Search results

1 – 10 of over 25000
Content available
Article
Publication date: 3 July 2017

Ryan Trudelle, Edward D. White, Dan Ritschel, Clay Koschnick and Brandon Lucas

The introduction of “should cost” in 2011 required all Major Defense Acquisition Programs (MDAP) to create efficiencies and improvements to reduce a program’s “will-cost”…

1008

Abstract

Purpose

The introduction of “should cost” in 2011 required all Major Defense Acquisition Programs (MDAP) to create efficiencies and improvements to reduce a program’s “will-cost” estimate. Realistic “will-cost” estimates are a necessary condition for the “should cost” analysis to be effectively implemented. Owing to the inherent difficulties in establishing a program’s will-cost estimate, this paper aims to propose a new model to infuse realism into this estimate.

Design/methodology/approach

Using historical data from 73 Departments of Defense programs as recorded in the selected acquisition reports (SARs), the analysis uses mixed stepwise regression to predict a program’s cost from Milestone B (MS B) to initial operational capability (IOC).

Findings

The presented model explains 83 per cent of the variation in the program acquisition cost. Significant predictor variables include: projected duration (months from MS B to IOC); the amount of research development test and evaluation (RDT&E) funding spent at the start of MS B; whether the program is considered a fixed-wing aircraft; whether a program is considered an electronic system program; whether a program is considered ACAT I at MS B; and the program size relative to the total program’s projected acquisition costs at MS B.

Originality/value

The model supports the “will-cost and should-cost” requirement levied in 2011 by providing an objective and defensible cost for what a program should actually cost based on what has been achieved in the past. A quality will-cost estimate provides a starting point for program managers to examine processes and find efficiencies that lead to reduced program costs.

Details

Journal of Defense Analytics and Logistics, vol. 1 no. 1
Type: Research Article
ISSN: 2399-6439

Keywords

Content available
Article
Publication date: 3 December 2019

Masoud Kavoosi, Maxim A. Dulebenets, Olumide Abioye, Junayed Pasha, Oluwatosin Theophilus, Hui Wang, Raphael Kampmann and Marko Mikijeljević

Marine transportation has been faced with an increasing demand for containerized cargo during the past decade. Marine container terminals (MCTs), as the facilities for connecting…

1557

Abstract

Purpose

Marine transportation has been faced with an increasing demand for containerized cargo during the past decade. Marine container terminals (MCTs), as the facilities for connecting seaborne and inland transportation, are expected to handle the increasing amount of containers, delivered by vessels. Berth scheduling plays an important role for the total throughput of MCTs as well as the overall effectiveness of the MCT operations. This study aims to propose a novel island-based metaheuristic algorithm to solve the berth scheduling problem and minimize the total cost of serving the arriving vessels at the MCT.

Design/methodology/approach

A universal island-based metaheuristic algorithm (UIMA) was proposed in this study, aiming to solve the spatially constrained berth scheduling problem. The UIMA population was divided into four sub-populations (i.e. islands). Unlike the canonical island-based algorithms that execute the same metaheuristic on each island, four different population-based metaheuristics are adopted within the developed algorithm to search the islands, including the following: evolutionary algorithm (EA), particle swarm optimization (PSO), estimation of distribution algorithm (EDA) and differential evolution (DE). The adopted population-based metaheuristic algorithms rely on different operators, which facilitate the search process for superior solutions on the UIMA islands.

Findings

The conducted numerical experiments demonstrated that the developed UIMA algorithm returned near-optimal solutions for the small-size problem instances. As for the large-size problem instances, UIMA was found to be superior to the EA, PSO, EDA and DE algorithms, which were executed in isolation, in terms of the obtained objective function values at termination. Furthermore, the developed UIMA algorithm outperformed various single-solution-based metaheuristic algorithms (including variable neighborhood search, tabu search and simulated annealing) in terms of the solution quality. The maximum UIMA computational time did not exceed 306 s.

Research limitations/implications

Some of the previous berth scheduling studies modeled uncertain vessel arrival times and/or handling times, while this study assumed the vessel arrival and handling times to be deterministic.

Practical implications

The developed UIMA algorithm can be used by the MCT operators as an efficient decision support tool and assist with a cost-effective design of berth schedules within an acceptable computational time.

Originality/value

A novel island-based metaheuristic algorithm is designed to solve the spatially constrained berth scheduling problem. The proposed island-based algorithm adopts several types of metaheuristic algorithms to cover different areas of the search space. The considered metaheuristic algorithms rely on different operators. Such feature is expected to facilitate the search process for superior solutions.

Content available
Article
Publication date: 1 March 2000

Angela K. Miles and Darla J. Domke-Damonte

This qualitative study examines stressors and coping mechanisms in bed and breakfast (B&B) homes.

1006

Abstract

This qualitative study examines stressors and coping mechanisms in bed and breakfast (B&B) homes.

Details

New England Journal of Entrepreneurship, vol. 3 no. 1
Type: Research Article
ISSN: 2574-8904

Content available
Article
Publication date: 15 December 2017

Maxim A. Dulebenets

The volumes of international containerized trade substantially increased over the past years. In the meantime, marine container terminal (MCT) operators are facing congestion…

1107

Abstract

Purpose

The volumes of international containerized trade substantially increased over the past years. In the meantime, marine container terminal (MCT) operators are facing congestion issues at their terminals because of the increasing number of large-size vessels, the lack of innovative technologies and advanced handling equipment and the inability of proper scheduling of the available resources. This study aims to propose a novel memetic algorithm with a deterministic parameter control to facilitate the berth scheduling at MCTs and minimize the total vessel service cost.

Design/methodology/approach

A local search heuristic, which is based on the first-come-first-served policy, is applied at the chromosomes and population initialization stage within the developed memetic algorithm (MA). The deterministic parameter control strategy is implemented for a custom mutation operator, which alters the mutation rate values based on the piecewise function throughout the evolution of the algorithm. Performance of the proposed MA is compared with that of the alternative solution algorithms widely used in the berth scheduling literature, including a MA that does not apply the deterministic parameter control strategy, typical evolutionary algorithm, simulated annealing and variable neighborhood search.

Findings

Results demonstrate that the developed MA with a deterministic parameter control can obtain superior berth schedules in terms of the total vessel service cost within a reasonable computational time. Furthermore, greater cost savings are observed for the cases with high demand and low berthing capacity at the terminal. A comprehensive analysis of the convergence patterns indicates that introduction of the custom mutation operator with a deterministic control for the mutation rate value would provide more efficient exploration and exploitation of the search space.

Research limitations/implications

This study does not account for uncertainty in vessel arrivals. Furthermore, potential changes in the vessel handling times owing to terminal disruptions are not captured.

Practical implications

The developed solution algorithm can serve as an efficient planning tool for MCT operators and assist with efficient berth scheduling for both discrete and continuous berthing layout cases.

Originality/value

The majority of studies on berth scheduling rely on the stochastic search algorithms without considering the specific problem properties and applying the guided search heuristics. Unlike canonical evolutionary algorithms, the developed algorithm uses a local search heuristic for the chromosomes and population initialization and adjusts the mutation rate values based on a deterministic parameter control strategy for more efficient exploration and exploitation of the search space.

Details

Maritime Business Review, vol. 2 no. 4
Type: Research Article
ISSN: 2397-3757

Keywords

Content available
Article
Publication date: 4 July 2018

Grace W.Y. Wang, Qingcheng Zeng, Chenrui Qu and Joan Mileski

Regardless of the facts showing a booming Chinese cruise market, cruise operations in China are very different from the current practices of the two major cruise markets – the US…

3549

Abstract

Purpose

Regardless of the facts showing a booming Chinese cruise market, cruise operations in China are very different from the current practices of the two major cruise markets – the US and the Mediterranean Sea. This study aims to quantify pricing strategies and possible incentive mechanisms of cruise operations in China.

Design/methodology/approach

Using optimization in economic-based game theory, the complexity of the pricing strategies and interaction and/or possible coordination within the cruise value-added chain can be captured.

Findings

The results show that a coordinative pricing strategy with Shapley profit redistribution within the value-added chain offers benefits to both cruise passengers and service suppliers. With two subsidy scenarios, one to the passenger and the other to the travel agent, a cooperative pricing strategy outperforms other strategies and successfully increases market shares and total revenue.

Originality/value

The advantages of coordination between participants in cruise value chain are quantified. Effective strategies for attracting players participating in cruise value chain are designed. This paper will provide market participants with strategies to enhance their decision-making processes.

Details

Maritime Business Review, vol. 3 no. 2
Type: Research Article
ISSN: 2397-3757

Keywords

Content available
Article
Publication date: 23 November 2021

Phuc Bao Uyen Nguyen

The purpose is to develop search and detection strategies that maximize the probability of detection of mine-like objects.

Abstract

Purpose

The purpose is to develop search and detection strategies that maximize the probability of detection of mine-like objects.

Design/methodology/approach

The author have developed a methodology that incorporates variational calculus, number theory and algebra to derive a globally optimal strategy that maximizes the expected probability of detection.

Findings

The author found a set of look angles that globally maximize the probability of detection for a general class of mirror symmetric targets.

Research limitations/implications

The optimal strategies only maximize the probability of detection and not the probability of identification.

Practical implications

In the context of a search and detection operation, there is only a limited time to find the target before life is lost; hence, improving the chance of detection will in real terms be translated into the difference between success or failure, life or death. This rich field of study can be applied to mine countermeasure operations to make sure that the areas of operations are free of mines so that naval operations can be conducted safely.

Originality/value

There are two novel elements in this paper. First, the author determine the set of globally optimal look angles that maximize the probability of detection. Second, the author introduce the phenomenon of concordance between sensor images.

Details

Journal of Defense Analytics and Logistics, vol. 5 no. 2
Type: Research Article
ISSN: 2399-6439

Keywords

Content available
Article
Publication date: 26 November 2020

Quazi Mohammed Habibus Sakalayen, Okan Duru and Enna Hirata

Bulk shipping mostly facilitates the smooth flow of raw materials around the globe. Regardless, forecasting a bulk shipbuilding orderbook is a seldom researched domain in the…

1188

Abstract

Purpose

Bulk shipping mostly facilitates the smooth flow of raw materials around the globe. Regardless, forecasting a bulk shipbuilding orderbook is a seldom researched domain in the academic arena. This study aims to pioneer an econophysics approach coupled with an autoregressive data analysis technique for bulk shipbuilding order forecasting.

Design/methodology/approach

By offering an innovative forecasting method, this study provides a comprehensive but straightforward econophysics approach to forecast new shipbuilding order of bulk carrier. The model has been evaluated through autoregressive integrated moving average analysis, and the outcome indicates a relatively stable good fit.

Findings

The outcomes of the econophysics model indicate a relatively stable good fit. Although relevant maritime data and its quality need to be improved, the flexibility in refining the predictive variables ensure the robustness of this econophysics-based forecasting model.

Originality/value

By offering an innovative forecasting method, this study provides a comprehensive but straightforward econophysics approach to forecast new shipbuilding order of bulk carrier. The research result helps shipping investors make decision in a capital-intensive and uncertainty-prone environment.

Details

Maritime Business Review, vol. 6 no. 3
Type: Research Article
ISSN: 2397-3757

Keywords

Content available
Article
Publication date: 1 March 2015

Yoon G. Lee, Margaret A. Fitzgerald, Kenneth R. Bartkus and Myung-Soo Lee

With data from the 2003 and 2005 National Minority Business Owners Survey, we examined the extent to which minority business owners differ from nonminority business owners in…

2571

Abstract

With data from the 2003 and 2005 National Minority Business Owners Survey, we examined the extent to which minority business owners differ from nonminority business owners in their reported use of adjustment strategies, and the relationship between the use of adjustment strategies and perceived business success. The sample consisted of 193 African American, 200 Mexican American, 200 Korean American, and 210 white business owners. Mexican American and Korean American business owners reported higher levels of adjustment strategy use than African American and white business owners. The ordinary least squares show that reallocating family resources to meet business needs and reallocating business resources to meet family needs were negatively associated with perceived business success, whereas hiring paid help was positively associated with perceived business success.

Details

New England Journal of Entrepreneurship, vol. 18 no. 1
Type: Research Article
ISSN: 2574-8904

Keywords

Content available
Article
Publication date: 1 March 2000

Jill Kickul and Lisa K. Gundry

Implications for opportunity identification, alliance formation, and strategic orientation of Internet entrepreneurs are presented as preliminary steps toward a new…

Abstract

Implications for opportunity identification, alliance formation, and strategic orientation of Internet entrepreneurs are presented as preliminary steps toward a new "netpreneurship" model of business formation.

Details

New England Journal of Entrepreneurship, vol. 3 no. 1
Type: Research Article
ISSN: 2574-8904

Content available
Article
Publication date: 1 March 2000

James B. Bronson and James W. Faircloth

In this article, a franchise model is proposed which integrates aspects of external growth with internally generated growth outcomes of lowered costs and differentiation.

1139

Abstract

In this article, a franchise model is proposed which integrates aspects of external growth with internally generated growth outcomes of lowered costs and differentiation.

Details

New England Journal of Entrepreneurship, vol. 3 no. 1
Type: Research Article
ISSN: 2574-8904

1 – 10 of over 25000