Development Of New Measurement System Research Articles

Advances in Microwave Large-Signal Metrology: From Vector-Receiver Load-Pull to Vector Signal Network Analyzer and Time-Domain Load-Pull Implementations (Invited Paper)

Radiofrequency (RF) power amplifiers (PAs) are important elements of modern communication systems. The most important components in PAs are the transistors, which are operated under large-signal regimes in such applications. Designing and optimizing PAs are challenging tasks that demand the highest accuracy on large-signal measurements at both device and circuit levels. Large-signal power transistor characterization demands the development and utilization of high-frequency and low-frequency load-pull systems. Furthermore, the static and dynamic characterization of two-input PAs requires the development of new measurement systems that consist of an nonlinear vector network analyzer (NVNA) and an arbitrary waveform generators (AWG). This paper reviews the research activities, achievements, and current research goals at CICESE Research Center in Mexico in the large-signal microwave metrology field.

Development of New Measurement System of Errors in the Multiaxial Machine Tool for an Active Compensation

Error compensation techniques have been widely applied to improve multiaxis machine accuracy. However, due to the lack of reliable instrumentation for direct and overall measurements, all the compensation methods are based on offline measurements of each error component separately. The results of these measurements are static in nature and can only reflect the conditions at the moment of measurement. These results are not representative under real working conditions because of disturbances from load deformations, thermal distortions, and dynamic perturbations. This present approach involves the development of a new measurement system capable of dynamically evaluating the errors according to the six degrees of freedom. The developed system allows the generation of useful data that cover all machine states regardless of the operating conditions. The obtained measurements can be used to evaluate the performance of the machine, calibration, and real time compensation of errors. This system is able to perform dynamic measurements reflecting the global accuracy of the machine tool without a long and expensive analysis of various error sources contribution. Finally, the system exhibits compatible metrological characteristics with high precision applications.

Measuring the business value of IT outsourcing: a systems approach

Purpose – The purpose of this study is to examine information technology (IT) outsourcing measurement systems. This paper proposes a systemic framework which can be used to support the evaluation of existing and the development of new measurement systems in the outsourcing context. The framework is built on the multidimensional characteristics of the business value created by IT outsourcing (ITO). Design/methodology/approach – After the conceptual discussion, this paper develops a systemic procedure for evaluating and developing measurement systems. The proposed procedure is applied in a multinational corporation operating in the electronics industry and conducting global business. First, the characteristics of the previous measurement system are evaluated, then the systemic properties of the current system are assessed and, finally, a new measurement system is proposed. Findings – The findings reveal that the measurement systems differ on many levels, namely, input, measurement process and output. The framework provides a structure for proper comparison of alternative measurement systems. When comparing the results to the most commonly used ITO theories, specifically the resource-based view and transaction cost economics, it is somewhat surprising that individual elements such as the cost of outsourcing and focus on core competencies were not weighed any higher in the final results. Practical implications – Organizations have difficulties in measuring actual benefits, opportunities, costs or risks involved in outsourcing transactions. The proposed framework forms a basis to resolve the measurement problems and even support the actual sourcing decisions. The applicability of the proposed approach was verified by evaluating three different types of measurement systems in a multinational corporation conducting global business in the electronics industry. Originality/value – Different kinds of measurement systems can be evaluated by the same systemic framework. The evaluation process is not limited to qualitative or quantitative assessments, but the same framework can be used in both cases.

Development of new measurement system of thoracic excursion with biofeedback: reliability and validity

BackgroundRespiratory rehabilitation reduces breathlessness from patient with respiratory dysfunction. Chest expansion score, which represents the circumference magnitude of the thoracic cage, is used for a target when treating patients with respiratory disease. However, it is often difficult for patients to understand the changes in the respiratory status and be motivated for therapy continuously. We developed a new measurement system with biofeedback named BREATH which shows chest expansion scores in real time. The purpose of this study was to determine the reliability and validity of the novel system in advance of clinical application.MethodsThree evaluators measured chest expansion in 33 healthy individuals using tape measure, which is used for the measurement traditionally, and BREATH. The wire for BREATH system was threaded over the thoracic continuously and the data was recorded automatically; whereas the tape was winded and measured each maximal expiration and inspiration timing by evaluator. All participants were performed both measurement simultaneously for three times during deep breath. In this study, we studied chest expansion score without using biofeedback data of BREATH to check the validity of the result. To confirm intra- and inter-evaluator reliability, we computed intra-class correlations (ICCs). We used Pearson’s correlation coefficient to evaluate the validity of measurement result by BREATH with reference to the tape measure results.ResultsThe average (standard deviation) chest expansion scores for all, men and women by the tape measure were 5.53 (1.88), 6.40 (1.69) and 5.22 (1.39) cm, respectively, and those by BREATH were 3.89 (2.04), 4.36 (1.83) and 2.89 (1.66) cm, respectively. ICC within and among the three evaluators for BREATH and the tape measure were 0.90-0.94 and 0.85-0.94 and 0.85 and 0.82, respectively. The correlation coefficient between the two methods was 0.76-0.87.ConclusionThe novel measurement system, BREATH, has high intra- and inter-evaluator reliabilities and validity; therefore it can lead us more effective respiratory exercise. Using its biofeedback data, this system may help patients with respiratory disease to do exercises more efficiently and clinicians to assess the respiratory exercise more accurately.

Resurgence in Ice Nuclei Measurement Research

Understanding cloud and precipitation responses to variations in atmospheric aerosols remains an important research topic for improving the prediction of climate. Knowledge is most uncertain, and the potential impact on climate is largest with regard to how aerosols impact ice formation in clouds. In this paper, we show that research on atmospheric ice nucleation, including the development of new measurement systems, is occurring at a renewed and historically unparalleled level. A historical perspective is provided on the methods and challenges of measuring ice nuclei, and the various factors that led to a lull in research efforts during a nearly 20-yr period centered about 30 yr ago. Workshops played a major role in defining critical needs for improving measurements at that time and helped to guide renewed efforts. Workshops were recently revived for evaluating present research progress. We argue that encouraging progress has been made in the consistency of measurements using the present generation of ice nucleation instruments. Through comparison to laboratory cloud simulations, these ice nuclei measurements have provided increased confidence in our ability to quantify primary ice formation by atmospheric aerosols.

EDITORIAL

EDITORIAL

Deconstructing job satisfaction

In this paper I argue that standard treatments of job satisfaction have inappropriately defined satisfaction as affect and in so doing have obscured the differences among three separate, if related, constructs. These key constructs are overall evaluative judgments about jobs, affective experiences at work, and beliefs about jobs. I show that clearly separating these constructs is consistent with current, basic research and theory on attitudes as well as with current research and theory on “subjective well-being” (SWB). I also argue that the separation of the constructs can produce better criterion predictions than job satisfaction has by itself, suggests new areas of research that cannot be envisioned when satisfaction and affect are treated as equivalent constructs, and requires the development of new measurement systems.

Gravity field determination and characteristics: Retrospective and prospective

Gravimetry has had a long history, using pendulums, torsion balances, and static spring gravimeters. Relative accuracy adequate for many geophysical problems was already attained by 1900, but it took another half century to build readily portable gravimeters. Calibration and datum definition remained problems until the 1970s when free‐fall absolute gravimeters were developed that now have a precision of 10−3 mGal. The problems of geographic inaccessibility and field party costs (notably in areas of greatest tectonic interest) are now being overcome by airborne gravimetry that has already achieved accuracies of 1–3 mGal with resolutions of 10 to 20 km. Satellite techniques are the best way to determine the long‐wavelength variations of the gravity field. The resolution of the models has steadily improved with the number of satellites and the precision of the observations. The best current model includes tracking data from more than 30 satellites, satellite altimetry, and surface gravimetry and has a resolution of about 290 km (harmonic degree 70) with the most recent improvements coming from Doppler orbitography and radiopositioning integrated by satellite (DORIS) tracking of the SPOT 2 satellite and satellite laser ranging (SLR), DORIS, and Global Positioning System (GPS) tracking of the TOPEX/POSEIDON satellite. Meanwhile, radar altimetry has become the dominant technique to infer the marine geoid with a resolution of tens of kilometers or shorter. Similarly, the gravity fields of the Moon, Venus, and Mars have been determined to harmonic degrees 70,75, and 50, respectively, although tracking limitations result in variations of spatial resolution. Modeling Earth's gravity field from the abundance of precise data has become an increasingly complex task, with which the development of computer capacity has kept pace. Contemporary solutions now entail about 10,000 parameters, half of them for effects other than the fixed gravity field of Earth. Temporal variations arising from tides have long been well modeled, and nontidal changes are now being identified. The improvement in gravitational models engendered corresponding advances in geophysical interpretation. Isostatic models were refined and expanded to account for regional thermal and tectonic histories. Interpretation of the long‐wave‐length gravity field determined by satellite techniques has been mainly in terms of plate tectonics as a manifestation of mantle convection. Gravity has been significant in inferring that there must be a large increase in viscosity with depth (most strongly, from the apparent slow sinking of subducted slabs). The prospects for increasing accuracy and resolution in the determination of Earth's gravity field rest primarily with the development of new measurement systems. Airborne gravimetry is taking promising new steps using GPS, but significant global model improvement awaits a dedicated satellite gravimetry system, and future satellite altimeter missions will do more for ocean dynamics studies than geoid improvement. Advances in interpretation will occur through the development of other data, such as seismic tomography, and larger‐scale computer modeling of tectonics and convection.