Table of Content

25 August 2021, Volume 30 Issue 8

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Theory Analysis and Methodology Study

Study on Site Location-routing Optimization of Security Patrol in Emergencies

DING Zhao-wei, YANG Jian-hua, WANG Ai, WANG Xin

2021, 30(8):  1-6.  DOI: 10.12005/orms.2021.0239

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The security patrol takes the congress center as the protection target to site the location of the command center and plan patrol routes. Considering the impact of patrol area environment, guard personnel and emergencies on patrol optimization.based on the police's security system scheme, we set up an optimization model for command center site location and patrol routes planning under different constraint conditions. We design and simulate a security region according to the characteristics of real region. Experts use the CPTED theory to analyze, evaluate and classify the specific crime space, and use the idea of genetic algorithm to simulate the optimization strategy and an optimal patrol strategy based on the overall emergency level is realized.

Large Group Decision Making Method Based on Incomplete Probabilistic Linguistic Evaluation Information Considering Authoritative Expert and Its Application in Site Selection of Hot Dry Rock Exploration

XU Xuan-hua, HOU Yu-zhou, HE Ji-shan

2021, 30(8):  7-13.  DOI: 10.12005/orms.2021.0240

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Due to the limitations of expert's knowledge background and professional field, it is difficult to get complete evaluation information in large group decision making (LGDM). In order to maximize the professional contributions of every expert, this paper proposes a LGDM of incomplete evaluation information in the form of probabilistic linguistic term set (PLTs). Firstly, we identify the authoritative experts under different attributes according to the degree of professional recognition and professional hesitation of the expert. Secondly, optimization functions are established to complete the evaluation information. Then, this paper proposes a two-stage similarity measurement method. At the same time, group consensus level can be measured and adjusted to obtain a result with high consensus level. Finally, the reliability and advancement of the proposed method are verified through the case application and comparative analysis of hot dry rock exploration site selection in the southeast coastal area of China.

A Heuristic Algorithm for Solving Flexible Resource Constrained Proactive Project Scheduling Problem

MA Yong, HE Zheng-wen, JIANG Bo, WANG Neng-min

2021, 30(8):  14-20.  DOI: 10.12005/orms.2021.0241

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In an uncertain environment, a schedule with high robustness can ensure the smooth execution of the project. Considering that resources may have multiple skills in reality, which can affect the development of a robust schedule, this paper studies the proactive project scheduling problem with flexible resource constraints. Firstly, the research problem is defined. Then, from the perspective of robustness maximization, the optimization model is constructed. Based on the analysis of the model, it is decomposed into two sub-models: one is classical robust optimization model and the other is skill allocation model for resources. Subsequently, a heuristic algorithm based on the peak clipping algorithm is designed to solve the problem. Finally, a practical case is introduced to verify the effectiveness of the algorithm and the influence of key parameters on the schedule robustness is analyzed. The following conclusions are drawn: with the extension of the project deadline, and the increase of the resource availability or resource flexibility, the schedule robustness increases.

Research on Resource Allocation Heuristic Algorithm for Robust Project Scheduling

PANG Nan-sheng, YE Bo-tong

2021, 30(8):  21-27.  DOI: 10.12005/orms.2021.0242

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The study of project scheduling problem has become an important content to improve the robustness of project scheduling through reasonable resource allocation. The authors propose a Max-PRUA resource allocation heuristic algorithm for improving the robustness of project scheduling by generating a reasonable resource allocation scheme. To reduce the impact of additional constraints on schedule robustness, the algorithm allocates resources by maximizing the use of priority relationship and unavoidable resource arc to reduce the amount of resources with additional constraints. The Max-PRUA algorithm also constructs a dynamic activity group GRAand introduces a local search algorithm for the optimal resource allocation scheme. We can choose the best solution from a variety of resource allocation schemes, which are obtained by rearranging the activities in the group GRA. Finally, the algorithm is validated and compared with other algorithms by extensive simulation experiments. The results show that the algorithm can adapt to the projects affected by different scales and different factors, and the resource allocation scheme generated by the algorithm has little influence on the scheduling plan robustness. The algorithm is an effective algorithm.

Multi-Objective Model for Fuzzy Permutation Flow Shop Scheduling

CHEN Ke-jia, DUAN Rui-ming, LIU Bi-yu, ZHOU Xiao-min

2021, 30(8):  28-36.  DOI: 10.12005/orms.2021.0243

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A fuzzy multi-objective model is proposed for the permutation flow shop scheduling with fuzzy processing time and fuzzy due date. As to the objective of satisfaction maximization, a preference satisfaction schedule model is set up based on pessimistic criterion. Then the model is modified in consideration of possibility. To select Pareto optimal solutions, the fuzzy set theory and probability theory are introduced. The results of fuzzy makespan are dealt with defuzzication based on area compensation, which makes the comparison of Pareto solutions easier. Random examples and one typical example are selected to conduct optimized calculation. The numerical results show the effectiveness of the model.

Max-NPV of Distributed Multi-project Scheduling Problem with Resource Flexibility Constraints

LIU Wan-lin, ZHANG Jing-wen, LIU Wan-jun

2021, 30(8):  37-43.  DOI: 10.12005/orms.2021.0244

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The existing studies on distributed resource constrained multi-project scheduling problem have assumed that the global resource limit cannot be broken during the multi-project duration and taken the makespan as the optimization objective. Considering global resources that can be obtained from the outside, this study constructs an integer programming model of distributed flexible resource-constrained multi-project scheduling problem with the objective of max-NPV and designs an effective algorithm to solve the problem. Firstly, the problem is defined and project cash flow calculation is determined. Then, due to NP-hard of the problem, a genetic-simulated annealing hybrid algorithm (GA_SA) is designed to solve the model. Finally, other algorithms used to compare with GA_SA algorithm are designed through multiple numerical experiments, and the impact of key parameters on the net present value of multi-projects is analyzed. The results demonstrate that the GA_SA algorithm has good solution effects, and global resource with flexible usage status can improve the performance of distributed multi-project profit significantly.

Optimization Model and Algorithms for the Shift Scheduling and Rostering Problem in Call Centers

HU Xiu-wu, XU Yue, WANG Xiu-li

2021, 30(8):  44-51.  DOI: 10.12005/orms.2021.0245

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Call centers work out the weekly scheduling schemes via flexibly arranging agents' duties while ensuring each one is assigned to a constant shift throughout the week. An integer programming model is formulated with respect to the practical scenario. Based on the analysis of data characteristics and optimization properties, two constructive heuristics are proposed by defining the metrics of shifts that effectively satisfy requirements of telephone service of intervals. The performance of the model and algorithms is evaluated on data from enterprise instances. The experimental results illustrate that the integer programming model is suitable for solving small-scale problems, while the heuristics can achieve (near-)optimal solutions at low computational cost for large-scale problems. Finally, the influence of the same shift regulation that ensures agents' work regularity on human resource cost is discussed.

Optimization of Unmanned Vehicle Distribution Path under Intelligent Network Connection

WANG Yu-qin, HU Hui, LIU Fu-xin, WANG Yan-hui, ZHAO Jiao, HAN Yi

2021, 30(8):  52-58.  DOI: 10.12005/orms.2021.0246

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Combined with the characteristics of information sharing and real-time route selection ofunmanned vehicle in the environment of intelligent network, the optimization of its routingproblem is studied. Through the introduction of key point update strategy, the path selection strategy of pre-planning and real-time adjustment for unmanned vehicle is formulated, and a two-stage VRP model based on real-time traffic information is proposed in the intelligent network connection environment. The pre-planning stage model determines the initial path, including the customer points to be served by each vehicle, The real-time adjustment model adjusts routes of each vehicle. The optimization model is solved by genetic algorithm, and the feasibility of the model and algorithm is verified by an example. The research results show that the optimization model of unmanned vehicle constructed in this paper can effectively combine the characteristics of real-time communication and route selection of unmanned vehicles, and save the delivery time. The research has certain exploration significance for the promotion and application of unmanned vehicle in the field of third-party logistics distribution.

Optimizing Transportation Network of Steel Products under “Port before Factory” Based on Low-Carbon Environmental Protection Factor

HUANG Xiao-ling, REN Yu-ting, ZHANG Jia-an, WANG Dan, CHEN Ji-hong, LUO Xun-jie

2021, 30(8):  59-66.  DOI: 10.12005/orms.2021.0247

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Most of China's steel enterprises are in the inland, and steel products for export need to be transported to the port by long distance, and then sent to all parts of the world by sea, so the establishment of cooperation between ports and steel enterprises are particularly important. Compared with railway and waterway transportation, the carbon emissions per unit converted turnover of highway transportation are higher. However, inland transportation in China mostly uses road transportation, which aggravates air pollution. This paper puts forward the transportation problem with iron and steel products based on the combined transportation of the “Port before Factory” mode, so as to strengthen the cooperation between ports and steel industries. In order to reduce operation cost and carbon emissions, an optimization model of steel products transportation network is established, which aims at minimizing carbon emission cost, transportation cost, storage cost and time window penalty cost. The particle swarm optimization with ring topology and improved harmony search is designed to solve the model. Finally, the sensitivity analysis of storage cost is carried out to explore its impact on the “Port before Factory” mode. The results show that the “Port before Factory” mode can not only effectively reduce the total cost and carbon emissions in the transportation network, but also enhance the tightness between port and steel enterprises under reasonable storage costs.

A Relief Drug Pre-positioning Model via an Option Contract

LIU Yang, TIAN Jun, ZHOU Kun

2021, 30(8):  67-74.  DOI: 10.12005/orms.2021.0248

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The demand of relief drug after a sudden disaster is growing at an explosive rate. Adequate emergency drugs play important roles in mitigating and controlling casualties, guaranteeing relief effect and reducing economic loss. Owing to natural and consumable characteristics of relief drug, our today's nationalpre-positioning model of relief drug is more likely to result in short supply of relief drugs or expired products. It is also hard to guarantee a long-term cooperation relationship between governments and pharmaceutical enterprises. So how to scientifically and reasonably pre-position relief drug is becoming a key problem for governments. This paper introduces an option contract into relief drug management system by considering this system as a relief supply chain. A relief drug pre-positioning(RDP)model is established. The optimal decisions of the government and the enterprise are derived. The conditions that the relief supply chain coordination is achieved and the government and the enterprise will be better off are uncovered. The research shows that the RDP model can improve the total reservation quantity of relief drug, reduce the government's inventory risk, guarantee the enterprise's reasonable profit and control the government's cost. The research findings provide insights into establishing a long-term relationship between two sides and offer important managerial strategies for the government's pre-positioning relief drug.

Study on Protecting Critical Infrastructure Systems Based on the UTA Method

ZHENG Dou-dou, GONG Jing, GAO lei

2021, 30(8):  75-80.  DOI: 10.12005/orms.2021.0249

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The critical infrastructure systems are the lifelines of cities, but they are unstable and vulnerable due to frequent emergencies. A good protection plan should consider multiple objectives such as resilience, cost, and etc., which often conflict with each other and thus make it difficult to make the final decision. This study explores the potentials and applicability of the UTA method, a multi-objective technique, under the context of protecting the critical infrastructure systems. The UTA model obtains preference information by interacting with decision makers and constructs the preference model of decision makers based on the principles of linear programming and value functions. The case study of the power grid system in C county indicates that the UTA method could help decision makers to achieve tradeoffs between multiple goals in the decision-making process and finally choose the plan that the decision makers are most satisfied with.

Sustainable Closed-loop Supply Chain Network Planning Based on Interactive Fuzzy Programming

ZHANG Tian-rui, WEI Ming-qi, GAO Xiu-xiu, WANG Shu-mei

2021, 30(8):  81-86.  DOI: 10.12005/orms.2021.0250

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Under the condition of uncertain market demand, facility cost and product recovery rate, an interactive possibility planning method is adopted to study the design of sustainable closed-loop supply chain network composed of multiple factories, distribution points, markets and waste points. Based on the sustainable closed-loop supply chain network structure, a mixed integer programming model is constructed, which aims to minimize the operation cost and environmental damage, and maximize the social benefits. At the same time, the improved epsilon constraint method is introduced to transform the multi-objective optimization problem into the single-objective optimization problem. On this basis, a two-stage possibility programming method is proposed, which uses TH fuzzy method to deal with the uncertain parameters. A numerical example is used to verify the effectiveness of the sustainable closed-loop supply chain network model established in this paper. At the same time, sensitivity analysis is carried out for pessimistic optimistic value, the lowest acceptable level of uncertain parameters and adjustable parameters. Comparison with other fuzzy methods shows that the TH fuzzy method adopted in this paper can obtain stable optimal solution.

Approximation Scheme for Single Machine Rescheduling Problem with an Unavailable Interval and Job Rejection

JIN Miao-miao, WU Meng-jie, LUO Wen-chang

2021, 30(8):  87-92.  DOI: 10.12005/orms.2021.0251

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In this paper, we consider the single machine rescheduling problem with an unavailable interval and job rejection. In this problem, given a set of jobs to be processed on a single machine, each job has its processing time and its weight and a planned schedule with the goal to minimize the total weighted completion time has been made. The promised deliver time for each job is determined based on its completion time in the planned schedule. However, before the formal job processing begins, a given interval that is originally used to process jobs in the planned schedule becomes unavailable due to the temporary occupation for maintaining the machine. The planned schedule becomes unfeasible and is required to reschedule. To assure that the tardiness penalty for jobs is not too much in the adjusted schedule, the decision-maker has the option to reject some jobs by paying the corresponding reject costs. The task is to determine the accepted set of jobs and the rejected set of jobs and reschedule the accepted jobs subject to a given unavailable interval on the machine to minimize the sum of the total weighted completion time for the accepted jobs, the total reject cost for the rejected jobs and the weighted maximum tardiness penalty. This problem is NP-hard. We propose a pseudo-polynomial time dynamic programming exact algorithm and a fully polynomial time approximation scheme by using the sparse technique.

Ordering Decision in a Capital-constrained Supply Chain with RFID Applications

YANG Hong-lin, DOU Tian-dan, GAO Ming-yun

2021, 30(8):  93-98.  DOI: 10.12005/orms.2021.0252

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The applications of RFID not only effectively reduce the inventory loss rate but also inevitably lead to greater operational costs of the supply-chain enterprises, especially the medium and small sized enterprises with limited capital. We consider a two-echelon supply chain with a manufacturer and a capital-constrained retailer to depict the influence of RFID application. The retailer may borrow the manufacturer's credit to fund its business. To reduce inventory loss, both members plan to employ RFID. With a wholesale price contract, we construct Stackelberg game models with trade credit financing for two kinds of RFID application timing. We characterize the conditions under which both members prefer to adopt RFID. We find that when RFID's tag cost is lower or when the inventory loss recovery rate of RFID is higher than a certain threshold, both members prefer to employ RFID. We also find that when RFID's tag cost or tag cost-sharing coefficient is relatively low or when the inventory loss recovery rate of RFID is relatively high, the manufacturer tends to set a higher wholesale price than that without RFID application. The retailer correspondingly orders less quantity. Through designing a revenue sharing contract, the coordination of the supply chain with RFID application is achieved.

Dual Channel Supply Chain Coordination Strategy Based on Uniform Pricing and Promotion

GUO Jin-sen, YANG Ping, ZHOU Yong-wu, YANG Yu-zhen

2021, 30(8):  99-107.  DOI: 10.12005/orms.2021.0253

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A dual-channel supply chain coordination strategy model based on uniform pricing and promotional effort is established under the diseconomies of scale condition. Through the analysis of the model, the retailer and manufacturer's optimal operation strategies are given under the centralized and decentralized decision model. It is showed that the wholesale price contract can't coordinate the supply chain under the manufacturer's diseconomies of scale condition. Although the revenue sharing contract can coordinate the supply chain, but can't ensure that the profit of retailer and manufacturer is always higher than that in the decentralized wholesale price contract condition. Furthermore, the revenue sharing contract with fixed compensation not only can ensure that the total profit is equal to the profit of the centralized condition, but also guarantee the profit of the two partners higher than the decentralized wholesale price contract condition. Finally, in order to satisfy the principle of fairness and rationality, the Nash consultation theory is used to give the optimal compensation amount of supply chain under different bargaining power.

Research on Low Carbon Supply Chain Financing Decision under the Purchase Capital Constraint of the Retailer

ZHANG Ke-yong, LI Chun-xia, YAO Jian-ming, LI Jiang-xin

2021, 30(8):  108-116.  DOI: 10.12005/orms.2021.0254

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In the government subsidized low-carbon supply chain, the issue of financing decisions for retailer with insufficient procurement funds is studied. The internal financing model is divided into manufacturer financing, manufacturer investment and portfolio financing, and the external financing model is divided into bank lending and equity financing. The results show that the portfolio financing effect is the best when the manufacturer provides internal financing. But only when the ratio of the manufacturer's investment model is equal to the manufacturer's investment rate, the optimal combination ratio exists, which means that both parties accept the combined financing model. When manufacturers do not provide internal financing, the retailer's risk aversion characteristics will not affect the choice of external financing channels, and the bank lending will be more beneficial to the retailer than equity financing. As the proportion of manufacturer's investment model and the bank lending rate increase, the retailer's optimal financing decision changes from portfolio financing to bank lending.

Equilibrium of Low Carbon Supply Chain Finance Decision with Stochastic Demand under Shareholding Strategy

TAN Le-ping, SONG Ping, YANG Qi-feng

2021, 30(8):  117-126.  DOI: 10.12005/orms.2021.0255

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When the demand is stochastic and affected by emissions level of manufacturer, under the influence of cap-and-trade, the paper researches the optimal decision and profit of manufacturer pure bank loan and portfolio financing of supplier shareholding, and analyses consumer preference, carbon low carbon trading and supplier's investment holdings to the influence of the optimal decision and profits of supply chain. The research shows that, without funding constraints, simple bank loan and portfolio financing, consumers' low carbon preference, carbon trading price and shareholding ratio are positively correlated with manufacturers' emission reduction level and profit as well as the profit of supply chain system. and supplier's wholesale price and manufacturer's production are positively correlated with consumers' low-carbon preference, and negatively correlated with carbon trading price, while shareholding ratio is negatively correlated with supplier's wholesale price, and positively correlated with manufacturers' production and emission reduction level. Under the shareholding strategy, the emission reduction level and production capacity of the manufacturer are the highest, followed by that of the manufacturer without capital constraints, and the lowest when the bank simply borrows money. When there is no capital constraint, the wholesale price of supplier is the highest, followed by pure bank loan, and the shareholding strategy is the lowest. When the shareholding ratio meets certain conditions, the profit of supplier and manufacturer is better than that of bank loan alone, and can be better than that without capital constraints, which improves the competitiveness and efficiency of the supply chain.

Water Quality Prediction Model Parameters Estimation for Sudden Water Pollution Accidents Based on Bayesian Inference

YANG Hai-dong, LUI Bi-yu

2021, 30(8):  127-132.  DOI: 10.12005/orms.2021.0256

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The accuracy of parameters is the premise and guarantee for accurately constructing the water quality prediction model of sudden water pollution accidents. This paper first constructs the parameter estimation model by Finite Difference Method and Bayesian inference, then obtains reasonable model parameters thorough Metropolis-Hasting sampling method, and finally taking a sudden water pollution accident in a certain open channel as an example, the effects of different observation noises on the calibration results are discussed under the two scenarios of control flow and non-control flow by comparing with the results obtained by the finite difference-simplex method. The results show that the finite difference-Bayesian method has strong applicability and a good anti-noise, which gives a high precision parameter value. It provides a new way for constructing the predication model of sudden pollution accidents.

Railway Freight Demand ForecastingBased on Decompose-ensemble Method

XU Fei, REN Shuang

2021, 30(8):  133-138.  DOI: 10.12005/orms.2021.0257

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Railway freight volume is affected by many factors. Accurate forecasting can provide an important reference for the future planning of the railway industry, and it can also enable the railway sector to formulate transportation policies that are in line with the current freight market. Freight volume data is non-linear and unstable. It is difficult to describe the overall characteristics using traditional single prediction models for prediction, and the prediction accuracy needs to be improved.Based on the principle of decomposition-ensemble, this paper uses the variational modal decomposition algorithm to decompose the freight volume into high-frequency and low-frequency modes. Based on the characteristics of each modal, a prediction model is established, and the obtained prediction results are added up as the forecast value of the final freight volume. The empirical results show that the decomposition-ensemble forecasting method improves the accuracy of forecasting compared with the traditional single forecasting model and can be well applied in the research of railway freight volume demand forecasting.

Application Research

Extension of Integrated Importance Measure in Compound Systems under Gamma Distribution

GAO Yan-san, CHEN Li-wei, MA Jing

2021, 30(8):  139-146.  DOI: 10.12005/orms.2021.0258

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Integrated importance measure(IIM)analysis can not only effectively identify the weak links of the system, but also allocate resources reasonably and maximize the normal running time of the whole system. In this paper, the IIM of the component of the two-state deterioration system is analyzed. Assuming that the life of the component obeys the gamma distribution, the equivalent formulas for calculating the IIM of two typical hybrid systems, parallel-series and series-parallel are derived, and the physical meaning is given at the same time. Taking the hydraulic energy hybrid system of Boeing 737 as an example, the IIM of each component and thesimulation case analysis are calculated. The final case analysis results show that in the two-state hybrid with gamma distribution, the IIM of the component is positively correlated with the failure rate and the scale parameter, and negatively correlated with the shape parameter.

Analyzing Recreational Fishery Satisfaction Based on Bayesian Multiple Ordered Probit Model

QIU Ying-ying, WANG Er-da, YU Yang

2021, 30(8):  147-152.  DOI: 10.12005/orms.2021.0259

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Tourist satisfaction is an important referral information for management decision makings of recreational fishery scenic spots. Through exploring the relationship between individual aspects of tourist satisfaction and the overall tourist satisfaction, managers can obtain important information about a better understanding of the tourists' preferences and their consumption behaviors as well as the tourism product designs. There are a large number of the studies associated with the consumers' satisfaction. Nevertheless, little attentions has been paid to the satisfaction issues on the recreational fisheries. To fill out the gap, we attempt to explore the relationship between the individual aspects of the tourists' satisfactions and the overall tourism satisfaction as they are engaged in various types of leisure fishery activities. We conductthe field survey through interviewing a total of 1510 tourists with regards to their satisfaction with the various aspects in their recreational activities based on the eleven National Recreation Fishery Demonstration Bases. The data is utilized in estimating the Bayesian multiple ordered probit model by applying a MCMC. The estimated posterior results are used to reflect the contribution of seven divisor satisfactions to the overall tourist satisfaction. The study results indicate that recreational experience, scenic environment, and food consumption are three divisor satisfactions which exert the greatest influence on the overall tourist satisfaction with each counting for 43.58%, 24.67%, and 10.62%, respectively.

Inventory Routing and Dynamic Regional Pricing with Horizontal Collaboration Strategy

YANG Hua-long, YU Ze-tao, XIN Yu-chen

2021, 30(8):  153-161.  DOI: 10.12005/orms.2021.0260

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Inventory routing and pricing are three constrained and inter-influenced decision-making problems in Vendor Management Inventory (VMI), which is the key to decreasing operation cost and improving profit of vendors. In view of inventory routing and pricing problem with multiple vendors, many kinds of products and various regions in VMI pull supply chain, a product differentiation pricing strategy for different regional customer and different time period is put forward, and an allocation plan for rental vehicle driver cost and fuel cost of joint distribution is designed. Hereby, an inventory routing and dynamic regional pricing (IRDRP) model is established considering the vendor horizontal collaboration (HC) strategy. The results of numerical example show that the vendors' product price will go down slightly, the running distance of delivery vehicles will be shortened obviously, the delivery amount to customers is more balanced in every time periods, and the number of inventory will decrease significantly at the end of each time period with HC strategy. This research indicates that no matter how different the proportion of supply scale among vendors is, their profits can be significantly increased with the implementation of inventory routing and dynamic regional pricing. It can help to achieve the goal of win-win cooperation of vendor alliance.

Model of Connecting Service Pricing under Revenue Sharing Strategies

QU Chen-rui, ZENG Qing-cheng, CHEN Chao, ZHANG Qian

2021, 30(8):  162-168.  DOI: 10.12005/orms.2021.0261

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There exists a strong complementary relationship between mainline and feeder line in liner shipping network. Shippers would obtain better connecting service with more convenience, which is improved by vertical cooperation between mainline carrier and feeder carrier. In this paper, the pricing issue of shipping service, which connects mainline with feeder line, has been studied in consideration of competition among parallel substitute itineraries. A Bertrand model is developed to analyze the equilibrium state of shipping market under two types of transport chain, namely centralized and decentralized structures. The superiority of the centralized transport chain has been proven. And then, the deduced equilibrium result could provide carriers upstream and downstream with decision support. Moreover, a reasonable revenue sharing mechanism is designed for decentralized transport chain. The results show that the possibility of pareto improvement exists in the decentralized structure of transport chain, and the coordination of transport chain could be achieved through the revenue sharing mechanism.

Studyon Models of SocialInfluence Maximizationwith Deterministic Threshold

WENG Ker-rui, LUI Wei

2021, 30(8):  169-174.  DOI: 10.12005/orms.2021.0262

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Social influence maximization with deterministic thresholds requires that the incoming influenceof an activated agent should benoless than afixed threshold and active nodes spread influence to their out neighbors until nonew node is activated. The objective is to seek the optimal p seedt maximize the spread of influence. This problem has wide applications in the marketing activities of new products, technology penetration, and information dissemination. We presented two integer programming formulations which are based on diffusion results and diffusion processes respectively. The experiments solved by the Gurobi Optimizer show that the later formulation has a better performance and a smaller number of diffusion steps can save significant time while the solution quality is well preserved. Finally, based on optimal solution of the models, the computing performance of greedy algorithm is tested.

Study of In-store Referral Strategies of E-retailers with Suppler Discriminatory Pricing

LUO Ming, LI Zeng-lu

2021, 30(8):  175-180.  DOI: 10.12005/orms.2021.0263

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The supplier's wholesale price strategies always have a profound impact on the downstream decision. In this paper, we study the downstream retailers' referral strategies considering two wholesale pricing models, i.e. uniform pricing model and discrimination pricing model. Firstly, we establish the uniform pricing model, and then solve this decision model by backward induction. The results show that: when the consumer cognition is similar, with the increase in referral fee, the equilibrium referral strategies are not retailer referral, but only the strong retailer (retailer 1) referral and mutual referral in proper sequence. Secondly, we derive the optimal solutions in discrimination pricing model, and find that discrimination wholesale price strategy can improve the competitiveness of the weak retailer (retailer 2). With the change in consumer cognition and referral fee, diversified equilibrium is presented. Finally, we find that the supplier's profit in discriminatory pricing model is not always better than that in uniform pricing model due to the influence of retailers' referral strategies.

Study on Solution Approach for Firm's Financial Distress via Equity Refinancing and Strategic Debt Service

TAN Chun-ping, QIN Xue-zhi, WANG Wen-hua, WANG Lin

2021, 30(8):  181-189.  DOI: 10.12005/orms.2021.0264

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The company will default and get into financial distress if it cannot pay the coupon and principal due to illiquidity. After default, bankruptcy liquidation is not the only way out, and the company can revive through debt restructuring. Strategic debt service, which means the temporary payment of reduced coupon, is one of the important debt restructuring methods adopted by shareholders and creditors. In addition, the company also uses equity refinancing to solve financial distress. This paper clarifies the relationship between company's financial distress and strategic debt service, making strategic debt service an incentive compatible tool with the characteristics of revenue-sharing and risk-sharing to alleviate company's financial distress while effectively protecting the interests of creditors. It gives a comprehensive scheme which combines equity refinancing with strategic debt service to alleviate the company's financial distress, and offers the implementation sequence of concerned tactics. The appropriate boundary conditions of company coupon payment, debt renegotiation, equity refinancing and strategic debt service are described. The influencing factors of pricing and credit spread are analyzed. Besides, the feasibility basis of equity refinancing under strategic debt service is given, and the optimal debt restructuring boundary and the optimal reduced coupon are determined by means of renegotiation based on maximizing the interests of both shareholders and creditors. The study finds that based on incentive compatibility theory,the approach of taking strategic debt service after company's financial distress with equity refinancing will avoid the over-pricing of the company caused by the speculative behavior of strategic debt service to a certain extent, reduce the default boundary and generally increase the value of the debt and slow down the growth of credit spreads to some extent. Besides, there is an inverted u-shaped relationship between equity refinancing costs and credit spreads. Moreover, the strategic debt payment is not affected by liquidity and equity refinancing, and generally can be guaranteed within the firm's payment ability based on the Nash equilibrium game model.

Asymmetric Risk Spillovers between the Chinese Stock Market and Index Futures Market Based on Granger Non-causality Test in Quantiles

REN Xian-ling, SUN Wen-yue

2021, 30(8):  190-197.  DOI: 10.12005/orms.2021.0265

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Facing financial market risk coming from negative and positive changes in prices, the psychology and behavior of investors might substantially differ. In this regard, we hypothesize that risk transmission mechanism between Chinese stock market and its index futures market might also substantially differ. Considering that, this paper decomposes Chinese stock market volatility and its index futures market volatility into downside semivariance and upside semivariance respectively, which can serve as a measure of downside risk and upside risk, using realized semivariance with 5-minute high frequency data from January 4, 2016 to April 30, 2019. Then this paper utilizes Granger non-causality test in mean and quantiles to distinguish risk spillovers between Chinese stock and futures market due to negative returns and positive returns, in order to reveal asymmetries in risk spillovers that emerge due to downside risk and upside risk. The analysis is conducted in a comparative way by using both Granger non-causality test in mean and quantiles. The results show that there exist both significant downside risk spillovers and significant upside risk spillovers between Chinese stock and futures market, and it provides ample evidence showing the asymmetry at quantile level, which is in contrast with the symmetry at mean level. On one hand, the downside risk spillovers from the futures market to the stock market are significant at all quantile intervals, while the upside risk spillovers from the futures market to the stock market are only significant at middle quantile intervals and extremely high quantile intervals. On other hand, the downside risk spillovers from the stock market to the futures market are significant at extreme quantile intervals, while the upside risk spillovers from the stock market to the futures market are significant at low quantile intervals and middle quantile intervals.

Application of Black-Litterman Model in Large-scale Asset Allocation: Improvement Based on Currency Cycle and Risk Parity Strategy

ZHOU Liang

2021, 30(8):  198-204.  DOI: 10.12005/orms.2021.0266

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The Black-Litterman model can effectively solve the problem that the mean-variance model is too sensitive to the input (especially the expected return), which makes it widely used in practice. This paper uses the risk equilibrium strategy to construct the market equilibrium portfolio, and asset rotation income based on the currency cycle to construct the subjective view. After the subjective viewpoint confidence level is appropriately simplified, the improved Black-Litterman model is formed. With the data of the three major large-scale assets of stocks, commodities and bonds in China's capital market, an empirical test of the improved Black-Litterman model reveals that, through the adjustment of relative confidence levels, the improved Black-Litterman model effectively balances the market equilibrium portfolio with subjective views, and the Black-Litterman portfolio performs better in both risk control and yield relative to other asset allocation strategies and single asset buy-and-hold strategies. The empirical conclusions fully illustrate the effectiveness of the Black-Litterman model, and also indicate the direction of model improvement from the three aspects of market equilibrium, subjective views and confidence levels.

Influence Mechanism of Performance Compensation Commitment on Double Price Deviation of Private Placement & Acquisitions

JIAN Guan-qun, LI Bing-xiang

2021, 30(8):  205-210.  DOI: 10.12005/orms.2021.0267

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The original intention of the performance compensation commitment system is to reduce the valuation premium. This paper discusses the influence mechanism of performance compensation commitment under the influence of the growth rate of earnings forecast on the double price deviation of private placement &acquisitions, so as to reveal the path of the system. Hierarchical regression analysis shows that: performance compensation commitment has a positive impact on double price deviation; performance compensation commitment has a negative impact on earnings forecast growth; the growth rate of earnings forecast has a positive impact on double price deviation; the mediating effect of the growth rate of earnings on performance commitment and price deviation shows a “cover effect”. Further analysis shows that performance compensation commitment has the function of value enhancement and promote mutual benefit and win-win result. The high price deviation obtained by large shareholders is the embodiment of value compensation. The research results enrich and expand the relevant research of performance compensation commitment and double price deviation, which is of great significance to the reasonable arrangement of system and the value of contract.

Management Science

Study on the Influence Mechanism of Employer-Employee Game on Human Resource Sharing ——Viewed From the Perspective of Ownership

BI Yan-zhao, ZHANG Jie, ZHAO Shu-ming, ZHANG Feng

2021, 30(8):  211-216.  DOI: 10.12005/orms.2021.0268

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Based on the perspective of ownership, this paper constructs a game model which is composed of the new employer, old employer and employee, and researches the influencing mechanism of two ownership effects: endowment effect and allowance effect that affect human resource sharing. The results show that the new employer's relative competitiveness divides the state of human resources sharing game; The increasing ownership effect will promote the employment relation, inhibiting the formation of human resources sharing; The new employer's increasing relative competitiveness has a positive impact on human resources sharing; The cost allowance should be controlled below a certain threshold, or it will affect the sustainability of cost allowance, and the employee's cost allowance are revenue-oriented. It will promote the mutual benefit and sharing of the human resources among enterprises to choose the right cooperative enterprise and guide the ownership effects.

Effect of Environmental Regulation on Export Product Quality ——Empirical Analysis Based on Industry Panel Data

NING Ye, ZHANG Ya-nan, LIU Qi

2021, 30(8):  217-224.  DOI: 10.12005/orms.2021.0269

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Taking environmental regulation (ER) as the independent explanatory variable, this paper applies fixed effects model to make an empirical analysis of the effect of ER on the export product quality, based on the data of ER and export product quality in China's 19 industries from 2003 to 2010. The results show that the impact of ER on the export product quality is “U-shaped”, that is, the cost effect is greater than the innovation effect in early stage of ER enhancement, because the improvement of operating cost leads to the decline of productquality. Then the innovation effect is greater than the cost effect in late enhancement of ER, because research and development (R&D) promote the product quality improvement. The sensitivity of different industries to environmental regulation is different. The impact of ER on the export product quality in light pollution industries is inverted “U-shaped”, with the effect of promoting before inhibiting. Possibly because of the light pollution industries, the mild environmental regulation can stimulate the enterprise to innovate to improve product quality, but excessively strict regulation will cause serious economic pressure. And it presents the opposite case in heavy pollution industries with “U-shaped” by the effect of inhibiting before promoting, which means that environmental regulation firstly has limited effect, and then the stimulation of the role of innovation greatly improves the quality of export products. Based on the above empirical study, some policy suggestions are proposed such as effective use of ER to improve export product quality and develop green trade.

Research on the Influencing Factors of Distributed Innovation of Manufacturing Enterprises Based on Discourse Analysis and PLS-DEMATEL Method

QU Xiao-yu

2021, 30(8):  225-232.  DOI: 10.12005/orms.2021.0270

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Based on qualitative and quantitative analysis, the paper uses discourse analysis to identify key influencing factors of distributed innovation of manufacturing enterprises, and constructs the relationship model of the influencing factors of distributed innovation, and uses PLS-DEMATEL method to discuss the importance and type of each influencing factor. The results show that distributed innovation of manufacturing enterprises is influenced by trigger force, enabling force, collaborative force, situational force and disturbing force. Every factor includes some subcategories. For example, trigger force includes location factors, interest expectations, entrepreneur cognition, and resource factors. The rank of each factor's importance is enabling force>trigger force>disturbing force>situational force>collaborative force. The trigger force, situational force and disturbing force are cause factors, and enabling force and collaborative force are result factors.

A Bi-objective Home Health Care Scheduling Problem: Based on Costs and Overtime

XIANG Ting, LI Yan-feng

2021, 30(8):  233-239.  DOI: 10.12005/orms.2021.0271

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Home health care industry gradually develops with the continuously aging population. In this paper, the home health care scheduling problem is formulated as a bi-objective mixed-integer programming problem which aims at minimizing the total costs and the maximum overtime. The maximum skill deviation and maximum working time are considered, as well as the nurse-patient skill matching, the overtime cost, the overtime duration and the workload balance. To solve the proposed problem, an improved NSGA-II and an improved SPEA-II are developed. The computational results show that the costs decrease as the maximum overtime increase. The maximum skill deviation and unit waiting penalty can affect the objectives obviously. Both algorithms perform well in small instances, while the efficiency of improved SPEA-II is better than the improved NSGA-II in the middle and large instances.