Performance is a critical non-functional parameter for real-time systems and performance analysis is an important task making it more challenging for complex real-time systems. Mostly performance analysis is performed after the system development but an early stage analysis and validation of performance using system models can improve the system quality. In this paper, we present an early stage automated performance evaluation methodology to analyse system performance using the UML sequence diagram model annotated with modeling and analysis of real-time and embedded systems (MARTE) profile. MARTE offers a performance domain sub-profile that is used for representing real-time system properties essential for performance evaluation. In this paper, a transformation technique and transformation rules are proposed to map the UML sequence diagram model into a Generalized Stochastic Timed Petri net model. All the transformation rules are implemented using a metamodel based approach and Atlas Transformation Language (ATL). A case study from the manufacturing domain a Kanban system is used for validating the proposed technique.

This study describes a high-gain, ultra-wideband quad-port THz MIMO antenna designed for 6G, TWPAN, and next-generation wireless communications. The design uses fractal radiating elements, graphene-based tunability, and a defective ground structure (DGS) to improve bandwidth, isolation, and impedance matching. The antenna’s tiny polyimide substrate (130 × 130 μm²) enables an ultra-wide bandwidth of 62 THz, a peak gain of 15.24 dB, and port-to-port isolation of 43 dB, resulting in strong MIMO performance. Integrating metasurface structures and graphene tuning allows for dynamic frequency reconfiguration, making it suitable for a wide range of wireless applications. The performance study reveals good spatial diversity and low signal distortion, with an envelope correlation coefficient (ECC) of less than 0.05 and a Diversity Gain (DG) of nearly 10 dB. Additionally, the Total Active Reflection Coefficient (TARC) and Channel Capacity Loss (CCL) are kept to a minimum, maximising spectral efficiency. UV photolithography and electron beam evaporation (EBE) are employed to fabricate the antenna, yielding high precision and minimal losses. Compared to existing designs, it outperforms them in terms of gain, isolation, and multi-band operation. The suggested THz MIMO antenna’s scalability, compact form factor, and customisable properties make it an attractive choice for future 6G wireless networks, sub-THz IoT systems, and ultra-fast personal area networks (PANs). Future research will focus on adaptive beamforming, real-world prototypes, and experimental validation to improve its application in next-generation THz communication systems.

Adoption of LED lighting in large scale has opened a debate on how to evaluate performance of commercially available LED lighting products. In this paper a review of existing photometric flicker metrics and measurement methods for LED lighting products is discussed. There is an urgent need to characterize potentially visible temporal light artifacts, or popularly known as flicker from light sources. Conventional light sources like incandescent and discharge lamps modulate light output, but the severity and diversity of light modulation exhibited by LED lighting products has generated curiosity in quantifying and understanding flicker and its impact on human health and productivity. Flicker metrics like flicker index and percentage flicker are not made available in datasheets of LED lighting products. It is critical for lighting designer to obtain this important information from LED luminaire manufacturers or conduct independent testing of LED luminaires to measure flicker metrics. The data reported in this paper show great inconsistency in flicker profile waveforms (flicker profiles) of some typically commercially available LED lighting products. Flicker is hence an important characteristic that the lighting designer needs to consider in assessing LED products. This paper presents a traditional method to develop a minimum suggested performance criteria for flicker measurement and reporting, understanding the performance needs of known lighting applications and including results from significant researchers in the field. It is important to minimize the chance of mismatching LED lighting products is installed in areas where flicker can be very serious health hazard or where it can hamper productivity and human comfort.

This paper analyses a project conducted to study the performance of LED luminaires in a road lighting application. Economic performance of the LED lighting as compared to HPSV lighting was also analyzed. This paper analyses the option of replacing HPSV lighting with LED lighting. Road lighting forms an important part of infrastructure in any modern city. Government agencies therefore must take up this responsibility more seriously because of its planned significance for economic and social stability. Well-designed road lighting can give long term qualitative and quantitative benefits for both Government and public.

This work presents our effort to predict the long term reliability of LED arrays using the application of accelerated life testing principles. Assessment of long term reliability and performance of LED arrays is a testing exercise but it is also vital for successful acceptance of Solid State Lighting (SSL) systems. The objective of this work is to analyze IESNA LM-80 test data obtained from the LED manufacturers to study how failure is accelerated by stress and fit an acceleration model to the data. This acceleration model can be used to accurately project the reliability of the LED arrays under normal operating conditions. The methodology was to apply statistical analysis to LM-80 test data and obtain accelerated models for life-stress relationships and life-time distributions. The Arrhenius-Weibull, Generalised Eyring-Weibull and Inverse Power-Weibull models were obtained and were compared for their effectiveness in to predicting the reliability of LED arrays.

LED luminaires are extensively used in a variety of applications. The LEDs are driven by from fraction of an ampere to nearly one ampere. LED luminaires are required to operate at high temperatures, depending on the application. High-power LED luminaires generate too much heat. If the heat generated is not dissipated away from the LED device it will affect the useful operating life and color characteristics of the luminaire. This work examines the need and rewards of detailed thermal modeling of LED luminaires. The purpose of this work is to develop a thermal model of LED luminaire such that the model represents the actual physical system. This model will be useful in reducing the experimental analysis. The scope of this work is to develop a thermal model of LED luminaire and validate it theoretically.