Search results for: hierarchical cluster analysis
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 27536

Search results for: hierarchical cluster analysis

27176 Manufacturing Facility Location Selection: A Numercal Taxonomy Approach

Authors: Seifoddini Hamid, Mardikoraeem Mahsa, Ghorayshi Roya

Abstract:

Manufacturing facility location selection is an important strategic decision for many industrial corporations. In this paper, a new approach to the manufacturing location selection problem is proposed. In this approach, cluster analysis is employed to identify suitable manufacturing locations based on economic, social, environmental, and political factors. These factors are quantified using the existing real world data.

Keywords: manufacturing facility, manufacturing sites, real world data

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27175 Multi Tier Data Collection and Estimation, Utilizing Queue Model in Wireless Sensor Networks

Authors: Amirhossein Mohajerzadeh, Abolghasem Mohajerzadeh

Abstract:

In this paper, target parameter is estimated with desirable precision in hierarchical wireless sensor networks (WSN) while the proposed algorithm also tries to prolong network lifetime as much as possible, using efficient data collecting algorithm. Target parameter distribution function is considered unknown. Sensor nodes sense the environment and send the data to the base station called fusion center (FC) using hierarchical data collecting algorithm. FC builds underlying phenomena based on collected data. Considering the aggregation level, x, the goal is providing the essential infrastructure to find the best value for aggregation level in order to prolong network lifetime as much as possible, while desirable accuracy is guaranteed (required sample size is fully depended on desirable precision). First, the sample size calculation algorithm is discussed, second, the average queue length based on M/M[x]/1/K queue model is determined and it is used for energy consumption calculation. Nodes can decrease transmission cost by aggregating incoming data. Furthermore, the performance of the new algorithm is evaluated in terms of lifetime and estimation accuracy.

Keywords: aggregation, estimation, queuing, wireless sensor network

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27174 Abdominal Organ Segmentation in CT Images Based On Watershed Transform and Mosaic Image

Authors: Belgherbi Aicha, Hadjidj Ismahen, Bessaid Abdelhafid

Abstract:

Accurate Liver, spleen and kidneys segmentation in abdominal CT images is one of the most important steps for computer aided abdominal organs pathology diagnosis. In this paper, we have proposed a new semi-automatic algorithm for Liver, spleen and kidneys area extraction in abdominal CT images. Our proposed method is based on hierarchical segmentation and watershed algorithm. In our approach, a powerful technique has been designed to suppress over-segmentation based on mosaic image and on the computation of the watershed transform. The algorithm is currency in two parts. In the first, we seek to improve the quality of the gradient-mosaic image. In this step, we propose a method for improving the gradient-mosaic image by applying the anisotropic diffusion filter followed by the morphological filters. Thereafter we proceed to the hierarchical segmentation of the liver, spleen and kidney. To validate the segmentation technique proposed, we have tested it on several images. Our segmentation approach is evaluated by comparing our results with the manual segmentation performed by an expert. The experimental results are described in the last part of this work.

Keywords: anisotropic diffusion filter, CT images, morphological filter, mosaic image, multi-abdominal organ segmentation, mosaic image, the watershed algorithm

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27173 Reality Shock Affecting the Motivation to Work of New Flight Attendants: An Exploratory Qualitative Study of Flight Attendants Who Left Their Jobs Early

Authors: Hiromi Takafuji

Abstract:

Flight attendant:FA is one of popular occupation, especially in Asian countries, and the decision to be hired is made after clearing a high multiplier. On the other hand, immediately after joining the company, they experience unique stress due to the fact that the organization requires them to perform security and customer service duties in a highly specialized and limited space and time. As a result, despite the high level of difficulty in joining the company, many new recruits retire early at a high rate. It is commonly said that 30% of new graduates leave the company within three years in Japan and speculated that Reality Shock:RS is one of the causes of this. RS is that newcomers experience refers to the stress caused by the difference between pre-employment expectations and post-employment reality. The purpose of this study was to elucidate the mechanism by which the expertise required of new FA and the expectation of expertise held by each of them cause reality shock, which affects motivation and the decision to leave. This study identified the professionalism required of new FA and the impact of that expectation for professionalism on RS through an exploratory study of the experiences and psychological processes of FA who left within three years. Semi-structured in-depth interviews were conducted with five FA who left a major Japanese airline at an early stage, and their experiences were categorized, integrated, and classified by qualitative content analysis. They were chosen under a number of controlled conditions. Then two major findings emerged: first, that pre-employment expectations defining RS were hierarchical, and second, that training amplified expectations of professionalism, which strongly influenced early turnover. From these, this study generated a model of RS generative process model of FA that expectations are hierarchical and influential. This could contribute to the prevention of mental health deterioration by reality shock among new FA.

Keywords: reality shock, flight attendant, early turnover, qualitative study

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27172 Place Attachment as Basic Condition for Wellbeing and Life Satisfaction in East African Wetland Users

Authors: Sophie-Bo Heinkel, Andrea Rechenburg, Thomas Kistemann

Abstract:

The current status of wellbeing and life satisfaction of subsistence farmers in a wetland in Uganda and the contributing role of place attachment has been assessed. The aim of this study is to shed light on environmental factors supporting wellbeing in a wetland setting. Furthermore, it has been assessed, how the emotional bonding to the wetland as ‘place’ influences the peoples’ wellbeing and life satisfaction. The results shed light on the human-environment-relationship. A survey was carried out in three communities in urban and rural areas in a wetland basin in Uganda. A sample (n=235) provided information about the attachment to the wetland, the participants’ relation to the place of their residence and their emotional wellbeing. The Wellbeing Index (WHO-5) was assessed as well as the Perceived Stress Scale (PSS-10) and Rosenberg’s Self-Esteem scale (RSE). Furthermore, the Satisfaction With Life Scale (SWLS) was applied as well as the Place Attachment Inventory (PAI), which consists of the two intertwined dimensions of place identity and place dependence. Beside this, binary indicators as ‘feeling save’ and ‘feeling comfortable’ and ‘enjoying to live at the place of residence’ have been assessed. A bivariate correlation analysis revealed a high interconnectivity between all metric scales. Especially, the subscale ‘place identity’ showed significances with all other scales. A cluster analysis revealed three groups, which differed in the perception of place-related indicators and their attachment to the wetland as well as the status of wellbeing. First, a cluster whose majority is dissatisfied with their lives, but mainly had a good status of emotional well-being. This group does not feel attached to the wetland and lives in a town. Comparably less persons of this group feel safe and comfortable at their place of residence. In the second cluster, persons feel highly attached to the wetland and identify with it. This group was characterized by the high number of persons preferring their current place of residence and do not consider moving. All persons feel well and satisfied with their lives. The third group of persons is mainly living in rural areas and feels highly attached to the wetland. They are satisfied with their lives, but only a small minority is in a good emotional state of wellbeing. The emotional attachment to a place influences life satisfaction and, indirectly, the emotional wellbeing. In the present study it could be shown that subsistence farmers are attached to the wetland, as it is the source of their livelihood. While those living in areas with a good infrastructure are less dependent on the wetland and, therefore, less attached to. This feeling also was mirrored in the perception of a place as being safe and comfortable. The identification with a place is crucial for the feeling of being at “home”. Subsistence farmers feel attached to the ecosystem, but they also might be exposed to environmental and social stressors influencing their short-term emotional wellbeing. The provision of place identity is an ecosystem service provided by wetlands, which supports the status of wellbeing in human beings.

Keywords: mental health, positive environments, quality of life, wellbeing

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27171 Determinants of Domestic Violence among Married Women Aged 15-49 Years in Sierra Leone by an Intimate Partner: A Cross-Sectional Study

Authors: Tesfaldet Mekonnen Estifanos, Chen Hui, Afewerki Weldezgi

Abstract:

Background: Intimate partner violence (hereafter IPV) is a major global public health challenge that tortures and disables women in the place where they are ought to be most secure within their own families. The fact that the family unit is commonly viewed as a private circle, violent acts towards women remains undermined. There are limited research and knowledge about the influencing factors linked to IPV in Sierra Leone. This study, therefore, estimates the prevalence rate and the predicting factors associated with IPV. Methods: Data were taken from Sierra-Leone Demographic and Health Survey (SDHS, 2013): the first in its form to incorporate information on domestic violence. Multistage cluster sampling research design was used, and information was gathered by a standard questionnaire. A total of 5185 respondents selected were interviewed, out of whom 870 were never been in union, thus excluded. To analyze the two dependent variables: experience of IPV, ‘ever’ and 'last 12 months prior to the survey', a total of 4315 (currently or formerly married) and 4029 women (currently in union) were included respectively. These dependent variables were constructed from the three forms of violence namely physical, emotional and sexual. Data analysis was applied using SPSS version 23, comprising three-step process. First, descriptive statistics were used to show the frequency distribution of both the outcome and explanatory variables. Second, bivariate analysis adopting chi-square test was applied to assess the individual relationship between the outcome and explanatory variables. Third, multivariate logistic regression analysis was undertaken using hierarchical modeling strategy to identify the influence of the explanatory variables on the outcome variables. Odds ratio (OR) and 95% confidence interval (CI) were utilized to examine the association of the variables considering p-values less than 0.05 statistically significant. Results: The prevalence of lifetime IPV among ever married women was 48.4%, while 39.8% of those currently married experienced IPV in the previous year preceding the survey. Women having 1 to 4 and more than 5 number of ever born babies were almost certain to encounter lifetime IPV. However, women who own a property, and those who referenced 3-5 reasons for which wife-beating is acceptable were less probably to experience lifetime IPV. Attesting parental violence, partner’s dominant marital behavior, and women afraid of their partner were the variables related to both experience of IPV ‘ever’ and ‘the previous year prior to the survey’. Respondents who concur that wife-beating is sensible in certain situations and occupations under the professional category had diminished chances of revealing IPV in the year prior to the data collection. Conclusion: This study indicated that factors significantly correlated with IPV in Sierra-Leone are mostly linked with husband related factors specifically, marital controlling behaviors. Addressing IPV in Sierra-Leone requires joint efforts that target men raise awareness to address controlling behavior and empower security in affiliations.

Keywords: husband behavior, married women, partner violence, Sierra Leone

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27170 Investigation of Genetic Diversity of Tilia tomentosa Moench. (Silver Lime) in Duzce-Turkey

Authors: Ibrahim Ilker Ozyigit, Ertugrul Filiz, Seda Birbilener, Semsettin Kulac, Zeki Severoglu

Abstract:

In this study, we have performed genetic diversity analysis of Tilia tomentosa genotypes by using randomly amplified polymorphic DNA (RAPD) primers. A total of 28 genotypes, including 25 members from the urban ecosystem and 3 genotypes from forest ecosystem as outgroup were used. 8 RAPD primers produced a total of 53 bands, of which 48 (90.6 %) were polymorphic. Percentage of polymorphic loci (P), observed number of alleles (Na), effective number of alleles (Ne), Nei's (1973) gene diversity (h), and Shannon's information index (I) were found as 94.29 %, 1.94, 1.60, 0.34, and 0.50, respectively. The unweighted pair-group method with arithmetic average (UPGMA) cluster analysis revealed that two major groups were observed. The genotypes of urban and forest ecosystems showed a high genetic similarity between 28% and 92% and these genotypes did not separate from each other in UPGMA tree. Also, urban and forest genotypes clustered together in principal component analysis (PCA).

Keywords: Tilia tomentosa, genetic diversity, urban ecosystem, RAPD, UPGMA

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27169 Energy-Efficient Clustering Protocol in Wireless Sensor Networks for Healthcare Monitoring

Authors: Ebrahim Farahmand, Ali Mahani

Abstract:

Wireless sensor networks (WSNs) can facilitate continuous monitoring of patients and increase early detection of emergency conditions and diseases. High density WSNs helps us to accurately monitor a remote environment by intelligently combining the data from the individual nodes. Due to energy capacity limitation of sensors, enhancing the lifetime and the reliability of WSNs are important factors in designing of these networks. The clustering strategies are verified as effective and practical algorithms for reducing energy consumption in WSNs and can tackle WSNs limitations. In this paper, an Energy-efficient weight-based Clustering Protocol (EWCP) is presented. Artificial retina is selected as a case study of WSNs applied in body sensors. Cluster heads’ (CHs) selection is equipped with energy efficient parameters. Moreover, cluster members are selected based on their distance to the selected CHs. Comparing with the other benchmark protocols, the lifetime of EWCP is improved significantly.

Keywords: WSN, healthcare monitoring, weighted based clustering, lifetime

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27168 Hybrid Algorithm for Frequency Channel Selection in Wi-Fi Networks

Authors: Cesar Hernández, Diego Giral, Ingrid Páez

Abstract:

This article proposes a hybrid algorithm for spectrum allocation in cognitive radio networks based on the algorithms Analytical Hierarchical Process (AHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) to improve the performance of the spectrum mobility of secondary users in cognitive radio networks. To calculate the level of performance of the proposed algorithm a comparative analysis between the proposed AHP-TOPSIS, Grey Relational Analysis (GRA) and Multiplicative Exponent Weighting (MEW) algorithm is performed. Four evaluation metrics is used. These metrics are the accumulative average of failed handoffs, the accumulative average of handoffs performed, the accumulative average of transmission bandwidth, and the accumulative average of the transmission delay. The results of the comparison show that AHP-TOPSIS Algorithm provides 2.4 times better performance compared to a GRA Algorithm and, 1.5 times better than the MEW Algorithm.

Keywords: cognitive radio, decision making, hybrid algorithm, spectrum handoff, wireless networks

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27167 Anthropometric Analysis for the Design of Workstations in the Interior Spaces of the Manufacturing Industry in Tijuana, Mexico

Authors: J. A. López, J. E. Olguín, C. W. Camargo, G. A. Quijano, R. Martínez

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This paper presents an anthropometric study conducted to 300 employees in a maquiladora industry that belongs to the cluster of medical products as part of a research project to pretend simulate workplace conditions under which operators conduct their activities. This project is relevant because traditionally performed a study to design ergonomic workspaces according to anthropometric profile of users, however, this paper demonstrates the importance of making decisions when the infrastructure cannot be adapted for economic whichever put emphasis on user activity.

Keywords: anthropometry, biomechanics, design, ergonomics, productivity

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27166 Pattern Recognition Based on Simulation of Chemical Senses (SCS)

Authors: Nermeen El Kashef, Yasser Fouad, Khaled Mahar

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No AI-complete system can model the human brain or behavior, without looking at the totality of the whole situation and incorporating a combination of senses. This paper proposes a Pattern Recognition model based on Simulation of Chemical Senses (SCS) for separation and classification of sign language. The model based on human taste controlling strategy. The main idea of the introduced model is motivated by the facts that the tongue cluster input substance into its basic tastes first, and then the brain recognizes its flavor. To implement this strategy, two level architecture is proposed (this is inspired from taste system). The separation-level of the architecture focuses on hand posture cluster, while the classification-level of the architecture to recognizes the sign language. The efficiency of proposed model is demonstrated experimentally by recognizing American Sign Language (ASL) data set. The recognition accuracy obtained for numbers of ASL is 92.9 percent.

Keywords: artificial intelligence, biocybernetics, gustatory system, sign language recognition, taste sense

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27165 Influence of Iron Ore Mineralogy on Cluster Formation inside the Shaft Furnace

Authors: M. Bahgat, H. A. Hanafy, S. Lakdawala

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Clustering phenomenon of pellets was observed frequently in shaft processes operating at higher temperatures. Clustering is a result of the growth of fibrous iron precipitates (iron whiskers) that become hooked to each other and finally become crystallized during the initial stages of metallization. If the pellet clustering is pronounced, sometimes leads to blocking inside the furnace and forced shutdown takes place. This work clarifies further the relation between metallic iron whisker growth and iron ore mineralogy. Various pellet sizes (6 – 12.0 & +12.0 mm) from three different ores (A, B & C) were (completely and partially) reduced at 985 oC with H2/CO gas mixture using thermos-gravimetric technique. It was found that reducibility increases by decreasing the iron ore pellet’s size. Ore (A) has the highest reducibility than ore (B) and ore (C). Increasing the iron ore pellet’s size leads to increase the probability of metallic iron whisker formation. Ore (A) has the highest tendency for metallic iron whisker formation than ore (B) and ore (C). The reduction reactions for all iron ores A, B and C are mainly controlled by diffusion reaction mechanism.

Keywords: shaft furnace, cluster, metallic iron whisker, mineralogy, ferrous metallurgy

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27164 Factors That Influence Decision Making of Foreign Volunteer Tourists in Thailand

Authors: Paramet Damchoo

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The purpose of this study is to study the factors that influence the decision making of foreign volunteer tourists in Thailand. A sample size was 400 drawn from 10 provinces of Thailand using cluster sampling method. The factor analysis was used to analysis the data. The findings indicate that volunteer tourism which was based in Thailand contained a total of 45 activities which could be divided into 4 categories. The most of these tourists were from Europe including UK and Scandinavia which was 54.50 percent. Moreover, the tourists were male rather than female and 63.50 Percent of them ware younger than 20 years old. It is also found that there are 67.00 percent of the tourists used website to find where the volunteer tourism was based. Finally, the factors that influence the decision making of foreign volunteer tourists in Thailand consist of a wide variety of activities together with a flexibility in their activities and also low prices.

Keywords: decision making, volunteer tourism, special interest tourism, GAP year

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27163 Mesoporous Na2Ti3O7 Nanotube-Constructed Materials with Hierarchical Architecture: Synthesis and Properties

Authors: Neumoin Anton Ivanovich, Opra Denis Pavlovich

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Materials based on titanium oxide compounds are widely used in such areas as solar energy, photocatalysis, food industry and hygiene products, biomedical technologies, etc. Demand for them has also formed in the battery industry (an example of this is the commercialization of Li4Ti5O12), where much attention has recently been paid to the development of next-generation systems and technologies, such as sodium-ion batteries. This dictates the need to search for new materials with improved characteristics, as well as ways to obtain them that meet the requirements of scalability. One of the ways to solve these problems can be the creation of nanomaterials that often have a complex of physicochemical properties that radically differ from the characteristics of their counterparts in the micro- or macroscopic state. At the same time, it is important to control the texture (specific surface area, porosity) of such materials. In view of the above, among other methods, the hydrothermal technique seems to be suitable, allowing a wide range of control over the conditions of synthesis. In the present study, a method was developed for the preparation of mesoporous nanostructured sodium trititanate (Na2Ti3O7) with a hierarchical architecture. The materials were synthesized by hydrothermal processing and exhibit a complex hierarchically organized two-layer architecture. At the first level of the hierarchy, materials are represented by particles having a roughness surface, and at the second level, by one-dimensional nanotubes. The products were found to have high specific surface area and porosity with a narrow pore size distribution (about 6 nm). As it is known, the specific surface area and porosity are important characteristics of functional materials, which largely determine the possibilities and directions of their practical application. Electrochemical impedance spectroscopy data show that the resulting sodium trititanate has a sufficiently high electrical conductivity. As expected, the synthesized complexly organized nanoarchitecture based on sodium trititanate with a porous structure can be practically in demand, for example, in the field of new generation electrochemical storage and energy conversion devices.

Keywords: sodium trititanate, hierarchical materials, mesoporosity, nanotubes, hydrothermal synthesis

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27162 Channel Characteristics and Morphometry of a Part of Umtrew River, Meghalaya

Authors: Pratyashi Phukan, Ranjan Saikia

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Morphometry incorporates quantitative study of the area ,altitude,volume, slope profiles of a land and drainage basin characteristics of the area concerned.Fluvial geomorphology includes the consideration of linear,areal and relief aspects of a fluvially originated drainage basin. The linear aspect deals with the hierarchical orders of streams, numbers, and lenghts of stream segments and various relationship among them.The areal aspect includes the analysis of basin perimeters,basin shape, basin area, and related morphometric laws. The relief aspect incorporates besides hypsometric, climographic and altimetric analysis,the study of absolute and relative reliefs, relief ratios, average slope, etc. In this paper we have analysed the relationship among stream velocity, channel shape,sediment load,channel width,channel depth, etc.

Keywords: morphometry, hydraulic geometry, Umtrew river, Meghalaya

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27161 Design of a Technology Transfer Scheme for the Aeronautical Sector in Alentejo-Andalusia

Authors: J. Munuzuri, L. Onieva, J. Guadix, P. Cortes

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The aeronautical sector represents the main source of industrial development in the South of the Iberian Peninsula, with the establishment of key players like Embraer in Alentejo or Airbus in Andalusia. Subsequently, the economic promotion policies implemented in both neighbouring regions seek to consolidate a trans-border aeronautical cluster to gain critical mass and seek synergies between companies and research centres. The first step of the proposed scheme entails the identification of common interests shared by companies, technological centres and university research groups in both regions. This involves determining the specific type of activities carried out at the different companies established in the two regions (ranging from OEMs to SMEs) and also building a catalogue of available infrastructures and skills on the side of research centres and universities. The results of this first step reveal potential one-to-one partnerships, and also highlight the aggregate strengths and needs of the two regions within the aeronautical sector, taking into account both the current scenario and its expected evolution. The second step of the scheme focuses on the particularly relevant companies identified in the first step, and consists of the completion of in-depth technological audits liable to suggest potential development actions or R&D projects in those companies, counting when possible on the capabilities shown by other members of the cluster. These technological audits follow a three-round process aimed at identifying specific needs, validating those identifications and suggesting possible actions to be taken. The final objective of this methodology is to enhance the economic activity in the aeronautical sector in both regions, always with an innovative perspective. The success of the scheme should be measured in terms of partnerships created, R&D projects initiated, and spin-off companies generated.

Keywords: aeronautical sector, technological audits, technology transfer, trans-border cluster

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27160 Maximization of Lifetime for Wireless Sensor Networks Based on Energy Efficient Clustering Algorithm

Authors: Frodouard Minani

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Since last decade, wireless sensor networks (WSNs) have been used in many areas like health care, agriculture, defense, military, disaster hit areas and so on. Wireless Sensor Networks consist of a Base Station (BS) and more number of wireless sensors in order to monitor temperature, pressure, motion in different environment conditions. The key parameter that plays a major role in designing a protocol for Wireless Sensor Networks is energy efficiency which is a scarcest resource of sensor nodes and it determines the lifetime of sensor nodes. Maximizing sensor node’s lifetime is an important issue in the design of applications and protocols for Wireless Sensor Networks. Clustering sensor nodes mechanism is an effective topology control approach for helping to achieve the goal of this research. In this paper, the researcher presents an energy efficiency protocol to prolong the network lifetime based on Energy efficient clustering algorithm. The Low Energy Adaptive Clustering Hierarchy (LEACH) is a routing protocol for clusters which is used to lower the energy consumption and also to improve the lifetime of the Wireless Sensor Networks. Maximizing energy dissipation and network lifetime are important matters in the design of applications and protocols for wireless sensor networks. Proposed system is to maximize the lifetime of the Wireless Sensor Networks by choosing the farthest cluster head (CH) instead of the closest CH and forming the cluster by considering the following parameter metrics such as Node’s density, residual-energy and distance between clusters (inter-cluster distance). In this paper, comparisons between the proposed protocol and comparative protocols in different scenarios have been done and the simulation results showed that the proposed protocol performs well over other comparative protocols in various scenarios.

Keywords: base station, clustering algorithm, energy efficient, sensors, wireless sensor networks

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27159 Combining Bio-Molecular and Isotopic Tools to Determine the Fate of Halogenated Compounds in Polluted Groundwater

Authors: N. Balaban, A. Buernstein, F. Gelman, Z. Ronen

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Brominated flame retardants are widespread pollutants, and are known to be toxic, carcinogenic, endocrinic disrupting as well as recalcitrant. The industrial complex Neot Hovav, in the Northern Negev, Israel, is situated above a fractured chalk aquitard, which is polluted by a wide variety of halogenated organic compounds. Two of the abundant pollutants found in the site are Dibromoneopentyl-glycol (DBNPG) and tribromoneopentyl-alcohol (TBNPA). Due to the elusive nature of the groundwater flow, it is difficult to connect between the spatial changes in contaminant concentrations to degradation. In this study, we attempt to determine whether these compounds are biodegraded in the groundwater, and to gain a better understanding concerning the bacterial community in the groundwater. This was achieved through the application of compound-specific isotope analysis (CSIA) of carbon (13^C/12^C) and bromine (81^Br/79^Br), and new-generation MiSeq pyrosequencing. The sampled boreholes were distributed among three main areas of the industrial complex: around the production plant of TBNPA and DBNPG; along the Hovav Wadi (small ephemeral stream) which crosses and drains the industrial complex; and downstream to the industrial area. TBNPA and DBNPG are found in all three areas, with no clear connection to the proximity of the borehole to the production plant. Initial isotopic data of TBNPA from boreholes in the area surrounding the production plant, reveal no changes in the carbon and bromine isotopic values. When observing the microbial groundwater community, the dominant phylum is Proteobacteria. Known anaerobic dehalogenating bacteria such as Dehalococcoides from the Chloroflexi phylum have also been detected. A statistical comparison of the groundwater microbial diversity using a multi-variant ordination of non-metric multidimensional scaling (NMDS) reveals three main clusters in accordance to spatial location in the industrial complex: all the boreholes sampled adjacent to the production plant cluster together and separately from the Wadi Hovav boreholes cluster and the downstream to the industrial area borehole cluster. This work provides the basis for the development and implication of an isotopic fractionation based tool for assessing the biodegradation of brominated organic compounds in contaminated environments, and a novel attempt to characterize the spatial microbial diversity in the contaminated site.

Keywords: biodegradation, brominated flame retardants, groundwater, isotopic fractionation, microbial diversity

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27158 Sustainable Marine Tourism: Opinion and Segmentation of Italian Generation Z

Authors: M. Bredice, M. B. Forleo, L. Quici

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Coastal tourism is currently facing huge challenges on how to balance environmental problems and tourist activities. Recent literature shows a growing interest in the issue of sustainable tourism from a so-called civilized tourists’ perspective by investigating opinions, perceptions, and behaviors. This study investigates the opinions of youth on what makes them responsible tourists and the ability of coastal marine areas to support tourism in future scenarios. A sample of 778 Italians attending the last year of high school was interviewed. Descriptive statistics, tests, and cluster analyses are applied to highlight the distribution of opinions among youth, detect significant differences based on demographic characteristics, and make segmentation of the different profiles based on students’ opinions and behaviors. Preliminary results show that students are largely convinced (62%) that by 2050 the quality of coastal environments could limit seaside tourism, while 10% of them believe that the problem can be solved simply by changing the tourist destination. Besides the cost of the holiday, the most relevant aspect respondents consider when choosing a marine destination is the presence of tourist attractions followed by the quality of the marine-coastal environment, the specificity of the local gastronomy and cultural traditions, and finally, the activities offered to guests such as sports and events. The reduction of waste and lower air emissions are considered the most important environmental areas in which marine-coastal tourism activities can contribute to preserving the quality of seas and coasts. Areas in which, as a tourist, they believe possible to give a personal contribution were (responses “very much” and “somewhat”); do not throw litter in the sea and on the beach (84%), do not buy single-use plastic products (66%), do not use soap or shampoo when showering in beaches (53%), do not have bonfires (47%), do not damage dunes (46%), and do not remove natural materials (e.g., sand, shells) from the beach (46%). About 6% of the sample stated that they were not interested in contributing to the aforementioned activities, while another 7% replied that they could not contribute at all. Finally, 80% of the sample has never participated in voluntary environmental initiatives or citizen science projects; moreover, about 64% of the students have never participated in events organized by environmental associations in marine or coastal areas. Regarding the test analysis -based on Kruskal-Wallis and Mann and Whitney tests - gender, region, and studying area of students reveals significance in terms of variables expressing knowledge and interest in sustainability topics and sustainable tourism behaviors. The classification of the education field is significant for a great number of variables, among which those related to several sustainable behaviors that respondents declare to be able to contribute as tourists. The ongoing cluster analysis will reveal different profiles in the sample and relevant variables. Based on preliminary results, implications are envisaged in the fields of education, policy, and business strategies for sustainable scenarios. Under these perspectives, the study has the potential to contribute to the conference debate about marine and coastal sustainable development and management.

Keywords: cluster analysis, education, knowledge, young people

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27157 Routing and Energy Efficiency through Data Coupled Clustering in Large Scale Wireless Sensor Networks (WSNs)

Authors: Jainendra Singh, Zaheeruddin

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A typical wireless sensor networks (WSNs) consists of several tiny and low-power sensors which use radio frequency to perform distributed sensing tasks. The longevity of wireless sensor networks (WSNs) is a major issue that impacts the application of such networks. While routing protocols are striving to save energy by acting on sensor nodes, recent studies show that network lifetime can be enhanced by further involving sink mobility. A common approach for energy efficiency is partitioning the network into clusters with correlated data, where the representative nodes simply transmit or average measurements inside the cluster. In this paper, we propose an energy- efficient homogenous clustering (EHC) technique. In this technique, the decision of each sensor is based on their residual energy and an estimate of how many of its neighboring cluster heads (CHs) will benefit from it being a CH. We, also explore the routing algorithm in clustered WSNs. We show that the proposed schemes significantly outperform current approaches in terms of packet delay, hop count and energy consumption of WSNs.

Keywords: wireless sensor network, energy efficiency, clustering, routing

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27156 Self-Supervised Attributed Graph Clustering with Dual Contrastive Loss Constraints

Authors: Lijuan Zhou, Mengqi Wu, Changyong Niu

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Attributed graph clustering can utilize the graph topology and node attributes to uncover hidden community structures and patterns in complex networks, aiding in the understanding and analysis of complex systems. Utilizing contrastive learning for attributed graph clustering can effectively exploit meaningful implicit relationships between data. However, existing attributed graph clustering methods based on contrastive learning suffer from the following drawbacks: 1) Complex data augmentation increases computational cost, and inappropriate data augmentation may lead to semantic drift. 2) The selection of positive and negative samples neglects the intrinsic cluster structure learned from graph topology and node attributes. Therefore, this paper proposes a method called self-supervised Attributed Graph Clustering with Dual Contrastive Loss constraints (AGC-DCL). Firstly, Siamese Multilayer Perceptron (MLP) encoders are employed to generate two views separately to avoid complex data augmentation. Secondly, the neighborhood contrastive loss is introduced to constrain node representation using local topological structure while effectively embedding attribute information through attribute reconstruction. Additionally, clustering-oriented contrastive loss is applied to fully utilize clustering information in global semantics for discriminative node representations, regarding the cluster centers from two views as negative samples to fully leverage effective clustering information from different views. Comparative clustering results with existing attributed graph clustering algorithms on six datasets demonstrate the superiority of the proposed method.

Keywords: attributed graph clustering, contrastive learning, clustering-oriented, self-supervised learning

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27155 Chain Networks on Internationalization of SMEs: Co-Opetition Strategies in Agrifood Sector

Authors: Emilio Galdeano-Gómez, Juan C. Pérez-Mesa, Laura Piedra-Muñoz, María C. García-Barranco, Jesús Hernández-Rubio

Abstract:

The situation in which firms engage in simultaneous cooperation and competition with each other is a phenomenon known as co-opetition. This scenario has received increasing attention in business economics and management analyses. In the domain of supply chain networks and for small and medium-sized enterprises, SMEs, these strategies are of greater relevance given the complex environment of globalization and competition in open markets. These firms face greater challenges regarding technology and access to specific resources due to their limited capabilities and limited market presence. Consequently, alliances and collaborations with both buyers and suppliers prove to be key elements in overcoming these constraints. However, rivalry and competition are also regarded as major factors in successful internationalization processes, as they are drivers for firms to attain a greater degree of specialization and to improve efficiency, for example enabling them to allocate scarce resources optimally and providing incentives for innovation and entrepreneurship. The present work aims to contribute to the literature on SMEs’ internationalization strategies. The sample is constituted by a panel data of marketing firms from the Andalusian food sector and a multivariate regression analysis is developed, measuring variables of co-opetition and international activity. The hierarchical regression equations method has been followed, thus resulting in three estimated models: the first one excluding the variables indicative of channel type, while the latter two include the international retailer chain and wholesaler variable. The findings show that the combination of several factors leads to a complex scenario of inter-organizational relationships of cooperation and competition. In supply chain management analyses, these relationships tend to be classified as either buyer-supplier (vertical level) or supplier-supplier relationships (horizontal level). Several buyers and suppliers tend to participate in supply chain networks, and in which the form of governance (hierarchical and non-hierarchical) influences cooperation and competition strategies. For instance, due to their market power and/or their closeness to the end consumer, some buyers (e.g. large retailers in food markets) can exert an influence on the selection and interaction of several of their intermediate suppliers, thus endowing certain networks in the supply chain with greater stability. This hierarchical influence may in turn allow these suppliers to develop their capabilities (e.g. specialization) to a greater extent. On the other hand, for those suppliers that are outside these networks, this environment of hierarchy, characterized by a “hub firm” or “channel master”, may provide an incentive for developing their co-opetition relationships. These results prove that the analyzed firms have experienced considerable growth in sales to new foreign markets, mainly in Europe, dealing with large retail chains and wholesalers as main buyers. This supply industry is predominantly made up of numerous SMEs, which has implied a certain disadvantage when dealing with the buyers, as negotiations have traditionally been held on an individual basis and in the face of high competition among suppliers. Over recent years, however, cooperation among these marketing firms has become more common, for example regarding R&D, promotion, scheduling of production and sales.

Keywords: co-petition networks, international supply chain, maketing agrifood firms, SMEs strategies

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27154 3D Carbon Structures (Globugraphite) with Hierarchical Pore Morphology for the Application in Energy Storage Systems

Authors: Hubert Beisch, Janik Marx, Svenja Garlof, Roman Shvets, Ivan Grygorchak, Andriy Kityk, Bodo Fiedler

Abstract:

Three-dimensional carbon materials can be used as electrode materials for energy storage systems such as batteries and supercapacitors. Fast charging and discharging times are realizable without reducing the performance due to aging processes. Furthermore high specific surface area (SSA) of three-dimensional carbon structures leads to high specific capacities. One newly developed carbon foam is Globugraphite. This interconnected globular carbon morphology with statistically distributed hierarchical pores is manufactured by a chemical vapor deposition (CVD) process from ceramic templates resulting from a sintering process. Via scanning electron (SEM) and transmission electron microscopy (TEM), the morphology is characterized. Moreover, the SSA was measured by the Brunauer–Emmett–Teller (BET) theory. Measurements of Globugraphite in an organic and inorganic electrolyte show high energy densities and power densities resulting from ion absorption by forming an electrochemical double layer. A comparison of the specific values is summarized in a Ragone diagram. Energy densities up to 48 Wh/kg and power densities to 833 W/kg could be achieved for an SSA from 376 m²/g to 859 m²/g. For organic electrolyte, a specific capacity of 100 F/g at a density of 20 mg/cm³ was achieved.

Keywords: BET, carbon foam, CVD process, electrochemical cell, Ragone diagram, SEM, TEM

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27153 Resilience in Children: A Comparative Analysis between Children with and without Parental Supervision Bandar Abbas

Authors: N. Taghinejad, F. Dortaj, N. Khodabandeh

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This research aimed at comparing resilience among male and female children with and without parental supervision in Bandar Abbas. The sample consists of 200 subjects selected through cluster sampling. The research method was comparative causal and Conner and Davidson’s questionnaire form resilience was used for data collection. Results indicated that there is no difference between children with and without parental supervision regarding their resilience capacity. These findings may be challenging and useful for psychologists, officials of children’s affairs and legislators.

Keywords: resilience, children , children with parental supervision, children without parental supervision

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27152 Molecular and Phytochemical Fingerprinting of Anti-Cancer Drug Yielding Plants in South India

Authors: Alexis John de Britto

Abstract:

Studies were performed to select the superior genotypes based on intra-specific variations, caused by phytogeographical, climatic and edaphic parameters of three anti cancer drug yielding mangrove plants such as Acanthus ilicifolius L., Calophyllum inophyllum L. and Excoecaria agallocha L. using ISSR (Inter Simple Sequence Repeats) markers and phytochemical analysis such as preliminary phytochemical tests, TLC, HPTLC, HPLC and antioxidant tests. The plants were collected from five different geographical locations of the East Coast of south India. Genetic heterozygosity, Nei’s gene diversity, Shannon’s information index and Percentage of polymorphism between the populations were calculated using POPGENE software. Cluster analysis was performed using UPGMA algorithm. AMOVA and correlations between genetic diversity and soil factors were analyzed. Combining the molecular and phytochemical variations superior genotypes were selected. Conservation constraints and methods of efficient exploitation of the species are discussed.

Keywords: anti-cancer drug yielding plants, DNA fingerprinting, phytochemical analysis, selection of superior genotypes

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27151 Bandwidth Efficient Cluster Based Collision Avoidance Multicasting Protocol in VANETs

Authors: Navneet Kaur, Amarpreet Singh

Abstract:

In Vehicular Adhoc Networks, Data Dissemination is a challenging task. There are number of techniques, types and protocols available for disseminating the data but in order to preserve limited bandwidth and to disseminate maximum data over networks makes it more challenging. There are broadcasting, multicasting and geocasting based protocols. Multicasting based protocols are found to be best for conserving the bandwidth. One such protocol named BEAM exists that improves the performance of Vehicular Adhoc Networks by reducing the number of in-network message transactions and thereby efficiently utilizing the bandwidth during an emergency situation. But this protocol may result in multicar chain collision as there was no V2V communication. So, this paper proposes a new protocol named Enhanced Bandwidth Efficient Cluster Based Multicasting Protocol (EBECM) that will overcome the limitations of existing BEAM protocol. And Simulation results will show the improved performance of EBECM in terms of Routing overhead, throughput and PDR when compared with BEAM protocol.

Keywords: BEAM, data dissemination, emergency situation, vehicular adhoc network

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27150 Alcoxysilanes Production from Silica and Dimethylcarbonate Promoted by Alkali Bases: A DFT Investigation of the Reaction Mechanism

Authors: Valeria Butera, Norihisa Fukaya, Jun-Chu Choi, Kazuhiko Sato, Yoong-Kee Choe

Abstract:

Several silicon dioxide sources can react with dimethyl carbonate (DMC) in presence of alkali bases catalysts to ultimately produce tetramethoxysilane (TMOS). Experimental findings suggested that the reaction proceeds through several steps in which the first molecule of DMC is converted to dimethylsilyloxide (DMOS) and CO₂. Following the same mechanistic steps, a second molecule of DMC reacts with the DMOS to afford the final product TMOS. Using a cluster model approach, a quantum-mechanical investigation of the first part of the reaction leading to DMOS formation is reported with a twofold purpose: (1) verify the viability of the reaction mechanism proposed on the basis of experimental evidences .(2) compare the behaviors of three different alkali hydroxides MOH, where M=Li, K and Cs, to determine whether diverse ionic radius and charge density can be considered responsible for the observed differences in reactivity. Our findings confirm the observed experimental trend and furnish important information about the effective role of the alkali hydroxides giving an explanation of the different catalytic activity of the three metal cations.

Keywords: Alcoxysilanes production, cluster model approach, DFT, DMC conversion

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27149 The Syllable Structure and Syllable Processes in Suhwa Arabic: An Autosegmental Analysis

Authors: Muhammad Yaqub Olatunde

Abstract:

Arabic linguistic science is redirecting its focus towards the analysis and description of social, regional, and temporal varieties of social, regional, and temporal varieties in order to show how they vary in pronunciation, vocabulary, and grammar. This is not to say that the traditional Arabic linguists did not mention scores of dialectical variations but such works focused on the geographical boundaries of the Arabic speaking countries. There is need for a comprehensive survey of various Arabic dialects within the boundary of Arabic speaking countries and outside showing both the similarities and differences of linguistic and extra linguistic elements. This study therefore examines the syllable structure and process in noun and verb in the shuwa Arabic dialect speaking in North East Nigeria [mainly in Borno state]. The work seeks to establish the facts about this phenomenon, using auto- segmental analysis. These facts are compared, where necessary; using possible alternative analysis, with what operate in other related dialects within and outside Arabic speaking countries. The interaction between epenthesis and germination in the language also generate an interesting issue. The paper then conclude that syllable structure and process in the language need to recognize the existence of complex onset and a complex rhyme producing a consonant cluster in the former and a closed syllable in the letter. This emerges as result of resyllabification, which is motivated by these processes.

Keywords: Arabic, dialect, linguistics, processes, resyllabification

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27148 A Heuristic Based Decomposition Approach for a Hierarchical Production Planning Problem

Authors: Nusrat T. Chowdhury, M. F. Baki, A. Azab

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The production planning problem is concerned with specifying the optimal quantities to produce in order to meet the demand for a prespecified planning horizon with the least possible expenditure. Making the right decisions in production planning will affect directly the performance and productivity of a manufacturing firm, which is important for its ability to compete in the market. Therefore, developing and improving solution procedures for production planning problems is very significant. In this paper, we develop a Dantzig-Wolfe decomposition of a multi-item hierarchical production planning problem with capacity constraint and present a column generation approach to solve the problem. The original Mixed Integer Linear Programming model of the problem is decomposed item by item into a master problem and a number of subproblems. The capacity constraint is considered as the linking constraint between the master problem and the subproblems. The subproblems are solved using the dynamic programming approach. We also propose a multi-step iterative capacity allocation heuristic procedure to handle any kind of infeasibility that arises while solving the problem. We compare the computational performance of the developed solution approach against the state-of-the-art heuristic procedure available in the literature. The results show that the proposed heuristic-based decomposition approach improves the solution quality by 20% as compared to the literature.

Keywords: inventory, multi-level capacitated lot-sizing, emission control, setup carryover

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27147 Energy Efficient Clustering with Reliable and Load-Balanced Multipath Routing for Wireless Sensor Networks

Authors: Alamgir Naushad, Ghulam Abbas, Shehzad Ali Shah, Ziaul Haq Abbas

Abstract:

Unlike conventional networks, it is particularly challenging to manage resources efficiently in Wireless Sensor Networks (WSNs) due to their inherent characteristics, such as dynamic network topology and limited bandwidth and battery power. To ensure energy efficiency, this paper presents a routing protocol for WSNs, namely, Enhanced Hybrid Multipath Routing (EHMR), which employs hierarchical clustering and proposes a next hop selection mechanism between nodes according to a maximum residual energy metric together with a minimum hop count. Load-balancing of data traffic over multiple paths is achieved for a better packet delivery ratio and low latency rate. Reliability is ensured in terms of higher data rate and lower end-to-end delay. EHMR also enhances the fast-failure recovery mechanism to recover a failed path. Simulation results demonstrate that EHMR achieves a higher packet delivery ratio, reduced energy consumption per-packet delivery, lower end-to-end latency, and reduced effect of data rate on packet delivery ratio when compared with eminent WSN routing protocols.

Keywords: energy efficiency, load-balancing, hierarchical clustering, multipath routing, wireless sensor networks

Procedia PDF Downloads 51