IMEKO Event Proceedings

Page 796 of 822 Results 7951 - 7960 of 8218

Christian Schuss, Tore Leikanger, Bernd Eichberger, Timo Rahkonen
Using Ambient Light Sensors on Smartphones to Improve the Performance of Solar Chargers

This paper discusses the opportunities that exist to collect environmental data with the help of portable devices such as mobile phones. Under indoor environmental conditions, ambient data is vital in order to improve the performance of solar energy chargers. Sensing the light intensity and the temperature level can significantly contribute towards improving the output power of photovoltaics. For example, if the most beneficial location is known for deploying solar chargers in buildings, up to 100 times more solar energy can be collected during the same amount of time in a less suitable location. Moreover, the amount of gathered energy can be predicted and provided as helpful information for users. We analyse the performance of different types of ambient light sensors which are available in today’s smartphones. Additionally, we present a measurement platform which allows the gathering of ambient data with any type of mobile phone.

Zbigniew Czaja, Bogdan Bartosinski
Using an IEEE1149.1 Test Bus for Fault Diagnosis of Analog Parts of Electronic Embedded Systems

The new solution of a BIST called the JTAG BIST for self-testing of analog parts of electronic embedded systems is presented in the paper. The JTAG BIST consists of the BCT8244A and SCANSTA476 integrated circuits of Texas Instruments controlled via the IEEE 1149.1 bus. The BCT8244A is a scan test device with octal buffers, and the SCANSTA476 is a 12-bit ADC with 8 analog input channels. A self-testing approach is based on the fault diagnosis method in which we stimulate the tested analog part by a single square pulse using the BCT8244A and we sample the time response of the analog part two times with the SCANSTA476. The measurement results are used for a fault detection and also a single soft fault localization of the analog part.

P. Daponte, R. Holcer, L. Horniak, L. Michaeli, S. Rapuano

Digital post processing of output data is often used to enhance the ADC Effective Number Of Bits (ENOB). In particular, it can be used to partially recover ENOB restrictions caused by nonlinearities. The paper deals with advantages and disadvantages coming from the application of a proposed nonlinearity correction method based on the Bayes theorem. It allows the reduction of large scale errors in output signal by means of the use of dithering with low peakpeak voltage instead of a high amplitude one. The paper gives a brief description of the method. Then, the results of an experimental investigation carried out on actual ADC output data are presented and discussed.

Zbigniew Humienny, Marcin Berta

The paper presents general concept and some examples of the new modules of the application Geometrical Tolerancing that has been consequently developed by the authors for a couple of years to effectively present and disseminate the ISO GPS system fundamental concepts, definitions, interpretations and rules in technicaluniversities and industry. The package structure and main capabilities are shown and discussed through a few screen shoots. The application starts from the main window in which the user can click on one from the 14 tolerancing symbols or any modifier to open the new window with list of particular symbol/modifier applications. The selection of the case (e.g. roundness, coaxiality of an axis to the common axis, etc.) opens the next window with relevant tolerance and datum indicators attached to the workpiece. There are on screen notes and the context po-pup windows to explain requirements defined by the specification. Selection of the interpretation button at each case window activates the sequence of animations controlled by the user in which she/he is instructed how the datum (or the datum system) is established, next the tolerance zone is presented (running translation and/or rotation of the zone clearly shows its unlocked degrees of freedom) and finally the user triggers the geometrical deviation evaluation. The concepts of the geometrical deviations verification are demonstrated for the selected tolerances. Due many interactive animations enriched by prompts and questions the user has opportunity to control step by step the assessment of the geometrical deviations on the actual parts.

M. Leber, A. Polajnar, B. Buchmeister

Satisfying consumers` requirements for product quality, price and production times constitutes nowadays a vast and sophisticated field of activities which penetrate all business functions of a company. These requirements present a serious problem to companies. It is very important that the management insists on introduction and perfection of individual methods at all company’s levels and provides continuous on-job training of the staff.
In a dynamic and competitive marketing and globalization environment, benchmarking, TRIZ, QFD and FMEA have proved to be efficient tools of the TQM system. These methods help us develop products that will satisfy consumers, bring profit to the company and create a favorable image of the company. We used the methods in a case study which proved their justification and suitability also in further assessment and development of products.

Markovski, A., Velkoska-Markovska, L., Petanovska-Ilievska, B.
Using computer vision softwares in morphological analyses of European Chestnut (Castanea sativa Mill.) genotypes

It is investigated 20 European Chestnut (Castanea sativa Mill) genotypes from the slopes of Vodno and Skopska Crna mountains in northern part of FYROM during 2014-2015. Tools from two image analyzing softwares - Image J and Tomato analyzer are used in measurements. Among the investigated characteristics of Chestnut genotypes it is noted a large level of polymorphism. The Type 15 is characterized with twice as big nut mass as most of other investigated genotypes. The investigated genotypes show differences in the nut anatomy. The Types 12, 7 and 9 are included in the group with large nuts. The Vodno genotypes are larger in average than the genotypes collected from Skopska Crna mountan. According to CIELab color system the nut skin of genotype 15 is characterized with unusually light brown coloration, while the most attractive are the nuts from the Type 8. The investigated genotypes show differences in the nut anatomy, especially the Type 11 which is characterized with significantly higher value for lobedness degree, small seed coat area and seed coad thickness and low percent of hilum presence. Large differences in the leaves dimension and form are also determined.

Mark Vesterbacka, K. Ola Andersson, Niklas U. Andersson, J. Jacob Wikner

In this paper we discuss some properties of different codes with their respective sets of weights to be used in digital-to-analog converters (DACs). The thermometer (unratioed) code is widely used instead of a binary code in the most significant bits of a segmented DAC to reduce errors due to weight and timing mismatch. The binary and thermometer codes are two extremes, where the first offers a small digital hardware cost and the latter a large cost. We have investigated some of the properties of these codes and codes with properties in-between; such as linear, polynomial, and segmented codes. Some new ideas and results on using different sets of weights and how to generate them are presented. We present simulation results for some low-order polynomial codes.

L. Asnin, V. Backmutsky, M. Sedlachek

This paper presents the results of comparison of a new method of magnitude spectrum estimation of periodical signals in Power Systems, which uses Discrete Fourier Transform (DFT) and special FIR filters, with other methods of spectrum analysis, based on a preliminary estimation of the dynamically changed signal frequency. The main purpose of the suggested method is to reduce the leakage errors under conditions of desynchronization between the signal and the sample frequencies. Digital modeling of this method shows that accuracy of the estimation of magnitudes of the signal harmonics increases essentially by reference to other methods based on the interpolation of samples. This method can be used especially in Power System dynamics investigation (relay protection, UPS tuning, etc).

Bengt E. Jonsson

This work surveys various figures-of-merit (FOM) that have been used to evaluate and compare measured ADC performance, and takes a first step towards a systematic classification and analysis. Strengths and weaknesses associated with selected figures-of-merit are discussed, and their potential sweet spots or parametric bias is examined using a combination of theoretical analysis and a near-exhaustive set of scientifically reported experimental data. A commonly used FOM is shown to have a distinct, and highly predictable sweet spot with respect to ENOB, and a strong bias towards scaled manufacturing technologies. It is therefore concluded that a continued discussion and treatment of the topic is motivated.

Radu Varbanescu, Ana Lucia Varbanescu

Symbolic Sensors can answer a query by a qualitative answer, using linguistic symbols instead of the usual numerical representation. Because there are no sensors with a built-in symbolic behaviour, the solution is to develop add-on modules for enhancing common sensors with such a set of features. These add-ons can be built either in software or in hardware. This paper focuses on the hardware solution and it aims to solve the lack of flexibility issue by using reconfigurable devices such as FPGAs. These devices allow dynamic reconfiguration and they provide the required flexibility for the entire system, without having a significant decrease in performance. The experiments conducted during the research prove that such a solution is efficient and reliable, thus being a serious alternative for the older solutions developed in software.

Page 796 of 822 Results 7951 - 7960 of 8218