scholarly journals Effect of Phase I Estimation on Phase II Control Chart Performance with Profile Data

2014 ◽  
Vol 32 (1) ◽  
pp. 79-87 ◽  
Author(s):  
Yajuan Chen ◽  
Jeffrey B. Birch ◽  
William H. Woodall
Keyword(s):  
Phase I ◽  
Control Chart ◽  
Phase Ii ◽  
Profile Data

Robust approaches for monitoring logistic regression profiles under outliers

2017 ◽  
Vol 34 (4) ◽  
pp. 494-507 ◽  
Author(s):  
Ahmad Hakimi ◽  
Amirhossein Amiri ◽  
Reza Kamranrad
Keyword(s):  
Logistic Regression ◽  
Robust Control ◽  
Phase I ◽  
Control Chart ◽  
Phase Ii ◽  
Control Charts ◽  
Likelihood Estimation ◽  
Estimation Of Parameters ◽  
Content Type ◽  
Practical Applications

Purpose The purpose of this paper is to develop some robust approaches to estimate the logistic regression profile parameters in order to decrease the effects of outliers on the performance of T2 control chart. In addition, the performance of the non-robust and the proposed robust control charts is evaluated in Phase II. Design/methodology/approach In this paper some, robust approaches including weighted maximum likelihood estimation, redescending M-estimator and a combination of these two approaches (WRM) are used to decrease the effects of outliers on estimating the logistic regression parameters as well as the performance of the T2 control chart. Findings The results of the simulation studies in both Phases I and II show the better performance of the proposed robust control charts rather than the non-robust control chart for estimating the logistic regression profile parameters and monitoring the logistic regression profiles. Practical implications In many practical applications, there are outliers in processes which may affect the estimation of parameters in Phase I and as a result of deteriorate the statistical performance of control charts in Phase II. The methods developed in this paper are effective for decreasing the effect of outliers in both Phases I and II. Originality/value This paper considers monitoring the logistic regression profile in Phase I under the presence of outliers. Also, three robust approaches are developed to decrease the effects of outliers on the parameter estimation and monitoring the logistic regression profiles in both Phases I and II.

scholarly journals On Phase-I Monitoring of Process Location Parameter with Auxiliary Information-Based Median Control Charts

Mathematics ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 706 ◽  
Author(s):  
Shahid Hussain ◽  
Sun Mei ◽  
Muhammad Riaz ◽  
Saddam Akber Abbasi
Keyword(s):  
Phase I ◽  
Control Chart ◽  
Phase Ii ◽  
Control Charts ◽  
Auxiliary Information ◽  
Location Parameter ◽  
Attractive Alternative ◽  
Location Parameters ◽  
The Mean ◽  
Two Phases

A control chart is often used to monitor the industrial or services processes to improve the quality of the products. Mostly, the monitoring of location parameters, both in Phase I and Phase II, is done using a mean control chart with the assumption that the process is free from outliers or the estimators are correctly estimated from in-control samples. Generally, there are question marks about such kind of narratives. The performance of the mean chart is highly affected in the presence of outliers. Therefore, the median chart is an attractive alternative to the mean chart in this situation. The control charts are usually implemented in two phases: Phase I (retrospective) and Phase II (prospective/monitoring). The efficiency of any control chart in Phase II depends on the accuracy of control limits obtained from Phase I. The current study focuses on the Phase I analysis of location parameters using median control charts. We examined the performance of different auxiliary information-based median control charts and compared the results with the usual median chart. Standardized variance and relative efficacy are used as performance measures to evaluate the efficiency of median estimators. Moreover, the probability to signal measure is used to evaluate the performance of proposed control charts to detect any potential changes in the process. The results revealed that the proposed auxiliary information based median control charts perform better in Phase I analysis. In addition, a practical illustration of an industrial scenario demonstrated the significance of the proposed control charts, in which the monitoring of concrete compressive strength is emphasized.

scholarly journals Change Point Detection with Robust Control Chart

2011 ◽  
Vol 2011 ◽  
pp. 1-20
Author(s):  
Ng Kooi Huat ◽  
Habshah Midi
Keyword(s):  
Robust Control ◽  
Phase I ◽  
Control Chart ◽  
Phase Ii ◽  
Control Process ◽  
Change Point Detection ◽  
Process Data ◽  
To Come ◽  
Point Detection ◽  
Control Limits

Monitoring a process over time using a control chart allows quick detection of unusual states. In phase I, some historical process data, assumed to come from an in-control process, are used to construct the control limits. In Phase II, the process is monitored for an ongoing basis using control limits from Phase I. In Phase II, observations falling outside the control limits or unusual patterns of observations signal that the process has shifted from in-control process settings. Such signals trigger a search for assignable cause and, if the cause is found, corrective action will be implemented to prevent its recurrence. The purpose of this paper is to introduce a new methodology appropriate for constructing a robust control chart when a nonnormal or a contaminated data that may arise in phase I state. Through extensive Monte Carlo simulations, we examine the behaviors and performances of the proposed MM robust control chart when there is a process shift in mean.

Guidelines for automating Phase I of control charts by considering effects on Phase-II performance of individuals control chart

2019 ◽  
Vol 32 (2) ◽  
pp. 223-243 ◽  
Author(s):  
Murat Atalay ◽  
Murat Caner Testik ◽  
Serhan Duran ◽  
Christian H. Weiß
Keyword(s):  
Phase I ◽  
Control Chart ◽  
Phase Ii ◽  
Control Charts

Bewegungstherapie und körperliche Aktivität bei Patienten mit Herzinsuffizienz

Praxis ◽  
2018 ◽  
Vol 107 (17-18) ◽  
pp. 951-958 ◽  
Author(s):  
Matthias Wilhelm
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Körperliche Aktivität ◽  
Phase Iii

Zusammenfassung. Herzinsuffizienz ist ein klinisches Syndrom mit unterschiedlichen Ätiologien und Phänotypen. Die überwachte Bewegungstherapie und individuelle körperliche Aktivität ist bei allen Formen eine Klasse-IA-Empfehlung in aktuellen Leitlinien. Eine Bewegungstherapie kann unmittelbar nach Stabilisierung einer akuten Herzinsuffizienz im Spital begonnen werden (Phase I). Sie kann nach Entlassung in einem stationären oder ambulanten Präventions- und Rehabilitationsprogramm fortgesetzt werden (Phase II). Typische Elemente sind Ausdauer-, Kraft- und Atemtraining. Die Kosten werden von der Krankenversicherung für drei bis sechs Monate übernommen. In erfahrenen Zentren können auch Patienten mit implantierten Defibrillatoren oder linksventrikulären Unterstützungssystemen trainieren. Wichtiges Ziel der Phase II ist neben muskulärer Rekonditionierung auch die Steigerung der Gesundheitskompetenz, um die Langzeit-Adhärenz bezüglich körperlicher Aktivität zu verbessern. In Phase III bieten Herzgruppen Unterstützung.

How to Make COVID-19 Contact Tracing Apps work: Insights from Behavioral Economics (Preprint)

2021 ◽  
Author(s):  
Ian Ayres ◽  
Alessandro Romano ◽  
Chiara Sotis
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Network Effects ◽  
Risky Behaviors ◽  
Contact Tracing ◽  
Risk Compensation ◽  
Main Function ◽  
Double Blind ◽  
Compensation Theory ◽  
Pros And Cons

BACKGROUND Due to network effects, Contact Tracing Apps (CTAs) are only effective if many people download them. However, the response to CTAs has been tepid. For example, in France less than 2 million people (roughly 3% of the population) downloaded the CTA. Consequently, CTAs need to be fundamentally rethought to increase their effectiveness. OBJECTIVE This study aimed to show that CTAs can still play a key role in containing the pandemic, provided that they take into account insights from behavioral sciences. Moreover, we study whether emphasizing the virtues of CTA to induce people to download them makes app users engage in more risky behaviors (risk compensation theory) and whether feedback on a user’s behavior affects future behaviors. METHODS We perform a double-blind online experiment (n=1500) divided in two phases. In Phase I respondents are randomly assigned to one of three different groups: Pros of the app, Pros and Cons of the app and Control I. Respondents in the Pros group were shown information on the advantages of CTAs. Participants in the Pros and Cons group were shown information on both the advantages and the problems that characterize CTAs. Last, respondents in the Control I group were not given any information on CTAs. All participants are then asked how worried they are about the pandemic, how likely they are to download the app, and on how they intend to behave (e.g. attend small and large gathering, wear a mask, etc.). A week later we carried out Phase II. Participants in Phase II were randomly assigned to different in-app notifications in which they were informed on how much risk they were taking compared to the average user. We then ask participants their intentions for future behaviors to investigate whether these notifications were effective in making respondents more prudent. RESULTS All 1500 participants completed phase I of the experiment, whereas 1303 (86.9%) completed also phase 2. The main findings are: i) informing people on the pros of the app make them less worried about the pandemic (p=.004), ii) informing people about both the pros and the cons of the app makes them more likely to download the app (p=.07); iii) carefully devised in-app notification induce people to state that they will: attend less large gatherings (p= .05) and less small gatherings (p= .001), see less people at risk (p=.004), that they stay more at home (p=.006) and wear more often the mask (p=.09). We do not find support for the risk-compensation theory. CONCLUSIONS we suggest that CTAs should be re-framed as Behavioral Feedback Apps (BFAs). The main function of BFAs would be providing users with information on how to minimize the risk of contracting COVID-19, e.g. to provide information on how crowded a store is likely to be at a given time of the day. Moreover, the BFA could have a rating system that allows users to flag stores that do not respect safety norms, such as mandating customers to wear a mask or not respecting social distancing. These functions can inform the behavior of app users, thus playing a key role in containing the spread of the virus even if a small percentage of people download the BFA. While effective contact tracing is impossible when only 3% of the population downloads the app, less risk taking by small portions of the population can produce large benefits. BFAs can be programmed so that users can also activate a tracing function akin to the one currently carried out by CTAs. Making contact tracing an ancillary, opt-in function might facilitate a wider acceptance of BFAs.

scholarly journals Analysis of the ex-vivo transformation of semen, saliva and urine as they dry out using ATR-FTIR spectroscopy and chemometric approach

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tanurup Das ◽  
Abhimanyu Harshey ◽  
Ankit Srivastava ◽  
Kriti Nigam ◽  
Vijay Kumar Yadav ◽  
...  
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Ex Vivo ◽  
Body Fluids ◽  
Biochemical Changes ◽  
Partial Least Square ◽  
The Body ◽  
Slow Phase ◽  
Time Since Deposition ◽  
Dry Out

AbstractThe ex-vivo biochemical changes of different body fluids also referred as aging of fluids are potential marker for the estimation of Time since deposition. Infrared spectroscopy has great potential to reveal the biochemical changes in these fluids as previously reported by several researchers. The present study is focused to analyze the spectral changes in the ATR-FTIR spectra of three body fluids, commonly encountered in violent crimes i.e., semen, saliva, and urine as they dry out. The whole analytical timeline is divided into relatively slow phase I due to the major contribution of water and faster Phase II due to significant evaporation of water. Two spectral regions i.e., 3200–3400 cm−1 and 1600–1000 cm−1 are the major contributors to the spectra of these fluids. Several peaks in the spectral region between 1600 and 1000 cm−1 showed highly significant regression equation with a higher coefficient of determination values in Phase II in contrary to the slow passing Phase I. Principal component and Partial Least Square Regression analysis are the two chemometric tool used to estimate the time since deposition of the aforesaid fluids as they dry out. Additionally, this study potentially estimates the time since deposition of an offense from the aging of the body fluids at the early stages after its occurrence as well as works as the precursor for further studies on an extended timeframe.

scholarly journals Detoxification of the tricyclic antidepressant opipramol and its analog – IS-noh by UGT enzymes before and after activation by phase I enzymes in rat liver microsomes

2021 ◽  
Author(s):  
Anna Mieszkowska ◽  
Koleta Hemine ◽  
Anna Skwierawska ◽  
Ewa Augustin ◽  
Zofia Mazerska
Keyword(s):  
Phase I ◽  
Rat Liver ◽  
Phase Ii ◽  
Oxidation Product ◽  
Liver Microsomes ◽  
Correct Selection ◽  
Rat Liver Microsomes ◽  
Recombinant Enzymes ◽  
Data Set ◽  
Phase I Enzymes

AbstractThe present studies were carried out to evaluate the simultaneous one-pot metabolism of opipramol (IS-opi) and analog (IS-noh) by phase I and phase II enzymes present in rat liver microsomes (RLM) as an alternative to separate testing with recombinant enzymes. This approach allows for more time-saving and cost-effective screening of the metabolism of newly discovered drugs. We also considered that the lack of results for phase II, including UGT, often creates problems in correct selection of valuable compounds. Moreover, microsomes data set is richer in the contest and provides medical scientist to determine also the susceptibility of drugs to undergo phase I and then phase II. In the present work, we have shown that IS-noh was metabolized in vitro by phase I enzymes to the oxidation product, which was next transformed with UGTs to glucuronide. The results showed also that the previously known oxidation product of opipramol was changed to previously no reported glucuronidation product by UDP-glucuronosyltransferases. In addition, unlike IS-noh, opipramol did not prove to be the substrate for UGTs. Therefore, tricyclic antidepressants depending on the structure can trigger a different response after contact with UGT enzymes. Some will metabolize directly with UGTs, others only after activation by phase I enzymes.

scholarly journals Nurses’ educational needs when dealing with aggression from patients and their families: a mixed-methods study

BMJ Open ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. e041711
Author(s):  
Kana Sato ◽  
Yoshimi Kodama
Keyword(s):  
Mixed Methods ◽  
Nursing Students ◽  
Phase I ◽  
Phase Ii ◽  
Mixed Methods Study ◽  
Self Awareness ◽  
Two Phase ◽  
Sequential Mixed Methods ◽  
Nursing Professionals ◽  
Educational Contents

ObjectivesTo explore the type of education needed for nurses when dealing with aggression from patients and their families.DesignA two-phase sequential mixed-methods study.SettingThis study was conducted in Japan, with phase I from March to November 2016 and phase II in November 2018.Main outcome measuresThe challenges faced by nurses when dealing with incidents of aggression from the neutral perspective of neither nurse nor patient/family and perceptions of the educational contents developed in this study. Descriptive analyses were used to examine the data retrieved from both phases.ParticipantsPhase I entailed semistructured interviews among 11 neutral-party participants who observed aggressive incidents between nurses and patients/families. Phase II consisted of a web survey conducted among 102 nursing students and 308 nursing professionals.ResultsPhase I resulted in the identification of the following five main educational components: understanding the mechanisms of anger and aggression, maintaining self-awareness, observant listening, managing the self-impression, and communicating based on specific disease characteristics. Each component was related to improved communication through self-awareness. The results of phase II indicated that participants positively perceived these educational contents as likely to be effective for dealing with aggression from patients/families.ConclusionsThis study clarified the type of education needed for nurses when dealing with aggression based on multiple viewpoints. Specifically, neutral-party interviews revealed that communication should be improved through self-awareness. A subsequent survey among nurses and nursing students showed that the identified educational contents were positively received.

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