As we all know that Taiwan is an island surrounded by oceans. Around the island are many international commercial harbors, domestic fishery harbors and harbors for industrial purposes. However, these harbors are facing safety challenges from the strong wind induced waves during monsoon seasons and typhoon due to tropical depressions. The material degradation, fatigue induced from vibrations and the forced deformation of the whole structural system can not usually be observed until serious damages are realized. It is too late to do the fixing job or to replace the damaged components for the harbor while spending multi-million dollars on rebuilding the damaged facilities is the left choice. If we may find the gradual damages of the harbor in advance and establish a procedure to do the minor fixing or correcting works then during the hash environmental situations the serious damages may be prevented and lots of money can be saved also. There are many ways to do a routine inspection on the structures. However, for the structures in the harbor usually it is not quite easy to do this due to the fact that most structures are under the water. Therefore how to find the efficient and economic methods to investigate the harbor damages corresponding to various material constructions and based on the examination results to establish an alert system and to grade the damage-state will be important. The investigation methods may generally be divided into a general method and method of more detailed. The general methods usually need more experiences but less equipment. However, for the more detailed examination, more advanced equipment and scheme are required. After the inspection how to coordinate the raw data and find the relationship between the data and the damage-state of the structure will be one of the tasks. It is the purpose of this project to find efficient means for the inspection and set up a standard procedure to inspect the harbor structures routinely. In terms of the method, timing, schedule, frequency and appropriateness the evaluation standard for the structural damage is suggested and based on the evaluated results the damage grade is defined quantitatively for the harbor structures. Thus the harbor bureau may effectively manage the harbor structure and maintain the operational safety for the harbor.

Abstract Traditional synchronous motion control of a multi-cylinder system was always achieved by using hydraulic loops design and constrained linkage mechanisms. Therefore, these control methodologies always have many disadvantages, such as inaccuracy, cost expensive, and huge volume of the equipment, and so on. In this paper, the nonlinear control strategy was proposed to control the proportional directional valves of two-cylinder electro-hydraulic system in order to achieve synchronous motion under the consideration of unbalanced and uncertainty loading. Besides, in order to explore influence of different loading to the system, two-cylinder mechanism was designed to have individual loading device without any hardware constrain between two pistons. And the maximum loading capacity for one piston is 210kg. Due to the highly complicated coupling effect of internal pressure and flow rate for two cylinders, in this paper, feedforward controller with three fuzzy controllers was designated to overcome the problem of synchronous motion. In the first, the feedforward controller of each cylinder is developed to track a desire velocity trajectory. Then, the fuzzy control of each cylinder was specified to improve the individual tracking performance. Finally, the third fuzzy controller was performed to compensate the coupling effect of two-cylinder in order to progressively improve the performance of synchronous motion. According to the experimental results, the proposed control strategy for synchronous motion of two-cylinder system was verified and the maximum synchronous error of the total system was controlled to be within 10mm. Keyword: synchronous motion; proportional directional valve; fuzzy controller; feedforward controller

<p>Advanced development environments are essential for efficient realization of complex industrial products. Powerful equation-based object-oriented (EOO) languages such as Modelica are successfully used for modeling and virtual prototyping complex physical systems and components. The Modelica language enables engineers to build large, sophisticated and complex models. Modelica environments should scale up and be able to handle these large models. This thesis addresses the scalability of Modelica tools by employing incremental compilation and dynamic loading. The design, implementation and evaluation of this approach is presented. OpenModelica is an open-source Modelica environment developed at PELAB in which we have implemented our strategy for incremental compilation and dynamic loading of functions. We have tested the performance of these strategies in a number of different scenarios in order to see how much of an impact they have on the compilation and execution time.</p><p>Our solution contains an overhead of one or two hash calls during runtime as it uses dynamic hashes instead of static arrays.</p>

One of the major challenges in fracturing low permeability/tight/unconventional gas formations is the loss of frac water and well productivity due to fluid entrapment in the matrix or fracture. Field results have indicated that only 15-30% of the frac fluid is recovered at the surface after flow back is initiated. Past studies have suggested that this water is trapped in the rock matrix near the fracture face and remains trapped due to the high capillary pressure in the matrix. Significant efforts have been made in the past to understand the impact of liquid blocking in hydraulically fractured conventional gas wells. Numerous remediation measures such as huff and puff gas cycling, alcohol or surfactant based chemical treatments have been proposed to reduce fracture face damage. However, when considering hydraulic fractures in unconventional reservoirs horizontal wells, the fluid may also be trapped within the fracture itself and may impact the cleanup as well as productivity. This study shows that under typical gas flow rates in tight / shale gas formations, liquid loading within the fractures is likely to occur. Most of the previous simulation studies consider a 2D reservoir model and ignore gravity, considering the high vertical anisotropy (or extremely low vertical permeability) in these tight reservoirs matrix. However, this study presents the results of 3D simulations of liquid loading in hydraulic fractures in horizontal wells, including gravity and capillary pressure effects. Both CMG IMEX and GEM have been used to study this phenomenon in dry and wet gas cases. The impact of drawdown, fracture and reservoir properties on liquid loading and well productivity is presented. Results show that low drawdown, low matrix permeability or low initial gas rates aggravate the liquid loading problem inside the fracture and thereby impact the cleanup and gas productivity during initial production. A clear understanding of the phenomena could help in selection of optimal production facilities and well profile. / text

Logistics plays a more and more important role in manufacturing company to sharp competitive in today’s supply chain integration. As the end of logistics in manufacturer, container loading intellectualization has attracted more and more focuses. Harmonious coordination between planning and execution ground high performance of the container loading. Several challenges exist in business operations. Firstly, container loading planning is time-consuming. Several case-based constraints exist in the optimization defined by different customers and the Customs. Secondly, execution driven by container loading is inefficient. Operators may use unclear or unreadable paper-based guidance during execution which is inconvenient to handle. Besides, due to various situations, shipping documentations are complex. Afterwards Order-picking, a critical part in executions, is a costly activity. Thirdly, coordination during whole container loading process is another challenge. Information sharing between planning and execution is delayed and inaccurate. The whole procedure usually cannot be monitored by managers in a remote office. Problems cannot be addressed without timely provision of data. This research targets to establish a smart container loading platform based on real life practices and constraints. Unlike common warehouse operation, warehouse executions are driven by container loading. To overcome the challenges, an integrated solution is proposed with three main parts. The first one is to establish RFID-enabled real-time smart environment where device-level data is collected timely with bidirectional communications under Wi-Fi occasionally connected situation. Secondly, Service-oriented Architecture (SOA) is applied in rule-based computation and heterogeneous information sources integration. In rule-based computation, constraint is computed and wrapped as rule. It is a kind of service which is restored in service repository according to its properties. Under different cases, several rules are addressed and invoked in a specified sequence to realize different business logics. And the platform should communicate with heterogeneous sources within short time. Systems wrap application programming interfaces (API) as web services which can be invoked flexibly at any time. Data fetch process is divided into several threads which extract data concurrently. Thirdly, container loading optimal model is provided based on practical constraints. Based on various rules, shipments are clustered as groups before loading. To load containers more equally, heuristic algorithm is provided with reducing container capacity continuously until other constraints are violated or more shipment groups are separated. Four contributions have been made in this study. Firstly, a five-layer system architecture is proposed for small and medium enterprises (SMEs) applications especially in occasionally connected network environment, rule-based computations, and efficient data exchanges. Secondly, several practical constraints of loading planning are addressed and a heuristic algorithm is designed. Shipments can be equally loaded while satisfying most conflicted constraints. Thirdly, a solution for auto-ID enabled warehouse execution is provided. The solution is driven by container loading equipped with real-time information capturing and processing. Fourthly, a guidance can be refereed for real life implementations in SME. The guidance summarizes system customization procedures with reengineered resources. / published_or_final_version / Industrial and Manufacturing Systems Engineering / Master / Master of Philosophy

A suite of models were integrated to predict the potential of a large liquid hydrocarbon storage tank fire escalating and involving neighbouring tanks, as a result of thermal loading. A steady state pool fire radiant heat model was combined with a further model, in order to predict the distribution of thermal loading over the surface of an adjacent tank, and another model was incorporated to predict the thermal response of the contents of the adjacent tank. In order to predict if, or when, an adjacent tank will ignite, the radiant heat from the fire received by the adjacent tank must be quantified. There are a range of mathematical models available in the literature to calculate the radiant heat flux to a specified target and each of these models is based on assumptions about the fire. The performance of three of these models, which vary in complication, was analysed (the single point source model, the solid flame model and the fire dynamics simulator computational fluid dynamics model) and, in order to determine the performance of each model, the predictions made by each of the models were compared with actual experimental measurements of radiant heat flux. Experiments were undertaken involving different liquid fuels and under a range of weather conditions and, upon comparing the predictions of the models with the experimental measurements, the solid flame model was found to be the one most appropriate for safety assessment work. Thus, the solid flame model was incorporated into the thermal loading model, in order to predict the distribution of radiant heat flux falling onto an adjacent tank wall and roof. A model was developed to predict the thermal response of the contents of an adjacent tank, in order to predict variations in the liquid and vapour temperature, any increase in the vapour space pressure and the evolution of the vapours within the given time and the distribution of thermal loading over the surface of the tank as predicted by previous models; of particular importance was the identification of the possibility of forming a flammable vapour/air mixture outside the adjacent tank. To assess the performance of the response model, experiments were undertaken at both laboratory and field scale. The laboratory experiments were conducted in the Chemical Engineering Laboratory at Loughborough University and required the design and construction of an experimental facility representing a small-scale storage tank exposed to an adjacent fire. The field scale experiments were undertaken at Centro Jovellanos, Asturias, Spain. An experimental vessel was designed and fabricated specifically to conduct the laboratory tests and to measure the response of a tank containing hydrocarbon liquids to an external heat load. The vessel was instrumented with a network of thermocouples and pressure transmitter and gauge, in order to monitor the internal pressure and distribution in temperature throughout the liquid and its variation with time. The model predicting the thermal response of an adjacent tank was shown to produce predictions that correlated with the experimental results, particularly in terms of the vapour space pressure and liquid surface temperature. The vapour space pressure is important in predicting the time when the vacuum/pressure valve opens, while the liquid surface temperature is important as it governs the rate of evaporation. Combining the three models (the Pool Fire model, the Thermal Loading model and the Response model) forms the basis of the storage tanks spacing international codes and presents a number of innovative features, in terms of assessing the response to an adjacent tank fire: such features include predicting the distribution of thermal load on tanks adjacent to the tank on fire and thermal load on the ground. These models can predict the time required for the opening of the pressure vacuum relief valve on adjacent tanks and the release of the flammable vapour/air mixture into the atmosphere. A wide range of design and fire protection alternatives, such as the water cooling system and the minimum separation distance between storage tanks, can be assessed using these models. The subsequent results will help to identify any recommended improvements in the design of facilities and management systems (inspection and maintenance), in addition to the fire fighting response to such fires.

A finite element analysis approach is used to determine the susceptibility to wrinkles for thin sheets with clamped ends when subjected to tensile loading. The model problem chosen to do this analysis is the stretching of a thin sheet with clamped-ends. In the preliminary analysis, a stress analysis of thin sheets is done to study the stresses that develop under these boundary conditions. The analysis shows that there is a stretch-induced compressive stress in the transverse direction to the applied load that causes wrinkles. Then, the parametric study is conducted to determine the effect of aspect ratio and strain on the compressive stress. Based on the results of the parametric study, a critical strain value for each aspect ratio is determined for which the corresponding compressive stress is zero. Further buckling analysis is performed to find the buckling modes of the model problem that shows a limit of aspect ratio below which buckling is not possible under given conditions. Finally, post-buckling analysis shows the nature of wrinkles observed in the model problem for different aspect ratios. / text

Το θέμα της παρούσας εργασίας αφορά την αποτίμηση της απόκρισης των τοιχοπληρωμένων πλαισίων οπλισμένου σκυροδέματος, έναν τομέα που έχει απασχολήσει πληθώρα ερευνητών τις τελευταίες δεκαετίες. Παρότι έχουν προταθεί πολλές διαφορετικές λύσεις για την προσομοίωση των τοιχοπληρώσεων, δεν έχει ακόμη προκύψει ένα ενιαίο και αξιόπιστο προσομοίωμα ικανό να αναπαραστήσει με ακρίβεια τα διαφορετικά χαρακτηριστικά της απόκρισης που εμφανίζονται κατά περίπτωση. Στην παρούσα εργασία προτείνεται ένα νέο απλοποιητικό προσομοίωμα για την ανάλυση των τοιχοπληρώσεων μετά την τροποποίηση του υπάρχοντος προσομοιώματος των Crisafulli and Carr (2007) και διερευνάται η εφαρμογή και η κατάλληλη βαθμονόμηση του για την ανελαστική ανάλυση τοιχοπληρωμένων πλαισίων οπλισμένου σκυροδέματος υπό την δράση πλευρικών ανακυκλιζόμενων φορτίων. Στο προτεινόμενο προσομοίωμα συνδυάζονται μία σειρά από μέλη/ελατήρια προκειμένου να ληφθούν υπόψη ανεξάρτητα η συμπεριφορά της τοιχοπλήρωσης σε διαγώνια θλίψη και διάτμηση. Η αξιοπιστία του προσομοιώματος επαληθεύεται με διαθέσιμα πειραματικά δεδομένα σε τοιχοπληρωμένα πλαίσια, επιδεικνύοντας ικανοποιητικό βαθμό συμφωνίας. Η πολυπλοκότητα των προσομοιωμάτων των τοιχοπληρώσεων έγκειται στην πληθώρα των παραμέτρων που απαιτούνται για τον ορισμό τους. Για το λόγο αυτό η αριθμητική εφαρμογή του προσομοιώματος συνοδεύεται από μία εκτεταμένη παραμετρική μελέτη που στοχεύει στην διερεύνηση της ευαισθησίας του προσομοιώματος σε κάθε μία από τις παραμέτρους που υπεισέρχονται στον ορισμό του επιτρέποντας εν τέλει την ταυτοποίηση των κρίσιμων ποσοτήτων και την καθοδήγηση του μέλλοντα χρήστη σχετικά με την επιλογή τους. / The assessment of the response of masonry infilled RC frame structures has been a major challenge over the last decades. While several modeling approaches have been proposed, none can cover all aspects observed in the tests. The present paper introduces a simplified model built on the approach established by Crisafulli and Carr (2007) and addresses its calibration and implementation in a nonlinear analysis software for the evaluation of the in-plane lateral response of infilled RC frames. The proposed model uses a set of elements/springs to account separately for the compressive and shear behavior of masonry. The efficiency of the modeling approach is validated with available experimental data, yielding satisfactory matching. The most intricate issue encountered when attempting to represent a masonry panel is the plethora of the material parameters involved and the lack of complete and available test results. Thus, the numerical investigation is accompanied by a parametric study on the sensitivity of the model to the various parameters to identify the critical modeling quantities and provide guidance on their selection.

In the final major degrees project was investigated the efficiency of loading equipment working in cargo terminals. In the beginning of project was simulated the methodology of loading equipment efficiency investigation and using it were analyzed container and metal store as terminal activity. Loading equipment working in container terminal were investigated using the theory of massive service. Also in the project were used economical and quantitative methods of management for detailed known of investigation object. In the investigation time of company AB “Lietuvos geležinkeliai“ were checked the few last years data of results in reloading works. Also in the project was investigated metal stores as cargo terminal modernization expedience, which was reasoned by calculations of productivity and according it was formulated the investment project for cranes and were given suggestions and conclusions. The main purposes of this project were to create methodology of loading equipment efficiency investigation and to analyze the expedience of loading equipment working in some Lithuanian metal stores.

A static phosphorus loading model, as proposed by G.K. Nurnberg (1998, Limnology and Oceanography, 43, 1544-1552) is applied to Langford Lake, BC to determine the likely sources of phosphorus entering the lake and to predict the consequences of further urbanizing the watershed. Export coefficients are calibrated to local conditions by assuming that the phosphorus concentration of the epilimnion during the spring and early summer is explained by only external loading. Internal loading amounts, as quantified by examining the lake's phosphorus profile, are compared against estimates derived from sediment analysis. Internal loading is determined to be the largest contributor of phosphorus to the lake (69%), while septic fields are the greatest external contributor (10%). It is found that the anticipated increase in the phosphorus load, resulting from urban expansion, can be largely offset by removing the remaining septic fields within the watershed and using low-impact design features in all new developments.