An Adaptive Ramp Generator for ADC Built-in Self-Test

An adaptive ramp generator based on linear histogram was proposed for the built-in selftest (BIST) of analog to digital convertor (ADC) in CMOS image sensor. By comparing the generated ramp signal to a reference voltage and feeding back a calibration signal, the slope adjustment was implemented, and high linearity and precision of ramp slope were realized. By modulating the pulse width and reference voltage, sweep length varied from microsecond to second and signal swing could reach 3 V with 5.6 mW power consumption. The ramp was used as input to an ideal 10-bit single-slope ADC, and the corresponding DNL and INL were 0.032 LSB and 0.078 LSB, re-spectively.

Modeling and Simulation for Complex Repairable System with Built-in Test Equipment

In order to research the effects of built-in test(BIT) on the system and select BITand test strategy,the complex repairable systems with BITequipment are modeled and simulated by using Simulink.Based on the model,the influences of different built-in test equipments,maintenance time and error probabilities on the system usability are evaluated.The simulation results showthat they effect on the system differently.The simulation method of complex system based on Simulink provides a technique approach to research the effects of BITon the system and select BITand test strategy.

BOARD-LEVEL BUILT-IN SELF-REPAIR METHOD OF RAM

This paper describes the method of built-in self-repairing of RAM on board, designs hardware circuit, and logic for the RAM's faults self-repairing system based on FPGA. The key technology is that it utilizes FPGA to test RAM according to some algorithm to find out failure memory units and replace the faulty units with FPGA. Then it can build a memory that has no fault concern to external controller, and realizes the logic binding between external controller and RAM. Micro Controller Unit (MCU) can operate external RAM correctly even if RAM has some fault address units. Conventional MCS-51 is used to simulate the operation of MCU operating external memory. Simulation shows FPGA can complete the faulty address units' mapping and MCU can normally read and write external RAM. This design realizes the RAM's built-in self-repairing on board.

Tests and error analysis of a self-positioning shearer operating at a manless working face

Self-positioning of a shearer is the key technology for mining with a man-less working face. In an underground coal mine all radio navigation; satellite positioning or celestial navigation methods have their limitations. We analyzed an inertial navi-gation system intended to guide the movement a shearer and designed a self-positioning device for the shearer. Simulation tests were also performed on the system. We analyzed the errors observed in these tests to show that the main reason for the low preci-sion of the self-positioning system is accumulated error in the inertial sensor. A Kalman filtering algorithm used in combination with the shearer motion model effectively reduces the measurement errors of the self-positioning system by compensating for gyroscopic drift. Finally, we built an error compensation model to reduce accumulated errors using continuous correction to provide self-positioning of the shearer within a certain range of accuracy.

Uptake of HIV Self-testing among Men Who have Sex with Men in Beijing, China： a Cross-sectional Study

Objective To examine HIV self-testing uptake and its determinates among men who have sex with men （MSM） in Beijing, China. Methods A cross-sectional online survey was conducted in Beijing, China in 2016. Participants were users of a popular Chinese gay networking application and had an unknown or negative HIV status. Univariate and multivariate logistic regression analyses were conducted to examine factors associated with HIV self-testing based on adjusted odds ratio （AOR） and 95% confidence interval （CI）. Results Among the 5,996 MSM included in the study, 2,383 （39.7%） reported to have used HIV self-testing kits. Willingness to use an HIV self-test kit in the future was expressed by 92% of the participants. High monthly income （AOR = 1.49; CI = 1.10-2.02; P = 0.010）, large number of male sex partners （≥2： AOR = 1.24; CI = 2.09-1.43; P = 0.002）, sexual activity with commercial male sex partners （〉 2： AOR = 1.94; CI = 1.34 -2.82; P = 0.001）, long-term drug use （AOR = 1.42; CI = 1.23-1.62; P 〈 0.001）, and long-term HIV voluntary counseling and testing （VCT） attendance （AOR = 3.62; CI = 3.11-4.22; P 〈 0.001） were all associated with increased odds of HIV self-testing uptake. Conclusion The nearly 40% rate of HIV self-testing uptake among MSM in our sample was high. In addition, an over 90% willingness to use kits in the future was encouraging. HIV self-testing could be an important solution to help China achieve the global target of having 90% of all people living with HIV diagnosed by 2020.

Integration of Tracer Test Data to Refine Geostatistical Hydraulic Conductivity Fields Using Sequential Self-Calibration Method

On the basis of local measurements of hydraulic conductivity, geostatistical methods have been found to be useful in heterogeneity characterization of a hydraulic conductivity field on a regional scale. However, the methods are not suited to directly integrate dynamic production data, such as, hydraulic head and solute concentration, into the study of conductivity distribution. These data, which record the flow and transport processes in the medium, are closely related to the spatial distribution of hydraulic conductivity. In this study, a three-dimensional gradient-based inverse method--the sequential self-calibration （SSC） method--is developed to calibrate a hydraulic conductivity field, initially generated by a geostatistical simulation method, conditioned on tracer test results. The SSC method can honor both local hydraulic conductivity measurements and tracer test data. The mismatch between the simulated hydraulic conductivity field and the reference true one, measured by its mean square error （MSE）, is reduced through the SSC conditional study. In comparison with the unconditional results, the SSC conditional study creates the mean breakthrough curve much closer to the reference true curve, and significantly reduces the prediction uncertainty of the solute transport in the observed locations. Further, the reduction of uncertainty is spatially dependent, which indicates that good locations, geological structure, and boundary conditions will affect the efficiency of the SSC study results.

Shake-table testing of a self-centering precast reinforced concrete frame with shear walls

The seismic performance of a self-centering precast reinforced concrete （RC） frame with shear walls was investigated in this paper. The lateral force resistance was provided by self-centering precast RC shear walls （SPCW）, which utilize a combination ofunbonded prestressed post-tensioned （PT） tendons and mild steel reinforcing bars for flexural resistance across base joints. The structures concentrated deformations at the bottom joints and the unbonded PT tendons provided the self-centering restoring force. A 1/3-scale model of a five-story self-centering RC frame with shear walls was designed and tested on a shake-table under a series of bi-directional earthquake excitations with increasing intensity. The acceleration response, roof displacement, inter-story drifts, residual drifts, shear force ratios, hysteresis curves, and local behaviour of the test specimen were analysed and evaluated. The results demonstrated that seismic performance of the test specimen was satisfactory in the plane of the shear wall; however, the structure sustained inter-story drift levels up to 2.45%. Negligible residual drifts were recorded after all applied earthquake excitations. Based on the shake-table test results, it is feasible to apply and popularize a self-centering precast RC frame with shear walls as a structural system in seismic regions.

A note on self-normalized Dickey-Fuller test for unit root in autoregressive time series with GARCH errors

In this article, the unit root test for AR（p） model with GARCH errors is considered. The Dickey-Fuller test statistics are rewritten in the form of self-normalized sums, and the asymptotic distribution of the test statistics is derived under the weak conditions.

Support-Vector-Machine-Based False Alarm Filter of Mechatronic Built-in Test

Diagnosing intermittent fault is an important approach to reduce built-in test（BIT） false alarms. Aiming at solving the shortcoming of the present diagnostic method of intermittent fault, and according to the merit of support vector machines （ SVM） which can be trained with a small-sample, an SVM-based diagnostic model of 3 states that include OK state, intermittent state and faulty state is presented. With the features based on the reflection coefficients of an alarm rate （ AR ） model extracted from small vibration samples, these models are trained to diagnose intermittent faults. The experimental results show that this method can diagnose multiple intermittent faults accurately with small training samples and BIT false alarms are reduced.

Feasibility of a finger prick-based self-testing kit in first- and second-degree relatives of children with coeliac disease

AIM:To assess feasibility of a finger prick-based kit as method for self-testing of first and second-degree relatives of coeliac disease (CD) patients. METHODS:A total number of 379 subjects were invited to participate in this study,consisting of 197 first- degree and 182 second-degree relatives of CD patients. The self-testing kit (BiocardTM) was sent out with included instructions for use. Completed tests were sent back to the study coordinator for assessment. RESULTS:One hundred and ninety-six invited relatives carried out the BiocardTM test at home. Amongst these,70% were children. In 97% of the cases the test was performed correctly. Three tests revealed a positive result,all of which were later confirmed by serology and histology as coeliac disease.CONCLUSION:Our study indicates that BiocardTM test is a reliable,easy to use and well-accepted tool for home testing of first- and second-degree relatives of CD patients.

Robustness self-testing of states and measurements in the prepare-and-measure scenario with 3 → 1 random access code

Recently, Tavakoli et al.proposed a self-testing scheme in the prepare-and-measure scenario, showing that self-testing is not necessarily based on entanglement and violation of a Bell inequality [Phys.Rev.A 98 062307(2018)].They realized the self-testing of preparations and measurements in an N → 1(N ≥ 2) random access code(RAC), and provided robustness bounds in a 2 → 1 RAC.Since all N → 1 RACs with shared randomness are combinations of 2 → 1 and 3 → 1 RACs, the3 → 1 RAC is just as important as the 2 → 1 RAC.In this paper, we find a set of preparations and measurements in the3 → 1 RAC, and use them to complete the robustness self-testing analysis in the prepare-and-measure scenario.The method is robust to small but inevitable experimental errors.

Assessing the Acceptability and Willingness to Use HIV Self-Testing among Student Nurses in a Private Nursing College, Gauteng Province, South Africa

Globally, there is increasing evidence that HIV self-testing (HIVST) is commonly practiced among health care workers (HCWs). Although HIVST kits are available in South Africa, their distribution and use remain unregulated and its acceptability, undocumented. The aim of the study was to explore the acceptability of HIV self-testing among student nurses, examine their willingness to use self-testing, and evaluate their views on the implementation of a regulated HIV self-testing programme. This was a qualitative explorative study, and six focus group discussions were conducted with 67 student nurses recruited from a private nursing college, in Pretoria, South Africa. Thematic analysis and NVivo10 qualitative software were used for data analysis. The nurses perceived HIVST as an acceptable option for HIV testing and most were willing to self-test. Self-testing will provide confidential and accessible HIV testing services, reduce the stigma associated with the condition, and increase partner testing and disclosure. HIVST is more likely to be practised if self-testing kits are easily accessible and affordable, and there are strategies to educate people before the adoption of HIVST. The lack of pre- and post-test counselling, the risk of inaccurate test results, and lack of strategies for the confirmation of self-testing results were the main arguments against HIVST. The high acceptance of HIVST among nurses suggests that HIVST is a feasible option to increase the uptake of HIV-testing among HCWs. However, pre- and post-test counselling should be considered important components in the implementation of self-testing services. Educational and awareness campaigns should precede the roll-out of the self-testing programs.

HIV Self-Testing Kits Uptake in Mashonaland West Province, Zimbabwe, 2019-2020: A Secondary Data Analysis

Background: Human Immuno-Deficiency Virus Self-Testing (HIVST) is a process where an individual who wants to know their HIV status collects a specimen, performs a test and interprets the result by themselves. HIVST data from the Zimbabwe AIDS and TB Program (ATP) directorate showed that between 2019-2020, only 31% of the target HIVST kits were distributed in the country. Mashonaland West Province was one of the least performing provinces in meeting targets for HIVST kits distribution. Gaps in the implementation of the HIVST in the province ultimately affect the nationwide scaleup of targeted testing, a key enabler in achieving HIV epidemic control. We analyzed HIVST trends in Mashonaland West Province to inform HIV testing services programming. Methods: We conducted a cross-sectional study using HIVST secondary data obtained from the District Health Information Software 2 (DHIS2) electronic database. We conducted regression analysis for trends using Epi Info 7.2 and tables, bar graphs, pie charts and linear graphs were used for data presentation. Results: A total of 31,070 clients accessed HIVST kits in Mashonaland West Province from 2019-2020. A slightly higher proportion (50.4% and 51.7%) of females as compared to males accessed HIVST kits in 2019 and 2020 respectively. Overall, an increase in the trend of HIVST kits uptake was recorded (males R2 = 0.3945, p-value = 0.003 and females R2 = 0.4739, p-value = 0.001). There was generally a decline in the trend of community-based distribution of HIVST kits from the third quarter of 2019 throughout 2020 (R2 = 0.2441, p-value = 0.006). Primary distribution of HIVST kits remained the dominant method of distribution, constituting more than half of the kits distributed in both 2019 (67%) and 2020 (86%). Conclusion: Mashonaland West Province was mainly utilising facility-based distribution model for HIVST over the community-based distribution model. We recommended training more community-based distribution agents to increase community distribution of HIVST kits.

The Theoretically Studies and Field Testing of Self-Insulation Exterior Wall in the Hot Summer and Cold Winter Zone

The energy efficiency design of the exterior wall in the buildings of the hot summer and cold winter zone of China should consider the heat prevention in summer and the heat insulation in winter. The self-insulation of the exterior?wall is a more feasible design to satisfy the energy efficiency of buildings in the?zone. However, the systematic research is urgently needed for the self-insulation of the exterior wall in the hot summer and cold winter zone of China. The paper tested the thermal performance of the common non-clay materials such as shale sintered hollow brick, sand autoclaved aerated concrete block, etc. by means of indoor experiments. The energy efficiency effect of the common materials was verified using dynamic calculation soft PKPM and several constitutions of exterior wall with different main bricks and insulation materials on the heat bridge were simulated, too. Besides, the tests of the thermal performance of exterior wall in real constructions were carried out to testify the practical effect of the recommended constitutions of exterior wall with different main bricks and insulation materials on the heat bridge. The conclusions are: the physical and thermal properties of the six non-clay wall material are better than the clay porous brick;the thermal performance of the non-clay brick can be improved obviously through the rational arrangement of the holes;shale sintered hollow brick after increasing the holes and rationalizing the hole arrangement and sand autoclaved aerated concrete block are recommended for buildings in the hot summer and cold winter area of China. The dynamic calculation results show that the thermal performances?of the non-clay materials are all satisfied with the energy efficiency;The heat transfer coefficient of the exterior wall with composition?③,?in which?the main wall was sand autoclaved aerated concrete block and the material on the heat bridge was sand autoclaved aerated concrete plate, is the smallest among the three recommended compositions.

AVAILABILITY MODEL FOR SELF TEST AND REPAIR IN FAULT TOLERANT FPGA-BASED SYSTEMS

Dynamically reconfigurable Field Programmable Gate Array(dr-FPGA) based electronic systems on board mission-critical systems are highly susceptible to radiation induced hazards that may lead to faults in the logic or in the configuration memory. The aim of our research is to characterize self-test and repair processes in Fault Tolerant(FT) dr-FPGA systems in the presence of environmental faults and explore their interrelationships. We develop a Continuous Time Markov Chain(CTMC) model that captures the high level fail-repair processes on a dr-FPGA with periodic online Built-In Self-Test(BIST) and scrubbing to detect and repair faults with minimum latency. Simulation results reveal that given an average fault interval of 36 s, an optimum self-test interval of 48.3 s drives the system to spend 13% of its time in self-tests, remain in safe working states for 76% of its time and face risky fault-prone states for only 7% of its time. Further, we demonstrate that a well-tuned repair strategy boosts overall system availability, minimizes the occurrence of unsafe states, and accommodates a larger range of fault rates within which the system availability remains stable within 10% of its maximum level.

一种基于分压电路的绑定后TSV测试方法

对硅通孔(Through Silicon Via,TSV)进行绑定后测试可以有效地提升三维集成电路的性能和良率。现有的测试方法虽然对于开路和桥接故障的测试能力较高,但是对于泄漏故障的测试效果较差,并且所需的总测试时间较长。对此,提出了一种基于分压电路的TSV绑定后测试方法。该方法设计了一种分压电路,进行泄漏故障测试时可以形成一条无分支的电流路径,有效提高了对泄漏故障的测试能力。此外,该方法测试开路故障和泄漏故障时的电流路径不会相互干扰,可以同时测试相邻TSV的开路故障和泄漏故障。实验结果表明,该方法可以测试10 kΩ以下的弱泄漏故障,并且在工艺偏差下依然能够保持较高的测试能力。相比同类测试方法,该方法所需面积开销更小,所需总测试时间更少。

预应力CFRP布加固混凝土梁受弯试验

目的 研究不同加固方法下预应力碳纤维布加固混凝土梁的受弯性能,解决桥梁加固缺陷的问题。方法 制作了5根试验梁,其中一根为对比梁,不做任何加固处理,其余4根分别采用不同的锚固方式、不同的初始张拉力及不同的加固位置进行加固,通过控制变量,进行加载试验,分析其受弯性能的差异。结果 经加固后的试验梁承载能力与刚度明显增加,与对比梁相比,极限荷载分别提升了25%、22.06%、30.78%及36.76%;各试验梁达到屈服荷载时,经加固的试验梁挠度均小于对比梁产生的挠度,且模腔自锁式锚具锚固的试验梁挠度小于穿孔式自锁锚具锚固的试验梁挠度,相同锚固方法下初始张拉力较大的试验梁挠度要小于初始张拉力较小的试验梁挠度。结论 使用预应力碳纤维布加固混凝土梁能够有效提高混凝土梁的抗弯性能,提升效果与加固位置、锚固方式及初始张拉力大小有关。

临时造口患者造口接受度现状及其与自我管理行为的关系研究

目的了解临时造口患者的造口接受度现状,分析其影响因素及其与自我管理行为的关系。方法采用便利抽样法,选取2022年3-11月在北京协和医院普外科行临时造口患者126例,采用一般资料调查表、造口自我管理行为问卷、中文版造口接受度问卷进行问卷调查。结果临时造口患者中文版造口接受度问卷总分为(33.52±2.92)分,条目均分为(2.79±0.73)分,处于中等水平。单因素分析结果显示:不同年龄、文化程度、保留造口时间、主要照顾者及有无合并症对患者造口接受度有影响(P<0.05);Pearson相关性分析结果显示:造口接受度总分与自我管理行为总分及其5个维度均呈正相关(r=0.589、0.617、0.178、0.235、0.416、0.306,P<0.05);多元线性回归分析显示:文化程度、有无合并症及自我管理行为中造口护理维度是造口接受度的影响因素(P<0.01)。结论临时造口患者回归社会后的心理状态是医护人员亟待关注的问题,其造口接受度处于中等水平,可根据影响因素构建有效干预措施提高患者造口接受度,促进自我管理行为,帮助其顺利适应造口生活。

大规模芯片内嵌存储器的BIST测试方法研究

随着大规模芯片的块存储器(block random access memory,BRAM)数量不断增多,常见的存储器内建自测试(memory build-in-self test,Mbist)方法存在故障覆盖率低、灵活性差等问题。为此,提出了一种新的基于可编程有限状态机的Mbist方法,通过3个计数器驱动的可编程Mbist控制模块和算法模块集成8种测试算法,提高故障覆盖率和灵活性。采用Verilog语言设计了所提出的Mbist电路,通过Modelsim对1 Kbit×36的BRAM进行仿真并在自动化测试系统上进行了实际测试。实验结果表明,该方法对BRAM进行测试能够准确定位故障位置,故障的检测率提高了15.625%,测试效率提高了26.1%,灵活性差的问题也得到了很大改善。