Joonhyouk Jang

Learn More
As the demand for the high-speed processing of mass data increases, the use of in-memory systems is increasing. In-memory systems enable data to be accessed in memory, thereby allowing for its high-speed processing. However, as the size and volume of the data increases, its recovery speed from a replicated server gets slower. In this paper, we propose a(More)
The portion of HFT in market is growing rapidly. To process hundreds of thousands of orders per second which are requested by algorithms trading, not by humans, trading systems are required to equip high performance computer, network devices, and efficient software solutions. To achieve performance requirements, financial trading software processes data in(More)
Recently, many studies have been conducted on key-value store as a platform for distributed storage services. A key-value store manages data as key-value pairs using hash tables. In this paper, we propose a hybrid hash table management technique to improve the performance of single nodes in a key-value store. The proposed scheme uses cuckoo hashing and(More)
Data stores in distributed systems maintain backup servers for data recovery. Most existing data stores use non-volatile storage to store backup data. However, high-performance systems may require the use of the main memory for backup storage instead of disks due to the performance gap between the disks and the memory. In this paper, we present an expected(More)
Using InfiniBand technologies, the performance of key-value stores can be greatly improved because of RDMA features and the ultra-low latency of InfiniBand. However, maximizing the benefits of InfiniBand for key-value stores is still challenging because of the data consistency problem between RDMAs and CPU-aware memory accesses. In this paper, we propose a(More)
In this paper, we propose a steganography-based software watermarking scheme to protect Android applications from software piracy. Considering the resource limitations in mobile devices, it is difficult to apply previous software watermarking schemes in mobile applications. To decrease the watermarking overhead in a watermarking scheme, such as a slowdown(More)
Flash file systems that are not cleanly unmounted (e.g., in the event of power failure or an abnormal shutdown) may cause a scan of all flash memory when the system is remounted in order to gather all inode information and store it in RAM. This results in an unacceptably long flash file system mounting time depending mainly on the size. This long(More)
The traditional TCP/IP protocol stack is associated with shortcomings related to the context-switching overhead and redundant data copying. The software-based TOE (TCP/ IP Offload Engine), also known as lightweight TCP/IP, was developed to optimize the TCP/IP protocol stack to run on an embedded system. In this paper, we propose the design of a lightweight(More)
A software birthmark is a set of characteristics extracted from an executable program. Software birthmark techniques are used to detect program theft by determining the similarity between two different programs. In this paper, we propose a software birthmark based on a graph-based structure comparison scheme. By enhancing the function level comparison and(More)