Developing a two-stage model for a sustainable closed-loop supply chain with pricing and advertising decisions
در حال توسعه یک مدل دو مرحله ای برای یک زنجیره تامین حلقه بسته پایدار با تصمیمات قیمت گذاری و تبلیغات-2021
Closed-Loop Supply Chain (CLSC) has become a critical problem due to its effects on various factors including economic motivations, environmental concerns, and social impacts. Moreover, there are coordination tools, such as pricing and advertising, which impact its performance. In this paper, we offer a two-stage approach to model and solve a sustainable CLSC, taking into account pricing, green quality, and advertising. In the first stage, optimal decisions on pricing, greening, and advertising are made, while in the second stage, a fuzzy multi- objective Mixed Integer Linear Programming (MILP) model is used to maximize the total profit, reduce CO2 emissions, and improve social impacts. Suitable solution methods are introduced according to the scale of the problem. For small-scale instances, an augmented ϵ-constraint method is used to solve the problem. For large-scale instances, approximations are required, and a Lagrangian relaxation algorithm solves the problem in polynomial time. The performance of the proposed model is evaluated through various numerical examples. The results illustrate the applicability and efficiency of the model, while confirming significant improvements in sustainable objectives under optimal pricing, green quality, and advertising. Besides, the proposed Lagrangian relaxation method significantly reduces the computational time for large-scale instances, with only a 2.308% deviation from the optimal results.
Keywords: Sustainable closed-loop supply chain | Multi-objective programming | Supply chain pricing | Augmented ϵ-constraint | Lagrangian relaxation | CO2 emissions
The choice of cooperation mode in the bioenergy supply chain with random biomass feedstock yield
انتخاب حالت همکاری در زنجیره تأمین انرژی زیستی با عملکرد خوراک زیست توده تصادفی-2021
A successful cooperation mode between bioenergy producers and farmers can effectively promote the supply of biomass feedstock, which plays an important role in the bioenergy industry. In this study, we examine two prevailing cooperation modes in bioenergy supply chain, namely contract farming (CF) and land as shares (LS). This study assesses how each cooperation mode influences the planting acreage, the feedstock quality and the profits of supply chain participants. Under CF, the farmer and the bioenergy producer sign a contract in which the bioenergy producer purchases all feedstock produced by the farmer. Under LS, the farmer converts their land use rights into company shares, so that the bioenergy producer will share part of sales revenue with the farmer. First, we find that the optimal planting scale of biomass feedstock under LS is larger than that under CF when the bioenergy market size is sufficiently large. If the market size is relatively small, the supply quantity of biomass feedstock under LS depends on the marginal value of feedstock quality. Second, when the bioenergy market is sufficiently large, the farmer and the bioenergy producer under LS can achieve a win-win situation, which improves the reliability of the bioenergy supply chain. Third, we extend our model to the case where the government implements subsidies for biomass feedstock. We find that when the subsidy is high enough, the biomass feedstock quantity under LS will be larger. In addition, government subsidy does not necessarily improve the profit of all supply chain participants and excessive government subsidy may adversely affect the reliability of the bioenergy supply chain.
Keywords: Bioenergy supply chain | Contract farming | Land as shares | Government subsidy
Evaluation of infrared thermography combined with behavioral biometrics for estrus detection in naturally cycling dairy cows
ارزیابی ترموگرافی مادون قرمز همراه با بیومتریک رفتاری برای تشخیص فحلی در گاوهای شیری دوچرخه سواری طبیعی-2021
Low estrus detection rates (>50%) are associated to extended calving intervals, low economic profit and reduced longevity in Holstein dairy cows. The objective of this study was to evaluate the accuracy of infrared thermography and behavioral biometrics combined as potential estrus alerts in naturally (not induced) cycling dairy cows housed in a tie-stall barn. Eighteen first lactation cows were subjected to transrectal ultrasonography to determine spontaneous ovulation. The dominant follicle (DF) disappearance was used retrospectively as an indirect indicator of ovulation, and to establish the estrus period (48–24 h prior the DF disappearance). Raw skin temperature (Raw IR) and residual skin temperature (Res IR) were recorded using an infrared camera at the Vulva area with the tail (Vtail), Vulva area without the tail (Vnotail), and Vulva’s external lips (Vlips) at AM and PM milking from Day 14 until two days after ovulation was confirmed. Behavioral biometrics were recorded on the same schedule as infrared scan. Behavioral biometrics included large hip movements (L-hip), small hip movements (S-hip), large tail movements and small tail movements to compare behavioral changes between estrus and nonestrus periods. Significant increases in Raw IR skin temperature were observed two days prior to ovulation (Vtail; 35.93 ± 0.27 C, Vnotail; 35.59 ± 0.27 C, and Vlips; 35.35 ± 0.27 C) compared to d 5 (Proestrus; Vtail; 35.29 ± 0.27 C, Vnotail; 34.93 ± 0.31 C, and Vlips; 34.68 ± 0.27 C). No significant changes were found for behavioral parameters with the exception of S-hip movements, which increased at two days before ovulation (d 2; 11.13 ± 1.44 Events/5min) compared to d 5 (7.30 ± 1.02 Events/5min). To evaluate the accuracy of thermal and behavioral biometrics, receiver operating characteristic curve analysis was performed using Youden index (YJ), diagnostic odds ratio, positive likelihood ratio (LR+), Sensitivity, Specificity and Positive predicted value to score the estrus alerts. The greatest accuracy achieved using thermal parameters was for Res IR Vtail PM (YJ = 0.34) and L-hip PM (YJ = 0.27) for behavioral biometrics. Combining thermal and behavioral parameters did not improve the YJ index score but reduced the false-positive occurrence observed by increasing the diagnostic odds ratio (26.62), LR+ (12.47), Specificity (0.97) and positive predicted value (0.90) in a Res IR Vtail PM, S-hip AM, S-hip PM combination. The combination of thermal and behavioral parameters increased the accuracy of estrus detection compared to either thermal or behavioral biometrics, independently in naturally cycling cows during milking.
Keywords: Combined-parameters | First-lactating | Movement-frequency | Preovulation | Skin temperature
Inventory model for sustainable operations of a closed-loop supply chain: Role of a third-party refurbisher
مدل موجودی برای عملیات پایدار یک زنجیره تأمین حلقه بسته: نقش یک مرمت کننده شخص ثالث-2021
Journal Pre-proof This paper investigates the joint decision on inventory and refurbishing strategies in a closed-loop supply chain, consisting of a manufacturer responsible for the production and first-market sales and a third-party refurbisher responsible for the refurbishment and second market. Based on a game-theoretic model, we investigate the effects of supply chain structures on the production operations, sales price of a refurbished product, profits and environmental performance. Through numerical analyses, we reveal that the integrated system yields higher first-market sales and a larger production lot size, while the decentralized one shows higher second-market sales and a larger refurbishing lot. Interestingly, the integrated system sets the higher price for the refurbished item due to channel conflict issues. Efforts to increase the second-market sales can harm the over- all supply chain profit by leading to the decrease in the higher-margin first-market sales. We also show that the difference in pricing decisions and inventory holding cost components allows a better operational performance of the third-party refurbishers process in the decentralized system. Then, it leads to the better environmental performance in the decentralized system, enhancing the refurbishing rate and sales of refurbished items while reducing scrap costs. By investigating the overall performance of integrated and decentralized supply chains, we offer important implications to practicing supply chain managers by revealing how the third-party refurbisher can help the sustainable operations of a closed-loop supply chain. We also contribute to the body of knowledge by incorporating pricing and lot sizing issues into the context of closed-loop supply chain management.
Keywords: inventory | closed-loop supply chain | sales return | refurbishment
Who will take on green product development in supply chains? Manufacturer or retailer
چه کسی توسعه محصول سبز را در زنجیره های تامین به عهده خواهد گرفت؟ تولید کننده یا خرده فروش-2021
: This paper investigates the optimal decisions, profits and social welfare in a green supply chain (GSC) when the manufacturer or retailer conducts green product development. Two Stackelberg game models are constructed here: the manufacturer-led green product development model (MD model) and retailer-led green product development model (RD model), and it is assumed that the green product developer is risk-averse. Then the optimal decisions and members’ profits under two models are obtained. Through comparing them, the results show that the product greenness and leader’s profit are always higher in MD model, but in which model the retail price, wholesale price and follower’s profit are higher/lower is related to the cost coefficient of green product development, the leaders’ risk aversion, and demand uncertainty. Moreover, the risk aversion and demand uncertainty have a negative impact on most decisions and profits, but their impact on followers’ profits under two models and the wholesale price of RD model are still affected by the cost coefficient of green product development. Finally, numerical experiments are used to compare the total profits and social welfare under two models. The results indicate that in most cases, the GSC’s total profit under RD model is higher, but the social welfare under MD model is higher.
Keywords: Green product development | Green supply chain management | Stackelberg game | Risk aversion
Conceptual MINLP approach to the development of a CO2 supply chain network – Simultaneous consideration of capture and utilization process flowsheets
رویکرد مفهومی MINLP برای توسعه یک شبکه زنجیره تامین CO2 - در نظر گرفتن همزمان صفحه های جریان فرآیند ضبط و استفاده-2021
A large fraction of anthropogenic CO2 emissions comes from large point sources such as power plants, petroleum refineries, and large industrial facilities. A significant decrease of these CO2 emissions can be achieved with CO2 capture, utilization, and storage (CCUS) technologies. This study proposes a conceptually simplified model for the optimization of combined CO2 supply networks and capture and utilization technologies by the mixed-integer non-linear programming (MINLP) approach. The objective is to maximize the profit of CCUS technologies, considering chemisorption using methyl-diethanolamine (MDEA) as a capture technology and conversion of CO2 to CH3OH as a utilization technology. Additionally, avoided tax from reduced CO2 emissions is considered as a revenue. A hypothetical case study of five larger point sources of CO2 was investigated, namely coal power plants, biogas plant, aluminium production plant and two cement plants. Two scenarios were considered: i) Scenario A considering different values of the CO2 tax, and ii) Scenario B considering different flue gas flowrates at different values of the CO2 tax. The results show the potential of model-based optimization in reducing the amount of CO2 in the atmosphere by CCUS technology. Furthermore, the results in Scenario A show that CCUStechnology is only profitable if the price of CO2 emissions is higher than 110 €/t emitted CO2. Moreover, the results in Scenario B show that both the profit and the production of CH3OH depend to a large extent on the flue gas flow.
KEYWORDS: Point sources of CO2 | Carbon capture | Storage and utilization (CCUS) | Supply network optimization | Process optimization | MINLP approach
The complexity analysis and chaos control in omni-channel supply chain with consumer migration and advertising cost sharing
تجزیه و تحلیل پیچیدگی و کنترل هرج و مرج در زنجیره تامین کانال های همه کانال با مهاجرت مصرف کننده و به اشتراک گذاری هزینه تبلیغات-2021
Based on omni-channel retailing, considering consumer migration and advertising cost sharing, this paper builds a dynamic price and advertising game model of omni channel supply chain with BOPS (buy-online pickup-in store). Based on game theory and chaotic dynamics theory, we analysis equilibrium points and local stability of the system. Besides, we focus on the stability and complexity of the system with respect to adjustment parameters, the migration rate of the online consumer (MROC), the migration rate of traditional consumer (MRTC) and advertising cost sharing rate (ACSR). These factors are discussed by numerical simulation. Such as 3D stable region, attraction basins and bifurcation diagram. Results show that over high adjustment parameter, MRTC and ACSR lead the system to lose control and show complexity behaviors. As the system go into a chaotic state, the profits of manufacturer and retailer tend to decline. Finally, because of the effects of chaos, the paper proposes the feedback control method to control efficiently the chaotic system. The results provide some managers with relevant management insights in an omni-channel supply chain.
Keywords: Omni-channel | Complexity | Consumer migration | Chaos control | Advertising
Pricing decisions in a decentralized biofuel supply chain with RIN mechanism considering environmental impacts
تصمیمات قیمت گذاری در زنجیره تأمین سوخت زیستی غیرمتمرکز با مکانیسم RIN با در نظر گرفتن تأثیرات زیست محیطی-2021
This study develops pricing models in a decentralized biofuel supply chain focusing on both economic and environmental aspects. Environmental impacts are used as a measure to reflect the environmental objective function calculated based on ReCiPe method. A bi-level multi-objective stackelberg game model considering farmers and biorefineries as followers and the blender as leader is proposed. An ε-constraint method is utilized to convert the multi-objective model to a single-objective one. The bi-level model is then transformed to a solvable integrated model. Finally, a real case study of switchgrass bioethanol is presented to illustrate the performance of the proposed model. Results show that focusing on environmental goals results in the increasement of selling prices and profits of farmers and biorefineries and decreasment of about %7 in economic profit of the blender. Therefore, tradeoff analyses are performed for objective functions leading to 10 Pareto optimal solutions which give managerial insights to the blender. Moreover, sensitivity analyses are provided with respects to price elasticity and final fuel’s price and results show logical trends in selling prices.
Keywords: Biofuel supply chain | Pricing | Decentralized decision making | Environmental impacts | Multi-objective optimization
Optimal generic and brand advertising efforts in a decentralized supply chain considering customer surplus
تلاش بهینه تبلیغات عمومی و تجاری در یک زنجیره تأمین غیرمتمرکز با توجه به مازاد مشتری-2021
While the previous researches of advertising efforts decisions focus on only the firms’ profit target, no literatureintroduces corporation social responsibility target into advertising efforts decisions of a supply chain (SC). To fill this gap, we consider a two-stage SC with a manufacturer and a retailer where the SC members consider the customer surplus. Both the retailer and the manufacturer can invest in generic advertising efforts to influence and increase the products’ sales volumes. This paper investigates the following four scenarios: (1) The retailer cares the customer surplus (Model I); (2) The manufacturer cares the customer surplus (Model II); (3) Both the retailer and the manufacturer care the customer surplus (Model III); (4) We then extend the model III to the case that the manufacturer invests in both the generic and brand advertising efforts (Model IV). The objective of this paper is to determine the optimal retail price, the optimal advertising efforts, and the optimal profits of SC members, and find the influence of customer concern level on the SC performance. Finally, numerical examples are conducted to investigate the influence of the customer concern levels of the retailer or the manufacturer on the profits of the SC members and the entire SC. We also study the joint impacts of the customer concern levels of the retailer and the manufacturer on the SC performance. We find that the SC obtains the highest profits when the retailer’s customer concern level and the manufacturer’s customer concern level are relatively high, and the best cooperative strategy for the retailer and the manufacturer is that they improve customer concern level simultaneously.
Keywords: Supply chain management | Advertising efforts | Pricing strategies | Consumer surplus
Price and quality decisions in a vertically-differentiated supply chain with an “Online-to-Store” channel
تصمیمات قیمت و کیفیت در یک زنجیره تأمین کاملاً متمایز با کانال «فروشگاه از طریق فروشگاه»-2021
Because of the prevalence of “Online-to-Store (OS)” channel, customers can purchase differentiated products online and pick up in-store. We develop a Stackelberg game-theoretic model to study the impact of an OS channel on quality levels, demands, prices, and profits of a manufacturer and a retailer in a supply chain. We assume that the retailer acts as a Stackelberg leader, and the manufacturer acts as a Stackelberg follower. The manufacturer produces and sells two products with vertically-differentiated quality levels to the retailer who in turn sells the products to customers through a Store channel, an Online channel, or an OS channel. The retailer incurs a handing cost if the OS channel is available, and consumers bear a shipping cost and a transaction cost when the products are purchased from the Online and Store channels, respectively. We find that the manufacturer should reduce both products’ quality levels and wholesale prices, whereas the retailer can increase the selling prices for a relatively small shipping cost and a not too small handling cost. When the products are available both online and in-store, however, the quality levels, wholesale prices and selling prices might increase for a small shipping cost and a not too small handling cost. Compared to the case in which both products are available online only with the OS channel, adding the Store channel is always beneficial for both parties. The intuition behind these results hinges on the trade-off between the handling cost and the increased market demand for the retailer. Moreover, the quality levels, the wholesale prices of both products, and the selling price of the low-quality product would decrease, while the selling price of the high-quality product increases for a sufficiently low transaction cost and a not too small shipping cost.
Keywords: Game theory | Online-to-store | Vertically-differentiated supply chain | Pricing | Quality