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        검색결과 18

        1.
        2024.04 구독 인증기관·개인회원 무료
        고자리꽃파리는 양파 및 마늘 등 백합과 Allium 속에 속하는 농작물에 중요한 해충으로 전 세계적으로 온대지역에 서 경제적 해충으로 취급하고 있다. 본 연구에서는 기존 자료를 바탕으로 월동번데기의 성충으로 우화모델를 작성하 고 포장 실측자료와 비교하여 평가하였다. 월동번데기 발육모형으로 선형과 비선형모형을 작성하고 발육기간 분포 모형과 결합하여 예찰모형을 작성하였다. 비선형발육모형 작성시 3-매개변수 락틴모형 적용뿐만 아니라 4-매개변 수 모형의 마지막 변수 값을 선형모형의 절편값으로 대체하여 저온에서 선형성이 강화도록 변형시켰다. 성충우화 50% 예측에서 일일평균온도를 이용하는 경우 적산온도 모형을 비롯하여 발육률 적산모형(선형식 및 비선형식) 모두 실측치와 큰 차이가 있었다. 시간별온도를 입력값으로 한 경우 3-매개변수 모형을 제외한 사인곡선 적산온도 모형, 선형 발육률 적산모형, 4-매개변수 비선형 발육률 적산모형의 평균편차는 3일과 차이가 없었다. 최종적으로 선형모형 및 4-매개변수 비선형모형을 바탕으로 시간별온도자료를 이용한 발육률 적산모형은 선발하였다. 그 결과 선형 발육률 적산모형이 두 포장적합 집단(1984, 1987)에서 실측일과 편차가 3일과 차이가 없었다. 비선형 발육률 적산모형은 1984년 적합은 0.8일 편차로 정확하였으나 1987년 집단에서 평균편차가 6.5일로 다소 증가하였다.
        8.
        2018.07 구독 인증기관·개인회원 무료
        The purpose of this study is to assess the role of marketing to the area of strategic alliances. We suggest that marketing capability – the ability to deploy resources to serve customers better- is a key determinant that facilitates value creation in strategic alliances. Specifically, we investigate the interaction effects of marketing capability on performance of strategic alliance experience and types of strategic alliances (introducing three types: SI-SF alliance, AI-SF alliance and AI-DF alliance), and whether these interaction effects are moderated by high vs. low technological industry. This study analyzed the panel data from 39 international firms and their 2,158 alliances during the period 1994 - 2014, 21 firms from computer industry (high-tech industry) and 18 firms from food industry (low-tech industry), respectively. The results indicate that the contribution of marketing capability on the relationships between alliance experience, types of strategic alliances and firm value varies with environmental contexts. First, when a firm has strong marketing capability, the effect of strategic alliance experience on firm value is greater than those of firms with low marketing capability. Also, the strength of its interaction effect is lower in high-tech industry than low-tech industry. Second, when a firm has strong marketing capability, the effects of three different types of strategic alliances on firm value are greater than those of firms with low marketing capability. However, their interaction effects to firm value were significant only in high-tech industry. Specifically, when a firm has strong marketing capability, the stock market reacts most favorably to the AI-DF alliance than those of SI-SF alliance and AI-SF alliance in high-tech industry. In contrast, even a firm has strong marketing capability, the stock market reacts favorably only to AI-SF alliance in low-tech industry. In sum, our research suggests that the interactive performance impact of marketing capability to the strategic alliance experience and the types of strategic alliances can be obtained in particular environmental contexts.
        9.
        2017.07 구독 인증기관·개인회원 무료
        This paper aims to expand our understanding on the success factors of small businesses, which comprise of more than 90 percent of all businesses in U.S. in 2016. One of the most critical issues behind small business success is the competition, which becomes increasingly intense. Not only small businesses fiercely compete with larger competitors (e.g. Emergence of mega-retailers such as Wal-Mart has intensified the competition in the grocery industry, and, as a result, many mom and pop stores have gone out of business.), but also the competition against each other (i.e. competition between small businesses) becomes increasingly aggressive. Yet, the current literature in marketing have less investigated the issue of competition between small businesses, while issues on competition between small and large businesses have been somewhat explored. Another phenomenon in small business that has not received much attention is the competition between generalist and specialist firms. This phenomenon of specialist versus generalist competition is in fact frequently observed in many industries. Therefore, we study competition between small businesses, focusing on the competition between generalist and specialist small businesses. We examine how competitive intensity, as well as market environmental factors, affect the performance of small businesses. Specifically, we decompose the competitive intensity into two types, one between generalists and the other between specialists, in order to identify the differential effects of competition between generalist and specialist, and examine their impacts on the generalist and specialist performance. Given the research questions above, we develop the following hypotheses based on the past research in marketing. First, we expect competition has a positive effect on generalist performance, while we expect the opposite effect on specialist performance. We also expect that the effect of competition becomes weaker, as the competition becomes more intense. That is, the positive (negative) impact of competition on generalist (specialist) performance becomes less significant as there are more competitors in the market. We further expect that competition between the same type of businesses (e.g. between generalists) has a positive effect on their performance, while competition between the difference types (e.g. between generalist and specialist) has a negative effect on their performance. Moreover, we expect that market environmental factors have differential effects on the performance of generalist and specialist. To test the aforementioned hypotheses on the small business competition between generalist and specialist, we collected data from the health care industry on private physician practices (offices) in Korea. Out data contain, for each practice, monthly sales, number of doctors, number of nurses, type of practice, number of beds and zip code it is located in. We also have data on average consumer spending, average medical spending, percentage of patients over sixty years old for each zip code. Moreover, we have data on competition between the same type of offices (e.g. between generalists and between specialists) and competition between different types (e.g. between generalist and specialist). Note that our data collected from the Korean health care industry fit our research questions well. First, the majority of medical service providers in Korea are small private practices with an average number of two doctors, and the share of generalist and specialist practices are about half-and-half. Second, unlike the U.S. health care industry, generalist physicians in Korea usually practice a number of different fields, while specialist physicians focus on their own specialties. Third, patients in Korea do not usually distinguish between generalist and specialist offices, and they do not usually have a primary care physician. As a result, patients can easily switch between physicians, and in fact the switching is highly likely, as all medical information is centralized by government. Our main findings are as follows. First, we find that competition has a positive effect on generalist performance, while it has a negative effect on specialist performance. Specifically, we find that generalist benefits from competition with both generalist and specialist, while specialist suffers from the competition with both specialist and generalist. As competition becomes intense, meaning the number of physician offices increases, it would attract more patients to visit the area where physician offices are clustered (clustering effect), while it becomes easier for patients to switch from one to the other nearby offices. In particular, as generalist usually treats multiple fields (specialties), generalist tends to benefit from the patients who switch from specialist. In other words, generalists benefit from competition, as they free ride on clustering of physicians including specialists, while specialists would suffer from competition. Second, our findings show that as the competition becomes more intense, its effect on business performance becomes weaker. That is, a high level of competition weakens the benefits and damages imposed on the performance of generalist and specialist, respectively. When there are more physician offices to switch, the effect of free riding becomes weaker, as patients have more options to choose from. Thus, the benefit of generalist from free riding becomes weaker, as well as the negative effect on specialist performance. Moreover, our findings suggest that market environmental factors do influence the business performance. Specifically, the performance of both generalist and specialist improves as the number of doctors increases. However, an increase in the number of nurses has a different effect on generalist and specialist. Employing a larger group of nurses has a negative effect on generalist because it might cause the operation of the office to be less efficient. However, since specialist’s practice usually involves a more technical and sophisticated processes, a larger group of nurses could make the office more efficient having a positive impact on the sales performance. Similarly, we find the effects of other environmental factors have differential impacts on the performance of specialist versus generalist.
        10.
        2008.10 구독 인증기관·개인회원 무료
        Recently Transgenesis was achieved in Bombix mori. For stable and effective transgenesis in B.mori, B.mori cytoplasmic actin gene (BmA3) promoter was used to expression of marker gene, the green fluorescent protein(GFP). Green fluorescent protein expression for selection of transformants was visible in all larval, pupal, and adult tissues but, unexpectdly, was not detectable in embryos. So, it spend times and money on rearing of silkworm. Furthermore, the BmA3 promoter is predominantly active in the midgut, which makes it difficult to reliably identify transformants since autofluorescence of many insect foods can mask low-level fluorescence and only allows the detection of strongly expressing individuals with potentially multiple insertions. Therefore, we need more intensely promoter than BmA3 promoter for selected by expression of GFP in embryos and selected by reliable expression of GFP in larvae. We performed dot blot hybridization to develop strong promoter. Nine differentially expressed clones were isolated and we focused one clone of them which has high similarity with heat shock protein 70 gene from D.melanogaster. We named it as bHSP70 (Bombyx mori heat shock protein 70). Expression from the hsp70 promoter was strong and heat shock-dependent. And Drosophila hsp70 promoter appears useful for regulating expression of Exogenous DNA. So, we analyzed transcriptional activity of promoter with bHSP70 gene by using dual luciferase assay system. bHSP70 promoter has about 264 folds more intensely than BmA3 promoter. Also, when bHSP70 promoter treated heat shock(42℃), transcriptional activity incresed 2 times more than normal condition. Therefore, we suggest that bHSP70 promoter is more effective candidate for stable transformation and selection of transformants.
        11.
        2012.06 KCI 등재 서비스 종료(열람 제한)
        광나무(L. lucidum)는 ursolic acid와 oleanolic acid를 다량 포함하고 있다. 본 연구에서는 광나무 열매, 줄기, 잎 세 부위 추출물의 항주름 효능을 평가하였다. 광나무 추출물은 human skin fibroblasts에서 독성이 없을 뿐만 아니라 MMP-1과 MMP-2의 발현을 감소시키고 COL1A1의 발현을 증가시켰다. 이들 추출물은 모두 농도 의존적으로 COL1A1의 발현을 증가시켰으며 MMP-1과 MMP-2의 발현을 감소시켰다. 광나무 세 부위 추출물 가운데, 열매 부위에 가장 많은 양의 ursolic acid 와 oleanolic acid가 함유되어 있었으며 가장 강한 COL1A1 upregulating 효과와 MMP-1과 MMP-2 downregulating 효과를 나타냈다. 이처럼 항주름 효능을 보이는 광나무 열매 추출물은 기능성 화장품 소재로 개발될 수 있는 가능성이 있다.
        14.
        2007.03 KCI 등재 서비스 종료(열람 제한)
        ‘Taegang’ is a new six-rowed covered barley cultivar developed by the National Institute of Crop Science (NICS), R.D.A. This cultivar is developed from a cross between ‘Suwon287’ and ‘Olbori’ in 1992. An F8 selection was made at NCES in 2000 and it was te
        15.
        2007.03 KCI 등재 서비스 종료(열람 제한)
        ‘Gwangan’ is a new six-rowed covered barley cultivar developed by the National Institute of Crop Science (NICS), R.D.A in 2004. This cultivar is developed from a cross between “Mirak” and ‘Milyang59’ in 1995. An F6 selection was made at Milyang in 2001 an
        16.
        2003.04 KCI 등재 서비스 종료(열람 제한)
        “Jaeanchal” is a new six-rowed, naked and waxy barley cultivar developed by National Crop Experiment Station (NCES), RDA in 2001. This cultivar was derived from a cross between “Suwon261” and “SB881115-6” in 1989. The final selection was made at NCES in 1
        17.
        2003.04 KCI 등재 서비스 종료(열람 제한)
        A new two-rowed naked waxy barley cultivar, 'Pungsanchal', was developed for split polished grains by the National Crop Experiment Station(NCES), RDA in 2001. This cultivar was derived f rom a cross between 'SB901258GG-B' and 'Suwon212' in 1991. The f ina
        18.
        2000.06 KCI 등재 서비스 종료(열람 제한)
        An extensive investigation has been made for the possible utilization of polypropylene spunbonded fabrics in rice seedling nursery. Considering the cropping systems available in southern part of Korea, sowing dates were fixed at April 5 and April 20 for single cropping and May 6 and May 26 for double cropping. Nursery period was fixed to 35 days for each sowing date. Four different thickness of polypropylene spunbonded fabrics, 40, 60, 80, 100 g/m2 , were tested in rice seedling nursery. The temperature and light intensity were not significantly different among the thickness of polypropylene spunbonded fabrics. Light intensity was significantly reduced in polypropylene spunbonded fabric (72.2 Klux) compared with polyethylene mm (85.5 Klux), however, the reduced light intensity was enough for seedling growth. The temperature in the polypropylene spunbonded fabric covering during low air temperature was higher than that in polyethylene mm tunnel. At transplanting, the rice seedlings grown in polypropylene spunbonded fabric condition was shorter (17cm) but healthier than those in polyethylene mm (23cm). The estimated possible nursery periods using the polypropylene spunbonded fabric covering may start from April 1 at Chinju (plain area in Southern Korea, 20m altitude) and April 15 at Susang (mountainous area, 430m altitude). Labour hours and cost were reduced by about 28% and 48%, respectively.