Production improvement in ACM manufacturing company using lean manufacturing approach

ACM Sdn. Bhd. is a manufacturing company, in which to continuously commit on improvement process which based on the fundamental goal, to minimize or eliminate waste while maximizing production flow. The purpose of this study is to develop a value stream mapping for a ACM Sdn. Bhd. and it was begin with creating a current state map and understand the production flow and the current cycle times. This provides the information needed to produce a future state map. The goal is to identify and eliminate the waste, which is any activity that does not add value to the final product, in the production process. In order to collect the information needed, the study was conducted within the production facility to enable the researcher gained knowledge and familiarized with the production flow and the activities being performed at the shop floor. Parameters such as cycle times, down times, work in process (WIP) for inventory and material, and information flow paths were recorded. This information will enable the researcher to visualize the current state of the process activities by mapping the material and information flow and looking for opportunities to eliminate wastes. ARENA simulation software package was used to simulate and analyze the process flow and times. Result from the analysis shows that there are areas where the ACM Sdn. Bhd. can further improve their production system. Improvements in cycle times of 13-22% are possible by new arrangement of the layout. The results can be used as a guide to the ACM for improvement and implement the lean manufacturing concept in their manufacturing system

RNA polyhedrojen algoritminen suunnittelu

The field of bottom-up nanotechnology has been the subject of much research in the recent years. Most of that research has focused on creating nano-scale shapes and structures using multiple strands. DNA origamis and various tile-based schemes are perhaps the most famous examples. No such robust design schemes exist for the design of single stranded RNA structures, however, despite their potential to offer a cheap and sound approach to nanomanufacturing. In this thesis, we study the problem of designing single-stranded RNA polyhedral wireframes, i.e., such RNA strands that fold into the wireframe of a given polyhedron. We introduce a kissing-loop based design scheme, which routes an RNA strand around a spanning tree of a polyhedron, and we show how to do the routing on arbitrary polyhedra while avoiding knots. We also introduce a design tool, Sterna, which is based on these principles. It allows the user to convert a 3D model of a polyhedron into an RNA secondary and tertiary structures, which can be further developed into a primary structure with the additional scripts we have provided. Finally, we design three RNA polyhedra, which are synthesized and imaged in a project related to this master's thesis. The resulting images lend credence to the soundness of Sterna and the underlying design process.Yksi koostavan (engl. bottom-up) nanoteknologian keskeisiä tutkimusalueita viime vuosina on ollut DNA-nanoteknologia, so. nanokokoisten kappaleiden ja rakennelmien tuottaminen biopolymeereistä. Niinsanotut DNA-origamit ja -laatoitukset ovat tämän lähestymistavan tunnetuimpia esimerkkejä. Vastaavaa yleistä menetelmää ei toistaiseksi ole ollut nanorakenteiden tuottamiseen yksisäikeisistä RNA-polymeereistä, vaikka nämä periaatteessa tarjoaisivat edullisen ja skaalautuvan lähtökohdan nanovalmistukselle. Tässä diplomityössä tarkastelemme 3D-monitahokkaiden rautalankamallien laskostamista yksisäikeisistä RNA-polymeereistä. Kehitämme automatisoidun suunnitteluprosessin, joka tuottaa syötteenä annettua monitahokasta vastaavaan muotoon laskostuvan RNA-emästen jonon. Käyttämämme menetelmä perustuu RNA-säikeen reitittämiseen monitahokkaan virittävän puun ympäri ja rakenteen sulkemiseen ns. silmukkapareilla (engl. kissing loop motif). Esitämme myös, miten mielivaltaisen monitahokkaan virittävä puu on mahdollista reitittää tuottamatta topologisia solmuja, jotka estäisivät vastaavan RNA-polymeerin laskostumisen. Toteuttamamme Sterna-suunnitteluohjelman avulla käyttäjä voi tuottaa mistä tahansa 3D-monitahokasmallista sen muotoon laskostuvan RNA-jonon sekundääri- ja tertiäärirakennekuvaukset. Tarjoamme myös ohjelman, jonka avulla nämä voidaan edelleen täydentää emästiedoilla biosynteesiä varten tarvittavaksi RNA-primäärirakenteeksi. Käyttöesimerkkeinä suunnittelemme kolme RNA-monitahokasta, jotka on syntetisoitu ja kuvannettu tämän diplomityön kumppanihankkeissa. Saadut tulokset todentavat suunnittelumenetelmämme ja siihen pohjautuvan Sterna-työkalun oikeellisuutta

Doctor of Philosophy

dissertationRecent advancements in mobile devices - such as Global Positioning System (GPS), cellular phones, car navigation system, and radio-frequency identification (RFID) - have greatly influenced the nature and volume of data about individual-based movement in space and time. Due to the prevalence of mobile devices, vast amounts of mobile objects data are being produced and stored in databases, overwhelming the capacity of traditional spatial analytical methods. There is a growing need for discovering unexpected patterns, trends, and relationships that are hidden in the massive mobile objects data. Geographic visualization (GVis) and knowledge discovery in databases (KDD) are two major research fields that are associated with knowledge discovery and construction. Their major research challenges are the integration of GVis and KDD, enhancing the ability to handle large volume mobile objects data, and high interactivity between the computer and users of GVis and KDD tools. This dissertation proposes a visualization toolkit to enable highly interactive visual data exploration for mobile objects datasets. Vector algebraic representation and online analytical processing (OLAP) are utilized for managing and querying the mobile object data to accomplish high interactivity of the visualization tool. In addition, reconstructing trajectories at user-defined levels of temporal granularity with time aggregation methods allows exploration of the individual objects at different levels of movement generality. At a given level of generality, individual paths can be combined into synthetic summary paths based on three similarity measures, namely, locational similarity, directional similarity, and geometric similarity functions. A visualization toolkit based on the space-time cube concept exploits these functionalities to create a user-interactive environment for exploring mobile objects data. Furthermore, the characteristics of visualized trajectories are exported to be utilized for data mining, which leads to the integration of GVis and KDD. Case studies using three movement datasets (personal travel data survey in Lexington, Kentucky, wild chicken movement data in Thailand, and self-tracking data in Utah) demonstrate the potential of the system to extract meaningful patterns from the otherwise difficult to comprehend collections of space-time trajectories

Continuum mechanics and implicit material point method to underpin the modelling of drag anchors for cable risk assessment

The last years have seen an extraordinary expansion of the wind offshore industry towards new markets. With this development, wind farms are being pushed further offshore, leading to new challenges in maintaining their infrastructures. Data have revealed that one of the assets most susceptible to risks are power cables transporting the electricity generated offshore to the onshore transmission system. Whenever there is no alternative to shielding the cables, these are buried in the seabed to ward off the threat of drag anchors. Understanding the embedment process of drag anchors deployed by ships for mooring purposes is critical to determining the appropriate burial depth of cables. In turn, this protection strategy must include the influence exerted by the seabed conditions. Historically, studies have focused on lab and field tests, whose results have been recently called into question. The lack of an appropriate scientific tool to investigate the anchor cable interaction has recently fostered this process examination via numerical methods. Among these, the Material Point Method (MPM) is well-placed to master large deformation mechanics without mesh distortion and retains all of the advantages of a Lagrangian method. As a matter of fact, the MPM is the main object of investigation of this thesis, whose ultimate goal is to: 1. include inertia forces in the context of finite strain elasto-plasticity for solid materials; 2. expand the above point to handle the presence of water in the porous seabed; and 3. model the friction between the anchor and the surrounding soil. This work has dedicated particular attention to the compliance of the MPM discretised algorithms with the underlying continuum formulation. In this sense, this work’s primary contributions comprise: • a conservation law consistent MPM algorithm for solid mechanics; • a constitutive relationship for porous materials respectful of the solid mass conservation; and • a rigorous assessment of the frictional contact formulations available in the MPM literature

Deeply subducted continental fragments - Part 2: Insight from petrochronology in the central Sesia Zone (western Italian Alps)

Subducted continental terranes commonly comprise an assembly of subunits that reflect the different tectono-metamorphic histories they experienced in the subduction zone. Our challenge is to unravel how, when, and in which part of the subduction zone these subunits were juxtaposed. Petrochronology offers powerful tools to decipher pressure–temperature–time (P–T–t) histories of metamorphic rocks that preserve a record of several stages of transformation. A major issue is that the driving forces for re-equilibration at high pressure are not well understood. For example, continental granulite terrains subducted to mantle depths frequently show only partial and localized eclogitization. The Sesia Zone (NW Italy) is exceptional because it comprises several continental subunits in which eclogitic rocks predominate and high-pressure (HP) assemblages almost completely replaced the Permian granulite protoliths. This field-based study comprises both main complexes of the Sesia terrane, covering some of the recently recognized tectonic subunits involved in its assembly; hence our data constrain the HP tectonics that formed the Sesia Zone. We used a petrochronological approach consisting of petrographic and microstructural analysis linked with thermodynamic modelling and U–Th–Pb age dating to reconstruct the P–T–t trajectories of these tectonic subunits. Our study documents when and under what conditions re-equilibration took place. Results constrain the main stages of mineral growth and deformation, associated with fluid influx that occurred in the subduction channel. In the Internal Complex (IC), pulses of fluid percolated at eclogite facies conditions between 77 and 55 Ma with the HP conditions reaching  ∼  2 GPa and 600–670 °C. By contrast, the External Complex (EC) records a lower pressure peak of  ∼  0.8 GPa for 500 °C at  ∼  63 Ma. The juxtaposition of the two complexes occurred during exhumation, probably at  ∼  0.8 GPa and 350 °C; the timing is constrained between 46 and 38 Ma. Mean vertical exhumation velocities are constrained between 0.9 and 5.1 mm year−1 for the IC, up to its juxtaposition with the EC. Exhumation to the surface occurred before 32 Ma, as constrained by the overlying Biella Volcanic Suite, at a mean vertical velocity between 1.6 and 4 mm year−1. These findings constrain the processes responsible for the assembly and exhumation of HP continental subunits, thus adding to our understanding of how continental terranes behave during subduction

Computing Volumes and Convex Hulls: Variations and Extensions

Geometric techniques are frequently utilized to analyze and reason about multi-dimensional data. When confronted with large quantities of such data, simplifying geometric statistics or summaries are often a necessary first step. In this thesis, we make contributions to two such fundamental concepts of computational geometry: Klee's Measure and Convex Hulls. The former is concerned with computing the total volume occupied by a set of overlapping rectangular boxes in d-dimensional space, while the latter is concerned with identifying extreme vertices in a multi-dimensional set of points. Both problems are frequently used to analyze optimal solutions to multi-objective optimization problems: a variant of Klee's problem called the Hypervolume Indicator gives a quantitative measure for the quality of a discrete Pareto Optimal set, while the Convex Hull represents the subset of solutions that are optimal with respect to at least one linear optimization function.In the first part of the thesis, we investigate several practical and natural variations of Klee's Measure Problem. We develop a specialized algorithm for a specific case of Klee's problem called the “grounded” case, which also solves the Hypervolume Indicator problem faster than any earlier solution for certain dimensions. Next, we extend Klee's problem to an uncertainty setting where the existence of the input boxes are defined probabilistically, and study computing the expectation of the volume. Additionally, we develop efficient algorithms for a discrete version of the problem, where the volume of a box is redefined to be the cardinality of its overlap with a given point set.The second part of the thesis investigates the convex hull problem on uncertain input. To this extent, we examine two probabilistic uncertainty models for point sets. The first model incorporates uncertainty in the existence of the input points. The second model extends the first one by incorporating locational uncertainty. For both models, we study the problem of computing the probability that a given point is contained in the convex hull of the uncertain points. We also consider the problem of finding the most likely convex hull, i.e., the mode of the convex hull random variable

Data-Driven Methods to Build Robust Legged Robots

For robots to ever achieve signicant autonomy, they need to be able to mitigate performance loss due to uncertainty, typically from a novel environment or morphological variation of their bodies. Legged robots, with their complex dynamics, are particularly challenging to control with principled theory. Hybrid events, uncertainty, and high dimension are all confounding factors for direct analysis of models. On the other hand, direct data-driven methods have proven to be equally dicult to employ. The high dimension and mechanical complexity of legged robots have proven challenging for hardware-in-the-loop strategies to exploit without signicant eort by human operators. We advocate that we can exploit both perspectives by capitalizing on qualitative features of mathematical models applicable to legged robots, and use that knowledge to strongly inform data-driven methods. We show that the existence of these simple structures can greatly facilitate robust design of legged robots from a data-driven perspective. We begin by demonstrating that the factorial complexity of hybrid models can be elegantly resolved with computationally tractable algorithms, and establish that a novel form of distributed control is predicted. We then continue by demonstrating that a relaxed version of the famous templates and anchors hypothesis can be used to encode performance objectives in a highly redundant way, allowing robots that have suffered damage to autonomously compensate. We conclude with a deadbeat stabilization result that is quite general, and can be determined without equations of motion.PHDElectrical Engineering: SystemsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/155053/1/gcouncil_1.pd

Structural and Geochronological Investigations into Mid-Crustal Shear Zones, Shetland, Scottish Caledonides

Strain in the lithosphere localises into weakened regions known as shear zones, which are often sites of repeated reactivation, reworking and poly-metamorphism. Mature shear zones are composite areas that include spatially and temporally heterogeneous combinations of coaxial and non-coaxial deformation, such as transpression and transtension. Due to their heterogeneous nature, determining the structural evolution and regional significance of shear zones is challenging. Such areas of ductile deformation are associated with the SE-dipping North Roe Nappe and the N-S striking Walls Boundary Fault (WBF) on NW Mainland Shetland. Here, the metamorphic basement and bounding strike-slip WBF provide pre-Permian geological links between the Scottish, Norwegian and Greenland sectors of the Caledonian orogen. Field mapping, microstructural characterisation and Rb-Sr geochronology in combination with other published work in the area show that NW Mainland Shetland was subject to Neoarchaean (c. 2800 – 2700 Ma), Neoproterozoic (827 Ma – 697 Ma) and Caledonian (487 – 404 Ma) deformation. Weakly-defined Neoarchaean deformation is preserved in the structurally lowest sections of the Uyea Gneiss Complex below the North Roe Nappe. Within the North Roe Nappe, Neoproterozoic deformation is mainly found in coaxially-deformed decimetre-scale horizons. The main ductile fabrics found on NW Mainland Shetland formed during top-to-the NW thrusting and top-to-the N/sinistral shearing, dated to be broadly Caledonian in age. Bounding the coaxially-deformed Neoproterozoic horizons are decimetre-scale horizons of non-coaxial top-to-the W thrusting and NNE-SSW sinistral shearing interleaved with antithetic top-to-the E extensional and NNE-SSW dextral shears. Due to a lack of overprinting evidence and overlapping geochronological ages, non-coaxial deformation in the North Roe Nappe is interpreted to have developed broadly coevally during the Caledonian (c. 440-404 Ma). The results from this study suggest that Shetland was subject to inclined transpression during the Caledonian (Grampian-Scandian) orogeny. During transpression, Neoproterozoic material was locally vertically and laterally extruded along foliation-parallel channels in unconfined transpression. As Caledonian deformation is observed throughout NW Mainland Shetland, the westernmost limit of Caledonian deformation and the northern continuation of the Moine Thrust is either obscured by post-Caledonian brittle faults or lies offshore to the west of Shetland. Post-Caledonian dextral reactivation of the WBF resulted in localised strain being focused into bedding-parallel and fold limb-parallel shears. This study highlights the importance of combining field, microstructural and geochronological data in determining the structural evolution of reactivated, transpressional shear zones