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        검색결과 222

        61.
        2019.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        To improve the performance of carbon nanofibers as electrode material in electrical double-layer capacitors (EDLCs), we prepare three types of samples with different pore control by electrospinning. The speciments display different surface structures, melting behavior, and electrochemical performance according to the process. Carbon nanofibers with two complex treatment processes show improved performance over the other samples. The mesoporous carbon nanofibers (sample C), which have the optimal conditions, have a high sepecific surface area of 696 m2 g−1, a high average pore diameter of 6.28 nm, and a high mesopore volume ratio of 87.1%. In addition, the electrochemical properties have a high specific capacitance of 110.1 F g−1 at a current density of 0.1 A g−1 and an excellent cycling stability of 84.8% after 3,000 cycles at a current density of 0.1 A g−1. Thus, we explain the improved electrochemical performance by the higher reaction area due to an increased surface area and a faster diffusion path due to the increased volume fraction of the mesopores. Consequently, the mesoporous carbon nanofibers are demonstrated to be a very promising material for use as electrode materials of high-performance EDLCs.
        4,000원
        63.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        흰가루병은 시설 재배 박과류 작물에 광범위하게 발생하여 큰 경제적 피해를 유발하는 병으로서 흰가루병에 의한 피해를 예방하기 위해 실제 현장에서 사용할 수 있는 효과적인 방제체계의 개발이 필요하다. 본 연구에서는 시설오이 재배지의 흰가루병에 대해 오이흰가루병에 등록된 서로 다른 계통의 4개 약제와 2종의 유기농 자재의 약제 교호살포 체계별 방제효과를 조사하였다. Pyraclostrobin EC (Pyr, a.i. 22.9%), Hexaconazole SC (Hex, a.i. 2%), Flutianil EC (Flu, a.i. 5%), Penthiopyrad EC (Pen, a.i. 20%) 등 4종의 화학약제를 단일약제 반복처리 및 조합처리 방식으로 총 3회 처리한 결과 Pyr → Flu → Pen 처리구는 87%의 높은 방제가를 나타낸 반면, Pyr 연속 3회 처리구는 32.5%의 낮은 방제가를 나타내어 해당 약제에 대한 저항성이 있음을 확인하였다. Pyr → Flu → Pen 처리구와 보호용 살균제인 Iminoctadine-trisalbesilate SC (Imi)를 처리한 구 그리고 유기농 자재 2종의 교호살포 처리구의 방제가를 조사한 결과 Imi → Flu → Pen 처리구의 방제가는 89%로 가장 높게 나타났으며, 유기농자재 교차살포 처리구의 방제가는 66.3%로 나타났다. 시험 결과를 바탕으로 Pyr → Flu → Pen, Imi → Flu → Pen 처리구는 시설 오이 재배지 내 발생하는 흰가루병 피해를 최소화할 수 있는 효과적인 약제교호살포체계로 생각된다.
        4,000원
        64.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 셀프리더십이 진로동기에 미치는 영향을 확인하고 그 과정에서 자기통제력과 취업 스트레스의 매개효과를 검증하고자 하였다. 이를 위해 263명의 대학생들의 자료를 분석하였다. 본 연구의 주요 결과는 다음과 같다. 첫째 셀프리더십, 진로동기, 자기통제력, 취업스트레스 간에는 유의미한 상관관계를 보였다. 진로동기와 취업스트레스의 상관은 유의하지 않았다. 둘째 셀프리더십과 진로동기, 셀프리더십과 자기통제력, 자기통제력과 진로동기, 자기통제력과 취업스트레스는 서로 유의미한 영향을 미치는 것이 확인되었다. 즉 셀프리더십은 진로동기와 자기통제력에 긍정적인 영향을 미치며, 자기통제력 또한 진로동기에 긍정적인 영향을 주었다. 그리고 자기통제력 수준이 높을수록 취업스트레스가 낮다는 점도 확인하였다. 셋째 셀프리더십이 진로동기에 영향을 미치는데 있어서 자기통제력을 경유할 때 그 크기가 증가하였다. 이 사실은 진로동기를 이해하는 데 있어서 셀프리더십과 자기통제력의 중요성을 확인해 준다. 이러한 결과를 토대로 본 연구의 의의와 제한점을 논의하였다.
        6,000원
        65.
        2018.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Laminate composites composed of 0.95Pb(Zr0.52Ti0.48)O3-0.05Pb(Mn1/3Sb2/3)O3 piezoelectric ceramic and Fe-Si-B based magnetostrictive amorphous alloy are fabricated, and the effect of control of the areal dimensions and the thickness of the piezoelectric layer on the magnetoelectric(ME) properties of the laminate composites is studied. As the aspect ratio of the piezoelectric layer and the magnetostrictive layer increases, the maximum value of the ME voltage coefficient(αME) increases and the intensity of the DC magnetic field at which the maximum αME value appears decreases. Moreover, as the thickness of the piezoelectric layer decreases, αME tends to increase. The ME composites exhibit αME values higher than 1 Vcm−1Oe−1 even at the non-resonance frequency of 1 kHz. This study shows that, apart from the inherent characteristics of the piezoelectric composition, small thicknesses and high aspect ratios of the piezoelectric layer are important dimensional determinants for achieving high ME performance of the piezoelectric-magnetostrictive laminate composite.
        3,000원
        66.
        2018.10 구독 인증기관·개인회원 무료
        2017년 경북지역은 약 700ha 이상의 면적에서 미국선녀벌레의 피해를 입었다. 그 중 600ha의 피해면적이 떫은감 주요 생산지인 청도군에서 발생하였다. 미국선녀벌레의 효율적인 방제를 위해 2018년 5월 상순에 침투이행성 약제를 토양에 처리하여 약충이 부화하기 전감나무 수체 내 약제를 이행시켜 방제효과를 조사하였다. 토양입제처리의 방제효과 조사를 위하여 토양입제 단독처리(5월 상순), 경엽살포 단독처리(6월 중순), 토양입제(5월 상순) 및 경엽살포(6월 중순) 체계처리를 비교하였다. 조사결과 토양입제 단독처리 시 약제처리 후 약 70일 이상 90%이상의 방제효과가 지속되었고, 경엽살포 단독처리 시 약제처리 후 약 2주 동안 90%이상의 방제효과를 보인 뒤 방제효과가 감소하였다. 또한 토양입제 및 경엽살포 체계처리 시 약제처리 후 약 70일 동안 95%이상의 높은 방제효과를 보였다.
        67.
        2018.10 구독 인증기관·개인회원 무료
        This study investigated number of eggs, hatch rate, toxicities and LT (lethal time) values of Culex pipiens and Aedes albopictus using Aquatain™(Aqua mosquito film). Aquatain™ is a covering agent applied on the surface of water for the control of larva and pupa of mosquito. It forms molecule layer on the surface of the water to lower the surface tension of the water, to prevent flooding of the larva of the mosquito larvae, or to suffocate by obstructing breathing. Cx. pipiens and Ae. albopictus larvae observed 99.9% and 1% larvicidal effect after 24h, respectively. However, both mosquito pupae were showed 100% mortality after 24 h. The AMF™ was treated with three doses (0.5, 1, 2 folds) to observe the LT value in larvae and pupae stages of Cx. pipiens and Ae. albopictus. The LT values of Ae. albopictus pupa was similar regardless of dose, but the LT value of Cx. pipiens pupa decreased as the dose increased. However, Ae. albopictus larvae showed 18.6 folds longer LT90 time than Cx. pipiens larvae. Both species mosquito showed statistically significant differences in the number of eggs laid and hatch rate at recommended dose. Therefore, Aquatain AMF™ may be used to control mosquitoes, although the activity varies depending on the species of mosquito.
        68.
        2018.10 구독 인증기관·개인회원 무료
        소나무재선충병의 예방을 위하여 실시하는 예방나무주사는 소나무재선충 피해를 예방할 수 있는 매우 효과적인 방제방법이지만 매개충에 대해서는 효과가 밝혀진 바 없다. 본 연구는 살선충제와 살충제가 혼합된 약제를 나무주사하여 소나무재선충병의 예방효과 뿐만 아니라 신초를 후식하는 하늘소류에 대해 소화중독에 의해 매개충살충까지 동시에 가능한 방제방법을 개발하기 위하여 실시하였다. Abamectin+Sulfoxaflor DC을 비롯한 3개 약종 2018년 3월 6일에 소나무에 나무주사 후 90여일 이 경과한 6월 5일에 소나무 가지에 망대를 설치하고 각 망대에 솔수염하늘소 1마리씩을 접종하여 7, 14, 21일의 살충율을 조사하였다. 나무주사된 3약종 모두 솔수염하늘소에 대하여 살충력이 우수한 것으로 나타났으며, 경기도 남양주시 잣나무림에 Abamectin+Sulfoxaflor DC를 나무주사 후 산란유인목을 설치하여 현장 실험을 실시한 결과 대조구와 비교하여 유충에 의해 발생된 목설흔이 매우 적게 나타나 소나무재선충병 방제에 적용 가능성을 확인할 수 있었다.
        69.
        2018.10 구독 인증기관·개인회원 무료
        농업용 무인멀티콥터를 활용한 방제면적은 수도작은 물론 밭작물에서도 방제 범위가 확대되고 있다. 밭작물은 작물의 형태가 다양하여 비행속도, 살포높이 등을 최적화하는 연구가 필요하다. 본 연구에서는 배추, 대파, 고추에서 발생하는 나방류에 대하여 무인멀티콥터의 살포 높이에 따른 방제효과를 확인하였다. 살포된 약제가 작물에 부착되는 정도를 조사한 결과, 배추는 2m, 대파는 3~4m, 고추는 모든 높이에서 비슷한 부착정도를 보였지만, 전체적으로 부착량이 적고 불균일 하였다. 살포 높이별 방제효과는 작물별로 각각 배추(9~10엽기)는 2m높이, 고추(약 1.2m)는 2~3m, 대파(약 60cm)는 2, 3, 4m 각각 비등한 방제효과를 보였다. 각각의 작물모두 경엽처리 대비 약효가 미흡하였으며, 고추는 4m높이 살포시 방제효과가 현저히 낮았다.
        70.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구는 급성기 뇌졸중 환자에서 동작관찰 체간훈련이 체간조절능력, 균형, 일상생활수행능력에 미치는 효과를 알아보고자 실시하였다. 연구방법 : 2017년 7월 3일부터 2018년 4월 30일까지 전북 익산 소재의 W 대학병원에 입원한 급성기 뇌졸중 환자 14명을 실험군과 대조군으로 무작위 할당하였다. 두 군 모두 일반적인 물리·작업치료를 실시하였다. 추가적으로 실험군에는 동작관찰 체간훈련을, 대조군은 풍경관찰 체간훈련을 각 1일 1회 30 분, 주 5회, 총 3주간 실시하였다. 치료 중재 전·후 체간조절능력을 측정하기 위해 체간 손상 척도 (Trunk Impairment Scale; TIS), 균형능력을 측정하기 위해 수정된 기능적 팔 뻗기 검사(Modified Functional Reach Test; M-FRT)와 버그균형척도(Berg Balance Scale; BBS)를 사용하였고, 일상생활활동 수행능력을 평가하기 위해 한국판 수정된 바델 지수(Korean version of Modified Barthel Index; K-MBI)을 사용하였다. 결과 : 3주 중재 후, 두 그룹에서 중재 전·후 체간조절능력, 균형, 일상생활수행능력에서 유의한 차이가 나타났으며 (p<.05), 중재 후 두 그룹 간 변화량의 차이는 TIS와 M-FRT에서 유의한 차이가 나타났다(p<.05). 결론 : 본 연구 결과 동작관찰 체간훈련이 급성기 뇌줄중 환자의 체간조절능력, 균형, 일상생활수행능력을 향상시킬 수 있는 중재 방법으로 나타났다. 따라서 기립 훈련기에서 동작관찰 체간훈련은 급성기 뇌졸중 환자에게 능동적이고 동적인 체간훈련을 제공할 수 있는 새로운 중재 방법으로 사용될 수 있을 것이다.
        4,500원
        71.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study is intended to look into the effect of construction safety supervision system on risk control and reduction. To achieve this, a survey was carried out to 114 companies in construction, ordering, contract and management. The overall findings were as follows. The effect of construction safety supervision system on risk control and reduction showed that factors of supervision system, supervision cost and supervision method had a positive effect on risk control and reduction. And their perception of the introduction of safety supervision system in construction sites according to process showed that there was a difference between them according to the field of ordering, contract and supervision. There was the biggest difference between owner and contractor in double supervision system, but no difference between them in the perception of risk reduction. These results show that all ordering, contract and supervision are positively needed for the introduction of construction safety supervision. This means that there is a difference between owner and contractor in the perception of process according to system operation. All companies agree to system improvement by the settlement of safety supervision system for the prevention of safety accidents and safe construction, but the systematic complement of safety supervision is the burden of contractor. And there is a big difference between owner and contractor in the perception of responsibility and concern for cost burden.
        4,000원
        72.
        2018.07 구독 인증기관 무료, 개인회원 유료
        Introduction In the past study, the relationship between the power structure of marketing and research and development (R&D) and NPD performance was not consistent (Atuahene-Gima & Evangelista, 2000; Engelen & Brettel, 2012; Li & Atuahene-Gima, 1999, 2001). The inconsistency may result from each study in different industrial contexts. It reflects every NPD project faces different environmental uncertainties. Furthermore, we adopt the external control perspective to glue power structure and NPD performance under a certain external environment together. Therefore, this paper tends to fulfill the gap of prior study, and the main objective of this research is to investigate whether the power structure of marketing and R&D functions have different linear relationships under the different level of environmental uncertainty. A NPD team is like a cross-functional organization that the NPD team is composed of multiple functions, and it has independent budgets. The members in the team will allocate their limited resources like budgets or positions to respond environments and to maximize profits. Theoretical Development When a NPD team faces the high market uncertain situation, marketing function can gather more resources because of its own power. Thus, R&D members in a NPD team may have less determination in the process of NPD. Even though they create a new product, marketing specialists make most decisions in the NPD team. According to function’s contribution argument, the more contribution of a certain function to the NPD process, the more positive related to the new product success (Atuahene-Gima and Evangelista, 2000; Atuahene-Gima and Luca, 2008; Li and Atuahene-Gima, 1999). Therefore, the current study proposes the hypothesis1 described below: H1: Market uncertainty will strengthen the relationship between power structure leaned to marketing and NPD successes. When a NPD team encounters the fast technological change situation, R&D function has more resources because of power. New product teams, however, usually have scare resources, so that another important function like marketing will have fewer resources than R&D function. Thus, marketers in a NPD team may have less determination in the process of NPD. The marketers may have some influence on launch stage like sales and promotion or distribution channels (Hsieh et al., 2008), but R&D specialists make most decisions in a NPD team. Therefore, the current study proposes the hypothesis2described below: H2: Technological uncertainty will strengthen the relationship between power structure leaned to R&D and NPD successes. Eisenhardt and her colleagues indicated that the organizations in high velocity environments have better performance when they decentralize the power structure (Eisenhardt, 1989; Eisenhardt and Bourgeois, 1988). They also described that this firm tended to introduce a new product line, and that its channel partners were fighting with each other by price wars but the dominant marketing function did not have enough time to perform its regular job. To maintain its power and resources, the dominant function may highlight its importance, so it will withhold external information and enable other members to perceive the external environment what dominant function expect them to perceive. When organizations find a lot of environmental changes, it is too late. Therefore, in the beginning organizations adopted decentralized power structure, and allocated resources equally. The members in organizations may not snatch resources, so they may not take political actions also. For the specialists in new product development team, they could not control their unique knowledge to withhold the information and to satisfy their own self-interests. Therefore, the relationship between marketing and R&D power distribution in a NPD team and new product financial performance is weakened in high velocity environments (Eisenhardt and Bourgeois, 1988). The hypothesis3 in the current study is below: H3: the relation between the power distribution in new product development teams and new product development successes is inverted U curve under the high technological and market uncertainty. Coping environment could rely on top manager’s backgrounds like marketing, technology or finance (Hambrick and Mason, 1984). To maintain the status of the dominant function, the dominant function will lead the organization to identify the important problems related to its function. In order to ensure keeping their power, moreover, the dominant function could institute some regulations or create norms. According to resource dependence perspective, if an organization has higher the formalization of power, the dominant function could gather more resources because of legitimacy. Further, the higher formalization of power may strengthen the relationship between power distribution and performance. Thus, our hypothesis 4 is below: H4: Under the higher formalization of power in a new product development team, the stronger relationship between the marketing and R&D power distribution and new product performance than under the lower degree of formalization of power situation. Research Design The current study used questionnaire survey and purposive sampling method to collect data. In order to eliminate the bias of common method variance (CMV), this study conducted multiple sources including project managers, the member charging marketing, and the member charging R&D to administrate questionnaires differently. In order to avoid selection bias, this study, moreover, asked the informants select the most recent new products developed and launched for minimum of twelve months. We sent three types of questionnaires to project managers, the member charging marketing, and the member charging R&D respectively. The current study sent questionnaires to 112 firms, and 69 firms are returned. The response rate is 61.61%. At new product level, there are 207 new product projects, and 100 firms are returned. The response rate is 48.31%. We also do tests of bias due to nonresponse which were conducted by using a comparison of early to late respondents’ all variable means (Armstrong & Overton, 1977). No evidence of a bias was found. The current study applied Moorman’s (1995) operationalization of new product performance is that the extent to which the product has achieved the objective of market share, sales, return on assets, profit margin, and return on investment during the first 12 months of its life in the marketplace. These items were used a 7-point Likert scale where 1 was “low” and 7 was “high”. This research adopted Homburg et al. (1999) scale to measure the power structure between marketing and R&D functions by using 100-point constant-sum scale for each NPD issue, and other previous studies also used issue-based perceptual power scale (Enz, 1989; Hinings et al., 1974; Pfeffer, 1981; Verhoef and Leeflang, 2009). The current study adopted Jaworski and Kohli’s (1993) scale to measure market and technological turbulence. The items were used a 7-point Likert scale where 1 was “extremely disagree” to 7 was “extremely agree”. In order to rule out other effects, we controlled industrial category, firm age, the number of marketing and R&D members involved in the NPD process, environmental hostility. Result and Conclusion The first finding is that under low market uncertainty and high technological uncertainty, balance of power structure tends to swing to the side of R&D function, and achieve better in NPD performance. Take IC design of High-tech industry as an instance, NPD project ends to perform better when the balance of power structure swing to the side of R&D function. The second finding is that under high market uncertainty and low technological uncertainty, NPD formalization helps to strengthen the relationship between marketing and NPD performance. Take frozen dessert in the food industry or leisure and sports fabrics in the textile industry as examples, formalization of NPD process can help marketing-driven NPD projects perform better in market. These findings advanced the understanding of the relationship between the power structure of marketing and R&D and NPD performance, rather than focusing on a single function, marketing or R&D. Furthermore, examining the relationship between the power structure of marketing and R&D and NPD performance in different environment uncertainty situations explained the inconsistency of the relationship between the power structure of marketing and R&D and NPD performance in past studies. Finally, this research conditionally supported the moderating effect of NPD formalization on the relationship between the power structure of marketing and R&D and NPD performance, and this exploration never been found.
        3,000원
        73.
        2018.07 구독 인증기관·개인회원 무료
        There has been a heated discussion worldwide over tourist deviances that disrupt lives of local residents and cause damage to companies, city authorities, and the natural environment. Previous studies primarily turn to discrepancies in the cultural and educational background between tourists and local residents to explain such phenomena. Nonetheless, the possibility of people inclining to misbehave simply because they are away from home has rarely been investigated. In this study, we seek to examine factors rooted in the nature of tourism that are accountable for such phenomena. According to the definition by UNWTO (1995), one of the key characteristics of tourism is the displacement of usual environment. Tourism, therefore, is inevitably associated with surroundings of unacquainted others residing in the unfamiliar environment. Following the social control paradigm, previous studies have revealed that people are more likely to enforce social control on in-group members than on out-group members (Nugier, Chekroun, Pierre & Niedenthal, 2009). We further propose that psychological closeness between people and surrounding others would have an impact on their expectation to receive others’ social contrail and consequently their intention to engage in the counternormative behavior. Using an experimental study, we found that participants in the travel condition, compared with those in the home condition, feel less close to surrounding others and are more likely to misbehave. Such effect is mediated by the perceived social control. Implications for organization and companies in the tourism sector are drawn to prevent the spread of tourist misbehavior. Limitations and future directions would also be discussed.
        74.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Corrosion inhibitors including calcium hydroxide have been used to prevent corrosion in the pipes for tap water supply. The corrosion index (i.e., Langelier Index) differs by area and water quality. The corrosion indices of the areas studied differed by more than 2.0. The ‘homogenized’ calcium hydroxide was added to the treated water at the K water treatment plant, in order to increase the value of the corrosion index and the concentration of calcium. As the result, the concentration of calcium was increased while the turbidity and pH changed little. The corrosion rate of the tap water with the 'homogenized' calcium hydroxide could be slowed down pretty much. The results suggested that the technology of 'homogenization' of calcium hydroxide can applied to tap water and desalinated water to prevent corrosion in water pipes even in corrosive pipes.
        4,000원
        75.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        벼 이앙기별 인산에 의한 논조류 발생과 제초제에 의한 방제 효과는 다음과 같다. 1. 단작 및 이모작 벼 재배지에서 총출현 종수는 61종으로 녹조류 34종, 규조류 16종, 유글레나 7종, 그리고 남조류 4종이 발생하였고, 녹조류, 규조류는 이모작지가 많았고, 유글레나는 같았으며 남조류는 단작이 많았다. 2. 인산을 이앙전에 50%처리하고 분얼기에 50% 시비하였을 때 총인이 0.06 mg L-1로 가장 높았고, 조류 발생량도 무인산 대비 6월 6일 이앙한 구에서 14.8 mg 20 ml-1으로 3배 이상, 6월 20일에 이앙한 구에서 9.8 mg 20 ml-1 2배 이상 증가하였다. 3. 벼 생육단계별 분얼기, 유수형성기, 그리고 수잉기의 토양 인산의 함량은 관행 및 인산분시별로 유수형성기가 인산의 함량이 116.5~191.8 mg kg-1으로 가장 높은 경향이었으며 무 처리구에서는 15.5~29.1 mg kg-1로 낮았다. 이앙시기별로는 이앙이 빠를수록 높은 경향이었으며, 인산분시별로는 관행에 비해 분시하였을 때 높은 경향을 보였다. 4. 클로로필-a 함량은 6월 6일 이앙한 구에서는 제초제 처리 후 7일에 가장 낮은 6.3 mg m-3 이고, 7월 상순에 무처리구에서 75.8 mg m-3 로 가장 높았다. 6월 20일 이앙한 구에서는 제초제 처리후 7일에 가장 높은 경향이었으며 제초제 처리 후 14일과 21일은 감소하는 경향이었다 5. 논조류 억제율은 quinoclamine이 단작에서 59.2%, 이모 작에는 44.4%로 가장 높았으며, 다음으로 bromobutide + imazosulfuron + pyraclonil > benzobicyclon + mefenacet + peno xsulam >무처리 순이었다.
        4,000원
        76.
        2018.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Applicability of corrosion inhibitor was evaluated using pilot scale water distribution pipe simulator. Calcium hydroxide was used as corrosion inhibitor and the corrosion indices of the water were investigated. Corrosion indices, Langelier saturation index (LI) increased by 0.8 and calcium carbonate precipitation potential (CCPP) increased by 9.8 mg/L. This indicated that corrosivity of water decreased by corrosion inhibitor and the effects lasted for 18 days. Optimum calcium hydroxide dose was found to be 3~5 mg/L for corrosion inhibition. We suggest that monitoring of CCPP as well as LI need to be conducted to control corrosivity of water.
        4,000원
        77.
        2018.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 마찰력에 따른 TMD의 작동-정지조건과 각 조건에 따른 운동방정식을 정리하고, TMD의 마찰계수가 풍진동 제어성능에 미치는 영향을 수치해석을 통하여 확인하였다. 일반적인 하중과 달리 풍하중은 크기와 방향의 변화가 크기 때문에 TMD 는 마찰력에 의하여 작동-정지상태를 반복하게 되므로, TMD의 마찰계수를 주요 변수로 설정하였다. 또한 외부하중의 크기, 구조물의 진동수, TMD의 질량비도 매개변수로 설정하여 TMD의 제진성능에 대한 영향을 파악하고자 하였다. 자유진동, 조화강제진동, 풍진동에 대한 수치해석의 결과, 외부하중의 크기가 작고, 구조물의 진동수가 낮을수록 마찰계수에 의한 TMD의 제진성능의 손실이 커질 수 있음을 확인하였으며, 초고층 건물에 대한 TMD 설계시 마찰계수의 영향을 반드시 고려하여야 할 것으로 판단된다.
        4,000원
        78.
        2017.12 구독 인증기관 무료, 개인회원 유료
        According to a recent survey of the stress recognition levels felt by teenagers, 34.9% experienced ' sad or frustrated ' levels with their daily lives being disrupted by more than two weeks in a row and it turned out that the older you are, the higher your stress perception levels are.(청소년백서, 2014). Jeju Island has eight regular high schools (27%) among 30 schools. Middle school students in Jeju are experiencing relatively high admission stress compared to other regions in order to enter regular high schools in the level equalization zone. High school students are also experiencing a higher level of academic awareness in college admissions by the academic reports, adding to the academic stress. Appropriate stress for adolescents provides new stimuli, gives motivation and energy, and can lead to the rehabilitation of learning, however, stress builds up when they are unable to deal with it on their own, leading to experiences of physical and psychological maladaptation as well as drug abuse, delinquency, maladjustment, school violence and suspension.
        4,200원
        79.
        2017.10 구독 인증기관·개인회원 무료
        We selected the trap plant that could attract Ricania spp. adult effectively and the systemic chemicals that could beused at the same time in 2016. Ricania spp. has recently spread throughout Chungnam province since its occurrence in2010. We found that sunflowers could attract them effectively in pre-oviposition period of Ricania spp. and selected thesystemic chemicals could be used with sunflower simultaneously. The sunflower attracted their adults about 90 to 95percent in pre-oviposition period. The systemic chemicals was dinotefuran SG 50% and the control effect of it was 96.2%.The control effect of dinotefuran transferred to sunflower was excellent, and the density of adult in blackberry field couldbe kept low in pre-poviposion period of Ricania spp. The above results show the possibility of using sunflower as atrap plant to control Ricania spp. adults.
        80.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        식물 기생성 선충은 토양 병해의 중요한 요인 중 하나로 작물 생산에 심각한 피해를 일으키지만 토양 속에서 일어나므로 그 피해를 판단하기 어렵다. 식물 기생성 선충은 주로 오이나 당근, 상추 등 많은 작물의 뿌리를 통하여 침입하는데 이때 생긴 상처를 통하여 토양 전염 병원균의 감염이 발생되고 또한 바이러스도 전파하여 작물의 많은 수확 손실을 가져온다. 본 연구에서는 뿌리혹선충 방제를 위한 친환 경적인 방법을 찾고자 유기성 부산물의 퇴비 처리에 의한 상추의 뿌리혹선충 방제 효과와 상추 수확량, 토양 화학성분 및 미생물밀도를 분석하였다. 퇴비를 처리하지 않은 무처리구와 퇴비 처리량(3, 10kg/3.3m2) 별 효과를 비교한 결과, 퇴비 처리량의 증가에 따라 상추의 뿌리혹선충 발병이 유의성 있 게 감소하였으며(R2=0.230, p=0.022) 따라서 수확량은 증가하였다(R2=0.360, p=0.004). 상추 근권 토 양 중 방선균의 밀도도 퇴비 처리에 의하여 약 10배 정도 유의성 있게 증가하였으며(R2=0.276, p=0.013), 방선균 밀도와 수확량 간에 높은 정의 상관관계가 확인되었다(R2=0.232, p=0.021). 각 처리 구의 토양 성분을 분석 비교한 결과 퇴비를 처리한 토양에서 유기물 함량과 양이온 교환용량이 높게 나 타났다. 이러한 결과로 볼 때 충분히 완숙된 유기성 부산물 퇴비 처리는 상추의 뿌리혹선충의 발병율을 낮추고 좋은 미생물인 방선균 밀도를 증가시킴과 동시에 토양의 지력도 향상시켜 상추 생산량을 증가 시킬 수 있는 친환경적이고 효과적인 뿌리혹선충 방제법 임을 알 수 있었다.
        4,200원
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