Tieming Liu

Oklahoma State University | Oklahoma State · School of Industrial Engineering and Management

Objective The paper aims to address the problem of massive unlabeled patients in electronic health records (EHR) who potentially have undiagnosed diabetic retinopathy (DR). It is desired to estimate the actual DR prevalence in EHR with 96 % missing labels. Materials and methods The Cerner Health Facts data are used in the study, with 3749 labeled...

With the increasing availability of electronic health records (EHR), significant progress has been made on developing predictive inference and algorithms by health data analysts and researchers. However, the EHR data are notoriously noisy due to missing and inaccurate inputs despite the information is abundant. One serious problem is that only a sm...

Replacing equipment at the most economical time not only helps to save state transportation agencies (STAs) costs for operatingthe fleet but also keeps the fleet’s level of service at an optimal level. Prior research studies focused on developing alternative economic-oriented equipment replacement models rather than the equivalent annual cost (EAC)...

Diabetic retinopathy (DR) is a leading cause for blindness among working-aged adults. The growing prevalence of diabetes urges for cost-effective tools to improve the compliance of eye examinations for early detection of DR. The objective of this research is to identify essential predictors and develop predictive technologies for DR using electroni...

Two effective strategies that mitigate a firm’s demand risk are resource flexibility investment and responsive pricing. In addition to demand uncertainties firms also face capacity uncertainties and capacity disruptions and the effectiveness of these strategies under these risks are less clear. We investigate the value of resource flexibility and r...

Early and accurate diagnoses of sepsis enable practitioners to take timely preventive actions. The existing diagnostic criteria suffer from deficiencies, such as triggering false alarms or leaving conditions undiagnosed. This study aims to develop a clinical decision support system to predict the risk of sepsis using tree augmented naive Bayesian n...

In this paper, the authors investigate the impact of in-store promotion and its spillover effect on private label introductions. Studying different retail supply chain scenarios in which the retailer carrying a national brand may introduce its own private label product and promote either the national brand or the private label inside the store, the...

This paper proposes an incentive-based coordination mechanism between a wind energy supplier (WES) and a conventional energy supplier (CES) to achieve a Pareto improvement. To comply with its day-ahead schedules and hedge against the intermittent wind energy generation, the WES is allowed to outsource a backup power capacity from the CES via making...

[This corrects the article on p. 139 in vol. 24, PMID: 29770247.].

Objectives The objective of this study was to compare the performance of two popularly used early sepsis diagnostic criteria, systemic inflammatory response syndrome (SIRS) and quick Sepsis-related Organ Failure Assessment (qSOFA), using statistical and machine learning approaches. Methods This retrospective study examined patient visits in Emerge...

This paper studies a coordination mechanism between a renewable energy supplier and a conventional supplier in a regional electricity market. The intermittent nature of the renewable supplier results in random power shortage. Though the renewable supplier can buy backup power from a conventional supplier who prepares backup capacity to cover the sh...

A dataset is called imbalanced when the number of examples from one class outnumbers the number of the instances from another class. Learning from imbalanced datasets is one of the major challenges in machine learning. While a standard classifier could have a very good performance on a balanced dataset, when applied to an imbalanced dataset, its pe...

Diabetes, one of the most serious and fast growing chronic health conditions, often leads to other serious complications such as neurological, renal, ophthalmic, and heart diseases. Research has shown that more than 85% of diabetic patients develop at least one of these complications. Therefore, studying comorbidities among diabetic patients using...

Black ice, a thin sheet of glazed ice on a road surface, is hard to spot by drivers, because it usually has the same color as the road. It is very hazardous and causes many car accidents each year. Unfortunately, the current static road warning signs (such as "Ice May Form on Bridge") may not draw enough attention from drivers. In order to provide...

Diabetes is a common chronic disease that may lead to several complications. Diabetic retinopathy (DR), one of the most serious of these complications, is the most common cause of vision loss among diabetic patients. In this paper, we analyzed data from more than 1.4 million diabetics and developed a clinical decision support system (CDSS) for pred...

In the past two decades, many store-brand products have been introduced by their retailers as having low-cost alternatives to existing brands. However, many store-brand products are perceived with lower quality because their manufacturers do not own the brands. In this paper, we investigate using extended warranties to coordinate the quality decisi...

Transportation cost is an important factor to determine the optimal size of a biofuel refinery. In this article, we analyze the impact of logistic costs on the optimal size of a biofuel refinery by analyzing the trade-off between the switchgrass transportation cost and the economic scale of cellulosic ethanol production. To calculate the transporta...

In price-time bi-parameter bidding (A+B bidding), the owner has to calculate unit time value (UTV) before letting projects because contract time must be converted into dollar value. This study investigates the impacts of different UTVs on the competitiveness of contractors in the A+B bidding process using the entire set of historical A+B bidding pr...

This paper examines the effects of renewable portfolio standard (RPS) regulation on regional electricity markets. A regional market with one or two power suppliers with the capacity to generate renewable energy and access the tradable green certificate (TGC) market is considered. A monopoly model and a Nash game duopoly model to study the effects o...

In this paper we consider a retailer that makes multistage decisions about replenishment order quantity and selling price in a finite planning horizon with fixed ordering cost. Demand for the product is uncertain, and price and time dependent. This kind of problems have been studied by several researchers using stochastic dynamic programming that r...

In this paper, we describe an application of prescriptive analytics to enhance data-driven decision making at a specialty steel bar products supplier and manufacturer in North America. As part of the company's daily business, it must make available-to-promise (ATP) decisions, which determine in real time the dates by which it can promise delivery o...

In a recent paper, Liu (2008) considers the lot-sizing problem with lower and upper bounds on the inventory levels. He proposes an O(n^2) algorithm for the general problem, and an O(n) algorithm for the special case with non-speculative motives. We show that neither of the algorithms provides an optimal solution in general. Furthermore, we propose...

This paper studies sales effort coordination for a supply chain with one manufacturer and two retail channels, where an online retailer offers a lower price and free-rides a brick-and-mortar retailer's sales effort. The free riding effect reduces brick-and-mortar retailer's desired effort level, and thus hurts the manufacturer's profit and the over...

In this article, we study optimal production and admission control policies in manufacturing systems that produce two types of products: one type consists of identical items that are produced to stock, while the other has varying features and is produced to order. The model is motivated by applications from various industries, in particular, the au...

This paper examines structure indices for process flexibility planning with efficiency loss in cross production. We generalise the Structural Flexibility Index and the Graph Expander Index by incorporating shrinking capacity factors. These two deterministic indices are computationally tractable and they allow for simple analysis of alternative syst...

Green product innovation focused on environment and consumers benefits is increasing becoming an efficient sustainable strategy for firm and supply chain. Consumer can pay substantial premium for green innovative product, greenness itself is not a well-defined concept, and detecting violation of green innovation is very difficulty for consumer and...

In a firm, potential conflict exists between manufacturing and sales departments. Salespersons prefer to order from manufacturing departments in advance so that they can secure products in the amount they need to satisfy customers in time. This time in advance strategy is defined as “lead-time hedging.” While this hedging strategy is good for the s...

In this paper, we study the stochastic version of lot-sizing problems with inventory bounds and order capacities. Customer demands, inventory bounds, and costs are subject to uncertainty and dependent with each other throughout the finite planning horizon. Two models in stochastic programming are developed: the first one has inventory-bound constra...

This paper presents a model for applying revenue management to on-demand IT services. The multinomial logit model is used to describe customer choice over multiple classes with different service-level agreements (SLAs). A nonlinear programming model is provided to determine the optimal price or service level for each class. Through a numerical anal...

We consider a manufacturer serving two customer classes where one wants the item immediately and the second receives a discount to accept a delay. We show that an (S,R,B) base-stock policy is optimal under differentiation and non-differentiation where S, R, and B are the order-up-to, reserve-up-to, and backlog-up-to amounts.

This paper studies a economic lot sizing (ELS) problem with both upper and lower inventory bounds. Bounded ELS models address inventory control problems with time-varying inventory capacity and safety stock constraints. An O(n2) algorithm is found by using net cumulative demand (NCD) to measure the amount of replenishment requested to fulfill the c...

Many firms are exploring production and supply chain strategies when customers may be segmented into different classes based on service level or priority. Such segmentation can result in a more efficient production system as well as a better match between supply and demand. In this research, we analyze a system with customer classes 1 and 2, where...

We consider a manufacturer (i.e., a capacitated supplier) that produces to stock and has two classes of customers. The primary customer places orders at regular intervals of time for a random quantity, while the secondary customers request a single item at random times. At a predetermined time the manufacturer receives advance demand information re...

This study considers the job scheduling problem of minimizing the weighted waiting time variance (WWTV) of jobs. It is an extension of WTV minimization problems in which we schedule a batch of n jobs, for servicing on a single resource, in such a way that the variance of their waiting times is minimized. WWTV minimization finds its applications for...

In recent years, many manufacturing companies have started exploring innovative revenue management technologies in an effort to improve their operations and ultimately their bottom lines. Methods such as differentiating customers based on their sensitivity to price and delays are employed by firms to increase their profits. These developments call...

Process integration can improve production flexibility and efficiency. The modeling and simulation technology used to analyze and to optimize the production processes is one of its most important components. Workflow technology and the Control and Integration Net method, which are support technologies for modeling and simulation, have their own str...