bluuebunny/crossref_metadata_2025 huggingface dataset:
Dispersibility of silane‐functionalized alumina nanoparticles in syndiotactic polypropylene
Authors: Truong Le Thuy , Larsen Åge , Holme Børge , Diplas Spyros , Hansen Finn Knut , Roots Jaan , Jørgensen Sissel
Published: January 2010

The dispersibility of silane‐functionalized alumina nanoparticles (NPs) in syndiotactic polypropylene (sPP) was investigated. The Al2O3 NP surface was modified with two different silane coupling agents, (3‐chloropropyl)triethoxysilane and (octyl)triethoxysilane, to create hydrocarbon groups, or their halogen derivatives, for the enhanced hydrophobic interaction with the sPP matrix. Transmission electron microscopy studies showed that the presence of hydrophobic groups improved the dispersibility of alumina NPs in the sPP matrix. A good dispersibility was found in both (3‐chloropropyl)triethoxysilane‐modified Al2O3/sPP nanocomposites and (octyl)triethoxysilane‐modified Al2O3/sPP nanocomposites. Copyright © 2010 John Wiley & Sons, Ltd.
Characterizing the surface acidity of bentonite by various methods
Authors: Bilgiç C. , Topaloglu Yazıcı D. , Vural N.
Published: January 2010

Surface acidity of bentonite was investigated by using three methods. The first method was inverse gas chromatography; the acid‐base character of bentonite surface was estimated by the retention time with different nonpolar and polar probes at infinite dilution region. The adsorption specific free energy (ΔGSP), specific enthalpy (ΔHSP), and specific entropy (ΔSSP) of polar probes on bentonite were determined. By correlating ΔHSP with donor and acceptor numbers of the probes, the acidic (KA) and the basic (KD) parameters of the sample were calculated. The second method was recording the spectrums of pyridine by Fourier transform infrared spectroscopy (FTIR); the spectrum of pyridine bonded by Bronsted and Lewis acid sites was obtained. The last method was modified amine titration by using Hammett indicators. Copyright © 2010 John Wiley & Sons, Ltd.
The effects of shadow‐fading on QoS‐aware routing and admission control protocols designed for multi‐hop MANETs
Authors: Hanzo Lajos , Tafazolli Rahim
Published: January 2010

Providing quality‐of‐service (QoS) assurances in a mobilead hocnetwork (MANET) is difficult due to node mobility, contention for channel access, a lack of centralised coordination, and the unreliable nature of the wireless channel. QoS‐aware routing (QAR) and admission control (AC) protocols comprise two of the most important components of a system attempting to provide QoS guarantees in the face of the above‐mentioned difficulties.

This paper presents a comparative study, utilising a realistic shadow fading channel, of the performance of several state‐of‐the‐art amalgamated QAR‐AC protocols, which are designed for providing throughput guarantees to applications. The advantages and drawbacks of their particular features are highlighted. For an environment where link quality varies rapidly, the results of the study highlight the ineffectiveness of previously‐proposed methods of relying merely on the success of route discovery to perform AC, of relying on the exceeding of the MAC layer retransmission count for link failure detection, of existing congestion detection schemes and of careful re‐admission of data sessions rather than fast re‐routing after shadowing‐induced link failures. Based on the lessons learnt, design guidelines for future QAR and AC protocols operating in a mobile shadow‐fading‐afflicted environment are presented. Copyright © 2010 John Wiley & Sons, Ltd.
A pragmatic approach to area coverage in hybrid wireless sensor networks
Authors: Ahmed Nadeem , Kanhere Salil S. , Jha Sanjay
Published: January 2010

Success of Wireless Sensor Networks (WSN) largely depends on whether the deployed network can provide desired area coverage with acceptable network lifetime. This paper seeks to address the problem of determining the current coverage achieved by the non‐deterministic deployment of static sensor nodes and subsequently enhancing the coverage using mobile sensors. We identify three key elements that are critical for ensuring effective area coverage in Hybrid WSN: (i) determining the boundary of the target region and evaluating the area coverage (ii) locating coverage holes and maneuvering mobile nodes to fill these voids, and (iii) maintaining the desired coverage over the entire operational lifetime of the network. We propose a comprehensive solution that addresses all of the aforementioned aspects of the area coverage, called MAPC (mobility assisted probabilistic coverage). MAPC is a distributed protocol that operates in three distinct phases. The first phase identifies the boundary nodes using the geometric right‐hand rule. Next, the static nodes calculate the area coverage and identify coverage holes using a novel probabilistic coverage algorithm (PCA). PCA incorporates realistic sensing coverage model for range‐based sensors. The second phase of MAPC is responsible for navigating the mobile nodes to plug the coverage holes. We propose a set of coverage and energy‐aware variants of the basic virtual force algorithm (VFA). Finally, the third phase addresses the problem of coverage loss due to faulty and energy depleted nodes. We formulate this problem as an Integer Linear Program (ILP) and propose practical heuristic solutions that achieve similar performance as that of the optimal ILP solution. A guiding principle in our design process has been to ensure that the MAPC can be readily implemented in real‐world applications. We implemented the boundary detection and PCA algorithm (i.e., Phase I) of the MAPC protocol on off‐the‐shelf sensor nodes and results show that the MAPC can successfully identify boundary nodes and accurately determine the area coverage in the presence of real radio irregularities observed during the experiments. Extensive simulations were carried out to evaluate the complete MAPC protocol and the results demonstrate that MAPC can enhance and maintain the area coverage, while reducing the total energy consumption by up to 70% as compared with the basic VFA. Copyright © 2010 John Wiley & Sons, Ltd.
Network infrastructure extension using 802.1D‐based wireless mesh networks
Authors: Campos Rui , Duarte Ricardo , Sousa Filipe , Ricardo Manuel , Ruela José
Published: January 2010

Ubiquitous Internet access is becoming a major requirement for end‐users due to the increasing number of services and applications supported over the Internet. Extending the coverage of current Wi‐Fi infrastructures installed in companies, universities and cities, has been considered a solution to help in fulfilling this requirement, namely when it comes to wireless and nomadic Internet access.

This paper describes and analyses a new and simple solution, called Wi‐Fi network Infrastructure eXtension (WiFIX), aimed at extending current Wi‐Fi infrastructures. WiFIX is based on standard IEEE 802.1D bridges and a single‐message protocol that is able to self‐organize the network, and it only requires software changes in IEEE 802.11 access points (APs); no changes to IEEE 802.11 stations are needed. Overhead analysis and experimental results show both the higher efficiency of the solution compared to the IEEE 802.11s draft standard and its good performance as far as data throughput, delay and packet loss are concerned. Copyright © 2010 John Wiley & Sons, Ltd.
Peak‐to‐average power ratio reduction in space–time coded MIMO‐OFDM via preprocessing
Authors: Zhu Dalin , Natarajan Balasubramaniam , Dyer Justin S.
Published: January 2010

In this paper, we propose a trellis exploration algorithm based preprocessing strategy to lower the peak‐to‐average power ratio (PAPR) of precoded MIMO‐OFDM. We first illustrate the degradation in PAPR due to optimal linear precoding in MIMO‐OFDM systems. Then we propose two forms of multi‐layer precoding (MLP) schemes to reduce PAPR. In both schemes, the inner‐layer precoder is designed to optimize system capacity/BER performance. In the first MLP scheme (MLP‐I), a common outer‐layer polyphase precoding matrix is employed. In the second MLP scheme (MLP‐II), data stream corresponding to every transmit antenna is precoded with a different outer‐layer polyphase precoding matrix. Both outer‐layer precoders are custom designed using the trellis exploration algorithm by applying the aperiodic autocorrelation of OFDM data symbols as the metric to minimize. Simulation results indicate that both MLP schemes show superior PAPR performance over conventional MIMO‐OFDM with and without precoding. In addition, MLP better exploits frequency diversity resulting in BER performance gains in multi‐path environments. Copyright © 2010 John Wiley & Sons, Ltd.
Reducing computational complexity using transmitter correlation value‐assisted schedulers in multiuser MIMO uplink
Authors: Gong Peng , Cao Ning , Kim Duk Kyung
Published: January 2010

In this paper, a threshold bounded antenna selection scheduler (TBS) and a computational complexity bounded antenna selection scheduler (CCBS) are proposed to reduce computational complexity in multiple input multiple output (MIMO) uplink. In contrast to previous works, a spatially correlated MIMO channel model is considered and a transmitter correlation value (TCV) is newly introduced to assist the antenna selection in addition to the channel gain. For the TBS or CCBS, with predetermined threshold of TCV or ratio of successful antennas (RSAs), full searching (FS) and sub searching (SS) are applied more efficiently to user equipments (UEs) compared with previous schedulers. As a result, the number of candidate antennas in the scheduling set can be reduced, which translates into a lower computational complexity in terms of number of evaluated antenna combinations. Additionally, compared with the TBS, the peak computational complexity can be further reduced by the CCBS. Simulation results show that with proposed schedulers the computational complexity can be reduced by at least 50% with an acceptable compromise of capacity. Copyright © 2010 John Wiley & Sons, Ltd.
Are gobiid fish more susceptible to predation if parasitized byEustrongylides excisus? An answer from robbed snakes
Authors: Sloboda Michal , Mihalca Andrei Daniel , Falka Istvan , Petrželková Klára J. , Carlsson Martin , Ghira Ioan , Modrý David
Published: January 2010

Aspects of the predator–prey relationship between dice snake,Natrix tessellataand gobiid fish infected withEustrongylides excisuswere studied in Lake Sinoe, Romania. A population of snakes residing here shows a high prevalence of subcutaneous larvae of this nematode. The hypothesis of the altered motility in infected fish leading to increased depredation by snakes was tested by comparing gobiids collected from dice snakes with gobiids caught via electrofishing. Out of a total of seven identified gobiid species, three were used for analysis: syrman gobyNeogobius syrman, mushroom gobyNeogobius eurycephalus, and round gobyNeogobius melanostomus. No significant differences in prevalence and intensity ofE.excisusinfection were found between fish caught by snakes and those obtained by electrofishing. However, significantly higher abundance ofE.excisuslarvae in fish caught by snakes was reported. These findings suggest limited influence of the presence ofE.excisuslarvae in studied gobiids regarding their susceptibility to predation by dice snakes.
Competitive Binding of Off‐Flavor Compounds with Soy Protein and β‐Cyclodextrin in a Ternary System: A Model Study
Authors: Arora Akshay , Damodaran Srinivasan
Published: January 2010

Removal of soy protein (SP)‐bound 2‐nonanone by β‐cyclodextrin (βCD) was studied using an equilibrium dialysis technique. It was observed that in the presence of βCD, a significant (p < 0.05) amount of SP‐bound 2‐nonanone could be removed in a concentration‐dependent manner. Up to 94% of SP‐bound 2‐nonanone was stripped from SP when 6 mM βCD was present in the system. However, in thermodynamic terms, the net standard free energy change for transfer of 2‐nonanone from SP to βCD, i.e., , was essentially zero, implying that the apparent equilibrium binding constant for the formation of βCD–2‐nonanone complex was essentially same as that for the SP–2‐nonanone complex formation in the ternary system. This indicated that stripping‐off of 2‐nonanone from SP by βCD was driven by the mass action ratio. Based on these results, it is shown that βCD can be used effectively for removing SP‐bound off‐flavor carbonyl compounds.
Short-term monitoring of the Spanish government balance
Authors: Leal Teresa , Pedregal Diego J. , Pérez Javier J.
Published: January 2010

We construct multivariate, state-space mixed-frequencies models for the main components of the Spanish General Government sector made up of blocks for each one of its subsectors: Central Government, Social Security and aggregate of Regional and Local government sectors. Each block is modelled through its total revenue and expenditure categories, and encompasses a number of indicators, depending on data availability. The mixed-frequencies approach is particularly relevant for the case of Spain, given its institutional set-up and the specific data availability for the different subsectors. All in all, we provide models detailed enough in coverage, while at the same time manageable, to be used: (1) for real-time monitoring of fiscal policies with a focus on quarterly developments of the General Government sector, (2) for the monitoring of general government sub-sectors for which intra-annual data coverage is limited (Regional and Local governments), (3) to bridge (translate) into National Accounts available monthly information for the subsectors of the general government.
Mitochondrial potassium channels and reactive oxygen species
Authors: Malinska Dominika , Mirandola Sandra R. , Kunz Wolfram S.
Published: January 2010

Pretreatment of tissues with potassium channel openers (KCO's) has been observed to be cytoprotective in a broad variety of insults. This phenomenon has been proposed to be intimately linked to activation of mitochondrial potassium channels which apparently modulate the mitochondrial production of reactive oxygen species (ROS). This critical review summarizes literature findings about the mitochondrial production of ROS, the action of KCO's on mitochondrial ROS production and the putative link to the cytoprotective action of these drugs.
ATP‐triggered ADP release from the asymmetric chaperonin GroEL/GroES/ADP7 is not the rate‐limiting step of the GroEL/GroES reaction cycle
Authors: Tyagi Navneet K. , Fenton Wayne A. , Horwich Arthur L.
Published: January 2010

The GroEL/GroES protein folding chamber is formed and dissociated by ATP binding and hydrolysis. ATP hydrolysis in the GroES‐bound (cis) ring gates entry of ATP into the opposite unoccupied trans ring, which allosterically ejects cis ligands. While earlier studies suggested that hydrolysis of cis ATP is the rate‐limiting step of the cycle (t
½
∼ 10 s), a recent study suggested that ADP release from the cis ring may be rate‐limiting (t
½
∼ 15–20 s). Here we have measured ADP release using a coupled enzyme assay and observed a t
½ for release of ⩽4–5 s, indicating that this is not the rate‐limiting step of the reaction cycle.
Regulation of HOXA2 gene expression by the ATP‐dependent chromatin remodeling enzyme CHD8
Authors: Yates Joel A. , Menon Tushar , Thompson Brandi A. , Bochar Daniel A.
Published: January 2010

MINT‐7542769: CHD8 (uniprotkb:Q9HCK8) physically interacts (MI:0914) with RbBP5 (uniprotkb:Q15291), ASH2L (uniprotkb:Q9UBL3) and WDR5 (uniprotkb:P61964) by anti tag coimmunoprecipitation (MI:0007)
The age of metamorphism of sillimanite-bearing schists at the Kyakhtinskoe deposit (southwestern Transbaikalia)
Authors: Izbrodin I.A. , Ripp G.S. , Doroshkevich A.G. , Sergeev S.A. , Matukov D.I. , Posokhov V.F.
Published: January 2010

Results of U-Pb (SHRIMP II) and Rb-Sr dating of sillimanite schists in southwestern Transbaikalia are presented, which testify to high-temperature metamorphism in the Late Mesozoic. The metamorphism might have been related to the formation of metamorphic cores or tectonoplutonic activity accompanied by the formation of rift structures in Transbaikalia and Mongolia.
Cobalt behavior during natural and technogenic oxidative leaching of Co-containing pyrites (Letnee chalcopyrite deposit, Southern Urals)
Authors: Gaskova O.L. , Belogub E.V. , Makarov D.V.
Published: January 2010

Cobalt behavior during the oxidation of sulfide ores, unlike that during the oxidation of Co ores, is poorly known. Moreover, cobalt sulfates are rare in the world. Complex hydrous cobalt-containing and cobalt sulfates have been found in technogenic zones at the Letnee chalcopyrite deposit (Southern Urals). They have been identified at pit bottoms, in the ore stockpile, as well as directly on ore fragments and the evaporation barriers of underdump water puddles. The paper reports the first experimental data on the oxidative leaching of Co-containing sulfide ores in the laboratory. Also, parts of a thermodynamic model for Co behavior in oxidized zones are presented.

Experiments have revealed an increase in acidity up to pH = 4.14, along with transport of sulfate sulfur and metals into solution. This suggests acid mine drainage during the development of the Letnee deposit. The published stability diagrams for hydrous Cu, Mg, Zn, Co, and Ni sulfates were analyzed and compared with mineralogical finds in a technogenic oxidized zone. This made it possible to explain the precipitation sequence of minerals from solutions during their concentration by evaporation. As salts of these elements are highly soluble, significant contents of toxic metals will inevitably remain in equilibrium solution, necessitating additional waste-water treatment (for example, creating sorption geochemical barriers). Therefore, the paper describes regularities in Co behavior during its sorption on solid phases.
Notes on three earthquakes in Santiago de Cuba (14.10.1800, 18.09.1826, 07.07.1842)
Authors: Cotilla M.O. , Córdoba D.
Published: January 2010

Damage and parameters of the earthquakes of October 14, 1800, September 18, 1826, and July 7, 1842, in Santiago de Cuba, in southeastern Cuba, have been studied. A quantitative re-evaluation of the size of the events is not feasible due to a lack of data. Hence, we have reinterpreted existing data to establish likely intensities and determine the epicentral region of occurrence. Available data do not permit accurate depth determinations. Intensities estimated from contemporary documentary sources give maximum values of 8, 8–9 and 8 (MSK scale), respectively. These seismic shocks were located in the Southeastern Seismotectonic Province of Cuba, Plate Boundary Zone Caribbean—North Atmerican. The earthquakes are associated with the Oriente fault system.
Association of dietary fat, vegetables and antioxidant micronutrients with skin ageing in Japanese women
Authors: Nagata Chisato , Nakamura Kozue , Wada Keiko , Oba Shino , Hayashi Makoto , Takeda Noriyuki , Yasuda Keigo
Published: January 2010

Daily diet may have implications for skin ageing. However, data on the relationship between diet and the parameters of skin conditions are scarce. The present study aimed to examine the associations of biophysical properties of the skin of women with intakes of fats and antioxidant micronutrients as well as food groups as sources of these nutrients. In a cross-sectional study, we measured the hydration, surface lipids and elasticity of the skin of 716 Japanese women using non-invasive techniques. The extent of facial wrinkles in the crow's-foot area was determined by observation using the Daniell scale. Each subject's usual diet was determined with the use of a validated FFQ. After controlling for covariates including age, smoking status, BMI and lifetime sun exposure, the results showed that higher intakes of total fat, saturated fat and monounsaturated fat were significantly associated with increased skin elasticity. A higher intake of green and yellow vegetables was significantly associated with a decreased Daniell wrinkling score. Intake of saturated fat was significantly inversely associated with the Daniell wrinkling score after additional adjustment for green and yellow vegetable intake. Further studies with more accurate measurement methods are needed to investigate the role of daily diet in skin ageing.
Geochronology and structural relationships of mesothermal gold mineralization in the Palaeoproterozoic Jokisivu prospect, southern Finland
Authors: SAALMANN K. , MÄNTTÄRI I. , PELTONEN P. , WHITEHOUSE M. J. , GRÖNHOLM P. , TALIKKA M.
Published: January 2010

The palaeoproterozoic Svecofennian orogen in southern Finland contains a number of orogenic gold occurrences. The Jokisivu gold deposit, comprising auriferous quartz veins, is hosted by syn-tectonic quartz diorites to gabbros. Mineralization occurs in approximately WNW–ESE- and WSW–ENE-trending shear zones, which probably branch from regional-scale NW–SE-trending shears. Ore zone fabrics post-date regional-scale folding and the metamorphic peak, and can be correlated with late Svecofennian regional shear tectonics (D6; 1.83–1.78 Ga), indicating that mineralization formed during the late stages of orogenic evolution. SIMS and TIMS U–Pb dating of three samples place tight constraints on the age of gold mineralization. Zircons from both unaltered and altered quartz diorites have ages of 1884±4 Ma and 1881±3 Ma, respectively. These are interpreted as the crystallization age of the rock and as providing the maximum age for mineralization. Zircon rims from an altered quartz diorite from the ore zone give ages of c. 1802±15 Ma, which overlap with the 1801±18 Ma titanite (mean Pb–Pb) age from the ore zone. The ages are similar to the age of the pegmatite dyke that cuts the ore zone and whose zircon age of 1807±3 Ma is approximately the same as the 1791±2 Ma monazite age (TIMS) giving the minimum age of the gold mineralization. The mineralization and its structural framework can be correlated with coeval late Svecofennian shear tectonics related to WNW–ESE-oriented shortening in southern Finland. Extensive c. 1.8 Ga granite magmatism, shear zone development and associated gold mineralization are of regional importance also in the northern and western Fennoscandian Shield (Finnish Lapand and Sweden). A Cordilleran-type setting can explain the widespread distribution of magmatism and gold mineralization associated with shortening, as well as the required heat source triggering hydrothermal fluid flow along shear zones.
THE ASSOCIATION OF SOCIAL SUPPORT AND ACTIVITIES WITH HEALTH IN SOUTH KOREA: DIFFERENCES IN AGE AND GENDER
Authors: MOON SANG-SIK , PARK SANG-MI , CHO SUNG-IL
Published: January 2010

This study investigated gender difference in the effects of social support, including emotional support and instrumental support (such as help when sick and financial assistance), and social activities on perceived health of middle-aged and older adults in South Korea. Data were acquired from 3771 men and 4954 women aged 40 years and older who participated in the 2005 cross-sectional survey of the Seoul Citizens Health and Social Indicators Survey. Using multiple regression analysis, both age- and gender-specific differences related to social support and engagement in social activities and self-rated poor health were examined. Poor emotional support from close friends, relatives or someone with whom one could talk about worries was strongly associated with poor self-rated health in men, with the greatest effect in older men. Lack of engagement in social activities was associated with self-rated poor health in older adults, especially in older men. Poor instrumental support was associated with perceived poor health only in middle-aged women. As a health improvement strategy for men aged 65 years and older especially, emotional support should be considered. Measures should be considered for encouraging social activities by older adults, particularly older men.
Executive functioning in high-IQ adults with ADHD
Authors: Antshel K. M. , Faraone S. V. , Maglione K. , Doyle A. E. , Fried R. , Seidman L. J. , Biederman J.
Published: January 2010

Background

To examine the association between psychological tests of executive functioning and functional outcomes among high-IQ adults with attention deficit hyperactivity disorder (ADHD).

Method

Subjects were high-IQ adults with (n=64) and without ADHD (n=53). Subjects were administered a battery of neuropsychological tests assessing executive functioning.

Results

High-IQ adults with ADHD performed less well than those without ADHD on several psychological tests of executive functioning, including the Wisconsin Card Sorting Test (WCST), Stroop Color and Word Test, Rey–Osterrieth Complex Figure Test (ROCF), California Verbal Learning Test (CVLT) and an auditory continuous performance test (CPT). Test performance in the high-IQ adult ADHD group, however, was average. In the entire sample, performance on several tests of executive functioning including the ROCF and the CVLT were significant predictors of real-world functioning.

Conclusions

High-IQ adults with ADHD perform less well on tests of executive functioning relative to high-IQ control participants. Performance on several tests of executive functioning was a significant predictor of functioning.
Desiderata for a History of Austrian Sexualities
Authors: Bunzl Matti
Published: January 2010

The history of sexuality is a recent field. As a domain of scholarly inquiry, it emerged in the late 1970s, partially the outgrowth of women's history and partially the product of the lesbian/gay movement. Its foundational text is the first volume of Michel Foucault'sThe History of Sexuality, published in French in 1976 and translated into English two years later. This is among the rare books that are truly pathbreaking, taking what was regarded as a “natural” phenomenon and showing its deep historicity.
The United Kingdom government's ‘business case’ approach to the regulation of retirement
Authors: FLYNN MATTHEW
Published: January 2010

In the Employment Equality (Age) Regulations 2006, the United Kingdom government set a ‘default’ retirement age of 65 years after which an employer can compulsorily retire workers, and made it obligatory for employers to consider the ‘business case’ for any employees' requests to continue in work after the default age. This is a ‘light touch’ approach to reducing age discrimination at the workplace and to changing the established ‘culture of retirement’. While encouraging productive staff to remain in post beyond 65 years of age, it leaves implementation of the policies and achievement of their goals to the discretion of employers. This article explores how British employers are adapting to the law, by drawing from interviews with 70 managers from a wide range of organisations. Overall the collected evidence shows the limits of a business case approach as a means of changing employers' practices. It was found that line managers, rather than senior managers or human resources specialists, generally decide which employees can stay employed after age 65 years. Consequently, the research suggests that opportunities for workers aged 65 or more years to stay employed are more the result of individual arrangements with their immediate managers than changes in an organisation's policies and practices. Altogether, the evidence suggests that consolidation rather than eradication of the established retirement culture has occurred.
Stochastic optimization-based approach for multifingered grasps synthesis
Authors: Bounab Belkacem , Labed Abdenour , Sidobre Daniel
Published: January 2010

In this paper, we propose an approach for computing suboptimal grasps of polyhedral objects. Assumingnhard-finger contact with Coulomb friction model and based on central axes of the grasp wrench, we develop a new necessary and sufficient condition forn-finger grasps to achieve force-closure property. Accordingly, we reformulate the proposed force-closure test as a new linear programming problem, which we solve using an interior point method. Furthermore, we present an approach for finding appropriate stable grasps for a robotic hand on arbitrary objects. We use the simulated annealing technique for synthesizing suboptimal grasps of 3D objects. Through numerical simulations on arbitrary shaped objects, we show that the proposed approach is able to compute good grasps for multifingered hands within a reasonable computational time.
Sound source tracking considering obstacle avoidance for a mobile robot
Authors: Uchiyama Naoki , Sano Shigenori , Yamamoto Akihiro
Published: January 2010

Sound source tracking is an important function for autonomous robots, because sound is omni-directional and can be recognized in dark environment. This paper presents a new approach to sound source tracking for mobile robots using auditory sensors. We consider a general type of two-wheeled mobile robot that has wide industrial applications. Because obstacle avoidance is also an indispensable function for autonomous mobile robots, the robot is equipped with distance sensors to detect obstacles in real time. To deal with the robot's nonholonomic constraint and combine information from the auditory and distance sensors, we propose a model reference control approach in which the robot follows a desired trajectory generated by a reference model. The effectiveness of the proposed method is confirmed by experiments in which the robot is expected to approach a sound source while avoiding obstacles.
The Role of the Institute
Authors: Sadler D. H.
Published: January 2010

When, last year, you did me the honour of electing me your President you gave me the duty, and the privilege, of composing and delivering a Presidential Address. It does not lie within my abilities to make a grand survey of the present state of any great and important navigational development—such as might fittingly form the central theme of such an Address, and which has, in fact, been so admirably treated by my predecessors in this office. I have, however, been privileged to serve on the inner councils of the Institute since the earliest days of its conception, and feel that I may be in a position to take the Institute of Navigation itself as a central theme. I do so at this time particularly because the by-laws of the Institute quite rightly operate to ensure that no one person shall remain on the Council indefinitely and I must be the last to have such continuous service since the foundation. But there is a more cogent reason: the Institute was founded in the enthusiasm of the immediate post-war application of war-time navigational methods to civil use, and its precise role was deliberately left vague. It will be my object this afternoon to examine the extent to which the Institute is fulfilling its initial purpose and, on the basis of seven years' experience, how it can best play its part in the future.
Instrument Requirements for Civil Aircraft
Authors: Majendie A. M. A.
Published: January 2010

In modern air navigation, fuel consumption and cruise control present problems inseparable from those of pure navigation. Captain Majendie's paper, which was prepared for another purpose (but has not previously been published), is therefore of particular interest to navigators, because of the light it sheds on these related matters.

Instruments are to a very real extent the basic tools of both the pilot and navigator of a civil transport aircraft, and it is difficult to draw any clear line between their respective requirements. The following notes have been put together to try to give a survey of some of the most useful lines of development in this field. Clearly, such a survey must be in very general terms, but it is hoped that it may be of value in setting the various problems discussed into some sort of general perspective.
I—Navigation in Ocean Racing
Authors: Illingworth J. H.
Published: January 2010

In its essence, navigation in ocean races is the same as navigation on any other voyage; the processes are the same and the drill is not very different. But it is a specialized thing and there are certain interesting problems which demand special solutions and special ways of doing things. To start with, the vessel is propelled by wind and one cannot, in the ordinary course of events, lay off one's mean course and steer it; the course will be continually varying, and the whole of the navigational problem is coloured by this fact. Again, navigation in ocean racing demands a much higher accuracy than navigation in an ordinary sailing vessel, where a landfall within five or perhaps even more miles in good visibility will be quite enough; the difference between spot-on and five miles away may well be the difference between winning an ocean race and otherwise.
II—Navigatim a Midget Submarine
Authors: Place B. C. G.
Published: January 2010

Although an X-craft is a complete submarine in miniature, it does not fire torpedoes but carries two large mines which are dropped under the enemy ship at anchor in its harbour and time-fused to explode when the X-craft has retired to a safe distance. Each mine—or side-charge, as they are called—carries a heavy weight of explosive, but is fitted with internal buoyancy tanks so that its weight on the boat in water is negligible. Each side-charge is faired nicely to the hull to avoid catching nets or wires and well streamlined to keep its effect on the boat's performance to a minimum. In this article I will illustrate some of the navigational problems which arise in operating X-craft by giving an account of the attack we made on the Tirpitz in 1943
The Use of A.P. 3270 for Surface Navigation
Authors: Tyrrell A. J. R.
Published: January 2010

The full value of A.P. 3270 (Sight Reduction Tables for Air Navigation, Vol. I, Selected Stars, H.M. Stationery Office) does not yet seem to have been fully appreciated by surface navigators. As well as increasing the speed with which sights can be reduced, the tables offer all the advantages of a star globe or planisphere in planning a series of sights. The navigator can thus concentrate on the most suitable stars for cut, magnitude and azimuth. Since observations can be planned for a time at dusk when the horizon is still firm and the star just visible through the telescope (or, at dawn, when the star is still visible and the horizon firm), a more accurate sextant altitude can be obtained.
Plotting as an Aid to the Avoidance of Collisions at Sea
Authors: Forrest G. C.
Published: January 2010

I think that the impression which would be left by the Institute Working Party's Report (Journal, Vol. VII, p. 219) in the mind of any of the learned gentlemen of the Admiralty courts would be that a ship which did not keep a radar plot should be considered guilty of ‘neglect of any precaution’ under Article 29 of the Collision. Regulations, and this impression could lead to a miscarriage of justice.
The Accuracy of Dead Reckoning in the Air
Authors: Durst C. S.
Published: January 2010

In 1953 an Institute working party was set up to investigate the accuracy of dead reckoning in air navigation and to attempt to produce error data covering a wide range of operational conditions. Dead reckoning errors fall into two categories, those due to wind finding and forecasting, and those due to instruments. Mr. Durst's paper surveys the whole problem, laying particular emphasis on the meteorological aspects, and represents the main progress in this subject to date.

The error of a dead reckoning position in the air will depend on the accuracy of the initial position from which the departure is made, the accuracy of the course steered (compass error), the accuracy of distance flown (airspeed-indicator or engine-revolution error), and the accuracy of the wind used (forecast error, found-wind error, &c). These quantities can be expressed mathematically, as is done in Appendix I, and it will be seen that if a pair of fixes is available it is possible to derive the dead reckoning error. The standard error that will arise when a large number of D.R. positions have been calculated on different occasions using a large number of aircraft and observers can be written symbolically; the expressions are fairly simple provided that the errors made in the different classes listed above (e.g. the errors in compass and distance run) are not closely correlated.
The Navigational Implications of Mr. Durst's Paper
Authors: Parker J. B.
Published: January 2010

It is not possible at this stage to do more than hint at the possible alterations in navigational procedures which the new knowledge contained in Mr. Durst's paper on the accuracy of dead reckoning in the air logically leads to. This is so for two reasons. First, existing navigational procedures differ so widely between civil and military users (and amongst civil users themselves) that detailed modifications to existing procedures require separate consideration in the light of the different current navigational drills at present used. Secondly, only two particular areas of the world, the North Atlantic and Central Africa, were considered in the paper, though these are fairly representative of extra tropical and tropical latitudes (there will, of course, be variations from place to place owing to the known variability of the general circulation of the atmosphere). Nevertheless, the data obtained by the meteorological statisticians is of such interest and importance that certain broad applications suggest themselves.
An American Collection of Source Books for the History of Navigation
Authors: Taylor E. G. R.
Published: January 2010

A country that frowns on rich men must be content to let its rare books cross the ocean. Certainly it will lose all those which make no appeal to the literary man, and those to which the devotee of ‘pure’ science is indifferent, since these are the two groups who might be consulted before such a transference, or whose protests would be listened to. Hence it is that, because only a tiny minority has as yet been interested in the crude beginnings of applied science and technology, a discerning American member of the Institute, Mr. Henry C. Taylor, has formed a collection of about one hundred and fifty books which tell the story of how skippers and pilots were taught to set course and make port during the Great Age of Discovery and Colonization. Nearly half of these books are in English, and this is understandable, for although the pioneers of the new methods of navigation were the Portuguese, the English sailor took pride of place after the defeat of the Spanish Armada. Mr. Taylor appears at one time to have been satisfied with the breezy statement of Captain Smith of Virginia in 1626 that the seaman was sufficiently equipped if he had his Almanack, his Waggoner, a manual or two, and knew a good instrument-maker like Master Bates on Tower Hill. But one book leads to another, and, having got together these half-dozen books, he began to study them.
Some Problems in Space Travel
Authors: Porter J. G.
Published: January 2010

We were taught at school that a stone which is thrown forward in a horizontal direction from the edge of a cliff will describe a curved path which is a parabola. The path is in fact an ellipse—but that is not the only thing we were taught at school which turned out to be erroneous in after life. This error arises from the elementary assumption that all vertical lines are parallel; but the vertical in fact is the direction of a plumb line, and all such lines converge towards the centre of the Earth. With a small initial velocity the stone will describe a small ellipse which intersects the surface of the Earth, but with greater speeds the ellipse becomes larger, until it finally clears the Earth completely and returns to the thrower. Although the stone is now circling the Earth, it is still ‘falling’ freely in a gravitational field, and from this point of view all such orbits are referred to as ‘free orbits’, the stone being in a state of ‘free fall’.
The Polar Flight of Aries IV
Authors: Bower D.
Published: January 2010

In October 1954, Aries IV, a Canberra aircraft from the Royal Air Force Flying College, made the first flight by a British jet over the North Geographical Pole. This paper describes the navigation aspects of that flight, together with a later series of training flights for which it was a preparation.

For several years it has been the practice for navigator students at the Royal Air Force Flying College to carry out high-latitude flights as part of the normal syllabus of training. Hitherto only piston-engined aircraft have been used, but in 1954 it was decided to extend the scope of activities to include Canberras, the first flights to take place in December of that year from an airfield in northern Norway. A preliminary survey was necessary to confirm the practicability of the proposed navigation technique under actual conditions, and it was agreed that this should take the form of a flight towards the North Geographical Pole. A further object of the survey was the selection of a suitable operating base; the choice lay between Bardufoss and Bödo.
The Stranding of the Revenge in 1579
Authors: Naish G. P. B.
Published: January 2010

It is a notable compliment to the captains and masters (particularly to the masters) who served Elizabeth I that she lost no important ship of her Royal Navy by stress of weather or by stranding throughout her long reign. She lost two ships to the enemy for both the Jesus of Lubeck and the Revenge surrendered to superior Spanish forces after hard fights. The Revenge was a moderate-sized ship or galleon of 450–500 tons, described by Monson as being ‘low and snug in the water, like a galliasse’. She was built at Deptford in 1575–7 and carried a ship's company of 250 men and an assorted armament of 38 guns, large and small. Although of middle size, she was Drake's flagship in the Armada campaign and again in the voyage to Lisbon in 1589. She was Frobisher's flagship in 1590 and Grenville's in 1591, when she was captured in epic circumstances and soon after capture overwhelmed in a hurricane with her prize crew. In August 1579, when she became the flagship of Sir John Perrot in a voyage to Ireland, she was a new ship. Her master was John Gray, who was still her master under Drake in 1588. The Revenge was considered an unlucky ship. Both Sir Richard Hawkins and Monson list the tale of her misfortunes and Hawkins writes of her : ‘The Revenge, which was ever the unfortunatist ship the late queen's majesty had during her reign; for coming out of Ireland, with Sir John Perrot, she was like to be cast away upon the Kentish coast’. He blames her name for this ill-luck, for revenge should rightly be taken by God alone and not by man.
Airfield Surface Movement Indication at London Airport
Authors: Hansford R. F.
Published: January 2010

The past few years have seen a great increase in the amount of traffic at airports throughout the world. Today a rate of thirty aircraft movements per hour is by no means unknown and sixty movements per hour can realistically be forecast for the near future.
Collision at Sea
Authors: Sharpey-Schafer J. M.
Published: January 2010

Although only a small percentage of the world's total tonnage is involved, the number of collisions which take place at sea each year is large. There must also be a fairly large number of ‘near misses’, and, daily, officers have to consider the implications of situations which could give rise to collision. It is by no means certain that all seafarers put the same interpretation on the Collision Regulations or on such phrases as ‘the ordinary practice of seamen’, ‘ample time’ &c. Indeed, with some 1600 to 1850 collisions each year, it is almost certain that they do not.
The Value of Meteorological Forecasts for Airline Operation
Authors: Williams J. E. D.
Published: January 2010

A number of members have been invited to contribute to a general discussion on the value of meteorology to navigation. It is hoped to follow Mr. Williams' contribution with others dealing with different aspects of the subject.

Years ago there was weather in which birds and airmen alike walked. Now, although operations through particular airports affected by below-minima weather may be interrupted, airline services are rarely cancelled because of weather en-route. As aircraft tend to fly faster and higher, and navigational aids slowly improve, the weather information required by the short-range operator tends to be conditioned by the question: Can my aircraft operate through airport X at time T? The long-range operator is still interested in two other questions: What route will give the most favourable component, and What is that component? Having the meteorologist's answer to these and other, less vital, questions, the operator plans his flight on the assumption that the forecast is quite correct and equips and fuels his aircraft on the assumption that it is wholly false. The operator has learned to compensate for the errors of forecasting; possibly all the airline accidents in recent years in which unexpected weather deterioration played a major part could have been avoided with sound airmanship. The most realistic way, therefore, to consider the value of forecasting to airline operation is to attempt to evaluate the cost to operators of the measures they take to protect life and equipment against forecast error and speculate on what would happen if no forecasting were attempted.
Alexander Neckham and the Pivoted Compass Needle
Authors: May W. E.
Published: January 2010

Historians of the mariner's compass (particularly those of the last century) have introduced into the literature of the subject a number of statements which can be shown to be incorrect, or at the least to be extremely doubtful. Unfortunately it is just these ‘facts’ which have been seized upon by later historians and appear in one authoritative book after another. I have myself fallen into one stock trap or another in the past.
Early Pole Star Tables
Authors: Freiesleben H. C.
Published: January 2010

E. G. R. Taylor's interesting and noteworthy book The Mathematical Practitioners of Tudor and Stuart England shows that navigation was at first based on the experience of practitioners; men of science were too remote from practical requirements. There was a big gap between what interested them and what the seaman could understand and apply.
John Dee and the Nautical Trianggle, 1575
Authors: Taylor E. G. R.
Published: January 2010

The name of John Dee (1527–1608) is one which every navigator, whether seaman or airman, has good cause to respect. For he was the first to try to teach unscholarly English sailors the use of the spherical triangle to find the distance and direction of some desired haven on the globe. Nor was that his only contribution to nautical science. Yet historians have treated him slightingly, dubbing him astrologer and alchemist, by which words they understand ‘charlatan’. Consequently the popular picture of him is of a servile, ignoble figure, eager to dupe the first Elizabeth and her courtiers. The acclaimed mathematician, and the ever-ready instructor are forgotten. It is true, of course, that Dee cast horoscopes, and that he hoped to find the formula for transmuting the baser metals into gold. It is true, besides, that in middle age he took to crystal-gazing, believing that he conversed with angelic spirits. Hence when in 1583 he went abroad at the invitation of the Polish Prince Lasky, a mob broke into his house at Mortlake and wrecked his library, which contained over 4000 books and manuscripts, besides scientific instruments. But by this date his work on navigation had come to an end. Yet his simple account of his meeting with the medium Edward Kelly (who was indeed a cheat) reveals him as a sincere man. Kelly at once asked to see what feats he could perform, but, says Dee, ‘I truly excused myself therein, as not in ye vulgarly accounted magic either studied or exercised. But… I brought forth to him my stone in ye frame … and said to. him that I was credibly informed that to it, after a sort, were answerable aliqui boni Angeli—certain good Angels.’ We should perhaps echo, therefore, the judgment of Disraeli—Dee's imagination often predominated over his science—but science he had.