• International Journal of Naval Architecture and Ocean Engineering
• /
• v.8 no.5
• /
• pp.496-510
• /
• 2016

Simulation technology is a type of shipbuilding product lifecycle management solution used to support production planning or decision-making. Normally, most shipbuilding processes are consisted of job shop production, and the modeling and simulation require professional skills and experience on shipbuilding. For these reasons, many shipbuilding companies have difficulties adapting simulation systems, regardless of the necessity for the technology. In this paper, the data model for shipyard production simulation model generation was defined by analyzing the iterative simulation modeling procedure. The shipyard production simulation data model defined in this study contains the information necessary for the conventional simulation modeling procedure and can serve as a basis for simulation model generation. The efficacy of the developed system was validated by applying it to the simulation model generation of the panel block production line. By implementing the initial simulation model generation process, which was performed in the past with a simulation modeler, the proposed system substantially reduced the modeling time. In addition, by reducing the difficulties posed by different modeler-dependent generation methods, the proposed system makes the standardization of the simulation model quality possible.

• International Journal of Advanced Culture Technology
• /
• v.10 no.2
• /
• pp.233-239
• /
• 2022

Recently, research is being conducted on the rapid service provision and reliability of the instance-based rather than the existing IP-based structure. Research is mainly conducted through Block cloud, a platform that combines service-centric networking (SCN) and blockchain. In addition, the Internet of Things network has been proposed as a fog computing environment in the structure of the existing cloud computing. Fog computing is an environment suitable for real-time information processing. In this paper, we propose a new Internet network structure based on fog computing that requires real-time for rapid processing of IoT services. The proposed system applies IoTA, the third-generation blockchain based on DAG, to the block cloud. In addition, we want to propose a basic model of the object block chain and check the application services of electric vehicles.

• Journal of Electrical Engineering and Technology
• /
• v.5 no.1
• /
• pp.61-69
• /
• 2010

This paper presents a study of a DFIG wind power generation system for real-time simulations. For real-time simulations, the Real-Time Digital Simulator (RTDS) and its user friendly interface simulation software RSCAD are used. A 2.2MW grid-connected variable speed DFIG wind power generation system is modeled and analyzed in this study. The stator-flux oriented vector control scheme is applied to the stator/rotor side converter control, and the back-to-back PWM converters are implemented for the decoupled control. The real-wind speed signal extracted by an anemometer is used for a realistic, reliable and accurate simulation analysis. Block diagrams, a mathematical presentation of the DFIG and a control scheme of the stator/rotor-side are introduced. Real-time simulation cases are carried out and analyzed for the validity of this work.

• Journal of Institute of Control, Robotics and Systems
• /
• v.21 no.9
• /
• pp.827-835
• /
• 2015

In this paper, we present the implementation method of Dynamic Matrix Control(DMC) block for use with a Rapid Control Prototyping(RCP) system and consider the speed control of a DC motor using the developed DMC block. Firstly, we briefly introduce a lab-built RCP system. Secondly, we present a method for implementing a DMC block using C-language, which enables the DMC algorithm to be represented in a library block that can be used in a Simulink environment. Finally, we use the developed DMC block for the speed control of a DC motor, through which we show that the DMC-based control system can be easily implemented and applied to the real-time control of systems with relatively fast dynamics.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.494_495
• /
• 2009

This paper presents a study of DFIG wind power generation system for real-time simulation. For real-time simulation, the real-time digital simulator (RTDS) and its user friendly interface simulation software (RSCAD) are used. 2.2MW grid-connected variable speed DFIG wind power generation system is modeled and analyzed in this study. Stator-flux oriented vector control scheme is applied to stator, rotor side converter control, and back-to-back PWM converters are implemented for the decoupled control. The real-wind speed signal extracted by an anemometer is used for realistic and accurate simulation analysis. Block diagrams for DFIG and control scheme of stator, rotor-side are introduced. Real-time simulation cases are carried out and analyzed for the validity of this work.

• Journal of Broadcast Engineering
• /
• v.16 no.6
• /
• pp.969-976
• /
• 2011

In this paper, a terrestrial transmission system is proposed for the next generation digital television (DTV) system by applying a hybrid multi-input multi-output (MIMO) technology based on linear dispersion codes (LDCs). The digital video broadcasting-2nd generation terrestrial (DVB-T2) system adopted a space time block code (STBC) for improving receive performance. However, the data rate of STBC is not increased in proportion to the transmitter. The hybrid STBC scheme utilizes several STBC transmission blocks for increasing data rate. It is possible to increase the data rate and performance in the receiver by utilizing LDC. The performances of the proposed and conventional hybrid STBC schemes are evaluated through computer simulations.

• Journal of Korea Multimedia Society
• /
• v.25 no.7
• /
• pp.922-931
• /
• 2022

Recently, the need for health information management platforms has been increasing for efficient medical and IT technology research. However, health information is requiring security management by law. When permissioned blockchain technology is used to manage health information, the integrity is provided because only the authenticated users participate in bock generation. However, if the blockchain server is attacked, it is difficult to provide security because user authentication, block generation, and block verification are all performed on the blockchain server. In this paper, therefore, we propose a Health Information Management Server, which uses a permissioned blockchain algorithm and asymmetric cryptography. Health information is managed as a blockchain transaction to maintain the integrity, and the actual data are encrypted with an asymmetric key. Since using a private key kept in the institute local environment, the data confidentiality is maintained, even if the server is attacked. 1,000 transactions were requested, as a result, it was found that the server's average response time was 6,140ms, and the average turnaround time of bock generation was 368ms, which were excellent compared to those of conventional technology. This paper is that a model was proposed to overcome the limitations of permissioned blockchains.

• 한국전산유체공학회:학술대회논문집
• /
• 2001.10a
• /
• pp.152-156
• /
• 2001

Three dimensional orthogonal grid generation is able to control effectively the grid spacing near the boundaries, but there are some difficulty to meshing complex geometry. The mesh complex geometry by orthogonal grid generation method must divide block of geometry It is required a careful skill, and long time. Its also difficulty to make unstructured mesh on complex geometry. Particularly, three dimensional geometry must have more time and effort. Recently, there have been growing interests in mesh generation of complex grometry, aslike an automobile headlamp, the heart. The method of easily meshing complex geometry is resarched to solve them. We suggest octree grid into one among these methods. As octrce grid is automaticaly adapted at the boundaries by determine the level operations to control the grid spacing near the boundaries are unnecessary. In this paper we showed throe dimensional mesh generation, and heat-flow analysis on the octree mesh.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.7
• /
• pp.3608-3628
• /
• 2017

Several block cipher modes of operation have been proposed in the literature to protect sensitive information. However, different security analysis models have been presented for attacking them. The analysis indicated that most of the current modes of operation are vulnerable to several attacks such as known plaintext and chosen plaintext/cipher-text attacks. Therefore, this paper proposes a secure block cipher mode of operation to thwart such attacks. In general, the proposed mode combines one-time chain keys with each plaintext before its encryption. The challenge of the proposed mode is the generation of the chain keys. The proposed mode employs the logistic map together with a nonce to dynamically generate a unique set of chain keys for every plaintext. Utilizing the logistic map assures the dynamic behavior while employing the nonce guarantees the uniqueness of the chain keys even if the same message is encrypted again. In this way, the proposed mode called SPCBC can resist the most powerful attacks including the known plaintext and chosen plaintext/cipher-text attacks. In addition, the SPCBC mode improves encryption time performance through supporting parallelized implementation. Finally, the security analysis and experimental results demonstrate that the proposed mode is robust compared to the current modes of operation.

• KIPS Transactions on Computer and Communication Systems
• /
• v.3 no.10
• /
• pp.377-382
• /
• 2014

Analysis techniques of the data over time from the mobile environment and IoT, is mainly used for extracting patterns from the collected data, to find meaningful information. However, analytical methods existing, is based to be analyzed in a state where the data collection is complete, to reflect changes in time series data associated with the passage of time is difficult. In this paper, we introduce a method for analyzing multi-block streaming data(AM-MBSD: Analysis Method for Multi-Block Stream Data) for the analysis of the data stream with multiple properties, such as variability of pattern and large capacitive and continuity of data. The multi-block streaming data, define a plurality of blocks of data to be continuously generated, each block, by using the analysis method of the proposed method of analysis to extract meaningful patterns. The patterns that are extracted, generation time, frequency, were collected and consideration of such errors. Through analysis experiments using time series data.