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1.
IH Bjerkli R Myklebust S R?is?nen S Telimaa LE Stenfors 《Canadian Metallurgical Quarterly》1996,36(3):205-213
Dopaminergic agents and carbidopa/levodopa have become the preferred treatment for both the restless legs (RL) syndrome and for periodic limb movements in sleep (PLMS). For once-nightly treatments with carbidopa/ levodopa, a problem with morning end-of-dose rebound increases in leg movements has been reported to occur in the about one-fourth of the patients. In our clinical studies a previously unreported but far more significant problem of markedly augmented RL symptoms occurred in the afternoon and the evening prior to taking the next nightly dose. A systematic prospective evaluation of this augmentation in 46 consecutive patients treated with carbidopa/ levodopa for RL syndrome or PLMS disorder found this augmentation to be the major adverse effect of treatment. Augmentation occurred for 31% of PLMS patients and 82% of all RL patients. It was greater for subjects with more severe RL symptoms and for patients on higher doses (> or = 50/200 mg carbidopa/levodopa) but was unrelated to gender, age or baseline severity of PLMS. This augmentation was severe enough to require medication change for 50% of the RL patients and 13% of PLMS patients. Augmentation resolved with cessation of the medication and could be minimized by keeping the dose low. 相似文献
2.
Anita Gupta Jingyue Li Reidar Conradi Harald Rønneberg Einar Landre 《Empirical Software Engineering》2009,14(2):227-255
The benefits of software reuse have been studied for many years. Several previous studies have observed that reused software
has a lower defect density than newly built software. However, few studies have investigated empirically the reasons for this
phenomenon. To date, we have only the common sense observation that as software is reused over time, the fixed defects will
accumulate and will result in high-quality software. This paper reports on an industrial case study in a large Norwegian Oil
and Gas company, involving a reused Java class framework and two applications that use that framework. We analyzed all trouble
reports from the use of the framework and the applications according to the Orthogonal Defect Classification (ODC), followed
by a qualitative Root Cause Analysis (RCA). The results reveal that the framework has a much lower defect density in total
than one application and a slightly higher defect density than the other. In addition, the defect densities of the most severe
defects of the reused framework are similar to those of the applications that are reusing it. The results of the ODC and RCA
analyses reveal that systematic reuse (i.e. clearly defined and stable requirements, better design, hesitance to change, and
solid testing) lead to lower defect densities of the functional-type defects in the reused framework than in applications
that are reusing it. However, the different “nature” of the framework and the applications (e.g. interaction with other software,
number and complexity of business logic, and functionality of the software) may confound the causal relationship between systematic
reuse and the lower defect density of the reused software. Using the results of the study as a basis, we present an improved
overall cause–effect model between systematic reuse and lower defect density that will facilitate further studies and implementations
of software reuse.
相似文献
Anita GuptaEmail: |
3.
Øyvind Hauge Claudia Ayala Reidar Conradi 《Information and Software Technology》2010,52(11):1133-1154
ContextOpen source software (OSS) is changing the way organizations develop, acquire, use, and commercialize software.ObjectiveThis paper seeks to identify how organizations adopt OSS, classify the literature according to these ways of adopting OSS, and with a focus on software development evaluate the research on adoption of OSS in organizations.MethodBased on the systematic literature review method we reviewed publications from 24 journals and seven conference and workshop proceedings, published between 1998 and 2008. From a population of 24,289 papers, we identified 112 papers that provide empirical evidence on how organizations actually adopt OSS.ResultsWe show that adopting OSS involves more than simply using OSS products. We moreover provide a classification framework consisting of six distinctly different ways in which organizations adopt OSS. This framework is used to illustrate some of the opportunities and challenges organizations meet when approaching OSS, to show that OSS can be adopted successfully in different ways, and to organize and review existing research. We find that existing research on OSS adoption does not sufficiently describe the context of the organizations studied, and it fails to benefit fully from related research fields. While existing research covers a large number of topics, it contains very few closely related studies. To aid this situation, we offer directions for future research.ConclusionThe implications of our findings are twofold. On the one hand, practitioners should embrace the many opportunities OSS offers, but consciously evaluate the consequences of adopting it in their own context. They may use our framework and the success stories provided by the literature in their own evaluations. On the other hand, researchers should align their work, and perform more empirical research on topics that are important to organizations. Our framework may be used to position this research and to describe the context of the organization they are studying. 相似文献
4.
Sediments filling reservoirs is a common problem in the world today, with an estimated 1% of the capacity of hydropower reservoirs being lost annually through sedimentation. One of the most used techniques for reducing this problem is reservoir flushing. During a flood, the water level is drawn down, causing increased velocities, therefore facilitating erosion and sediment transport. During the flushing, water from the reservoir will be lost, resulting in significant economic implications for the reservoir owner. The success of reservoir flushing depends on several parameters, including water discharge, sediment properties and reservoir geometry. This study describes the use of Computational Fluid Dynamics (CFD) as a modern method to predict the reservoir flushing process. A three‐dimensional numerical model (SSIIM 2), with an adaptive, non‐orthogonal and unstructured grid has been used. Through the application of special modified algorithms (e.g., wetting/drying, free water surface), numerical modelling of sediment movement can be an alternative for planning and optimizing the flushing process for complex reservoir geometries. The numerical model was tested against data from a physical model study of the Kali Gandaki hydropower reservoir in Nepal. The total quantity of flushed out sediments, and the bed deformation in six cross‐sections, were compared, highlighting a good correspondence between the results. These include the cross‐sectional shape of a 90‐degree bend, for which secondary currents influenced the results. The study indicates that numerical models might become a useful tool for reservoir flushing predictions. 相似文献
5.
Several studies have documented the occurrence of high ventilation rates during cardiopulmonary resuscitation, but to date, there have been no scientific investigation of the causes of hyperventilation. The objective of the current study was to test the effects of socio-emotional stressors on lay rescuers' ventilation rate in a simulated resuscitation setting using a manikin model. A within-subjects experiment with randomized order of conditions tested lay rescuers' ventilation rate on an intubated manikin during exposure to socio-emotional stressors and during a control condition where no external stressors were present. Ventilation rates and subjective workload were significantly higher during exposure to socio-emotional stressors than during the control condition. All but one of the nine participants ventilated at a higher ventilation rate in the experimental condition. All nine participants rated the subjective workload to be higher during exposure to socio-emotional stressors. Hence, exposure to socio-emotional stressors is associated with increased ventilation rates performed by lay rescuers during simulated cardiac arrest using a manikin model. These findings might have implications for the understanding of the type of situations which hyperventilation may occur. Awareness of these situations may have implications for training of lay rescues. 相似文献
6.
Protein concentrates prepared by expanded bed adsorption (EBA) chromatography from industrial potato juice (PJ) were analysed for chemical composition, color, enzyme activities, thermal properties and selected functional properties (solubility and emulsifying stability). Two EBA multi-modal resins, MIMO I-45 and MIMO 1300 (UpFront Chromatography), were employed under various pH conditions resulting in four potato protein concentrates, A-D. Concentrate B contained an electrophoretically pure protease inhibitor fraction (20-21 kDa), whereas concentrate A, C and D contained both patatin (41 kDa) and protease inhibitors. The potato protein concentrates were explored for the presence of transitions from native to denatured states using differential scanning calorimetry (DSC). Concentrate C had lower heat of transition (ΔH) and T-onset than the other concentrates. The concentrate containing protease inhibitors exhibited the highest denaturation temperature and enthalpy. All concentrates differed significantly (P < 0.05) in color brightness, with concentrate B and D emerging as the brightest. The solubility of the concentrates was evaluated at pH 6 and pH 4.5. All concentrates had lower solubility at pH 4.5 than at pH 6 (70-80%). The stability of emulsions (1% protein, 20% oil, 0.08% xanthan gum) against creaming was analysed with a new method based on the Single electrode Capacitance Probe (SeCaP) technology. Small differences among concentrates were observed by the new SeCaP method. 相似文献
7.
本文讨论了运用整体综合方法评价不确定性对油气投资决策影响的必要性。我们认为,仅对于投资决策评价各种要素的综合性常规精确模型增添处理不确定性的功能,是不能有效达到上述目的的。此外我们还认为,这种方法即使是可行的,也并不是人们所期望的。因此我们提出了在决策支持系统中引入整体和概率评价方法的概念。这种整体分析方法有两种要素。一种是技术要素,它综合了各种评价和决策工具。另一种是模拟思路要素,它全面考虑了不确定性的广度和规模。为了更全面、准确和严格地评价不确定性对投资决策过程的影响,这种方法要牺牲一部分技术精度和细节。这种系统的基本组成主要有各领域的简化要素模型、蒙特卡罗模拟工具以及模拟语言,可用于满足用户的特殊要求、综合不同要素之间的相互依赖关系、执行决策逻辑以及作为学习结果更新信息。文中说明了这种系统如何识别哪种不确定性对决策影响最大、如何评价信息采集(数据、技术分析)的价值以及如何在缓解和/或利用不确定性的下一步计划中促进灵活性。其他应用还有优化开发情景、评价真实的选择情景以及为投资组合分析的输入数据生成统一的风险现金流。这种系统的应用已通过其综合技术决策和经营决策的能力,使多学科资产管理团队的工作实现了真正的以价值驱动为重点。 相似文献
8.
The conductivity of nominal CaWO4, CaW0.99Ta0.01O4–δ, 0.7(CaWO4)–0.3(La0.99Ca0.01NbO4–δ), and Ca0.9La0.1WO4+δ has been studied by means of a.c. impedance measurements. Proton conductivity was observed for CaW0.99Ta0.01O4–δ, which displayed exothermic hydration with enthalpy and entropy of –82 kJ/mol and –120 J/molK, respectively. The proton mobility in CaW0.99Ta0.01O4–δ was low, with enthalpy and preexponential factor of mobility of 82 kJ/mol and 0.7 cm2K/Vs. The high enthalpy of mobility is interpreted to reflect association between the acceptor dopant and protonic defects, whereas the low preexponential factor of mobility may reflect a lower proton concentration than assumed. Rietveld refinement indicated low solubilities of La on Ca‐site and Ta on W‐site. Proton conductivity was also observed in undoped CaWO4, however, not in Ca0.9La0.1WO4+δ. The conductivity of 0.7(CaWO4)–0.3(La0.99Ca0.01NbO4–δ) behaved much like that of undoped LaNbO4, likely due to a very low acceptor dopant concentration. 相似文献
9.
Chest compression is a vital part of cardiopulmonary resuscitation (CPR). This paper demonstrates how the compression depth can be estimated using the principles of inertia navigation. The proposed method uses accelerometer sensors, one placed on the patient's chest, the other beside the patient. The acceleration-to-position conversion is performed using discrete-time digital signal processing (DSP). Instability problems due to integration are combated using a set of boundary conditions. The proposed algorithm is tested on a mannequin in harsh environments, where the patient is exposed to external forces as in a boat or car, as well as improper sensor/patient alignment. The overall performance is an estimation depth error of 4.3 mm in these environments, which is reduced to 1.6 mm in a regular, flat-floor controlled environment. 相似文献
10.
Chilbert M.A. Swiontek T. Myklebust J.B. Prieto T.E. Sances A. Jr. Leffingwell C. Henderson J.D. Jr. 《IEEE transactions on bio-medical engineering》1989,36(8):864-869
Electrical fibrillation of the human heart results in many unfortunate deaths. Because little information is available on short duration high current fibrillation, current levels below 1 and 50 A were used to induce ventricular fibrillation in hogs. Application times ranged between 16 ms and 3 s. Fibrillation was only produced when currents were applied during the T-wave period of the cardiac cycle. However, only 50 percent of the current application during the T-wave caused fibrillation. The total body resistance of the hogs was also measured at the high voltages and currents. The average resistance for 90 current applications was 284 omega. Trends in the data show that the total resistance decreases for increasing voltage, for increasing electrode size, and for current applications following the first current application. 相似文献