bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Interpretation of Phase and Intensity Data from AMCW Light Detection Sensors for Reliable Ranging
Authors: Adams M.D. , Probert P.J. 
Published: March 2007

The analysis of sensor range data and its application to mo bile robot navigation are of crucial importance in the field of mobile robotic research. We analyze the range data produced by an amplitude- modulated continuous wave (AMCW) light detection and ranging sensor and show that by physically modeling such sensors, we not only can produce reliable range estimates, but can also quantify our certainty in each range data point. We discuss the noise in the sensor and show the importance of using both phase and intensity data for calibration and data interpretation. We consider in detail the phenomenon of "mixed pixel points" whereby false range measurements occur when the light beam transmitted is split between two or more surfaces of differing range and/or reflectivity. We describe a new algorithm capable of detecting sudden changes in surface reflectance and/or range in order to identify these "spurious" data points. We quantify the regions over which the detection method will work, as we consider its sensitivity to changes in range and surface reflectance, while also quantifying the possibility of falsely predicting a discontinuity.
An Experimental Study of Nonlinear Stiffness, Hysteresis, and Friction Effects in Robot Joints with Harmonic Drives and Torque Sensors
Authors: Kircanski Nenad M. , Goldenberg Andrew A. 
Published: March 2007

Despite widespread industrial applicatzon of harmonic drives, the source of some elastokinetic phenomena and their impact on overall system behavior has not been fully addressed thus far. Some of these phenomena severely influence the behavior of robot arms, both in free and constrained motions, when the end effector is in contact with an environment. The primary goal of this study is to derive an effective, control-oriented model of a harmonic-drive-based robot joint. Systematic observations of an experimental robot with harmonic drives has revealed that the harmonic drive could not entirely transmit the input torque to the output shaft, due to a nonlinear meshing process between the flexible and circular spline teeth. The torque transmitted to the output shaft might saturate at a much lower value than expected (e.g., motor torque multiplied by the gear ratio). This phenomenon may severely influence the system behavior, par ticularly in force/impedance control tasks when full joint-torque capacity and wide bandwidth are needed. To understand the harmonic-drive behavior, as well as to derive a convenient form of its model, we have shown restrained motion experi ments to be much more useful than free-motion experiments. In this article, we also introduce mathematical models and describe experiments related to other physical phenomena, such as nonlinear stiffness, hysteresis, and soft windup. The goal of our modeling strategy was not to develop a precise and possi bly complicated model, but to generate an appropriate model that could be easily used by control engineers to improve joint behavior To visualize the developed model, equivalent mechan ical and electrical schemes of the joint are introduced. Finally, a simple and reliable estimation procedure has been established for obtaining joint parameters, to ascertain the integrity of the proposed model.
Information Invariants for Distributed Manipulation
Authors: Donald Bruce Randall , Jennings James , Rus Daniela 
Published: March 2007

In Donald (1995), we described a manipulation task for coop erating mobile robots that can push large, heavy objects. There, we asked whether explicit local and global communication between the agents can be removed from a family of pushing protocols. In this article, we answer in the affirmative. We do so by using the general methods of Donald (1995), analyzing information invariants. We discuss several measures for the information complexity of the task: (1) How much internal state should the robot retain? (2) How many cooperating agents are required, and how much communication between them is necessary? (3) How can the robot change (side effect) the environment to record state or sensory information for performing a task? (4) How much information is provided by sensors? and (5) How much computation is required by the robot? To answer these questions, we develop a notion of information invariants. We develop a technique whereby one sensor can be constructed from others by adding, deleting, and reallocating 1) through 5), among collaborating autonomous agents. We add a resource to measures 1) through 5) and ask: 6) How much information is provided by the task mechanics? By answering this question, we hope to develop information invariants that explicitly trade- off resource 6) with resources 1) through 5). The protocols we describe here have been implemented in several different forms, and we report on experiments to measure and analyze information invariants using a pair of cooperating mobile robots for manipulation experiments in our laboratory.
Model-Based Planar Contour Following in the Presence of Pose and Model Errors
Authors: Demey Sabine , Bruyninckx Herman , De Schutter Joris 
Published: March 2007

This article shows how the use of a geometric model during planar contour following with a force-controlled robot results in a higher quality (i.e., faster and/or more accurate) task execution, even in the presence of pose and model errors. Neither the pose (i.e., position and orientation) of the contour nor the starting point on the contour have to be known in advance. The contour is described by curvature and/or orientation of the normal direction, as a function of arc length. The con tour is identified on-line from the sensor measurements, and matched on-line with its model. This yields an estimate of the point in the model that corresponds to the real contact point. The curvature from the model is then used to generate feed- forward velocity set points. The article compares a nonrecursive deterministic least- squares matching strategy with recursive stochastic matching strategies, based on the extended Kalman filter and the Page- Hinkley hypothesis test. Matching is preferably based on cur vature profiles, since these are Euclidean invariant and hence reduce the search space of the matching. On contours with piecewise constant curvature, however, the extended Kalman- filter strategy uses the orientation of the normal direction. Extensive experimental evaluation of these strategies is given, including shape matching based on data during a deburring task. 1. The definition of this tangent frame is based on the Frenet frame; see Section 2.1. 2. Curvature, arc length, and orientation of the normal are defined in Section 2.1.
Honour as a Red Herring
Authors: Lever Alison 
Published: March 2007

Ideals relating to 'honour' and 'shame' have been presented by anthropologists as components of a shared value system which is typical of Mediterranean communities. Critics such as Herzfeld (1980) and Davis (1977) have noted respectively that concern with social standing linked to definitions of what constitutes socially desirable behaviour are not characteristics confined to the Mediterranean area, and that material considerations are inextricably linked to 'honour' Research in the Castilian pueblo of San Santiago suggests that writers on honour/shame value systems in Spanish pueblos have tended to concentrate on the values of middle aged married men who are fathers and who carry economic weight in pueblos, with regard to each other. We have been told less of their views with regard to those in different age, family position, and gender categories, and in different classes. Furthermore, these others may merely pay lipservice to the values of dominant groups, while holding very different views themselves. The argument presented here is that the way values have been described by many anthropologists has been misleading, and that honour/shame has become a 'red herring', distracting attention from the values of non-dominant groups, as well as failing to account for the way values change.
Who's Afraid of Feminist Criticism? Who's Afraid of Biblical Humour? the Case of the Obtuse Foreign Ruler in the Hebrew Bible
Authors: Brenner Athalya 
Published: March 2007

Several foreign rulers (Egyptian, Moabite, Cannanite, Persian, 'Babylonian' and Israelite) are configured in the Hebrew Bible as obtuse. This paper explores the configuration from two perspectives: humour and feminist concerns. The foreign rulers are presented as ludicrous, with bitter humour bordering on malice and contempt for their (im)potence. Their reported inadequacy is satirized by scornful allusions to their maleness and male sexuality, at times also to their bodily functions. These rulers' ineptitude is negatively mirrored by their relations with women and the latter's smarter actions. The configuration discloses the political and gender ideologies it is grounded in. 'Foreign' means a threat; humour is an important weapon for the politically powerless. Females are inferior social agents, and their resourcefulness amplifies male (foreign) shortcomings. The reading offered is corroborated by the exclusion of the offensive materials from Flavius Josephus's recounting of the relevant texts.
Putting the Historic House Into the Course of History
Authors: O'ConneH Peter S. 
Published: March 2007

We have dealt thus long on the old parsonage because it was a silent influence, every day fashioning the sensitive, imaginative little soul that was growing up in its own sphere of loneliness there.... [E]very day, as the little maiden grew, some quaint, original touch was put in the forming character by these sur- roundings (Stowe, 1878:178-179). Notwithstanding all we have done to modemize the old house, we seem scarcely to have disturbed its air of antiquity.... There are dark closets, and strange nooks and corners, where the ghosts of former occupants might hide themselves in the day time, and stalkforth, when night conceals all our sacrile gious improvements (in Stewart, 1932:150).
Persistence, Continuity, and Change in the Jamaican Working-Class Family
Authors: Patterson Orlando 
Published: March 2007

One of the most difficult prob lems facing the student of culture is that of deciding whether two corresponding pat terns, separated by time and/or space, are continuous, or whether they resemble each other purely by coincidence. The problem is quite familiar to students of cultural transmission and cultural change ( see Steward, 1972:88-92; Social Science Re search Council, 1954:973-1002; Heine- Geldern, 1968:169-173). Historians and sociologists concerned with social change in a general way, how ever, tend to overlook the extreme impor tance of this problem, operating, instead, within an implicitly dogmatic criterion of continuity. The object of this paper is to attempt to clarify this problem and to indicate its importance to all students of social and cul tural change. Toward this end, we propose to define and distinguish between three closely related concepts centering on the problem of correspondence, to establish reasonably rigorous criteria for using them, and finally, to indicate their importance by applying them to a case study of social change in the familial patterns of lower- class Jamaicans.
Survivors and Status: Widowhood and Family in the Early Modern Netherlands
Authors: Wyntjes Sherrin Marshall 
Published: March 2007

This study juxtaposes the theoretical continuity of customary law with the pragmatic realities of daily life, as these pertained to the rights and privileges of widows in the early modern north Netherlands. The database consists of approximately 1, 000 individuals from noble, gentry, and propertied middle-class families. These were tabulated and cross-referenced as part of a computer-assisted study using several hundred archival sources, in cluding prenuptial and marriage contracts, registers offiefs and other possessions, and testaments. The study demonstrates that widows' legal rights, exercised within and outside the family sphere, were the basis of their visible authority and power during the early modern period. ' These individuals have been identified through a number of cross-referenced sources, of which the most useful are RA Utr., Booth, Inventaris Hands chriften, no. 378, which consists of more than twenty handwritten volumes by a seventeenth-century con temporary of many of the families under scrutiny here; and Wittert, 1910-1912. Further, numerous other archival references such as leenregisters (or feudal land registers) in RA Utr., Rechterlijke Arc hieven, nos. 1863 and 1871 provide a listing of fiefs and the families which held them spanning several centuries. Prenuptial and marriage contracts and wills have been reviewed in the archives listed in the bibliography. Every extant document of this sort per taining to these individuals has come under scrutiny as a basis for these conclusions. 2As one lijftochtbrief of 1617 put it: "We make this [document] each of us of our own free will and without the influence of another, out of the greatest affection and matrimonial love which each of this couple holds and bears toward the other" (RA Utr. , Archief Slot Zuylen, no. 114). 3This seems substantiated by RA Utr., Huisarchief Rijnhuyzen, nos. 126-27, unfortunately in private hands and relatively inaccessible.
Family and Fertility in Rural Ohio: Wood County, Oiuo in 1860
Authors: Graham James Q. 
Published: March 2007

One of the lacunae in research on nineteenth-century American house holds is the relative scarcity of systematic studies using individual-level census data on rural populations. This essay uses individual-level data from the 1860 federal manuscript census of Wood County, Ohio to provide base-line data for comparison with similar studies by other scholars whose focus has been on regions other than the rural Midwest. The questions that were asked and the methods and techniques that were used to analyze the data in this essay were selected to increase comparability with other work. The variables analyzed are wealth, age, sex, ethnicity, structural type of household, fertility, rural-urban residence, and the occupation of married household heads. The findings are, for the most part, supportive of other research on the same subjects.
Possibility of Using a Time Constant in Fire Codes for Smoke Management in Atria
Authors: Chow W.K. , Li J. 
Published: March 2007

The concept of using a time constant, a parameter describing the smoke filling process including atrium geometry and design of the fire, is further reviewed. Time constants of 138 local atria were investigated. The smoke filling time required to fill 80% of the space volume of 69 atria to satisfy the criteria for applying the NFPA smoke filling equation was evaluated with a slow t2-fire. The two-layer zone model ASET was used to calculate the smoke filling time for all 138 atria. The time for the smoke front to reach the ceiling is included to modify the calculation. The time constant has to be considered with the maximum allowed population density at the atrium floor. Evacuation time required in each atrium was also simulated using buildingEXODUS. It is confirmed that time constant is a better parameter than space volume that is used in the current fire codes, and is thus recommended to the Authority for smoke management in atria.
The Extinction Oxygen Index of Polyester-Cotton Blended Fabrics
Authors: Allen J. , Horrocks A.R. , Price D. 
Published: March 2007

Limiting and extinction oxygen index techniques have been used to study the effects that fabric variables and blend composition have on the burning be haviour of 20/80, 50/50 and 65/35 polyester-cotton blended fabrics. Whilst LOI values were not dependent on ignition time, they were for a given blend com position dependent on fabric area density. Lo values determined at zero area density were little dependent on blend composition for the blends studied. EOI values, as shown previously for single fibre component fabrics, were de pendent on igniter application times. Derived [EOI]o values at zero ignition times, like LOI, increased with area density. Zero area density or "free-fibre" ex tinction oxygen index Eo values, like LOI and Lo, varied only slightly with blend composition. However, when compared with respective values for pure polyester and cotton fabrics, the respective magnitudes of blend Eo values pro vide a better indication than do Lo values of the difference of blend from indi vidual component fibre burning behaviour. Thus it is considered that the ex tinction concept provides a better indication of the variations of flammable character of polyester-cotton blends compared to the individual fibre-con taining fabrics.
Alkali Metal Ions and Their Effects on Smoldering and Ignition of Cotton Upholstery Fabrics-A Literature Review
Authors: Yeh K. , Song Z. , Reznichenko J. , Jang K.O. 
Published: March 2007

Several studies have previously suggested that alkali metal ions such as potassium and sodium play a critical role in the smoldering and igni tion of cotton upholstery fabrics. We have conducted an extensive review of the relevant literature to identify potential sources of these ions and to delineate possible mechanisms by which they affect the smoldering and ignition of cotton upholstery fabrics. The hazard associated with the cigarette ignition of cotton upholstery fabrics is addressed in terms of statistics on fire fatalities. Potential sources of alkali metal ions on the cotton fiber have been identified as being (1) from soil and agricultural chemicals used during the growth of the cotton plant and (2) from alkali agents used in textile wet processes such as dyeing and finishing. A general framework and pathway of cellulose degradation, smoldering com bustion and ignition to flaming combustion is presented. Potential effects of alkali ions on each of these processes have been analyzed. The most probable role of these ions is suggested to be a catalytic effect on the oxidation of car bonaceous char (smoldering combustion).
Major Learning Efforts: Recent Research and Future Directions
Authors: Tough Allen 
Published: March 2007

Adults spend a remarkable amount of time each year at their major ef forts to learn. In fact, a typical learning effort requires 100 hours. And the typical adult conducts five of them a year: 500 hours altogether. Some of these learning projects rely on instructors and classes, but over 70 percent are self-planned and others rely on friends and peer groups. This picture of the adult's major learning efforts has emerged in just the past seven years. Many basic surveys and several in-depth studies have con tributed to our understanding. This paper presents a review of that research and some high-priority directions for the future.
Homeless Black Youth: A Case of Persistent Unemployment
Authors: Simpson John H. 
Published: March 2007

Black youth growing up in northern central cities during the late fifties and sixties were relegated to enforced idleness due to an unemployment crisis that has persisted over time. This crisis eventuated in their homelessness, social problem that will continue through the next decade. Using data compiled from studies in three northern central cities, the author of this paper suggests that homelessness among today's black youth began four decades ago. This homelessness trend was precipitated mainly by the post World War II baby booni, black southern migration to northern central cities, the subsequent transition of those cities, and the changing technological, labor market demands for which black youth have yet to be prepared.
Wastage within the library and information profession: a report
Authors: Elkin Judith , Nankivell Clare 
Published: March 2007

The Class of '88 Study of the National Cohort Study of Newly Qualified Librarians and Information Workers, Birmingham Polytechnic, identified wastage as a crucial issue of the 90s. Wastage is taken to mean the loss of qualified librarians and information professionals, who leave the profes sion shortly after qualifying (20 per cent of the qualified workforce leave the profession in less than 3 years after qualifying). A questionnaire survey was conducted in 1988, 1989 and 1991 to determine the factors governing wastage. Concludes that action is needed to nurture and develop the skills and enthusiasm of new professionals; and to improve the pay and career structure of library and information science and the nature and number of posts available. The Study felt that if these improvements are not intro duced soon, the consequences for the profession could be catastrophic. 'I started outside the profession and stayed out'. This is just one com ment reflecting the wastage of new professionals in the library and information field. This article identi fies one of the main issues facing library and information employers and educators today; that of wastage. It discusses the extent of wastage in the library and information profes sion and why wastage occurs and places this discussion in the context of the changing employment climate of the 1990s.
The effect of the Education Reform Act on public library services to children
Authors: Heeks Peggy 
Published: March 2007

This article investigates the effects of the 1988 Education Reform Act (ERA) on school library services (SLS), the support services to schools provided by most Local Education Authorities (LEAs) in England and Wales. While the research aimed to present an over all picture, it had a particular interest in the management of change and, with this in mind, established a close contact with 14 authorities over the project time-span. It was obvious, from the time of the Education Reform Bill, that the new legislation would have a major effect on SLS: it was less apparent that it would affect public library ser vices to children. However, the research did find that the Act was having an impact on children's library services, and this article attempts to identify the nature and extent of that impact, and to discuss possible future implications.
Collaboration Task Analysis by Identifying Multi-Context and Collaborative Linkage
Authors: Hasegawa Akiko , Itoh Kiyoshi , Kumagai Satoshi 
Published: March 2007

Collaboration task is a complex process because it involves diversified individuals and organizations. They have different per spectives and resources while sharing a particular goal. In order to support collaboration task, capturing general workflow and states of resources is important in the initial stage of system development. Multi-Context Map (MCM) is useful for describing concurrency and contextual switches of general workflow, while clarifying both information and material flows within the task. This paper is an extended version of a paper entitled, "Collaboration Task Analysis by Identifying Multi-Context and Collaborative Linkage," which appeared in Con current Engineering in 1999. We propose Collaborative Linkage Map (CLM), which is complementary to MCM, and configuration process of CLM to integrate it with MCM. The purpose of CLM is to specify state transitions of resources, which are transferred among the collaborators in the general workflow. Those states of CLM are defined as a combination of Personnel-State Transition Diagram (P-STD), Material-STD (M-STD), and Collabora tion-STD (C-STD). P-STD shows state transitions of personnel and M-STD represents those of materials. C-STD describes the relation ship between P-STD and M-STD. The construction process of CLM is incremental. First, one P-STD and one M-STD are selected from a list of state transition diagrams (STDs). Next, Collaboration-State (C-S) is defined as a common state, which can be shared between P-STD and M-STD, is selected. Next, P-STD and M-STD is connected by C-S to build C-STD. Therefore, C-STD is obtained as a collection of the C-Ss. Finally, two P-STDs are selected, and one state, which can be shared between collaborators, is selected to be defined as Communication-Inventory (C-I).