to Spanish heritage speakers’ vowel production based on speech style. However, there is little investigation reported on Spanish heritage speakers’ vowel production in regard to task modality by incorporating own comparison groups of monolinguals and late bilinguals. Thus, the present study investigates the influence of speech style on Spanish heritage speakers’ vowel production by comparing Spanish-English early and late bilinguals and Spanish monolinguals. The study was guided by the following research question: How do early bilinguals (heritage speakers) differ/relate to advanced L2 speakers of Spanish (late bilinguals) and Spanish monolinguals in their vowel quality (acoustic distribution) and quantity (duration) based on speech style? The participants were a total of 11 speakers of Spanish: 7 early Spanish-English bilinguals with a similar linguistic background (simultaneous bilinguals of the second generation); 2 advanced L2 speakers of Spanish; and 2 Spanish monolinguals from Mexico. The study consisted of two tasks. The first one adopted a semi-spontaneous style by a solicited narration of life experiences and a description of a favorite movie with the purpose to collect spontaneous speech. The second task was a reading activity in which the participants read two paragraphs of a Mexican literary essay 'La nuez.' This task aimed to obtain a more controlled speech style. From this study, it can be concluded that early bilinguals and monolinguals show a smaller formant vowel space overall compared to the late bilinguals in both speech styles. In terms of formant values by stress, the early bilinguals and the late bilinguals resembled in the semi-spontaneous speech style as their unstressed vowel space overlapped with that of the unstressed vowels different from the monolinguals who displayed a slightly reduced unstressed vowel space. For the controlled data, the early bilinguals were similar to the monolinguals as their stressed and unstressed vowel spaces overlapped in comparison to the late bilinguals who showed a more clear reduction of unstressed vowel space. In regard to stress, the monolinguals revealed longer vowel duration overall. However, findings of duration by stress showed that the early bilinguals and the monolinguals remained stable with shorter values of unstressed vowels in the semi-spontaneous data and longer duration in the controlled data when compared to the late bilinguals who displayed opposite results. These findings suggest an implication for Spanish heritage speakers and L2 Spanish vowels research as it has been frequently argued that Spanish bilinguals differ from the Spanish monolinguals by their vowel reduction and centralized vowel space influenced by English. However, some Spanish varieties are characterized by vowel reduction especially in certain phonetic contexts so that some vowels present more weakening than others. Consequently, it would not be conclusive to affirm an English influence on the Spanish of these bilinguals.

Keywords: Spanish-English bilinguals, Spanish monolinguals, spontaneous and controlled speech, vowel production.

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3893 Hypothesis on Annual Sea Level Variation and Increased Volume Transport in Korea Strait

Authors: Young-Taeg Kim, Gwang Ho Seo, Hyungju Oh, Ho Kyung Ha, Kuk Jin Kim

Abstract:

Kim et al., hypothesized an increase in volume transport in the Korea Strait based on the concurrent increase in water temperature and mean sea level observed by the Korea Hydrographic and Oceanographic Agency (KHOA) in the vicinity of the Korea Strait from 2000 to 2009. Since then, to our best knowledge, no definitive studies have been reported on the increase in volume transport through the Korea Strait, but the observed water temperature (2000-2021) and sea level (1989-2021) in the Korea Strait and East Sea have been found to be increasing. In particular, the rapid increase rate in the mean sea level rise (2.55~3.53 mm/y) in these areas cannot be explained by only steric effect due to the increased water temperature. It is more reasonable interpretation that the sea level rise is due to an increase in the volume transport of warm and salty currents. If the increase in the volume transport is explained by the geostrophic equation without considering the sea level rise in the Korea Strait, the current velocity should increase. However, up to now, there are no reports of an increase in current velocity from direct observations using ADCP (e.g., observations of Camellia) or from various numerical models. Therefore, the increase in volume transport cannot be explained by the geostrophic equation. Another possible explanation for the increase in the volume transport is the effect of wind. Although Korea is dominated by monsoon, it is affected by winds according to El Niño and La Niña, which have a cycle of about 3 to 4 years. During El Niño (La Niña), northerly winds (southerly winds) prevail in Korea. Consequently, it is inferred that the transported volume in the Korea Strait slowly increases interannually. However, in this study, it was difficult to find a clear correlation between annually-averaged mean sea level and El Niño (or La Niña) during 1989-2021. This is probably due to the interactions of the PDO (Pacific Decadal Oscillation) and AO (Arctic Oscillation) along with the ENSO (El niño-Southern Oscillation). However, it is clear that the interannual variability of winds is affecting the volume transport in the Korean Strait. On the other hand, the effect of global sea level rise on the volume transport in the Korea Strait is small compared to the interannual variability of the volume transport, but it seems to play a constant role.

Keywords: mean sea level, volume transport, El nino, La nina

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3892 A Monolithic Arbitrary Lagrangian-Eulerian Finite Element Strategy for Partly Submerged Solid in Incompressible Fluid with Mortar Method for Modeling the Contact Surface

Authors: Suman Dutta, Manish Agrawal, C. S. Jog

Abstract:

Accurate computation of hydrodynamic forces on floating structures and their deformation finds application in the ocean and naval engineering and wave energy harvesting. This manuscript presents a monolithic, finite element strategy for fluid-structure interaction involving hyper-elastic solids partly submerged in an incompressible fluid. A velocity-based Arbitrary Lagrangian-Eulerian (ALE) formulation has been used for the fluid and a displacement-based Lagrangian approach has been used for the solid. The flexibility of the ALE technique permits us to treat the free surface of the fluid as a Lagrangian entity. At the interface, the continuity of displacement, velocity and traction are enforced using the mortar method. In the mortar method, the constraints are enforced in a weak sense using the Lagrange multiplier method. In the literature, the mortar method has been shown to be robust in solving various contact mechanics problems. The time-stepping strategy used in this work reduces to the generalized trapezoidal rule in the Eulerian setting. In the Lagrangian limit, in the absence of external load, the algorithm conserves the linear and angular momentum and the total energy of the system. The use of monolithic coupling with an energy-conserving time-stepping strategy gives an unconditionally stable algorithm and allows the user to take large time steps. All the governing equations and boundary conditions have been mapped to the reference configuration. The use of the exact tangent stiffness matrix ensures that the algorithm converges quadratically within each time step. The robustness and good performance of the proposed method are demonstrated by solving benchmark problems from the literature.

Keywords: ALE, floating body, fluid-structure interaction, monolithic, mortar method

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3891 Study on Seismic Performance of Reinforced Soil Walls in Order to Offer Modified Pseudo Static Method

Authors: Majid Yazdandoust

Abstract:

This study, tries to suggest a design method based on displacement using finite difference numerical modeling in reinforcing soil retaining wall with steel strip. In this case, dynamic loading characteristics such as duration, frequency, peak ground acceleration, geometrical characteristics of reinforced soil structure and type of the site are considered to correct the pseudo static method and finally introduce the pseudo static coefficient as a function of seismic performance level and peak ground acceleration. For this purpose, the influence of dynamic loading characteristics, reinforcement length, height of reinforced system and type of the site are investigated on seismic behavior of reinforcing soil retaining wall with steel strip. Numerical results illustrate that the seismic response of this type of wall is highly dependent to cumulative absolute velocity, maximum acceleration, and height and reinforcement length so that the reinforcement length can be introduced as the main factor in shape of failure. Considering the loading parameters, mechanically stabilized earth wall parameters and type of the site showed that the used method in this study leads to most efficient designs in comparison with other methods which are generally suggested in cods that are usually based on limit-equilibrium concept. The outputs show the over-estimation of equilibrium design methods in comparison with proposed displacement based methods here.

Keywords: pseudo static coefficient, seismic performance design, numerical modeling, steel strip reinforcement, retaining walls, cumulative absolute velocity, failure shape

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3890 Deflection Effect on Mirror for Space Applications

Authors: Maamar Fatouma

Abstract:

Mirror optical performance can experience varying levels of stress and tolerances, which can have a notable impact on optical parametric systems. to ensure proper optical figure and position of mirror mounting within design tolerances, it is crucial to have a robust support structure in place for optical systems. The optical figure tolerance determines the allowable deviation from the ideal form of the mirror and the position tolerance determines the location and orientations of the optical axis of the optical systems. A variety of factors influence the optical figure of the mirror. Included are self-weight (Deflection), excitation from temperature change, temperature gradients and dimensional instability. This study employs an analytical approach and finite element method to examine the effects of stress resulting from mirror mounting on the wavefront passing through the mirror. The combined effect of tolerance and deflection on mirror performance is represented by an error budget. Numerical mirror mounting is presented to illustrate the space application of performance techniques.

Keywords: opto-mechanical, bonded optic, tolerance, self-weight distortion, Rayleigh criteria

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3889 Effects of the Gap on the Cooling Performance of Microchannels Heat Sink

Authors: Mohammed W. Sulaiman, Chi-Chuan Wang

Abstract:

Due to the improved performance of electronic systems, the demand for electronic cooling devices with high heat dissipation has increased. This research evaluates plain microchannel cold plates with a gap above the microchannels. The present study examines the effect of the gap above straight fin microchannels in the cold plate using the dielectric Novec 7000 as a working fluid. The experiments compared two transparency cover with the same geometry and dimension for the test section. One has a gap above the microchannels (GAM) 1/3 of fin height, and another one with no gap above the microchannels (NGAM); the mass flux ranges from 25 to 260 kg/m2s, while the heat flux spans from 50 to 150 W/cm2. The results show quite an improvement in performance with this space gap above the microchannels. The test results showed that the design of the GAM shows a superior heat transfer coefficient (HTC), up 90% than that of NCBM. The GAM design has a much lower pressure drop by about 7~24% compared to the NGAM design at different mass flux and heat flux at the fully liquid inlet. The proposed space gap of 0.33% of fin height above the microchannels enables the surface temperature to decrease by around 3~7 °C compared to no gap above the microchannels, especially at high heat fluxes.

Keywords: microchannels, pressure drop, enhanced performance, electronic cooling, gap

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3888 Space Telemetry Anomaly Detection Based On Statistical PCA Algorithm

Authors: Bassem Nassar, Wessam Hussein, Medhat Mokhtar

Abstract:

The crucial concern of satellite operations is to ensure the health and safety of satellites. The worst case in this perspective is probably the loss of a mission but the more common interruption of satellite functionality can result in compromised mission objectives. All the data acquiring from the spacecraft are known as Telemetry (TM), which contains the wealth information related to the health of all its subsystems. Each single item of information is contained in a telemetry parameter, which represents a time-variant property (i.e. a status or a measurement) to be checked. As a consequence, there is a continuous improvement of TM monitoring systems in order to reduce the time required to respond to changes in a satellite's state of health. A fast conception of the current state of the satellite is thus very important in order to respond to occurring failures. Statistical multivariate latent techniques are one of the vital learning tools that are used to tackle the aforementioned problem coherently. Information extraction from such rich data sources using advanced statistical methodologies is a challenging task due to the massive volume of data. To solve this problem, in this paper, we present a proposed unsupervised learning algorithm based on Principle Component Analysis (PCA) technique. The algorithm is particularly applied on an actual remote sensing spacecraft. Data from the Attitude Determination and Control System (ADCS) was acquired under two operation conditions: normal and faulty states. The models were built and tested under these conditions and the results shows that the algorithm could successfully differentiate between these operations conditions. Furthermore, the algorithm provides competent information in prediction as well as adding more insight and physical interpretation to the ADCS operation.

Keywords: space telemetry monitoring, multivariate analysis, PCA algorithm, space operations

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