Jun Zhuang
SUNY: University at Buffalo, Industrial Engineering, Faculty Member
In the food industry, manufacturers may add some chemical additives to augment the appearance or taste of food. This may increase the food demand and sales profits, but may also cause health problems to consumers. The government could use... more
In the food industry, manufacturers may add some chemical additives to augment the appearance or taste of food. This may increase the food demand and sales profits, but may also cause health problems to consumers. The government could use a punishment policy to regulate and deter such risky behavior but could also benefit from economic prosperity and tax income based on their revenues. This generates a tradeoff for the government to balance tax income, punishment income, and health risks. Adapting to government regulations, the manufacturers choose the level of chemical additives, which impacts the consumer demand. To our knowledge, no prior work has studied the strategic interactions of regulating the government and the manufacturers, faced with strategic customers. This paper fills this gap by (a) building a governmentmanufacturer model and comparing the corresponding decentralized and centralized models; and (b) applying the 2008 Sanlu food contamination data to validate and illu...
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U nderstanding and adapting to an evolving terrorist threat presents a significant challenge to intelligence and law enforcement communities around theworld. The goal of this paper is to introduce a new approach to developing dynamic... more
U nderstanding and adapting to an evolving terrorist threat presents a significant challenge to intelligence and law enforcement communities around theworld. The goal of this paper is to introduce a new approach to developing dynamic profiles for terrorist organizations to give decisionmakers a new tool to analyze the evolution of terrorist organizations and estimate the likelihood of future attacks. The proposed method builds on aspects of Bayesian probability and multi-objective decision analysis to adapt to the terrorist threats of the 21stCentury.This approachadds to the current literature by proposing a new dynamic structure for assessingandadapting to a constantly changing landscape of terrorist threats, ideologies, and leadership. The proposed method could potentially reduce the time necessary to develop a profile for a terrorist organization, and provide an efficient method of estimating terrorist strategy and impact. These profiles could then be adjusted based on terrorist ...
Take-away food (also referred to as “take-out” food in different regions of the world) is a very convenient and popular dining choice for millions of people. In this article, we collect online textual data regarding “take-away food... more
Take-away food (also referred to as “take-out” food in different regions of the world) is a very convenient and popular dining choice for millions of people. In this article, we collect online textual data regarding “take-away food safety” from Sina Weibo between 2015 and 2018 using the Octopus Collector. After the posts from Sina Weibo were preprocessed, users’ emotions and opinions were analyzed using natural language processing. To our knowledge, little work has studied public opinions regarding take-away food safety. This paper fills this gap by using latent Dirichlet allocation (LDA) and k-means to extract and cluster topics from the posts, allowing for the users’ emotions and related opinions to be mined and analyzed. The results of this research are as follows: (1) data analysis showed that the degree of topics have increased over the years, and there are a variety of topics about take-away food safety; (2) emotional analysis showed that 93.8% of the posts were positive; and ...
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In general, architectural design is a loosely structured, open-ended activity that includes problem definition, representation, performance evaluation, and decision making. A number of approaches have been proposed in the literature to... more
In general, architectural design is a loosely structured, open-ended activity that includes problem definition, representation, performance evaluation, and decision making. A number of approaches have been proposed in the literature to organize, guide, and facilitate the design process. The main objective of this paper is to seek a logical and rigorous means to aid in developing an optimized design that is acceptable to the customer or user of the product. The convention design approaches heavily involve decision making, which is integral to the architectural design process and is an important element in nearly all phases of design. There is a need to reframe the decision-making process to transform and improve the design process in order for finial building to achieve the performance goals. The first step in making an effective design decision is to understand the stakeholders' and team players' (architect, engineer, client, and consultant) different preferences based on th...
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In recent years, various types of terrorist attacks occurred, causing worldwide catastrophes. According to the Global Terrorism Database (GTD), among all attack tactics, bombing attacks happened most frequently, followed by armed... more
In recent years, various types of terrorist attacks occurred, causing worldwide catastrophes. According to the Global Terrorism Database (GTD), among all attack tactics, bombing attacks happened most frequently, followed by armed assaults. In this article, a model for analyzing and forecasting the conditional probability of bombing attacks (CPBAs) based on time-series methods is developed. In addition, intervention analysis is used to analyze the sudden increase in the time-series process. The results show that the CPBA increased dramatically at the end of 2011. During that time, the CPBA increased by 16.0% in a two-month period to reach the peak value, but still stays 9.0% greater than the predicted level after the temporary effect gradually decays. By contrast, no significant fluctuation can be found in the conditional probability process of armed assault. It can be inferred that some social unrest, such as America's troop withdrawal from Afghanistan and Iraq, could have led t...
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The objective of this paper is to help both public and private sectors make better decisions in defensive resource allocation through public and private partnerships (PPPs). In this paper, efficient PPPs are studied with regard to... more
The objective of this paper is to help both public and private sectors make better decisions in defensive resource allocation through public and private partnerships (PPPs). In this paper, efficient PPPs are studied with regard to disaster preparedness using a decentralized model (sequential game where the public sector is the first mover) and a centralized model. This paper identifies the best public investment policies by evaluating the effectiveness of incentive provisions based on the various private strategic responses. This paper also provides insights into understanding (a) how to construct optimal public and private partnerships and (b) whether, when, and to what extent public and private investments in disaster preparedness could form better PPPs. We study the conditions of the private and public sectors’ allocation strategies when they are strategic complements or substitutes. We find that the private sector that has a higher target valuation or lives in more risky areas i...
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Oil spills are a characteristic risk of oil drilling and production. There are safety regulations set to reduce the risk of technological failures and human error. It is the oil company's decision to follow such laws and the... more
Oil spills are a characteristic risk of oil drilling and production. There are safety regulations set to reduce the risk of technological failures and human error. It is the oil company's decision to follow such laws and the government's decision to enforce them. Companies are balancing between safety efforts and production competition with other companies. To our knowledge, no previous research has considered the impact of competition in a government–company regulatory game. This paper fills the gap by modeling and comparing two games: a one-company game without competition and a two-company game with competition, both with the government as a regulator. The objectives of all players are to maximize their expected revenue and minimize their losses. Our results indicate that competition increases a company's threshold for risk and therefore requires stricter government regulation. These results could be generalized and applied to other industries including airline, nucle...
Research Interests: Business, Marketing, Computer Science, Economics, Game Theory, and 15 moreIndustrial Organization, Homeland Security, Risk, Regulation, Decision Analysis, Oil Spill, Production economics, Airline Industry, Business and Management, Coal Mining, Nuclear power, Revenue, Disaster, HUMAN ERROR, and Government Regulation
Due to the complexity of the wargaming structure, it may be difficult to completely solve some wargames involving large number of players, player options, system states, mission types, and uncertainties of operation/campaign results. Thus... more
Due to the complexity of the wargaming structure, it may be difficult to completely solve some wargames involving large number of players, player options, system states, mission types, and uncertainties of operation/campaign results. Thus it is important to develop and improve heuristics, which is studied in this paper. In particular, we transform a paper-based six-player wargame into a computer-based one using Matlab programming and its graphical user interface (GUI). We design 2-4 heuristics for each of the players, ...
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Abstract: We discuss strategic interactions between an attacker and either centralized or decentralized defenders, and identify conditions under which centralized defender decision making is preferred. One important implication of our... more
Abstract: We discuss strategic interactions between an attacker and either centralized or decentralized defenders, and identify conditions under which centralized defender decision making is preferred. One important implication of our results is that partial secrecy about defensive allocations (disclosure of the total level of defensive investment, but secrecy about which resources are defended) can be a strategy for achieving more cost-effective attack deterrence. In particular, we show that such partial secrecy can be potentially beneficial when security investments are discrete (e.g., as in the use of air
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In certain critical infrastructures, correlations between cyber and physical components can be exploited to launch strategic attacks, so that disruptions to one component may affect others and possibly the entire infrastructure. Such... more
In certain critical infrastructures, correlations between cyber and physical components can be exploited to launch strategic attacks, so that disruptions to one component may affect others and possibly the entire infrastructure. Such correlations must be explicitly taken into account in ensuring the survival of the infrastructure. For large discrete infrastructures characterized by the number of cyber and physical components, we characterize the cyber–physical interactions at two levels: (i) the cyber–physical failure correlation function specifies the conditional survival probability of the cyber sub-infrastructure given that of the physical sub-infrastructure (both specified by their marginal probabilities), and (ii) individual survival probabilities of both sub-infrastructures are characterized by first-order differential conditions expressed in terms of their multiplier functions. We formulate an abstract problem of ensuring the survival probability of a cyber–physical infrastru...
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We consider infrastructures consisting of a network of systems, each composed of discrete components. The network provides the vital connectivity between the systems and hence plays a critical, asymmetric role in the infrastructure... more
We consider infrastructures consisting of a network of systems, each composed of discrete components. The network provides the vital connectivity between the systems and hence plays a critical, asymmetric role in the infrastructure operations. The individual components of the systems can be attacked by cyber and physical means and can be appropriately reinforced to withstand these attacks. We formulate the problem of ensuring the infrastructure performance as a game between an attacker and a provider, who choose the numbers of the components of the systems and network to attack and reinforce, respectively. The costs and benefits of attacks and reinforcements are characterized using the sum-form, product-form and composite utility functions, each composed of a survival probability term and a component cost term. We present a two-level characterization of the correlations within the infrastructure: (i) the aggregate failure correlation function specifies the infrastructure failure pro...
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Though the choices of terrorists’ attack targets are vast, their resources are limited. In this paper, a game-theoretical model is proposed to study both the defender’s (government) and the attacker’s (terrorist) expenditures among... more
Though the choices of terrorists’ attack targets are vast, their resources are limited. In this paper, a game-theoretical model is proposed to study both the defender’s (government) and the attacker’s (terrorist) expenditures among multiple targets under budget constraints to guide investment in defense. We study how the defender’s and the attacker’s equilibrium allocations depend on the budget constraints, target valuations, cost effectiveness of their investments, and inherent defense levels of targets in both sequential-move and simultaneous-move games. The equilibrium solutions are provided using the Karush–Kuhn–Tucker conditions. At the subgame-perfect Nash equilibrium, the defender’s total marginal effects are the same among targets. Moreover, the defender’s total marginal effects can be decomposed into direct and indirect effects. We also use the multiple-infrastructure and multiple-urban-area data sets to demonstrate the model results. The regression analysis shows that both...
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Most attacker-defender games consider players as risk neutral, whereas in reality attackers and defenders may be risk seeking or risk averse. This article studies the impact of players' risk preferences on their equilibrium behavior... more
Most attacker-defender games consider players as risk neutral, whereas in reality attackers and defenders may be risk seeking or risk averse. This article studies the impact of players' risk preferences on their equilibrium behavior and its effect on the notion of deterrence. In particular, we study the effects of risk preferences in a single-period, sequential game where a defender has a continuous range of investment levels that could be strategically chosen to potentially deter an attack. This article presents analytic results related to the effect of attacker and defender risk preferences on the optimal defense effort level and their impact on the deterrence level. Numerical illustrations and some discussion of the effect of risk preferences on deterrence and the utility of using such a model are provided, as well as sensitivity analysis of continuous attack investment levels and uncertainty in the defender's beliefs about the attacker's risk preference. A key contri...
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Hundreds of billions of dollars have been spent in homeland security since September 11, 2001. Many mathematical models have been developed to study strategic interactions between governments (defenders) and terrorists (attackers).... more
Hundreds of billions of dollars have been spent in homeland security since September 11, 2001. Many mathematical models have been developed to study strategic interactions between governments (defenders) and terrorists (attackers). However, few studies have considered the tradeoff between equity and efficiency in homeland security resource allocation. In this article, we fill this gap by developing a novel model in which a government allocates defensive resources among multiple potential targets, while reserving a portion of defensive resources (represented by the equity coefficient) for equal distribution (according to geographical areas, population, density, etc.). Such a way to model equity is one of many alternatives, but was directly inspired by homeland security resource allocation practice. The government is faced with a strategic terrorist (adaptive adversary) whose attack probabilities are endogenously determined in the model. We study the effect of the equity coefficient o...
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Attackers' private information is one of the main issues in defensive resource allocation games in homeland security. The outcome of a defense resource allocation decision critically depends on the accuracy of estimations about the... more
Attackers' private information is one of the main issues in defensive resource allocation games in homeland security. The outcome of a defense resource allocation decision critically depends on the accuracy of estimations about the attacker's attributes. However, terrorists' goals may be unknown to the defender, necessitating robust decisions by the defender. This article develops a robust-optimization game-theoretical model for identifying optimal defense resource allocation strategies for a rational defender facing a strategic attacker while the attacker's valuation of targets, being the most critical attribute of the attacker, is unknown but belongs to bounded distribution-free intervals. To our best knowledge, no previous research has applied robust optimization in homeland security resource allocation when uncertainty is defined in bounded distribution-free intervals. The key features of our model include (1) modeling uncertainty in attackers' attributes, wh...
Research Interests: Computer Science, Game Theory, Terrorism, Homeland Security, Resource Allocation, and 12 moreRisk Management, Medicine, Multidisciplinary, Risk Analysis, Uncertainty, Robust optimization, United States, Robustness (evolution), Security Measures, Theoretical Models, Private Information Retrieval, and Private Information
In this article, we explore reasons that a defender might prefer secrecy or deception about her defensive resource allocations, rather than disclosure, in a homeland-security context. Our observations not only summarize and synthesize the... more
In this article, we explore reasons that a defender might prefer secrecy or deception about her defensive resource allocations, rather than disclosure, in a homeland-security context. Our observations not only summarize and synthesize the results of existing game-theoretic work, but also provide intuitions about promising future research directions.
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A government defends against a terrorist who attacks repeatedly and stockpiles its resources over time. The government defends an asset and attacks the terrorist's resources. The terrorist defends its resources and attacks the... more
A government defends against a terrorist who attacks repeatedly and stockpiles its resources over time. The government defends an asset and attacks the terrorist's resources. The terrorist defends its resources and attacks the government. We find four possible equilibrium solutions: (1) the government attacks only, deterring the terrorist; (2) both players defend and attack; (3) the government defends but does
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Research Interests: Game Theory, Nonprofit Studies, Nonprofit, Philanthropy, Nonprofit Communication, and 9 moreNonprofit organizational effectiveness, Nonprofit Organizations, Corporate Governance and Voluntary Disclosure, Donation, Charity, Applied Communication, Communication and media Studies, Charitable Behavior, and Cross sector Collaboration
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We analyze how a government allocates its resources between attacking to downgrade a terrorist's resources and defending against a terrorist attack. Analogously, the terrorist allocates its resources between attacking a... more
We analyze how a government allocates its resources between attacking to downgrade a terrorist's resources and defending against a terrorist attack. Analogously, the terrorist allocates its resources between attacking a government's asset and defending its own resources. A two-stage game is considered where the government moves first and the terrorist moves second. We show that (a) when the terrorist's resources are low, the government attacks the terrorist's resources sufficiently to deter the terrorist from attacking and does not defend; (b) when the terrorist's resources are high, both the government and terrorist defend and attack. We analyze T periods of the two-stage game between two myopic players. First we assume no linkages between periods. We show that after an attack the government may enjoy incoming resources, which deter the terrorist for some periods. Between periods the terrorist's resources may change because of arithmetically and geometricall...
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Research Interests: Mathematics, Monte Carlo Simulation, Biomass, Agricultural Economics, Sensitivity Analysis, and 15 moreCellulase, Ethanol Fuel, Solid State Fermentation, Environmental Issues, Economic analysis, Ethanol Production, Ethanol, Enzyme production, Enzyme, Pulp and Paper Industry, Agricultural and Bioresource Engineering, Submerged, Submerged Fermentation, Clostridium thermocellum, and Other Engineering
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Rice is the staple food of nearly half of the population of the world, most of whom live in developing countries. Ensuring domestic supply of rice from outside sources is difficult for developing countries as less than 5% of total... more
Rice is the staple food of nearly half of the population of the world, most of whom live in developing countries. Ensuring domestic supply of rice from outside sources is difficult for developing countries as less than 5% of total world's production is available for international trade. Hence, in order to ensure domestic food security, eg, food availability and access, governments provide subsidy in agriculture. In many occasions, public money used for subsidy goes toward promoting undesirable crops like tobacco. Although the ...
We analyze how a government allocates resources between defending against a terrorist attack and attacking a terrorist's resource, and how a terrorist allocates resources between attacking a government's asset and defending its... more
We analyze how a government allocates resources between defending against a terrorist attack and attacking a terrorist's resource, and how a terrorist allocates resources between attacking a government's asset and defending its resource. A two-stage game is considered where the government moves first. When the terrorist's resource is small, the government attacks the terrorist's resource to deter the terrorist. When the terrorist's resource is intermediate, the terrorist attacks and defends, while the government only attacks. When ...
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In this paper, we develop a model for the timing and deterrence of terrorist attacks. The defendermoves first and the attacker second in a two stage game which is repeated over T periods. Westudy the effects of dynamics of several... more
In this paper, we develop a model for the timing and deterrence of terrorist attacks. The defendermoves first and the attacker second in a two stage game which is repeated over T periods. Westudy the effects of dynamics of several critical components of counter-terrorism games, including the unit defense costs (eg, immediately after an attack, the defender would easilyacquire defensive funding), unit attack costs (eg, the attacker may accumulate resources as timegoes), and the asset valuation (eg, the asset valuation may ...
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Critical infrastructures rely on cyber and physical components that are both subject to natural, incidental or intentional degradations. Game theory has been used in studying the strategic interactions between attackers and defenders for... more
Critical infrastructures rely on cyber and physical components that are both subject to natural, incidental or intentional degradations. Game theory has been used in studying the strategic interactions between attackers and defenders for critical infrastructure protection, but has not been extensively used in complex cyber-physical networks. This paper fills the gap by modeling the probabilities of successful attacks in both cyber and physical spaces as functions of the number of components that are attacked and defended ...
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Long queues in emergency departments (EDs) lead to overcrowding, a phenomenon that can potentially compromise patient care when medical interventions are delayed. There are several causes of this problem, one of which is inadequate... more
Long queues in emergency departments (EDs) lead to overcrowding, a phenomenon that can potentially compromise patient care when medical interventions are delayed. There are several causes of this problem, one of which is inadequate resource allocation. In this paper, we propose using a modified version of the square root staffing (SRS) rule to satisfy the probability of delay target. We use the concepts of kinetics and biological modeling to approximate the fluid behavior of the queueing process. We are then able to estimate the offered load and the appropriate service grade necessary to construct a staffing policy that meets the target. Additionally, we show how to utilize Pontryagin's maximum principle to find the optimal number of providers that minimizes delay and staffing costs. Finally, we demonstrate the implementation of our model using data from a hospital in upstate New York.
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Like many other engineering investments, the attacker's and defender's investments may have limited impact without initial capital to "warm up" the systems. This article studies such "warm... more
Like many other engineering investments, the attacker's and defender's investments may have limited impact without initial capital to "warm up" the systems. This article studies such "warm up" effects on both the attack and defense equilibrium strategies in a sequential-move game model by developing a class of novel and more realistic contest success functions. We first solve a single-target attacker-defender game analytically and provide numerical solutions to a multiple-target case. We compare the results of the models with and without consideration of the investment "warm up" effects, and find that the defender would suffer higher expected damage, and either underestimate the attacker effort or waste defense investment if the defender falsely believes that no investment "warm up" effects exist. We illustrate the model results with real data, and compare the results of the models with and without consideration of the correlation between the "warm up" threshold and the investment effectiveness. Interestingly, we find that the defender is suggested to give up defending all the targets when the attack or the defense "warm up" thresholds are sufficiently high. This article provides new insights and suggestions on policy implications for homeland security resource allocation.
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ABSTRACT The outcomes of a defender-attacker game depend on the defender’s resources delivered through military supply chains. These are subject to disruptions from various sources, such as natural disasters, social disasters, and... more
ABSTRACT The outcomes of a defender-attacker game depend on the defender’s resources delivered through military supply chains. These are subject to disruptions from various sources, such as natural disasters, social disasters, and terrorism. The attacker and defender are at war; the defender needs resources to defeat the attacker, but those resources may not be available due to a supply chain disruption that occurs exogenously to the game. In this paper, we integrate a defender-attacker game with supply chain risk management, and study the defender’s optimal preparation strategy. We provide analytical solutions, conduct numerical analysis, and compare the combined strategy with other protection strategies. Our results indicate that: (a) the defender benefits in a defender-attacker game by utilizing supply chain risk management tools; and (b) the attacker’s best response resource allocation would not be deterred by capacity backup protection and/or inventory protection. The feature of this paper is that the defender, being the downstream user of the supply chain, is involved in a strategic contest against the attacker. This model is different than game theory applied to private-sector supply chains because most game theoretic models of private sector supply chains usually explore relationships between suppliers and firms in the same supply chain or between multiple firms competing in the marketplace for customers. Therefore, supply chain risk management for such a military application imposes effects that have not been studied before.