Labor Intensities Research Articles

Migration and deposition characteristics of micro-dust in the human upper airway in dust-polluted tunnel environments.

Dust pollution in coal mine tunneling environment can cause serious hazards. This study presents a numerical analysis of the migration, deposition and escape characteristics of micro-dust in the human upper airway (HUA) under different labor intensities. The maximum deviation between simulation and experimental results was 8.97 %. The findings reveal that the expiratory flow was affected by the secondary motion, and two secondary vortices were formed around the posterior pharyngeal wall, which was prone to dust deposition. As the expiratory intensity increased, a large amount of 1-15 μm small-sized dust was deposited in the pharynx, and the deposition fraction (DFd) of 15 μm dust increased the most, reaching 77.13 %; 20-80 μm large-sized dust was difficult to exhale, and most were deposited near the nasal turbinate and nasopharynx. With the increase of density, the escape rate (ERd) of 1-15 μm dust showed a decreasing trend. The deposition of large-sized dust over 20 μm in nasopharyngeal region was more affected by density changes, but this fluctuation was reduced with increasing particle size. The study will help assess the human health risks of dust environment, develop more effective dust monitoring and control technologies and strategies for a cleaner, safer working air environment.

Research on Downhole MTATBOT Positioning and Autonomous Driving Strategies Based on Odometer-Assisted Inertial Measurement.

In response to the current situation of backward automation levels, heavy labor intensities, and high accident rates in the underground coal mine auxiliary transportation system, the mining trackless auxiliary transportation robot (MTATBOT) is presented in this paper. The MTATBOT is specially designed for long-range, space-constrained, and explosion-proof underground coal mine environments. With an onboard perception and autopilot system, the MTATBOT can perform automated and unmanned subterranean material transportation. This paper proposes an integrated odometry-based method to improve position estimation and mitigate location ambiguities for simultaneous localization and mapping (SLAM) in large-scale, GNSS-denied, and perceptually degraded subterranean transport roadway scenarios. Additionally, this paper analyzes the robot dynamic model and presents a nonlinear control strategy for the robot to autonomously track a planned trajectory based on the path-following error dynamic model. Finally, the proposed algorithm and control strategy are tested and validated both in a virtual transport roadway environment and in an active underground coal mine. The test results indicate that the proposed algorithm can obtain more accurate and robust robot odometry and better large-scale underground roadway mapping results compared with other SLAM solutions.

A heat stress control method for miners based on internal heat storage

In high-temperature mines, miners are exposed to high temperatures for long, increasing body temperature and causing diseases such as heatstroke. Therefore, adjusting the environmental parameters of the working face has become the key to managing thermal stress. Based on the binary method, the predicted thermal strain model (PHS) was transformed into a computer program to determine the zero inflection point of human body heat storage. When workers’ body heat storage reached the zero inflection point, changes in working face temperature, wind speed, and physiological parameters were analyzed under different labor intensities. The results indicate that the higher the labor intensity, the higher the air humidity, and the lower the working face environment temperature that maintains zero heat storage for the human body. A wind speed of 2.5 m/s is optimal for maintaining zero heat storage for the human body. When the wind speed is too high or too low, the working surface environment temperature required to maintain zero heat storage for the human body is relatively low. A thermal stress control method was proposed based on research, providing a reference for adjusting wind speed and refrigeration equipment in high-temperature mining working faces.

Experimental investigation on physiological and perceptual thermal responses through simulated hot-humid deep mine conditions

Miners in underground space often experience discomfort and heat strain due to combination of hot-humid environment and strenuous physical intensity. To investigate the impacts of manipulated variables, amounts of trials were conducted in a controlled climate chamber, with air temperatures of 29 °C and 32 °C, air velocities of 0.8 m/s and 1.8 m/s, and labor intensities of 3 km/h and 5 km/h, respectively. The physiological responses of mean skin temperature (Tmsk), oral temperature (Tor), sweat loss (SW), and heart rate (HR) were measured during these trials, along with the perceptual responses of thermal sensation vote, thermal comfort vote, thermal satisfaction vote, thermal acceptability vote, air movement expectation vote. The results indicate that Tmsk, Tor, SW and HR exhibit an upward trend in response to increasing air temperature and labor intensity, but decrease with rising air velocity. Tmsk and Tor are primarily affected by air temperature, while SW and HR are predominantly influenced by labor intensity. Notably, increased air temperature and labor intensity have negative effects on perceptual sensations, whereas augmentation in air velocity can marginally mitigate perceptual sensations. Tmsk and sweating rate exhibit the potential to serve as an indicator for evaluating and forecasting perceptual sensation. Tmsk values of 36 °C and 35 °C can be identified as the maximum thresholds for miners' thermally acceptable and comfortable skin temperatures. The findings can provide valuable references for understanding thermal responses of individuals in hot-humid deep mine conditions, and establish a robust basis for promoting working safety and comfort of miners.

Corporate Tax Cuts and the Decline of the Manufacturing Labor Share

We document a strong empirical connection between corporate taxation and the manufacturing labor share, both in the US and across OECD countries. Our estimates associate 30 percent to 60 percent of the observed decline in labor shares with the fall in corporate taxation. Using an equilibrium model of an industry where firms differ in their capital intensities, we show that lower corporate tax rates reduce the labor share by raising the market share of capital-intensive firms. The tax elasticity of the labor share depends on the joint distribution of labor intensities and value added at the micro level. Given the empirical distribution in the US manufacturing sector, our quantitative analysis suggests that corporate tax cuts explain a significant part of the decline in the manufacturing labor share since the 1950s. The shift away from traditionally large, labor-intensive production units raised the concentration of market shares and reduced the concentration of employment.

A quick identification model for assessing human anxiety and thermal comfort based on physiological signals in a hot and humid working environment

We propose a simple and quick method for quantifying workers' anxiety and thermal comfort levels using physiological signals. Nine subjects enrolled in a series of controlled laboratory experiments involving varying temperature, relative humidity, and labor intensities. A total of 40 experiments were conducted, and 1592 groups of anxiety data and 1624 groups of thermal comfort data were obtained, respectively. During 2-h-working trials, Electroencephalogram (EEG), photoplethysmography (PPG), and pupil diameter of each subject were collected synchronously, and the State-Trait Anxiety Inventory (STAI) and thermal comfort vote (TCV) were completed in stages. Random Forest was adopted to screen out the appropriate sensitivity feature indicators of anxiety levels and thermal comfort levels from the 70 features of the 10 EEG channels. Finally, Random Forest, Gradient Boosting Decision Tree, K-nearest Neighbor Algorithm, and Support Vector Machine were used to determine relevant physiological data combinations and modeling algorithms. The Precision of the anxiety level and thermal comfort level quick identification model based on Random Forest Algorithm can reach 81.04% and 84.79%, respectively. This suggests that the proposed quick identification method for assessing workers' anxiety and thermal comfort levels holds promise. Physiological data need to be obtained by monitoring only PPG, pupil diameter, and 5 EEG channels. By processing these data, the workers' anxiety and thermal comfort level could be judged realistically to ensure their safety. It is suggested that PPG, pupil diameter, and EEG should be considered all together in the future study of anxiety and thermal comfort.

Study on the coal dust deposition fraction and site in the upper respiratory tract under different particle sizes and labor intensities

In order to study the dust exposure amount and coal dust deposition rule of coal miners under different labor intensity in coal mine environment, an airflow-particle two-phase coupling calculation model of human upper respiratory tract was established based on Euler-Lagrange framework, and the airflow field in the upper respiratory tract and the characteristics of coal dust deposition were simulated and studied. By comparing the experimental data, the relative error of simulation is in the range of 1.5 %–11.2 %. The results showed that the total deposition fraction of 1 μm dust was the smallest (0.61–1.20 %), and was relatively less affected by respiratory intensity, and the overall distribution was uniform. When the dust particle size increased to 7.07 μm, the total dust deposition fraction in the nasal cavity, pharynx and larynx was in the range of 11.10 %–20.91 %, and increased with the respiratory intensity. When the dust particle size was large, the dust particles of 20 μm and 80 μm were mostly concentrated in the front of the nasal cavity, and the deposition amount of 80 μm dust was about 99.52 %. It was found that with the increase of dust particle size or the increase of labor intensity, the possibility of dust being transported into lungs became smaller. The fitting function of 7.07 μm dust escape rate and labor intensity was obtained, for example, Y7.07μm = 91.73–0.22n (n is labor intensity), and the escape rate of dust with 7.07 μm particle size was up to 88.90 %. Most of them escape from the upper respiratory tract and enter the lungs, which provides theoretical guidance for quantifying the accumulated dust exposure amount in the lungs and monitoring respiratory dust concentration.

Study On Dust Exposure Amount and Deposition Rule of Personnel Under the Influence of Different Labor Intensities in Coal Mine

Study On Dust Exposure Amount and Deposition Rule of Personnel Under the Influence of Different Labor Intensities in Coal Mine

Business strategy and systematic risk: Evidence from China

AbstractGuided by their business strategies, firms develop their competitive advantages and overcome systematic risks by allocating their limited resources. This study explores how advertising, labor, R&D, cost, and capital intensities are correlated with the systematic risks of 10 industries in the Chinese market. The results show that these correlations vary between industries. To easily adapt to market variations and reduce systematic risks, decision‐makers are advised to design their business strategies according to the characteristics of their respective industries.

Redistribution and wage inequality

This paper explores how redistribution affects skilled-unskilled wage inequality through the general equilibrium approach. We analyze six redistribution policies, which includes redistribution from (1) skilled labor to unskilled labor, (2) unskilled labor to skilled labor, (3) capital owners to skilled labor, (4) capital owners to unskilled labor, (5) skilled labor to capital owners, and (6) unskilled labor to capital owners. We find that redistribution policy (1) will reduce wage inequality, while redistribution policy (2) will increase wage inequality. For redistribution policies (3)–(6), how redistribution affects wage inequality depends on the labor intensities of the skilled sector and the unskilled sector. The result shows that redistribution does not necessarily reduce skilled-unskilled wage inequality.

Automatic Control for Fluorite Floatation Process

According to the conditions of the low level of automation and low laboratory productivity, an automatic control system for flotation process was designed and developed innovator based on the SIEMENS S7 PLC series software and hardware. The structure and function of the control system are introduced carefully. The control strategies of the pulp level the air flow-rate and the flotation reagent feeding are described in detail. The control software and human-machine interface are designed and developed. The actual industrial application results show that the control system operates steadily, safely and reliably, the worker labor intensities are decreased obviously, and the work condition is improved the competitiveness of the enterprise is enhanced. The method can automatically adjust the reagent feeding when the work-condition varies, so that the technical indexes can be controlled within their target ranges. The successful application has shown that the proposed method has practical significance and high potential of being further applied in optimal control of mineral industry.

The reality of the industrial sector In the GCC and manufacturing strategies

No doubt , that the GCC countries have already allocated and spent huge sums of capital on the industrial development processes, and they have achieved significant developments in the fields of physical infrastructure and in distribution activities (commercial and credit), however these countries still suffer from production and export concentration in few primary extractive products : oil and gas and weak technical linkages (forward and backward) within their manufacturing sectors in general . With the absence of long-term and stable strategic framework there are no development patterns being determined to ensure the diversification of production and structural integration of the economies concerned. Here, the study attempts to identify weaknesses and focus on strategies that can address the two most important topics, one related to the size of industrial firms and the other to technological patterns according to the (labour and capital intensities) of production.

Employment creation in EU related to renewables expansion

Expansion of renewable energy is a key element in the EU Energy and Climate policy framework, as is contributes to Greenhouse Gas reduction and improved energy security, while they can also create employment opportunities. There has been an intense debate on the quantification of these employment effects. Most studies have focused on estimating gross employment impacts and ignored the effects between different sectors, while they commonly use aggregate data and sectoral classification. This paper investigates the net employment impacts from the projected transformation of the EU energy sector towards Renewable Energy Sources (RES), by combining the employment factor approach and general equilibrium analysis. Detailed, up-to-date data at a very disaggregated level are used to compare the labour intensities of RES relative to fossil fuels and assess the employment impacts of the recent Clean Energy Package proposals. RES technologies are estimated to be on average more labour intensive and have a higher domestic job content relative to fossil fuels. The low-carbon transition would lead to the net creation of 200,000 direct jobs in energy sectors. Direct RES jobs represent about 1% of the EU workforce in 2050 and are mostly created in the construction of solar photovoltaics, the supply and production of advanced biofuels and in the manufacturing and installation of wind turbines. In contrast, employment would be eliminated in conventional energy supply sectors, especially in coal mining (which is a labour intensive activity), refineries and refuelling stations. The economy-wide general equilibrium modelling confirms the positive employment impacts of RES expansion and shows that the low-carbon transition would lead to the reallocation of 1.3% of the EU’s workforce across sectors by 2050.

Employment Protection and Firm Relocation: Theory and Evidence

We examine the determinants of the decision to relocate activities abroad for firms located in OECD countries. We argue that particular firm‐specific features play a crucial role for the link between employment protection and relocation. Stricter employment protection laws over time in the current production location discourage firms’ relocation abroad. While larger, more productive firms and firms with higher labour intensities have, ceteris paribus, higher propensities to relocate, they also face higher exit barriers if the country from which they consider relocating has strict employment protection laws. Our predictions are supported empirically, using firm‐level panel data for 28 OECD countries over the period 1997–2007.

ANALYSIS OF INFLUENCE FACTORS ON UKRAINIAN REGIONS DEVELOPMENT OF HOUSING AND MUNICIPAL ECONOMY

It is determined that the specific feature of housing and communal services is the territorial dissociation of housing and communal facilities that require round-the-clock reliable operation, the need for operative, and in some cases - emergency nature of the work of huge volumes and labor intensities, which involve the widespread use of machines, mechanisms and means of small mechanization of various purposes. A number of industrial constraints have been formed, which are the subject of an annual survey of electricity, gas, steam and air conditioners, and water supply, sewerage, waste management companies. In order to find out the trend in the changes in the influence of each factor on the prospects of branch development, the linear trends of the enterprises of industrial production of electricity supply, gas, steam and conditioned air, and water supply enterprises, sewage, waste management were determined. According to the classical definitions, the positive values of the trend line coefficients indicate an increase in the indicators, and negative ones – a decrease; the greater the absolute value of the determined coefficient, the « faster » is the increase or decrease. Similar statistical data processing was carried out for water supply, sewage, waste management companies. Linear trend coefficients for each of the factors of influence were counted. It was revealed that the weight of the influence factors and their ranking are identical in both branches. And the tendency to change their influence over time is excellent. So, despite the greatest impact of financial constraints, over time, « claims » to them gradually decrease. Lack of labor will eventually become more significant. That is, enterprises of industrial production of electricity, gas, steam and air conditioning supply, and enterprises of water supply, sewage, waste management over time depend less on demand, raw materials, materials, equipment. It is noted that the financial results of the utilities enterprises directly depend on the size of capital investments. Financial results of the enterprise industry during the observation time highly depend on financial restrictions, which in the future only increase. Lack of labor has almost no effect on enterprise activity.

Employment Protection and Firm Relocation: Theory and Evidence

We examine the determinants of the decision to relocate activities abroad for firms located in OECD countries. We argue that particular firm-specific features play a crucial role for the link between employment protection and relocation. Stricter employment protection laws in the current production location discourage firms' relocation abroad. While larger, more productive firms and firms with higher labour intensities have, ceteris paribus, higher propensities to relocate, they also face higher exit barriers if the country from which they consider relocating has strict employment protection laws. Our predictions are supported empirically, using firm level data for 28 OECD countries.

Building Inventory and Refurbishment Scenario Database Development for Switzerland

SummaryMaterial usage and the related embodied environmental impact have grown in significance in the built environment. Therefore, cities and governments need to develop strategies to reduce both the consumption of resources during usage phase as well as the embodied impact of the current building stock. This article proposes a new component‐based building inventory database as a basis to develop such strategies using building stock modeling. The developed database clusters the building stock according to building typology (single‐family houses, multifamily houses, and office buildings), age, and the main construction systems of the different building components. Based on the component makeup, it lists the necessary material input and waste output for different refurbishment options for each building component. The advantages of the proposed database structure are shown based on two applications for the developed database for Switzerland. The component‐based database allows optimization of refurbishment strategies not only from an energetic perspective, but also with respect to materials, both on the input (sourcing of materials) and the output (waste streams) level. The database structure makes it possible to continuously extend the data set by adding new refurbishment options or add data such as component‐specific lifetimes, costs, or labor intensities of the refurbishment options. In combination with an aligned economic model, this would give an even more holistic view, impact, and feasibility of different refurbishment scenarios both in environmental and economic terms.

Labour Market Effects of Large-Scale Agricultural Investment: Conceptual Considerations and Estimated Employment Effects

Summary Large-scale agricultural investments (LSAIs) in general and their socio-economic implications in particular have been heavily debated in recent years. While some claim that LSAIs are an important catalyst for development in neglected rural areas, others caution that they pose a risk to rural communities’ livelihoods. The extent to which LSAIs provide benefits for local communities is hence still contested. This paper sets out to conceptually understand what effects the establishment of a large-scale farm has on the rural labor market in low- and middle-income countries. In addition, we empirically address the question of whether large-scale farming as recorded in the Land Matrix creates or destroys employment. We develop a transition matrix to identify several scenarios based on key determinants of the direct employment creation potential of LSAIs, namely the former land use, the crop type and the production model. We empirically assess the actual importance of these scenarios and the employment creation to be expected from this sample of LSAIs based on labor intensities. We further look into the net employment effects for land formerly used by smallholder farmers. Our analysis shows that LSAIs massively crowd out smallholder farmers, which is only partially mitigated through the cultivation of labor intensive crops and the application of contract farming schemes. This holds true for all regions targeted by LSAIs, although regional differences are found in terms of magnitude. The paper concludes that these effects tend to be large on the local scale (i.e., in the immediate surroundings of the investment site) but small in relation to total national employment in agriculture. However, indirect employment creation related to LSAIs, which is discussed but not empirically addressed in this paper, needs to be taken into account to have the full picture.

Assessing social risks of global supply chains: A quantitative analytical approach and its application to supplier selection in the German automotive industry

Risk management in Supply Chains has gained increasing attention over the last years. At the same time the pressure to consider social issues in global and interconnected supply chains has risen as well. These issues pose risk to supply chains since their occurrence may cause adverse stakeholder reaction through e.g. reputational losses. Despite the growing importance of supplier management as a key process within supply chains and the frequently articulated demand for a quantitative assessment of associated risks, such approaches are missing so far. Thus, the aim of this paper is to develop a model to efficiently estimate and assess social risks along global supply chains. For this purpose, Leontief’s Input Output model is combined with country risks and sector specific labour intensities. In addition, a fuzzy analytical hierarchy process is used to weigh the various considered social risks. Thereby the focus is on the upstream supply chain of actors in a supply chain. The approach is developed generally, opening the possibility of adaption to different types of input-output data bases and using different social risks discussed in social life cycle assessment. The fuzzy analytical hierarchy process facilitates the operational application in companies, where different people with differing preferences are involved, e.g. in procurement decisions. The model is applied to a case study of a German premium car manufacturer to demonstrate and validate the approach. It is shown, how – based on the developed model – the assessment of supply chains risks can be carried out. The approach allows an assessment of the supply chain as a whole, i.e. considering all upstream tiers, and of specific tiers. Furthermore, a sensitivity analysis with regard to the obtained weights is conducted to verify the final aggregative risk values. The results show that there are huge differences in the social risks associated with different suppliers as well as different risk structures along the n-tier chain. This helps prioritizing any projects with the aim to improve the living and working conditions. In summary the model has a great benefit for practitioners in purchasing functions of focal companies and can be a helpful tool to support the efficient handling of social issues along supply chains. At the same time, its academic contributions lie in extending the life cycle sustainability analysis through a (multi-regional) socially extended input output model (SEIO) for social risk assessment in sustainable supply chain management.

Piecewise Linear Model for Multiskilled Workforce Scheduling Problems considering Learning Effect and Project Quality

Workforce scheduling is an important and common task for projects with high labour intensities. It becomes particularly complex when employees have multiple skills and the employees’ productivity changes along with their learning of knowledge according to the tasks they are assigned to. Till now, in this context, only little work has considered the minimum quality limit of tasks and the quality learning effect. In this research, the workforce scheduling model is developed for assigning tasks to multiskilled workforce by considering learning of knowledge and requirements of project quality. By using piecewise linearization to learning curve, the mixed 0-1 nonlinear programming model (MNLP) is transformed into a mixed 0-1 linear programming model (MLP). After that, the MLP model is further improved by taking account of the upper bound of employees’ experiences accumulation, and the stable performance of mature employees. Computational experiments are provided using randomly generated instances based on the investigation of a software company. The results demonstrate that the proposed MLPs can precisely approach the original MNLP model but can be calculated in much less time.