• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.6
• /
• pp.215-220
• /
• 2014

Most of studies on wave height algorithms that are using at buoys describe algorithms using double integral to determine the position data from the acceleration data measured from the accelerometer. but sometimes, it can involve some cumulative error in that process, and result in misjudgment or unstabe system. On the other hand, It is widely known that the motion of fluid particles on or underneath a linear progressive wave is periodic and elliptic. This fact is considered in this article and leads a improved algorithms with no integral processing.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.5
• /
• pp.937-943
• /
• 2009

In this paper, the algorithm discriminating the existence and nonexistence of bolts and nuts using image processing in an automobile T-Bar influencing the vibration of a frame, is introduced. To distinct whether bolts and nuts exist or not, the features of bolts and nuts are learned, and then these feature values are matched using a statistical pattern matching algorithm. Furthermore, the minimum and maximum variation rate of pixel values are used since the matching rate is low with the large variation of pixel values of bolts and nuts in each image. The proposed method in this paper is very efficient in the automation of inspection requiring real time since the inspection time is significantly reduced compared with the conventional methods.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.12 no.4
• /
• pp.694-704
• /
• 1988

A recursive parameter estimation scheme utilizing the variance perturbation method is applied to the workpiece deflection model during CNC turning process, in order to improve the cylindricity of slender workpiece. It features that it is based on exponentially weighted recursive least squares method with post-process measurement of finish surfaces at two locations and it does not require a priori knowledge on the time varying deflection model parameter. The measurements of finish surfaces by using two proximity sensors mounted face to face enable one to identify the straightness, guide-way, run-out eccentricity errors. Preliminary cutting tests show that the straightness error of the finish surface due to workpiece deflection during cutting is most dominant. Identifying the errors and recursive updating the parameter, the off-line control is carried out to compensate the workpiece deflection error, through single pass cutting. Experimental results show that the proposed method is superior to the conventional multi-pass cutting and the direct compensation control in cutting accuracy and efficiency.

• Journal of the Korean Chemical Society
• /
• v.35 no.6
• /
• pp.713-719
• /
• 1991

Electrochemical impedance measurement system using Fourier transform was constructed in the range of the frequencies up to 100 kHz. This system consists of pseudo-random noise generator, specially designed potentiostat, fast data acquisition system, system controller, and computer interface. The performance of the constructed system was found to be almost same as the commercially available system using lock-in amplifier. Measuring time was significantly reduced because the minimum time for the measurement depended on one cycle of the lowest frequency used. It would be possible to study time-varying electrochemical impedance systems such as the initial stages of corrosion processes using this system.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.12 no.5
• /
• pp.55-60
• /
• 2012

Longitudinal transmission-line modal theory is applied to analyze maximum power transfer in plasmonic grating-assisted directional couplers (P-GADC) based on silicon waveguide. By defining a coupling efficiency amenable to rigorous analytical solutions and interference between even and odd modes, the power exchange of TE modes as a function of propagation distance is evaluated. The numerical result reveals that maximum power transfer occurs at a grating period ${\Lambda}_{eq}=10.26{\mu}m$, in which the insertion loss of supermodes is equal to each other. That is, it is generally different from conventional phase-matching condition or minium gap condition of GADC.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.8
• /
• pp.965-970
• /
• 2011

We develop a diagnostic system to monitor failures in an engine-assembly line. Existing techniques such as sensory analysis, time domain analysis, frequency analysis, and statistical analysis have limitations in the diagnosis of engine-assembly failure when there are abnormal vibration waveforms (crashing and damping signals) during the assembly. We use a wavelet technique to deal with crashing and damping signals. We also implement a new technique for developing diagnostic rules from sensor data, and we demonstrate its validity.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.1
• /
• pp.185-191
• /
• 2004

This article is concerned with cloth wearing system issues arising in the computer graphics. In particular, we study the issues of fabric drape properties for representing cloth wearing system. The convex points based on distance function are calculated to represent useful fabric drape properties. The information such as perimeter area, max and min point among convex point, the average distance between convex points are extracted. A strategy of a circularity based on the perimeter and area is considered for fabric drape property measurement. By experimental result, the circularity is most powerful factor to represent the drape property among the several characteristics. The measured drape properties will contribute to cloth wearing system development.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2001.05a
• /
• pp.532-536
• /
• 2001

In responding to rapid technological change, ITU standardization activities is changing. For example, ITU-T has established new approval process for technical Recommendations, named Alternative Approval Process. This process shortens standard approval period form 9 months to 2 months. In this paper, we analyze the new approval process, AAP, step by step. And finally, we discuss .ITU reform issues such as decision making right of private industry organizations which is ongoing.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2005.05a
• /
• pp.39-42
• /
• 2005

공간 데이터 웨어하우스 구축기는 소스 데이터의 변경 사항을 일괄처리의 형태로 공간 데이터 웨어하우스에 적재한다. 또한, 공간 데이터 웨어하우스 서버는 사용자의 질의에 빠른 응답을 하기위해 적재된 데이터로 색인을 구축한다. 색인을 구성하는 기존 기법으로는 벌크 삽입 기법 및 색인 전송 기법이 있다. 벌크 삽입 기법은 색인을 구성하기 위한 클러스터링 비용이 필요하며 검색 성능도 떨어진다. 또한, 색인 전송 기법은 주기적인 소스 데이터의 변경을 지원하지 않는다는 문제점이 있다. 본 논문에서는 이와 같은 문제점을 해결하기 위해 공간 데이터 웨어하우스에서 부분 색인 전송을 이용한 효율적인 색인 재구성 기법을 제안한다. 제안 기법은 구축기에서 색인의 구조에 맞게 클러스터링된 클러스터들을 부분 색인으로 구성하여 페이지 단위로 전송한다. 공간 데이터 웨어하우스 서버에서는 전송된 부분 색인의 물리적 사상 문제를 해결하기 위해 물리적으로 연속된 공간을 예약하고 예약된 공간에 부분 색인을 기록한다. 기록된 부분 색인은 공간 데이터 웨어하우스 서버에 있던 기존 색인에 삽입된다. 부분 색인이 기존 색인에 직접 삽입됨으로써 색인 재구성을 위한 검색, 분할, 재조정 비용은 최소가 된다.

• Journal of the Korean Chemical Society
• /
• v.35 no.5
• /
• pp.469-479
• /
• 1991

According to the recent paper by B. Fricke (J. Chem. Phys. 84, 862 (1986)), it is reported that the atomic polarizability (${\alpha}$) correlates very strongly with the first ionization potential (IP) within the groups of elements. In our study, we obtained very significant correlations between $ln\alpha$ and IP as well as lnIP by employing the least squares method. In examining the correlations of various atomic electronegativities with their first ionization potentials and the atomic polarizability within the groups of elements, good correlation coefficients are obtained except for groups 3a and 4a. Within the periods of elements, good correlation coefficients are obtained with no exception. This allows a very good prediction of various atomic polarizabilities undetermined.