Open Access. Powered by Scholars. Published by Universities.®

Systems Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

1,582 Full-Text Articles 1,859 Authors 352,472 Downloads 67 Institutions

All Articles in Systems Engineering

Faceted Search

1,582 full-text articles. Page 48 of 51.

Stability Of Traffic Flow Behavior With Distributed Delays Modeling The Memory Effects Of The Drivers, Rifat Sipahi, Fatihcan M. Atay, Silviu-Julian Niculescu 2010 Northeastern University

Stability Of Traffic Flow Behavior With Distributed Delays Modeling The Memory Effects Of The Drivers, Rifat Sipahi, Fatihcan M. Atay, Silviu-Julian Niculescu

Rifat Sipahi

Stability analysis of a single-lane microscopic car-following model is studied analytically from the perspective of delayed reactions of human drivers. In the literature, the delayed reactions of the drivers are modeled with discrete delays, which assume that drivers make their control decisions based on the stimuli they receive from a point of time in the history. We improve this model by introducing a distribution of delays, which assumes that the control actions are based on information distributed over an interval of time in history. Such an assumption is more realistic, as it takes into consideration the memory capabilities of the ...


An Alternative Characterization Of Robust Stability And Stability Radius For Linear Time Delay Systems, Bahram Shafai, Hanai Sadaka, Rifat Sipahi, Jie Chen 2010 Northeastern University - Dept. of Electrical & Computer Engineering

An Alternative Characterization Of Robust Stability And Stability Radius For Linear Time Delay Systems, Bahram Shafai, Hanai Sadaka, Rifat Sipahi, Jie Chen

Rifat Sipahi

No abstract provided.


Transportation Delays In Supply Networks: Stability Analysis & System Design, Rifat Sipahi, Stefan Lanmer, Silvia-Julian Niculescu, Dirk Helbing 2010 Northeastern University

Transportation Delays In Supply Networks: Stability Analysis & System Design, Rifat Sipahi, Stefan Lanmer, Silvia-Julian Niculescu, Dirk Helbing

Rifat Sipahi

No abstract provided.


Stability Of A Linear Time Invariant Dynamics With 3 Independent Delays, Rifat Sipahi 2010 Northeastern University

Stability Of A Linear Time Invariant Dynamics With 3 Independent Delays, Rifat Sipahi

Rifat Sipahi

No abstract provided.


First Order Approximation Of The Stability Regions Of Time Delay Systems -- Removed From View At The Discretion Of Northeastern University Libraries (9/16/2010), Rifat Sipahi, Silviu-Julian Niculescu 2010 Northeastern University

First Order Approximation Of The Stability Regions Of Time Delay Systems -- Removed From View At The Discretion Of Northeastern University Libraries (9/16/2010), Rifat Sipahi, Silviu-Julian Niculescu

Rifat Sipahi

No abstract provided.


Delay Modeling In Supply Network Dynamics: Performance, Synchronization, Stability, Rifat Sipahi 2010 Northeastern University

Delay Modeling In Supply Network Dynamics: Performance, Synchronization, Stability, Rifat Sipahi

Rifat Sipahi

Recent research results in Industrial Engineering and Business disciplines specifically emphasize the critical role of delays in the functionality of supply networks. Delays are inevitable and pervasive; they arise due to the time needed for material deliveries, information flow and human perception towards adjusting to new decisions. Delays are endangering as they contaminate decision-making which ultimately leads to poor performance, synchronization problems and fluctuating inventory levels resulting in major economical losses. It is critical to state that inventory regulation and synchronization in supply networks even without delays is an open problem today due to large scale of the network, nonlinearities ...


An Efficient Numerical Approach For The Stability Analysis Of A Class Of Lti Systems With Arbitrary Number Of Delays, Rifat Sipahi 2010 Northeastern University

An Efficient Numerical Approach For The Stability Analysis Of A Class Of Lti Systems With Arbitrary Number Of Delays, Rifat Sipahi

Rifat Sipahi

Abstract: A practical and numerically efficient algorithm is presented for determining the stability robustness map of a general class of higher order linear time invariant (LTI) systems in the parametric space of arbitrary number of independent delays. The stability of this class of dynamics is of particular interest in low-gain design and multi-agent control problems. The backbone of the new algorithm is inspired by a scaled frequency sweeping technique which enables the exhaustive determination of stability switching hypersurfaces in the parametric space of delays, without requiring nested loops. Two case studies are presented in order to demonstrate the strength of ...


Energetyka Niskoemisyjna, Wojciech M. Budzianowski 2010 Wroclaw University of Technology

Energetyka Niskoemisyjna, Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.


A Conceptual Framework To Support A Multi-Level Planning Capability, Jitu Patel, Michael C. Dorneich, David Mott, Ali Bahrami, Cheryl Giammanco 2010 Iowa State University

A Conceptual Framework To Support A Multi-Level Planning Capability, Jitu Patel, Michael C. Dorneich, David Mott, Ali Bahrami, Cheryl Giammanco

Michael C. Dorneich

Over the years, military planning has attracted a lot of attention by researchers with the aim of providing automated planning support tools. There have been some successes (e.g., DART system which was used for movement during Gulf war) however, to-date, planning still remains a very human activity with little or no automated support tools. Why? A possible reason for this predicament is that researchers have not fully conceptualized the problem. For instance, a common approach has been to consider planning as a single process or a homogenous set of problems to be solved. Unfortunately, military planning is not a ...


International Space Station Systems Engineering Case Study, Air Force Center for Systems Engineering, Bill Stockman, Joe Boyle, John Bacon 2010 Air Force Institute of Technology

International Space Station Systems Engineering Case Study, Air Force Center For Systems Engineering, Bill Stockman, Joe Boyle, John Bacon

AFIT Documents

This case study on the International Space Station considers what many believe to have been the ultimate international engineering project in history. The initial plans involved the direct participation of 16 nations, 88 launches and over 160 spacewalks-more space activities than NASA had accomplished prior to the 1993 International Space Station decision. Probably more important was the significant leap in System Engineering (SE) execution that would be required to build and operate a multi-national space station. In a short period of time, NASA and its partners had to work out how to integrate culturally different SE approaches, designs, languages and ...


Additive/Subtractive Rapid Pattern Manufacturing For Casting Patterns And Injection Mold Tooling, Matthew C. Frank, Frank Peters, Rajesh Kumar Karthikeyan 2010 Iowa State University

Additive/Subtractive Rapid Pattern Manufacturing For Casting Patterns And Injection Mold Tooling, Matthew C. Frank, Frank Peters, Rajesh Kumar Karthikeyan

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

This paper presents a Rapid Pattern Manufacturing system that involves both additive and subtractive techniques whereby slabs are sequentially bonded and milled using layered toolpaths. Patterns are grown in a bottom-up fashion, both eliminating the need for multi-axis operations and allowing small features in deep cavities. Similar approaches exist in the literature; however, this system is able to provide a larger range of both materials and sizes, from smaller conventional injection mold tooling to very large wood or urethane sand casting patterns. This method introduces a novel sacrificial support structure approach by integrating a flask into the pattern build process ...


Patient-Specific Bone Implants Using Subtractive Rapid Prototyping, Matthew C. Frank, Ashish Mukund Joshi, Donald D. Anderson, Thaddeus P. Thomas, M. James Rudert, Yuki Tochigi, J. Lawrence Marsh, Thomas D. Brown 2010 Iowa State University

Patient-Specific Bone Implants Using Subtractive Rapid Prototyping, Matthew C. Frank, Ashish Mukund Joshi, Donald D. Anderson, Thaddeus P. Thomas, M. James Rudert, Yuki Tochigi, J. Lawrence Marsh, Thomas D. Brown

Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters

This research involves the development of rapid manufacturing for patient-specific bone implants using a Subtractive Rapid Prototyping process. The geometry of segmental defects in bone, resulting from traumatic injury or cancerous tumor resection, can be reverse-engineered from medical images (such as CT scans), and then accurate defect fillers can be automatically generated in advanced synthetic or otherwise bioactive/biocompatible materials. This paper presents a general process planning methodology that begins with CT imaging and results in the automatic generation of process plans for a subtractive RP system. This work uniquely enables the rapid manufacturing of implant fillers with several key ...


Quality Assurance In Engineering Education: A Systems Perspective, Mildred Genevieve Louidor 2010 University of Tennessee, Knoxville

Quality Assurance In Engineering Education: A Systems Perspective, Mildred Genevieve Louidor

Masters Theses

Engineering education reform has been a topic of discussion for the last twenty years. The concern has only intensified in recent years as stakeholders strive to improve quality in engineering education. Today, stakeholders are recognizing that one of the keys to successful engineering education reform is in taking a systems view of higher education. Academic departments within the higher education system are organized around academic disciplines for the purpose of creating, transferring, and applying knowledge in three principal areas: teaching, research and service. This study addresses the need for quality improvement in the engineering higher education system by first completing ...


Developing Sustainable Life Support System Concepts, Evan A. Thomas 2010 Portland State University

Developing Sustainable Life Support System Concepts, Evan A. Thomas

Mechanical and Materials Engineering Faculty Publications and Presentations

Sustainable spacecraft life support concepts may allow the development of more reliable technologies for long-duration space missions. Currently, life support technologies at different levels of development are not well evaluated against each other, and evaluation methods do not account for long-term reliability and sustainability of the hardware. This paper presents point-of-departure Sustainable System Mass (SSM) evaluation criteria for life support systems that may allow more robust technology development, testing, and comparison. An example sustainable water recovery system concept is presented.


Second-Generation International Space Station Total Organic Carbon Analyzer Verification Testing And On-Orbit Performance Results, Nicole L. Bentley, Evan A. Thomas, Michael Van Wie, Chad Morrison 2010 Portland State University

Second-Generation International Space Station Total Organic Carbon Analyzer Verification Testing And On-Orbit Performance Results, Nicole L. Bentley, Evan A. Thomas, Michael Van Wie, Chad Morrison

Mechanical and Materials Engineering Faculty Publications and Presentations

The International Space Station (ISS) total organic carbon analyzer (TOCA) is designed to autonomously assess recovered water quality by providing an indication of total organic carbon (TOC). The current TOCA has been on the ISS since November 2008. Functional checkout and operations revealed complex operating considerations. Specifically, failure of the hydrogen (H2) catalyst resulted in development of an innovative oxidation analysis method. This method reduces activation time and limits the H2 produced during analysis, while retaining the ability to indicate TOC concentrations within 25% accuracy. Subsequent testing and comparison to archived samples returned from the station and tested on the ...


Post-Project Risk Perception And Systems Management Reaction, Baqer Alali 2010 Old Dominion University

Post-Project Risk Perception And Systems Management Reaction, Baqer Alali

Engineering Management & Systems Engineering Theses & Dissertations

The objective of this research is to identify whether risk management in projects has any role in risk management in systems. Projects, systems, and risk management are three integral concepts in the management of various enterprises and agencies. Risk management is a common concept in systems and project processes. To avoid failures or crisis during their life cycles, projects and systems managers practice risk management. Projects and systems have well defined life cycles during which the risk is defined, controlled, and managed. Risk management is conducted in each phase of projects and systems. Projects are initiated to close certain operational ...


Hybrid Genetic Algorithm For Optimizing Environmental/Economic Power Dispatch, Dr. Adel A. Elbaset 2010 Minia University

Hybrid Genetic Algorithm For Optimizing Environmental/Economic Power Dispatch, Dr. Adel A. Elbaset

Dr. Adel A. Elbaset

الملخص العربي من أهم القضايا التي تهم العاملين في مجال البيئه في هذه الاّونه هي قضيه تقليل الأنبعثات الملوثه من كافه المصادر. يقدم هذا البحث طريقه جديده لتغذيه الأحمال وتوزيعها بين وحدات التوليد الكهربائيه المختلفه بطريقه إقتصاديه أخذين في الأعتبار تقليل الأنبعاثات الملوثه الصادره من وحدات التوليد التي تعمل بالوقود الأحفوري. مسأله أخذ تأثير الأنبعاثات الملوثه وإقتصاديات التشغيل علي توزيع الأحمال عبارة عن مساله مثاليه غير خطيه متعددة القيود والأهداف تم تحويلها إلي داله ذات هدف واحد عن طريق معامل العقوبه (Penalty factor) . يقدم هذا البحث طريقه للحل تعتمد علي نموذج رياضي باستخدام طريقة الحساب الجيني المختلط (Hybrid Genetic ...


Ground Support Equipment For Northrop Grumman Massive Heat Transfer Experiment, Michael A. Manuel, Christopher J. Sparber, Greg A. Trent 2010 California Polytechnic State University - San Luis Obispo

Ground Support Equipment For Northrop Grumman Massive Heat Transfer Experiment, Michael A. Manuel, Christopher J. Sparber, Greg A. Trent

Aerospace Engineering

California Polytechnic State University students designed, built, and certified ground support equipment for the Northrop Grumman Massive Heat Transfer Experiment. The Cal Poly design team built the 10000, 20000, and 30000 assemblies to meet Northrop Grumman requirements. The requirements included interface limitations, design load factors, delivery, and testing specifications. The design process consists of requirements generation, conceptual design, preliminary design, design reviews, manufacturing, and certification. The hardware was successfully completed and is used at the Johnson Space and Kennedy Space Center.


Ergonomic Methods To Improve Safety In The Construction Sector And Reduce Costs, Mona Barjasteh 2010 California Polytechnic State University - San Luis Obispo

Ergonomic Methods To Improve Safety In The Construction Sector And Reduce Costs, Mona Barjasteh

Industrial and Manufacturing Engineering

Many small construction companies have difficulty providing a safe working environment for their employees because of their lack of resources. There is a need to provide a manual for small construction companies employing 10 or fewer workers with the best ergonomic solutions of the top most common injuries. Accidents in the construction field are very high with nearly 175,00o nonfatal injuries and 1,121 deaths in 2002. The nonfatal cases occur 7.1 times per 100 full time workers, while serious injuries occur 2.8 times per 100 full time workers. This information reveled the importance of focusing on ...


Process Improvement For The Department Of Surgery Sierra Vista Medical Center, Jessica Paz 2010 California Polytechnic State University - San Luis Obispo

Process Improvement For The Department Of Surgery Sierra Vista Medical Center, Jessica Paz

Industrial and Manufacturing Engineering

This report proposes and analyzes process improvement methods for the Surgical Services Department at Sierra Vista Regional Medical Center. The department currently operates with an average of 25% of elective cases starting on time. This can be attributed to a number of inefficiencies that occur throughout the hospital.

The following Industrial Engineering methods were utilized to improve patient flow:  creation of a data collection system to quantify delays  use of simulation and facility redesign techniques to determine feasibility and benefits of moving towards a surgical center model  development of a user interfaced database to record and analyze the occurrences of ...


Digital Commons powered by bepress