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        검색결과 460

        284.
        2005.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        6,300원
        286.
        1998.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 지진격리장치의 일종인 마찰 단진자 시스템(FPS)의 교량에의 적용에 관한 연구이다. FPS에 의하여 지진 격리된 교량과 지진 격리되지 않은 교량의 지진하중 작용시의 응답을 비교하기 위하여 축소모델 교량을 이용한 진동대 실험을 수행하였다. 연구결과, 본 장치를 설치한 경우 지진하중에 대한 지지능력이 향상하는 것으로 나타났다. 또한, 활동면 곡류반경에 의해 조절이 가능한 F.P.S 베어링의 강성은 입력된 kwlsfur의 강도와는 무관하며, 활동면의 마찰계수에 따라 속도가 변화하여 약진시에는 활동면에서의 속도가 작으므로 강진시와 비교하여 지진하중에 의하여 발생하는 마찰력도 감소하게 되었다. 한편 F.P.S 베어링의 마찰특성은 반복된 실험에서도 변화하지 않았고, 영구변형은 약적으로도 작았을 뿐만 아니라 누적되지도 않았다.
        4,000원
        287.
        1997.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        남부지방에서 분리한 곤충병원성곰팡이 Beauveria bassiana GY1-17균주를 이용하여 산림해충인 오리나무잎벌레(Agelastica coerulea), 밤나무혹나방(Meganola melancholica), 회양목명나방(Glyphodes perspectalis), 잔디해충인 등얼룩풍뎅이(Blitopertha orientalis), 채소해충인 배추좀나방(Plutella xylostella) 및 거세미나방(Agrotis segetum)의 생물적 방제 가능성을 알아보기 위하여 실험한 결과, 오리나무잎벌레와 배추좀나방유충은 7.0~2.0 conidia/ml 농도에서 처리 7일과 5일후 100%의 치사율을 나타내었다. 밤나무혹나방유충은 0.03875~3.1 conidia/ml 처리에서 66.7~100%의 높은 치사율을 보였으나 회양목명나방유충은 2.0~2.0conidia/ml 처리에서도 전혀 치사되지 않았다. 등얼룩풍뎅이유충은 3.7 conidia/ml 농도에서 46.7%의 치사율을 보였고, 거세미나방유충은 2.5 conidia/ml 농도에서 63.3% 치사율을 나타내었다.
        4,000원
        289.
        1994.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 수치해석의 목적은 앵글 강부재의 극저사이클 파괴실험으로부터 얻어진 거동의 재현 빛 특히, 부재중에 서 가장 심한 웅력을 받는 부분에 대한 국소 웅력-변형률의 이력과 누적상황을 추적하는 것이다. 이를위해, 범용 구조해석 프로그램인 MSC/NASTRAN을 이용하여, 재료 및 기하학적 비선형을 고려한 대변형 3 차원 유한요소해석을 행하였다. 해석은 2 단계 즉, 해석 I 파 n 로 나누어 실시하였으며, 본 해석의 첸반적인 가동 은 실험결과와 매우 잘 일치하였다.
        4,000원
        291.
        2020.04 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The study aims to investigate the relationship between hedging with derivatives and subsequent firm-level stock price crash risk. Our sample consists of KOSPI- and KOSDAQ-listed companies from 2004 to 2014. The total firm-year observation is 4,886. We find that hedging with derivatives is related to greater possibilities of crash risk. The results suggest that the complexity of economic and financial reporting for derivatives may aggravate the company's information opacity, ultimately increasing the crash risk. We contribute to the growing body of literature on hedging with derivatives. Academics and practitioners have debated on whether or not hedging enhances transparency or rather makes the information environment more opaque. Theoretical research on the role of corporate hedging on information environment shows that hedging enhances earnings informativeness. Meanwhile, pieces of anecdotal and empirical evidence show that the economic and financial reporting complexity of derivatives can harm information transparency. Our results shed light on the question of whether and how hedging with derivatives affects information environment by examining the relationship between hedging with derivatives and crash risk. Furthermore, our findings provide useful insights for policymakers and practitioners. Specifically, our results raise a need for a more transparent disclosure on corporate hedging activities with derivatives.
        292.
        2019.06 KCI 등재 서비스 종료(열람 제한)
        본 연구는 방사선학과 학생들을 대상으로 전공만족도가 진로결정몰입에 미치는 영향을 알아보고자 실시하였다. 구조화된 설문지를 사용하여 218명의 방사선학과 학생들을 대상으로 자가 보고식 조사를 실시하였다. 방사선과 학생들의 전공만족도는 ‘보통’ 정도였으며 진로결정몰입도는 ‘보통’에서 ‘미몰입’ 수준으로 1 학년에서 가장 낮게 나타났고 4학년에서 가장 높게 나타났다. 전공만족도는 진로결정몰입도에 영향을 주고 있었는데 특히, 하부요인인 전공 자부심이 진로결정 몰입에 가장 많은 영향을 주고 있었다. 본 연구에서 방사선학과 학생들의 진로결정몰입도는 미몰입 수준으로 낮게 나타나서 진로결정몰입도를 향상시킬 수 있는 방안이 필요한 것으로 보인다.
        293.
        2018.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This study was conducted to compare the volatile flavor compounds of Artemisia annua L. after extraction by simultaneous steam distillation extraction (SDE) and solid-phase micro extraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) analysis. Via SDE and SPME processes, 79 (1,254.00 mg/kg) and 39 (488.74 mg/kg) compounds were identified respectively. The compounds extracted by SDE included 27 alcohols, 13 aldehydes, 22 hydrocarbons, 3 esters, 12 ketones, 1 oxide and 1 N-containing compound, on the other hand, using the SPME method, 7 alcohols, 5 aldehydes, 1 ester, 18 hydrocarbons, 7 ketones, and 1 oxide were extracted. The major volatile flavor compounds of Artemisia annua L. isolated by the two methods were caryophyllene oxide, -caryophyllene, camphor, -selinene, -muurolene, 1,8-cineol, (E)-pinocarveol and pinocarvone. β β γ The sesquiterpene named caryophyllene oxide was the most abundant volatile flavor compound with relative contents of 234.16 mg/kg and 195.44 mg/kg obtained by the SDE and SPME methods, respectively. Among the identified volatiles, sabinene, β-pinene, α-terpinene, γ-terpinene, yomogi alcohol, myrtenol, (Z)-nerolidol, p-cymen-8-ol and eugenol were detected by the SDE method only while (E)-anethole and α-cubebene were detected by the SPME method only. This study confirmed that the composition and contents of the volatile flavor compounds vary between different extraction methods. More volatile flavor compounds were identified using the SDE method than the SPME method.
        294.
        2018.02 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 CT영상기반 3차원 고관절모델을 이용한 컴퓨터시뮬레이션을 통해서 고관절의 운동범위 (Range of Motion)를 측정하는 방법을 제시하였다. 본 연구에서는 그 측정방법에 대한 기술적인 사항을 제시하고, 그 기술이 재현성 있게 실현할 수 있도록 대퇴골두 중심점의 결절, 대퇴골 외전(Abduction)/내전(adduction)회전축, 굽힙(flexion)/신전(extension) 회전축을 정의하고 측정하는 명확한 방법을 제시하였다. 외전각은 해부학적인 시상면(Sagittal plane)상의 Anterior-Posterior축에 대해 아래쪽(Inferior)면으로부터 Lateral 쪽으로의 회전각으로 정의된다. 최대외전각은 대퇴골두가 엉덩이뼈(Pelvis)의 절구(Acetabulum)의 테두리와 겹치지 않고 Anterior-Posterior축을 중심으로 회전할 수 있는 최대 외전각으로 결정된다. 굴곡각은 해부학적인 관상면(Coronal plane)상의 Medial-Lateral축에 대해 아래쪽(Inferior)면으로부터 회전각으로 정의된다. 최대굴곡각은 대퇴골이 Medial-Lateral축을 중심으로 엉덩이뼈(Pelvis)의 절구(Acetabulum)의 테두리와 겹치지 않고 회전할 수 있는 최대 굴곡각으로 결정된다. 정상고관절에 비해 인공고관절술을 받은 해당 환자의 경우, 외전에서는 60도 정도, 굽힘에서는 4도 정도 운동범위가 줄어들 수 있다는 예측이 나왔다. 본 연구에서 행한 시뮬레이션을 해보고 외전의 경우 운동범위의 감소가 예측되므로, 대퇴골두를 조금 큰 것을 고르거나 대퇴골목부의 길이 (femoral neck offset)를 길게 시술해야 할 필요가 있음을 의미한다.
        295.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        This study aimed to improve job performance for student with disabilities through competency-based instructionally designed indoor gardening course. In this study, The first step is that job analysis such as task range, eligibility, core competency, index of capability, etc was done by a focus group composed of 10 specialists in the industry and academia. The second step is developing a diagnostic tool of indoor gardening activity competency. The third step is the selection of diagnostic test students. The 4th step is selection of subjects for competency diagnostic testing. The 5th step is competency diagnostic testing The 6th step is analysis of competency improvement for instructional design. In result, average of cognitive competency improved from 1.80 to 3.96, physical competency from 1.86 points to 4.06 points and social competency from 2.30 points to 4.40 points after 15 weeks course. We found that effect of indoor gardening instructional design on job competency improvement. The next step is the establishment of instruction guidelines for indoor garden assistant manager or all kind of assistant job as university students with disabilities.
        296.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        We investigated traditional knowledge about ethnobotanical uses around national parks in the northern areas of Province Gyeongsangbuk-do, with the focus on the Sobeaksan National Park area. Interviews were carried out to 138 residents at 42 places from 7 counties and/or cities, and verified species and usage information were categorized by taxonomic groups, usage, and used parts. The ethnobotanical species of the regions consisted of a total of 277 taxa: 244 species, 3 subspecies, 28 varieties, and 2 forma in 213 genera of 79 families. The significant native plants included one Endangered Species (Paeonia obovata Max.) and four endemic species (Salix hallaisanensis H. Lev., Aconitum pseudolaeve Nakai, Paulownia coreana Uyeki, and Cirsium setidens (Dunn) Nakai, Sasa coreana Nakai). About 17 Approved Species for Delivering Overseas designated by Korea Ministry of Environment have been also traditionally valuable in the regions. The main usage of the plants were edible (185 taxa) and medicinal (175 taxa). Leaves were most commonly used parts (109 taxa), followed by stems (73 taxa), fruits (69 taxa), roots (67 taxa), and wholes (57 taxa). The traditional usage of plants were diverse as those useful parts. Leaves, fruits and seeds were used as edible and medicinal; sprouts (young shoots) were mainly used as edible; but roots and flowers were used as medicinal. The study does not only provides examples of traditional uses of native plants, but also facilitates sustainable managements and developments of ethnobotanical knowledge for the contemporary society.
        297.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to apply a horticultural therapy program to childhood cancer patients, to analyze their psychosocial changes and thus to examine its possibility as a way to manage the recovery of childhood cancer patients. This study was conducted on patients who were diagnosed with childhood cancer, and they were divided into the experimental group (8 patients who visited H association offices located in 3 cities and participated in the horticultural program) and the control group (5 patients who did not participate in the program). The homogeneity between the two groups before conducting the program was compared, and there was no statistically significant difference, which proved that the two groups were homogeneous. After conducting the program, the score of social immaturity, one of the sub-categories of problem behaviors, of the experimental group was statistically significantly lower than that of the control group (p=.019). Changes before and after the program within the groups were compared, and the somatization score (p=.039) of the experimental group (p=.039) after the program was 1.13, down from 2.13 before the program. The social immaturity score (p=.017) of the experimental group after the program was 1.00, down from 2.63 before the program, and the attention problem score (p=.026) of the group after the program was 1.25, down from 2.50 before the program. The total problem behavior score (p=.034) of the experimental group after the program was 9.63, down from 18.50 before the program, showing a statistically significant decrease. The cumulative subjective mood score (p=.000) of the experimental group throughout the entire sessions after the program was 7.82, up from 6.99 before the program, showing a statistically significant increase. Therefore, it can be concluded that the horticultural therapy program developed based on the ‘relaxationsocial support-cognitive behavior’ strategy was effective to reduce the negative psychosocial state of childhood cancer patients.
        298.
        2017.11 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        장 건강에 유익한 프리바이오틱스 소재를 개발하기 위하여 배변을 촉진하는 효능을 지닌 붉은팥을 식품 발효에 이용되는 Bacillus subtilis KCCM 11965P로 발효하여 다음과 같은 결과를 얻었다. 붉은팥의 일반성분은 회분 3.35±0.04%, 조단백질 21.1±0.19%, 조지방 0.35±0.02% 함 유되었다. 붉은팥 원물 1%, 3%, 5%와 Bacillus subtilis KCCM 11965P 3% (v/v)를 접종하여 0, 24, 48, 72시간 배양 하였다. 배양액의 총균수를 측정한 결과 붉은팥 원물을 3% 첨가한 후 72시간 배양군에서 Bacillus subtilis KCCM 11965P 발효가 가장 적합하였다. 발효 시간에 증가함에 따라 총 폴리페놀 함량과 DPPH 라디칼 소거활성이 증가하였다. Protease 활성은 붉은팥 원물 5% 첨가한 후 72시간 배양한 군(2.69±0.003 unit/mL)에서 활성이 가장 높았다. 발효시간과 붉은팥 원물 첨가 농도가 증가함에 따라 α -amylase 활성도 증가하였으며, 붉은팥 원물 5% 첨가한 후 72시간 배양한 군에서 0시간 배양군(1.0±0.1 unit/mL) 보다 26.0±0.2 unit/mL로 증가하였다. Bacillus subtilis KCCM 11965P로 72시간 배양한 후 유리아미노산을 측정한 결과 leucine은 붉은팥 원물 5% 첨가한 0시간 배양군 5.22 mg/L 에서 67.59 mg/L로 증가하였으며, 비필수아미노산인 tyrosine은 5% 첨가 0시간 배양군 10.08 mg/L에서 259.35 mg/L로 증가하였다. 이와 같이 Bacillus subtilis KCCM 11965P로 붉은팥을 발효하면 항산화 활성, protease 효소활성, 및 α-amylase 효소 활성이 증가하였으며, 유리아미노 산과 유기산이 증가하였다. 붉은팥을 발효하는데 Bacillus subtilis KCCM 11965P가 적합할 것으로 판단되며, 붉은팥은 프로바이오틱스를 활성화시켜 장 건강을 증진시킬 수 있는 프리바이오틱스 소재로 개발할 수 있는 가능성을 시사 하였다.
        299.
        2017.09 KCI 등재 서비스 종료(열람 제한)
        Present study aimed to determine the effect of ‘bitter melon’, a popularly used fruit in Bangladesh and several other Asian countries, on high-fat-diet-induced type 2 diabetes. To investigate the effect, ethanol extract from bitter melon (BME) as a dietary supplement with mouse chow was used. BME was found to significantly attenuate the high-fat diet (HFD) -induced body weight and total fat mass. BME also effectively reduced the insulin resistance induced by the HFD. Furthermore, dietary supplementation of BME was highly effective in increasing insulin sensitivity and reducing hepatic fat and obesity. These results indicate that BME could be effective in attenuating type 2 diabetes and could therefore be a preventive measure against type 2 diabetes.
        300.
        2017.05 서비스 종료(열람 제한)
        Background: Mahonia Nepalensis DC. (Hoang lien o ro), the specie of the family Berberidaceae, is widely distributed in the high mountainous areas at altitudes 1700 – 1900 m of Vietnam. It is found that the stem of Mahonia nepalensis indicated anti-inflammatory, anti-bacterial and antifungal activities and they are used particularly for the treatment of eczema, psoriasis, and other skin conditions. However, no study on the antioxidant and anti-cancer activities of Mahonia Nepalensis stem has been previously reported. The aim of this study was to evaluate anti-oxidant and anti-cancer activities of Mahonia Nepalensis stem. Methods and Results: The stem pieces of Mahonia Nepalensis were dried and extracted three times with 100% methanol. After that, the extract was suspended in distilled water and then partitioned with n-hexane, ethyl-acetate (EtOAc) and butanol (water saturated BuOH) fractions were then evaporated using a vacuum rotary evaporator. Evaluation of the anti-oxidative activity of Mahonia Nepalensis was carried out using a DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-producing system. The results revealed that the ethyl acetate fraction of M. nepalensis possessed higher potential DPPH radical scavenging activity (IC50, 81.88 ± 1.33㎍/㎖) than other fractions as well as BHT (2,6-Di-tert-Butyl-4-methylphenol) (IC50, 250.49 ± 1.60㎍/㎖). The reducing power assay was also investigated and EtOAc fraction showed higher absorbance values than other fractions. At 1.0 mg/ml concentration, EtOAc fraction showed absorbance of 1.72, be higher than Ascorbic acid. Cell viability was evaluated according to the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyl tetrazolium Bromide) assay. By MTT assay, all fractions showed a significant reduction in cell viability on COLO 205 (Human colon carcinoma cell) at the highest concentration tested (200㎍/ ㎖) with over 70% decrease in cell viability was obtained, and the highest significantly inhibiting effect occurred in butanol fraction with approximately 90% reduction in cell viability. Conclusion: We demonstrated that Mahonia Nepalensis stem extract has highly potential in anti-cancer activity. Further studies are necessary in order to explore the variety of Mahonia Nepalensis stem to be applied as a valuable natural material.