• Korean Journal of Environmental Biology
• /
• v.28 no.2
• /
• pp.101-107
• /
• 2010

Metal ions are essential to life. However, some metals such as mercury are harmful, even when present at trace amounts. Toxicity of mercury arises mainly from its oxidizing properties. Ionizing radiation (IR) is an active tool for destruction of cancer cells and diagnosis of diseases, etc. IR induces DNA double strand breaks in the nucleus, In addition, it causes lipid peroxidation, ceramide generation, and protein oxidation in the membrane, cytoplasm and nucleus. Yeasts have been a commonly used material in biological research. In yeasts, the physiological response to changing environmental conditions is controlled by the cell types. Growth rate, mutation and environmental conditions affect cell size and shape distributions. In this work, the effect of IR and mercury chloride (II) on the morphology of yeast cells were investigated. Saccharomyces cerevisiae cells were treated with IR, mercury chloride (II) and IR combined with mercury chloride (II). Non-treated cells were used as a control group. Morphological changes were observed by a scanning electron microscope (SEM). The half-lethal condition from the previous experimental results was used to the IR combined with mercury. Yeast cells were exposed to 400 and 800 Gy at dose rates of 400Gy $hr^{-1}$ or 800 Gy $hr^{-1}$, respectively. Yeast cells were treated with 0.05 to 0.15 mM mercury chloride (II). Oxidative stress can damage cellular membranes through a lipidic peroxidation. This effect was detected in this work, after treatment of IR and mercury chloride (II). The cell morphology was modified more at high doses of IR and high concentrations of mercury chloride(II). IR and mercury chloride (II) were of the oxidative stress. Cell morphology was modified differently according to the way of oxidative stress treatment. Moreover, morphological changes in the cell membrane were more observable in the frequently stress treated cells than the temporarily stress treated cells.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1202-1205
• /
• 2005

This paper describes a method for vision-based person identification that can detect, track, and recognize person from video using multiple cues: height and dressing colors. The method does not require constrained target's pose or fully frontal face image to identify the person. First, the system, which is connected to a pan-tilt-zoom camera, detects target using motion detection and human cardboard model. The system keeps tracking the moving target while it is trying to identify whether it is a human and identify who it is among the registered persons in the database. To segment the moving target from the background scene, we employ a version of background subtraction technique and some spatial filtering. Once the target is segmented, we then align the target with the generic human cardboard model to verify whether the detected target is a human. If the target is identified as a human, the card board model is also used to segment the body parts to obtain some salient features such as head, torso, and legs. The whole body silhouette is also analyzed to obtain the target's shape information such as height and slimness. We then use these multiple cues (at present, we uses shirt color, trousers color, and body height) to recognize the target using a supervised self-organization process. We preliminary tested the system on a set of 5 subjects with multiple clothes. The recognition rate is 100% if the person is wearing the clothes that were learned before. In case a person wears new dresses the system fail to identify. This means height is not enough to classify persons. We plan to extend the work by adding more cues such as skin color, and face recognition by utilizing the zoom capability of the camera to obtain high resolution view of face; then, evaluate the system with more subjects.

• Journal of the Korean Society of Costume
• /
• v.63 no.1
• /
• pp.56-63
• /
• 2013

This study provides comparative analysis on the parodying of the body and political powers in the traditional animation and Shrek Series based on the discourse of Foucault. For the research, parody theories and Foucault's discourse were reviewed through the literature study, and Shrek Series was analyzed through positive study. The Shrek Series overturned stereotypes of the traditional animation by means of parody, especially showing a true body and a political power in the post-modern society. Foucault focused on the body and newly changed political power in the post-modern society. A body was changed into resistant and combative forms rather than obedient and submissive under control of the community power. In addition, political power was changed into relationship-oriented, decentralized and creative power rather than the centralized and class-based. In the traditional fairy tales, heroes and heroines are beautiful and perfect characters who obtain wealth and honor and live a happy life forever. However, heros and heroines in the Shrek Series are not attractive and do not have the ideal body shape, but rather have creative and active personalities and show indifference towards wealth and honor. Furthermore, their dress colors show the change into lower value and higher chroma. The Shrek Series is a future-oriented animation which created a fluid body and a creative political power in the post-modern society.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2018.06a
• /
• pp.74-74
• /
• 2018

Ti-6Al-4V alloys have been widely used as orthopedic materials because of their excellent corrosion resistance and mechanical properties. However, it does not bind directly to the bone, so it requires a surface modification. This problem can be solved by nanotube and micropore formation. Plasma electrolytic oxidation (PEO) treatment for micropore, which combines high-voltage spark and electrochemical oxidation, is a new way of forming a ceramic coating on light metals such as titanium and its alloys. This method has excellent reproducibility and can easily control the shape and size of the Ti alloy. In this study, formation of bioactive surface by PEO-treatment after $2^{nd}$ ATO technique of Ti-6Al-4V alloy was invesgated by various instrument. Nanotube oxide surface structure was formed on the surface by anodic oxidation treatment in 0.8 wt.% NaF and 1M $H_3PO_4$ electrolytes. After nanotube formation, nanotube layer was removed by ultrasonic cleaning. PEO-treatment was carried out at 280V for 3 minutes in the electrolytic solution containing the bioactive substance (Mg, Zn, Mn, Sr, and Si). The surface of Ti-6Al-4V alloy was observed by field emission scanning electron microscopy (FE-SEM, S-4800 Hitachi, Japan). An energy dispersive X-ray spectrometer (EDS, Inca program, Oxford, UK) was used to analyze the spectra of physiologically active Si, Mn, Mg, Zn, and Sr ions. The PEO film formed on the Ti-6Al-4V alloy surface was characterized using an X-ray diffractometer (TF-XRD, X'pert Philips, Netherlands). It is confirmed that bioactive ions play an essential role in the normal bone growth and metabolism of the human skeletal tissues.

• The Journal of the Korea Contents Association
• /
• v.6 no.11
• /
• pp.161-171
• /
• 2006

As the very important artistic elements expressing a visual image, the color has been increasing the power of expression. But the relationship between the remarkable peculiarity of colors in accordance with other artistic elements inside the picture plane makes difficult to express an effective expression of color. In the adaptation of color as well as artistic style between & by W. Disney co. is very different each other in the manner of expression. By revealing the difference of the practical use of color and it's principle of those two works, I want to formulate a suitable use of color. In this paper, focus on how to active application of color in relationship between other artistic element and expressive peculiar of color. A right is not only the dominant component in color, but contrast also. A contrast is the most considerable element for modeling order. To emphasize expressive peculiar of color, an artist control artistic element properly and can make expressive energy of brightness & shape.

• Archives of Craniofacial Surgery
• /
• v.22 no.5
• /
• pp.239-246
• /
• 2021

Background: Bone grafts can provide an optimal environment for permanent tooth to erupt and enhance the stability of the alveolar maxilla. Although autologous bone is an optimal source for osteogenesis, its inevitable donor site morbidity has led to active research on bone substitutes. This study was designed to evaluate the safety and feasibility of using biphasic calcium phosphate (BCP; Osteon) as a bone substitute in dogs. Methods: Bilateral third and fourth premolars of four 15-week-old mongrel dogs were used. All teeth were extracted except the third premolar of the right mandible, which was used as a control. After extraction of the premolars, each dog was administered BCP (Osteon), demineralized bone matrix (DBM; DBX), and no graft in the hollow sockets of the right fourth premolar, left fourth premolar, and left third premolar, respectively. Radiographs were taken at 2-week intervals to check for tooth eruption. After 8 weeks, each dog was sacrificed, and tooth and bone biopsies were performed to check for the presence of tooth and bone substitute particle remnants. Results: Four weeks after the operation, permanent tooth eruptions had started at all the extraction sites in each dog. Eight weeks after the operation, all teeth had normally erupted, and histological examination revealed BCP particles at the right fourth premolar. Conclusion: In all four dogs, no delay in the eruption of the teeth or shape disfigurement of permanent teeth was observed on gross inspection and radiologic evaluation. On histological examination, most of the BCP and DBM were replaced by new bone. Bone substitutes can be used as graft materials in patients with alveolar clefts.

• Korean Journal of Materials Research
• /
• v.33 no.12
• /
• pp.530-536
• /
• 2023

The theoretical capacity of silicon-based anode materials is more than 10 times higher than the capacity of graphite, so silicon can be used as an alternative to graphite anode materials. However, silicon has a much higher contraction and expansion rate due to lithiation of the anode material during the charge and discharge processes, compared to graphite anode materials, resulting in the pulverization of silicon particles during repeated charge and discharge. To compensate for the above issues, there is a growing interest in SiO_x materials with a silica or carbon coating to minimize the expansion of the silicon. In this study, spherical silica (SiO₂) was synthesized using TEOS as a starting material for the fabrication of such SiO_x through heating in a reduction atmosphere. SiO_x powder was produced by adding PVA as a carbon source and inducing the reduction of silica by the carbothermal reduction method. The ratio of TEOS to distilled water, the stirring time, and the amount of PVA added were adjusted to induce size and morphology, resulting in uniform nanosized spherical silica particles. For the reduction of the spherical monodisperse silica particles, a nitrogen gas atmosphere mixed with 5 % hydrogen was applied, and oxygen atoms in the silica were selectively removed by the carbothermal reduction method. The produced SiO_x powder was characterized by FE-SEM to examine the morphology and size changes of the particles, and XPS and FT-IR were used to examine the x value (O/Si ratio) of the synthesized SiO_x.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.10
• /
• pp.1307-1313
• /
• 2011

The mechanical limited slip differential (LSD) in vehicles is being replaced by the electromagnetic LSD because of its fast response and better active control characteristics. The coil housing made of STS 304 is one of the most important parts in the solenoid assembly of the electromagnetic LSD. High geometrical accuracy is a prerequisite for the manufacture of such coil housings, but precision machining is difficult because of the use of STS 304 thin plate and the variance in machining variables. The aim of this study is to optimize the mean and variance of the shape accuracy in the coil housing by finding a robust solution for the machining process conditions. The mean and standard deviation of the jaw contact pressure, cutting speed, and feed rate are considered to be the major parameters for minimizing the geometrical mean and variance. The response surface model based on the second-order Taylor series is combined together to minimize the mean and variance of the shape accuracy of the coil housing.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.62 no.1
• /
• pp.1-8
• /
• 2017

We investigated the effect of silicate coating of rice seeds on bakanae disease incidence and the quality of seedlings raised in seedling boxes and transplanted into pots. The silicate-coated rice seed (SCS) was prepared as follows. Naturally infested rice seeds not previously subjected to any fungicidal treatment were dressed with a mixture of 25% silicic acid at pH 11 and 300-mesh zeolite powder at a ratio of 50 g dry seed - 9 mL silicic acid - 25 g zeolite powder. The following nursery conditions were provided : Early sowing, dense seeding in a glass house with mulching overnight and no artificial heating, which were the ideal conditions for determining the effect on the seed. The nursery plants were evaluated for Gibberella. fujikuroi infection or to determine the recovery to normal growth of infected nursery plants in the Wagner pot. Seedlings emerged 2-3 days earlier for the SCS than they did for the non-SCS control, while damping-off and bakanae disease incidence were remarkably reduced. Specifically, bakanae disease incidence in the SCS was limited to only 7.8% for 80 days after sowing, as compared to 91.6% of the non-SCS control. For the 45-days-old SCS nursery seedlings, the fresh weight was increased by 11% and was two times heavier, with only mild damage compared to that observed for non-SCS. Even after transplanting, SCS treatment contributed to a lower incidence of further infections and possibly to recovery of the seedlings to normal growth as compared to that observed in symptomatic plants in the pot. The active pathogenic macro-conidia and micro-conidia were considerably lower in the soil, root, and seedling sheath base of the SCS. In particular, the underdeveloped macro-conidia with straight oblong shape without intact septum were isolated in the SCS ; this phenotype is likely to be at a comparative etiological disadvantage when compared to that of typical active macro-conidia, which are slightly sickle-shaped with 3-7 intact septa. A active intact conidia with high inoculum potential were rarely observed in the tissue of the seedlings treated only in the SCS. We propose that promising result was likely achieved via inhibition of the development of intact pathogenic conidia, in concert with the aerobic, acidic conditions induced by the physiochemical characteristics associated with the air porosity of zeolite, alkalinity of silicate and the seed husk as a carbon source. In addition, the resistance of the healthy plants to pathogenic conidia was also important factor.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.24 no.1
• /
• pp.27-40
• /
• 1997

This study investigated the effects of laser irradiation on the exposed pulp and the possibility of direct pulp capping with the $CO_2$ laser. Results were obtained from the observation of the residual pulpal healing process. Class V cavities on 48 anterior teeth from 8 adult dogs were prepared and pulp chambers were intentionally opened with dental explorer. The control group consisted of 16 teeth. $Dycal^{(R)}$(Caulk Co., U.S.A.) was applied to exposed site once bleeding was stopped. Cavities were sealed with $I.R.M^{(R)}$. In the experimental group 1 (16 teeth), laser(LASERSAT $CO_2^{(R)}$, Satelec Co.) was irradiated on the exposed pulp. The laser procedure followed the manufacturers recommendations for the treatment of human pulp(1.5 Watts, 0.2 seconds, unfocused), and cavities were sealed with $I.R.M^{(R)}$. In the experimental group 2 (16 teeth), laser was irradiated on the exposed pulp in a more powerful dosage(5.0 Watts, 0.2 seconds, unfocused), and cavities were sealed with $I.R.M^{(R)}$. Two dogs were sacrificed immediately after experiment and the others were sacrificed at intervals of one, three, and eight weeks respectively. All teeth were routinely processed and the pulpal tissues and odontoblastic layers were observed by the light microscope. The results were as follows; 1. In the control group, the initial mild inflammation had improved to normal by week eight. An active formation of reparative dentin was observed at week three, and at week eight, a firm dentin bridge was present beneath the $Dycal^{(R)}$ with no inflammatory responses in the remaining pulp. 2. In the experimental group 1, immediately following irradiation, the superficial shape of the exposed pulp was crater-like. And it was lined with the coagulated layer, $60{\sim}70{\mu}m$ in width. Moderate inflammatory pulpal conditions existing at week one were improved to mild at week eight. And from the week three specimens, a reparative dentin formation was observed in the adjacent odontoblastic layer of the exposed site. A dentin bridge at the exposed site, however, did not form during the experimental period. 3. In the experimental group 2, the width of the coagulation layer lining the crater was $70{\sim}130{\mu}m$. Beneath the coagulated layer, severe inflammatory pulpal responses were observed at week one, and conditions did not improve during the experimental period.