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      • KCI등재

        The Factors Affecting Attitudes Toward HSDPA Service and Intentionto Use: A Cross-Cultural Comparison between Asia and Europe

        Hae Sung Jung,Jong Kuk Shin,박민숙,Hong-Seob Jung,Graham Hooley,Nick Lee,Hyokjin Kwak,Sung Hyun Kim 한국마케팅과학회 2009 마케팅과학연구 Vol.19 No.4

        HSDPA (High-Speed Downlink Packet Access) is a 3.5-generation asynchronous mobile communications service based on the third generation of W-CDMA. In Korea, it is mainly provided in through videophone service. Because of the diffusion of more powerful and diversified services, along with steep advances in mobile communications technology, consumers demand a wide range of choices. However, because of the variety of technologies, which tend to overflow the market regardless of consumer preferences, consumers feel increasingly confused. Therefore, we should not adopt strategies that focus only on developing new technology on the assumption that new technologies are next-generation projects. Instead, we should understand the process by which consumers accept new forms of technology and devise schemes to lower market entry barriers through strategies that enable developers to understand and provide what consumers really want. In the Technology Acceptance Model (TAM), perceived usefulness and perceived ease of use are suggested as the most important factors affecting the attitudes of people adopting new technologies (Davis 1989; Taylor and Todd 1995; Venkatesh 2000; Lee et al. 2004). Perceived usefulness is the degree to which a person believes that a particular technology will enhance his or her job performance. Perceived ease of use is the degree of subjective belief that using a particular technology will require little physical and mental effort (Davis, 1989; Morris and Dillon 1997; Venkatesh 2000). Perceived pleasure and perceived usefulness have been shown to clearly affect attitudes toward accepting technology (Davis et al. 1992). For example, pleasure in online shopping has been shown to positively impact consumers' attitudes toward online sellers (Eighmey and McCord, 1998; Mathwick, 2002; Jarvenpaa and Todd 1997). The perceived risk of customers is a subjective risk, which is distinguished from an objective probabilistic risk. Perceived risk includes a psychological risk that consumers perceive when they choose brands, stores, and methods of purchase to obtain a particular item. The ability of an enterprise to revolutionize products depends on the effective acquisition of knowledge about new products (Bierly and Chakrabarti 1996; Rothwell and Dodgson, 1991). Knowledge acquisition is the ability of a company to perceive the value of novelty and technology of the outside (Cohen and Levinthal 1990), to evaluate the outside technology that has newly appeared (Arora and Gambaradella, 1994), and to predict the future evolution of technology accurately (Cohen and Levinthal 1990). Consumer innovativeness is the degree to which an individual adopts innovation earlier than others in the social system (Lee, Ahn, and Ha 2001; Gatignon and Robertson 1985). That is, it shows how fast and how easily consumers adopt new ideas. Innovativeness is regarded as important because it has a significant effect on whether consumers adopt new products and on how fast they accept new products (Midgley and Dowling 1978; Foxall 1988; Hirschman 1980). We conducted cross-national comparative research using the TAM model which empirically verified the relationship between the factors that affect attitudes - perceived usefulness ease of use perceived pleasure perceived risk innovativeness and perceived level of knowledge management - and attitudes toward HSDPA service. We also verified the relationship between attitudes and usage intention for the purpose of developing more effective methods of management for HSDPA service providers. For this research 346 questionnaires were distributed among 350 students in the Republic of Korea. Because 26 of the returned questionnaires were inconsistent or had missing data 320 questionnaires were used in the hypothesis tests. In UK 192 of the total 200 questionnaires were retrieved and two incomplete ones were discarded bringing the total to 190 questionnaires used for statistical analysis. The results o... HSDPA (High-Speed Downlink Packet Access) is a 3.5-generation asynchronous mobile communications service based on the third generation of W-CDMA. In Korea, it is mainly provided in through videophone service. Because of the diffusion of more powerful and diversified services, along with steep advances in mobile communications technology, consumers demand a wide range of choices. However, because of the variety of technologies, which tend to overflow the market regardless of consumer preferences, consumers feel increasingly confused. Therefore, we should not adopt strategies that focus only on developing new technology on the assumption that new technologies are next-generation projects. Instead, we should understand the process by which consumers accept new forms of technology and devise schemes to lower market entry barriers through strategies that enable developers to understand and provide what consumers really want. In the Technology Acceptance Model (TAM), perceived usefulness and perceived ease of use are suggested as the most important factors affecting the attitudes of people adopting new technologies (Davis 1989; Taylor and Todd 1995; Venkatesh 2000; Lee et al. 2004). Perceived usefulness is the degree to which a person believes that a particular technology will enhance his or her job performance. Perceived ease of use is the degree of subjective belief that using a particular technology will require little physical and mental effort (Davis, 1989; Morris and Dillon 1997; Venkatesh 2000). Perceived pleasure and perceived usefulness have been shown to clearly affect attitudes toward accepting technology (Davis et al. 1992). For example, pleasure in online shopping has been shown to positively impact consumers' attitudes toward online sellers (Eighmey and McCord, 1998; Mathwick, 2002; Jarvenpaa and Todd 1997). The perceived risk of customers is a subjective risk, which is distinguished from an objective probabilistic risk. Perceived risk includes a psychological risk that consumers perceive when they choose brands, stores, and methods of purchase to obtain a particular item. The ability of an enterprise to revolutionize products depends on the effective acquisition of knowledge about new products (Bierly and Chakrabarti 1996; Rothwell and Dodgson, 1991). Knowledge acquisition is the ability of a company to perceive the value of novelty and technology of the outside (Cohen and Levinthal 1990), to evaluate the outside technology that has newly appeared (Arora and Gambaradella, 1994), and to predict the future evolution of technology accurately (Cohen and Levinthal 1990). Consumer innovativeness is the degree to which an individual adopts innovation earlier than others in the social system (Lee, Ahn, and Ha 2001; Gatignon and Robertson 1985). That is, it shows how fast and how easily consumers adopt new ideas. Innovativeness is regarded as important because it has a significant effect on whether consumers adopt new products and on how fast they accept new products (Midgley and Dowling 1978; Foxall 1988; Hirschman 1980). We conducted cross-national comparative research using the TAM model which empirically verified the relationship between the factors that affect attitudes - perceived usefulness ease of use perceived pleasure perceived risk innovativeness and perceived level of knowledge management - and attitudes toward HSDPA service. We also verified the relationship between attitudes and usage intention for the purpose of developing more effective methods of management for HSDPA service providers. For this research 346 questionnaires were distributed among 350 students in the Republic of Korea. Because 26 of the returned questionnaires were inconsistent or had missing data 320 questionnaires were used in the hypothesis tests. In UK 192 of the total 200 questionnaires were retrieved and two incomplete ones were discarded bringing the total to 190 questionnaires used for statistical analysis. The results of the o...

      • KCI등재

        데이터 산업에서 창업 활성화를 위한 데이터 거래소 제안

        이영환(Nick Lee),전희주(Jun Hui ju),윤정연(Yoon Jeong yeon) 한국창업학회 2015 한국창업학회지 Vol.10 No.2

        As data markets sprout up all around the world, we, the researchers, propose a methodology to classify data markets hoping to be developed for the theory of them. In particular, we pay attention to the evolutionary nature of rapid market advancements and development. Although many data markets are vastly different in their characteristics as they serve different markets and customers, they share common attributes to determine the advancements, in their added values and automation. Therefore, to classify markets according to the relative status of evolution, two measurements to compare how advanced markets are defined: the degree of value added and the degree of automation. Given the measurements, we classify the markets into four different types: Tailor-Made, Do-It-Yourself, Grocery, and Financial-Exchange. As for the first three types of the four, a large number of instances can be found in the real world. Yet, the last one, Financial-Exchange type data market, which is theoretically the most advanced type, does not globally exist. Thus, we have investigated and a possible theoretical model of it for the sake of the completeness of the research. In this paper, we present the model for a possible implementation as a new business model. We find that the model offers many advantages over other types of data markets, especially in the area of data security and privacy information protection. Finally, we investigated how the theoretical model may be viable as a business model of its own kind.

      • 상표자산과 구매의도와의 관계에 관한 국제비교연구 : 아시아와 유럽의 의류시장을 중심으로

        김경훈,고은주,Graham Hooley,Nick Lee,이동해,정홍섭,전병주,문학일 가야대학교 2009 가야대학교 논문집 Vol.18 No.-

        본 연구는 상표자산의 구성요소에 대한 선행요인을 분석하고 이를 토대로 하여 상표자산 구성요소와 상표자산 영향요인간의 관계 그리고 상표자산 구성요소와 구매의도간의 관계를 규명하고 한국과 영국을 중심으로 비교하여 상표자산관리 방안을 도출해보고자 하였다 연구결과, 정보탐색은 제품지식에 정(+)의 영향을 미치며, 상표태도와 상표지식은 상표 충성도와 상표 가치에 정(+)의 영향을 미치는 것으로 나타났다 그리고 상표충성도와 상표가치는 구매의도에 정(+)의 영향을 미치는 것으로 나타났다. 정보원천의 경우, 한국에서는 제품지식에 정(+)의 영향을 미치고 있는 반면, 영국에서는 영향을 미치지 않는 것으로 나타났다. Brand equity is one of the most important concepts in business practice as well as in academic research. Successful brands can allow marketers to gain competitive advantage (Lassar et al.,1995), including the opportunity for successful extensions, resilience against competitors' promotional pressures, and the ability to create barriers to competitive entry (Farquhar, 1989). Branding plays a special role in service firms because strong brands increase trust in intangible products (Berry, 2000), enabling customers to better visualize and understand them. They reduce customers' perceived monetary, social, and safety risks in buying services, which are obstacles to evaluating a service correctly before purchase. Also, a high level of brand equity increases consumer satisfaction, repurchasing intent, and degree of loyalty. Brand equity can be considered as a mixture that includes both financial assets and relationships. Actually, brand equity can be viewed as the value added to the product (Keller, 1993), or the perceived value of the product in consumers' minds. Mahajan et al. (1990) claim that customer-based brand equity can be measured by the level of consumers’ perceptions. Several researchers discuss brand equity based on two dimensions: consumer perception and consumer behavior. Aaker (1991) suggests measuring brand equity through price premium, loyalty, perceived quality, and brand associations. Viewing brand equity as the consumer’s behavior toward a brand, Keller (1993) proposes similar dimensions: brand awareness and brand knowledge. Thus, past studies tend to identify brand equity as a multidimensional construct consisted of brand loyalty, brand awareness, brand knowledge, customer satisfaction, perceived equity, brand associations, and other proprietary assets (Aaker, 1991, 1996; Blackston, 1995; Cobb-Walgren et al., 1995; Na, 1995). Other studies tend to regard brand equity and other brand assets, such as brand knowledge, brand awareness, brand image, brand loyalty, perceived quality, and so on, as independent but related constructs (Keller, 1993; Kirmani and Zeithaml, 1993). Walters(1978) defined information search as, "A psychological or physical action a consumer takes in order to acquire information about a product or store." But, each consumer has different methods for informationsearch. There are two methods of information search, internal and external search. Internal search is, "Search of information already saved in the memory of the individual consumer"(Engel, Blackwell, 1982) which is, "memory of a previous purchase experience or information from a previous search."(Beales, Mazis, Salop, and Staelin, 1981). External search is "A completely voluntary decision made in order to obtain new information"(Engel & Blackwell, 1982) which is, "Actions of a consumer to acquire necessary information by such methods as intentionally exposing oneself to advertisements, taking to friends or family or visiting a store."(Beales, Mazis, Salop, and Staelin, 1981). There are many sources for consumers’ information search including advertisement sources such as the internet, radio, television, newspapers and magazines, information supplied by businesses such as sales people, packaging and in-store information, consumer sources such as family, friends and colleagues, and mass media sources such as consumer protection agencies, government agencies and mass media sources. Understanding consumers’ purchasing behavior is a key factor of a firm to attract and retain customers and improving the firm’s prospects for survival and growth, and enhancing shareholder’s value. Therefore, marketers should understand consumer as individual and market segment. One theory of consumer behavior supports the belief that individuals are rational. Individuals think and move through stages when making a purchase decision. This means that rational thinkers have led to the identification of a consumer buying decision process. This decision process with its different levels of involvement and influencing factors has been widely accepted and is fundamental to the understanding purchase intention represent to what consumers think they will buy. Brand equity is not only companies but also very important asset more than product itself. This paper studies brand equity model and influencing factors including information process such as information searching and information resources in the fashion market in Asia and Europe. Information searching and information resources are influencing brand knowledge that influences consumers purchase decision. Nine research hypotheses are drawn to test the relationships among antecedents of brand equity and purchase intention and relationships among brand knowledge, brand value, brand attitude, and brand loyalty. H1. Information searching influences brand knowledge positively. H2. Information sources influence brand knowledge positively. H3. Brand knowledge influences brand attitude. H4. Brand knowledge influences brand value. H5. Brand attitude influences brand loyalty. H6. Brand attitude influences brand value. H7. Brand loyalty influences purchase intention. H8. Brand value influence purchase intention. H9. There will be the same research model in Asia and Europe. We performed structural equation model analysis in order to test hypotheses suggested in this study. The model fitting index of the research model in Asia was X2=195.19(p=0.0), NFI=0.90, NNFI=0.87, CFI=0.90, GFI=0.90, RMR=0.083, AGFI=0.85, which means the model fitting of the model is good enough. In Europe, it was X2=133.25(p=0.0), NFI=0.81, NNFI=0.85, CFI=0.89, GFI=0.90, RMR=0.073, AGFI=0.85, which means the model fitting of the model is good enough. From the test results, hypotheses were accepted. All of these hypotheses except one are supported. In Europe, information search is not an antecedent of brand knowledge. This means that sales of global fashion brands like jeans in Europe are not expan

      • KCI등재

        다중해상도 탐색을 이용한 반복 일반화 허프 변환

        이경미(Kyoung-Mi Lee),W. Nick Street(W. Nick Street) 한국정보과학회 2003 정보과학회논문지 : 소프트웨어 및 응용 Vol.30 No.9·10

        이 논문은 주어진 영상에 존재하는 물체를 자동적으로 탐지하기 위한 시간과 공간 효율적인 방법을 소개한다. 일반화 허프 변환(Generalized Hough Transform: GHT)은 다양한 모양의 물체를 찾기 위해 자동 물체 탐지를 하는 강력한 템플릿(template) 매칭 알고리즘이다. 다양한 모양과 크기의 물체를 찾기 위해 서로 다른 많은 템플릿을 GHT에 적용해야 한다. GHT로 찾아진 모든 경계선은 보다 정교한 경계선을 찾기 위한 초기 외곽선으로 사용된다. 그러나, GHT의 주요 단점은 과도한 시간과 공간을 요구하는 것이다. 이런 단점을 극복하기 위해서, 제안된 알고리즘은 공간 효율적 방법인 반복적 GHT(iterative GHT: IGHT)를 사용한다. 또한, 원래 영상의 크기를 이분의 일 크기와 사분의 일 크기로 줄여서 다중 해상도 탐색을 이용한다. 사분의 일 영상에서 첫 번째 IGHT를 수행하여 획득한 정보를 이용하고, 세포 크기의 범위를 줄여 이분의 일 크기의 영상에서 탐색공간을 제한한다. 이분의 일 크기의 영상에서 두 번째 IGHT를 수행한 후, 세포핵은 세부 탐색에 의해 찾아지고, 정확한 경계선을 결정하기 위한 에지 정보에 의해 분할된다. 실험결과는 이 방법이 정확도의 손실이 없으면서, 수행시간과 메모리 사용을 줄이고 있음을 보여준다. This paper presents an efficient method for automatically detecting objects in a given image. The GHT is a robust template matching algorithm for automatic object detection in order to find objects of various shapes. Many different templates are applied by the GHT in order to find objects of various shapes and size. Every boundary detected by the GHT scan be used as an initial outline for more precise contour-finding techniques. The main weakness of the GHT is the excessive time and memory requirements. In order to overcome this drawback, the proposed algorithm uses a multiresolution search by scaling down the original image to half-sized and quarter-sized images. Using the information from the first iterative GHT on a quarter-sized image, the range of nuclear sizes is determined to limit the parameter space of the half-sized image. After the second iterative GHT on the half-sized image, nuclei are detected by the fine search and segmented with edge information which helps determine the exact boundary. The experimental results show that this method gives reduction in computation time and memory usage without loss of accuracy.

      • KCI등재

        The Factors Affecting Attitudes Toward HSDPA Service and Intention to Use: A Cross-Cultural Comparison between Asia and Europe

        Jung, Hae-Sung,Shin, Jong-Kuk,Park, Min-Sook,Jung, Hong-Seob,Hooley, Graham,Lee, Nick,Kwak, Hyok-Jin,Kim, Sung-Hyun Korean Academy of Marketing Science 2009 마케팅과학연구 Vol.19 No.4

        HSDPA(高速下行分组接入)是在第三代的W-CDMA技术基础上的3.5代移动通信异步服务. 在韩国, 它主要是通过提供可视电话服务. 由于更强大和多元化的服务扩散, 随着移动通信技术迅速的进步, 消费者需要更多的选择. 然而, 由于各种技术, 不论消费者偏好往往会溢出市场, 消费者感到越来越迷惑. 因此, 我们不应该采取只注重发展假设是下一代新技术项目的战略相反, 我们应该了解消费者接受新的形式和技术的过程, 通过制定战略, 使开发人员能够理解并提供消费者真正想要的, 从而降低进入市场的障碍. 在技术接受模型(TAM)中, 感知到的有用性和使用的简单性被认为是影响人们接受新技术的态度的最重要因素(Davis, 1989; Taylor and Todd, 1995; Venkatesh, 2000; Lee et al., 2004). 感知到的有用性是一个人相信某种特定的技术能提高他或她工作绩效的程度. 感知易用性是主观认为使用某种特定技术不需要太多体力和精力的付出的程度(Davis, 1989; Morris and Dillon, 1997; Venkatesh, 2000). 感知的愉悦性和感知的有用性已经被清楚的证明对接受技术的态度有影响(Davis et al., 1992). 比如, 网上购物的愉悦性已经表现出对消费者对网上商家的态度有积极的影响(Eighmey and McCord, 1998; Mathwick, 2002; Jarvenpaa and Todd, 1997). 消费者的感知风险是一种主观风险. 这种风险和客观可能的风险是有显著区别的. 感知风险包括心理上的风险, 这是当消费者为某一特定物品而选择品牌, 商店和购买方式时所感知到的. 企业革新产品的能力取决于有效的获得有关新产品的知识(Bierly and Chakrabarti, 1996; Rothwell and Dodgson, 1991). 知识获取是公司感知外界新事物和技术的价值的能力(Cohen and Levinthal, 1990); 是公司评估外界最新的技术的能力(Arora and Gambaradella, 1994); 是公司正确预测这项科技对未来革新的能力(Cohen and Levinthal, 1990). 消费者创新是一种在社会体系中比其他人更早接受创新的程度(Lee, Ahn, and Ha, 2001; Gatignon and Robertson, 1985). 也就是说, 它显示了消费者如何快速、方便地接受新的思路. 创新被认为是重要的, 因为它对消费者是否接受新产品和他们多快接受新产品有显著的影响(Midgley and Dowling, 1978; Foxall, 1988; Hirschman, 1980). 我们用技术接受模型来进行跨国家的研究比较, 此模型实证验证了影响态度的因素-感知有用性, 易用性, 感知愉悦, 感知风险, 创新和感知的知识管理水平-和对HSDPA服务的态度之间的关系. 我们为HSDPA服务提供商开发更有效的管理方法还验证了态度和使用意图之间的关系. 在本研究中, 我们在韩国350名学生中分发了346份问卷调查. 由于其中26份收回的问卷时不完整的或者有缺失数据, 所以在假设检验时320份问卷被使用. 在英国, 200份问卷收回了192份, 舍弃了两份不完整的之后, 总共有190份问卷用于统计分析中. 整体模型的分析结果如下: 韩国, x2=333.27(p=0.0), NFI=0.88, NNFI=0.88, CFI=0.91, IFI=0.91, RMR=0.054, GFI=0.90, AGFI=0.84; 英国, x2=176.57(p=0.0), NFI=0.88, NNFI=0.90, CFI=0.93, IFI=0.93, RMR=0.062, GFI=0.90, AGFI=0.84. 在韩国消费者中, 从有关影响HSDPA服务的使用意图和态度之间的关系的假设检验的结果中, 感知的有用性, 易用性, 乐趣, 知识管理的高水平和促进创新对HSDPA移动手机的态度有积极的影响. 然后, 易用性和感知的乐趣对HSDPA服务的使用意图没有直接的影响. 这可能是因为在日常生活中使用视频电话还不是必需的这一现实. 而且消费者对HSDPA视频电话的态度和使用意图有直接的关系, 这些态度包括感知的有用性, 易用性, 乐趣, 知识管理的高水平和创新. 这些关系构成了购买意图

      • EphA2 immunoconjugate as molecularly targeted chemotherapy for ovarian carcinoma.

        Lee, Jeong-Won,Han, Hee Dong,Shahzad, Mian M K,Kim, Seung Wook,Mangala, Lingegowda S,Nick, Alpa M,Lu, Chunhua,Langley, Robert R,Schmandt, Rosemarie,Kim, Hye-Sun,Mao, Shenlan,Gooya, John,Fazenbaker, Ch U.S. Dept. of Health, Education, and Welfare, Publ 2009 Journal of the National Cancer Institute Vol.101 No.17

        <P>EphA2 is overexpressed in many types of human cancer but is absent or expressed at low levels in normal epithelial tissues. We investigated whether a novel immunoconjugate containing an anti-EphA2 monoclonal antibody (1C1) linked to a chemotherapeutic agent (monomethyl auristatin phenylalanine [MMAF]) through a noncleavable linker maleimidocaproyl (mc) had antitumor activity against ovarian cancer cell lines and tumor models.</P>

      • KCI등재

        Development of Roundup Ready Bentgrass for the Control of Poa annua

        Nick E. Christians(닉 크리스챤스),Jeong-Ho Lee(이정호) 한국잡초학회·한국잔디학회 2006 Weed & Turfgrass Science Vol.20 No.1

        애뉴얼 블루그래스는 골프장에서 방제하기가 대단히 어려운 잡초이다. 방제가 어려운 이유로는 애뉴얼 블루그래스의 경우 불량환경에서도 왕성하게 종자생산을 할 수 있는 특성과 또한 낮은 예초환경에서도 적응력이 있기 때문이다. 하지만 무엇보다도 유전적으로 다양성이 있기 때문에 골프장의 잔디에 비해 우점할 수 있는 것이다. 일반적으로 애뉴얼 블루그래스는 일년생 한지형 잔디로, 생육형은 주형이다. 하지만 포복경이 있어 다년생의 특성을 갖는 생태형이 다른 애뉴얼 블루그래스도 있다. 골프장에서 애뉴얼 블루그래스 방제를 위해 화학적 방법과 재배적 방법에 관한 수많은 연구가 지난 85년간 진행되었다. 연구결과 일부 종류의 애뉴얼 블루그래스방제에 성공적인 결과도 있지만, 모든 종류의 애뉴얼 블루그래스 방제에 성공적인 방법은 아직 없는 실정이다. 이 모든 방제 방법들 중에 Roundup ready creeping bentgrass의 사용은 다양한 종류의 새포아풀을 방제 할 수 있다. Roundup readgy bentgrass는 Roundup에 내성이 있어 약해 피해 없이 생존이 가능하다. 따라서 골프장에서 이 새로운 기술을 활용하면 새포아풀이 없는 그린, 티, 훼어웨이를 유지할 수 있다. Annual bluegrass(Poa annua L.) is a problem weed that is very difficult to control on golf courses. There are some reasons that make Poa annua such a difficult weed to be controled. One of these reasons is this plant's ability to reproduce its seed even under stressful conditions. Another reason is its adaptation to low mowing heights. Above all things, the greatest competitive advantage of Poa annua is its genetic diversity. Generally, Poa annua is a bunch type and annual type cool-season grass, but some types act as weak perennials and have stolons. There has been much research on controlling annual bluegrass in golf course turf with chemical and cultural techniques. This research has been conducted for more than 85 years. There has been some progress in controlling some types of Poa annua, but these methods have not been successful on every biotype. Among all of the techniques, Roundup ready creeping bentgrass has the most promise of controlling the diverse types of Poa annua. Roundup ready bentgrass is capable of tolerating the effects of Roundup(glyphosate) while it kills other plants including Poa annua. By using this new technology, we can make Poa annua free greens, tees, and fairways.

      • KCI등재

        Comparison of Urea and Methylene Urea at Four Mixing Depths on the Growth and Establishment of Poa pratensis L. in Sand-based Systems

        Sangkook Lee,David D Minner,Nick E Christians 한국잡초학회·한국잔디학회 2020 Weed & Turfgrass Science Vol.9 No.1

        Nitrogen (N) may be easily leached from a sand-based system. Frequent application of N is a way to reduce leaching. Repeated applications result in increasing cost. Slow-release fertilizers were designed to provide a steady release of N over time. Use of slow-release N sources has been promoted as a more efficient N fertilizer strategy. This study was conducted to evaluate N leaching, root and shoot growth, and nitrogen use efficiency (NUE) when urea and methylene urea were placed at four mixing depths in a sand-based system. Grass clipping samples were collected every two weeks, dried and weighed. Root dry weight and root organic matter were evaluated at the end of the study. Leachate was collected weekly and analyzed for nitrate-nitrogen (NO₃-N) content. Surface applied urea produced the largest clipping yield and the best NUE for total mass yield, with the lowest NO₃-N loss due to leaching. When applied subsurface, Methylene urea at the deepest mixing depth of 22.9 cm produced 121% more shoot growth, 57% less NO₃-N leaching, and 46% more NUE for total mass than urea. Split applications of surface applied urea provided the best establishment of Kentucky bluegrass sod on sand-based systems based on the results of the study.

      • C1-Ten Is a Protein Tyrosine Phosphatase of Insulin Receptor Substrate 1 (IRS-1), Regulating IRS-1 Stability and Muscle Atrophy

        Koh, Ara,Lee, Mi Nam,Yang, Yong Ryoul,Jeong, Heeyoon,Ghim, Jaewang,Noh, Jeongeun,Kim, Jaeyoon,Ryu, Dongryeol,Park, Sehoon,Song, Parkyong,Koo, Seung-Hoi,Leslie, Nick R.,Berggren, Per-Olof,Choi, Jang Hy American Society for Microbiology 2013 Molecular and cellular biology Vol.33 No.8

        <P>Muscle atrophy occurs under various catabolic conditions, including insulin deficiency, insulin resistance, or increased levels of glucocorticoids. This results from reduced levels of insulin receptor substrate 1 (IRS-1), leading to decreased phosphatidylinositol 3-kinase activity and thereby activation of FoxO transcription factors. However, the precise mechanism of reduced IRS-1 under a catabolic condition is unknown. Here, we report that C1-Ten is a novel protein tyrosine phosphatase (PTPase) of IRS-1 that acts as a mediator to reduce IRS-1 under a catabolic condition, resulting in muscle atrophy. C1-Ten preferentially dephosphorylated Y612 of IRS-1, which accelerated IRS-1 degradation. These findings suggest a novel type of IRS-1 degradation mechanism which is dependent on C1-Ten and extends our understanding of the molecular mechanism of muscle atrophy under catabolic conditions. C1-Ten expression is increased by catabolic glucocorticoid and decreased by anabolic insulin. Reflecting these hormonal regulations, the muscle C1-Ten is upregulated in atrophy but downregulated in hypertrophy. This reveals a previously unidentified role of C1-Ten as a relevant PTPase contributing to skeletal muscle atrophy.</P>

      • KCI등재

        Interpreting Soil Tests for Turfgrass

        Jeong-Ho Lee(이정호),Young-Kyoo Joo(주영규),Nick Christians(닉 크리스챤스) 한국잡초학회·한국잔디학회 2006 Weed & Turfgrass Science Vol.20 No.2

        잔디 작물에 익숙하지 않은 토양 분석 실험실에서는 잔디 생육에 필요한 인에 대하여서는 과대평가를 하나, 칼륨에 대한 요구도는 대해서는 과소평가를 하는 경향이 있다. 그 이유는 부분적으로 잔디, 정원식물 및 농작물 사이에는 뿌리 발달의 차이가 있기 때문이다. 일반적으로 잔디는 토양으로부터 인을 흡수하는데 좀 더 효율적이기 때문에 인산질 비료에 대한 요구도가 적은 편이다. 작물 재배시에는 농작물의 생산량이 주 목적이지만, 잔디밭 관리의 목적은 생산량이 아니기 때문에 근본적으로 칼륨요구 수준이 다르다. 최대의 엽조직 생산을 위해 요구되는 수준 이상의 칼륨은 스트레스에 대한 내성을 증가시킬 수 있기 때문에 칼륨 시비 수준을 높일 경우 잔디밭에 유익하다. 또한 토양분석 실험에 대한 철학에도 차이가 있다. 어떤 연구소는 기본적인 양이온 치환의 용량 접근법(BCSR)을 선호하는 반면, 다른 연구소는 사용 가능한 성분의 충분양(SLAN)에 대한 컨셉을 사용한다. 연구소에 따라 이 두 가지 방법을 모두 사용할 수도 있다. BCSR 이론의 사용은 대부분 비료 살포 남용을 야기한다. 그리고 문제가 될만한 비료의 살포와 제품들은 때때로 양이온의 비율의 불균형을 예증하기 위해 사용된다. 토양 실험에 있어서의 BCSR 비율 이론의 유용성은 토양의 구성에 따라 달라질 수 있고 특히 모래로 조성된 지반에서 수행된 토양분석은 문제가 될 수 있다. 또 다른 토양 실험의 문제는 경기장 또는 골프장 그린에 사용된 모래지반이 유리된 칼슘 탄산염을 함유하고 있을 때 발생한다. pH7.0의 암모늄 초산염 추출액은 양이온 치환량의 측정과 양이온 비율의 측정을 한쪽으로 치우치게 할 수 있는 과다한 양의 칼슘을 용해한다. 용질의 pH를 8.1로 맞추는 것은 석회질 토양에서의 실험 절차의 정확성을 향상시킬 수 있다. Soil testing laboratories unfamiliar with turfgrasses will often overestimate the plant’s need for phosphorus and underestimate the need for potassium. This is partly due to differences in rooting between grasses and many garden plants and crops. The grasses are generally more efficient in extracting phosphorus from the soil, reducing their need for phosphorus fertilizer. The fact that crop yield is often the primary objective in field crop production, and is usually of little interest in turfgrass management, may affect soil test interpretation for potassium. Potassium levels above those required for maximum tissue yield of grasses may improve stress tolerance and turfgrasses will usually benefit from higher applications of this element. There are also differences in soil testing philosophies. Some laboratories use the sufficiency level of available nutrients(SLAN) approach, whereas others prefer the basic cation saturation ratio(BCSR) approach. Some will use a combination of the two methods. The use of the BCSR theory easily lends itself to abuse and questionable fertilizer applications and products are sometimes recommended citing imbalances in cation ratios. The usefulness of the BCSR ratio theory of soil testing varies with soil texture and interpretations on tests performed on sand-based media are particularly a problem. Other soil testing problems occur when sand-based media used on sports fields and golf greens contain free calcium carbonate. The ammonium acetate extractant at pH 7.0 dissolves excessive amounts of calcium that can bias cation exchange capacity measurements and measurements of cation ratios. Adjusting the pH of the extractant to 8.1 can improve the accuracy of the testing procedure for calcareous media.

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