bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationship between array excitation distribution and radiation pattern ripple depth
Authors: Kijima Makoto , Yamada Yoshihide 
Published: July 2007

AbstractTo develop a radiation pattern synthesis technique for array antennas, the relationship between the ripple depth of the radiation pattern and the flatness of the array excitation amplitude distribution is clarified analytically. The roots of the representation equation of the radiation pattern are shifted radially from Schelkunoff's unit circle so that the ripple depth is changed. The ripple depth of the radiation pattern and the flatness of the excitation amplitude distribution are expressed by approximate equations in terms of the amount of the shift of the root. If the amount of the shift of the root is eliminated from these two equations, the relationship between the ripple depth and the flatness of the excitation amplitude distribution can be derived.Approximate equations indicate that the relationship between the two is almost independent of the sidelobe level and is determined mainly by the number of elements. As a numerical example, an asymmetrically shaped pattern is generated for a 20‐element array antenna with an element spacing of 0.5 wavelengths. The approximate equations and the rigorously calculated results are compared for error evaluation. It is confirmed that the approximate equations yield accurate evaluations if the ripple depth is more than 4 dB. Flatter excitation amplitude distributions reduce the influence of fabrication error and the mutual coupling of the elements and thereby improve the accuracy of the excitation coefficients. Useful design data also are obtained.
Energy flux densities of electromagnetic waves
Authors: Tokumaru Shinobu 
Published: July 2007

AbstractIn time‐harmonic electromagnetic fields, the Poynting vector, the cross product of electric field with the complex conjugate of the magnetic field, is well known as an energy flux density vector. Here, a new type of vector is proposed in which the cross products of electric and magnetic fields with their corresponding complex conjugates are taken, and its relationship with the Poynting vector is established as a pair of Max‐wellian‐type equations. Moreover, the usefulness of this vector is demonstrated by the examples of optical theorem, reciprocity theorem and decomposition of radiated power into circularly polarized fields, where it supplements the Poynting vector. This vector, like the Poynting vector, can also be considered as the energy flux density vector of the electromagnetic wave.
Radiation pattern analysis of an antenna mounted on a finite ground plane with a dielectric coating
Authors: Hasebe Nozomu , Takahashi Yoshihiro , Tanioka Noritaka 
Published: July 2007

AbstractThe airborne antenna may be considered to be small since it is mounted on a conductor which is large compared to the wavelength and its radiation pattern has to include the diffracted fields from the conductor. Moreover, thick dielectric coating on the body, which is used as insulating material, causes a serious distortion of the radiation pattern; and this is confirmed through measurements that the effect is quite large.This paper proposes a method of analysis where the effect of dielectric material on the radiation pattern is estimated analytically using a simple plane conductor model. Analysis is based on the excitation of the surface wave which propagates inside the dielectric sheet and making assumptions about the radiation mechanism, its diffracted field is calculated by the uniform theory of diffraction (UTD) method. The availability of this method of analysis was confirmed by comparing the measured results of this model with the calculated values. From the measured and analytical results, it was confirmed that a large effect is produced in the axially back direction of the rocket due to dielectric coating on the body.
Transmission‐type wide‐band periodic filter
Authors: Itanami Takao 
Published: July 2007

AbstractThe transmission‐type periodic branching filter presently is used as the multiplexer/demultiplexer for communication satellites. This type of filter can be applied to the submillimeter band multibeam communication satellite, in an attempt to realize large‐capacity communication for the efficient use of frequencies in the future. It can also be applied to the branching filter in the optical communication, aiming similarly at the largecapacity communication, if the filter is constructed using the dielectric transmission line.To realize such an application, it is desired to improve the performance of the conventional periodic branching filter to realize a wider bandwidth and sharper roll‐off of the amplitude transmission response. The conventional periodic branching filter is composed of two 90‐deg hybrids, a quarter‐wavelength transmission line and a resonator. This type of filter has a narrow usable relative bandwidth of approximately 6 percent, with a frequency response of third‐order elliptic function type.This paper proposes a new transmission‐type periodic branching filter with two resonators. It is composed of two hybrids and two resonators of different kinds. A bandwidth of approximately twice the width of the conventional filter and an approximately three‐times sharper roll‐off of the amplitude transmission response, with the frequency response of fifth‐order elliptic function type, are obtained.This paper discusses the theoretical characteristics, design method and the result of experiment for this periodic branching filter. As a result of experimental construction, it was verified that the wide‐band, low‐loss property and the sharp roll‐off of amplitude characteristic can be realized.
Design and characteristics of a transfer system using centralized transfer connectors
Authors: Watanabe Ichiro , Kobayashi Hideo , Ueno Koji , Uenoya Takuya 
Published: July 2007

AbstractIn the transfer of optical trunk cables, it is advantageous from the viewpoints of repeater span and line losses to carry out the task via devices installed at the network center.This paper investigates the optimization of the drive conditions of the transfer connector and deviations of the synchronism between the centers. Achievement of synchronous transfer time of less than 10 ms equal to that of DWS and its design guidelines are clarified.Further, to suppress the transfer failure probability in the case of burst error in the control line, the variable abort ratio method is used in the synchronous controller and the possibility of achieving failure rates below 10−5 is indicated.Finally, the performance of the manufactured synchronous transfer system optimized for field applications, and its synchronous transfer characteristics are indicated. From the results, it is shown that the system can be put into practical uses.
Effects of cell losses on picture quality in ATM networks
Authors: Iai Satoru , Kitawaki Nobuhiko 
Published: July 2007

AbstractAsynchronous transfer mode (ATM) is viewed as the technique that forms the basis of broadband integrated services digital networks (B‐ISDN). In ATM, the cell losses that accompany congestion during cell multiplexing are believed to cause a significant deterioration in quality. In this paper, we study the effects of cell losses on image quality from the standpoint of subjective evaluations. First, the impairment factors that cause deterioration in the received video are extracted for the various network and terminal configurations that are assumed. Next, with the impairment factors as the parameters, a computer simulation was created of the impairment that accompanies cell loss and the subjective quality was studied using a 320‐frame video signal. It was clearly shown that of all the impairment factors, the five major influences on quality are the number of lost cells, the number of picture elements (pels) in the impaired region, the amplitude distortion of the image in the impaired region, the shape of the impaired region, and the bursti‐ness of cell loss. In addition, when consecutive frames are inquired as a result of cell loss, except when only one segment is seen, the total number of impaired frames hardly affects subjective image quality. Finally, based on these evaluation results, we discuss cell loss quality in pulse code modulation (PCM) and provide guidelines for designing networks and terminals.
Distribution of the maximum in air pollution fields
Authors: Aberg Sofia , Guttorp Peter 
Published: July 2007

AbstractAir quality standards are set to protect public health. The values of the standards are often based on health effect studies, without any statistical considerations. In order to judge if a standard is met measurements of ambient air quality are taken at monitoring stations, and these measured values are used to decide whether or not the standard has been violated. In this paper we examine the statistical quality of some air quality standards by taking both measurement error and variability of the ambient field away from the monitoring sites into account. In particular we study the distribution of the maximum of the ambient field conditional on a measured monitoring value at the value prescribed by the standard. The distribution of the maximum is computed using a Rice method and relies on a generalization of upcrossings of a level in one dimension to two dimensions. Copyright © 2007 John Wiley & Sons, Ltd.
β‐Catenin transcriptional activity is inhibited downstream of nuclear localisation and is not influenced by IGF signalling in oesophageal cancer cells
Authors: Kiely B. , O'Donovan R.T. , McKenna S.L. , O'Sullivan G.C. 
Published: July 2007

AbstractAberrant expression/localisation of β‐catenin has been implicated in the progression of oesophageal cancer. As a member of the Wnt‐signalling pathway, activated β‐catenin translocates into the nucleus and drives gene transcription. Insulin‐like growth factors (IGFs) have been implicated in modulation of β‐catenin localisation and transcriptional activity. We have demonstrated that β‐catenin is abundantly expressed by oesophageal cancer cells, and is both cytoplasmic and nuclear in location. β‐catenin was transcriptionally inactive in 4 of 5 cell lines. All cells expressed the IGF‐1 receptor. Addition of exogenous IGFs activated the PI‐3 kinase pathway but did not enhance β‐catenin/T‐cell factor‐ (TCF) mediated transcription. Activation of Wnt signalling by lithium induced β‐catenin stabilisation in 2 cell lines but this did not increase transcriptional activity. In contrast 2 cell lines without lithium‐enhanced stabilisation or re‐distribution of β‐catenin did exhibit β‐catenin/TCF‐mediated transcriptional activity. This study shows that β‐catenin accumulation and nuclear localisation is not indicative of transcriptional activity, and therefore is not supportive of a major role in these oesophageal cancer cells. It also questions the value of immunohistochemical studies that examine only expression. Co‐operative signalling from other growth factors or adhesive molecules is likely to be required to relieve nuclear inhibition of transcriptional activity, and the nature of this is currently unknown. © 2007 Wiley‐Liss, Inc.
Induction of cell cycle arrest and apoptosis in human nasopharyngeal carcinoma cells by ZD6474, an inhibitor of VEGFR tyrosine kinase with additional activity against EGFR tyrosine kinase
Authors: Xiao Xia , Wu Jiangxue , Zhu Xiaofeng , Zhao Peng , Zhou Jinlin , Liu Quentin Qiang , Zheng Limin , Zeng Musheng , Liu Ranyi , Huang Wenlin 
Published: July 2007

AbstractZD6474 is a vascular endothelial growth factor receptor (VEGFR) and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor. The present study was undertaken to investigate the direct antiproliferative effect of ZD6474 on human nasopharyngeal carcinoma (NPC) in vitro and the antitumor activity on NPC xenografts in vivo. Results indicated that ZD6474 treatment inhibited EGFR phosphorylation and led to a dose‐ and time‐dependent decrease in NPC cell (CNE‐1, CNE‐2 and C666‐1) proliferation. Further investigation demonstrated G0/G1 cell cycle arrest in all 3 cell lines, which was associated with an upregulation of p21 and/or p27, and downregulation of CDK4, CDK6 and CDK2. ZD6474 treatment also induced apoptosis in CNE‐1 and CNE‐2 cells. The apoptosis mechanisms involved reduction of Bcl‐2 and/or Bcl‐XL, induction of Bak and/or Bax, and activation of caspases‐3, ‐9 and/or ‐8. The in vivo antitumor activity was evaluated in CNE‐2 and C666‐1 xenografted nude mice. Administration of ZD6474 (25–100 mg/kg/day, once‐daily, p.o.) produced a dose‐dependent inhibition of tumor growth and prolonged survival in both models. This study suggests that ZD6474 exerts direct antiproliferative effects on NPC cell lines in vitro by inducing G0/G1 arrest and apoptosis, and potent antitumor effects on NPC xenografts in vivo. It indicates that ZD6474 may offer a new and effective treatment for human NPC. © 2007 Wiley‐Liss, Inc.
The mechanism of elevated toxicity in HepG2 cells due to combined exposure to ethanol and ionizing radiation
Authors: Ogony Joshua , Matthews Richard , Anni Helen , Shannon Katie , Ercal Nuran 
Published: July 2007

AbstractEthanol and ionizing radiation exposure are independently known to cause tissue damage through various mechanisms. The non‐enzymatic and enzymatic metabolism of ethanol, the latter via the cytochrome P450 2E1dependent pathway produces free radicals, which deplete cellular glutathione (GSH). Ionizing radiation exposure has been shown to induce lipid peroxidation, DNA damage, protein oxidation and GSH depletion. It was postulated that cells sensitized by ethanol will be susceptible to additional insult, such as by radiation through increased oxidative stress. In this investigation, cultured liver cells (HepG2, human hepatocellular liver carcinoma) were exposed to ethanol, followed by ionizing radiation. The antioxidant status of the cells was evaluated by an array of techniques. Levels of glutathione, cysteine (CYS), and malondialdehyde (MDA) were measured by HPLC. Activities of antioxidant enzymes, catalase and glutathione reductase (GR) were determined enzymatically. Apoptosis was evaluated by the caspases‐3 assay and fluorescence microscopy. The data showed that combined treatment with ethanol and radiation resulted in the lowest levels of GSH, and highest MDA level compared with the control. The catalase activity was lower in the combined exposure groups, when compared with the single agent exposure groups, and the glutathione reductase activity was the highest in the combined exposure groups and lowest in the control. These findings suggest that a combination of ethanol and ionizing radiation results in greater toxicity in vitro through elevated oxidative stress. Copyright © 2007 John Wiley & Sons, Ltd.
An integrative transactional process model of stress in organizations
Authors: Schuler Randall S. 
Published: July 2007

AbstractIn this paper a definition and a conceptualization of stress in organizations are offered. Stress is defined as a perceived dynamic state about something important. The model developed in this paper incorporates organizational and individual stressors, individual appraisal of the stressors and individual responses to the stress including short term, intermediate and long term responses, both voluntary and involuntary. Critical to the model is the definition of stress based on individual need for the resolution of dynamic states of uncertainty. Previous research from the medical and health sciences are used along with that from organizational sciences to develop the integrative transactional process model. Finally several hypotheses based on the model are suggested.
Objective job conditions, social support and perceived stress among blue collar workers
Authors: Wells James A. 
Published: July 2007

AbstractThe hypothesis that perceived supportive relations mediate the association between extra‐individual (objective) job conditions and perceptions of occupational stress is tested in a population of blue collar workers. Responses to a mailed questionnaire (N = 1830) include measures of social support from four sources (supervisor, coworkers, spouse, friends/relatives) and measures of perceived stress (five job pressures and four need deprivations). In addition, company records and expert ratings by company, union and study personnel provide measures of objective job conditions which are commensurate with the subjective reports.Associations between objective job conditions and perceived stress are significant but modest in size. Controls for age, education, exposure to noxious agents and physical effort on the job do not alter associations between objective conditions and perceived stress.For five of the nine indicators of perceived stress, social support and objective conditions interact in determining perceptions. This is interpreted as a buffering effect in which social support provides a context that significantly alters perceptions of job conditions. The effect of supervisor support is especially important in regard to buffering.It is suggested that research on the quality of work should be especially aware of the conditional nature of the relationship between objective job conditions and perceptions.
Negotiations after the sale: The roots and ramifications of conflict in an acquisition
Authors: Mirvis Philip H. 
Published: July 2007

AbstractThis paper presents a case study of negotiations over the combination of a small manufacturing firm into a multi‐billion dollar conglomerate following its 'white knight' acquisition. It focuses on the strategic and tactical conflicts between the two firms and traces these to the party's emotional reactions to the combination. Feeling of loss versus gain in the two firms, each party's sense of uncertainty and threat, and their moves toward proactive versus reactive control in the combination are analysed to identify the roots of strategic conflict. These feelings, plus incompatibilities in the two company's managements, business systems, corporate cultures, and goals for combination ramify in conflict in the negotiations themselves. The paper concludes with a more generic model illustrating contextual features of combinations that shape human reactions and conflicts in negotiations after the sale.
Social support, autonomy, and hierarchical level as moderators of the role characteristics‐outcome relationship
Authors: Beehr Terry A. , Drexler John A. 
Published: July 2007

AbstractAlthough previous theory suggests that social support, job autonomy, and hierarchical level moderate role characteristics‐employee outcome relationships, the strength of these moderating effects among 2046 bank employees was practically zero. These theoretical moderators and three role characteristics (conflict, ambiguity, and overload) did have direct relationships with the outcomes (job satisfaction and job search intent), as summarized by canonical correlation. Recommendations for future research are offered.
Experimental research on race and sex discrimination: The record and the prospects
Authors: Rosenstein Joseph , Hitt Michael A. 
Published: July 2007

AbstractResearch in industry regarding race and sex access discrimination is reviewed. Review of sex discrimination research suggests that negative access discrimination exists for female applicants when the position is male‐stereotyped and positive access discrimination exists when it is female‐stereotyped. Results on race discrimination are few in number with mixed results, some showing reverse discrimination and others showing discrimination against blacks. More complex studies examining interactions between race and sex also provide mixed results. Recent evidence, which suggests that selection decisions are much more complex than have been studied, may account for the conflicting findings. Future research with more imaginative and complex designs and larger sample sizes is needed. Research designs should be selected to facilitate better measurement of the effects of civil rights law enforcement.
The informal rules of working relationships
Authors: Henderson Monika , Argyle Michael 
Published: July 2007

AbstractIt was expected that there would be informal rules of several kinds for working relationships. In the first study subjects rated 33 common rules and a number of relationship‐specific rules for three work roles. It was found that certain rules were strongly endorsed for work‐mates, superiors and subordinates. These provide a maintenance function by regulating general and relationship‐specific sources of conflict. Rules about cooperation, help and fairness applied strongly to work‐mates, rules about consideration and skilful use of power to supervisors, rules about using initiative and accepting orders and criticism to subordinates. Rules about reward were also obtained and these tended to be task‐focused rather than intimacy sustaining.In the second study one hundred and twenty‐four subjects rated the degree of dissatisfaction which they would feel for 11 types of rule violation by each of four work colleagues varying in degree of intimacy. Some level of dissatisfaction was expressed for each rule violation particularly maintenance rules, and the degree of expressed dissatisfaction increased with increased closeness to the work colleague.Study I was replicated in three other countries — Italy, Hong Kong and Japan, and cross‐cultural comparisons were made. While there was some cross‐cultural consistency for certain maintenance rules, there were cultural differences both in the type of rules endorsed and the strength of endorsement. Japanese relationships in particular were most dissimilar to other countries, characterized by greater homogeneity of overall rule structure within the four work roles, and by lower levels of intimacy and emotional expressiveness towards the other person in each relationship.
Focus of Attention at Work and Leader‐Follower Relationships
Authors: Gardner1 Donald G. , Dunham Randall B. , Cummings L. L. , Pierce Jon L. 
Published: July 2007

AbstractThree different studies examine moderating effects of focus of attention at work on leader‐follower relationships, using the typology developed by Howell, Dorfman, and Kerr (1986). Survey data were collected from over 1300 subjects. Results indicate that: (1) high focus on the supervisor while at work enhances leader behaviour‐subordinate satisfaction and behaviour relationships, (2) high focus on off‐job factors while at work enhances leader behaviour‐subordinate satisfaction relationships, and (3) high focus on off‐job factors while at work weakens leader behaviour‐subordinate behaviour relationships. Theoretical implications for the study of organizational behaviour are discussed, as well as practical issues for enhancing leader behaviour effectiveness in work organizations.
The role and expectancy participation model: An empirical assessement and extension
Authors: Fry Louis W. , Hellriegel Don 
Published: July 2007

AbstractFour hypotheses were investigated. The results substantially support and extend the usefulness of Schuler's role and expectancy participation model (1980). Schuler's model posits that participation intervenes to attenuate the relationships between job objectives and role conflicts and ambiguity. Also, participation, role conflict and role ambiguity are assumed to intervene to attenuate the relationships between job objectives and job satisfaction. The four hypotheses were tested using a sample of 187 retail store managers. Results revealed that job objectives were related to the role variables and satisfaction. Participation significantly attenuated the job objectives, role conflict and job satisfaction relationships. Implications for the use of the attributes of job objectives approach to integrate other objective setting paradigms are discussed.