• Title/Summary/Keyword: VAM

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Effect of VA Mycorrhizal Fungi on Alleviation of Salt Injury in Hot Pepper (Capsicum annuum L.) (VA 균근균(菌根菌) 접종(接種)에 의한 고추의 염류장해(鹽類障害) 경감효과(輕減效果))

  • Sohn, Bo-Kyoon;Huh, Sang-Man;Kim, Kil-Yong;Kim, Yong-Woong
    • Korean Journal of Soil Science and Fertilizer
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    • v.33 no.6
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    • pp.482-492
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    • 2000
  • Vesicular arbuscular mycorrhizal (VAM) fungi are known to increase plant growth as well as to enhance salt tolerance of plants where plant roots are colonized by VAM. In pot experiment, pepper was grown in soil containing 0, 200, 400, and $600P\;kg\;ha^{-1}$ with and without mycorrhizal inoculum. Pots were irrigated with saline water containing 0.5, 2.0, and $6.0dS\;m^{-1}$. At 0, 200, and $400P\;kg\;ha^{-1}$ of three EC treatments, plant hight in mycorrhizal treatments was significantly different compared to nonmycorrhizal treatments. However, plant hight at $600P\;kg\;ha^{-1}$ was not different between mycorrhizal and nomycorrhizal treatments. Leaf area at $0P\;kg\;ha^{-1}$ of three EC treatments, and $200P\;kg\;ha^{-1}$ of $6.0dS\;m^{-1}$ in mycorrhizal treatments significantly increased compared to nonmycorrhizal treatments. However, these increase were not discovered in high salinity and P level. Level of EC affected dry weight, and especially, interection of P and EC, or P and VA inoculation highly affected root dry weight. R/S ratio generally decreased in mycorrhizal treatments. Significantly decreased R/S ratio was shown at 0, 400, and $600P\;kg\;ha^{-1}$ of $6.0dS\;m^{-1}$. Chlorophyll content generally increased with decreased salinity and P level where mycorrhizal treatments showed higher chlorophyll content compared to nonmycorrhizal treatments. The benefits of VAM inoculation on fruit production was discovered at only low P level and salinity. Mycorrhizal dependency on dry weight basis was generally shown in $0P\;kg\;ha^{-1}$ of three EC treatments and 0.5, $2.0dS\;m^{-1}$ of $200P\;kg\;ha^{-1}$ level. Colonization rate ranged 3.3 to 43.3% and number of spores was 47.7 to 198.3 $100g^{-1}$ soil. Colonization rate and number of spores increased with decreased P level and salinity where there was high correlation ($r=0.858^{**}$) between both. Also improved uptake of mineral nutrients was discovered at mycorrhizal treatments in decreased P level and salinity.

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Changes of Soil Microbial Phospholipid Fatty Acids as Affected by Red Pepper Cultivation and Compost Amendment (고추재배지에서 퇴비시용에 따른 토양 미생물의 인지질지방산 변화)

  • Park, Kee-Choon;Kim, Su-Jung
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.2
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    • pp.194-199
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    • 2010
  • Compost as a soil amendment is of importance in enhancing the soil chemical and microbial qualities; however, soil microbial community can vary depending on the composition, and the amount of compost applied to plant in the soil. Responses of soil microbial properties to compost applications with 0, 30, and 60 Mg $ha^{-1}$ were investigated in silt loam soils where red pepper(Capsicum annuum L.) was mainly cultivated in Yeongyang, Gyeongbuk, Korea. The analysis of phospholipid fatty acids (PLFAs) extracted from soil showed that compost amounts significantly increased PLFAs representing as bacteria, fungi, and VAM-fungi as well as the ratio of fungi/bacteria, and monounsaturated/saturated PLFAs. Increasing the amount of compost significantly increased Gram-/Gram+ PLFAs' ratio, but significantly decreased monounsaturated/saturated PLFAs' ratio. Therefore, this result shows that compost would vary to a limited extent the microbial community in red pepper field. However, increase in compost application would change the subgroup structure of microbial community only.

Vesicular-Arbuscular Mycorrhizal Fungi Found in the Soils around the Roots of the Leguminous Plants (콩과(科) 식물(植物) 주변(周邊)의 토양(土壤)에서 발견(發見)되는 VA-mycorrhizae)

  • Kim, Jun-Tae;Kim, Chong-Kyun
    • The Korean Journal of Mycology
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    • v.20 no.3
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    • pp.171-182
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    • 1992
  • Ten species of the leguminous plants were collected from the soils around Kongiu National University $(127^{\circ}\;08'\;41"\;E,\;36^{\circ}\;28'\;04"\;N)$. All of them were infected with VA-mycorrhizae in the root tissues, and twelve azygospores or chlamydospores of VA-mycorrhizal fungi were found and identified (twelve species of four genera); Acaulospora denticulata, A. scrobiculata, Gigaspora margarita, Glomus australe, Gl. constrictum, Gl. convolutum, Gl. diaphanum, Gl. flavisporum, Gl. glomerulatum, Gl. manihotis, Gl. tortuosum, Scleroystis microcarpus. Seven among them were not reported in Korea yet (seven species of three genera); A. denticulata, Gl. australe, Gl. constrictum, Gl. convolutum, Gl. diaphanum, Gl. flavisporum, S. microcarpus.

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Characteristics of Potato Virus Y (PVY) Mutant Isolated from PVY Resistance Breeding Line in Korea (국내 감자바이러스 Y (PVY) 저항성 육성 계통에서 분리한 PVY Mutant의 특성)

  • Kim, Jae-Hyun;Kuem, Wan-Soo;Lee, Sin-Ho;Kim, Jeong-Soo;Jeon, Yong-Ho;Jung, Suk-Hun;Chung, Youl-Young;Park, Yong-Hack
    • Journal of the Korean Society of Tobacco Science
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    • v.28 no.2
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    • pp.100-110
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    • 2006
  • A mutant of Potato vims Y (PVY) was occurred in PVY resistance flue-cured tobacco breeding line KF0402 $(TC1146{\times}KF117)$ showing vein necrosis at Suwon in Korea. This isolate, PVY-SWM, was differentiated from other PVY based on biological properties and nucleotide sequence analyses of coat protein gene. PVY-SWM caused typical symptoms on 21 indicator plants as compared to the PVY-TOJC37. Remarkably, the PVY-SWM induced distinctly different symptom of systemic vein necrosis on tobacco cultivars V.SCR, PBD6, TN86, TN90, Virgin A Mutant (VAM), Wislica, NC744, KB108 and KB111, which were reported to have the recessive potyvirus resistance gene va. In RT-PCR assays with specific primers for detection of PVY, a single band of about 800bp in length was produced. The amplified DNA was cloned and the nucleotide sequence was determined. The coat protein gene of PVY-SWM showed 88.4%-99.0% and 92.5%-98.5% identities to the 12 different PVY isolates of Genbank Database at the nucleotide and amino acidi respectively. Multiple alignments as well as cluster dendrograms of PVY-SWM isolate revealed close phylogenetic relationship to the $PVY^{NTN}$ subgroup.

High-Temperature Oxidation Behavior of Fe-22%Cr-5.8%Al Alloy (Fe-22%Cr-5.8%Al 합금의 고온 산화 거동)

  • Kim, Song-Yi;Choi, Sung-Hwan;Yun, Jung-Yeul;Kong, Young-Min;Kim, Byoung-Kee;Lee, Kee-Ahn
    • Journal of the Korean institute of surface engineering
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    • v.44 no.1
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    • pp.13-20
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    • 2011
  • This study investigated the high temperature oxidation behavior of Fe-22%Cr-5.8%Al alloy and the oxidation kinetics of the alloy were discussed. Bulk samples were prepared by VAM (vacuum arc melting) and hot forging. High temperature oxidation testes were isothermally conducted up to 100 hours in 79%$N_2$+21%$O_2$ environment at three different temperatures ($900^{\circ}C$, $1000^{\circ}C$, $1100^{\circ}C$). The weight gain was measured after oxidation according to oxidation time (2, 4, 6, 8, 10, 15, 20, 25, 30, 60, 80, 100 hours). The weight gain significantly increased with increasing oxidation temperature. As the temperature increased, the oxidized samples showed sequential formation of $Al_2O_3$, Cr-rich oxide, Fe-rich oxide. The activation energy of high temperature oxidation was obtained as 306.63 KJ/mol. $Al_2O_3$ were developed on the surface in the early stage of oxidation, representing protective role of oxidation. However, Fe-based and Cr-based oxides leaded to breakaway of oxide layer, thus resulted in the significant increase of additional oxidation.

Contents of Soil Microbial Phospholipid Fatty Acids as Affected by Continuous Cropping of Pepper under Upland (노지 고추 연작 토양의 미생물 인지질 지방산 함량)

  • Hwang, Jae-Moon;Park, Kee-Choon;Kim, Su-Jung
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.6
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    • pp.1012-1017
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    • 2010
  • This study was carried out to investigate the effect of continuous cropping of pepper on soil microbial phospholipid fatty acids (PLFAs) under upland applied without any pesticides and chemical herbicides from 2000 to 2009. Microbial PLFAs were analysed from soils sampled in 2009. Soil microbial diversities showed PLFAs of monoplanting of pepper were distinct from those of monoplanting of garlic and interplanting of garlic and pepper by principle component 2 (PC2). Furthermore, soil microbial activity of monoplanting of pepper significantly decreased PLFAs representing as VAM-fungi, whereas it significantly increased in actinomycetes and saturated/monounsaturated PLFAs' ratio. The results drove continuous cropping of pepper would vary the microbial community and their specific activity. Soil microbial activities in continuous cropping system would depend on crop root systems.

A Study on the Intention to use the Artificial Intelligence-based Drug Discovery and Development System using TOE Framework and Value-based Adoption Model (TOE 프레임워크와 가치기반수용모형 기반의 인공지능 신약개발 시스템 활용의도에 관한 실증 연구)

  • Kim, Yeongdae;Lee, Won Suk;Jang, Sang-hyun;Shin, Yongtae
    • Journal of Information Technology Services
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    • v.20 no.3
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    • pp.41-56
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    • 2021
  • New drug discovery and development research enable clinical treatment that saves human life and improves the quality of life, but the possibility of success with new drugs is significantly low despite a long time of 14 to 16 years and a large investment of 2 to 3 trillion won in traditional methods. As artificial intelligence is expected to radically change the new drug development paradigm, artificial intelligence new drug discovery and development projects are underway in various forms of collaboration, such as joint research between global pharmaceutical companies and IT companies, and government-private consortiums. This study uses the TOE framework and the Value-based Adoption Model, and the technical, organizational, and environmental factors that should be considered for the acceptance of AI technology at the level of the new drug research organization are the value of artificial intelligence technology. By analyzing the explanatory power of the relationship between perception and intention to use, it is intended to derive practical implications. Therefore, in this work, we present a research model in which technical, organizational, and environmental factors affecting the introduction of artificial intelligence technologies are mediated by strategic value recognition that takes into account all factors of benefit and sacrifice. Empirical analysis shows that usefulness, technicality, and innovativeness have significantly affected the perceived value of AI drug development systems, and that social influence and technology support infrastructure have significant impact on AI Drug Discovery and Development systems.

The Effect of Restaurant Owners' Perceived Benefits and Sacrifices on the Continuous Use Intention of Food Delivery App Services: Focusing on the Value-Based Adoption Model (외식업 점주의 배달앱 서비스 이용에 대한 지각된 혜택 및 희생이 지속이용의도에 미치는 영향: 가치기반수용모델을 중심으로)

  • Lee, Young Seok;Song, Jae Min;Yang, Sung Byung
    • The Journal of Information Systems
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    • v.30 no.2
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    • pp.215-241
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    • 2021
  • Purpose The purpose of this study is to analyze the impact of perceived value on the intention of continuous use of food delivery app services form the perspective of restaurant owners. We adopt the value-based acceptance model (VAM) in order to derive influential factors (i.e., perceived benefits and perceived sacrifices) that affect perceived value, which in turn leads to the continuous use of food delivery app services. In addition, the moderating role of restaurant type in the relationship between perceived benefits/sacrifices and perceived value. Design/methodology/approach An online survey was conducted on restaurant owners who are using domestic food delivery app services. Samples were collected using the quota sampling method in accordance with the current market share of food delivery app services. A total of 235 participants (restaurant owners) were identified as a valid sample and used for the final analysis. Findings Research findings of the study are as follows. First, sales increase and operational effort decrease among perceived benefits had a significant positive impact on perceived value. Second, perceived cost among perceived sacrifices had a significant negative impact on perceived value. Third, perceived value had a significant positive effect on the intention of continuous use. Finally, the moderating role of restaurant type was found only in the effect of operational effort decrease on perceived value.

A Study on the Perceived Value of Video Conferencing Platform: Focused on Heuristic-Systematic Model and Value-based Adoption Model (화상회의 플랫폼의 지각가치에 관한 연구: 휴리스틱-체계적 모델과 가치기반수용모델을 중심으로)

  • Tran, To-Diem-Hang;Kim, Min-Sook
    • Asia-Pacific Journal of Business
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    • v.12 no.2
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    • pp.205-222
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    • 2021
  • Purpose - Due to the Covic-19 pandemic, the perceived value of video conferencing platforms has been increased drastically. However, there is little guidance on how service providers can improve video conferencing platforms. The purpose of this study is to investigate the factors that influence the users' perceived value of video conferencing services based on the heuristic-systematic model and the value-based adoption model. Design/Methodology/Approach - In this paper, we theoretically explore the relationship of the antecedents of perceived value(credibility, expertise, attractiveness, economic feasibility, security, and interactivity) and its outcomes (perceived usefulness, perceived risk and perceived value). The outcomes of this research is a conceptualization of antecedents of perceived value supported by research hypothesis based on the existing literature. A total of 100 valid questionnaires were collected to empirically test the research model. Findings - The analysis results showed that credibility, economic feasibility, and interactivity positively influenced perceived usefulness. On the other hand, credibility, professionalism and interactivity negatively influenced perceived risk. Perceived usefulness positively affects perceived value and perceived risk has a negative effect on perceived value. The brand image as a moderating variable was found to decrease the effect of perceived risk on perceived value. Research Implications - The contribution of this study is significant for video conferencing providers as follows. First, a service provider can actively utilize influencers or referees with high credibility and expertise to maximize the perceived usefulness of users. Second, economic feasibility should be ensured in respect of users through various alliance discount strategies. Third, a video conferencing service company needs to build a positive brand image in order to increase users' perceived value.

An Empirical Study on Perceived Value and Continuous Intention to Use of Smart Phone, and the Moderating Effect of Personal Innovativeness (스마트폰의 지각된 가치와 지속적 사용의도, 그리고 개인 혁신성의 조절효과)

  • Han, Joonhyoung;Kang, Sungbae;Moon, Taesoo
    • Asia pacific journal of information systems
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    • v.23 no.4
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    • pp.53-84
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    • 2013
  • With rapid development of ICT (Information and Communications Technology), new services by the convergence of mobile network and application technology began to appear. Today, smart phone with new ICT convergence network capabilities is exceedingly popular and very useful as a new tool for the development of business opportunities. Previous studies based on Technology Acceptance Model (TAM) suggested critical factors, which should be considered for acquiring new customers and maintaining existing users in smart phone market. However, they had a limitation to focus on technology acceptance, not value based approach. Prior studies on customer's adoption of electronic utilities like smart phone product showed that the antecedents such as the perceived benefit and the perceived sacrifice could explain the causality between what is perceived and what is acquired over diverse contexts. So, this research conceptualizes perceived value as a trade-off between perceived benefit and perceived sacrifice, and we need to research the perceived value to grasp user's continuous intention to use of smart phone. The purpose of this study is to investigate the structured relationship between benefit (quality, usefulness, playfulness) and sacrifice (technicality, cost, security risk) of smart phone users, perceived value, and continuous intention to use. In addition, this study intends to analyze the differences between two subgroups of smart phone users by the degree of personal innovativeness. Personal innovativeness could help us to understand the moderating effect between how perceptions are formed and continuous intention to use smart phone. This study conducted survey through e-mail, direct mail, and interview with smart phone users. Empirical analysis based on 330 respondents was conducted in order to test the hypotheses. First, the result of hypotheses testing showed that perceived usefulness among three factors of perceived benefit has the highest positive impact on perceived value, and then followed by perceived playfulness and perceived quality. Second, the result of hypotheses testing showed that perceived cost among three factors of perceived sacrifice has significantly negative impact on perceived value, however, technicality and security risk have no significant impact on perceived value. Also, the result of hypotheses testing showed that perceived value has significant direct impact on continuous intention to use of smart phone. In this regard, marketing managers of smart phone company should pay more attention to improve task efficiency and performance of smart phone, including rate systems of smart phone. Additionally, to test the moderating effect of personal innovativeness, this research conducted multi-group analysis by the degree of personal innovativeness of smart phone users. In a group with high level of innovativeness, perceived usefulness has the highest positive influence on perceived value than other factors. Instead, the analysis for a group with low level of innovativeness showed that perceived playfulness was the highest positive factor to influence perceived value than others. This result of the group with high level of innovativeness explains that innovators and early adopters are able to cope with higher level of cost and risk, and they expect to develop more positive intentions toward higher performance through the use of an innovation. Also, hedonic behavior in the case of the group with low level of innovativeness aims to provide self-fulfilling value to the users, in contrast to utilitarian perspective, which aims to provide instrumental value to the users. However, with regard to perceived sacrifice, both groups in general showed negative impact on perceived value. Also, the group with high level of innovativeness had less overall negative impact on perceived value compared to the group with low level of innovativeness across all factors. In both group with high level of innovativeness and with low level of innovativeness, perceived cost has the highest negative influence on perceived value than other factors. Instead, the analysis for a group with high level of innovativeness showed that perceived technicality was the positive factor to influence perceived value than others. However, the analysis for a group with low level of innovativeness showed that perceived security risk was the second high negative factor to influence perceived value than others. Unlike previous studies, this study focuses on influencing factors on continuous intention to use of smart phone, rather than considering initial purchase and adoption of smart phone. First, perceived value, which was used to identify user's adoption behavior, has a mediating effect among perceived benefit, perceived sacrifice, and continuous intention to use smart phone. Second, perceived usefulness has the highest positive influence on perceived value, while perceived cost has significant negative influence on perceived value. Third, perceived value, like prior studies, has high level of positive influence on continuous intention to use smart phone. Fourth, in multi-group analysis by the degree of personal innovativeness of smart phone users, perceived usefulness, in a group with high level of innovativeness, has the highest positive influence on perceived value than other factors. Instead, perceived playfulness, in a group with low level of innovativeness, has the highest positive factor to influence perceived value than others. This result shows that early adopters intend to adopt smart phone as a tool to make their job useful, instead market followers intend to adopt smart phone as a tool to make their time enjoyable. In terms of marketing strategy for smart phone company, marketing managers should pay more attention to identify their customers' lifetime value by the phase of smart phone adoption, as well as to understand their behavior intention to accept the risk and uncertainty positively. The academic contribution of this study primarily is to employ the VAM (Value-based Adoption Model) as a conceptual foundation, compared to TAM (Technology Acceptance Model) used widely by previous studies. VAM is useful for understanding continuous intention to use smart phone in comparison with TAM as a new IT utility by individual adoption. Perceived value dominantly influences continuous intention to use smart phone. The results of this study justify our research model adoption on each antecedent of perceived value as a benefit and a sacrifice component. While TAM could be widely used in user acceptance of new technology, it has a limitation to explain the new IT adoption like smart phone, because of customer behavior intention to choose the value of the object. In terms of theoretical approach, this study provides theoretical contribution to the development, design, and marketing of smart phone. The practical contribution of this study is to suggest useful decision alternatives concerned to marketing strategy formulation for acquiring and retaining long-term customers related to smart phone business. Since potential customers are interested in both benefit and sacrifice when evaluating the value of smart phone, marketing managers in smart phone company has to put more effort into creating customer's value of low sacrifice and high benefit so that customers will continuously have higher adoption on smart phone. Especially, this study shows that innovators and early adopters with high level of innovativeness have higher adoption than market followers with low level of innovativeness, in terms of perceived usefulness and perceived cost. To formulate marketing strategy for smart phone diffusion, marketing managers have to pay more attention to identify not only their customers' benefit and sacrifice components but also their customers' lifetime value to adopt smart phone.