71 research outputs found

    ApproxHPVM: A retargetable compiler framework for accuracy-aware optimizations

    Get PDF
    With the increasing need for machine learning and data processing near the edge, software stacks and compilers must provide optimizations for alleviating the computational burden on low-end edge devices. Approximate computing can help bridge the gap between increasing computational demands and limited compute power on such devices. We present ApproxHPVM, a portable optimizing compiler and runtime system that enables flexible, optimized use of multiple software and hardware approximations in a unified easy-to-use framework. ApproxHPVM uses a portable compiler IR and compiler analyses that are designed to enable accuracy-aware performance and energy tuning on heterogeneous systems with multiple compute units and approximation methods. ApproxHPVM automatically translates end-to-end application-level quality metrics into accuracy requirements for individual operations. ApproxHPVM uses a hardware-agnostic accuracy-tuning phase to do this translation that provides greater portability across heterogeneous hardware platforms. ApproxHPVM incorporates three main components: (a) a compiler IR with hardware-agnostic approximation metrics, (b) a hardware-agnostic accuracy-tuning phase to identify error-tolerant computations, and (c) an accuracy-aware hardware scheduler that maps error-tolerant computations to approximate hardware components. As ApproxHPVM does not incorporate any hardware-specific knowledge as part of the IR, it can serve as a portable virtual ISA that can be shipped to all kinds of hardware platforms. We evaluate ApproxHPVM on 9 benchmarks from the deep learning domain and 5 image-processing benchmarks. Our results show that our framework can offload chunks of approximable computations to special-purpose accelerators that provide significant gains in performance and energy, while staying within user-specified application-level quality metrics with high probability. Across the 14 benchmarks, we observe from 1-9x performance speedups and 1.1-11.3x energy reduction for very small reductions in accuracy. ApproxTuner extends ApproxHPVM with a flexible system for dynamic approximation tuning. The key contribution in ApproxTuner is a novel three-phase approach to approximation-tuning that consists of development-time, install-time, and run-time phases. Our approach decouples tuning hardware-independent and hardware-specific approximations, thus providing retargetability across devices. To enable efficient autotuning of approximation choices, we present a novel accuracy-aware tuning technique called predictive approximation-tuning. It can optimize the application during development-time and can also refine the optimization with (previously unknown) hardware-specific approximations at install time. We evaluate ApproxTuner across 11 benchmarks from deep learning and image processing domains. For the evaluated convolutional neural networks, we show that using only hardware-independent approximation choices provides a mean speedup of 2.2x (max 2.7x) on GPU, and 1.4x mean speedup (max 1.9x) on the CPU, while staying within 2 percentage points of inference accuracy loss. For two different accuracy-prediction models, our predictive tuning strategy speeds up tuning by 13.7x and 17.9x compared to conventional empirical tuning while achieving comparable benefits

    Spontaneous spinal subarachnoid haemorrhage: a rare complication of dengue fever / Nur Hidayati Mohd Sharif … [et al.]

    Get PDF
    A 37-year-old woman presented with a short history of fever and bilateral lower limb weakness. She also had impaired sensory function up to T4 spine level and lax anal tone. Laboratory investigations confirmed dengue infection with mild thrombocytopenia. MRI of the spine showed a spinal subarachnoid haemorrhage from the level of T4 till T9. Despite medical and surgical interventions, her lower limb weakness persists. A high index of suspicion is needed to recognise dengue-related neurological complications. This diagnosis should be considered in any patients from dengue endemic areas presenting with acute febrile illness with atypical neurological manifestations

    A critical edition of Part 1 of al-Shantamari's commentary on al-Hamasa.

    Get PDF
    Abstract Not Provided

    Short-term complications after bilateral internal mammary artery grafting--a retrospective study

    Get PDF
    Objectives: To analyze our experience of conducting Bilateral Internal Mammary Artery (BIMA) grafting, using both pedicled and free grafts for coronary revascularization, assessing the safety and efficacy of the procedure and comparing any differences observed between the two techniques of harvesting the grafts.Methods: A retrospective cross sectional study was conducted in July 2010 in which all 48 patients undergoing bilateral internal mammary artery grafting for coronary bypass surgery at the Aga Khan University Hospital from 1996 to 2010 were reviewed and evaluated. The main outcome measures were perioperative mortality and early morbidity with particular reference to cerebrovascular accidents, sternal wound complications and re-opening for bleeding. Chi-square test was used to elicit any meaningful associations between patient characteristics and post-operative outcomes.Results: Of the 48 patients undergoing bilateral IMA grafting, 46 were males and 2 females. The mean age was 48 +/- 9.4 years. Dyslipidaemia and smoking were the most common identifiable risk factors for coronary vascular disease. Following the 40 elective and 8 emergent surgeries, there was one hospital death. The most common post-operative complications were arrhythmias and wound infection. Diabetes and obesity were not observed to be associated with an increased risk of developing surgical site infection.CONCLUSIONS: Our study suggests that the short-term efficacy and the safety profile of bilateral IMA grafting for coronary revascularization is clinically acceptable. Long-term follow-up studies should be done to assess the cardiac event-free survival of these individuals evaluating its applicability as a routine for coronary artery bypass grafting in Pakistan

    Sustainable Campus Income Generation Initiative and Social Entrepreneurship at a Public University

    Get PDF
    Campuses with substantial acreage have the advantage of biodiversity, populace, and facilities that would allow the initiation of multi projects for income generation and sustainability.  For Universiti Teknologi MARA Cawangan Selangor (UCS), the fish pekasam project originated from the natural resources available on campus, which are the twelve lakes inhabited with tilapias and other fishes. Elements of social entrepreneurship from the sale of the pekasam (fermented) fish allowed for income generation to the campus. Aside from that, direct training was given to the students and staff who participated in the project. The initiative helped increase the campus's happiness index.Keywords: sustainable campus; narrative research; social entrepreneurship; fish pekasameISSN: 2398-4287 © 2020. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BYNC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia.DOI: https://doi.org/10.21834/e-bpj.v5i13.194

    Investigation of Polyacrylamide Hydrogel-based Molecularly Imprinted Polymers using Protein Gel Electrophoresis

    Get PDF
    In conjunction with polyacrylamide gel electrophoresis (PAGE), molecular imprinting methods have been applied to produce a multi-layer mini-slab in order to evaluate how selectively and specifically a hydrogel-based molecularly imprinted polymer (MIP) binds bovine haemoglobin (BHb, ~64.5 kDa). A three-layer mini-slab comprising an upper and lower layer and a MIP, or a non-imprinted control polymer dispersion middle layer has been investigated. The discriminating MIP layer, also based on polyacrylamide, was able to specifically bind BHb molecules in preference to a protein similar in molecular weight such as bovine serum albumin (BSA, ~66 kDa). Protein staining allowed us to visualise the protein retention strength of the MIP layer under the influence of an electric field. This method could be applied to other proteins with implications in effective protein capture, disease diagnostics and protein analysis

    Collapsibility of PMMA based material in direct investment casting

    Get PDF
    Over recent years, the rapid growth of Additive manufacturing (AM) has benefits the Direct Investment Casting (DIC) process for intricate design in which significantly reduces the cost when associated with low volume production. Nevertheless, ceramic shells cracking has been recognized as critical problem when involved direct casting in which leads to incomplete collapsibility. Therefore, this study presents a numerical and experimental on poly(methyl) methacrylate (PMMA) pattern collapsibility for investment casting process and the stress analysis study on the ceramic shells. Study revealed that there were significant average of 5.8 % reduction of stress between square and polygon patterns. This study was conducted to examine the collapsibility of AM materials in the IC process

    A preliminary study on operation management for one-way EV car sharing system in university campus

    Get PDF
    Car sharing using electric vehicles(EVs) is effective in local society and community from the viewpoint of economy and the protection of the natural environment. For instance, Univerisiti Putra Malaysia (UPM), which has two large campuses, has a plan to use a small number of small EVs as one of transportation methods. When a large number of people share a small number of vehicles in this way, the confliction of usage requests by users may cause inconvenience to users and ineffective operation of vehicles. In addition, because the degree of legal compliance with usage time and operation rules relies on social and cultural backgrounds, operation methods may be affected by them. Therefore, a framework for supporting operation management in consideration of characteristics of the local society and community is necessary in order to efficiently operate a limited number of vehicles without detracting from the convenience of users. We have been developing an operation management support system for one-way EV car sharing in the university campus to improve user convenience and vehicle operation efficiency. In this presentation, we clarify the issues of operation management for car sharing system. We also introduce an overview of the operation management support system and propose several reservation methods of vehicles

    Investigation of Particulate Matter (PM10) Pollution in Ipoh City, Malaysia

    Get PDF
    Air pollution is one of the phenomena that adversely affect the environment and negatively impact human health. Air pollution occurs when there are excessive air pollutants in the atmosphere. This study aims to identify and discuss the sources of PM10 emissions according to land use around Ipoh using descriptive and boxplot analysis. There are five areas selected as a sampling location for this study: Ipoh, Lahat, Chemor, Tanjung Rambutan, and Simpang Pulai that located in Hulu Kinta and Sungai Raya district. This sampling location's primary focus is located around Ipoh city, concentrated in the industrial area. Ten land use-based sampling stations are selected to measure. PM10 data were recorded for one week during working and non-working days in July 2020 on 10 sampling stations around Ipoh. The result shows PM10 concentrations consist of industrial, infrastructure and utility, commercial, residential, and recreational areas, as shown PM10 values ​​were recorded for one week during working days and non-working days on 10 observation stations using Portable Laser Aerosol Spectrometer and Dust Monitor Model 1.108. Based on the observations, two stations show the daily average mean of PM10 exceeding 100 μg/m3 outlined in the Malaysian Ambient Air Quality Standard (MAAQS) at S6 (175.78 μg/m3) and S10 (103.79 μg/m3). This situation is driven by the presence of limestone-based industrial areas as well as quarrying activities. The findings also show that PM10 concentration is higher during working days rather than non-working days. Overall, PM10 concentrations that exceed the limit will have a detrimental effect on the environment and human health
    corecore