The Experts below are selected from a list of 126 Experts worldwide ranked by ideXlab platform
Vasilios I Manousiouthakis - One of the best experts on this subject based on the ideXlab platform.
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on the state space approach to mass heat exchanger network design
Chemical Engineering Science, 1998Co-Authors: Miguel J Bagajewicz, Robert Pham, Vasilios I ManousiouthakisAbstract:In this paper, the conceptual framework and applications of the State Space Approach to Process Synthesis are presented. It is shown that the State Space Approach contains the concept of a Network Superstructure as a special case. Additionally, through various Operators, it is shown to provide increased flexibility in formulating process network synthesis problems. As an example, it is demonstrated that an Assignment Operator can be used to facilitate the solution of large-scale problems. Pinch Operators are also employed in solving combined heat and mass exchange network synthesis problems. To demonstrate the usefulness of this new approach, two important problems are discussed. First, a one-step procedure is developed that minimizes the total annualized cost (TAC) of heat/mass exchange networks. Next, a novel problem, namely the pinch-based calculation of Minimum Utility Cost for a separable heat and mass exchange network, is solved.
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On the state space approach to mass/heat exchanger network design*
Chemical Engineering Science, 1998Co-Authors: Miguel J Bagajewicz, Robert Pham, Vasilios I ManousiouthakisAbstract:In this paper, the conceptual framework and applications of the State Space Approach to Process Synthesis are presented. It is shown that the State Space Approach contains the concept of a Network Superstructure as a special case. Additionally, through various Operators, it is shown to provide increased flexibility in formulating process network synthesis problems. As an example, it is demonstrated that an Assignment Operator can be used to facilitate the solution of large-scale problems. Pinch Operators are also employed in solving combined heat and mass exchange network synthesis problems. To demonstrate the usefulness of this new approach, two important problems are discussed. First, a one-step procedure is developed that minimizes the total annualized cost (TAC) of heat/mass exchange networks. Next, a novel problem, namely the pinch-based calculation of Minimum Utility Cost for a separable heat and mass exchange network, is solved.
Miguel J Bagajewicz - One of the best experts on this subject based on the ideXlab platform.
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on the state space approach to mass heat exchanger network design
Chemical Engineering Science, 1998Co-Authors: Miguel J Bagajewicz, Robert Pham, Vasilios I ManousiouthakisAbstract:In this paper, the conceptual framework and applications of the State Space Approach to Process Synthesis are presented. It is shown that the State Space Approach contains the concept of a Network Superstructure as a special case. Additionally, through various Operators, it is shown to provide increased flexibility in formulating process network synthesis problems. As an example, it is demonstrated that an Assignment Operator can be used to facilitate the solution of large-scale problems. Pinch Operators are also employed in solving combined heat and mass exchange network synthesis problems. To demonstrate the usefulness of this new approach, two important problems are discussed. First, a one-step procedure is developed that minimizes the total annualized cost (TAC) of heat/mass exchange networks. Next, a novel problem, namely the pinch-based calculation of Minimum Utility Cost for a separable heat and mass exchange network, is solved.
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On the state space approach to mass/heat exchanger network design*
Chemical Engineering Science, 1998Co-Authors: Miguel J Bagajewicz, Robert Pham, Vasilios I ManousiouthakisAbstract:In this paper, the conceptual framework and applications of the State Space Approach to Process Synthesis are presented. It is shown that the State Space Approach contains the concept of a Network Superstructure as a special case. Additionally, through various Operators, it is shown to provide increased flexibility in formulating process network synthesis problems. As an example, it is demonstrated that an Assignment Operator can be used to facilitate the solution of large-scale problems. Pinch Operators are also employed in solving combined heat and mass exchange network synthesis problems. To demonstrate the usefulness of this new approach, two important problems are discussed. First, a one-step procedure is developed that minimizes the total annualized cost (TAC) of heat/mass exchange networks. Next, a novel problem, namely the pinch-based calculation of Minimum Utility Cost for a separable heat and mass exchange network, is solved.
Robert Pham - One of the best experts on this subject based on the ideXlab platform.
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on the state space approach to mass heat exchanger network design
Chemical Engineering Science, 1998Co-Authors: Miguel J Bagajewicz, Robert Pham, Vasilios I ManousiouthakisAbstract:In this paper, the conceptual framework and applications of the State Space Approach to Process Synthesis are presented. It is shown that the State Space Approach contains the concept of a Network Superstructure as a special case. Additionally, through various Operators, it is shown to provide increased flexibility in formulating process network synthesis problems. As an example, it is demonstrated that an Assignment Operator can be used to facilitate the solution of large-scale problems. Pinch Operators are also employed in solving combined heat and mass exchange network synthesis problems. To demonstrate the usefulness of this new approach, two important problems are discussed. First, a one-step procedure is developed that minimizes the total annualized cost (TAC) of heat/mass exchange networks. Next, a novel problem, namely the pinch-based calculation of Minimum Utility Cost for a separable heat and mass exchange network, is solved.
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On the state space approach to mass/heat exchanger network design*
Chemical Engineering Science, 1998Co-Authors: Miguel J Bagajewicz, Robert Pham, Vasilios I ManousiouthakisAbstract:In this paper, the conceptual framework and applications of the State Space Approach to Process Synthesis are presented. It is shown that the State Space Approach contains the concept of a Network Superstructure as a special case. Additionally, through various Operators, it is shown to provide increased flexibility in formulating process network synthesis problems. As an example, it is demonstrated that an Assignment Operator can be used to facilitate the solution of large-scale problems. Pinch Operators are also employed in solving combined heat and mass exchange network synthesis problems. To demonstrate the usefulness of this new approach, two important problems are discussed. First, a one-step procedure is developed that minimizes the total annualized cost (TAC) of heat/mass exchange networks. Next, a novel problem, namely the pinch-based calculation of Minimum Utility Cost for a separable heat and mass exchange network, is solved.
Woo Hyong Lee - One of the best experts on this subject based on the ideXlab platform.
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A study of dynamic memory management in C++ programs
Computer Languages Systems & Structures, 2002Co-Authors: Woo Hyong Lee, Morris ChangAbstract:Recently, the importance of dynamic memory management has been increased significantly as there is a growing number of development in object-oriented programs. Many studies show that dynamic memory management is one of the most expensive components in many software systems. It can consume up to 30% of the program execution time. Especially, in C++ programs, it tends to have object creation and deletion prolifically. These objects tend to have short life-spans. This paper describes an integrated study of the C++'s memory allocation behavior, a memory tracing tool and memory managements based on the empirical study of C++ programs. First, this paper summarizes the hypothesis of situations that invoke the dynamic memory management explicitly and implicitly. They are: constructors, copy constructors, overloading Assignment Operator=, type conversions and application specific member functions. Second, a dynamic memory tracing tool, called mtrace++, is introduced to study the dynamic memory allocation behavior in C++ programs. Third, a dynamic memory allocation strategy, called O-Reuse, to reuse the allocated objects to speed up the object management. At the later part of this paper, an automatic dynamic memory management, called GC++, is discussed. GC++ collects unreferenced objects automatically with high speed of allocation/deallocation processes. The performance gains of O-Reuse and GC++ are come from the utilization of memory allocation/deallocation behavior.
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A study of the allocation behavior of C++ programs
Journal of Systems and Software, 2001Co-Authors: J. Morris Chang, Woo Hyong Lee, Witawas Srisa-anAbstract:Abstract The object-oriented programming (OOP) language systems tend to perform object creation and deletion prolifically. An empirical study has shown that C++ programs can have 10 times more memory allocation and deallocation than comparable C programs. However, the allocation behavior of C++ programs is rarely reported. This paper attempts to locate where the dynamic memory allocations are coming from and report an empirical study of the allocation behavior of C++ programs. Firstly, this paper summarizes the hypothesis of situations that invoke the dynamic memory management explicitly and implicitly. They are: constructors, copy constructors, overloading Assignment Operator=, type conversions and application-specific member functions. Secondly, the development of a source code level tracing tool is reported as a procedure to investigate the hypothesis. Most of the five C++ programs traced are real-world applications. Thirdly, allocation patterns, object size and age distribution are summarized. Among other things, we found that objects tend to have a very short life-span, and most of them are created through constructors and copy constructors. With these findings, we may improve the performance of dynamic memory management through, a profile-based strategy or reusing objects.
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IPCCC - Measuring dynamic memory invocations in object-oriented programs
1999 IEEE International Performance Computing and Communications Conference (Cat. No.99CH36305), 1999Co-Authors: Morris Chang, Woo Hyong Lee, Y. HasanAbstract:Dynamic memory management has been a high cost component in many software systems. Studies have shown that memory intensive C programs can consume up to 30% of the program runtime in memory allocation and liberation. The OOP language system tends to perform object creation and deletion prolifically. An empirical study shown that C++ programs can have ten times more memory allocation and deallocation than comparable C programs. However, the allocation behavior of C++ programs is rarely reported. This paper attempts to locate where the dynamic memory allocations are coming from and report an empirical study of dynamic memory invocations in C++ programs. Firstly, this paper summarizes the hypothesis of situations that invoke the dynamic memory management explicitly and implicitly. They are: constructors, copy constructors, overloading Assignment Operator=, type conversions and application specific member functions. Secondly, the development of a source code level tracing tool is reported as the procedure to investigate the hypothesis. Thirdly, results include behavioral patterns of memory allocations. With these patterns, we may increase the reusability of the resources. For example, a profile-based strategy can be used to improve the performance of dynamic memory management. The C++ programs that were traced include Java compiler, CORBA compliant and visual framework.
Y. Hasan - One of the best experts on this subject based on the ideXlab platform.
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IPCCC - Measuring dynamic memory invocations in object-oriented programs
1999 IEEE International Performance Computing and Communications Conference (Cat. No.99CH36305), 1999Co-Authors: Morris Chang, Woo Hyong Lee, Y. HasanAbstract:Dynamic memory management has been a high cost component in many software systems. Studies have shown that memory intensive C programs can consume up to 30% of the program runtime in memory allocation and liberation. The OOP language system tends to perform object creation and deletion prolifically. An empirical study shown that C++ programs can have ten times more memory allocation and deallocation than comparable C programs. However, the allocation behavior of C++ programs is rarely reported. This paper attempts to locate where the dynamic memory allocations are coming from and report an empirical study of dynamic memory invocations in C++ programs. Firstly, this paper summarizes the hypothesis of situations that invoke the dynamic memory management explicitly and implicitly. They are: constructors, copy constructors, overloading Assignment Operator=, type conversions and application specific member functions. Secondly, the development of a source code level tracing tool is reported as the procedure to investigate the hypothesis. Thirdly, results include behavioral patterns of memory allocations. With these patterns, we may increase the reusability of the resources. For example, a profile-based strategy can be used to improve the performance of dynamic memory management. The C++ programs that were traced include Java compiler, CORBA compliant and visual framework.
