• Title/Summary/Keyword: impact coefficient

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Prediction Equation for Chloride Diffusion in Concrete Containing GGBFS Based on 2-Year Cured Results (2년 양생 실험결과를 이용한 고로슬래그 미분말 콘크리트의 염화물 확산 예측식)

  • Yoon, Yong-Sik;Cho, Sung-Jun;Kwon, Seung-Jun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.2
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    • pp.1-9
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    • 2019
  • GGBFS(Ground Granulated Blast Furnace Slag), one of the representative concrete mineral admixtures, improves the long-term durability and engineering performance of concrete by latent hydraulic activity. In this study, considering 3 levels of W/B(0.37, 0.42, 0.47) and GGBFS replacement ratio(0 %, 30 %, 50 %), durability performances for chloride attack are evaluated, and equations which predict behavior of accelerated chloride diffusion are proposed. Also, the relationship between accelerated chloride diffusion coefficient and passed charge is evaluated. In target curing day, accelerated chloride diffusion tests(Tang's method, ASTM C 1202) and compressive strength(KS F 2405) are performed. In the 730 day's results of accelerated chloride diffusion coefficient, GGBFS concrete has up to 28 % of decreasing ratio compared to OPC concrete, and in those of passed charge, GGBFS concrete has up to 29 % of decreasing ratio compared to OPC concrete. Also, it is deemed that the impact of variation of W/B is less in GGBFS concrete than in OPC concrete. The equations which predict accelerated chloride diffusion coefficient and passed charge are drawn, based on the characteristics of mixture and test results. The equation which predicts passed charge shows slightly higher coefficient of determination than that which predicts accelerated chloride diffusion coefficient.

Study on the Free Roll Decay and Resistance Performances of Fishing Vessels by Varying Appendages (어선 부가물 별 자유 횡 동요 감쇠 및 저항성능에 관한 연구)

  • Mijin Yoon;Janghoon Seo;Dong-Woo Park;Chanjae Lee;Intae Kim;Dong Nam
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.6
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    • pp.688-696
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    • 2023
  • In the present study, free roll decay and resistance performances of fishing vessels were evaluated with the combinations and variations of in the parameters of appendages which are attached to improve motion performance of fishing vessels. Computational Ffluid Ddynamics was used to perform free roll decay and resistance analysis. The roll period and decay coefficient were derived by the variations in the combination and dimensions of the primary appendages of the bilge keel and the under keel. It was observed thatThe variations of in the length of the under keel did not significantly impact to the roll damping coefficient. Conversely, for the bilge keel, an increase in the length and angle resulted in an increase in the roll damping coefficient. Comparison of resistance performance was additionally assessed among the selected hulls with the appendages and bare hull. The resistance of the hull with the appendages was higher than that of the bare hull due owing to the changes of in the pressure on the surface of the hull and trim angle. Throughout the present study, the impact of appendage parameter and arrangement on the free roll decay and resistance performance of fishing vessels were was assessed,. which This will be beneficial for the application of appendages to fishing vessels.

A Study on Spatial Pattern of Impact Area of Intersection Using Digital Tachograph Data and Traffic Assignment Model (차량 운행기록정보와 통행배정 모형을 이용한 교차로 영향권의 공간적 패턴에 관한 연구)

  • PARK, Seungjun;HONG, Kiman;KIM, Taegyun;SEO, Hyeon;CHO, Joong Rae;HONG, Young Suk
    • Journal of Korean Society of Transportation
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    • v.36 no.2
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    • pp.155-168
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    • 2018
  • In this study, we studied the directional pattern of entering the intersection from the intersection upstream link prior to predicting short future (such as 5 or 10 minutes) intersection direction traffic volume on the interrupted flow, and examined the possibility of traffic volume prediction using traffic assignment model. The analysis method of this study is to investigate the similarity of patterns by performing cluster analysis with the ratio of traffic volume by intersection direction divided by 2 hours using taxi DTG (Digital Tachograph) data (1 week). Also, for linking with the result of the traffic assignment model, this study compares the impact area of 5 minutes or 10 minutes from the center of the intersection with the analysis result of taxi DTG data. To do this, we have developed an algorithm to set the impact area of intersection, using the taxi DTG data and traffic assignment model. As a result of the analysis, the intersection entry pattern of the taxi is grouped into 12, and the Cubic Clustering Criterion indicating the confidence level of clustering is 6.92. As a result of correlation analysis with the impact area of the traffic assignment model, the correlation coefficient for the impact area of 5 minutes was analyzed as 0.86, and significant results were obtained. However, it was analyzed that the correlation coefficient is slightly lowered to 0.69 in the impact area of 10 minutes from the center of the intersection, but this was due to insufficient accuracy of O/D (Origin/Destination) travel and network data. In future, if accuracy of traffic network and accuracy of O/D traffic by time are improved, it is expected that it will be able to utilize traffic volume data calculated from traffic assignment model when controlling traffic signals at intersections.

A Study on the Impact Factors of Contents Diffusion in Youtube using Integrated Content Network Analysis (일반영향요인과 댓글기반 콘텐츠 네트워크 분석을 통합한 유튜브(Youtube)상의 콘텐츠 확산 영향요인 연구)

  • Park, Byung Eun;Lim, Gyoo Gun
    • Journal of Intelligence and Information Systems
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    • v.21 no.3
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    • pp.19-36
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    • 2015
  • Social media is an emerging issue in content services and in current business environment. YouTube is the most representative social media service in the world. YouTube is different from other conventional content services in its open user participation and contents creation methods. To promote a content in YouTube, it is important to understand the diffusion phenomena of contents and the network structural characteristics. Most previous studies analyzed impact factors of contents diffusion from the view point of general behavioral factors. Currently some researchers use network structure factors. However, these two approaches have been used separately. However this study tries to analyze the general impact factors on the view count and content based network structures all together. In addition, when building a content based network, this study forms the network structure by analyzing user comments on 22,370 contents of YouTube not based on the individual user based network. From this study, we re-proved statistically the causal relations between view count and not only general factors but also network factors. Moreover by analyzing this integrated research model, we found that these factors affect the view count of YouTube according to the following order; Uploader Followers, Video Age, Betweenness Centrality, Comments, Closeness Centrality, Clustering Coefficient and Rating. However Degree Centrality and Eigenvector Centrality affect the view count negatively. From this research some strategic points for the utilizing of contents diffusion are as followings. First, it is needed to manage general factors such as the number of uploader followers or subscribers, the video age, the number of comments, average rating points, and etc. The impact of average rating points is not so much important as we thought before. However, it is needed to increase the number of uploader followers strategically and sustain the contents in the service as long as possible. Second, we need to pay attention to the impacts of betweenness centrality and closeness centrality among other network factors. Users seems to search the related subject or similar contents after watching a content. It is needed to shorten the distance between other popular contents in the service. Namely, this study showed that it is beneficial for increasing view counts by decreasing the number of search attempts and increasing similarity with many other contents. This is consistent with the result of the clustering coefficient impact analysis. Third, it is important to notice the negative impact of degree centrality and eigenvector centrality on the view count. If the number of connections with other contents is too much increased it means there are many similar contents and eventually it might distribute the view counts. Moreover, too high eigenvector centrality means that there are connections with popular contents around the content, and it might lose the view count because of the impact of the popular contents. It would be better to avoid connections with too powerful popular contents. From this study we analyzed the phenomenon and verified diffusion factors of Youtube contents by using an integrated model consisting of general factors and network structure factors. From the viewpoints of social contribution, this study might provide useful information to music or movie industry or other contents vendors for their effective contents services. This research provides basic schemes that can be applied strategically in online contents marketing. One of the limitations of this study is that this study formed a contents based network for the network structure analysis. It might be an indirect method to see the content network structure. We can use more various methods to establish direct content network. Further researches include more detailed researches like an analysis according to the types of contents or domains or characteristics of the contents or users, and etc.

An Analysis of the Impact of Strategic Festival Planning on Festival Satisfaction and Urban Regeneration : Focusing on the Gimje Horizon Festival (전략적 축제기획이 축제만족과 도시재생에 미치는 영향 분석: 김제지평선축제를 중심으로)

  • Kim, Namhee
    • 지역과문화
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    • v.7 no.1
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    • pp.59-98
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    • 2020
  • An empirical study utilizing data was performed with a variable called 'strategic planning' for festivals in order to look into the impact of a cultural tourism festival on urban regeneration. As a success factor of a festival, strategic festival planning was drawn up, and the following hypotheses were set: Seven strategic factors verified through an exploratory factor analysis will have a positive impact on festival satisfaction (festival success) and on urban regeneration, and festival satisfaction will have a positive impact on urban regeneration by having a mediating effect on it. For the analysis, the Gimje Horizon Festival was selected as it was considered as a typical case of urban regeneration through a festival, and the relationship between the festival and urban regeneration was understood by conducting a combined analysis of a quantitative analysis through a survey, a literature search, field investigations and in-depth interviews. The quantitative analysis indicates that strategic planning has a positive impact on festival satisfaction (festival success) and on urban regeneration and that festival satisfaction has a positive impact on urban regeneration. The same study result as the quantitative analysis result was obtained even through a qualitative analysis. This shows that the higher the path coefficient of strategic planning, the higher the path coefficient of festival satisfaction and urban generation and that with better strategic planning, the effects of festival satisfaction and urban regeneration are maximized. In other words, when planning and implementing a festival by actively incorporating the seven strategic planning factors which were suggested as festival success factors earlier in this study beginning from the stage of festival planning, it is likely to have a positive impact not only on the success of the festival but also on urban regeneration. This is an implication that gives a new alternative to software-based urban regeneration through festivals. It is meaningful to present the importance of festival planning and the direction of planning to maximize the effect of urban regeneration to festival planners and urban regeneration experts. This study is believed to serve as a momentum for people to take a new approach to studies on festivals and urban regeneration utilizing software in the future.

Impact of Resourcefulness and Communication Style on Nursing Performance in Hospital Nurses (간호사의 자원동원성, 의사소통유형이 간호업무성과에 미치는 영향)

  • Lee, Hea-Shoon;Oak, Ji-Won
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.19 no.2
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    • pp.253-260
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    • 2012
  • Purpose: This study was done to identify the impact of resourcefulness and communication style on nursing performance in nurses working in hospitals. Method: Though a convenience sampling method 312 nurses were recruited between from July 4 and 17, 2011. Data were collected using a questionnaire, which included items on work related characteristics, resourcefulness, communication style, and nursing performance. Data were analyzed using t-test, ANOVA, Scheffe test, Pearson correlation coefficient and hierarchical regression analysis. Results: The major findings of this study were as follow; 1) There were significant relationships between nursing performance and resourcefulness ($p$<.001), informative communication style ($p$<.001), affiliativeness communication style ($p$<.001), and dominance communication style ($p$<.001). 2) The nursing performance was significantly associated with career in current department, resourcefulness, informative communication style, affiliativeness communication style, and dominance communication style in capability which explained 45.6% of variance in nursing performance. Conclusion: The results of this study demonstrate a relationship between resourcefulness, communication style, and nursing performance in hospital nurses indicating the need to use the study results to plan programs to prompt nurses in their use of resourcefulness and communication style in nursing care.

Electron Scattering at Grain Boundaries in Tungsten Thin Films

  • Choe, Du-Ho;Kim, Byeong-Jun;Lee, Seung-Hun;Jeong, Seong-Hun;Kim, Do-Geun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.243.2-243.2
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    • 2016
  • Tungsten (W) is recently gaining attention as a potential candidate to replace Cu in semiconductor metallization due to its expected improvement in material reliability and reduced resistivity size effect. In this study, the impact of electron scattering at grain boundaries in a polycrystalline W thin film was investigated. Two nominally 300 nm-thick films, a (110)-oriented single crystal film and a (110)-textured polycrystalline W film, were prepared onto (11-20) Al2O3 substrate and thermally oxidized Si substrate, respectively in identical fabrication conditions. The lateral grain size for the polycrystalline film was determined to be $119{\pm}7nm$ by TEM-based orientation mapping technique. The film thickness was chosen to significantly exceed the electron mean free path in W (16.1 and 77.7 nm at 293 and 4.2 K, respectively), which allows the impact of surface scattering on film resistivity to be negligible. Then, the difference in the resistivity of the two films can be attributed to grain boundary scattering. quantitative analyses were performed by employing the Mayadas-Shatzkes (MS) model, where the grain boundary reflection coefficient was determined to be $0.42{\pm}0.02$ and $0.40{\pm}0.02$ at 293 K and 4.2 K, respectively.

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The Influence of Industrial Structure Upgrading on Carbon Emission Efficiency in China

  • Song, Luyan
    • The Journal of Industrial Distribution & Business
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    • v.10 no.2
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    • pp.7-15
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    • 2019
  • Purpose - The industrial structure upgrading can play an important role in promoting the carbon emission efficiency. Thus, this paper attempts to study the impact of industrial structure upgrading on carbon emission efficiency in order to reduce carbon emissions. Research design, data, and methodology - This paper selects panel data of 30 provinces and municipalities (autonomous regions) in China from 2001 to 2016, and divides them into three regions. The Moore index is used to measure the industrial structure upgrading, the non-radial SBM model based on undesired output is used to measure the slack variable to calculate the total factor carbon emission efficiency. Finally the impact of industrial structure upgrading on the carbon emission efficiency are analyzed. Results - It is found that the Moore index and the carbon emission efficiency in the eastern region is the highest in the three regions. Conclusions - The influence of various influencing factors on carbon emission efficiency is different between regions. The Moore index has a positive effect on the carbon emission efficiency in the eastern region, and has a negative influence coefficient on the central region. The effect on the western region is not obvious.

Platform Strategy and Market Response Impact on the Success of Crowdfunding: A Chinese Case

  • Guo, Li;Zhou, Dongmei;Chen, Yang;Huy, Ratanak
    • Asian Journal of Innovation and Policy
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    • v.4 no.3
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    • pp.397-409
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    • 2015
  • Nowadays, crowdfunding presents a promising development. This research focuses on the influence of platform strategy and market response on the success of crowdfunding from the perspective of the elaboration likelihood model (ELM) theory. Detailed product specifications, crowdfunding difficulty coefficient, vivid advertising video such as introduction and music, and recommendations from relevant figures are all used to depict platform strategy. Meanwhile, we use the number of lovers, followers, comments and 1 RMB backers to measure the level of market response. And thus, we model the impact of platform strategy and market response on crowdfunding success with empirical studies based on 400 samples of observed value. We found firstly that there exist significant positive relations between the total amount of funds pledged and detailed product specification, vivid advertising video, recommendations from relevant figures and the number of 1 RMB backers. Secondly, the crowdfunding difficulty of projects affects negatively, and significantly, the total amount of funds pledged. Thirdly, the influence of the number of lovers and followers on funds pledged is not significant.

The Impact of Safety Climate and Fatigue on Safety Performance of Operating Room Nurses (수술실 간호사의 안전분위기와 피로 수준이 안전이행에 미치는 영향)

  • Choi, U-Eun;Kim, Hyun-Young
    • Journal of Korean Academy of Nursing Administration
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    • v.22 no.5
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    • pp.471-479
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    • 2016
  • Purpose: This study was conducted to evaluate the level of safety climate, fatigue, and safety performance and to identify the impact of safety climate and fatigue on the safety performance of operating room nurses. Methods: The study design was a descriptive survey. Participants were 174 operating room nurses from two general hospitals and two university hospitals in S and D cities. Three structurally designed questionnaires were used to evaluate their safety climate, fatigue, and safety performance. Collected data were analyzed using descriptive analysis, t-tests, ANOVAs, Pearson correlation coefficient, and stepwise multiple regression. Results: Safety performance of operating room nurses had a mean of 3.26 on a 5-point scale. 'Current department career'(${\beta}=.17$, p=.006) and 'safety climate (work-unit contribution) (${\beta}=.63$, p<.001) accounted for 39% of the variance in operating room nurses' safety performance. Conclusion: Findings indicate that work-unit contribution towards safety climate is an important factor in increasing operating room nurses' safety performance. Therefore, it is essential to find motivational properties consistent with the characteristics of the operating room environment.