RESILIENCE OF NETWORKED INFRASTRUCTURE WITH EVOLVING COMPONENT CONDITIONS: A PAVEMENT NETWORK APPLICATION

This thesis deals with quantifying the resilience of a network of pavements. Calculations were carried out by modeling network performance under a set of possible damage-meteorological scenarios with known probability of occurrence. Resilience evaluation was performed a priori while accounting for optimal preparedness decisions and additional response actions that can be taken under each of the scenarios. Unlike the common assumption that the pre-event condition of all system components is uniform, fixed, and pristine, component condition evolution was incorporated herein. For this purpose, the health of the individual system components immediately prior to hazard event impact, under all considered scenarios, was associated with a serviceability rating. This rating was projected to reflect both natural deterioration and any intermittent improvements due to maintenance. The scheme was demonstrated for a hypothetical case study involving Laguardia Airport. Results show that resilience can be impacted by the condition of the infrastructure elements, their natural deterioration processes, and prevailing maintenance plans. The findings imply that, in general, upper bound values are reported in ordinary resilience work, and that including evolving component conditions is of value

Modeling the Truck Appointment System as a Multi-Player Game

Background: Random truck arrivals at maritime container terminals are one of the primary reasons for gate congestion. Gate congestion negatively affects the terminal’s and drayage firms’ productivity and the surrounding communities in terms of air pollution and noise. To alleviate gate congestion, more and more terminals in the USA are utilizing a truck appointment system (TAS). Methods: This paper proposes a novel approach to modeling the truck appointment system problem. Unlike previous studies which largely treated this problem as a single-player game, this study explicitly models the interplay between the terminal and drayage firms with regard to appointments. A multi-player bi-level programming model is proposed, where the terminal functions as the leader at the upper-level and the drayage firms function as followers at the lower-level. The objective of the leader (the terminal) is to minimize the gate waiting cost of trucks by spreading out the truck arrivals, and the objective of the followers (drayage firms) is to minimize their own drayage cost. To make the model tractable, the bi-level model is transformed to a single-level problem by replacing the lower-level problem with its equivalent Karush–Kuhn–Tucker (KKT) conditions and the model is solved by finding the Stackelberg equilibrium in one-shot simultaneous-moves among players. For comparison purposes, a single-player version of the TAS model is also developed. Results: Experimental results indicate that the proposed multi-player model yields a lower gate-waiting cost compared to the single-player model, and that it yields higher cost savings for the drayage firms as the number of appointments per truck increases. Moreover, the solution of the multi-player model is not dependent on the objective function coefficients, unlike the single player model. Conclusions: This study demonstrates that a TAS is more effective if it considers how the assigned appointment slot affects a truck’s drayage cost. It is recommended that terminal operators and port authorities initiate conversations with their TAS providers about incorporating this element into their TAS

Sustainable waste disposal technology selection: the stratified best-worst multi-criteria decision-making method

Waste disposal technology selection is a key problem in the field of municipal solid waste (MSW). This decision may have long-term impacts on environmental development and economic growth. The literature suggests using multi-criteria decision-making (MCDM) methods to address this problem. MCDM techniques commonly require decision makers to assign weightings of importance to the decision criteria based on which, the available technologies are ranked. However, this technology selection problem is concerned with selecting a technology to be used for a relatively long period of time. It is important to take into consideration any uncertainty the decision maker may have with regard to the weightings of the criteria in the future. To take this uncertainty into consideration, this study suggests utilizing a recently developed MCDM technique, namely the stratified MCDM. This technique is designed to help decision makers structure the uncertain future through the consideration of a set of states, which are placed in different strata. The paper shows how the stratified MCDM technique in combination with the best-worst method (labelled stratified BWM) can be employed to compute the ranking of the available technologies. This research is expected to stimulate future applications of the stratified BWM to facilitate long-term decision making

Comparing the outcomes of open surgical procedure and percutaneously peritoneal dialysis catheter (PDC) insertion using laparoscopic needle: A two month follow-up study

Background: This study was performed to compare the outcomes of open surgical procedure and percutaneously peritoneal dialysis catheter (PDC) insertion using laparoscopic needle. Methods: This randomized clinical trial study was conducted in the Nephrology Department in Noor Hospital, Isfahan, Iran between 2009 and 2010. 64 uremic patients were randomized into two study groups using random allocation software. Thirty four catheters were inserted percutaneously (P group) and 30 catheters were placed surgically (S group). Collected information included demographic data, body mass index, and cause of renal disease, duration of operation and length of hospitalization. Outcomes were considered as mechanical and infectious complications. Results: There were no significant differences in age, gender, the mean of body mass index, having history of hemodialysis, diabetes mellitus, hypertension, ischemic heart disease, and length of hospitalization. Hemopenitoneom was more frequent in S group than P group (13.3% versus 3.2%; p < 0.0001). There was no significant difference between two groups in early peritonitis, early leakage, hernia, hollow viscous perforation, catheter obstruction, and malpositioning and the time of peritoneal dialysis onset. Outflow failure and the exit site infection were more frequent in S group than P group (p < 0.0001). Mean of the operative time was longer in S group than P group (27.70 ± 2.79 minutes versus 10.48 ± 1.91 minutes, p < 0.001). Conclusions: Percutaneous catheter insertion has fewer rate of complications and is less time consuming in comparison with surgical method

EFFECT OF FETUIN ON POST-THAWED ARABIAN STALLION SEMEN PARAMETERS

In this study, the effect of fetuin added to INRAFreeze extenders on the freezability of Arabian stallionsemen was investigated. With the help of artificial vagina, semen was taken from stallions. It wasdiluted with INRA96 to remove seminal plasma. After dilution, first 2 ml of MAXIFreeze solutionand then diluted semen were added into a 50 ml falcon tube. The sperm were centrifuged at 3000rpm for 10 minutes. After centrifugation, the supernatant was removed. INRAFreeze was then addedto the centrifuged semen. Sperm were incubated at room temperature for 10 minutes. Then it wasdivided into three equal parts. In the first group, 5 mg/ml fetuin (FET5), in the second group 10 mg/ml fetuin (FET10) and control groups were formed. Sperm were equilibrated at 4oC for 75 minutes.Following equilibration, semen was frozen in 0.50 ml straws in a controlled freezing system (MicroDigitcool, IMV Technologies). Thawing was carried out at 38±2oC for 30 seconds. Mean values ofmotility and other sperm motion parameters (VAP, VSL, VCL, ALH, BCF, STR, LIN, Elongation,Area) were evaluated with computer aided sperm analysis system (Hamilton Thorne Biosciences,IVOS). While there was a statistical difference between the groups in terms of motility (p&lt;0.05),there was no statistical difference between the groups for the mean values of other sperm motionparameters.</p