• Title/Summary/Keyword: A487

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Development of Optimal Blank Shape Design Program Using the Initial Velocity of Boundary Nodes (초기 속도법을 이용한 최적 블랭크 설계 프로그램의 개발)

  • 심현보;이상헌;손기찬
    • Transactions of Materials Processing
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    • v.11 no.6
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    • pp.487-494
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    • 2002
  • A new method of optimal blank shape design using the initial nodal velocity (INOV) has been proposed for the drawings of arbitrary shaped cups. With the given information of tool shape and the final product shape, corresponding initial blank shape has been found from the motion of boundary nodes. Although the sensitivity method, the past work of the present authors, has been proved to be excellent method to find optimal blank shapes, the method has a problem that a couple of deformation analysis is required at each design step and it also exhibits an abnormal behaviors in the rigid body rotation prevailing region. In the present method INOV, only a single deformation analysis per each design stage is required. Drawings of practical products as well as oil-pan, have been chosen as the examples. At every case the optimal blank shapes have been obtained only after a few times of modification without predetermined deformation path. The deformed shape with predicted optimal blank almost coincides with the target shape at every case. Through the investigation the INOV is found to be very effective in the arbitrary shaped drawing process design.

Waardenburg Syndrome Type IV De Novo SOX10 Variant Causing Chronic Intestinal Pseudo-Obstruction

  • Hogan, Anthony R.;Rao, Krishnamurti A.;Thorson, Willa L.;Neville, Holly L.;Sola, Juan E.;Perez, Eduardo A.
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.22 no.5
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    • pp.487-492
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    • 2019
  • Waardenburg syndrome (WS) type IV is characterized by pigmentary abnormalities, deafness and Hirschsprung's disease. This syndrome can be triggered by dysregulation of the SOX10 gene, which belongs to the SOX (SRY-related high-mobility group-box) family of genes. We discuss the first known case of a SOX10 frameshift mutation variant defined as c.895delC causing WS type IV without Hirschsprung's disease. This female patient of unrelated Kuwaiti parents, who tested negative for cystic fibrosis and Hirschsprung's disease, was born with meconium ileus and malrotation and had multiple surgical complications likely due to chronic intestinal pseudo-obstruction. These complications included small intestinal necrosis requiring resection, development of a spontaneous fistula between the duodenum and jejunum after being left in discontinuity, and short gut syndrome. This case and previously reported cases demonstrate that SOX10 gene sequencing is a consideration in WS patients without aganglionosis but with intestinal dysfunction.

Development and Evaluation of a Finding Meaning in Life CD Program for Life-esteemed Education of Older School-age Children (초등학생의 생명존중교육을 위한 삶의 의미발견 CD 프로그램 개발 및 효과)

  • Kang, Kyung-Ah;Kim, Shin-Jeong;Song, Mi-Kyung
    • The Journal of Korean Academic Society of Nursing Education
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    • v.17 no.3
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    • pp.487-500
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    • 2011
  • Purpose: The purpose of this study was to develop a finding meaning in life CD program about life-esteemed education and to identify the effect of the program. Methods: The life-esteemed education philosophy and the concepts of logotherapy were applied as a theoretical framework for this program. This program was developed through the process of planning, designing, developing, and evaluating with a content validity test. To identify the effect of the program, one experimental group design was applied to 54 students. Data were collected before the program started and one week and five weeks after the program finished. Results: The program was developed based on the students' needs and evaluation of the CD's content and consists of five periods: Dinosaur Park of Promise, Hill of Fragrance, Garden of Love, Forest of Acceptance, and My Lake. Each post-test score of knowledge, attitude, and practice on meaning of life was significantly higher than pretest scores. Conclusion: This program can be effective for life-esteemed education in elementary school students. Moreover, it is encouraged that the program will be utilized in more life-esteemed education for elementary school students.

Probabilistic seismic assessment of mega buckling-restrained braced frames under near-fault ground motions

  • Veismoradi, Sajad;Darvishan, Ehsan
    • Earthquakes and Structures
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    • v.15 no.5
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    • pp.487-498
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    • 2018
  • Buckling-restrained braces are passive control devices with high level of energy dissipation ability. However, they suffer from low post-yield stiffness which makes them vulnerable to severe ground motions, especially near-field earthquakes. Among the several methods proposed to improve resistance of BRB frames, mega-brace configuration can be a solution to increase frame lateral strength and stiffness and improve distribution of forces to prevent large displacement in braces. Due to the limited number of research regarding the performance of such systems, the current paper aims to assess seismic performance of BRB frames with mega-bracing arrangement under near-field earthquakes via a detailed probabilistic framework. For this purpose, a group of multi-story mega-BRB frames were modelled by OpenSEES software platform. In the first part of the paper, simplified procedures including nonlinear pushover and Incremental Dynamic Analysis were conducted for performance evaluation. Two groups of near-fault seismic ground motions (Non-pulse and Pulse-like records) were considered for analyses to take into account the effects of record-to-record uncertainties, as well as forward directivity on the results. In the second part, seismic reliability analyses are conducted in the context of performance based earthquake engineering. Two widely-known EDP-based and IM-based probabilistic frameworks are employed to estimate collapse potential of the structures. Results show that all the structures can successfully tolerate near-field earthquakes with a high level of confidence level. Therefore, mega-bracing configuration can be an effective alternative to conventional BRB bracing to withstand near-field earthquakes.

Thermal Decompostion of Methane Using Catalyst in a Fluidized Bed Reactor (유동층반응기에서 촉매를 이용한 메탄 열분해)

  • Jang, Hyun-Tae;Lee, Ji-Yun;Cha, Wang-Seog
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.2
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    • pp.487-492
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    • 2008
  • In this paper, Thermocatalytic decomposition of methane in a fluidized bed reactor (FBR) was studied. The technical approach is based on a single-step decomposition of methane over carbon catalyst in air/water vapor free environment. The factors affecting methane decompostion catalyst activity in methane decomposition reactions were examined. The fluidization phenomena in a gas-fluidized bed of catalyst was determined by the analysis of pressure fluctuation properties, and the results were confirmed with characteristics of methane decomposition. The effect of parameters on the H2 yield was examined for methane decompostion. The decompstion rate was affected by the fluidization quality such as mobility, U-Umf, carbon attrition, elutriation and effectiveness density of fluidization gas.

Estimable functions of fixed-effects model by projections (사영에 의한 모수모형의 추정가능함수)

  • Choi, Jae-Sung
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.3
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    • pp.487-494
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    • 2012
  • This paper discusses a method for getting a basis set of estimable functions of model parameters in a two-way fixed effects model. Since the fixed effects model has more parameters than those that can be estimated, model parameters are not estimable. So it is not possible to make inferences for nonestimable functions of parameters. When the assumed model of matrix notation is reparameterized by the estimable functions in a basis set, it also discusses how to use projections for the estimation of estimable functions.

Voltage Balance Control of Cascaded H-Bridge Rectifier-Based Solid-State Transformer with Vector Refactoring Technology in αβ Frame

  • Wong, Hui;Huang, Wendong;Yin, Li
    • Journal of Power Electronics
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    • v.19 no.2
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    • pp.487-496
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    • 2019
  • For a solid-state transformer (SST), some factors, such as signal delay, switching loss and differences in the system parameters, lead to unbalanced DC-link voltages among the cascaded H-bridges (CHB). With a control method implemented in the ${\alpha}{\beta}$ frame, the DC-link voltages are balanced, and the reactive power is equally distributed among all of the H-bridges. Based on the ${\alpha}{\beta}$ frame control, the system can achieve independent active current and reactive current control. In addition, the control method of the high-voltage stage is easy to implement without decoupling or a phase-locked loop. Furthermore, the method can eliminate additional current delays during transients and get the dynamic response rapidly without an imaginary current component. In order to carry out the controller design, the vector refactoring relations that are used to balance DC-link voltages are derived. Different strategies are discussed and simulated under the unbalanced load condition. Finally, a three-cell CHB rectifier is constructed to conduct further research, and the steady and transient experimental results verify the effectiveness and correctness of the proposed method.

An investigation on the maximum earthquake input energy for elastic SDOF systems

  • Merter, Onur
    • Earthquakes and Structures
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    • v.16 no.4
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    • pp.487-499
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    • 2019
  • Energy-based seismic design of structures has gradually become prominent in today's structural engineering investigations because of being more rational and reliable when it is compared to traditional force-based and displacement-based methods. Energy-based approaches have widely taken place in many previous studies and investigations and undoubtedly, they are going to play more important role in future seismic design codes, too. This paper aims to compute the maximum earthquake energy input to elastic single-degree-of-freedom (SDOF) systems for selected real ground motion records. A data set containing 100 real ground motion records which have the same site soil profiles has been selected from Pacific Earthquake Research (PEER) database. Response time history (RTH) analyses have been conducted for elastic SDOF systems having a constant damping ratio and natural periods of 0.1 s to 3.0 s. Totally 3000 RTH analyses have been performed and the maximum mass normalized earthquake input energy values for all records have been computed. Previous researchers' approaches have been compared to the results of RTH analyses and an approach which considers the pseudo-spectral velocity with Arias Intensity has been proposed. Graphs of the maximum earthquake input energy versus the maximum pseudo-spectral velocity have been obtained. The results show that there is a good agreement between the maximum input energy demands of RTH analysis and the other approaches and the maximum earthquake input energy is a relatively stable response parameter to be used for further seismic design and evaluations.

The Relationship Between Transformational Leadership, Prosocial Behavioral Intentions, and Organizational Performance

  • SALIM, Ansa;RAJPUT, Nahid Abdul Rauf
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.1
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    • pp.487-493
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    • 2021
  • This study examines the relationship between three major elements -Transformational leadership, Prosocial Behavioral Intentions, and Organizational Performance of full-time academics from different universities and colleges in Oman. A total of 322 full-time employees from different universities and technical colleges participated in an online survey and hardcopy survey. The data was collected using the primary data collection method. Structured scales were adopted for the study to include all the variables under study (Garcia-Morales et al., 2012; Baumsteiger et al., 2019). The adopted questionnaire was slightly modified to align with the circumstances of universities as well as colleges in Oman. A hypothesis is formed to find out the significant contributions among different sample categories. The correlation method was used to find out the relationship. It was evident from the result that there exists a significant relationship between major variables under study. This study reveals an important characteristic of transformational leadership towards prosocial behavioral intentions as it has a connection with organizational performance. There is limited research available to find out the relationship between prosocial behavioral intentions, transformational leadership, and organizational performance. This research focuses on identifying the antecedents and factors influencing organizations' performance efficiently and productively.

Surface Electrical Conductivity and Growth Behavior of Aluminum 3003 Oxide Film (알루미늄 3003 산화피막 성장 거동에 의한 표면 절연 특성 관찰)

  • Subin, Park;Chanyoung, Jeong
    • Corrosion Science and Technology
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    • v.21 no.6
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    • pp.487-494
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    • 2022
  • Anodizing is a typical electrochemical surface treatment method that can improve the corrosion and insulating properties of aluminum alloys. The anodization process can obtain a dense structure. It can be used to artificially grow the thickness of an anodization film. Aluminum 3003 alloy used in this study is the most commonly used alloy for batteries due to its high strength and excellent formability as well as its weldability and corrosion resistance. Aluminum 3003 alloy was anodized at 0 ℃ with 0.3 M oxalic acid at 20 V, 40 V, or 60 V for 1 hour, 6 hours, or 12 hours. As a result of analyzing the composition of each specimen with an Energy Dispersive Spectrometer (EDS), aluminum was converted into an oxide film. The thickness of the formed anodization film increased when the applied voltage and anodization time increased. High corrosion potential values and low corrosion current density values were observed for the thickest oxide layer. The anodization film formed by anodization acted as a protective layer. The electrical resistance increased as the applied voltage and anodization time increased.