• KCID journal
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• v.17 no.2
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• pp.28-34
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• 2010

This study re-exams hydrologic stability on spillway outlet capacity of agricultural reservoirs using hydrologic data with current rainfall condition instead of project hydrologic data applied at design on Backgok reservoir located in Chungbuk province. It is concluded that Backgok reservoir is not hydrologically stable and therefore structural measures including the extension of spillway and non structural measures should be taken. Continuous basic plan for river maintenance including additional bank reinforcement to bottom river shall be carried out. Due to high peak flood with more than 290% compared to 200 year frequency probability flood which was design standard of the past in view of the results of calculating PMF according to revised design standard for reservoirs, there could a problem for securing rationality in case of applying PMF with design flood. Therefore, hydrological stability, construction, and maintenance cost shall be synthetically studied and reasonal application shall be made if the decision is made on applying PMF with design flood.

• Korean Journal of Computational Design and Engineering
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• v.14 no.2
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• pp.87-95
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• 2009

This paper describes the design of the ossicular replacement prosthesis for the people who have problem of hearing because of middle ear disease. Also the simulation results of the designed product for verification by finite element analysis software (ABAQUS) are presented. New model is applied to middle ear FE analysis which was generated in previous study. The full replacements of ossicular prosthesis for ossicles (malleus, incus and stapes) are made of Hydroxyapatite and Titanium. Although other existing prosthesis models consider only sound amplification effect, current type has damper system which is operating on the audible frequencies. High frequency sound transmitted to inner ear can be reduced and the prosthesis and inner ear can be prevented from damage.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1992.10a
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• pp.2-29
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• 1992

According to the increase of occupation density of microwave frequency band on use microwave environments have been congested extensively. For shielding unnecessary electromagnetic wave of preventing the electromagnetic wave reflection a good conductor a low resistive material or a lossy material is mainly used. As a method to measure the absorbing characteristics of microwave absorber the fundamental microwave measuring method can be used. There is however a big problem in measuring errors since the wavelength of microwave is very short especially as in the case as microwave absorber for RADAR. Therefore this research aimed to a converting adaptor of 20mm${\Phi}$ coaxial tube from a Type-N connector to 20mm${\Phi}$ coaxial tube and to use it for designing microwave absorber and evaluating absorbing characteristics. Furthermore the measurements of absorbing characteristics and material constants have performed and reviewed which were carried out by using the coaxial tube in the short type and by using rectangular waveguide respectively As a result the validity of the measured values have been confirmed.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.671-675
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• 2000

In this study, an FRF-based structural damage identification method (SDIM) is proposed for plate structures. The present SDIM is derived from the partial differential equation of motion of the damaged plate, in which damage is characterized by damage distribution function. Various factors that might affect the accuracy of the damage identification are investigated. They include the number of modal data used in the analysis and the damage-induced modal coupling. In the present SDIM, an efficient iterative damage self-search method is introduced. The iterative damage search method efficiently reduces the size of problem by searching out and then by removing all damage-free zones at each iteration of damage identification analysis. The feasibility of the present SDIM is studied by some numerically simulated tests.

• 전기의세계
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• v.20 no.5
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• pp.15-18
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• 1971

Up to now, there have been numerous investigations about the effect of diffusion on the wave propagation in gaseous plasmas, but not so much in semiconductor magnetoplasmas. However, currently, it becomes the centor of interest to work with the latter problem, and this paper deals with the dispersion equation including diffusion effect in the latter case to see how diffusion affects the equation in which diffusion term is neglected in the first place, and the analysis is based on the assumption that the plasma can be treated as a hydrodynamical fluid, since, from a macroscopic view point, the plasma interacting with a magnetic field can be considered as a magneto-hydrodynamical fluid, an electrically conducting fluid subjected to electromagnetic force, and the system is linear. The results of the relation and computation show that in the non-streaming case the diffusion terms appear in the equation as perturbation terms and the amplitude of the wave vector changes parabolically with the variation of the angular frequency and the longitudinal modes are observed.

• Journal of Communications and Networks
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• v.16 no.5
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• pp.559-567
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• 2014

In this paper, a framework for power allocation of downlink transmissions in orthogonal frequency division multiple access-based decode-and-forward cellular relay networks is investigated. We consider a system with a single base station communicating with multiple users assisted by multiple relays. The relays have limited power which must be divided among the users they support in order to maximize the data rate of the whole network. Advanced power allocation schemes are crucial for such networks. The optimal relay power allocation which maximizes the data rate is proposed as an upper bound, by finding the optimal power requirement for each user based on knapsack problem formulation. Then by considering the fairness, a new relay power allocation scheme, called weighted-based scheme, is proposed. Finally, an efficient power reallocation scheme is proposed to efficiently utilize the power and improve the data rate of the network. Simulation results demonstrate that the proposed power allocation schemes can significantly improve the data rate of the network compared to the traditional scheme.

• The Korean Journal of Rehabilitation Nursing
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• v.1 no.1
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• pp.43-50
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• 1998

The literature review for fall in the elderly has been done for the better quality of life of increasing elderly people toward 21 st century. Because 30 to 50% of over sixty five years old persons have experiences of fall, five percent of the fallen have trauma such as bone fracture requiring hospitalization and three quarter of people who die as fall are over 65 year old, fall is important health problem of them. There are very little societal interest in and research related to fall. Therefore, among recent foreign and our literatures studying literature review of frequency of fall, risk factors and assessing method for tall, and the management of fall prevention program, I would like to find research direction. Conclusivelly, we should study extensively the survey of the elderly's fall and on the basis of it. developing fall prevention program, promote the elderly's health through fall prevention.

• Journal of Biomedical Engineering Research
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• v.17 no.2
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• pp.209-214
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• 1996

The display of biological signals in raster scan monitors often involves a multirate sampling operation which consists of decimation .and interpolation. All electroencephalouaphic (EEG) samples of 10 to 30 seconds (2, 500 to 7, 500 samples at 250[Hz] sampling frequency) must be displayed in the computer screen to keep the aspect ratio of the paper polygraph output. Since the current afrorclable display technology Plots at most 2, 000 Pixels Per row, sDme signal samples need to be discarde4 This Paper studies methods to perform this operation characterizing them from the signal processing viewpoint and compares the display quality among several decimation techniques. Experimental results show that a nonlinear operation such as the peak detection method could be preferable to the canonical linear filtering to reduce aliasing.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.4
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• pp.159-165
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• 2012

The accurate focusing position should be determined for accurate measurements In VMS. Camera lens focusing is an important problem in computer vision and video measuring systems (VMS) that use CCD cameras and high precision XYZ stages. Camera focusing is a very important step in high precision measurement systems that use computer vision technique. The auto focusing process consists of two steps, the focus value measurement step and the exact focusing position determination step. It is suitable for eliminating high frequency noises with lower processing time and without blurring. An automatic focusing technique is applied to measure a crater with a one-dimensional search algorithm for finding the best focus. Throughout this paper, the suggested algorithm for the Auto focusing was combined with the learning. As a result, it is expected that such a combination would be expanded into the system of recognizing voices in a noisy environment.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.190-190
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• 2000

This paper presents a multirate state feedback control (MRSFC) method for systems sensitive to disturbance and noise based on the multirate estimator design using the current estimator. MRSFC updates the controller output slower than the measurement sampling frequency of system output by a lifting factor R=T$\sub$c//T$\sub$s/. The closed-loop MRSFC system is less sensitive to disturbance and noise due to filtering effect than the conventional single-rate control system. The multirate estimator gain is obtained from solving a conventional pole placement problem such that MRSFC has the same spectrum of eigenvalues in the s-plane as the single-rate control. We applied the proposed multirate state feedback controller to a galvanometer servo system. Simulation and experimental results show that settling and tracking performances are improved compared with a conventional single-rate pole placement control (PPC).