A single-chip CMOS transceiver for 802.11a/b/g wireless LANs

A dual-band trimode radio fully compliant with the IEEE 802.11a, b, and g standards is implemented in a 0.18-/spl mu/m CMOS process and packaged in a 48-pin QFN package. The transceiver achieves a receiver noise figure of 4.9/5.6 dB for the 2.4-GHz/5-GHz bands, respectively, and a transmit error vector magnitude (EVM) of 2.5% for both bands. The transmit output power is digitally controlled, allowing per-packet power control as required by the forthcoming 802.11 h standard. A quadrature accuracy of 0.3/spl deg/ in phase and 0.05 dB in amplitude is achieved through careful analysis and design of the I/Q generation parts of the local oscillator. The local oscillators achieve a total integrated phase noise of better than -34 dBc. Compatibility with multiple baseband chips is ensured by flexible interfaces toward the A/D and D/A converters, as well as a calibration scheme not requiring any baseband support. The chip passes /spl plusmn/2 kV human body model ESD testing on all pins, including the RF pins. The total die area is 12 mm/sup 2/. The power consumption is 207 mW in the receive mode and 247 mW in the transmit mode using a 1.8-V supply.     

Reflections for a sociological study on the cultural acceptance of the NICTs

This article is based on the writer's participant observations of multidisciplinary Nordic-Japanese discussions in August 1997 and October 1998 concerning the cultural acceptance of the new information and communication technologies (NICT) in Japan, China and the Nordic countries. Concepts and theoretical ideas from the sociology of technology and science are applied. The main question is how to frame sociologically a study on the local differences in attitudes toward and the adoption of NICT. The main results are: (1) NICT products are carriers of metaphoric meanings of society and the individual; (2) the image of the information society attached to the computer is less attractive than the metaphoric contents carried by the mobile phone; (3) the mobile phone is more persuasively independent from cultural differences, because of its independence from the cultural differences, the mobile phone is more attractive to the majority of consumers. Its metaphoric reference unlike the computers, is non-verbal and therefore unanalysable and for the same reason also more capable of being freely constructed locally and individually.     

Explaining media choice: theoretical discussion and an empirical experiment

The paper is based on a review of research on media selection and related topics on the one hand and on an explorative pilot survey on the other. In summarising the review, the authors propose that the factors explaining media choice be grouped into five categories: (1) the properties of the media itself affect its choice, (2) properties of the user affect media choice, (3) the communication situation plays an important role, (4) macro factors explain media choice, and (5) media choice can be explained as the outcome of a dynamic multiparty negotiation process. The pilot survey compares Japanese and Finnish students’ preference of media in various communication situations. The survey results encourage reserving, local macro factors or culture, a certain amount of explanatory force in explaining media choice.     

Modeling the silicon–hafnia interface

We report first-principles calculations of the structure and electronic properties of several different silicon–hafnia interfaces. The structures have been obtained by growing HfO_x layers of different stoichiometry on Si(1 0 0) and by repeated annealing of the system using molecular dynamics. The interfaces are characterised via their electronic and geometric properties. Moreover, electronic transport through the interfaces has been calculated using finite-element-based Green's function methods. We find that oxygen always diffuses towards the interface to form a silicon dioxide layer. This results in the formation of dangling Hf bonds in the oxide, saturated by either Hf diffusion or formation of Hf–Si bonds. The generally poor performance of the interfaces suggests that it is important to stabilise the system with respect to oxygen lattice diffusion.     

Stress corrosion and thermal fatigue — Experiences and countermeasures in austenitic SS pipings of finnish bwr-plants

A summary of the existence of pipe cracking in Finnish BWR plants is presented covering both thermal fatigue and IGSCC cases. Countermeasures against cracking are evaluated and the measures applied are summarized. Also the results of a research program to monitor ageing of the weld heat affected zones in a pipeline section of a shut-down cooling system are summarized.     

Stress rupture of polypropylene

Tensile stress rupture is an important engineering property of plastics required in desiging parts subject to continuous or intermittent stress over long periods of time, especially in corrosive environments. This paper presents tensile stress rupture results on polypropylene and some of their applications in a program conducted over the past several years. Among the structural and compositonal paramaters studied in this work are the effects of molecular weight, molecular weight distribution, isotactic content, polyblends, and fillers on the shape and slope of the stress rupture-time curve. Data are presented showing the interrelationships between these variables, and the agreement with current stress rupture theories is discussed.     

Activation and suppression of antecedents during reinstatement.

In 3 experiments, the nature of the search for antecedents during reading was investigated by examination of the effects of reinstatement on long-term memory for potential antecedents. Participants read passages that contained 2 possible antecedents; one appearing early in the passages and the other appearing late. Experiment 1 showed that reinstated antecedents were strengthened in long-term memory whereas potential but nonselected antecedents that fell in the path of an antecedent search were suppressed. Experiments 2 and 3 showed that this suppression was restricted to concepts that shared a high degree of featural overlap with the target antecedent and with the anaphoric phrase prompting the search. Results are discussed in terms of antecedent search as a resonance process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prevalence of data operators' musculoskeletal symptoms during the workday and workweek

. The aim of this report, which is part of a study on the factors of mental load in office work, was to determine whether 30 data operators' musculoskeletal symptoms varied during the workday and workweek. An ergonomic survey was also carried out to find measures to improve the workstations and to motivate the operators to recognize problem areas. The results showed that all musculoskeletal symptoms increased during the workday, but symptoms in the neck and shoulders most of all. There were no differences in the prevalences of symptoms between the beginning and the end of the workweek. In response to the questions on mental-load factors, operators described their work as not mentally demanding but as very pressing at times. They felt they received insufficient feedback and that their work was not appreciated by the work organization. These results led to the following recommendations: job rotation; increased feedback;, more instruction on how to adjust the worksite. Excercises for relaxation and the improvement of muscle awareness were also recommended.     

Modelling constrained calcitonin gene-related peptide analogues

The calcitonin gene-related peptide (CGRP) is a 37-residue peptidewith pronounced physiological activities, making it an interestinglead for drug development In our previous work, we designedconstrained analogues of the peptide. The biological activitiesof these proved that the disulfide bridges created favouredthe active conformations of the peptide. Here we report themolecular modelling of the conformation of domains involvedin receptor activation. Our approach was to create sets of possibleconformations for three differently constrained bioactive regionsby a random search of conformational space and molecular modelling.The conformations were compared, and those allowed for all derivativeswere considered relevant for receptor activation. This approachresulted in one favoured group of conformations characterizedby an inverse -turn followed by a -turn, defining the conformationof the tripeptide region with a similar sequence in all activeanalogues. The models may also be used for the design of peptideand non-peptide analogues of CGRP.