• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.736-740
• /
• 2007

It is not always convenient to consider isotropic meshes where the edge length depends on the orientation of the edge. It is desirable to go for anisotropic mesh strategy instead. There are many instances where the solution shows directional features such as great variations along certain directions with less significant changes along other ones. Anisotropic meshes considered to be worthy in these cases. By using anisotropic elements we can resolve the solution accurately with few elements. Many techniques have been used as a common feature that the shape, size and orientation of the triangle elements are controlled by specifying metric tensor. This paper attempts at clear understanding of the estimation and equidistribution of the error and discusses the parameters like reliability and effectivity of an anisotropic mesh in a mathematical manner. Also we study some of applications of anisotropic mesh.

• Journal of the Korean Society for Railway
• /
• v.2 no.3
• /
• pp.46-53
• /
• 1999

In this paper, made was a study on a mesh generation method based on the pollution error. This method is designed for the control of the pollution error in any patch of elements of interest. It is a well-known fact that the pollution error estimates are much more than the local one. When the pollution error is significant, nothing can be said about the reliability of any estimator based on local computations in the patch. Reliable a posteriori error estimation is possible by controlling the pollution error in the patch through proper design of the mesh outside the patch. This design is possible by equally distributing the pollution error indicators over the mesh outside the patch. The mesh generated from the conventional feedback pollution-adaptive mesh generation algorithm needs many iterations. Therefore, the solution time is significant. But the remeshing scheme in the proposed method was used here. It was shown that the pollution-adaptive mesh improves the E.I., simply denoted as Effectivity Index, on the patch of interest, and the pollution error reduces less than the local error.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.54 no.5
• /
• pp.251-258
• /
• 2005

Recently, the domestic and foreign power trends are the supply of high quality power and environment conservation technology based on the new energies development. So, the dispersed generation systems, such as photovoltaic, fuel cell, and battery are to be introduced in distribution systems. According to the situation change, power of high Quality and reliability are required in distribution systems with dispersed generation. Up to now, the voltage in distribution systems are regulated by ULTC of substation and pole transformer of primary feeders. These days, Step Voltage Regulator(SVR) is getting established at distribution feeders to regulate effectively voltage of primary ffeders that voltage drop exceeds $5\%$. But, because SVR is operated independently with ULTC of substation, SVR can not take play to its full effectivity. Under these circumstances, in order to deliver suitable voltages to as many customers as possible, new optimal voltage regulation algorithms are required in distribution system. So, this paper presents optimal voltage regulation algorithm to regulate voltage effectively for ULTC and SVR in distribution systems with dispersed generation systems.

• Journal of Haehwa Medicine
• /
• v.18 no.1
• /
• pp.19-28
• /
• 2009

Objectives: This study was conducted to help clinical studies for treating Functional Dyspepsia with acupuncture. We inspected tendency of studies of acupuncture treatment for functional dyspepsia and analyzed the assessing instrument for it by scrutinizing Pubmed recent publications. Materials and Methods: We inspected 8 theses and scrutinized their objectives, periods, participants, materials and methods, the instrument of assessment for the studies, and criteria and symptom score for questionaire, results and JADAD score. Results: 1. Most studies were published by oriental doctors except one which was published by an American doctor. More and more studies are being published in America and written in English recently. So it is considered that western doctors think that the acupuncture treatment is useful as unorthodox medicine for functional dyspepsia. 2. Among the 4 clinical studies, 2 studies were RCT and 1 study was not RCT and 1 study with vagueness. All 4 clinical studies were not double-blinded because they were about comparison between acupuncture treatment and medicine. 3. ST36, PC6, CV12, BL21 were chiefly used, and auricular point, ST40, SP6 were also used. Manual acupuncture were used in 2 studies, and low frequency pulse and electroacupuncture were used in other studies respectively. 4. 4 clinical studies used 0~3 points symptom score as the instrument of assessment. Additional assessments were on gastric emptying time, EGG and plasma level of motilin. All thesis were not verified of validity and reliability. 5. Among the 4 reviewed thesis, 2 theses were about acupuncture as one of the various treatment of functional dyspepsia, and the other 2 theses were about efficacy of acupuncture treatment. And the result generally showed effectivity of acupuncture treatment. Conclusion: Acupuncture treatment for functional dyspepsia is considered useful as in unorthodox medicine by western doctors, and it is necessary to provide objective instrument for assessing acupuncture treatment for functional dyspepsia.