Convex Relationship Research Articles

Trade Liberalization and the Performance of the Manufacturing Subsector in Nigeria

Trade liberalization is a widely accepted policy for fostering economic growth, particularly in developing countries. Advocates argue that open economies, through increased competition, specialization, and access to global markets, outperform closed economies. However, the short-term effects on developing economies like Nigeria remain debated, especially within the manufacturing sector. Nigeria's trade policy has fluctuated between protectionism and openness, significantly influencing its manufacturing performance. Critics, drawing from dependency theory, argue that liberalization exposes weaker economies to exploitation by stronger nations, leading to trade imbalances and inhibiting industrial growth. This study investigates the nonlinear effects of trade liberalization on Nigeria’s manufacturing sector, addressing a gap in the literature by employing a quadratic approach to determine threshold effects. By incorporating a quadratic form of the trade variable, the study tests the hypothesis that trade liberalization initially boosts the manufacturing sector but results in diminishing returns as openness intensifies. The research is framed within the Laffer Curve of Trade, suggesting that beyond a certain threshold, excessive openness may harm the manufacturing sector. The AutoRegressive Distributed Lag (ARDL) model is used to assess both short-run and long-run effects, with findings indicating a convex relationship between trade liberalization and manufacturing output, highlighting the critical importance of identifying optimal policy thresholds to maximize industrial growth.

Gender Power, the Top Management Team, and Firm Credit Default Risk

This paper considers the impact of the composition of the top management team on the credit default risk of the firm. Finance theory suggests that shareholders prefer higher levels of risk than the risk-averse executives managing the firm. Increasing the influence of female executives may reduce credit default risk, as female executives have been shown to be associated with lower firm risk. Alternatively, as diversity has been shown to improve the quality of group decision-making, a higher but optimal credit default risk may result. This paper uses a matched sample of 6,652 firm-year observations of publicly traded American firms over the period 2010–2020 to investigate the relationship between gender power within the top management team and credit default risk as measured by the Altman Z-score. This paper finds a convex relationship between the Altman Z-score and the influence of female executives. In other words, top management teams where power is shared between female and male executives accept higher levels of credit default risk than teams dominated by just female (or just male) executives. However, this paper also finds that an excessively high credit risk is negatively associated with the influence of female executives.

Non-Equilibrium Enhancement of Classical Information Transmission.

Information transmission plays a crucial role across various fields, including physics, engineering, biology, and society. The efficiency of this transmission is quantified by mutual information and its associated information capacity. While studies in closed systems have yielded significant progress, understanding the impact of non-equilibrium effects on open systems remains a challenge. These effects, characterized by the exchange of energy, information, and materials with the external environment, can influence both mutual information and information capacity. Here, we delve into this challenge by exploring non-equilibrium effects using the memoryless channel model, a cornerstone of information channel coding theories and methodology development. Our findings reveal that mutual information exhibits a convex relationship with non-equilibriumness, quantified by the non-equilibrium strength in transmission probabilities. Notably, channel information capacity is enhanced by non-equilibrium effects. Furthermore, we demonstrate that non-equilibrium thermodynamic cost, characterized by the entropy production rate, can actually improve both mutual information and information channel capacity, leading to a boost in overall information transmission efficiency. Our numerical results support our conclusions.

Task execution latency minimization for energy-sensitive IoTs in wireless powered mobile edge computing: A DRL-based method

Wireless powered mobile edge computing (MEC) has become a vital component of future 6G networks, offering efficient computational capabilities to internet of things (IoT) devices and ensuring a stable energy supply. In this paper, we propose an innovative design for a wireless powered MEC-assisted energy-sensitive IoT systems. The system integrates wireless power technology (WPT), allowing IoT devices to efficiently perform tasks under wireless power supply without consuming their battery energy. Therefore, we formulate a dynamic computational task execution latency minimization (DCTELM) problem to tackle the impacts of unpredictable energy requirements and potential communication latency on resource allocation. We also analyze the differences between time division multiple access and non-orthogonal multiple access communication protocols. Given the complexity and dynamic nature of this problem, we define it as a mixed integer nonlinear programming problem. To address this problem, we introduced an enhanced deep reinforcement learning (DRL) algorithm. First, the DCTELM problem is transformed into a Markov decision process (MDP), which simplifies the structure of the problem. Then, after determining the offloading decision, we reveal the convex relationship between resource allocation and task latency. Furthermore, the action space of MDP is further reduced, and a multi-head proximal policy optimization (PPO) algorithm is proposed to deal with the simplified MDP problem. This process reduces the complexity of problem solving, decreases the consumption of computational resources. Simulation results demonstrate that our method outperforms other baselines in terms of computation latency, particularly with the introduction of an exploration strategy during the training phase, which significantly reduces task latency.

The convex relationship between plant cover and biomass: Implications for assessing species and community properties

AbstractQuestionsCover and biomass serve as common measures of species abundance in plant ecology. However, the underlying relationship between these two measures and its implications remain poorly understood. This makes results based on cover and biomass difficult to compare.LocationsWet meadow, southeast of České Budějovice, Czech Republic (48°57′ N, 14°36′ E).MethodWe developed theoretical expectations for systematic differences in characterizing vegetation using cover and biomass for species and community characteristics, including species diversity, temporal dynamics, and responses to experimental manipulations. We then tested these expectations using cover and biomass data from an experimental study of fertilization and dominant removal spanning 14 years (2001–2014).ResultsConsistent with our expectations, on average, species biomass corresponded to the power of species cover, with a power coefficient slightly below 3/2. Community diversity indices calculated using cover and biomass were tightly correlated but were higher for cover. Temporal variabilities based on cover and biomass for individual species were also correlated, but higher for biomass than cover. Though strongly correlated, cover data show much stronger asynchrony, suggesting higher importance of compensatory dynamics. However, using the sum of individual species' cover values as a measure of total community abundance or productivity is problematic. Such a measure is nearly independent of total biomass and leads to contradictory results when used to characterize temporal variability. Species‐ and community‐level responses to treatments were congruent between the measures.ConclusionsOur study provides theoretical background for a convex relationship between plant cover and biomass. The data analysis confirms the relationship and its consequences for describing species‐ and community‐level properties. Most characteristics are well correlated between cover and biomass, but with one metric systematically shifted higher in many cases. Total abundance is the most sensitive measure and is well characterized by sum of biomass, but not by sum of cover. Understanding these systematic differences allows meaningful comparison of studies based on biomass and cover.

Do public frontline managers involve frontline professionals in managerial decision-making in response to crisis? Evidence from Danish hospitals during COVID-19

ABSTRACT This article investigates whether public frontline managers respond to crisis by involving frontline professionals more in managerial decision-making by utilizing a survey among physicians employed at public hospital departments before and during the COVID-19 crisis. The findings show a positive relationship between how affected the departments were by the crisis and how much the frontline professionals were involved in operational decisions about how to solve problems in the organization. Furthermore, exploratory analyses reveal a potential convex relationship between crisis affectedness and involvement in strategic decisions about the overall goals, direction, and priorities of the organization.

Local and General Patterns of Terrestrial Water‐Carbon Coupling

AbstractTerrestrial carbon uptake and water availability have coupled feedbacks; specifically water uptake for plant growth and soil drying via transpiration. While we might expect this coupling over time at arid sites, climatic water availability also widely covaries geographically with biomass variables that control photosynthetic rates. Using eddy covariance data globally, we find convex, positively‐covarying relations between carbon uptake and a turbulent flux metric controlled by land surface moisture (r = 0.73 monthly across sites) at the site level. We estimate a general, empirical relationship based on site‐wise water‐carbon dynamics. Most sites, and the general relationship, show strong power‐law dependence, implicating the role of sub‐seasonal land‐cover dynamics. We also find that long‐term mean carbon/water states follow a similar convex relationship to the site‐specific temporal dynamics. We discuss opportunities and caveats for space‐for‐time frameworks of carbon/water feedback processes globally.

Analysis of driving behavior in weak lane disciplined traffic at the merging and diverging sections using unmanned aerial vehicle data

The complexity of vehicular interactions at the merging and diverging sections is more severe due to the multiple decisions the driver has to make in a short time. The present study investigates and quantifies the driving behavior at the toll plaza’s merging and diverging sections. High-quality trajectory data for more than 7500 vehicle trajectories was derived from traffic video footage recorded by two Unmanned Aerial Vehicles (UAVs) operating concurrently upstream and downstream of the toll plaza. The data was extracted at 5 Hz, generating more than 5 million data points for the study. This approach facilitated a comprehensive and simultaneous capture of traffic dynamics. Various macroscopic and microscopic traffic parameters, like lateral and longitudinal speeds, following time, perception time, longitudinal standstill distance, and lateral clearance in the upstream and downstream sections, have been determined under weak lane disciplined traffic conditions. The mean speed in the merging section is 33.13 % lower than in the diverging section. Additionally, the average lateral speed in the merging section is 1.65 km/h, in contrast to 2.08 km/h in the diverging section, reflecting a 26 % increase. The lane changing and merging is prominent only up to 120 m to 140 m from the toll plaza in the merging section, and for diverging, 100 m to 200 m towards the toll plaza. The average following time in the diverging section is 5.7 s; for the merging section, it is 6.94 s, which is 13.86 % higher. The average perception time for the diverging section is 15.32 s; for the merging section, it is 13.13 s, which is 14.29 % lower. It has been observed that lateral clearance has a concave relationship with the speed in the merging section, whereas a convex relationship is in the diverging section due to the geometrical changes. The results presented in the study are expected to imitate heterogeneous traffic conditions observed in the field more realistically and will accelerate the understanding of behavioral aspects in complex interactive environments like that at merging and diverging sections of toll plazas.

Does the Cash Conversion Cycle Affect Firm Profitability? Some Empirical Evidence from Listed Firms in North Macedonia

Abstract This study aims to investigate the potential relationship between the cash conversion cycle (CCC) and firm profitability for the period from 2011 to 2019. To do this, a fixed effects panel regression model is applied to a sample of firms listed on the Macedonian Stock Exchange. Firm profitability is measured by the return on assets (ROA) ratio, while the liability ratio, firm size, current ratio, acid test and liquidity ratio are used as control variables. Our main finding is a decreasing and convex relationship between cash conversion cycle and profitability. In terms of working capital management policy, this implies that firms with a shorter cash conversion cycle perform better than others, since financial managers repay suppliers and reduce investments in working capital.

Steeper at the top: cognitive ability and earnings in Finland and Norway

Abstract We document a convex relationship between earnings rank and cognitive ability for men in Finland and Norway using administrative data on over 350,000 men in each country: the top earnings percentile score on average 1 standard deviation higher than median earners, while median earners score about 0.5 standard deviation higher than the bottom percentile of earners. Top earners also have substantially less variation in cognitive test scores. While some high-scoring men are observed to have very low earnings, the lowest cognitive scores are almost absent among the top earners. Overall, the joint distribution of earnings rank and ability is very similar in Finland and Norway. We find that the slope of the ability curve across earnings ranks is steepest in the upper tail, as is the slope of the earnings curve across cognitive ability. The steep slope of the ability curve across the top earnings percentiles differs markedly from the flat or declining slope recently reported for Sweden.

How Important Is Variation in Extrinsic Reproductive Isolation to the Process of Speciation?

The strength of reproductive isolation (RI) between two or more lineages during the process of speciation can vary by the ecological conditions. However, most speciation research has been limited to studying how ecologically dependent RI varies among a handful of broadly categorized environments. Very few studies consider the variability of RI and its effects on speciation at finer scales-that is, within each environment due to spatial or temporal environmental heterogeneity. Such variation in RI across time and/or space may inhibit speciation through leaky reproductive barriers or promote speciation by facilitating reinforcement. To investigate this overlooked aspect of speciation research, we conducted a literature review of existing studies of variation in RI in the field and then conducted individual-based simulations to examine how variation in hybrid fitness across time and space affects the degree of gene flow. Our simulations indicate that the presence of variation in hybrid fitness across space and time often leads to an increase in gene flow compared to scenarios where hybrid fitness remains static. This observation can be attributed to the convex relationship between the degree of gene flow and the strength of selection on hybrids. Our simulations also show that the effect of variation in RI on facilitating gene flow is most pronounced when RI, on average, is relatively low. This finding suggests that it could serve as an important mechanism to explain why the completion of speciation is often challenging. While direct empirical evidence documenting variation in extrinsic RI is limited, we contend that it is a prevalent yet underexplored phenomenon. We support this argument by proposing common scenarios in which RI is likely to exhibit variability and thus influence the process of speciation.

Cumulative nitrogen enrichment alters the drivers of grassland overyielding

Effects of plant diversity on grassland productivity, or overyielding, are found to be robust to nutrient enrichment. However, the impact of cumulative nitrogen (N) addition (total N added over time) on overyielding and its drivers are underexplored. Synthesizing data from 15 multi-year grassland biodiversity experiments with N addition, we found that N addition decreases complementarity effects and increases selection effects proportionately, resulting in no overall change in overyielding regardless of N addition rate. However, we observed a convex relationship between overyielding and cumulative N addition, driven by a shift from complementarity to selection effects. This shift suggests diminishing positive interactions and an increasing contribution of a few dominant species with increasing N accumulation. Recognizing the importance of cumulative N addition is vital for understanding its impacts on grassland overyielding, contributing essential insights for biodiversity conservation and ecosystem resilience in the face of increasing N deposition.

The influence of trauma on internal integration: An approach‐avoidance analysis in disaster relief operations

Disaster relief workers face unique factors in their operating environments that can inhibit internal integration. For example, disaster relief often involves exposure to traumatic events affecting relief workers’ commitment to cooperation and the organization. As such, disaster relief organizations dedicate substantial amounts of scarce resources to support workers exposed to trauma. Unfortunately, contradictory views exist in the literature on how trauma exposure affects commitment and integrative behaviors and how supervisor support influences these relationships. Based on the approach‐avoidance coping theory, we test whether trauma exposure has positive or negative effects. We test our hypotheses on data from 300 disaster relief workers collected using a 2 × 3 factorial scenario‐based experiment. We find that trauma exposure evokes avoidance coping behaviors, which decrease individuals’ cooperative disposition, and approach coping behaviors, which motivate organizational commitment. Next, we show that both forms of commitment have a nonlinear convex relationship with internal integration and mediate the relationship between trauma exposure and internal integration. Finally, we find that supervisor support amplifies these relationships. When exposed to trauma, supervisor approach and avoidance orientations provide higher internal integration levels than subjects exposed to no supervisor support. These findings extend the literature on disaster relief management, integration, and support, guiding decision‐making regarding support investments in disaster relief organizations.

PERILAKU DAN PENGARUH PENDIRI TERHADAP INFORMATIVITAS HARGA SAHAM: PERUSAHAAN PUBLIK KELUARGA DI INDONESIA

This study examines the relationship between founder as controller, age of founder, and dispersion of control on the informativeness of company stock prices. We argue that behavioral heterogeneity exists in family firms that are still majority owned and controlled by the founder. Using unbalanced panel data from 262 observations, first, this research finds support for the hypothesis that there is a convex relationship between founder voting rights and the informativeness of company stock prices. Second, older founders demonstrate more stewardship behavior than younger founders. Finally, high power dispersion in founding family firms creates agency conflicts between family owners that decrease the informativeness of firm stock prices. This finding is consistent with previous family business literature which reports that mixed behavior among family members can influence the informativeness of family company share prices.
 
 Keywords: Family Companies, Behavior Of Company Founders, Ownership Of Founders, Age Of Founders, Stock Price Informativeness

Football Players With Hip Dysplasia: The Relationship Between Muscle Strength, Functional Performance, Self-reported Sport and Recreation, Cartilage Defects, and Sex. A Cross-sectional Study.

OBJECTIVE: In symptomatic football players with hip dysplasia, we aimed to explore the relationships between self-reported sport and recreation ability and (1) hip muscle strength, (2) functional performance, and investigate if these relationships were modified by sex or cartilage defects. METHODS: In this cross-sectional study, football players (n = 50) with longstanding (>6 months) hip and/or groin pain, a positive flexion/adduction/internal rotation test, and a lateral-center-edge angle <25° were included. Hip muscle strength and functional performance were assessed. Self-reported sport and recreation ability was quantified using the sports and recreational subscales from the International Hip Outcome Tool-33 (iHOT-Sport) and the Copenhagen Hip and Groin Outcome Score (HAGOS-Sport). Relationships were evaluated using regression models with sex and cartilage defects as potential effect modifiers. RESULTS: There was a positive linear relationship between the one-leg-rise test and the iHOT-Sport subscale (β = 0.61; 95% CI: 0.09, 1.14). A polynomial (concave) relationship was found between peak eccentric adduction strength and the HAGOS-Sport subscale (β = -30.88; 95% CI: -57.78, -3.99). Cartilage defects modified the relationship between peak isometric adduction strength and HAGOS-Sport, with those with cartilage defects having a polynomial (convex) relationship (β = 36.59; 95% CI: 12.74, 60.45), and those without cartilage defects having no relationship. CONCLUSION: One-leg-rise performance and adduction strength were associated with self-reported sport and recreation ability, indicating a possible relationship between physical function, hip joint structure, and sport and recreation ability in football players with hip dysplasia. J Orthop Sports Phys Ther 2023;53(10):1-8. Epub: 8 September 2023. doi:10.2519/jospt.2023.12026.

Valuating the capital structure under incomplete information

Can higher uncertainty increase the valuation (market-to-book value) of young firms compared to more established ones? As the current market shows higher levels of uncertainty about companies’ expected cash flows and changes in firm value, the question of the fundamental convex relationship between the two becomes more relevant. This paper aims to study how cash flow uncertainty affects the capital structure/leverage of a firm over time. A simple Bayesian learning framework is employed to assess leverage ratios in the presence of parameter uncertainty about expected cash flow. This study provides an analytical solution for leverage as a function of firm age and explores the implications using numerical results. The model links market leverage with expected cash flow volatility and firm age. Young firms face uncertainty about their expected cash flows and hence their firm value. Managers continuously update their evaluation of leverage ratios when they observe realized cash flow until firms reach maturity. Therefore, the paper provides a novel explanation of why the leverage ratio for many start-ups increases over time: the resolution of uncertainty decreases upside shock expectations as the firm ages. This result is useful both for academics, who can test the formulas derived in this paper for various industries, countries, and conditions, and for practitioners, who can use them to calibrate algorithmic trading models when linking uncertainty and firm valuation.

A new objective function designed for the calibration of stratigraphic forward models

This paper presents a novel and quantitative method of comparing facies successions of distinct sizes and resolutions, adapted for the automated calibration of stratigraphic forward models (SFM). The method, which corresponds to the calculation of an objective function, consists of correlating time-sampled SFM results with space-sampled well logs using a strategy inspired by methods of automated well log correlation. The method was designed to be generic and to accept multi-variate definition of facies, so that it can be applied in a variety of geological contexts (e.g., mixed carbonate-clastic environments). The method demonstrated properties suitable for automated calibration, such as a smooth and almost convex relationship with individual simulation parameters. The method was applied to a case-study using gradient-based, meta-heuristic, Bayesian, and random optimization strategies in an 8-dimensional uncertain space. The results show that calibrated models can be found, but there are still non-uniqueness issues due to compensation effects between uncertain parameters. Therefore, a calibration strategy capable of identifying these multiple solutions is necessary to propagate geological uncertainties in petroleum system assessments and field production predictions.

Gauging the impact of the strength of patent systems on renewable energy consumption

In recent years, renewable energy consumption has been at the centre stage of academic debate. Little is however known about the potential impact of the strength of patent systems (IPRs) and renewable consumption. This study addresses this issue using a GMM methodological framework for a panel of 47 developed and developing economies over the period 1998–2017. To the best of our knowledge this is the first study where two alternative indices that measure differences in strength of patent systems are employed to explore the underlying relationship whilst at the same time controlling for other potential determinants of renewable energy consumption. We find that protection of intellectual property rights across nearly all estimated models and country groups tends to have a negative impact on renewable energy consumption whilst a convex relationship is established when nonlinearities are explored. Finally, the global financial crisis is found to have a negative impact on renewable energy in both developed and developing economies. Further probing indicates that in a depressed economic environment the strength of IPRs might have a significant role to play in encouraging more renewable energy consumption.

The X-Sentiment and Stock Illiquidity: A Convex Relationship

The X-Sentiment and Stock Illiquidity: A Convex Relationship

Effect of abnormal occlusal contact on temporomandibular joint

Occlusion, temporomandibular joint and masticatory muscle are in a functional system, which cooperate and influence each other. When any one of these elements is abnormal, it will affect the function of other elements. The normal occlusal relationship is the convex-concave relationship of apical fossa contact, and the masticatory movement trajectory is teardrop-like, which is helpful to promote the normal mandibular functional movement. The abnormal occlusal contact relationship changes the convex-concave relationship of apical fossa contact into convex relationship, which will form abnormal masticatory movement trajectory, and may even cause abnormal movement and stress of temporomandibular joint and abnormal contractile activity of masticatory muscle. The longer the duration of this abnormal occlusal relationship, the greater the damage to bone and soft tissue. scissors bite, openbite and crossbite are common occlusal abnormalities in clinic, so this article will focus on the effects of these three abnormal occlusal contacts on the temporomandibular joint.