• Structural Engineering and Mechanics
• /
• v.23 no.1
• /
• pp.75-95
• /
• 2006

Two-step identification approaches for effective bridge health monitoring are proposed to alleviate the issues associated with many unknown parameters faced in real structures and to improve the accuracy in the estimate results. It is suitable for on-line monitoring scheme, since the damage assessment is not always needed to be carried out whereas the alarming for damages is to be continuously monitored. In the first step for screening potentially damaged members, a damage indicator method based on modal strain energy, probabilistic neural networks and the conventional neural networks using grouping technique are utilized and then the conventional neural networks technique is utilized for damage assessment on the screened members in the second step. The effectiveness of the proposed methods is investigated through a field test on the northern-most span of the old Hannam Grand Bridge over the Han River in Seoul, Korea.

• Journal of Biomedical Engineering Research
• /
• v.2 no.2
• /
• pp.103-108
• /
• 1981

In this paper, the reaction time and the accuracy of saccade eye movement are measured by using random pulse and periodic pulse, random pulse step and periodic pulse step through the subject utilizing the infra-red method.

• Archives of Pharmacal Research
• /
• v.12 no.4
• /
• pp.254-256
• /
• 1989

Synthesis of spiro 1, 4-dihydropyridines by a novel and facile one step method is reported. Structures and reaction are also reported with a support by another synthetic routes.

• Economic and Environmental Geology
• /
• v.26 no.3
• /
• pp.421-429
• /
• 1993

Dissolution reactions of chemical grade zinc sulfide and natural sphalerite were studied in ferric chloride solution as an oxidant. To enhance the leaching reaction, ultrasonic technique was employed in this investigation. For the reaction with pure zinc sulfide, chemical reaction was the rate limiting step in the range of low conversion irrespective of applying ultrasonic wave. And the diffusion through liquid film instead of diffusion through product layer of free sulfur was the rate determining step because ultrasonic vibration removes the product from reaction zone. In the case of sphalerite with the ultrasonic vibrator, it was found that inert mineral layer diffusion was the rate determining step, in which the elemental sulfurs formed were removed by the ultrasonic action. Experimental results showed that the ultrasonic technique proved to be the methods which can significants improve the leaching performance.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.58 no.4
• /
• pp.748-755
• /
• 2009

This paper proposes a 18-step back-to-back voltage source converter using four sets of 3-Level converter module with auxiliary circuit to increase the number of steps. The proposed back-to-back voltage source converter has an independent control capability of active power and reactive power at the interconnected ac system. The operational feasibility of proposed system was verified through computer simulations with PSCAD/EMTDC software. The feasibility of hardware implementation was verified through experimental results with a scaled hardware model. The proposed back-to-back converter can be widely applied for interconnecting the renewable energy source to the power grid.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.24 no.6
• /
• pp.1074-1079
• /
• 1987

We present a fast, constructive algorithm for the automatic placement of standard cells, which consists of two steps. The first step is responsible for cell-row assignment of each cell, and converts the circuit connectivity into a multi-stage graph under to constraint that sum of the cell-widths in each stage of the multi-state graph does not exceed maximum cell-row width. Generatin of feed-through cells in the final layout was shown to be drastically reduced by this step. In the second step, the position of each cell within the row is determined one by one from left to right so that the cost function such as the local channel density is minimized. Our experimental result shows that this algorithm yields near optimal results in terms of the number of feed-through cells and the horizontal tracks, while running about 100 times faster than other iterative procedures such as pairwise interchange and generalized force directed relaxation method.

• Journal of Electrical Engineering and Technology
• /
• v.5 no.3
• /
• pp.435-442
• /
• 2010

This paper proposes an 18-step back-to-back (BTB) voltage source converter using four sets of 3-Level converter modules with auxiliary circuits to increase the number of steps. The proposed BTB voltage source converter has the independent control capability of active power and reactive power at the interconnected ac system. The operational feasibility of the proposed BTB converter was verified through many simulations with PSCAD/EMTDC software. The feasibility of hardware implementation was verified through experimental results with a scaled hardware prototype. The proposed BTB converter could be widely applied for interconnecting the renewable energy source to the power grid.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.03a
• /
• pp.490-495
• /
• 2009

In this study, estimate solution of ultimate axial capacity for axial loaded pile is proposed using step-wised shape. This is verified for effective appling on realistic factor by calibration chamber tests. Estimation method of ultimate axial capacity in this study is verified by calibration chamber test. The results of ultimate axial capacity through this proposed method have sufficiently low standard derivations and COVs. Also, this is verified through test that method is similarly resulted with measured values.

• Food Science of Animal Resources
• /
• v.43 no.2
• /
• pp.374-381
• /
• 2023

In a previous study, 'response surface methodology (RSM) using a fullest balanced model' was proposed to improve the optimization of food processing when a standard second-order model has a significant lack of fit. However, that methodology can be used when each factor of the experimental design has five levels. In response surface experiments for optimization, not only five-level designs, but also three-level designs are used. Therefore, the present study aimed to improve the optimization of food processing when the experimental factors have three levels through a new approach to RSM. This approach employs three-step modeling based on a second-order model, a balanced higher-order model, and a balanced highest-order model. The dataset from the experimental data in a three-level, two-factor central composite design in a previous research was used to illustrate three-step modeling and the subsequent optimization. The proposed approach to RSM predicted improved results of optimization, which are different from the predicted optimization results in the previous research.

• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.313-315
• /
• 2005

In a power system, an out-of-step condition causes a variety of risk such as serious damage to system elements, tripping of loads and generators, mal-operation of relays, etc. Therefore, it is very important to detect the out-of-step condition and take a proper measure. Several out-of-step detection methods have been employed in relays until now Mo,;t common method used for an out-of-step detection is based on the transition time through the blocking impedance area in R-X diagram. Also, the R-R dot out-of- step relay, the out-of-step prediction method and the adaptive out-of-step relay using the equal area criterion (EAC) and Global Positioning Satellite (GPS) technology have been developed. This paper presents the out-of-step detection algorithm using the time variation of the complex power. The complex power is calculated and the mechanical power of the generator is estimated by using the electrical power, and then the out-of-step detection algorithm, which is based on the complex Power and the estimated mechanical power, is presented. This algorithm, may detect the instant when the generator angle passes the Unstable Equilibrium Point (UEP). The proposed out-of-step algorithm is verified and tested by using Alternative Transient Program/Electromagnetic Transient Program (ATP/EMTP) MODELS.