Current Layout Research Articles

A heuristic approach for petrochemical plant layout considering steam pipeline length

Plant layout design affects both investment and performance of a factory. To maximize the economic benefits of a petrochemical factory, a large number of factors must be considered simultaneously, such as material flow, heat flow and safety. However, conventional principles for plant layout design and optimization do not involve the heat flow, resulting in higher construction investment. To solve this problem, a new heuristic approach is proposed in this paper based on the current layout design principles. Both material flow (pipelines for process streams) and heat flow (pipelines for steam) are considered. Three optimization methods with different objective functions are used to optimize the layout. The application of proposed approach is illustrated with a case study. The optimal scheme and pipeline networks can be obtained, and the pipeline length is reduced significantly.

Design out crime on your campus with low‐cost best practices

Even if you don't have any formal guidelines for crime prevention through environmental design in place on your campus, odds are you're already implementing several of the strategies to make your campus a safer space. If you're looking for quick and inexpensive ways to boost campus safety, you can easily implement CPTED practices on your campus immediately. Ed Book, chief of police at Santa Fe College in Florida; Richard Schneider, Ph.D., current adjunct professor and retired full‐time professor of urban and regional planning at the University of Florida at Gainesville; and Art Hushen, president of the National Institute of Crime Prevention, shared some tips and best practices for implementing CPTED on your campus, regardless of your current layout and architectural design.

Heuristic methods for the leather nesting problem in the automotive industry

In this paper, we address a real leather nesting problem (LNP) with holes and quality zones that arises in the automotive industry. We describe two approaches for the solution of the LNP. The first approach consists in a constructive heuristic, while the second relies on local search methods. The constructive heuristic is based on a simulation of the positioning of a piece so as to evaluate its fitness within the hide and within the current layout. The later approach suggested in this paper is based in a local search method whose neighbourhood structure operates on cutting patterns. In order to improve this procedure, we also describe an improvement of our constructive heuristic to apply it at each iteration of the local search procedure. The proposed methods were implemented and tested on real instances of the automotive industry. The obtained results for both heuristics illustrate the adequacy and the potential of the proposed approaches.

Identifying Privacy Concerns on the Formation of Courtyards

Rapid changes due to the globalization process, cause in disappearance of traditional values and identity in the new architectural designs, particularly in the historical settlements. Presence of courtyard in the houses of Middle Eastern and Mediterranean countries dates back to nearly six thousand years ago. Privacy is one of the fundamental notions in the spatial organization of the traditional houses in this region and courtyard is the main component that assists achieving privacy in such houses. Kashan as one of the ancient cities of Iran possessing a considerable number of distinctive traditional courtyard houses, is crucial to be interrogated in terms of its traditional architecture to maintain its values and to sustain identity of the city. Space syntax as an effective method to clarify the spatial pattern of buildings and the degree of privacy in the interior spaces is applied in this study to identify privacy concerns on the formation of courtyards in the spatial organization of the traditional houses of Kashan. This paper may contribute in providing an approach for distribution of spaces in the house according to their level of privacy and its relationship in the process of current house layout design

Numerical Modeling of Dust Lifting from a Complex-Geometry Industrial Stockpile

This paper investigates the dust lifting phenomenon at the coal and iron ore stockpile at the Port of Koper, Slovenia. Dust lifting presents a serious environment and health hazard, thus the main objective of our study was to propose efficient measures for wind erosion reduction. A numerical model of the stockpile was created using the computational fluid dynamics (CFD) software. Wind velocity fields above the piles were calculated for the current stockpile layout and for several modified cases with rearranged piles and added porous barriers. Results from numerical modelling were used in the USEPA model to determine dust emission factors. Comparison of selected cases shows a positive, although limited effect of porous fences and barriers on reduction of local velocities and consequently, dust erosion rate. On the other hand, pile rearrangement has little effect and may not be practical for implementation. Realistic stockpile geometry with adjacent structures has shown to cause wind velocity distributions, which are not consistent with the most studied cases of regular pile shapes and layouts. The angle of incoming wind is a key factor influencing effectiveness of both solid and porous windbarriers. The proposed placement of porous barriers between the piles has shown to be effective in reducing wind exposure and dust emission. To maintain the dust emissions at an acceptably low level, other measures such as spraying with water and crust-forming liquids may still be necessary at higher wind velocities.

A staggered approach to structural shape and topology optimization

AbstractThis contribution is concerned with the design and evaluation of a staggered approach to computational shape and topology optimization. The main idea is to interrelate a classical boundary variation scheme based on the results from shape sensitivity analysis and an evolutionary‐type element removal procedure that relies on the topological sensitivity as a rejection criterion. The key ingredient in this perspective is to consider an advancing front algorithm that is gradually removing, from the evolving boundary of the domain, a number of finite elements based on the evaluation of the topological sensitivity.This process is repeated until the minimum topological sensitivity is no longer encountered at the boundary but in the interior of the domain, such that a topological change is to be considered for the current design layout. However, we first aim to establish a more accurate approximation of the true optimal shape of the newly established (zig‐zag representation) of the design boundary. This is achieved by the evaluation of the shape sensitivity and the accompanying boundary variations obtained by a basic descent algorithm. Only then, we create a hole in the interior of the domain by removing all cells that are adjacent to the nodal point that exhibits the minimum topological sensitivity and resume the advancing front algorithm to alter the newly established design boundary. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Non-standardised treatment rooms present an obstacle to efficient and prompt patient care

This project intended to determine whether the current layout of treatment rooms is conducive to the straightforward location of equipment, by analysing whether foundation year one (FY1) doctors were able to quickly and successfully perform routine tasks on a range of unfamiliar wards. An initial

ELECTRONIC JOURNAL TO RECORD STUDENTS’ PROGRESS (CADETS, STUDENTS) AS A MEANS OF RATIONALIZATION OF THE EDUCATIONAL PROCESS

The article presents the results of a study concerning development and implementation of electronic logbook for recording the students’ progress (cadets, students) in the National Academy of State Border Guard Service of Ukraine named after Bohdan Khmelnytsky as an effective instrument of rationalization of the educational process. A positive result is achieved through more efficient use of working time of scientific and teaching staff, the possibility of early detection of learning problems, predict and compensate for further learning activities of students (cadets, students). Current journal layout has been designed to spreadsheet MS Excel, but subsequently proposed to build electronic journal-based network architecture "client-server". Electronic Journal of students progress is built on the principles of objectivity, impartiality, flexibility, affordability, convenience and security.

Solving the container pre-marshalling problem using variable length genetic algorithms

In container terminals, the yard area consists of a set of blocks, which consists of a set of bays. Each bay consists of a set of stacks, which consists of a set of tiers. In the container pre-marshalling problem, an initial layout of a bay is converted to a final desired layout. The final layout follows the given loading schedule of this bay. This has a direct impact on the most important container terminal performance measure: the vessel loading time. The deviation between the current layout and the desired layout is expressed by the value of the mis-overlays. The objective of the pre-marshalling problem is to eliminate the mis-overlays with the minimum number of container movements. In this article, a variable chromosome length genetic algorithm was applied to solve the problem. The results of the new solution approach were compared against benchmark instances and the results were remarkably better.

Seeing is believing: increasing intraoperative awareness to scattered radiation in interventional procedures by combining augmented reality, Monte Carlo simulations and wireless dosimeters.

Surgical staff performing image-guided minimally invasive surgical procedures are chronically exposed to harmful ionizing radiation. Currently, no means exist to intraoperatively depict the 3D shape and intensity of scattered radiation fields or to assess the body-part exposure of clinicians. We propose a system for simulating and visualizing intraoperative scattered radiation using augmented reality. We use a multi-camera RGBD system to obtain a 3D point cloud reconstruction of the current room layout. The positions of the clinicians, patient, table and C-arm are used to build a radiation propagation simulation model and compute the deposited dose distribution in the room. We use wireless dosimeters to calibrate the simulation and to evaluate its accuracy at each time step. The computed 3D risk map is shown in an augmented reality manner by overlaying the simulation results onto the 3D model. Several 3D visualizations showing scattered radiation propagation, clinicians' body-part exposure and radiation risk maps under different irradiation conditions are proposed. The system is evaluated in an operating room equipped with a robotized X-ray imaging device by comparing the radiation simulation results to experimental measurements under several X-ray acquisition setups and room configurations. The proposed system is capable to display intraoperative scattered radiation intuitively in 3D by using augmented reality. This can have a strong impact on improving clinicians' awareness of their exposure to ionizing radiation and on reducing overexposure risks.

Suzhal – An Alternative Layout to Improve Productivity and Worker Well-being in Labor Demanded Lean Environment

Ergonomics continues to be relevant in work-places in which a significant amount of manual labor exists, such as in some of the Cellular manufacturing Systems (CMS). In order to distribute the workload evenly over all the workers in the line, some of the industries resorted to the practice of rotating all the workers through all workstations in the cell (Nagare cell) that prevents monotony and boredom. The presence of automated equipment in the cell will hamper this strategy for job rotation. This study aims to demonstrate the application of ergonomically designed looping layout in the assembly cell in the labor demanded lean manufacturing environment. The study was conducted in a process line in an automobile ancillary unit. The current process line which was conventional U-shaped line was simulated and the productivity has been verified and validated with the real life environment. Process map showed that the operators walked long distances, felt stress in certain workstations and that inventory piled up at the bottleneck workstation. We identify sub-cells within the cell. With the same manpower, we develop a new layout (Suzhal) and make workers rotate within each sub-cell. The proposed layout was simulated and results have been compared with the current layout. The analysis shows a reduction in the total operating cycle time, higher alertness among operators, better distribution of workloads in the group and hence higher productivity.

Non-uniformity study on readout circuit for uncooled IR detector

For long line uncooled infrared detectors, the non-uniformity of different detecting elements is the key parameter in measuring the circuit performance. So far there have been few research reports in this area. Most uncooled infrared detector circuits require corresponding blind detector for readout circuit design, which increases the complexity of uncooled infrared detector. In addition, the performances of these circuits need to be further improved in practical applications. In order to achieve high performance readout of the long line uncooled infrared detectors, a kind of 160 element readout circuit based on current mirror is designed in this paper. The readout circuit is composed of current mirror input part, capacitor feedback transimpedance amplifier (CTIA), and correlated double sampling (CDS) output circuit. The circuit is fabricated by using the 0.5 micron technology. The non-uniformity of circuit is obviously improved by reasonable parameter setting and current mirror circuit layout. Transconductance amplifier CTIA with capacitance negative feedback is used in the circuit. The integral capacitor consists of three capacitors whose capacitances are 10 pF, 20 pF and 20 pF respectively, thus the circuit can realize different integration capacitances, which forms different magnifications. The circuit can meet different response rates of uncooled detectors. Folded-cascode structure is adopted as the CMOS differential amplifier. The open loop gain is over 80 dB. This single-state folded-cascode construct can overcome the two-stage amplifier’s disadvantages, which easily leads to oscillations. The CDS N SF (source follow) and P SF are adopted as the circuit output, the output swing can easily be greater than 2 V. On average, the CDS N SF and P SF power consumptions are very low. So the total power consumption of 160 line circuit is lower than 100 mW. In the test, the non-uniformity of the readout circuit decreases from 10% to 1%. This result is in accordance with simulation result on non-uniformity. The other test results of total power consumption and the output amplitude also agree with simulation results. The readout circuit has good noise characteristics and the output noise is lower than 1 mV. When the readout circuit and uncooled infrared detector are connected, the infrared signal can be well read out. When the integration time is 20 μups, the device response is 0.294 mV/Ω. The overall system performance is very good. This circuit design based on current mirror has laid the technical foundation for developing readout circuit of the very large scale uncooled infrared detector in the future.

The VESUVIO Spectrometer Now and When?

The current layout and mechanics of the VESUVIO spectrometer are presented in light of spectroscopic measurements using electron-volt neutrons. A brief background to the theoretical framework of deep inelastic neutron scattering is presented, with focus on data collection and instrumental design. The current capabilities and research themes for VESUVIO are discussed, and possible future instrumental developments highlighted which will enhance the instrument's ability to meet scientific inquiry and expectation.

Hybrid Self-Organization Based Facility Layout Planning

A novel hybrid two-stage method of facility layout planning, based on self-organized clustering, is presented. In the first stage, a self-organizing map (SOM) is applied in order to organize the production process into production cells which encapsulate products with similar properties and similar machining requirements. In the second stage, the internal layout of each cell is optimized by an expert operator, taking into account various local restrictions, technological specifications, and methods of transportation. The method combines the advantages of both algorithmic and manual expert-based approaches to layout planning. The proposed method was applied in a real production company environment with promising results indicating a 42% reduction in intensity-length efficiency measure with respect to the current layout.

Optimizing the number and location of time point stops

Public transport service is subject to multiple sources of uncertainty that impact its reliability. Holding control strategies are a common method to prevent the deterioration of service reliability along the route. This paper expands on previous studies by considering the general case of determining both the optimal number and optimal location of the time point stops (TPS) where holding takes place, and assessing their impacts on transit performance using simulation. Holding times are determined based on a real-time headway-based holding strategy designed to improve service regularity by seeking uniform headways along the route. The evaluation of the performance of alternative TPS layouts is simulation-based, using BusMezzo, a transit operations simulation model which models the dynamic performance of bus transit systems. The proposed framework also considers the multiple objectives incorporating passenger and operator points of view. The simulation-based optimization framework was applied in a case study with one of the premium bus lines in Stockholm, Sweden, using two solution methods—greedy and genetic algorithms. A multi-objective evaluation was conducted considering both passenger and operator perspectives. The results demonstrate that transit performance varies considerably with alternative TPS layouts. The best solution obtained by the proposed methodology reduces total weighted passenger journey times and cycle times compared to both the current layout and the case of no holding control. The proposed method could assist transit agencies and operators in evaluating and recommending alternative time point layouts.

Analysis of China's new energy conservation policy and the provincial decomposition of the energy consumption target

To compensate for the limitation of the energy intensity indicator and to constrain energy consumption growth more directly and severely, China had decided to implement the Total Energy Consumption Control (TECC) policy during the 12th Five-Year Plan (FYP). This paper analyzes the situation of energy consumption in 3 scenarios based on the energy consumption trend during the 11th FYP, the energy intensity reduction target during the 12th FYP, and the TECC policy. The Energy Conservation Comprehensive Evaluation System (ECCES) which includes 5 indicators reflecting energy conservation responsibility and 3 indicators reflecting energy conservation difficulty has been built, and Analytic Hierarchy Process (AHP) and Entropy methods are used to determine the weights of 8 basic indicators. According to the ranking of comprehensive evaluation scores of ECCES, 30 provinces are divided into 5 clusters, which are assigned 3%, 3.5%, 4.2%, 5.5%, and 6.8% of controlled energy consumption growth rate, respectively. By comparing and analyzing energy consumption situations in 3 scenarios, we find that the TECC policy has the strongest constraint effect, and can achieve unification of provincial and national energy conservation goals. The provincial decomposition result of energy consumption controlled target of TECC policy roughly remains consistent with the current economic and energy development layout of China that the provinces in southeast coastal developed areas are assigned lower controlled energy consumption growth rate while the backward inland provinces are assigned higher growth rates.

Evacuation dynamic and exit optimization of a supermarket based on particle swarm optimization

A modified particle swarm optimization algorithm is proposed in this paper to investigate the dynamic of pedestrian evacuation from a fire in a public building—a supermarket with multiple exits and configurations of counters. Two distinctive evacuation behaviours featured by the shortest-path strategy and the following-up strategy are simulated in the model, accounting for different categories of age and sex of the pedestrians along with the impact of the fire, including gases, heat and smoke. To examine the relationship among the progress of the overall evacuation and the layout and configuration of the site, a series of simulations are conducted in various settings: without a fire and with a fire at different locations. Those experiments reveal a general pattern of two-phase evacuation, i.e., a steep section and a flat section, in addition to the impact of the presence of multiple exits on the evacuation along with the geographic locations of the exits. For the study site, our simulations indicated the deficiency of the configuration and the current layout of this site in the process of evacuation and verified the availability of proposed solutions to resolve the deficiency. More specifically, for improvement of the effectiveness of the evacuation from the site, adding an exit between Exit 6 and Exit 7 and expanding the corridor at the right side of Exit 7 would significantly reduce the evacuation time.

Simulation of Thermal Comfort Conditions of an Air-Conditioned Cafeteria in the Tropics

This paper studies the current thermal comfort condition of an air-conditioned cafeteria based on objective measurements and computational fluid dynamics (CFD) modeling. Indoor comfort parameters such as temperature and airflow rate were simulated by a CFD tool. The results from field measurements and predicted values were then compared and contrasted. A simulated model that has the same geometrical configuration as the cafeteria was set as a benchmark model. Several additional models with different configuration of cafeteria layouts were proposed to achieve the required air temperature. It was found that the predicted results from the proposed models showed even distributions of airflow characteristics and temperature gradients. To maintain a thermally-acceptable air temperature of 28 °C, it is proposed that an additional air-conditioning unit be retrofitted to the current cafeteria layout.

A method of production fine layout planning based on self-organising neural network clustering

Organising and optimising production in small and medium enterprises with batch production and many different products can be very difficult due to high complexity of possible solutions. The paper presents a method of fine layout planning that rearranges production resources and minimises work and material flow transfer between production cells. The method is based on self-organising map clustering which organises the production cells into groups sharing similar product properties. The proposed method improves the internal layout of each cell with respect to a material flow diagram and a from-to matrix, and fine workspace positioning also considers various restrictions on placement, specifications and types of transportation. The method is particularly suitable for improving the existing layouts. The method was applied in the Slovenian company KGL d.o.o. and promising results were achieved. A reduction by more than 40% in the total transport length with respect to the current production layout was observed.

A double-sided silicon micro-strip Super-Module for the ATLAS Inner Detector upgrade in the High-Luminosity LHC

The ATLAS experiment is a general purpose detector aiming to fully exploit the discovery potential of the Large Hadron Collider (LHC) at CERN. It is foreseen that after several years of successful data-taking, the LHC physics programme will be extended in the so-called High-Luminosity LHC, where the instantaneous luminosity will be increased up to 5 × 1034 cm−2 s−1. For ATLAS, an upgrade scenario will imply the complete replacement of its internal tracker, as the existing detector will not provide the required performance due to the cumulated radiation damage and the increase in the detector occupancy. The current baseline layout for the new ATLAS tracker is an all-silicon-based detector, with pixel sensors in the inner layers and silicon micro-strip detectors at intermediate and outer radii.The super-module is an integration concept proposed for the strip region of the future ATLAS tracker, where double-sided stereo silicon micro-strip modules are assembled into a low-mass local support structure. An electrical super-module prototype for eight double-sided strip modules has been constructed. The aim is to exercise the multi-module readout chain and to investigate the noise performance of such a system. In this paper, the main components of the current super-module prototype are described and its electrical performance is presented in detail.