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        검색결과 208

        61.
        2019.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to fabricate an ophthalmic lens by copolymerizing two types of carbon nanotubes and hydrophilic hydrogel lens materials, and to investigate its application as an ophthalmic lens material by analyzing its physical properties and antimicrobial effect. For polymerization, HEMA (2-hydroxyethyl methacrylate), EGDMA (ethylene glycol dimethacrylate), a crosslinking agent, and AIBN (azobisisobutyronitrile), an initiator, are used as a basic combination, and a single-walled carbon nanotube and a single-walled, carboxylic-acid-functionalized carbon nanotube are used as additives. To analyze the physical properties, the water content, refractive index, breaking strength, and antimicrobial effect of the fabricated lenses are measured. The fabricated lenses satisfies all the basic properties of the basic hydrogel ophthalmic lens. The water content increases with increasing amount of additive and decreases with addition of 0.2% ratio of nanoparticles. The refractive index is inversely proportional to the water content result. As a result of the antimicrobial test of the fabricated lens, the addition of carbon nanotubes shows an excellent antimicrobial effect. Therefore, it is considered that the fabricated lens can be applied as a functional material for basic ophthalmic hydrogel lenses.
        4,000원
        62.
        2019.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, to investigate the effect of physical and chemical properties of butanol on the engine performance and combustion characteristics, the coefficient of variations of IMEP (indicated mean effective pressure) and fuel conversion efficiency were obtained by measuring the combustion pressure and the fuel consumption quantity according to the engine load and the mixing ratio of diesel oil and butanol. In addition, the combustion pressure was analyzed to obtain the pressure increasing rate and heat release rate, and then the combustion temperature was calculated using a single zone combustion model. The experimental and analysis results of butanol blending oil were compared with the those of diesel oil under the similar operation conditions to determine the performance of the engine and combustion characteristics. As a result, the combustion stabilities of D.O. and butanol blending oil were good in this experimental range, and the indicated fuel conversion efficiency of butanol blending oil was slightly higher at low load but that of D.O. was higher above medium load. The premixed combustion period of D.O. was almost constant regardless of the load. As the load was lower and the butanol blending ratio was higher, the premixed combustion period of butanol blending oil was longer and the premixed combustion period was almost constant at high load regardless of butanol blending ratio. The average heat release rate was higher with increasing loads; especially as butanol blending ratio was increased at high load, the average heat release rate of butanol blending oil was higher than that of D.O. In addition, the calculated maximum. combustion temperature of butanol blending oil was higher than that of D.O. at all loads.
        4,000원
        64.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to develop a standardized job description for dietitians using the DACUM technique. To examine the validity of job description through DACUM, dietitians were surveyed relative to importance, performance, and difficulty. The survey was conducted April 1-30, 2014. A total of 217 questionnaires were used in the analysis. The final developed job description for dietitians included six duties, 38 tasks, and 210 task elements. DACUM’s findings include six duties: nutrition management, food service operation management, hygiene safety management, community food and nutrition program management, organization management, and professionalism strengthening. There were 5.1 points regarding importance, 4.1 points regarding performance, 4.9 points regarding difficulty, and statistically significant differences (p<0.001). Dietitians responded that ‘nutrition management’ and ‘hygiene safety management’ were the most important. ‘Hygiene and safety management’ showed the highest performance, and ‘community food and nutrition program management’ and ‘professionalism strengthening'' showed the highest difficulty. Thus, it is considered that the job analysis results can be used to evaluate and improve the subjects’ training program. Dietitians’ jobs are subject to various environmental changes, such as demographic changes, health care system changes, and the development of the food industry, and thus, should be reviewed and analyzed periodically.
        5,100원
        65.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구는 치매진단 이후에 불가피하게 나타나는 치매환자의 인지기능, 수단적 일상생활수행능력의 저하가 그들을 돌보는 보호자의 부양부담감에 어떠한 영향을 미치는 지에 대한 주요인을 분석하기 위하여 실시하였다. 연구방법 : 지역사회에 거주하는 치매환자 및 보호자 126쌍을 대상으로 치매선별용 간이정신상태검사 (Mini-Mental State Examination for Dementia Screening; MMSE-DS), 한국형 도구적 일상생활수행능력(Korean version-Instrumental Activities of Daily Living; K-IADL), 단축형 자릿 부양부담 척도(Short Zarit Burden Inventory; S-ZBI)를 사용한 평가를 실시하였다. 자료수집에 대한 분석은 기술통계, 독립표본 t 검정, 일원배치 분산분석, 피어슨 상관분석, 단계적 다중회귀분석을 사용하였다. 결과 : 보호자의 부양부담감에 부정적인 영향을 미치는 주요인은 인지기능 영역에서는 언어기능, 수단적 일상생활수행능력 영역에서는 음식준비, 교통수단, 전화사용으로 나타났다. 일반적인 특성 중에서는 동거 형태, 학력, 나이가 보호자 부양부담감에 영향을 미치는 변수임을 확인하였다. 결론 : 본 연구는 지역사회 치매환자의 돌봄 과정에서 보호자의 부양부담에 부정적인 영향을 미치는 주요인을 제시한다는 점에서 연구의 의의가 있다. 향후 연구에서는 대상자의 특성 및 돌봄 환경의 차이를 고려한 추가적인 연구들이 이뤄져야 할 것이다.
        4,300원
        66.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        “Yangliping TECH”is known as “the first public company of performing arts industry in new third board stick market”, Yang liping is the most eye-catching golden signboard. Although the stock market brief mentioned that the company's main source of revenue is the imaging series of commercial products, and its boutique hotel operation and other industrial chains. But we also know that the biggest risk for public companies is over-reliance on “Yang liping's personal brand”. At present, it seems that Yang liping company is in a good rising period in China's performing arts market and new three board stock market, and its development space is still large. We don't know how far it will go. If Yang liping company can develop in a scientific and sustainable way, it is bound to explore an effective market operation mechanism. This is what China's performing arts industry should learn from.
        4,300원
        67.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate job understanding, performance, and job satisfaction of 150 school foodservice employees in Chungnam area from April 23, 2018 to May 18, 2018. The score of the relationship with colleagues was in the order of elementary school, middle school, and high school (p<0.05). Job understanding was ranked as follows: middle school, elementary school, and high school (p<0.05). Questionnaires on performance of food ingredients and working process management had 4.8 points for the cook and 4.6 points for the cooking staff (p<0.05). Based on the subjects’ position, the hygienic safety management performance was higher in cooks than in cooking staff (p<0.05). Job satisfaction showed higher points in elementary school and middle school subjects in all items as compared to subjects of high school (p<0.05). Cooks showed more job satisfaction compared to cooking staff (p<0.05). There was a significant positive correlation (r=.253, p<0.01) between job satisfaction and job performance. Job understanding showed a significant positive correlation with job performance. Job satisfaction had a positive correlation with performance for hygienic safety management (r=.275, p<0.01).
        4,000원
        68.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        한국에 있어서 한우는 경제 동물일 뿐 만 아니라 중요한 유전자원 중 하나이다. 그러나 현재 한우의 번식 능력 개량을 위한 연구는 매우 미흡한 실정이다. 한우의 번식 능력에 대한 기초 자료를 확보하기 위해 전북지역(정읍시)에서 인공수정 된 암소 총 33,281두에 대한 105,017개의 번식기록(2010-2017)을 이용하여 임신기간(GP), 분만 후 첫 종부기간(CFSI), 분만 후 임신간격(CCI), 수태당 종부회수(NAIPC), 첫 종부 임신율 (FSCR)을 계산하여 분석에 활용하였다. 전체적으로 GP 는 287.602±4.797일, CFSI와 CCI는 각각 77.513±34.417 및 88.433±42.194일 이였다. 또한 FSCR는 62.365%였으며, NAIPC 는 1.411회로 나타났다. 2017년의 FSCR과 NAIPC는 각각 67.497% 및 1.344회로 2013년 62.366% 및 1.402에 비해 유의적으로 증가하였다(p<0.05). 가을과 겨울에는 번식기간이 더 길었으며, NAIPC는 봄과 여름에 비해 유의적으로 증가하는 것으로 나타났다(p<0.05). 3~7산차 암소의 경우 NAIPC가 1.323±0.669~1.339±0.689회로 다른 그룹에의 1.401±0.772~1.446±0.854회 보다 우수한 것으로 나타났다. 반면, 1산차 암소의 경우 FSCR와 NAIPC가 각각 60.217% 및 1.506±0.937회로 가장 저조한 것으로 나타났다. 본 연구 결과 한우의 번식효율은 산차에 따라, NAIPC는 계절에 따라 영향 받는 것으로 나타났으며, 전체적인 번식효율은 과거에 비해 지속적으로 향상되고 있는 것으로 나타났다.
        4,000원
        70.
        2019.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this theoretical study, a design and performance analysis theory of a micro flowrate and high pressure air-compressor is developed. The governing equations are from the gas state equation and fluid dynamic theories because the working fluid in the air compressor is in a gas phase. A case study was conducted to design a reciprocating type of air compressor which the target performance was 0.6liter/min in the volume flowrate with 5atg in air pressure at 1,600rpm rotational speed. Geometrical size of the model air compressor designed is 10mm in stroke, 20mm in bore with 4.79 compression ratio. From the performance analysis of the model compressor, it was found that the air volume flowrate produced was 0.6liter/min with 5.81atg in pressure. The design theory of a micro-size high-pressure air compressor developed in this study is expected to be very useful design tools in NANO technology industry.
        4,000원
        71.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, blockchain technology has been recognized as one of the most important issues for the 4th Industrial Revolution which can be represented by Artificial Intelligence and Internet of Things. Cryptocurrency, named Bitcoin, was the first successful implementation of blockchain, and it triggered the emergence of various cryptocurrencies. In addition, blockchain technology has been applied to various applications such as finance, healthcare, manufacturing, logistics as well as public services. Distributed consensus algorithm is an essential component in blockchain, and it enables all nodes belonging to blockchain network to make an agreement, which means all nodes have the same information. For example, Bitcoin uses a consensus algorithm called Proof-of-Work (PoW) that gives possession of block generation based on the computational volume committed by nodes. However, energy consumption for block generation in PoW has drastically increased due to the growth of computational performance to prove the possession of block. Although many other distributed consensus algorithms including Proof-of-Stake are suggested, they have their own advantages and limitations, and new research works should be proposed to overcome these limitations. For doing this, above all things, we need to establish an evaluation method existing distributed consensus algorithms. Based on this motivation, in this work, we suggest and analyze assessment items by classifying them as efficiency and safety perspectives for investigating existing distributed consensus algorithms. Furthermore, we suggest new assessment criteria and their implementation methods, which can be used for a baseline for improving performance of existing distributed consensus algorithms and designing new consensus algorithm in future.
        4,000원
        72.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This study, compared and verified the test results of post-bearing capacity and the test results of a full-scale vehicle crash test on flat ground and slope ground. METHODS: The results of the bearing capacity test on the barrier post show that, the bearing capacity of the banking section ground and flat ground was relatively large. In the full-scale vehicle crash test, the maximum deformation of the barrier was not large, and the occupant safety indexes(THIV, PHD) were relatively similar. The post-bearing capacity test is a static load test. RESULTS: Therefore, there was a large difference on the flat ground and on the banking section ground because of the effect of soil failure. On the other hand, the full-scale vehicle crash test is close to the impact load. CONCLUSIONS: Therefore, it can be concluded that the whole barrier system was not affected by soil failure alone.
        4,000원
        73.
        2018.12 구독 인증기관 무료, 개인회원 유료
        The AtoN Simulator provides simulation circumstances, which include the topographical and environmental characteristics of a primary harbor, as well as the characteristics of navigating a ship and maritime traffic. The AtoN planning expert can design a safer and more efficient distribution of AtoN using the simulator. AtoN simulation system is a system that adds AtoN part such as AtoN attribute and modeling to ship handling simulation system. AtoN 3D modeling and motion characteristics implemented in existing ship handling simulations were not perfect. Therefore, there was inconvenience in 3D simulation. Therefore, AtoN attribute construction and 3D modeling are required for AtoN simulation system. This study researched the AtoN 3D modeling for AtoN simulator. The AtoN analysis surveyed the AtoN for 3D modeling. Modeling design was designed to be similar to the actual AtoN on the basis of such an analysis of the AtoN scale. Modeling was AtoN 3D modeling based on the design drawings. Each AtoN was grouped into a Main Category and Sub Category. Specific data were easily changed using the 3D tools.
        4,000원
        74.
        2018.11 구독 인증기관 무료, 개인회원 유료
        To ensure the safety and functionality of a railroad bridge, maintaining the integrity of the bridge via continuous structural health monitoring is important. However, most structural integrity monitoring methods proposed to date are based on modal responses which require the extracting process and have limited availability. In this paper, the applicability of the existing damage identification method based on free-vibration reponses to time-domain deflection shapes due to moving train load is investigated. Since the proposed method directly utilizes the time-domain responses of the structure due to the moving vehicles, the extracting process for modal responses can be avoided, and the applicability of structural health evaluation can be enhanced. The feasibility of the presented method is verified via a numerical example of a simple plate girder bridge.
        3,000원
        75.
        2018.10 구독 인증기관 무료, 개인회원 유료
        This study is to investigate the effects of support program satisfaction in the organizational trust and the management performance for the start-up business to suggest institutes and working-level officials with an theoretical and practical implication. For this, we performed empirical analysis, in particular we examined mediation effects of the organizational trust. We surveyed a questionnaire for 247 start-up companies of incubation center. We performed reliability and correlation analyses etc. through SPSS 23 and performed structural equation model analysis etc. through Amos 23. As a result, first, pilot product, marketing, financial account, education and consulting appeared effective effects in management performance but law did not appear effective. Second, education and consulting appeared positive by mediation of the organizational trust. This means the organizational trust factor has to be considered in support programs like education and consulting.
        3,000원
        76.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 한우 암소비육에 있어서 고 에너지의 육성용 TMR(TDN 72.7%DM, CP 13.65%DM)을 육성기(8~12개월령) 및 비육기(13~24개월령)까지는 제한급여하고, 이후 비육 마무리기(25~32개월령)까지 자유 채식시켰을 때, 증체수준, 도체특성 및 경제성에 미치는 영향을 구명하고자 수행되었다. 공시축은 한우 암소 35두(8개월령)를 이용하여 Control구(5두), T1(10두), T2(10두) 및 T3(10두)구로 나누어 난괴법으로 배치하였다. 공시사료는 전기간 동일한 육성용 TMR을 Control구에서는 자유채식 시켰고, T1, T2, T3구에서는 각각 체중의 1.8%, 1.6% 및 1.5%로 제한하여 24개월령까지 급여하였다. 한우 암소의 체중은 비육마무리기간에서 Control구에 비해 T1, T2 및 T3 처리구가 각각 4.9%, 3.6% 및 2.5% 높은 것으로 나타났다 (p<0.05). 일일증체량은 육성기에는 Control구와 T1구가 다른 처리구에 비해 높았으며(p<0.05), 비육마무리기의 T1 처리구가 다른 처리구에 비해 높았다(p<0.05). 건물섭취량과 TDN 섭취량은 비육마무리기간에서 T1구가 가장 높았다(p<0.05). 고 에너지의 육성우용 TMR을 전 기간동안 급여함으로써 도체중과 배최장근 단면적이 일반적인 한우 암소비육 결과에 비해 현저히 증가되었다. 처리구별 도체중은 Control구에 비해 T1구가 약 11.6% 많았으며(p<0.05), 지방색과 성숙도는 Control구에서 높았다(p<0.05). 근내지방도, 육색 및 조직감은 처리구간 유의적 차이는 없었으나, 육량등급 출현율에 있어서는 Control구에서 A등급이 60%로서 다른 처리구에 비해 높았다. 육질등급에서 1++ 등급 출현율은 Control, T1, T2 및 T3구에서 각각 0%, 20%, 20% 및 0%로 나타났다. 순수익은 Control구에 비해 T1과 T2구가 각각 15% 및 13% 증가되었으나 T3구는 2% 감소한 것으로 나타났다. 결론적으로, 한우 미경산우 비육 시, 고에너지의 육성용 사료를 육성기부터 비육기(13~24개월령)까지 체중의 1.8% 수준으로 제한 급여하는 것이 전 기간 동안 자유채식시키는 것보다 도체중이나 육질등급 증가로 경제성이 향상되어 한우암소 고급육생산 프로그램 개발에 활용할 수 있을 것으로 판단된다.
        4,200원
        79.
        2018.05 구독 인증기관·개인회원 무료
        This study considers zone-based registration (ZBR) and distance-based registration (DBR). A mobile station performs location registration whenever the MS reaches a new zone or the specified distance. These two schemes seem to be similar but, in DBR, the mobile station (MS) is in the center of the location area right after location registration differently from in ZBR. In this study, we point out some problems of the previous analysis method and propose an improved analysis method of ZBR and DBR. Using the improved analysis method, we show that the previous analysis includes some problems, and that the performances of two registration methods in our study are enhanced more than in the previous study. This results of this study should be useful to analyze the performance of various location registration schemes.
        80.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 4연동 벤로형 유리온실의 냉·난방 부하를 고려한 PV 시스템의 적정 패널 설치 면적을 도출하기 위하여 BES 기법을 이용하여 온실 및 PV 시스템의 에너지 모델을 설계하였으며 동적 에너지 시뮬레이션을 수행하였다. 대상 작물은 파프리카로 선정하였으며 작물의 적정생육온도를 고려하여 냉·난방장치 및 환기장치의 가동조건을 설정하였다. 2012년부터 2016년까지 총 5년 동안의 기간별 냉·난방부하 및 최대 냉·난방 부하를 환 기팬의 환기량 조건 별로 분석을 실시하였다. 온실의 냉 ·난방 부하 산정과 함께 PV 시스템의 설치 각도에 따른 전력 생산량을 분석하였으며 신재생에너지 공급의무비율을 적용하여 최적 PV 시스템 설계 방안을 도출하였다. 환기팬의 환기량 60AE·hr-1 조건에서 대상 온실의 기간 평균 냉방 부하로 인한 전력 소모량은 174,310kWh, 기간 평균 난방 부하로 인한 전력 소모량은 458,903kWh 로 총 633,213kWh의 전력 소모량이 산정되었다. PV 시스템은 설치 각도를 30o로 설정하는 조건에서 가장 높은 전력 생산량이 나타났으며 월별 최적 각도를 적용하는 조건에서는 고정형 PV 시스템보다 약 5.7% 많은 전력 을 생산하는 것으론 산정 되었다. 최종적으로 대상 온실에 적합한 PV 시스템 패널 면적을 도출한 결과, 고정형 PV 시스템은 521m2의 패널이 필요한 것으로 산정되었고, 가변형 PV 시스템의 경우 494m2의 패널이 필요한 것으로 산정되었다. 본 연구를 통하여 4연동 벤로형 유리온실의 냉·난방 부하를 고려한 PV 시스템의 필요 패널 설치 면적을 도출할 수 있었으며 PV 시스템의 온실 적용 가능성 및 경 제성 평가의 기초 자료로 활용 가능할 것으로 판단된다. 한편, 본 연구에서는 작물 특성 데이터를 확보하지 못하여 작물의 에너지 교환을 고려하지 않았다. 보다 정확한 결과를 도출하기 위해서는 현장 실험 데이터에 기반을 둔 추가 연구가 필요할 것으로 판단된다.
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