• 한국통신학회논문지
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• 제19권6호
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• pp.1140-1148
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• 1994

본 논문에서는 음성신호의 프랙탈 차원을 이용하여 한국어 모음인식 실험을 수행하였다. 프랙탈 차원은 Minkowski-Bouligand 차원을 사용하였으며, 형태학적 커버링(morphological covering) 방법을 이용하여 구하였다. 프렉탈 차원과 더불어 기존에 우수한 음성 인식 파라메타로 알려져 있는 LPC 켐스트럼(cepstrum)을 함께 사용하였으며, 프랙탈 차원의 음성인식에의 유용성 여부를 조사하였다. 다양한 자음환경에서의 모음인식 실험결과, LPC 켐스트럼 만을 사용하는 경우 및 프렉탈 차원과 LPC 켐스트럼을 함께 사용하는 경우의 모음 오인식율이 각각 5.6% 및 3.2%로 얻어졌다. 이는 LPC 켑스트럼에 프렉탈 차원을 추가함으로써 오인식되는 데이터가 40%이상 감소되는 결과이며, 프랙탈 차원이 음성인식에 있어서 유용한 특징 파라메터임을 보여준다.

• Elastomers and Composites
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• 제52권1호
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• pp.27-34
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• 2017

In this experiment, blends of ethylene vinyl acetate rubber (EVM) with a vinyl acetate (VA) content greater than 40 wt% and ethylene propylene rubber (EPM) were prepared by mechanical mixing; a number of parameters of the blends, including oil resistance, morphological and dynamic mechanical properties and flame retardancy, were subsequently measured. In the $100^{\circ}C$ oil resistance test, both the ammonium polyphosphate/dipentaerythritol/expandable graphite (APP/DPER/EG) and aluminum hydroxide (ATH) flame retardant systems showed an increase in volume change with increasing EPM content. For the ATH system, the dispersion shape was coarse and aggregation was observed. The results of a dynamic mechanical test showed slightly higher E' and E'' for the APP/DPER/EG flame retardant system when compared to the single ATH system. For both the APP/DPER/EG and ATH systems, the limited oxygen index (LOI) tests performed at increasing content of EPM showed a LOI value higher than 30, indicating excellent flame resistance.

• 대한두경부종양학회지
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• 제14권1호
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• pp.76-80
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• 1998

Generally, the papillary carcinoma generally has a favorable prognosis, and several variants of pathologic heterogeneity are recognized. Variants that are regarded as more aggressive are tall cell, columnar cell, and diffuse sclerosing types. Seventeen cases of papillary thyroid carcinoma showing clinically aggressive behavior, invading extrathyroidal structures, were retrospectively reviewed to evaluate the morphological variants of the tumors. Six of them were found to be pure papillary and nine were mixed types regarded as non-aggressive variants. Four cases were found to be tall cell variants, two cases of non-extrathryoidal invasion and two of extrathyroidal invasion regarded as aggressive variants. Our findings suggest that the prognosis of papillary carcinoma not always be based on its morphological variant and more attention should be given to other clinical parameters.

• 생약학회지
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• 제49권1호
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• pp.28-39
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• 2018

This study investigated the effect of snail extract on the growth parameters of old female rats (27 weeks). Rats were administered orally with snail extract at a dose of 100 mg/kg, 200 mg/kg, chondroitin sulfate 10 mg/kg and 0.9% saline (control) for 8 weeks. Bone mineral density (BMD) and serum concentrations of insulin-like growth factor 1 (IGF-1) and insulinlike growth factor-binding protein 3 (IGFBP-3) were significantly higher in rats exposed to snail extract for 8 weeks. MG-63 cells (human osteoblast-like cells) were treated with snail extract for 48 h. Their differentiation and proliferation was investigated with Western blot and morphological changes observed via immunofluorescence staining of ${\beta}-catenin$. Treatment with snail extract significantly increased the levels of growth factors including ${\beta}-catenin$ and IGF-1. The snail extract affected osteoblast formation. Morphological changes in MG-63 cells were observed via immunofluorescence staining. Treatment with snail extract increased the expression of ${\beta}-catenin$ in MG-63 cells. Results suggest that the treatment of MG-63 cells with snail extract increased the longitudinal growth and growth factor levels. Snail extract may be pharmacologically effective in osteogenic differentiation in vitro and represents a potential therapeutic agent for bone formation.

• Toxicological Research
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• 제8권2호
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• pp.285-302
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• 1992

Human and rat hepatocytes were isolated by nonperfusion method and cultured for longer than 5 days. Human liver biopsy sample and rat liver were used as hepatocyte source. Several physical and chemical factors which were influencing on hepatocyte isolation procedure were examined and a batch isolation procedure was established for small size sample of rat liver. Isolated hepatocytes showed normal morphlologica characteristics in microscopy and electron microscopical examinations and a morphologica response to phalloidin. Isolated cells were cultured as a monolayer and proven to have intact morphological characteristics for longer than 15 days. Because human liver sample is harder and tighter compared with rat liver, a standard procedure for rat hepatocytes was slightly modified to reduce mechanical damage. Similarly with rat hepatocytes, isolated human hepatocytes showed a normal morphological characteristics and could be cultured for longer than 15days. Human and rat hepatocytes were examined on their functional integrities including cytochrome-P450 related enzyme activity and it's inducibility, hormonal inducibility of AIB uptake and TAT activity, albumin synthesis, DNA synthesis, cellular protein maintenance. In all parameters used in the present study, human and rat hepatocytes showed normal functional characteristics.

• Macromolecular Research
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• 제13권1호
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• pp.62-67
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• 2005

This paper investigated the effect of biodegradation behavior on the oxidation of cellulose nanofiber mats. The cellulose mats were produced through electro spinning. The diameter of an electrospun fiber varied from 90 to 240 nm depending on the electrospinning parameters, such as the solution concentration, needle diameter, and rotation speed of a grounded collector. Oxidized cellulose (OC).mats containing different carboxyl contents were prepared using $NO_2$ as an oxidant. The total carboxyl content of the cellulose nanofiber mats obtained after oxidation for 20 h was $20.6\%$. The corresponding carboxyl content was important from a commercial point of view because OC containing $16-24\%$ carboxyl content are used widely in the medical field as a form of powder or knitted fabric. Degradation tests of the OC mats were performed at $37^{\circ}C$ in phosphate-buffered saline (pH 7.4). Microscopy techniques were introduced to study the morphological properties and the degradation behavior of the OC mats. Morphological changes of the mats were visualized using optical microscopy. Within 4 days of exposure to PBS, the weight loss of the OC mats was $>90\%$.

• 한국분무공학회지
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• 제17권3호
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• pp.128-133
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• 2012

The present study aims to examine the influence of flame spray distance on the thermal behavior of micro-metal particles and the morphological characteristics of $Ni_{20}Cr$ layers coated on the preheated SCM415 substrates by using the conventional flame spray system. Commercially available nickel-based $Ni_{20}Cr$ particles with a mean diameter of $45{\mu}m$ were used. In addition, CFD simulations using a commercial code (FLUENT ver. 6.3.26) were conducted to estimate temperature and velocity distributions of the continuous and discrete phases before impact on the substrate. From FE-SEM images of coated layers on the substrates, it was observed that as the spray distance decreased, the metal particle morphology showed splash-like patterns and such a short stretch shape, resulting from higher particle momentums and the impact of partially melted particles. Moreover, it was found that the spray distance should be considered as one of important parameters in controlling the porosity and the adhesion strength.

• Journal of Plant Biotechnology
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• 제48권4호
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• pp.236-245
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• 2021

This study aimed to characterize the morphological variations in the vegetative and floral traits of 73 wild Lilium amabile plants from six habitats in Korea. It was observed that L. amabile is distributed nationwide at any altitude from 300 m (Mt Mangdaeam) to 1550 m (Mt Halla). The majority of the natural habitats of L. amabile were found on mountain slopes, and some were found in rugged mountain regions. The down-facing flowers of this species not only had many blotches but also dense trichomes, and the flowering time was found to be from mid-June to mid-July. ANOVA revealed significant variations in vegetative and floral traits among the six habitats, indicating that the environment has substantial influences on the various growth parameters of L. amabile, such as plant height; number of leaves, bracts, papillae, and flowers; leaf angle; and lengths of the anther, longest blotch, and nectary of the petiole. In addition, the vegetative and floral traits were found closely correlated with each other under the direct impact of the environment. These findings will facilitate to find the appropriate environmental conditions for the conservation and development of L. amabile population as future lily-breeding materials.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2022년도 추계학술대회
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• pp.29-29
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• 2022

The fast-changing climatic conditions make plants to be vulnerable to many abiotic stresses. Drought stress is one of the limiting factors that affect pepper production in water deficient regions. It affects plant growth and development by altering physiological, morphological, and metabolic processes. Breeding drought tolerant varieties is one of the mitigation strategies to overcome the ever increasing drought disaster. Hence, screening of new drought tolerant pepper genotypes is essential. The current study was aimed to identify new drought tolerant genotypes among the collection of pepper genetic resources. In total, 70 pepper genotypes were screened for drought tolerance after exposure to drought stress condition. The pepper genotypes were classified as highly tolerant, intermediate, or severely sensitive to drought stress based on the phenotypic analysis. Consequently, 13 genotypes significantly exhibited higher recovery rate after drought stress and were classified as highly tolerant. Comparative analysis of morphological and physiological parameters and expression of drought responsive genes between tolerant and susceptible pepper genotypes will be presented and discussed. The identified tolerant genotypes will be useful resources for breeding drought tolerant pepper cultivars.

• 한국정밀공학회지
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• 제29권5호
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• pp.578-583
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• 2012

The pharmacological therapies and whole body vibration as non-pharmacological therapies were known to have adverse side effects. Therefore, partial stimulation was suggested and its effects were evaluated. This study aimed to evaluate the site-specific effects of partial stimulator for treatment of osteoporosis induced by estrogen deficiency. Sixteen virginal Sprague-Dawley rats (12 weeks old) were divided into 2 groups(no stimulation, stimulation groups). All rats were ovariectomised to induce osteoporosis. After 3 weeks of operation, the right tibiae in rats of stimulation group (frequency: 10Hz, cycle: 1500, strain on bone surface: $2000{\mu}{\varepsilon}$) were stimulated perpendicularly at right tibia by using partial stimulator for 6 weeks (3days/week). The right tibiae in rats were scanned, before stimulation (0 week) and at 6 weeks after stimulation by using in-vivo micro computed tomography. For investigation of changes in morphological characteristics, structural parameters were measured and calculated. At 6 weeks the morphological characteristics (relative value) in stimulation group were significantly enhanced than those in no stimulation group (p<0.05). In this study, we find that after 6 weeks of partial stimulation, the morphological characteristics of tibia trabecular bone were enhanced. Thus, we concluded that partial stimulation could be used to treat osteoporosis.