• The Transactions of the Korea Information Processing Society
• /
• v.6 no.5
• /
• pp.1312-1322
• /
• 1999

The world of linearity, which is regular, predictable and irrelevant to time sequence in most natural phenomenon, is a very small part. In fact, signals generated from natural phenomenon with which we're in contact are showed only slight linearity. Therefore it is very difficult to understand and analyze natural phenomenon with only predictable and regular linear systems. Due to these reasons researches concerning non-linear signals that of analysis were excluded being regarded as noise are being actively carried out. Countless signals generated from nonlinear system have the information about itself, and analyzing those signals and get information from it, that will be able to be used effectively in so may fields. Hence, in this paper we used a higher order spectrum, especially the bispectrum. After we prove the validity applying bispectrum to logistic map, which is typical chaotic signal. Subsequently by showing the result applying for actual signal analysis of EEG according to auditory stimuli, we show that higher order spectra is a very useful parameter in analysis of non-linear signals and the result of EEG analysis according to auditory stimuli.

• Journal of IKEEE
• /
• v.25 no.4
• /
• pp.778-781
• /
• 2021

In this paper, we propose the 16-layer 3D NAND Flash memory compact modeling using SPICE. In the same structure and simulation conditions, the channel potential about Down Coupling Phenomenon(DCP) and Natural Local Self Boosting (NLSB) were simulated and analyzed with Technology Computer Aided Design(TCAD) tool Atlas(Silvaco^TM) and SPICE, respectively. As a result, it was confirmed that the channel potential of TCAD and SPICE for the two phenomena were almost same. The SPICE can be checked the device structure intuitively by using netlist. Also, its simulation time is shorter than TCAD. Therefore, using SPICE can be expected to efficient research on 3D NAND Flash memory.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.11a
• /
• pp.248-251
• /
• 2006

This paper provides the basic theory and numerical results of shell design optimization considering the appearance of close natural frequencies in optimization process. In this study the fundamental natural frequency to be maximized is considered as the objective function and the initial volume of structures is used as the constraint function. In addition, the constraints related to natural frequency is also adopted to avoid the natural frequency closeness phenomenon during the optimization iteration. The Coon's patch is used to represent the shape and thickness distribution of shells. A degenerated shell finite element is adopted to calculate the fundamental natural frequency of the shells. The SQP available in the optimizer DoT is used to search optimum solution. From numerical results, the introduction of the frequency constraint into shell design optimization can deeply affect on the final optimum shape of shells although it is likely to be used to avoid the frequency closeness phenomenon.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.17 no.6
• /
• pp.800-809
• /
• 2014

The gridded environmental data is usually provided by the numerical simulation coupled with a data assimilation technique and various inter- or extrapolation algorithms, both of which are based on the observation spanning from simple equipments to satellites. But it is difficult to represent the natural phenomenon such as sea mount, internal-wave, warm eddy in modeling or observation because of increase in the complexity of model. This paper introduces the algorithm artificially representing the natural phenomenon and the techniques applying it to the gridded volume data and smoothing for natural effects. Moreover, the inserted results are analyzed by use of graphical tool. The results can be used for the battle simulation or acoustic model.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.6
• /
• pp.804-810
• /
• 2001

Transition of flows in natural convection in a horizontal cylindrical annulus is investigated for the fluid with Pr=0.2. The unsteady streamfunction-vorticity equation is solved with finite difference method. As Rayleigh number is increased, the steady crescent-shaped eddy flow bifurcates to a time-periodic flow with like-rotating eddies. After the first Hopf bifurcation, however, a reverse transition from oscillatory to a steady flow occurs by the flow pattern variation. Hysteresis phenomenon occurs between the solution branches of up-scan and down-scan stages, and dual solutions with one steady and one oscillatory flow are found. Overall Nusselt of the flows at the flows at the down-scan stage is greater than that at the up-scan stage.

• Journal of Ginseng Research
• /
• v.27 no.2
• /
• pp.66-71
• /
• 2003

We screened preventives (preventers) from natural resources to prevent the rust phenomenon in ginseng roots. We examined that how these influence on the rusty phenomenon and the growth of 2 years old ginsengs treated in the preventers. All treats which was compounding preventers & improvers were so excellent of the ginsengs growth. Especially, the growth of 2 years old ginsengs treated with bio-preventer of ICPE-C105 and ICPE-P107R were increased to 73%, 28% compared with nontreatment, respectively. Though rusty ginseng of rate was emerged 58% in control, preventers ICPE-C 105 and ICPE-P107 were emerged of each 16.7%, 20%. It was affirmed effective of preventer. On the other hands, amounts of ginsenoside treated with preventatives showed to be changed. The total ginsenoside was increased to 71% with treatment ICPE-C105R which is the highest among groups compared to control, and ICPE-P$\_$107/R was increased to 50%. To sum up with total results, it is biotic preventatives (ICPE-C$\_$105/R and ICPE-P$\_$107/R) which we created improve both a high yield of ginseng roots and the inhibition of the rusty phenomenon. phenomenon.

• Journal of the Korean Applied Science and Technology
• /
• v.28 no.3
• /
• pp.290-298
• /
• 2011

Natural Omija belongs to magnoliaceae was known to possess natural odor, taste, color, and various pharmaceutical & chemical characteristics. Omija extraction was extracted using ethanol as a solvent. Omija extract showed a light red-violet color of viscous liquid state. Some conclusions from the result of characteristic experiment were obtained as follows. From the result of antimicrobial experiment, occurrence of staphylococuss aureus and aspergillus niger as microbes was decreased according to the passage of time. This phenomenon could know that Omija component is affected to antimicrobial effect. From the result of dye experiment, fiber dyeing showed with some ivory color after dyed to cotton and silk. This phenomenon could know that Omija component is affected to dyeing effect from observation of scanning electron microscope(SEM). From the result of instrument analysis, inorganic components of K(107.30ppm), Na(2.110ppm), Ca(0.935ppm), Mg(0.891ppm), Li(0.270ppm) etcs from Omija were detected with ICP/OES, and aromatic components of benzene(10.808), a-pinene(13.996), phenol(14.183), ${\beta}$-terpene(15.840), a-terpinolene(17.616) etcs from Omija were also detected with GC/MSD.

• Journal of Mechanical Science and Technology
• /
• v.14 no.7
• /
• pp.744-751
• /
• 2000

To achieve lower flying height for high areal recording density, the laser zone texturing of the disk needs to be designed to reduce glide height. One problem of the laser bump design is that the regular laser bump pattern often produces glide resonance phenomenon, which leads to failure of the glide height test. However, it was found in this study that glide resonance is an intrinsic problem of the glide head used and resonance phenomenon depends on the type of the head slider, that is, the natural frequency of the slider body. Therefore, higher glide height or glide failure caused by glide resonance does not lead to head/media interface problem in the real drive operating conditions in which the data head is used. Pseudo-random bump pattern greatly reduces the glide resonance. Smaller bump pitch will also help to reduce the glide resonance. However, as bump spacing becomes smaller, glide height will be increased due to increased air pressure developed around the bumps. Lowering bump height is the most effect way to reduce glide avalanche.

• Architectural research
• /
• v.12 no.2
• /
• pp.1-7
• /
• 2010

Science (natural science) is the systematic attempt to understand and interpret the nature phenomenon. For this reason, architects have used science to adapt nature to their design. With the rise of modern science, architecture became more closely related with science. Science available to develop new technology for architecture and it influenced architect's idea and concept. Symbolically, Architects use method or process of science to generate building form. The Rules of compositing particles in the chemistry or DNA (deoxyribonucleic acid) in the biology are used to generate a form of building. Literally, Architects use technology as a tool of science to improve physical performance of architecture. Like mathematical understanding of structure load enabled people to construct enclosure without columns or any of support system inside of architecture. Still natural phenomenon is not fully understood as science and science is still discovering a new phenomenon or changing its theory to adapt new discovery. New discovery or limitation of science influenced architecture throughout the history. This paper is to discuss how architectural theories are rest upon idea set forth by science. In addition, how technology as a tool of science has been utilized in architecture.

• Journal of KSNVE
• /
• v.10 no.6
• /
• pp.955-962
• /
• 2000

The paper deals with a theoretical study on the vibrational characteristics of piezoelectric torsional transducers. The differential equations of piezoelectric torsional motion have been derived in terms of the circumferential displacement and the electric potential. Applying mechanical and electrical boundary conditions has yielded the characteristic equations of natural vibration in several transducer types. Numerical results have clarified the effect of the piezoelectric phenomenon on the mechanical resonance and the effect of the elastic block of a Langevin-type transducer on the natural frequency.