검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 66

        1.
        2024.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Forbush decreases (FDs), as the transient event of decreasing cosmic ray (CR) intensity, show the main phase of a sudden decrease within approximately one day and the recovery phase over several days. FDs are associated with abrupt solar wind events such as interplanetary shocks (IP shocks) and magnetic clouds. FD generation is explained by drift due to the magnetic field strength and by diffusion caused by magnetic turbulence. The FDs and the IP shocks from 1998 to 2004 in the solar maximum period were chosen to determine a more effective generation of FD between drift and diffusion. Seventy FDs with a CR variation of more than 3.0% and a minimum value of less than −1.5% were selected using Oulu neutron monitor data. The Advanced Composition Explorer satellite identified 292 IP shocks and we divided them into two sections: the pre-sheath region ahead of the shock front and the post-sheath region behind the shock front. The magnetic field strength, magnetic turbulence, solar wind speed, and solar wind turbulence of the post-sheath regions were analyzed. Most (62/70) of the FDs were associated with the post-sheath regions of the IP shocks. The important factors that generated the FDs were drift by the large physical properties in the post-sheath regions and diffusion by the strong turbulence in the post-sheath regions. The increase in the magnitude of interplanetary magnetic field (IMF) shows larger in the IP shocks associated with FD (2.33 times) than in those not associated with an FD (1.70 times) between the pre-sheath and post-sheath regions. On the other hand, the increase in turbulence of IMF was the same for IP shocks associated with an FD and not associated with an FD. Although it was difficult to determine the dominant factor for the generation of FDs, the present study suggested that the drift by the magnetic field strength may play a more significant role than the diffusion by the magnetic turbulence.
        4,000원
        2.
        2024.04 구독 인증기관·개인회원 무료
        An unrecorded gall midge was discovered from inflorescence galls on Castanopsis sieboldii (Makino) Hatus. ex T.Yamaz. & Mashiba, which is one of major components in evergreen forests on the Korean Peninsula. The galls occurred on 20 trees out of 230 on Yokiji Island. The gall midge was identified as Schizomyia castanopsisae Elsayed & Tokuda, 2018 (Diptera: Cecidomyiidae), using morphological characters and mitochondrial DNA cytochrome oxidase subunit 1 (COI) region sequences of gall midge’s larvae. The Barcode sequences of 40 samples collected from Yokji Island were identical, and the individuals from Yokji Island formed a clade with the individuals from Kyushu, with robust bootstrap support in a maximum likelihood tree. This result suggests the gall midges may have migrated from Kyushu, Japan to Yokji Island, South Korea. However, it is too early to determine if the gall midge is truly invasive or not at present due to paucity of distribution data in the country.
        3.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Cadmium (Cd) is toxic heavy metal that accumulates in organisms after passing through their respiratory and digestive tracts. Although several studies have reported the toxic effects of Cd exposure on human health, its role in embryonic development during preimplantation stage remains unclear. We investigated the effects of Cd on porcine embryonic development and elucidated the mechanism. Methods: We cultured parthenogenetic embryos in media treated with 0, 20, 40, or 60 μM Cd for 6 days and evaluated the rates of cleavage and blastocyst formation. To investigate the mechanism of Cd toxicity, we examined intracellular reactive oxygen species (ROS) and glutathione (GSH) levels. Moreover, we examined mitochondrial content, membrane potential, and ROS. Results: Cleavage and blastocyst formation rates began to decrease significantly in the 40 μM Cd group compared with the control. During post-blastulation, development was significantly delayed in the Cd group. Cd exposure significantly decreased cell number and increased apoptosis rate compared with the control. Embryos exposed to Cd had significantly higher ROS and lower GSH levels, as well as lower expression of antioxidant enzymes, compared with the control. Moreover, embryos exposed to Cd exhibited a significant decrease in mitochondrial content, mitochondrial membrane potential, and expression of mitochondrial genes and an increase in mitochondrial ROS compared to the control. Conclusions: We demonstrated that Cd exposure impairs porcine embryonic development by inducing oxidative stress and mitochondrial dysfunction. Our findings provide insights into the toxicity of Cd exposure on mammalian embryonic development and highlight the importance of preventing Cd pollution.
        4,000원
        4.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study was designed to investigate the antiproliferative activity and molecular mechanisms of Bibimbap in HT-29 human colorectal adenocarcinoma cells. Bibimbap extract inhibited the proliferation of HT-29 cells by 50% at a concentration of 10.1±0.17 mg/mL for 48 h. The population of live cells decreased slightly, and the morphology changed with a reduction in cell volume (pyknosis) with Bibimbap. Treatment with 5 mg/mL of Bibimbap resulted in slight cell shrinkage. Furthermore, as the Bibimbap dose increased to 10 mg/mL, these characteristics were more evident, and HT-29 cells exhibited partial detachment by staining with the DNA-binding dye Hoechst 33342. Flow cytometric analysis by Annexin V and PI double staining showed that Bibimbap increased the levels of apoptosis. Analysis of the mechanism of these events showed that Bibimbap-treated cells exhibited a mitochondria-dependent apoptotic pathway through the modulation of caspase-3, caspase-8, caspase-9, and poly-ADP ribose polymerase, as well as Bax and Bcl-2 expression in dose- and time-dependent manners. Consequently, Bibimbap exerts a significant antiproliferative effect on HT-29 human colorectal adenocarcinoma cells.
        4,000원
        5.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Speed management is essential for enhancing children’s safety in school zones. The objectives of this study are to analyze how digital-based school zone signs and newly proposed signage for increasing visibility influence speed reductions and how the new system facilitates drivers obeying the speed limits. METHODS : A before/after analysis technique with comparison groups (widely used to evaluate safety effects) was employed. To effectively capture the safety effects of the new system, two significant measures were selected as the measures of effectiveness: the rates of change in space mean speeds and speed limit compliance. RESULTS : With three target sites and three comparison sites, the mean space speeds after installing the new systems were found to be slightly reduced for all target sites (the reduction rates of the space mean speed were found to be 5% for site A, 1% for site B, and 6% for site C). The lack of a constant tendency in speed reduction effects at all sites might be owing to the fact that the speed data collection was conducted before the driver's system adaptation was sufficiently performed. Regarding the speed limit compliance rate, significant increases were observed at two sites (10% for site A and 51% for site C), but site B did not show an increasing effect. The reason for the absence of this effect is that the installation of crosswalks and speed bumps at the target site affected the driver's compliance with the speed limit. CONCLUSIONS : An insufficient amount of evaluation results was obtained for the new guidance system. However, the new guidance system method provides an alternative approach to improving children's safety, i.e., by inducing drivers to actively slow down in school zones.
        4,000원
        9.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, data from the 7th (2016~2018) and 8th (2019) Korea National Health and Nutrition Examination Surveys were used, which included 5,325 subjects. Health behavior, dietary and nutrient intake status, physical measurement and biochemical characteristics, and risk factors for elderly related chronic diseases were classified and analyzed according to the changing composition of single households and other households in the current society. As a result, the ratio of current smokers and drinkers in young adult single households, walking less than 30 minutes per day, subjective health status was poor, breakfast rate less than three times per week, eating out frequency more than once a day, lipid intake ratio to total calories, saturation fatty acid intake were significantly higher. In addition, waist circumference, and diastolic blood pressure were significantly higher. However, dietary fiber intake level was significantly lower. The results for hypertension, which is the representative chronic disease that causes old age-related chronic diseases, were significantly higher in single households (ORs=1.400 (95% CI: 1.095, 1.791), p=0.007). Although young adults may not have showed particularly serious health problems yet, education is believed as important to recognize and prevent age-related disease risk factors.
        4,000원
        10.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The main purpose of this study was to examine the correlation between the consumption of red ginseng-based ‘SSR’ for 30 days and the reduction in human fatigue, blood component changes, and immune cell activity in 35 human subjects. ‘SSR’ is composed of zinc oxide, folic acid, and D-α-tocopherol with red ginseng as the main component. According to the protocol criteria of the study, 35 subjects who understood the purpose of the study and signed an informed consent form were selected. The fatigue survey was conducted through a questionnaire, and after taking ‘SSR', a decreased tendency of physical, mental, and neurosensory fatigue was observed. In hematological analysis, no significant changes were observed in the levels of WBC, RBC, and hemoglobin; however, AST (SGOT) and ALT (SGPT) levels were statistically significantly decreased. In immunological analysis, it was observed that the proliferative effect of T cells (CD3+CD4+) was greater than that of NK cells (CD16+CD56+). The collected data were subjected to t-test analysis using the SPSS 25.0 statistical program. The result from this study proposes that ‘SSR’ can be used as a functional food material as it reduces human fatigue and enhances immune function.
        4,200원
        11.
        2020.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We investigate the plausibility of mass return, from stellar mass loss processes within the central ~100 pc region of the Milky Way (the inner nuclear bulge), as a mass supply mechanism for the Circumnuclear Disk (CND). Gas in the Galactic disk migrates inward to the Galactic centre due to the asymmetric potential caused by the Galactic bar. The inward migration of gas stops and accumulates to form the central molecular zone (CMZ), at 100{200 pc from the Galactic center. It is commonly assumed that stars have formed in the CMZ throughout the lifetime of the Galaxy and have diffused inward to form a 'r-2 stellar cusp' within the inner nuclear bulge. We propose that the stars migrating inward from the CMZ supply gas to the inner nuclear bulge via stellar mass loss, resulting in the formation of a gas disk along the Galactic plane and subsequent inward migration down to the central 10 pc region (CND). We simulate the evolution of a gas distribution that initially follows the stellar distribution of the aforementioned stellar cusp, and illustrate the potential gas supply toward the CND.
        4,000원
        12.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The concentrations of volatile organic compounds (VOCs) and odor-inducing substances were measured using selected ion flow tube mass spectrometers (SIFT-MS) and a drone equipped with an air quality monitoring system. SIFT-MS can continuously measure the concentration of VOCs and odor-inducing substances in realtime without any pre-treating steps for the sample. The vehicle with SIFT-MS was used for real-time measurement of VOC concentration at the site boundaries of pollution sources. It is possible to directly analyze VOCs concentration generated at the outlets by capturing air from the pollution sources with a drone. VOCs concentrations of nine spots from Banwol National Industrial Complex were measured by a vehicle equipped with SIFT-MS and were compared with the background concentration measured inside the Metropolitan Air Quality Management Office. In three out of the nine spots, the concentration of toluene, xylene, hydrogen sulfide, and methyl ethyl ketone was shown to be much higher than the background concentration. The VOCs concentrations obtained using drones for high-concentration suspected areas showed similar tendencies as those measured using the vehicle with SIFTMS at the site boundary. We showed that if both the drone and real-time air quality monitoring equipment are used to measure VOCs concentration, it is possible to identify the pollutant sources at the industrial complex quickly and efficiently check sites with high concentrations of VOCs.
        4,000원
        13.
        2019.12 구독 인증기관 무료, 개인회원 유료
        Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans (Aa), Tannerella forsythia (Tf), Prevotella intermedia (Pi), and Fusobacterium nucleatum (Fn) are major periodontal pathogens. Lipopolysaccharides (LPSs) from periodontal bacteria play an important role in periodontal pathogenesis by stimulating host cells to produce inflammatory cytokines. In this study, highly pure LPSs from the five major periodontopathogens were prepared, and their monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α)-inducing activities were compared in human umbilical vein endothelial cells (HUVECs) and THP-1 macrophagic cells, respectively. In HUVECs, LPSs from Aa and Fn were potent stimulators for MCP-1 induction; however, LPSs from Pg, Pi, and Tf were much weaker MCP-1 inducers. In THP-1 cells, LPSs from Pg, Aa, and Fn were relatively strong inducers of TNF-α, whereas LPSs from Pi and Tf produced little activity. The Toll-like receptor (TLR)2/TLR4 dependency of various LPSs was also determined by measuring NF-κB reporter activity in TLR2- or TLR4-expressing 293 cells. LPSs from Aa, Fn, and Tf stimulated only TLR4; however, LPSs from Pg and Pi stimulated both TLR2 and TLR4. These results suggest that LPSs from major periodontal bacteria differ considerably in their cell-stimulating activity.
        4,000원
        14.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We developed a wet scrubber by applying cyclone flow to the gas flow and using a spiral filter structure. While the size of a new scrubber was about half that of a conventional scrubber, the device showed relatively high efficiency in pollutants removal such as particulate matter and compounds inducing odor. The new scrubber installed in a plating industry showed a higher removal efficiency of about 5% for dust, about 23% for hydrogen chloride, and about 23% for sulfur dioxide compared to the conventional scrubber. Plurality of tubes in the spiral filer housing are arranged to be vertically shifted from each other. Because the upward residual gas does not directly rise vertically, the residence time of gas between the filter plates is extended. Thus, the purification efficiency of the pollutants was enhanced in the new scrubber. In addition, the new scrubber developed in this study is more cost effective because the cost saving in manufacturing it compared with a conventional scrubber increases with increasing the size of equipment. It is expected that a scrubber with better dust collecting efficiency can be obtained by carrying out a study in connection with facilities capable of controlling acidity of washing water.
        4,000원
        15.
        2018.07 구독 인증기관 무료, 개인회원 유료
        Introduction Advertisers use substantial resources to design effective multimedia ads, hoping to leave lasting remnants of brand information in the long-term memory of consumers (Wedel & Pieters, 2000). Brands use music as a way of expressing their personality and image with the public, and the sound must combine in a positive way and be in synergy with the other elements of the advertisement.(Sá, 2010). In the same way as priming concepts, there is an academic controversy on this theme in the academic literature. The explanation relies on the argument that ad music or background music is perceived initially when the stimulus happens, in a commercial for example, slowing or even inhibiting the consequent processing of branded message elements and reducing the recall to the background. The degree of this recall reduction depends on the music structural features as well as the advertised brand. (Hampshire et. al, 2010). So in this context we get to the research question: The stimulated music priming can be the induction item to brand recall advertised in a TV commercials. The purpose of this research is to analyse whether musical priming induces a greater recall of brands, with the utilization of Neuromarketing tools. Gap Gerald Gorn (1982) published "The Effects of Music on Advertising on Behaviour of Choice: A Classical Conditioning Approach" that proliferated dramatically in academic literature (as evidenced by 881 citations in Google Scholar, 266 in the Web of Knowledge in 2015. Gorns´ hypotheses have until now, been widely accepted by academia, which can be summarized as "cross modal" conditioning (in this case, a musical stimulus that influences affective responses to a visual stimulus) can effectively change consumer behaviour through a single exposure. The Gorn´s hypotheses still have relevance to the practice of traditional advertising and the current one, but they are subject to much controversy. Several authors (Allen & Madden 1985; Kellaris & Cox 1989) have argued that these effects may have been due to demand artefacts, rather than conditioned by Gorn's (1982) postulates. They cite as possible failure causes in the conclusions, for example, that demand artefacts may be the result of the presence of a non-blind experimenter, and that the research design may have explicitly related to music with the product, later corroborated by Vermeulen et al. (2014). Methodology The experiment was done in Pacífico Business School Neuroscience Lab in Lima, Peru in December 2017 with the presence of the researcher and two assistants. Research design For this research, was recruited a population of 80 millennials students (aged from 25 to 35 years old of both sex). – First, was edited six TV commercial unknown with music/jingles spots with the duration 20-30 seconds. Research equipment: In the Lab was used iMotions system through the implementation of the FACET module. Such module analyses the face images, in order to detect the movement by tension or relaxation of the muscles, identifying the Action Units (AU) after the detection of such units the correlation of the AU by the use of the Facial Action Coding System (FACS) deploys a value related with the probability of the emotion being displayed by the subject. For the registration of eye movements of the students a Tobii X2-30 device was used, with a Tobii pro3.4.8 software, manufactured by Tobii Technology (Tobii, 2014). This device works at a sampling frequency of 60 Hz and has a spatial resolution of less than 0.5º. The eye tracker was attached to a 24-inch TFT computer monitor with a maximum resolution of 1920 x 1200 pixels. Pre-test: All 80 members of the initial group in the Lab were initially stimulated the six videos, and at the same time they assures that they not recognized the spots. If positive, we asked to what TV commercial was related. From the group that did not recognize the spot we selected 40 individuals for the experiment. Another not stimulated group of 40 individuals was used as the control group in order to have external validity and reliability . Stimulus: To verify musical priming the experiment group repeated the test two other times (after 10 days after initial stimulation, to avoid short-term memories). After the experiment was asked to the participants to answered a questionnaire based on Well’s Brand Awareness scale (1993) that sought to verify the priming effect and attitude in relation to the brand. Findings Monitoring of eye tracking in real time and watching video of each participant’s session clearly revealed that in this pilot study the control group participants had a difficult time to recognize the TV commercials. The target group shown priming effect in both two spots. Average rated target group (M = 4.07, SD = 0.78) was significantly higher than control group [M = 3.57, SD = 0.94, t(135.7) = 3.47, p < 0.001].The results also suggest that music’s temporal differences provoked important priming effects. In the TD group, fixations were classified for 81.69 % (SD = 10.50) of the experiment. The overall looking duration (after filtering) did not differ between the groups (mean/SD for ASD = 10.41/1.91 s; mean/SD for TD = 11.02/1.45; t(80) = 1.437, ns). The total number of fixations (per TV commercial) was not significantly different between the groups (mean/SD for ASD = 36.05/12.10; mean/SD for TD = 45.00/22.36; ns, Mann–Whitney U Test). Similarly, the fixation rate (fixations per second) was equal across groups (mean/SD for ASD = 3.95/3.48 fixations/second; mean/SD for TD = 4.44/3.34; ns, Mann–Whitney U Test). The results inferred the power of music in priming effect. Originality/value and practical implications The utilization of neuroscience tools brought a new perspective, as stimuli reactions were observed in real time without self-related marketing and behavioural test exhaustive replicated before. Music is still an unexplained paradigm in human behaviour, but there is no discussion about its importance and business potentiality
        3,000원
        16.
        2018.07 구독 인증기관·개인회원 무료
        This study presents a machine learning approach using conditional inference tree (Ctree) to determine how brand equity can be used to factually engage consumers into social media brand-related activities. Using the Ctree algorithm (Hothorn, Hornik, & Zeileis, 2006), a predictive model was computed using self-reported data on consumers’ perceptions of brand equity (Aaker, 1991) and engagement into social media brand-related behavior (Muntinga, Moorman, & Smit, 2011) from a sample of 690 individuals. The predictive modeling analysis revealed 5 different rules (patterns) that trigger social media brand-related behavior. Each rule comprises behavioral engagement discriminating low, medium, and high levels of consumption, contribution, and creation of brand-related social media content. Additionally, the analysis portrait 5 subtypes of consumers according to their behavior. This study has incremental explanatory power over preceding consumer brand engagement studies, in that it demonstrates how to manage brand equity to factually engage consumers into social media brand-related activities, therefore, generating valuable insights that may be used to support business.
        17.
        2018.05 구독 인증기관·개인회원 무료
        The objective of this study was to evaluate the effectiveness of various crack inducers to be used in the advanced reinforced concrete pavement (ARCP) by conducting yard tests. Some of cracks are induced in ARCP to reduce the stresses in steel bars and to form more uniformly spaced cracks so that the required steel bar amount can be decreased and at the same time the pavement performance can be improved. In this study, an experimental ARCP was constructed for the length of 22.4 m, width of 1.12 m, and thickness of 0.26 m. The anchor lugs were placed at both ends of ARCP to pretend continuities of the system. 8 crack inducers with a uniform spacing of 2.8 m were installed in different manners when placing concrete, so the test length of the experimental ARCP was 19.6 m. The variables of crack inducers included the shape, material, installed depth, and installing method. The basic shape of the crack inducer represented a round face and a flat opposite face with a height of 50 mm and a width of 10 mm. The slightly different shaped crack inducers were installed for inducing cracks at both ends of ARCP. The crack inducers were primarily made of glass fiber reinforced plastic (GFRP) but a crack was induced using a polyethylene sheet inducer. The installed depths of the crack inducers were 30, 40 and 70 mm to the top of the crack inducer from the pavement surface. Most crack inducers were preinstalled on the transverse steel bar locations before concrete pouring, but 2 crack inducers were installed just after concrete placement when concrete was still fresh. The temperature measurement sensors of i-Buttons and thermocouples were installed at the top, middle and bottom of slab to measure the temperature variations of slab. The displacement transducers were also installed at the crack locations to measure the crack width movements. The experimental results showed that the cracks were induced at all the locations where the crack inducers were placed. In addition to the induced cracks, just one crack was formed naturally. The crack patterns on the surface of pavement were all comparable. The crack width measurement data showed that there were slight differences in the crack width movements among the cracks but all the cracks including both the induced and naturally formed cracks moved little within a 0.1 mm range. Therefore, any type of the crack inducers employed in this study can be used to initiate cracks in ARCP.
        18.
        2018.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        지면반사도 정보는 열평형 및 환경/기후 모니터링에 중요하다. 본 연구에서는 정지궤도위성의 Geostationary Environment Monitoring Spectrometer (GEMS) 관측에서 300-500 nm 파장 영역의 지면반사도 산출 시에 오차 유발 요 소에 대한 민감도를 조사하였다. 장차 GEMS 지면반사도 산출 시에 오차 분석을 위하여 극궤도 위성의 MODerate resolution Imaging Spectroradiometer (MODIS; 공간 해상도 1 km×1 km) 자료 및 Ozone Mapping Instrument (OMI; 12 km×24 km) 자료 그리고 복사전달모델 수치실험도 분석에 사용하였다. 본 연구에서 오차 유발 요소는 구름, 레일리 산란, 에어로졸, 오존 그리고 지면 특성이다. GEMS 저해상도(8 km×7 km)에서의 구름 탐지율은 MODIS 대비 약 79% 이었으나, GEMS 화소의 운량이 40% 이하에서는 상대적으로 낮았다. 이러한 경향은 구름 이외의 다른 효과(에어로졸, 지면 특성)로 인하여 주로 발생하였다. RGB 영상과 복사전달모델 계산을 기초로 조사된 레일리 산란 효과는 육지에 비하여 해양 지역에서 뚜렷하였다. 지면반사도가 0.2보다 작은 경우에 위성관측 대기상단 반사도는 에어로졸 양에 비례 하였으나, 0.2보다 큰 경우에는 그 반대 경향을 보였다. 또한 에어로졸 양에 의한 지면반사도 산출 오차는 자외선 영역 에서 파장에 따라 급격하게 증가하였으나, 가시광선에서는 일정하거나 다소 감소하였다. 오존 흡수는 자외선 영역(328- 354 nm) 중 328 nm에서 가장 크게 나타났다. 지면반사도가 0.15인 육지 경우에 음의 오존전량 아노말리(-100 DU)로 인한 지면반사도 산출 오차는 +0.1이었다. 본 연구는 GEMS 위성관측을 이용한 지면반사도 원격탐사의 정확도를 높이 는데 기여할 수 있다.
        4,600원
        20.
        2016.10 구독 인증기관·개인회원 무료
        Two different types of acetylcholinesterae (AChE1 and AChE2) are present in majority of insects, including the Western honey bee. Out of the two honey bee AChEs (AmAChEs), the soluble AmAChE1 with little catalytic activity is widely distributed in both neuronal and non-neuronal tissues, including fat body. In this study, to identify stresss factors that can induce AmAChE expression, we tested various conditions that honey bees can encounter in natural setting, including heat shock, cold shock, bacterial challenge (Escherichia coli and Staphylococcus aureus) and Varroa mite infestations, and evaluated their effects on AmAChE expression. Among the stress factors tested, only heat shock condition induced AmAChE expression in a dose dependet manner. This finding suggests that one function of AmAChE1 is related with thermoregulations, especially against heat shock stress in honey bees.
        1 2 3 4