Akash Deep

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

Prediction of event such as failure event or critical warning event plays an important role in reliability engineering. In this paper, we present a semiparametric method to predict event occurrences for an individual unit in real time using recurrent event data. The intensity of event occurrence is modeled using the extended Cox proportional-hazard...

While a large number of degradation models for industrial systems have been proposed by researchers over the past few decades, the modeling of impacts of maintenance actions has been mostly limited to single-component systems. Among multi-component models, past work either ignores the general impact of maintenance, or is limited to studying failure...

The aim of this work is to reduce the experimental trials required to optimize the parameters of fused filament fabrication (FFF) to meet specific product requirements. Balancing conflicting objectives within budget is a challenge for functional prototyping and direct manufacturing. Herein, we present and validate a multi-objective optimization app...

In this article, the problem of industrial system working condition identification in the context of complex operation modes is considered. The problem is challenging due to the fact that the system dynamics are significantly affected by the operation modes. Specifically, the condition monitoring signals may behave quite differently for different o...

Accurate estimation of remaining useful life (RUL) of a unit is critical to fulfill reliability commitments. In the presence of hard failures (i.e., absence of a predefined failure threshold), accurate prognosis of RUL using condition monitoring (CM) signals becomes challenging. To tackle this problem, we present a prognostic framework by jointly m...

In this article, we study sequences of events with unknown event types commonly arising in customer service processes, such as claim processing, and present a novel approach for detecting outliers and online monitoring of the progression of such sequences until termination. In our approach, we create a series of semi-parametric Cox PH regression mo...

Maintenance records of industrial equipment contain rich descriptive information in free-text format, such as, involved parts, failure mechanisms, operating conditions, etc. Our objective is to leverage this unstructured textual information to identify groups of similar maintenance jobs. We use a natural language based approach and propose a novel...

Event logs, comprising data on the occurrence of different types of events and associated times, are commonly collected during the operation of modern industrial machines and systems. It is widely believed that the rich information embedded in event logs can be used to predict the occurrence of critical events. In this paper, we propose a recurrent...

Recent advances in information and communication technology are enabling availability to event sequence data from equipment fleets comprising potentially a large number of similar units. The data from a specific unit may be related to multiple types of events, such as occurrence of different types of failures, and are recorded as part of the unit’s...

Bubble dynamics and site interaction are studied numerically by solving conservation of mass, momentum, and energy equations for the liquid and vapor phases. The liquid-vapor interface is tracked by a volume of fluid method. The effects of applied mean heat flux, site-site interactions, orientation of the boiling surface, inclination of nucleating...

We report numerical study of film boiling around hot and horizontal cylinders in a saturated water pool to establish interfacial interactions leading towards dryout. Volume of Fluid based finite volume discretization is performed in the domain for incorporation of source term in mass momentum and energy conservation equations due to phase change. A...

Breaking and making of interface of bubbles is tracked using volume of fluid function. Two closely spaced trapezoidal pockets in which constant heat flux is applied, acts as nucleation sites in the bottom boundary of the domain. Saturated water at normal atmospheric pressure is used as working fluid. From simulation results, we observed that at the...

We have presented here the details (compilation) of image analysis carried out under on experimental and numerical output images and videos. The best thing about images is that they are simply matrices whereby the pixel size (mxn) is simply the rows m and columns n. The best way to manipulate matrices is to use matlab. In a given image, pixel size...

In film boiling from horizontal cylinders the mutual configuration and stacking pattern play significant role in vapor formation, bubble growth and subsequent departure which dictates the heat flux from the heater assembly. Present paper reports numerical simulation of boiling heat transfer around horizontal cylinder array to understand the phenome...

Stability of vapor film over a horizontal heater drags attention due to its widespread applications in nuclear reactors, metal processing, manufacturing and chemical refineries. Existence of vapor film around the heater can cause advantages as well as disadvantages for various applications in industry and daily life. Hence understanding the film fo...