• Proceedings of the KSME Conference
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• 2003.04a
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• pp.503-506
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• 2003

In general, the reinforcement of a structure is performed with cylinders. In this study, it is attempted to compare the safety Circular reinforcement with 4 fins and Honey-comb at the equal mass. Circular reinforcement with 4 fins have two kind of the models One has no hole in the upper and lower plates. The other has holes, and it is divided by 3 cases. And the maximum stress is investigated for the circular reinforcement with 4 fins and Honey-comb. The results shows that honey-comb is more strength than the others. And reinforcement with 4 fins of hole case2's maximum stress is 82% by compare 10 honey-comb.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.848-853
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• 2001

Electrostatic actuation was adopted for ease of fabrication. We proposed a new driving scheme that uses the vector sum of force generated by comb-finger and by parallel plate. The moving and fixed electrodes are arranged to maximize the driving force. In this paper, an electrostatic field analysis is performed by Maxwell analysis tool for micro actuators. From the analysis, a comb-parallel type micro-actuator with 4${\mu}{\textrm}{m}$ width, 6${\mu}{\textrm}{m}$ overlap and 45${\mu}{\textrm}{m}$ height could be designed. In order to compare the new type of actuator with the conventional comb type of actuator, we arranged that both types have the same area and the same number of actuators. To make a high aspect ratio structure, we are developing fabrication process using SU-8 and electro-plating.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.535-538
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• 2002

We simulated Frequency-shifted feedback laser using AOM inside the cavity. We analyze instantaneous oscillation frequency at peak spectral intensity and Comb bandwidth of output spectrum from Wigner-Ville distribution of intracavity electric field. The Comb bandwidth is defined as the product of the saturation-broadened bandwidth and the total resonant modes contributing to FSF operation.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.8
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• pp.368-374
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• 2002

In this paper, we introduce a procedure to obtain a equivalent circuit of comb-line band pass filter. By employing equivalent circuits of each asymmetrical coupled line. we composed the full equivalent circuit of comb-line bandpass filter and derived simple design equations for extracting each line's impedance. To show the validity of design equations, we simulated and fabricated a planar type comb-line bandpass filter, which has center frequency 1.8㎓, band-width 50㎒ and four resonators. The resulting filter is very compact, have broad stop band with the second pass band centered at four times the center frequency of the first pass band. The experimental results show exact performances of design specification.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.965-970
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• 2010

Because of a large number of subcarriers, the high PAPR(Peak-to-Average Power Ratio) is the major drawback of NC-OFDM system used for wireless communication system. Comb type pilot assignment is more efficient and lower computational complexity for the channel estimation than the block type pilot. However, even if the CAZAC(Constant Amplitude Zero Autocorrelation) matrix transform is used for the PAPR reduction of the data symbols, PAPR increases when the pilot is inserted in comb type with the data symbols. Therefore, in this paper, we additionally use a new SLM technique in order to lower the PAPR again even in the comb type pilot. Also, a new SLM technique suggested in this paper does not need any additional bandwidth for sending selection information for SLM. This combined method has good PAPR reduction performance and efficient data transmission.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.6 s.324
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• pp.9-15
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• 2004

In MIMO-OFDM systems, conventional channel estimation techniques using comb type training symbols give relatively large mean squared errors(MSEs) at the edge subcarriers. To reduce the MSEs at these subcarriers, a cyclic comb type training structure is proposed. In the proposed cyclic training structure, all types of training symbols are transmitted cyclically at each antenna. At the receiver, the channel frequency responses that are estimated using each training symbol are averaged with weights obtained from the corresponding MSEs. Computer simulations showed that the proposed cyclic training structure gives more SNR gain than the conventional training structure.

• The Journal of Fisheries Business Administration
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• v.47 no.3
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• pp.15-33
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• 2016

This study aims to analyze effectiveness of the resource use under the total allowable catch system (TACs) of Comb pen shell, a species among TAC targeting ones through its stock assessment based on the surplus production model such as the Clark Yoshimoto Pooley (CYP) model. Particularly, this study is separated into five analysis periods in order to understand changes in Comb pen shell resource and its efficient use after TAC system implemented in 2001. The results of this study are as follows. First, five sustainable yield curves (SYCs) and exponential growth functions (EGFs) produced by the surplus production model based on Gompertz growth function to compare before and after implementation of the Korean TAC system show that the TAC system has generated a positive stock rebuilding effect for Comb pen shell caught by the diver fishery since 2001. Secondly, five profits based on differences between the sustainable total revenue (STR) and the total cost (TC) with respect to fishing efforts present that the TAC system has increased efficiency of resource use of Comb pen shell caught by the diver fishery after implementation of the Korean TAC system. In conclusion, the Korean TAC system has increased efficiency of resource use as well as has led a positive stock rebuilding effect for Comb pen shell.

• Journal of Life Science
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• v.19 no.1
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• pp.52-57
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• 2009

This study was carried out to investigate the antioxidative and antimicrobial activities of Celastrus orbiculatus (CO). CO was extracted with methanol and then further fractionated with n-hexane (COMH), butanol (COMB), methanol (COMM) or aqueous (COMA) to get active fractions. The antioxidative activity of fractions from CO was investigated by measuring the scavenging activities of CO against DPPH radical, peroxynitrite ($ONOO^-$) and reactive oxygen speicies (ROS). Among the various solvent fractions, the COMB showed a marked scavenging effect against DPPH radical, peroxynitrite ($ONOO^-$) and reactive oxygen species(ROS). The antimicrobial activity was increased in proportion to its concentration by the paper disk method. Among the various solvent fractions, the COMM and COMB fractions of CO showed strong antimicrobial activities. The results suggest that The CO may be suitable for development as a food preservative and alternative antioxidant.

• Journal of IKEEE
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• v.18 no.1
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• pp.19-24
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• 2014

We report stable, wideband, flat-topped, 10 GHz optical frequency comb generation from a semiconductor-based mode-locked ring laser with an intra-cavity high finesse Fabry-Perot etalon. We demonstrate a stable 10 GHz comb with greater than 200 lines within a spectral power variation below 1 dB, which is the largest value obtained from a similar mode-locked laser in our knowledge. Greater than 20 dB of the spectral peak to deep ratio at 0.02 nm resolution, ~92 femtosecond timing jitter over 1 kHz to 1 MHz range, and non-averaged time traces of pulses confirm very stable optical frequency comb lines.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.6
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• pp.124-131
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• 2008

There are many factors which affect the acoustical properties of a micro-speaker. Among the factors, the shape of the diaphragm is considered in this study. As an investigating method, the finite element methods and measurement techniques applied to study the acoustical properties according to diaphragm shape. In order to vary the stiffness of the diaphragm, the some patterns of comb teeth, such as the angle and the number of comb teeth, are applied to diaphragm. We can confirm that the change of the stiffness by the changing diaphragm shape affects the vibration and sound properties of the speaker. As a result, the reduction of the angle of the comb teeth increases the diaphragm stiffness and shifts the resonance frequency to a higher frequency range. The number of the comb teeth is related to the stiffness of the edge part.