Multiphase Strategy Research Articles

Flooding and Mental Health interventions for vulnerable groups

Abstract Issue/Problem The UK is increasingly vulnerable to flooding due to climate change, which significantly affects mental health. Vulnerable populations are disproportionately impacted, experiencing stress, anxiety, and other severe mental health issues, requiring effective intervention strategies. Description of the problem The UK’s third Climate Change Risk Assessment (CCRA) highlights flooding as a key challenge, with mental health impacts representing a major health burden. Effective interventions are crucial for these communities. Results UKHSA’s flooding and mental health guidance is incorporated into flooding and health advice documents for the public and frontline responders. It includes assessment and support strategies for health and social care staff, emergency responders, and local authorities. It focuses on those most at risk and promotes a phased approach to care-from immediate safety and shelter to long-term psychological support. This strategy accommodates the prolonged nature of mental health recovery, requiring adaptable and sustained interventions. Lessons Addressing the mental health impacts of flooding demands a comprehensive, multi-phase strategy that adapts to the evolving needs of affected populations. Early intervention and long-term support are vital to mitigate the extensive psychosocial damage. Key messages • Flooding severely affects mental health, necessitating structured, long-term interventions. • Flexible support strategies that evolve over time are crucial for effective recovery, ensuring that interventions meet the changing needs of those impacted by flooding.

Multiphase Fe-doped Ni3S2/MoOx electrocatalyst prepared by facile one-step hydrothermal for full-cell water splitting: Effect of Mo on physical and electrochemical properties

Herein, we develop a multiphase strategy to improve the HER performance by incorporating the MoOx phase with the addition of MoCl5 during the one-step hydrothermal. Adding MoCl5 at 0.5 mmol (MFN-0.5) yields the best HER performance, with an overpotential of 261 mV at a current density of 100 mA/cm2. The MFN-0.5 catalyst exhibits excellent performance for both HER and OER, enabling it to drive full-cell water splitting with cell potentials of 1.50 and 1.71 V at 10 and 100 mA/cm2, respectively. We further scale up the MFN-0.5 (4 ×4 cm2) for a single stack-cell electrolyzer, requiring a cell potential of 1.85 V to achieve a large current density of 250 mA/cm2. Incorporating the MoOx phase accelerates the water dissociation step and protects the metal sulfide surface from oxidation under anodization in an alkaline environment. Our findings offer a promising approach for developing highly efficient catalysts for electrolytic water-splitting applications.

Scenario Planning Analysis for Commercial Housing Developer Company (Case Study: PT. TRIFECTA ADI PERKASA)

Indonesia’s Law no.1 (2011) necessitates the provision of affordable housing by the government, implicating both public and private sectors. Intermediate commercial housing enterprise, PT Trifecta Adi Perkasa, navigates such a mandate amid various unpredictable elements using scenario planning. This approach involves exhaustive external and internal analyses using PESTEL, Porter’s Five Forces, and Resource-based methods, viewed through a SWOT framework. This multi-phase strategy incorporates first-hand and secondary data assessing current and impending property-related issues. The process culminates in four prospective strategies and an ensuing five-year operational plan, buffering against future uncertainties.

A Novel Multi-Phase Strategy for Optimizing CO2 Utilization and Storage in an Oil Reservoir

In this paper, an innovative multi-phase strategy is developed and numerically tested to optimize CO2 utilization and storage in an oil reservoir to support low carbon transition. In the first phase, the water-alternating-gas (WAG) injection is conducted to simultaneously store CO2 and produce crude oil in the reservoir from the respective injection and production wells. In the second phase, the injection and production wells are both shut in for some time to allow CO2 and water to be stratigraphically separated. In the third phase, CO2 is injected from the upper part of the reservoir above the separated water layer to displace water downwards, while fluids continue to be produced in the water-dominated zone from the lower part of the production well. Lastly, the production well is finally shut in when the produced gas–water ratio (GWR) reaches 95%, but CO2 injection is kept until the reservoir pressure is close to the fracture pressure of its caprocks. The numerical simulations show that implementing the proposed multi-phase strategy doubles CO2 storage in comparison to applying the WAG injection alone. In particular, 80% of the increased CO2 is stored in the third phase due to the optimized perforation. In addition, the CO2 injection rate in the last phase does not appear to affect the amount of CO2 storage, while a higher CO2 injection rate can reduce the CO2 injection time and accelerate the CO2 storage process. In the proposed strategy, we assume that the geothermal energy resources from the produced fluids can be utilized to offset some energy needs for the operation. The analysis of energy gain and consumption from the simulation found that at the early stage of the CO2-WAG phase, the energy gain mostly comes from the produced oil. At the late stage of the CO2-WAG phase and the subsequent phases, there is very little or even no energy gain from the produced oil. However, the geothermal energy of the produced water and CO2 substantially compensate for the energy loss due to decreasing oil production. As a result, a net energy gain can be achieved from the proposed multi-phase strategy when geothermal energy extraction is incorporated. The new multi-phase strategy and numerical simulation provide insights for practical energy transition and CO2 storage by converting a “to be depleted” oil reservoir to a CO2 storage site and a geothermal energy producer while enhancing oil recovery.

Methodology for the development of National Multidisciplinary Management Recommendations using a multi-stage meta-consensus initiative

BackgroundMethods for developing national recommendations vary widely. The successful adoption of new guidance into routine practice is dependent on buy-in from the clinicians delivering day-to-day patient care and must be considerate of existing resource constraints, as well as being aspirational in its scope. This initiative aimed to produce guidelines for the management of head and neck squamous cell carcinoma of unknown primary (HNSCCUP) using a novel methodology to maximise the likelihood of national adoption.MethodsA voluntary steering committee oversaw 3 phases of development: 1) clarification of topic areas, data collection and assimilation, including systematic reviews and a National Audit of Practice; 2) a National Consensus Day, presenting data from the above to generate candidate consensus statements for indicative voting by attendees; and 3) a National Delphi Exercise seeking agreement on the candidate consensus statements, including representatives from all 58 UK Head and Neck Multidisciplinary Teams (MDT). Methodology was published online in advance of the Consensus Day and Delphi exercise.ResultsFour topic areas were identified to frame guideline development. The National Consensus Day was attended by 227 participants (54 in-person and 173 virtual). Results from 7 new systematic reviews were presented, alongside 7 expert stakeholder presentations and interim data from the National Audit and from relevant ongoing Clinical Trials. This resulted in the generation of 35 statements for indicative voting by attendees which, following steering committee ratification, led to 30 statements entering the National Delphi exercise.After 3 rounds (with a further statement added after round 1), 27 statements had reached ‘strong agreement’ (n = 25, 2, 0 for each round, respectively), a single statement achieved ‘agreement’ only (round 3), and ‘no agreement’ could be reached for 3 statements (response rate 98% for each round). Subsequently, 28 statements were adopted into the National MDT Guidelines for HNSCCUP.ConclusionsThe described methodology demonstrated an effective multi-phase strategy for the development of national practice recommendations. It may serve as a cost-effective model for future guideline development for controversial or rare conditions where there is a paucity of available evidence or where there is significant variability in management practices across a healthcare service.

Bacterial Necromass Is Rapidly Metabolized by Heterotrophic Bacteria and Supports Multiple Trophic Levels of the Groundwater Microbiome.

ABSTRACTPristine groundwater is a highly stable environment with microbes adapted to dark, oligotrophic conditions. Input events like heavy rainfalls can introduce the excess particulate organic matter, including surface-derived microorganisms, thereby disturbing the groundwater microbiome. Some surface-derived bacteria will not survive this translocation, leading to an input of necromass to the groundwater. Here, we investigated the effects of necromass addition to the microbial community in fractured bedrock groundwater, using groundwater mesocosms as model systems. We followed the uptake of 13C-labeled necromass by the bacterial and eukaryotic groundwater community quantitatively and over time using a complementary protein-stable and DNA-stable isotope probing approach. Necromass was rapidly depleted in the mesocosms within 4 days, accompanied by a strong decrease in Shannon diversity and a 10-fold increase in bacterial 16S rRNA gene copy numbers. Species of Flavobacterium, Massilia, Rheinheimera, Rhodoferax, and Undibacterium dominated the microbial community within 2 days and were identified as key players in necromass degradation, based on a 13C incorporation of >90% in their peptides. Their proteomes comprised various proteins for uptake and transport functions and amino acid metabolization. After 4 and 8 days, the autotrophic and mixotrophic taxa Nitrosomonas, Limnohabitans, Paucibacter, and Acidovorax increased in abundance with a 13C incorporation between 0.5% and 23%. Likewise, eukaryotes assimilated necromass-derived carbon either directly or indirectly. Our data point toward a fast and exclusive uptake of labeled necromass by a few specialists followed by a concerted action of groundwater microorganisms, including autotrophs presumably fueled by released, reduced nitrogen and sulfur compounds generated during necromass degradation.IMPORTANCE Subsurface microbiomes provide essential ecosystem services, like the generation of drinking water. These ecosystems are devoid of light-driven primary production, and microbial life is adapted to the resulting oligotrophic conditions. Modern groundwater is most vulnerable to anthropogenic and climatic impacts. Heavy rainfalls, which will increase with climate change, can result in high surface inputs into shallow aquifers by percolation or lateral flow. These inputs include terrestrial organic matter and surface-derived microbes that are not all capable to flourish in aquatic subsurface habitats. Here, we investigated the response of groundwater mesocosms to the addition of bacterial necromass, simulating event-driven surface input. We found that the groundwater microbiome responds with a rapid bloom of only a few primary degraders, followed by the activation of typical groundwater autotrophs and mixotrophs, as well as eukaryotes. Our results suggest that this multiphase strategy is essential to maintain the balance of the groundwater microbiome to provide ecosystem services.

ARCHAEOLOGICAL INVESTIGATIONS IN THE NORTHERN PORTION OF ANCIENT TULA

AbstractSalvage excavations along the right of way of a 2 km stretch of proposed highway crossing the northern part of the Postclassic city of Tula, Hidalgo utilized a multi-phase investigation strategy, featuring pedestrian survey and exploratory test-pitting. This fieldwork led to extensive excavation in five localities, which uncovered significant portions of both elite and non-elite residential compounds, a possible administrative structure, and two temples, one of which is the earliest example of a twin temple pyramid in western Mesoamerica. The diversity of structures and corresponding functions encountered in excavation are comparable to those found in previous excavations that suggest the city was organized into barrios, each with its own political, religious, social, and other institutions that mimic those of the larger urban polity. While these investigations confirm previous evidence of considerable destruction of the ancient city in recent decades, they also demonstrate that significant portions are still intact.

A specious relevance between theory and practice: Insights into temperature parameter and multi-phase strategy of anaerobic digestion of straw

Anaerobic digestion (AD) of straw is a highly complex and dynamic process. The temperature range of mesophilic (30–40 °C) and thermophilic (50–65 °C) are usually recommended in textbook notion. The two-phase strategy is usually applied based on the classical theory, including acidification-phase and methanation-phase. However, both the optimized temperature parameter and the enhanced multi-phase strategy solely focus on the local AD process. A specious relevance between theory and practice during AD process of straw has always been argued. Classical AD theory was not necessarily the sufficient approach to guide the anaerobic biological transformation of straw. More profound investigations of optimum temperature are still needed, uniquely synergistic mechanisms of functional microorganisms, as well as process stability, should be taken into account. Besides, additional research should focus on the matching between the physicochemical properties and process parameters/strategies choosing. A multi-stage operation strategy based on straw material composition is a potential operation approach to improve its efficiency. Furthermore, more comprehensive attention should be paid to the collaborative response mechanism by coupling substrate, temperature, and microbial in complex AD systems for straws.

Impact of International Trade of Higher Education on Universities' Performance

The central theme of the research work was to examine the impact of International Trade of Higher Education (IToHE) on universities' performance. The nature of the article was descriptive; as a consequence, the data of the study was assembled by means of survey and interview. The targeted population was comprised of all BS, MS, PhD students, faculty and administration from all general public universities of Punjab, which were included in the HEC ranking in 2015. The purposive sampling technique and multiphase strategy were applied to specify the sample. Data was collected via two research instruments. To assemble quantitative data, a questionnaire was planned on six factors, i.e. Leadership role (LR), Quality Teaching (QT), Research (R), University Ranking (UR), Community Perception (CP) and International Trade of Higher Education (IToHE). According to the triangulation result, findings illustrated that Academia should do productive work instead of producing passive labor. The study recommended further researches in the field of cross border mobility and its role in university, society and country development.

A Novel CNN Training Framework: Loss Transferring

As one of the indispensable components in convolutional neural network (CNN), loss function assists in updating parameters of CNN models during the training phase. Generally, different loss functions can assist convolutional neural network (CNN) to learn different feature representations, and different feature representations can be treated as different knowledge learned from objects. In this paper we introduce a novel training framework, namely Loss Transferring (LT), to improve the generalization ability of CNN. LT contains multiple training phases, and each training phase uses a different loss function. Under this framework, CNN models can combine different knowledge of objects by transferring the knowledge learned via one loss function to another. LT contains two components, i.e., loss function set and training strategy. In order to build appropriate loss function set, we establish two basic guides. And according to these basic guides, we design a new loss function in the last layer of CNN models (layer before softmax operation), namely Near Classifier Hyper-Plane (N-CHP) loss, which makes the learned object features belonging to the same category have the minimum intra-class distance and be near the classifier hyper-plane. Based on the two loss function set $\{\text {MSE, softmax}\}$ and $\{\text {N-CHP, softmax}\}$ , we setup two specific training methods, $LT_{\text {MSE, softmax}}$ and $LT_{\text {N-CHP, softmax}}$ , which can be universally applied to different CNN models with low additional computation cost. Meanwhile, two training strategies, multi-phase strategy 1 and multi-phase strategy 2, are further proposed to improve the training efficiency of LT. Extensive experimental results on shallow, moderate and deep models with four benchmark datasets, including MNIST, SVHN, CIFAR-10 and CIFAR-100, demonstrate that CNN models can bring obvious performance improvements when working with $LT_{\text {MSE, softmax}}$ and $LT_{\text {N-CHP, softmax}}$ , which verifies the effectiveness of LT and the proposed two basic guides.

Mission-based multidisciplinary optimization of solar-powered hybrid airship

This paper presented a multidisciplinary optimization methodology of a high altitude solar-powered hybrid airship. A multidisciplinary model of the hybrid airship is proposed including the geometry, aerodynamics, structures, propulsions and energy consisting of the photovoltaic array and energy stored system (ESS). To achieve a continuous flight and reduce the total mass and energy cost, a multi-phase strategy including the climb, daytime cruise, glide and nighttime cruise is proposed. The mission-based optimization is achieved through an enhanced collaborative optimization and the result shows a large decrease in the total mass compared with a baseline design.Since the flight altitude has a great influence on the hybrid airship with the multi-phase strategy, a multi-objective optimization achieved by NSGA-II (Non-dominated Sort Genetic Algorithm-II), is carried out to discuss the design tradeoffs in different altitudes. The result also indicates that the multi-objective optimization provides a solution set so that the optimal design of the hybrid airship in different flight altitudes could be obtained.

Optimizing treatment protocols for spinal manipulative therapy: study protocol for a randomized trial

BackgroundLow back pain is a common and costly condition. Spinal manipulative therapy (SMT) is a treatment supported in some guidelines, although most clinical trials examining SMT report small effect sizes. Enhancing the effects of SMT requires an understanding of underlying mechanisms and a systematic approach to leverage understanding of mechanisms to create more effective treatment protocols that are scalable in clinical practice. Prior work has identified effects on spinal stiffness and lumbar multifidus activation as possible mechanisms. This project represents a refinement phase study within the context of a multi-phase optimization strategy (MOST) framework. Our goal is to identify an optimized SMT treatment protocol by examining the impact of using co-intervention exercise strategies that are proposed to accentuate SMT mechanisms. The optimized protocol can then be evaluated in confirmation phase clinical trials and implementation studies.MethodsA phased, factorial randomized trial design will be used to evaluate the effects of three intervention components provided in eight combinations on mechanistic (spinal stiffness and multifidus muscle activation) and patient-reported outcomes (pain and disability). All participants will receive two sessions then will be randomly assigned to receive six additional sessions (or no additional treatment) over the next three weeks with factorial combinations of additional SMT and exercise co-interventions (spine mobilizing and multifidus activating). Outcome assessments occur at baseline, and one week, four weeks, and three months after enrollment. Pre-specified analyses will evaluate main effects for treatment components as well as interaction effects.DiscussionBuilding on preliminary findings identifying possible mechanisms of effects for SMT, this trial represents the next phase in a multiphase strategy towards the ultimate goal of developing an optimized protocol for providing SMT to patients with LBP. If successful, the results of this trial can be tested in future clinical trials in an effort to produce larger treatment benefits and improve patient-centered outcomes for individuals with LBP.Trial registrationClinicalTrials.gov, NCT02868034. Registered on 16 August 2016.

Assessment of Mixture and Eulerian Multiphase Models in Predicting the Thermo-Fluidic Transport Characteristics for Fly Ash-Water Slurry Flow in Straight Horizontal Pipeline

ABSTRACTThe thermo-fluidic transport characteristics of the fly ash–water slurry flow in a straight horizontal pipe are predicted by deploying two different multiphase modeling strategies, viz. the mixture and the Eulerian multiphase models. Comparisons between the two model predictions in terms of the pressure drop and heat transfer coefficient are done along with the comparisons between the single (water) and the two phase system (slurry). Spherical fly ash particles, with diameter of 13 µm for an average inflow velocity ranging from 1 to 5 m/s and particle concentrations within 0–40% by volume for each velocity are considered as the dispersed phase carried by the carrier phase water. Significant differences between the two model predictions can be observed both from the qualitative and quantitative perspectives. This finally leads to the appropriate choice of the multiphase model for predicting the thermo-fluidic transport characteristics in slurry flow.

An intervention strategy for improving residential environment and positive mental health among public housing tenants: rationale, design and methods of Flash on my neighborhood!

BackgroundIn Canada, public housing programs are an important part of governmental strategies to fight poverty and public exclusion. The Flash on my neighborhood! project is a four-year multiphase community-based participatory action research strategy currently implemented in six public housing developments (n = 1009 households) across the province of Québec, Canada. The goal is to reduce the mental health disparities faced by these public housing tenants compared to the general population, while identifying which environmental and policy changes are needed to turn public housing settings into healthier environments.MethodsThe protocol involves three successive, interconnected phases: 1) Strengths and needs assessment, including community outreach and recruitment of tenants to collaborate as peer researchers, an exploratory qualitative component (photovoice), a systematic neighborhood observation, and a household survey; 2) Action plan development, including a community forum and interactive capacity-building and discussion sessions; 3) Action plan implementation and monitoring. The entire intervention is evaluated using a mixed-method design, framed within a multiple case study perspective. Throughout the project and particularly in the evaluation phase, data will be collected to record a) contextual factors (tenants’ previous experience of participation, history of public housing development, etc.); b) activities that took place and elements from the action plan that were implemented; and c) short- and medium-term outcomes (objective and perceived improvements in the quality of the residential setting, both physically and in terms of mental health and social capital).DiscussionThe study will provide unprecedented evidence-based information on the key ingredients of a collective intervention process associated with the increased collective empowerment and positive mental health of public housing tenants.

A multiphase DMOC‐based trajectory optimization method

SummaryDiscrete mechanics and optimal control (DMOC) is a methodology that takes advantage of variational structure to solve certain optimal control problems for mechanical systems. This paper proposes to combine a multiphase strategy with the original DMOC method, resulting in a new multiphase DMOC (MDMOC) method and making optimal trajectory generation more efficient. The advantages of the proposed method are demonstrated mathematically, and in addition, a quadrotor, unmanned aerial vehicle, simulation example is presented to show its superiority over the DMOC method. Furthermore, to show its potential application, an arbitrarily chosen controller was used to track the desired trajectory generated by MDMOC. This new MDMOC methodology can also be applied to other mechanical systems such as mobile robots and underwater gliders.

Multiphase Oscillatory Flow Strategy for in Situ Measurement and Screening of Partition Coefficients.

Taking advantage of the difference between the surface energies of aqueous and organic solvents on a Teflon substrate, a fully automated small-scale strategy is developed on the basis of gas-driven oscillatory motion of a biphasic slug for high-throughput in situ measurement and screening of partition coefficients of organic substances between aqueous and organic phases. The developed oscillatory flow strategy enables single partition coefficient data point measurement within 8 min (including the sample preparation time) which is 360 times faster than the conventional "shake-flask" method, while using less than a 30 μL volume of the two phases and 9 nmol of the target organic substance. The developed multiphase strategy is validated using a conventional shake-flask technique. Finally, the developed strategy is extended to include automated screening of partition coefficients at physiological temperature.

Shaped charge simulation using SPH in cylindrical coordinates

Purpose – The purpose of this paper is to investigate the applicability of the smoothed particle hydrodynamics (SPH) method in the jet formation process of a cylindrical-shaped charge (CSC). Different SPH formulations, suggested in other works, to other applications, are brought together in order to build a model that represents the phenomenon of detonation of a CSC in a more realistic way. Design/methodology/approach – A two-dimensional (2D) SPH formulation using cylindrical coordinates is adopted to simulate CSCs. The problem of fluid-solid interaction between the detonation wave of the explosive and the metal liner, numerically unstable due to the great difference in density between the phases, is resolved adopting the multi-phase strategy. A new proposition of artificial viscosity is incorporated in order to account the convergence effect of the liner particles toward the axis of symmetry of the charge. Two numerical examples are used to validate the formulation. In the first, the velocity and length differences between the jets formed from a CSC and a linear-shaped charge (LSC) using planar detonation on both are compared. In the second example, the effect of the conical cavity angle in the maximum jet velocity is evaluated, comparing the simulated results of CSC with four different cavity angles, with the experimental results. Findings – The results show that the 2D SPH method in cylindrical coordinates is able to simulate the detonation process of a CSC. Accordingly with the formulations used, the following conclusions can be made: the multi-phase strategy is able to capture the multi-material interface of the fluid-solid interaction between the detonation wave and the metal liner; and in the cylindrical geometry, a second artificial viscosity is necessary in order to include the convergence effect of the particles toward the axis of symmetry and obtaining more realistic results for the jet velocity. Originality/value – The applicability of the SPH method to simulate LSCs has been tested and verified in other works, but there are not references that address the application of the SPH method to simulate CSCs. CSCs are widely used in the defense industry and in the oil industries. In the oil industry, the perforating process may currently be the most common use of such a device. For this reason, it is believed that the proposed formulation in this paper is a good alternative to these specific applications.

Metallo-supramolecular complexes mediated thermoplastic elastomeric block copolymer

Orthogonal multi-phase strategy has been applied to generate a novel type of thermoplastic elastomeric block copolymer which was obtained via anionic polymerization. Functional terpyridine groups which can potentially form metallo-supramolecular complexes with a variety of metal ions has been introduced to the polystyrene-b-polyisoprene (PS-PI) living chain ends through the termination reaction in an optimized condition. Iron(II), cobalt(II) and zinc(II) metal ions have been used to form metal-ligand complexes with the terpyridine end groups, which can phase separate from the polymer matrix to form hybrid clusters. The formation of metallo-supramolecular hybrid clusters have dramatic effects on the micro-phase separated structures of the PS-PI diblock copolymer, which have been characterized by transmission electron microscopy, small-angle X-ray scattering and atomic force microscopy. This type of hybrid material containing hard PS nanophase and metal-ligand clusters exhibit distinct mechanic properties such as increased modulus, higher yield strength and improved toughness, which is further discussed in light of nature of the metal-ligand bonds and the liability of the clusters. The utilization of metallo-supramolecular complex and its high tunability is potential to fabricate new types of supramolecular nanocomposite materials.

Multiphase analysis by linkage, quantitative transmission disequilibrium, and measured genotype: systolic blood pressure in complex Mexican American pedigrees.

We apply a multiphase strategy for pedigree-based genetic analysis of systolic blood pressure data collected in a longitudinal study of large Mexican American pedigrees. In the first phase, we conduct variance-components linkage analysis to identify regions that may harbor quantitative trait loci. In the second phase, we carry out pedigree-based association analysis in a selected region with common and low-frequency variants from genome-wide association studies and whole genome sequencing data. Using sequencing data, we compare approaches to pedigree analysis in a 10 megabase candidate region on chromosome 3 harboring a gene previously identified by a consortium for blood pressure genome-wide association studies. We observe that, as expected, the measured genotype analysis tends to provide larger signals than the quantitative transmission disequilibrium test. We also observe that while linkage signals are contributed by common variants, strong associations are found mainly at rare variants. Multiphase analysis can improve computational efficiency and reduce the multiple testing burden.

Path planning for multiple mobile robots under double-warehouse

This work investigates the conflict-free path planning problems for efficient guidance of multiple mobile robots under the dynamic double-warehouse environment, a challenging problem that appears recurrently in a wide range of applications such as the service robots moving in a multistory building. United with two symmetrical transfer elevators, double-warehouse consists of two parallel warehouses. Within each warehouse, the polynomial based paths are subject to constraints such as motion boundaries, kinematics constraints, obstacle-avoidance, limited resource of elevators and smoothness. We formulate the shortest path planning problems as one time-varying nonlinear programming problem (TNLPP) while restricted to the above constraints, and apply the multi-phase strategy to reduce their difficulty. We present the new variant algorithms of PSO named constriction factor and random perturb PSO (Con-Per-PSO) and the simulating annealing PSO (SA-PSO) to achieve the solution. Numerical simulations verify that, our approach can fulfill multiple mobile robots path planning problems under double-warehouse successfully.