CLOMP: Accurately Characterizing OpenMP Application Overheads

Despite its ease of use, OpenMP has failed to gain widespread use on large scale systems, largely due to its failure to deliver sufficient performance. Our experience indicates that the cost of initiating OpenMP regions is simply too high for the desired OpenMP usage scenario of many applications. In this paper, we introduce CLOMP, a new benchmark to characterize this aspect of OpenMP implementations accurately. CLOMP complements the existing EPCC benchmark suite to provide simple, easy to understand measurements of OpenMP overheads in the context of application usage scenarios. Our results for several OpenMP implementations demonstrate that CLOMP identifies the amount of work required to compensate for the overheads observed with EPCC. We also show that CLOMP also captures limitations for OpenMP parallelization on SMT and NUMA systems. Finally, CLOMPI, our MPI extension of CLOMP, demonstrates which aspects of OpenMP interact poorly with MPI when MPI helper threads cannot run on the NIC.     

干式色调剂(墨粉)技术介绍(1)

革命性的开发电子摄影术(译者注:也称为电子照相术或静电成像过程或静电复印方法)被视为是二十世纪最耀眼的发明创造之一。在即刻生成、复制并转印成硬拷贝文件这件事出现之前,人们几乎不可想象会存在这种情况。色调剂是所有采用电子照相成像过程的复印机、打印机和传真机的基本构成部分(译者注:当今习惯称为耗材之一)。     

The plutonium/hydrogen reaction: The pressure dependence of reaction initiation time

The hydrogen pressure dependence of the initiation time (I_t) of the plutonium hydriding reaction has been determined over a hydrogen pressure range of 10-1000 mbar for plutonium covered in a dioxide over-layer. The data show that hydriding initiation time is inversely proportional to hydrogen pressure. This observation is consistent with a model of hydriding attack in which the dioxide over-layer acts as a diffusion barrier, controlling the flow of hydrogen to the oxide/metal interface. The low scatter and reproducibility of the experimental data set illustrate the importance of synthesising a reproducible oxide layer prior to determining this experimental parameter.     

Public safety investigations—A new evolutionary step in safety enhancement?

A historical overview highlights the evolutionary nature of developments in accident investigations in the transport industry. Based on a series of major events outside transportation, the concept of accident investigations has broadened to other domains and to a widening of the scope of the investigation. Consequently, existing investigation boards are forced to adapt their mandates, missions and methods. With the introduction of social risk perception and application of the concept of safety investigation in the public sector, a change of focus towards the aftermath and non-technical issues of a more generic nature emerges. This expansion has also gained the interest of social sciences and public governance, generating new underlying models and theories on risk and responsibility. The evolutionary development of safety investigations is demonstrated by the various organisational forms which shaped accident investigations in different countries. Underneath these organisational differences, a need for a common methodology and a reflection on fundamental notions is discussed. In particular differences among human operator models, the allocation of responsibilities in design concepts and methodological issue are elaborated. The needs and opportunities for a transition from accident prevention towards systems change are indicated. At present, the situation is ambiguous. An encompassing inventory can only provide a general oversight over emerging trends and lacks analytic rigor on specific topics. The societal dimensions, institutional changes at the level of governance and control and the powers that advocate or challenge investigations are not yet fully described.Therefore, in the conclusions a small number of critical challenges and threats are identified that should be open to scrutiny in order to facilitate a new, evolutionary step in safety enhancement.     

Triphasic ceramic coated hydroxyapatite as a niche for goat stem cell-derived osteoblasts for bone regeneration and repair

Current treatment strategies for the repair or replacement of bone use synthetic implants with stem cells and their progeny––a new approach to address unmet medical needs. This study has evaluated the effect of a silica-coated bioactive ceramic, namely HASi in comparison to hydroxyapatite (HA) on the adhesion, proliferation and osteogenic differentiation of goat bone marrow-derived mesenchymal stem cells in vitro in a prolonged culture of 28 days. The cellular activities were significantly enhanced on HASi signifying the role of silica to stimulate osteoblast cells. The fabrication of such a ‘cell-ceramic construct using autologous MSCs’ is aimed for the transplantation to a large bone defect site in the goat femur model which still remains a formidable challenge in Orthopedic surgery.     

Fabricated carbon from minimally processed coke and coal tar pitch as a carbon-sequestering construction material

We report the mechanical fracture strength and physical properties of fabricated carbons made from pulverized metallurgical coke bonded with coal tar pitch, followed by pyrolysis. Tensile strength from diametral compression of discs ranged from 9.7 ± 1.3 MPa for materials bonded with 13 wt% pitch to 63 ± 7.1 MPa for materials bonded with 40 wt% pitch. Materials made by dry mixing pulverized pitch with coke were comparable with materials made by mixing coke powder with a solution of pitch in toluene. Strength increased with pyrolysis temperature. Pyrolyzed pitch-bonded coke was significantly stronger and lighter than ordinary Portland cement concrete.     

Development of Undergraduate Students’ Professional Skills

The development of engineering students’ professional skills has gained considerable national attention from Accreditation Board for Engineering and Technology, the National Academy of Engineering, ASCE, and other constituents. There is little debate that these professional skills are necessary. Engineering programs have tried many approaches to develop these skills in the undergraduate programs. Colorado State University (CSU) has developed a new approach modeled on the type of professional development that occurs in the professional environment. This new Professional Learning Institute (PLI) provides students with a broad array of workshops, presentations, and experiential opportunities addressing the areas of cross cultural communication and teamwork, innovation, leadership, ethics, and public service. This program introduces students to the concept of professional development through required extracurricular activities, includes minimum requirements along with requirements to earn certificates in specialty areas for motivated students. The majority of offerings in the PLI are presented by leaders from the engineering profession who have teamed with CSU to provide high quality programs for our students.     

Dissemination of the Coping Power program: Importance of intensity of counselor training.

This study examined an important but rarely investigated aspect of the dissemination process: the intensity of training provided to practitioners. Counselors in 57 schools were randomly assigned to 1 of 3 conditions: Coping Power–training plus feedback (CP-TF), Coping Power–basic training (CP-BT), or a comparison condition. CP-TF counselors produced reductions in children’s externalizing behavior problems and improvements in children’s social and academic skills in comparison to results for target children in both the comparison and the CP-BT conditions. Training intensity was critical for successful dissemination, although the implementation mechanism underlying this effect remains unclear, as condition effects were not significant for completion of session objectives but were significant for the quality of counselors’ engagement with children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processes and outcomes of psychotherapists' personal therapy: Replication and extension 20 years later.

In this replication and extension of a national survey of psychotherapists conducted in 1987, American psychologists (n = 219), counselors (n = 191), and social workers (n = 192) reported in 2007 on the processes and outcomes of their personal therapy experiences. Of the 85% who sought therapy at least once, women, men, and members of all three professions were equally as likely to have received personal treatment. Their top reasons for seeking therapy were marital–couple distress (20%), depression (13%), need for self-understanding (12%), and anxiety–stress (10%). Approximately 24% used psychotropic medication in combination with personal therapy. More than 90% of therapists reported positive outcomes across multiple domains. The modal lasting lessons from personal treatment related to therapist reliability, skill, and empathy. The results are tentatively compared with those obtained in 1987, thus chronicling the evolution of personal therapy among psychologists and social workers during the past 20 years. (PsycINFO Database Record (c) 2010 APA, all rights reserved)