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        검색결과 683

        301.
        2016.07 구독 인증기관 무료, 개인회원 유료
        This research was conducted in order to examine the effects of user socio-demographics and recently introduced streamlined technology readiness index TRI 2.0 (Parasuraman & Colby, 2015) on mobile device use in B2B digital services. Mobile adoption has been studied from a consumer perspective, but to the best of the authors’ knowledge, very few studies explore mobile use in B2B markets. Mobile marketing is becoming a strategic effort in companies, as digital services not only in B2C but also in B2B sector are getting increasingly mobile (Leeflang, Verhoef, Dahlström & Freundt 2014). This raises an interest to better understand the characteristics of those mobile enthusiasts who primarily use B2B services via a mobile device rather than via a personal computer. The study tests hypotheses with a large data set of 2,306 business customers of which around 10 percent represent these innovative mobile enthusiasts. Technology readiness is an individual’s propensity to embrace and use new technologies for accomplishing goals in home life and at work (Parasuraman & Colby, 2015; Parasuraman, 2000). Parasuraman and Colby (2015) recently introduced an updated version of the original Technology Readiness Index (TRI 1.0) scale called TRI 2.0 to better match with the recent changes in the technology environment. At the same time they streamlined the scale to a compact 16-item version so that it is easier for researchers to adopt it as a part of research questionnaires. Likewise the original scale, TRI 2.0 consists of four dimensions: optimism, innovativeness, discomfort, and insecurity. Optimism and innovativeness are motivators of technology adoption while discomfort and insecurity are inhibitors of technology readiness, and these motivator and inhibitor feelings can exist simultaneously (Parasuraman & Colby, 2015). Optimism is a general positive view of technology containing a belief that technology offers individuals with increased control, flexibility and efficiency in their lives. Innovativeness refers to a tendency to be a pioneer and thought leader in adopting new technologies. Discomfort reflects a perception of being overwhelmed by technology and lacking control over it. Moreover, insecurity reflects distrust and general skepticism towards technology, and includes concerns about the potential harmful consequences of it. As individuals differ in their propensity to adopt new technologies (Rogers, 1995), the authors propose that technology readiness influences mobile device use of B2B customers: H1: Optimism has a positive effect on mobile device use of B2B digital services. H2: Innovativeness has a positive effect on mobile device use of B2B digital services. H3: Insecurity has a negative effect on mobile device use of B2B digital services. H4: Discomfort has a negative effect on mobile device use of B2B digital services. The earlier literature argues that socio-demographic factors such as gender (Venkatesh & Morris, 2000; Chong, Chan & Ooi, 2012), age (Venkatesh, Thong & Xu, 2012; Chong et al., 2012; Kongaut & Bohlin 2016), education (Agarwal & Prasad, 1999; Chong et al., 2012; Puspitasari & Ishii 2016) and occupation (Okazaki, 2006) influence technology adoption behavior in general, and mobile adoption in particular. For example, men are nearly twice as likely as women to adopt mobile banking, and age is a negative determinant (Laukkanen, 2016). Higher educated use mobile devices more for utilitarian purposes, while lower educated use mobile devices more for entertainment (Chong et al., 2012). Moreover, research suggests that occupational factors influence mobile use (Okazaki, 2006). The authors hypothesize: H5: Males are more likely than females to use mobile device for B2B digital services. H6: Age has a negative effect on the use mobile device for B2B digital services. H7: Customers with higher education level have a higher likelihood for using mobile device for B2B digital services than customers with lower education level. H8: Occupation has an effect on the use mobile device for B2B digital services. The study tests hypotheses with a data collected among B2B customers of four large Finnish companies, all representing different industry fields. The large sample (n=2306) consists of procurement decision-makers all experienced with using B2B digital services. The sample shows that over 90 percent of the B2B customers are still using a computer (laptop or desktop computer) as their primary access device for digital services in their work. The sample divides between females and males in proportion to 46 and 54 percent respectively. University degree represents a majority with 42 percent, while only 2,7 percent of the respondents have a comprehensive or elementary school education. Over half of the sample represent top management or middle management with 24,6 and 28,4 percent respectively, while 9 percent are entrepreneurs, 21,2 percent represent experts, and 16,7 percent are officials or employess. Mean age of the respondents is 51,6 years, ranging from 18 to 81 years. The study uses logistic regression analysis with backward stepwise method in which the dependent variable is a dichotomous binary variable indicating the respondent’s primary access device for B2B digital services with 0=computer and 1=mobile device. As for the independent variables, the study measures individual’s technology propensity with recently introduced 16-item TRI 2.0 scale from Parasuraman and Colby (2015) using a five-point Likert scale ranging from Strongly disagree=1 to Strongly agree=5. The authors used confirmatory factor analysis to verify the theory-driven factor structure of the TRI 2.0 scale, i.e. optimism, innovativeness, discomfort, and insecurity. The analysis show that the measurement model for the TRI 2.0 scale provides an adequate fit and standardized regression estimates for all measure items exceed 0.60 (p<0.001) except for one item in discomfort (β=0.516) and one item in insecurity (β=0.480). After removing these two items the model shows an excellent fit with χ2=478.033 (df=71; p<0.001), CFI=0.965, RMSEA=0.050. Moreover, discriminant validity is supported, as the square root of the average variance extracted (AVE) value of each construct is greater than the correlations between the constructs (Fornell & Larcker, 1981). In addition, composite reliability values vary from 0.726 to 0.852 supporting convergent validity of the TRI 2.0 factors (Table 1). Thereafter, the factor scores of the latent factors showing sufficient internal consistency were imputed to create composite measures. These composite measures were used as independent variables in the logistic regression model. With regards to socio-demographic variables, age is measured as a continuous variable, while gender, education, and occupation are categorical independent variables in the model. The results of the logistic regression analysis show that innovativeness, insecurity, age, and occupation are statistically significant predictors of mobile device use in B2B services, supporting hypotheses H2, H3, H6, H8. The stepwise analysis procedure removed optimism (p=0.860), education (p=0.789), gender (p=0.339), and discomfort (p=0.159) from the model as they proved to be non-significant predictors of mobile device use. The results indicate that occupation is the strongest predictor for mobile device use in B2B digital services so that the top management has the greatest likelihood as the odds ratios of middle management, experts, and officials/employees are 0.610, 0.282, and 0.178 respectively. This means that, for example, the odds of the top management using mobile device as their primary channel for B2B digital services are 1.64 (1/0.610) times greater than the odds of the middle management, and 5.62 (1/0.178) times greater than the odds of the officials/employees. Interestingly the β-value for the entrepreneurs is positive indicating that their likelihood for mobile device use is even greater than the likelihood of the top management. However, the p-value (0.913) indicates that the difference is not statistically significant. With regards to age of the B2B customer, the results indicate a negative relationship with mobile device use. The odds ratio [Exp(β)=0.979] claims that the odds of a B2B customer to use mobile device as the primary channel for digital services decrease by 2 percent for each additional year of age. Regarding the TRI 2.0 constructs, the results show that innovativeness is a highly significant positive predictor for mobile device use, while perceived insecurity has a negative effect (Table 2). Literature suggests that B2B customers increasingly use mobile devices but yet little is known about those individuals most enthusiastic in using B2B digital services via a mobile device. Thus, the current study attempts to better understand those mobile enthusiasts who among the first have adopted mobile devices as their primary method to access B2B digital services. The results suggest that occupation is the most significant predictor of mobile use among B2B customers, implying that top managers are among the most likely to adopt and use mobile device for business services. Moreover, younger B2B customers use mobile devices more eagerly as the results suggest the likelihood for mobile device use degreases by 2 percent with every added year of age. The results further imply that out of the four TRI 2.0 dimensions innovativeness and insecurity influence in the mobile device use of B2B customers, innovativeness positively and insecurity negatively as the theory proposes. Innovativeness represents individual’s tendency to be a pioneer and thought leader in terms of technology adoption, while insecurity stems from the general skepticism and distrust of technology. These results imply that B2B customers who mainly access B2B digital services via a mobile device are open minded towards the possibilities new technologies can provide for them. Moreover, it appears that those B2B customers still accessing digital services primarily via a computer are more skeptical than mobile users towards technology in general. Compared to the use of mobile devices for individual purposes, business related use is more functional in nature, and thus, mobile devices and technologies must be convenient to use, offer real benefits for example in forms of mobility and portability, and be reliable in order for B2B customers to use them. Interestingly, our results do not support the effects of generally positive attitudes towards technology reflecting optimism, or discomfort of using technologies to influence mobile use among B2B customers. In addition, there are organizational factors (e.g. voluntariness of use) that the authors omit in the current study. These may limit the findings. Mobility will be a key driver in the ongoing digital revolution of marketing and sales. Understanding online behavior of mobile enthusiasts assists B2B marketing and sales leaders to plan and implement more effective mobile marketing strategies. Rogers (1995) has shown that the majority will follow the early adopters, and the adaptation cycle has even shortened during the last years (Downes & Nunes, 2014). Thus, mobile devices are evidently becoming the primary method in accessing B2B digital services.
        4,000원
        302.
        2016.07 구독 인증기관·개인회원 무료
        This research aims at analyzing the role of digital technologies for communication in the personalization of cultural heritage visitors’ experience and the potential of such technologies in valorizing cultural heritage sites. In order to explore such a phenomenon through a pilot study, a conceptual framework has been developed in the attempt to better conceptualize the modern notion of digital cultural heritage. The theoretical foundations are experiential marketing (Schmitt, 1999), authenticity in visitors’ experience (Neuhofer et al., 2014), and engineering studies on successful application of technologies in cultural heritage sites (Sparacino, 2004). From the proposed conceptual framework some relevant insights have emerged. In particular, main findings deal with digital technologies being characterized by three particular kinds of artificial intelligence, namely (a) perceptive intelligence, (b) interactive intelligence, and (c) narrative intelligence. Specifically, perceptive intelligence allows a digital technology to seize visitors’ movements inside the museum (Barrera et al., 2013). Interactive intelligence is the kind of intelligence that permits a digital technology to elaborate visitors’ preferences (Sparacino, 2004). Narrative intelligence, finally, enables a digital technology to communicate with visitors (Karaman et al., 2014). Technologies with such features, then, may potentially stimulate positive feelings and emotions in visitors. Particularly, the storytelling of digital personalization of cultural heritage sites can effectively personalize visitors’ experience and uplifts the visit toward an authentic and unique experience (Frow and Payne, 2007; Sani, 2011). Since these technologies could help visitors in fully understanding their personal interests towards arts and cultural heritage, they can also act as instruments of cultural heritage sites promotion. Specifically, these technologies can suggest visitors’ successive cultural heritage sites and also stimulate visitors to suggests others to visit particular sites due to their positive experience (Sweeney et al., 2012).Finally, this study stresses the importance of digital technologies as instruments of experiential marketing by improving visitors’ experience. Moreover, digital technologies for cultural heritage may be interpreted as a key competitive advantage for cultural heritage sites. In particular, digital technologies may be interpreted as strategic levers in order to stimulate the diffusion of word-of-mouth marketing in cultural heritage.Finally, this study stresses the importance of digital technologies as instruments of experiential marketing by improving visitors’ experience. Moreover, digital technologies for cultural heritage may be interpreted as a key competitive advantage for cultural heritage sites. In particular, digital technologies may be interpreted as strategic levers in order to stimulate the diffusion of word-of-mouth marketing in cultural heritage.
        303.
        2016.07 구독 인증기관·개인회원 무료
        The purpose of this paper is to understand the digital differentiation in social members’ information use via digital devices. Though the attention to the digital differentiation becomes far more increasing, there are only few literatures dealing with quantitative approaches about the digital differentiation. The term ‘digital differentiation’ represents the availability of the information user. It is different from ‘digital divide’ of which the main parameter is accessibility to the information. Once accessibility meets a certain level, availability is considered as a more important factor than accessibility when evaluating the progress of ICT(Information and Communication Technology). We present a model that can describe the digital differentiation phenomenon by using the methodology borrowed from the graph theory, inverse optimization and other established research theory related to digital differentiation. We provide some insights to reduce digital differentiations and therefore our analysis can be used as a guideline for policy maker who desires to mitigate digital differentiations.
        305.
        2016.07 구독 인증기관 무료, 개인회원 유료
        With increasing challenges like climate change, companies are confronted with rising expectations from stakeholders, especially consumers. The paper investigates consumers’ reactions towards CSR strategies using a case-study and focus-groups. Results imply that digitally-based strategies at the core of newly found fashion companies are perceived generally positive, although with mixed impressions.
        4,000원
        306.
        2016.06 구독 인증기관 무료, 개인회원 유료
        This paper presents how Digital Knowledge Ecosystem such as “Govi Nena” (translates as agriculture intelligence) can be used to provide a more effective and practical solution to eliminate the inefficiencies in agricultural markets and achieve higher productivity and price stability. In order to establish the framework to analyze the system, this paper uses a set of hypothetical scenarios faced by value chain actors based on a review of the literature, established knowledge and recent developing country experiences. The scenario analysis reveals that “Govi Nena” enables farmers to make effective production decisions, deepens the level of value chain integration, and enhances the level of welfare for the society as a whole.
        4,000원
        307.
        2016.06 구독 인증기관 무료, 개인회원 유료
        본 연구는 정보사회로의 진입으로 인한 노년층 정보 불평등을 야기시키는 디지털 격 차에 대한 해소방안, 특히 미디어 소외 계층으로 노년층의 스마트 미디어 사용과 디지털 격차에 대한 이슈에 집중하여 노년층에서 발생되고 있는 스마트 미디어 사용과 관 련한 디지털 격차의 유형과 발생 요인을 분석하였다. 연구결과, 노년층 스마트 미디어 디지 털 격차의 유형은 ‘접근격차’, ‘이용격차’ 및 ‘활용격차’로 분류되어졌다. 노년층이 스마트 미 디어 사용에 있어서 발생하는 접근, 이용, 활용 등 3가지 격차에 영향을 미치는 요인을 분 석한 결과, 첫째, 접근격차에는 소득, 학력, 신체적 만족도, 사회적 만족도가 영향력을 가지 고 있었다. 즉, 접근격차의 경우 경제력과 학력이 노년층에게 영향을 미치는 것으로 나타났 고, 추가적으로 신체적 만족도와 사회적 만족도가 높은 노년층이 스마트 미디어 접근이 수 월하다는 것을 발견하였다. 둘째, 이용격차의 경우 설명력을 가지고 있는 변인은 연령, 지 역, 학력, 신체적 만족도 그리고 사회적 만족도로 나타났는데, 연령이 낮을수록, 학력이 높 을수록 스마트 미디어 기본적 이용에 익숙하였으며 중소도시의 노년층이 이용에 덜 불편함 을 느끼는 것으로 나타났다. 셋째, 활용격차에 영향을 미치는 요인은 성별, 연령, 학력, 사 회적 만족도로 나타났고, 남성이며 연령이 낮고 고학력의 노년층이 스마트 미디어의 응용 능력이 높은 것으로 나타났다.
        5,800원
        308.
        2016.06 구독 인증기관 무료, 개인회원 유료
        기존 오프라인 음반시장에서 디지털음원시장 의 중심체계로 급변한 국내 음악시장은 대형 유 통사 위주의 기형적인 수익분배구조와 저작권자 의 보호보다는 소비자 후생을 우선시하는 정부의 저작권 정책으로 말미암아, 음악창작자의 저작권 행사를 위한 기초는 아직 체계적으로 정립되지 않은 실정이다. 이에 본 연구에서는 저작권인센 티브의 관점에서 점진적으로 발전해나가는 국내 디지털음원시장의 다양한 저작권제도들을 살펴 보았다. 특히 현행 저작권법 규정에 따른 저작권 사용료율 결정에 있어 승인의 문제점, 집중관리 제도 복수경쟁체제 도입의 필요성, 신탁범위선택 제의 필요성, 홀드백제도의 필요성을 집중분석하 여 이러한 제도가 음원권리자의 인센티브에 어떠 한 영향을 미칠지 연구하고 향후 어떠한 제도로 발전해나감이 바람직할지에 대해 고찰하였다. 본 연구에서 살펴본 바와 같이 저작권 행사의 함의 는 저작권 보호를 통한 음악창작의 다양성 증진 이지, 시장 내 이해관계자들 간의 균형이 아니다. 저작권 행사로 인한 소비자 후생 혹은 시장참여 자들 간의 수익분배는 저작권법적 수단이 아닌 경쟁법적 수단으로 해결을 도모해야 할 것이며, 앞으로 정책당국도 이점을 고려하여 저작권 제도 를 탄력적으로 운영함이 보다 바람직할 것으로 생각된다.
        4,000원
        309.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        With increasing interest, there have been studies on LiDAR(Light Detection And Ranging)-based DEM(Digital Elevation Model) to acquire three dimensional topographic information. For producing LiDAR DEM with better accuracy, Filtering process is crucial, where only surface reflected LiDAR points are left to construct DEM while non-surface reflected LiDAR points need to be removed from the raw LiDAR data. In particular, the changes of input values for filtering algorithm-constructing parameters are supposed to produce different products. Therefore, this study is aimed to contribute to better understanding the effects of the changes of the levels of GroundFilter Algrothm’s Mean parameter(GFmn) embedded in FUSION software on the accuracy of the LiDAR DEM products, using LiDAR data collected for Hwacheon, Yangju, Gyeongsan and Jangheung watershed experimental area. The effect of GFmn level changes on the products’ accuracy is estimated by measuring and comparing the residuals between the elevations at the same locations of a field and different GFmn level-produced LiDAR DEM sample points. In order to test whether there are any differences among the five GFmn levels; 1, 3, 5, 7 and 9, One-way ANOVA is conducted. In result of One-way ANOVA test, it is found that the change in GFmn level significantly affects the accuracy (F-value: 4.915, p<0.01). After finding significance of the GFmn level effect, Tukey HSD test is also conducted as a Post hoc test for grouping levels by the significant differences. In result, GFmn levels are divided into two subsets ( ‘7, 5, 9, 3’ vs. ‘1’). From the observation of the residuals of each individual level, it is possible to say that LiDAR DEM is generated most accurately when GFmn is given as 7. Through this study, the most desirable parameter value can be suggested to produce filtered LiDAR DEM data which can provide the most accurate elevation information.
        4,200원
        310.
        2016.06 구독 인증기관·개인회원 무료
        현재 아스팔트 포장 분야는 최근의 이상기후(집중호우 및 폭설)로 인하여 수분으로 인한 파손(점착력 약화로 인한 박리 및 포트홀)이 증가하고 있는 실정이다. 이에 국토교통부에서는 『아스팔트 혼합물 생산 및 시공 지침(2014)』의 재료 선정 과정에서 동적수침 시험을 통하여 피복잔류율이 50% 미만이면 박리방 지 재료를 사용토록 규정하고 있다. EN 12697-11에 규정되어있는 동적수침 시험은 골재와 아스팔트 사 이의 박리 저항성 평가하고 이 결과를 통해 아스팔트 혼합물의 수분 저항성을 평가하는 시험법으로, 피복 잔류율 평가는 검사자의 주관적인 육안 평가를 통해 이루어지기 때문에 시험결과의 객관성 및 신뢰성이 부족하다고 할 수 있다. 본 연구에서는 동적수침시험의 객관성 및 신뢰성 향상을 위하여, Digital Image Analysis(DIA)를 도입하였으며, Mesh Analysis를 통하여 DIA의 기준값을 선정하였다. Mesh Analysis 를 위하여 시험 후 건조된 시료를 동일한 조건에서 스캔하여 총 400(20×20) 개의 mesh로 나누어 각 셀 에 대한 피복율을 육안조사를 통하여 총 5 단계의 가중치를 적용하여 계산하였다. DIA는 이미지 파일을 화소(Pixel) 값을 기반으로 처리하는 기법으로, Mesh Analysis에 이용된 25비트 컬러 이미지 파일을 그 레이 이미지(화소값 0(검정색)~255(흰색))로 변환한 후 기준값을 바탕으로 변환된 흑백의 이미지를 이용 하여 피복율을 계산하는 분석방법이다. 보다 객관적인 피복율 비교를 위하여 BBS 시험을 수행하여 얻어 진 점착력을 피복율과 비교하였다. Fig. 1(a)는 피복율과 점착력의 비교결과, Fig. 1(b)는 AP-3를 기준으 로 계산된 피복율과 점착력의 재료에 따른 변동비율 결과를 보여준다. Fig. 1에서 육안평가 결과의 경향은 다른 평가방법과 다른 경향을 나타냈으며 즉, 육안평가는 시료 종 류에 따른 피복율 경향 파악에는 적합한 방법이 될 수는 있으나, 객관적인 피복율 평가에는 미흡한 것으 로 판단된다. 반면에 DIA는 Mesh Analysis 및 BBS 결과와 비교적 유사한 경향을 보였으며, 동적수침시 험의 피복율 평가에 DIA를 적용하는 것은 결과의 신뢰성 및 객관성 측면에서 도움이 될 수 있을 것으로 판단된다.
        311.
        2016.05 구독 인증기관 무료, 개인회원 유료
        The aim of this study is to investigate the effect of wear resistance with 3D printing of DLP(Digital Light Processing). For this purpose, three wear factor which are wear loss, coefficient of friction and friction force applied to test wear-resistance. Wear test of ball-on-disk has been performed using steel balls to determine the variation of wear characteristics. Finally, the coefficient of wear was calculated by the Archard wear equation with 3D printing of DLP.
        4,000원
        314.
        2016.04 구독 인증기관·개인회원 무료
        This study was performed to apply and to utilize the digital forecasting information for Integrated Pest Management at pepper field in Chungbuk province. Chemical spray according to the forecasting prediction using FarmIPM and NCPMS were compare to the that of no control and conventional control. Pests such as Oriental tobacco budworm, Western flower thrips, and Cotton aphids were investigated the control effect by the forecasting modeling information at three pepper plots. Damaged fruit ratio (%) of Oriental tobacco budworm was ordered into no treatment (30) > forecasting (20) > conventional (12), but damages by other pest was insignificant. The frequency of forecasting control was ordered into NCPMS (31) > conventional control (17) > FarmIPM (8). Damaged fruit ratio (%) of Oriental tobacco budworm was ordered into no treatment (35.5) > NCPMS (26.1) > FarmIPM (24.6) > conventional (13.9). Density of western flower thrips was higher but had no problematic by the chemical control when it is hard to analyze the damage by cotton aphid occurrence. Damage by cotton aphids has no prediction of forecasting but done with 6th chemical spray, and their damage ratio (%) was ordered into no treatment (67.7) > FarmIPM (16.2) > NCPMS (11.3) > conventional treatment (4.8). At an analysis of economic value, gross profit was highest in FarmIPM and next to NCPMS > conventional control.
        315.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to set up the optimal exposure condition according to detector type considering image quality (IQ) with radiation dose in chest digital radiography. We used three detector type such as flat-panel detector (FP) and computed radiography (CR), and charge-coupled device (CCD). Entrance surface dose (ESD) was measured at each exposure condition combined tube voltage with tube current using dosimeter, after attaching on human phantom, it was repeated 3 times. Phantom images were evaluated independently by three chest radiologists after blinding image informations. Standard exposure condition using each institution was 117 kVp-AEC at FP and 117 kVp-8 mAs at CR, and 117 kVp-8 mAs at CCD. Statistical analysis was performed by One way ANOVA (Dunnett T3 test) using SPSS ver. 19.0. In FP, IQ scores were not significant difference between 102 kVp-4 mAs and 117 kVp-AEC (28.4 vs. 31.1, p=1.000), even though ESD was decreased up to 50% (62.3 μGy vs. 125.1 μGy). In CR, ESD was greatly decreased from 117 kVp-8 mAs to 90 kVp-8 mAs without significant difference of IQ score (p=1.000, 24.6 vs. 19.5). In CCD, IQ score of 117 kVp-8 mAs was similar with 109 kVp-8 mAs (29.6 vs. 29.0), with decreasing from 320.8 μGy to 284.7 μGy (about 11%). We conclude that optimal x-ray exposure condition for chest digital radiography is 102 kVp-4 mAs in FP and 90 kVp-8 mAs in CR, and 109 kVp-8 mAs in CCD.
        4,000원
        316.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 TV산업에서 지배적 디지털 TV에 영향을 미치는 지배적 디 자인 결정요인과 제품핵심요소를 규명하는 것이다. 이를 위하여, 전문가 설문조사를 통해 자 료를 수집하고, 구조방정식 모형을 이용하여 분석하였다. 연구 결과, 지배적 디자인의 결정요 인은 디스플레이, 디자인, 특성에 영향을 주고 디스플레이와 디자인이 지배적 디지털 TV를 만드는 데 영향을 주는 것으로 밝혀졌다. 본 연구는 우리나라 TV기업이 지속적으로 지배적 디자인을 선도하여 선도자로서의 역할을 유지토록 사업전략 수립의 기초자료로써 큰 의미가 있다 하겠다.
        6,600원
        317.
        2015.10 구독 인증기관·개인회원 무료
        Analyzing asphalt mixture images can provide crucial information not only for generating advanced geometry structure in several numerical computations (i.e. FEM and/or DEM) codes, but also for numerically evaluating the material microstructure. It is well known that 3D X-Ray Computer Tomography (CT) can provide accurate and realistic microstructure information of asphalt mixtures; however, this technology still presents two limitations: 1) the equipment is very expensive and, therefore, only few pavement agencies can afford it, and 2) the software required to generate realistic image of asphalt mixture with three-phase structure (aggregate, asphalt binder and air-voids) is based on a global thresholding algorithm which cannot be easily accessed and edited by users and practitioners. In this paper, accurate and realistic 2D three-phase asphalt mixture images were generated using an advanced DIP analysis code (implemented on MATLABTM) and a common flatbed scanner, which can be easily purchased at relatively low price. The threshold algorithm was developed based on the computed results of Gmm (maximum specific gravity), Gmb (bulk specific gravity), VMA (voids in mineral aggregates) of given asphalt mixtures which can be experimentally obtained in a laboratory environment. 2D three-phase images of asphalt mixtures were derived from grey scale images (color intensity from 0 to 255) obtained from original RGB (Red-Green-Blue) scale images with a dual-threshold computation techniques (i.e. one step for computing air voids phase, T1, and a second step for computing asphalt binder (and/or mastic) phase, T2). An example of DIP analysis results is shown in Figure 1. Based on the computation results, quite accurate and good visual agreement was observed between RGB scale image and DIP analyzed image. The findings indicate that this advanced DIP analysis technique can provide reliable geometry and microstructural information for several numerical simulations such as finite element method (FEM) and discrete element modeling (DEM). This research work represents a solid base for performing simple 2D microstructure analysis using 2- and 3-point correlation function and for developing the Moon Cannone Falchetto (MCF) model which will be introduced in the next annual KSRE conference.
        318.
        2015.10 구독 인증기관·개인회원 무료
        최근 기후변화로 인한 집중호우의 강도와 빈도가 증가하면서 아스팔트 포장의 포트홀 발생이 급격히 증가하고 있다. 포트홀은 아스팔트 포장에 침투된 수분이 교통하중과 함께 간극수압을 야기하여 아스팔트 포장의 골재 표면과 아스팔트 바인더 사이의 점착력을 약화시켜 박리가 발생하여 포장이 파손되는 것을 말한다. 이로 인해 아스팔트 포장체의 조기 파손이 발생하게 되면 아스팔트 포장의 공용성을 감소시키고 유지·보수비용을 증가시키므로 사용재료에 대한 점착력 특성을 파악하는 작업이 반드시 필요하다. 본 연 구에서는 아스팔트 포장시공에 많이 사용되는 3가지 종류의 아스팔트 바인더(PG58-22, PG64-22, PG76-22)를 선정해서 동적수침시험(Dynamic Immersion Test)과 바인더 점착력 시험(Bitumen Bond Strength, BBS Test)을 수행하여 각 아스팔트 바인더의 점착력을 평가하였다. 동적수침시험은 EN 12697-11 기준에 의해 수행되었으며, 주관적인 결과분석방법(육안평가)의 개선을 위해 DIA(Digital Image Analysis)를 통해 객관적인 평가를 수행하였다. 각 시편은 기존에 적용되던 육안조사와 무게변화 의 방법을 수행하는 동시에 객관적인 평가를 위해 Mesh Analysis 방법을 적용하였다. 각 시편을 동일한 조건에서 스캔하여 얻어진 이미지 파일을 총 400(20×20)개의 mesh로 나뉘어 각 cell에 대한 피복율을 5 단계의 가중치를 적용하여 계산하였다(Equation 1). Mesh Analysis의 결과를 적용하여 얻어진 기준값 (Threshold Value) 36을 기준으로 DIA를 수행하여 최종 점착력을 비교 ․ 분석하였다. Fig. 1은 동적수침 시험과 BBS Test로 얻어지는 수분민감성과 상온에서의 점착력결과를 나타낸 것이다. 본 연구에서는 DIT의 각 평가 방법을 비교하였고, 그 결과를 BBS 시험과 비교하여 아스팔트 바인더의 점착력을 평가하였으며, 도출된 결론은 다음과 같다. 기존의 DIT 육안평가 방법은 평가자 간의 차이가 크 기 때문에 주관적인 결과를 도출할 가능성이 있으며, DIA를 이용하여 보다 객관적인 평가를 수행할 수 있 을 것으로 판단된다. BBS 시험결과 PG등급이 높을수록 상온에서의 점착력이 좋다는 것을 확인할 수 있 었고, DIT 시험결과 또한 동일한 경향을 보이는 것으로 나타났다.
        319.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Stellar mass is an important parameter of galaxies. We estimate the dynamical mass of an elliptical galaxy by its velocity dispersion and effective radius using the Hernquist model in the framework of MOdified Newtonian Dynamics (MOND). MOND is an alternative theory to the dark matter paradigm. In MOND the dynamical mass is the same as the baryonic mass or luminous mass, and in elliptical galaxies most of the baryons reside in stars. We select elliptical galaxies between redshift 0.05 and 0.5 from the main galaxy sample and the luminous red galaxy sample in the Sloan Digital Sky Survey. We nd that the stellar mass-to-light ratio at different redshift epochs can be fitted by a gamma distribution, and its mean is smaller at smaller redshifts.
        3,000원
        320.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        data. Recent developments in unmanned aerial vehicle (UAV) technology provide cost effective and real time applications for site specific data collection. For the mapping of herbage biomass (BM) on a hill pasture, we tested a UAV system with digital cameras (visible and near-infrared (NIR) camera). The field measurements were conducted on the grazing hill pasture at Hanwoo Improvement Office, Seosan City, Chungcheongnam-do Province, Korea on May 17 and June 27, 2014. Plant samples were obtained from 28 sites. A UAV system was used to obtain aerial photos from a height of approximately 50 m (approximately 30 cm spatial resolution). Normalized digital number (DN) values of Red and NIR channels were extracted from the aerial photos and a normalized differential vegetation index using DN (NDVIdn) was calculated. The results show that the correlation coefficient between BM and NDVIdn was 0.88. For the precision management of hilly grazing pastures, UAV monitoring systems can be a quick and cost effective tool to obtain site-specific herbage BM data.
        4,000원