Chung Hwan Kim

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Performance bugs are frequently observed in commodity software. While profilers or source code-based tools can be used at development stage where a program is diagnosed in a well-defined environment, many performance bugs survive such a stage and affect production runs. OS kernel-level tracers are commonly used in post-development diagnosis due to their(More)
Audit logging is an important approach to cyber attack investigation. However, traditional audit logging either lacks accuracy or requires expensive and complex binary instrumentation. In this paper, we propose a Windows based audit logging technique that features accuracy and low cost. More importantly, it does not require instrumenting the applications,(More)
Cloud application marketplaces of modern cloud infrastructures offer a new software deployment model, integrated with the cloud environment in its configuration and policies. However, similar to traditional software distribution which has been suffering from software piracy and reverse engineering, cloud marketplaces face the same challenges that can deter(More)
• Static objects are identified using kernel-exported mapping information. • Dynamic object [de]allocations are reported by annotated kernel memory functions with hypercalls. • Memory ranges are extracted from function arguments and return values. • Call stack information is used to derive data types. • Pages that contain allocated kernel objects are(More)
Parallelism • Inter-block: No dependencies among different blocks at translation time • Intra-block: Blocks can be fragmented into instructions, each fetched to a core Limitations of GPUs • Great computation power but high overhead for data transmission Develop heuristics to select blocks for GPU translator • Assume branch is not taken • Translate(More)
PURPOSE To evaluate the survival rate and long term clinical outcomes of hybrid total knee arthroplasty (TKA). MATERIALS AND METHODS We retrospectively analyzed 113 hybrid TKAs (NexGen) in 86 patients that were followed for more than 10 years. Kaplan-Meier survival curves were generated using revision as an end point. Knee Society Score (KSS) and range of(More)
Diagnosis of performance problems is an essential part of software development and maintenance. This is in particular a challenging problem to be solved in the production environment where only program binaries are available with limited or zero knowledge of the source code. This problem is compounded by the integration with a significant number of(More)
My research interests broadly span the areas of operating systems and dynamic/static program analysis with a focus on building secure and robust program execution environments. Cyber attacks against personal and enterprise computers are rapidly evolving. Due to the rise of mobile computing, cloud computing, cyber-physical systems, and the " Internet of(More)
Project: Iterative backtracking via deterministic virtual machine replay and virtual machine introspection. Researching in the area of secure and robust execution environments for various system domains (from server/cloud to cyber-physical systems) using advanced operating system and program analysis/instrumentation techniques. Designed and implemented a(More)
We propose a security analysis system that enables tracking and understanding system intrusions fully and precisely, using deterministic virtual machine replay and virtual machine introspection. Understanding the behaviors of system intrusions is important for malware defense systems to discover their vulnerabilities and prevent them to be exploited for the(More)