Jin-Seok Choi

The installation of smart grids by utilities is driving the growth of the energy industry, allowing energy management systems (EMSs) to improve operational efficiency. Increasing consumers' interest in efficient energy consumption and distributed energy resources requires an EMS that can manage large numbers of powered devices within homes, buildings, and residential areas. An energy management agent (EMA) is a technology standard under development by ISO/IEC JTC 1/SC 25/WG 1. The EMA standard o

Suitably aggregated data burst enhances link utilization and reduces data processing complexity of optical transport networks rather than just transmitting each bursty input traffic from access networks. This data burst generation method is called as a burst assembly process and has two assembly parameters, timer and threshold, for regulating burst release time and burst size. Since the traffic characteristics of data burst generated at the burst assembler may affect network performance, the dec

This letter proposes a secure and efficient handover authentication scheme that requires a light-weight Diffie-Hellman operation at mobile nodes. Our scheme provides more enhanced securities like the PFS, PBS, and so on than the existing security-context-transfer schemes. Also, the mobile node delegates the exponent operation for the DH to the access router to reduce computational cost on it.

In the smart grid roadmap, the number of smart meter installations has grown at a large scale from the grid to homes. To accommodate such a large scale of smart meter installations, advanced metering infrastructure (AMI) facilitates a hierarchical communication architecture for bidirectional data flows between a meter data management system (MDMS) and smart meters via data concentrator units (DCUs). This paper evaluates the traffic load, throughput and end-to-end delay performance of meter data

This paper presents the design and evaluation of a generalized topology discovery, operational monitoring, and provisioning (G-TOP) controller for a carrier-grade transport network. The G-TOP controller is a vendor-specific extension of the stateful PCE that integrates network topology discovery, path computation, and provisioning functions, but decouples the switch specific management framework. The G-TOP protocol enables the G-TOP controller to collect topology information, set up LSPs, and mo

This letter presents a hierarchical distributed topology discovery protocol on the use of hierarchical path computation elements (PCEs) for orchestrating multi-domain software-defined networking. The challenge of this protocol is how child PCEs can maintain an abstract inter-domain topology while preserving intra-domain confidential information in a hierarchical PCE-based orchestration architecture. The experimental results show that the proposed protocol evenly distributes path computation burd

This paper presents an overarching orchestration architecture that combines hierarchical orchestration and distributed orchestration architectures for multi-carrier and multi-domain software-defined transport networks (SDTNs). The objective of this study is to investigate how to combine the hierarchical topology discovery architecture and the distributed per-domain provisioning architecture, in which a set of child orchestrators (COs) enables end-to-end provisioning services in peer-to-peer envi

We propose a new multiple access protocol to support both fixed- and variable-length messages, in a wavelength division multiple access (WDM) based local network using a passive star coupler. The proposed protocol is the dynamic wavelength allocation scheme based on a contention-based reservation protocol. In the proposed protocol, a whole message can be transmitted after the first reservation of the control channel is successfully completed. To reserve the subsequent slots, the status informati

We propose a Local Mobility Anchor (LMA) initiated route optimization protocol for a smooth transition from the old optimized path to a new optimized path after handover in Proxy Mobile IP (PMIP). The LMA initiated protocol can reduce the handover latency and achieve fast recovery of the optimized path after handover. As a result, the proposed protocol solves the out-of-sequence delivery problem during the route optimization procedure.

The performance of the preemptive priority queueing strategy in an input queueing switch with two priority classes is considered. A new queueing model is proposed which consists of two independent input buffers with separate head of line (HOL) queues. This model takes account of the priority queue structure as well as the influence of the preemptive priority scheme for output contention. By applying the approximation techniques of the flow conservation rule and an equivalent queueing model, the

This thesis describes a research project on the development of a new grade of low cost spring steel with exceptional mechanical properties on the basis of a complete understanding and quantification of the metallurgical processes taking place during the various stages of the heat treatment. The new composition in combination with a new 2-step tempering treatment resulted in a steel with a tensile strength in excess of 2400 MPa and a reduction of area for quasi-static tensile fracture of more tha

This article contributes to state-of-the-art energy management agent (EMA) standards, an emerging re ference model, and its framework architectures. EMA can collect energy demand and autonomously manage energy consumption/generation in energy systems. The EMA reference model provides guidance on whether EMA is the right technology for the energy management framework (EMF) of heterogeneous energy systems. The EMA framework architecture details how EMAs can be harmonized to enable cooperative ener