Leaky Bucket-Inspired Power Output Smoothing with Load-Adaptive Algorithm

The renewables will constitute an important part of the future smart grid. As a result, the growing portion of renewable generation in the power grid will bring challenges to the operations of the power grid because of the fluctuation and intermittency properties of renewables. In order to make the operations of power grid stable and reliable, the power outputs from renewable energy sources must be smoothed. In this paper, we propose a scheme inspired from the idea of the leaky bucket mechanism for smoothing the power output from a renewable energy system. In our proposed method, the settings of energy storage size and power output level have significant effects on the system performance and thus needs to be determined. An optimization framework is thus proposed for storage and power output planning of the renewable energy system. To operate our proposed scheme practically, a load-adaptive power smoothing algorithm is devised aiming to match the power output level with the actual load in the grid. Our simulation studies show that the proposed algorithm can reduce the operation cost comparing to other algorithms and maintain high renewable energy utilization.postprin

A Novel Online Scheduling Algorithm for Hierarchical Vehicle-to-Grid System

SAC-SGC.1: Smart Grid Energy Managementpostprin

Unpacking the thinking and making behind a slow technology research product with slow game

Motivated by prior work on everyday creativity, we adopt a design-oriented approach seeks to move beyond designing for explicit interactions to also include the implicit, incremental and, at times even, unknowing encounters that slowly emerge among people, technologies, and artifacts over time. We contribute an investigation into designing for slowness grounded in the practice of making a design artifact called Slow Game. We offer a detailed critical-reflective accounting of our process of making Slow Game into a research product. In attending to key design moves across our process, we reveal hidden challenges in designing slow technology research products and discuss how our findings can be mobilized in future work

Metformin Use and Gastric Cancer Risk in Diabetic Patients After Helicobacter pylori Eradication

Background: Although prior studies showed metformin could reduce gastric cancer (GC) risk in patients with diabetes mellitus (DM), they failed to adjust for Helicobacter pylori infection and glycemic control. We aimed to investigate whether metformin reduced GC risk in H. pylori -eradicated diabetic patients and its association with glycemic control. Methods: This was a territory-wide cohort study using hospital registry database, recruiting all diabetic patients who were prescribed clarithromycin-based triple therapy for H. pylori infection from 2003 to 2012. Subjects were observed from H. pylori therapy prescription until GC diagnosis, death or end of study (December 2015). Exclusion criteria included GC diagnosed within first year of H. pylori therapy, prior history of GC or gastrectomy, and failure of H. pylori eradication. The hazard ratio (HR) of GC with metformin (defined as at least 180-day use) was estimated by Cox model with propensity score adjustment for covariates (age, sex, comorbidities, medications [including insulin], and time-weighted average hemoglobin A1c [HbA1c]). All statistical tests were two-sided. Results: During a median follow-up of 7.1 years (IQR:4.7–9.8), 37 (0.51%) of 7,266 diabetic patients developed GC at a median age of 76.4 years (IQR: 64.8–81.5 years). Metformin use was associated with a reduced GC risk (adjusted HR:0.49; 95% CI:0.24–0.98). There was a trend towards a lower GC risk with increasing duration (ptrend =0.01) and dose of metformin (ptrend=0.02) HbA1c level was not an independent risk factor for GC. Conclusions: Metformin use was associated with a lower GC risk among H. pylori -eradicated diabetic patients in a duration- and dose-response manner, which was independent of HbA1c level

Statins Were Associated with a Reduced Gastric Cancer Risk in Patients with Eradicated Helicobacter Pylori Infection: A Territory-Wide Propensity Score Matched Study

BACKGROUND: Individuals may still develop gastric cancer even after Helicobacter pylori eradication. We aimed to investigate statin effect on gastric cancer development in H. pylori-eradicated subjects. METHODS: All adult subjects who were prescribed clarithromycin-based triple therapy between 2003 and 2012 were identified in this retrospective cohort study utilizing a territory-wide electronic healthcare database. Patients were observed from index date of H. pylori therapy, and censored at gastric cancer diagnosis, death, or December 2015 (study end date). Statin use was defined as ≥180-day use after index date. Exclusion criteria included gastric cancer diagnosed within the first year after index date, previous gastric cancer or gastrectomy, and H. pylori treatment failure. Subdistribution hazard ratio (SHR) of gastric cancer with statins was calculated by competing risk regression with propensity score (PS) analysis matching 19 variables (age, sex, comorbidities, and other drug usage, including proton pump inhibitors, nonsteroidal anti-inflammatory drugs, aspirin, cyclooxygenase-2 inhibitors, and metformin). RESULTS: During a median follow-up of 7.6 years (interquartile range = 5.1-10.3), 169 (0.27%) of 63,605 patients developed gastric cancer at an incidence rate of 3.5 per 10,000 person-years. Among 22,870 PS-matched subjects, statins were associated with a lower gastric cancer risk (SHR = 0.34; 95% confidence interval, 0.19-0.61), in a duration- and dose-response manner (Ptrend < 0.05). CONCLUSIONS: Statins were associated with a lower gastric cancer risk in a duration- and dose-response manner among H. pylori-eradicated patients. IMPACT: This study provides evidence on the additional benefits of statins as chemopreventive agents against gastric cancer among H. pylori-eradicated patients

Conversational agents in healthcare: a systematic review.

Objective: Our objective was to review the characteristics, current applications, and evaluation measures of conversational agents with unconstrained natural language input capabilities used for health-related purposes. Methods: We searched PubMed, Embase, CINAHL, PsycInfo, and ACM Digital using a predefined search strategy. Studies were included if they focused on consumers or healthcare professionals; involved a conversational agent using any unconstrained natural language input; and reported evaluation measures resulting from user interaction with the system. Studies were screened by independent reviewers and Cohen's kappa measured inter-coder agreement. Results: The database search retrieved 1513 citations; 17 articles (14 different conversational agents) met the inclusion criteria. Dialogue management strategies were mostly finite-state and frame-based (6 and 7 conversational agents, respectively); agent-based strategies were present in one type of system. Two studies were randomized controlled trials (RCTs), 1 was cross-sectional, and the remaining were quasi-experimental. Half of the conversational agents supported consumers with health tasks such as self-care. The only RCT evaluating the efficacy of a conversational agent found a significant effect in reducing depression symptoms (effect size d = 0.44, p = .04). Patient safety was rarely evaluated in the included studies. Conclusions: The use of conversational agents with unconstrained natural language input capabilities for health-related purposes is an emerging field of research, where the few published studies were mainly quasi-experimental, and rarely evaluated efficacy or safety. Future studies would benefit from more robust experimental designs and standardized reporting. Protocol Registration: The protocol for this systematic review is registered at PROSPERO with the number CRD42017065917

Aspirin and Risk of Gastric Cancer After Helicobacter pylori Eradication: A Territory-Wide Study

Background: Despite successful H. pylori (HP) eradication, some individuals remain at risk of developing gastric cancer (GC). Previous studies showed that aspirin was associated with a reduced GC risk. However, whether aspirin can reduce GC risk in HP-eradicated subjects remains unknown. We aimed to determine the chemopreventive effect of aspirin in HP-eradicated subjects. Methods: We identified subjects who had received a prescription of clarithromycin-based triple therapy for HP between 2003 and 2012 from a territory-wide healthcare database. The observation period started from commencement of HP therapy (index date), and the follow-up was censored at the end of the study (December 2015), death or GC diagnosis. Aspirin use was defined as ≥once weekly use. Subjects who failed HP eradication or diagnosed with GC within 12 months of HP therapy were excluded. The hazard ratio (HR) of GC with aspirin use was calculated by Cox model with propensity score adjustment for age, sex, comorbidities and concurrent medications. All statistical tests were two-sided. Results: The median follow-up was 7.6 years (IQR: 5.1-10.3 years), and 169 (0.27%) out of 63,605 patients developed GC. The incidence rate of GC was 3.5 per 10,000 person-years. Aspirin use was associated with a reduced GC risk (HR 0.30, 95% CI: 0.15-0.61). The risk of GC decreased with increasing frequency, duration and dose of aspirin (all p-trend <0.001). Conclusions: Aspirin use was associated with a frequency-, dose- and duration-dependent reduction in GC risk after HP eradication. The effect was most prominent in those who used aspirin daily or for ≥ 5 years

Association Between Acute Neuropsychiatric Events and Helicobacter pylori Therapy Containing Clarithromycin

Importance: There is a concern that Helicobacter pylori therapy containing clarithromycin might be associated with acute neuropsychiatric events. / Objective: To examine the association between H pylori therapy containing clarithromycin and acute neuropsychiatric events. / Design, Setting, and Participants: A self-controlled case series study was conducted using the Clinical Data Analysis and Reporting System database in Hong Kong to explore any association. The exposure of interest was H pylori therapy containing clarithromycin in the outpatient setting. Study patients, 18 years or older at cohort entry, must have had both exposure to H pylori therapy containing clarithromycin and their first recorded neuropsychiatric events between January 1, 2003, and December 31, 2012. A post hoc nested case-control analysis was also performed in patients receiving H pylori therapy containing clarithromycin. / Main Outcomes and Measures: The primary outcome was composite neuropsychiatric events, while secondary outcomes were psychotic events and cognitive impairment. Risk periods in the self-controlled case series analysis were defined as 14-day preexposure period, current use (days 1-14 since prescription start date) and recent use (days 15-30). Age-adjusted incidence rate ratios (IRR) were estimated using the conditional Poisson regression. / Results: Of 66 559 patients who had at least 1 outpatient prescription of H pylori therapy containing clarithromycin. Their mean (SD) age at cohort entry was 50.8 (14.8 years); their mean age at first exposure was 55.4 (14.8) years, and 30 910 were male (46.4%). A total of 1824 patients had their first recorded composite neuropsychiatric events during the study period. An increased IRR of 4.12 (35 composite neuropsychiatric events during 72 person-years; 95% CI, 2.94-5.76) during current use was observed but not in recent use (9 events during 82 person-years; IRR, 0.95; 95% CI, 0.49-1.83) and 14-day preexposure period (14 events during 72 person-years; IRR, 1.63; 95% CI, 0.96-2.77) vs baseline (1766 events during 16 665 person-years). Similarly, both the risk of psychotic events and cognitive impairment increased during current use vs baseline, although this subsequently returned to baseline incidence levels during recent use. The crude absolute risks of composite neuropsychiatric events, psychotic events, and cognitive impairment during current use were 0.45, 0.12, and 0.12 per 1000 prescriptions, respectively. The nested case-control analysis also gave similar results to that of the self-controlled case series analysis. / Conclusions and Relevance: This study shows evidence of a short-term increased risk of neuropsychiatric events associated with H pylori therapy containing clarithromycin

Effects of helicobacter pylori treatment on incidence of gastric cancer in older individuals

Background & Aims: Although eradication of Helicobacter pylori infection reduces the risk of gastric cancer, few data are available on its effects in older subjects. We compared the age-specific risk of gastric cancer in a large cohort of subjects who received H pylori eradication therapy vs a matched general population. / Methods: We searched the Hospital Authority database of Hong Kong to identify individuals with H pylori infection who had received a course of clarithromycin-containing eradication therapy from January 2003 through December 2012. We compared the gastric cancer incidence in this cohort with the expected incidence for the local general population by retrieving the gastric cancer incidence of the age- and sex-matched population from 2003 through 2014 (the latest available year) from the Hong Kong Cancer Registry. The primary outcome was the incidence of gastric cancer development in the cohort treated for H pylori infection vs the expected number of gastric cancer cases in the general population. Analyses were conducted by a priori age groups of less than 40 years, 40–59 years, and 60 years or older. / Results: Among 73,237 subjects infected with H pylori who received eradication therapy, 200 (0.27%) developed gastric cancer during a median follow-up time of 7.6 years. Compared with the matched general population, the gastric cancer risk was significantly lower in subjects 60 years or older who had received H pylori treatment (standardized incidence ratio [SIR], 0.82; 95% confidence interval [CI], 0.69–0.97; P = .02) but not in younger groups. When data were stratified based on time from H pylori treatment (less than 5 years, 5–9 years, and 10 or more years), the risk of gastric cancer was significantly lower than the general population 10 or more years after eradication in the group 40–59 years old (SIR 0.32; 95% CI, 0.08–0.88; P = .04) and the group 60 years or older (SIR, 0.42; 95% CI, 0.42–0.84; P = .02) than the other age groups. / Conclusions: In an analysis of data from a public hospital database on Hong Kong, we associated treatment of H pylori infection with a lower risk of gastric cancer, particularly in older subjects, 10 or more years after treatment