2,339 research outputs found

    Rancang Bangun Alat Penyiram Tanaman Otomatis Berbasis Arduino Nano

    Get PDF
    Design an automatic plant watering device that uses the Arduino Nano platform as its base. The aim of this research is to develop an efficient and water- saving plant watering automation system. This tool is designed to monitor soil moisture and automatically water plants when soil moisture drops below a specified limit. This tool development method involves designing both hardware and software. On the hardware side, the soil moisture sensor and water pump are controlled by Arduino Nano, while on the software side, an Arduino program was developed to set the watering algorithm based on soil moisture data. Test results show that this tool can work well in maintaining the desired soil moisture level and reducing water waste. In the context of modern agriculture which increasingly demands resource efficiency, this automatic plant watering device can be a valuable solution for farmers and plant lovers. Additionally, integration with remote control via smartphone app provides ease of use and better monitoring. This research makes a positive contribution in developing agricultural automation technology that is environmentally friendly and sustainable

    Recommendations and illustrations for the evaluation of photonic random number generators

    Full text link
    The never-ending quest to improve the security of digital information combined with recent improvements in hardware technology has caused the field of random number generation to undergo a fundamental shift from relying solely on pseudo-random algorithms to employing optical entropy sources. Despite these significant advances on the hardware side, commonly used statistical measures and evaluation practices remain ill-suited to understand or quantify the optical entropy that underlies physical random number generation. We review the state of the art in the evaluation of optical random number generation and recommend a new paradigm: quantifying entropy generation and understanding the physical limits of the optical sources of randomness. In order to do this, we advocate for the separation of the physical entropy source from deterministic post-processing in the evaluation of random number generators and for the explicit consideration of the impact of the measurement and digitization process on the rate of entropy production. We present the Cohen-Procaccia estimate of the entropy rate h(ϵ,τ)h(\epsilon,\tau) as one way to do this. In order to provide an illustration of our recommendations, we apply the Cohen-Procaccia estimate as well as the entropy estimates from the new NIST draft standards for physical random number generators to evaluate and compare three common optical entropy sources: single photon time-of-arrival detection, chaotic lasers, and amplified spontaneous emission

    Synchronising C/C++ and POWER

    Get PDF
    Shared memory concurrency relies on synchronisation primitives: compare-and-swap, load-reserve/store-conditional (aka LL/SC), language-level mutexes, and so on. In a sequentially consistent setting, or even in the TSO setting of x86 and Sparc, these have well-understood semantics. But in the very relaxed settings of IBM®, POWER®, ARM, or C/C++, it remains surprisingly unclear exactly what the programmer can depend on. This paper studies relaxed-memory synchronisation. On the hardware side, we give a clear semantic characterisation of the load-reserve/store-conditional primitives as provided by POWER multiprocessors, for the first time since they were introduced 20 years ago; we cover their interaction with relaxed loads, stores, barriers, and dependencies. Our model, while not officially sanctioned by the vendor, is validated by extensive testing, comparing actual implementation behaviour against an oracle generated from the model, and by detailed discussion with IBM staff. We believe the ARM semantics to be similar. On the software side, we prove sound a proposed compilation scheme of the C/C++ synchronisation constructs to POWER, including C/C++ spinlock mutexes, fences, and read-modify-write operations, together with the simpler atomic operations for which soundness is already known from our previous work; this is a first step in verifying concurrent algorithms that use load-reserve/store-conditional with respect to a realistic semantics. We also build confidence in the C/C++ model in its own terms, fixing some omissions and contributing to the C standards committee adoption of the C++11 concurrency model
    • …
    corecore