• Title/Summary/Keyword: Dynamic approach

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Analyzing the Adoption of Online Payment using System Dynamics (시스템 다이내믹스를 이용한 온라인 지불결제 서비스 수용에 관한 분석)

  • Mu, Hong-Lei;Lee, Young-Chan
    • Journal of Industrial Convergence
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    • v.16 no.1
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    • pp.1-14
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    • 2018
  • Online retail business has provided internet-based companies with the opportunities to be connected with online customers from all over the world. However, many online customers do not complete their transactions online even if they have already choose what they want because they perceive online payment service is risky or perceive difficulty of paying online. A large body of researchers have examined the important variables that influence online payment, however, these studies can hardly predict the future development tendency after five or ten years since the environment of online market changes so fast more than ever. Therefore, the purpose of this study is to examine the importance of factors affecting online payment and to provide long term dynamic decision making model for third-party payment companies and online service providers. To serve the purpose, this study used system dynamics approach to develop a model of online payment adoption and to simulate various development paths for ten years. The analysis results show that the number of online payment customers increase continuously in ten years, and service quality, system quality, and effort expectancy are key factors for customers to pay online.

Experience of nursing students about the barriers to patient education: a qualitative study in Iran

  • Abbasi, Mohammad;Rabiei, Leili;Masoudi, Reza
    • Korean journal of medical education
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    • v.30 no.4
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    • pp.327-337
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    • 2018
  • Purpose: Patient education is a dynamic and continuous process that should be implemented during the entire time of hospital stay and even afterward. Studies have shown the typically poor quality of patient education in Iran and its failure to convey the required knowledge and skills to patients. The purpose of this study was to survey the experience of nursing students in regard to the challenges of patient education in hospitals. Methods: This qualitative study was conducted using the conventional qualitative content analysis approach on a sample of 21 undergraduate nursing students (4th semester and beyond), which was drawn from the Qom Nursing and Midwifery School through purposive sampling with maximum variation. Data were collected through semi-structured interviews conducted over a period of 45 to 75 minutes, and were analyzed using the conventional qualitative content analysis. Results: Results were derived from the experiences of 21 nursing students (nine males, 12 females) about the research subject. The primary themes identified in the study were the student-related, patient-related, instructor-related, education environment-related, and curriculum-related barriers to patient educations. Conclusion: Participants believed that patient education in Iranian hospitals is faced with many challenges. Nursing instructors and curriculum planners should ensure more emphasis on patient education at the initial semesters of nursing education curriculum and make sure that it is included in the evaluation of students. Hospital officials should provide a dedicated education environment with suitable facilities, tools, and atmosphere for patient education. Also, special education programs need to be developed for less educated patients.

Efficient parameters to predict the nonlinear behavior of FRP retrofitted RC columns

  • Mahdavi, Navideh;Ahmadi, Hamid Reza;Bayat, Mahmoud
    • Structural Engineering and Mechanics
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    • v.70 no.6
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    • pp.703-710
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    • 2019
  • While fiber-reinforced plastic (FRP) materials have been largely used in the retrofitting of concrete buildings, its application has been limited because of some problems such as de-bonding of FRP layers from the concrete surface. This paper is the part of a wide experimental and analytical investigation about flexural retrofitting of reinforced concrete (RC) columns using FRP and mechanical fasteners (MF). A new generation of MF is proposed, which is applicable for retrofitting of RC columns. Furthermore, generally, to evaluate a retrofitted structure the nonlinear static and dynamic analyses are the most accurate methods to estimate the performance of a structure. In the nonlinear analysis of a structure, accurate modeling of structural elements is necessary for estimation the reasonable results. So for nonlinear analysis of a structure, modeling parameters for beams, columns, and beam-column joints are essential. According to the concentrated hinge method, which is one of the most popular nonlinear modeling methods, structural members shall be modeled using concentrated or distributed plastic hinge models using modeling parameters. The nonlinear models of members should be capable of representing the inelastic response of the component. On the other hand, in performance based design to make a decision about a structure or design a new one, numerical acceptance should be determined. Modeling parameters and numerical acceptance criteria are different for buildings of different types and for different performance levels. In this paper, a new method was proposed for FRP retrofitted columns to avoid FRP debonding. For this purpose, mechanical fasteners were used to achieve the composite behavior of FRP and concrete columns. The experimental results showed that the use of the new method proposed in this paper increased the flexural strength and lateral load capacity of the columns significantly, and a good composition of FRP and RC column was achieved. Moreover, the modeling parameters and acceptance criteria were presented, which were derived from the experimental study in order to use in nonlinear analysis and performance-based design approach.

Estimation of wind pressure coefficients on multi-building configurations using data-driven approach

  • Konka, Shruti;Govindray, Shanbhag Rahul;Rajasekharan, Sabareesh Geetha;Rao, Paturu Neelakanteswara
    • Wind and Structures
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    • v.32 no.2
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    • pp.127-142
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    • 2021
  • Wind load acting on a standalone structure is different from that acting on a similar structure which is surrounded by other structures in close proximity. The presence of other structures in the surrounding can change the wind flow regime around the principal structure and thus causing variation in wind loads compared to a standalone case. This variation on wind loads termed as interference effect depends on several factors like terrain category, geometry of the structure, orientation, wind incident angle, interfering distances etc., In the present study, a three building configuration is considered and the mean pressure coefficients on each face of principle building are determined in presence of two interfering buildings. Generally, wind loads on interfering buildings are determined from wind tunnel experiments. Computational fluid dynamic studies are being increasingly used to determine the wind loads recently. Whereas, wind tunnel tests are very expensive, the CFD simulation requires high computational cost and time. In this scenario, Artificial Neural Network (ANN) technique and Support Vector Regression (SVR) can be explored as alternative tools to study wind loads on structures. The present study uses these data-driven approaches to predict mean pressure coefficients on each face of principle building. Three typical arrangements of three building configuration viz. L shape, V shape and mirror of L shape arrangement are considered with varying interfering distances and wind incidence angles. Mean pressure coefficients (Cp mean) are predicted for 45 degrees wind incidence angle through ANN and SVR. Further, the critical faces of principal building, critical interfering distances and building arrangement which are more prone to wind loads are identified through this study. Among three types of building arrangements considered, a maximum of 3.9 times reduction in Cp mean values are noticed under Case B (V shape) building arrangement with 2.5B interfering distance. Effect of interfering distance and building arrangement on suction pressure on building faces has also been studied. Accordingly, Case C (mirror of L shape) building arrangement at a wind angle of 45º shows less suction pressure. Through this study, it was also observed that the increase of interfering distance may increase the suction pressure for all the cases of building configurations considered.

Mid-course Trajectory Optimization for Boost-Glide Missiles Based on Convex Programming (컨벡스 프로그래밍을 이용한 추진-활공 유도탄의 중기궤적 최적화)

  • Kwon, Hyuck-Hoon;Hong, Seong-Min;Kim, Gyeong-Hun;Kim, Yoon-Hwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.1
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    • pp.21-30
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    • 2021
  • Mid-course trajectory of the missiles equipped with seeker should be designed to detect target within FOV of seeker and to maximize the maneuverability at the point of transition to terminal guidance phase. Because the trajectory optimization problems are generally hard to obtain the analytic solutions due to its own nonlinearity with several constraints, the various numerical methods have been presented so far. In this paper, mid-course trajectory optimization problem for boost-glide missiles is calculated by using SOCP (Second-Order Cone Programming) which is one of convex optimization methods. At first, control variable augmentation scheme with a control constraint is suggested to reduce state variables of missile dynamics. And it is reformulated using a normalized time approach to cope with a free final time problem and boost time problem. Then, partial linearization and lossless convexification are used to convexify dynamic equation and control constraint, respectively. Finally, the results of the proposed method are compared with those of state-of-the-art nonlinear optimization method for verification.

A Study on the Factors for Leveling the Playing Field in Trade Negotiations between the Republic of Korea and the United States: -A Political-Economic Approach to Textile Negotiations(1969 through 1972)- (한-미 통상협상에서의 균등화전략 요소에 관한 연구 - 한-미 섬유협상(1969-1972년)에 대한 정치경제학적 접근 -)

  • Kim, Bong-Hyun;Kwak, Ro-Sung
    • International Area Studies Review
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    • v.13 no.2
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    • pp.550-572
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    • 2009
  • This paper investigates the textile negotiations between Korea and the U.S. which Korea, as a weaker party in the bilateral trade negotiation, was recognized as making a good performance by Odell(1985). Using the documents of Korean governments at the time - Ministry of Foreign Affairs and the Ministry of Commerce and Industry - telegrams and reports from various sources the paper picks a leveling factor during the negotiations. In the paper, we used a dynamic concept of power for describing the negotiating power, and showed Korea succeeded in making the negotiation symmetric using the Special Cooperative Relationship(SCR) as one of the most conspicuous leveling factors during the textile negotiations with the U.S. The paper contributes to finding the factors that can be used in the negotiations with power asymmetry as a leveling factor for weaker country. Also, based on the findings from the paper, future negotiators can get insights on which factors be used, and how to use those factors for leveling the negotiations with a stronger counterpart.

The Rhetoric of Revelation and the Politics of Prophecy: A Reading of Ginsberg's "Howl" and "Kaddish" (계시의 수사와 정치학-긴즈버그의 「울부짖음」과 「캐디쉬」를 중심으로)

  • Son, Hyesook
    • Journal of English Language & Literature
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    • v.57 no.4
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    • pp.529-552
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    • 2011
  • My essay aims at reading Ginsberg's "Howl" and "Kaddish" with the concept of 'shaman-prophet-poet' to illustrate the dynamic relationship between his poetics and radical politics. Throughout his widely-ranging career, Ginsberg represents himself as a poet-prophet and commands a typical rhetoric of revelation as a way of decentering Cold War orthodoxies. While well aware of the oppressive and pervasive power of the dominant post-war ideologies, he adopts 'madness' to oppose conventional political, social, and religious institutions; by way of entering into the madness of this world and actively engaging himself as a victim, he can finally heal both himself and the world. This dual function of poet characterizes his rhetoric of revelation, but it doesn't appeal to the mainstream of American critical ideology where the post-structural approach to language and subject gives a skeptical look at any account of active human agency and humanistic belief in the possibility of language. In "Howl" and "Kaddish," Ginsburg persuades the reader of the truth of his own vision through the convincing and realistic portraits of his contemporaries as well as his own mother and family. Different from his visionary predecessors such as Emerson and Whitman, Ginsberg knew the difficulty of a negotiation between history and divine vision, and attempted to imbricate his family, friends, and even the larger social and political units within his visionary experience in order to avoid naive idealism, escapism, or solipsism. Furthermore, he deconstructs the Logos of Western prophecy and replaces it with the groundless identity and the nontheistic epistemology of Buddhism, which, in turn, leads to emptying his powerful language of absolutist meaning and prevents his prophecy from becoming re-reified as divine essentialism. Ginsberg's idea of poet and poem revitalizes the skeptical view on language and literary representation of our contemporary critical community which is unwilling to engage the experimental scope of his radical prophecy.

An Effective Anonymization Management under Delete Operation of Secure Database (안전한 데이터베이스 환경에서 삭제 시 효과적인 데이터 익명화 유지 기법)

  • Byun, Chang-Woo;Kim, Jae-Whan;Lee, Hyang-Jin;Kang, Yeon-Jung;Park, Seog
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.17 no.3
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    • pp.69-80
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    • 2007
  • To protect personal information when releasing data, a general privacy-protecting technique is the removal of all the explicit identifiers, such as names and social security numbers. De-identifying data, however, provides no guarantee of anonymity because released information can be linked to publicly available information to identify them and to infer information that was not intended for release. In recent years, two emerging concepts in personal information protection are k-anonymity and $\ell$-diversity, which guarantees privacy against homogeneity and background knowledge attacks. While these solutions are signigicant in static data environment, they are insufficient in dynamic environments because of vulnerability to inference. Specially, the problem appeared in record deletion is to deconstruct the k-anonymity and $\ell$-diversity. In this paper, we present an approach to securely anonymizing a continuously changeable dataset in an efficient manner while assuring high data quality.

Design and Implementation of Web-browser based Malicious behavior Detection System(WMDS) (웹 브라우저 기반 악성행위 탐지 시스템(WMDS) 설계 및 구현)

  • Lee, Young-Wook;Jung, Dong-Jae;Jeon, Sang-Hun;Lim, Chae-Ho
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.22 no.3
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    • pp.667-677
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    • 2012
  • Vulnerable web applications have been the primary method used by the attackers to spread their malware to a large number of victims. Such attacks commonly make use of malicious links to remotely execute a rather advanced malicious code. The attackers often deploy malwares that utilizes unknown vulnerabilities so-called "zero-day vulnerabilities." The existing computer vaccines are mostly signature-based and thus are effective only against known attack patterns, but not capable of detecting zero-days attacks. To mitigate such limitations of the current solutions, there have been a numerous works that takes a behavior-based approach to improve detection against unknown malwares. However, behavior-based solutions arbitrarily introduced a several limitations that made them unsuitable for real-life situations. This paper proposes an advanced web browser based malicious behavior detection system that solves the problems and limitations of the previous approaches.

Lifetime seismic performance assessment of high-rise steel-concrete composite frame with buckling-restrained braces under wind-induced fatigue

  • Liu, Yang;Li, Hong-Nan;Li, Chao;Dong, Tian-Ze
    • Structural Engineering and Mechanics
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    • v.77 no.2
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    • pp.197-215
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    • 2021
  • Under a severe environment of multiple hazards such as earthquakes and winds, the life-cycle performance of engineering structures may inevitably be deteriorated due to the fatigue effect caused by long-term exposure to wind loads, which would further increase the structural vulnerability to earthquakes. This paper presents a framework for evaluating the lifetime structural seismic performance under the effect of wind-induced fatigue considering different sources of uncertainties. The seismic behavior of a high-rise steel-concrete composite frame with buckling-restrained braces (FBRB) during its service life is systematically investigated using the proposed approach. Recorded field data for the wind hazard of Fuzhou, Fujian Province of China from Jan. 1, 1980 to Mar. 31, 2019 is collected, based on which the distribution of wind velocity is constructed by the Gumbel model after comparisons. The OpenSees platform is employed to establish the numerical model of the FBRB and conduct subsequent numerical computations. Allowed for the uncertainties caused by the wind generation and structural modeling, the final annual fatigue damage takes the average of 50 groups of simulations. The lifetime structural performance assessments, including static pushover analyses, nonlinear dynamic time history analyses and fragility analyses, are conducted on the time-dependent finite element (FE) models which are modified in lines with the material deterioration models. The results indicate that the structural performance tends to degrade over time under the effect of fatigue, while the influencing degree of fatigue varies with the duration time of fatigue process and seismic intensity. The impact of wind-induced fatigue on structural responses and fragilities are explicitly quantified and discussed in details.