• 대한전기학회논문지:전력기술부문A
• /
• 제52권10호
• /
• pp.571-576
• /
• 2003

XML Web Service based on internet can cause problems on transmission speed and data error. Also system analysis results simulated by several different research groups can hardly have reliability because of error data that come from improperly managed files. In order to solve this problems, algorithm sever using XML Web Service is shared on the internet so widely that various application programs based on basic analysis module with a united IO can be developed. And also XML Dataset DB is interacted with XML Web Service, which prevents propagation of error data. It causes to improve reliabilityon the load flow analysis result and solve the problems on data error or transmission speed that can possibly come from internet.

• 한국자동차공학회논문집
• /
• 제20권2호
• /
• pp.1-7
• /
• 2012

A Failure data from operating condition includes various failures. Reliability evaluation by operating condition is more correct than test condition. Additional, the evaluation result by operating condition is widely used for quality assurance, forecasting amount of manufacturing at EOL. To discover valuable things from the failure data, arrangement of the failure data and information technique to handle data is needed among many failure data. This paper introduces a reliability prediction program to solve this problem based on the failure. And new technologies for parameters estimation with method of Graphic-Wizard-Parameters-Estimation and Genetic Algorithm are introduced.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권8호
• /
• pp.2984-3004
• /
• 2015

Designing a new reversible data hiding technique with a high embedding rate and a low compression rate for vector quantization (VQ) compressed images is encouraged. This paper proposes a novel lossless data hiding scheme for VQ-compressed images based on the joint neighboring coding technique. The proposed method uses the difference values between a current VQ index and its left and upper neighboring VQ indexes to embed n secret bits into one VQ index, where n = 1, 2, 3, or 4. The experimental results show that the proposed scheme achieves the embedding rates of 1, 2, 3, and 4 bits per index (bpi) with the corresponding average compression rates of 0.420, 0.483, 0.545, and 0.608 bit per pixel (bpp) for a 256 sized codebook. These results confirm that our scheme performs better than other selected reversible data hiding schemes.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권5호
• /
• pp.2029-2046
• /
• 2016

Energy consumption is an important index in mobile ad hoc networks. Data packet transmission increases among nodes, particularly in big data communication. However, nodes may be unable to transmit data packets because of energy over-consumption. Consequently, information may be lost and network communication may block. While opportunistic network is a kind of mobile ad hoc networks, researchers do not focus on energy consumption in opportunistic network communication. This study proposed an effective sensor energy supply scheme that can be applied in opportunistic networks. This scheme considers nodes sensor requests and communication model. In this scheme, nodes do not only accomplish energy supply in communication, but also extend communication time in opportunistic networks. Compared with the Spray and Wait algorithm and the Binary Spray and Wait algorithm in simulations, the proposed scheme extends communication time, increases data packet transmission, and accomplishes energy supply among nodes.

• 정보저장시스템학회논문집
• /
• 제3권1호
• /
• pp.13-16
• /
• 2007

The purpose of this paper is real time tilt servo control of the holographic data storage system. Holographic data storage device is a next generation data storage device with high storage density, high transfer rate and short access time. This device is very sensitive to a disturbance due to the enormous storage density. As to the recording material changed disc type, the media continuously vibrates as the disc rotates. When disc rotates, deviation, eccentricity and unbalance disturbance are occurred. This disturbances cause disc tilt, finally reference beam does not illuminates to correct incidence angle. Therefore real time tilt servo control is essential. In this paper, the algorithm is proposed to make real time tilt detection in angle multiplexing of the holographic data storage system with an additional servo beam and the experiments are performed.

• 한국수소및신에너지학회논문집
• /
• 제30권6호
• /
• pp.614-620
• /
• 2019

In the present study, the wind characteristics were analyzed according to the time averages to evaluate the performance of small wind turbines required for the development of energy independent village. Measuring data of wind speed were recorded between January 2016 and April 2016 every second. Experimental data is averaged out using 5, 10, 15, 20 and 30 minute time steps. Throughout the experimental data analysis, 5 minutes averaged data is used to analyze the performance of the wind turbine, because it produces a minimum turbulence intensity in wind speed. The measuring power of the wind turbine is less than the designed value due to the unsteady nature wind of sudden changes in magnitude of wind speed and wind angle. Detailed wind conditions are also analysed using two variable Weibull probability density functions.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제55권9호
• /
• pp.423-428
• /
• 2006

In this paper we propose a new watermarking scheme using a data matrix and a cryptograph key. The data matrix of two-dimensional bar codes is a new technology capable of holding relatively large amounts of data compared to the conventional one-dimensional bar code. And a cryptograph key is used to prevent a watermark from malicious attacks. We encoded the copyright information into a data matrix bar code, and it was spread as a pseudo random pattern using the owner key. The experimental results show that the proposed scheme has good quality and is robust to various attacks, such as JPEG compression, filtering and resizing. Also the performance of the proposed scheme is verified by comparing the copyright information with the information which is extracted from the watermark.

• 전기학회논문지P
• /
• 제56권1호
• /
• pp.28-36
• /
• 2007

Sensor networks are usually composed of tens or thousands of tiny devices with limited resources. Because of their limited resources, many researchers have studied on the energy management in the WSNs(Wireless Sensor Networks), especially taking into account communications efficiency. For effective data transmission and sensor fault detection in sensor network environment, a new remote monitoring system based on PCA(Principle Component Analysis) and AANN(Auto Associative Neural Network) is proposed. PCA and AANN have emerged as a useful tool for data compression and identification of abnormal data. Proposed system can be effectively applied to sensor network working in LEA2C(Low Energy Adaptive Connectionist Clustering) routing algorithms. To verify its applicability, some simulation studies on the data obtained from real WSNs are executed.

• 한국소음진동공학회논문집
• /
• 제22권10호
• /
• pp.932-939
• /
• 2012

Recently, data centers are being established because IT and telecommunication industries are growing. The data centers have to install emergency generators to prevent unexpected shutdown of the electrical power supply. When the data centers are located in the densely populated urban area, the operating noise of the emergency generators can be a cause of people's complaints. In this case, it is necessary to establish effective countermeasure by noise & vibration specialists. To achieve this, noise reduction measure using noise measurement data and 3D noise analysis method have been employed in this study.

• 한국소음진동공학회논문집
• /
• 제16권8호
• /
• pp.806-813
• /
• 2006

An important factor of vibration test using MAST(multi axial simulation table) system is the reliance of input excitation source. Generally the generation of input excitation source is obtained by the measured data on special road in proving ground. The measured data on special road have more exciting energy than the data of real fields, therefore the time and expense for test can be reduced. But the magnitude of input excitation source must be defined by comparison with the excited energy on real field. The object of this paper makes the data base of domestic roads for the definition of input excitation source which is obtained by the measured data on special road in proving ground. These real field data on domestic roads are analyzed by the power spectral density and interrelationship index.