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The aim of this paper is to demonstrate that root impulse energy (RIE) testing is a practical and robust “go/no go” test technique for PCB material losses that can be deployed on the PCB production floor.

The study used the RIE method, employing time domain reflectometry techniques on industry standard impedance test coupons modified to include short reference lines and longer test lines. Practical considerations for the use of the methodology on the production floor, such as coupon design, probe layout and environmental conditions were investigated.

RIE with a 250 ps reflected risetime appears suitable for discerning significant differences in material loss properties provided proper coupon design is incorporated into the panel design and frequencies of interest are limited to a limit commensurate with high reliability and repeatability.

The RIE test proposed does not replace conventional impedance control techniques that are currently in use. However, a suitable standard for loss and cross test equipment calibration is key and will need to be established before this new measurement technique can gain widespread trust throughout the industry.

The paper shows RIE testing is a practical and achievable test method; it is easily deployed and offers repeatable, reliable discrimination between PCBs fabricated with a range of varying base material loss characteristics.

The media has even been very critical of some East Asian countries’ use of digital contact-tracing to control Covid-19. For example, South Korea has been criticised for its use of privacy-infringing digital contact-tracing. However, whether their type of digital contact-tracing was unnecessarily harmful to the human rights of Korean citizens is open for debate. The purpose of this paper is to examine this criticism to see if Korea’s digital contact-tracing is ethically justifiable.

This paper will evaluate Korea’s digital contact-tracing through the lens of the four human rights principles to determine if their response is ethically justifiable. These four principles were originally outlined in the European Court of Human Rights, namely, necessary, proportional, scientifically valid and time-bounded (European Court of Human Rights 1950).

The paper will propose that while the use of Korea’s digital contact-tracing was scientifically valid and proportionate (albeit, in need for improvements), it meets the necessity requirement, but is too vague to meet the time-boundedness requirement.

The Covid-19 pandemic has proven to be one of the worst threats to human health and the global economy in the past century. There have been many different strategies to tackle the pandemic, from somewhat laissez-faire approaches, herd immunity, to strict draconian measures. Analysis of the approaches taken in the response to the pandemic is of high scientific value and this paper is one of the first to critically engage with one of these methods – digital contact-tracing in South Korea.

Relational dynamics between patients and staff in forensic settings can be complicated and demanding for both sides. Reflective practice groups (RPGs) bring clinicians together to reflect on these dynamics. To date, evaluation of RPGs has lacked quantitative focus and a suitable quantitative tool. Therefore, a self-report tool was designed. This paper aims to pilot The Relational Aspects of CarE (TRACE) scale with clinicians in a high-secure hospital and investigate its psychometric properties.

A multi-professional sample of 80 clinicians were recruited, completing TRACE and attitudes to personality disorder questionnaire (APDQ). Exploratory factor analysis (EFA) determined factor structure and internal consistency of TRACE. A subset was selected to measure test–retest reliability. TRACE was cross-validated against the APDQ.

EFA found five factors underlying the 20 TRACE items: “awareness of common responses,” “discussing and normalising feelings;” “utilising feelings,” “wish to care” and “awareness of complicated affects.” This factor structure is complex, but items clustered logically to key areas originally used to generate items. Internal consistency (α = 0.66, 95% confidence interval (CI) = 0.55–0.76) demonstrated borderline acceptability. TRACE demonstrated good test–retest reliability (intra-class correlation = 0.94, 95% CI = 0.78–0.98) and face validity. TRACE indicated a slight negative correlation with APDQ. A larger data set is needed to substantiate these preliminary findings.

Early indications suggested TRACE was valid and reliable, suitable to measure the effectiveness of reflective practice.

The TRACE was a distinctive measure that filled a methodological gap in the literature.

We analyze the sizes of standard cointegration tests applied to data subject to linear interpolation, discovering evidence of substantial size distortions induced by the interpolation. We propose modifications to these tests to effectively eliminate size distortions from such tests conducted on data interpolated from end-of-period sampled low-frequency series. Our results generally do not support linear interpolation when alternatives such as aggregation or mixed-frequency-modified tests are possible.

Additive manufacturing is a fabrication technology with flexibility and economy. 18Ni300 is one of maraging steels with ultra-high strength, superior toughness, so it is an excellent candidate of structural material. This paper aims to explore the feasibility of using direct laser metal deposition method to fabricate18Ni300, and the evolution of its microstructure and defects is studied.

The experiments were conceived from single-trace-single-layer (STSL) test to multi-trace-multi-layers (MTML) test via single-trace-multi-layers (STML) test. The microstructure, defects and mechanical properties were analyzed.

The STML results showed that the columnar/equiaxed transformation occurred at the top part and the grain size increased with the layer number increasing, and it was explained by an innovative attempt combining columnar/equiaxed transformation model and the change of grain size. The MTML test with the interlayer orthogonal parallel reciprocating scanning pattern resulted in the grain growing along orthogonal directions; with the increase of overlap rate, the length and the area of the columnar grain decreased. What is more, the later deposition layer had lower micro-hardness value because of heat history.

Direct laser metal deposition method was a novel additive manufacturing method to manufacture 18Ni300 components, as 18Ni300 maraging steel was mainly manufactured by selective laser melting (SLM) method nowadays. It was useful to manufacture maraging steel parts using direct laser deposition method because it could manufacture larger parts than SLM method. Influence of processing parameters on forming quality and microstructure evolution was studied. The findings will be helpful to understand the forming mechanism of laser additive manufacturing of 18Ni300 components.

We provide a new characterization of the equality of two positive-definite matrices A and B, and we use this to propose several new computationally convenient statistical tests for the equality of two unknown positive-definite matrices. Our primary focus is on testing the information matrix equality (e.g. White, 1982, 1994). We characterize the asymptotic behavior of our new trace-determinant information matrix test statistics under the null and the alternative and investigate their finite-sample performance for a variety of models: linear regression, exponential duration, probit, and Tobit. The parametric bootstrap suggested by Horowitz (1994) delivers critical values that provide admirable level behavior, even in samples as small as n = 50. Our new tests often have better power than the parametric-bootstrap version of the traditional IMT; when they do not, they nevertheless perform respectably.

The study aims is to explore the cointegration level among major Asian stock indices from pre- COVID-19 to post COVID-19 times.

Johansen cointegration test is employed to know the long run relationship among the stock market indices of Hong Kong, Indonesia, Malaysia, Korea, India, Japan, China, Taiwan, Israel and South Korea. The empirical testing was done to analyze whether any significant change has been induced by the COVID-19 pandemic on the cointegrating relationship of the selected markets or not. Through statistics of trace test and maximum eigen value, total number of cointegrating equations present among all the indices during different study periods were analyzed.

The presence of cointegration was found during all the sample periods and the findings suggests that the selected stock markets are associated with each other in general. During COVID-19 crisis period the cointegration level was reduced and again it regained its original level in the next year and again reduced in the subsequent next year. So, the cointegrating relationship among selected stock market indices remains dynamic and no evidence of impact of COVID-19 on this dynamism was found.

The study has explored the level of cointegration among the major stock indices of Asian nations in the pre, during, post-crisis and the most recent periods. The interconnectedness of the stock markets during the COVID-19 times has been compared with similar periods in different years immediately preceding and succeeding the COVID-19 times which has not been done in any of the existing study.

This paper investigates the short‐run and the long‐run relationship among productivity growth, inflation and monetary policy in the U.S. economy. Under the trivariate ECM analysis, the test results indicate that it is monetary policy which plays the predominant role in the relationship under investigation.

The purpose of this paper is to look at the contemporaneous movement of the stock market indices of the five most COVID-infected countries, namely, the USA, Brazil, Russia, India and UK after the first wave along with market indices of the three least affected countries, namely, Hong Kong, South Korea and New Zealand during the first wave.

Data have been collected from the website of Yahoo finance on daily closing values of five indices. Augmented Dickey–Fuller test with its three forms has been applied to check the stationarity of the select five indices at the level and at the first difference before the pandemic, during the pandemic and post-first wave of the pandemic. Johansen cointegration test is applied to find out that there is no cointegration among the select five indices.

The five countries do neither fall in the same economic and political zone nor do they have the same economic status. But during the period of pandemic and the new-normal period, the cointegration is very distinct. The developing and developed nations thus stood at an indifferentiable stage of the economic crisis which is well reflected in their stock markets. However, the least three COVID-affected countries do not show any cointegration during the pandemic time.

The comovement even seen during the normal time in the other studies is not compared to a similar period in earlier years. But, in this study to look into the exclusive effect of COVID pandemic, the period most affected with it is compared with the period after it and that in the immediate past year had no effect.