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        검색결과 938

        103.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study identified single nucleotide polymorphisms (SNPs) that affect the body weight of chickens. Analysis of body weight showed that the Cornish breed had the highest body weight, and the Korean native chicken (Gray Brown) had the lowest body weight. TSH is composed of an α-subunit and a β-subunit, and the TSH-β gene encoding the β-subunit has been reported to be associated with obesity. In chickens, it is located on chromosome 26 and is reported to be associated with growth. The calcium-sensing receptor gene (CaSR) plays a role in the regulation of extracellular calcium homeostasis and is responsible for calcium absorption in the urinary tract, which affects the eggshell quality in poultry. It was shown that TSH-β was strongly correlated with weight in Cornish and Korean native (Gray Brown) chickens, particularly in those with the CC trait. However, CaSR showed no association with body weight in poultry; it was associated with calcium and the eggshell. Thus, selection for TSH-β can be used to produce individuals with more favorable traits in terms of body weight.
        4,000원
        104.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Highly luminescent carbon quantum dots (CQDs) are developed as fluorescent probes for selective detection of the heavy-ion Fe3+, where the CQDs exhibit excellent nontoxicity, functionalizability, sensitivity, and selectivity. Biomass-based CQDs and nitrogen-doped CQDs (N-CQDs) are synthesized for the selective detection of Fe3+ by using H2O2 as an oxidant and polyetherimide (PEI) as a nitrogen precursor by a green hydrothermal synthesis method. The prepared CQDs and N-CQDs exhibit an elliptical morphology and with an average particle size of 7 and 4 nm, respectively, and emit blue photoluminescence at 445 and 468 nm under excitation at 367 and 343 nm, respectively. The CQDs and N-CQDs exhibit good water solubility because of the abundant hydroxyl and carboxyl/carbonyl groups and graphic/pyrrolic/pyridinic nitrogen on the surfaces, giving rise to a quantum yield of about 24.2% and 30.7%, respectively. Notably, the Matrimony vine-PEI-based CQDs exhibit excellent Fe3+ selectivity and sensitivity relative to the Matrimony vine-based CQDs due to complexation of the numerous phenolic hydroxyl groups and nitrogen-containing groups with Fe3+, leading to increased fluorescence quenching, which greatly improves the sensitivity of detection. The minimum detection limit was 2.22 μmol L− 1 with a complexation constant of 44.7.
        4,000원
        105.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Highly Oriented Pyrolytic Graphite (HOPG) was half covered using aluminum foil and exposed to irradiation with 70 keV C+ ions at room temperature (~ 25 ℃). The surface layer (height = 178.3 ± 4.7 nm) of the irradiated area was destroyed, many nano-sized dendritic protrusions were observed and smooth inner layer was exposed. The peak area ratio (ID/IG) in Raman spectra increased after ion irradiation, indicating that a change in atomic structure and transformation from the sp2 to sp3 phase. The mechanical properties were explored using atomic force microscopy in peakforce mode, which revealed that the Young’s modulus of the exposed inner layer was similar to unirradiated area, while the Young’s modulus of the dendritic protrusions was higher. There findings provided further understanding of the HOPG at nanoscale, which is of value for practical implementation in related fields.
        4,000원
        106.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Robot-assisted gait training (RAGT) is an effective method for walking rehabilitation. Additionally, the body weight support (BWS) system reduces muscle fatigue while walking. However, no previous studies have investigated the effects of RAGT with BWS on isokinetic strength of quadriceps and hamstring muscles. Objects: The purpose of this study was to investigate the effects of torque, work, and power on the quadriceps and hamstring muscles during RAGT, using the BWS of three conditions in healthy subjects. The three different BWS conditions were BWS 50%, BWS 20%, and full weight bearing (FWB). Methods: Eleven healthy subjects (7 males and 4 females) participated in this study. The Walkbot_S was used to cause fatigue of the quadriceps and hamstring muscles and the Biodex Systems 4 Pro was used to measure the isokinetic torque, work, and power of them. After RAGT trials of each of the three conditions, the subjects performed isokinetic concentric knee flexion and extension, five at an angular velocity of 60°/s and fifteen at an angular velocity of 180°/s. One-way repeated analysis of variance was used to determine significant differences in all the variables. The least significant difference test was used for post-hoc analysis. Results: On both sides, there were significant differences in peak torque (PT) of knee extension and flexion between the three BWS conditions at an angular velocity of 60°/s and 180°/s conditions. A post-hoc comparison revealed that the PT in the BWS 50% was significantly greater than in the BWS 20% and the FWB and the PT in the BWS 20% was significantly greater than in the FWB. Conclusion: The results of this study suggest that the lower BWS during RAGT seems to lower the isokinetic torque, work, and power of the quadriceps and hamstring muscles because of the muscle fatigue increase.
        4,300원
        107.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Postural control deficit is a major characteristic in patients with chronic ankle instability (CAI). Elastic ankle tapings are commonly used to facilitate postural control in patients with CAI as well as prevent relapse of a lateral ankle sprain. However, equivocal evidence exists concerning the effect of elastic ankle taping on postural control. Objects: This study aimed to evaluate the effects of elastic ankle tapings using kinesio taping (KT) and dynamic taping (DT) on static and dynamic postural control in patients with CAI. Methods: Fifteen subjects with CAI were participated in this study. The participants performed tests under three conditions (barefoot, KT, and DT). Static postural control was evaluated using the one-leg standing test (OLST) and dynamic postural control using the modified Star Excursion Balance Test (mSEBT). One-way repeated-measures analysis of variance was used to compare center of pressure (CoP) data and normalized mSEBT reach distances among the three conditions (with α = 0.05). Results: The CoP parameters (path length, ellipse area, and mean velocity) of the OLST significantly decreased on applying KT and DT compared with those when barefoot. The normalized reach distances in the anteromedial (AM), medial (M), and posteromedial (PM) directions of the mSEBT significantly increased with DT compared to that in the control condition. Further, the higher reach distances with KT compared with those in the control condition were obtained in the M and PM directions of the mSEBT. No significant differences were identified in any of the OLST and SEBT parameters between the two different taping applications. Conclusion: KT and DT improved static postural control during the OLST compared with the control condition. Moreover, these tapes improved dynamic postural control during the mSEBT compared to the control. Therefore, elastic ankle tapings are useful prophylactic devices for the prevention and treatment of ankle sprain in people with CAI.
        4,000원
        108.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Muscle undergoes change continuously with aging. Sarcopenia, in which muscle mass decrease with aging, is associated with various diseases, the risk of falling, and the deterioration of quality of life. Obesity and sarcopenia also have a synergy effect on the disease of the older adults. Objects: This study examined the risk factors for sarcopenia, sarcopenic obesity, and sarcopenia without obesity and developed prediction models. Methods: This machine-learning study used the 2008–2011 Korea National Health and Nutrition Examination Surveys in the analysis. After data curation, 5,563 older participants were selected, of whom 1,169 had sarcopenia, 538 had sarcopenic obesity, and 631 had sarcopenia without obesity; the remaining 4,394 were normal. Decision tree and random forest models were used to identify risk factors. Results: The risk factors for sarcopenia chosen by both methods were body mass index (BMI) and duration of moderate physical activity; those for sarcopenic obesity were sex, BMI, and duration of moderate physical activity; and those for sarcopenia without obesity were BMI and sex. The areas under the receiver operating characteristic curves of all prediction models exceeded 0.75. BMI could predict sarcopenia-related disease. Conclusion: Risk factors for sarcopenia-related diseases should be identified and programs for sarcopenia-related disease prevention should be developed. Data-mining research using population data should be conducted to enhance the effectiveness of early treatment for people with sarcopenia-related diseases through predictive models.
        4,000원
        109.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 타오바오 라이브 스트리밍 쇼핑의 특성과 주관적 규범이 라이브 스트리밍 쇼핑 사용 의도에 어떤 영향을 미치는지에 대해 조사하였다. 타오바오 라이브 스트리밍 쇼핑의 특성인 ‘인식된 즐거움’, ‘신뢰성’, ‘상호작용성’, ‘즉시성’과 ‘주관적 규범’이 타오바오 라이브 스트리밍 쇼핑의 사용 의도에 미치는 영향을 파악하기 위해 몰입이론과 합리적 행동 이론을 기반으로 연구를 진행하였다. 중국인 335명을 대상으로 설문조사를 실시하였으며 결과는 다음과 같다. ‘상호작용성’을 제외한 나머지 특성인 ‘인식된 즐거움’, ‘신뢰성’ 및 ‘즉시성’이 타오바오 라이브 스트리밍 쇼핑 사용에 대한 태도에 긍정적인 영향을 미치는 것으로 나타났다. 타오바오 라이브 스트리밍 쇼핑 사용에 대한 태도는 타오바오 라이브 스트리밍 쇼핑 사용 의도에 긍정적인 영향을 미치는 것으로 나타났으며 ‘주관적 규범’이 사용 의도에 긍정적인 영향을 줄 수 있는 것으로 나타났다. 본 연구는 타오바오 라 이브 스트리밍 쇼핑의 특성과 ‘주관적 규범’이 라이브 스트리밍 쇼핑 이용 의도에 어떤 영향을 미치는지 이해하는데 도움이 될 뿐만 아니라 다양한 라이브 스트리밍 쇼핑에 관한 마케팅 전략을 개발 하는데 도움이 될 수 있다.
        7,800원
        110.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        During the COVID-19 pandemic, the obligatory wearing of masks has led to increased consumer demand and the diversification of mask design. Accordingly, it is necessary to understand the inner meaning and characteristics of masks in the pandemic situation. Therefore, the purpose of this research is to analyze the characteristics of fashionable masks and their new cultural meaning under the COVID-19 pandemic. This research is based on literature review and empirical research. Drawing on an investigation of the historical evolution of masks and their transition under the pandemic (exhibiting differences in mask culture among countries and regions), this study analyzed 54 distinctive fashion masks designed by fashion brands and influencers that appeared from January 2020 to January 2021. The characteristics of fashion masks identified under the influence of the pandemic are as follows: Message delivery on political issues and human rights; psychological defense and expression of individuality; and conspicuous display via luxurious materials and luxury brand logos; moreover, the design of the mask uses the same material, color, pattern, decoration, and other methods as clothing to achieve the overall style. Over the course of the pandemic (and even in post-pandemic lifestyle), fashion masks are becoming more diversified conveying new social and cultural meanings.
        4,900원
        111.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study is to investigate morphological characteristics of Hanbok images in children’s books and propose a direction for the modernization and globalization of traditional culture. This study examines 43 children’s books by contemporary foreign illustrators that contain Hanbok illustrations and analyzes them from postcolonial perspective. The results include the following three attributes: first, the transformation of clothing structure and donning method that confuse fundamentals of Korean costume; second, the Westernization of silhouette drawing with tailored garments analogous to Western dress; and third, extension to East Asian dress that represents Hanbok mixed with Chinese or Japanese costume and use what is considered to be the East Asian patterns instead of Korean traditional ones. These attributes are based on Eurocentrism, which expresses and interprets the East from the Western view point with continuously distorted image of the East. Korean illustrators also painted Hanbok incorrectly, which could influence foreign illustrators. Nevertheless, traditional dress illustrated in various ways has artistic value and has a popular global impression. Further, it enables children to experience either own or other cultures through dress illustrations. Thus, the outsider requires an in-depth understanding of other cultures, while the insider needs a critical perception of their own culture as described by others while revisiting the original resources. Furthermore, we suggest follow-up research on Hanbok for subsequent generations; publishing translated books on various topics, producing and disseminating a primer for diverse readers, and essentially receiving counsel from experts.
        5,200원
        112.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sperm cryopreservation is an important method of assisted reproductive techniques and storing genetic resources. It plays a vital role in genetic improvement, livestock industrial preservation of endangered species, and clinical practice. Consequently, the cryopreservation technique is well organized through various studies, especially on Korean native cattle (Hanwoo). However, the cryopreservation technique of Korean native brindled cattle, which is one of the native cattle species in Korea, is not well organized. Therefore, it is necessary to develop a Supplementary Table technique for the cryopreservation of Korean native brindled cattle. For this purpose, it is important to first evaluate the quality of the currently produced cryopreserved sperm of Korean native brindled cattle. In this study, we randomly selected 72 individual Korean native brindled cattle semen samples collected from 8 different region research centers and used them to evaluate sperm functions. We focused on the quality evaluation of cryopreserved Korean native brindled cattle semen following the measurement of motion kinematics, capacitation status, intracellular ATP level, sperm motility, and cell viability. Then, the values of each of the eight groups were derived from various sperm parameters of nine individual samples, including sperm motility, kinematics, cellular motility, and intracellular ATP levels, which were used to compare and evaluate sperm function. Overall, differences in various sperm parameters were observed between most of the research centers. Particularly, the deviations of motility and motion kinematics were high according to the sample. Therefore, we suggest that it is necessary to develop a standard method for the cryopreservation of Korean native brindled cattle semen. We also suggest the need for sperm quality evaluation of the cryopreserved semen of Korean native brindled cattle before using artificial insemination to attain a high fertility rate.
        4,000원
        117.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent years, various methods of measuring body temperature have been developed using wireless biosensors to facilitate an early detection of pregnancy and parturition in cows. However, there are no studies on real-time monitoring of cattle body temperature throughout pregnancy. Therefore, we investigated the daily mean ruminal temperature in pregnant cows throughout pregnancy using a ruminal bio-capsule sensor and then evaluated the temperature variation between pregnant and non-pregnant cows. In pregnant cows, the mean and standard deviation of ruminal temperature was 38.86 ± 0.17℃. Ruminal temperature in pregnant cows slowly decreased until 180 to 190 days after artificial insemination and after that, the temperature increased dramatically until just before parturition. Furthermore, the means ruminal temperature was significantly different between pregnant and nonpregnant cows. The mean and standard deviation of ruminal temperature were as follows: 38.68 ± 0.01℃ from days 80 to 100, 38.78 ± 0.02℃ from days 145 to 165, 38.99 ± 0.45℃ from days 200 to 220, 39.14 ± 0.38℃ from days 250 to 270 before parturition. Therefore, our results could provide useful data for early detection of pregnancy and parturition in Korean cows.
        4,000원
        118.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Since the 2010 foot and mouth (FMD) epidemic, the Korean government has applied a FMD vaccination to pigs. A FMD vaccine is injected to pigs by intramuscular (IM) route. One of the drawbacks in FMD vaccine IM injection is that it would result in an abnormal meat on the injection spot. An abnormal meat due to FMD vaccine IM injection would cause economic loss to pig farmers. An intradermal (ID) injection would be an alternative method for FMD vaccination. The goal of current study was to compare the antibody formation rate between FMD vaccine IM injection and ID injection. The antibody formation rate was measured by the FMD serotype O vaccination percent inhibition (PI) value. In total 350 pigs (175 for FMD vaccine IM injection and 175 for FMD vaccine ID injection) were included in the study. In results, the PI values of FMD vaccine IM injection group were significantly higher than it of FMD vaccine ID injection group. However, the proportions of pigs with PI value was higher than 50, which is a legislative requirement for marketing pigs, for both FMD vaccine IM and ID injection groups at week 20 or 23 were not significantly different. The current results indicated that a FMD vaccine ID injection could be an alternative method of IM injection.
        4,000원
        119.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Lightweight and flexible electromagnetic interference (EMI) shielding materials are in great demand for wearable EMI device. In the present work, lightweight and flexible carbon nanotube (CNT)/ferroferric oxide ( Fe3O4) composite film was made through a feasible chemical vapor deposition process for CNT film synthesis, followed by a hydrothermal reduction process for Fe3O4 coating. In the as-prepared composite, CNT film and Fe3O4 particles work as conductive skeleton and strong magnetic particle, respectively. The as-prepared composite film shows a novel EMI shielding effectiveness (SE) of 91 dB in the X-band, a small thickness of 0.09 mm and a low density of 0.86 g/cm3, which is superior to most of the carbonbased EMI materials.
        4,000원
        120.
        2021.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The Ozone Dynamics Investigation Nano-Satellite (ODIN) is a CubeSat design proposed by Chungnam National University as contribution to the CubeSat Competition 2019 sponsored by the Korean Aerospace Research Institute (KARI). The main objectives of ODIN are (1) to observe the polar ozone column density (latitude range of 60 to 80 in both hemispheres) and (2) to investigate the chemical dynamics between stratospheric ozone and ozone depleting substances (ODSs) through spectroscopy of the terrestrial atmosphere. For the operation of ODIN, a highly ecient power system designed for the speci c orbit is required. We present the conceptual structural design of ODIN and an analysis of power generation in a sun synchronous orbit (SSO) using two di erent con gurations of 3U solar panels (a deployed model and a non-deployed model). The deployed solar panel model generates 189.7 W through one day which consists of 14 orbit cycles, while the non-deployed solar panel model generates 152.6 W. Both models generate enough power for ODIN and the calculation suggests that the deployed solar panel model can generate slightly more power than the non-deployed solar panel model in a single orbit cycle. We eventually selected the non-deployed solar panel model for our design because of its robustness against vibration during the launch sequence and the capability of stable power generation through a whole day cycle.
        4,000원