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        검색결과 1,214

        303.
        2018.10 구독 인증기관·개인회원 무료
        Tetranychus urticae and Myzus persicae are one of the most serious insect pests in many crops, vegetables, flowers, and fruit trees worldwide. Many insecticides have been developed to control green peach aphid and two spotted spider mite, but resistance to almost all insecticides has reduced their control effect. Particular groups of plant-beneficial microbials are not only root colonizers that provide plant disease suppression, but in addition are able to infect and kill insect larvae. Antimicrobial compounds produced by biocontrol microbes are effective weapons against a vast diversity of organisms such as fungi, nematodes, and viruses. In this study, we evaluated the effectiveness of mixtures plant extracts and improvement of culture process biocontrol microbials on insecticidal activity. Azadirachta indica and Derris elliptica mixed with micorbials, which are nutrient sources of mung bean extract and lecithin, were more effective than other the mixtures. Leaf spraying with the mixture of Pseudomonas fluorescens significantly showed the highest insecticidal power in vivo for 24 hours after treatment. The effect of spraying mixture was more than 50% at 2000 times dilution, and the spraying concentration of 90% or more showed a dilution of up to 500 times. Our results indicated that the nutrient sources of microbe act as a key antimicrobial metabolite in biocontrol of insect pests, and mixing with plant extracts can provide synergistic effects as an optimal usage of the biocontrol agents.
        304.
        2018.10 구독 인증기관·개인회원 무료
        애벌레의 번지점프는 포식자로부터 몸을 지키기 위한 방어 전략이다. 본 연구는 애벌레가 어떠한 감각 자극에 반응하여 번지점프를 하는지 확인하기 위한 연구이며, 본 연구를 수행하기 위해 2018년 목포대학교 승달산 부근에서 애벌레를 채집하여, 시각(애벌레 시야로 접근), 바람(일정한 세기를 위해 선풍기를 이용한 바람), 촉각(애벌레의 몸을 나뭇가지로 자극)에 대한 반응(번지점프)을 조사하였다. 조사결과 28종 78마리의 애벌레가 방어 전략으로 번지점프를 사용하였다. 또한 애벌레의 자극에 대한 번지점프를 비교해 본 결과 시각, 바람에 반응을 보이는 빈도수가 촉각에 비해 현저하게 적게 나타나는 것을 실험적으로 확인하였다. 애벌레의 번지점프가 포식자로부터 몸을 지키기 위한 생존전략이라는 것을 추가적으로 검증하기 위해 포식자(개미로 가정)가 접근 시 발생하는 진동(포식자가 접근할 때 표면에 나타나는 진동)과 포식자와의 접촉(개미가 애벌레에 접촉)에 대한 애벌레의 반응을 조사하였다. 실험 결과 포식자가 접근 시 발생하는 진동보다는 포식자의 접촉(촉각)이 애벌레의 번지점프를 유도한다는 사실을 확인하였다. 두 실험결과에서 간접적인 자극인 시각, 바람, 진동보다 직접적인 자극인 촉각에 보이는 반응이 현저하게 높게 나타난다. 이는 애벌레의 번지점프는 애벌레와 포식자의 접촉이후 보이는 최종적인 애벌레의 방어 전략이라는 것을 시사하고 있다.
        305.
        2018.10 구독 인증기관·개인회원 무료
        본 연구에서는 피식자의 flash display와 크기에 따른 생존율을 확인하였다. Flash display는 생물체가 가지는 방어 기작 중의 하나로, 피식자가 포식자로부터 도망을 갈 때, 예를 들어, 개구리 다리 안쪽의 색이 몸 색과 다른 경우나, 속날개의 색이 겉날개의 색과 다른 경우(ex. 뒷날개나방) 포식자에게 시각적으로 큰 혼란을 주어 생존율을 높이는 방어 기작 이다. 이를 연구하기 위해 visual studio enterprise 6.0프로그램으로 피식자의 크기와 색을 변경 가능 하게한 시뮬레이션을 만든 후 사람을 포식자로 설정하여 일반인 총 120명, 연령대는 10~50대 중 후반을 대상으로 실험 하였다. 실험 결과로 flash display를 사용하는 피식자의 생존율이 그렇지 않은 피식자 보다 높을 것으로 예상 하였고, 크기는 작을수록 더욱 유리 할 것으로 예측 하였다. 조사 결과 피식자의 크기와 색이 생존율과 상관관계에 있다는 것과 flash display 효과가 피식자의 생존율을 더욱 높여주었음을 발견하였다. 또한 flash display의 색이 주변 환경(이번 실험에서는 녹색 계통의 풀숲을 사용하였다.)과 확실하게 다른 색(녹색 계통의 색이 아닌 색)을 띄는 개체의 생존율이 flash display를 사용하지 않은 개체 보다 월등히 높았음을 확인하였다. 이는 Flash display가 피식자의 생존율을 높이는 요인이라는 것을 시사하고 있다.
        306.
        2018.10 구독 인증기관·개인회원 무료
        Insecticidal and repellent effects of herb extracts were tested against Aedes albopictus and Ochlerotatus togoi that are common among mosquitoes which inhabit Korea. Herb extracts from Mentha×piperita, Ocimum basilicum, and Nepeta cataria were extracted using distilled water and 70% ethanol respectively. Both kinds of mosquitoes were raised in environment control rearing system with air temperature of 25℃, humidity of 70%, and light condition of 14:10(L:D). Insecticidal effect was verified by feeding extracts to mosquitoes(Park et al., 2016.); repellent effect, by measuring their radial distance from extract by time. N. cataria extract using distilled water as a solvent is predominant in insecticidal effect; O. basilicum, using 70% ethanol. In particular, N. cataria has the most outstanding repellent effect.
        307.
        2018.10 구독 인증기관·개인회원 무료
        Herbicides have consistently contributed to yield increases in crop production for many decades however, those same herbicides are facing the loss of effectiveness because of the rapid spread of weed resistance. Since the first instance of herbicide resistance to triazine herbicides over 50 years ago, resistant biotypes have been observed to the major herbicides numbering more than 150 different weed species due to excessive use of single mode of action (MoA)treatments combined with limited crop rotation practices. In the US, the most well-known broad-spectrum herbicide used in major crops, glyphosate is facing huge challenges due to the appearance of many resistant weed species. The consequences of the loss of effectiveness of the current herbicide choices, coinciding with an increasing world population with improved living standards, is beginning to present a severe constraint on food security globally. Unfortunately, the agriculture industry has been unable to find any new mechanism in the last 30 years. The absence of choices of novel active ingredients along with the increased costs of developing new entities is forcing the industry to rely on older modes of action which, with limited application, means lower annual yields of the major crops as the number of resistant weed species increases. The Chemical Genomics group in FMC Agricultural Solutions Discovery has been building ‘Chemistry to Gene’ (C2G) capability to identify new MoAsby applying chemical genomics tools. We have recently discovered that compounds described in WO2017075559A1, are potent selective herbicides with novel action that control many grasses. As a result of knowledge of the mechanism of this area of chemistry, we have extended the work to include a ‘Gene to Chemistry’ (G2C) approach to provide new structural starting points for more synthesis projects.
        308.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It has been reported that gastrocnemius tightness and posterior talar glide are crucial factors influencing ankle dorsiflexion. However, the relationship of ankle dorsiflexion and these factors is not identified in previous studies. The purpose of this study was to identify the relationship of ankle dorsiflexion passive range of motion and gastrocnemius tightness and posterior talar glide. Twenty-five male subjects participated in this study. Bilateral weight-bearing ankle dorsiflexion passive range of motion and amount posterior talar glide of participants were measured using an inclinometer. Change in myotendinous junction of medial gastrocnemius was measured using ultrasonography to identify gastrocnemius tightness. Pearson product moment correlations were performed to examine correlations between ankle dorsiflexion passive range of motion and gastrocnemius tightness and posterior talar glide. Present findings revealed significant correlation between ankle dorsiflexion passive range of motion and gastrocnemius tightness (p=0.017, r=0.336). Also, ankle dorsiflexion passive range of motion was correlated with posterior talar glide (p=0.001, r=0.470). The present findings provide experimental evidence for factors influencing weight-bearing ankle dorsiflexion.
        3,000원
        309.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the SW industry, the diversification of global markets and technology trends are changing due to the emergence of new services, and IT companies are in need of strategic change different from the previous one. In this study, SWOT analysis was performed by extracting the internal environmental factors and external environmental factors through the previous studies to improve the project performance competence of small IT companies, and the SWOT Matrix was reconstructed through the pairwise comparison. Based on this, the purpose of this research was to propose the project performance competency improvement plans for small IT companies based on importance and priority, and the following four strategies were derived from the result of SWOT-AHP analysis. SO strategy was drawn in direction to invest R & D in new SW industry to enhance technology competitiveness of SMEs in order to develop SMEs, and in order to secure competitiveness of SW industry, WO strategy is drawn the cultivation of professional technical manpower through SW policy. ST Strategy presented technical management through SW system improvement policy to improve SW environment, and WT Strategy presented awareness training on the construction and necessity of project management system construction. Using the strategies presented in this study, it is expected that the managers of small IT firms will be presented as references to measure the performance competence factors of current organizations and company organizations.
        4,000원
        310.
        2018.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        As research evidence for the facilitative effects of reading strategies on reading comprehension has been accumulating, research and pedagogical interests in prereading strategies such as prediction and schema activation are increasing. Yet, little research evidence of how actual performance on such tasks may be related to reading comprehension is sparse. This study explores whether prediction abilities and content schema are related to Korean middle school EFL learners’ reading comprehension abilities in English, and whether such potential relations may differ for factual and inferential comprehension. The study participants were one hundred thirty-seven Korean seventh grade students, and their performance on schema activation, prediction, and reading comprehension abilities was investigated, while controlling for their overall language proficiency and literacy skills. The findings indicated that although both prediction abilities and content schema facilitated reading comprehension, prediction abilities were a relatively stronger predictor of both factual and inferential comprehension. The results further suggest the need to provide effective trainings on pre-reading strategies.
        5,200원
        311.
        2018.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        This study was carried out to investigate the protective effect of prednisolone in rabbit primary cultured articular chondrocytes treated with sodium nitroprusside (SNP), a nitric oxide donor. After a cell phenotype was determined, the MTT assay and Western blot analysis of type II collagen, cylooxygenase-2 (COX-2) and phosphorylated extracellular regulated kinase (pERK) were performed in the control, SNP (298 μg/ml) alone or SNP plus prednisolone (0.05-50 μg/ml)-treated rabbit articular chondrocytes. Immunofluorescence staining of type II collagen was also performed. Cell morphology indicated that SNP treatment induced cytotoxicity, and that the SNP-induced cytotoxicity was inhibited by prednisolone treatment. MTT assay showed that the SNP treatment resulted in a significant decrease in the level of cell viability compared with that of control (p<0.01), and that the prednisolone treatment resulted in a decrease in the SNP-induced cytotoxicity. SNP treatment resulted in a decrease in the level of type II collagen, compared with the control chondrocytes. The prednisolone treatment recovered the down-regulated expression of type II collagen induced by SNP, showing a significant level in 5 μg/ml of the prednisolone treatment group compared to the SNP treatment group (p<0.05). A significant increase in COX-2 was significantly induced by the SNP treatment compared to control chondrocytes (p<0.01). The COX-2 expression was decreased by the prednisolone treatment, showing a significant level in 50 μg/ml of the prednisolone treatment group compared to the SNP treatment group (p<0.05). These phenomena was confirmed by immunofluorescence staining. Furthermore, the SNP treatment significantly induced a decrease of pERK expression compared to the control chondrocytes (p<0.01). The prednisolone treatment recovered its expression, showing a significant level in 0.5 μg/ml of the prednisolone treatment group compared to the SNP treatment group (p<0.05). Taken the above results together, prednisolone is considered to inhibit SNP-induced cell death and dedifferentiation, and modulated expression of COX-2 and pERK in rabbit articular chondrocytes.
        4,000원
        312.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Effect of the nonuniform grid on the two-dimensional transport equation was investigated in terms of theoretical analysis and finite difference method (FDM). The nonuniform grid having a typical structure of the numerical weather forecast model was incorporated in the vertical direction, while the uniform grid was used in the zonal direction. The staggered and non-staggered grid were placed in the vertical and zonal direction, respectively. Time stepping was performed with the third-order Runge Kutta scheme. An error analysis of the spatial discretization on the nonuniform grid was carried out, which indicated that the combined effect of the nonuniform grid and advection velocity produced either numerical diffusion or numerical adverse-diffusion. An analytic function is used for the quantitative evaluation of the errors associated with the discretized transport equation. Numerical experiments with the non-uniformity of vertical grid were found to support the analysis.
        4,000원
        313.
        2018.07 구독 인증기관·개인회원 무료
        Digital channels have been rising to the major shopping paths from the past few years, yet it is interesting to notice that more and more digital retailers advance into offline channel nowadays due to the benefits. For example, the digital retailing giant Amazon opened its first bricks-and-mortar bookstore in 2015. Dell, which distributes its products only in the catalog and digital channels, entered the leading retail stores such as Best Buy and Walmart. The digital retailers’ strategy trend that moves into the real world reveals the unique and powerful capabilities of the offline distribution channel and the importance of launching products in the offline channel. Previous studies in marketing have investigated various complement and substitute impacts of offline channel introduction (i.e., Avery et al. 2012, Wang and Goldfarb 2017). However, most of the literature focus on the pc-based online channel and catalog, there is little research about the impact of offline channel introduction on smartphone-based mobile channel. Although mobile channel is similar to online channel in many ways (i.e., internet access and convenient shopping), it can be distinguished from online channel in terms of search and access, leading to a different interplay with offline channel. This research, therefore, aims to investigate how product launching in offline channel affects purchases in mobile channel versus online channel, and deepen the understanding by exploring the moderating effect of offline store intensity. Besides, we also explore the interaction between two digital channels: online channel and mobile channel. As most of the multi-channel retailers offer products in both online and mobile channels, it is incremental to know the interplay between these two digital channels. Using data from a representative multichannel retailer selling beauty products, we find the following three empirical results. First, product introduction in offline channel has a positive effect on online and mobile sales, and the effect is greater for mobile. Second, as offline store increases, the positive impact of offline product launch weakens on online channel, and even turns to negative once the number of offline stores reaches a threshold. However, the influence on mobile channel stays the same. The results reflect that the complementary interplay between offline and mobile channel is relatively stronger than between online channel. Finally, within the digital channels, online purchases only increase with the growth of sales performance within online channel, whereas mobile purchases are positively affected by both within mobile channel sales and across online channel sales. Our findings contribute critical academic and managerial implications for multichannel retailing.
        314.
        2018.07 구독 인증기관·개인회원 무료
        Marketing academics and practitioners have discerned the evolution in the prominence of digital, social media and mobile marketing based on technological innovations. Digital marketing has evolved over time from a specific marketing of products and services using digital channels to activities, institutions and processes facilitated by digital technologies. From an inclusive perspective, digital marketing refers to an adaptive, technology-enabled process by which firms collaborate with customers and partners to jointly create, communicate, deliver and sustain value for all stakeholders. Digital technologies allow the new adaptive process, institution and processes in marketing communication. The adaptive process creates value in new ways in new digital environments. Institutions build foundational capabilities to create such value jointly for their customers and for themselves. Processes create value through new customer experiences and through interactions among customers. The purpose of the assessment is to establish the current status of research evaluating digital marketing communication and to show how digital technology has shaped marketing communication evaluations. This study provides a broad disciplinary review of key cited works in digital marketing communication research and examines the effectiveness of various evaluation approaches, including new directions designed to capture meaningful insights and marketing communication value in digital marketing communication.
        315.
        2018.07 구독 인증기관·개인회원 무료
        Customer engagement has become a prominent issue in hospitality and tourism industry. However, customer engagement, is not easily defined or uniformly measured because a number of diverse factors must be considered. While meeting planners are important customers to CVBs, their engagement with CVBs has rarely been studied. Therefore, the purpose of this study was to develop and test a model of meeting planners’ engagement in CVBs empirically. Survey data were collected from a variety of meeting planners, which resulted in 305 usable responses for data analysis. Two step analyses (measurement model and structural model) were implemented. In addition, the moderating effect of reputation and familiarity were examined among the paths of the constructs. The results showed that the hypotheses were supported while familiarity has less salient impact than reputation on customer engagement in the event industry.
        316.
        2018.07 구독 인증기관·개인회원 무료
        Virtual reality refers to an immersive computer-generated, interactive, 3D environment that offers media richness and interactivity. VR provides high media richness verified by the sensory depth and breadth of an interface. The purpose of this study is to investigate the relationships among mindsets, VR experience, perceived interactivity, attitude and purchase. This study clarifies the concept of VR experience and enlightened the relationship between VR experience, perceived interactivity, attitude and purchase intention. The study clarifies technology-driven experience, especially VR experience that can be differentiated from direct and indirect experience. The study can be a starting point to identifying how new technology boosts experiences by reflecting types of VR experience including spatial experience, presence experience, sensory experience and behavioral experience .
        317.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cannibalism is a widely observed phenomenon in the animal kingdom. However, it is rarely found among birds outside nests in the wild because it occurs irregularly and it is almost impossible to monitor animal behavior constantly. On 17 January 2017, this behavior was directly observed from a group of vultures feeding on a conspecific in a paddy field near Lake Geumho in Haenam-gun (34°35ʹ58.25ʺ N, 126°26ʹ57.64ʺ E). It was observed and recorded with the binoculars and a camera with a telephoto lens in a car approximately 20 m (or 60 m) away from the site. The observer approached the feeding site after the last vulture had finished feeding and flown away and found remains of a vulture, including body feathers, skull, sterna keel, and both legs. It was the first report of cannibalism in Cinereous vulture Aegypius monachus in its overwintering grounds. The remaining skeleton was very fleshy, and the surrounding grass was wet with the blood of vulture. No other traces of a mammal or bird that could have been the vultures’ prey were found. This report provides a detailed account of the events related to this rare observation and the causes that might have led to it.
        4,000원
        318.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Kang, Minjung. 2018. “Functions of I mean in American Talk Shows”. The Sociolinguistic Journal of Korea 26(2). 63~84. This paper aims to find out roles of the discourse marker I mean in American talk shows. Ten interviews from six talk shows were analyzed for the investigation and the results indicate that there are some unique functions of I mean which do not seem to be mentioned in early studies: counter-accounting and footing shift functions. This study suggests that the counter-accounting function of I mean can appear in utterance-initial position when the interviewee does not agree with what the interviewer has mentioned. Also, the interviewee can use I mean as a footing shift marker to switch stances from an informative one to an entertaining one (or vice versa). Since these two functions seem to be connected to the institutional settings and goals of talk shows, it is crucial to study functions of I mean in accordance with types of institutional talk.
        5,800원
        319.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        K-means algorithm is one of the most popular and widely used clustering method because it is easy to implement and very efficient. However, this method has the limitation to be used with fixed number of clusters because of only considering the intra-cluster distance to evaluate the data clustering solutions. Silhouette is useful and stable valid index to decide the data clustering solution with number of clusters to consider the intra and inter cluster distance for unsupervised data. However, this valid index has high computational burden because of considering quality measure for each data object. The objective of this paper is to propose the fast and simple speed-up method to overcome this limitation to use silhouette for the effective large-scale data clustering. In the first step, the proposed method calculates and saves the distance for each data once. In the second step, this distance matrix is used to calculate the relative distance rate (Vj) of each data j and this rate is used to choose the suitable number of clusters without much computation time. In the third step, the proposed efficient heuristic algorithm (Group search optimization, GSO, in this paper) can search the global optimum with saving computational capacity with good initial solutions using Vj probabilistically for the data clustering. The performance of our proposed method is validated to save significantly computation time against the original silhouette only using Ruspini, Iris, Wine and Breast cancer in UCI machine learning repository datasets by experiment and analysis. Especially, the performance of our proposed method is much better than previous method for the larger size of data.
        4,000원
        320.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was an attempt to explore how EFL college-level learners perceive flipped learning or flipped classroom approach which would be practiced with Content-Based Instruction (CBI) courses. As an effort to find a way for the CBI learners to be served more effectively in terms of earning content-knowledge and improving L2-using skills, the new approach of flipped learning has been tapped into first of all by looking into their expectations and concerns that they might have if the new approach would be employed in their CBI classroom. The analysis of the data provided by the 159 participants revealed that they did not show clear preference or strong negative attitude toward the new approach. While the young college-level learners appeared technology-savvy, they did not seem confident enough in the new approach mainly due to the on-line component of the flipped classroom approach, which would require more responsibility of their learning. The study also made suggestions on what should be considered if the new approach can be successfully implemented and help the learners earn better learning experience.
        7,000원