Optimal Robust PID control for first- and second-order plus dead-time processes

The present study proposes a new design method for a proportional-integral-derivative (PID) control system for first-order plus dead-time (FOPDT) and over-damped second-order plus dead-time (SOPDT) systems. What is presented is an optimal PID tuning constrained to robust stability. The optimal tuning is defined for each one of the two operation modes the control system may operate in: servo (reference tracking) and regulation (disturbance rejection). The optimization problem is stated for a normalized second-order plant that unifies FOPDT and SOPDT process models. Different robustness levels are considered and for each one of them, the set of optimal controller parameters is obtained. In a second step, suitable formulas are found that provide continuous values for the controller parameters. Finally, the effectiveness of the proposed method is confirmed through numerical examples

Optimal Robust PID control for first- and second-order plus dead-time processes

The present study proposes a new design method for a proportional-integral-derivative (PID) control system for first-order plus dead-time (FOPDT) and over-damped second-order plus dead-time (SOPDT) systems. What is presented is an optimal PID tuning constrained to robust stability. The optimal tuning is defined for each one of the two operation modes the control system may operate in: servo (reference tracking) and regulation (disturbance rejection). The optimization problem is stated for a normalized second-order plant that unifies FOPDT and SOPDT process models. Different robustness levels are considered and for each one of them, the set of optimal controller parameters is obtained. In a second step, suitable formulas are found that provide continuous values for the controller parameters. Finally, the effectiveness of the proposed method is confirmed through numerical examples

Development of a Novel Scoring System for Predicting the Risk of Colorectal Neoplasia: A Retrospective Study.

The purpose of this study was to develop a novel scoring system to screen subjects who have a high risk for colorectal neoplasia.We retrospectively analyzed 1061 subjects undergoing total colonoscopy (TCS) for the first time at Gihoku Kosei Hospital. The characteristics and habits of the subjects were analyzed using a multivariate logistic regression analysis. The risk score was established according to each odds ratio of the individual risk factors, and the correlations between the sum of the risk scores and the prevalence of colorectal neoplasia for each individual were evaluated.Age 45-59 (risk score: 2 points) and ≥60 (3 points), male gender (1 point), and habitual alcohol consumption ≥21g daily (1 point) were extracted as the significant risk factors for colorectal neoplasia. When the risk groups were determined by summing up these risk scores, the prevalence rates of colorectal neoplasia were 8.8% for the low risk group (0-2 points), 30.5% for the low-moderate risk group (3 points), 39.1% for the high-moderate risk group (4 points), and 57.6% for the high risk group (5 points). In comparison with the low risk group, the odds ratio of the low-moderate risk, the high-moderate risk, and the high risk groups were 4.6, 6.7, and 14.1 folds, respectively.Our scoring system, which linearly correlates with the prevalence rate of colorectal neoplasia, may be an effective tool for screening the subjects who have a high risk for colorectal neoplasia. These subjects, therefore, should be recommended to undergo TCS

Cumulative incidence and risk factors for medication-related osteonecrosis of the jaw during long-term prostate cancer management

Abstract Bone-modifying agents (BMA) are extensively used in treating patients with prostate cancer with bone metastases. However, this increases the risk of medication-related osteonecrosis of the jaw (MRONJ). The safety of long-term BMA administration in clinical practice remains unclear. We aimed to determine the cumulative incidence and risk factors of MRONJ. One hundred and seventy-nine patients with prostate cancer with bone metastases treated with BMA at our institution since 2008 were included in this study. Twenty-seven patients (15%) had MRONJ during the follow-up period (median, 19 months; interquartile range, 9–43 months). The 2-year, 5-year, and 10-year cumulative MRONJ incidence rates were 18%, 27%, and 61%, respectively. Multivariate analysis identified denosumab use as a risk factor for MRONJ, compared with zoledronic acid use (HR 4.64, 95% CI 1.93–11.1). Additionally, BMA use at longer than one-month intervals was associated with a lower risk of MRONJ (HR 0.08, 95% CI 0.01–0.64). Furthermore, six or more bone metastases (HR 3.65, 95% CI 1.13–11.7) and diabetes mellitus (HR 5.07, 95% CI 1.68–15.2) were risk factors for stage 2 or more severe MRONJ. MRONJ should be considered during long-term BMA administration in prostate cancer patients with bone metastases

Risk Score.

<p>Risk Score.</p

Multivariate predictors of colorectal neoplasia analyzed using a multiple logistic regression analysis.

<p>The plot shows the odds ratios (black squares), and 95% CIs (horizontal lines). P-values show the interaction between the prevalence of colorectal neoplasia and any subgroup variable. a. Significant risk factor of colorectal neoplasia by the Pearson χ² test (P < 0.001). b. Significant risk factor of colorectal neoplasia by the Pearson χ² test (P < 0.01).</p

Prevalence and risk of colorectal neoplasia in each group.

<p>Prevalence and risk of colorectal neoplasia in each group.</p