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        검색결과 93

        21.
        2018.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Electromagnetic interference (EMI) shielding is an important issue in modern daily life due to the increasing prevalence of electronic devices and their compact design. This study estimated EMI-shielding effect (EMI-SE) of small (8–14×17 mm) Hanji (Korean traditional paper) doped with carbon nanotubes (CNTs) and compared to Hanji without CNT using 2H (92.1 MHz) and 23Na (158.7 MHz) nuclear magnetic resonance (NMR) peak area data obtained from 1 M NaCl in D2O samples in capillary tubes that were wrapped in the Hanji samples. The simpler method of using the variation of reflected power and tuning frequency by inserting the sample into an NMR coil was also tested at 242.9, 158.7, and 92.1 MHz. Overall, EMI shielding was relatively more effective at the higher frequencies. Our results validated that NMR methods to be useful to evaluate EMI-SE, particularly for small, flexible shielding materials, and demonstrated that EMI shielding by absorption is dominant in Hanji mixed with CNT.
        4,000원
        22.
        2018.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 방문객 유형별로 장성 편백치유의 숲(Jangseong Pyunbaek Healing Forest: JPHF) 내 ‘치유필드’의 이용객 수에 대한 지각(perceived number of users: PNU)과 이용객수에 대한 평가기준(evaluative standards)을 설정, 비교하기 위해 시행되었다. 2017년 9월 중 JPHF 내 ‘치유필드’ 이용객을 대상으로 편의표본추출 방법을 통해 선정된 158명의 표본으로부터 설문지기법을 이용하여 자료를 수집하였다. 치유필드 방문객 중 휴양객(일반 휴양을 목적으로 한 방문객) 은 49.3%, 치유객(건강 및 치유를 목적으로 한 방문객) 15.3%, 휴치객(휴양과 치유를 동일정도로 추구하는 방문객) 35.3%로 구성되어 있었다. 응답자가 지각하는 치유필드 이용객수는 전체적으로는 평균 23.8명(중앙값: 20.0명)으로 나타났으며, 방문객 유형별 평균범위는 21.1-27.8명(중앙값: 20.0명 동일)으로 조사되었다. 응답자의 PNU는 혼잡지각(perceived crowding: PC)(r=0.23) 및 치유경험 방해 지각(perceived interference of healing experience: PIHE) (r=0.20)과 낮은 상관관계를 나타냈다. 방문객 유형 간에 치유필드 적정이용객수(optimal number of users: ONU)는 차이가 없었다. 전체적으로 적정이용객수는 평균 28.9명(중앙값: 25.0명)으로 나타났으며 방문객 유형별 적정이용객수 범위는 평균 25.4-31.4명(중앙값: 25.0-27.5명)으로 분석되었다. 또한 최대 허용가능 이용 객수(maximum acceptable number of users: MANU)는 전체적으로 38.1명으로 나타났으며, 방문객 유형별로는 휴양객 36.9명, 치유객 32.0명, 휴치객 38.0명으로 각각 조사되었다. 방문객 유형별로는 MANU에 차이가 없었다. 응답자의 PC는 평균 2.73(SD: 3.26, 9점 척도), PIHE는 평균 3.26(SD: 1.77, 9점 척도)으로 나타났으며 방문객 유형별로는 휴치객이 휴양객에 비해 통계적으로 높은 PC와 PIHE를 보였다. PNU가 ONU를 초과한 그룹은 그렇지 않은 그룹에 비해 높은 PC와 PIHE를 나타냈다. 연구결과를 토대로 관리적 관점에서의 시사점을 제시하였으며 본 연구의 한계점과 추후 연구에 대하여 토의하였다.
        4,500원
        23.
        2017.11 구독 인증기관·개인회원 무료
        This study investigated the interactions between starch and starch - derived materials and fluorescent materials. Many researchers have used fluorescent materials to monitor the internal structure of starch, which is an effective method. The purpose of this study was to observe the internal structure of starch by using fluorescent material and to check how much fluorescent material could be loaded inside the starch. For this, a standard curve of the fluorescent material was obtained and a linear graph corresponding to the concentration was obtained. Next, the incorporation of the fluorescent material into the starch was confirmed by CLSM in the infusion experiment. Infusion experiments were carried out to quantify the amount of fluorescent substance in starch, but the error was confirmed in this experiment. The error was caused by the action of starch and the fluorescent substances FD4 and NaFl, resulting in an increase or decrease in fluorescence intensity. To find the cause, dextrin, amylose and amylopectin, which are starch-derived substances, and α, β, γ-cyclodextrin, which can form inclusion compounds, were used. The fluorescent materials were merbromin, NaFl, and FITC. As a result, the fluorescence intensity of the fluorescent material was significantly influenced by the concentration of amylose and amylopectin. This result implies that there may be errors in the analysis of the phenomenon or observation of the starch using the fluorescent substance. We still do not know exactly the cause of this phenomenon, so further research is needed.
        25.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The microstructure, flexural properties, electrical conductivity, thermal conductivity and electromagnetic interference (EMI) shielding effectiveness (SE) of epoxy composites filled with multi-walled carbon nanotubes (CNTs), exfoliated graphite nanoplatelets (xGnPs) and CNT-xGnP hybrid filler were investigated. The EMI SE of the CNT-xGnP hybrid composite was higher than 25 dB at 100 MHz while that of the xGnP based composite was almost zero. The flexural modulus of the CNT-xGnP based epoxy composite continuously increased to 3.32 GPa with combined filler content up to 10 wt% while that of the CNT based epoxy composites slightly decreased to 1.96 GPa at 4 wt% CNT, and dropped to 1.57 GPa at 5 wt% loading, which is lower than that of epoxy. The CNT and CNT-xGnP samples had the same EMI SE at the same surface resistivity, because samples with the same surface conductivity have the same amount of the charge carriers.
        4,000원
        26.
        2017.04 구독 인증기관·개인회원 무료
        Nitric oxide (NO) is an immune mediator in several insects. In addition, eicosanoids mediate various immune responses in response to microbial challenges. This study focuses on cross-talk between two immune mediators. Nitric oxide synthase (SeNOS) of Spodoptera exigua was predicted in its cDNA sequence by interrogation to the transcriptomes and validated by RT-PCR against developmental stage and larval tissues. RNA interference (RNAi) of SeNOS suppressed nodule formation of S. exigua larvae against heat-killed Xenorhabdus hominickii. RNAi of SeNOS also suppressed NO levels in fat body and hemocytes along with suppression of PLA2 activity. NOS-specific inhibitor, L-NAME, also inhibited PLA2 activity, but its enantiomer, D-NAME, did not. However, PLA2 of dexamethasone or oxindole did not suppress NO levels in the immune tissues. In addition, X hominickii did not inhibit up-regulation of NO levels. These results suggest that NO signal activates PLA2 to produce eicosanoids to mediate immune responses
        27.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        복숭아순나방(Grapholita molesta)은 두 가지 주요 성페로몬 성분(Z-8-dodecenyl acetate and E-8-dodecenyl acetate)을 갖고 있다. 이 성 페로몬 성분의 생합성 과정 분석은 포화지방산의 10번 탄소에 이중결합을 합성하는 불포화효소(Δ10 DES)가 종 특이적 광학이성체 형성에 필수 적이라고 제시하였다. 그러나 이 효소의 분자적 특징에 대해서 분석되지 않았다. 본 연구는 복숭아순나방 성페로몬 샘의 전사체에서 Δ10 DES로 추정된 불포화효소(Gm-comp1575)의 단백질 기능 영역을 분석하였다. Gm-comp1575 유전자는 370개의 아미노산 서열 정보를 암호하고 있으며 분자량은 약 43.2 kDa 그리고 등전위점(pI)은 8.77로 추정되었다. 이 불포화효소는 4개의 막투과영역을 지니고 있으며, 6개의 탄수화물 결합 위 치가 아미노 말단과 세포내 영역에서 갖는 것으로 추정되었다. 분자계통분석은 Gm-comp1575가 다른 종에서 알려진 Δ10 DES와 유사성이 높은 것으로 밝혀졌다. Gm-comp1575 전사체는 암컷 성페로몬 샘 및 다른 복부 조직에서 발현되었다. 이 유전자 발현에 대한 RNA 간섭 처리는 처녀 암컷으로 하여금 사과원에서 수컷을 유인하는 능력을 크게 감소시켰다. 이러한 결과는 Gm-comp1575가 복숭아순나방의 성페로몬 생합성과 관련 이 있는 유전자라고 제시하고 있다.
        4,000원
        28.
        2016.10 구독 인증기관·개인회원 무료
        Beauveria bassiana JEF-007 with strong virulence against Riptortus pedestiris was selected for the Agrobacerium tumefaciens-mediated transformation(AtMT). AtMT generated two transformants, B1-06 and C1-49, showed significantly reduced virulence against R. pedestris. To identify the virulence-related genes, thermal asymmetric interlaced(TAIL) PCR and flanking region analysis were performed. From the analysis, two genes, Complex I intermediated-associated protein 30(CIA30) and Autophagy protein 22(Atg22), possibly related virulence in B. bassiana JEF-007. For the analysis of two putative virulence-related genes in JEF-007, hairpin RNA interference (hpRNAi) is under consideration. This work can provide the functional roles of the virulence-related genes in B. bassiana JEF-007.
        30.
        2016.04 구독 인증기관·개인회원 무료
        Integrin is a heterodimer protein that locates on cell membrane to interact with neighboring cells or extracellular matrix. A transcriptome analysis of the brassica leaf beetle, Phaedon brassicae, midgut identified both α and β subunits of integrin. RNA interference of β subunit genes significantly impaired survival of both larvae and adults of P. brassicae. A recombinant bacteria expressing double-stranded RNA specific to β integrin of P. brassicae were constructed and showed significant oral toxicities.
        31.
        2016.04 구독 인증기관·개인회원 무료
        Expression of hairpin RNA corresponding to the part of COPA transcript was done by agroinfiltration in soybean plants and was confirmed by qRT-PCR. In a pot experiment, T. urticae was infested on agroinfiltrated soybean plants and T. urticae mortality was observed and compared with control plants overtime. Significantly higher mortalities of T. urticae were observed in the COPA-agroinfiltrated soybean plants from post-infestation day 2 (15 ±5%), day 4 (50 ±10 %). At post-infestation day 6, mortality reached to (70 ± 15%). To validate the observed COPA silencing effect in T. urticae fed on the agroinfiltrated soybean plant expressing COPA hairpin RNAs, qRT-PCR analysis was performed. The transcript level of COPA gene was decreased in T. urticae fed on agroinfiltrated soybean plants expressing COPA hairpin RNA from post-infestation day 2. At post-infestation day 2, 4 and 6, COPA transcript levels were reduced by 23.8, 20.7 and 18.8 fold, respectively compared to post-infestation day 1 (control). The results obtained in this study also ruled that the plant mediated production and uptake of silencing (dsRNAs/siRNAs) is an effective way to trigger RNAi in the T. urticae.
        32.
        2016.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        TGS(Tomographic Gamma Scan)분석 기술은 방사성폐기물 드럼을 10×10×16개의 단위부피로 분할하여 분할단위 마다 밀 도 및 방사능 농도를 각각 측정하기 때문에 기존 기술에 비해 높은 분석정확도를 갖는 장점에 비하여 낮은 정밀도를 갖는 단 점이 있다. 이를 보완하기 위해 하나의 에너지를 구별하는 전흡수피크(Full Energy Peak)의 범위(ROI : Region of Interest) 를 넓게 설정하여 정밀도를 최적화한다. 하지만 전흡수피크의 범위 증가는 인접한 에너지를 방출하는 핵종간 상호간섭이 발 생할 확률이 높아진다. 본 연구에서는 TGS분석에서 기준 핵종인 137Cs(661.66 keV 반감기 30.5 년) 정량분석에 간섭을 일으 키는 원인을 규명하였으며 그 원인으로 인접한 110mAg(657.75 keV 반감기 249.76 일)임을 확인하였다. 이러한 간섭을 제거 할 수 있는 방안으로 최적화된 ROI를 결정할 수 있는 새로운 교정기술을 개발하였으며 본 교정기술을 적용 후 정확도 검사 에서 기준핵종 137Cs을 정확히 판정함을 확인하였다.
        4,000원
        34.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Radio sources are very weak, as they can travel through large distances. Radio sources also have photons with low energies compared to others electromagnetic waves (EM). Microwave photons have a little more energy than radio waves, infrared photons have still more, then visible, ultraviolet, X-rays, and the most energetic electromagnetic wave is gamma-rays. Radio astronomy studies are restricted due to radio frequency interference (RFI) produced by people. If this disturbance is not minimized, it poses critical problems for astrophysical studies. The purpose of this paper is to profile RFI maps in Peninsular Malaysia with a minimum mapping technique for RFI interference. Decision-making processes using GIS (Geographical Information System) for the selection requires gathering information for a variety of parameters. These factors affecting the selection process are also taken into account. In this study, various factors or parameters are involved, such as the availability of telecommunications transmission (including radio and television), rainfall, water lines and human activity. This mapping step must be followed by RFI site testing in order to identify areas of low RFI. This study will benefit radio astronomy research, especially regarding the RFI profile.
        3,000원
        35.
        2015.04 구독 인증기관 무료, 개인회원 유료
        This work is for evaluating the intentional interference against GNSS receiver on surface ships. The case study was performed under considerable assumptions based on the GPS jamming events around the Korean Peninsula in recent years. The propagation loss
        3,000원
        36.
        2014.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to examine the effect of three cognitive tasks on gait at a preferred walking speed, and at a fast speed, using dual-task methodology. A total of 29 stroke patients participated in the study. All 29 subjects performed 2 motor tasks (10-meter walk task and timed up and go task each at a preferred and a fast speed) and three cognitive tasks [Stroop, word list generation (WLG), serial subtraction (SS)] under dual-task conditions [cognitive-motor interference (CMI)] in a randomized order. Gait speeds were measured in six different conditions. A repeated-measure analysis of variance was employed to compare the results of the Stroop training, WLG, and SS tasks during preferred and fast walking. A Bonferroni adjustment use for post hoc analysis. The level of statistical significance was set at α=.05. A CMI effect occurred for performance of a 10-meter walking task at two different speed and a cognitive task (p<.05). Stroop had a significantly greater effect than SS and WLG (p<.05). The timed up and go task was affected when performed with fast walking speed during Stroop cognitive task (p<.05), but was not affected if performed with preferred walking speed during a cognitive task (p>;.05). This study showed that CMI of Stroop can be used as a rehabilitation program for stroke patients.
        4,000원
        37.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, methods that usea carbon-based filler, a conductive nanomaterial, have been investigated to develop composite fillers containing dielectric materials. In this study, we added geometric changes to a carbon fiber, a typical carbon-based filler material, by differentiating the orientation angle and the number of plies of the fiber. We also studied the electrical and electromagnetic shield characteristics. Based on the orientation angle of 0˚, the orientation angle of the carbon fiber was changed between 0, 15, 30, 45, and 90˚, and 2, 4, and 6 plies were stacked for each orientation angle. The maximum effect was found when the orientation angle was 90˚, which was perpendicular to the electromagnetic wave flow, as compared to 0˚, in which case the electrical resistance was small. Therefore, it is verified that the orientation angle has more of an effect on the electromagnetic interference shield performance than the number of plies.
        4,000원
        38.
        2014.10 구독 인증기관·개인회원 무료
        The ectoparasitic honey bee mites was originally confined to the Asian honey bee(Apis cerana etc.), mites had become widely established in the world and have continued to cause extensive bee colony deaths. Mites attach to adults and developing brood, where they feed on their blood. If left untreated, mites can deform bees and eventually kill the colony. Varroa destructor and Tropilaelaps clareae has plagued European honey bees, Apis mellifera. Differences in mite tolerance are reported between two honey bee species A. mellifera and A. cerana. We were counted number of mites(V. destructor and T. clareae) form 20 colonies. V. destructor and T. clareae has very similar behavior in honeybee colony. When behaviorally close, two competing species may populational interfere, and thereby affect their population dynamics. We tested for populational interference (PI) between two populational competing honeybee mites, V. destructor and T. clareae, by investigating their population dynamics when they competed on the same colony.
        39.
        2014.10 구독 인증기관·개인회원 무료
        Rice stripe virus (RSV) is one of the serious plant pathogenic viruses for rice transmitted by small brown planthopper, SBPH, Laodalphax striatellus. RNA interference (RNAi) is an universal gene-knockdown mechanism in eukaryotic organisms which includes insects,and has been considered as an alternative strategy to control insect pests. Hence, we applied this technique to interfere the translation of target RNA genes to knockdown the virus gene on RSV-viruliferous L. striatellus. Three out of seven RSV genes, RdRp, NS3, and NCP were used as target genes and each dsRNA targeting the viral genes were delivered to the insects indirectly through the rice leaves by irrigation. As a result, not only the relative expression level of target genes decreased but also those of non-target genes and the replication of RSV genome as well. In summary, leaf-mediated dsRNA feeding methods would be useful in the knockdown of target genes on piercing-sucking insects. The genes used in this experiment can be utilized for the development of pest-resistant transgenic plants based on RNAi.
        40.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Previous studies have reported that decreased cognitive ability has been consistently associated with significant declines in performance of one or both tasks under a dual-task walking condition. This study examined the relationship between specific cognitive abilities and the dual-task costs (DTCs) of spatio-temporal gait parameters in stroke patients. The spatio-temporal gait parameters were measured among 30 stroke patients while walking with and without a cognitive task (Stroop Word-Color Task) at the study participant's preferred walking speed. Cognitive abilities were measured using Computerized Neuropsychological Testing. Pearson's correlation coefficients (r) were calculated to quantify the associations between the neuropsychological measures and the DTCs in the spatio-temporal gait parameters. Moderate to strong correlations were found between the Auditory Continuous Performance test (ACPT) and the DTCs of the Single Support Time of Non-paretic (r=.37), the Trail Making A (TMA) test and the DTCs of Velocity (r=.71), TMA test and the DTCs of the Step Length of Paretic (r=.37), TMA test and the DTCs of the Step Length Non-paretic (r=.36), the Trail Making B (TMB) test and the DTCs of Velocity (r=.70), the Stroop Word-Color test and the DTCs of Velocity (r=-.40), Visual-span Backward (V-span B) test and the DTCs of Velocity (r=-.41), V-span B test and the DTCs of the Double Support Time of Non-paretic (r=.38), Digit-span Forward test and the DTCs of the Step Time of Non-paretic (r=-.39), and Digit-span Backward test and the DTCs of the Single Support Time of Paretic (r=.36). Especially TMA test and TMB test were found to be more strongly correlated to the DTCs of gait velocity than the other correlations. Understanding these cognitive features will provide guidance for identifying dual- task walking ability.
        4,000원
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