Coordination Problems Research Articles

Research on Optimization of University Classroom Lighting Environment Based on Computer Simulation

In order to improve the comfort of classroom users and improve the lighting environment of university classrooms, this paper puts forward different optimization schemes based on computer simulation. Dialux, a lighting environment design software, is used to numerically simulate the lighting environment of university classrooms. The classroom lighting scheme is optimized and different solutions are proposed. Through computer simulation, the effect of lighting is compared and analyzed, in order to find the most beneficial scheme for students’ mental health, which provides the basis for intelligent control of classroom lighting. The results show that the average illuminance decreases with the increase of suspension height, and the illuminance uniformity increases first and then decreases with the increase of suspension height. The solution of adjusting the projection direction and surface reflectivity of lamps is not suitable, and upgrading the type of lamps can solve the lighting environment problems and control glare. Increasing the number of lamps and adjusting the arrangement of lamps can improve the lighting environment, increase the average value but reduce the uniformity, but lead to a significant increase in energy consumption. Intelligent control based on computer simulation can solve the coordination problem of energy consumption and lighting effect. Through comparative analysis of the effects of different schemes on the classroom lighting environment in colleges and universities based on computer simulation, this paper provides data support for the selection of improved schemes, which is conducive to the selection of more suitable intelligent lighting control schemes, to ensure students’ mental health and work efficiency, and has certain reference significance for creating a healthy and comfortable classroom lighting environment.

The Pathogenesis and Treatment Methods for Rett Syndrome

Rett Syndrome is a neurological condition primarily affecting women. Its symptoms include decreased brain size, inability to speak, and coordination problems. Several gene mutations have been discovered to play a role in this disease, with the MeCP2 mutation being the most widely known and frequent cause. Scientists are also attempting to create medicines targeting the genetic mutations that may provide a cure. However, the mechanism behind how MeCP2 affects the human brain on a molecular level remains to be discovered. This article summarises the important findings regarding the causes and the treatments of Rett Syndrome. It compares the current methods to treat this disease, including DAYBUE, the newly FDA-approved medicine and the only current medicine that targets Rett Syndrome. Future studies could revolve around the root causes of Rett Syndrome, such as the lack of MeCP2 in neurons, and attempt to solve the problem fundamentally. The findings are significant for humans to advance on finding a cure for this neurological disease.

Unmasking Sturge-Weber syndrome in adulthood: A case with extrafacial port-wine stain and delayed neurological symptoms

Background: Sturge-Weber Syndrome (SWS) is a rare neurocutaneous disorder characterized by a facial port-wine birthmark, leptomeningeal angiomatosis, and glaucoma. This case report highlights the challenges of diagnosing SWS when presenting with atypical features. Here, we present a 55-year-old man with an extra facial port-wine stain and delayed-onset seizures, deviating from the classic triad. Case Presentation: A 55-year-old man presented with a recent seizure and a characteristic port-wine birthmark extending beyond the typical facial region. Neurological examination revealed no weakness, speech difficulties, or coordination problems. Ophthalmological examination didn’t reveal glaucoma. Limited resources restricted access to advanced imaging like MRI scans. However, based on the constellation of clinical findings, including the facial birthmark with angiomatosis and the new-onset seizure, the patient received a diagnosis of SWS. Treatment with Levetiracetam was initiated to prevent future seizures, and patient education on managing diabetes and hypertension was provided. Clinical Discussion: This case underscores the importance of considering SWS in diagnosing adult-onset seizures, especially with a characteristic facial birthmark. The delayed presentation and isolated seizure suggest potentially less severe brain involvement. Resource limitations necessitated a clinical diagnosis and treatment with readily available medications. Conclusion: This case highlights the challenges of diagnosing atypical SWS presentations. Early diagnosis is crucial for prompt management and improved patient outcomes. Future research should focus on developing robust diagnostic tools and exploring novel treatment options for atypical SWS presentations.

The argument for near-term human disempowerment through AI

AbstractMany researchers and intellectuals warn about extreme risks from artificial intelligence. However, these warnings typically came without systematic arguments in support. This paper provides an argument that AI will lead to the permanent disempowerment of humanity, e.g. human extinction, by 2100. It rests on four substantive premises which it motivates and defends: first, the speed of advances in AI capability, as well as the capability level current systems have already reached, suggest that it is practically possible to build AI systems capable of disempowering humanity by 2100. Second, due to incentives and coordination problems, if it is possible to build such AI, it will be built. Third, since it appears to be a hard technical problem to build AI which is aligned with the goals of its designers, and many actors might build powerful AI, misaligned powerful AI will be built. Fourth, because disempowering humanity is useful for a large range of misaligned goals, such AI will try to disempower humanity. If AI is capable of disempowering humanity and tries to disempower humanity by 2100, then humanity will be disempowered by 2100. This conclusion has immense moral and prudential significance.

The disaster of the century, Kahramanmaras earthquake: A qualitative study on the experiences of the earthquake victims and search and rescue teams

This study aimed to explore the experiences of earthquake victims who experienced the Kahramanmaras earthquakes and individuals who actively served in search and rescue teams in the field. In this qualitative study, data were collected through semi-structured, in-depth interviews and focus group discussions (FGDs) forms from 47 earthquake victims living in various tent cities and 46 members of search and rescue teams in the Kahramanmaras and Hatay provinces. In-depth individual and focus group interviews were conducted using the maximum variation sampling method, which is a purposive sampling method, to identify the experiences of the participants. Data were analyzed using the content analysis method. The results revealed that search and rescue teams faced problems in coordination and transportation, communication, debris safety, and multidisciplinary reinforcement of their teams, especially during the intervention phase. Earthquake victims, on the other hand, were affected psychosocially and faced many problems such as access to the allocation of resources and aids and lack of information before, during, and after the earthquakes. In this context, these themes on the experiences of large-scale earthquakes that caused great psychosocial, economic, and social devastation from the perspectives of earthquake victims and search and rescue teams can contribute to the planning of early disaster prevention and response strategies for policymakers to improve disaster management at national and international levels.

A high speed and sensitive protection for distribution network with DGs using ferrite rings as line boundary

AbstractThere exist problems of hard coordination and threshold setting as well as low sensitivity in overcurrent relay due to the bidirectional and small fault current when distributed generators are integrated into the distribution network. This paper introduces ferrite rings (FRs) to act as boundaries of distribution feeders, and a peak time of voltage traveling wave‐based protection is proposed. The characteristics of FRs are analyzed and their feasibility as line boundary is validated. The fault characteristics of internal and external faults are analyzed when FRs are installed at both ends of the protected feeder. The results show that the peak time of the voltage travelling wave of the internal fault is far smaller than that of the external faults. According to the difference, the fault detection method and the protection scheme are proposed. Simulations in PSCAD and experiment validate that the proposed protection principle can reliably distinguish between internal and external faults. Besides, the proposed protection scheme has higher sensitivity compared to ROCOV‐based protection.

Large-scale group hierarchical DEMATEL method with automatic consensus reaching

Decision-making trial and evaluation laboratory (DEMATEL) is widely used because of its ability to effectively analyze nonlinear relationships between factors in complex systems. With the increasing complexity of decision-making problems, large-scale group decision-making (LSGDM) has become the norm. Most existing DEMATEL methods are only suitable for small-scale groups and simple systems. This study, therefore, proposes a large-scale group hierarchical DEMATEL method that considers consensus reaching. The DEMATEL method for LSGDM faces three challenges: large differences in knowledge structures, difficulty coordinating expert opinions, and slow group-consensus convergence. To address these challenges, first, we use hierarchical decomposition to decompose the complex system into simple systems with different levels to reduce the difficulty of decision-making in complex systems. Second, considering the limitations of expert knowledge and experience, we use the basic probability assignment function to extract the opinions of experts at different levels of subsystems and factors. Third, we divide experts into different clusters using K-means clustering to solve the problem of difficult expert-opinion coordination. Fourth, we design two types of consensuses (intrasubgroup and intersubgroup consensus) and an efficient new type of opinion autocorrection mechanism to solve the problem of the slow convergence of intragroup consensus and improve the efficiency of consensus reaching. Finally, we demonstrate the superiority of the proposed method through data analysis and method comparison.

Coordinating to avoid the catastrophe

“Tipping points” for dangerous climate damages can transform climate protection into a coordination problem. If the location of the threshold is known, Nash equilibria exist in which the catastrophe is averted even without a climate agreement. However, there usually exists also an equilibrium in which no country exerts effort to prevent it, and the catastrophe occurs. We model equilibrium selection among non-cooperative countries with the help of an external randomization device, and analyze how it affects coalition formation. We find that results are much more nuanced than in the case where non-cooperative countries always coordinate on preventing the catastrophe. In some cases, a “coalition of free-riders” forms that is detrimental to welfare. In other cases, a “threshold equilibrium” emerges in which coalition members commit to do more than the outsiders, and the coalition is just large enough to become active. The grand coalition is also an equilibrium outcome, but is often unstable towards deviations by groups of countries.

Towards a disequilibrated macroeconomics

This paper elaborates on four different reasons why the assumption of continual dynamic stochastic general equilibrium, which is now standard in mainstream macroeconomics but is not used in agent based macro, makes a macro model less useful: (1) it assumes away most coordination problems, (2) it hides possible instabilities, (3) it makes money look unimportant, and (4) it makes inflation look trivial.

The synergy complement control approach for seamless limb-driven prostheses

Limb-driven control allows for direct control by using residual limb movements rather than unnatural and complex muscle activation. Existing limb-driven methods simultaneously learn a variety of possible motions, ranging from a residual limb to entire arm motions, from human templates by relying on linear or nonlinear regression techniques. However, the map between a low-dimensional residual limb movement and high-dimensional total limb movement is highly underdetermined. Therefore, this complex, high-dimensional coordination problem cannot be accurately solved by treating it as a data-driven black box problem. Here we address this challenge by introducing the residual limb-driven control framework synergy complement control. Firstly, the residual limb drives a one-dimensional phase variable to simultaneously control the multiple joints of the prosthesis. Secondly, the resulting prosthesis motion naturally complements the movement of the residual limb by its synergy components. Furthermore, our framework adds information on contextual tasks and goals and allows for seamless transitions between these. Experimental validation was conducted using subjects with preserved arms employing an exo-prosthesis setup, and studies involving participants with and without limb differences in a virtual reality setup. The findings affirm that the restoration of lost coordinated synergy capabilities is reliably achieved through the utilization of synergy complement control with the prosthesis.

Разработка методики определения параметров преобразования систем координат на основе метода нелинейного программирования первого порядка при сопровождении строительства зданий и сооружений

Objective: to analyze the advantages and disadvantages of existing nonlinear programming methods for solving problems of coordinate system transformation (SC). To consider the need to convert the coordinates of points from local SC to urban. To determine the possibility of using the generalized reduced gradient method to transform the coordinates of points located both at a distance between points of about 150 m and at a distance of about 1.5 km. Methods: the theoretical foundations of this method are revealed. Information is provided on the procedure for performing transformations of coordinate systems. The algorithm of the generalized reduced gradient (OPG) method is given. A study has been conducted on the transformation of coordinate systems of starting points from SK1 to SK2 using the OPG method. The requirement for the value of the mean square error (SQR) of determining the position of the starting points when converting them from one coordinate system to another is justified. Results: a check was performed on the possibility of applying the obtained transformation parameters to recalculate the coordinates of points from the local SC to the city SC. Based on the verification of the obtained transformation parameters, the possibility of using them to recalculate the coordinates of points located at a distance of about 1,5 km was revealed. The need for additional research on the application of the generalized reduced gradient method to solve coordinate system transformation problems has been identified. Practical significance: the necessity of transformation of coordinate systems in the field of construction of buildings and structures is shown. The possibility of applying the generalized reduced gradient method to transform coordinate systems is presented. Using this method will allow you to convert the coordinates of the starting points from the local coordinate system to the coordinate system of the city with geodetic support for the construction of buildings and structures of various categories.

Newsvendor model for a dyadic supply chain with push-pull strategy under shareholding and risk aversion

This paper investigates the optimization and coordination problem in the framework of classic push and pull newsvendor models under shareholding and CVaR criterion. A decentralized supply chain consisting of upstream supplier and the downstream manufacturer is considered. Firstly, taking the risk aversion into account, the optimal decision-makings are investigated under shareholding in push, pull supply chain respectively. By comparison it is found that the optimal order or production quantity depends on the degree of member’s risk aversion and shareholding ratio. Furthermore, the combined contracts are designed to coordinate the supply chain and optimal coordination parameters are obtained. Besides, the impacts of risk-averse preference and the shareholding fraction on supply chain performance are also investigated. The results indicate that in push supply chain the optimal ordering increases in the risk-averse parameter of the downstream manufacturer and the percentage of shares held by the upstream supplier in the downstream manufacturer. However, the optimal wholesale price makes the opposite change. In pull supply chain, the optimal production quantity is independent of the shareholding fraction and decreases with regards to the supplier’s risk aversion. Lastly, some numerical examples are given to illustrate the theoretical results and some suggestions to supply chain management are also provided.

Board governance model, institutions, financial performance, and environmental performance: Stakeholder supremacy or coordination problems?

AbstractThis study aims to determine the mediating effect of environmental performance (EP) on the relationship among the board governance model (BGM, i.e., one‐ or two‐tier board), institutions (regulatory quality, rule of law, and control of corruption), and financial performance (FP). Motivated by the theoretical disputes surrounding the effectiveness of BGM, this study draws upon the supremacy of shareholders versus stakeholder's perspective and the coercive pressure from institutional theory to explain corporate legitimacy practices. Thus far, only a few studies have explored the role of BGM and institutions in a firm's EP and FP. By analyzing 1112 listed firms in emerging markets from 2013 to 2020, this study shows that institutions positively affect EP and FP through a regulatory quality indicator. Specifically, the two‐tier board indicator improves EP at the expense of FP. Despite the increasing pressure to embrace sustainable practices in countries that adopt the one‐tier board model, the formalization of stakeholder supremacy within the two‐tier board structure is considered beneficial. EP does not act as a mediator in the relationship between BGM and FP.

북·중·러 연합의 형성과 전망

This study analyzes the North Korea, China, and Russia coalition amidst complex global crises like the US-China strategic competition, the US-Russia crisis, and the North Korean nuclear issue, using coordination games and problems as analytical tools. In the ‘New Cold War’ context, they identify a focal point, form coalitions, and coordinate strategies based on reactive anti-US policies and confrontations with coalitions involving ROK, the US, and Japan. However, differing perspectives on the ‘New Cold War’ and external factors leading to divergent focal points resulted in strategic uncertainty. Forming a stable grand coalition as an institution is challenging, and there is a risk of abandonment when forming a specific coalition based on interests. Moreover, the emergence of spoilers within the coalition breeds apprehension among other nations, rendering the coalition unsustainable. Consequently, the sustainability of the North Korea-China-Russia coalition diminishes, fostering ongoing non-cooperative behavior amidst a temporary phase of adhesion.

The continuously evolving phenotype of succinic semialdehyde dehydrogenase deficiency.

The objective of the study is to evaluate the evolving phenotype and genetic spectrum of patients with succinic semialdehyde dehydrogenase deficiency (SSADHD) in long-term follow-up. Longitudinal clinical and biochemical data of 22 pediatric and 9 adult individuals with SSADHD from the patient registry of the International Working Group on Neurotransmitter related Disorders (iNTD) were studied with in silico analyses, pathogenicity scores and molecular modeling of ALDH5A1 variants. Leading initial symptoms, with onset in infancy, were developmental delay and hypotonia. Year of birth and specific initial symptoms influenced the diagnostic delay. Clinical phenotype of 26 individuals (median 12 years, range 1.8-33.4 years) showed a diversifying course in follow-up: 77% behavioral problems, 76% coordination problems, 73% speech disorders, 58% epileptic seizures and 40% movement disorders. After ataxia, dystonia (19%), chorea (11%) and hypokinesia (15%) were the most frequent movement disorders. Involvement of the dentate nucleus in brain imaging was observed together with movement disorders or coordination problems. Short attention span (78.6%) and distractibility (71.4%) were the most frequently behavior traits mentioned by parents while impulsiveness, problems communicating wishes or needs and compulsive behavior were addressed as strongly interfering with family life. Treatment was mainly aimed to control epileptic seizures and psychiatric symptoms. Four new pathogenic variants were identified. In silico scoring system, protein activity and pathogenicity score revealed a high correlation. A genotype/phenotype correlation was not observed, even in siblings. This study presents the diversifying characteristics of disease phenotype during the disease course, highlighting movement disorders, widens the knowledge on the genotypic spectrum of SSADHD and emphasizes a reliable application of in silico approaches.

Large-scale deep reinforcement learning method for energy management of power supply units considering regulation mileage payment

To improve automatic generation control (AGC) performance and reduce the wastage of regulation resources in interconnected grids including high-proportion renewable energy, a multi-area integrated AGC (MAI-AGC) framework is proposed to solve the coordination problem of secondary frequency regulation between different areas. In addition, a cocktail exploration multi-agent deep deterministic policy gradient (CE-MADDPG) algorithm is proposed as the framework algorithm. In this algorithm, the controller and power distributor of an area are combined into a single agent which can directly output the power generation command of different units. Moreover, the cocktail exploration strategy as well as various other techniques are introduced to improve the robustness of the framework. Through centralized training and decentralized execution, the proposed method can nonlinearly and adaptively derive the optimal coordinated control strategies for multiple agents and is verified on the two-area LFC model of southwest China and the four-area LFC model of the China Southern Grid (CSG).

Labor market traps

Abstract Some products, notably but not only platforms, increase in value for users as the number of other users increases. These interaction or network effects can result in ‘product market traps’ (Bursztyn et al., 2023) where people who use the product would be better off if they all stopped using it and switched to another product, but cannot because of coordination problems. A parallel but overlooked phenomenon is the labor market trap, where employees would be better off if they collectively left an employer, job, or profession, but cannot because of the difficulty of coordination. Product market and labor market traps pose a challenge to public policy because of the complexity of people's behavior in networks, but can be mitigated in some cases with relatively simple taxes and regulatory interventions.

Pursuing a Grand Theory: Douglass C. North and the early making of a New Institutional Social Science (1950-1981)

PurposeThe paper provides a detailed historical account of Douglass C. North's early intellectual contributions and analytical developments in pursuing a Grand Theory for why some countries are rich and others poor.Design/methodology/approachThe author approaches the discussion using a theoretical and historical reconstruction based on published and unpublished materials.FindingsThe systematic, continuous and profound attempt to answer the Smithian social coordination problem shaped North's journey from being a young serious Marxist to becoming one of the founders of New Institutional Economics. In the process, he was converted in the early 1950s into a rigid neoclassical economist, being one of the leaders in promoting New Economic History. The success of the cliometric revolution exposed the frailties of the movement itself, namely, the limitations of neoclassical economic theory to explain economic growth and social change. Incorporating transaction costs, the institutional framework in which property rights and contracts are measured, defined and enforced assumes a prominent role in explaining economic performance.Originality/valueIn the early 1970s, North adopted a naive theory of institutions and property rights still grounded in neoclassical assumptions. Institutional and organizational analysis is modeled as a social maximizing efficient equilibrium outcome. However, the increasing tension between the neoclassical theoretical apparatus and its failure to account for contrasting political and institutional structures, diverging economic paths and social change propelled the modification of its assumptions and progressive conceptual innovation. In the later 1970s and early 1980s, North abandoned the efficiency view and gradually became more critical of the objective rationality postulate. In this intellectual movement, North's avant-garde research program contributed significantly to the creation of New Institutional Economics.

Decisions of dual-channel fresh agricultural product supply chains based on information sharing

PurposeThis paper studies the optimal decision-making and coordination problem of a dual-channel fresh agricultural product (FAP) supply chain. The purpose is to analyze the impact of information sharing on optimal decisions and propose a coordination mechanism to encourage supply chain members to share information.Design/methodology/approachThe two-echelon dual-channel FAP supply chain includes a manufacturer and a retailer. By using the Stackelberg game theory and the backward induction method, the optimal decisions are obtained under information symmetry and asymmetry and the coordination contract is designed.FindingsThe results show that supply chain members should comprehensively evaluate the specific situation of product attributes, coefficient of freshness-keeping cost and network operating costs to make decisions. Asymmetric information can exacerbate the deviation of optimal decisions among supply chain members and information sharing is always beneficial to manufacturers but not to retailers. The improved revenue-sharing and cost-sharing contract is an effective coordination mechanism.Practical implicationsThe conclusions can provide theoretical guidance for supply chain managers to deal with information asymmetry and improve the competitiveness of the supply chain.Originality/valueThis paper combines the three characteristics that are most closely related to the reality of supply chains, including horizontal and vertical competition of different channels, the perishable characteristics of FAPs and the uncertainty generated by asymmetric demand information.

Democratizing social scientists’ impact on federal policy: Using the evidence act to help government and ourselves

It is common for social scientists to discuss the implications of our research for policy. However, what actions can we take to inform policy in more immediate and impactful ways, regardless of our existing institutional affiliations or personal connections? Focusing on federal policy, I suggest that the answer requires understanding a basic coordination problem. On the government side, the Foundations of Evidence-based Policymaking Act (2018) requires that large federal agencies pose, communicate, and answer research questions related to their effects on people and communities. This advancement has opened the black box of federal agency policy priorities, but it has not addressed capacity challenges: These agencies often do not have the financial resources or staff to answer the research questions they pose. On the higher education side, we have more than 150,000 academic social scientists who are knowledge producers and educators by training and vocation. However, especially among those in disciplinary departments, or those without existing institutional or personal connections to federal agencies, we often feel locked out of federal policymaking processes. In this article, I define the coordination problem and offer concrete actions that the academic and federal government communities can take to address it. I also offer leading examples of how academics and universities are making public policy impact possible in multiple governmental spheres. I conclude by arguing that both higher education institutions and all levels of government can do more to help academic social scientists put our knowledge to work in service of the public good.