The Power of Change-Point Test for Two-Phase Regression

In this paper, the roughness of the model function to the basis functions and its properties have been considered. We also consider some conditions to take the limit of the roughness when the observations are i.i.d. An explicit formula to calculate the power of change-point test for the two phases regression through the roughness was obtained.

Application of Rollout Strategy to Test Points Selection for Integer-Coded Fault Wise Table

Test points selection for integer-coded fault wise table is a discrete optimization problem. The global minimum set of test points can only be guaranteed by an exhaustive search which is eompurationally expensive. In this paper, this problem is formulated as a heuristic depth-first graph search problem at first. The graph node expanding method and rules are given. Then, rollout strategies are applied, which can be combined with the heuristic graph search algorithms, in a computationally more efficient manner than the optimal strategies, to obtain solutions superior to those using the greedy heuristic algorithms. The proposed rollout-based test points selection algorithm is illustrated and tested using an analog circuit and a set of simulated integer-coded fault wise tables. Computa- tional results are shown, which suggest that the rollout strategy policies are significantly better than other strategies.

Selection of Minimal Test Points Set for Integer-Coded Fault Wise Table

Test points selection for integer-coded fault wise table is a discrete optimization problem. On one hand, traditional exhaustive search method is computationally expensive. On the other hand, the space complexity of traditional exhaustive is low. A tradeoff method between the high time complexity and low space complexity is proposed. At first, a new fault-pair table is constructed based on the integer-coded fault wise table. The fault-pair table consists of two columns： one column represents fault pair and the other represents test points set that can distinguish the corresponding faults. Then, the rows are arranged in ascending order according to the cardinality of corresponding test points set. Thirdly, test points in the top rows are selected one by one until all fault pair are isolated. During the test points selection process, the rows that contain selected test points are deleted and then the dimension of fault-pair table decreases gradually. The proposed test points selection algorithm is illustrated and tested using an integercoded fault wise table derived from a real analog circuit. Computational results suggest show policies are better than the exhaustive strategy.

Damage Position of Concrete Beam Based on Test of Even Change Point

The quantitative analysis of damage position of concrete beam is established.The method of damage position free of models used in this paper is based on the variations of strain mode and test of even change point.The discrete model and the position criterion are presented.Numerical example is conducted,the result demonstrates that the method of damage position is correct and effective.

Bamboo Taper Effect on Center Point Bending Test

Bamboo became the best material choice for sustainable construction because it is fully renewable materials. Indonesian people traditionally choose bamboo for their housing since a long time ago. Bamboo stems usually have unique shape. Its geometrical shape assumed as tapered hollow pipe. This study aims to find the effect of bamboo taper to its strength properties on center point bending test. The ratio between the Modulus of Rupture （S~） calculated in the center point, and the maximum bending stress along the beam is called strength ratio of taper （Ct）. The theoretical calculation results Ct value is 1 if the taper lower than 0.023, while Ct value become lower if the taper is higher than 0.023. The survey on Ampel （Bambusa vulgaris Schrad.）, Tali （Gigantochloa apus （BI. Ex Schult. f） Kurz）, Gombong （Gigantochloa verticillata （Willd.） Munro）, and Mayan （Gigantochloa robusta Kurz.） found that the overall taper range is -0.0047-0.0088 and 0-0.0127 for inner and outer taper respectively. On that overall range the Ct value is always 1, so it is reasonable to ignore the taper effect on one point bending test.

Interpretation of data and treatment of Jing-well point temperatures test

The Jing-well point temperatures test method is a method to diagnose and guide the treatment of diseases by measuring the subjects' symmetrical well point temperature. it is improved from the method of knowing heat sensitivity. The application of Jing-well point temperatures test method is wide, and it can be used in internal and external gynecology and pediatrics and facial features department. at the same time, it has the advantage of objective and accurate diagnosis. The old law has some shortcomings, such as poor intuition, unavoidable omission of information, incomplete interpretation of information and so on. In this paper, Excel software is used to transform the data into line chart form, which improves the intuition and comprehensiveness of this method, so that the data can be better interpreted and used. It is newly proposed in this article that in addition to observing the longitudinal di fference of well point temperature, more attention should be paid to the horizontal contrast difference of well point temperature in different meridians. The article also summarizes a number of treatment methods, including acupuncture, moxa moxibustion, cupping and scraping, and the selection of acupoints, including mother acupoints, tenderness points and heat-sensitive moxibustion, so that doctors can combine traditional Chinese medicine professional knowledge in clinic.

A Point-of-Care Test System for Biochemical Blood Analysis Based on ADUC824

A point-of-care test system has been studied in this paper.It was used to determine substances in blood such as Hemoglobin (HB),Aspartate Aminotransferase (AST),Creatine Kinase (CK) and so on.Based on the principle of amperometric determination,the research on detecting weak current signals was carried on.At the same time as to the weak signals (nA level),magnifying,sampling and processing the signals were also studied.Controlled by ADUC824 and assisted by other units, every substance could be determined automatically and rapidly integrated with the corresponding biosensor.In the experiment, the minimum detectable current of the instrument (YT2005-1) is 0.2 nA.With regard to the 1 nA which the experiment demanded,it could be up to the mustard.And the system can provide results in 180 s with a long term stability.

Optimal Test Points Selection Based on Multi-Objective Genetic Algorithm

A new approach to select anoptimal set of test points is proposed. The described method uses fault-wise table and multi-objective genetic algorithm to find the optimal set of test points. First, the fault-wise table is constructed whose entries are measurements associated with faults and test points. The selection of optimal test points is transformed to the selection of the columns that isolate the rows of the table. Then, four objectives are described according to practical test requirements. The multi-objective genetic algorithm is explained. Finally, the presented approach is illustrated by a practical example. The results indicate that the proposed method can efficiently and accurately find the optimal set of test points and is practical for large scale systems.

Point-of-Care Testing vs. Laboratory Testing during High Patient Volume Situations

Introduction: Our aim was to determine what patient volume, if any, in-laboratory testing provides results faster than Point-of-Care-Testing (POCT). Methods: To evaluate POCT effectiveness during high volume situations, POCT was compared to in-laboratory testing during busy periods with large numbers of patients. Our setting was an urban level 1 trauma center with an academic emergency medicine department (ED) and annual patient volume of 70,000. Patients seen requiring laboratory testing during peak volume between 11 a.m. and 7 p.m. were enrolled over a five-week period. One tube of blood was sent to the laboratory and the other tube was run in the ED using POCT. Turnaround time was recorded as time from when the tube was received to when the result was available. We also completed a time-motion study to assess the number of POCT machines that would be needed to process the entire average hourly hospital laboratory volume. Results: We collected 539 hematology and chemistry specimens. The POCT group was significantly faster than in-laboratory testing, with mean POCT [complete blood count (CBC) and chemistry] 3.5 minutes compared to in-laboratory CBC test time of 30.9 minutes and chemistry test time of 55 minutes. As the volume of samples peaked, there was a slight but insignificant decrease in POCT turnaround time. If POCT was used to process the entire average hospital laboratory volume which approached 54 samples an hour, 3 POCT machines would be necessary to maintain turnaround times. Conclusion: Even during ED high volume situations, POCT provided results significantly faster than in-laboratory testing.

Evaluation of a Plasma hCG Method for Point of Care Testing with the Aim of Shortening Test-Turnaround-Times

Objective: To examine the correlation between plasma hCG results obtained with the new i-STAT&reg hCG point of care test with those concomitantly obtained from the central hospital laboratory utilizing the same patient samples. Methods: Prospective cross-sectional laboratory test evaluation. We compared plasma hCG results obtained with the i-STAT&reg hCG test (Abbott Point of Care, Princeton, NJ, USA) with Architect Ci8200 (Abbott Laboratories, Abbott Park, IL, USA). We also calculated the total coefficient of variation (CV) for the i-STAT&reg method. Results: The two methods showed a good linear correlation (R2 = 0.994;slope 1.03) and CV for the i-STAT&reg method was 2.1% - 5.2%. Conclusion: We suggest that the i-STAT&reg hCG blood assay could be used as a complement to urine hCG assays in clinical situations when rapid test results are needed and urine is not available.

Security Framework for Managing Data Security within Point of Care Tests

Point of Care (PoC) devices and systems can be categorized into three broad classes (CAT 1, CAT 2, and CAT 3) based on the context of operation and usage. In this paper, the categories are defined to address certain usage models of the PoC device. PoC devices that are used for PoC testing and diagnostic applications are defined CAT 1 devices;PoC devices that are used for patient monitoring are defined as CAT 2 devices (PoCM);PoC devices that are used for as interfacing with other devices are defined as CAT 3 devices (PoCI). The PoCI devices provide an interface gateway for collecting and aggregating data from other medical devices. In all categories, data security is an important aspect. This paper presents a security framework concept, which is applicable for all of the classes of PoC operation. It outlines the concepts and security framework for preventing security challenges in unauthorized access to data, unintended data flow, and data tampering during communication between system entities, the user, and the PoC system. The security framework includes secure layering of basic PoC system architecture, protection of PoC devices in the context of application and network. Developing the security framework is taken into account of a thread model of the PoC system. A proposal for a low-level protocol is discussed. This protocol is independent of communications technologies, and it is elaborated in relation to providing security. An algorithm that can be used to overcome the threat challenges has been shown using the elements in the protocol. The paper further discusses the vulnerability scanning process for the PoC system interconnected network. The paper also presents a four-step process of authentication and authorization framework for providing the security for the PoC system. Finally, the paper concludes with the machine to machine (M2M) security viewpoint and discusses the key stakeholders within an actual deployment of the PoC system and its security challenges.

Point-of-Care Testing Using Three Dimensional Optical Biosensor Based on Microfluidic Technology

We have presented a three dimensional optical protein chip that fulfills the demanding for point-of-care diagnostics in terms of ease-of-use (one step assay), miniaturization (5 μl). The artful combination of magnetic nanoparticles on chip and total internal reflection imaging (TIRI) technology permits the sensitive and rapid detection of hs-CRP (high-sensitivity C-reactive protein). The whole test was complete within 10 min using “all in one step” assay with a limit of detection of 0.1 ng/mL hs-CRP. The measuring range for hs-CRP could be extended to 10 ng/mL. The chip can also be used to detect more parameters in blood samples.

Process of Designing Robust, Dependable, Safe and Secure Software for Medical Devices: Point of Care Testing Device as a Case Study

This paper presents a holistic methodology for the design of medical device software, which encompasses of a new way of eliciting requirements, system design process, security design guideline, cloud architecture design, combinatorial testing process and agile project management. The paper uses point of care diagnostics as a case study where the software and hardware must be robust, reliable to provide accurate diagnosis of diseases. As software and software intensive systems are becoming increasingly complex, the impact of failures can lead to significant property damage, or damage to the environment. Within the medical diagnostic device software domain such failures can result in misdiagnosis leading to clinical complications and in some cases death. Software faults can arise due to the interaction among the software, the hardware, third party software and the operating environment. Unanticipated environmental changes and latent coding errors lead to operation faults despite of the fact that usually a significant effort has been expended in the design, verification and validation of the software system. It is becoming increasingly more apparent that one needs to adopt different approaches, which will guarantee that a complex software system meets all safety, security, and reliability requirements, in addition to complying with standards such as IEC 62304. There are many initiatives taken to develop safety and security critical systems, at different development phases and in different contexts, ranging from infrastructure design to device design. Different approaches are implemented to design error free software for safety critical systems. By adopting the strategies and processes presented in this paper one can overcome the challenges in developing error free software for medical devices (or safety critical systems).

Reusing Test Cases Based on the Function Point

Reusing test cases from existing test case library is quite common in the software testing field. Testing practice tells us that there is a strong relationship between the granularity of a function unit under testing and that of the test case. A function unit with small granularity usually results in the test cases with the same small granularity. Therefore a test case defined as the function point,i. e.,the smallest size function unit,was provided for the first time.Though test cases with smaller granularity usually have better reusability,the cost of accurately reusing and integrating such test cases is also higher. In order to balance the test case reusability and the cost of test case reuse,a novel test case reuse model based on the function point was proposed in this paper. In this model,a reusable test case for specification-based testing was defined and some reuse strategies and three formal reuse methods were given. Finally,the complete automatic software process was realized by a reusing generation tool. The new method has improved reuse accuracy,while greatly enhances the software productivity.

型钢-UHPC轻型组合桥面板及其抗弯性能研究

正交异性钢桥面是目前800m以上国内外特大跨径钢桥的唯一选择,主因是自重轻、强度高、架设方便。但其存在疲劳开裂风险大、运维成本高的缺点。随着高性能材料UHPC的研发和应用,为构建自重轻、病害少、经济性好的桥面新结构提供了可能性。经过多年研究,作者提出一种新型桥面板结构——型钢-UHPC轻型组合桥面结构,将型钢、钢板条与UHPC组合,桥面板的形成无任何板件焊接,因而具有高抗疲劳性,且与传统钢桥面相比,自重持平、造价减半,可作为除“正交异性钢桥面”外的“第二种”大跨径钢桥的桥面结构方案。该文研究这种轻型组合桥面板预制板及横向接缝的抗弯性能,制作4个条带模型(包括2个预制板试件和2个接缝试件),开展三点弯曲的横向接缝负弯矩试验和预制板正弯矩试验,并对试验结果进行分析;基于“条带法”建立预制板试件极限承载力计算模型,提出接缝试件的UHPC开裂名义拉应力计算方法;基于某斜拉桥应用实例,进行整体计算和局部计算,验证新型组合桥面结构在实桥上应用的可行性。研究结果表明:(1)型钢与UHPC间在极限状态前相对滑移非常小,具有良好的协同受力性能;(2)预制板试件的正弯矩极限承载力以型钢屈服控制,而接缝试件负弯矩极限承载力以UHPC开裂和加密钢筋断裂控制;(3)接缝试件的“T形”接缝、加密钢筋、燕尾形的企口、交错式切割型钢钢条等构造设计对接缝整体抗弯拉性能有很好的提高效果;(4)预制板试件极限承载力计算模型所得计算值与试验值吻合良好,该模型搭配名义拉应力计算方法,可帮助工程实际问题的设计与应用;(5)试验结果与实桥的有限元计算值相比,新型桥面结构均有1.3倍以上的安全系数,新型组合桥面应用于实桥具有可行性。

应用于食品检测领域的分子即时检测技术研究进展

食品安全问题关系人类民生。为有效预防和控制食品安全风险,减少食品安全经济损失,迫切需要开发出针对食源性病原体、食物掺假、转基因作物的高特异性、高敏感性、快速的核酸检测技术。即时检测(point-of-care testing,POCT)作为一种新兴的快速检测手段,由于其检测速度快、操作简单、现场检查等特点,在食品检测领域应用广泛。本文首先介绍了POCT技术的发展历史,而后根据食品安全事件的特点,从食源性致病菌、食物掺假、转基因作物3个方向分析了食品检测的主要对象,阐述了分子POCT技术在食品检测领域的应用现状,最后对应用于食品检测领域的分子POCT技术存在的问题和解决办法进行了分析总结,对食品检测分子POCT技术的发展方向进行了展望。本文有助于进一步了解分子POCT技术在食品检测中的应用,并为分子POCT技术在食品快速检测中的研究和应用提供参考。

基于数字图像相关的地聚物混凝土轨枕的力学性能分析

随着混凝土轨枕在我国的广泛应用,混凝土的生产带来大量的能源消耗和碳排放。地聚物作为一种新型低碳材料,能在节能减碳的同时消耗矿渣和粉煤灰等固废。目前,针对地聚物应用于铁路轨枕的相关研究,如混合使用水泥与粉煤灰、矿渣的地聚物混凝土轨枕及其裂缝扩展特性的研究还比较有限。本文设计2种配合比的地聚物混凝土并制造成轨枕,使用数字图像相关(Digital Image Correlation)技术,在轨下截面的三点弯曲实验下分析2种配合比下轨枕挠度、裂缝扩展特性及裂缝宽度发展规律。研究结果表明,2种配合比地聚物混凝土轨枕的抗弯承载力均高于普通混凝土轨枕。相比于普通混凝土轨枕,地聚物混凝土轨枕在较低的静荷载作用下挠度较大,但随着荷载的增加轨枕挠度的增长速度较慢,刚度损失较小,弹性阶段延续的荷载区间更长,这种特征在配合比为Geo50的地聚物混凝土轨枕上更为显著。2种配合比的轨枕微裂纹萌生的荷载相近,分别为130 kN和120 kN。在较低荷载下2种轨枕裂缝扩展相差不大,在较高荷载下配合比为Geo100的地聚物轨枕的裂缝发展加快,裂缝宽度值和增长速度都大于Geo50。配合比为Geo100的地聚物混凝土轨枕主要表现为受弯正截面破坏,配合比为Geo50的地聚物混凝土轨枕主要表现为受剪斜拉破坏。掺入部分水泥代替矿渣和粉煤灰的地聚物能使所制成轨枕在较高的荷载下保持更高刚度和更缓慢的裂缝扩展速度,该方案有助于推动地聚物应用于混凝土轨枕,促进铁路双碳战略贯彻与实施。

基于RPA等温扩增的松材线虫快速检测技术体系建立

利用松材线虫Bursaphelenchus xylophilus基因组分析和等温扩增技术,设计生产松材线虫野外快速检测技术产品并测试其效果。结果表明:比较分析松材线虫和拟松材线虫Bursaphelenchus mucronatus基因组发现松材线虫特异性基因Bx-gene12,以此为基础设计特异性扩增引物和探针,对采集自不同地区的松材线虫、拟松材线虫和松树内其他线虫株系采用研磨颗粒以1500 r/min转速震荡5 min的破碎方法有效释放线虫DNA,40℃等温扩增15 min反应条件下可有效区分松材线虫和其他线虫,检测灵敏度达到100 fg或1条线虫;该快速检测方法在25 min内有效检测出染病黑松Pinus thunbergii和赤松Pinus densiflora松木内的松材线虫。利用RPA等温扩增技术实现25 min内对野外环境下松材线虫的快速检测,可为松材线虫病及时有效防控提供支持。

胸痛发作时床边即时检测心肌钙蛋白T诊断急性心肌梗死的价值

目的确定胸痛症状发作后不同时间间隔内,床边心肌肌钙蛋白T(point of care troponin-T testing,POCT-cTnT)对急性心肌梗死(acute myocardial infarction,AMI)的诊断性能,了解其在快速排除AMI方面的意义。方法这项回顾性研究包括了2019年1月至2022年12月期间出现胸痛症状的6024例患者。在入院时测量了POCT-cTnT和中心实验室cTnI水平。通过按时间窗口划分的受试者工作特征(receiver operating characteristics,ROC)分析,评估POCT-cTnT在诊断AMI时的准确性。结果总体而言,POCT-cTnT诊断AMI的AUC为0.826(95%CI:0.816~0.836),灵敏度和特异度分别为72.81%和86.26%。根据胸痛发作的时间进行区间分组(<3 h、3~6 h、6~12 h、12~24 h、24~72 h和≥72 h),6~12 h以后的分组AUC值分别为0.918、0.928、0.920和0.908,差异无统计学意义(P>0.05),均要高于6 h时以内的组(P<0.001);根据胸痛发作时间点进行分组,≥8 h组的AUC为0.921,阴性预测值(negative predictive value,NPV)98.1%和阴性似然比(negative likelihood ratio,-LR)0.11,其AUC高于≥3 h、≥2 h、≥1 h和overall组(P<0.05),而与≥4 h以后的各时间组相比,差异无统计学意义(P>0.05)。结论胸痛发作时间对单次检测POCT-cTnT诊断AMI的性能存在一定的影响,结合胸痛发作至就诊时间,可能提高其诊断或排除AMI的可靠性。在胸痛发作4 h后,单次POCT-cTnT检测能可靠地诊断或排除AMI;当胸痛发作8 h后,其诊断或排除AMI方面具有更高的可靠性。

即时检测仪器与电化学发光仪检测心脏标志物的对比研究

目的:对比分析两种即时检测(POCT)仪器与Roche电化学发光仪检测心脏标志物的相关关系,为临床检验选择POCT仪器提供参考。方法:选取2020年11月在中国中医科学院西苑医院就诊的20例患者血液样本,其浓度范围覆盖检测结果可报告范围,使用两种POCT仪器(分别命名为仪器A和仪器B)检测血浆肌红蛋白(Myo)、肌酸激酶同工酶质量(CKMB mass)、心肌钙蛋白I(cTnI)、氨基末端脑钠肽前体(NT-proBNP)/B型钠尿肽(BNP)的浓度水平,以电化学分析仪检测结果为参考,分别采用pearson相关分析和Kappa检验评价两种POCT仪器与Roche电化学发光仪检测结果的相关性和一致性。结果:仪器A和仪器B检测结果与Roche电化学发光仪检测Myo、CK-MB mass、cTnI、NT-proBNP/BNP结果均有较好的相关性(r_(仪器A)=O.994、0.989、0.917、0.996,r_(仪器B)=0.928、0.934、0.883、0.977,P<0.05)。在一致性比较中,仪器A检测Myo、CK-MB mass、cTnI、NT-proBNP与电化学分析仪的符合率分别为90%、100%、70%和100%;仪器B检测结果的符合率分别为90%、95%、70%和100%,两种POCT仪器与Roche电化学发光仪均具有较好的一致性(Kappa_(仪器A)=0.798、1.00、0.429、1.00,Kappa_(仪器B)=0.794、0.886、0.429、1.00)。两种仪器的精密度均<10%。结论:两种POCT仪器均能满足临床检测要求,在检测心脏标志物时与电化学发光仪有较好的相关性。