• Title/Summary/Keyword: Diffusion theory

Search Result 482, Processing Time 0.025 seconds

Public Electric Car Charging Locations Based on Car Navigation Data in Seoul (네비게이션 데이터를 바탕으로 한 서울시의 공공 전기차 충전소 위치)

  • Taekyung Kim;Jangyoung Kim;Yoon Gi Yang
    • Information Systems Review
    • /
    • v.18 no.4
    • /
    • pp.1-15
    • /
    • 2016
  • Electric cars are expected to increase quality of life by reducing air pollution and to contribute to economic growth by creating new businesses. However, electric car adoption has lagged and has not satisfied public expectation. One of the primary reasons for this outcome is the slow charging speed or inconvenience of charging a battery. Under the insufficient diffusion of electric cars, pushing business entities to construct charging facilities is undesirable for a policy maker to increase the adoption rate because of cost and management issues. This study adopts the design science methodology to interpret the problem of deploying electric car charging stations in the view of information systems. A trip planning algorithm is suggested on the basis of the theory of range anxiety. We investigate issues related to the current charging locations using data from drivers' car navigation devices. We also review its applicability to trip planning to obtain insights.

A Study on the Spread of YouTube Political Issues and the Attribution of the Issue, Focusing on the Issue of the Constitutional Court's Ruling on the 'Complete deprivation of prosecutorial powers' Act (유튜브 정치 이슈의 확산 양산과 이슈 속성 연구: '검수완박' 법안 헌법재판소 판결 이슈를 중심으로)

  • Insool Cho;Juhyun Hong
    • The Journal of the Convergence on Culture Technology
    • /
    • v.10 no.1
    • /
    • pp.193-203
    • /
    • 2024
  • In a situation where news usage through YouTube is rapidly increasing, this study investigated which attributes of issues news producers prominently report on based on the two-stage agenda setting theory to empirically investigate the influence of various news producers on YouTube. Through the research results, we confirmed that broadcasters have the influence to set the agenda and form public opinion on YouTube, and discovered the possibility of a two-stage agenda setting effect occurring in the YouTube environment. We criticized whether news producers abuse emotional words due to their partisanship when reporting political issues, and discussed that an emotional approach to political issues can have a negative impact on news users' perception of reality.

Effect of Ta/Cu Film Stack Structures on the Interfacial Adhesion Energy for Advanced Interconnects (미세 배선 적용을 위한 Ta/Cu 적층 구조에 따른 계면접착에너지 평가 및 분석)

  • Son, Kirak;Kim, Sungtae;Kim, Cheol;Kim, Gahui;Joo, Young-Chang;Park, Young-Bae
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.28 no.1
    • /
    • pp.39-46
    • /
    • 2021
  • The quantitative measurement of interfacial adhesion energy (Gc) of multilayer thin films for Cu interconnects was investigated using a double cantilever beam (DCB) and 4-point bending (4-PB) test. In the case of a sample with Ta diffusion barrier applied, all Gc values measured by the DCB and 4-PB tests were higher than 5 J/㎡, which is the minimum criterion for Cu/low-k integration without delamination. However, in the case of the Ta/Cu sample, measured Gc value of the DCB test was lower than 5 J/㎡. All Gc values measured by the 4-PB test were higher than those of the DCB test. Measured Gc values increase with increasing phase angle, that is, 4-PB test higher than DCB test due to increasing plastic energy dissipation and roughness-related shielding effects, which matches well interfacial fracture mechanics theory. As a result of the 4-PB test, Ta/Cu and Cu/Ta interfaces measured Gc values were higher than 5 J/㎡, suggesting that Ta is considered to be applicable as a diffusion barrier and a capping layer for Cu interconnects. The 4-PB test method is recommended for quantitative adhesion energy measurement of the Cu interconnect interface because the thermal stress due to the difference in coefficient of thermal expansion and the delamination due to chemical mechanical polishing have a large effect of the mixing mode including shear stress.

A qualitative study on the process of maintaining the 'eating alone'(honbob) lifestyle (직장인의 '혼밥' 유지 과정에 대한 질적 연구)

  • Hye Jin Kwon;Younga Ju
    • Korean Journal of Culture and Social Issue
    • /
    • v.24 no.4
    • /
    • pp.657-689
    • /
    • 2018
  • The purpose of this study is to develop a substantive theory on 'eating alone'(honbob)and the process of maintaining the lifestyle of eating alone for the need of a non-judgmental understanding on the new 'honbob' lifestyle. Data were collected through in-depth interviews with 10 male and female workers in Seoul and Gyeonggi-do, who voluntarily eat alone over 70% of their meals per week with the minimum duration of 5 years. Data analysis was performed using grounded theory proposed by Strauss & Corbin (1998) in the qualitative research method. As a result, a paradigm model on the process of maintaining 'honbob' was derived. Based on categorical analysis, the causal condition was 'not trying to tune' and the central phenomenon was 'following the desire to set efficiency as the top priority. Contextual conditions were 'the atmosphere of fierce competition', 'weakening of organizational culture', 'diffusion of individualistic culture'. The intervening conditions were 'personal trait and emotional experience', 'job characteristics of less organization culture'. The action/interaction strategies were 'accepting internal conflicts', 'acting in autonomy', 'finding relationship through media', and 'distancing from superficial relationship'. The consequences were 'enjoying time for self-exploration', 'valuing self-care', 'becoming a epicurean conventionalist', and 'becoming aware of the need for balance'. The core category has been shown as 'self-oriented in accordance to priority of efficiency and being able to appreciate the importance of social group'. The Such phenomenon passes through four different stages - first, the stage of weighing time efficiency while beginning hon-bob; second, the stage of conflict when one feels nervous and not free from others' view; third, the stage of adjustment to justify his/her 'hon-bob'; and the final stage of balance to perceive the importance of social group while going on 'honbob'. The study had the aim of increasing the understanding and acceptance of the new 'honbob' lifestyle through an in-depth exploration of office worker's 'honbob' experience and the process of maintaining 'honbob' so the society can better accept it and, further, to embrace co-existence of various cultures.

The Framework of Research Network and Performance Evaluation on Personal Information Security: Social Network Analysis Perspective (개인정보보호 분야의 연구자 네트워크와 성과 평가 프레임워크: 소셜 네트워크 분석을 중심으로)

  • Kim, Minsu;Choi, Jaewon;Kim, Hyun Jin
    • Journal of Intelligence and Information Systems
    • /
    • v.20 no.1
    • /
    • pp.177-193
    • /
    • 2014
  • Over the past decade, there has been a rapid diffusion of electronic commerce and a rising number of interconnected networks, resulting in an escalation of security threats and privacy concerns. Electronic commerce has a built-in trade-off between the necessity of providing at least some personal information to consummate an online transaction, and the risk of negative consequences from providing such information. More recently, the frequent disclosure of private information has raised concerns about privacy and its impacts. This has motivated researchers in various fields to explore information privacy issues to address these concerns. Accordingly, the necessity for information privacy policies and technologies for collecting and storing data, and information privacy research in various fields such as medicine, computer science, business, and statistics has increased. The occurrence of various information security accidents have made finding experts in the information security field an important issue. Objective measures for finding such experts are required, as it is currently rather subjective. Based on social network analysis, this paper focused on a framework to evaluate the process of finding experts in the information security field. We collected data from the National Discovery for Science Leaders (NDSL) database, initially collecting about 2000 papers covering the period between 2005 and 2013. Outliers and the data of irrelevant papers were dropped, leaving 784 papers to test the suggested hypotheses. The co-authorship network data for co-author relationship, publisher, affiliation, and so on were analyzed using social network measures including centrality and structural hole. The results of our model estimation are as follows. With the exception of Hypothesis 3, which deals with the relationship between eigenvector centrality and performance, all of our hypotheses were supported. In line with our hypothesis, degree centrality (H1) was supported with its positive influence on the researchers' publishing performance (p<0.001). This finding indicates that as the degree of cooperation increased, the more the publishing performance of researchers increased. In addition, closeness centrality (H2) was also positively associated with researchers' publishing performance (p<0.001), suggesting that, as the efficiency of information acquisition increased, the more the researchers' publishing performance increased. This paper identified the difference in publishing performance among researchers. The analysis can be used to identify core experts and evaluate their performance in the information privacy research field. The co-authorship network for information privacy can aid in understanding the deep relationships among researchers. In addition, extracting characteristics of publishers and affiliations, this paper suggested an understanding of the social network measures and their potential for finding experts in the information privacy field. Social concerns about securing the objectivity of experts have increased, because experts in the information privacy field frequently participate in political consultation, and business education support and evaluation. In terms of practical implications, this research suggests an objective framework for experts in the information privacy field, and is useful for people who are in charge of managing research human resources. This study has some limitations, providing opportunities and suggestions for future research. Presenting the difference in information diffusion according to media and proximity presents difficulties for the generalization of the theory due to the small sample size. Therefore, further studies could consider an increased sample size and media diversity, the difference in information diffusion according to the media type, and information proximity could be explored in more detail. Moreover, previous network research has commonly observed a causal relationship between the independent and dependent variable (Kadushin, 2012). In this study, degree centrality as an independent variable might have causal relationship with performance as a dependent variable. However, in the case of network analysis research, network indices could be computed after the network relationship is created. An annual analysis could help mitigate this limitation.

Time Dependent Evaluation of Corrosion Free Life of Concrete Tunnel Structures Based on the Reliability Theory (해저 콘크리트 구조물의 신뢰성 이론에 의한 시간 의존적 내구수명 평가)

  • Pack, Seung Woo;Jung, Min Sun
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.15 no.3
    • /
    • pp.142-154
    • /
    • 2011
  • This study predicted the probability of corrosion initiation of reinforced concrete tunnel boxes structures using the Monte Carlo Simulation. For the inner wall and outer wall in the tunnel boxes, exposed to airborne chloride ion and seawater directly respectively, statistical values of parameters like diffusion coefficient D, surface chloride content $C_s$, cover depth c, and the chloride threshold level $C_{lim}$ were examined from experiment or literature review. Their average values accounted for $3.77{\times}10^{-12}m^2/s$, 3.0% by weight of cement, 94.7mm and 45.5mm for outer wall and inner wall, respectively, and 0.69% by weight of cement for D, $C_s$, c, and $C_{lim}$, respectively. With these parametric values, the distribution of chloride contents at rebar with time and the probability of corrosion initiation of the tunnel boxes, inner wall and outer wall, was examined by considering time dependency of chloride transport. From the examination, the histogram of chloride contents at rebar is closer to a gamma distribution, and the mean value increases with time, while the coefficient of variance decreases with time. It was found that the probability of corrosion initiation and the time to corrosion were dependent on the time dependency of chloride transport. Time independent model predicted time to corrosion initiation of inner wall and outer wall as 8 and 12 years, respectively, while 178 and 283 years of time to corrosion was calculated by time dependent model for inner wall and outer wall, respectively. For time independent model, the probability of corrosion at 100 years of exposure for inner wall and outer wall was ranged 59.5 and 95.5%, respectively, while time dependent model indicated 2.9 and 0.2% of the probability corrosion, respectively. Finally, impact of $C_{lim}$, including values specified in current codes, on the probability of corrosion initiation and corrosion free life is discussed.

A Study on the Reactivity Effect due to Expansion of Diagrid and Pad (Diagram와 Pad의 팽창에 의한 반응도 효과에 대한 연구)

  • Young In Kim;Keun Bae Oh;Kun Jong Yoo;Mann Cho
    • Nuclear Engineering and Technology
    • /
    • v.16 no.2
    • /
    • pp.70-79
    • /
    • 1984
  • With the help of the nuclear computational system for a large LMFBR (KAERI-26 group cross section library/1DX/2DB), the reactivity coefficients for the diagrid expansion and the pad expansion at the beginning of cycle of the equilibrium core of SUPER-PHENIX I are calculated and reviewed. the core is described using R-Z geometry model, and a two-dimensional multigroup diffusion theory is used. For reference cases, reactivity calculations for radial and axial uniform expansion are performed, and also calculated are reactivity variations due to changes in material density and core volume. The reactivity coefficient for the diagrid expansion is calculated to be -0.553pcm/mil. The temperature coefficient corresponding to the above value is -1.0766pcm/$^{\circ}C$ and is well in accord with the French datum of -1.09pcm/$^{\circ}C$ within 1.2% difference. With the use of 4he calculational method for the diagrid expansion effect, reactivity calculations for the pad expansion bringing about nonuniform expansion are performed, which show that the calculational method is very useful in the analysis of the pad expansion effect. The reactivity coefficients for the pad expansion are calculated to be -0.2743 pcm/mil and -0.2786pcm1mi1 for the averaged expansion model and for the integrated pancake model, respectively. Under the assumption of the free expanding core the temperature reactivity coefficients for each model are obtained to be -0.5766pcm/$^{\circ}C$ and -0.5858pcm/$^{\circ}C$, both of which agree with the French datum of -0.574pcm/$^{\circ}C$ within 2% difference.

  • PDF

Exploratory Research of Possibilities and Limiatation of Drone Journalism (재난재해 대응수단으로 드론저널리즘의 가능성과 한계에 관한 탐색적 연구)

  • Cho, Hang-Min
    • Journal of Digital Convergence
    • /
    • v.16 no.8
    • /
    • pp.71-79
    • /
    • 2018
  • This study discussed the meaning of a drone, and especially drone journalism and legal and ethical issues around that, at an introductory dimension, which is used in various social bases, but is still just an academic discussion at the beginning stage. As a methodology, content analysis was used. It seems that drone journalism has high diffusibility as a technology with high 'relative advantage', 'compatibility', 'trial ability' and 'observability' and low 'complexity' in terms of the diffusion of innovation theory. However, it will be very likely that controversies will be raised, such as safety issue due to collision and crash, a dispute over violation of privacy that may seriously infringe privacy like individual portrait rights and a controversy about the accuracy and source of information as drone filming low price and ease of use. Suggest solutions to legal and ethical issues based on existing research. Technical stability is required. Also, it is necessary to change the awareness of journalists about the drones coverage and to educate ethics, and it is necessary to establish social public opinion on issues such as privacy violation and establish system and legal measures through it. Future research is expected to carry out empirical research including journalists and public awareness surveys.

Dispersion of Particle Pulse in Human Lung Airway (인체기관지내의 입자펄스 확산 실험)

  • 이진원;이동엽;추경호
    • Journal of Biomedical Engineering Research
    • /
    • v.19 no.5
    • /
    • pp.511-518
    • /
    • 1998
  • In order to develop the aerosol bolus technique which is thought to be a potential tool for probing geometries or abnormalities of small airways, an experimental system of measuring fast time variations of particle concentration in the inhaled and exhaled breathing air was developed. The system generates monodisperse sebacic acrid particles of 1 micron size and 1.2 of geometric standard deviation in high concentration of $10^8$ particles/cc, delivers a short pulse of particles at the controlled instant during inhalation using a solenoid valve, and measures the fast change of particle concentration in using the laser light scattering. Successful operation of the generator and the measuring system was confirmed by smooth concentration profiles in inhalation. It was also confirmed that maintaining a constant breathing rate is essential to stable outputs and any disturbance in flow rate near the mode (maximum concentration) induces a large number of spurious peaks in the exhalation. Experimental data without strict control of breathing flow rate showed a substantial amount of scatter. The measured results showed an improvement in scatter over the existing results. When compared with theoretical predictions from 1-D convective diffusion equation and other experiments, general characteristics of dispersion for several penetration depths showed a good agreement, but there exists some difference in absolute values, which is attributed to the difference in body conditions. Improvements are needed in the theory, especially in relation to correcting for the effect of breathing flow rate.

  • PDF

The Meaning of the 'Collective Intelligence' in the Transmedia Discourse (트랜스미디어 담론에 대한 집단지성론적 고찰)

  • Kim, Ki-Hong
    • Cartoon and Animation Studies
    • /
    • s.40
    • /
    • pp.261-285
    • /
    • 2015
  • Transmedia has become a significant theme in the media studies sector and an academic discourse itself since its wide diffusion through Henry Jenkins' seminar book Convergence Culture. The aim of this essay is to examine the authentic intention of the proposer to understand its profound meaning and value in the research discourse. Firstly, Transmedia has originated as a part of the convergence culture research context, which is an identical approach in the 'active audience' research tradition. Thus, a history of the research in terms of Birmingham Cultural Studies tradition and its implication is scrutinized. Secondly, in respect of Pierre Levy's 'collective intelligence' which made significant influence on the making of the Convergence Culture and Transmedia Storytelling, the meaing of the transmedia discourse is studied. Thirdly and finally, the implication of this concept as a critical theory or Critique in the Cultural Studies tradition, which has highlighted the importance of the revelation of the binary oppositions and structures of dominance/resistance, with the interpretation of the role of the collective intelligence idea in the transmedia discourse, is studied.