Retrofit of heat exchanger networks with pressure recovery of process streams at sub-ambient conditions

This paper presents a new mathematical programming model for the retrofit of heat exchanger networks (HENs), wherein the pressure recovery of process streams is conducted to enhance heat integration. Particularly applied to cryogenic processes, HENs retrofit with combined heat and work integration is mainly aimed at reducing the use of expensive cold services. The proposed multi-stage superstructure allows the increment of the existing heat transfer area, as well as the use of new equipment for both heat exchange and pressure manipulation. The pressure recovery of streams is carried out simultaneously with the HEN design, such that the process conditions (streams pressure and temperature) are variables of optimization. The mathematical model is formulated using generalized disjunctive programming (GDP) and is optimized via mixed-integer nonlinear programming (MINLP), through the minimization of the retrofit total annualized cost, considering the turbine and compressor coupling with a helper motor. Three case studies are performed to assess the accuracy of the developed approach, including a real industrial example related to liquefied natural gas (LNG) production. The results show that the pressure recovery of streams is efficient for energy savings and, consequently, for decreasing the HEN retrofit total cost especially in sub-ambient processes.

Edge caching with mobility prediction in virtualized LTE mobile networks

Abstract Mobile Edge Computing enables the deployment of services, applications, content storage and processing in close proximity to mobile end users. This highly distributed computing environment can be used to provide ultra-low latency, precise positional awareness and agile applications, which could significantly improve user experience. In order to achieve this, it is necessary to consider next-generation paradigms such as Information-Centric Networking and Cloud Computing, integrated with the upcoming 5th Generation networking access. A cohesive end-to-end architecture is proposed, fully exploiting Information-Centric Networking together with the Mobile Follow-Me Cloud approach, for enhancing the migration of content-caches located at the edge of cloudified mobile networks. The chosen content-relocation algorithm attains content-availability improvements of up to 500 when a mobile user performs a request and compared against other existing solutions. The performed evaluation considers a realistic core-network, with functional and non-functional measurements, including the deployment of the entire system, computation and allocation/migration of resources. The achieved results reveal that the proposed architecture is beneficial not only from the users’ perspective but also from the providers point-of-view, which may be able to optimize their resources and reach significant bandwidth savings.

The computer aided system for planning efficient routes. Final report.

Indiana Department of Transportation, Indianapolis

NOR network transduction procedures : "merging of gates" and "substitution of gates" for fan-in and fan-out restricted networks, NETTRA-G3-FIFO and NETTRA-PG1-FIFO /

"December 1974."--T.p.

Lower bounds on merging networks /

Bibliography: leaf 16.

A branch-and-bound algorithm for optimal AND-OR networks (the algorithm description)

Bibliography: p. 39.

Design of diagnosable MOS networks /

"UILU-ENG 79 1745"--Cover.

Design of optimal one-bit adder networks by integer linear programming /

"July 15, 1971."

Optimal networks with NOR-OR gates and Wired OR logic /

Originally presented as the author's thesis (M.S.), University of Illinois at Urbana-Champaign.

A code for designing optimal networks by implicit enumeration using the all-interconnection inequality formulation : (a programming manual for ILLODIE-AIF) /

Thesis (M.S.)--University of Illinois at Urbana-Champaign.

Reference manual of FORTRAN program ILLOD-(NOR-B) for optimal NOR networks

Mode of access: Internet.

Synthesis of optimal networks with NOR and NAND gates by integer programming /

"January 18, 1971."

Simulation of continuous networks with MODEL /

Includes bibliographical references.

A study of certain factors affecting computation times in designing optimal NOR networks by the implicit enumeration method using the feed-forward formulation /

Bibliography: p. 27-29.

Pruning and branching methods for designing optimal networks by the branch-and-bound method

Includes bibliographical references.