• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1A
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• pp.70-75
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• 2005

The efficient hardware design of the the algorithm is important in wide variety of DSP. One example is OFDM(Orthogonal Frequency Division Multiplexing) based WLAN(Wireless Local Area Network) systems which place high requirements on throughput and power consumption on FFT. The output RAM is composed of two banks of $64{\times}W.$ The banks are swapped immediately following the falling edge or the start signal strobe. This bank swapping allows 64-Point FFT to continue Processing samples and to continue filling the alternative bank, without affecting the data flow outputs.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.5
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• pp.1470-1477
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• 2016

This study has designed and evaluated the safety of watertight damper for Offshore Rigs. The watertight damper is an improved design for conventional DN 350 butterfly valve. Numerical analysis has been performed to investigate the safety factor and seat leakage of the designed 3-type disk dampers. The structure analysis results present the deformations, the equivalent stresses and the safety factor. It was confirmed that the designed disk, rib-disk and streamlined disk of watertight damper are safe enough in maximum operating pressure of 0.98MPa. The results show that the disk damper had the smallest maximum deformations and stress among 3-type disk dampers and the safety factor was 4.3. Therefore it is confirmed that the disk damper has the most excellent strength. Also linear static structural analysis was individually conducted for disk and body. The results show that the maximum disk deformation was larger than the body deformation, Therefore the disk damper is causes no seat leakage.

• Applied Microscopy
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• v.15 no.2
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• pp.89-97
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• 1985

The ultrastructure of the trachea of the compound eye in adult cabbage butterfly, Pieris rapae L., was studied. Trachea under the basement membrane is divided into tracheoles of the ommatidia which blanched 4 tracheoles during 2 divisions. Tracheoles of the ommatidia originated from one tracheolar cell and its nuclear is located under the basement membrane and its cytoplasm enveloped the retinular cell and the retinular pigment cell. The modified structure of tracheoles is located at the first division area of the ommatidia and its size is $8{\mu}mX4.5{\mu}m$. And the length of its taenidium is $0.1{\sim}0.6{\mu}m$, diameter $0.15{\mu}m$, and interval $0.3{\mu}m$.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.6
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• pp.799-803
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• 2018

We demonstrated memory thin-film transistors (MTFTs) with organic ferroelectric polymer poly(vinylidene fluoride-co-trifluoroethylene) and an amorphous oxide semiconducting indium gallium zinc oxide channel on the elastomeric substrate. The dielectric constant for the P(VDF-TrFE) thin film prepared on the elastomeric substrate was calculated to be 10 at a high frequency of 1 MHz. The voltage-dependent capacitance variations showed typical butterfly-shaped hysteresis behaviors owing to the polarization reversal in the film. The carrier mobility and memory on/off ratio of the MTFTs showed $15cm^2V^{-1}s^{-1}$ and $10^6$, respectively. This result indicates that the P(VDF-TrFE) film prepared on the elastomeric substrate exhibits ferroelectric natures. The fabricated MTFTs exhibited sufficiently encouraging device characteristics even on the elastomeric substrate to realize mechanically stretchable nonvolatile memory devices.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.85-94
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• 1998

Herbicides play a very important role in modern agriculture. However, the herbicide applied to the agricultural field may accumulate in the field, converting the advantages to environment pollution. Many small animals in the ecosystem such as alderfly, earthworm, butterfly, loach, frog, firefly, some birds and aquatic organisms have been known to disappear gradually. In addition, several behavior of herbicides including adsorption by soil, movement by water, photodecomposition, volatilization to air, absorption by plant, metabolism by soil microorganisms and so on, are proceeded while the herbicide remained in the environment. In this review, fate and behavior of herbicides in the environment and their effect on ecosystem after their application are focused on four aspects : the first is the absorption and metabolism of herbicides by plant; the second is the residues of herbicides in soil and water environments: the third is the accumulation and release of herbicides in aquatic organisms and the fourth is the translocation of herbicides in model agricultural ecosystem. Many factors may affect the behavior and fate of herbicides after their application, climatic conditions and soil properties seem to be the most important. Therefore, the fate and behavior of herbicide in Taiwan, located on subtropical region, may differ from those in Korea.

• Journal of Fashion Business
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• v.12 no.5
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• pp.126-140
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• 2008

This thesis aims to examine the symbolism of color in the clothing of women, focusing on the protagonist of the movie Elizabeth: The Golden Age (2007). At the beginning of the movie, the Queen wears gowns with cartwheel ruff and wheel farthingales, symbolizing the attempt of establishing a powerful majesty. However, the Queen falls in love with Walter Raleigh and her clothing comes to emphasize femininity displaying her cleavage. Later on, her clothing indicates charismatic authority as she prepares for the Spanish war. At the end of the movie, the Queen who led the the country to victory in war puts on a luxurious gown with butterfly wings that reminds of a fairy queen. The colors of the Queen's clothing are categorized into three groups. First, the color red represents two opposite allegories. The positive image of red denotes Christ's blood, the love of God, and noble status of the Queen's image as a savior of England. On the other hand, red represents lewdness and evil which insinuate that the Queen is being attacked on her religious and political genuineness. Second, the color blue represents Saint Maria, chastity, and divinity. Third, the color goldw and white represent the Queen's ideals which are chastity as a virgin Queen and divinity.

• Nano
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• v.13 no.12
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• pp.1850149.1-1850149.10
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• 2018

Ferroelectric particles have been applied in the photocatalytic field because the spontaneous polarization results in the internal electric field, which can accelerate the separation and migration of photogenerated carriers. In this study, the $BaTiO_3$ (BT) fibers are synthesized by electrospinning. The BT fibers calcined above $800^{\circ}C$ exhibit a strong ferroelectric property, which is verified by a typical butterfly-shaped displacement-voltage loop. It is found that the BT fibers with the single-domain structure exhibit better photocatalytic performance than that with the multi-domain configuration. When the single-domain transforms into multi-domain, the integrated internal electric field correspondingly breaks up, inducing that the internal electric field might cancel each other out and diminish the separation of photogenerated carriers. Also, the Au nanoparticles can improve the photocatalytic activity further on account of the surface plasmon resonance. Therefore, it is suggested that Au nanoparticles decorated on ferroelectric BT nanomaterials are promising photocatalysts.

• Korean journal of applied entomology
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• v.58 no.2
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• pp.121-127
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• 2019

The discipline that deals with the role of insects in various activities that affect human aesthetics is called cultural entomology. This study investigated the kinds of insects appearing in modern traditional three-verse Korean poem, Sijo from the perspective of cultural insects. The subject literature surveyed 6,604 works and examined insect words. Among them, there were 215 works that appeared insect words and there were 26 works containing insect words in the title. All of the insect words appeared 257 times and were distinguished by 30 kinds of insects. The most commonly used insect words appeared 57 times as a butterfly, 45 crickets, and 44 insects. Studies in the field of cultural entomology will be needed through various works of art.

• Journal of Korean Elementary Science Education
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• v.38 no.1
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• pp.149-162
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• 2019

The purpose of this study was to develop an education for sustainable development(ESD) program using community resources in Paju and to investigate the influences on ESD competencies of 6th graders. The community resources used were Unjeong lake park, environmental circulation center, environmental management center, currency museum, butterfly museum, experience center for peaceful unification, Yulgok arboretum, and Jangsan observatory. The newly developed program was related to creative-experience activity and composed of 15 sessions for 6th-grade class in elementary school, including all of the environmental, economic, and social aspects of ESD. Two classes of the 6th grade were divided into the experimental group and the control group. The results to examine the effects of the program were as follows. First, it was proven that ESD program using community resources did not help improving the perception and function competencies of learners except for the thinking abilities. Second, it contributed to the improvement of learners' attitude competencies, especially in self-reflective attitude and other-oriented attitude. Also, according to in-depth interview, the students were constantly developing their values for sustainable development, reflecting their thoughts and behaviors in a reflective way and improving their attitude toward life.

• International journal of steel structures
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• v.18 no.5
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• pp.1784-1800
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• 2018

Tension-shear loading is a common loading condition in steel structures during the earthquake shaking. To study ductile fracture in structural steel under multiple stress states, experimental investigations on the different fracture mechanisms in Chinese Q235 steel were conducted. Different tension-shear loading conditions achieved by using six groups of inclined notch butterfly configurations covering pure shear, tension-shear and pure tension cases. Numerical simulations were carried out for all the specimens to determine the stress and strain fields within the critical sections. Two tension-shear fracture models were calibrated based on the hybrid experimental-numerical procedure. The equivalent fracture strain obtained from the round bar under tensile loading was used for evaluating these two models. The results indicated that the tension-shear criterion as a function of the shear fracture parameter had better performance in predicting the fracture initiation of structural steel under different loading conditions.