Jong Hyuk Choi

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We present a new arrangement of directory bits called the segment directory to improve directory storage efficiency: a segment directory can point to several sharing processors with almost the same number of bits as the pointer which can point to only one. Many directory overflows can be eliminated by using the segment directory element in place of the(More)
Commercial Scale-Out is a new research project at IBM Research. Its main goal is to investigate and develop technologies for the use of large scale parallelism in commercial applications, eventually leading to a commercial su-percomputer. The project leverages and explores the features of IBM's BladeCenter family of products. A significant challenge in(More)
This paper presents a mesh with virtual buses as the bandwidth-efficient implementation of the mesh with multiple broadcasting on which many computational problems can be solved with reduced time complexity. The new system provides a low latency and high bandwidth communication mechanism without the disadvantage of the dual network approach: the possible(More)
Most cases of Middle East Respiratory Syndrome (MERS) infection in Korea (outbreak: May 11-July 4, 2015) occurred in hospital settings, with uncertain transmission modes in some cases. We performed an in-depth investigation epidemiological survey on the 178th case to determine the precise mode of transmission. A 29- year-old man living in Pyeongtaek(More)
OBJECTIVES No children-specified review and meta-analysis paper about the short-term effect of fine particulate matter (PM2.5) on hospital admissions and emergency department visits for asthma has been published. We calculated more precise pooled effect estimates on this topic and evaluated the variation in effect size according to the differences in study(More)
Recently several studies reported that the renal toxicity of lead (Pb) and cadmium (Cd) may exist in even a low level exposure. In terms of the deterioration of tubular function, it affects the loss of divalent metals and leads to other complications, so renal tubular effect of heavy metals should be well managed. Considering the exposure to heavy metals in(More)
This paper describes our effort to improve the performance of the connection management subsystem of the OpenLDAP directory server. Two proposed architec-tures, the multi-listener and the lightweight listener architectures will be described and compared to each other in this paper. This paper will also describe our effort to improve the synchronization of(More)