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        검색결과 107

        6.
        2023.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The Wide-Angle Polarimetric Camera (PolCam) is installed on the Korea’s lunar orbiter, Danuri, which launched on August 5, 2022. The mission objectives of PolCam are to construct photometric maps at a wavelength of 336 nm and polarization maps at 461 and 748 nm, with a phase angle range of 0◦–135◦ and a spatial resolution of less than 100 m. PolCam is an imager using the push-broom method and has two cameras, Cam 1 and Cam 2, with a viewing angle of 45◦ to the right and left of the spacecraft’s direction of orbit. We conducted performance tests in a laboratory setting before installing PolCam’s flight model on the spacecraft. We analyzed the CCD’s dark current, flat-field frame, spot size, and light flux. The dark current was obtained during thermal / vacuum test with various temperatures and the flat-field frame data was also obtained with an integrating sphere and tungsten light bulb. We describe the calibration method and results in this study.
        4,000원
        11.
        2021.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The present study investigated Korean-accented English (KoE) intelligibility and conducted experiments in Korea, Japan, and the USA to test the benefits of listener’s familiarity and identify the key phonological features of KoE. In the experiments, the participants were asked to transcribe the target (KoE) of 100 English statements each containing a target word representing one of the nine features. The transcription data were administered to four groups, depending upon the degree of KoE familiarity (length of exposure). The results indicated that KoE was most intelligible to native English speakers with lower familiarity and least intelligible to the Japanese participants with low KoE familiarity. Although the listeners’ familiarity did not necessarily either facilitate or impede the intelligibility of KoE, the listeners with higher familiarity with KoE tended to recognize the voiced consonants of KoE better. The findings also indicated which KoE characteristics affected the overall intelligibility level, suggesting ways to prioritize KoE features in English language learning in Korean classrooms.
        6,100원
        13.
        2020.09 구독 인증기관 무료, 개인회원 유료
        Acacetin, which is present in damiana (Turnera diffusa ) and black locust (Robinia pseudoacacia ), has several pharmacologic activities such as antioxidant, anti-inflammatory, and anti-proliferative effects on cancer cells. However, the effect of acacetin on head and neck cancers has not been clearly established. This study aimed to examine the effects of acacetin on cell growth and apoptosis induction in FaDu human pharyngeal carcinoma cells. These were investigated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, Live/Dead cell assay, 4′,6-diamidino-2-phenylindole dihydrochloride staining, caspase-3 and caspase-7 activation assay, and immunoblotting in FaDu cells. Acacetin induced FaDu cell death in a dose-dependent manner, with an estimated IC50 value of 41.9 µM, without affecting the viability of L-929 mouse fibroblasts as normal cells. Acacetin treatment resulted in nuclear condensation in the FaDu cells. It promoted the proteolytic cleavage of procaspase-3, -7, -8, and -9 with increasing amounts of the cleaved caspase isoforms in FaDu cells. Acacetin-induced apoptosis in FaDu cells was mediated by the expression of Fas and activation of caspase-8, caspase-3, and poly (ADP-ribose) polymerase. Immunoblotting showed downregulation of the anti-apoptotic mitochondrial proteins Bcl-2 and Bcl-xL, but upregulation of the mitochondria-dependent pro-apoptotic proteins Bax and Badin FaDu cells after acacetin treatment. These findings indicate that acacetin inhibits cell proliferation and induces apoptotic cell death in FaDu human pharyngeal carcinoma cells via both the death receptor-mediated extrinsic apoptotic pathway and the mitochondria-mediated intrinsic apoptotic pathway.
        4,000원
        15.
        2019.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The purpose of this paper is to examine the intelligibility and attitude towards four English varieties to Korean-speaking learners (KSLs) of English, who have been exposed mainly to General American (or Korean-accented English) in their English language learning classrooms throughout the primary and secondary schools. A total of 105 Korean undergraduate students listened to a recording in one of the four accents (General American, British, Australian, and Korean-accented English) and completed an intelligibility test followed by a questionnaire survey on attitudes. Analysis revealed that British English was most intelligible to KSLs among four varieties whereas that of Australian was least intelligible. Attitudes toward an English variety did not exert a strong force that may contribute to the level of intelligibility. The findings also showed at which phonological features identified KSLs were most sensitive to intelligibility differences. We conclude that the more exposed English variety to KSLs, the more favorable attitudes can be formed, but is not necessarily intelligible. What the findings demonstrate is that attitudes are not the best explanation of intelligibility and call for improvement in ways of directing KSLs’ attention to some phonological features in a learnability perspective.
        5,700원
        16.
        2019.04 구독 인증기관·개인회원 무료
        The fumigation toxicity of carbonyl sulfide to T. castaneum as a storage grain pest was evaluated. Carbonyl sulfide (COS) is registered in Australia for microorganism present in soil, root and fertilizer. the fumigation activity of carbonyl sulfide was investigated in 12 L desiccator for 24 h exposure to eggs, larvae, pupae, adults of T. castaneum. Eggs and pupae were showed 87.3% and 95.6% mortality for 25 mg/L of COS, respectively. Larvae and adults were investigated with 80.0% and 100.0% mortality at 15 mg/L treatment, respectively. Therefore, the eggs of T. castaneum showed the highest tolerance to COS.
        17.
        2019.04 구독 인증기관·개인회원 무료
        The fumigation activity of phosphine (PH3) to T. castaneum as a storage grain pest was evaluated. The lethal concentration time (LCT) value of each developmental stage (egg, early larva, late larva, pupa and adult) of T. castaneum was analyzed in 12 L desiccator. At the T. castaneum larva stages, exposure for 4 h showed low LCT value, especially in early stage larvae (LCT99 = 0.32 mg·h/L) which is very high susceptibility to PH3. However, T. castaneum eggs were observed very high tolerance to PH3 at LCT99 77.47 mg·h/L. Therefore, the fumigant activity of PH3 against T. castaneum can be found to be significantly different depending on developmental stage.
        19.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the short-term effects of lumbar rotational mobilization under the single-leg standing (SLS) position. Fifteen healthy individuals were recruited, and randomized to agroup of trunk rotational exercise (TRE) and lumbar rotational mobilization (LRM). Trunk twist rotational exercise was performed to the TRE group, and mobilization was applied to the LRM group on the lumbar spine. Velocity of the center of pressure (VCOP) and center of pressure (COP) for each participant were measured through SLS. COPs were not significantly increased or decreased after treatment in both groups. VCOPs also did not change considerably except on the right side when the eye was closed. There was no significant difference between COPs and VCOPs in two groups. This study suggests that trunk rotation exercise and lumbar rotation mobilization would have similar effects on balance ability.
        4,000원
        20.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The original focus of this study was to investigate the immediate effects of lumbar rotational mobilization on the one-legged standing ability. Fifteen subjects (6 men and 9 women, mean age = 22.77 (SD = 1.21), mean height = 165.46cm (SD = 11.65), mean weight = 61.46kg (SD = 8.29) volunteers from healthy individuals were recruited and randomized to a lumbar rotational mobilization (LRM) group and a trunk rotational exercise (TRE) group. Mobilization (grade 3 or 4) was applied to the LRM group on the lumbar spine (L1 to L5) in a side-lying, and trunk twist exercise (left and right side) was applied the to the TRE group with lunge position. Center of pressure (COP) and the velocity of the center of pressure (VCOP) of each participant were measured as a balance ability through one leg standing position. Results are as follows. In within-group difference, the COP of the LRM group reduced during standing with the right foot, but the VCOP change of the LRM was not statistically significant. In between-groups difference, COP of TRE group was decreased compared with LRM group only during left leg standing in the eyes (p <.05). The results of this study suggest that LRM is more effective than TRE in improving balance ability.
        4,000원
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