• Proceedings of the Korean Geotechical Society Conference
• /
• 2002.10a
• /
• pp.259-264
• /
• 2002

In this study the shear strengths of a poorly grad ed rock material(d/sub max/≤50.8mm, C/sub u/=1.86) were determined by large direct shear test and large triaxial test. The obtained stress-strain curves by the above large shear tests for the rock materials are similar to the loose sand's or normally consolidated clay's curve, in which the peak strength does not appear obviously. And for the uniformly graded rock material the shear strength by large direct shear test may be overestimated around 1.54∼1.70 times that of large triaxial test.

• Wind and Structures
• /
• v.22 no.6
• /
• pp.635-662
• /
• 2016

This paper deals with the comparison of different control strategies for the Induction generators in wind energy conversion system. Mainly, two types of induction machines, Self excited induction generator (SEIG) and doubly Fed Induction generators (DFIG) are studied. The different control strategies for SEIG and DFIG are compared. For SEIG, Electronic load Controller mechanism, Static Compensator based voltage regulator are studied. For DFIG the main control strategy namely vector control, direct torque control and direct power control are implemented. Apart from these control strategies for both SEIG and DFIG to improve the performance, the ANFIS based controller is introduced in both STATCOM and DTC methods. These control methods are simulated using MATLAB/SIMULINK and performances are analyzed and compared.

• 한국전기화학회:학술대회논문집
• /
• 2002.07a
• /
• pp.203-206
• /
• 2002

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2004.11a
• /
• pp.302-303
• /
• 2004

• Fashion & Textile Research Journal
• /
• v.6 no.5
• /
• pp.625-633
• /
• 2004

A comparison between the body types of Korean and Mongolian women was made and analyzed to provide a foundation for securing the Mongolian fashion market. 404 adults within the 18 to 24 age group were studied. From the results of comparing 27 items of direct anthropometric measurements, 15 items were shown to have significant differences. Mongolian women were larger in values for 13 items than were Korean women except two items, which are back waist length and arm length. From the results of comparing 25 items of index values, 19 items were shown to have significant differences. The comparison of the anatomical proportions showed that the lower half of Mongolian women's bodies were longer and their shoulder and hips were wider than those of Korean women. Based on these direct anthropometric measurements and index values, Korean and Mongolian women were categorized into 4 Types; Type 1 is average body type with tall height and longer lower half of the body. Type 2 is slimmer body type with average height. Type 3 is average body type with shorter height. Lastly, type 4 is obese body type with average height.

• Tribology and Lubricants
• /
• v.14 no.1
• /
• pp.23-27
• /
• 1998

The characteristics of friction in direct acting OHC vane train system have been investigated by the comparison of experimental and theoretical results. A modified friction model was presented to calculate the friction force at cam/tappet contact. A simple experimental system was evaluated to measure the friction force and the camshaft driving torque. The friction force was measured by using the dynamic loadcell. Good agreement was found between theoretical and experimental results in friction force, but there was a little difference in driving torque.

• 제어로봇시스템학회:학술대회논문집
• /
• 1987.10a
• /
• pp.851-856
• /
• 1987

A direct computation algorithm of two dimensional fast Fourier transform (2D-FFT) is considered here for implementation in mesh connected multiprocessor array of both a 2D-toroidal and a rectangular type. Results are derived for a hardware algorithm including data allocation and interprocessor communications. A performance comparison is carried out between the proposed direct 2D-FFT computation and the conventional one to show that a new algorithm gives higher speedup under a reasonable assumption on the speeds of operations.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 1999.10a
• /
• pp.155-161
• /
• 1999

Many direct integration methods have been developed for dynamic analysis of structures, In order to compare each other methods and give guideline for selecting a time increment the amplification matrix is constructed according to algorithm of each method and stability and accuracy analysis is done. Four story shear building under external excitations is analyzed by each method and the RMS errors of displacements of top floor and compared with each other.

• Journal of the Korean Society of Safety
• /
• v.16 no.3
• /
• pp.111-116
• /
• 2001

This study is conducted to review the ratio of direct and indirect cost accompanied by industrial accident in construction sites. It is surveyed that how to use safety cost in construction work is most efficient in comparison with several items of safety cost through the regression analysis.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.10
• /
• pp.15-20
• /
• 2013

In this paper, wireless power transfer system using the magnetic resonance was designed and applied to LED lighting for implementation of wireless lighting. This lighting was made by the converted DC driving type and the direct AC driving type. In the former, transferred AC power was rectified into DC and regulated to the specified voltage value, which leads to produce the loss at the rectifying and regulating circuit. In the latter, wireless-transferred AC power was directly applied to LED, which get rid of the loss derived from the additional circuit. For the efficiency-comparison between the former and the latter, the power at each stage was measured when the same optical output radiated from LED lighting part. The result revealed that the direct AC driving type had 18% higher efficiency than the DC driving type and confirmed that LED lighting using magnetic resonance wireless power transfer system can be efficient by direct AC power supply. And the direct AC driving type had the simple circuit structure and the simple LED lighting formation, so this can leads to various application.