• Journal of Korea Technology Innovation Society
• /
• v.8 no.1
• /
• pp.116-134
• /
• 2005

This paper investigates the relationships between export and firm characteristics, focusing on technology factors. It is based on a longitudinal data covering listed firms in the Korean manufacturing industry. A regression model for the determinant of export/sales ratio including dynamic adjustment process is tested on a cross-section sample of the year 2001. Empirical findings suggest that there is no significant relationship between export/sales ratio and firm's technological level. The hypotheses concerning human capital intensity and physical capital intensity are also rejected. But we found a positive and inversely U-shaped relationship between firm size and export/sales for basic material and capital good industry. As a dynamic aspect, we found that the pattern of export/sales ratio changed unstably over the last decade. Finally, some policy implications are presented.

• Journal of Biosystems Engineering
• /
• v.14 no.1
• /
• pp.8-15
• /
• 1989

Agricultural materials do not react in a purely elastic manner, and their responses when subjected to stress and strain are appeared from a combination of elastic and viscous behavior. Various researchers have studied the mechanical and rheological properties of the many agricultural materials, but those properties are available mostly foreign varieties of agricultural products. Rheological properties of rice seedlings become important to formulate the principles governing their mechanical behavior. The objectives of this study were to experimentally determine the stress relaxation properties of rice seedlings such as three Japonica-type and one Indica ${\times}$ Japonica hybrid in the transplanting age. The results of this study are summarized as follows; 1. The stress relaxation behavior could be described by the generalized Maxwell model. 2. The phenomenon of stress relaxation happened abruptly just after loading and this phenomenon weakened with the loading time lapsed. 3. With increase of the initial stress, the stress relaxation intensity and residual stress increased, while the relaxation time was constant with increased, while the relaxation time was constant with increase of the level of initial stress. 4. With increase of loading rate, the stress relaxation intensity increased, while the relaxation time and residual stress decreased.

• Journal of Nutrition and Health
• /
• v.33 no.6
• /
• pp.668-674
• /
• 2000

This study was to examine effects of the eight month exercise program at lactate threshold level intensity on 11 women patients of ischemic heart disease. The %body fat and systolic blood pressure were decreased and the aerobic capacioties of oxygen consumption as well as oxygen consumption at lactate threshold were improved through the exercise program arranged by this study. The lipid variables concerned with coronary heart disease were changed a little except that triglyceride was significantly decreased during the exercise program. The effects obtained from exercise program during four months lasted to the end of the exercise program. In case we control the exercise intensity according to increase of oxygen consumption at lactate threshold the exercise program conducted by this study will be effective to the treatment for ischemic heart disease patients.(Korean J Nutrition 33(6) . 668~674, 2000)

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.17 no.1
• /
• pp.35-41
• /
• 2017

We propose a novel multi-photodiode array (MPDA) based retinal implant IC with on/off stimulation strategy for a visual prosthesis with improved spatial resolution. An active pixel sensor combined with a comparator enables generation of biphasic current pulses when light intensity meets a threshold condition. The threshold is tuned by changing the discharging time of the active pixel sensor for various light intensity environments. A prototype of the 30-channel retinal implant IC was fabricated with a unit pixel area of $0.021mm^2$, and the stimulus level up to $354{\mu}A$ was measured with the threshold ranging from 400 lx to 13120 lx.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.99.3-99
• /
• 2001

In fluorescence mode confocal scanning microscope, level of detected signal is very low. In object scanning type confocal scanning microscope, the additional optical system with objective lens and plane mirror was proposed to increase signal intensity, but there was none for beam scanning type confocal scanning microscope. We propose reflecting optical systems which improve signal intensity in beam scanning type confocal scanning microscope. We choose one of the proposed optical systems and design the optical system, i.e., select optical components and assign distances between the selected components. To design the optical system, we use finite ray tracing method and make cost function to be minimized.

• 한국전산유체공학회:학술대회논문집
• /
• 2010.05a
• /
• pp.242-246
• /
• 2010

To determine the trajectories and the impact of rain drops on the facade of a tall building, a particle tracking method is employed form steady state simulation of turbulent flow around the building. The simulation is performed for the upper part of the building comprising a detailed louver system. Rain is trapped at relative high rates on the roof and the penthouse, with Local Intensity Factors (LIF's) of the order of 1. The upper parapets and upper floors get a fair amount of wetting with LIF's of the order of 0.6. The wetting decreases downwards reaching values of 0.2 to 0.25 at the level of the louver system.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1998.03a
• /
• pp.316-322
• /
• 1998

Super precision working technique and machine tool have been developing continually thanks to advanced electronic field. To obtain good result. it is necessary to investigate surface state in grinding with ${\mu}{\textrm}{m}$ level. There were so many researches to satisfy these demands using non-contact methods through the computer vision. In this study, the texture of working surface was analyzed. cooccurrence matrice was obtained from the surface roughness. Texture parameter was obtained by means of position operator compose of $\theta$. d according to variation of angle direction and distance. As a result, it was found that surface texture was more effected by direction ($\theta$) then distance(d).

• Journal of KSNVE
• /
• v.6 no.6
• /
• pp.843-849
• /
• 1996

Locations and emission characteristics of noise source of motor vehicles are great important factors to control the road traffic noise in effective ways. From results of this study on emission characteristics of engine and exhaust noise, we could find that every noise emission of different kind of vehicles has smilar pattern. The main emission locations of engine noise for the front of vehicle became the space between the road surface and bottom of the body and radiator grill, and for the side of vehicle became the space between the road surface and bottom nearby the front wheel. In case of exhaust noise of passenger-car and light truck, all the highest sound intensity level located near surface of road. But it is hard to conclude the height of noise source of driving vehicles with only results of this study. So further studies are needed to check the emission characteristics of noise.

• Phonetics and Speech Sciences
• /
• v.6 no.3
• /
• pp.165-169
• /
• 2014

Intelligibility of speech transmitted to listeners can significantly be degraded in noisy environments such as in auditorium and in train station due to ambient noises. Noise-masked speech signal is hard to be recognized by listeners. Among the conventional methods to improve speech intelligibility, consonant-vowel intensity ratio (CVR) approach reinforces the powers of overall consonants. However, excessively reinforced consonant is not helpful in recognition. Furthermore, only some of consonants are improved by the CVR approach. In this paper, we propose the corrective weighting (CW) approach that reinforces the powers of consonants according to syllable-type such as consonant-vowel-consonant (CVC), consonant-vowel (CV) and vowel-consonant (VC) in Korean differently, considering the level of listeners' recognition. The proposed CW approach was evaluated by the subjective test, Comparison Category Rating (CCR) test of ITU-T P.800, showed better performance, that is, 0.18 and 0.24 higher than the unprocessed CVR approach, respectively.

• Carbon letters
• /
• v.8 no.4
• /
• pp.292-298
• /
• 2007

In order to investigate functional groups on the surface of Multi-walled Carbon Nanotubes (MWCNTs) induced by oxyfluorination, XPS (X-ray photoelectron spectroscopy) analysis was carried out. All core level spectra of MWCNTs were deconvoluted to several Pseudo-Voigt functions (sum of Gaussian-Lorentzian functions). Both O1s and F1s binding energy of oxyfluorinated MWCNTs shifted high value as increment of fluorine mixing ratio. The carbon-fluorine covalent bonding concentration increased as increment of fluorine mixing ratio. The shape and intensity of OF10-MWCNTs are similar with those of as-received MWCNTs. However, the intensity and binding energies of main peak position of OF20-MWCNTs and OF30-MWCNTs were dramatically increased by oxyfluorination.