Less is More: Exploiting the Standard Compiler Optimization Levels for Better Performance and Energy Consumption

This paper presents the interesting observation that by performing fewer of the optimizations available in a standard compiler optimization level such as -O2, while preserving their original ordering, significant savings can be achieved in both execution time and energy consumption. This observation has been validated on two embedded processors, namely the ARM Cortex-M0 and the ARM Cortex-M3, using two different versions of the LLVM compilation framework; v3.8 and v5.0. Experimental evaluation with 71 embedded benchmarks demonstrated performance gains for at least half of the benchmarks for both processors. An average execution time reduction of 2.4% and 5.3% was achieved across all the benchmarks for the Cortex-M0 and Cortex-M3 processors, respectively, with execution time improvements ranging from 1% up to 90% over the -O2. The savings that can be achieved are in the same range as what can be achieved by the state-of-the-art compilation approaches that use iterative compilation or machine learning to select flags or to determine phase orderings that result in more efficient code. In contrast to these time consuming and expensive to apply techniques, our approach only needs to test a limited number of optimization configurations, less than 64, to obtain similar or even better savings. Furthermore, our approach can support multi-criteria optimization as it targets execution time, energy consumption and code size at the same time.Comment: 15 pages, 3 figures, 71 benchmarks used for evaluatio

Semi-free forearm flap for pharyngeal-esophageal reconstruction after radiation therapy

AbstractReconstruction of the pharynx and upper esophagus uses various procedures, including pedicled or free flap. Pharyngoplasty with free forearm flap provides excellent functional results. In radiation-related pharyngeal stenosis, recipient vascularization is often poor, especially in the venous system. The authors describe pharyngeal reconstruction with semi-free forearm flap, pedicled on the cephalic vein, to minimize the risk of venous thrombosis, which is the main factor of free forearm flap necrosis. Taking the case of a laryngectomy with complete pharyngeal stenosis after radiation therapy and iterative neck surgery, the technique of pharyngeal-esophageal reconstruction by semi-free forearm flap is described in a context of impaired vascularization

COGEMA Experience on Retrieving and Automatically Remote Cutting Large Metallic Structures Using Special Saw During Nuclear Decommissioning Operations

Used spent fuel baskets have been stored in the La Hague North-West concrete-lined pits until decommissioning. In 1998, COGEMA decided to retrieve, cut and condition these spent fuel baskets. This paper describes the experience gained, since the start up of this operation in 1999, discusses resulting dosimetry and waste produced, during retrieving and remotely cutting of LL activity large metallic structures. This process result in significantly lower exposures to workers in the D and D operations. In addition the work was carried out in an environmentally safe manner with reasonable financial costs

Effect of wing-mounted nacelles on a 42 deg swept supercritical wing configuration at near-sonic speeds

An investigation was made to assess the effect of wing-mounted nacelles on a supercritical wing configuration at near-sonic Mach numbers. The investigation was made by utilizing the Cornell Aeronautical Laboratory 8-foot transonic tunnel and covered a Mach number range from 0.90 to 0.99. Force data and pressure measurements at selected locations were obtained. The investigation with the nacelles on included the effect of spanwise location of the nacelle (semispan locations of 35 and 70 percent) and the effect of area ruling for the nacelles located at the 35 percent semispan station. Tests were also made with the outboard nacelle extended forward so that it was directly adjacent to the inboard nacelle location. These tests provided a direct assessment of the extent of the nacelle interference flow field in a lateral direction

Minimally invasive osteotomy for distal radius malunion: A preliminary series of 9 cases

AbstractThe rate of malunion after distal radius fractures is 25% after conservative treatment and 10% after surgery. Their main functional repercussion related to ulno-carpal conflict is loss of wrist motion. We report a retrospective clinical series of minimally invasive osteotomies. The series consisted of 9 cases of minimally invasive osteotomies with volar locking plate fixation. All osteotomies healed. The average pain was 5.3/10 preoperatively and 2.1/10 at last follow-up. The mean Quick DASH was 55.4/100 preoperatively and 24.24/100 at last follow-up. Compared to the opposite side, the average wrist flexion was 84.11%, the average wrist extension was 80.24%, the average pronation was 95.33% and the average supination was 93.9%. With similar results to those of the literature, our short series confirms the feasibility of minimally invasive osteotomy of the distal radius for extra-articular malunion.TypeCase-series.Level of evidenceIV