Partition Layout Research Articles

Deep-learning-based generative design for optimal reactive silencers

A deep-learning-based generative design method is proposed to improve the frequency-dependent characteristics of a reactive silencer, and it has been validated both numerically and experimentally. The noise attenuation performance of the reactive silencer is evaluated with its transmission loss (TL), which varies with frequency and strongly depends on the partition layout inside the reactive silencer. The artificial neural network model for the generative design of the reactive silencer consists of three subnetwork models: the generator, predictor, and converter. The generator model created numerous partition layouts, and their TL curves were estimated using the predictor model. A converter model was developed to identify the frequency-dependent characteristics of the TL curves in a low-dimensional latent space. The latent space was extensively investigated to successfully select the optimal partition layouts satisfying given design requirements, including the target shape of the TL curve and its averaged target TL value. The effectiveness of the proposed method was demonstrated by applying it to three reactive silencer design problems with different design requirements. Among the three optimal silencers, one was physically investigated, and its noise attenuation performance was validated with an acoustic experiment. Because the artificial neural network model of the proposed method was developed for a normalized silencer and requires no prior knowledge of acoustics, it can be easily applied to reduce duct noise in the industry.

Influence of partition layouts on speech privacy in open-plan offices

Different partition layouts were compared to determine how to increase speech privacy while maintaining communication efficiency between workers in an open-plan office. A preliminary survey was used to determine current usage and conditions of partitions in open-plan offices. The survey results were used to select four partition layouts for testing: face-to-face, parallel, crossed-rod, and orthogonal. A computer modeling was used to test the partition layouts at three different partition heights: 1.2, 1.5, and 1.8 m. The modeling results showed that the parallel- and crossed-rod-type layouts offered the best speech privacy at the lowest partition height, but the differences among layouts disappeared as the partition height was increased. Furthermore, an acoustic field experiment was performed using partitions with a 1.5 m height following the ISO 3382-3 standard. The experimental results showed that the face-to-face layout resulted in the least speech privacy. Based on these results, an open-plan office needs to ensure that workers are spaced a sufficient distance apart and that they do not face each other to ensure speech privacy. Additionally, speech privacy should be considered in the design stage of the office space.

Conformal frequency selective rasorber in S, C, X-band with low backward-scattering

In this paper, a polarization-insensitive high transmittance bandpass filter with low radar cross section (RCS) in both S- and X-band is proposed. This is the first study to use the partition layout loading approach for conformal structures with transmissive windows, reducing the operating band RCS. Curved structures have stronger radiation at a smaller angle to the incident wave, and that is how their scattering differs from uniform scattering from flat structures. The structure is divided by analyzing the radiative contribution of different regions. The surface was discussed in regions according to surface angles, and a new partition layout loading method was used to suppress the side currents and decreased backward scattering, achieving a backward RCS reduction of more than 10 dB at 4-8 GHz (66.7%). The bandpass layer operating at 6.9 GHz is designed through equivalent circuit theory. In combination with the lossy layer, absorption above 0.8 at 3.7-5.6 GHz and 9.1-12.5 GHz was achieved. Further, the structure was fashioned into a curved surface with varying curvature, demonstrating its effective absorption and transmission properties across different curvatures. A 15 × 15 cell structure was designed and fabricated, and there was good agreement between the test results and simulation results. The proposed structure has important applications in radomes, conformal structures, and electromagnetic shielding.

The effects of desk-partition layout on cough droplet dynamics relating to seasonal influenza

The use of physical dividers as control measures for short-range viral transmission in indoor settings has gained increasing attention. However, the understanding regarding their correct usage under different seating arrangements is incomplete. In this study, we focused on assessing the effectiveness of physical dividers in impeding the transient transmission of cough droplets in three representative layouts using the large-eddy simulation technique with the Eulerian–Lagrangian model. We computationally also investigated the effects of ventilation on viral droplet transmission under three representative desk-divider layouts. The ventilation approach was tested using two different ventilation rates (1.0 and 1.8 m/s). A comparative analysis of the ventilation flow fields, topologies, and particle directions has been studied. The findings indicate that the sitting arrangements, ventilation rates, and partition layouts play a significant role in designing effective control measures for indoor infection under the office setup considered. The protected occupied zone ventilation (POV) worked best in situations of low ventilation (1.0 m/s) for cross-partition in protecting the three healthy persons. In addition, the POV performed well for low (1.0 m/s) and high (1.8 m/s) ventilation rates for face-to-face layout. The side-by-side configuration performed poorly for the POV considered in protecting the healthy person seated directly opposite the infected person. The numerical predictions may be used to validate other experimental studies and educate office workers and engineers on indoor airborne infection control.

Evaluation of the effects of partition design on circadian daylighting in open-plan offices

Due to the changes in the modern human lifestyle, the average time people spend in interior spaces has increased, which calls attention to providing appropriate indoor lighting. Many studies have shown the considerable influence of luminous conditions on human circadian rhythm, productivity, and well-being. While the influence of a building’s architectural characteristics on the visual aspects of daylight has been extensively examined in the literature, there has been comparatively less emphasis on assessing these affects within the context of circadian daylighting considerations. The current study has employed a simulation-based approach to investigate the influence of interior space configurations; in particular, office space’s partition layout, height, and optical properties on the circadian potential of the space. Specifically, the study aimed to examine the impact of two partition layouts – arranged perpendicular and parallel to the window – alongside nine different materials featuring various color hues and reflection levels, and three distinct partition heights. Results indicate that, generally, the circadian potential of the office space rises with the increase of the melanopic reflectance of the partition material and the decrease of partition height. With partitions higher than the eye level, arranging them in a parallel position to the window would result in a better non-visual environment, whereas with lower partition heights, the perpendicular arrangement of partitions to the window would be a more suitable choice in most of the investigated cases. This study suggests a decision-making model to assist designers in creating efficient office spaces, particularly in terms of circadian lighting conditions.

A Novel Receiving Subarray Partition Layout Model for Microwave Power Transmission with Smaller Power Dispersion

A Novel Receiving Subarray Partition Layout Model for Microwave Power Transmission with Smaller Power Dispersion

Double-Sided Wearable Multifunctional Sensing System with Anti-interference Design for Human-Ambience Interface.

Multifunctional sensing systems play important roles in a variety of applications, incluing health surveillance, intelligent prothetics, human-machine/ambinece interfaces, and many others. The richness of the signal and the decoupling among multiple parameters are essential for simultaneous, multimodal measurements. However, current multifunctional sensing fails to decouple interferences from various signals. Here, we propose a double-sided wearable system that both enables multifunctional sensing and avoids the interferences among multiple parameters. Specifically, the sensitivities of system modules to strain are controlled through customizing the pattern and morphology of sensing electrodes as well as the modification of active materials. Compensation of temperature drift and selection of sensing mechanisms ensure the thermal stability of the system. The encapsulation of modules resists the interferences of proximity, normal pressure, and gas molecules at the same time. A double-sided partition layout with serpentine interconnections reduces the effect of motion artifacts and ensures simultaneous operation of electrochemical-sensing modules. Cooperation among decoupled modules acts as the bridge between the perception of ambience changes and the timely feedback of the human body. In addition, to sense the signal at the interface, modules for energy harvesting and storage are also integrated into the system to broaden its application scenarios.

Partition layout inside a muffler integrated with a thermoelectric generator: Multi-physics analysis and optimal design

A multi-physics-analysis-based topology optimization (TO) method is proposed to optimally design the internal partition layout of a muffler integrated with a thermoelectric generator (TEG). The basic equations governing the acoustical behavior, heat transfer, and fluid flow in the muffler are introduced, and their interaction is designated for exact numerical analysis in terms of acoustics, heat transfer, and fluid mechanics. To implement density-based TO, one design variable is assigned to each finite element in the design domain, and interpolation functions suitable for each physics phenomenon are employed. In the TO problem formulation, the sum of the squared acoustic pressures at the outlet of the muffler for multi-target frequencies is selected as an objective function to achieve broadband noise attenuation. The temperature of the TEG and the pressure drop are constrained for high energy recovery efficiency and fluid passage, respectively. The optimization problem formulated for the muffler design is solved for various design conditions. Optimal partition layouts are obtained depending on the location and length of the TEG, the upper limit value of the pressure drop, and the number of target frequencies in the same frequency band. The noise attenuation performances of each partition layout are compared, and their expected recovery energies are calculated. One optimal partition layout is discussed in terms of acoustics, heat transfer, and fluid mechanics. The numerical results strongly support the validity of our proposed method for the optimal design of a muffler integrated with a TEG.

RETRACTED: Modeling and solving the two-sided U-type assembly line balance based on a heuristic algorithm of a multi-priority rule

In order to improve the efficiency of assembly line and optimize the layout, this paper presents a collaborative optimization model for a two-sided U-type assembly line and a novel design with p-l partition layout is proposed to minimize number of workstations without increasing the length of the assembly line. Considering the task orientation and time sequencing in cross-workstation, the mathematical model of two-sided U-type assembly line balancing problem is derived. A multi-level priority rule heuristic algorithm is developed to drive the optimization process. The multi-level priority rule heuristic algorithm, modified particle swarm optimization algorithm, and the bi-objective integer programming method are applied to 20 classic examples, respectively. The calculation results suggest that the optimal results of the proposed method account for 90%, which verifies the rationality of the collaborative optimization model and algorithm, and provides a useful reference for the modeling and solution of the two-sided U-type assembly line balancing problems.

Partition Layout Loading of Frequency Selective Surface Absorbers on the Curved Surfaces for the Significant RCS Reduction

In this article, the significant radar cross section (RCS) reduction of curved surfaces in the low microwave frequency band is reported. The design method of partition layout loading of frequency selective surface (FSS) absorbers to control the surface current is put forward. Comparison of the scattering field intensities of different zones on the curved surface clearly shows that surface current should be suppressed in a large zone to effectively reduce the RCS of the curved surface at these frequencies. FSS absorbers under normal and 45° angle of incidence are designed and placed on the different zones of the curved surface to realize the partition layout loading, and remarkable RCS reduction has been obtained. Specifically, more than 15-dB RCS reduction is achieved in 1.05–1.45 GHz, and absorption above 90% is obtained from 0.95 to 1.5 GHz for TE polarization. The great agreement between the simulated and measured results validates the proposed design method.

Evacuation Optimization Strategy for Large-Scale Public Building Considering Plane Partition and Multi-Floor Layout.

Large-scale public buildings (e.g., stadiums and comprehensive hospitals) in modern cities provide places for various social activities. However, all of these public places encounter the scenario of large passenger flow and crowd gathering, which is highly likely to induce serious safety problems, such as stampedes. Previous studies have shown that efficient evacuation is an important way to ensure the safety of dense crowds in public places. This study aims to explore the optimization methods to improve the evacuation efficiency of public buildings. Two strategies considering plane partition and multi-floor layout are proposed for plane evacuation and vertical evacuation, respectively. Simulation scenarios and models of large stadiums and high-rise hospitals are established to verify the strategies. The results show that plane partition could effectively shorten the total evacuation time, which is due to the optimization of the initial exit choice of individuals and the avoidance of regional congestion in some evacuation channels or exits. Multi-floor layout optimization is an effective management method to arrange the different features of different floors, which could improve the evacuation efficiency for the whole multi-floor building. This study is helpful for building designers and managers to improve the building space layout design and the daily safety management mode.

Assessment of Different Envelope Configurations via Optimization Analysis and Thermal Performance Indicators: A Case Study in a Tropical Climate

Passive solutions for more energy-efficient buildings are critical to improving our odds in the current energy crisis. This work focuses on assessing the thermal performance of different envelope construction layouts in a tropical climate through proposed indicators regarding the thermal mass degree (TMD) and insulation degree (ID). For this, a numerical study was performed for a reference building (RB) in Panama City and validated with the electricity consumption bills. Behavioral and sensitivity analyses were employed to identify critical heat gains and the most important envelope constructions, resulting in the layouts of the roof and external walls. Optimization analyses were performed to find adequate layouts to reduce the discomfort hours. Different roofs, external walls, internal partition layouts, and glazing types were evaluated. Results indicated that the adequate envelope configuration is a roof layout with low TMD and ID, along with wall layouts with high TMD and low ID.

Effects of MnSO4 on grain output, protein and Mn content of quinoa strains (Chenopodium quinoa Willd.)

Quinoa is a new crop with great potential in the world. Micronutrients are vital components for balances both growth and development in plants. An experiment was designed for the sake of researching the impacts of MnSO4 on output and quality parameters of Quinoa strains in Wuhan. Four repetitions stochastic complete block design is used for the partition layout. Major zones were MnSO4 (contains 28% pure manganese) (2, 4 and 6 g·m−2), and sub-zones were Quinoa cultivars (L-1, L-2 and L-3). The meaningful influence of MnSO4 on the number of fertile ears, the amount of seeds in each ear, the weight of a thousand seeds, grain output, the contents of proteins and manganese in grain. The significant influence of cultivar on number of fertile ears, the weight of a thousand grains, grain output and protein content. The highest values of fertile ear, amount of grain, the weight of a thousand grains, harvest index, grain output, the contents of grain proteins and Mn were achieved in applying 6 g MnSO4 per m2. In addition, the highest amount of fertile ears, amount of grains per ear, grain harvest and grain manganese content were related to“L-3”cultivar. The results show that cultivation of“L-3”cultivar and application of 6 g MnSO4 per m2 is recommended for Wuhan.

THE EFFECTS OF INTERNAL PARTITION ON INDOOR DAYLIGHTING PERFORMANCE OF STUDENT RESIDENTIAL BUILDING IN IPOH, PERAK

The installation of an internal partition has resulted in lowering the illumination level inside a building. Therefore, this study is intended to evaluate the effects of several internal partition layout on indoor daylighting performance in student residential rooms. Several options of internal partition were simulated using Climate Based Daylight Modelling (CBDM) to suggest the effective partition layout to overcome low daylighting level inside the room at the annual level. The findings indicate that the internal partition perpendicular to the window layout has been proven to have the highest annual daylight sufficiency in a student residential room in the tropics.

Design and Implementation of EMC System Layout for Rail Trains

Nowadays, China’s urbanization process is rapid, and the rail transit system has become a good solution for the traffic congestion problem. The electromagnetic compatibility (EMC) of rail transit system is an important guarantee for the safe and reliable operation of rail trains. To this end, this paper proposes an EMC layout scheme for rail trains, and designs their electrical equipment layout and electrical wiring layout. In addition, according to the distribution of the train body equipment, the rail trains are divided into three parts, i.e. the roof, the interior and the bottom, and their associated EMC partition layouts are given. Finally, the layout scheme is tested by taking the Shanghai Metro Line 6 as a test rail train. The test results show that the proposed scheme can greatly improve the EMC performance of the rail trains and achieve the expected design goals.

Reassembling Linux-based Hybrid RAID.

Network-attached storage (NAS) is a system that uses a redundant array of disks (RAID) to create virtual disks comprising multiple disks and provide network services such as FTP, SSH, and WebDAV. Using these services, the NAS's virtual disks store data about individuals or groups, making them a critical analysis target for digital forensics. Well-known storage manufacturers like Seagate, Synology, and NETGEAR use Linux-based software RAID, and they usually support Berkeley RAID (e.g., RAID 0, 1, 5, 6, and 10) as well as self-developed hybrid RAID. Those manufacturers have published data on the introduction and features of hybrid RAID, but there is not enough information to reassemble RAID from a digital forensic perspective. Besides, digital forensic tools (such as EnCase, FTK, X-ways, and RAID Reconstructor) do not support automatic RAID reassembly for hybrid RAID, so research on hybrid RAID reassembly methods is necessary. This paper analyzes the disk array composed of hybrid RAID and explains the layout of disk array, partition layout in hybrid RAID, and hybrid RAID configuration strategy. Furthermore, it suggests parameters that are required for RAID reassembly and then propose a hybrid RAID reassembly procedure using them. Finally, we propose a proof-of-concept tool (Hybrid RAID Reconstructor) that identifies hybrid RAID from disk array and parse RAID parameters.

Topology optimization of internal partitions in a flow-reversing chamber muffler for noise reduction

A topology-optimization-based design method for a flow-reversing chamber muffler is suggested to maximize the transmission loss value at a target frequency considering flow power dissipation. Rigid partitions for high noise reduction should be carefully placed inside the muffler to avoid extreme flow power dissipation due to a 180° change in flow direction from an inlet to an outlet. The optimal flow path for minimum flow power dissipation is well known to change depending on the Reynolds number, which is a function of the inlet flow velocity. To optimize the partition layout with an optimal flow path in an expansion chamber at a given Reynolds number, a flow-reversing chamber muffler design problem is formulated by topology optimization. The formulated topology optimization problem is implemented using the finite element method with a gradient-based optimization algorithm and is solved for various design conditions such as the target frequencies, rigid partition volumes, Reynolds numbers, non-design domain settings, and allowed amounts of flow power dissipation. The effectiveness of our suggested approach is verified by comparing the optimized partition layouts obtained by the suggested method and previous methods.

덕트 밖에서 계산된 삽입 손실을 고려한 머플러 최적 설계

Abstract : In this study, we formulate an acoustical topology optimization problem to optimally design a partition layout inside the expansion chamber of a muffler. The lower-limit insertion loss value at a target frequency is constrained, and the partition volume is selected as an object function. In this study, we calculate the insertion loss outside the duct, while to determine the noise-attenuation performance, we use the insertion loss value calculated inside the duct or transmission loss value obtained in a previous study. We employ the finite-element model for acoustical analysis, and we determine the transmission of an incident acoustic wave through each finite element using the functions of design variables that change continuously between “0” and “1.” The rigid body elements, which totally reflect incident waves, build up partitions. Finally, we compare optimal topologies that depend on the target frequency and the allowed lower-limit value of insertion loss. § 이 논문은 대한기계학회 창립 70주년 기념 학술대회(2015. 11. 10-14., ICC제주) 발표논문임. † Corresponding Author, jinwoolee@ajou.ac.kr Ⓒ 2016 The Korean Society of Mechanical Engineers

Optimal partition layout of expansion chamber muffler with offset inlet/outlet

An optimal partition layout inside an expansion chamber muffler with an offset inlet/outlet is systematically designed by using topology optimization to achieve the desired characteristics in terms of acoustics and fluid mechanics. To that end, a partition volume minimization problem is formulated by applying acoustical and flow topology optimization methods. The partition volume is set as an objective function with constraints imposed on the target values of the transmission loss and pressure drop. The finite element method is employed for the acoustical and flow analyses. A design variable is assigned to each finite element such that it changes continuously between 0 and 1 to determine the state of the associated finite element. The design variables are updated during the optimization process and parameterized to converge to 0 or 1 at the end of the process. Finite elements with design variables of 1 build up rigid partitions which are optimally placed to achieve the target values of transmission loss and pressure drop. Different optimal partition layouts are obtained depending on the target frequency, the target values of transmission loss and pressure drop, and the initial values of the design variables. An experiment-based validation strongly supports the validity of the proposed muffler design method.

Modelling effect of non-structural partitions on floor modal properties

Non-structural cladding and partitions can have significant stiffening effects on the vertical vibration behaviour of floors in buildings. Such effects are currently difficult to quantify and use in design. To quantify them, modal properties of two structurally identical full-scale floors in a real fitted-out building were measured and compared to results for the same floors prior to installation of internal partitions and cladding panels. In its bare frame state the modal properties of both floors were found to be nominally identical. However, when tested after the installation of internal partitions and external cladding panels, it was found that the addition of these non-structural elements increased the stiffness of both floors and also altered significantly their modes of vibration, in particular natural frequencies and mode shapes. The fundamental natural frequencies increased by 30% for both fitted out floors relative to their bare state. However, the change in modal properties varied from floor to floor and this difference was attributed to the differing partition layouts on and below each floor.This paper also proposes a numerical modelling approach to account for these effects. The measured modal properties of the structural system in its bare frame state were used initially to update a three dimensional finite element (FE) model of the bare multi-storey frame system featuring the tested floors. Linear elastic spring elements were subsequently included representing the internal partitions and external cladding panels. The bare frame FE model was further updated to determine appropriate spring constants by correlation with modal parameters measured on the fully completed building. For the particular type of cladding and partitions used, it was found that the cladding vertical stiffness is about twice its partitions counterpart. Also, and as expected, the vertical stiffnesses estimated through this process were lower than, but comparable with, the stiffnesses of these elements based on their ideal cross-sectional properties.