An Evaluation of First-Come, First-Served Scheduling in a Geometrically-Constrained Wet Bulk Terminal

In 2022, a new sea lock at IJmuiden is expected to open, permitting an increase in marine traffic of larger ships from the sea to the port. In the interest of facilitating operations, we evaluate the impact of the current first-come, first-served (FCFS) admittance policy in the context of berth allocation for a wet bulk terminal in the port. Four model types are constructed: optimal FCFS; no FCFS with fixed arrival times; 48-h arrival time relaxation; and complete arrival time relaxation. Comparison of the model types is done by means of a rolling time window: of each day within the time frame, a schedule was created for the following 2 weeks, after which the objective value was calculated. When comparing the average of all objective values, it was found that the optimal FCFS model already shows an improvement compared to the historical situation. Between the FCFS and the no FCFS model, there are no considerable differences, because the vessels are constrained to be scheduled on/after their arrival time at the port. When relaxation is allowed, a considerable efficiency gain is possible, especially if larger ships arrive at the port.

Download Full-text

Abstract P651: Should I Stay or Go: Seeking Stroke Care During Covid-19

Stroke ◽

10.1161/str.52.suppl_1.p651 ◽

2021 ◽

Vol 52 (Suppl_1) ◽

Author(s):

Kathyrn J Libby ◽

Linda Couts ◽

Paige Schoenheit-Scott ◽

Lindsay L Olson-Mack ◽

Amelia Kenner Brininger ◽

...

Keyword(s):

San Diego ◽

Arrival Time ◽

Stroke Care ◽

Time Frame ◽

San Diego County ◽

Stroke Patients ◽

Discharge Data ◽

Hospital Arrival ◽

The Impact ◽

At Home

Introduction: On March 16, 2020 San Diego County implemented a stay at home order in response to COVID-19 pandemic; followed by the state of California instituting a shelter in place order. Locally, San Diego County’s stroke receiving centers (SRC) determined a 30% drop in stroke code activations between March-April 2020 compared to the same time in 2019 indicating a possible delay in seeking care. Utilizing discharge data, we sought to understand the impact of the stay at home order on the timeliness of seeking care. Hypothesis: We hypothesized an increase in last known normal (LKN) to hospital arrival time and a decrease in alteplase (tPA) and endovascular therapy (EVT) treatment rates between March 16-June 30 2020 compared to March 16-June 30 2019. Methods: AIS patients presenting to one of 16 SRC in San Diego County between March 16-June 30 in 2019 and 2020, discharged from the hospital or treated in the ED and transferred to another facility were included. Patients arriving as transfers from another facility were excluded. Results: In 2019, of 1,342 AIS cases LKN time was recorded for 85.6% of cases; of 1,092 cases in 2020 86.4% of cases had a LKN. Average LKN to arrival was 20.5 hours in 2019 and 32.4 hours in 2020 (p = .001, 95% CI [4.79, 18.93]). In 2019, 209 (15.6%) received tPA and 91 (6.8%) had EVT. In 2020, 144 (13.2%) received tPA and 75 (6.9%) had EVT. Odds that a case in 2019 received tPA was 1.21 times that of cases in 2020 (p=.09). Odds that a case in 2019 had EVT was .99 times that of cases in 2020 (p=.93). Conclusion: Ischemic stroke patients arriving between March 16-June 30, 2020 had a longer LKN to arrival time compared to the same time frame in 2019. The longer time to arrival may have been due to patients waiting longer to seek care, as anecdotal information from patients eluded to. The odds of receiving tPA or EVT treatment in 2020 compared to 2019 were not statistically significant. This may be due to patients experiencing acute symptoms accessing healthcare at the same rate in 2020 as 2019. Analysis of percent of patients arriving within 4 hours of LKN and average NIHSS are important next steps to determine this. Regardless, during a time of community crisis, it is important to broadcast community messaging focusing on the importance of seeking emergency care for stroke-like symptoms.

Download Full-text

Assessment of the performance of the inter-arrival time algorithm to identify ice shattering artifacts in cloud particle probe measurements

Atmospheric Measurement Techniques ◽

10.5194/amt-8-761-2015 ◽

2015 ◽

Vol 8 (2) ◽

pp. 761-777 ◽

Cited By ~ 38

Author(s):

A. Korolev ◽

P. R. Field

Keyword(s):

Particle Size ◽

Arrival Time ◽

Time Algorithm ◽

Sample Volume ◽

Ice Crystals ◽

Cloud Particle ◽

Measured Concentration ◽

Arrival Times ◽

Microphysical Properties ◽

The Impact

Abstract. Shattering presents a serious obstacle to current airborne in situ methods of characterizing the microphysical properties of ice clouds. Small shattered fragments result from the impact of natural ice crystals with the forward parts of aircraft-mounted measurement probes. The presence of these shattered fragments may result in a significant overestimation of the measured concentration of small ice crystals, contaminating the measurement of the ice particle size distribution (PSD). One method of identifying shattered particles is to use an inter-arrival time algorithm. This method is based on the assumption that shattered fragments form spatial clusters that have short inter-arrival times between particles, relative to natural particles, when they pass through the sample volume of the probe. The inter-arrival time algorithm is a successful technique for the classification of shattering artifacts and natural particles. This study assesses the limitations and efficiency of the inter-arrival time algorithm. The analysis has been performed using simultaneous measurements of two-dimensional (2-D) optical array probes with the standard and antishattering "K-tips" collected during the Airborne Icing Instrumentation Experiment (AIIE). It is shown that the efficiency of the algorithm depends on ice particle size, concentration and habit. Additional numerical simulations indicate that the effectiveness of the inter-arrival time algorithm to eliminate shattering artifacts can be significantly restricted in some cases. Improvements to the inter-arrival time algorithm are discussed. It is demonstrated that blind application of the inter-arrival time algorithm cannot filter out all shattered aggregates. To mitigate against the effects of shattering, the inter-arrival time algorithm should be used together with other means, such as antishattering tips and specially designed algorithms for segregation of shattered artifacts and natural particles.

Download Full-text

Temporal dispersion of the emergence of intelligence: an inter-arrival time analysis

International Journal of Astrobiology ◽

10.1017/s1473550411000024 ◽

2011 ◽

Vol 10 (2) ◽

pp. 131-135 ◽

Cited By ~ 9

Author(s):

Thomas W. Hair

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Arrival Time ◽

Time Analysis ◽

Arrival Times ◽

The Galaxy ◽

Sphere Of Influence ◽

The Impact ◽

Temporal Dispersion

AbstractMany reasons for why extraterrestrial intelligences might avoid communications with our civilization have been proposed. One possible scenario is that all civilizations follow the lead of some particularly distinguished civilization. This paper will examine the impact the first successful civilization could have on all other subsequent civilizations within its sphere of influence and the ramifications of this as it relates to the Fermi Paradox. Monte Carlo simulation is used to map the inter-arrival times of early civilizations and to highlight the immense epochs of time that the earliest civilizations could have had the Galaxy to themselves.

Download Full-text

Evaluating Total Electron Content (TEC) Detrending Techniques in Determining Ionospheric Disturbances during Lightning Events in A Low Latitude Region

Remote Sensing ◽

10.3390/rs13234753 ◽

2021 ◽

Vol 13 (23) ◽

pp. 4753

Author(s):

Louis Osei-Poku ◽

Long Tang ◽

Wu Chen ◽

Chen Mingli

Keyword(s):

Total Electron Content ◽

Communication Systems ◽

Time Window ◽

Ionospheric Disturbance ◽

Time Frame ◽

Global Navigation Satellite Systems ◽

Electron Content ◽

Total Electron ◽

Satellite Systems ◽

The Impact

Total Electron Content (TEC) from Global Navigation Satellite Systems (GNSS) is used to ascertain the impact of space weather events on navigation and communication systems. TEC is detrended by several methods to show this impact. Information from the detrended TEC may or may not necessarily represent a geophysical parameter. In this study, two commonly used detrending methods, Savitzky–Golay filter and polynomial fitting, are evaluated during thunderstorm events in Hong Kong. A two-step approach of detection and distinguishing is introduced alongside linear correlation in order to determine the best detrending model. Savitzky–Golay filter on order six and with a time window length of 120 min performed the best in detecting lightning events, and had the highest moderate positive correlation of 0.4. That the best time frame was 120 min suggests that the observed disturbances could be travelling ionospheric disturbance (TID), with lightning as the potential source.

Download Full-text

Coming-of-Age Cinema in New Zealand

10.3366/edinburgh/9781474429443.001.0001 ◽

2017 ◽

Author(s):

Alistair Fox

Keyword(s):

Coming Of Age ◽

Belief Systems ◽

Time Frame ◽

New Wave ◽

Art Cinema ◽

Literary Sources ◽

French New Wave ◽

Significant Phenomenon ◽

The Impact ◽

New Zealanders

This book investigates the coming-of-age genre as a significant phenomenon in New Zealand’s national cinema, tracing its development from the 1970s to the present day. A preliminary chapter identifies the characteristics of the coming-of-age film as a genre, tracing its evolution and the influence of the French New Wave and European Art Cinema, and speculating on the role of the genre in the output of national cinemas. Through case studies of fifteen significant films, including The God Boy, Sleeping Dogs, The Scarecrow, Vigil, Mauri, An Angel at My Table, Heavenly Creatures, Once Were Warriors, Rain, Whale Rider, In My Father’s Den, 50 Ways of Saying Fabulous, Boy, Mahana, and Hunt for the Wilderpeople, subsequent chapters examine thematic preoccupations of filmmakers such as the impact of repressive belief systems and social codes, the experience of cultural dislocation, the expression of a Māori perspective through an indigenous “Fourth Cinema,” bicultural relationships, and issues of sexual identity, arguing that these films provide a unique insight into the cultural formation of New Zealanders. Given that the majority of films are adaptations of literary sources, the book also explores the dialogue each film conducts with the nation’s literature, showing how the time frame of each film is updated in a way that allows these films to be considered as a register of important cultural shifts that have occurred as New Zealanders have sought to discover their emerging national identity.

Download Full-text

Measurement of the Sea Surface Height with Airborne GNSS Reflectometry and Delay Bias Calibration

Remote Sensing ◽

10.3390/rs13153014 ◽

2021 ◽

Vol 13 (15) ◽

pp. 3014

Author(s):

Feng Wang ◽

Dongkai Yang ◽

Guodong Zhang ◽

Jin Xing ◽

Bo Zhang ◽

...

Keyword(s):

Wind Speed ◽

Arrival Time ◽

Elevation Angle ◽

Satellite System ◽

Sea Surface Height ◽

Antenna Pattern ◽

Sea Surface ◽

Observation Method ◽

Global Navigation Satellite ◽

The Impact

Sea surface height can be measured with the delay between reflected and direct global navigation satellite system (GNSS) signals. The arrival time of a feature point, such as the waveform peak, the peak of the derivative waveform, and the fraction of the peak waveform is not the true arrival time of the specular signal; there is a bias between them. This paper aims to analyze and calibrate the bias to improve the accuracy of sea surface height measured by using the reflected signals of GPS CA, Galileo E1b and BeiDou B1I. First, the influencing factors of the delay bias, including the elevation angle, receiver height, wind speed, pseudorandom noise (PRN) code of GPS CA, Galileo E1b and BeiDou B1I, and the down-looking antenna pattern are explored based on the Z-V model. The results show that (1) with increasing elevation angle, receiver height, and wind speed, the delay bias tends to decrease; (2) the impact of the PRN code is uncoupled from the elevation angle, receiver height, and wind speed, so the delay biases of Galileo E1b and BeiDou B1I can be derived from that of GPS CA by multiplication by the constants 0.32 and 0.54, respectively; and (3) the influence of the down-looking antenna pattern on the delay bias is lower than 1 m, which is less than that of other factors; hence, the effect of the down-looking antenna pattern is ignored in this paper. Second, an analytical model and a neural network are proposed based on the assumption that the influence of all factors on the delay bias are uncoupled and coupled, respectively, to calibrate the delay bias. The results of the simulation and experiment show that compared to the meter-level bias before the calibration, the calibrated bias decreases the decimeter level. Based on the fact that the specular points of several satellites are visible to the down-looking antenna, the multi-observation method is proposed to calibrate the bias for the case of unknown wind speed, and the same calibration results can be obtained when the proper combination of satellites is selected.

Download Full-text

Impact of COVID-19 pandemic on HIV viremia: a single-center cohort study in northern Italy

AIDS Research and Therapy ◽

10.1186/s12981-021-00355-x ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Ilaria Izzo ◽

Canio Carriero ◽

Giulia Gardini ◽

Benedetta Fumarola ◽

Erika Chiari ◽

...

Keyword(s):

Time Window ◽

Time Windows ◽

Continuum Of Care ◽

Northern Italy ◽

Hiv Diagnosis ◽

Hiv Patients ◽

Before And After ◽

Missed Visits ◽

Hiv Continuum Of Care ◽

The Impact

Abstract Background Brescia Province, northern Italy, was one of the worst epicenters of the COVID-19 pandemic. The division of infectious diseases of ASST (Azienda Socio Sanitaria Territoriale) Spedali Civili Hospital of Brescia had to face a great number of inpatients with severe COVID-19 infection and to ensure the continuum of care for almost 4000 outpatients with HIV infection actively followed by us. In a recent manuscript we described the impact of the pandemic on continuum of care in our HIV cohort expressed as number of missed visits, number of new HIV diagnosis, drop in ART (antiretroviral therapy) dispensation and number of hospitalized HIV patients due to SARS-CoV-2 infection. In this short communication, we completed the previous article with data of HIV plasmatic viremia of the same cohort before and during pandemic. Methods We considered all HIV-patients in stable ART for at least 6 months and with at least 1 available HIV viremia in the time window March 01–November 30, 2019, and another group of HIV patients with the same two requisites but in different time windows of the COVID-19 period (March 01–May 31, 2020, and June 01–November 30, 2020). For patients with positive viremia (PV) during COVID-19 period, we reported also the values of viral load (VL) just before and after PV. Results: the percentage of patients with PV during COVID-19 period was lower than the previous year (2.8% vs 7%). Only 1% of our outpatients surely suffered from pandemic in term of loss of previous viral suppression. Conclusions Our efforts to limit the impact of pandemic on our HIV outpatients were effective to ensure HIV continuum of care.

Download Full-text

Optimizing a Reverse Supply Chain Network for Electronic Waste under Risk and Uncertain Factors

Applied Sciences ◽

10.3390/app11041946 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1946

Author(s):

Linh Thi Truc Doan ◽

Yousef Amer ◽

Sang-Heon Lee ◽

Phan Nguyen Ky Phuc ◽

Tham Thi Tran

Keyword(s):

Supply Chain ◽

Electronic Waste ◽

Decision Makers ◽

Reverse Supply Chain ◽

Satisfactory Solution ◽

Level Of Satisfaction ◽

Proposed Model ◽

Objective Value ◽

The Right ◽

The Impact

Minimizing the impact of electronic waste (e-waste) on the environment through designing an effective reverse supply chain (RSC) is attracting the attention of both industry and academia. To obtain this goal, this study strives to develop an e-waste RSC model where the input parameters are fuzzy and risk factors are considered. The problem is then solved through crisp transformation and decision-makers are given the right to choose solutions based on their satisfaction. The result shows that the proposed model provides a practical and satisfactory solution to compromise between the level of satisfaction of constraints and the objective value. This solution includes strategic and operational decisions such as the optimal locations of facilities (i.e., disassembly, repairing, recycling facilities) and the flow quantities in the RSC.

Download Full-text

Abstract P99: Impact of the Covid-19 Pandemic on Stroke Thrombolysis Rate and Delay to Thrombolysis Treatment in a Regional Stroke Centre in London, UK

Stroke ◽

10.1161/str.52.suppl_1.p99 ◽

2021 ◽

Vol 52 (Suppl_1) ◽

Author(s):

Brian Drumm ◽

Paul Bentley ◽

Zoe Brown ◽

Lucio D’Anna ◽

Tsering Dolkar ◽

...

Keyword(s):

Arrival Time ◽

Negative Impact ◽

Public Awareness ◽

Stroke Severity ◽

Time Intervals ◽

Neurological Outcomes ◽

Stroke Thrombolysis ◽

Prehospital Delays ◽

The Impact ◽

Stroke Centre

Introduction: There are reports of changes in the numbers of stroke admissions and time intervals to receiving emergency treatments during the COVID-19 pandemic. We examined the impact of the COVID-19 pandemic on the stroke thrombolysis rate and delay to thrombolysis treatment in a regional stroke centre in London, UK. Methods: COVID-19 testing began at our hospital on 3 March 2020. Clinical data for all acute stroke admissions were routinely collected as part of a national Sentinel Stroke National Audit Programme (SSNAP) and all thrombolysis data were entered into our local thrombolysis database. We retrospectively extracted the relevant patient data for the period of March to May 2020 (COVID group) and compared to the same period in 2019 (pre-COVID group). Results: Compared with pre-COVID, there was a 17.5% fall in total stroke admissions (from 315 to 260) during COVID; but there were no significant differences in the demographics, stroke severity, proportions with known time of onset, or median onset-to-arrival time. The thrombolysis rates amongst ischemic strokes were not significantly different between the two groups (59/260=23% pre-COVID vs. 41/228=18% COVID, p=.19). For thrombolysis patients, their stroke severity and demographics were similar between the two both groups. Median onset-to-needle time was significantly longer by 22 minutes during COVID [127 (IQR 94-160) vs. 149 (IQR 110-124) minutes, p=.045]; this delay to treatment was almost entirely due to a longer median onset-to-arrival time by 16 minutes during COVID (p=.029). Favorable early neurological outcomes post-thrombolysis (defined as an improvement in NIHSS by ≥4 points at 24 hours) were similar (45% vs. 46%, p=.86). Conclusion: COVID-19 pandemic had a negative impact on prehospital delays which in turn significantly increased onset-to-needle time, but without affecting the chance of a favorable early neurological outcome. Our data highlight the need to maintain public awareness of taking immediate action when stroke symptoms occur during the COVID-19 pandemic.

Download Full-text

Sex and Conception Probability

10.1093/acrefore/9780190632366.013.179 ◽

2021 ◽

Author(s):

Justin C. Konje ◽

Oladipo A. Ladipo

Keyword(s):

Menstrual Cycle ◽

Sexual Intercourse ◽

Time Window ◽

Continuous Process ◽

Female Genital Tract ◽

Human Reproduction ◽

Current Evidence ◽

Fertile Window ◽

Time Period ◽

The Impact

Central to the survival of any species is the ability to procreate. In most cases, procreation is sexual, involving a process that ensures appropriate and timed contact between the male and female gametes. Successful human reproduction is premised on sexual intercourse occurring at a time when there is a receptive endometrium as well as an ovum ready for fertilization by spermatozoa. This time window of the menstrual cycle known as the fertile or fecund window is poorly defined and highly variable from one individual to another. Furthermore, while spermatogenesis is a continuous process, the impact of too frequent intercourse (defined as that occurring more than every 2 to 3 days) on fertilization has often been thought to be associated with a decreased fertilization potential of spermatozoa. Current evidence challenges previously held views on the fertile window and how it is determined, the timing of intercourse and how it is related to conception and miscarriages, the length of the luteal phase, and the precise time period during which the chances of fertilization are highest in any given menstrual cycle. The ability of spermatozoa to survive in the female genital tract for 5 days means fertilization can occur up to 5 days from sexual intercourse. During each menstrual cycle, there is a window of 5 to 6 days for fertilization to occur, and this period is defined not by the length of the cycle but by the timing of ovulation, with the chances of fertilization highest with intercourse occurring 1 to 2 days before ovulation.

Download Full-text