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Forward markets are believed to aggregate information about future spot prices and reduce the cost of producing the commodity. We develop a measure of the extent to which forward and spot prices agree in markets with transaction costs. Using this measure, we show that day-ahead prices better reflect real-time prices at all locations in California’s electricity market after the introduction of financial trading. We then present evidence suggesting that operating costs and input fuel use fell after the introduction of financial trading on days when the nonconvexities inherent to the production and transmission of electricity are especially relevant. (JEL D23, D24, G13, L94, L98, Q48)

The world’s first offshore methane hydrate extraction was conducted in 2013 at the Daini-Atsumi Knoll located in the eastern Nankai Trough. The results indicated that the gas production rate of a single vertical well cannot meet the requirement for commercialisation of methane hydrate production. Therefore, a trial multi-well system has been considered for future hydrate production. Understanding the ‘influence distance’ of extraction wells within methane hydrate turbidite reservoir formations, such as that of the Nankai Trough, is significant to the design of the proposed multi-well system. In this study, the boundary effects are examined for cases involving different values of permeability and initial hydrate saturation for the modelled turbidite formations. A relationship is proposed to predict the longest simulation time for a given set of lengths and parameters. The two concepts of critical production time (CPT) and turbidity/homogeneity coefficient ratio (THCR) are introduced to analyse the interaction between the effects of model size and heterogeneities. It is found that the CPT can be normalised by the radius of the model; the THCR is affected by the relative thickness of the sand and clay layers.

Imperfect information and learning are introduced into a production-based asset pricing model. Our model features slow learning about firms’ exposure to aggregate productivity shocks over time. In contrast to a full information case, our framework provides a unified explanation for the stylized empirical features of the cross-section of stocks that differ in capital age: old capital firms (1) have higher capital allocation efficiency; (2) are more exposed to aggregate productivity shocks and, hence, earn higher expected returns, which we refer to as capital age premium; and (3) have shorter cash-flow duration, when compared with young capital firms.

The main aim of this paper is to derive data for labour-augmenting technology (LAT) through growth accounting from a CES production function compatible with the stylized facts of growth. We solve a CES function for its LAT term and insert data. This provides LAT levels for alternative elasticities of substitution for 70 countries, 1950-2017. These LAT data then are analysed in relation to topics in the literature. Results are as follows. (i) The percentage growth rates of LAT are shown to fall over time (productivity slowdown) for all elasticity values in a panel data analysis with slope homogeneity. (ii) The standard growth result of a GDP growth rate equal to that of LAT and labour input holds only for LAT data based on low elasticities of substitution indicating that the economies are not in steady states. (iii) Matching the labour/capital share ratios from CES functions with those of PWT9.1 if the MPL-to-wage ratio is 1.6, the elasticities of substitution vary around 0.8. For this value, (iv) 13 of 69 countries have a productivity slowdown; (v) LAT growth rates are negatively related to their levels ten years ago without strongly changing the coefficient of variation or kernel density distribution over time.

In our model, a venture seeks capital through an initial coin offering (ICO). The ICO enables the venture to collect demand information from decentralized investors. The venture makes a tradeoff between ensuring the project’s success and forecasting market demand through token size and token price. We find that the higher the demand uncertainty and production cost, the greater the venture’s incentive to learn from its investors. To identify when the venture has an incentive to raise funds through an ICO, we compare it with traditional bank financing and analyze the venture’s preference between the two financing options. The results show that when demand uncertainty is high, an ICO can provide both financing and information benefits, whereas when demand uncertainty is low, although the venture does not collect information through an ICO, it can still get financing benefit. Only when demand uncertainty is intermediate, the venture prefers bank financing. In addition, we find that although the revenue sharing effect of the ICO results in an underinvestment issue, it can also alleviate the loss caused by the increased cost of production. Therefore, with high information accuracy, as production cost goes up, ICOs become more attractive than bank financing for the venture.

As a relatively large production and trade industry in China's manufacturing sector, apparel manufacturing has entered the data analytics era with much-enhanced productivity by using information technology. The extent to which the state-of-the-art information technologies can increase the productivity of this entire industry has not been fully investigated. This article selects 30 Chinese listed apparel manufacturing enterprises from 2012 to 2018 as a sample and analyzes the impact of information technology investment on their performance using the panel fixed effect and random effect models. In addition, the moderating effect of enterprise equity concentration on the abovementioned relationship is studied. Equity concentration reflects the distribution of equity from the total amount. Excessive equity concentration enables large shareholders to obtain higher control rights with smaller cash flows, seizing the interests of small and medium shareholders and digging tunnels. This is, thus, not conducive to healthy and long-term development of the firm. The results show that information technology, such as software investment, hardware investment, and total information technology investment, can improve the enterprise performance. Among them, software investment has the greatest impact on the enterprise performance. When the proportion of the software investment increases by 1%, the enterprise performance increases by 17.6%. The equity concentration has a negative impact on the relationship between the investment in information technology and enterprise performance.

To maximize productivity, manufacturers must organize and equip their workforces to efficiently handle variable workloads. Their success depends on their ability to assign experienced and skilled workers to specialized tasks and coordinate work on production lines. Worker turnover may disrupt such efforts. We use staffing, productivity, and pay data from within a major consumer electronics manufacturer’s supply chain to study how firms should manage worker turnover and its effects using production decisions, wages, and inventory. We find that worker turnover impedes coordination between assembly line coworkers by weakening knowledge sharing and relationships. Publicly available unit-cost estimates imply that worker turnover accounts for $206–274 million in added direct expenses alone from defectively assembled units failing the firm’s stringent quality control. To evaluate managerial alternatives, we structurally estimate a dynamic equilibrium model (an Experience-Based Equilibrium) encompassing (1) workers’ endogenous turnover decisions and (2) the firm’s weekly planning of its production scheduling and staffing in response. In counterfactual analyses, a less turnover-prone, hence more productive, workforce significantly benefits the firm, reducing its variable production costs by 4.5%, or an estimated $928 million for the studied product. Such benefits justify paying higher efficiency wages even to less skilled workforces; furthermore, interestingly, rational inventory management policies incentivize self-interested firms to reduce rather than tolerate turnover. This paper was accepted by Vishal Gaur, operations management. Funding: The authors gratefully acknowledge support from the data sponsor, and K. Moon gratefully acknowledges support from the Wharton Dean’s Research Fund and the Claude Marion Endowed Faculty Scholar Award of the Wharton School. Supplemental Material: The online appendices are available at https://doi.org/10.1287/mnsc.2022.4476 .

Motivated by the practices of production sourcing in the apparel manufacturing industry, this article investigates an apparel manufacturing supply chain wherein an original brand manufacturer (OBM) may either outsource production to a competitive manufacturer (CM) or a non-CM (NCM) or set up factories to produce in-house, namely, Strategy C, Strategy NC, and Strategy N, respectively. If the OBM outsources production to the CM, technology spillover happens, and the CM is able to manufacture products with the same consumers’ preference level as the OBM does. We find that the OBM prefers Strategy N regardless of the manufacturing level and consumers’ product preference level when the investment cost is low. However, the OBM prefers Strategy C or NC when the investment cost is high. Specifically, when the manufacturing level is high, or the manufacturing level is medium, and the consumers’ product preference level is high, the OBM prefers Strategy NC; otherwise, the OBM prefers Strategy C. Furthermore, we demonstrate that employing the dual-sourcing strategy wherein the OBM outsources production to both CM and NCM simultaneously does not necessarily help OBM effectively mitigate the negative impact of technology spillover and delivery uncertainty, which depends on specific conditions.

Consumers gain information about the evolving value of a product both prior to purchase and when owning a product. We consider a model where both these types of gaining information are possible. The information gained when owning the product may affect future product purchases. We characterize when the consumer chooses to purchase the product if the consumer does not own it, the expected interval of time between purchases, and the expected number of product purchases over time. We find that, keeping product duration fixed, the optimal fixed price is independent of the initial product valuation if that valuation is sufficiently low such that a consumer not owning the product does not purchase it immediately, and characterize how the price charged affects the consumer information gathering strategy. When the firm can also choose product duration and there are no costs of production, we find that the firm chooses an expected production duration that is infinitely small, and charges a flow price for the consumer to use the product. We also characterize how the extent of learning when owning and when not owning the product, the duration of the product, and the discount rate affect the optimal consumer and firm strategies.

Industries differ in the extent to which they can offshore their production. I document that industries with low offshoring potential carry a sizeable risk premium compared with industries with high offshoring potential, suggesting that the possibility to offshore affects industry risk. A two-country dynamic trade model in which offshoring allows firms to secure market share against foreign competitors can rationalize the empirical findings. This paper was accepted by Gustavo Manso, finance. Supplemental Material: The online appendix and data files available at https://doi.org/10.1287/mnsc.2022.4393 .

Motivated by the practices of technology investment in the new energy vehicle manufacturing industry, this article investigates an outsourcing supply chain in which an original brand manufacturer (OBM) possessing the core new energy technology R&D outsources production to a competitive manufacturer (CM). To cater to market demands and increase market competitiveness, the CM may actively invest in technology with the OBM or by himself, or not, i.e., Strategies JI, OI, and NI, respectively. In particular, owing to technology spillover effect, the CM could use the technology inferior to the OBM's to produce his own-branded products in Strategy NI. Our results reveal that the OBM consistently profits the most in Strategy JI. However, the CM's preference strategy is influenced by the competition intensity, technology spillover level, consumers’ product preference, and cost-sharing ratio. In specific, when both the competition intensity and technology spillover are weak or the competition intensity is strong for arbitrary technology spillover level, the CM may prefer Strategy JI or OI depending on consumers’ product preference and cost-sharing ratio and never prefers Strategy NI. However, when the competition intensity is weak but the technology spillover level is strong, the CM may prefer Strategy NI in certain situations. Furthermore, our study extends the model to involve variable production costs, and reveals that the main results derived in the basic model still hold.

У статті запропоновано класифікацію благ за чинниками розміщення їхнього виробництва, урахуванням властивостей технологій виробництва благ, ресурсів, які застосовуються в цих технологіях, забруднень, що утворюються під час виробництва, а також самих благ. У статті наведено матрицю для класифікації видів економічних благ.

Drawing on social exchange theory and institutional theory, this article extends the literature on sustainable operations by examining the mediating and moderating effects of buyer–supplier relation and institutional context on the relationships among internal green practice, external green practice, and environmental performance. This article analyzes data from 440 firms in three categories of market (the institutional context): industrialized Western, emerging Western, and emerging Asian markets. Both internal green practice and external green practice have positive direct impacts on firms’ environmental performance. More specifically and interestingly, external green practice partially mediates the relationship between internal green practice and environmental performance, and this process is moderated by the quality of the buyer–supplier relation. A higher quality of buyer–supplier relation helps to achieve a better outcome. In addition, the examined relationships vary between the emerging market and developed market: that is, they depend on the institutional context. The findings have implications for both practitioners and policymakers on how to improve environmental performance through leveraging green practice and buyer–supplier relation and what policies on green supply chain management might best be used in different markets.

This research study investigates the factors associated with pelletisation in the production of fly-ash aggregates and its performance in concrete. To investigate this influence, experiments were carried out in different stages to explore the effect of factors responsible for pelletisation, which were designed through Taguchi's experimental design. Additionally, the influence of each parameter on the engineering properties of the produced aggregates was determined using Grey relational analysis. Further, considering the optimised pelletisation factors of the laboratory-scale studies and with the help of an industrial-scale pelletiser, mass production of fly-ash aggregates was carried out and characterised for their engineering properties. The test results indicate that these aggregates are mainly governed by water content followed by the angle and speed of pelletizing disc. It is observed from the results that the engineering properties of aggregates produced on an industrial scale are found to be better than sintered aggregates and also comparable with that of natural aggregates except for water absorption. The properties of concrete produced with fly-ash aggregates, light weight sintered aggregates and natural aggregates were also studied. The results showed that properties of concrete produced with fly-ash aggregates are in good correlation with those of conventional concrete produced with natural aggregates.

Iraq suffers from economic and social problems and challenges, the most important one which is unemployment and the weak ability to generate income and employment. The importance of the benefiting from the experiences of countries in the field of developing small projects, where the active role of the state in drawing the features of a strategy to enhance the competitive advantages of projects in an attempt to overcome the obstacles that these projects suffer from, whether in terms of administrative aspects or the absence of organizations responsible for guiding investors or in terms of commercial and technical support The financial environment and the lack of an institutional framework and an incubating legislative environment, as well as infrastructure as basic ingredients for the development of the small projects. The small projects sector has the ability to achieve economic and social benefits due to its major role in expanding the production base, diversifying sources of income, creating job opportunities for the unemployed, especially young people, and expanding the investment circle. In Iraq, we find that small and medium-sized projects that have stopped working for several reasons need great support in light of the difficult circumstances that are characterized by the instability of the economic situation and the situation in the Iraqi market of dumping various commodities, the high general level of prices, the lack of influence of the exchange rate on local prices and the lack of profitable investment opportunities The absence of credit facilities. Where all these factors combine to pose difficult challenges for owners of small and medium projects to be reflected on the Iraqi economy.

Organic fertilizers have been used since the dawn of mankind to improve soil fertility and promote crop growth. However, the process of preparing organic fertilizers for use in agricultural activities is a labour-intensive and time-consuming procedure. Thus, in order to reduce labour costs and improve the efficiency of organic fertilizer preparation, automated organic fertilizer mixers were developed. For this research work, an improved organic fertilizer mixer based on the Internet of Things (IoT) technology capable of monitoring the status of fertilizer production remotely and providing updates and alerts to workers was developed. The aim of this work was to further reduce labour workload and costs, thus increasing efficiency of the organic fertilizer mixing process. In order to accommodate the IoT monitoring system, several modifications and design changes were carried out on the prototype of an automated organic fertilizer mixer. Tests conducted on the prototype unit showed that it performs as required. The IoT monitoring system successfully captures and uploads information on the weight of agricultural waste mixture in the storage drum to the IoT platform. This information can then be used to alert workers on when to add more agricultural waste material to the mixture or remove the processed organic fertilizer. Furthermore, an overall operational cost comparison of different organic fertilizer production methods showed that the automated organic fertilizer prototype provides operational cost savings of over 5 times when compared to current automated systems. Future work includes further automation to the agricultural waste filling and organic fertilizer removal process.

Since we have required so much food to be a major economic country in the world, existing or traditional farming methods and storage methods are not adequate to increase production and maintenance for future purposes. The Internet of Things in Agriculture leads to creativity in areas such as Crop Maintenance and Tracking, Animal Farming, Fishing, Millet Crops, and so on. This paper investigates the different technologies, protocols, sensors used in recent research in sustainable farming.

Sun-oriented solar power production with sunlight-based vitality plays an important role. In reality, untimely or innovative countries gracefully take a move forward. When oil is used for power era, it contributes to a rise in poisoning and greenhouse gases. This creates natural complications. Another human need for existence can be filled by using numerous sun- oriented developments in vitality, the planet can still prevent worldwide problems which can also serve to decrease pollution at the same time. In far-off areas where communities of citizens do not approach electricity photovoltaic frameworks are added many any administration offices have taken the amounts of action to allow creativity in sun-driven vitality to be used for power production. Single axis monitoring devices are discussed in this article. This analysis supports the findings. In comparison with the static systems, the single axis monitoring system is more accurate. In either scenario, a single axis monitoring system is simpler to accomplish in cost and adaptability viewpoints than a static one.

In this paper, a comprehensive production planning problem under uncertain demand is investigated. The problem intertwines two NP-hard optimization problems: an assembly line balancing problem and a capacitated lot-sizing problem. The problem is modelled as a two-stage stochastic program assuming a risk-averse decision maker. Efficient solution procedures are proposed for tackling the problem. A case study related to mask production is presented. Several insights are provided stemming from the COVID-19 pandemic. Finally, the results of a series of computational tests are reported.

The product recall is becoming a challenging issue in supply chain management, and both suppliers and manufacturers are motivated to exert recall efforts to improve supply chain performance. Considering a supply chain composed of one supplier and one manufacturer with product recalls and demand uncertainty, we investigate the contract design by integrating the revenue sharing contract with three cost sharing policies, namely, fixed-rate cost sharing (Contract F), linear cost sharing (Contract L), and threshold-based cost sharing (Contract T), to coordinate the production quantity and recall efforts. Results show that cost sharing could improve the product recall probability and supply chain profits, but only Contract T can coordinate the supply chain in both production quantity and recall efforts. Moreover, the cost sharing rate in Contract T first decreases and then increases as the recall cost increases. When the recall cost is small (large), Contract T (Contract F) is optimal for the manufacturer. In contrast to our intuition, we find Contract L could overmotivate supply chain members to exert a recall effort that is greater than the first-best when the cost coefficient of recall efforts is large enough. However, demand uncertainty will mitigate the impact of product recalls on motivating recall efforts.

According to previous studies, the workforce competencies of engineers in manufacturing industries generally comprise technical, generic, and knowledge competencies. However, these categories of workforce competencies are insufficient for firms whose manufacturing processes are very easily interrupted by anomalies and whose core competency is highly related to production yield. In addition to drawing attention to the importance of identifying engineers’ problem-solving competencies, this article proposes a procedure to identify and rate workforce competencies for firms in the manufacturing industry. An IC packaging process engineer was used as an example to illustrate the proposed competency identification and rating procedure. In contrast to previous studies, this article suggests that problem-solving competencies can be identified from engineers’ responses to the anomalies commonly encountered in each step of the manufacturing process and that operational competency can be identified from the knowledge, techniques, or capabilities required to fulfill a task in each step of the manufacturing process. For the IC packaging and testing industry, this article can help human resources not only evaluate the competency of job candidates but also design training courses according to the job tenure of engineers. Furthermore, this article results can be used to design teaching material for apprenticeship to help engineers develop competencies in a structured manner and enhance their sensitivities to production-line problems.

Introduction Only 5% to 15% of individuals with amputation living in low- and middle-income countries (LMICs) have access to proper prostheses. Mainly, prosthetic costs are too high, and facilities are not within reach. Measurement and production of traditional prosthetic sockets are time-consuming, labor-intensive, and highly dependent on the experience and skills of the personnel involved. Materials and Methods This report describes the workflow to produce low-cost patella tendon bearing transtibial prosthetic sockets. Using computer-aided design (CAD) and computer-aided manufacturing (CAM), transtibial prostheses can be easily produced in rural areas. The size of the residual limb was scanned with a handheld 3D-scanner (Einscanner Pro Plus), and the sockets were printed using fused filament fabrication (FFF) with an Ultimaker S5. The foot was made locally, and the other prosthetic parts were imported. The 3D-printed socket costs US $20 (excluding value-added tax [VAT]). The total material cost of the prosthesis, including the other prosthetic materials, amounts to approximately US $100 (excluding VAT). Assuming the asset cost of the devices, the costs of one local employee, overhead expenses, a profit margin, and the VAT included, a 3D-printed prosthesis could be sold for US $170. Conclusions This report provides a blueprint to produce low-cost 3D-printed transtibial prosthetic sockets. Further research will be conducted to replace the imported prosthetic parts for local products and to automatize the digital design process. Clinical Relevance With this workflow, prosthetic sockets can be produced consistently, which makes it a suitable method in LMICs.

Co-production in climate change has arisen in response to improving climate knowledge. Climate service co-production provides climate knowledge for decision-making, benefiting vulnerable communities with useful and usable information such as flooding risk areas. A climate service co-production project, including mapping technologies, has been conducted in Jakarta, Indonesia. However, it has not been integrated into mainstream spatial planning. This paper investigates an enabling environment for the integration of climate service co-production and spatial planning using a collaborative governance framework. We conducted semi-structured interviews, photovoice, and focus group discussions. The results highlight factors to enable integration; (1) an institutional reform to put climate service co-production on the agenda, (2) top-down priorities aligned with local-level needs, (3) local government will and leadership to execute the tasks and actions towards climate resilience, (4) trust of the local government with the community, (5) integrated geospatial data to have an effective climate knowledge to spatial planning.

One of the most important oil derivatives in our time, which all the world seeks to obtain and produce a lot is lubricating oils, which are used for several important purposes and the most important is to keep the thermal engines from damage or collapse due to the phenomenon of friction of the moving parts mechanically at a high temperatures and pressure is relatively high as well as the wear phenomenon This research effort focuses on a comparative study of five types of mix crude Libyan oils (El-Feel Field, Al Wafa Field, Amina Field, Brega Field and Al-Sedra Field) for produced the lubricated oil experimentally . Test carried out on the production the lubrication oil by measuring the physical properties include: normal boiling point, pour point, specific gravity (Sp. gr.), standard density (API), dynamic viscosity , kinematics viscosity , Acentric factor and Watson factor (K or K ). It’s found from the practical results of the production the lubricating oil from crude oil for atmospheric distillation of crude oil practically depends on measurement two physical properties very accurately Watson factor first and then the API. The results from the tests showed that, mix crude oil of Amena, El-Sedra and El-Feel fields suitable than others for production the lubricated oil at atmospheric and then use the vacuum distillation columns. Other results observation, that’s two others types are impossible to produce the lubricated oil. Also, the results observed that’s the useful mole percentage of lubricated oil cutoff has range very small from 2 to 17 % for these types of Libyan crude oils, this percentage will be increase when use vacuum distillation with added some additives materials. In addition, practical results have been found that not all the cutoff produced from atmospheric distillation within the range of temperatures between 370 and 550 oC are lubricating oils, but other compounds are oil derivatives suitable for different fuel depending on the chemical structure of these extracts. The final conclusion of this work is that any crude oil with a light Arabic class (has a relative density API less than 38 and a K lower than 12.1) is suitable for the production of lubricated oils from the crude oil.

This study considers a repairable production system operated under an age-based preventive replacement policy that is subject to independent random production waits and failures. In addition to the age-based replacement policy, we propose a maintenance model that uses production waits to schedule preventive replacement. That is, a decision maker can preventively replace the system either during a production wait or at the age threshold, whereas if a failure occurs during production, the decision maker must decide whether to perform a minimal repair or a corrective replacement to restore the system. Under the above setting, we develop a semi-Markov decision process (SMDP) to obtain the optimal maintenance policy that minimizes the long-run average maintenance cost rate. We establish the existence of the optimal maintenance policy and provide an algorithm to numerically obtain the optimal action for each state. We further generalize the model to incorporate imperfect maintenance and the nonhomogeneous arrival of production waits. In the latter case, it is computationally intractable to optimize the SMDP using a value iteration algorithm due to the curse of dimensionality. To address this challenge, we further develop an approximate dynamic programming framework to generate high-quality solutions. An attractive feature of our model is its generality, such that the model includes many existing maintenance models as special cases. A real-world example from a steel factory is used to demonstrate the proposed model.

Additive manufacturing enables the production of complex structures with emerging approaches showing great promise in the food industry for design customization. Three-dimensional food printing has...

Development is a process that takes place in society to improve the existing living conditions to change from an undesirable current situation to a desired future situation within a specific period of time using the available resources. The traditional industries express the depths of the Egyptian conscience as they are a factor of communication between generations. The traditional industries have cultural, social and economic aspects and therefore must be preserved. The importance of traditional industries is due to the fact that they are characterized by many values. This study will deal with basic aspects of these industries, and their marketing and production in a scientific and practical manner. It increases the efficiency of its production and marketing in quantity and quality.

In this article, we study a multiproduct multiperiod production planning problem faced by a cash-strapped manufacturer, who utilizes inventory-based financing (IBF) to capture additional demand during peak season, which otherwise will not be met due to cash shortage. Each product has a unique selling season and its production incurs a significant setup cost. We formulate the problem as an integer program and show the special case with one product is NP-hard. By exploiting the inherent structure of three distinct but related decisions, i.e., the production, financing, and working capital allocation decisions, we develop a Lagrangian relaxation-based branch-and-bound procedure to solve the model. Through a series of numerical experiments using real data, this article presents managerial insights into how the manufacturer's optimal production plan could differ with and without IBF. In an optimal plan, we show the profit maximizing strategy for the cash-strapped manufacturer is to overstock and pledge inventories to secure more loans prior to peak demand periods.

Mahogany (Swietenia macrophylla King) is one of the most valuable wood species found in the American Continent. This study is an evaluation of the production of particleboards using wood residues from the branches and trunk of a mahogany tree. It was designed to test the feasibility of production and the mechanical and physical characteristics of the finished particleboards, as well as to compare the results with similar studies and the requirements of normative documents. The particles were generated from the trunk and branches of a mahogany tree separately and mixed in different proportions to test their influence on the final product. They were bonded using 12% polyurethane resin from renewable resources and pressed under 90º C and 3.5 MPa for 10 minutes. The specimens were prepared and tested according to the guidelines established by the NBR 14810 regarding the static bending, internal bond, stiffness and thickness swelling (24h) tests. The results indicated that there is no significant correlation between the trunk-branches proportion and the Modulus of Elasticity/Rupture values. The production of the particleboards using the residues is feasible and the results of most of the tests fitted the normative requirements, which means that with the refinement of the production process it is possible to have a good product that fully complies with the technical standards. Resumo A madeira de mogno (Swietenia macrophylla King) é uma das mais valiosas encontradas no Continente Americano. Esse trabalho visou avaliar a produção de painéis de partículas de resíduos dos galhos e troncos dessa espécie. Foram avaliados a viabilidade de produção, as propriedades físicas e mecânicas e, além disso, foi realizada a comparação dos resultados com estudos similares e requisitos de normas. Os painéis foram fabricados a partir dos resíduos do tronco e dos galhos, de forma separada e misturados em diferentes proporções para testar sua influência no produto final. Foram aglomerados usando resina de poliuretano e prensados a 90°C e 3,5 MPa por 10 minutos. As amostras foram testadas para flexão estática, aderência interna, rigidez e inchamento (24 h), de acordo com as recomendações da NBR 14810. Os resultados indicaram que não houve correlação significativa entre a proporção tronco-galhos e os valores de módulo de elasticidade/ruptura. A produção dos painéis foi considerada viável e os resultados da maioria dos testes atenderam aos requisitos normativos.

With the prosperity of global trade and maritime transportation, dry port is playing a significant role in freight transport industry through relieving seaport congestion and facilitating improved logistics solutions. This article studies the rail shuttle service pricing and scheduling problem in a dry port system with one dry port and multiple shippers. Bilevel models are developed to address the interaction between the dry port and shippers, with the dry port as the leader and individual shippers as followers. The optimal properties of the proposed bilevel model are analyzed, and a solution procedure is proposed to obtain the global optimal solution. Numerical studies are carried out to investigate the sensitivity of optimal decisions, and performance of both parties with respect to various system parameters. This study shows that offering a higher storage price could not always bring higher profit for the dry port. An extremely high storage price will reduce shippers’ total costs, especially for shippers with high production rates. If the seaports’ cutoff time is short, shippers with low production rates would have to bear high expenses. It is also found that low setup costs at shippers will bring not only cost savings for shippers, but also profit improvement for the dry port.

The species Schleichera oleosa (Kusum), being rich in nutritional, medicinal and processing qualities can play a very important role in the livelihood security of the rural communities through enhanced household income, employment generation and environmental protection. People of many states of India are becoming increasingly aware about the potential importance of this species in terms of its ethnobotany and lac production in their livelihood security. Value addition of all the components especially seed oil for biodiesel production, lac production and processing of bark for exploiting their nutritional and medicinal properties is a long-term strategy. There is need of increasing the area and plantation of this valuable species and enhancing their processed products. Moreover, to domesticate this species on farmer's field, there is a need to develop good cultivars. Hence, there is an ample scope in developing propagation methods and suitable good cultivars through nursery management programme. Dissemination of improved production technologies, value addition and marketing strategies regarding Kusum trees and its products to the farmers/entrepreneurs/lac based industries is of utmost importance for promoting it as agribusiness.

The output gap, the difference between potential and actual output, has a direct impact on policy decisions, e.g., monetary policy. Estimating this gap and its further analysis remain the subject of controversial debates due to methodological problems. We propose a local polynomial regression combined with a Self-Exciting Threshold AutoRegressive (SETAR) model and its forecasting extension for a systematic output gap estimation. Furthermore, local polynomial regression is proposed for the (multivariate) OECD production function approach and its reliability is demonstrated in forecasting output growth. A comparison of the proposed gap to the Hodrick–Prescott filter as well as to estimations by experts from the FED and OECD shows a higher correlation of our output gap with those from those economic institutions. Furthermore, sometimes gaps with different magnitude and different positions above or below the trend are observed between different methods. This may cause competing policy implications which can be improved with our results.

Informal public transport is generally understood as transport services that are provided in absence or violation of state regulations. This paper argues that attempts to define the informality of public transport through such liberal economic lenses are insufficient in explaining the processes which lead to production of informalities. Discussing the operation of Vikrams (individually-owned and privately-operated shared autorickshaws plying on fixed routes) in Dehradun, India, this paper uncovers the multifaceted role of the state in producing and sustaining informalities in public transport provisions. It offers a more nuanced view of informality in transport studies than its commonplace understanding as a spontaneous, self-regulating, entrepreneurial aggregate. The paper argues that informality in transport studies should be understood as a heterogeneous practice that is a product of wider structural contexts situated in the politico-historical understandings of public transport in evolving spatio-temporal moments. In the case presented in this paper these include imperial legal legacies and its intersections with shifting postcolonial political economies and territorial structures.

Following state-level legal changes that increase labor dismissal costs, firms increase their innovation in new processes that facilitate the adoption of cost-saving production methods, especially in industries with a large share of labor costs in total costs. Firms with high innovation ability exhibit larger increases in process innovation and capital-labor ratios - an effect driven by both increases in capital investment and decreases in employment. By facilitating the adjustment of the input mix when conditions in input markets change, innovation ability allows firms to mitigate value losses and is a key driver of their performance.

Problem definition: In high-product-variety businesses like fashion, mass production (MP) systems create environmental waste in the form of overproduction on a colossal scale. Mass customization (MC) has been proposed—without solid evidence—as a solution. In this paper, we analyze whether MC can indeed offer a win-win solution that helps both the bottom line and the environment. We also study the impact of three real policy options: promoting MC, charging a disposal fee for overproduction, and recycling. Academic/practical relevance: There is increasing interest in mass-customizing fashion goods, not only because consumers value customization, but also because MC is perceived to be environmentally friendly. Our paper puts this advocacy for MC to the test. We contribute to the literature, which has been largely silent on the issue, by uncovering when MC offers a win-win and relating such market outcomes to policy ideas. Methodology: We develop an analytical model of an MP firm adopting MC (going hybrid). The firm’s profit-maximizing variety, price, and inventory decisions then form the basis of our understanding the environmental impact of adopting MC and assessing various policy options. Results: Adopting MC can be a win-win, but it can also increase overproduction and hurt the environment. Our policy analyses reveal two kinds of insights. The first kind is about whether a policy expands win-win outcomes—encouraging sustainable adoption of MC. Among the policy ideas we explore, only promoting MC so as to increase consumers’ tolerance for waiting for mass-customized products can do that unambiguously. The second kind of insight is about whether a policy reduces the hybrid firm’s environmental impact. Only a disposal fee and costly recycling programs can do that unambiguously. Managerial implications: For MC adoption to be a win-win, policy makers must (1) work on convincing consumers to wait for bespoke fashion; (2) target MP firms with low cost of variety (high product-mix flexibility) with disposal fees or costly recycling programs; and (3) encourage those with relatively higher cost of variety to develop/acquire technology that would make recycling profitable. History: This paper has been accepted for the Manufacturing & Service Operations Management Special Section on Responsible Research in Operations Management. Supplemental Material: The online appendix is available at https://doi.org/10.1287/msom.2022.1088 .

This paper studies productivity and preferences in scientific research. Collaboration is increasingly important for innovation in science and other domains, but we have limited understanding of the factors researchers use to choose their collaborators and the projects they work on. Here, we use a model of strategic network formation and a recently developed econometric method to examine this question in the context of economics researchers. We learn that research teams with more collaborators tend to produce papers with higher impact, and without increasing individual costs of communication and coordination. This suggests the trend toward larger research teams in economics will continue.

Clean and renewable energy plays important role in achieving carbon neutrality and nature sustainability, especially the application of green hydrogen in new energy system. Hydrogen (H2) produced from visible light has attracted attention owing to its high conversion efficiency and cleaner process. In this review, different photocatalyst preparation methods which can directly design the same structure were clarified. Also, different mechanism design which can realize different electron transfers were also proposed. Thus, various morphologies and different mechanisms of electron transfer have been summarized and evaluated. Also, the methods of photocatalysts’ construction were mentioned, all H2 production reactions depend on the amount of reaction sites and photo-generate electrons. It was evident that the concentration of reaction sites and photo-generate electrons play important roles in efficient H2 production. This review provides fundamental knowledge to design and construct variable morphologies with different electron transfer processes to enhance efficiency of H2 production.

Manufacturers are pursuing energy-efficient production in response to the fluctuating energy price, growing global competition, rigorous international laws, and severe environmental crisis. This article proposes to boost the energy efficiency of production systems by controlling the production. It extends the existing energy-saving control research by presenting integrated modeling, analyzing, and controlling approaches. The work starts from the modeling of the production systems and establishes an analytical model to systematically quantify the production loss resulted from energy-saving control and the various disruptions. A dynamic control algorithm is proposed to reduce energy consumption and maintain desirable productivity. Simulation studies are utilized to demonstrate the application of the proposed method and verify its effectiveness.

The use of recycled plastics is critical in the transition to a circular economy. However, for certain types of plastics, the recycling process is economically unviable. Government-driven incentives, such as a policy imposing a minimum fraction of recycled plastics to be used in production processes of plastic goods, offer an exit from this impasse. In this paper, we study how a firm's investment behavior is affected by policy uncertainty governing the introduction of such a regulatory measure. Specifically, we adopt a real option approach to study the two-step investment of a firm in its transition to the use of recycled plastics. A clear trade-off can be distinguished. On the one hand, investing early causes unnecessary profit losses before the policy implementation. On the other hand, a lack of investment leads to market exclusion after the policy implementation. For our case study on the use of recycled polyethylene, we find that firms plan their first investment step, so that the timing of the second investment step approximates their projection on the policy implementation time. Moreover, we find that the firm's value is maximized when the capacity of the first investment is smaller than the capacity of the second investment.

Microalgae originating from wastewater has been exhibiting particularly promising results in terms of biohydrogen production and wastewater treatment. This paper aims to review the factors affecting production, pretreatment techniques to improve synthesis, advanced technologies utilized for enhancing biohydrogen production, and techno-economic feasibility evaluation of the processes at a commercial scale. Microalgae possess metabolic components to synthesize biohydrogen using photobiological and fermentative processes but must undergo pretreatment for efficient biohydrogen production. The efficiency of these processes is influenced by factors such as the microalgae species, light intensity, cell density, pH, temperature, substrates, and the type of bioreactors. Moreover, many limitations, such as oxygen sensitivity, altered thylakoid constitution, low photon conversion efficiency, light capture disruption, and the evolution of harmful by-products hinder the sustainability of biohydrogen production processes. High operational and maintenance costs serve as the major bottleneck in the scaling up of the process as an industrial technology. Therefore, future research needs to be directed towards increasing optimization of the processes by reducing energy and resource demand, recycling metabolic wastes and process components, genetically engineered microalgae to adopt more efficient routes, and conducting pilot studies for commercialization.

We study the aggregate consequences of the Social Security Disability Insurance (DI) program, focusing on the role of complementarity between heterogeneous human capital. First, we develop and estimate a wage process in which individuals' human capital comprises (pure) labor and experience, and their efficiencies are affected by disability. We find that older workers are more experience-abundant, and that disability causes a smaller loss in the efficiency of experience than it does in the efficiency of labor. Further, the estimated aggregate production technology shows that labor and experience are complementary inputs. Combining these empirical results with a structural general equilibrium model, we analyze the labor market implications of removing the DI program. Removal of the DI program induces an increase in the relative supply of experience, thus affecting the marginal productivities of inputs and wages of all workers in the economy. Despite the increased labor market entry of disabled workers, the aggregate productivity may increase in the counterfactual economy, thanks to the complementarity between labor and experience.

This paper examines potential entrants’ strategic product market decisions in response to incumbents’ accounting information and related disclosure. I predict that potential entrants are more likely to enter markets in which the incumbents’ accounting information suggests higher future production costs that are specific to the incumbents themselves. I further hypothesize that the relation is stronger when the accounting signals are accompanied by more extensive supplementary disclosure. Using detailed U.S. airline industry data and hedge accounting disclosure under SFAS 133, I find that potential entrants are more likely to enter routes in which the incumbents’ lower accumulated other comprehensive income from fuel hedges suggests that the incumbent will have higher future production costs. This entry pattern is stronger when incumbents have more transparent annual report disclosure regarding their fuel hedge programs. The entry pattern is also stronger after a systematic increase in risk management disclosure requirements following the (exogenous) adoption of SFAS 161. The findings are consistent with the notion that accounting information and disclosure affect product market competition.

A striking feature of micro-level plant data is the presence of significant variation in factor cost shares across plants within an industry. We develop a methodology to decompose this variation into idiosyncratic and group-specific components and to use cluster analysis to recover the number and membership of groups using breaks in the dispersion of factor cost shares across firms. We apply our methodology to Chilean plant-level data and find that group-specific variation accounts for approximately one-third of the variation in factor shares across firms. We motivate our results with an economic model in which group-specific variation can arise from differences in production technologies or through distortions that affect different groups of firms. We evaluate several potential explanations for our results and argue that our findings are most consistent with the interpretation of group-specific variation arising from the presence of multiple production technologies. Under this interpretation, ignoring groups overstates the gains from eliminating mis-allocation by roughly one-third.

Plant essential oils are natural and aromatic compounds that are found in small amounts in plants and have many interesting applications as flavors and fragrances in perfumery, cosmetics, pharmaceutical, food, agriculture, industry and etc. Essential oils can be produced by various techniques including conventional, novel and biotechnology methods. can be considered as a good alternative to conventional methods due to short extraction time, higher efficiency and quality, non-degradable compounds due to heat, no pollution and etc. Recently, due to the limitations and disadvantages of methods of extraction from intact plants, scientists have been trying to move their way to biotechnology methods and make a variety of plant aromatic compounds by microorganisms. In the biotechnology method, there is no any concern about factors such climate conditions, supply shortages, natural disasters, plant diseases and etc. and a product with very high efficiency and quality is obtained.

This paper assesses the rationale, design, and impacts of border carbon adjustments (BCAs). Large disparities in carbon pricing between countries raise concerns about competitiveness and emissions leakage. BCAs are potentially the most effective domestic instrument for addressing these challenges—but design details are critical. For example, limiting coverage of the BCA to energy-intensive, trade-exposed industries facilitates administration, and initially benchmarking BCAs on domestic emissions intensities would ease the transition for trading partners with emission-intensive production. It is also important to consider how to apply BCAs across countries with different approaches to emissions mitigation. BCAs alone do not solve the free-rider problem in carbon pricing, but might be a step to an effective international carbon price floor.

We empirically examine the effects of index investing using predictions derived from a Grossman-Stiglitz framework. An increase in index investing leads to lower information production as measured by Google searches, EDGAR views, and analyst reports, yet price informativeness remains unchanged. The findings are consistent with an equilibrium in which investors choose to be informed active traders whenever it is profitable. As index investing increases there are fewer informed active investors (so aggregate information production drops), but the remaining mix of informed and uninformed active investors adjusts until the returns to active investing are unchanged -- thus price informativeness is unchanged.

The primary objective of the case study is to help students understand, model, and solve capacity planning problems (i) when the production yield is uncertain and (ii) if the yield of first production is low, the product can be produced a second time. The dimension of random yield emphasizes supply chain management challenges beyond the traditional newsvendor problem, which has a nice closed-form solution. The dimension of operational flexibility underscores the importance of modeling skills, such as influence diagrams, that can be used to brainstorm, model, and solve new problems. Extensive use of the case in graduate supply chain management courses shows that in the absence of a mathematical model, students systematically deviate from optimal capacity usage. Usually, the presence of backup flexibility reduces first-period production. However, students’ responses often suggest cutting first production too much. When it is available, students consistently overuse the flexibility of second-period production. Overall, students believed the case was challenging and that it provides a valuable learning experience.

Recently, frequent emergencies seriously impact the people's life and production. The timely emergency material can save more people. Hence, emergency material demand prediction is a core of emergency rescue. However, the emergency is a continuous uncertain evolution process. The emergency of different periods has various situations. The time-varying and uncertain characteristics of emergency have made this representation and prediction work much more complex. In order to address this concern, this paper proposes a time-varying intuitionistic fuzzy set (TVIFS) to precisely depict the time-varying scenario and the uncertainty of emergencies. For utilizing the TVIFS of different time frames, we deeply explore the integral aggregation operator of TVIFS, which can take full account of decision hesitation and possible information. Due to the different time importance of different time frames, we investigate the integral of TVIFS with constant period weight in advance. Considering the time-varying period weight, the TVIFS integral with time-varying period weight is investigated. For the sake of calculation feasibility, inspired by the relationship between continuity and dispersion, we translate the TVIFS integral with variable period weight into the TVIFS integral with constant period weight. Furthermore, we develop time-varying intuitionistic fuzzy case-based reasoning model to forecast the emergency materials demand by designing hybrid similarity between cases. Finally, we elaborate the application of time-varying intuitionistic fuzzy case-based reasoning model by using an example of forest fire and verify the validity of our proposed method.

In this paper, we propose to use production executions to improve the quality of testing for certain methods of interest for developers. These methods can be methods that are not covered by the existing test suite, or methods that are poorly tested. We devise an approach called PANKTI which monitors applications as they execute in production, and then automatically generates differential unit tests, as well as derived oracles, from the collected data. PANKTI's monitoring and generation focuses on one single programming language, Java. We evaluate it on three real-world, open-source projects: a videoconferencing system, a PDF manipulation library, and an e-commerce application. We show that PANKTI is able to generate differential unit tests by monitoring target methods in production, and that the generated tests improve the quality of the test suite of the application under consideration.