Parallel Assembly Research Articles

APPROACHES TO THE DESIGN OF A PLANAR PARALLEL MANIPULATOR

Manipulator is an important part of a whole robot assembly, forming the mechanical infrastructure of a mechatronic system. Selection of the manipulator affects a broad area extending from modelling to design, from control to operation and furthermore from accuracy to its economy. This study aimed methods of design and operation of a parallel planar robotic assembly have been demonstrated. Modules of the assembly with two degrees of freedom have been designed on a twopoint, two-velocity and three point-position bases. Ways of actuating and controlling the motion of the assembly have been shown. Efficiency and effectiveness of the approaches have been illustrated numerically

Balancing stochastic parallel assembly lines

In industrial systems, efficient design of production units is important for productivity. An assembly line is a special type of industrial systems, and it has been widely used in various manufacturing industries. One possible way to achieve high efficiency in an assembly line design is to use two or more assembly lines, referred to as parallel assembly lines. Additionally, the occurrence of random events in industrial systems is inevitable. Among these random events that disturb the production process are operator unavailability, technical failures in the production line, loss of motivation, lack of training, non-qualified operators, complex tasks, etc. So, it is more realistic to consider industrial systems as stochastic context rather than deterministic one. For this purpose, in this paper, the problem of balancing parallel assembly lines with stochastic task times (SPALBP) is introduced and characterised for the first time. A chance-constrained, piecewise-linear, mixed integer programming (CPMIP) formulation and a tabu search (TS) algorithm are proposed to model and to solve the SPALBP. The objective of CPMIP and TS algorithm is minimizing the number of stations for a given cycle time. A simple lower bound calculation on the number of stations for SPALBP is proposed, and an example problem is solved using the proposed CPMIP. A set of test problems taken from the literature is solved in order to test the proposed TS algorithm, and some computational properties of the proposed solution methodologies are given. The computational results show that the proposed algorithm is very effective and successful for the SPALBP.

Feasibility Study of a Multipole Electromagnet Using a Parallel Iron-Core Structure

This paper presents a design concept of a multipole electromagnet using a parallel iron-core structure. An electromagnet can be used in many types of magnetic study area, such as work on magnetic susceptibility, the Hall effect research, the magneto-optical effect, and in hysteresis measurements. In electromagnets, generally, only a single probe can be used at a time due to the single pole structure, and it is challenging to measure many samples simultaneously. In this paper, a multipole electromagnet is proposed. It has a parallel iron-core structure and a high-temperature superconducting coil, unlike the conventional electromagnet system. The electromagnet with such a structure enables multiple probes to be used simultaneously. To verify the feasibility of the structure, a small-scale multipole electromagnet was designed using commercialized finite element method software. Based on the design results, a parallel iron-core and coil assembly was fabricated and the performance of the magnet was evaluated.

Parallel assembly of actin and tropomyosin, but not myosin II, during de novo actin filament formation in live mice.

Many actin filaments in animal cells are co-polymers of actin and tropomyosin. In many cases, non-muscle myosin II associates with these co-polymers to establish a contractile network. However, the temporal relationship of these three proteins in the de novo assembly of actin filaments is not known. Intravital subcellular microscopy of secretory granule exocytosis allows the visualisation and quantification of the formation of an actin scaffold in real time, with the added advantage that it occurs in a living mammal under physiological conditions. We used this model system to investigate the de novo assembly of actin, tropomyosin Tpm3.1 (a short isoform of TPM3) and myosin IIA (the form of non-muscle myosin II with its heavy chain encoded by Myh9) on secretory granules in mouse salivary glands. Blocking actin polymerization with cytochalasin D revealed that Tpm3.1 assembly is dependent on actin assembly. We used time-lapse imaging to determine the timing of the appearance of the actin filament reporter LifeAct-RFP and of Tpm3.1-mNeonGreen on secretory granules in LifeAct-RFP transgenic, Tpm3.1-mNeonGreen and myosin IIA-GFP (GFP-tagged MYH9) knock-in mice. Our findings are consistent with the addition of tropomyosin to actin filaments shortly after the initiation of actin filament nucleation, followed by myosin IIA recruitment.

X-ray computed tomography comparison of individual and parallel assembled commercial lithium iron phosphate batteries at end of life after high rate cycling

X-ray computed tomography (X-ray CT) across multiple length scales is utilized for the first time to investigate the physical abuse of high C-rate pulsed discharge on cells wired individually and in parallel.. Manufactured lithium iron phosphate cells boasting high rate capability were pulse power tested in both wiring conditions with high discharge currents of 10C for a high number of cycles (up to 1200) until end of life (<80% of initial discharge capacity retained). The parallel assembly reached end of life more rapidly for reasons unknown prior to CT investigations. The investigation revealed evidence of overdischarge in the most degraded cell from the parallel assembly, compared to more traditional failure in the individual cell. The parallel-wired cell exhibited dissolution of copper from the anode current collector and subsequent deposition throughout the separator near the cathode of the cell. This overdischarge-induced copper deposition, notably impossible to confirm with other state of health (SOH) monitoring methods, is diagnosed using CT by rendering the interior current collector without harm or alteration to the active materials. Correlation of CT observations to the electrochemical pulse data from the parallel-wired cells reveals the risk of parallel wiring during high C-rate pulse discharge.

Coupling of Elementary Electronic Excitations: Drawing Parallels Between Excitons and Plasmons.

Recent advances in understanding the theoretical and experimental properties of excitons and plasmons have led to several technological breakthroughs. Though emerging from different schools of research, the parallels they possess both in their isolated and assembled forms are indeed interesting. Employing the larger framework of the dipolar coupling model, these aspects are discussed based on the excitonic transitions in chromophores and plasmonic resonances in noble metal nanostructures. The emergence of novel optical properties in linear, parallel, and helical assemblies of chromophores and nanostructures with varying separation distances, orientations, and interaction strengths of interacting dipolar components is discussed. The very high dipolar strengths of plasmonic transitions compared to the excitonic transitions, arising due to the collective nature of the electronic excitations in nanostructures, leads to the emergence of hot spots in plasmonically coupled assemblies. Correlations on the distance dependence of electric field with Raman signal enhancements have paved the way to the development of capillary tube-based plasmonic platforms for the detection of analytes.

Simulation-based Planning of a Kind of Complex Product General Assembly Line

The assembly process of a kind of complex product consists of many parallel assembly workstations with re-entrant process and resource constraints. The traditional production experience and manual computing has not been able to provide a convincing reference for new production line planning considering capacity analysis, resources allocation and optimization. In this paper, by analyzing the characteristics of this category production line, an assembly system planning method combined with discrete event simulation technology for the product is described to verify and improve the planning scheme. Several scenarios are experimented and compared based on the analysis of line throughput, cycle time, bottlenecks and work-in-process control strategy. The simulation-based planning method provides sufficient data support for design decision-making of the new production line.

SAGE2: parallel human genome assembly.

De novo genome assembly of next-generation sequencing data is a fundamental problem in bioinformatics. There are many programs that assemble small genomes, but very few can assemble whole human genomes. We present a new algorithm for parallel overlap graph construction, which is capable of assembling human genomes and improves upon the current state-of-the-art in genome assembly. SAGE2 is written in C ++ and OpenMP and is freely available (under the GPL 3.0 license) at github.com/lucian-ilie/SAGE2. ilie@uwo.ca. Supplementary data are available at Bioinformatics online.

Laser-assisted selective lithography of reduced graphene oxide for fabrication of graphene-based out-of-plane tandem microsupercapacitors with large capacitance

We present a laser lithography technique that uses a focused laser beam to fabricate out-of-plane tandem microsupercapacitors (MSCs) from reduced graphene oxide (rGO) with large areal capacitance. By controlling the depth of focus in a laser beam focused by an objective lens during laser lithography on a graphene oxide (GO) film, a rGO/GO/rGO structure is formed in the GO film, and subsequently, two independent interdigitated electrodes (IDEs) were fabricated on the top and bottom surfaces of the GO film. The out-of-plane tandem MSC with a parallel assembly of two rGO-IDEs showed two times larger areal capacitance than an in-plane single MSC with one rGO-IDE in the same MSC device footprint. The laser-assisted selective lithography technique using a focused laser beam developed in this study can be further applied to improve the energy density of MSCs without increasing the electrode area by vertically stacking multiple out-of-plane tandem IDEs.

Simultaneous liquid chromatography/mass spectrometry determination of both polar and “multiresidue” pesticides in food using parallel hydrophilic interaction/reversed-phase liquid chromatography and a hybrid sample preparation approach

Pesticide testing of foodstuffs is usually accomplished with generic wide-scope multi-residue methods based on liquid chromatography tandem mass spectrometry (LC–MS/MS). However, this approach does not cover some special pesticides, the so called “single-residue method” compounds, that are hardly compatible with standard reversed-phase (RP) separations due to their specific properties. In this article, we propose a comprehensive strategy for the integration of single residue method compounds and standard multiresidue pesticides within a single run. It is based on the use of a parallel LC column assembly with two different LC gradients performing orthogonal hydrophilic interaction chromatography (HILIC) and reversed-phase (RPLC) chromatography within one analytical run. Two sample aliquots were simultaneously injected on each column, using different gradients, being the eluents merged post-column prior to mass spectrometry detection. The approach was tested with 41 multiclass pesticides covering a wide range of physicochemical properties across several orders of log Kow (from −4 to +5.5). With this assembly, distinct separation from the void was attained for all the pesticides studied, keeping similar performance in terms of sensitivity, peak area reproducibility (<6 RSD% in most cases) and retention time stability of standard single column approaches (better than±0.1min). The application of the proposed approach using parallel HILIC/RPLC and RPLC/aqueous normal phase (Obelisc) were assessed in leek using LC–MS/MS. For this purpose, a hybrid QuEChERS (Quick, easy, cheap, effective, rugged and safe)/QuPPe (quick method for polar pesticides) method was evaluated based on solvent extraction with MeOH and acetonitrile followed by dispersive solid-phase extraction, delivering appropriate recoveries for most of the pesticides included in the study within the log Kow in the range from −4 to +5.5. The proposed strategy may be extended to other fields such as sport drug testing or environmental analysis, where the same type of variety of analytes featuring poor retention within a single chromatographic separation occurs.

Self-Correction Strategy for Precise, Massive, and Parallel Macroscopic Supramolecular Assembly.

Macroscopic supramolecular assembly (MSA) represents a new advancement in supramolecular chemistry involving building blocks with sizes beyond tens of micrometers associating through noncovalent interactions. MSA is established as a unique method to fabricate supramolecularly assembled materials by shortening the length scale between bulk materials and building blocks. However, improving the precise alignment during assembly to form orderly assembled structures remains a challenge. Although the pretreatment of building blocks can ameliorate order to a certain degree, defects or mismatching still exists, which limits the practical applications of MSA. Therefore, an iterative poststrategy is proposed, where self-correction based on dynamic assembly/disassembly is applied to achieve precise, massive, and parallel assembly. The self-correction process consists of two key steps: the identification of poorly ordered structures and the selective correction of these structures. This study develops a diffusion-kinetics-dependent disassembly to well identify the poorly aligned structures and correct these structures through iterations of disassembly/reassembly in a programmed fashion. Finally, a massive and parallel assembly of 100 precise dimers over eight iteration cycles is achieved, thus providing a powerful solution to the problem of processing insensitivity to errors in self-assembly-related methods.

A beam search approach for solving type II robotic parallel assembly line balancing problem

In a robotic assembly line, a series of stations are arranged along a conveyor belt and a robot performs on tasks at each station. Parallel assembly lines can provide improving line balance, productivity and so on. Combining robotic and parallel assembly lines ensure increasing flexibility of system, capacity and decreasing breakdown sensitivity. Although aforementioned benefits, balancing of robotic parallel assembly lines is lacking – to the best knowledge of the authors- in the literature. Therefore, a mathematical model is proposed to define/solve the problem and also iterative beam search (IBS), best search method based on IBS (BIBS) and cutting BIBS (CBIBS) algorithms are presented to solve the large-size problem due to the complexity of the problem. The algorithm also tested on the generated benchmark problems for robotic parallel assembly line balancing problem. The superior performances of the proposed algorithms are verified by using a statistical test. The results show that the algorithms are very competitive and promising tool for further researches in the literature.

3-D Sidewall Interconnect Formation Climbing Over Self-Assembled KGDs for Large-Area Heterogeneous Integration

Massively parallel chip assembly based on multi-interposer block concept is demonstrated for large-area heterogeneous system integration. The chips are aligned in parallel by liquid surface tension and assembled on the Si interposers through oxide-oxide bonding at room temperature without thermocompression. 3-D Cu sidewall interconnects (the width is approximately $20~\mu \text{m}$ ) climbing over 100- $\mu \text{m}$ -thick self-assembled chips are formed with a spin-on thick photoresist by electroplating. In addition, 3-D Cu interconnects with a width of nearly $10~\mu \text{m}$ are successfully formed across polyimide slopes formed on the sidewall of self-assembled chips. The electrical properties of the 3-D sidewall interconnects are characterized by the daisy chains, resistance distribution, and characteristic fluctuation of CMOS fabricated on the self-assembled chips.

Large-scale parallel genome assembler over cloud computing environment.

The size of high throughput DNA sequencing data has already reached the terabyte scale. To manage this huge volume of data, many downstream sequencing applications started using locality-based computing over different cloud infrastructures to take advantage of elastic (pay as you go) resources at a lower cost. However, the locality-based programming model (e.g. MapReduce) is relatively new. Consequently, developing scalable data-intensive bioinformatics applications using this model and understanding the hardware environment that these applications require for good performance, both require further research. In this paper, we present a de Bruijn graph oriented Parallel Giraph-based Genome Assembler (GiGA), as well as the hardware platform required for its optimal performance. GiGA uses the power of Hadoop (MapReduce) and Giraph (large-scale graph analysis) to achieve high scalability over hundreds of compute nodes by collocating the computation and data. GiGA achieves significantly higher scalability with competitive assembly quality compared to contemporary parallel assemblers (e.g. ABySS and Contrail) over traditional HPC cluster. Moreover, we show that the performance of GiGA is significantly improved by using an SSD-based private cloud infrastructure over traditional HPC cluster. We observe that the performance of GiGA on 256 cores of this SSD-based cloud infrastructure closely matches that of 512 cores of traditional HPC cluster.

Dynamic Sub-10-nm Nanostructured Ultrathin Films of Sugar-Polyolefin Conjugates Thermoresponsive at Physiological Temperatures.

Spin-casting of a cellobiose-atactic polypropene (CB-aPP) conjugate (1) from a 0.1% (w/w) n-butanol/hexane solution onto highly oriented pyrolytic graphite (HOPG) and carbon-coated Si(100) spontaneously produced microphase-separated sub-10-nm nanostructured ultrathin films in the form of alternating CB and aPP lamellar domains (d = 6.60 ± 0.68 nm) that are oriented perpendicular to the substrate surface. Thermal annealing at modest temperatures (e.g., 50-100 °C), and as low as the physiologically relevant temperature of 38 °C, serves to drive a structural transition that yields a parallel stacked bilayer assembly as the thermodynamically favored nanostructure. These results establish the advantage of low molecular weight, narrow polydispersity, and amorphous, low Tg, poly(α-olefinate)s (xPAOs) as a new class of hydrophobic building block for amphiphilic materials, and sugar-PAO conjugates in particular, for the development of stimuli-responsive, nanostructured materials for technological applications at physiological temperatures.

Boundary element quadrature schemes for multi- and many-core architectures

In the paper we study the performance of the regularized boundary element quadrature routines implemented in the BEM4I library developed by the authors. Apart from the results obtained on the classical multi-core architecture represented by the Intel Xeon processors we concentrate on the portability of the code to the many-core family Intel Xeon Phi. Contrary to the GP-GPU programming accelerating many scientific codes, the standard x86 architecture of the Xeon Phi processors allows to reuse the already existing multi-core implementation. Although in many cases a simple recompilation would lead to an inefficient utilization of the Xeon Phi, the effort invested in the optimization usually leads to a better performance on the multi-core Xeon processors as well. This makes the Xeon Phi an interesting platform for scientists developing a software library aimed at both modern portable PCs and high performance computing environments. Here we focus at the manually vectorized assembly of the local element contributions and the parallel assembly of the global matrices on shared memory systems. Due to the quadratic complexity of the standard assembly we also present an assembly sparsified by the adaptive cross approximation based on the same acceleration techniques. The numerical results performed on the Xeon multi-core processor and two generations of the Xeon Phi many-core platform validate the proposed implementation and highlight the importance of vectorization necessary to exploit the features of modern hardware.

Interconnection between Parallel Assembly Pathways in Large Ribosome Subunit Biogenesis

Interconnection between Parallel Assembly Pathways in Large Ribosome Subunit Biogenesis

Yield prediction in parallel homogeneous assembly

We investigate the parallel assembly of two-dimensional, geometrically-closed modular target structures out of homogeneous sets of macroscopic components of varying anisotropy. The yield predicted by a chemical reaction network (CRN)-based model is quantitatively shown to reproduce experimental results over a large set of conditions. Scaling laws for parallel assembling systems are then derived from the model. By extending the validity of the CRN-based modelling, this work prompts analysis and solutions to the incompatible substructure problem.

Multi-objective mixed-model parallel assembly line balancing with a fuzzy adaptive biogeography-based algorithm

Multi-objective mixed-model parallel assembly line balancing with a fuzzy adaptive biogeography-based algorithm

Multi-objective mixed-model parallel assembly line balancing with a fuzzy adaptive biogeography-based algorithm

Parallel assembly lines (PALs) typify a production facility comprising of two or more straight assembly lines arranged in parallel to assemble similar products or different models of the same product. The configuration of PALs poses new challenges for the optimal design of the lines since the efficacy of the assembly system can be improved by combining stations of adjacent lines when balancing them. As a consequence, the multi-objective mixed-model parallel assembly line balancing problem is addressed in this paper. The hierarchical objectives to be optimised include: 1) minimising number of workstations; 2) minimising number of stations; 3) simultaneously minimising workload variation and maximising work-relatedness. The fuzzy BBO (F-BBO) algorithm is developed to tackle this problem and its performances are evaluated against several well-known algorithms under different instances of benchmark problems. The experimental results show that the solution quality of the proposed F-BBO is significantly better than the contestant algorithms.