浅谈对计划计量工程师的理解

在项目管理中,没有科学的计划统计,没有准确的计量验工,各项管理就如空中楼阁、虚而不实,管理过程中就不能很好地找到切入点,错失一些转眼即逝的市场机遇。因此,重视计划计量工程师在项目管理中的作用,势在必行。

雷达装备计量保障计划的优化方法

针对目前部队在制定装备计量保障计划时存在的效率低、难以达到计量保障力量的合理配置,易造成人力、物力和财力浪费等问题,提出了制定雷达旅团装备计量保障计划的排序优化方法。首先介绍雷达旅团计量保障计划的相关概念,然后建立了描述制定计量保障计划的数学模型,并提出了求解模型的优化方法,最后通过实例对模型进行了验证。

欧洲计量研究计划对中国微电子计量技术发展的借鉴

微电子技术作为一种新兴的技术,是当今世界电子信息产业的核心之一。随着微电子技术的迅猛发展,对我国微电子计量技术发展提出了更高要求。欧盟自2009年起,开始了针对纳米、通信、先进制造等领域的计量研究计划(EMRP),以保证欧盟在政治、经济上的先进性。在信息时代高速发展的背景下,跟踪和研究欧洲计量研究计划中与微电子计量相关的研究,借鉴欧盟先进的微电子计量建设经验,对中国微电子计量技术跨越式发展有重要的研究意义。

我国企业年金会计计量研究

我国对于企业年金的会计计量很少考虑企业年金缴费的精算以及年金基金公允价值的变动,对企业年金提存计量的科学性造成很大的影响,使信息使用者无法清晰得了解企业实际持有的企业年金额以及应承担的企业年金支付义务,从而导致利益分配的不公平性。本文在区分企业年金不同类型的基础上,从企业的角度出发,对两种企业年金的计量属性、计量方法、计量特点进行了探讨,并就如何具体计量企业年金各项确认要素进行了分析,建议企业年金的缴费与税收筹划相配合,考虑精算方法与公允价值。

美国海军装备计量标识管理介绍

介绍了美国海军装备计量标识管理制度。对美国海军装备计量技术活动、计量和校准计划、计量需求目录内容进行了说明,并介绍了计量标识管理的一些规定,详细说明了美海军计量标识的种类、用法、样式、注意事项等情况。

远程校准技术纵览

远程校准技术是信息技术与传统计量测试技术相结合的必然结果。本文描述了远程校准技术的创建历史,发展过程及最新国际动态,以及在我国开展远程校准技术的实际意义、远程校准技术的优点,并详细介绍了美国、英国和日本开展远程校准技术研究的详细情况及一些对你的实际工作有用的应用实例。

从欧洲计量联合研究计划（EMRP）看计量前沿科技的发展

欧洲计量联合研究计划（EMRP）由欧盟第七框架计划支持、欧盟成员国共同参与，是世界首个大型计量科技合作研发计划。该计划以前沿科技和新领域研究为主题，前瞻性地指出了许多具有战略意义的研究方向，对推进我国计量领域的科技规划、项目布局和国际合作具有积极的指导意义。本文介绍了EMRP的形成发展、研究内容和未来规划，分析其成功要素及对我国计量科研工作的启示。

Quantitative analysis of deformation in hollow cylinder tests on anisotropic clay formations

A series of triaxial laboratory experiments are performed on thick-walled hollow cylindrical samples of boom clay.The aim of this testing program is to better understand the anisotropic deformation during the excavation.The testing conditions are similar to those to be experienced by host rocks around disposal galleries for radioactive waste.X-ray computed tomography is performed at different steps for each test with the samples remaining inside the loading cell.Initial analysis of the tomography images allows of the observation of the deformation of the central hole.In addition,particles manual tracking and 3D volumetric digital image correlation processing methods are considered being used to analyze the particles displacements and the boundary deformation of the sample quantitatively.An unsymmetrical damaged zone is induced around the hole,with a reverse deformation trend being found at the boundary after unloading,which indicates that the significant anisotropic deformation of boom clay can be induced by mechanical unloading.

Evaluation of photon beam dose calculation accuracy of treatment planning systems using in vivo dosimetry

Objective The treatment planning system currently represents one of the basics of radiation therapy,because it is the only method to estimate patient dose delivery fast forward and accurately represent estimated tumor location of the tumor with the possibility of estimating densities in the tissue surrounding the tumor to overcome dose calculation defects but radial estimated the patient.Despite the flaws associated with the systems and calculates the dose of your programs in all programs currently existing in the world.Than necessary,to the existence of a review of the accuracy of accounts and how to confirm the radiation dose to the patient programs.Methods A total of 35 cancer patients were considered for this study,with 245 field measurements made with low-and high-energy diode detectors for brain and prostate cases.The treatments for all patients were planned using Eclipse Treatment Planning System version 13.6.Results Of the 105 field measurements made for the prostate cancer patients,16 included discrepancies outside the ±5% action level.Of the 145 measurements taken of the brain cases,there were four outside the ±5% action level.The results indicated a higher degree of accuracy.The study revealed that,for the prostate measurements,the higher discrepancy in the doses for the particular fields(exceeding the action level) may have been due to the isocenter being very close to the jaws and multi-leaf collimator of the linear accelerator machine.As a result,scatter from the jaws and the multi-leaf collimator could have contributed to the high dose delivered to the diode;hence,a probable higher discrepancy of the dose in more brain cases due highest quality of VMAT technique and fixation system.Conclusion A greater percentage of the observed discrepancies were well within the set tolerance level.However,it is recommended that the positioning of the diode on the patient's skin and the angular sensitivity of the diodes be reconsidered.It is also recommended that a more accurate calculation of expected diode values be performed,especially for fields that pass through the table.These efforts would achieve action levels of ±5%.

Bone marrow-sparing intensity-modulated radiotherapy for postoperative treatment of cervical cancer

Objective： The aim of this study was to compare bone marrow-sparing intensity-modulated radiotherapy （IMRT） with IMRT without entering pelvic bone marrow as a planning constraint in the treatment of cervical cancer after hysterectomy. Methods： For a cohort of 10 patients, bone marrow-sparing IMRT and routine IMRT planning were designed. The prescribed dose was 45 Gy/1.8 Gy/25f, 95% of the planning target volume received this dose. Doses were computed with a commercially available treatment planning system （TPS） using convolution/superimposition （CS） algorithm. Plans were compared according to dose-volume histogram （DVH） analysis in terms of planning target volume （PTV） homogeneity and conformity indices （HI and CI） as well as organs at risk （OARs） dose and volume parameters. Results： Bone marrow-sparing IMRT had an vantages over routine IMRT in terms of CI, but inferior to the latter for HI. Compared with routine IMRT, V5, Vl0, V20, V30, V40 of pelvic bone marrow of bone marrow-sparing IMRT reduced by 1.81%, 8.61%, 31.81%, 29.50%, 28.29%, respectively. No statistically significant differences were observed between bone marrow-sparing IMRT and routine IMRT in terms of small bowel, bladder and rectum. Conclusion： For patients with cervical cancer after hysterectomy, bone marrowsparing IMRT reduced the pelvic bone marrow volume irradiated at all dose levels and might be conducive to preventing the occurrence of acute bone marrow toxicity.

An algorithm for trajectory prediction of flight plan based on relative motion between positions

Traditional methods for plan path prediction have low accuracy and stability. In this paper, we propose a novel approach for plan path prediction based on relative motion between positions(RMBP) by mining historical flight trajectories. A probability statistical model is introduced to model the stochastic factors during the whole flight process. The model object is the sequence of velocity vectors in the three-dimensional Earth space. First, we model the moving trend of aircraft including the speed(constant, acceleration, or deceleration), yaw(left, right, or straight), and pitch(climb, descent, or cruise) using a hidden Markov model(HMM) under the restrictions of aircraft performance parameters. Then, several Gaussian mixture models(GMMs) are used to describe the conditional distribution of each moving trend. Once the models are built, machine learning algorithms are applied to obtain the optimal parameters of the model from the historical training data. After completing the learning process, the velocity vector sequence of the flight is predicted by the proposed model under the Bayesian framework, so that we can use kinematic equations, depending on the moving patterns, to calculate the flight position at every radar acquisition cycle. To obtain higher prediction accuracy, a uniform interpolation method is used to correct the predicted position each second. Finally, a plan trajectory is concatenated by the predicted discrete points. Results of simulations with collected data demonstrate that this approach not only fulfils the goals of traditional methods, such as the prediction of fly-over time and altitude of waypoints along the planned route, but also can be used to plan a complete path for an aircraft with high accuracy. Experiments are conducted to demonstrate the superiority of this approach to some existing methods.

Accuracy characterization and measurement point planning for workpiece localization

This paper addresses the problem of accuracy characterization and measurement point planning for 3-D workpiece localization in the presence of part surface errors and measurement errors. Two frame-invariant functions of the infinitesimal rigid body displacement are defined to quantify the localization accuracy required by manufacturing processes. Then, two kinds of frame-invariant indices are derived to characterize the sensitivities of the accuracy measures to the sampling errors at the measurement points. With a dense set of discrete points on the workpiece datum surfaces pre-defined as candidates for measurement, planning of probing points for accurate recovery of part location is modeled as a combinatorial problem focusing on minimizing the accuracy sensitivity index. Based on an interchange rule, a greedy algorithm is developed to efficiently find a near-optimal solution. It is also shown that if the number of the measurement points is sufficiently large, there is no need to optimize their positions. Example confirms the validity of the presented indices and algorithm. Keywords localization - fixture - accuracy - uncertainty assessment - measurement planning - optimal design - heuristic algorithm