Intermodal Competition: Cargo Airships versus Long-Haul Trucking for Perishable Commodities

Intermodal competition changes with changes in technology, economics, and environmental concerns. Trucks and airships are generally considered not to be competitors, but this depends on the distance of haul. The tonne-kilometer cost of trucking rises much more quickly with distance than it does the cost of a cargo airship. At some distance, the two modes are direct substitutes. The costs of the Mexico-Canada refrigerated truck supply chain are compared with the costs of a 100t-lift, electrically-powered airship. The flight characteristics of the Hindenburg Zeppelin are used as a model for a modern cargo airship. The supply chain cost of trucking tomatoes is used to test the theorical proposition. The cost difference works out to about US10￠/kg (5￠/lb) advantage for trucking Mexican tomatoes to Canada. However, this cost disadvantage of the airship could be made up by their vibrationless ride, better air circulation and one-day service versus four days by truck. This alternative form of transportation could have a positive impact on worldwide north-south distribution of food. Airships can overcome trade barriers and distance to open new markets for perishable food exports. In addition, they would reduce the carbon emissions of transport. Canada imports 160,000 refrigerated truckloads of fruits and vegetables by from the southern US and Mexico. With an average driving distance of 3,000 km, these trucks emit 606,000 MT of CO2 annually. Airships powered by hydrogen fuel cells would have zero-carbon emissions. Markets are not yet incorporating the environmental advantage of airships in any freight comparison, but inevitably this will be important.

Model of Combined Transport of Perishable Foodstuffs and Safety Inspection Based on Data Mining

There is still no effective means to analyze in depth and utilize domestic mass data about agricultural product quality safety tests in china now. The neural network algorithm, the classification regression tree algorithm, the Bayesian network algorithm were selected according to the principle of selecting combination model and were used to build models respectively and then combined, innovatively establishing a combination model which has relatively high precision, strong robustness and better explanatory to predict the results of perishable food transportation meta-morphism monitoring. The relative optimal prediction model of the perishable food transportation metamorphism monitoring system could be got. The relative perfect prediction model can guide the actual sampling work about food quality and safety by prognosticating the occurrence of unqualified food to select the typical and effective samples for test, thus improving the efficiency and effectiveness of sampling work effectively, so as to avoid deteriorated perishable food’s approaching the market to ensure the quality and safety of perishable food transportation. A solid protective wall was built in the protection of general perishable food consumers’ health.

A Note on an Economic Lot-sizing Problem with Perishable Inventory and Economies of Scale Costs:Approximation Solutions and Worst Case Analysis

This paper presents an economic lot-sizing problem with perishable inventory and general economies of scale cost functions. For the case with backlogging allowed, a mathematical model is formulated, and several properties of the optimal solutions are explored. With the help of these optimality properties, a polynomial time approximation algorithm is developed by a new method. The new method adopts a shift technique to obtain a feasible solution of subproblem and takes the optimal solution of the subproblem as an approximation solution of our problem. The worst case performance for the approximation algorithm is proven to be （4√2 ＋ 5）/7. Finally, an instance illustrates that the bound is tight.

Intermodal Freight Network Design for Transport of Perishable Products

The amount of perishable products transported via the existing intermodal freight networks has significantly increased over the last years. Perishable products tend to decay due to a wide range of external factors. Supply chain operations mismanagement causes waste of substantial volumes of perishable products every year. The heretofore proposed mathematical models optimize certain supply chain processes and reduce decay of perishable products, but primarily deal with local production, inventory, distribution, and retailing of perishable products. However, significant quantities of perishable products are delivered from different continents, which shall increase the total transportation time and decay potential of perishable products as compared to local deliveries. This paper proposes a novel optimization model to design the intermodal freight network for both local and long-haul deliveries of perishable products. The objective of the model aims to minimize the total cost associated with transportation and decay of perishable products. A set of piecewise approximations are applied to linearize the non-linear decay function for each perishable product type. CPLEX is used to solve the problem. Comprehensive numerical experiments are conducted using the intermodal freight network for import of the seafood perishable products to the United States to draw important managerial insights. Results demonstrate that increasing product decay cost may significantly change the design of intermodal freight network for transport of perishable products, cause modal shifts and affect the total transportation time and associated costs.

Study of the Option Ordering Policy concerning Perishable Farm Produce Based on Revenue Sharing Contract

This paper considers the two-echelon supply chain system which consists of single agricultural producers and retailers,and analyzes the impact of sharing ratio on the option ordering quantity,and retailers and producers' expected profits.Studies have shown that in the case of decentralization,when the revenue sharing ratio is between 0 and 0.3,the option ordering quantity of farm produce is a decreasing function of the sharing ratio; when the revenue sharing ratio is between 0.3 and 1,the option ordering quantity of farm produce is an increasing function of sharing ratio; when the revenue sharing ratio is between 0.421 and 1,the agricultural producers and retailers' expected profits are an increasing function of sharing ratio.Finally,through the numerical calculation,the applicability of the conclusions is verified,to provide a reference for the supply chain management practices.

An Inventory Model for Perishable Items with Time Varying Stock Dependent Demand and Trade Credit under Inflation

In the classical inventory models, it is assumed that the retailer pays to the supplier as soon as he received the items and in such cases the supplier offers a cash discount or credit period (permis-sible delay) to the retailer. In this paper we presented an inventory model for perishable items with time varying stock dependent demand under inflation. It is assumed that the supplier offers a credit period to the retailer and the length of credit period is dependent on the order quantity. The purpose of our study is to minimize the present value of retailer’s total cost. Numerical examples are also given to demonstrate the presented mode.

A literature review of perishable medical resource management

In recent decades,healthcare providers have faced mounting pressure to effectively manage highly perishable and limited medical resources.This article offers a comprehensive review of supply chain management pertaining to such resources,which include transplantable organs and healthcare products.The review encompasses 93 publications from 1990 to 2022,illustrating a discernible upward trajectory in annual publications.The surveyed literature is categorized into three levels:Strategic,tactical,and operational.Key problem attributes and methodologies are analyzed through the assessment of pertinent publications for each problem level.Furthermore,research on service innovation,decision analytics,and supply chain resilience elucidates potential areas for future research.

DYNAMIC PRICING UNDER TEMPERATURE CONTROL FOR PERISHABLE FOODS

Consumers pay more and more attention to the quality of perishable roods, which is mainly affected by storage temperature. This paper presents a dynamic pricing model for perishable foods under temperature control. To maximize the total profit, the optimal price and storage temperature are obtained using Pontryagin＇s maximum principle. A static pricing model is provided to compare with the dynamic one. It is shown by a numerical example that the dynamic policy can make more revenue than the static one. Moreover, the managerial implications are analyzed and the effectiveness of the proposed method is demonstrated.

COORDINATING PRICING, ORDERING AND ADVERTISING FOR PERISHABLE PRODUCTS OVER AN INFINITE HORIZON

Numerous empirical studies show that advertising effort can stimulate demand in both current and future periods, and there is an interaction between pricing, advertising and ordering decisions. How do these decisions interact with each other and what is the effect of advertising on pricing and ordering decisions？ To understand this interaction, we consider a newsvendor-type firm that sells a perishable product in a stable market and dynamically determines the joint ordering, pricing and advertising strategies. The problem is modeled as an infmite horizon newsvendor problem with an advertising carryover effect and price-sensitive demand. We characterize the optimal pricing, advertising and inventory strategies and their comparative statics, and consider how this policy differs from the traditional approach without the advertising effect. We show that the optimal effective advertising level is monotonically increasing with the effective advertising level in the previous period, and hence the optimal strategies （advertising, pricing, inventory level） globally converge to the steady states in the long run. We numerically show that the optimal policy can reap significant profit, which underscores the importance of the advertising-driven ordering and pricing strategies.

The risk management of perishable supply chain based on coloured Petri Net modeling

The supply chain of perishable products is a combination of information organization,sharing and integration.The information modeling of supply chain is constructed to abstract key quality information including environment information,processing procedures and product quality assessments based on principle of quality safety factors and property of decay rate.The coloured Petri Net is applied for integrated description of independent information classification,aiming at risk identification and risk management framework.Well,according to the quality deterioration tendency,risk grades management and decision-making system are established.Practically,the circulation system of aquatic products is studied in this paper for full processing description.The simulation experiments are manipulated on environmental information,processing information and product quality information by the coloured Petri Net.Eventually,the conclusion turns out precisely as such that the coloured Petri Net conclusive for information classification and information transmission while integrated information management is available of efficient risk identification and decision-making system in supply chain of perishable products.Meanwhile,the validity of evaluating management and shelf-life estimation of perishable products are technically feasible.

Production plan for perishable agricultural products with two types of harvesting

Many crops in China have two or more harvesting methods;however,little research has focused on this phenomenon.The current study proposes an operational model that looks to maximize grower profits.This model considers a production plan for a perishable crop that has two harvesting methods:harvesting unripe produce at a lower operational cost but with a long lead time,and harvesting ripe crops at a higher operational cost but with quick turnaround.This study proposes a heuristic algorithm by which to pinpoint the optimal plan for the model;the model results indicate that for a crop with two harvesting methods,significant savings can be obtained by applying an optimal production plan.The current study’s main contribution is a production model for crops that feature two harvesting methods and for which the market poses varying demands.

On the Quasi-Concavity of Equipment Sharing Games with Perishable Raw Materials

We study the equipment sharing problem where a group of food&beverage companies share the same equipment of a contractor and wish to have their processing tasks coordinated such that the total cost is minimized.The raw materials to be processed are perishable,which incur a decay cost as time goes.One key issue of this equipment sharing problem is how to allocate the total cost among the participants.We apply cooperative game theory to tackle this issue and formulate the problem as an equipment sharing game.First,we study the 1-equipment sharing game in which all participants share one equipment.We show that the 1-equipment sharing game is quasi-concave when the fixed operation cost is larger than a certain value.We then discuss the special case where the processing time for all participants is equal.For this case,we further investigate the properties of the 1-equipment sharing game and the multi-equipment sharing game.We identify the conditions under which the Shapely value and the T-value can be easily calculated for the 1-equipment and multi-equipment sharing games.

Inventory Policy and Heuristic for Long-Term Multi-product Perishable Inventory Routing Problem with Static Demand

This work considers a long-term Perishable Inventory Routing Problem with multiple products,static demand,and single vehicle,in the setting of Vendor Managed Inventory.By analyzing the optimal solutions of long-term cases that can be solved in Python+Gurobi within 2 h,we capture some patterns of optimal solutions.Utilizing these patterns,experiments show that under certain conditions,the mathematical models of multi-product problems could be simplified to single-product problems,which have the same optimal solutions while taking less time to solve.Managerial insights were generated that for products with static demand in the long term,delivery should be arranged at the store level rather than at the product level.Products in the same store should have the same delivery pattern,no matter how different the unit holding costs are.By further analyzing the optimal solutions of the simplified models,we find that optimal value will stabilize in the long term,and the optimal solution is very close to the solution point where total inventory holding cost and transportation cost are close.Based on these findings,we have developed a heuristic that always provides optimal or close-to-optimal solutions with far less computational time,compared with Python+Gurobi.

An EOQ model with backordering for perishable items under multiple advanced and delayed payments policies

This study investigated an economic order quantity (EOQ) model with completebackorder for fixed lifetime perishable items under multiple advance and delayedpayments policies. Here, a new type of business policy is consideredwhere supplieroffers the retailer to pay a fraction of the purchasing cost before the order deliverybymultiple equal installments starting from the ordering time and the rest amountafter the delivery by multiple equal installments. Here, some theoretical results areillustrated to determine the conditions of existence and uniqueness of the optimalsolutions. A closed form solution is determined to solve the proposed model underapproximation. Some numerical examples are provided to examine the validity ofthe proposed model. Finally, sensitivity analyses are presented to obtain the effectof optimal policy and provide some managerial insights of the model.

Publish or Perish被引分析工具在外语教学研究中的应用

被引分析是最常见的科学计量学研究方法,主要用来证明作者或其成果在所属专业领域内的影响力。Publish or Perish是一种在线被引分析软件,依据Google Scholar数据库来查询作者或成果的被引次数,并提供相关的统计数据分析。文章主要介绍了该工具的功能及使用方法,并结合实例探讨了其在外语教学研究中的应用。

Agri-food Supply Chain Management: Literature Review

The purpose of this paper is to present a critical review of prior literature relating to agri-food supply chain management. An in-depth analysis has been carried out to identify the influential information from the literature. This paper has identified gaps to be explored about agricultural supply chain management (SCM) practices which may be used by researchers to enrich theory construction and practitioners may concentrate on establishing the extent and frontiers of agri-food SCM. This research work is the first attempt to make a critical literature review of available literature on agri-food SCM practices for developing countries like India. The research articles and other materials related to the agri-food supply chain management were collected from online data bases like Scopus, EBSCO and Google Scholar for the period of 10 years (2006-2016). The study performs content analysis and is followed by descriptive analysis. In the next phase, the literature in the field of agri-food supply chain management is classified into four broad categories viz. general literature review of agri-food supply chain, policies affecting the segments of agri-food supply chain, individual segments of agri-food SCM (structure of supply chain segments and conduct of supply chain segments) and performance of supply chain segments. These four categories are comprehensively reviewed and elaborated the research gap in the literature based on agri-food supply chain management. Finally, potato supply chain of India is considered as a case example for comprehensive analysis and elaborated in detail.

Cyber Secure Framework for Smart Containers Based on Novel Hybrid DTLS Protocol

The Internet of Things (IoTs) is apace growing, billions of IoT devicesare connected to the Internet which communicate and exchange data among eachother. Applications of IoT can be found in many fields of engineering and sciencessuch as healthcare, traffic, agriculture, oil and gas industries, and logistics. Inlogistics, the products which are to be transported may be sensitive and perishable, and require controlled environment. Most of the commercially availablelogistic containers are not integrated with IoT devices to provide controlled environment parameters inside the container and to transmit data to a remote server.This necessitates the need for designing and fabricating IoT based smart containers. Due to constrained nature of IoT devices, these are prone to different cybersecurity attacks such as Denial of Service (DoS), Man in Middle (MITM) andReplay. Therefore, designing efficient cyber security framework are required forsmart container. The Datagram Transport Layer Security (DTLS) Protocol hasemerged as the de facto standard for securing communication in IoT devices.However, it is unable to minimize cyber security attacks such as Denial of Serviceand Distributed Denial of Service (DDoS) during the handshake process. Themain contribution of this paper is to design a cyber secure framework by implementing novel hybrid DTLS protocol in smart container which can efficientlyminimize the effects of cyber attacks during handshake process. The performanceof our proposed framework is evaluated in terms of energy efficiency, handshaketime, throughput and packet delivery ratio. Moreover, the proposed framework istested in IoT based smart containers. The proposed framework decreases handshake time more than 9% and saves 11% of energy efficiency for transmissionin compare of the standard DTLS, while increases packet delivery ratio andthroughput by 83% and 87% respectively.

BC driven IoT-based food quality traceability system for dairy product using deep learning model

Food traceability is a critical factor that can ensure food safety for enhancing the credibility of the product,thus achieving heightened user satisfaction and loyalty.The Perishable Food SC(PFSC)requires paramount care for ensuring quality owing to the limited product life.The PFSC comprises of multiple organizations with varied interests and is more likely to be hesitant in sharing the traceability details among one another owing to a lack of trust,which can be overcome by using Blockchain(BC).In this research,an efficient scheme using BC-Deep Residual Network(BC-DRN)is developed to provide food traceability for dairy products.Here,food traceability is determined by using various modules,like the Internet of Things(IoT),BC data management,Food traceability BC architecture,and DRN-based food quality evaluation modules.The devised BC-DRN-based food quality traceability system is examined based on its performance metrics,like sensitivity,response time,and testing accuracy,and it has attained better values of 0.939,109.564 s,and 0.931.

Effective inventory management using postponement strategy with fuzzy cost

In this article, we consider a two level supply chain to evaluate the impact ofpostponement strategy on the retailer. Here the cost parameters are fuzzified.Signed distance method is used to defuzzify and to obtain the estimation of thetotal cost in the fuzzy sense. The common variable production cost, commonfixed cost and the common unit holding cost per unit time are assumed to befuzzy in nature. Inventory models are formulated for postponement system andindependent system such that the total average inventory cost function per unittime is minimized. Algorithms are given to derive the optimal solutions of theproposed model. Theoretical analysis and the computational procedure helps tostudy the impact of deterioration rate on the optimal inventory policies. Acomparative study between the postponement system and independent systemconsidering fuzzy costs is also made.

L~■-convexity and its applications in operations

L■-convexity, one of the central concepts in discrete convex analysis, receives significant attentions in the operations literature in recent years as it provides a powerful tool to derive structures of optimal policies and allows for efficient computational procedures. In this paper, we present a survey of key properties of L■-convexity and some closely related results in lattice programming, several of which were developed recently and motivated by operations applications. As a new contribution to the literature, we establish the relationship between a notion called m-differential monotonicity and L■-convexity. We then illustrate the techniques of applying L■-convexity through a detailed analysis of a perishable inventory model and a joint inventory and transshipment control model with random capacities.