bluuebunny/crossref_metadata_2025 huggingface dataset:
The Hybridization Barrier between Herbaceous Medicago sativa and Woody M. arborea Is Weakened by Selection of Seed Parents
Authors: Bingham Edwin , Armour David , Irwin John
Published: May 2013

Medicago sativa, alfalfa or lucerne, and M. arborea were considered reproductively isolated until recently. Then, in 2003, an alfalfa genotype was identified that produced a few seeds and progeny with hybrid traits after a large number of pollinations by M. arborea. A derivative of this alfalfa genotype also produced a low frequency of progeny with hybrid traits. Thus, the hybridization barrier was weakened by selection of seed parents. Hybrids from both events expressed traits from M. arborea and M. arborea-specific DNA bands, although more of the M. sativa genome was retained, based on the DNA results. Thus, there was chromatin elimination during embryogenesis, resulting in partial hybrids (hereafter hybrids). However, more than 30 hybrids with an array of M. arborea traits have been obtained thus far, and research continues on the nature of the hybrids. Traits have been genetically transmitted in crosses, and selected traits are in use for alfalfa breeding. This paper reviews the first hybrids and then focuses on further weakening of the hybridization barrier with the discovery of a more efficient hybridizer derived from crossing Medicago sativa subspecies, sativa, coerulea and falcata. This genotype was found to have reproductive abnormalities associated with its complex subspecies origin that are best described as hybrid breakdown. In effect, this subspecies derivative is a bridge-cross parent that consistently produces hybrids. Reproductive abnormalities in the bridge-cross parent are reported and discussed.
Surrounding Risks
Authors: Steffensen Mogens
Published: May 2013

Research in insurance and finance was always intersecting although they were originally and generally viewed as separate disciplines. Insurance is about transferring risks between parties such that the burdens of risks are borne by those who can. This makes insurance transactions a beneficial activity for the society. It calls on detection, modelling, valuation, and controlling of risks. One of the main sources of control is diversification of risks and in that respect it becomes an issue in itself to clarify diversifiability of risks. However, many diversifiable risks are not, by nature or by contract design, separable from non-diversifiable risks that are, on the other hand, sometimes traded in financial markets and sometimes not. A key observation is that the economic risk came before the insurance contract: Mother earth destroys and kills incidentally and mercilessly, but the uncertainty of economic consequences can be more or less cleverly distributed by the introduction of an insurance market. [...]
A New Self-Calibrated Procedure for Impact Detection and Location on Flat Surfaces
Authors: Somolinos José , López Amable , Morales Rafael , Morón Carlos
Published: May 2013

Many analyses of acoustic signals processing have been proposed for different applications over the last few years. When considering a bar-based structure, if the material through which the sound waves propagate is considered to be acoustically homogeneous and the sound speed is well known, then it is possible to determine the position and time of impact by a simple observation of the arrival times of the signals of all the transducers that are strategically disposed on the structure. This paper presents a generalized method for impact detection and location on a flat plate, together with a calibration procedure with which to obtain the sound speed from only one set of measurements. This propagation speed is not well known as a result of either imprecise material properties or the overlapping of longitudinal and transversal waves with different propagation velocities. The use of only three piezoelectric sensors allows the position and time of impact on the flat plate to be obtained when the sound speed is well known, while the use of additional sensors permits a larger detection area to be covered, helps to estimate the sound speed and/or avoids the wrong timing of difference measurements. Experimental results are presented using a robot with a specially designed knocking tool that produces impacts on a metallic flat plate.
Distributed Fiber Optical Sensing of Oxygen with Optical Time Domain Reflectometry
Authors: Eich Susanne , Schmälzlin Elmar , Löhmannsröben Hans-Gerd
Published: May 2013

In many biological and environmental applications spatially resolved sensing of molecular oxygen is desirable. A powerful tool for distributed measurements is optical time domain reflectometry (OTDR) which is often used in the field of telecommunications. We combine this technique with a novel optical oxygen sensor dye, triangular-[4] phenylene (TP), immobilized in a polymer matrix. The TP luminescence decay time is 86 ns. The short decay time of the sensor dye is suitable to achieve a spatial resolution of some meters. In this paper we present the development and characterization of a reflectometer in the UV range of the electromagnetic spectrum as well as optical oxygen sensing with different fiber arrangements.
Decoupling Intensity Radiated by the Emitter in Distance Estimation from Camera to IR Emitter
Authors: Cano-García Angel , Galilea José , Fernández Pedro , Infante Arturo , Pompa-Chacón Yamilet , Vázquez Carlos
Published: May 2013

Various models using radiometric approach have been proposed to solve the problem of estimating the distance between a camera and an infrared emitter diode (IRED). They depend directly on the radiant intensity of the emitter, set by the IRED bias current. As is known, this current presents a drift with temperature, which will be transferred to the distance estimation method. This paper proposes an alternative approach to remove temperature drift in the distance estimation method by eliminating the dependence on radiant intensity. The main aim was to use the relative accumulated energy together with other defined models, such as the zeroth-frequency component of the FFT of the IRED image and the standard deviation of pixel gray level intensities in the region of interest containing the IRED image. By using the abovementioned models, an expression free of IRED radiant intensity was obtained. Furthermore, the final model permitted simultaneous estimation of the distance between the IRED and the camera and the IRED orientation angle. The alternative presented in this paper gave a 3% maximum relative error over a range of distances up to 3 m.
Assessment of the Impact of Business Activity in Sustainability Terms. Empirical Confirmation of Its Determination in Spanish Companies
Authors: Pajuelo Moreno María Luisa
Published: May 2013

Because the issue of sustainability presents urgent problems crucial to the future of mankind, there has been serious discussion of the role accounting should play. In this context, a new line of research, still at a relatively unexplored, embryonic stage, has arisen, which tries to establish measurement of business sustainability and so compensate for the lack of information currently existing about the net impact of the company’s activity. Full Cost Accounting could allow sustainability to be translated into the language of business, together with analysis and comparison of its progress, so it might be the most appropriate vehicle for more participatory, democratic accounting, with greater dialogue, giving the accountant a much more active role, this being necessary in order to generalize the research, development and use. To analyze the current situation, a survey of 192 Spanish companies was carried out to obtain at first hand the perception of strategic positioning adopted with regard to Sustainable Development, measurement of the contribution of business activity to its achievement and the rendering of accounts carried out.
Le Contre Colotès de Plutarque et son prologue
Authors: Morel Pierre-Marie , Verde Francesco
Published: May 2013

Une vue d’ensemble du traité de Plutarque et l’analyse de son prologue permettent de discerner les principaux thèmes et les grands choix stratégiques qui vont structurer l’ensemble du traité : l’inculture de Colotès, l’incohérence des épicuriens, la posture de juge impartial et lucide que se donne Plutarque, l’immoralité du mode de vie épicurien. Le prologue apparaît ainsi comme un texte en lui-même solidement structuré et soigneusement pensé.
The lives and opinions of Socrates and Stilpo as defended by Plutarch against the insidious yet ignorant attacks of Colotes
Authors: Opsomer Jan
Published: May 2013

Dans les chapitres 17 à 23 de
l’Adversus Colotem,
Plutarque défend Socrate et Stilpon contre les critiques de Colotès.
J’examine l’insertion de cette section dans le contexte plus large de
l’œuvre, les liens entre la section sur Socrate et Stilpon, les
critiques de Colotès et les contre-arguments ainsi que les stratégies
polémiques de Plutarque. Ce faisant, je tente de démêler les
différentes couches de ce texte complexe. Socrate est présenté comme
un imposteur et un sceptique par Colotès. Plutarque affirme que la
philosophie de Socrate implique certes une méfiance radicale à l’égard
des sens, mais que cela n’empêche ni Socrate ni ses disciples de vivre
leur vie quotidienne. La philosophie socratique doit être préférée de
très loin à l’épicurisme. Stilpon, un mégarique, appartient également
à la tradition socratique. Plutarque apporte son soutien à la bonne
réputation morale de ce philosophe à l’esprit vif contre le mauvais
traitement que Colotès lui avait infligé. Ce dernier avait aussi
attaqué le rejet par Stilpon de toute prédication, à l’exception de la
prédication d’identité. Plutarque affirme que l’argument de Stilpon
est un pur exercice dialectique et ne menace aucunement nos vies
quotidiennes. Plutarque lance en outre une contre-attaque contre la
philosophie épicurienne du langage, et plus particulièrement la
suppression du niveau intermédiaire – celui des significations. Le
fameux argument de Stilpon, tel qu’il est présenté par Plutarque,
revient à nier la relation ontologique à laquelle correspond la
prédication ordinaire. La conclusion de Plutarque – selon laquelle
Stilpon nous invite simplement à abandonner l’usage du verbe « être »
comme copule – ne convient pas à l’argument tel qu’il le présente. La
meilleure explication de ce décalage est l’hypothèse que Plutarque a
copié l’argument de manière assez fidèle sans l’analyser dans le
détail. Cela expliquerait également le fait que l’argument ne fasse
aucun usage de la théorie platonicienne de la prédication dans le Sophiste.
Plutarch’s polemic against Colotes’ view on legislation and politics. A reading of Adversus Colotem 30-34 (1124D-1127E)
Authors: Roskam Geert
Published: May 2013

À la fin de son Adversus Colotem, Plutarque attaque la
conception épicurienne de la politique (1124D-1127E). Son point de
départ est une citation littérale de Colotès. Ce dernier avait
apparemment conclu son pamphlet polémique par une appréciation
enthousiaste de l’œuvre de législateurs anciens. Plutarque réagit
fermement en opposant les médiocres résultats de la pensée d’Épicure
aux réalisations impressionnantes des membres des autres écoles
philosophiques.Dans cet article, on examine de près la position
de l’épicurien Colotès et la réponse de Plutarque. Les différents
arguments sont analysés un par un, et cette analyse de détail montre
qu’aucun des arguments critiques de Plutarque ne saurait convaincre un
épicurien. Pourtant, plusieurs d’entre eux posent des questions
pertinentes et projettent une lumière intéressante sur les stratégies
polémiques de Plutarque et sur ses conceptions philosophiques.
La moisson des Argonautiques et la poétique d’Apollonios dans le chant III
Authors: Létoublon Françoise
Published: May 2013

Un’analisi comparativa dei
paragoni presenti nel canto III delle Argonautiche e di quelli omerici
mostra che Apollonio s’ispira fortemente ai suoi modelli, in modo
particolare nella forma ed nel lessico. Eppure, nella maggior parte
dei casi, egli porta i confronti omerici lontano dal loro contesto
d’origine per adattarli ai suoi intenti. Nella prima parte del canto
III, i similitudini rispondono alla volontà comune di evidenziare le
pene che l’amore suscita nell’animo e nel comportamento di Medea.
Nella seconda parte, le prove che Giasone deve superare danno luogo,
in modo sorprendente, ad immagini guerriere funzionali alla
descrizione dei preparativi, ma in seguito Apollonio ricorre ad un
lessico artigianale ed agricolo per evocare dei compiti che consistono
effettivamente nell’aggiogare e tirare una coppia di tori, in
un’aratura, in una semina ed in una mietitura. L’aspetto più notevole
è che molti paragoni riuniti verso la fine del canto non sembrano
trovare un corrispondente in alcun modello omerico, come se il
racconto di questa prova inedita avesse progressivamente liberato
Apollonio dalla sua dipendenza da Omero.
Evidence for Added Value of Baseline Testing in Computer-Based Cognitive Assessment
Authors: Roebuck-Spencer Tresa M. , Vincent Andrea S. , Schlegel Robert E. , Gilliland Kirby
Published: May 2013

Context:

Large-scale baseline cognitive assessment for individuals at risk for concussion is a common part of the protocol for concussion-surveillance programs, particularly in sports. Baseline cognitive testing is also being conducted in US military service members before deployment. Recently, the incremental validity of large-scale baseline cognitive assessment has been questioned.

Objective:

To examine the added value of baseline cognitive testing in computer-based neuropsychological assessment by comparing 2 methods of classifying atypical performance in a presumed healthy sample.

Design:

Cross-sectional study.

Setting:

Military base.

Patients or Other Participants:

Military service members who took the Automated Neuropsychological Assessment Matrix (ANAM) before and after deployment (n = 8002).

Main Outcome Measure(s):

Rates of atypical performance in this healthy, active-duty sample were determined first by comparing postdeployment scores with a military normative database and then with each individual's personal baseline performance using a reliable change index.

Results:

Overall rates of atypical performance were comparable across these 2 methods. However, these methods were highly discordant in terms of which individuals were classified as atypical. When norm-referenced methods were used, 2.6% of individuals classified as normal actually demonstrated declines from baseline. Further, 65.7% of individuals classified as atypical using norm-referenced scores showed no change from baseline (ie, potential false-positive findings).

Conclusions:

Knowing an individual's baseline performance is important for minimizing potential false-positive errors and reducing the risks and stresses of misdiagnosis.
Service to the South African society through prophetic testimony as a liturgical act
Authors: De Klerk Ben J.
Published: May 2013

It is suggested that a clear prophetic voice of the congregational gathering could change the society to which the congregants belong. The problem is that this prophetic voice seems to have disappeared in many cases. A solution might be found if the point of view is taken that the prophetic voice in the congregational gathering is heard in the liturgical acts or rites. In the science of Liturgy attention must be given to the revitalisation of the gift of prophesy. In this article the prophetic testimony of the Old Testament prophets and of the Prophet, Jesus Christ, were used as sources. Following in the footsteps of Brueggemann, an effort will be made to establish in relevant scripture passages what the attitude and practise of prophetic testimony should be. The possibility of rendering service through prophetic testimony as a liturgical act in the South African society is wide open. Prophetic testimony serves to criticise the dominant perception in order to dismantle it, but is also serves to energise persons and communities by its promise of another time and situation towards which the community of faith could move.
Epilepsy in tropics: Indian perspective
Authors: Joshua Shejoy P , Mahapatra Ashok Kumar
Published: May 2013

Epilepsy is a common neurological disorder affecting 0.5‑1% of the population in India. The causes and treatment protocols vary widely. A proper understanding of the causes and treatment strategies is essential for managing this patient group. This article analyzes the common causes of epilepsy in India and provides a brief summary on the available treatment strategies.
Xanthogranulomatous colloid cyst of the third ventricle
Authors: Alugolu Rajesh , Krishna Chandrasekhar Yandrapati Bala Venkata , Shukla Dinesh , Sahu Barada Prasad , Srinivas Bheemanathi Hanuman
Published: May 2013

Colloid cyst in the third ventricle is a common entity, whereas a variant of it, namely xanthogranulomatous, is quite rare. The closest imaging differential diagnosis is a purely third ventricular craniopharyngioma. We herein describe a case of xanthogranulomatous colloid cyst presenting with hydrocephalus.
Basal Cell Adenocarcinoma of the Minor Salivary Glands Involving Palate and Maxillary Sinus
Authors: Sarath Prathi Venkata , Kannan N. , Patil Rajendra , Manne Rakesh Kumar , Swapna Beeraka , Suneel Kumar K. V.
Published: May 2013

Basal cell adenocarcinoma (BCAC) is a rare neoplasm accounting for only 2.9% of all salivary gland neoplasms. BCAC involving palatal minor salivary glands are exceedingly rare, and only 10 cases have been reported in the literature. The treatment of choice is surgical excision. Here, we report a case of a 55-year-old male patient with massive BCAC of palatal minor salivary gland extending into the maxillary sinus. This is the first case of BCAC treated by radiotherapy followed by chemotherapy. A follow-up check conducted after 14-months showed good prognosis.
Testicular adrenal rest "tumor" or Leydig cell tumor? A report of a challenging case with literature review
Authors: Ali Hiba Hassan , Samkari Alaa , Arabi Haitham
Published: May 2013

Congenital adrenal hyperplasia (CAH) refers to group of inherited diseases resulting from impaired adrenal steroidogenesis, and its most common cause is 21-hydroxylase deficiency. Testicular adrenal rest tumors (TARTs) are an important complication of CAH, which probably develop from ectopic remnants of intra-testicular adrenal tissue stimulated by Adrenocorticotropic hormone (ACTH) hypersecretion. These lesions are typically located within the rete testis and are bilateral, synchronous, nodular and multiple. TART usually, but not always, responses to suppressive medical therapy. TART leads to testicular structural damage, spermatogenesis disorders, infertility and most importantly, mass-forming lesions that could be mistaken for Leydig cell tumor (LCT). The later has a significantly different behavior with up to 10% of being malignant. Nowadays, due to advances in diagnosing and treating CAH, mass-forming TART is rarely encountered. As a result, there is the paucity in the medical literature regarding its features from pathological perspective. We herein present a case of mass-forming TART and we discuss the clinical, radiological, and morphological features as well as the major differential diagnosis of this rare lesion.
Evaluation of selected soil properties for indicating cattle activity at off-stream watering and river access sites in southern Alberta
Authors: Miller J. J. , Curtis T. W. , Bremer E. , Chanasyk D. S. , Willms W. D.
Published: May 2013

Miller, J. J., Curtis, T. W., Bremer, E., Chanasyk, D. S. and Willms, W. D. 2013. Evaluation of selected soil properties for indicating cattle activity at off-stream watering and river access sites in southern Alberta. Can. J. Soil Sci. 93: 343–358. Off-stream watering troughs may reduce surface water pollution by shifting nutrient distribution from natural watering sites along the river to around artificial water troughs some distance from the river. The objective of our study was to evaluate the suitability of nine soil properties for assessing the impacts of cattle activity adjacent to eight watering sites. Nine surface (0–5 cm) soil properties were evaluated along four 100-m transects at the five off-stream water troughs and three river access sites along the Lower Little Bow River in southern Alberta over 4 yr (2007–2010). The properties included P (total P, soil test P or STP), N (total N, NO3-N, NH4-N), total C, total C:total N ratio (TC:TN), chloride (Cl), and soil bulk density. Soil test P was significantly (P≤0.05) enriched at 65% of site-year comparisons, followed by total C (63%), NO3-N (55%), total P and TC:TN (50%). This suggested that these soil properties were relatively good indicators of cattle activity at the majority (>50%) of watering sites. Chloride was a valid indicator only in non-saline areas (100% of four non-saline sites). Total C and TC:TN ratios were not valid indicators in the calcareous soils at all sites because of possible confounding influence of inorganic C. Overall, we recommend Cl as an indicator of cattle activity at watering sites not affected by soil salinity and high natural Cl levels, and STP as the best overall indicator of cattle activity at off-stream watering sites and river access sites. Certain soil properties were also influenced by distance from watering site, stocking rate, precipitation, and age of water trough.
Evidence for spring mountain snowpack retreat from a Landsat-derived snow cover climate data record
Authors: Crawford C. J.
Published: May 2013

Abstract. A Landsat snow cover climate data record (CDR) of visible mountain snow-covered area (SCA) across interior northwestern USA during spring was compared with ground-based snow telemetry (SNOTEL) snow-water-equivalent (SWE) measurements and mean surface temperature and total precipitation observations. Landsat spring SCA on 1 June was positively correlated with 15 May and 1 June SWE, negatively correlated with spring temperatures (April–June), and positively correlated with March precipitation. Using linear regression with predicted residual error sum-of-squares (PRESS) cross-validation, spring SCA was reconstructed (1901–2009) for the mountains of central Idaho and southwestern Montana using instrumental spring surface temperature records. The spring SCA reconstruction shows natural internal variability at interannual to decadal timescales including above average SCA in the 1900s, 1910s, 1940s-1970s, and below average SCA in the 1920s, 1930s, and since the mid 1980s. The reconstruction also reveals a~centennial trend towards decreasing spring SCA with estimated losses of −36.2 % since 1901. Based on the inferred thermal relationship between temperature and snow, strong evidence emerges for mountain snowpack retreat triggered by spring warming, a signal that includes both feedback and response mechanisms. Expanding snow cover CDRs to include additional operational satellite retrievals will add temporal SCA estimates during other snow accumulation and melt intervals for improved satellite-instrumental climate model calibration. Merging Landsat snow cover CDRs with instrumental climate records is a formidable method to monitor climate-driven changes in western US snowpack extent over 20th and 21st centuries.
Kristeva’s Sadomasochistic Subject and the Sublimation of Violence
Authors: Oliver Kelly
Published: May 2013

Do representations of violence incite or quell violent desires and actions?  This question--the question of the relation between mimesis and catharsis--is as old as Western Philosophy itself.  In this essay, I attempt to think through how Kristeva might describe the difference between representations of violence that perpetuate violent desires and actions versus representations of violence that sublimate violent desires and thereby prevent violent actions.
Julia Kristeva and the Politics of Life
Authors: Hansen Sarah K.
Published: May 2013

In her recent writings on the powers and limits of psychoanalysis, Julia Kristeva develops a theory of power and subjectivity that engages implicitly, if not explicitly, with biopolitical themes. Exploring these engagements, this paper draws on Kristeva to discuss the mute symptoms of homo sacer and the regulatory power of the spectacle. Staging an uncommon (and sometimes antagonistic) conversation between Kristeva, Agamben, and Foucault, I construct a field of inquiry that I term the “psychic life of biopolitics.”
Review Essay: Ann Murphy, Violence and the Philosophical Imaginary
Authors: Gilson Erinn
Published: May 2013

Review essay of Ann V. Murphy, Violence and the Philosophical Imaginary.
Book Review: Benoît Peeters, Derrida: A Biography
Authors: Brittingham John Thomas
Published: May 2013

A review of Benoit Peeters, Derrida: A Biography, trans. Andrew Brown (Cambridge: Polity, 2013).
Julia Kristeva’s The Severed Head
Authors: DeArmitt Pleshette
Published: May 2013

This paper was presented as part of a roundtable on Kristeva’s The Severed Head at the inaugural meeting of the Kristeva Circle on October 13, 2012.
Music, Affect, Method, Data: Reflections on the Carroll Versus Kivy Debate
Authors: Konečni Vladimir J.
Published: May 2013

The comprehensive exchange between Noël Carroll and Peter Kivy, which took place in 2007, addressed key issues in the relationship between music and affect. More than in any prior philosophical debate on this topic, experimental psychologists’ methods and data played a significant role. However, to a nontrivial extent, the findings-perhaps especially the dubious-were misconstrued or misused, usually without acknowledging the existence of contrary data-based opinion within the psychology of music itself. Therefore, one objective of the present article is to identify the specific problematic features and shed light on the broader context shared by the two disciplines. A complementary goal is to examine contributions to philosophers’ transgressions by music psychologists’ insufficiently conscientious reporting, frequent overgeneralizations, and unawareness of philosophers’ critical arguments. Another objective is to examine the current status of key concepts-the relevant music, basic emotions, mood, expression, induction, movement and dance, and methods (including introspection and experimental procedures)- thus perhaps enabling the discussion of music and affect to proceed with fewer misunderstandings. Finally, the article moves beyond the initial debate and builds on a remarkable agreement of philosophical and psychological opinion on a key issue (the induction of non-basic emotions by absolute music) to reach a new conceptual ground.
Cognitive Processing of Scrambled Faces
Authors: Rakover Sam S. , Cahlon Baruch
Published: May 2013

We propose a model, face-checking, that is based on first-order relational properties and discriminates between different faces (regular and scrambled) and predicts their similarity choice in 2 orientations: upright and inverted. The results of an experiment confirmed the model’s predictive ability. An alternative hypothesis, which is based on facial configural information, failed to provide an efficient explanation for these findings, as the proposed model does. The model shows how components of first-order relational properties are mathematically integrated and involved in face processing.
Development, Test and Validation of a Mechatronic Device for Spasticity Quantification
Authors: Ferreira João F. , Moreira Vitor , Lima Carlos S. , Soares Filomena , Machado José , Leão Celina P.
Published: May 2013

Abstract Spasticity is a common pathological phenomenon in clinical practices, frequently expressed as a stroke, multiple sclerosis or cerebral palsy. The accurate quantification of spasticity allows early action to prevent the potentially irreversible consequences. The aim of this work is to develop and implement a mechatronic device for the accurate quantification of spasticity, which is able to differentiate spasticity from other motor disorders. The proposed method is based on the quantification of the tonic stretch reflex threshold (TSRT) for the assessment of the range of motion of the limb affected by spasticity. In order to validate the developed device, experimental trials have been conducted, considering the flexor muscle of the elbow joint. The developed device was tested, first in a laboratory environment with healthy subjects and secondly, in a clinical environment with the collaboration of patients with spasticity. The evaluations in th clinical environment were performed on three different days in order to evaluate the reproducibility of the obtained results. The experimental trials confirm the sensibility, reproducibility and reliability of spasticity quantification based on the TSRT method. This project has been developed in cooperation with the Hospital of Braga and Fisimaia rehabilitation clinic, both in Portugal.
Mixed Marker-Based/Marker-Less Visual Odometry System for Mobile Robots
Authors: Lamberti Fabrizio , Sanna Andrea , Paravati Gianluca , Montuschi Paolo , Gatteschi Valentina , Demartini Claudio
Published: May 2013

Abstract When moving in generic indoor environments, robotic platforms generally rely solely on information provided by onboard sensors to determine their position and orientation. However, the lack of absolute references often leads to the introduction of severe drifts in estimates computed, making autonomous operations really hard to accomplish. This paper proposes a solution to alleviate the impact of the above issues by combining two vision-based pose estimation techniques working on relative and absolute coordinate systems, respectively. In particular, the unknown ground features in the images that are captured by the vertical camera of a mobile platform are processed by a vision-based odometry algorithm, which is capable of estimating the relative frame-to-frame movements. Then, errors accumulated in the above step are corrected using artificial markers displaced at known positions in the environment. The markers are framed from time to time, which allows the robot to maintain the drifts bounded by additionally providing it with the navigation commands needed for autonomous flight. Accuracy and robustness of the designed technique are demonstrated using an off-the-shelf quadrotor via extensive experimental tests.
Characterization of Optical Absorption and Polarization Dependence of Single-Layer Graphene Integrated on a Silicon Wire Waveguide
Authors: Kou Rai , Tanabe Shinichi , Tsuchizawa Tai , Warabi Kaori , Suzuki Satoru , Hibino Hiroki , Nakajima Hirochika , Yamada Koji
Published: May 2013

Optical absorption efficiency of graphene integrated onto a silicon photonic platform was characterized at around 1.55-µm optical telecommunications wavelength. Micro-Raman spectroscopy performed after the completion of all fabrication processes confirmed that transferred chemical-vapor-deposited graphene is a single layer (>90% coverage) without any significant damage. Absorption efficiencies of the single-layer graphene (SLG) on a silicon wire waveguide, obtained by measuring different lengths (cutback method) of the SLG from 2.5 to 200 µm, were 0.09 and 0.05 dB/µm for TE- and TM-polarized light. The unusual relationship in the polarization dependency can be explained by strong surface-plasmon-porlariton support in the TM mode.
Performance of GaN Metal–Oxide–Semiconductor Field-Effect Transistor with Regrown n+-Source/Drain on a Selectively Etched GaN
Authors: Kim Do-Kywn , Kim Dong-Seok , Chang Sung-Jae , Lee Chang-Ju , Bae Youngho , Cristoloveanu Sorin , Lee Jung-Hee , Hahm Sung-Ho
Published: May 2013

We proposed and fabricated normally off GaN MOSFETs with an epitaxially regrown n+ GaN source/drain after a short period of dry etching on a sapphire substrate. The regrown S/D MOSFET after dry etching (MOSFET A) exhibited enhanced performance in terms of current drivability and access resistance compared with the same MOSFET without the surface etching before the regrowth (MOSFET B). While MOSFET A has a saturation drain current of 10 mA/mm at V
G = 8 V, a field-effect mobility of 22 cm2 V-1 s-1, and a series resistance R
SD of 0.57 kΩ, MOSFET B has 3 mA/mm, 12 cm2 V-1 s-1, and 0.93 kΩ, respectively. The electrical characteristic of MOSFET A was also much more improved than that of MOSFET B at low temperatures. Mobility degradation at low temperatures was related to the effect of impurity scattering caused by crystal defects generated during the metal organic chemical vapor deposition (MOCVD) growth.
Enhanced Photoluminescence from InGaN/GaN Quantum Wells on A GaN/Si(111) Template with Extended Three-Dimensional GaN Growth on Low-Temperature AlN Interlayer
Authors: Jiang Quanzhong , Lewins Christopher J. , Allsopp Duncan W. E. , Bowen Chris R. , Wang Wang N. , Satka Alexander , Priesol Juraj , Uherek Frantisek
Published: May 2013

This paper describes a low-cost route for the reduction of dislocations during growth of GaN on Si(111) using metalorganic vapour phase epitaxy (MOVPE) through three-dimensional (3D) island growth on a low temperature AlN layer which introduces a compressive stress into the over-lying GaN layer to compensate for the thermal mismatch stress between the nitride layer and Si(111) substrate. Such a 3D growth process leads to the reduction of grain twist as the result of the reduction in the number of dislocations having a component parallel to the basal plane. The dislocation reduction process leads to a more uniform luminescence from InGaN/GaN quantum wells, as revealed by spectrally-resolved cathodoluminescence imaging of the cross-section of samples.
Ga(In)N Photonic Crystal Light Emitters with Semipolar Quantum Wells
Authors: Heinz Dominik , Leute Robert Anton Richard , Kizir Seda , Li Yijia , Meisch Tobias , Thonke Klaus , Scholz Ferdinand
Published: May 2013

We present directional photonic crystal light emitters produced as periodic semipolar GaInN quantum wells, grown by selective area metal organic vapour phase epitaxy. The emitted angle-dependent modal structure for sub-micrometer stripes and embedded photonic crystal structures is analyzed experimentally in detail, and the introduction of an Al0.12Ga0.88N cladding layer is investigated. We provide a complete simulation based on the finite-difference time-domain method, which allows to identify all leaky modes as well as their spectral and angular dependence.
Polarization Analysis of Light Scattered by Pollen Grains of Cryptomeria japonica
Authors: Iwai Toshiaki
Published: May 2013

Pollinosis to airborne pollen grains is a severe problem that concerns the whole world. Almost spring allergies in Japan are caused by pollen grains of Japan cedar (Cryptomeria japonica) during the period of pollination from February to May. One of the key technologies in a pollen monitoring and forecast system is a pollen sensor. The pollen grain of Japan cedar is identified by introducing the degree of polarization to the optical sensor based on the scattered intensity. The detectability and discriminability in identifying the pollen grains of Japan cedar from the polystyrene spherical particles and the Kanto loam grains are achieved up to 95 and 86%, respectively.
Exciton-to-Carrier Conversion Processes in a Low-Band-Gap Organic Photovoltaic
Authors: Yonezawa Kouhei , Kamioka Hayato , Yasuda Takeshi , Han Liyuan , Moritomo Yutaka
Published: May 2013

A bulk heterojunction (BHJ) based on a donor (D) polymer and an acceptor (A) fullerene derivative is a promising organic photovoltaic (OPV). We investigated femtosecond charge dynamics after D (at 633 nm) and A (at 400 nm) excitations in a prototypical low-band-gap and highly efficient OPV, i.e., poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7)/[6,6]-phenyl C71-butyric acid methyl ester (PC70BM). The photoinduced absorption (PIA) spectra of the blend film were decomposed into three PIAs, i.e., donor exciton (D*), acceptor exciton (A*), and carrier (D+) components. The analysis revealed that D*→D+conversion predominates in 633 nm excitation, while A*→D+conversion predominates in 400 nm excitation. The carrier formation times of both processes are nearly the same (τrise∼0.2–0.3 ps).
Fabrication of L10-Ordered MnAl Films for Observation of Tunnel Magnetoresistance Effect
Authors: Saruyama Haruaki , Oogane Mikihiko , Kurimoto Yuta , Naganuma Hiroshi , Ando Yasuo
Published: May 2013

We succeeded in fabricating L10-ordered MnAl films with a high perpendicular magnetic anisotropy energy of 107 erg/cm3 and a small average film roughness of 0.4 nm by using a molten Mn–Al sputtering alloyed target and optimizing the substrate temperature. In addition, we investigated the tunnel magnetoresistance (TMR) effect in magnetic tunnel junctions (MTJs) with the prepared L10-ordered MnAl electrode. The TMR effect was observed at RT in an MTJ with a very thin Co50Fe50 layer inserted into the MnAl electrode and MgO tunneling barrier interface. This is the first observation of the TMR effect in MTJs with an L10-ordered MnAl electrode.
Methodology for Evaluating Operation Temperatures of Fin-Type Field-Effect Transistors Connected by Interconnect Wires
Authors: Takahashi Tsunaki , Oda Shunri , Uchida Ken
Published: May 2013

A new methodology for evaluating operation temperatures of transistors connected by interconnect wires is developed. Thermal characteristics of fin-type field-effect transistors (FinFETs) and interconnect wires are modeled using simple equivalent thermal circuits. The temperature nodes are the source, drain, gate, substrate, and hot spot, where the lattice temperature is the highest. By calculating heat flows from the hot spot to the other four nodes, the thermal resistances R
th's for bulk and silicon-on-insulator (SOI) FinFETs are extracted. It is shown that the source R
th is higher than the drain R
th because of asymmetric temperature distributions in the device. The thermal resistances of interconnect wires and vias are given as analytical expressions. By combining the device R
th's and the analytical R
th's for the interconnect wires and vias, device temperatures can be obtained. The validity of the proposed methodology was confirmed by temperature simulations of a circuit where two devices were connected in parallel. It is demonstrated that high-thermal-conductivity interconnect materials, such as carbon nanotubes, are effective for lowering device temperatures when interconnects are extremely downscaled such as systems at the 14 nm technology node.
Heterojunction Diodes Comprising p-Type Ultrananocrystalline Diamond Films Prepared by Coaxial Arc Plasma Deposition and n-Type Silicon Substrates
Authors: Katamune Yūki , Ohmagari Shinya , Al-Riyami Sausan , Takagi Seishi , Shaban Mahmoud , Yoshitake Tsuyoshi
Published: May 2013

Heterojunction diodes, which comprise boron-doped p-type ultrananocrystalline diamond/hydrogenated amorphous carbon composite (UNCD/a-C:H) films prepared by coaxial arc plasma deposition and n-type Si substrates, were electrically studied. The current–voltage characteristics showed a typical rectification action. An ideality factor of 3.7 in the forward-current implies that carrier transport is accompanied by some processes such as tunneling in addition to the generation–recombination process. From the capacitance–voltage measurements, the built-in potential was estimated to be approximately 0.6 eV, which is in agreement with that in a band diagram prepared on the assumption that carriers are transported in an a-C:H matrix in UNCD/a-C:H. Photodetection for 254 nm monochromatic light, which is predominantly attributable to photocurrents generated in UNCD grains, was evidently confirmed in heterojunctions. Since dangling bonds are detectable by electron spin resonance spectroscopy, their control might be an important key for improving the rectifying action and photodetection performance.
Thermal Boundary Resistance of W/Al2O3 Interface in W/Al2O3/W Three-Layered Thin Film and Its Dependence on Morphology
Authors: Kawasaki Shizuka , Yamashita Yuichiro , Oka Nobuto , Yagi Takashi , Jia Junjun , Taketoshi Naoyuki , Baba Tetsuya , Shigesato Yuzo
Published: May 2013

We investigated the dependence of the thermal boundary resistance of the W/Al2O3 interface in W/Al2O3/W three-layered thin films on the interface morphology. The layered structures, Al2O3 thin layers with thicknesses from 1 to 50 nm covered by top and bottom W layers with a thickness of 100 nm, were fabricated by magnetron sputtering using a W target (99.99%) and an Al2O3 target (99.99%). The fabrication of polycrystalline W and amorphous Al2O3 films was confirmed by structural analysis. The morphology of the bottom W layer/Al2O3 layer and Al2O3 layer/top W layer interfaces showed a wavelike structure with a roughness of about 1 nm. Thermophysical properties and thermal boundary resistance were measured by a pulsed light heating thermoreflectance technique. The thermal boundary resistance of the W/Al2O3 interface was 1.9×10-9 m2 K W-1, which corresponds to the thermal resistance of a 3.7-nm-thick Al2O3 film or a 120-nm-thick W film.
Suppression of Radial Divergence of Extremely Low Energy Ion Beam by an Electron Beam Injection to a Grounded Electrode
Authors: Hirano Yoichi , Kiyama Satoru , Sakakita Hajime , Koguchi Haruhisa , Shimada Toshio , Sato Yasuhiro
Published: May 2013

Transition to a highly focused state is observed in a hydrogen ion beam extracted from an ion source using concave-shaped electrodes. The beam has a low energy (∼95 eV) and a high current (∼60 mA) with a ∼60 mm diameter. The transition is induced by electron beam injection (1 keV and up to 50 mA) to a grounded electrode of an ion source from a direction obliquely opposite to the ion beam velocity. Probably, secondary electrons emitted from the electrode play an effective role in cancelling the beam ion space charge, since they are produced in the core region of ion beam immediately after the extraction. Comparison between the cases with and without an electron beam exhibits great improvements not only in a total ion beam current reaching a target, but also in the focusing of ion beam. The sudden transition to this highly focused state, which is triggered by a low electron beam current (∼9 mA), suggests that some kind of a nonlinear process plays an essential role in this focusing.
Diffusive Plasma Dechucking Method for Wafers to Reduce Falling Dust Particles
Authors: Jun Hyun-Su
Published: May 2013

A plasma dechucking method capable of effectively eliminating dust particles created during the plasma process was developed. Referred to as diffusive plasma dechucking (DPD), the method reduces the plasma potential and includes an argon gas purge to remove dust particles floating on top of the sheath after the main process. Experimental results indicate that DPD reduces the amount of falling dust particles after the process by approximately 50–80%. To analyze these results quantitatively, the Coulomb force and the neutral drag force exerted on the dust particles were considered. In addition, dust particle exhaust conditions were proposed with respect to dust particle size, plasma potential, and spatial electric field.
Simple Method of Determining the Temperature of Laser Diode Integrated into Heat-Assisted Magnetic Recording Head
Authors: Sato Takanobu , Etoh Hideki , Kitazawa Tazuko , Kotani Teruhisa , Iwata Noboru
Published: May 2013

We propose a new experimental method of determining the temperature of a laser diode (LD) integrated into a heat-assisted magnetic recording head that utilizes the temperature dependence of the peak wavelength on the LD. Furthermore, we experimentally show the temperature rise of the LD mounted on the trailing side of an Al2O3–TiC slider. On our sample head assembly, the temperature rise is about 4 °C when the optical output power and duty ratio of the LD are 15 mW and 50%, respectively.
Effect of Coating Self-Assembled Monolayer on Room-Temperature Bonding of Cu Micro-Interconnects
Authors: Qiu Lijing , Ikeda Akihiro , Asano Tanemasa
Published: May 2013

The effect of coating the surface of a Cu microbump with a 1-hexanethiol self-assembled monolayer (SAM) on room-temperature solid-phase bonding was investigated. The microbump was cone-shaped while the counterelectrode was planar. Room-temperature bonding was performed by applying ultrasonic vibration. Chemical analysis showed that the SAM coating suppressed the surface oxidation of Cu. However, it was shown that the SAM coating also reduced the mechanical strength of the bonded interface, whereas little effect was observed in the electrical resistance of bump interconnects.
Nearly 4-Inch-Diameter Free-Standing GaN Wafer Fabricated by Hydride Vapor Phase Epitaxy with Pit-Inducing Buffer Layer
Authors: Sato Tadashige , Okano Shinya , Goto Takenari , Yao Takafumi , Seto Ritsu , Sato Akira , Goto Hideki
Published: May 2013

A free-standing GaN wafer was fabricated by depositing a GaN buffer that induced the formation of pits (hereafter, pit-inducing GaN buffer) on a low-temperature-grown GaN buffer on the sapphire substrate. A high-temperature-grown GaN layer was grown on the pit-inducing GaN buffer that induced the formation of pits on the high-temperature-grown GaN layer. The pit-inducing buffer suppresses crack formation in the thick GaN film thereby releasing growth stress. Thermal stress in GaN on a sapphire system is also discussed on the basis of calculations utilizing a bilayer model. We have succeeded in the fabrication of a nearly 4-in.-diameter free-standing GaN thick wafer with a pit-inducing GaN buffer by one-stop hydride vapor phase epitaxy, which will lead to a low-cost fabrication of free-standing GaN wafers.
Growth Mode and Threading Dislocation Behavior of GaN Films Grown on Patterned Sapphire Substrate with Radial Stripe Pattern
Authors: Okuno Koji , Oshio Takahide , Shibata Naoki , Honda Yoshio , Yamaguchi Masahito , Amano Hiroshi
Published: May 2013

A sapphire substrate with a grooved stripe pattern along different radial directions was prepared to investigate the effects of stripe direction on the growth mode and threading dislocation (TD) behavior of GaN films. When the stripe direction is oriented parallel to [101̄0]sapphire, the GaN films have a triangular structure that is formed by the GaN{101̄1} facets. As the stripe direction rotates from [101̄0]sapphire, nanosteps with a step height of around 80 nm are formed on the GaN{101̄1} facets and then the coalescence of GaN on the ridges and grooves advances. GaN films with a smooth surface and a TD density as low as 2.0×108 cm-2 were achieved when the stripe direction was rotated 3° from [101̄0]sapphire. Our result indicates that the surface roughness and TD density of GaN films can be controlled by precisely adjusting the angle of the stripe direction from [101̄0]sapphire.
High-Temperature Heat-Treatment of c-, a-, r-, and m-Plane Sapphire Substrates in Mixed Gases of H2 and N2
Authors: Nomura Kazushiro , Hanagata Shoko , Kunisaki Atsushi , Togashi Rie , Murakami Hisashi , Kumagai Yoshinao , Koukitu Akinori
Published: May 2013

Orientation dependent decomposition of sapphire substrates and resultant AlN formation during heat treatment in an atmospheric-pressure mixed gas flow of H2 and N2 (H2/N2= 3/1) was investigated within the temperature range 980–1480 °C. AlN was formed on sapphire in the temperature range 1030–1430 °C for c-, a-, and m-plane sapphire, and 980–1430 °C for the r-plane sapphire. At 1480 °C, AlN was not formed, and only sapphire was decomposed by H2 with the ranking of m- > r- > a- > c-plane. The ranking was contrary to that of the amount of AlN formation at 1380 °C, which occurred by the reaction of gaseous Al generated by the sapphire decomposition and N2. This discrepancy was due to the shape of AlN formed on sapphire; whisker-like AlN does not protect c- and a-plane sapphire from decomposing, while layer-like AlN protects r- and m-plane sapphire from decomposing.