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        검색결과 41

        1.
        2024.04 구독 인증기관·개인회원 무료
        생태계내에서 중요한 수분매개체인 야생벌을 보전하기 위해서는 풍부도와 다양성을 모니터링 하는 것이 중 요하다. 충청남도 서천군의 마을숲에서 야생벌을 2년간 조사한 결과 총 9과 57종 3,258개체를 채집하였다. 우점 종은 애꽃벌과의 꼬마애꽃벌이 가장 많았으며, 다음으로 양봉꿀벌, 수염줄벌, 구리꼬마꽃벌이었다. 종수는 2월 부터 증가하다가 8월에 가장 많았으며, 개체수는 4월에 가장 많고 이후 줄어들었다. 야생벌의 종 목록 살펴보면, 꿀벌과가 16종으로 가장 많았으며, 애꽃벌과의 꼬마애꽃벌은 1종이지만 개체수는 2,084개체로 본 연구에서 가 장 많이 나타났다. 본 연구에서 조사된 결과는 향후 기후변화로 인한 수분매개 곤충의 영향을 파악하는데 유용하 게 쓰일 것이다.
        2.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        DWI 검사 시 인체 조직 및 병변에 근접한 공기는 영상왜곡을 가중해 병변 감별에 어려움을 준다. 이에 본 연구는 팬텀을 제작하 여 기하학적 왜곡을 줄여주는 SMS RESOLVE DWI를 통해 공기 자화율에 의한 왜곡 변화를 정량화하였다. 팬텀은 원통형으로 내부에 공기가 존재하도록 설계하였다. 제한된 환경 속에서 다양한 자화율에 의해 왜곡이 영상에 구현되도록 팬텀 내부에는 증류수, 젤라틴 외 혼합 물질과 공기를 구분되게 채웠다. 팬텀의 정렬을 다르게 하여 공기 있는 상태 실험을 진행 후, 공기 대신 혼합액 넣은 상태 실험을 같은 방식으로 진행하였고 혼합액 대신 증류수 넣은 상태 실험을 진행하였다. 3T MRI 장비로 T2WI, C DWI, SMS-RESOLVE DWI를 촬영하였고 파이썬 OpenCV로 이미지 유사도를 측정 후 비교 분석하였다. 실험 결과 공기 있는 상태 SMS-RESOLVE DWI b0에서 SSIM 평균 0.898, MSE 평균 0.068로 영상왜곡이 가장 적었다. SMS-RESOLVE DWI의 공기 자화율 왜곡 변화는 b0 기준 SSIM, MSE 모두 –0.033~0.003 이미지 유사도 차이를 보였다. SMS-RESOLVE DWI b1000은 수치상 이미지 유사도 차이가 크지 않거나 감쇄되는 때도 있어서 향후 SNR 보완에 초점을 둔다면 보다 개선된 영상진단 성능을 제공할 것으로 기대되고 오픈 소스 라이브러리를 통해 오차를 최소화한 이미지 처리와 유사도를 분석하는 새로운 시도는 앞으로의 연구 방향에 새 모델을 제시한다.
        4,600원
        3.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The coda /s/ is the most extensively studied phonological segment in Hispanic dialectology and sociolinguistics. However, the coda /s/ in Peruvian Andean Spanish has received relatively little attention. This study examines the variation in syllables and word-final /s/ in the city of Cusco, Peru. The statistical analysis of 2400 tokens from 24 sociolinguistic interviews reveals that the Spanish of Cusco is located within the conservative dialects with the predominant use of the sibilant [s] and that coda /s/ weakening is conditioned by linguistic factors, such as word position and the following phonological context. Additionally, younger speakers and those who have higher levels of education weaken codal /s/ more frequently than older generations and speakers with lower levels of education.
        6,600원
        6.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper examines the variation of the intervocalic /b, d, g/ in the Spanish spoken in one of the Andean Spanish varieties. One of the regional phonological features that characterize the Andean Spanish is the use of occlusive [b, d, g] in intervocalic positions where other standard varieties would favor approximate variants [ß, ð, ɣ]. This research provides the first quantitative study on the linguistic and extra-linguistic factors influencing the use of [b, d, g] in Andean Spanish. A total of 4,080 tokens from 24 speakers in the Tupe district were analyzed via multivariate statistical analysis with Goldvarb X. The results show that the most important extra-linguistic factors are speakers’ gender and age, with old female speakers producing significantly more occlusive [b, d, g] than other speakers. The results also indicate that the speakers are standardizing their use of /b, d, g/ but its process is quite different between the male and female speakers.
        6,600원
        8.
        2018.07 구독 인증기관·개인회원 무료
        The paper presents the longitude study of Internet technologies introduction into business model. Rapid spread of Internet technologies has a significant impact on the business models transformation. Today, information technology has become an integral part of communication with customers. In 2017 the penetration rate of the Internet in Russia reached 73%. Thus, almost 3/4 of the population is currently Internet users and be reached online. On the one hand, Internet communication speeds up and simplifies the processes; on the other hand, the key competitive advantage of direct selling business model is blurred. For ages business model was based on direct interpersonal contacts between the distributor and the customer. In this business model relationship creates more value than the product itself [Luk, Fullgrabe, Yi, 1996] and face-to-face meeting is the key descriptor [Sanan, 1997]. Direct selling is cultivated through relationships and provides customer-centric marketing opportunities [Harrison, Hair, 2017]. The question of this study is whether introduction of innovative Internet technologies into communication with customers is beneficial for traditional direct selling business model. Empirical research is based on comparative analysis of data from three survey waves (6380 respondents in 2011, 5638 respondents in 2014 and 6800 respondents in 2017). Effectiveness of Internet usage the for communicate with customers was analized in dynamics over the three waves of 2011, 2014, 2017. Using the one-way analysis of variance (ANOVA) method 15 (fifteen) hypotheses were checked. Nine (9) out of 15 (fifteen) hypotheses were confirmed. Research revealed that personalization determines the effectiveness of communication with customers via internet-based tools (e-mail, web site, social networks, professional social networks, video channels, blogs, microblogs, videoconferences and webinars, messaging applications and files). Nevertheless, face-to-face communication remains significant communication channel for success in direct-selling
        10.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목 적 : Synthetic MR을 기반으로 한 MAGiC은 수학적 연산 기법을 이용하여 각 픽셀의 T1, T2 relaxation map을 얻는 검사기법이다. 이를 이용해 한 번에 획득한 data로 다양한 대조도의 영상을 나타낼 수 있다. 하지만 아직까지 MAGiC의 이완 시간(relaxation time) 측정에 있어서 정확한 기준이 확립되어 있지 않다. 이에 본 연구에서는 자체 제작한 조영제 팬텀을 이 용해 MAGiC과 conventional spin echo(CSE) sequence로 T1, T2 이완시간과 이완율을 측정하고, 이를 기준으로 MAGiC 과 CSE를 비교 평가하였다. 대상 및 방법 : Gadolinium-based contrast agent(GBCA)팬텀을 제작하였으며 MAGiC과 CSE sequence를 사용하였다. T1 이완시간의 측정은 총 15개의 TR(20~10000msec)을 설정하였으며, TR을 제외한 다른 변수는 고정하였다. T2 이완시간 측정은 총 13개의 TE(10~560msec)를 설정하였으며, 마찬가지로 TE를 제외한 다른 변수는 모두 고정하였다. MAGiC과 CSE의 T1,T2 이완 시간을 측정하였으며 이완율의 오차율(error rate)을 통해 각 농도의 구간별 차이를 비교하였다. 결 과 : CSE와 MAGiC의 T1과 T2 이완시간 측정 결과 CSE T1이 MAGiC T1보다 평균 114.92 더 높게 측정되었으며 CSE T2 역시 MAGiC T2보다 평균 244.66 더 높게 측정되었다. 하지만 통계 분석 결과 T1 이완시간의 차이는 p>0.05로 통계적 유의함이 없었다. 반면 T2 이완시간의 차이는 p<0.05로 유의한 차이를 보였다. 각 몰농도별 relaxivity를 측정한 결 과 CSE의 r1은 평균 3.49±0.28, MAGiC의 r1은 평균 3.27±1.09로 측정되었으며, 몰농도 2mM과 4mM 구간에서 CSE의 r1이 각각 3.15, 3.47을 보여 MAGiC의 r1값인 1.48, 0.74와는 매우 큰 차이가 있었다. CSE의 r2는 3.97±0.63, MAGiC의 r2는 8.42±3.16으로 측정되었으며, 특히 몰농도가 낮은 0.025, 0.05, 0.1mM에서 CSE의 r2는 각각 2.38, 3.60, 3.55인 반 면 MAGiC의 r2는 각각 10.33, 14.26, 15.02로 약 5배의 차이가 나타났다. 결 론 : MAGiC은 CSE와 비교하여 T1이완시간의 측정은 CSE를 대변할 만큼 구현되었지만 T2 이완시간의 측정은 CSE에 비해 잘 표현하지 못함을 알 수 있었다. 따라서 향후 MAGiC은 T2 이완시간을 통한 영상의 표현에 있어서 CSE와의 차이를 보완 할 수 있는 많은 연구가 진행되어야 할 것으로 사료된다
        4,300원
        11.
        2017.05 구독 인증기관·개인회원 무료
        Alterations affecting the status of robustness and health can bring about physiological changes including hematological parameters in pigs. To identify quantitative trait loci (QTL) associated with 8 hematological phenotypes (one leukocyte trait, six erythrocyte traits, and one platelet trait), we performed a genome-wide association study using the Porcine SNP 60K BeadChip in an intercross population between Landrace and Korean native pigs. A total of 36,740 SNPs from 816 F2 offspring were analysed for each blood related traits after filtering by quality control. Data were analysed genome-wide rapid association using the mixed model and regression (GRAMMAR) approach. A total of 257 significant SNPs (P<1.36x10-6) on SSC3, 6, 8, 13, and 17 were detected for blood related traits in this study. Interestingly, the genomic region between 17.9 and 130 Mb on SSC8 was found to be significantly associated with RBC, MCV, and MCH. Our results include 5 significant SNPs within five candidate genes (KIT, IL15, TXK, ARAP2, and ERG) for hematopoiesis. Further validation of these identified SNPs could give valuable information for understanding the variation of hematological traits in swine.
        12.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        IT security service provides customers with the capability of protecting the networked information asset and infrastructures, and the scope of security service is expanding from a technology-intensive task to a comprehensive protection system for IT environment. To improve the quality of this service, a research model which help assess the quality is required. Several research models have been proposed and used in various service areas, but few cases are found for IT security service. In this work, a research model for the IT security quality has been proposed, based on research models such as SERVQUAL and E-S-QUAL. With the proposed model, factors which affect the service quality and the best quality measure have been identified. And the feasibility of using quantitative measures for quality has been examined. For analysis, structural equation modeling and various statistical methods such as principal component analysis were used. The result shows that satisfaction is the most significant measure affected by the proposed quality factors. Two quality factors, fulfillment and empathy, are the main determinants of the service quality. This leads to a strategy of quality improvement based on factors of emotion and perception, not of technology. The quantitative measures are considered as promising alternative measures, when combined with other measures. In order to design reliable quantitative measures, more work should be done on target processing time and users’ expectation. It is hoped that work of this research will provide efficient tools and methods to improve the quality of IT security service and help future research works for other IT service areas.
        4,000원
        13.
        2015.05 구독 인증기관·개인회원 무료
        Purpose: Since the advent of smart phones, the amount of time spending on their use has rapidly increased and there are several health concerns regarding sight, causing prolonged smart phones viewing. The purpose of this study was to estimate how much eyes become fatigued based on quantitative electroencephalogram(qEEG) and to analyze the correlation between the fatigue and attention using event-related potentials(ERPs) as objective assessments. Methods: here were thirty, healthy, right-handed subjects(male 15, female 15) participating in this study. 64-channel of qEEG data with their eye-closed was collected and they performed Go/Nogo tasks before and after watching smart phones. A questionnaire regarding the visual fatigue was also collected in both conditions. The changes of pre- and post-task of watching smart phones were analyzed and compared in terms of four wavebands and algorithms, delta(δ), theta(θ), alpha(α), beta(β), (α+ θ)/ β, α/ β, (α+θ)/(α+β), and θ/ β for fatigue detection. Results: The results clearly show that all four energy values of qEEG and algorithms related to the fatigue in the post-viewing condition significantly changed than those in the pre-viewing condition. As seen in the results of ERP, nogo-N2 amplitude only on Fz electrode was slightly higher and nogo-P3 amplitudes on Fz and Cz were considerably lower in the post-task than in the pre-watching. However, there were no significant differences of go-N2 and P3 found at any electrodes. The results of behavioral performance demonstrate that the error rates(ER) of nogo-condition were obviously increased after using smart phones and there was a tendency for reaction time(RT) to be delayed compared with before watching it. Conclusions: This research denotes that it can be a fairly useful measure for using qEEG and ERP when assessing the visual fatigue. Its findings suggest that a sustained smart phone viewing leads to the visual fatigue and it can have adverse effects on distraction.
        14.
        2014.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, based on the international standard the quantitative assessment model for the level of safety, health and environment was developed. As a result of applying this model, the company(workplace) which has established improvement plan based on quantitative assessment of short-term and long-term requirements, and implemented it was acquired more higher level of safety, health and environment by more than the existing ones.
        4,000원
        15.
        2014.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study tried to develop a basis for quantitative index of working postures associated with WMSDs (Work-related Musculoskeletal Disorders) that could overcome realistic restriction during application of typical checklists for WMSDs evaluation. The baseline data(for a total of 603 jbs) for this study was obtained from automobile manufacturing company. Specifically, data for back posture was analyzed in this study to have a better and more objective method in terms of job relevance than typical methods such as OWAS, RULA, and REBA. Major statistical tools were clustering, logistic regression and so on. The main results in this study could be summarized as follows; 1) The relationship between working posture and WMSDs symptom at back was statistically significant based on the results from logistic regression, 2) Based on clustering analysis, three levels for WMSDs risk at back were produced for flexion as follows: low risk(< 18.5°), medium risk(18.5°~ 36.0°), high risk(> 36.0°), 3) The sensitivities on risk levels of back flexion was 93.8% while the specificities on risk levels of back flexion was 99.1%. The results showed that the data associated with back postures in this study could provide a good basis for job evaluation of WMSDs at back. Specifically, this evaluation methodology was different from the methods usually used at WMSDs study since it tried to be based on direct job relevance from real working situation. Further evaluation for other body parts as well as back would provide more stability and reliability in WMSDs evaluation study.
        4,000원
        16.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to investigate of technology competitiveness for domestic engineering enterprise, using the quantitative and objective patent. In these result, the technology competitiveness(Patent Activity Index, Patent Family Size Index, Patent Impact Index, Technology strength) of our enterprise is far inferior to another country. So we should try to achieve our superiority in competitive power, we devote ourself to put through technical improvements of our domestic engineering enterprise in many ways.
        4,800원
        18.
        2012.04 구독 인증기관 무료, 개인회원 유료
        위험도 평가는 양적인 평가방법(정량적 평가방법)과 질적인 평가방법(정성적 평가방법)이 있다. 해상에서 정량적인 평가방법은 선박의 통항량, 통항분포, 속력, 길이, 침로, 흘수 및 해상의 수심 등의 기하학적인 자료를 토대로 위험도를 산출하는 방법이다. 본 연구에서는 VTS 통항데이터를 정량적인 평가툴인 IWRAP에 적용하여 목포항 진입수로의 속력별, 길이별 통항분포와 해상교통위험도를 평가분석 하고자 한다.
        3,000원
        19.
        2012.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated refinement behaviors of TiC powders produced under different impact energy conditions using a mechanical milling process. The initial coarse TiC powders with an average diameter of 9.3 were milled for 5, 20, 60 and 120 mins through the conventional low energy mechanical milling (LEMM, 22G) and specially designed high energy mechanical milling (HEMM, 65G). TiC powders with angular shape became spherical one and their sizes decreased as the milling time increased, irrespective of milling energy. Based upon the FE-SEM and BET results of milled powders, it was found initial coarse TiC powders readily became much finer near 100 nm within 60 min under HEMM, while their sizes were over 200 nm under LEMM, despite the long milling time of up to 120 min. Particularly, ultra-fine TiC powders with an average diameter of 77 nm were fabricated within 60 min in the presence of toluene under HEMM.
        4,000원
        20.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        현재 살균소독제의 국가 공인시험법은 시험관 내에서 행하는 현탁액시험법으로 실제 현장의 표면 살균을 정확히 평가하기에는 무리가 있다. 본 연구는 국제적으로 표준화 되어 있는 3가지 정량적 표면시험법간의 유효성 평가력 비교를 목적으로 E. coli와 S. aureus를 대상으로 시중 유통되는 대표적 5개 계열 살균소독제의 유효성을 평가하였다. 그 결과 E. coli와 S. aureus에 대한 각 방법별 살균소독력은 ASTM(1)법에서 5.18 ± 0.03, 5.27 ± 0.04 log cfu/carrier, ASTM (2)법에서 4.63 ± 0.04, 3.97 ± 0.03 log cfu/carrier, CEN EN 13697법의 청정조건(CEN(1))에서 6.14 ± 0.05, 5.31 ± 0.10 log cfu/carrier, 오염조건(CEN(2))에서 4.37 ± 0.02, 4.06 ± 0.01 log cfu/carrier로 나타났다. CEN(1)시험법이 ASTM(2)와 CEN(2) 시험법에 비해 살균소독력이 유의적으로 높게 평가되었다. 적용된 3개의 시험법 중 유리를 담체로 사용 한 ASTM(1)법에 비해 스테인리스 스틸을 사용한 ASTM(2) 와 CEN법 적용 시 살균소독효과가 낮게 평가되었다. 결론적으로 3 가지 국가 공인시험법간 유효성 평가결과가 달랐으며, 실제 식품제조 현장에서 사용되는 표면에서의 살균 소독력을 정확히 평가하기 어렵다는 것을 확인할 수 있었다.
        4,000원
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