Stepping Stone Research Articles

Adaptive control of resource flow to optimize construction work and cash flow via online deep reinforcement learning

Due to complexity and dynamics of construction work, resource, and cash flows, poor management of them usually leads to time and cost overruns, bankruptcy, even project failure. Existing approaches in construction failed to achieve optimal control of resource flow in a dynamic environment with uncertainty. Therefore, this paper proposes a model and method to adaptive control the resource flows to optimize the work and cash flows of construction projects. First, a mathematical model based on a partially observable Markov decision process is established to formulate the complex interactions of construction work, resource, and cash flows as well as uncertainty and variability of diverse influence factors. Meanwhile, to efficiently find the optimal solutions, a Deep Reinforcement Learning (DRL) based method is introduced to realize the continuous adaptive optimal control of labor and material flows, thereby optimizing the work and cash flows. To assist the training process of DRL, a simulator based on discrete event simulation is also developed to mimic the dynamic features and external environments of a project. Experiments in simulated scenarios illustrate that our method outperforms the vanilla empirical method and genetic algorithm, possesses remarkable capability in diverse projects and external environments, and a hybrid agent of DRL and empirical method leads to the best result. This paper contributes to adaptive control and optimization of coupled work, resource, and cash flows, and may serve as a step stone for adopting DRL technology in construction project management.

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is a retired critical care nurse who worked as a staff nurse, clinical nurse specialist, nurse educator, researcher, lecturer at a school of nursing and editor. The author has disclosed that she has no significant relationships with, or financial interest in, any commercial companies pertaining to this article.

Adaptation and pre-test of a shortened Stepping Stones and Creating Futures intervention focused on HIV for young men in rural South Africa.

Men's engagement in HIV prevention and treatment is suboptimal, including in South Africa. We sought to address this through adapting an evidence-based intervention, Stepping Stones and Creating Futures (SSCF), to strengthen its HIV content and provide a more scalable (shorter) intervention in rural South Africa. We then conducted a mixed methods pre-test of the intervention among young men aged 18-35 years. To adapt SSCF, we reviewed the current evidence base and worked with male Peer Navigators to update the SSCF theory of change (ToC) and manual. The revised intervention was ~45 hours (9 sessions) as opposed to ~63 hours and included a greater focus on HIV prevention and treatment technologies. Overall, 64% (n = 60) of men approached agreed to participate in the intervention, uptake (attending one session) among those who agreed was n = 35(58%) and retention (attending 6 or more sessions) was n = 25(71%). Qualitative data emphasized the intervention was acceptable, with young men describing it as something they liked. The qualitative data also broadly supported the intervention ToC, including the normalization of HIV in men's lives, and the importance of health for men in achieving their life goals. However, it also highlighted the need to focus more on HIV-related stigma and fear, and the importance of HIV self-testing kits in encouraging testing. We revised the ToC and manual in light of this data. The adapted SSCF is acceptable and supports the ToC. Next steps is an evaluation to look at effectiveness of the intervention.

Construction and Optimization of an Ecological Network in the Yellow River Source Region Based on MSPA and MCR Modelling.

The source region of the Yellow River (SRYR) is an important water conservation and farming area in China. Under the dual influence of the natural environment and external pressure, ecological patches in the region are becoming increasingly fragmented, and landscape connectivity is continuously declining, which directly affect the landscape patch pattern and SRYR sustainable development. In the SRYR, morphological spatial pattern analysis (MSPA) and landscape index methods were used to extract ecologically important sources. Based on the minimum cumulative resistance model (MCR), Linkage Mapper was used to generate a potential corridor, and then potential stepped stone patches were identified and extracted by the gravity model and betweenness centrality to build an optimal SRYR ecological network. The distribution of patches in the core area of the SRYR was fragmented, accounting for 80.53% of the total grassland area. The 10 ecological sources based on the landscape connectivity index and 15 important corridors identified based on the MCR model were mainly distributed in the central and eastern regions of the SRYR. Through betweenness centrality, 10 stepped stone patches were added, and 45 planned ecological corridors were obtained to optimize the SRYR ecological network and enhance east and west connectivity. Our research results can provide an important reference for the protection of the SRYR ecosystem, and have important guiding significance and practical value for ecological network construction in ecologically fragmented areas.

Buildings and Institutional Change: Stepping Stones or Stumbling Blocks?

AbstractThis study aims to throw some theoretical light on the relationship between institutions and the buildings housing them, particularly in the context of institutional change. Drawing on my ethnographic study of the UK Parliament buildings in London, I put forward a framework for analysing the effects that buildings and the artifacts within them may have on institutional change. This framework consists of three elements: (1) buildings enabling or constraining the activities performed inside; (2) spatial hierarchy; and (3) buildings as a resource. My intention is to draw scholars’ attention to the notion of buildings as sites of contestation – places where conflicts over nature and the extent of institutional change are played out. I conclude that redesigning buildings might be seen as a stepping stone to change, but also that buildings can be used to resist change and maintain the status quo. Although buildings ‘inhabited’ by institutions may appear to stand still, they never do; they change in time, both enabling and constraining those who use them and they have an ability to ‘act back’.

IMPLEMENTATION OF TRANSPORTATION METHODS IN OPTIMIZING THE DISTRIBUTION OF HIJAB PRODUCTS AT AYASHA HIJAB STORE

<em>The problem of transportation costs is a problem faced by many companies, especially those that distribute goods from various places to various destinations, and Ayasha Hijab's company is no exception. The company has 3 stores and supplies Bella square veils from 3 different warehouses. This of course has an impact on the company's expenses considering the distance and the increasing number of requests. The researcher tries to find a solution by using the linear program transportation solution method. Researchers processed data from the Ayasha Hijab Company with the NWC model and then second processing to get optimal results with stepping stones and MODI. As a result, the optimal cost for the stepping stone and MODI models is IDR 5.125.000. The Stepping Stone and MODI methods get the optimal solution and can save costs around IDR. 3.350.000 from the NWC method with a cost of IDR. 8.475.000. Secondary data obtained from the calculation of "Ayasha Hijab Store" has a minimum cost of around IDR. 10.000.000. So that the Stepping Stone method and the MODI method can save Bella Square distribution costs of IDR. 4.875.000.</em>

A Stepping Stone Approach to Norm Transitions

A Stepping Stone Approach to Norm Transitions

The Mosaico HIV Vaccine Study: A Step Back or a Stepping Stone for Future Vaccine Development?

Multidrug resistance to antiretroviral therapy, while uncommon, is associated with high rates of clinical progression and virologic failure. Lenacapavir is the first capsid inhibitor to be approved for the treatment of HIV infection in heavily treatment-experienced people with multi-resistant virus, who cannot be successfully treated with other available therapies due to resistance, intolerance or safety considerations. The key feature of lenacapavir is its long half-life, which allows its subcutaneous formulation to be administered every 6 months. This is crucial for a population with low adherence rates to antiretroviral therapy. This review discusses the characteristics of lenacapavir, including its mechanism of action, pharmacokinetics/pharmacodynamics and resistance profile, the key efficacy and safety data from clinical trials, and its place in the management of patients with multidrug-resistant HIV infection.

Joachim J. Krause, Omer Sergi, and Kristin Weingart, eds. Saul, Benjamin, and the Emergence of Monarchy in Israel: Biblical and Archaeological Perspectives

Joachim J. Krause, Omer Sergi, and Kristin Weingart, eds. <i>Saul, Benjamin, and the Emergence of Monarchy in Israel: Biblical and Archaeological Perspectives</i>

A combined approach of experimental and numerical modeling for 3D hydraulic features of a step-pool unit

Abstract. Step-pool systems are common bedforms in mountain streams and have been utilized in river restoration projects around the world. Step-pool units exhibit highly nonuniform hydraulic characteristics which have been reported to closely interact with the morphological evolution and stability of step-pool features. However, detailed information on the three-dimensional hydraulics for step-pool morphology has been scarce due to the difficulty of measurement. To fill in this knowledge gap, we established a combined approach based on the technologies of structure from motion (SfM) and computational fluid dynamics (CFD). 3D reconstructions of bed surfaces with an artificial step-pool unit built from natural stones at six flow rates were imported to CFD simulations. The combined approach succeeded in visualizing the high-resolution 3D flow structures for the step-pool unit. The results illustrate the segmentation of flow velocity downstream of the step, i.e., the integral recirculation cell at the water surface, streamwise vortices formed at the step toe, and high-speed flow in between. The highly nonuniform distribution of turbulence energy in the pool has been revealed, and two energy dissipaters of comparable magnitude are found to co-exist in the pool. Pool scour development during flow increase leads to the expansion of recirculation cells in the pool, but this expansion stops for the cell near the water surface when flow approaches the critical value for step-pool failure. The micro-bedforms (grain clusters) developed on the negative slope affect the local hydraulics significantly, but this influence is suppressed at the pool bottom. The drag forces on the step stones increase with discharge (before the highest flow value is reached). In comparison, the lift force consistently has a larger magnitude and a more widely varying range. Our results highlight the feasibility and great potential of the approach combining physical and numerical modeling in investigating the complex flow characteristics of step-pool morphology.

Iceland as Stepping Stone for Spread of Highly Pathogenic Avian Influenza Virus between Europe and North America.

Highly pathogenic avian influenza viruses (HPAIVs) of hemagglutinin type H5 and clade 2.3.4.4b have widely spread within the northern hemisphere since 2020 and threaten wild bird populations, as well as poultry production. We present phylogeographic evidence that Iceland has been used as a stepping stone for HPAIV translocation from northern Europe to North America by infected but mobile wild birds. At least 2 independent incursions of HPAIV H5N1 clade 2.3.4.4b assigned to 2 hemagglutinin clusters, B1 and B2, are documented for summer‒autumn 2021 and spring 2022. Spread of HPAIV H5N1 to and among colony-breeding pelagic avian species in Iceland is ongoing. Potentially devastating effects (i.e., local losses >25%) on these species caused by extended HPAIV circulation in space and time are being observed at several affected breeding sites throughout the North Atlantic.

Re-examining the relationship between measures of static and dynamic balance among young adults

Balance is essential to several activities of daily life, from the capacity to stand independently to the execution of complex sport movements. The extent to which balance can be improved has led researchers to consider whether underlying features of a general balance ability exists, and whether they can be used to predict performance on future balance tasks. Adjacent to this investigation is the debate between theorists who support a general motor ability (GMA) and those who advocate for motor specificity. The notion of task specificity has been supported within the literature, such as the highly cited study by Drowatzky and Zuccato (1967) that compared balance tasks, finding weak correlations between tasks assessed. The purpose of the current study was to replicate this classic study using a more mature, contemporary sample and investigate the relationship between six static and dynamic measures of balance among a young adult population to determine if there is continuing support for this notion. Standardized instructions and procedures were followed when completing the Stork Stand Test, Diver’s Stand Test, Bass Lengthwise Stick Test, Sideward Leap Test, Modified Bass Stepping Stone Test, and a Modified Balance Beam Test. Five hundred and seventy university students completed these six balance performance tests. A Spearman’s rank-order correlation test, assessing the relationship between the results, revealed significant weak to moderate correlations. These results contrasted with the original study that yielded weak correlations between balance tasks, with only one correlation reaching significance (Drowatzky &amp; Zuccato, 1967). While the nature of the tasks assessed made it difficult to draw conclusions with respect to the motor specificity hypothesis, they allowed further reflection on the complexity of balance, and on the specificity of practice hypothesis, thus calling to revisit the debate.

Induced Pluripotent Stem Cells, a Stepping Stone to In Vitro Human Models of Hearing Loss.

Hearing loss is the most prevalent sensorineural impairment in humans. Yet despite very active research, no effective therapy other than the cochlear implant has reached the clinic. Main reasons for this failure are the multifactorial nature of the disorder, its heterogeneity, and a late onset that hinders the identification of etiological factors. Another problem is the lack of human samples such that practically all the work has been conducted on animals. Although highly valuable data have been obtained from such models, there is the risk that inter-species differences exist that may compromise the relevance of the gathered data. Human-based models are therefore direly needed. The irruption of human induced pluripotent stem cell technologies in the field of hearing research offers the possibility to generate an array of otic cell models of human origin; these may enable the identification of guiding signalling cues during inner ear development and of the mechanisms that lead from genetic alterations to pathology. These models will also be extremely valuable when conducting ototoxicity analyses and when exploring new avenues towards regeneration in the inner ear. This review summarises some of the work that has already been conducted with these cells and contemplates future possibilities.

Predictors of Change in Stepping Stones Triple Interventions: The Relationship between Parental Adjustment, Parenting Behaviors and Child Outcomes.

The current study explored the process of change in Stepping Stones Triple P (SSTP) using a community-based sample of 891 families of children with developmental disabilities (DD) who participated in an SSTP intervention at a community level. A preliminary analysis of outcome data indicated that SSTP intervention was effective in reducing parental adjustment difficulties, coercive parenting, and children’s behavioral and emotional difficulties immediately after the intervention. The effects were maintained at 12-month follow-up. The results also indicated that change in parental adjustment over the course of intervention was significantly associated with a change in parenting behaviors. However, change in parenting behaviors but not change in parental adjustment, predicted children’s behavioral and emotional problems following the intervention. The results suggest that positive parenting skills are the most salient ingredient driving the change in child behaviors in SSTP interventions.

A Novel Approach Algorithm for Determining the Initial Basic Feasible Solution for Transportation Problems

In optimization, the transportation problem is of utmost significance. The fundamental idea for solving the transportation problem is to develop methods that lower the overall cost between the source and the destination. Numerous research techniques are given in the literature as solutions to transportation problems. The majority of strategies focus on locating the initial basic, feasible solution to the transportation problem, while some techniques concentrate on locating an optimal solution. To find an initial, basic, feasible solution, Vogel's approximation, the least-cost method, the northwest method, and other methods are used. The Modified Distribution Method and the Stepping Stone Method are gaining acceptance as the optimal solution to the transportation problem. In this research study, a model approach to figuring out the basic, feasible solution for transportation problems with balanced and unbalanced components is proposed based on the average unit cost value of columns and rows. A new table is created using the unit cost values and average unit cost values in the columns and rows and compared to the transportation problem to solve the problem by balancing demand and supply. The proposed methodology is effortless, easy to understand, and simple to use. Comparatively speaking, the algorithmic technique suggested by this work is less complex than the well-known meta-heuristic algorithms in the literature. Finally, provide a case study to demonstrate the proposed approach.

Miller, Stuart S. At the Intersection of Texts and Material Finds: Stepped Pools, Stone Vessels, and Ritual Purity among the Jews of Roman Galilee. Göttingen: V&amp;R Academic, 2015. 342 pp.

Article Miller, Stuart S. At the Intersection of Texts and Material Finds: Stepped Pools, Stone Vessels, and Ritual Purity among the Jews of Roman Galilee. Göttingen: V&R Academic, 2015. 342 pp. was published on October 1, 2022 in the journal Studies in Judaism, Humanities, and the Social Sciences (volume 4, issue 1).

Optimasi Distribusi Biaya Transportasi Melalui Metode Modified Distribution

Distribution is the action or process of supplying goods to stores and other businesses that sell to consumers. If a product or service is distributed from a company, it requires adequate means of transportation and usually requires too large distribution costs. Delivery of goods at this company does not use mathematical methods in calculating its distribution to several places correctly. The purpose of this research is to create an optimal, efficient and effective distribution model for this company by applying the North West Corner Method and the Modified Distribution Method in July, August and September 2021. North West Corner Method for the initial solution and Modified Distribution Method as the optimal solution is a variation of the Stepping Stone method. The results of this research show that the distribution costs incurred by the company after being calculated using the North West Corner Method and the Modified Distribution Method are Rp. 6,961,779, - from Rp. 7,000,000. Then these two methods are able to help companies save distribution costs incurred.

Metode Lowest Supply Lowest Cost (LSLC) Pada Masalah Transportasi Tidak Seimbang (Studi Kasus Pada Ditribusi Air Minum PT. Anugerah Berkah Bersaudara)

Distribution of goods is very important for the company. In order to get a bigger profit, the company tries to deliver the goods in the most effective way possible. There are several warehouse locations and several destinations, with different shipping costs, so the distribution problem can be solved using transportation methods. There are many methods that can be used to determine the optimal solution to the transportation problem. In this study, the Lowest Supply Lowest Cost (LSLC) method was used to determine the initial solution and the Stepping Stone method was used to determine the optimal solution for the distribution of Bottled Drinking Water at PT. Anugerah Berkah Brothers, with the aim of minimizing transportation costs. Distribution problems at PT. Anugerah Berkah Brothers is an unbalanced transportation problem, because the amount of inventory is greater than the amount of demand. Based on the results of the discussion obtained that PT. Anugerah Berkah brothers can save transportation costs from before as much as 8% of the initial cost.

MINIMASI BIAYA PENGIRIMAN TAHU MENGGUNAKAN METODE TRANSPORTASI

Basically, all companies both big and small are always connected to the distribution of goods. The XYZ company is UMKM, the factory that is located at Ujung Berung, Bandung. The Company has three tofu factories that will distribute tofu into four different markets. This factory does not have a tofu flow distribution which results in high postage costs. In this study, the tofu flow distribution will be determined so that the cost of distributing tofu can be minimized. The method that can be used to determine the cost of distribution of tofu is the transportation method. The transportation methods used to solve the problems in this research are North West Corner (NWC), Least Cost and Vogel's Approximation Method (VAM) to determine the initial solution. Then optimized using the Stepping Stones method to get the minimum distribution costs. The calculation results obtained will be compared with the costs used by the previous company, with the hope that the results of this study can be considered by the company to be used in the tofu distribution

Approximation algorithm for prize-collecting sweep cover with base stations

In a sweep cover problem, positions of interest (PoIs) are required to be visited periodically by mobile sensors. In this paper, we propose a new sweep cover problem: the prize-collecting sweep cover problem (PCSC), in which penalty is incurred by those PoIs which are not sweep-covered, and the goal is to minimize the covering cost plus the penalty. Assuming that every mobile sensor has to be linked to some base station, and the number of base stations is upper bounded by a constant, we present a 5-LMP (Lagrangian Multiplier Preserving) algorithm. As a step stone, we propose the prize-collecting forest with k components problem (PCFk), which might be interesting in its own sense, and presented a 2-LMP for rooted PCFk.