Jaemyoun Lee

• Master and PhD combination student
• PhD Student at Hanyang University

When integrated with push notifications, a live migration function can be used to ensure that systems have a high reliability in cases of hardware failures. However, the dependencies for a large range of hardware devices need to be addressed before realizing emergency live migration. Our platform introduces container-based light virtualization and...

Cloud computing systems require massive storage infrastructure, which has significant implications on power bills, carbon emissions, and the logistics of data centers. Various proprietary ‘cold storage’ services, based on spun-down disks or tapes, offer reduced tariffs, but also lead to extended times to first access. One way to improve cold storag...

Within mission-critical systems, the primary–backup scheme is a desirable approach for improving reliability and fault tolerance. It can be used to ensure a high mission success rate despite unexpected errors. However, it must cope with the need to maintain consistency between a primary and a backup whenever the primary encounters unexpected errors...

The power required to maintain a massive storage infrastructure is impractically high. Although research on the development of energy efficient storage systems has been conducted, it is still insufficient for easily comparing their performances. In this paper, we present a benchmark framework for large-scale object storage servers that is intended...

Cloud computing systems require a huge number of storage servers due to the growing implications of power bills, carbon emissions, and logistics of data centers. These considerations have motivated researchers to improve the energy efficiency of storage servers. Most servers use a lot of power irrespective of the amount of computing that they are d...

Cloud computing systems require a huge number of storage servers, with growing implications for power bills, carbon emissions and the logistics of data centers. These considerations have motivated researchers to improve the energy efficiency of storage servers. Most servers use a lot of power irrespective of the amount of computing that they are do...

Recent developments in IT have made real-time ECG monitoring possible, and this represents a promising application for the emerging HL7 standard for the exchange of clinical information. However, applying the HL7 standard directly to real-time ECG monitoring causes problems, because the partial duplication of data within an HL7 message increases th...

The amount of data located in storage servers increases continually with the growth of cloud and social networking services. Storage systems with very large capacities are prone to poor reliability and long latency, which can be addressed by using hybrid disks that contain both mechanical and flash memory storage. In Linux, these two types of devic...

Application loading times can be reduced by prefetching disk blocks into the buffer cache. Existing prefetching schemes for general workloads suffer from significant overheads and low accuracy. ClusterFetch is a lightweight prefetcher that identifies continuous sequences of I/O requests and identifies the files that trigger them. The next time that...

Hard disks are one of the largest sources of power consumption in large-scale storage systems. The disk spin up/down technique has been shown to be an effective solution to this problem. Accordingly, the Open Compute Project (OCP) proposed a storage server for cold data, known as Cold Storage, to reduce power consumption using the spin-down techniq...

The amount of data located in storage servers has dramatically increased with the growth in cloud and social networking services. Storage systems with very large capacities may suffer from poor reliability and long latency, problems which can be addressed by the use of a hybrid disk, in which mechanical and flash memory storage are combined. The Li...

New features are often added incrementally to avionics systems to minimize the need for redesign and recertification. However, it then becomes necessary to check that the timing constraints of existing as well as new applications are met. We facilitate these checks by introducing a new data switch that bounds the latency of end-to-end communication...

In recent years, much attention has been paid to the development of intelligent vehicles that integrate automotive technology into the information technology, with the aim of improving user friendliness and stability. The representative function is a autonomous driving and a cruise control. In designing such vehicles, it is critical to address the...

The development of cloud computing has caused the emergence of various services combining with it. Media Cloud is also one of the convergence services, and content protection from cloud service providers and service quality assurance are essential functions. This paper proposes a virtualization framework in order to provide media services securely...

3G video broadcast services employ forward error correction, together with Reed-Solomon erasure coding with appropriate interleaving, in the MAC layer to deal with bursts of errors. However, this method of error recovery is less effective at the margins of coverage where channel conditions are bad, so that mobiles experience higher error rates and...

Most of the single server model of cloud computing services have problems that are hard to solve, such as a service availability, insider attack, and vendor lock-in, etc. To solve these problems, the research about multicloud has emerged. Multicloud model can supplement previous cloud model`s weakness and provides new services to user. In this pape...

An input/output (I/O) device can incorporate mechanical devices that require physical movements, such as a hard drive seeking a track for a data read or write. Hence I/O operations on a computer can be extremely slow compared to data processing. When a program conducts many I/O operations, the processor often spends most idling as it waits for the...

During the last decade, the multitude of advances attained in terminal computers, along with the introduction of mobile hand-held devices, and the deployment of high speed networks have led to a recent surge of interest in Quality of Service (QoS) for video applications. The main difficulty is that mobile devices experience disparate channel condit...

Timing guarantees and predictive early analysis are essential considerations for the design of reliable and verified real-time avionics systems. In this paper, we consider an environmental monitoring avionic system, which allows physical circumstances to be visually monitored continuously in real-time. We analyze timing aspects on the partitions of...

Quality of service (QoS), and in particular reliability and low latency, are essential qualities of safety-critical wireless systems for medical applications. However, wireless links are typically prone to bursts of errors, with characteristics which vary over time. We propose a wireless system suitable for real-time remote patient monitoring in wh...

We present an adaptive framework for layered representation and transmission of electrocardiogram (ECG) data that can accommodate a time-varying wireless channel. The representation, combined with the layer-based earliest deadline first (LB-EDF) scheduler, ensures that the perceptual quality of the reconstructed ECG signal does not degrade abruptly...

High reliability and acceptable latency are major quality-of-service (QoS) considerations in the design of wireless telemetry systems. In this paper, we show how to analyze the QoS of the wireless telemetry system using its formal description written in the Architecture Analysis & Design Language (AADL) and integrated tool chain, with an exemplar e...

Guaranteeing high reliability and acceptable latency are major QoS considerations in the design of life-critical healthcare applications. To achieve those goals over error-prone wireless networks, proper error control is required. We propose a reference system model for wireless telemetry with medical-grade QoS. The system includes the combination...

Frequent bursts of errors are an unavoidable characteristic of the reception at mobile devices, but one which must be dealt with effectively in the provision of broadcast transmissions. The third generation partnership project 2 (3GPP2) broadcast and multicast services (BCMCS) employ forward error correction by Reed-Solomon coding with appropriate...

Reliability is an essential quality of safety-critical wireless systems for medical applications. However, wireless links are typically prone to bursts of errors, with characteristics which vary over time. We propose a wireless system suitable for realtime remote patient monitoring in which the necessary reliability is achieved by an efficient erro...

Network switches are typically designed for best- effort Internet traffic. Most of existing studies have been focused on improving throughput and delay performance in an average sense rather than providing guaranteed delay bound that is critical for real-time applications. It has not been fully investigated how to design an efficient packet switchi...