Multiple Dimensional Scaling Research Articles

A star selection strategy based on MDS and fast convex hull algorithm in COSPAS-SARSAT system

Abstract The space segment of the current COSPAS-SARSAT system is mainly supported by the Galileo system, and the positioning technology used is generally three-star time-difference positioning. Most of the antennas equipped in the Mission Control Centre (MCC) are not omnidirectional. In the case of Source of Search and Rescue (SAR) in a heavily shaded environment, it is necessary to use the different orbit time-sharing single satellite geolocations using TDOA, and the time-sharing will generate more satellite position data. In order to achieve the higher positioning accuracy of the solution, it is necessary to select the appropriate time and optimal geometrical distribution from the satellite positions. In this paper, we propose a satellite selection strategy based on Multiple Dimensional scaling (MDS) data degradation and a fast convex hull algorithm. The three-dimensional satellite data are downscaled to two-dimensional while maintaining their relative positional relationships, and the two-dimensional convex hull algorithm is used for Geometric Dilution of Precision (GDOP) minimum search star selection. By simulating the satellite position data in different orbits and time-sharing to complete the localization solution, the results show that compared with the traditional satellite selection method, the satellite selection strategy proposed in this paper is able to achieve better localization accuracy in a shorter period of time.

Dimensional effect of graphene nanostructures on cytoskeleton-coupled anti-tumor metastasis.

Interactions between inorganic materials and living systems can be strongly influenced by the dimensional property of the materials, which can in turn impact biological activities. Although the role of biomaterials at the molecular and cellular scales has been studied, research investigating the effects of biomaterials across multiple dimensional scales is relatively scarce. Herein, comparing the effectiveness of two-dimensional graphene oxide nanosheets (GOs) and three-dimensional graphene oxide quantum dots (GOQDs) (though not zero-dimensional because of their significant surface area) in cancer therapies, we have discovered that GOs, with the same mass concentration, exhibit stronger anti-cancer and anti-tumor metastasis properties than GOQDs. Our research, which employed liquid-phase atomic force microscopy, revealed that lower-dimensional GOs create a more extensive nano-bio interface that impedes actin protein polymerization into the cytoskeleton, leading to the prevention of tumor metastasis. These results help to better understand the underlying mechanisms and offer a dimensional perspective on the potential of optimizing the properties of graphene-based materials for clinical applications, e.g., cancer therapy.

Data-Driven Load Pattern Identification Based on R-Vine Copula and Random Forest Method

Massive residential power consumption information provides data support for the mining and analysis of load patterns. This article proposes a complete framework for load pattern identification, which mainly includes the clustering module and the classification module. Considering that the high-dimensional load profiling dataset will bring a heavy computational burden, multiple dimensional scaling is introduced in the process of data preprocessing. Then, an innovative mixture model based on regular vine copula mixture model (RVMM) is adopted for clustering typical load patterns. Finally, a random forest (RF) classifier constructed with certain load characteristic indexes and RVMM clustering results is employed as a supervised classification model to predict the categories of subsequent new customers, and the accuracy is calculated by the 10-fold cross-validation. It is demonstrated in the case study that the proposed RVMM algorithm exhibits better performance in the clustering validity evaluation. Besides, higher accuracy is achieved by the RF classifier.

Riverine Inputs Impact the Diversity and Population Structure of Heterotrophic Fungus-like Protists and Bacterioplankton in the Coastal Waters of the South China Sea

Labyrinthulomycetes protists (LP) play an important role in ocean carbon cycling with an ubiquitous presence in marine ecosystems. As one of the most important environmental factors, salinity is known to regulate their diverse metabolic activities. However, impacts of salinity gradient on their distribution and ecological functions in natural habitats remain largely unknown. In this study, the dynamics of LP abundance and community structure were examined in the surface water of plume, offshore, and pelagic habitats in the South China Sea (SCS). The highest (5.59 × 105 copies L−1) and lowest (5.28 × 104 copies L−1) abundance of LP were found to occur in the waters of plume and pelagic habitats, respectively. Multiple dimensional scaling (MDS) analysis revealed a strong relationship between salinity and LP community variation (p < 0.05, rho = 0.67). Unexpectedly, relative low LP diversity was detected in the brackish water samples of the plume. Moreover, our results indicated the genus Aplanochytrium dominated LP communities in offshore and pelagic, while Aurantiochytrium and Ulkenia were common in the plume. Physiological and metabolic features of these genera suggested that LP ecological functions were also largely varied along this salinity gradient. Clearly, the salinity gradient likely regulates the diversity and functional partitioning of marine protistan micro-eukaryotes in the world’s oceans.

Research on Transboundary Regulation of Plant-Derived Exogenous MiRNA Based on Biological Big Data.

In recent years, researchers have discovered plant miRNA (plant xenomiR) in mammalian samples, but it is unclear whether it exists stably and participates in regulation. In this paper, a cross-border regulation model of plant miRNAs based on biological big data is constructed to study the possible cross-border regulation of plant miRNAs. Firstly, a variety of human edible plants were selected, and based on the miRNA data detected in human experimental studies, screening was performed to obtain the plant xenomiR that may stably exist in the human body. Then, we use plant and animal target gene prediction methods to obtain the mRNAs of animals and plants that may be regulated, respectively. Finally, we use GO (Gene Ontology) and the Multiple Dimensional Scaling (MDS) algorithm to analyze the biological processes regulated by plants and animals. We obtain the relationship between different biological processes and explore the regulatory commonality and individuality of plant xenomiR in plants and humans. Studies have shown that the development and metabolic functions of the human body are affected by daily eating habits. Soybeans, corn, and rice can not only affect the daily development and metabolism of the human body but also regulate biological processes such as protein modification and mitosis. This conclusion explains the reasons for the different physiological functions of the human body. This research is an important meaning for the design of small RNA drugs in Chinese herbal medicine and the treatment of human nutritional diseases.

Face-voice space: Integrating visual and auditory cues in judgments of person distinctiveness.

Faces and voices each convey multiple cues enabling us to tell people apart. Research on face and voice distinctiveness commonly utilizes multidimensional space to represent these complex, perceptual abilities. We extend this framework to examine how a combined face-voice space would relate to its constituent face and voice spaces. Participants rated videos of speakers for their dissimilarity in face only, voice only, and face-voice together conditions. Multiple dimensional scaling (MDS) and regression analyses showed that whereas face-voice space more closely resembled face space, indicating visual dominance, face-voice distinctiveness was best characterized by a multiplicative integration of face-only and voice-only distinctiveness, indicating that auditory and visual cues are used interactively in person-distinctiveness judgments. Further, the multiplicative integration could not be explained by the small correlation found between face-only and voice-only distinctiveness. As an exploratory analysis, we next identified auditory and visual features that correlated with the dimensions in the MDS solutions. Features pertaining to facial width, lip movement, spectral centroid, fundamental frequency, and loudness variation were identified as important features in face-voice space. We discuss the implications of our findings in terms of person perception, recognition, and face-voice matching abilities.

Power Management for Plug-in Hybrid Electric Vehicle with Automated Mechanical Transmission using Multiple Dimensional Scaling Method

Background: The study of kerosene fuel for gasoline engines is of great significance to the supply, management, storage and transportation of military fuel, as well as its safety. Small aviation two-stroke kerosene engine fuel injection controller is the key technology of kerosene engines. It is very important to improve the performance of kerosene engine by controlling the air-fuel ratio accurately. Objective: The initial injection pulse spectrum was firstly obtained by numerical calculation in the absence of kerosene injection pulse spectrum, and then the injection controller was designed based on the initial injection pulse spectrum. Methodology: Firstly, a numerical model of the whole engine was established by using BOOST software. The air mass flow data of the inlet was obtained through numerical calculation. The amount of initial engine fuel injection was calculated according to the requirements of air-fuel ratios in each working condition, from which an initial injection pulse spectrum was obtained. Then, based on Free scale 16-bit embedded micro-controller MC9S12DP512, a kerosene engine fuel injection controller was developed, together with the circuit was also designed. According to the initial fuel injection pulse spectrum, a two-dimensional interpolation algorithm was developed by using assembly language and C language mixed programming, and the anti-electromagnetic interference ability of the controller was further enhanced. Finally, the accuracy of the initial injection pulse spectrum and the performance and reliability of the injection controller of the kerosene engine were verified by the kerosene engine bench test. Conclusion: The experimental results show that the numerical model was accurate, and the development time of the injection controller was shortened by using the numerical model to calculate the initial injection pulse spectra. The developed controller was stable and reliable, which can meet the control requirement.

Herbaceous Understory Indicators of Post-Harvest Recovery in Coast Redwood (<i>Sequoia sempervirens</i>) Forests

Assessment of forest recovery following disturbance is enhanced by the use of biological indicators. One such indicator, the abundance of understory species, was examined in coast redwood (Sequoia sempervirens) forests using non-metric multiple dimensional scaling (NMDS) and indicator species analysis (ISA). Randomly distributed 10 m diameter circular plots were employed to record the abundance of all understory species across three treatments: actively managed (0 - 45 years since harvest); mature second-growth (~80 - 120 years since harvest); and unharvested old-growth stands. NMDS with perMANOVA analysis signified separation between treatments with the shade tolerant herbaceous species Trillium ovatum, Viola sempervirens, and Oxalis oregana positively correlated with mature second-growth and old-growth treatments. ISA supported the inclusion of T. ovatum, with the addition of Prosartes hookerii, as indicators of mature second-growth and old-growth. Both NMDS and ISA specified associations for Ceanothus thyrsiflorus and Stachys bullata with actively-managed stands. Occurrence of non-natives was low across treatments, though significantly higher on actively managed stands, with the shade intolerant invasive plants, Cortaderia sp. and Myosotis latifolia, occurring exclusively in actively-managed sites.

Converging shock flows for a Mie-Grüneisen equation of state

Previous work has shown that the one-dimensional (1D) inviscid compressible flow (Euler) equations admit a wide variety of scale-invariant solutions (including the famous Noh, Sedov, and Guderley shock solutions) when the included equation of state (EOS) closure model assumes a certain scale-invariant form. However, this scale-invariant EOS class does not include even simple models used for shock compression of crystalline solids, including many broadly applicable representations of Mie-Grüneisen EOS. Intuitively, this incompatibility naturally arises from the presence of multiple dimensional scales in the Mie-Grüneisen EOS, which are otherwise absent from scale-invariant models that feature only dimensionless parameters (such as the adiabatic index in the ideal gas EOS). The current work extends previous efforts intended to rectify this inconsistency, by using a scale-invariant EOS model to approximate a Mie-Grüneisen EOS form. To this end, the adiabatic bulk modulus for the Mie-Grüneisen EOS is constructed, and its key features are used to motivate the selection of a scale-invariant approximation form. The remaining surrogate model parameters are selected through enforcement of the Rankine-Hugoniot jump conditions for an infinitely strong shock in a Mie-Grüneisen material. Finally, the approximate EOS is used in conjunction with the 1D inviscid Euler equations to calculate a semi-analytical Guderley-like imploding shock solution in a metal sphere and to determine if and when the solution may be valid for the underlying Mie-Grüneisen EOS.

Modulation of Multiscale 3D Lattices through Conformational Control: Painting Silk Inverse Opals with Water and Light.

Structural proteins from naturally occurring materials are an inspiring template for material design and synthesis at multiple scales. The ability to control the assembly and conformation of such materials offers the opportunity to define fabrication approaches that recapitulate the dimensional hierarchy and structure-function relationships found in nature. A simple and versatile directed assembly method of silk fibroin, which allows the design of structures across multiple dimensional scales by generating and tuning structural color in large-scale, macro defect-free colloidally assembled 3D nanostructures in the form of silk inverse opals (SIOs) is reported. This approach effectively combines bottom-up and top-down techniques to obtain control on the nanoscale (through silk conformational changes), microscale (through patterning), and macroscale (through colloidal assembly), ultimately resulting in a controllable photonic lattice with predefined spectral behavior, with a resulting palette spanning almost the entire visible range. As a demonstration of the approach, examples of "multispectral" SIOs, paired with theoretical calculations and analysis of their response as a function of changes of lattice constants and refractive index contrast are illustrated.

Genome-wide DNA methylation study of hip and knee cartilage reveals embryonic organ and skeletal system morphogenesis as major pathways involved in osteoarthritis.

BackgroundEvidence suggests that epigenetics plays a role in osteoarthrits (OA). The aim of the study was to describethe genome wide DNA methylation changes in hip and knee OA and identify novel genes and pathwaysinvolved in OA by comparing the DNA methylome of the hip and knee osteoarthritic cartilage tissues withthose of OA-free individuals.MethodsCartilage samples were collected from hip or knee joint replacement patients either due to primary OA or hip fractures as controls. DNA was extracted from the collected cartilage and assayed by Illumina Infinium HumanMethylation450 BeadChip array, which allows for the analysis of >480,000 CpG sites. Student T-test was conducted for each CpG site and those sites with at least 10 % methylation difference and a p value <0.0005 were defined as differentially methylated regions (DMRs) for OA. A sub-analysis was also done for hip and knee OA separately. DAVID v6.7 was used for the functional annotation clustering of the DMR genes. Clustering analysis was done using multiple dimensional scaling and hierarchical clustering methods.ResultsThe study included 5 patients with hip OA, 6 patients with knee OA and 7 hip cartilage samples from OA-free individuals. The comparisons of hip, knee and combined hip/knee OA patients with controls resulted in 26, 72, and 103 DMRs, respectively. The comparison between hip and knee OA revealed 67 DMRs. The overall number of the sites after considering the overlaps was 239, among which 151 sites were annotated to 145 genes. One-fifth of these genes were reported in previous studies. The functional annotation clustering of the identified genes revealed clusters significantly enriched in skeletal system morphogenesis and development. The analysis revealed significant difference among OA and OA-free cartilage, but less different between hip OA and knee OA.ConclusionsWe found that a number of CpG sites and genes across the genome were differentially methylated in OA patients, a remarkable portion of which seem to be involved in potential etiologic mechanisms of OA. Genes involved in skeletal developmental pathways and embryonic organ morphogenesis may be a potential area for further OA studies.Electronic supplementary materialThe online version of this article (doi:10.1186/s12891-015-0745-5) contains supplementary material, which is available to authorized users.

Thermal behaviour of autoclaved aerated concrete exposed to fire

The reaction to fire of autoclaved aerated concrete (AAC) has been investigated at multiple dimensional scales. Changes in the chemical composition were detected and analysed by means of thermal analysis methods. Then, the thermal conductivity after different heat treatments was measured at different temperatures ranging from 120°C to 720°C. Finally, the evolution of temperature in an AAC wall exposed to the standard fire of ISO 834 has been monitored by built-in temperature sensors. The results hereof were used as input for a transient and non-linear numerical model which has been set up to predict temperatures at different depths of the wall. Measured and calculated results have been compared and discussed.

A longitudinal study on the uses of mobile tablet devices and changes in digital media literacy of young adults

This study examined whether gaining access to a new digital device enhanced the digital media literacy of young adults and what factors determine such change. Thirty-five young adults were given a mobile tablet device and observed for one year. Participants engaged in an online community, responding regularly to online surveys and discussion forums. Digital media literacy, using multidimensional scales, was measured at the beginning and end of the study. Usage was measured every month to track changes over time. When measured with multiple dimensional scales, the participants’ digital media literacy levels increased over time. Those who used the tablet device for information access and social activities increased their digital media literacy in some dimensions. However, an increase in digital media literacy was not directly related to the time spent on the tablet.

Spatial and temporal changes in bird assemblages in forest fragments in an eastern Amazonian savannah

We investigated the effects of forest fragmentation on bird assemblages in an Amazonian savannah landscape with forest fragments that have been isolated for more than 100 years. The study was conducted in areas surrounding the village of Alter do Chão (2°31'S, 55°00'W), Santarém, Brazil. Bird surveys and measurements of tree density were undertaken in 25 areas, with 19 plots in forest fragments of different sizes and six in an area of continuous forest. Data on forest-fragment size, perimeter, and isolation were obtained from a georeferenced satellite image. Variation in number of bird species recorded per plot was not related to vegetation structure (tree density). The number of bird species recorded per plot increased significantly only with fragment area, but was not influenced by fragment shape or degree of isolation, even when considering species from the savannah matrix in the analysis. Fragments had fewer rare species. Multivariate ordination analyses (multiple dimensional scaling, [MDS]) indicated that bird species composition changed along a gradient from small to large forest fragments and continuous-forest areas. In the Amazonian savannah landscapes of Alter do Chão, the organization and composition of bird assemblages in forest fragments are affected by local long-term forest-fragmentation processes. Differences in the number of bird species recorded per plot and assemblage composition between forest fragments and continuous forest were not influenced by forest structure, suggesting that the observed patterns in species composition result from the effects of fragmentation per se rather than from preexisting differences in vegetation structure between sites. Nevertheless, despite their long history of isolation, the forest fragments still preserve a large proportion (on average 80%) of the avifauna found in continuous-forest areas. The fragments at Alter do Chão are surrounded by natural (rather than planted) grassland, with many trees in the savannah matrix and the landscape has vast areas covered by forest, which may have helped to ameliorate the influences of forest fragmentation.

A user term visualization analysis based on a social question and answer log

The authors of this paper investigate terms of consumers’ diabetes based on a log from the Yahoo!Answers social question and answers (Q&A) forum, ascertain characteristics and relationships among terms related to diabetes from the consumers’ perspective, and reveal users’ diabetes information seeking patterns. In this study, the log analysis method, data coding method, and visualization multiple-dimensional scaling analysis method were used for analysis. The visual analyses were conducted at two levels: terms analysis within a category and category analysis among the categories in the schema. The findings show that the average number of words per question was 128.63, the average number of sentences per question was 8.23, the average number of words per response was 254.83, and the average number of sentences per response was 16.01. There were 12 categories (Cause & Pathophysiology, Sign & Symptom, Diagnosis & Test, Organ & Body Part, Complication & Related Disease, Medication, Treatment, Education & Info Resource, Affect, Social & Culture, Lifestyle, and Nutrient) in the diabetes related schema which emerged from the data coding analysis. The analyses at the two levels show that terms and categories were clustered and patterns were revealed. Future research directions are also included.

Influence of Heavy Snow on the Feeding Behavior of Japanese Macaques (Macaca Fuscata) in Northern Japan

Natural disasters can degrade primate habitat and alter feeding behavior. Here, we examined the influence of unusually heavy snow on diet and feeding-site use by Japanese macaques (Macaca fuscata) in northern Japan. To compare the winter-feeding behavior under different snow conditions, we recorded the plant species foraged on by macaques in multiple transects of the Shirakami Mountains from 2008 to 2012 (excluding 2011). We used cluster analysis to describe foraged plant assemblages, and applied multiple dimensional scaling and decision tree modeling to evaluate annual variation in feeding-site use by macaques. Our cluster analysis revealed five types of foraged plant assemblages. The proportion of each type present in transects varied considerably across the years, indicating that the diet of macaques in heavy snow conditions was influenced more by resource accessibility than by preference. Multiple dimensional scaling and decision tree modeling demonstrated that heavy snow conditions restricted feeding-site use. Moreover, the distribution of refuges relative to severe external ambient environments was a stronger limiting factor for feeding-site use than was the availability of food resources. While most primate species facing unexpected starvation employ risk-prone foraging tactics (i.e., choosing the option with higher pay-off by accepting risk), Japanese macaques have a tendency to adopt risk-averse foraging behavior (i.e., minimizing energy loss when searching for preferred diet items under long-lasting heavy snow conditions), because winters with temperatures below freezing have higher thermoregulatory costs.

Visible agreement analyses of traditional Chinese medicine – a multiple-dimensional scaling qpproach

Visible agreement analyses of traditional Chinese medicine – a multiple-dimensional scaling qpproach

Visual agreement analyses of traditional chinese medicine: a multiple-dimensional scaling approach.

The study of TCM agreement in terms of a powerful statistical tool becomes critical in providing objective evaluations. Several previous studies have conducted on the issue of consistency of TCM, and the results have indicated that agreements are low. Traditional agreement measures only provide a single value which is not sufficient to justify if the agreement among several raters is strong or not. In light of this observation, a novel visual agreement analysis for TCM via multiple dimensional scaling (MDS) is proposed in this study. If there are clusters present in the raters in a latent manner, MDS can prove itself as an effective distinguisher. In this study, a group of doctors, consisting of 11 experienced TCM practitioners having clinical experience ranging from 3 to 15 years with a mean of 5.5 years from the Chinese Medicine Department at Changhua Christian Hospital (CCH) in Taiwan were asked to diagnose a total of fifteen tongue images, the Eight Principles derived from the TCM theorem. The results of statistical analysis show that, if there are clusters present in the raters in a latent manner, MDS can prove itself as an effective distinguisher.

Influence of species specificity and other factors on bacteria associated with the coral Stylophora pistillata in Taiwan.

Species of bacteria associated with Stylophora pistillata were determined by analyses of 16S ribosomal genes. Coral samples were taken from two distinct sites at Kenting, in the far south of Taiwan; three coral colonies at each site were tagged and sampled in the winter and summer of 2007. Six hundred 16S rRNA gene clones were selected and sequenced for diversity analysis and community comparison. LIBSHUFF and nonparametric multiple dimensional scaling analyses showed variations in the composition of the coral-associated bacteria in the different samples, suggesting that seasonal and geographic factors and variations in individual coral colonies were all vital drivers of the structure of the S. pistillata-associated bacterial community. To examine the association between species specificity and environmental impacts on the structure of the coral-associated bacterial community, we conducted an integrated, comparative analysis of 44 coral-associated bacterial data sets, including the present study's data. The clustering analysis suggests that the influence of spatial and temporal factors on the coral-associated bacteria population structure is considerable; nonetheless, the effect of species specificity is still detectable in some coral species, especially those from the Caribbean Sea.

Microsatellite and mitochondrial haplotype differentiation in blue mackerel (Scomber australasicus) from the western North Pacific

AbstractTzeng, C-H., Chen, C-S., Tang, P-C., and Chiu, T-S. 2009. Microsatellite and mitochondrial haplotype differentiation in blue mackerel (Scomber australasicus) from the western North Pacific. – ICES Journal of Marine Science, 66: 816–825. Blue (Scomber australasicus) and chub mackerel (Scomber japonicus) occur sympatrically in the western North Pacific. Blue mackerel were previously classified as a subspecies of S. japonicus based on morphological similarities. The practical management unit for blue mackerel is contentious owing to incomplete resolution by biological analyses. We used rapidly evolving microsatellites and slow-changing mitochondrial cytochrome b (mtCyt-b) markers to examine the phylogeographic relationships of the two species across four major hydrographic regions of the western North Pacific. Genetic variability was high in each hydrographic region and in the putative species unit, and Hardy–Weinberg equilibrium tests confirmed that blue and chub mackerel are separate genetic components. Population genetic and multiple-dimensional scaling analyses of the genotypes indicated clear genetic differences, and phylogenetic analyses of the mtCyt-b haplotypes showed a level of genetic divergence (FST = 0.038, p &lt; 0.001) consistent with separation of the two species. Based on the coalescence theory, the difference in mtCyt-b genes was small, indicating incipient speciation between blue and chub mackerel, with a diversification time of 1.9 million years ago (mya) during the Pleistocene when the East China Sea (ECS) and the South China Sea (SCS) were separated physically. Significant differences between populations of blue mackerel in the ECS and SCS were also found. Our findings confirm that blue mackerel is a valid biological species and that its populations in the ECS and SCS should be considered separate fishery stocks and conservation units for management.