bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiative consequences of low-temperature infrared refractive indices for supercooled water clouds
Authors: Rowe P. M. , Neshyba S. , Walden V. P.
Published: July 2013

Abstract. Simulations of cloud radiative properties for climate modeling and remote sensing rely on accurate knowledge of the complex refractive index (CRI) of water. Although conventional algorithms employ a temperature independent assumption (TIA), recent infrared measurements of supercooled water have demonstrated that the CRI becomes increasingly ice-like at lower temperatures. Here, we assess biases that result from ignoring this temperature dependence. We show that TIA-based cloud retrievals introduce spurious ice into pure, supercooled clouds, or underestimate cloud thickness and droplet size. TIA-based downwelling radiative fluxes are lower than those for the temperature-dependent CRI by as much as 1.7 W m−2 (in cold regions), while top-of-atmosphere fluxes are higher by as much as 3.4 W m−2 (in warm regions). Proper accounting of the temperature dependence of the CRI, therefore, leads to significantly greater local greenhouse warming due to supercooled clouds than previously predicted. The current experimental uncertainty in the CRI at low temperatures must be reduced to properly account for supercooled clouds in both climate models and cloud property retrievals.
Factors affecting the atmospheric occurrence and deposition of polychlorinated biphenyls in the Southern Ocean
Authors: Galbán-Malagón C. J. , Del Vento S. , Cabrerizo A. , Dachs J.
Published: July 2013

Abstract. Persistent organic pollutants, such as polychlorinated biphenyls, reach the Southern Ocean atmosphere through long-range atmospheric transport. In this study we report the largest data set available for the atmospheric occurrence of PCBs in the Southern Ocean surrounding the Antarctic Peninsula from samples obtained during three cruises in 2005, 2008 and 2009. The gas phase concentrations of total PCBs (σ25PCBs) ranged from 1 to 70 pg m-3, while the aerosol phase concentrations were significantly lower (0.04 to 0.4 pg m-3). The aerosol phase is enriched in the more hydrophobic congeners consistent with the model predictions of gas-particle partitioning. There is a net air to water diffusive flux of PCBs to the Southern Ocean, up to 50 times higher than the dry deposition flux of aerosol-bound PCBs. The air–water disequilibrium is higher for the more hydrophobic congeners consistent with the role of the biological pump removing PCBs from the water column by settling of PCBs bound to organic matter. The atmospheric half-lives of PCB 52 and 180 are of 3.8 and 1 days, respectively, as predicted from the measured atmospheric concentration and depositional fluxes. The volatilization of PCBs from Antarctic soils during the Austral summer drives higher gas phase concentrations in the atmosphere over Antarctica during the warmer periods. This temperature dependence is not observed for PCBs over the adjacent Southern Ocean, probably due to the importance of long-range atmospheric transport and atmospheric deposition modulating the atmospheric occurrence of PCBs.
The Gela Basin pockmark field in the strait of Sicily (Mediterranean Sea): chemosymbiotic faunal and carbonate signatures of postglacial to modern cold seepage
Authors: Taviani M. , Angeletti L. , Ceregato A. , Foglini F. , Froglia C. , Trincardi F.
Published: July 2013

Abstract. The geo-biological exploration of a pockmark field located at ca. 800 m below sea level in the Gela basin (Strait of Sicily, Central Mediterranean) provided a relatively diverse chemosymbiotic community and methane-imprinted carbonates. To date, this is the first occurrence of such a type of specialised deep-water cold-seep communities recorded from this key region, before documented in the Mediterranean as rather disjunct findings in its eastern and westernmost basins. The thiotrophic chemosymbiotic organisms recovered from this area include empty tubes of the vestimentiferan Lamellibrachia sp., loose and articulated shells of lucinids (Lucinoma kazani, Myrtea amorpha), vesicomyids (Isorropodon perplexum), and gastropods (Taranis moerchii). A callianassid decapod (Calliax sp.) was consistently found alive in large numbers in the pockmark mud. Their post-mortem calcified parts mixed with molluscs and subordinately miliolid foraminifers form a distinct type of skeletal assemblage. Carbonate concretions display δ13C values as low as −40‰ PDB suggesting the occurrence of light hydrocarbons in the seeping fluids. Since none of the truly chemosymbiotic organisms was found alive, although their skeletal parts appear at times very fresh, some specimens have been AMS-14C dated to shed light on the historical evolution of this site. Lamellibrachiav and Lucinoma are two of the most significant chemosymbiotic taxa reported from various Mediterranean cold seep sites (Alboran Sea and Eastern basin). Specimens from station MEDCOR78 (pockmark #1, Lat. 36°46´10.18" N, Long. 14°01´31.59" E, 815 m below sea level) provided ages of 11736 ± 636 yr cal BP (Lamellibrachia sp.), and 9609.5 ± 153.5 yr cal BP (L. kazani). One shell of M. amorpha in core MEDCOR81 (pockmark #6, Lat 36°45´38.89" N, Long 14°00´07.58" E, 822 m below sea level) provided a sub-modern age of 484 ± 54 yr cal BP. These ages document that fluid seepage at this pockmark site has been episodically sustaining thiotrophic macrobenthic communities since the end of the Younger Dryas stadial up to sub-recent times.
Differences in plant cover and species composition of semiarid grassland communities of central Mexico and its effects on net ecosystem exchange
Authors: Delgado-Balbuena J. , Arredondo J. T. , Loescher H. W. , Huber-Sannwald E. , Chavez-Aguilar G. , Luna-Luna M. , Barretero-Hernandez R.
Published: July 2013

Abstract. Changes in land use across the semiarid grasslands of northern Mexico have driven a decline of plant cover and alteration of plant species composition. A number of different plant communities have resulted from these changes. Their implications, however, on the carbon (C) cycle and regional carbon balance are still poorly understood. Here, we examined the effects of plant cover loss and changes in species composition on net ecosystem CO2 exchange (NEE) and their biotic and abiotic controls. NEE was measured in five representative plant community types within a semiarid grassland by temporarily enclosing the entire aboveground ecosystem using a chamber method (i.e., geodesic dome). Sites included an oat crop (crop), a moderately grazed grassland (moderate grazing), a 28 yr-old grazing exclosure (exclosure), an overgrazed site with low perennial grass cover (overgrazed), and an overgrazed site presenting shrub encroachment (shrub encroachment). For natural vegetation, rates of standardized daytime NEE for sites with a high plant cover (exclosure and moderate grazing) were similar (P > 0.05) as compared to sites with low plant cover (overgrazed and shrub encroachment). However, yearly total nighttime NEE (carbon loss) was more than double (P < 0.05) for sites with high plant cover compared to sites with low cover, resulting to slight C sinks for the low plant cover sites, and neutral or sources for the high plant cover sites as accounted by daytime and nighttime NEE annual balance. Differences in plant cover and its associated biomass defined the sensitivity to environmental controls. Thus, daytime NEE in low plant cover sites reached light compensation points at lower photosynthetic photon flux density than those from high plant cover sites. Differences in species composition did not influence NEE rates even though there were transient or permanent changes in C3 vs. C4 functional groups. Our results allowed the detection of the large variability and contribution of different plant communities to regional C balance in patchy landscapes. Identification of the role of landscape patches in the regional C balance as either sinks or sources may provide tools allowing land use management strategies that could favor C uptake in patchy landscapes.
Investigating the consistency between proxies and between proxies and models using data assimilation: a mid-Holocene case study
Authors: Mairesse A. , Goosse H. , Mathiot P. , Wanner H. , Dubinkina S.
Published: July 2013

Abstract. The mid-Holocene (6 thousand years before present) is a key period to study the consistency between model results and proxy data as it corresponds to a standard test for models and a reasonable number of proxy records are available. Taking advantage of this relatively large amount of information, we have first compared a compilation of 50 air and sea surface temperature reconstructions with the results of three simulations performed with general circulation models and one carried out with LOVECLIM, a model of intermediate complexity. The conclusions derived from this analysis confirm that models and data agree on the large-scale spatial pattern but underestimate the magnitude of some observed changes and that large discrepancies are observed at the local scale. To further investigate the origin of those inconsistencies, we have constrained LOVECLIM to follow the signal recorded by the proxies selected in the compilation using a data assimilation method based on a particle filter. In one simulation, all the 50 proxies are used while in the other two, only the continental or oceanic proxies constrains the model results. This assimilation improves the consistency between model results and the reconstructions. In particular, this is achieved in a robust way in all the experiments through a strengthening of the westerlies at mid-latitude that warms up the Northern Europe. Furthermore, the comparison of the LOVECLIM simulations with and without data assimilation has also objectively identified 16 proxies whose reconstructed signal is either incompatible with the one recorded by some other proxies or with model physics.
The large-scale impact of climate change to Mississippi flood hazard in New Orleans
Authors: Driessen T. L. A. , van Ledden M.
Published: July 2013

Abstract. The objective of this paper was to describe the impact of climate change on the Mississippi River flood hazard in the New Orleans area. This city has a unique flood risk management challenge, heavily influenced by climate change, since it faces flood hazards from multiple geographical locations (e.g. Lake Pontchartrain and Mississippi River) and multiple sources (hurricane, river, rainfall). Also the low elevation and significant subsidence rate of the Greater New Orleans area poses a high risk and challenges the water management of this urban area. Its vulnerability to flooding became dramatically apparent during Hurricane Katrina in 2005 with huge economic losses and a large number of casualties. A SOBEK Rural 1DFLOW model was set up to simulate the general hydrodynamics. This model included the two important spillways that are operated during high flow conditions. A weighted multi-criteria calibration procedure was performed to calibrate the model for high flows. Validation for floods in 2011 indicated a reasonable performance for high flows and clearly demonstrated the influence of the spillways. 32 different scenarios were defined which included the relatively large sea level rise and the changing discharge regime that is expected due to climate change. The impact of these scenarios on the water levels near New Orleans were analysed by the hydrodynamic model. Results showed that during high flows New Orleans will not be affected by varying discharge regimes, since the presence of the spillways ensures a constant discharge through the city. In contrary, sea level rise is expected to push water levels upwards. The effect of sea level rise will be noticeable even more than 470 km upstream. Climate change impacts necessitate a more frequent use of the spillways and opening strategies that are based on stages.
Large-sample hydrology: a need to balance depth with breadth
Authors: Gupta H. V. , Perrin C. , Kumar R. , Blöschl G. , Clark M. , Montanari A. , Andréassian V.
Published: July 2013

Abstract. A "Holy Grail" of hydrology is to understand catchment processes well enough that models can provide detailed simulations across a variety of hydrologic settings at multiple spatio-temporal scales, and under changing environmental conditions. Clearly, this cannot be achieved only through intensive place-based investigation at a small number of heavily instrumented catchments, or by regionalization methods that do not fully exploit our understanding of hydrology. Here, we discuss the need to actively promote and pursue the use of a "large catchment sample" approach to modeling the rainfall-runoff process, thereby balancing depth with breadth. We examine the history of such investigations, discuss the benefits (improved process understanding resulting in robustness of prediction at ungaged locations and under change), examine some practical challenges to implementation and, finally, provide perspectives on issues that need to be taken into account as we move forward. Ultimately, our objective is to provoke further discussion and participation, and to promote a potentially important theme for the upcoming IAHS Scientific Decade entitled "Panta Rhei".
A NOVEL IMAGE REGISTRATION ALGORITHM FOR SAR AND OPTICAL IMAGES BASED ON VIRTUAL POINTS
Authors: Ai C. , Feng T. , Wang J. , Zhang S.
Published: July 2013

Abstract. Optical image is rich in spectral information, while SAR instrument can work in both day and night and obtain images through fog and clouds. Combination of these two types of complementary images shows the great advantages of better image interpretation. Image registration is an inevitable and critical problem for the applications of multi-source remote sensing images, such as image fusion, pattern recognition and change detection. However, the different characteristics between SAR and optical images, which are due to the difference in imaging mechanism and the speckle noises in SAR image, bring great challenges to the multi-source image registration. Therefore, a novel image registration algorithm based on the virtual points, derived from the corresponding region features, is proposed in this paper. Firstly, image classification methods are adopted to extract closed regions from SAR and optical images respectively. Secondly, corresponding region features are matched by constructing cost function with rotate invariant region descriptors such as area, perimeter, and the length of major and minor axes. Thirdly, virtual points derived from corresponding region features, such as the centroids, endpoints and cross points of major and minor axes, are used to calculate initial registration parameters. Finally, the parameters are corrected by an iterative calculation, which will be terminated when the overlap of corresponding region features reaches its maximum. In the experiment, WordView-2 and Radasat-2 with 0.5 m and 4.7 m spatial resolution respectively, obtained in August 2010 in Suzhou, are used to test the registration method. It is shown that the multi-source image registration algorithm presented above is effective, and the accuracy of registration is up to pixel level.
URBAN EMERGENCY EVACUATION DATA FUSION BASED ON "ONE MAP"
Authors: Wen B. , Sun Q. , Chen H.
Published: July 2013

Abstract. Urban emergency evacuation is a complicated systems engineering, which relates to many departments. How to fuse different scale, different format, different mathematical base spatial data effectively provided by such as police, fire protection, medical and health organization, traffic, emergency rescue and so on is a realistic matter that decision-makers are faced with. This paper analyses the characteristic of multisource spatial data in urban emergency evacuation and assorts it, brings forward the fusion strategy of multisource spatial data based on "one map", designs the frame of multisource spatial data fusion, makes an experiment in the end. The experiment indicates that the efficiency and level of urban emergency evacuation decision-making advances remarkably supported by multisource spatial data fusion.
CLASSIFICATION OF POLARIMETRIC SAR IMAGE BASED ON THE SUBSPACE METHOD
Authors: Xu J. , Li Z. , Tian B. , Chen Q. , Zhang P.
Published: July 2013

Abstract. Land cover classification is one of the most significant applications in remote sensing. Compared to optical sensing technologies, synthetic aperture radar (SAR) can penetrate through clouds and have all-weather capabilities. Therefore, land cover classification for SAR image is important in remote sensing. The subspace method is a novel method for the SAR data, which reduces data dimensionality by incorporating feature extraction into the classification process. This paper uses the averaged learning subspace method (ALSM) method that can be applied to the fully polarimetric SAR image for classification. The ALSM algorithm integrates three-component decomposition, eigenvalue/eigenvector decomposition and textural features derived from the gray-level cooccurrence matrix (GLCM). The study site, locates in the Dingxing county, in Hebei Province, China. We compare the subspace method with the traditional supervised Wishart classification. By conducting experiments on the fully polarimetric Radarsat-2 image, we conclude the proposed method yield higher classification accuracy. Therefore, the ALSM classification method is a feasible and alternative method for SAR image.
A HIGH-EFFICIENCY FUSION METHOD OF MULTI-SPECTRAL IMAGE AND PANCHROMATIC IMAGE
Authors: Xue X. , Wang J. P. , Wang H. , Xiang F.
Published: July 2013

Abstract. With the development of modern remote sensing technology, a variety of earth observation satellites could continue to tremendously provide image data of different spatial resolution, time resolution, spectral resolution remote sensing, and the remote sensing data obtained is increasing with great capacity, which forms multi-source image pyramid in the same area. To play the advantages of a variety of remote sensing data, the application of remote sensing image fusion is a very important choice. When remote sensing data is large, fusion is large in computing capacity and time-consuming, so it is difficult to carry out rapid, real-time fusion. However, in some remote sensing applications, such as disaster prevention and relief quick, etc., timely fusion is required. Based on image fusion method of principal component analysis (PCA) and the advantage of parallel computing, a high-efficiency fusion method of multi-spectral image and panchromatic image is proposed. Beijing-1 Micro-satellite is a high-performance small satellite for earth observation，With Beijing-1 Micro-satellite remote sensing images as the experimental data, it is proved that good fusion results of multi-spectral image and panchromatic image can be obtained with the proposed method, and the fusion speed is also fast. At the same time, some measures of improving the efficiency of parallel image fusion are also discussed.
MONITORING THE CHANGES OF LAKES IN THE SOURCE REGION OF THREE RIVERS WITH REMOTE SENSING DATA FROM 1976 TO 2009
Authors: Chengfeng L. , Yuan W. , Haoyan J. , Zhengjun L.
Published: July 2013

Abstract. As the birthplace of Yangtze River, the Yellow River and Lancang Rive, Source Region of Three Rivers (SRTR) is an important resource for fresh water supplement in China. SRTR also has very obvious ecological function which forms ecological security barrier for China's Qinghai-Tibet plateau. The inland lakes here play an important role for the water cycle in the plateau. The monitoring results were extracted with TM data from 1976 to 2009. The results show that from 1976 to 2009 the lakes' area in SRTR dropped first and then expanded with 2000 as sector. The lakes area was 6778 km2 in 2009, about 1.90% of the whole region, and increased than 1976 by 133.15 km2. Most of the large lakes above 80 km2 have the same change trend. The expanded lakes increased in number gradually, while the changes in the amplitude and time characteristics were different. From 1976 to 2000, the number of new lakes increased while died lakes dropped; and from 2000 to 2009 it is just on the contrary. In the study the index of lake change trend (ILCT) was adopted to contrast lake atrophy condition. With ILCT 24.55 there is an expansion trend for the lakes in SRTR during the last 35 years. The lakes with ILCT's absolute value greater than 1 were those merged with or disconnected from surrounding smaller lakes. Here the precipitation and snow melt are main supplies for the lakes. The change of lakes' area has well correlated with precipitation, and weak correlated with temperature from 1976 to 2009. But from 2000 to 2009, there has a strong correlation with precipitation, temperature. All these show from the side that the precipitation and snow melt are important factors to influence the lakes’ change. The lakes have the coordination function for the good ecological environment in the region. The conclusions from the study can provide references in response to climate change research and rational utilization of water resources in SRTR.
THE DEVELOPMENT AND INDUSTRIALIZATION RECOMMENDATION OF CURRENT AERIAL REMOTE SENSING TECHNOLOGY
Authors: Hong Z.
Published: July 2013

Abstract. At present, the research development and industrialization of aerial remote sensing technology in China are faced with enormous requirements and developing chance. It is the strategic selection for remote sensing technology to perfect the construction of remote sensing technology system, implement the three strategies of science and technology development, standardize and improve the producing ability of remote sensing products, and make the remote sensing technology become a kind of industries. Based on industry economics principle and the characteristics of aerial remote sensing technology, this paper put forward the suggestions on technological development, industrialization, and market competition of aerial remote sensing industrialization.
THE APPLICATION OF REMOTE SENSING AND AERO-GEOPHYSICS DATA FUSION ON METALLOGENIC PROGNOSIS IN QIMANTAGE OF EAST KUNLUN MONTAIN AREA
Authors: Jia W. , Zhang H. , Lin J. , Zhao H.
Published: July 2013

Abstract. Based on west of Qimantage of East Kunlun mountain area, takes advantage of ASTER data, according to the altered mineral spectral characteristics, remote sensing alteration information is extracted. Incorporation the anomaly extraction results with high-precision aero geophysical data processing results, a multiple resource information fusion model is proposed. The fusion model of two totally different type of data which is a special attention in geospatial academia now, which can improve the accuracy of geospatial data application. our fusion result analysis show that it provides information more accurately and sufficiently than separate geospatial data application. The fusion can provide decision-making support for mineral resources prediction.
INTEGRATING MULTI-SOURCE IMAGERY DATA IN A GIS SYSTEM
Authors: Liu Q.
Published: July 2013

Abstract. More and more volumes of high quality imagery data are becoming available than ever and it brings a challenge to the industry on how to integrate data from multi-sources effectively and timely to extract information of improved accuracy for a widespread field of applications. Over the past decade, we have witnessed the advance of tightening integration of imagery data in a GIS system. Imagery data takes advantage of the geodatabase management architecture and enriches the GIS system. Empowered with intuitive user interface and advanced tools, ArcGIS provides a great platform for one-stop integration of multi-source, multi-resolution, and multi-temporal imagery data with pre-processing, managing, visualizing, analyzing and sharing functionalities. This paper will discuss some of the core imagery capabilities in ArcGIS including interactive and automatic data correction and registration, intelligent and versatile data models for data crawling, on-the-fly data processing, and data disseminating.
A New Calibration Method of Airborne Interferometric SAR
Authors: Mengmeng W. , Guoman H.
Published: July 2013

Abstract. The accuracy of system parameters is one of the key factors that limit the precision of DEM from airborne dual-antenna InSAR, so the interferometric calibration is of great significance. The traditional calibration method establishes the sensitivity equations to solve the different calibration parameters biases. This paper presents a new calibration method to improve the algorithm stability and suit for mass production. It introduces sensitivity analysis of every interferometric parameter and establishes a new model based on sensitivity equations. Finally, a set of airborne interferometric SAR data are adopted to do the experiment to illustrate the availability of the new method.
Mapping local singularities using magnetic data to investigate the volcanic rocks of the Qikou depression, Dagang oilfield, eastern China
Authors: Chen G. , Cheng Q. , Liu T. , Yang Y.
Published: July 2013

Abstract. The spatial structural characteristics of geological anomaly, including singularity and self-similarity, can be analysed using fractal or multifractal modelling. Here we apply the multifractal methods to potential fields to demonstrate that singularities can characterise geological bodies, including rock density and magnetic susceptibility. In addition to enhancing weak gravity and magnetic anomalies with respect to either strong or weak background levels, the local singularity index (α ≈ 2) can be used to delineate the edges of geological bodies. Two models were established to evaluate the effectiveness of mapping singularities for extracting weak anomalies and delineating edges of buried geological bodies. The Qikou depression of the Dagang oilfield in eastern China has been chosen as a study area for demonstrating the extraction of weak anomalies of volcanic rocks, using the singularity mapping technique to analyse complex magnetic anomalies caused by complex geological background. The results have shown that the singularities of magnetic data mapped in the paper are associated with buried volcanic rocks, which have been verified by both drilling and seismic survey, and the S–N and E–W faults in the region. The targets delineated for deeply seated faults and volcanic rocks in the Qikou depression should be further investigated for the potential application in undiscovered oil and gas reservoirs exploration.
Visual Servoing Tracking Control of a Ball and Plate System: Design, Implementation and Experimental Validation
Authors: Ho Ming-Tzu , Rizal Yusie , Chu Li-Ming
Published: July 2013

This paper presents the design, implementation and validation of real-time visual servoing tracking control for a ball and plate system. The position of the ball is measured with a machine vision system. The image processing algorithms of the machine vision system are pipelined and implemented on a field programmable gate array (FPGA) device to meet real-time constraints. A detailed dynamic model of the system is derived for the simulation study. By neglecting the high-order coupling terms, the ball and plate system model is simplified into two decoupled ball and beam systems, and an approximate input-output feedback linearization approach is then used to design the controller for trajectory tracking. The designed control law is implemented on a digital signal processor (DSP). The validity of the performance of the developed control system is investigated through simulation and experimental studies. Experimental results show that the designed system functions well with reasonable agreement with simulations.
Approaching Behaviour Monitor and Vibration Indication in Developing a General Moving Object Alarm System (GMOAS)
Authors: Dong Haiwei , Giakoumidis Nikolas , Figueroa Nadia , Mavridis Nikolaos
Published: July 2013

People who suffer from hearing impairment caused by illness, age or extremely noisy environments are constantly in danger of being hit or knocked down by fast moving objects behind them when they have no companion or augmented sensory system to warn them. In this paper, we propose the General Moving Object Alarm System (GMOAS), a system focused on aiding the safe mobility of people under these circumstances. The GMOAS is a wearable haptic device that consists of two main subsystems: (i) a moving object monitoring subsystem that uses laser range data to detect and track approaching objects, and (ii) an alarm subsystem that warns the user of possibly dangerous approaching objects by triggering tactile vibrations on an “alarm necklace”. For moving object monitoring, we propose a simple yet efficient solution to monitor the approaching behavior of objects. Compared with previous work in motion detection and tracking, we are not interested in specific objects but any type of approaching object that might harm the user. To this extent, we define a boundary in the laser range data where the objects are monitored. Within this boundary a fan-shape grid is constructed to obtain an evenly distributed spatial partitioning of the data. These partitions are efficiently clustered into continuous objects which are then tracked through time using an object association algorithm based on updating a deviation matrix that represents angle, distance and size variations of the objects. The speed of the tracked objects is monitored throughout the algorithm. When the speed of an approaching object surpasses the safety threshold, the alarm necklace is triggered indicating the approaching direction of the fast moving object. The alarm necklace is equipped with three motors that can indicate five directions with respect to the user: left, back, right, left-back and right-back. We performed three types of outdoor experiments (object passing, approaching and crossing) that empirically verified the effectiveness of our proposed algorithm. Furthermore, we analyzed the time and direction response based on neck vibrations. The statistical analysis (including hypothesis test) suggests that the chosen alarm necklace can provide a rapid indication for a quick human response.
Optimization-Based Design of a Small Pneumatic-Actuator-Driven Parallel Mechanism for a Shoulder Prosthetic Arm with Statics and Spatial Accessibility Evaluation
Authors: Sekine Masashi , Sugimori Kento , Gonzalez Jose , Yu Wenwei
Published: July 2013

Human arms undertake most tasks in the activities of daily living (ADLs). When designing shoulder prostheses for high-level upper-limb amputees, we should consider not only how to realize high degrees of freedom under weight and shape constraints but also the user's individual task space in daily life. An appropriate mechanical structure that can make full use of state-of-the-art actuators and a scheme to optimize the structure's configuration to match users' spatial access and manipulability requirements are essential. In our previous research, a small pneumatic-actuator-driven parallel mechanism was studied as a shoulder prosthetic arm. In this paper, a systematic procedure is proposed to design the mechanism for a shoulder prosthesis considering force and spatial accessibility. This procedure includes ADL measurements to obtain the task spaces for individual subjects, indexes to evaluate the force and spatial accessibility and an optimization process based on kinematic and statics models. With this approach, the parallel mechanism was optimized for one important ADL task group, considering the trade-off between its required force and working space. Moreover, it was confirmed that the proposed design procedure could find solutions for various spatial specifications. That is, the approach could be used for individualized shoulder prosthesis design.
Geostatistical Prediction of Ocean Outfall Plume Characteristics Based on an Autonomous Underwater Vehicle
Authors: Ramos Patrícia Alexandra Gregório
Published: July 2013

Geostatistics has been successfully used to analyse and characterize the spatial variability of environmental properties. Besides providing estimated values at unsampled locations, geostatistics measures the accuracy of the estimate, which is a significant advantage over traditional methods used to assess pollution. This work uses universal block kriging to model and map the spatial distribution of salinity measurements gathered by an Autonomous Underwater Vehicle in a sea outfall monitoring campaign. The aim is to distinguish the effluent plume from the receiving waters, characterizing its spatial variability in the vicinity of the discharge and estimating dilution. The results demonstrate that geostatistical methodology can provide good estimates of the dispersion of effluents, which are valuable in assessing the environmental impact and managing sea outfalls. Moreover, since accurate measurements of the plume's dilution are rare, these studies may be very helpful in the future to validate dispersion models.
Perceived Effectiveness of Information Technology Governance Initiatives Among IT Practitioners
Authors: Teo Wil Ly , Manaf Azizah Abd , Choong Phyllis Lai Fong
Published: July 2013

Information Technology (IT) governance has risen in importance in recent years, driven by various trends in IT development. With rapid growth in the country and the globalization of the IT sector, there is growing interest in IT governance in Malaysia. This study aims to explore whether IT practitioners with different job functions, education levels, education areas of specialization, certifications and experience levels have different perceptions of IT governance effectiveness in their organization. The results reveal differences in perceived IT governance effectiveness between different job function groups, but not between groups with different education levels, certification or experience levels. The findings for education area of specialization are not conclusive. The findings of this study will help IT managers to identify areas of focus to maximize effectiveness of IT governance initiatives through their IT staff. The implications of the findings are discussed at the end of the paper.
Minimizing Warehouse Space with a Dedicated Storage Policy
Authors: Fumi Andrea , Scarabotti Laura , Schiraldi Massimiliano M.
Published: July 2013

Given the increasingly significant impact of an efficient product-location strategy on warehouses' performance from a service level and operational costs perspective, this paper presents a possible operations research-oriented solution to provide a tangible reduction of the overall required warehousing space, thereby translating the storage location assignment problem (SLAP) into a vertex colouring problem (VCP). Developing the topic of their previous work on the development of an effective multi-product slot-code optimization heuristic, the authors focused on finding a cost-effective way to solve the SLAP through a mathematical-optimization approach. The formulation validation on a real industrial case showed its high optimization potential, and benchmarking simulations displayed performances significantly close to the best theoretical case. Indeed, the optimized value results were definitively close to the SLAP lower bound calculated assuming a randomized storage policy which, distinct from the developed solution, must inevitably be supported by warehouse management system software. On the contrary, the proposed methodology relies upon a dedicated storage policy, which is easily implementable by companies of all sizes without the need for investing in expensive IT tools.
The Effect of Slot-Code Optimization in Warehouse Order Picking
Authors: Fumi Andrea , Scarabotti Laura , Schiraldi Massimiliano M.
Published: July 2013

This work presents the effect, in terms of travel distance and material handling time reductions, of an optimal rather than a uniform item allocation in one-block picking warehouses, both with and without the use of a simple picking heuristic. Since developing efficient product-location strategies represents a critical issue in Operations Management, due to the impact on warehouse performance in terms of both service level and operation costs, this paper focuses on an effective quantification of obtainable travel time reductions, obtaining a significant result for manufacturing companies aiming to determine the most appropriate material handling resource configuration. Building on previous work on the effect of slot-code optimization on travel times in single/dual command cycles, the authors broaden the scope to include the most general picking case, thus widening the range of applicability and realising former suggestions for future research.
Identification and Isolation of Small CD44-Negative Mesenchymal Stem/Progenitor Cells From Human Bone Marrow Using Elutriation and Polychromatic Flow Cytometry
Authors: Hall Sean R.R. , Jiang Yajuan , Leary Elizabeth , Yavanian Greg , Eminli Sarah , O'Neill David W. , Marasco Wayne A.
Published: July 2013

The method of isolation of bone marrow (BM) mesenchymal stem/stromal cells (MSCs) is a limiting factor in their study and therapeutic use. MSCs are typically expanded from BM cells selected on the basis of their adherence to plastic, which results in a heterogeneous population of cells. Prospective identification of the antigenic profile of the MSC population(s) in BM that gives rise to cells with MSC activity in vitro would allow the preparation of very pure populations of MSCs for research or clinical use. To address this issue, we used polychromatic flow cytometry and counterflow centrifugal elutriation to identify a phenotypically distinct population of mesenchymal stem/progenitor cells (MSPCs) within human BM. The MSPC activity resided within a population of rare, small CD45−CD73+CD90+CD105+ cells that lack CD44, an antigen that is highly expressed on culture-expanded MSCs. In culture, these MSPCs adhere to plastic, rapidly proliferate, and acquire CD44 expression. They form colony forming units-fibroblast and are able to differentiate into osteoblasts, chondrocytes, and adipocytes under defined in vitro conditions. Their acquired expression of CD44 can be partially downregulated by treatment with recombinant human granulocyte-colony stimulating factor, a response not found in BM-MSCs derived from conventional plastic adherence methods. These observations indicate that MSPCs within human BM are rare, small CD45−CD73+CD90+CD105+ cells that lack expression of CD44. These MSPCs give rise to MSCs that have phenotypic and functional properties that are distinct from those of BM-MSCs purified by plastic adherence.
Blood Cell-Derived Induced Pluripotent Stem Cells Free of Reprogramming Factors Generated by Sendai Viral Vectors
Authors: Ye Lin , Muench Marcus O. , Fusaki Noemi , Beyer Ashley I. , Wang Jiaming , Qi Zhongxia , Yu Jingwei , Kan Yuet Wai
Published: July 2013

The discovery of induced pluripotent stem cells (iPSCs) holds great promise for regenerative medicine since it is possible to produce patient-specific pluripotent stem cells from affected individuals for potential autologous treatment. Using nonintegrating cytoplasmic Sendai viral vectors, we generated iPSCs efficiently from adult mobilized CD34+ and peripheral blood mononuclear cells. After 5–8 passages, the Sendai viral genome could not be detected by real-time quantitative reverse transcription-polymerase chain reaction. Using the spin embryoid body method, we showed that these blood cell-derived iPSCs could efficiently be differentiated into hematopoietic stem and progenitor cells without the need of coculture with either mouse or human stromal cells. We obtained up to 40% CD34+ of which ∼25% were CD34+/CD43+ hematopoietic precursors that could readily be differentiated into mature blood cells. Our study demonstrated a reproducible protocol for reprogramming blood cells into transgene-free iPSCs by the Sendai viral vector method. Maintenance of the genomic integrity of iPSCs without integration of exogenous DNA should allow the development of therapeutic-grade stem cells for regenerative medicine.
Amorphous Indium Gallium Zinc Oxide Thin-Film Transistors with a Low-Temperature Polymeric Gate Dielectric on a Flexible Substrate
Authors: Hyung Gun Woo , Park Jaehoon , Wang Jian-Xun , Lee Ho Won , Li Zhao-Hui , Koo Ja-Ryong , Kwon Sang Jik , Cho Eou-Sik , Kim Woo Young , Kim Young Kwan
Published: July 2013

Amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) with a solution-processed polymeric gate dielectric of cross-linked poly(4-vinylphenol) (c-PVP) film were fabricated on a poly(ethylene terephthalate) (PET) substrate on which an a-IGZO film, as the active channel layer, was deposited by radio frequency (RF) sputtering. The entire TFT fabrication process was carried out at a temperature below 110 °C. The device exhibited an on/off ratio of 1.5×106 and a high field-effect mobility of 10.2 cm2 V-1 s-1, which is, to our knowledge, the best result ever achieved among a-IGZO TFTs with polymeric gate dielectrics on a plastic substrate.
Bidirectional Two-Terminal Switching Device with Metal–Semiconductor–Semiconductor Structures for 4F2 Spin-Transfer-Torque Magnetoresistance Random Access Memory Cell
Authors: Kil Gyu-Hyun , Song Yun-Heub
Published: July 2013

We proposed a novel bidirectional two-terminal selective device for realizing a 4F2 cell size for spin-transfer-torque magnetoresistance random access memory (STT-MRAM). The proposed switching device is composed of a Schottky-barrier contact and a PN junction with a metal–semiconductor–semiconductor (M/S/S) structure. The proposed M/S/S switching device provides a current density of over 106 A/cm2, which is sufficient to write the magnetic tunnel junction (MTJ), and a bilateral current flow using a punch through with an extended depletion region at a junction. Furthermore, we investigated its switching characteristics by comparing parameters such as doping profile and junction length. From this work, it is expected that an M/S/S structure will be a promising switching device for STT MRAM.
Impact of Source/Drain Junction and Cell Shape on Random Telegraph Noise in NAND Flash Memory
Authors: Li Fu-Hai , Shirota Riichiro
Published: July 2013

A comprehensive numerical study of threshold voltage fluctuation (ΔV
T) in scaled NAND flash memory caused by random telegraph noise (RTN) and discrete dopant fluctuation (RDF) in both the channel and the cell-to-cell space [source/drain (S/D)] region was carried out. Following a three-dimensional (3D) Monte Carlo (MC) procedure, the statistical distribution of ΔV
T is estimated, considering the effects of both the random placement of discrete doping atoms and a discrete single trap at the tunnel oxide/substrate interface. The result demonstrates the significant influence of the doping in the S/D regions. For the cells with and without an S/D junction, the electron concentration in the S/D region is determined by the pass voltage of the unselected cell (V
pass) and the neighboring cell V
T (V
T(n)), owing to the fringing fields of neighboring floating gates (FGs). As a result, ΔV
T increases in the S/D region as V
pass - V
T(n) decreases. The fluctuation amplitude strongly depends on the [single-trap RTN] position along the cell length (L) and width (W) directions. For the cell shape with rounding of the active area (AA) at the shallow trench isolation (STI) edge, the results indicate that the high ΔV
T area moves from the AA edge towards the center area along the W-direction.
Effect of Plasma–Nitric Acid Treatment on the Electrical Conductivity of Flexible Transparent Conductive Films
Authors: Pham Viet Phuong , Jo Young Woo , Oh Jong Sik , Kim Soo Min , Park Jin Woo , Kim Sung Hee , Jhon Myung S. , Yeom Geun Young
Published: July 2013

A flexible transparent electrically conductive film (FTCF) was formed on a poly(ethylene terephthalate) film by spraying single-walled carbon nanotubes dispersed with sodium dodecyl benzene sulfonate in water and, to improve the electrical conductivity of FTCF, the effect on plasma treatment followed by nitric acid treatment was investigated. The Ar plasma treatment was effective in dissociating the surfactant and removing impurities attached to the surface of the carbon nanotubes (CNTs). Therefore, through a cyclic treatment composed of an Ar plasma treatment and nitric acid treatment, more effective removal of surfactant and impurities attached to the spray-coated CNTs could be obtained than a cyclic treatment without the plasma treatment. With the optimized cyclic treatment, the sheet resistance (Ωs) of the spray-coated CNTs could be decreased up to 45% by removing most of the surfactant and impurities. Using the repeated cyclic treatment, the FTCF having the Ωs of 160 Ω/□ at 81.5% optical transmittance at the wavelength of 550 nm could be obtained.
Effective Anchoring Energy of Nematic Liquid Crystals on Stripe Anchoring Patterns
Authors: Kim Jong-Hyun
Published: July 2013

Anchoring energy is a key factor that controls the response of liquid crystals to an external field. Nonuniform alignment in orientation and anchoring energy is now being developed to realize smart functions like multistability. Here, we numerically calculate the effective anchoring energy of a stripe anchoring pattern. We use the concepts of extrapolation length and virtually extended cell gap by the extrapolation length to calculate the distortion of the director. We formulated an empirical equation that shows the effective anchoring energy. The effective anchoring energy determined by this equation is close to the calculated effective anchoring in a wide range.
Control of Dip Shape in Photonic Nanostructures by Maskless Wet-Etching Process and Its Impact on Optical Properties
Authors: Hoshi Yusuke , Pan Wugen , Kiguchi Takanori , Ooi Kazufumi , Tayagaki Takeshi , Usami Noritaka
Published: July 2013

We demonstrate that maskless wet etching of self-assembled Ge quantum dot (QD) multilayers permits us to realize large-area photonic nanostructures, and their dip shape can be tuned by controlling structural parameters in the Ge QD multilayers. It is found that the reduction of Si spacer thickness brings about an increase in the dip depth and causes a reduction of reflectance at all the wavelengths. Furthermore, the presence of photonic nanostructures was shown to lead to the enhancement of photoluminescence intensity from Ge QDs. These results demonstrate that photonic nanostructures formed by this technique can enhance optical absorption in Ge QD multilayers.
How Important Is the Influence of Poisson Potential on the Band Structures of Terahertz Quantum-Cascade Lasers?
Authors: Li Hua , Hirakawa Kazuhiko , Cao Jun-Cheng
Published: July 2013

We have investigated the importance of Poisson potential induced by intentional doping on the band structures of two-well scattering injection terahertz quantum-cascade lasers, using a self-consistent Schrödinger–Poisson method. The calculated results show that the increase in doping density leads to a dramatic increase in Poisson potential, i.e., every 1010cm-2increase in sheet density brings about 0.58 meV Poisson potential. As the doping is increased from 3.6×1010to 3.0×1011cm-2, the calculated optical transition energy shows a significant shift (27% increase). By taking account of the free carrier absorption loss and the scattering injection efficiency, a narrow region doping in the wide GaAs well is recommended to minimize the influence of Poisson potential on the band structures.