• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.25 no.1
• /
• pp.24-26
• /
• 2014

Aging causes a variety of changes in the structure of the vocal fold (VF), resulting in aging-induced dysphonia (presbyphonia). Several studies have investigated the structure of the VF of elderly people from autopsy as well as animal studies. There is an increasing evidence on correlation of structural changes of VF with deteriorated voice in elderly. Although the cellular mechanisms of aging VF have only partially been elucidated, there are many recent advances in biological treatment on aging VF using bioactive molecules such as growth factors. In this study, I'd like to address aging-related structural, biological, and physiological changes in previous literature about human and rodent aging VFs, to provide further insight into the mechanisms responsible for presbyphonia and to translate the basic researches for future clinical trials.

• Journal of IKEEE
• /
• v.13 no.2
• /
• pp.175-180
• /
• 2009

This paper compare the operation characteristic and optimal design of Photovoltaic system by computer simulation. The operation characteristic of Photovoltaic system are evaluated and analyzed considering system parameters of specifications, installations, inclination, azimuth and surrounding conditions etc. From the basis of these results, this study will intend to develop an evaluation, analysis tool and construct database for optimal design of PV system.

• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.10
• /
• pp.911-916
• /
• 2015

In the nano/micro scale, material properties are dependent on the size-scale of a structure. However, conventional micro-scale tensile tests have limitations to obtain reliable values of nano-scale material properties owing to residual stress and elastic slippage in the gripping/aligning process. The indenter-driven nano-scale tensile test provides prominent advantages simple testing device, high-quality nano-scale metallic specimen with negligible residual stress. In this paper, two-types of specimens (a specimen with multi-testing parts and a specimen with a single-testing part) are discussed. Focused ion beam (FIB) is employed to fabricate a nano-scale specimen from a thin nickel film. Using the specimen with a single-testing part, we obtained a nano-scale stress-strain curve of electroplated nickel film.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.11
• /
• pp.2142-2144
• /
• 2015

3D FLS is a active sonar that can represent the underwater inside visually in forward direction. We discuss on the decrease of bubbles from breaking waves in 3D FLS frames. In the experiment using the bubbles reduction filter the effect of bubbles was decreased a lot.

• Transactions of Materials Processing
• /
• v.7 no.5
• /
• pp.474-480
• /
• 1998

In the present study a domain decomposition scheme using the substructuring method is developed for the computational efficiency of the finite element analysis of metal forming processes. in order to avoid calculation of an inverse matrix during the substructuring procedure, the modified Cholesky decomposition method is implemented. As obtaining the data independence by the substructuring method the program is easily paralleized using the Parallel Virtual machine(PVM) library on a work-station cluster connected on networks. A numerical example for a simple upsetting is calculated and the speed-up ratio with respect to various number of subdomains and number of processors. The efficiency of the parallel computation is discussed by comparing the results.

• Journal of the Korean Chemical Society
• /
• v.49 no.3
• /
• pp.292-299
• /
• 2005

• Proceedings of the Korea Information Processing Society Conference
• /
• 2006.05a
• /
• pp.521-524
• /
• 2006

인터넷 사용의 급증과 함께 Code-Red나 Slammer와 같은 웜이 급격히 확산 되고 있으며 네트워크를 통해 스스로 전파되면서 네트워크 자원을 고갈시킴으로써 문제가 더욱 심각해지고 있다. 이에 따라 웜을 탐지하기 위한 많은 방법들이 제시되었다. 본 논문에서는 DoS 탐지를 위해 고안 된 트래픽 비율 분석법을 이용하여 정상 네트워크와 웜이 발생 시키는 스캐닝 관련 행위에 대한 패킷 비율을 비교하였다. 이 방법을 통해 네트워크 내에서 웜에 감염된 호스트를 찾아내고 오탐지율을 최소화하는 방법과 웜 전파 행위를 탐지해 내는 방법에 대해서 제안한다. 또한 실제 네트워크에서 수집된 트래픽으로부터 웜의 특성을 분석해 본 결과 최근 웜들의 전파방식을 분석 할 수 있었다.

• Journal of the Korean Applied Science and Technology
• /
• v.15 no.3
• /
• pp.47-53
• /
• 1998

The polyimide film surface was modified with KOH aqueous solutions or sulfuric acid. The film thickness was increased by about 10% through the modification of film surface. Hydrolysis of amide bonds and hydration of water induced the increase. The polarity of the film surface increased and identified by contact angle measurement. The depth and roughness of modified was increased. After treatment of surface with water, alkyl and 4-pentyloxyaniline were introduced on the film surface by complex formation between anionic species formed on the imide surface and ammonium ion. The newly introduced alkyl group was identified by FT-IR spectroscopy. Surface polarity reduced dramatically and the roughness was increased after introduction of ammonium salt.

• Proceedings of the KIEE Conference
• /
• 1990.11a
• /
• pp.121-124
• /
• 1990

In this paper, we study the electrical conduction mechanism in Langmuir-Blodgett(LB) ultra thin films. The LB device was a metal/LB films/metal sandwich structure, where metal is electrode. In our experiments, the temperature depend on the current at above $0^{\circ}C$. This phenomena show that the electrical conduction current is a schottky current inherent to LB ultra thin films.

• Journal of electromagnetic engineering and science
• /
• v.3 no.1
• /
• pp.29-34
• /
• 2003

In this paper, we fabricated an 1.8 ㎓ differential VCO using a commercial 0.5 ${\mu}{\textrm}{m}$ SiGe BiCMOS process technology, The fabricated VCO consumes 16 ㎃ at 3 V supply voltage and has a 1.2 $\times$ 1.6 $mm^2$TEX>chip area. A phase noise measured at 100 KHz offset carrier is -110 ㏈c/Hz and a tuning range is 1795 MHz~1910 MHz when two varactor diodes are biased from 0 V to 3 V.