The roman conquered by delay: reducing the number of preemptions using sleep states

Sleep-states are emerging as a first-class design choice in energy minimization. A side effect of this is that the release behavior of the system is affected and subsequently the preemption relations between tasks. In a first step we have investigated how the behavior in terms of number of preemptions of tasks in the system is changed at runtime, using an existing procrastination approach, which utilizes sleepstates for energy savings purposes. Our solution resulted in substantial savings of preemptions and we expect from even higher yields for alternative energy saving algorithms. This work is intended to form the base of future research, which aims to bound the number of preemptions at analysis time and subsequently how this may be employed in the analysis to reduced the amount of system utilization, which is reserved to account for the preemption delay

Device power management for real-time embedded systems

A large part of power dissipation in a system is generated by I/O devices. Increasingly these devices provide power saving mechanisms to inter alia enhance battery life. While I/O device scheduling has been studied in the past for realtime systems, the use of energy resources by these scheduling algorithms may be improved. These approaches are crafted considering a huge overhead of device transition. The technology enhancement has allowed the hardware vendors to reduce the device transition overhead and energy consumption. We propose an intra-task device scheduling algorithm for real time systems that allows to shut-down devices while ensuring the system schedulability. Our results show an energy gain of up to 90% in the best case when compared to the state-of-the-art

Energy-conscious tasks partitioning onto a heterogeneous multi-core platform

Modern multicore processors for the embedded market are often heterogeneous in nature. One feature often available are multiple sleep states with varying transition cost for entering and leaving said sleep states. This research effort explores the energy efficient task-mapping on such a heterogeneous multicore platform to reduce overall energy consumption of the system. This is performed in the context of a partitioned scheduling approach and a very realistic power model, which improves over some of the simplifying assumptions often made in the state-of-the-art. The developed heuristic consists of two phases, in the first phase, tasks are allocated to minimise their active energy consumption, while the second phase trades off a higher active energy consumption for an increased ability to exploit savings through more efficient sleep states. Extensive simulations demonstrate the effectiveness of the approach

Slow down or race to halt: towards managing complexity of real-time energy management decisions

Existing work in the context of energy management for real-time systems often ignores the substantial cost of making DVFS and sleep state decisions in terms of time and energy and/or assume very simple models. Within this paper we attempt to explore the parameter space for such decisions and possible constraints faced

Analysis of Environmental Physical-Chemical Factors and Macroalga Species In The Coastal Water of Nusalaut, Central Maluku - Indonesia

AbstractThe physical-chemical factors of environment are very influential on the presence and the growth of macrolaga in waters. Well-maintained water habitat is a good environment for the growth of macroalgae. A research has been conducted on the physicochemical environmental factors and the macroalgae species in the coastal waters of Nusalaut Island using transect method, and it was a survey research on four different observation stations. The results of the research showed that station I (Amet Village) has the best physicochemical factors for the presence and the growth of macroalgae, compared to station II (Nalahia Village), station III (Sila Village) and station IV (Leinitu Village). The most widely found macro algae are from the Rhodophyta class, with a total of 17 species of macroalgae, of which 15 species are found in station I.  Keywords: Macroalga, environmental factors, the coastal water of Nusalaut Abstrak (Indonesian)Faktor fisik kimia lingkungan sangat berpengaruh terhadap kehadiran dan pertumbuhan makrolaga pada suatu perairan. Habitat perairan yang terjaga menjadi lingkungan yang baik bagi pertumbuhan makroalga. Telah dilakukan penelitian tentang faktor fisik kimia lingkungan dan jenis-jenis makroalga di perairan Pantai Pulau Nusalaut dengan menggunakan metode transek, dan merupakan penelitian survey pada empat stasiun pengamatan yang berbeda. Hasil penelitian menunjukkan bahwa stasiun I (Desa Amet) memiliki faktor fisik kimia terbaik bagi kehadiran dan pertumbuhan makroalga bila diabandingkan dengan stasiun II (Desa Nalahia), stasiun III (Desa Sila) dan stasiun IV (Desa Leinitu). Makroalga yang paling banyak ditemukan berasal dari kelas Rhodophyta, dengan total makroalga yaitu sebanyak 17 spesies, dimana 15 spesies diantaranya ditemukan pada satasiun I.  Kata kunci: Makroalga, faktor lingkungan, perairan pantai Nusalau

Comparing the schedulers and power saving strategies with SPARTS

We have developed SPARTS, a simulator of a generic embedded real-time device. It is designed to be extensible to accommodate different task properties, scheduling algorithms and/or hardware models for the wide variety of applications. SPARTS was developed to help the community investigate the behaviour of the real-time embedded systems and to quantify the associated constraints/overheads

Development of a Method for the Determination of Chromium and Cadmium in Tannery Wastewater Using Laser-Induced Breakdown Spectroscopy

This paper illustrates systematic development of a convenient analytical method for the determination of chromium and cadmium in tannery wastewater using laser-induced breakdown spectroscopy (LIBS). A new approach was developed by which liquid was converted into solid phase sample surface using absorption paper for subsequent LIBS analysis. The optimized values of LIBS parameters were 146.7 mJ for chromium and 89.5 mJ for cadmium (laser pulse energy), 4.5 μs (delay time), 70 mm (lens to sample surface distance), and 7 mm (light collection system to sample surface distance). Optimized values of LIBS parameters demonstrated strong spectrum lines for each metal keeping the background noise at minimum level. The new method of preparing metal standards on absorption papers exhibited calibration curves with good linearity with correlation coefficients, R2 in the range of 0.992 to 0.998. The developed method was tested on real tannery wastewater samples for determination of chromium and cadmium

Vestibular schwannomas: Clinical presentation, management and outcome

Objective: To review the demographic trends clinical spectrum, diagnosis, management and outcome of patients with vestibular Schwannoma and to identify areas where improvements are needed.Methods: All patients with vestibular schwannoma admitted to the Aga Khan University Hospital over the past 11 years were reviewed retrospectively.Results: The age range of majority of 22 patients analyzed, was 41-50 years (23%). Hearing loss was the most common presenting symptom (96%). Other clinical features included cranial nerve palsies (59%) and headache (55%). Fifty percent had signs of raised intracranial pressure. Neuroimaging revealed Stage IV b (tumor distorting the brainstem and compressing the 4th ventricle) in 50% cases. Neurosurgical intervention was carried out in 86%; mainly using the retrosigmoid approach. Postoperative complications included facial nerve palsy in 13 (65%) and hydrocephalus in 5 (25%) patients. Hearing determined clinically was preserved in three patients (14%). One patient died during the inpatient stay.Conclusion: Presentation of these patients is late and the outcome is poor

Clinical study on the use of nozovent in a tertiary care setting

Objective: To assess the effectiveness of the Nozovent device in Pakistani subjects at Aga Khan University Hospital, Karachi and Sir Ganga Ram Hospital, Lahore from 15 January 2001 to 15 January 2002.Methods: Sixty males and 40 females were selected by non probability purposive sampling, from OPD of ENT Department, complaining of nasal obstruction due to various reasons, e.g. vasomotor rhinitis, allergic rhinitis, congestion during pregnancy and menstruation, common cold, traumatic nose and nasal valve problem.Results: All patients benefited subjectively but the degree of relief varied in individuals.CONCLUSION: The Nozovent provides a unique method to relieve nasal obstruction with no side effects