bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uncertainties in Material and Geometric Strength and Load Variables
Authors: Hess Paul E. , Bruchman Daniel , Assakkaf Ibrahim A. , Ayyub Bilal M. 
Published: October 2008

ABSTRACTUncertainty in the basic load and strength variables of a ship structure can significantly affect structural performance and safety. Variations in strength, load and load effects greatly impact the reliability of a structural system. Understanding and including this variation, or uncertainty, in the design and analysis of ship structures requires the use of structural reliability‐based design and assessment methodologies.For example, the design strength is based on nominal values for variables such as yield stress of the material, plate thickness, modulus of elasticity, etc. The actual values of these variables are often different from the nominal, or design, values. These actual values tend to behave in a random manner, causing random behavior of the actual structural strength. Understanding the randomness of the basic strength variables allows the designer to account for this variability in the design strength of the structure.The moment methods for calculating reliability‐based, partial safety factors (Ang and Tang 1984 and Ayyub and White 1987) require probabilistic characteristics of both strength and load variables in the limit state equation. Relevant strength variables for ship plates are the material's yield strength (stress)(Fy), modulus of elasticity (E), Poisson's ratio (v), thickness (t), and length (a) and width (b) of a plate. The relevant load variables are the external pressures due to stillwater bending moment, wave bending moment, and dynamic loads. Uncertainty, reliability, and risk measures are vital to the analysis and design of an engineering system. The reliability of the system can be stated in reference to some performance criteria. The need for reliability analysis stems from the fact that there is the presence of uncertainty in the definition, understanding, modeling, and behavior prediction of the model or models describing the system.The objective herein is to compile statistical information and data based on literature review on both strength and load random variables relevant to ship structures for quantifying the probabilistic characteristics of these variables.
Assessment of Cumulative Lifetime Seaway Loads for Ships
Authors: Sikora Jerome P. , Michaelson Robert W. , Ayyub Bilal M. 
Published: October 2008

ABSTRACTThis paper presents a reliability‐based design methodology for primary seaway loadings on surface ships. The goal for such a design methodology is to have one consistent method for developing extreme primary hull girder loads for reliability‐based strength design criteria as well as lifetime exceedance loads for reliability‐based fatigue strength design criteria. The primary hull girder loads, i.e., vertical bending, lateral bending, and torsion, include contributions from both the low frequency (wave‐induced) and the high frequency (slam‐induced) domains for vertical and lateral bending. The contributions of secondary loads, such as hydrostatic and dynamic pressure loads, are important but are beyond the scope of this paper. A method is presented for calculating lifetime seaway loads as functions of ship and seaway parameters. The method is embodied in a PC based computer program called SPECTRA.
LHD 8 ‐ A Step Toward the All Electric Warship
Authors: Dalton Thomas , Boughner Abe , Mako C. David , Doerry Norbert 
Published: October 2008

ABSTRACTThe recently commissioned Iwo Jima (LHD 7) is the last ship with conventional steam propulsion that the U.S. Navy plans to build. The LHD 8 is the next ship of the class and will be built as a modified repeat design of the LHD 7. The key modifications are steam propulsion being replaced with a hybrid propulsion system of main gas turbine engines augmented with auxiliary propulsion motors and electric powered auxiliaries replacing those powered by steam. The LHD 8 will also be the first USN surface ship to implement a 4160 VAC Zonal Electrical Distribution System (AC ZEDS) as well as the integrated power system concept for electrical power generation, distribution and propulsion. These modifications embody the intent of the all electric warship concept for the future U.S. Navy. This paper presents the constraints and issues involved in the design process by addressing major design impacts and significant design concerns. This text explores the design options within the available trade space and illustrates specifically how the Fleet/mission requirements, LHD 7 hull design and propulsion shafting constraints, schedule and funding drove the propulsion system design.
Decision‐Aid System for Survivability of Damaged Conventional Military Submarines
Authors: Lee Dongkon , Lee Jaeyong , Lee Kyung‐Ho 
Published: October 2008

ABSTRACTEven small leakage in submarines can lead to serious consecutive damage, since they operate under high water pressure. Such leakage including damage to piping and the hull eventually result in human casualties and loss of expensive equipment as well as the loss of combat capabilities. In such cases, a decision‐making system is necessary to respond immediately to the damage in order to maintain the safety or the survival of the submarine. So it is necessary to have an automatic system that can generate responses and give advice to the operator on how to make decisions to maintain the survivability of the damaged vessel. In this paper, a knowledge‐based decision support system for submarine safety is developed. The domain knowledge is acquired from submarine design documents, design expertise, and interviews with operators. The knowledge consists of responses regarding damage of the pressure hull and piping systems. Expert elements are deduced to obtain the decision from the knowledge base, and the system makes recommendations on how to cope with damage to the hull and piping and whether the submarine should stay in the sea or to surface. It is demonstrated that the developed system is well simulated to the real situation through sample applications.
Blue‐Green Dye Lasers for Underwater Illumination
Authors: Pavlopoulos Theodore G. 
Published: October 2008

ABSTRACTAdvances in underwater viewing can be expected by employing powerful blue‐green dye lasers as illumination sources. For minimum transmission losses, the spectral characteristics of the seawater must coincide with the laser action spectral region. Propagation of light through the ocean environment is discussed. Presently available bluegreen laser systems are briefly reviewed. It was concluded that a commercially available dye laser, operating at the seawater transmission window, provides the best near termsolution. Such a dye laser is capable of delivering up to about 3 joules per pulse at a rate of 10 to 50 Hz. A synchronized video camera takes pictures of the illuminated area. In the future, a powerful blue‐green illumination source can be obtained by operating the dye laser with improved (high‐efficiency) laser dyes.
Applied Maintenance and Logistics Options in the Warfighters 21
Authors: Flynn John E. , Bryant Russell E. 
Published: October 2008

ABSTRACTAs the current review of Department of Defense (DOD) structures, capabilities, and plans are coming to completion and moving into implementation phases, a focus to maintain is the delivery of mission capabilities for the front line warfighters. The mission capabilities packages are supported by the material, and also by the materiel support process, which includes not only the hardware, but more importantly the people, training, maintenance and support, and the doctrine, concepts of operations, tactics, techniques, and procedures for the material.Following an updated discussion on operational engineering, this paper expands the authors’ concept of operational engineering, to several applied logistics options and discussions in support of rapid decisive operations. It finishes with an introductory discussion of a logistics commander operational planning tool, which potentially can support and enable generation of rapid decisive operations. This tool could assist combatant commanders and their warfighters to operate inside the decision cycle of opponents on the front lines.Further, the concepts addressed align with the Quadrennial Defense Review 2001 task: to “Provide sufficient mobility, including airlift, sealift, prepositioning, basing infrastructure, alternative points of debarkation, and new logistical concepts of operations, to conduct expeditionary operations in distant theaters against adversaries armed with weapons of mass destruction and other means to deny access to U.S. forces” [emphasis added](QDR 2001).
Human Systems Integration and Advanced Technology in Engineering Department Workload and Manpower Reduction
Authors: Lively Kenneth A. , Seman Anthony J. , Kirkpatrick Mark 
Published: October 2008

ABSTRACTAboard current ships, such as the DDG 51, engineering control and damage control activities are man‐power intensive. It is anticipated that, for future combatants, the workload demand arising from operation of systems under conditions of normal steaming and during casualty response will need to be markedly reduced via automated monitoring, autonomous control, and other technology initiatives.Current DDG 51 class ships can be considered as a manpower baseline and under Condition III typical engineering control involves seven to eight watchstanders at manned stations in the Central Control Station, the engine rooms and other machinery spaces. In contrast to this manning level, initiatives such as DD 21 and the integrated engineering plant (IEP) envision a partnership between the operator and the automation system, with more and more of the operator's functions being shifted to the automation system as manning levels decrease. This paper describes some human systems integration studies of workload demand reduction and, consequently, manning reduction that can be achieved due to application of several advanced technology concepts. Advanced system concept studies in relation to workload demand are described and reviewed including: Piecemeal applications of diverse automation and remote control technology concepts to selected high driver tasks in current DDG 51 activities. Development of the reduced ship's crew by virtual presence system that will provide automated monitoring and display to operators of machinery health, compartment conditions, and personnel health. The IEP envisions the machinery control system as a provider of resources that are used by various consumers around the ship. Resource needs and consumer priorities are at all times dependent upon the ship's current mission and the availability of equipment. pawnbrokers.
HSI Top Down Requirements Analysis
Authors: Malone Thomas B. , Carson Frances 
Published: October 2008

ABSTRACTThe major objective of the discipline of human systems integration (HSI) in system development is to ensure that requirements and considerations for the human element of the system will influence design. The system must be designed to facilitate and support human performance capability, safety, reliability, survivability and accommodation. This objective is achieved by addressing human requirements early in system design and development, in fact, at the very outset of the design process. How this is accomplished is through application of the HSI top down requirements analysis (TDRA). This paper describes the TDRA process, discusses applications of the TDRA, and compares TDRA with bottom‐up analysis.
Development of Interactive Electronic Checklists & Manuals for Navy Helicopter In‐flight Operations
Authors: Popp Ed. , Deaton John , Glenn Floyd , Barba Charles 
Published: October 2008

ABSTRACTThis paper presents an overview of a research effort to design an electronic version of a Navy helicopter NATOPS flight manual and applicable checklists for use by aircrews during normal and emergency in‐flight operations. The general concept for an Interactive Electronic NATOPS (IE‐NATOPS) is to provide a pilot in the cockpit with a computer‐based presentation of the information that is currently provided in hard‐copy manuals, providing operating information and procedures that are specific to each Navy aircraft. For the Navy, as well as for virtually all other military and commercial aviation applications, the benefits seem obvious ‐ context sensitivity, fast and cheap “updatability”, and the capacity for embedded intelligence and embedded intelligent training. The initial research efforts focused on the H‐46 helicopter, but switched to the SH‐60F, because of Navy plans to develop new H‐60 helicopters and phase out the H‐46. A prototype IE‐NATOPS “electronic kneeboard” system has been developed for the SH‐60F, including a capability to integrate with the aircraft alerting systems. In this paper a summary of two studies conducted on information requirements, on SH‐60F IE‐NATOPS design, and an evaluation of performance characteristics in emergency problem prosecution between baseline hard copy NATOPS and IE‐NATOPS will be presented.
Interoperability & Sensor Fusion
Authors: DeLong R. Peter 
Published: October 2008

ABSTRACTThis article, to be published in three parts, shows why interoperability of sensor fusion systems is a math problem, and how to solve it. Part I (Track Management) explains the minimum that sensor fusion systems must communicate to each other in order to interoperate. Part II (System Architecture) demonstrates that there are significant constraints on the architecture of interoperable sensor fusion systems. Part III (Seeking Solutions) discusses optimal solutions to the constrained architecture problem, along with the relationship of interoperability to other sensor fusion engineering problems. It concludes by outlining the steps necessary to make existing sensor fusion systems interoperate.
Human Systems Integration and Shipboard Damage Control
Authors: Runnerstrom Eric 
Published: October 2008

ABSTRACTAs the United States and other maritime nations move towards operating combatant ships with fewer people, human‐systems integration (HSI), or human‐centered design, is getting increasing attention in new ship designs. Aboard most ships operating today, damage control is a mostly manual, manpower intensive function. Consequently, it is a key area of concern for ship acquisition programs that need to produce ships that will operate with fewer people. Damage control also is critical to the survival of a warship and the safety of the crew. Consequently, it is very important to ship operators. It is no surprise, therefore, that damage control is a key function of concern when designing new ships to operate with fewer people. This paper discusses the state‐of‐the‐art in HSI and damage control aboard ships today as evidenced by the damage control performance of some of today's ships. The paper draws conclusions about the importance of HSI for effective damage control in new ship designs. The successful application of a human‐centered design approach in the development of a damage control supervisory control system for the U.S. Navy's Damage Control Automation for Reduced Manning (DC‐ARM) Program is described. Finally, major challenges to achieving effective HSI in new ship designs are presented.
Risk Metric for Multi‐Objective Design of Naval Ships
Authors: Brown Alan , Mierzwicki Timothy 
Published: October 2008

ABSTRACTThe DoD Risk Management Guide requires risk assessment of acquisition performance, cost, and schedule through the identification, subsequent analysis and prioritization of adverse program events based on their probability and consequences. This type of risk assessment is very important in concept exploration and design when considering new technologies, unique processes, and novel concepts.Uncertainty associated with the design process itself and the definition and selection of specific design alternatives can also have a significant impact on performance, cost, and schedule risk. Inherent, statistical and modeling uncertainty and uncertainty because of human error, must be considered in the design process, but uncertainty analysis requires a more detailed and computationally intensive probabilistic approach. It is most appropriate for post‐exploration design optimization, after specific cost and performance goals and thresholds have been set to maximize the probability of achieving these goals.In this paper, a two‐stage concept design strategy is proposed that uses a multi‐objective optimization and simplified risk event approach for concept exploration and a more rigorous multi‐disciplinary optimization with uncertainty for concept development. Concept exploration identifies nondominated design concepts and establishes the optimum relationship between effectiveness, cost, and risk given a broad selection of technologies and design alternatives. In this context, non‐dominated (N‐D) refers to designs with the maximum effectiveness for a given cost and level of risk. This is a global optimization design problem that considers a wide range of performance, cost and risk possibilities. Risk is defined using a separate objective attribute, an overall measure of risk (OMOR), which specifically addresses the high‐risk events associated with the selection of new technologies, processes, and concepts. With this perspective, decision‐makers may establish ratio‐nal requirements, select technologies, narrow the design space, and establish a non‐dominated concept baseline design or set of designs.Once these early decisions are made, concept development and the remaining design phases add detail, refine requirements and reduce risk. Optimization continues into concept development, but a single objective optimization based on uncertainty analysis is used, maximizing the probability of success (POS) of satisfying cost and effectiveness thresholds and other constraints established in concept exploration.The methodology and a simple application of the multi‐objective optimization and risk event approach are described in this paper.
Multi‐Agent Simulation of Human Behavior in Naval Air Defense
Authors: Calfee Sharif H. , Rowe Neil C. 
Published: October 2008

AbstractThe AEGIS Cruiser Air‐Defense Simulation Program models the operations of a combat information center team performing air defense for a U.S. Navy battle group. It uses multi‐agent system technology and is implemented in Java. Conceived primarily to assist personnel in air‐defense training and doctrine formulation, the simulation provides insight into the factors (skills, experience, fatigue, aircraft numbers, weather, etc.) that influence performance, especially under intense or stressful situations, and the task bottlenecks. It simulates air contacts (aircraft and missiles) as well as the actions and mental processes of the watchstanders. All simulated events are logged, to permit performance analysis and reconstruction for post‐scenario training. Validation of the simulation was done with the help of expert practitioners of air defense at the AEGIS Training & Readiness Center (ATRC), San Diego, California, USA.
A Statistical Examination of Sea Valve Failure Rates
Authors: Kauffmann Paul , Dean Anthony , Lunsford Phil 
Published: October 2008

AbstractThis paper presents the results of a study that targeted identification of statistical methods to characterize the failure rates and related probability distributions of sea valves across a broad range of hull classes. Beginning with maintenance records from sea valve assessment, the paper demonstrates the application of various statistical tools and the related strengths and weaknesses of each. These tools involve maximum likelihood estimators, empirical methods, and hypothesized distributions. Using these methods, failure rates and confidence intervals are estimated and compared. Finally this information is combined to formulate a cohesive view that allows a high level of confidence in predicting sea valve failure. This paper demonstrates use of statistical models as a tool to validate and improve maintenance systems, costs, and strategic maintenance management programs.
Computational and Experimental Analysis of Ballast Water Exchange
Authors: Wilson Wesley , Chang Peter , Verosto Stephan , Atsavapranee Paisan , Reid David F. , Jenkins Philip T. 
Published: October 2008

AbstractThe objective of the present study is to use experimental and computational fluid dynamics (CFD) methods to examine the flow behavior inside ballast tanks during flow‐through ballast water exchange (BWE), and to investigate the exchange effectiveness. Validation efforts are conducted based on comparisons with data collected in a 1/3‐scale model of a portion of a typical ballast tank for a bulk carrier. Comparisons between the measured data and computational predictions are in good agreement. Numerical simulations are also performed for a typical full‐scale ballast tank in a 35,000 dwt handysize bulk carrier, a ship type that represents a large proportion of the oceangoing vessels that ply the Great Lakes trade routes. The results of this study may help explain the variable results of ballast water exchange experiments documented to date, lead to ballast tank structural modification recommendations to improve overall ballast water exchange effectiveness, minimize deadspots, reduce sediment deposition and accumulation, and provide the insight and knowledge to select and enhance treatment technologies, thus reducing the threat of coastal invasive species being discharged in coastal ecosystems.
NOx Emissions Reduction Through Water Injection
Authors: Radloff Ernst 
Published: October 2008

AbstractTransport Canada is committed to protect the environment and to achieve a more sustainable transportation system. The Transportation Development Centre of Transport Canada, in collaboration with the Environment Research and Measurement Division of Environment Canada, is conducting research on marine emissions control technologies to lower greenhouse gas (GHG) emissions. » The ongoing work on emissions control technologies comprises both laboratory and field trials. An initial round of laboratory tests demonstrated the viability of a Water Injection System (WIS) to reduce NOx emissions. The results indicate that the WIS has achieved a 20 to 28% NOx reduction over a 25 to 75% load range with a maximum of 33% water injection. The WIS was optimized during laboratory bench tests and will be installed on a RORO vessel operating between Montreal, Quebec, and St. John's, Newfoundland. The WIS provides a cost‐effective solution for NOx reduction on Canadian vessels fitted with older medium‐speed engines.