bluuebunny/crossref_metadata_2025 huggingface dataset:
A new variant of saponite‐rich micrometeorites recovered from recent Antarctic snowfall
Authors: SAKAMOTO Kanako , NAKAMURA Tomoki , NOGUCHI Takaaki , TSUCHIYAMA Akira
Published: May 2010

Abstract– Eight saponite‐rich micrometeorites with very similar mineralogy were found from the recent surface snow in Antarctica. They might have come to Earth as a larger meteoroid and broke up into pieces on Earth, because they were recovered from the same layer and the same location of the snow. Synchrotron X‐ray diffraction (XRD) analysis indicates that saponite, Mg‐Fe carbonate, and pyrrhotite are major phases and serpentine, magnetite, and pentlandite are minor phases. Anhydrous silicates are entirely absent from all micrometeorites, suggesting that their parental object has undergone heavy aqueous alteration. Saponite/serpentine ratios are higher than in the Orgueil CI chondrite and are similar to the Tagish Lake carbonaceous chondrite. Transmission electron microscope (TEM) observation indicates that serpentine occupies core regions of fine‐grained saponite, pyrrhotite has a low‐Ni concentration, and Mg‐Fe carbonate shows unique concentric ring structures and has a mean molar Mg/(Mg + Fe) ratio of 0.7. Comparison of the mineralogy to hydrated chondrites and interplanetary dust particles (IDPs) suggests that the micrometeorites are most similar to the carbonate‐poor lithology of the Tagish Lake carbonaceous chondrite and some hydrous IDPs, but they show a carbonate mineralogy dissimilar to any primitive chondritic materials. Therefore, they are a new variant of saponite‐rich micrometeorite extracted from a primitive hydrous asteroid and recently accreted to Antarctica.
Feldspar in type 4–6 ordinary chondrites: Metamorphic processing on the H and LL chondrite parent bodies
Authors: KOVACH Hollis A. , JONES Rhian H.
Published: May 2010

Abstract– We have carried out a study of feldspar compositions in a suite of H and LL ordinary chondrites, of petrologic types 4, 5, and 6, in order to examine the process of recrystallization and equilibration of feldspar as the degree of metamorphism increases. In the H chondrites, there is little variation in feldspar compositions among the petrologic types, suggesting that homogenization of chondrule mesostasis, from which feldspar is presumed to have crystallized, occurred before feldspar crystallization began. The LL chondrites we studied are more complex. In Bjurböle (L/LL4), plagioclase in individual relict chondrules has distinct compositions, with a range of An/Ab ratios and low Or contents. This heterogeneity is most likely attributable to original compositional heterogeneity among chondrule mesostases: localized recrystallization of mesostasis must have occurred before diffusional equilibration took place. In Tuxtuac (LL5), the An/Ab ratio of plagioclase is more homogeneous, and plagioclase includes a significant Or component. In addition, we observe what appears to be exsolution of K‐feldspar from albitic host grains. In Saint Séverin (LL6), the An/Ab ratio of plagioclase is homogeneous, but plagioclase compositions show a range of Or contents, corresponding to a patchy distribution of K in individual feldspar grains. The observations in these LL chondrites are difficult to interpret with a simple model of progressive equilibration with increasing petrologic type. We suggest that the current criteria for assigning petrologic types are poorly defined: it is possible that the assigned petrologic types of these chondrites do not correlate with their peak temperatures. We propose that feldspar compositions might record conditions during the heating stage of metamorphism, and that the early stages of metamorphism may have occurred in the presence of fluids, rather than under the dry conditions that are commonly assumed.
Growth and luminescence characterization of dilute InPN alloys grown by molecular beam epitaxy
Authors: Umeno K. , Furukawa Y. , Urakami N. , Mitsuyoshi S. , Yonezu H. , Wakahara A. , Ishikawa F. , Kondow M.
Published: May 2010

The authors have investigated the growth and luminescence properties of InPN alloys grown by solid-source molecular-beam epitaxy (MBE). The N composition increases with decreasing growth rate, P2∕In flux ratio, and growth temperature. In this work, the highest N composition obtained is 0.56% for the InPN sample. The appropriate growth temperature is around 400°C. However, the growth-temperature window of the InPN alloys having a smooth surface is very narrow. In order to obtain photoluminescence (PL) emission from the InPN samples grown by solid-source MBE, InPN alloys must be grown under the condition of lower-plasma power since the grown-in point defects induced by N plasma are reduced. Thermal treatment is effective to improve the luminescence efficiency of InPN alloys, and the appropriate annealing temperature is around 700°C. However, the S-shape behavior is observed only for the annealed InPN samples by atomic rearrangements during thermal treatment, which is attributed to the weaker bond strength of In–N than that of In–P. In addition, the PL peak energy corresponding to the near-band edge emission redshifts with increasing annealing temperature. These results indicate that the luminescence properties of InPN alloys are unique in contrast to other dilute nitrides such as GaAsN and GaPN alloys.
Fabrication of complex three-dimensional nanostructures using focused ion beam and nanomanipulation
Authors: Jeon Jangbae , Floresca Herman Carlo , Kim M. J.
Published: May 2010

In this article, the authors present a fabrication/assembly method that grants the ability to create complex three-dimensional (3D) nanostructures. This method uses a combination of micro- and nanomachining capabilities with a focused ion beam (FIB) and six degrees of freedom (DOFs) 3D nanomanipulator. A dual beam of scanning electron microscope and a FIB system was used to ion beam mill a silicon piece in order to create tethered structures. Various 3D structures were further processed by the ion beam milling process and platinum chemical vapor deposition unit to form sub-100-nm features. The gas assisted deposition system was used to create a convex shape on the nanoairplane using the gray scale image digital patterning system. The six DOFs nanomanipulator was used to pick, rotate, and place the nanoflags onto the FIB defined Texas and United States maps made by the FIB. In addition, a multiwalled carbon nanotube was used as a flag pole, and then it was attached to a scanning probe microscope tip. The tip was then actuated to tapping mode to demonstrate the nanoflag waving. The assembly technique was also utilized to manipulate individual 100 nm polystyrene microspheres.
Depth profile analysis of helium in silicon with high-resolution elastic recoil detection analysis
Authors: Tomita Mitsuhiro , Akutsu Haruko , Oshima Yasunori , Sato Nobutaka , Mure Shoichi , Fukuyama Hirofumi , Ichihara Chikara
Published: May 2010

Helium depth profiling in silicon was investigated by high-resolution elastic recoil detection analysis (HERDA) using a high-resolution Rutherford backscattering spectrometry system. A 0.7 μm Mylar film was installed in front of the detector of this system to eliminate the background signals originating from incident nitrogen ions scattered at the sample surface. This film successfully eliminated the background signals without the loss of helium signals or serious degradation of the depth resolution. The HERDA has several attractive features for helium depth profiling in silicon, including high sensitivity (detection limit of 1 at. % or less), excellent depth resolution (less than 1 nm), and good quantitative accuracy, giving it significant advantages over other surface analysis methods such as secondary ion mass spectrometry.
Zn(II), Co(II) and Ni(II) complexes of a phosphorylthiourea derivative of 4-[(EtO)2P(O)CH2]-C6H4-NHC(S)NHP(O)(OiPr)2
Authors: Babashkina Maria G. , Safin Damir A.
Published: May 2010

The reaction of O,O′-diisopropyl phosphorisothiocyanatidate, (iPrO)2P(O)NCS, with diethyl-(4-aminobenzyl)phosphonate leads to the new N-phosphorylated thiourea derivative, 4-[(EtO)2P(O)CH2]-C6H4NHC(S)NHP(O)(OiPr)2 (HL). The reaction of its potassium salt KL with Zn(II) or Co(II) in aqueous EtOH leads to the complexes of formulae M(L-O,S)2 (ZnL2, CoL2). The metal cation in all complexes is coordinated by two deprotonated ligands through the sulfur atoms of the thiocarbonyl groups and the oxygen atoms of the phosphoryl groups. The reaction of KL with Ni(II) leads to the formation of two types of complexes: the blue Ni(L-N,S)2 complex, where the ligand is coordinated through the nitrogen atom of the phosphorylamide group and the sulfur atom of the thiocarbonyl groups and light red Ni(L-O,S)2 complex with the same coordination of L– anion as it was observed for ZnL2 and CoL2. According to UV/Vis spectral data, it was established that the metal cation of Ni(L-N,S)2 is in a square-planar environment in CH2Cl2, whereas the Ni(L-O,S)2 complex shows features of tetrahedral complexes.
Rate coefficients for electron impact excitation, de-excitation and laser gain calculations of the excited ions Co(XVII) up to Br(XXV)
Authors: Younis W. O. , Allam S. H. , El-Sherbini Th. M.
Published: May 2010

Rate coefficients for electron impact excitation, de-excitation, and total depopulation of the excited ions Co(XVII) up to Br(XXV) of the sodium isoelectronic sequence are calculated according to the analytical formulas of Vriens and Smeets. A simple modification has been made by substituting effective quantum numbers in Vriens' formulas to be applicable for the ions under consideration. The energy levels and transition probabilities have been calculated using Hibbert's configuration interaction computer package (CIV3). Level population densities are then calculated by solving the coupled rate equations involving the 19 levels 1s22s22p6nl, where n = 3,4,5 and l = 0,1,2,3. Positive gain coefficients are displayed for the transitions 4p(2P1/2) → 4s(2S1/2) and 4p(2P3/2) → 4s(2S1/2) at three selected electron temperatures, namel, 1/4, 1/2, and 3/4 the ionization potential of each ion, respectively.
Hole transport parameters in a PTOPT based organic solar cell
Authors: Gebremichael Bizuneh , Tessema Genene
Published: May 2010

The photovoltaic and charge transport properties of solar cells whose active layer is made from poly[3-(4-octylphenyl)-2, 2′-bithiophene](PTOPT) was studied. Devices are prepared in a sandwich-type structure of the form Al/PTOPT/PEDOT:PSS/ITO. The diodes showed good rectification needed for the PV cell. The symmetric nature of the semilogarithmic J–V plot under dark and low temperature reveals that there is a unipolar charge injection in both sides of the electrodes. Based on the space charge limited region J–V data, it was possible to study the electric field dependence of the hole transport, which enable us to derive important parameters such as the zero field mobility (μo) and the field activation factor (γ).
Incorporating correlated error structures into mixed forest growth models: prediction and inference implications
Authors: Meng Shawn X. , Huang Shongming
Published: May 2010

Three nonlinear mixed models with and without incorporating a function to model the serial correlation were compared with regard to their predictive abilities. Results showed that accounting for the serial correlation using the spatial power (SP(POW)) or Toeplitz (TOEP(X)) functions resulted in a large reduction in serial correlation and improved the fit of the models. The improved model fits, however, did not unanimously translate into improved model predictions when evaluated under different scenarios. In many cases, the models with the simple independent and identically distributed structure outperformed the models with the SP(POW) or TOEP(X) structure in terms of the models’ predictive ability. We also examined the effect of adjusting predictions based on the prediction theorem within the nonlinear mixed modeling framework. It was shown that, in general, the adjusted predictions had lower errors than those without adjustment, but the differences were small in many cases. The adjustment with three prior measurements was better in predictions than the adjustment with only one or two prior measurements for the models with the TOEP(X) structure, but not for SP(POW). A theoretical derivation was developed to prove the insensitivity of the models with the SP(POW) structure to the number of prior measurements. The implications of accounting for serial correlation on model inference and model predictions were discussed.
Historical human influence on forest composition and structure in boreal Fennoscandia
Authors: Josefsson Torbjörn , Gunnarson Björn , Liedgren Lars , Bergman Ingela , Östlund Lars
Published: May 2010

In studies on natural dynamics, biodiversity and reference conditions legacies of preindustrial human land use are often neglected. In this study, using archaeology and dendrochronology combined with field surveys on present forest characteristics, we assessed the naturalness of a protected forest landscape and examined the role of indigenous peoples in shaping forest structure in the past. Our results show that the studied Scots pine ( Pinus sylvestris L.) forest conforms to the generally accepted impression of pristine forests and that it has a long history of human utilization. Areas with human presence over long time periods, especially in and near settlements, show significant differences in current forest characteristics compared with the rest of the landscape: the forest is younger (mean age 140–190 years compared with >300 years), the volumes of deadwood lower (8–13 m3·ha–1 compared with >20 m3·ha–1), and the tree species composition is substantially different from the surrounding forest. We suggest that these disparities are strongly linked to past land use and that indigenous people can alter ecosystems substantially and that the legacies of their activity may last for centuries. Consequently, in ecological research and conservation strategies, forest characteristics should always be considered in the light of their historical context.
Genetic control of kraft pulp yield inEucalyptus globulus
Authors: Stackpole Desmond J. , Vaillancourt René E. , Downes Geoffrey M. , Harwood Christopher E. , Potts Brad M.
Published: May 2010

Pulp yield is an important breeding objective for Eucalyptus globulus Labill., but evaluation of its genetic control and genetic correlations with other traits has been limited by its high assessment cost. We used near infrared spectroscopy to study genetic variation in pulp yield and other traits in a 16-year-old E. globulus trial. Pulp yield was predicted for 2165 trees from 467 open-pollinated families from 17 geographic subraces. Significant differences between subraces and between families within subraces were detected for all traits. The high pulp yield of southern Tasmanian subraces suggested that their economic worth was previously underestimated. The narrow-sense heritability of pulp yield was medium (0.40). The significant positive genetic correlation between pulp yield and diameter (0.52) was at odds with the generally neutral values reported. The average of the reported genetic correlations between pulp yield and basic density (0.50) was also at odds with our nonsignificant estimate. Pulp yield of the subraces increased with increasing latitude, producing a negative correlation with density (–0.58). The absence of genetic correlations within subraces between pulp yield and density suggests that the correlation may be an independent response of the two traits to the same or different selection gradients that vary with latitude.
Simulation of Mediterranean forest carbon pools under expected environmental scenarios
Authors: Chiesi M. , Moriondo M. , Maselli F. , Gardin L. , Fibbi L. , Bindi M. , Running S. W.
Published: May 2010

Simulating the effects of possible environmental changes on the forest carbon budget requires the use of calibrated and tested models of ecosystem processes. A recently proposed simulation approach based on the use of the BIOME-BGC model was applied to yield estimates of present carbon fluxes and pools in Tuscany forests (central Italy). After the validation of these estimates against existing ground data, the simulation approach was used to assess the impact of plausible climate changes (+2 °C and increased CO2 concentration) on forest carbon dynamics (gross primary production (GPP), net primary production (NPP), and relevant allocations). The results indicate that the temperature change tends to inhibit all production and allocation processes, which are instead enhanced by the CO2 concentration rise. The combination of the two factors leads to a general increase in both GPP and NPP that is higher for deciduous oaks and chestnut (+30% and 24% for GPP and +42% and 31% for NPP, respectively). Additionally, vegetation carbon is slightly increased, while total soil carbon remains almost unchanged with respect to the present conditions. These findings are analyzed with reference to the Tuscany forest situation and previous studies on the subject.
A new method for evaluating forest thinning: growth dominance in managed Pinus resinosa stands
Authors: Bradford John B. , D’Amato Anthony W. , Palik Brian J. , Fraver Shawn
Published: May 2010

Growth dominance is a relatively new, simple, quantitative metric of within-stand individual tree growth patterns, and is defined as positive when larger trees in the stand display proportionally greater growth than smaller trees, and negative when smaller trees display proportionally greater growth than larger trees. We examined long-term silvicultural experiments in red pine ( Pinus resinosa Ait.) to characterize how stand age, thinning treatments (thinned from above, below, or both), and stocking levels (residual basal area) influence stand-level growth dominance through time. In stands thinned from below or from both above and below, growth dominance was not significantly different from zero at any age or stocking level. Growth dominance in stands thinned from above trended from negative at low stocking levels to positive at high stocking levels and was positive in young stands. Growth dominance in unthinned stands was positive and increased with age. These results suggest that growth dominance provides a useful tool for assessing the efficacy of thinning treatments designed to reduce competition between trees and promote high levels of productivity across a population, particularly among crop trees.
Cambial mortality in declining Austrocedrus chilensis forests: implications for stand dynamics studies
Authors: Amoroso Mariano M. , Daniels Lori D.
Published: May 2010

Living trees in declining Austrocedrus chilensis (D.Don) Pic. Sern. et Bizarri forests exhibit cambial mortality or death of part of the cambium causing incomplete formation of rings around the circumference, which represents a potential source of error when determining tree ages and years of death. We sampled 12 stands to quantify the incidence of cambial mortality and tested whether its occurrence is independent of the health condition and canopy position of living trees. Trees were cored and statistically cross-dated. Cambial mortality was identified when the outer-ring date differed from the year of sampling. Of the 811 trees sampled, 307 exhibited cambial mortality with duration ranging from 1 to 39 years. Cambial mortality was most common in subcanopy trees independent of their health condition. Symptomatic canopy trees also exhibited a greater than expected incidence of cambial mortality. The presence of cambial mortality represented a source of error when ages were estimated from ring counts, reiterating the importance of cross-dating for determining accurate tree ages. Cambial mortality also poses complex challenges for estimating the years of tree death. Using the cumulative frequency of cambial mortality duration, we present a novel method for estimating error in tree ages from ring counts and selecting class widths to more accurately depict age structures and mortality rates.
Effect of disturbance and distance from a riparian corridor on spiders in a temperate rainforest
Authors: Copley Claudia R. , Winchester Neville N.
Published: May 2010

In anthropogenically disturbed forested riparian ecosystems that contain vagile organisms, we expect dispersal to be a factor that determines patterns of diversity that differ from similar, but continuous, undisturbed habitats. We studied the effects of habitat alteration on community composition by characterizing the spider assemblage of a riparian corridor in an ancient forest and a regenerating coniferous forest in the Carmanah Valley, Vancouver Island, British Columbia. Spiders were collected over a 15 month period using Malaise traps set along transects perpendicular to Carmanah Creek. We recorded 76 genera and 113 species representing 23 families. In both the regenerating coniferous forest and the ancient forest, a large proportion of the species were of the family Linyphiidae. Species abundance was similar in the two habitats but diversity was greater in the regenerating coniferous forest. The ancient forest was dominated by the web-building guild. Spatial autocorrelation analysis revealed no overall pattern in the species assemblages relative to the riparian corridor. Bray–Curtis similarity measure and principal components analysis results indicate that spider assemblages in the two habitats were significantly different in composition. These results suggest that habitat changes affect assemblages of spiders by altering dispersal, and these responses are evident a decade after disturbance.
Foraging ecology of black-backed woodpeckers (Picoides arcticus) in unburned eastern boreal forest stands
Authors: Tremblay Junior A. , Ibarzabal Jacques , Savard Jean-Pierre L.
Published: May 2010

Managed coniferous forest dominates much of the black-backed woodpecker’s ( Picoides arcticus Swainson) breeding range. Despite this, little is known about the fine-scale foraging behaviour of this focal species in unburned managed forest stands in the absence of insect outbreaks. To investigate the foraging substrates used in such a habitat, we employed radio-telemetry to track a total of 27 black-backed woodpeckers. During two successive summers (2005–2006), 279 foraging observations were recorded, most of which were on dying trees, snags, and downed woody debris. Individuals frequently foraged by excavation, suggesting that in the absence of insect outbreaks the black-backed woodpecker forages mainly by drilling. The majority of foraging events occurred on recently dead snags with a mean dbh (±SE) of 18.3 ± 0.4 cm. Our results suggest that in unburned boreal forest stands, substrate diameter and decay class are important predictors of suitable foraging substrates for black-backed woodpeckers. We suggest that conservation efforts aimed at maintaining this dead-wood dependent cavity nesting species within the landscape, should endeavour to maintain 100 ha patches of old-growth coniferous forest. This would ensure the continuous production of a sufficient quantity of recently dead or dying trees to meet the foraging needs of this species.
Bud break and spring frost hardiness in Picea abies seedlings in response to photoperiod and temperature treatments
Authors: Fløistad Inger Sundheim , Granhus Aksel
Published: May 2010

Spring frost may result in detrimental damage in newly planted Picea abies (L.) Karst. seedlings if their growth rhythm is not sufficiently adapted to the climatic conditions on the forest site. The aims of this study were to evaluate how bud break and spring frost hardiness were influenced by short-day (SD) treatments with different timing and different temperature regimes during bud formation. Following winter storage, frost hardiness was tested after 1, 3 and 5 weeks in forcing conditions. The SD treatment advanced bud break compared with the control seedlings. In comparison, the effects of timing and the different temperatures on bud break were small. The SD treatment improved frost hardiness in first-year needles during dehardening. The early SD treatment resulted in improved frost hardiness in first-year needles and greater root collar diameter compared with later SD treatment. To avoid a second bud flush, it is important that a critical night length is attained when the SD treatment terminates. Low temperatures following the SD treatment resulted in increased hardiness of the needles and decreased hardiness of the stems. The contrasting effect of temperature in different plant tissues demonstrates the importance of examining different tissues following freezing tests.
SECURITY REQUIREMENT REPRESENTATION METHOD FOR CONFIDENCE OF SYSTEMS AND NETWORKS
Authors: KIM HYUNG-JONG , KIM HUY KANG , LEE HAE YOUNG
Published: May 2010

Software vulnerability is a key determiner of confidence in computer systems and networks. Usually, software requirements are listed at the beginning of software design, whereas vulnerabilities appear only after development is complete and sometimes only after the system is operational. Therefore, the security requirements during the design stage should address software vulnerabilities. This paper presents a method of representing software vulnerabilities as atomic vulnerabilities (AVs): an AV is an undividable cause-unit of vulnerability, and a set of AVs and the relationships among them represent software vulnerabilities. The AV concept originates from system theory and modeling methodology. AVs and the relationships among them can be used to construct a behavioral model of systems and networks with a focus on vulnerability. The logical relationships among AVs are named vulnerability expressions (VXs). With all the accumulated VXs of the systems and networks, we can set security requirements that resolve or circumvent vulnerabilities effectively and reinforce confidence in system and network robustness. The contribution of this paper is to use the concepts of AV and VX to derive the security requirements considering software vulnerabilities for secure systems and networks. The requirement derived can be used to complement the vulnerable situation caused by software that is developed without cognizance of security consideration.
LINGUISTIC AGGREGATION OPERATORS FOR LINGUISTIC DECISION MAKING BASED ON THE DEMPSTER-SHAFER THEORY OF EVIDENCE
Authors: MERIGÓ J. M. , CASANOVAS M. , MARTÍNEZ L.
Published: May 2010

In this paper, we develop a new approach for decision making with Dempster-Shafer theory of evidence by using linguistic information. We suggest the use of different types of linguistic aggregation operators in the model. We then obtain as a result, the belief structure — linguistic ordered weighted averaging (BS-LOWA), the BS — linguistic hybrid averaging (BS-LHA) and a wide range of particular cases. Some of their main properties are studied. Finally, we provide an illustrative example that shows the different results obtained by using different types of linguistic aggregation operators in the new approach.
LINGUISTIC SUMMARIZATION OF DATABASES WITH QUANTIRIUS: A REDUCTION ALGORITHM FOR GENERATED SUMMARIES
Authors: PILARSKI DANIEL
Published: May 2010

This paper deals with the issue of linguistic database summaries understood as linguistically quantified propositions. We show basic capabilities of Quantirius, our interactive system supporting the mining and the assessment of linguistic summaries in a database. The mining of linguistic summaries is realized by means of the concept of a protoform introduced by Zadeh. The assessment of validity degrees of summaries is done via Zadeh's fuzzy logic based calculus, extended by the use of cardinality patterns and triangular norms. The main part of the paper presents an idea of a further processing of the set of generated summaries. The proposed algorithm is composed of a reduction mechanism of summaries based on linguistic terms inclusion and a reduction of summaries by means of the overlapping unimodal linguistic terms. We then present an idea of the approval threshold computing for the truth degrees of summaries. Finally, we show that summaries generated by different protoforms can be joined in a master-detail-like relation, making an interesting structure of information contained in the database.
A NEW KIND OF FUZZY RELATIONAL EQUATIONS
Authors: QIN FENG , FANG PING
Published: May 2010

In this paper, a new kind of fuzzy relational equations (FREs for short) A ∘R*x = b is first introduced, and then the problem of solving solution to the FREs is discussed, where A is an m × n matrix, x and b are an n and an m dimensional column vectors, respectively. More specifically, their solvability and unique solvability are investigated, the corresponding necessary and sufficient conditions are presented, the complete solution set is obtained. It is worth noting the method to construct the complete solution set.
SELECTING THE BEST PERFORMING WEIBULL ESTIMATION METHOD FOR RANDOMLY RIGHT CENSORED DATA
Authors: BATES JONATHAN J. , ZAYAS-CASTRO JOSÉ L.
Published: May 2010

A total of nine methods are compared and tables are presented for selecting the best performing estimator for a two-parameter Weibull distribution using randomly right censored data. The results indicate that a best performing method can be selected given a certain sample size, censoring level, and shape parameter range. Such a comparison of estimators is necessary as the best performing method is shown to vary across these values. The estimation methods tested include the Maximum Likelihood Estimator, Kaplan-Meier Estimator, Piecewise Exponential Estimator, Földes, Rejt, and Winter Estimator, Klein, Lee, and Moeschberger Partially Parametric Estimator, Ross Estimator, White Estimator, Bain and Engelhardt Estimator, and the Modified Profile Maximum Likelihood Estimator. Recommendations are provided for applying the studied approach to other types of data and distributions.
RELIABILITY DESIGN EVALUATION AND OPTIMIZATION OF A NITROGEN GAS BOTTLE USING RESPONSE SURFACE METHOD
Authors: BHATTACHARJEE P. , RAMESH KUMAR K. , JANARDHAN REDDY T. A.
Published: May 2010

Optimization of any aerospace product results in increasing payload capacity of space vehicles. Essentially weight, volume and cost are the main constraints. Design optimization studies for aerospace system are increasingly gaining importance. The problem of optimum design under uncertainty has been formulated as reliability-based design optimization. The reliability based optimization, which includes robustness requirements leads to multi-objective optimization under uncertainty. In this paper Reliability, based design optimization study is carried out under linear constraint optimization to minimize the weight of a nitrogen gas bottle with specified target reliability. Response surface method considering full factorial experiment is used to establish multiple regression equation for induced hoop stress and maximum strain. Necessary data pertaining to design, manufacturing and operating conditions are collected systematically for variability study. Structural reliability is evaluated using Advanced First-Order Second-Moment Method (AFOSM). Finally, optimization formulation established and it has been discussed in this paper.
MONITORING AUTOCORRELATED PROCESSES WITH WAVELETS
Authors: BILEN CANAN
Published: May 2010

This paper develops a wavelet control chart for monitoring autocorrelated processes. The procedure uses the discrete wavelet transform of the original series, and traditional control charts are applied to the stream of wavelet coefficients. Unlike other control charts for monitoring autocorrelated processes found in the literature, the wavelet control chart does not require that a model be specified for the process data. The wavelet-based control chart is simple enough that it can be easily automated. Real and simulated data are used to illustrate the effectiveness of the proposed wavelet control chart.
DECOHERENCE OF A QUANTUM MEMORY COUPLED TO A COLLECTIVE SPIN BATH
Authors: WALTERS RICHARD , CLARK STEPHEN R. , JAKSCH DIETER
Published: May 2010

We study the quantum dynamics of a single qubit coupled to a bath of interacting spins as a model for decoherence in solid state quantum memories. The spin bath is described by the Lipkin-Meshkov-Glick model and the bath spins are subjected to a transverse magnetic field. We investigate the qubit interacting via either an Ising- or an XY-type coupling term to subsets of bath spins of differing size. The large degree of symmetry of the bath allows us to find parameter regimes where the initial qubit state is revived at well-defined times after the qubit preparation. These times may become independent of the bath size for large baths and thus enable faithful qubit storage even in the presence of strong coupling to a bath. We analyze a large range of parameters and identify those which are best suited for quantum memories. In general we find that a small number of links between qubit and bath spins leads to less decoherence and that systems with Ising coupling between qubit and bath spins are preferable.
APPLICATIONS OF ATOMIC ENSEMBLES IN DISTRIBUTED QUANTUM COMPUTING
Authors: ZWIERZ MARCIN , KOK PIETER
Published: May 2010

Thesis chapter. The fragility of quantum information is a fundamental constraint faced by anyone trying to build a quantum computer. A truly useful and powerful quantum computer has to be a robust and scalable machine. In the case of many qubits which may interact with the environment and their neighbors, protection against decoherence becomes quite a challenging task. The scalability and decoherence issues are the main difficulties addressed by the distributed model of quantum computation. A distributed quantum computer consists of a large quantum network of distant nodes — stationary qubits which communicate via flying qubits. Quantum information can be transferred, stored, processed and retrieved in decoherence-free fashion by nodes of a quantum network realized by an atomic medium — an atomic quantum memory. Atomic quantum memories have been developed and demonstrated experimentally in recent years. With the help of linear optics and laser pulses, one is able to manipulate quantum information stored inside an atomic quantum memory by means of electromagnetically induced transparency and associated propagation phenomena. Any quantum computation or communication necessarily involves entanglement. Therefore, one must be able to entangle distant nodes of a distributed network. In this article, we focus on the probabilistic entanglement generation procedures such as well-known DLCZ protocol. We also demonstrate theoretically a scheme based on atomic ensembles and the dipole blockade mechanism for generation of inherently distributed quantum states so-called cluster states. In the protocol, atomic ensembles serve as single qubit systems. Hence, we review single-qubit operations on qubit defined as collective states of atomic ensemble. Our entangling protocol requires nearly identical single-photon sources, one ultra-cold ensemble per physical qubit, and regular photodetectors. The general entangling procedure is presented, as well as a procedure that generates in a single stepQ-qubit GHZ states with success probability psuccess ~ ηQ/2, where η is the combined detection and source efficiency. This is significantly more efficient than any known robust probabilistic entangling operation. The GHZ states form the basic building block for universal cluster states, a resource for the one-way quantum computer.
TELEPORTING BIPARTITE ENTANGLEMENT USING MAXIMALLY ENTANGLED MIXED CHANNELS
Authors: CAMPBELL S. , PATERNOSTRO M.
Published: May 2010

The ability to teleport entanglement through maximally entangled mixed states as defined by concurrence and linear entropy is studied. We show how the teleported entanglement depends on the quality of the quantum channel used, as defined through its entanglement and mixedness, as well as the form of the target state to be teleported. We present new results based on the fidelity of the teleported state as well as an experimental setup that is immediately implementable with currently available technology.
UNITARY-CIRCUIT SEMANTICS FOR MEASUREMENT-BASED COMPUTATIONS
Authors: BEAUDRAP NIEL DE
Published: May 2010

One-way measurement based quantum computations (1WQC) may describe unitary transformations, via a composition of CPTP maps which are not all unitary themselves. This motivates the following decision problems. Is it possible to determine whether a "quantum-to-quantum" 1WQC procedure (having non-trivial input and output subsystems) performs a unitary transformation? Is it possible to describe precisely how such computations transform quantum states, by translation to a quantum circuit of comparable complexity? In this article, we present an efficient algorithm for transforming certain families of measurement-based computations into a reasonable unitary circuit model, in particular without employing the principle of deferred measurement.
AN INTRODUCTION TO ONE-WAY QUANTUM COMPUTING IN DISTRIBUTED ARCHITECTURES
Authors: CAMPBELL EARL T. , FITZSIMONS JOSEPH
Published: May 2010

This review provides a gentle introduction to one-way quantum computing in distributed architectures. One-way quantum computation shows significant promise as a computational model for distributed systems, particularly those architectures which rely on probabilistic entangling operations. We review the theoretical underpinnings of one-way quantum computation and discuss the practical issues related to exploiting the one-way model in distributed architectures.
CONSTRUCTING 2D AND 3D CLUSTER STATES WITH PHOTONIC MODULES
Authors: IONICIOIU RADU , MUNRO WILLIAM J.
Published: May 2010

Large-scale quantum information processing and distributed quantum computation require the ability to perform entangling operations on a large number of qubits. We describe a new photonic module which prepares, deterministically, photonic cluster states using an atom in a cavity as an ancilla. Based on this module, we design a network for constructing 2D cluster states and then we extend the architecture to 3D topological cluster states. Advantages of our design include a passive switching mechanism and the possibility of using global control pulses for the atoms in the cavity. The architecture described here is well-suited for integrated photonic circuits on a chip and could be used as a basis of a future quantum optical processor or in a quantum repeater node.
CAN QUANTUM MECHANICS HELP DISTRIBUTED COMPUTING?
Authors: BROADBENT ANNE , TAPP ALAIN
Published: May 2010

We present a brief survey of results where quantum information processing is useful for performing distributed computation tasks. We describe problems that are impossible to solve using classical resources but that become feasible with the help of quantum mechanics. We also give examples where the use of quantum information significantly reduces the need for communication. The main focus of the survey is on communication complexity but we also address other distributed tasks.
ESTIMATING PURITY AND ENTROPY IN STABILIZER STATE EXPERIMENTS
Authors: WUNDERLICH HARALD , PLENIO MARTIN B.
Published: May 2010

Many experiments in quantum information aim at creating graph states. Quantifying the purity of an experimentally achieved graph state could in principle be accomplished using full-state tomography. This method requires a number of measurement settings growing exponentially with the number of constituents involved. Thus, full-state tomography becomes experimentally infeasible even for a moderate number of qubits.

In this paper, we present a method to estimate the purity of experimentally achieved graph states with simple measurements. The observables we consider are the stabilizers of the underlying graph. Then, we formulate the problem as: "What is the state with the least purity that is compatible with the measurement data?" We solve this problem analytically and compare the obtained bounds with results from full-state tomography for simulated data.
CLASSICAL PROCESSING REQUIREMENTS FOR A TOPOLOGICAL QUANTUM COMPUTING SYSTEM
Authors: DEVITT SIMON J. , FOWLER AUSTIN G. , TILMA TODD , MUNRO W. J. , NEMOTO KAE
Published: May 2010

Dedicated research into the design and construction of a large-scale Quantum Information Processing (QIP) system is a complicated task.The design of an experimentally feasible quantum processor must draw upon results in multiple fields; from experimental efforts in system control and fabrication through to far more abstract areas such as quantum algorithms and error correction. Recently, the adaptation of topological coding models to physical systems in optics has illustrated a possible long-term pathway to truly large-scale QIP. As the topological model has well-defined protocols for Quantum Error Correction built in as part of its construction, a more grounded analysis of the classical processing requirements is possible. In this paper, we analyze the requirements for a classical processing system, designed specifically for the topological cluster state model. We demonstrate that via extensive parallelization, the construction of a classical "front-end" system capable of processing error correction data for a large topological computer is possible today.
MEASURING THE CONTRIBUTIONS OF KNOWLEDGE MANAGEMENT SYSTEMS TO THE STRATEGIC COMPETITIVENESS OF ORGANIZATIONS: A REVIEW AND A MODEL
Authors: GEISLER ELIE
Published: May 2010

Why and how do Knowledge Management Systems (KMS) contribute to the strategic competitiveness of organizations? This paper reviews the literature and proposes a model in which KMS is viewed from three different perspectives: (1) crucial resource; (2) driver of absorptive capacity; and (3) innovation adopted by the organization. The paper critiques the method used by KMS researchers whereby co-variation of KMS and competitiveness is utilized to study the relationship between these variables. The model proposed here is a multi-stage process. The successful use of KMS generates intermediate outcomes that in turn impact the organization and produces improved strategic competitiveness. The different approaches to KMS and the stage-process allow for the unique attributes of knowledge systems, different from information systems. The advantages and limitations of the model are discussed.
INNOVATION: IMPLICATIONS FOR GOODS AND SERVICES
Authors: OMACHONU VINCENT K. , EINSPRUCH NORMAN G.
Published: May 2010

The concepts of goods and services innovation have been discussed extensively in the academic literature. The research has been both selective (dealing with specific attributes such as R&D, process innovation, measurement of innovation, and use of information technology) and specific (dealing with specific industries such as banking, insurance, biotechnology, nanotechnology). This paper examines the concept of innovation in the context of "goods" and "services." The comparisons made between the two sectors are based on three distinct areas — definition, process, measurement. This paper also presents a conceptual framework showing the interactions among the various variables inherent in some of the distinct areas. Previous papers have highlighted the differences in innovation between goods and services. What is missing is how the intervening variables invoked in the discussions are themselves related to one another. While this paper reinforces the conclusions reached by other studies with regard to innovation, it specifically highlights on an aggregate scale, the areas in which goods and services differ. Future research should take these distinctions into account, not as single items but collectively. It is critical to consider how these innovation variables interact with one another in the context of goods and services. Perhaps the most significant contribution of this paper is in its presentation of the framework for understanding the innovation process as it relates to the goods and services sectors.
PERSPECTIVE: DETERMINING RESEARCH AND DEVELOPMENT EXPENDITURE TARGETS BASED ON AN AFFORDABILITY INDEX
Authors: WALWYN DAVID R.
Published: May 2010

Gross domestic expenditure on research and development (GERD), usually expressed as a percentage of gross domestic product (GDP), is a widely used indicator to reflect the research intensity within a national economy, and hence its capacity to develop new and innovative products or services. It is also used as a key target in the management of national innovation systems. For instance, the South African National Research and Development Strategy set a target of raising GERD/GDP to 'somewhat over 1%', and in 2002 the Barcelona European Council set an EU target of 3%. Despite its widespread usage, there is little discussion or agreement on how this target should be derived within a broad range of economic contexts and levels of affordability. In this paper, a composite indicator based on GERD/GDP, normalised for GDP per capita, is developed and its use in a number of countries explored and explained. As a result, a set of GERD/GDP targets for various categories of developing countries is proposed.
THE IMPACT OF TOP MANAGEMENT TEAM CONFLICT ON NEW PRODUCT DEVELOPMENT: A CROSS-CULTURAL PERSPECTIVE
Authors: HSIEH TSUN-JUI , CHUNG HSIEN-JUI , LO HSUAN
Published: May 2010

This study demonstrates how top management team (TMT) conflict impacts new product development (NPD) under cultural differences between Taiwan and the United States. Based on cultural differences, we compare Taiwan and the United States to explore how the heterogeneity of TMT composition leads to team conflict and how TMT conflict affects NPD outcomes in different stages. Several research propositions are presented and indicate that the higher TMT heterogeneity results in a higher degree of team conflict. Furthermore, cognitive conflict positively affects NPD initiation stage, but negative in the implementation stage. From a perspective of cultural differences, managers in Taiwan, compared with those in the United States, tend to sustain organizational cohesion and harmony, emphasize personal relationships, and sidestep direct conflict as much as possible. This cultural characteristic negatively affects NPD initiation, and also wears away the competitive advantages for Taiwanese companies.
Pre-Late Devensian high-arctic marine deposits in SW Scotland
Authors: Peacock J.D. , Everest J.D.
Published: May 2010

Synopsis

We present new interpretations of Digital Elevation Model (DEM) data and marine fossils collected from three sites on the Rhins of Galloway which, contrary to recent proposals, suggest that the landforms and deposits of the region do not represent evidence for a readvance during the Lateglacial Period. Rather we suggest that the high-arctic fauna found in the region are representative of an earlier, colder part of a Middle Devensian ice-free interval. The predominantly streamlined topography, and distinct lack of identifiable discrete moraine limits argues for only minor, local glacial advances, in combination with widespread rapid retreat across the peninsula at the end of the Lateglacial.
The palynology of the Pabay Shale Formation (Lower Jurassic) of SW Raasay, northern Scotland
Authors: Brittain Jennifer M. , Higgs Kenneth T. , Riding James B.
Published: May 2010

Synopsis

A thermally-mature palynomorph assemblage containing significant proportions of the characteristic dinoflagellate cyst
Liasidium variabile
Drugg 1978
was recovered from the Lower Jurassic Pabay Shale Formation of SW Raasay. This is the first record of this biostratigraphically important species from the Jurassic of onshore Scotland.
Liasidium variabile
is a zonal index for the Late Sinemurian in NW Europe, and this occurrence allows a correlation to the Oxynotum Zone of this substage. This is the first evidence for this chronozone on Raasay. Furthermore, the presence of morphotypes A and B of
Liasidium variabile
indicates a probable correlation to the Oxynotum Subzone of the Oxynotum Zone. This interpretation is not consistent with a hiatus within the Upper Sinemurian succession on Raasay.