Space Cost Research Articles

Surrogate-Assisted Evolutionary Multitasking for Expensive Minimax Optimization in Multiple Scenarios

Minimax optimization is a widely-used formulation for robust design in multiple operating or environmental scenarios, where the worst-case performance among multiple scenarios is the optimization objective requiring a large number of quality assessments. Consequently, minimax optimization using evolutionary algorithms becomes prohibitive when each quality assessment involves computationally expensive numerical simulations or costly physical experiments. This work employs evolutionary multitasking optimization and surrogate techniques to address the challenges of the high-dimensional search space and high computation cost of minimax optimization. To this end, finding the worst-case scenario for different candidate solutions is considered as the optimization of multiple problems that can be solved simultaneously using the evolutionary multitasking optimization approach. In order to further speed up the proposed algorithm, a surrogate model in the joint space of the decision and scenario spaces is built to replace part of the expensive function evaluations. A generation-based model management strategy using a statistical hypothesis test is designed to manage the surrogate model. Experimental results on both benchmark problems and an airfoil design application indicate that the proposed algorithm can find satisfactory solutions with a very limited computational budget.

Optimal choice of multiple line-of-sight measurements determining plasma hotspot velocity at the National Ignition Facility.

The measurement of plasma hotspot velocity provides an important diagnostic of implosion performance for inertial confinement fusion experiments at the National Ignition Facility. The shift of the fusion product neutron mean kinetic energy as measured along multiple line-of-sight time-of-flight spectrometers provides velocity vector components from which the hotspot velocity is inferred. Multiple measurements improve the hotspot velocity inference; however, practical considerations of available space, operational overhead, and instrumentation costs limit the number of possible line-of-sight measurements. We propose a solution to this classical "experiment design" problem that optimizes the precision of the velocity inference for a limited number of measurements.

Preliminary study on radiation safety management of Gas Dynamic Trap based D-T fusion volumetric neutron source

The fusion neutron source based on Gas Dynamic Trap (GDT) device has the advantages of high neutron flux, large testing space and low construction cost, so it is an ideal solution for high-flux fusion volumetric neutron source. As a new type of radioactive facility, how to carry out radiation safety management under the current nuclear safety regulatory laws and regulations in China is an important issue that must be addressed before the construction of this facility. In this paper, the radiation safety characteristics of GDT fusion neutron source was analyzed and the main radiation terms of GDT fusion neutron source were expounded. Combined with the existing nuclear safety regulatory laws and regulations in China, the key points of radiation protection and safety management in the process of construction and application of GDT fusion neutron source were put forward. It is recommended that the GDT neutron source should be managed as a class I radiological device. Prior to operation, radiation safety permit and nuclear material permit should be obtained, and special attention should be paid to the safety protection of radioactive tritium. This study will pay the way for the radiation safety management of the international high flux fusion neutron source ALIANCE project, and also provide the reference for the related nuclear and radiation safety management departments in China. 摘要： 随着聚变能研宄进入工程化阶段, 迫切需要高通量聚变体中子源开展材料和部件的辐照测试。基于气动磁镜 (Gas Dynamic Trap, GDT) 装置的聚变中子源具有中子通量高、测试空间大、建造成本低等优点, 是高通量聚变体中子 源的理想方案。作为一种新型的放射性装置, 在我国现行核安全监管法律法规体系下, 如何对其开展辐射安全管理是 在该装置建造之前必须要理清的问题。本文分析了 GDT 聚变体中子源的辐射安全特性, 阐明了 GDT 聚变体中子源 的主要辐射源项, 并结合我国现有核安全监管法律法规要求, 提出 GDT 聚变体中子源在建造及应用过程中的辐射防 护与安全管理要点, 建议 GDT 中子源作为I类射线装置管理, 运行之前应取得辐射安全许可证和核材料许可证, 特别 需要注意对放射性氚的安全防护。本文为国际高通量聚变体中子源 ALIANCE 的辐射安全管理工作提供指导, 同时可 供我国的核与辐射安全管理部门参考。

32.4: Investigation of Compensation Value of Black Matrix for Reducing Light Leakage on Curved Display

Recently, due to the advantages in the aspects of larger viewing angle, lower space cost and better visual match with the vehicle interiors, curved display has gained its large popularity in automotive display, whereas Black Matrix(BM) which is used to light shading will shift when flat panel is bonded with the curved cover lens, which will cause light leakage and other optical issues. In the case that little is known about how to determinate the exact compensation value of BM without measuring. In this paper, we propose a method to identify the optimum compensation value of BM in condition of different curvature radius and thickness of panel which can avoid overcompensating or insufficient compensating by using finite element analysis.

Self-Regulated Solar PV Systems: Replacing Battery via Virtual Inertia Reserve

The replacement of synchronous generator (SG) via inertia-less renewable energy sources (RES), proves to be a huge threat for grid stability. To protect the grid from failure, derivative controlled energy storing systems (ESS) are extensively used for providing virtual inertia support. However, the short life span, maintenance requirement, large space, and high cost of ESS; put an extra burden on the economics of microgrid. This paper proposes a novel PI damping based virtual inertia technique, which de-loads the PV for generating virtual inertia reserve (VIR). This VIR strengthen the weak microgrids and enhanced their dynamic response during the contingency period, without ESS. To test the effectiveness of the proposed model, different practical situations are simulated ranging from heavy rain conditions to deep RES penetration. Simulation results confirm the excellence of the proposed model over conventional and ESS based virtual inertia techniques.

A numerical study on evaluating the thermal environment in a space served by a bed-based air source heat pump (B-ASHP) system

Both air source heat pumps (ASHPs) and traditional Chinese-Kangs heating systems are widely used. However, they have their pros and cons. By combining the merits from both an ASHP and a Chinese-Kang heating system, a prototype bed-based ASHP (B-ASHP) system has been proposed, and its operating characteristics experimentally obtained under a fix set of design/operating parameters for the bed-based heating terminal. Therefore, a follow-up numerical study was carried out to numerically evaluate the impacts of optimizing these design/operating parameters, including the location, dimension, surface temperature and surface emissivity of the bed-based heating terminal, on the indoor thermal environment and the operating efficiency of the B-ASHP system. The numerical study results suggested that the variation in these parameters did impact both indoor thermal environment and the operating efficiency of the B-ASHP system, in terms of the uniformity of indoor thermal environment, indoor air velocity distribution and the output heating capacity, as well as the installation space requirement and cost implication. Therefore, care must be exercised in properly balancing all influencing parameters. Also, to both maintain an acceptable indoor thermal environment that can meet the Chinese National Standard, and achieve the best possible operating efficiency of the B-ASHP system, the bed surface temperature of its bed-based heating terminal may be set at around 35 °C. Furthermore, although the changes in surface emissivity did not significantly impact on indoor thermal environment, a higher surface emissivity should be preferred when a lower bed surface temperature was used, so as to further improve potentially the operating efficiency of the B-ASHP system.

A multi-objective Monarch Butterfly Algorithm for virtual machine placement in cloud computing

The growing demand for cloud computing adoption presents more challenges for researchers to make cloud computing more efficient and affordable for infrastructure providers and end users. The management of cloud computing involves investing in IT infrastructure in the first phase and investing in energy, maintenance and space costs in the second phase. However, energy costs account for a large portion of cloud management costs, and saving energy consumption can significantly reduce overall cloud management costs. Server consolidation is a strategy to improve data center energy efficiency and resource utilization. Virtual machine (VM) placement is considered one of the main problems with VM consolidation. The VM placement problem aims to reduce the number of active physical machines in data center to reduce data center power consumption and maintenance costs. However, the waste of data center resources has a significant impact on the energy efficiency of the data center, so it should be considered in the VM placement strategy. This paper proposes a new method based on the Monarch Butterfly Optimization algorithm (MBO) called MBO-VM for new virtual machine placement, designed to maximize packaging efficiency and reduce the number of active physical servers. CloudSim toolkit is used to test the efficiency of the proposed MBO-VM approach under real cloud workloads as well as synthetic workloads. Simulation results show that MBO-VM produces significantly better results compared with known VM placement techniques. The proposed MBO-VM can reduce the number of active servers more effectively and maximize the packaging efficiency.

Household intelligent storage wardrobe based on the principle of Huarong Road

A new type of intelligent wardrobe is proposed based on the application of home daily life. Through mechanism combination innovation and electric control, the device realizes the design of imitating Huarong lane of wardrobe, and realizes the intelligent access of users. Each storage rack moves to a place suitable for users to access clothes through the coordination of the moving pulley and the rack and pinion structure, and makes reasonable use of the space at a high place. The addition of intelligent electronic control module makes it more convenient for users to get the clothes they need. The device has superior performance, simple operation process, low cost in space and economy, wide target audience and good market prospect.

Adaptive Conflict Detection Algorithm Based on Rochester Software Transactional Memory

When the transactional memory system detects conflicts, the more read-write addresses are, the higher the false positive rate of this algorithm is. This paper studies the problem and proposes a new signature based optimization algorithm, adaptive increase signature algorithm (AISA). The algorithm can calculate the saturation value of the number of read-write addresses, and dynamically adjust the size of bit string through the calculated saturation value, thus greatly reducing the false positive rate. The experimental results show that AISA can control the false positive rate at a low level on the basis of considering the space cost, and its effect is almost the same as that of 6 times of space, which will improve the performance of transactional memory system greatly.

Examining the Financial Impact of Altered Fractionation in Breast Cancer: An Analysis Using Time-Driven Activity-Based Costing

PurposeValue-based care is increasingly informing treatment decisions in radiation oncology. Although reimbursement differences have been examined for accelerated whole breast irradiation (AWBI) and conventional whole breast irradiation (CWBI), the cost of care delivery is poorly understood. This article describes our experience evaluating costs for altered fractionation in early-stage breast cancer using a time-driven activity-based costing (TDABC) model. Methods and MaterialsProcess maps were developed for 2 treatment regimens, AWBI (42.5 Gy in 16 fractions + 10 Gy in 4 fractions boost) and CWBI (50 Gy in 25 fractions + 10 Gy in 5 fractions boost). Cost was determined based on aggregate cost of personnel, materials, equipment, space, and utilities per unit time and based on the relative proportion of capacity used. The total reimbursement for each regimen was calculated as the aggregate of all billable events during a course of radiation therapy, based on the 2019 Centers for Medicare & Medicaid Services physician fee schedule database. ResultsThe total cost of delivering courses of AWBI and CWBI was $6965 and $9267, respectively, a difference of $2302 (25%). Eighty-six percent of this difference was related to a lower cost of delivering daily treatments. The total reimbursement for AWBI or CWBI was $9665 or $12,908, respectively, a difference of $3243 (25%). Overall, 55% to 60% of total costs were related to personnel, with the remainder related to materials, utilities, space, and equipment. ConclusionsThis analysis shows how TDABC can be used to evaluate resource requirements for different radiation therapy fractionation schedules. We found a substantially lower cost for AWBI compared with CWBI, primarily resulting from fewer daily treatments. As the emphasis in health care shifts toward value-based care, TDABC can help identify opportunities to reduce costs and increase clinical efficiency.

A-MCTS: Adaptive Monte Carlo Tree Search for Temporal Path Discovery

An Attributed Dynamic Graph (ADG) contains multiple dynamic attributes associated with each edge in the graph, where people usually can specify multiple constraints in the attributes to illustrate their requirements, such as the total cost, the total travel time and the stopover interval of a flight between two cities. This inspires the Multi-Constrained Temporal Path (MCTP) discovery in ADGs, which is a challenging NP-Complete problem. The existing methods adopt Reinforcement Learning (RL) and Monte Carlo Tree Search (MCTS) in MCTP discovery. However, they require a certain degree of discovery experience to obtain better results, which can lead to the expensive cost of query time and storage space, and thus are not applicable in real-time applications. This motivates us to develop a new Adaptive Monte Carlo Tree Search algorithm (A-MCTS). A-MCTS dynamically adjusts the priority of historical records that are used in MCTS to improve the performance and reduce the size of required discovery experience. The experimental results on ten real-world dynamic graphs demonstrate that our proposed A-MCTS outperforms the state-of-the-art methods in terms of both efficiency and effectiveness.

Study on Hydrodynamic Characteristics of Wind Turbine Monopile under Nonlinear Wave

As wind power technologies become maturer, the monopile foundation of offshore wind turbine is widely used because of its simple structure, few occupied space and low cost. However, under severe sea conditions, the impact of nonlinear wave load applied against the monopile foundation on the system structure safety cannot be ignored. In this paper, the 5MW offshore wind turbine of the National Renewable Energy Laboratory (NREL) was taken as the research object, and the computational fluid analysis software ‘STARCCM +’ was used to study the hydrodynamic characteristics of the monopile foundation of the wind turbine under different wave parameters. This paper mainly analyzed the upper wave, pressure and wave forces around the monopile foundation of the wind turbine under the same period and different wave heights. And the wave force calculated by CFD was compared with the result based on potential flow theory. The research results showed that with the rise of wave height, the upper wave, pressure and wave force around the monopile foundation increase continuously, and the second-peak phenomenon appeared at some measuring points on the water surface of the monopile foundation. Because the CFD method considers the fluid viscosity and is more in line with the real sea conditions, it is more accurate to obtain wave forces based on this method.

Privacy-Preserving Distributed IDS Using Incremental Learning for IoT Health Systems

Existing techniques for incremental learning are computationally expensive and produce duplicate features leading to higher false positive and true negative rates. We propose a novel privacy-preserving intrusion detection pipeline for distributed incremental learning. Our pre-processing technique eliminates redundancies and selects unique features by following innovative extraction techniques. We use autoencoders with non-negativity constraints, which help us extract less redundant features. More importantly, the distributed intrusion detection model reduces the burden on the edge classifier and distributes the load among IoT and edge devices. Theoretical analysis and numerical experiments have shown lower space and time costs than state of the art techniques, with comparable classification accuracy. Extensive experiments with standard data sets and real-time streaming IoT traffic give encouraging results.

Optimizing kitting cells in mixed-model assembly lines

The evolution of assembly lines towards the production of highly customized goods requires some organizational changes. The use of kits, providing presorted parts to assembly stations, was initiated by the need to supply a multitude of parts and their variants to the assembly line. In this paper, we investigate the kitting cell design problem and propose an optimization model to minimize the material handling, investment, and space costs for kitting cells. We show that applying our model to an automotive company’s kitting cell can reduce the total cost by approximately up to 11% compared with heuristics approaches.

Skyline Diagram: Efficient Space Partitioning for Skyline Queries

Skyline queries are important in many application domains. In this paper, we propose a novel structure Skyline Diagram, which given a set of points, partitions the plane into a set of regions, referred to as skyline polyominos. All query points in the same skyline polyomino have the same skyline query results. Similar to kth-order Voronoi diagram commonly used to facilitate k nearest neighbor (kNN) queries, skyline diagram can be used to facilitate skyline queries and many other applications. However, it may be computationally expensive to build the skyline diagram. By exploiting some interesting properties of skyline, we present several efficient algorithms for building the diagram with respect to three kinds of skyline queries, quadrant, global, and dynamic skylines. In addition, we propose an approximate skyline diagram which can significantly reduce the space cost. Experimental results on both real and synthetic datasets show that our algorithms are efficient and scalable.

Nearpod. <www.nearpod.com>

Nearpod. <www.nearpod.com> Kelly Kidder Nearpod is a presentational tool that provides a high degree of customization for instructors and engaging interaction for students. Creating lessons is simple and intuitive and begins with selecting the type of slide you want to make. Each slide can be a "content" slide or an "activity" slide. Content slides allow for text, text with audio, images, GIFs, web content, videos, slideshows, or pdf files. There is also something uniquely relevant to foreign language, the Virtual Reality Field Trip. Activity slides allow for quiz games (think Kahoot), open-ended questions, matching pairs, quizzes, Flipgrid, Draw It, collaboration boards, polls, fill in the blank activities, and memory cards. The range in choices is amazing and allows for personalized, fun instruction. Nearpod is free at the silver level but additional storage space costs more. At certain subscriber levels, pre-made content is available for French and Spanish. Navigating Nearpod's interface is easy and several of the features are perfect for world language instruction. When making content slides, it is nice to be able to record pronunciations of the words and it is easy to provide comprehensible input. Similarly, the open-ended question slide makes it easy to read a passage or share a video and then pose a question. Students can provide output by looking at and describing images (they can easily record audio) in the target language. Another great feature for language teachers is the interactive video. Teachers can select video content and embed questions (multiple-choice or open-ended) straight into the video (much like Edupuzzle). Finally, if teachers have already created presentations in Google Slides or PowerPoint it is easy to upload these into Nearpod and to add activity slides to make them more interactive. Nearpod can be used LIVE in class (each student receives a code to join the lesson, no download necessary). Students can access the lesson on their individual device or Nearpod can be combined with Zoom when presenting. A third, self-paced option allows students to access lessons on their own time. Lessons can be designed to reinforce what has been taught in class, to provide all the instruction, or to be completed as homework. Speaking of homework or quizzes, Nearpod keeps reports for each class and each student so that teachers can assess participation. Quizzes, matching activities, and fill-in-the-blank are graded automatically. One of the few things less user friendly about Nearpod is that editing the lesson invalidates the lesson's code. It is annoying to create a lesson, send the code to students, and then decide to change or add something. However, the Nearpod team listens and frequently makes improvements, so this could change. In all, Nearpod has been, for me, the most user-friendly platform with the most variety. Accessing all of these features in one place saves time and effort. To see one of my lessons, please visit <share.nearpod.com/vsph/K6OrH65cNu>. [End Page 261] Kelly Kidder Lipscomb University (TN) Copyright © 2021 American Association of Teachers of French

Review of research, development and application of photovoltaic/thermal water systems

Abstract Among the many techniques for obtaining heat and electricity, solar thermal collectors, photovoltaic (PV) technology and PV/thermal (PV/T) technology have a very important place. The PV/T collectors enable the simultaneous conversion of solar radiation into thermal and electrical energy in a single device, with better space utilization and cost efficiency during construction. Specially designed PV/T collectors can replace the outer walls or roof covers and can be widely used in private houses, flat complexes, hospitals, schools, tourist and other objects for water heating and electrical energy generation. Due to their great application potential, hybrid collectors have been the subject of very intensive scientific research and technical development for many years. In this review article, the focus is on the research, development and application of the PV/T water systems in the last 10 years. The main task of researchers and manufacturers is to increase the efficiency of PV modules and thermal absorbers, using new materials and design types as well as their proper integration into the PV/T collector. It is also necessary to reduce the cost of these systems and make them more competitive in the market. In addition, the importance of PV/T systems is in providing energy in clean and environmentally friendly ways.

Evaluation of Rainfall Estimation Derived From Commercial Interactive DVB Receivers Using Disdrometer, Rain Gauge, and Weather Radar

Accurate measurement and monitoring of precipitation is crucial for many applications, such as flood and drought risk assessment and management. Conventional meteorological devices for estimating precipitation (i.e., rain gauges, disdrometers, active and passive remote sensors, be they ground-based, spaceborne, or airborne) have their own strengths and weaknesses. The latter are often related to time and space resolution, coverage, and cost. In the last two decades, several studies have been carried out to exploit opportunistic signals of terrestrial microwave communication links to improve precipitation estimation capability. This study describes and evaluates a method to retrieve rainfall rate from the signal-to-noise ratio obtained from commercial interactive digital video broadcasting (DVB) receivers [referred as to smart low-noise blocks (smartLNBs)]. During a 1-year measurement campaign carried out in Tuscany (Italy) with purposely deployed instruments, the precipitation values estimated from a set of SmartLNBs were compared with measurements from co-located rain gauges and disdrometer. The normalized mean absolute error (NMAE) and root-mean-square error (RMSE) obtained comparing the total cumulative precipitation from a SmartLNB and a disdrometer are 48.8% and 7.46 mm, respectively. Encouraging results also come from comparing the total precipitation amounts as measured by the SmartLNBs and by the rain gauges, with values of NMAE (respectively, RMSE) ranging between 44% and 82% (respectively, 5.2 and 11.5 mm).

Delivery system can vary ventilatory parameters across multiple patients from a single source of mechanical ventilation.

Current limitations in the supply of ventilators during the Covid19 pandemic have limited respiratory support for patients with respiratory failure. Split ventilation allows a single ventilator to be used for more than one patient but is not practicable due to requirements for matched patient settings, risks of cross-contamination, harmful interference between patients and the inability to individualize ventilator support parameters. We hypothesized that a system could be developed to circumvent these limitations. A novel delivery system was developed to allow individualized peak inspiratory pressure settings and PEEP using a pressure regulatory valve, developed de novo, and an inline PEEP 'booster'. One-way valves, filters, monitoring ports and wye splitters were assembled in-line to complete the system and achieve the design targets. This system was then tested to see if previously described limitations could be addressed. The system was investigated in mechanical and animal trials (ultimately with a pig and sheep concurrently ventilated from the same ventilator). The system demonstrated the ability to provide ventilation across clinically relevant scenarios including circuit occlusion, unmatched physiology, and a surgical procedure, while allowing significantly different pressures to be safely delivered to each animal for individualized support. In settings of limited ventilator availability, systems can be developed to allow increased delivery of ventilator support to patients. This enables more rapid deployment of ventilator capacity under constraints of time, space and financial cost. These systems can be smaller, lighter, more readily stored and more rapidly deployable than ventilators. However, optimizing ventilator support for patients with individualized ventilation parameters will still be dependent upon ease of use and the availability of medical personnel.

Patterns of triggers, ideation and motivational factors of contraceptive utilization among women and gate-keepers in Nigeria: a scoping study on the resilient and accelerated scale up of DMPA-SC in Nigeria (RASUDIN)

BackgroundWomen have unfair share in the burden of unintended pregnancy outcome and unhealthy interpregnancy intervals. An understanding of the triggers, ideation and motivational factors influencing utilization of modern contraceptives is relevant for efforts aimed at increasing utilization among the general public, specifically sexually active women. The objective of this study is to explore the triggers, ideation and motivational factors influencing the use of modern family planning methods including depot-medroxyprogesterone acetate subcutaneous (DMPA-SC).MethodsQualitative methods which include; Focus Group Discussions (FGDs) and In-depth Interviews (IDIs) were used to elicit information from women of reproductive age and gate-keepers in selected Nigerian states; Rivers, Ogun, Kwara, Niger, Anambra, Delta, Lagos, Enugu and Oyo. The categories of respondents include; unmarried women aged 18-25 years, women in union aged 18-24 years using modern family planning (FP), women in union aged 25-49 years using modern FP, women in union aged 26-49 years non-users of modern FP, community leaders, health facility focal person, husbands of current users of modern FP, husbands of non-users of modern FP, religious leaders, state FP coordinators and women aged 18-49 years who currently use DMPA-SC. Maximum variation sampling techniques was used to enlist participants to participate in both FGDs and IDIs.ResultsRespondents reported being motivated to use FP for reasons such as benefits of the method, economic situation, suitability of the methods, fear of unwanted pregnancy and its convenience. Further analysis showed that the unmarried respondents discussed more about fear of unwanted pregnancy and accessibility and affordability as a key motivator; while women in union discussed more on economic situations, encouragement from partners and benefits of FP when compared with the unmarried. In addition, respondents reported that their partners, health workers and friends influenced their decisions to use FP. Partners’ encouragement, personal experience, accessibility and availability, awareness of FP and its benefits; willingness to space children and costs were notable enablers of FP use. The triggers for FP use were; appointment cards, phone calls from health workers, reminders (text messages, phone alarms and partners’ support).ConclusionIncreasing utilization therefore requires a well-planned horizontal approach that considers all enabling factors influencing utilization including women’s empowerment. Family planning programmes that are client centered, address socio-cultural and gender norms and ensure access to contraceptive mix methods are recommended to improve utilization rate. This study recommends improved care-seeking behaviour through community-based awareness creation to address myths and misconceptions of family planning use, establishment of contraceptive delivery teams to prevent challenges of availability and accessibility, value clarification and tasks shifting among others to deal with the issue of inadequate family planning utilization.