The H1-Level 2 neural network trigger has been running successfully at Deutsches Elektronen Synchrotron (DESY) for four years. In order to provide increased selectivity at the higher luminosity ...planned for the HERA upgrade, an improved "intelligent" preprocessing has been devised. This system extracts complementary physics information from the Level 1 trigger stream and furnishes it to the L2 neural network in order to improve its decision. A new preprocessing board (the Data Distribution Board Version 2-DDB2) is currently being designed at the Max Planck Institute for Physics, Munich, Germany, in order to implement the necessary algorithms in fast field programmable gate arrays (FPGA), taking advantage of parallelism and pipelined structures in order to meet the timing requirement of 8 /spl mu/s. We present the different algorithmic steps and report on the current status of the DDB2 hardware upgrade.
Since 1996 the H1 experiment is fully equipped with two independent fast pattern recognition systems operating as second level triggers (L2). The decision time is 20 μs. One of the two is the neural ...network trigger. It runs an array of presently ten VME-boards with CNAPS 1064 chips (20 MHz, 128 Mcps) by Adaptive Solutions. The input trigger data from the detector components arrive in various formats on a 8 × 16 bit wide 10 MHz bus. Before usable as 8-bit input values to the CNAPS they are preprocessed by several bit-manipulating algorithms and arithmetic functions implemented on XILINX 4008 field programmable gate arrays (FPGA). The startup strategy for the new system is to concentrate on photoproduction channels or low multiplicity final states which so far could only be efficiently triggered with unacceptable high rates.
The tracking, calorimeter and muon detectors of the H1 experiment at HERA Arnault, C.; Bederede, D.; Bernard, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/1997, Letnik:
386, Številka:
2
Journal Article
Recenzirano
Technical aspects of the three major components of the H1 detector at the electron-proton storage ring HERA are described. This paper covers the detector status up to the end of 1994 when a major ...upgrading of some of its elements was undertaken. A description of the other elements of the detector and some performance figures from luminosity runs at HERA during 1993 and 1994 are given in a paper previously published in this journal.
Performance of the ATLAS hadronic end-cap calorimeter in beam tests Dowler, B; Pinfold, J; Soukup, J ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2002, Letnik:
482, Številka:
1-2
Journal Article
Recenzirano
Odprti dostop
Modules of the ATLAS liquid argon Hadronic End-cap Calorimeter (HEC) were exposed to beams of electrons, muons and pions in the energy range 6⩽E⩽200GeV at the CERN SPS. A description of the HEC and ...of the beam test setup are given. Results on the energy response and resolution are presented and compared with simulations. The ATLAS energy resolution for jets in the end-cap region is inferred and meets the ATLAS requirements.
Uterine cervical cytology smears are among the most cost-effective cancer prevention interventions available, but they are not infallible, and new or modified technologies have been and will be ...proposed to improve diagnostic accuracy. Before these new technologies are accepted, their performance attributes will be carefully studied and defined. Equally important in this era of fiscal constraints are cost/benefit analyses, for which we review certain guidelines.
In an effort to control rising costs in the health care sector, there has been a strong incentive to move toward a market system, and a variety of forces are acting to drive down expenditures. These same pressures will continue to be brought to bear on the providers of cervical cytology services. It must be emphasized that the technical knowledge required to define cost-effective medical practice lies within the medical profession itself, which must recognize the following: (a) Resources are finite; (b) Elimination of fraud, abuse and waste is not enough to bring health care expenditures down to levels considered acceptable to government and business; (c) The medical profession must take the responsibility to identify the health and economic consequences of the services it provides and make wise recommendations for allocation of resources to optimize health consequences. The analysis of costs and benefits must be viewed from a societal perspective and presented in terms of the marginal impact on current practice. This does not mean that new technologies must reduce cost; on the contrary, improvements in health can be expected to come at a price, but at a price commensurate with value gained in lives saved or in added quality adjusted life years. To be of value, a new technology for cervical cytology must be more effective in preventing cervical carcinoma. Dysplasia is considered a precursor of carcinoma, and detection of dysplasia has been a surrogate for prevention of cervical carcinoma, but dysplasia does not always lead to carcinoma, least of all mild dysplasia, and policy makers ultimately will insist that a favorable change in health outcome be effected by new technology before it is allocated resources. Alternatively, new technologies may lower cost, perhaps by modifying screening or rescreening procedures according to known risk; by improved cytopreparatory techniques that simplify, improve or speed screening; or by monitoring devices that minimize screening error. In each case the performance attributes of the instrument or human instrument process should be evaluated in the intended use environment.
While current cervical cytology methodology is one of the most effective means of cancer prevention, there continues to be development of new techniques to increase the sensitivity and specificity of this test. With present fiscal constraints, these will be subject to stringent cost/benefit analyses in which the medical profession must play a key role. Such analyses can be quite complicated, considering the additional costs or cost savings of clinical follow-up procedures and the reliability of dysplasias detected by cytology as a surrogate for cervical carcinoma in calculating quality of life years saved.
Increasing litigation over alleged false negative cervical cytologic (CC) smears threatens the viability of this test for cervical cancer detection. The problem appears to be largely American but is ...beginning to appear in some other countries. In the vast majority of cases there is either a settlement or jury verdict for the plaintiff based largely on the testimony of expert witnesses. Cases are judged on an individual basis without significant consideration of the general performance of the CC smear in laboratories operating in compliance with a wide array of laboratory regulations and with documented and comprehensive quality control practices in place. It is acknowledged that there are problem laboratories and cytology practitioners. There is an emerging issue of automated preparation and screening devices and issues of informed patient consent.
Cytology professionals have done an extraordinary and commendable job of educating the public about the benefits of the CC smear. We have been less successful and conscientious about explaining and defining the limitations of the CC test. There is a need for public and professional education as to the benefits and limitations of the CC smear for cervical cancer detection. The process suggested is to work with women's groups, public health agencies, government agencies, and state and national legislatures and to coordinate professional committees working on liability issues. Contextual information could be included with the CC smear report to indicate that a negative report confers a low probability of developing cervical cancer. It is suggested that appropriate language and a menu of statements be developed. Increased efforts should be directed to physician education with respect to informed consent concerning the benefits and limitations of CC smear testing and the application of new technology to improve smear accuracy. The process should include development of appropriate statements on the use of alternative technology. The profession should develop "process guidelines" for review of CC smears in the context of possible litigation, including standardized methods for blind slide review of smears that reduce or eliminate context and outcome bias. It is suggested that review panels be anonymous, that the process be standardized and that there be limitations on liability for participating organizations. Professional cytopathology and pathology societies should formulate acceptable guidelines for expert witnesses. The standards should be applicable to both defendant and plaintiff experts. All materials to the extent practical, including consultant opinions, should be available for peer review. Professional cytopathology and pathology societies should monitor expert testimony for objectivity and scientific accuracy.
For the near future, litigation will continue to focus on false negative CC smears on a case-by-case basis. Laboratories and individuals can reduce the risk of malpractice liability by directing their attention to proactive quality control and quality assurance methods. In the final analysis, consumer education about the benefits and limitations of the test is key to limiting malpractice claims. To stem the tide of continued medicolegal challenges to the integrity of cytology practice, the cytology community has now focused its efforts on developing and utilizing standards that convey to patients, attorneys and cytologists the contemporary status of and reasonable expectations for the practice of cytology. Guidelines such as those for uniform reporting terminology and clinical management of cervical abnormalities form the basis of cytology practice standards on which legal standards of practice can be based. Consensus conference reports, clinical management trials and scientifically valid studies of false negative rates that analyze the type, frequency and cause of missed cases represent sounder methods of establishing defensible
Optical digital imaging and its related technologies have applications in cytopathology that encompass training and education, image analysis, diagnosis, report documentation and archiving, and ...telecommunications. Telecytology involves the use of telecommunications to transmit cytology images for the purposes of diagnosis, consultation or education. This working paper provides a mainly informational overview of optical digital imaging and summarizes current technologic resources and applications and some of the ethical and legal implications of the use of these new technologies in cytopathology.
Computer hardware standards for optical digital imagery will continue to be driven mainly by commercial interests and nonmedical imperatives, but professional organizations can play a valuable role in developing recommendations or standards for digital image sampling, documentation, archiving, authenticity safeguards and teleconsultation protocols; in addressing patient confidentiality and ethical, legal and informed consent issues; and in providing support for quality assurance and standardization of digital image-based testing. There is some evidence that high levels of accuracy for telepathology diagnosis can be achieved using existing dynamic systems, which may also be applicable to telecytology consultation. Static systems for both telepathology and telecytology, which have the advantage of considerably lower cost, appear to have lower levels of accuracy. Laboratories that maintain digital image databases should adopt practices and protocols that ensure patient confidentiality. Individuals participating in telecommunication of digital images for diagnosis should be properly qualified, meet licensing requirements and use procedures that protect patient confidentiality. Such individuals should be cognizant of the limitations of the technology and employ quality assurance practices that ensure the validity and accuracy of each consultation. Even in an informal teleconsultation setting one should define the extent of participation and be mindful of potential malpractice liability.
Digital imagery applications will continue to present new opportunities and challenges. Position papers such as this are directed toward assisting the profession to stay informed and in control of these applications in the laboratory. Telecytology is an area in particular need of studies of good quality to provide data on factors affecting accuracy. New technologic approaches to addressing the issue of selective sampling in static image consultation are needed. The use of artificial intelligence software as an adjunct to enhance the accuracy and reproducibility of cytologic diagnosis of digital images in routine and consultation settings deserves to be pursued. Other telecytology-related issues that require clarification and the adoption of workable guidelines include interstate licensure and protocols to define malpractice liability.
The same sources cited for the authors' bibliography on the paragraph (Style, 1977, 11, 2, 107-118) are used as the basis for a bibliography on punctuation & style. B. Annesser
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