bluuebunny/crossref_metadata_2025 huggingface dataset:
An entrepreneurial model of corporate governance: devolving powers to subsidiary boards
Authors: Strikwerda J.
Published: August 2003

This article is concerned with “internal” corporate governance i.e. corporate governancewithinthe firm – in particular the delegation of decision‐making powers from the parent company board to the boards of divisions and subsidiaries. In fast‐moving businesses, companies must respond quickly to changes in technologies and markets and with this in mind international businesses are tending to delegate substantial discretion to the boards and management teams of subsidiaries. In researching divisionalized companies in financial services, electronics and process manufacturing the author discovered that much of the business was carried on among subsidiaries through a network of contracts and the resources which were held at the center were often made available to subsidiaries through license agreements. Such complex arrangements present parent boards with difficult issues which must be resolved if their companies are to act entrepreneurially. For example: what powers should be reserved for the parent board and what decisions should be delegated to subsidiary boards? Also should subsidiary companies have autonomous boards with independent non‐executive directors?
From literature center to knowledge portal: Shanghai Library in search of excellence 2.0
Authors: Miao Qihao
Published: August 2003

Five years ago Shanghai Library moved to a new home, and became famous, however, it has found that the “new building effect” has been fading. The library has to pursue a higher level of excellence. In making the five‐year plan from 2001‐2004, a knowledge strategy was proposed. According to the strategy, Shanghai Library should be a knowledge portal with knowledge navigation as the core concept of the service. Following the strategy, an integrated municipal library service system has been established, the knowledge base project, a thematic research service, was launched, and a knowledge management system is under construction to support the ambitious strategy.
A Model for Audit Engagement Planning of E‐Commerce
Authors: Pathak Jagdish
Published: August 2003

The impact of networking technologies on information systems (IS) and its auditing is growing dramatically. This growth is changing the nature of information systems in the modern organization, with special reference to e‐commerce. It would also be reasonable to infer that a corresponding effect is mounting on the information system's auditing function. This paper primarily stresses the identification of specific constructs which can contain the potential variables/critical success factors in audit engagement planning that contribute to the success/failure of audit engagement in e‐commerce‐centric technological scenario, and the same can be used to build a model for its empirical validity in future studies. The objective of this paper is to devise a model, based on the variables turned potential critical success factors to successfully perform audit engagement planning for the current state‐of‐the‐art e‐commerce technologies. The available literature is analyzed to identify appropriate candidates for factors that appear to materially affect the success of the e‐commerce audit resource planning function. Based on this model, an empirical examination, though not within the scope of this paper, is the next logical step in this direction to establish the validity of this model in the technologically complex e‐commerce milieu.
The Development of Embedded Audit Modules to Support Continuous Monitoring in the Electronic Commerce Environment
Authors: Debreceny Roger , Gray Glen L. , Tham Wai‐Lum , Goh Kay‐Yiong , Tang Puay‐Ling
Published: August 2003

An important developing area of assurance is continuous audit. Because of the real‐time, computer‐to‐computer characteristics of electronic commerce, the development of continuous audit techniques is even more critical. Proponents of continuous audit point to a future where auditors monitor entity's accounting information systems in real‐time or in quasi real‐time. A predecessor technology to continuous audit is the Embedded Audit Module (EAM). This study investigates the challenges in developing EAMs. These challenges are analyzed by the development of ten examples of EAM alerts in a fraud environment. The alerts employ stored database procedures and triggers to monitor the internal control environment. The alerts are complementary to the strengthening of a firm's internal control system by monitoring and reporting the irregularities in the control environment. The study provides guidance on the construction of EAMs and points to a number of limitations in their development. These limitations raise a number of issues that must be considered before continuous audit can be widely adopted. The study sets out a number of issues for future research.
An Exploratory Study of Employee Silence: Issues that Employees Don’t Communicate Upward and Why*
Authors: Milliken Frances J. , Morrison Elizabeth W. , Hewlin Patricia F.
Published: August 2003

ABSTRACT There is evidence from a variety of sources that employees often do not feel comfortable speaking to their bosses about organizational problems or issues that concern them. The purpose of this study was to shed light on the types of issues that employees are reluctant to raise, and identify why employees sometimes decide to remain silent rather than voice their concerns. We interviewed 40 employees and found that most had been in situations where they were concerned about an issue but did not raise it to a supervisor. Silence spanned a range of organizational issues, with several of our respondents indicating that they did not feel comfortable speaking to those above them about any issues or concerns. The most frequently mentioned reason for remaining silent was the fear of being viewed or labeled negatively, and as a consequence, damaging valued relationships. From our data, we develop a model of how the perceived consequences of voice contribute to silence, and a model of how the social and relational implications of speaking up can take away employees’ ability to have influence within an organizational setting.
Breaking Silence: Tactical Choices Women Managers Make in Speaking Up About Gender‐Equity Issues*
Authors: Piderit Sandy Kristin , Ashford Susan J.
Published: August 2003

ABSTRACT This study examines female managers’ assessments of how to speak up about the treatment of women in their organizations. Qualitative data from 172 women provide an in‐depth look at their theories about the right way to sell this issue. In addition, inductive exploration of the tactics chosen by 985 other women to address gender‐equity concerns yields four clusters of issue‐selling tactics for this issue. We draw from these two complementary analyses to suggest implications for the future study and practice of issue selling, and for shaping organizational cultures to support gender equity.
The changing sources of new mortgage debt
Authors: Talbot Richard
Published: August 2003

A much clearer understanding is needed of the forces driving the current upsurge in the mortgage market and of the key factors contributing to the exceptional growth of mortgage indebtedness. It would then be easier to judge whether the widely‐expected downswing in mortgage lending will be reasonably limited and gradual, or more pronounced and protracted.

This paper, by Richard Talbot, develops an appropriate analytical framework and model that traces the composition of incremental mortgage borrowing over the period since the mid‐1980s. Estimates have been compiled for the various elements of additional borrowing using data from the Survey of Mortgage Lenders and the Bank of England back to 1993, and other statistics on the earlier composition of bank approvals and building society advances.

This analysis of the debt aggregation process suggests that, at the level of the individual household, people simply will be unable, and indeed unwilling, to go on absorbing the relatively large amounts of incremental debt implied by many medium‐term forecasts for mortgage lending.
Religious Life Under Theocracy: The Case of Iran
Authors: Kazemipur Abdolmohammad , Rezaei Ali
Published: August 2003

The occurrence of the Islamic revolution in Iran in 1979, followed by a large‐scale “Islamization” of society, resulted in some unique developments with regard to religious life in this country. Over the past two decades, there has been a lively debate among social scientists about the nature of such developments, and over their implications for other Middle Eastern and Islamic societies. Most of the contributions to this debate so far have been limited to the examination of different theoretical possibilities, without strong references to empirical evidence. In the present study, we attempt to address this shortcoming in the existing literature on religious developments in Iran by relying on a rich set of empirical data recently gathered through a large‐scale national survey of values and attitudes in Iran. Through a composite index of religious sentiments, we explored the magnitude and the nature of religious sentiments among groups of different age and gender. Also, we examined changes with regard to religiosity in the period between 1975 and 2001. The outstanding finding is that the establishment of a theocratic regime in Iran has led to the transformation of the nature of faith, marked by a noticeable shift from “organized” to a more “personalized” religion, in which the emphasis is placed on beliefs rather than on practices. Also, among both beliefs and practices, more emphasis is placed on those with a purely individual nature, or with a social nature but organized through civic and nongovernmental bodies, as opposed to those commanded by the government. The article ends with a brief discussion of the implications of such developments for the existing debate among sociologists of religion on secularization and “de‐secularization.” Our findings indicate that any linear perspective on the demise or survival of religion in society will unreasonably brush aside the fact that religion is not merely a social institution, but also a “cultural resource” that individuals may draw upon, depending on their surrounding sociopolitical circumstances and their reading of those circumstances.
Is Spirituality Detrimental to Generativity?
Authors: Dillon Michele , Wink Paul , Fay Kristen
Published: August 2003

This article examines the relations between religiousness, spirituality, and generativity (concern for the welfare of future generations) in late adulthood using longitudinal life‐course data. Religiousness and spirituality were operationalized as distinct but overlapping dimensions of individual difference measuring involvement in traditional and nontraditional religious practices, respectively. In late adulthood, both religiousness and spirituality correlated positively with overall scores on self‐report and observer‐based measures of generativity. However, whereas religiousness was significantly related to the communal facets of generativity, spirituality was significantly related to its self‐expanding aspects. These differences were more pronounced after gender, cohort, social class, and the overlap between religiousness and spirituality were controlled. The respective relations among religiousness, spirituality, and generativity in late adulthood were also observed using religiousness scored in early, and spirituality scored in late‐middle, adulthood.
Stress during pregnancy is associated with developmental outcome in infancy
Authors: Huizink Anja C. , Robles de Medina Pascale G. , Mulder Eduard J.H. , Visser Gerard H.A. , Buitelaar Jan K.
Published: August 2003

Background: Animal studies show that prenatal maternal stress may be related to cognitive impairments in offspring. Therefore, we examined whether psychological and endocrinologic measures of stress during human pregnancy predicted developmental outcome of the infant at 3 and 8 months.

Method: Self‐report data about daily hassles and pregnancy‐specific anxiety and salivary cortisol levels were collected in 170 nulliparous women in early, mid‐ and late pregnancy in a prospective design, in which healthy infants born at term were followed up after birth.

Results: High levels of pregnancy‐specific anxiety in mid‐pregnancy predicted lower mental and motor developmental scores at 8 months (p < .05). High amounts of daily hassles in early pregnancy were associated with lower mental developmental scores at 8 months (p < .05). Early morning values of cortisol in late pregnancy were negatively related to both mental and motor development at 3 months (p < .05 and p < .005, respectively) and motor development at 8 months (p < .01). On average a decline of 8 points on the mental and motor development scale was found. All results were adjusted for a large number of covariates.

Conclusion: Stress during pregnancy appears to be one of the determinants of delay in motor and mental development in infants of 8 months of age and may be a risk factor for later developmental problems. Further systematic follow‐up of the present sample is needed to determine whether these delays are transient, persistent or even progressive.
The role of the clinician: three‐year predictive value of parents’, teachers’, and clinicians’ judgment of childhood psychopathology
Authors: Ferdinand Robert F. , Hoogerheide Kirsten N. , Van Der Ende Jan , Visser Jeroen Heijmens , Koot Hans M. , Kasius Marianne C. , Verhulst Frank C.
Published: August 2003

Background: The present study investigated the differential predictive value of parents’, teachers’, and clinicians’ reports of psychopathology for poor outcome in children referred to a child psychiatric outpatient clinic.

Method: A referred sample (N = 96), aged 6 to 12 years at initial assessment, was followed up after a mean interval of 3.2 years. Data on parent‐ and teacher‐reported problem behavior (Child Behavior Checklist and Teacher's Report Form), and clinician‐reported observations and self‐reports during a semi‐structured clinical interview (SCICA), were linked to outcome measures assessed with a parent questionnaire, including outpatient and inpatient treatment at Time 2, parent's wish for professional help for the child, school problems, and police/judicial contacts.

Results: Information from all three informants (clinicians, parents, and teachers) predicted measures of poor outcome after three years. Clinicians’ ratings on the SCICA predicted all five outcome measures. Independent of CBCL and TRF scores, SCICA scores predicted parental wish for help and inpatient treatment.

Conclusions: The present study was the first to report that clinician's ratings of self‐reported and observed behaviors in a semi‐structured interview (SCICA) make an important unique contribution to the multi‐axial assessment of problem behaviors.
Time perception deficits in attention‐deficit/ hyperactivity disorder and comorbid reading difficulties in child and adolescent samples
Authors: Toplak M.E. , Rucklidge J.J. , Hetherington R. , John S.C.F. , Tannock R.
Published: August 2003

Background: Our objective was to investigate time perception in Attention‐Deficit/Hyperactivity Disorder (ADHD) with and without comorbid reading difficulties (RD) in child and adolescent participants.

Method: In study 1, 50 children with ADHD (31 ADHD, 19 ADHD+RD) and age‐matched healthy controls (n = 50) completed three psychophysical tasks: duration discrimination (target duration of 400 ms versus a foil duration), frequency discrimination (a control condition to evaluate general perceptual ability), and a duration estimation task using the method of reproduction for intervals of 400 ms, 2000 ms, and 6000 ms. Study 2 used the same tasks with an adolescent sample (35 ADHD, 24 ADHD+RD, 39 controls).

Results: In both studies, children and adolescents with ADHD and ADHD+RD displayed some impairments in duration discrimination and the precision with which they reproduced the intervals on the estimation task, particularly the shorter 400 ms interval. The most severe impairments tended to occur in the comorbid ADHD+RD group. No impairments were found on the frequency discrimination task. ADHD participants also displayed significant intra‐individual variability in their performance on the estimation task. Finally, short‐term and working memory, estimated full‐scale IQ, and teacher report of hyperactivity/impulsivity were found to differentially predict performance on the time perception measures in the adolescent clinical sample.

Conclusions: Deficits in duration discrimination, duration estimation, and intra‐individual performance variability may have cascaded effects on the temporal organisation of behaviour in children and adolescents with ADHD and ADHD+RD.
Language abilities of siblings of children with autism
Authors: Pilowsky Tammy , Yirmiya Nurit , Shalev Ruth S. , Gross‐Tsur Varda
Published: August 2003

Background: Language abilities of siblings of children with autism were examined to explore the possibility that language abilities are behavioral markers specific to the genetic liability for autism, as part of the broader phenotype.

Method: Language abilities were compared among 27 siblings of children with autism, 23 siblings of children with mental retardation of unknown etiology (MR), and 22 siblings of children with developmental language disorders (DLD). Groups were matched by siblings’ age, gender, birth order, family size, ethnicity, family income and by probands’ gender and mental age.

Results: Siblings of children with autism achieved higher scores than siblings of children with DLD on receptive, expressive, and total language scales of the Children's Evaluation of Language Fundamentals and on verbal IQ. Moreover, within the DLD group, school problems in the domains of reading and arithmetic were more prevalent than within the other two groups. Only 2 siblings of children with autism received clinical diagnoses based on DSM‐IV criteria compared to 3 siblings of children with MR and 7 siblings of children with DLD.

Conclusions: After excluding data of the diagnosed siblings, no differences in language abilities could be discerned among the groups, except that more siblings in the DLD group were identified as having language difficulties. In summary, although language deficits characterize autism, siblings of children with autism were not found to demonstrate deficits in language skills assessed by formal language tests, IQ, or academic skills.
Affective neuroscience and psychophysiology: Toward a synthesis
Authors: Davidson Richard J.
Published: August 2003

This article reviews the author's program of research on the neural substrates of emotion and affective style and their behavioral and peripheral biological correlates. Two core dimensions along which affect is organized are approach and withdrawal. Some of the key circuitry underlying approach and withdrawal components of emotion is reviewed with an emphasis on the role played by different sectors of the prefrontal cortex (PFC) and amygdala. Affective style refers to individual differences in valence‐specific features of emotional reactivity and regulation. The different parameters of affective style can be objectively measured using specific laboratory probes. Relations between individual differences in prefrontal and amygdala function and specific components of affective style are illustrated. The final section of the article concludes with a brief discussion of plasticity in the central circuitry of emotion and the possibility that this circuitry can be shaped by training experiences that might potentially promote a more resilient, positive affective style. The implications of this body of work for a broader conception of psychophysiology and for training the next generation of psychophysiologists are considered in the conclusion.
Heritability and “environmentability” of electroencephalogram in infants: The twin study
Authors: Orekhova Elena V. , Stroganova Tatiana A. , Posikera Irina N. , Malykh Sergey B.
Published: August 2003

We estimated relative contribution of genetic and environmental factors to electroencephalogram (EEG) frequency and amplitude parameters in infants. EEG was registered in 49 pairs of monozygotic and 45 pairs of dizygotic twins aged 7–12 months during (1) visual attention and (2) darkness. The variability of occipital alpha frequency depended mainly on genetic, probably nonadditive factors. The mean heritability for the spectral amplitudes in the delta, theta, and alpha bands were 0.37, 0.13, and 0.22 during visual attention, and 0.22, 0.40, and 0.10 during darkness. The influence of shared environment was probable for many of the EEG parameters. It was greatest for the amplitude of the theta rhythm during visual attention. The theta amplitude depended on such a parameter of early social environmental enrichment as the number of caregivers in the family. The possible relationship between infant theta rhythm and developmental outcome is discussed. For many of the EEG parameters, heritability increased during the second half of the first year of life, thus supporting the hypothesis about amplification of genetic effects and decrease of common environmental influences with age.
Effects of positive and negative affect on electromyographic activity over zygomaticus major and corrugator supercilii
Authors: Larsen Jeff T. , Norris Catherine J. , Cacioppo John T.
Published: August 2003

Pleasant stimuli typically elicit greater electromyographic (EMG) activity over zygomaticus major and less activity over corrugator supercilii than do unpleasant stimuli. To provide a systematic comparison of these 2 measures, the authors examined the relative form and strength of affective influences on activity over zygomaticus major and corrugator supercilii. Self‐reported positive and negative affective reactions and facial EMG were collected as women (n=68) were exposed to series of affective pictures, sounds, and words. Consistent with speculations based on known properties of the neurophysiology of the facial musculature, results revealed a stronger linear effect of valence on activity over corrugator supercilii versus zygomaticus major. In addition, positive and negative affect ratings indicated that positive and negative affect have reciprocal effects on activity over corrugator supercilii, but not zygomaticus major.
The nature of unilateral motor commands in between‐hand choice tasks as revealed by surface Laplacian estimation
Authors: Vidal Franck , Grapperon Jacques , Bonnet Michel , Hasbroucq Thierry
Published: August 2003

From electroencephalographic recordings, we estimated the surface Laplacian over motor areas in a Stroop‐like between‐hand choice reaction time task in humans. Response‐locked averages showed a (negative) “motor potential” over the primary motor areas contralateral to the response. At the same time, a positive wave was observed over the primary motor areas ipsilateral to the response. These data suggest that, when a between‐hand choice is required, an inhibition of the primary motor cortex ipsilateral to the nonresponding hand is implemented. This observation is relevant to the interpretation of the lateralized readiness potential (LRP) because the LRP is blind to the respective contribution of the contralateral and ipsilateral motor cortices. In addition, a negative wave beginning about 200 ms before EMG onset and peaking about 50 ms before it occurred over the supplementary motor areas (FCz). This wave preceded the motor potential, which supports the view that the supplementary motor areas are upstream in a hierarchy of the motor command.
Effects of information and reward on stimulus‐preceding negativity prior to feedback stimuli
Authors: Kotani Yasunori , Kishida Sachiko , Hiraku Shiho , Suda Kazuhiro , Ishii Motonobu , Aihara Yasutsugu
Published: August 2003

The purpose of the present study was to investigate the effects of informational and motivational level of feedback stimuli on the stimulus‐preceding negativity (SPN). In the time estimation task, in which a visual stimulus was presented 3 s after a voluntary movement, (a) the information level (high information and low information) and (b) the motivation level (reward and no‐reward) for feedback stimuli were manipulated. Under the high‐information condition, subjects received feedback information about (1) correctness (correct or incorrect), (2) direction of error (under‐ or overestimate), and (3) degree of accuracy (accurate or less accurate) of their time estimation. In the low‐information condition, however, they received information about the correctness only. In the reward condition, they received a monetary reward for accurate time estimations but received nothing in the no‐reward condition. The results demonstrated a significant interaction of information by motivation level, showing that the SPN amplitude under the reward/high‐information was larger than that in the no‐reward/high‐information condition. The results are discussed in terms of emotional anticipation, taking into consideration the result of self‐report that subjects felt to be more motivated when they received precise information.
A Therapeutic Model for Supporting Families of Children with a Chronic Illness or Disability
Authors: Morison Jillian E. , Bromfield Leah M. , Cameron Heather J.
Published: August 2003

Background: A therapeutic model for supporting families of children with a chronic illness or disability is described. The model presupposes that the chronic illness and/or disability of a child constitutes a trauma for the entire family.

Method: This paper describes a therapeutic model currently in practice and links it back to psychological dynamics addressed through the clinical interventions and the principles that underlie the model of service.

Results: Service delivery comprises the interventions; counselling, psychological first aid, projects, peer groups, parent mentoring, social events and community education. The model is family centred, non‐illness specific, preventative, non‐linear and flexible.

Conclusions: The interventions offered in the model aim to address the psychological dynamics of hope, empowerment, reconnection, coping/resilience and reframing.
City of Superlatives
Authors: Beauregard Robert A.
Published: August 2003

A number of urban theorists have recently deployed a specific type of rhetoric to support claims that their city—Las Vegas, Miami, Los Angeles—deserves paradigmatic status. Using “superlatives” and assertions that their city is “first” on one or another measure, they have slipped into an academic boosterism at odds with a critical theoretical enterprise. This article explores how urban theorists might position themselves in relation to the city. Based on the premise that all knowledge is situated, it argues for an urban theory that is both critical and engaged.
Community Lost or Transformed? Urbanization and Social Ties
Authors: White Katherine J. Curtis , Guest Avery M.
Published: August 2003

Sociological theorists have generally emphasized the destructive effects of urbanization on social ties through the community lost perspective. A counterview, which we call the community transformed, has begun to emerge on the basis of other theorizing and empirical research. Yet the relationship of urbanization to social ties is still not well understood. In this article, we explore the total number of social ties, the number of kin and nonkin ties, the density or interconnection, and frequency of contact between ties among individuals residing within various U.S. settlement types. The results indicate that urbanization especially encourages the segmentation of social ties by discouraging density or interconnectedness. In addition, urbanization does have noteworthy effects in encouraging exclusively nonkin ties, which are presumably highly voluntaristic. Of the three definitions of urbanization that are tested, we find that metropolitanization is the most efficacious for understanding variations in social ties, especially exclusively nonkin ties.
Variable Speed Drive Volumetric Tracking for Airflow Control in Variable Air Volume Systems
Authors: Liu Mingsheng
Published: August 2003

An airflow control method has been developed for variable air volume (VAV) systems. This airflow control method is termed VSD volumetric tracking (VSDVT) since both the supply and return airflows are determined using signals of variable speed drives (VSD) instead of flow stations. Its performance is studied and compared with the fan tracking (FT) method using model simulations. For the simulation considered, the VSDVT maintains a constant building pressure and the required outside airflow under all load conditions, and reduces the annual supply and return air fan energy significantly. This paper presents the VSDVT method, the system models, and the simulation results.
Constant and Variable Stiffness and Damping of the Leg Joints in Human Hopping
Authors: Rapoport Svetlana , Mizrahi Joseph , Kimmel Eitan , Verbitsky Oleg , Isakov Eli
Published: August 2003

The present study deals with the stiffness and damping profiles of the leg joints during the ground-contact phase of hopping. A two-dimensional (sagittal plane) jumping model, consisting of four linked rigid segments and including the paired feet, shanks, thighs, and the head–arms–trunk segment, was developed. The segments were interconnected by damped torsional springs, representing the action of the muscles, tendons and ligaments across the joint and of the other joint tissues. A regressive function was used to express stiffness and damping, and included second-order dependence on angle and first-order dependence on angular velocity. By eliminating redundancies in the numerical solution using multicollinearity diagnostic algorithms, the model results revealed that the correct and sufficient nonlinearity for the joint stiffness is of the first order. Damping was found negligible. The stiffness profiles obtained were bell-shaped with a maximum near mid-stance and nonzero edge values. In predicting the joint moments, the obtained variable joint stiffnesses provided a closer agreement compared to a constant stiffness model. The maximal stiffness was found to be in linear correlation with the initial stiffness in each joint, providing support to the of muscles’ preactivation strategy during the flight phase of hopping. All stiffnesses increased with increasing hopping frequency. The model presented provides an effective tool for future designing of artificial legs and robots and for the development of more accurate control strategies.
Head Kinematics in Mini-Sled Tests of Foam Padding: Relevance of Linear Responses From Free Motion Headform (FMH) Testing to Head Angular Responses
Authors: Ivarsson J. , Viano D. C. , Lo¨vsund P. , Parnaik Y.
Published: August 2003

The revised Federal Motor Vehicle Safety Standard (FMVSS) No. 201 specifies that the safety performance of vehicle upper interiors is determined from the resultant linear acceleration response of a free motion headform (FMH) impacting the interior at 6.7 m/s. This study addresses whether linear output data from the FMH test can be used to select an upper interior padding that decreases the likelihood of rotationally induced brain injuries. Using an experimental setup consisting of a Hybrid III head-neck structure mounted on a mini-sled platform, sagittal plane linear and angular head accelerations were measured in frontal head impacts into foam samples of various stiffness and density with a constant thickness (51 mm) at low (∼5.0 m/s), intermediate (∼7.0 m/s), and high (∼9.6 m/s) impact speeds. Provided that the foam samples did not bottom out, recorded peak values of angular acceleration and change in angular velocity increased approximately linearly with increasing peak resultant linear acceleration and value of the Head Injury Criterion HIC36. The results indicate that the padding that produces the lowest possible peak angular acceleration and peak change in angular velocity without causing high peak forces is the one that produces the lowest possible HIC36 without bottoming out in the FMH test.
Automated Proactive Techniques for Commissioning Air-Handling Units
Authors: Katipamula Srinivas , Brambley Michael R. , Luskay Larry
Published: August 2003

Lack of or improper commissioning, the inability of the building operators to grasp the complexity controls, and lack of proper maintenance lead to inefficient operations and reduced lifetimes of equipment. If regularly scheduled manual maintenance or re-commissioning practices are adopted, they can be expensive and time consuming. Automated proactive commissioning and diagnostic technologies applied to parts of the commissioning process address two of the main barriers to commissioning: cost and schedules. Automated proactive commissioning and diagnostic tools can reduce both the cost and time associated with commissioning, as well as enhance the persistence of commissioning fixes. In the long run, automation even offers the potential for automatically correcting problems by reconfiguring controls or changing control algorithms dynamically. This paper discusses procedures and processes that can be used to automate and continuously commission the economizer operation and outdoor-air ventilation systems of an air-handling unit.
Development and Validation of Online Parameter Estimation for HVAC Systems
Authors: Wen Jin , Smith Theodore F.
Published: August 2003

Improving the energy efficiency of buildings by examining their heating, ventilating, and air-conditioning (HVAC) systems represents an opportunity. To improve energy efficiency, to increase occupant comfort, and to provide better system operation and control algorithms for these systems, online estimation of system parameters, including system thermophysical parameters and thermal loads, is desirable. Several reported studies have presented simulation results and assumed that the thermal loads are known. A difficulty in HVAC system parameter estimation is that most HVAC systems are nonlinear, have multiple and time varying parameters, and require an estimate of the thermal loads for a building zone. In this study, building zones and variable-air-volume units are modeled. The system parameters including the thermal loads are estimated using the recursive-least-squares method with a variable forgetting factor. The sensitivity of the estimation results to different factors is examined. The estimated parameters are used to predict the zone and variable-air-volume-discharge-air temperatures. Several experiments are used to validate the prediction results. The comparisons show good agreement between the experiments and the prediction results.
Energy spectra of field emission electrons from multiwalled carbon nanotubes
Authors: Oshima C. , Matsuda K. , Kona T. , Mogami Y. , Yamashita T. , Saito Y. , Hata K. , Takakura A.
Published: August 2003

We have measured energy spectra of field emission (FE) electrons from multiwalled carbon nanotubes in various conditions such as a tip temperature, electric fields, the emission direction, and adsorption. The observed spectra indicated that peak near EF originated from the FE electrons from the inner walls, while FE electrons forming the shoulder at deeper energy came from a surface wall. Both the position and the intensity of the shoulder changed from one specimen to the others; no spectra were the same as the others. The Fermi level of the surface wall is different from that of the inner walls under the FE condition.
Scanning tunneling microscopy and spectroscopy studies of the oxide nanofilms on the stainless steel surface
Authors: Chung Opti Naguan , Chung Sukmin
Published: August 2003

We have performed the scanning tunneling microscopy (STM) and scanning tunneling spectroscopy measurements of the oxide nanofilms formed on stainless steel at 450 °C in oxygen partial pressures (p′) of 1×10−7 and 1×10−9 Torr. The STM observations reveal that the films grown at p′ of 10−7 Torr consist of grains varying from 40 to 120 Å in size, while the films grown at p′ of 10−9 Torr consist of grains of about 400 Å. We also show that the native oxide layers of stainless steel surfaces exhibit subgrain structures with grains of size in the range 30–60 Å. The current–voltage characteristics allow us to identify iron oxides, in the films grown at p′ of 10−7 Torr, Fe3O4, and Fe2O3, whereas the films grown at p′ of 10−9 Torr are pure Cr2O3. We thus conclude that oxidation at p′ of 10−9 Torr develops complete Cr2O3 films with large grains, while oxidation at p′ of 10−7 Torr develops iron-rich oxide films with small grains.
Initial phases of CuInS2–Si heteroepitaxy
Authors: Calvet Wolfram , Pettenkofer Christian , Lewerenz Hans-Joachim
Published: August 2003

The heterojunction formation between silicon Si(111) and copper indium disulfide CuInS2 is investigated using ultraviolet photoelectron spectroscopy (UPS)/x-ray photoelectron spectroscopy (XPS) and low energy electron diffraction (LEED). Thin layers of CuInS2 films were deposited on hydrogen terminated Si(111) surfaces by molecular beam epitaxy (MBE). The film growth process starts from a partially sulfurized Si surface with a nominal composition of SiS0.8±0.1 and a thickness of 2.5±0.8 Å. The dependence of XPS measured substrate and film peak intensities and LEED patterns on deposition time indicates a disturbed layer-by-layer growth mode. In addition, a change in film stoichiometry from Cu rich to In rich is observed at the beginning of the film growth. The analysis of the Si 2p core level shows that the Si substrate is disturbed to a depth of about 7 Å beyond the initial hydrogenated surface. The hydrogenated surface exhibits a band bending of 0.4 eV. Upon S exposure, the band bending increases to 0.64 eV due to the donor character of S in Si and the electron affinity χ changes by 0.54 eV which can be attributed to dipole formation by adsorbed S. The MBE growth procedure results in a 2 nm thick film showing the valence band structure of CuInS2 with a total change in χ to about 0.7 eV on the completed junction. The band discontinuities of the Si/intermixed phase/2 nm CuInS2 structure were determined as ΔEL=0.35±0.05 eV and ΔEV=0.06±0.05 eV.
Embossing of polymers using a thermosetting polymer mold made by soft lithography
Authors: Xing Rubo , Wang Zhe , Han Yanchun
Published: August 2003

In this article we present a mechanical pattern transfer process where a thermosetting polymer mold instead of a metal, dielectric, ceramic, or semiconductor master made by conventional lithography was used as the master to pattern thermoplastic polymers in hot embossing lithography. The thermosetting polymer mold was fabricated by a soft lithography strategy, microtransfer molding. For comparison, the thermosetting polymer mold and the silicon wafer master were both used to imprint the thermoplastic polymer, polymethylmethacrylate. Replication of the thermosetting polymer mold and the silicon wafer master was of the same quality. This indicates that the thermosetting polymer mold could be used for thermoplastic polymer patterning in hot embossing lithography with high fidelity.
Photoelectric properties of nanostructural carbonaceous films containing Ni nanocrystals investigated by picosecond laser-induced photoelectric charge emission
Authors: Vouagner D. , Czerwosz E. , Champagnon B. , Wronka H. , Girardeau-Montaut J. P.
Published: August 2003

We present results of photoelectric properties of carbonaceous films containing metallic nanocrystals, investigated by pulsed laser-induced photoelectric charge emission and in situ work function measurements. Samples are multiphase carbonaceous thin films composed of Ni nanocrystals embedded in a graphite–fullerene matrix. Photoelectric measurements are performed in a vacuum chamber. Picosecond laser-induced photoelectric charge measurements are performed at 213 nm at a low laser intensity (∼1 MW cm−2). At this intensity, surface cleaning effects are clearly demonstrated by a photoelectric charge increase during pulsed irradiation correlated to an in situ photoelectric threshold lowering. Surface contamination is also observed after the exposition of samples to the ambient air. MicroRaman measurements are carried out before and after laser irradiation in order to control that no structural changes have occurred under the pulsed laser beam.
Semiconductor waveguide inversion in disordered narrow band-gap materials
Authors: Gilbert M. J. , Akis R. , Ferry D. K.
Published: August 2003

It has been previously demonstrated that it is possible to form the NOT gate in a coupled semiconductor waveguide structure in III–V materials. However, to this point, investigations have assumed the materials to be perfect. In this article, we present results of a semiconductor waveguide inverter in GaAs and InAs with disordered material effects included in the simulation. The behavior of the device clearly shows that with the inclusion of mild to moderate disorder in these materials, waveguide NOT gate function is still possible. Nevertheless, under heavy disorder in the system, clear switching becomes impossible.
Characteristics and mechanism of inductive coupled plasma etching of hydrogenated amorphous silicon carbide films
Authors: Choi W. K. , Shi J. , Chor E. F.
Published: August 2003

The inductive coupled plasma etching of as-prepared and annealed hydrogenated amorphous silicon carbide (a-Si1−xCx:H) films using CF4/O2 chemistry is reported. The etch rate of the as-prepared films decreases when the carbon content in the films decreases. The etch rate also reduces drastically when the films are annealed. The infrared spectroscopy results show the effusion of hydrogen when the film is annealed. A reduction in the porosity of the films causes the decrease in the etch rate. The etch rates of a-Si0.5C0.5:H and a-Si0.3C0.7:H films increase with the addition of oxygen (O2) to CF4 and reached a maximum value at 30%–20% of O2, respectively. The etch rates for all the films show similar trends as functions of reactive ion etching power, inductively coupled plasma power, and chamber pressure. It has been observed that above a critical dc bias of −400 V, the etch rate is found to be dependent more significantly on the ion flux than ion bombardment.
Application of the simplified bond-hyperpolarizability model to fourth-harmonic generation
Authors: Hansen J.-K. , Peng H. J. , Aspnes D. E.
Published: August 2003

We show that the simplified bond-hyperpolarizability model (SBHM), previously used to accurately describe anisotropies observed in second-harmonic generation from Si–dielectric interfaces, also describes anisotropies observed in fourth-harmonic generation (FHG). FHG data from (001)Si–SiO2 interfaces show two contributions: one from the intrinsic response of the interface bonds and the second from roughness. SBHM calculations yield excellent agreement with scaled ps and ss polarization data and the phases of the pp and sp equivalents with no adjustable parameters. The SHBM also precisely reproduces the anisotropy data for samples with systematic variations of interface roughness, and predicts relative amplitudes consistent with measured fields to factors of about 2.
Modeling of the transistor characteristics of a monolithic diamond vacuum triode
Authors: Wisitsora-at A. , Kang W. P. , Davidson J. L. , Li C. , Kerns D. V. , Howell M.
Published: August 2003

Transistor emission characteristics from a monolithic diamond vacuum triode fabricated by a self-aligning gate technique have been studied and modeled. The anode emission current of diamond triodes has been modeled per the Fowler–Nordheim triode equation and an empirical model for the emission transport factor described. The model was applied to two different diamond field emission triodes with distinct emission characteristics. A procedure for modeling parameter extraction is developed and demonstrated. The modeling results agree well with the experimental data. The empirical model can be incorporated into programs for field emission device simulation.
Development and validation of a simulation procedure to study the visibility of micro calcifications in digital mammograms
Authors: Carton Ann‐Katherine , Bosmans Hilde , Van Ongeval Chantal , Souverijns Geert , Rogge Frank , Van Steen Andreas , Marchal Guy
Published: August 2003

The visibility of micro calcifications is a determining factor for digital mammography. To address the problem of quantification, we developed a procedure to simulate micro calcifications into real mammograms. First, the shapes, sizes and x‐ray transmission coefficients of real micro calcifications were derived from the appearance of biopsy specimens in the raw data of magnified, digital images acquired at 27 kVp and Mo/Mo anode‐filter combination. This allowed us to create “ideal templates” of micro calcifications. The x‐ray transmissions of the real micro calcifications values were expressed in Al‐equivalent thickness. This made it possible to recalculate the x‐ray transmission characteristics of a particular ideal template for other x‐ray beam qualities. Extra corrections for differences in spatial resolution were based on the presampled two‐dimensional modulation transfer functions and on the difference in pixel size. Three radiologists compared the appearance of real and simulated micro calcifications in a two‐alternative forced choice (2AFC) evaluation. They perceived no differences between real and simulated lesions. Preliminary results show that it is possible to simulate micro calcifications with well defined characteristics that are indistinguishable from real ones. It should be noted, however, that the full potential of the approach has not been proven. In future work, these templates may be useful to evaluate particular aspects of digital mammograms, such as the effects of processing and of viewing conditions on the visibility of micro calcifications.
A quality assurance method for analyzing and verifying intensity modulated fields
Authors: Ma Lijun , Phaisangittisakul N. , Yu C. X. , Sarfaraz M.
Published: August 2003

A quality assurance method is developed for measuring, verifying and analyzing intensity modulated radiation fields. It is applicable for rotational and fixed‐beam intensity modulated radiation therapy (IMRT) treatments. A gantry‐mount device was constructed to measure the transmission dose of an IMRT field using radiographic films. A double‐exposure technique with optimal kernel estimate method was developed to minimize the errors from measurements. A confidence level test method was developed to detect the discrepancies between measured and prescribed IMRT fluence distributions. Our method was tested for rotational and fixed‐beam IMRT treatment verifications. The method was found insensitive to the hardware‐related parameters for rotational and fixed‐beam IMRT deliveries. The confidence level test was found to be more sensitive than linear correlation method in detecting relative small errors for cases with a few segments or narrow regions of interest. In conclusion, we demonstrated a quantitative method for verifying and analyzing IMRT treatment deliveries.
Comments on “Problems encountered with a radiation field analyzer”
Authors: Westerlund Kjell
Published: August 2003

To shield electrometer preamplifiers from radiation‐induced dark currents in its semiconductor components, it is suggested that the preamplifier be located some distance away from the water phantoms and covered with lead or copper (except for the front surface). (AIP)
Concerning comparisons of electron beam absorbed dose measurements in water and polystyrene
Authors: Mattsson L. O. , Nahum Alan E.
Published: August 2003

The calibration of electron beam absorbed doses in water and polystyrene phantoms is discussed and compared to the work of Kase et al. [Med. Phys. 9, 13 (1982)] who used different ionization chambers with electron beams at energies of 7.8 and 10.2 MeV. (AIP)
Reply
Authors: Kase K. R. , Bjärngard B. E.
Published: August 2003

The calibration of electron beam absorbed dose measurements in water and polystyrene phantoms is discussed in light of the critique by Mattsson and Nahum. The main point of our work is that if electron beam dose measurements are to be made in some phantom material other than water, the material should be carefully chosen so that the transfer of dose to water can be made in the least complicated manner.(AIP)