• Journal of Broadcast Engineering
• /
• v.20 no.6
• /
• pp.888-900
• /
• 2015

This paper proposes a blind watermarking scheme using DWT satisfying robustness, invisibility, and security to protect the ownership of digital image contents. This scheme does not determine any watermarking position by local image information. It rather inserts the watermark information into all the four lowest frequency subbands after transforming the host image by n-level 2-dimensional DWT, depending on, the sizes of the host image and the watermark data. Its watermark insertion methodology uses some weighting factors according to the kind of the subband and its energy level to adjust the invisibility and the robustness of the watermark. This method is experimented for various pixel-value change attacks and geometric attacks with various images having different resolutions and aspect ratios. With the experimental results and by comparing with existing methods, we show that the proposed method has a great deal of general usage with good watermark invisibility and good robustness against attacks.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.2
• /
• pp.149-156
• /
• 2017

Nuclear fuel requires high reliability and safety and therefore contains debris filtering devices to prevent failure-inducing debris from entering it. The debris filtering performance of nuclear fuel is one of the most important factors for fuel integrity. Therefore, the performance must be evaluated and the measurement must be reasonable. In this study, a calculation method of the comprehensive filtering efficiency using the weighted mean was proposed to establish a standard filtering efficiency index. To confirm the suitability of the proposed method, representative debris specimens were selected and the filtering efficiency with the weighted mean was compared with the efficiency of the arithmetic mean. The weighting factor of the weighted mean was introduced to produce a fair evaluation. In addition, the analysis of the debris filtering mechanism was performed according to the size of debris specimens, and the main dimensions of the filtering feature for commercial nuclear fuel.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2008.04a
• /
• pp.647-652
• /
• 2008

This paper focused on the application of finite element model updating technique to evaluate the structural properties of the reinforced concrete specimen using the data collected from shaking table tests. The specimen was subjected to six El Centro(NS, 1942) ground motion histories with different Peak Ground Acceleration(PGA) ranging from 0.06g to 0.50g. For model updating, flexural stiffness values of structural members(walls and slabs) were chosen as the updating parameters so that the converged results have direct physical interpretations. Initial values for finite element model were determined from the member dimensions and material properties. Frequency response functions(i.e. transfer functions), natural frequencies and mode shapes were obtained using the acceleration measurement at each floor and given ground acceleration history. The weighting factors were used to account for the relative confidence in different types of inputs for updating(i.e. transfer function and natural frequencies). The constraints based on upper/lower bound of parameters and sensitivity-based constraints were implemented to the updating procedure in this study using standard bounded variable least-squares(BVLS) method. The veracity of the updated finite element model was investigated by comparing the predicted and measured responses. The results indicated that the updated model replicates the dynamic behavior of the specimens reasonably well. At each stage of shaking, severity of damage that results from cracking of the reinforced concrete member was quantified from the updated parameters(i.e. flexural stiffness values).

• Korean Journal of Ecology and Environment
• /
• v.38 no.3 s.113
• /
• pp.281-288
• /
• 2005

BAT (Best Available Technology economically achievable) assessment is indispensible to effective management policy of industrial wastewater discharging facilities such as setting effluent limitations guidelines for individual industry based on the wastewater characteristics and treatment efficiency, making effluent limitations guidelines for new sources, and calculation of the reducible amount of emission load conforming to a total emission general plan and enforcement plan. This study reviewed foreign cases of BAT assessment and condition of domestic wastewater discharging facilities, and suggested BAT assessment guideline suitable for the domestic conditions. The major assessment factors and flow are; (1) Identification of pollution source characteristics, (2) Identification and survey on technology, (3) Selection of candidate technology, (4) Assessment of legislation adaptation, (5) Assessment of environmental factor, (6) Assessment of economical acceptability, (7) Total weighting value factor assessment on technological factor, and (8) Total assessment and final BAT selection. The result of this study can be utilized as a major policy data and a base of industrial wastewater management system.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.18 no.7
• /
• pp.725-731
• /
• 2008

This paper focused on the application of finite element model updating technique to evaluate the structural properties of the reinforced concrete specimen using the data collected from shaking table tests. The specimen was subjected to six El Centre (NS, 1942) ground motion histories with different peak ground acceleration (PGA) ranging from 0.06 g to 0.50 g. For model updating, flexural stiffness values of structural members (walls and slabs) were chosen as the updating parameters so that the converged results have direct physical interpretations. Initial values for finite element model were determined from the member dimensions and material properties. Frequency response functions (i.e. transfer functions), natural frequencies and mode shapes were obtained using the acceleration measurement at each floor and given ground acceleration history. The weighting factors were used to account for the relative confidence in different types of Inputs for updating (j.e. transfer function and natural frequencies) The constraints based on upper/lower bound of parameters and sensitivity-based constraints were implemented to the updating procedure in this study using standard bounded variable least-squares(BVLS) method. The veracity of the updated finite element model was investigated by comparing the predicted and measured responses. The results indicated that the updated model replicates the dynamic behavior of the specimens reasonably well. At each stage of shaking, severity of damage that results from cracking of the reinforced concrete member was quantified from the updated parameters (i.e. flexural stiffness values).

• Journal of the Korean GEO-environmental Society
• /
• v.17 no.9
• /
• pp.47-52
• /
• 2016

Unusual extreme weather events, which exceed a safe design capacity of the infrastructure, increase the frequency of natural disasters and has also been enlarged damage scale. Aging buildings and rapid urban progress act as weighting factors for the new composite disasters. Technological advances support detecting pre-disaster risk, real-time data analysis, and rapid response to the disaster site, but it is insufficient that emergency relief for buried alive must take advantage of the proven technologies through field tests. This study aims to evaluate directional drilling performance through underground soils and the reinforced concrete structure for primary lifeline installation in order to quickly provide relief supplies for buried alive when urban structures collapse.

• Journal of Advanced Navigation Technology
• /
• v.11 no.2
• /
• pp.203-208
• /
• 2007

Because the networks and systems become more complex, the implementation of the security countermeasures for important Information Systems becomes more critical consideration. The designers and developers of the security policy should recognize the importance of building security countermeasures by using both technical and non-technical methods, such as personnel and operational facts. Security countermeasures may be made for formulating an effective overall security solution to address threats at all layers of the information infrastructure. But all these works can be done after assuming who is the threat agent. In this paper we identify the treat agents for information systems, summarize the characteristics of threat agents, and apply weighting factors to them.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.8
• /
• pp.1581-1586
• /
• 2016

In this paper, we propose a central disaster monitoring system of the forest fire. This system provides the safe-zone and detection to reduce the suppression efforts. In existing system, it has a few providing the predicting of wildfire spread model and speed through topography, weather, fuel factor. This paper focus on the forest fire diffusion model and predictions of the path identified to ensure the safe zone. Also we have considering the forest fire of moving direction and speed for fire suppression and monitering. The proposed algorithm could provide the technique to analyze the attribute information that temperature, wind, smoke measured over time. This proposed central observing monitoring system could provide the moving direction of spred out forecast wildfire. This observing and monitering system analyze and simulation for the moving speed and direction forest fire, it could be able to predict and training the forest fire fighters in a given environment.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.3
• /
• pp.1599-1605
• /
• 2014

This study aimed to identify the relationship between depression of the elderly and low back pain. Data were obtained from cross-sectional surveys conducted as a part of the Community Health Survey 2008. The final analysis included data from 3,647 of the 3,649 elderly participants (aged over 65 years), as 2 responses were excluded since they were inaccurate. Data were analyzed with SPSS for Windows (ver. 19.0), using a Rao-Scott ${\chi}^2$-test and Logistic regression by applying a proper weighting. The significance threshold was set as p<0.05. Factors related to the depression of the elderly were low back pain, subjective health status, average sleep duration. Further, depression score was 1.38 times higher in elderly adults with low back pain than elderly adults without low back pain. In order to decrease depression of the elderly with low back pain the development of a program to decrease activities of daily living discomfort and management of low back pain will need to be determined. It is considered necessary to conduct further study to follow through the analysis of the various variables by applying them to the elderly with low back pain and depression.

• Water Engineering Research
• /
• v.6 no.2
• /
• pp.39-48
• /
• 2005

The Brazos River is one of the longest rivers contained entirely in the state of Texas, flowing over 700 miles from northwest Texas to the Gulf of Mexico. Today, the Brazos River Authority and Texas Commission on Environmental Quality interest in drought protection plan, waterpower project, and allowing the appropriation of water system-wide and water right within the Brazos River Basin to meet water needs of customers like farmers and local civilians in the future. Especially, this purpose of this paper primarily intended to provide the data for the engineering guidelines and make easily geological mapping tool. In the Brazos River basin, many stream-flow gage station sites are not working, and they can not provide stream-flow data sets enough for development of the Probable Maximum Flood (PMF) for use in the evaluation of proposed and existing dams and other impounding structures. Integrated GIS-Spatial Interpolation (GIS-SI) tool are composed of two parts; (1) extended GIS technique (new making interface for hydrological regionalization parameters plus classical GIS mapping skills), (2) Spatial Interpolation technique using weighting factors from kriging method. They are obtained from the relationship among location and elevation of geological watershed and existing stream-flow datasets. GIS-SI technique is easily used to compute parameters which get drainage areas, mean daily/monthly/annual precipitation, and weighted values. Also, they are independent variables of multiple linear regressions for simulation at un gaged stream-flow sites. In this study, GIS-SI technique is applied to the Brazos river basin in Texas. By assuming the ungaged flow at the sites of Palo Pinto, Bryan and Needville, the simulated daily/monthly/annual time series are compared with observed time series. The simulated daily/monthly/annual time series are highly correlated with and well fitted to the observed times series.