Ho Jin Choi

Recently, Graphic Processing Units (GPUs) have been widely used for general purpose applications such as machine learning applications, acceleration of cryptographic applications (especially, blockchains), etc. The development of CUDA makes this General-Purpose computing on GPU possible. In particular, currently GPU technology has been widely used for server-side applications so as to provide fast and efficient service to a number of clients. In other words, servers need to process a large amoun

Password-Based Key Derivation Function 2 (PBKDF2) is widely used cryptographic algorithm in order to generate secure keys to a password in various occasions. For example, it is used for file encryption and implementation of authentication systems, and so on. However, the generated derived key has a lower entropy than a general cryptography key, so its use is limited. To compensate for this the number of iteration counts of PBKDF2 should be increased. As the number of repetitive tasks increases,

Effective representation of DNA sequences is one of the important tasks in the study of genome sequences. In this paper, we propose a graphical representation of DNA sequences based on nucleotide ring structure. In the proposed representation, we convert DNA sequences into 16 dinucleotides on the surface of the hexagon so that it can preserve nucleotide's chemical property and positional information. Our approach can provide capability of efficient similarity comparison between DNA sequences and

Abstract Effective haptic performance in teleoperation control systems can be achieved by solving two major problems: the time‐delay in communication channels and the transparency of force control. The time‐delay in communication channels causes poor performance and even instability in a system. The transparency of force feedback is important for an operator to improve the performance of a given task. This article suggests a possible solution for these two problems through the implementation of

This paper presents a method for increasing the efficiency of checking the satisfiability of a structure known as a temporal database query(TDBQ), which is an essential component of temporal planning. We develop a new qualitative strategy for decomposing a TDBQ into nearly-independent sub-TDBQ's, whose satisfiability can be checked separately; if all sub-TDBQ's are satisfiable, we use an efficient method of testing for global consistency. To ensure the correctness of the procedure we must impose

Data encryption is essential for securely managing clients’ data in servers in data-centric ICT environment. Clients must encrypt the data before transmitting it to severs or other clients. Encrypting a large volumne of data requires a lot of time. Therefore, in order for servers and clients to not only secure but also smoothly communicate each other, the optimization of data encryption is necessary on both the server-side and the client-side. Especially, the server environment is responsible fo

Currently, cryptographic hash functions are widely used in various applications, including message authentication codes, cryptographic random generators, digital signatures, key derivation functions, and post-quantum algorithms. Notably, they play a vital role in establishing secure communication between servers and clients. Specifically, servers often need to compute a large number of hash functions simultaneously to provide smooth services to connected clients. In this paper, we present highly

본 논문에서는 원격제어 시스템의 시간지연 문제를 분석하고 그 문제를 신경망으로 보상한다. 스미스 예측기는 시간지연 시스템에서 정확한 모델을 필요로 한다. 스미스 예측기의 모델링 오차를 보상하기 위해 신경회로망을 사용한다. 스미스 예측기를 구성하기 위해 Radial Basis Function(RBF) 신경회로망이 사용된다. 시뮬레이션과 실험을 통해 제안하는 방법의 동작을 검증한다. In this paper, a time-delay problem of a tele-operated control system is investigated and compensated by neural network. The smith predictor requires an exact system model to deal with a time-delay in the system. To compensate for modeling errors in the configuration of the Smith predi

Protocols such as DNP and Modbus are widely used in many industrial networks, and security controls are often employed in a protocol gateway placed in-between public and trusted networks. In this paper, an architecture is proposed to protect the security controls running in a hardware-isolated space by providing an isolation environment to the protocol stack and security controls via TrustZone, even if the protocol stack is compromised. In addition, we evaluate whether our proposed architecture

Deep learning techniques have emerged as powerful tools for addressing complex and varied problems, achieving remarkable success across numerous AI domains. Despite their effectiveness, the inherent complexity of deep learning models makes them considered black boxes, reducing their interpretability and reliability. To address this challenge, we propose a novel approach called Attribute-guided Relevance Propagation (ARP). ARP enhances the interpretability of deep learning models by learning attr

Droplet jumping process on superhydrophobic surface draw quite an attention lately for extending the duration of dropwise condensation which enhance the heat transfer considerably compared to filmwise condensation. Most researches so far have been focused on analyzing the behavior of merged droplets. During the phase change, higher temperature gradient can be expected near the wall thus interface movement from condensation effect could be much greater compared to the top. This would increase the

This paper deals with monitoring sensor robot control system for the application of wireless sensor network. In order to control the direction and speed of robot via remote sensing environment, low power, low weight sensors with ad-hoc networking between robots' sensors have been used. These wireless sensor network based robot monitoring system can be used for remote observation and detection of robots in the areas such as factories, power plants and other dangerous areas which are difficult for