• Title/Summary/Keyword: Self-organized

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Cyanide Degradation from Plating Wastewater Using Iron Oxide Nanocomposite Layer (산화철 나노구조박막 이용한 도금폐수내의 시안제거)

  • Jang, Jun-Won;Kim, Hye-Ran;Lim, Hyeong-Seok;Park, Jae-Woo
    • Journal of Korean Society on Water Environment
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    • v.30 no.3
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    • pp.292-297
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    • 2014
  • We synthesized the self-organized nanoporous oxide with potentiostatic anodization of iron foil. The iron oxide nanocomposite (INCs) were fabricated in 1M $Na_2SO_4$ containing 0.5wt% NaF electrolyte holding the potential at 20, 40 and 60 V for 20min, respectively. Field Emmision Scanning Electron Microscopy (FESEM) and X-ray Diffractometer (XRD) were used to evaluate the micromorphology and crystalline structure of INC film. Also, this study was performed to evaluate the fenton reaction using INC film with hydroperoxide for degradation of cyanide dissolved in water. In case of INC-40V in the presence of $H_2O_2$ 3%, the first-order rate constant was found to be $1.7{\times}10^{-2}min^{-1}$, and indicated to be $1.2{\times}10^{-2}min^{-1}$ on commercial hematite powder. This result is shown to be good performance enough to replace the powder type for treatment of wastewater.

O&M Evaluating for Sewage Treatment Plants in China as a Developing Country (개발도상국 중국의 하수처리장 운영.관리능 평가)

  • Kim, Kwon-Youn;Moon, Yong-Taik;Kim, Hong-Suck;Kim, Ji-Yeon
    • Journal of environmental and Sanitary engineering
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    • v.21 no.3 s.61
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    • pp.27-36
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    • 2006
  • For the last 20 years, China has transformed itself from a rural economy into an industrial giant, averaging over 8 % annual growth of GDP. Unfortunately, this rapid growth has taken a significant toll on its natural resource base as well, particularly water resources. These problems have been exacerbated by a low level of sewage treatment technology and by the operating and maintenance (O&M). In case of urban areas, most big cities in China have a well functioning sewage system comprised of sewers and sewage treatment plants (STPs). Nevertheless, the existing STPs are still not capable of properly treating the sewage, both quantitatively and qualitatively. The rural areas in China cover a large land, with two-third of the nation's population. The low educational and poor economic states make it hard to process self-protection and management. In the surveyed area in Henan, there was no STPs put into use as of 2004, and the sewer lines are not well organized. The big issue for the currently planned STPs is the collection system not included in the plans.

Energetics of adsorptions on fcc(111) and binary system; An application of the modified embedded atom method

  • Hy. Shin;J. Seo;Kim, J.S.
    • Proceedings of the Korean Vacuum Society Conference
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    • 1999.07a
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    • pp.188-188
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    • 1999
  • The embedded atom method (EAM) of Daw and Baskes as a semiempirical method, has been successfully applied to the fcc or nearly filled d-band transition metals due to its computational feasibility and its methodological simplicity. Then Baskes modified the EAM (MEAM) to include directional bonding and applied it to metals, semiconductors, and diatomic gases, all of which have different types of bondings. Here, we present a detailed study of the energetics of adsorption on the fcc(111) surfaces and binary system within the framework of MEAM. In adsorption on fcc(111) surfaces, there are two energetically favored sites, so called, fcc site and hcp site, which may trigger stacking fault in the growth of films and might switch growth mode between 3D growth and layer by layer growth. We scrutinized the role of the hcp sites, which would offer dynamic growth pathways although the dynamics are not yet clear within the limited experimental resolution. Featuring these transient motions in the atomic level should contribute to the understanding the growth mechanisms on fcc(111) surface. And we also applied MEAM for initial stage energetics at the Cr coverage of sub- monolayer on W(110). We hope that recently observed extraordinary growth behavior at the Cr coverage of 0.7 monolayer, self- organized nano-scale lines, can be resolved in this MEAM binary system calculation.

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A University Hospital Employee's Knowledge, Attitude Toward, and Practice of Hospital Infectious Wastes (대학병원 종사자의 감염성 폐기물에 대한 지식, 태도 및 실천)

  • You, Hye-Sook;Yang, In-Hwa;So, Hyang-Sook
    • Korean Journal of Adult Nursing
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    • v.21 no.1
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    • pp.53-61
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    • 2009
  • Purpose: This study was to provide baseline data to arrange systematic management for the infectious waste. Methods: This data was collected by self-reported questionnaires from a total of 419 subjects, ie nurses, nurse's aides and laboratory technicians working at a university hospital located in G city. The collected data were analyzed by t-test or ANOVA, Tukey test, Pearson's correlation, and multiple regression analysis using SPSS/WIN 12.0. Results: The knowledge of the infectious waste was statistically significant in type of staff and level of education. Attitude was statistically significant in type of staff, age group, level of education, working period, and marital status. And also the practice of the subject was statistically significant in type of staff, age group, education level, the working periods, and marital status. There was positive association between attitude and practice(r=.63, ${\rho}$< 001). By means of multiple stepwise regression analysis, total variance explained by the attitude towards infectious wastes, single employee, and the working periods less than ten years was 44% of the practice of infectious wastes. Conclusion: An educational program focusing on strategy to change employee's attitude can be effective for building a well-organized management system.

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Factors That Influence the Intentions to Revisit Korea of Vietnamese Tourists

  • NGUYEN, Xuan Truong
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.4
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    • pp.247-258
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    • 2020
  • The study investigates the influences of different factors on revisit intention to Korea of Vietnamese tourists. A mixed-method including qualitative and quantitative methodologies were utilized. A focus group of 9 experts was carried out for reviewing and exploring different factors and the conceptual model. An in-depth interview with 19 participants was developed with an aim to develop and correct measurement items. The conceptual model was tested and developed using data collected by a questionnaire, from a sample of 473 respondents, who have visited Korea by both electronic and paper surveys with non-probability and convenience sampling techniques. The questionnaire in this research applied a 5-point Likert scale and was distributed both electronically using Google form and by questionnaire paper. The Bootstrap model was used for estimating the model parameters for retesting the reliability of the estimates. Factor analysis and Structural Equation Modelling are employed to analyze the data. Results showed that 427 tourists traveling by groups organized by travel companies and 46 tourists traveling on their own. The reliability, tangibility, empathy, and assurance had influences on tourists' intention to revisit a destination, especially through satisfaction mediating construct. Destination image, self-congruity, and the emergence of Hallyu had influences intension revisit through attitude and tourist motivation.

How Facebook Functions in a Social Movement: An Examination Using the Web Mining Approach

  • Cao, Wenny;Cheong, Angus;Li, Zizi
    • Asian Journal for Public Opinion Research
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    • v.1 no.4
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    • pp.268-291
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    • 2014
  • Social media is becoming more and more important in social movements. This study, adopting the web mining approach, attempts to investigate how social media, Facebook in particular, functioned in the "May 25 Protest" and the "May 27 Protest", two movements which broke out in Macao on 25 and 27 May 2014, respectively, against the Retirement Package Bill. In the two protests, Macao residents deployed Facebook to share information and motivated people's participation. Twelve events (181,106 people invited) and 36 groups/pages (41,266 members) related on Facebook were examined. Results showed that the information flow on Facebook fluctuated in accordance with the event development in reality. Multiple patterns of manifestation, such as video of adopted news or songs, designed profile (protest icon), original ironic pictures, self-organized clubs by undergraduates and white T-shirts as a symbol, among others, appeared online and interacted with offline actions. It was also found that social media assisted the information diffusion and provided persuasive reasons for netizens to join the movement. Social media helped to expand movement influence in providing a platform for diversified performances for actions taken in a protest, which could express and develop core and consistent movement repertoire.

Experience of Role Adaptation from Nurse to Member of the Nursing Faculty (간호사에서 교수로의 역할적응 경험)

  • Park, Kwang-Ok;Kim, Jong Kyung;Yu, Mi
    • Journal of Korean Academy of Nursing
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    • v.46 no.2
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    • pp.168-182
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    • 2016
  • Purpose: The purpose of this qualitative study was to evaluate the experience of role adaptation from nurse to member of the nursing faculty. Methods: Data were collected from 13 members of a nursing faculty through in-depth interviews. The main question asked was "Could you describe your experience from being a nurse to becoming a member of the nursing faculty?" Qualitative data from the field and transcribed notes were analyzed using Strauss and Corbin's grounded theory methodology. Results: The core experiential category of role adaptation from nurse to member of the nursing faculty was 'striving for survival from culture shock'. The participants used the following three interactional strategies: 'recognizing everything and entering the school environment', 'self-reflection on being a professor and integration of experiences', and 'finding a way of adapting'. Conclusion: The participants tried to adapt to life as a professor and reflected on and integrated their experiences into their new life on the faculty. College faculty need to understand the impact of changes and challenges faced by new professors during role adaptation and to support this adaptation through mentorship and organized orientation programs.

Design of Energy Efficient MAC protocol for Wireless Sensor Networks (무선센서네트웨크를 위한 에너지 효율적인 MAC 프로토콜 설계)

  • Kang, Hyun-Joong;Lim, Hyuk-Jin;Ju, Hui-Dong;Lee, Myung-Hun;Yoe, Hyun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.10a
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    • pp.445-448
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    • 2007
  • In this paper, we present an energy efficient MAC protocol for WSN(Wireless Sensor Networks). WSN is a self organized network to collect environmental data by small size sensor nodes which consist of wireless communication unit, MPU, sensing module etc.. In the WSN, such sensor nodes operate with limited energy and how efficient use this network has been debated recently. Therefore. we present a method to consume energy equaly by modifying existing S-MAC for efficient scheduling and data transmission.

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A Study on Kohenen Network based on Path Determination for Efficient Moving Trajectory on Mobile Robot

  • Jin, Tae-Seok;Tack, HanHo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.10 no.2
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    • pp.101-106
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    • 2010
  • We propose an approach to estimate the real-time moving trajectory of an object in this paper. The object's position is obtained from the image data of a CCD camera, while a state estimator predicts the linear and angular velocities of the moving object. To overcome the uncertainties and noises residing in the input data, a Extended Kalman Filter(EKF) and neural networks are utilized cooperatively. Since the EKF needs to approximate a nonlinear system into a linear model in order to estimate the states, there still exist errors as well as uncertainties. To resolve this problem, in this approach the Kohonen networks, which have a high adaptability to the memory of the inputoutput relationship, are utilized for the nonlinear region. In addition to this, the Kohonen network, as a sort of neural network, can effectively adapt to the dynamic variations and become robust against noises. This approach is derived from the observation that the Kohonen network is a type of self-organized map and is spatially oriented, which makes it suitable for determining the trajectories of moving objects. The superiority of the proposed algorithm compared with the EKF is demonstrated through real experiments.

Measurement of Effective Refractive Index of Anodic Aluminum Oxide Using a Prism Coupler

  • Gong, Su-Hyun;Cho, Y.H.;Stolz, Arnaud;Gokarna, Anisha;Dogheche, Elhadj;Ryu, Sang-Wan
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.195-195
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    • 2010
  • In recent years, Anodic aluminum oxide(AAO) has become popular and attractive materials. It can be easily fabricated and self-organized pore structures. It has been widely used as a biosensor membrane, photonic crystal for optical circuit and template for nanotube growth etc. In previous papers, the theory was developed that AAO shows anisotropic optical properties, since it has anisotropic structure with numerous cylindrical pores. It gives rise to the anisotropy of the refractive index called as birefringence. It can be used as conventional polarizing elements with high efficiency and low cost. Therefore, we would like to compare the theory and experimental results in this study. One method which can measure effective refractive index of thin film is the prism coupling technique. It can give accurate results fast and simply. Furthermore, we can also measure separately the refractive index with different polarization using polarization of the laser (TE mode and TM mode). We calculated the effective refractive index with effective medium approximations (EMAs) by pore size in the SEM image. EMAs are physical models that describe the macroscopic system as the homogeneous and typical method of all mean field theories.

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