• Title/Summary/Keyword: Short turn

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A Method for Indentifying Broken Rotor Bar and Stator Winding Fault in a Low-voltage Squirrel-cage Induction Motor Using Radial Flux Sensor

  • Youn, Young-Woo;Hwang, Don-Ha;Sun, Jong-Ho;Kang, Dong-Sik
    • Journal of Electrical Engineering and Technology
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    • v.6 no.5
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    • pp.666-670
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    • 2011
  • In this paper, a method for detecting broken rotor bar and stator winding fault in a low voltage squirrel-case induction motor using an air-gap flux variation analysis is proposed to develop a simple and low cost diagnosis technique. To measure the leakage flux in radial direction, a radial flux sensor is designed as a search coil and installed between stator slots. The proposed method is able to identify two kinds of motor faults by calculating load condition of motors and monitoring abnormal signals those are related with motor faults. Experimental results obtained on 7.5kW three-phase squirrel-cage induction motors are discussed to verify the performance of the proposed method.

Genetic and Environmental Control of Salmonella Invasion

  • Altier, Craig
    • Journal of Microbiology
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    • v.43 no.spc1
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    • pp.85-92
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    • 2005
  • An early step in the pathogenesis of non-typhoidal Salmonella species is the ability to penetrate the intestinal epithelial monolayer. This process of cell invasion requires the production and transport of secreted effector proteins by a type III secretion apparatus encoded in Salmonella pathogenicity island I (SPI-1). The control of invasion involves a number of genetic regulators and environmental stimuli in complex relationships. SPI-1 itself encodes several transcriptional regulators (HilA, HilD, HilC, and InvF) with overlapping sets of target genes. These regulators are, in turn, controlled by both positive and regulators outside SPI-1, including the two-component regulators BarA/SirA and PhoP/Q, and the csr post-transcriptional control system. Additionally, several environmental conditions are known to regulate invasion, including pH, osmolarity, oxygen tension, bile, $Mg^{2+}$ concentration, and short chain fatty acids. This review will discuss the current understanding of invasion control, with emphasis on the interaction of environmental factors with genetic regulators that leads to productive infection.

iPSC-Derived Natural Killer Cells for Cancer Immunotherapy

  • Karagiannis, Peter;Kim, Shin-Il
    • Molecules and Cells
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    • v.44 no.8
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    • pp.541-548
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    • 2021
  • The discovery of human pluripotent stem cells (PSCs) at the turn of the century opened the door to a new generation of regenerative medicine research. Among PSCs, the donors available for induced pluripotent stem cells (iPSCs) are greatest, providing a potentially universal cell source for all types of cell therapies including cancer immunotherapies using natural killer (NK cells). Unlike primary NK cells, those prepared from iPSCs can be prepared with a homogeneous quality and are easily modified to exert a desired response to tumor cells. There already exist several protocols to genetically modify and differentiate iPSCs into NK cells, and each has its own advantages with regards to immunotherapies. In this short review, we detail the benefits of using iPSCs in NK cell immunotherapies and discuss the challenges that must be overcome before this approach becomes mainstream in the clinic.

"Sally's Choice": Elizabeth Stoddard's Unique Story of the Civil War (「샐리의 선택」: 엘리자베스 스토다드의 독특한 남북 전쟁 이야기)

  • Jang, Ki Yoon
    • American Studies
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    • v.44 no.1
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    • pp.113-135
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    • 2021
  • The Civil War is widely accepted as the single most meaningful event in American history that overcame the most fatal crisis of internal division of the nation with much success. That meaningfulness in turn glorifies the North's triumph over the South and justifies hierarchical differences between the two. Yet, as shown in the studies of Civil War literature, such glorification and justification relies too much on the North-centered historical paradigm. This essay aims to offer a way of rectifying it by examining a short story by one of the persistently obscured writers of the period: Elizabeth Stoddard. The essay follows the cue of Alice Fahs's cultural-studies methodology of using popular wartime periodicals as the main resource of the war literature, and reads Stoddard's "Sally's Choice" as one of the examples that expose the hegemonic bias inside the North-directed discourse of the time. This essay is expected to demonstrate the necessity of expanding and deepening our conception of 'literature,' 'the Civil War,' and 'Civil War literature' in an ever-flexible and ever-changeable manner.

The Impact of Digital Video Marketing within the Context of TikTok in the Tourist Industry in Vietnam

  • Eun-Mi Lee;Pham Thi Quynh Anh
    • International Journal of Internet, Broadcasting and Communication
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    • v.16 no.3
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    • pp.56-63
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    • 2024
  • Tourism is a crucial sector in Vietnam, benefiting significantly from the surge in short video content and the rapid growth of TikTok, a popular new social media platform with a large daily user base. This study explores how digital video marketing factors on TikTok, such as perceived enjoyment, credibility, interactivity, and subtitling, affect users' awareness of destinations and their intention to visit. The findings indicate that perceived enjoyment, interactivity, and subtitling positively influence destination awareness, which in turn impacts the visit intention of TikTok users.

ISC-STS Proposal for Reliability Improvement of Communication System's (통신용 전원공급 신뢰성 증진을 위한 ISC-STS 제안)

  • Jung, Hyun-Chul;Hyun, Dong-Seok
    • The Transactions of the Korean Institute of Power Electronics
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    • v.13 no.5
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    • pp.383-390
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    • 2008
  • The SCR in Static Transfer Switch (STS) is used for reliability improvement of important load's power supply in industry field. However an average of 2% fault in thyristor(SCR) occurs, so that the attached mechanical switch is paralleled with SCR's both end points and SCR operates only during the $12{\sim}208$[mS] before operation of the mechanical switch. Also, an ISC (Ideal State Conditioning Interlock Device) - STS system that two power supply paths may not be thrown at the same time is developed to remove the overlap section perfectly when a short or earth fault is generated in one system. This method has reduced the fault rate remarkably through the reduction of SCR's fatigue degree by using SCR in conversion operation corresponding to 0.89 times a year. Also, in case of fault generations, it does not affect to supply power to the load, therefore it contributes to the promotion of reliability in the power supply.

Flow Visualization of Oscillation Characteristics of Liquid and Vapor Flow in the Oscillating Capillary Tube Heat Pipe

  • Kim, Jong-Soo;Kim, Ju-Won;Jung, Hyun-Seok
    • Journal of Mechanical Science and Technology
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    • v.17 no.10
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    • pp.1507-1519
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    • 2003
  • The two-phase flow patterns for both non-loop and loop type oscillating capillary tube heat pipes (OCHPs) were presented in this study. The detailed flow patterns were recorded by a high-speed digital camera for each experimental condition to understand exactly the operation mechanism of the OCHP. The design and operation conditions of the OCHP such as turn number, working fluid, and heat flux were varied. The experimental results showed that the representative flow pattern in the evaporating section of the OCHP was the oscillation of liquid slugs and vapor plugs based on the generation and growth of bubbles by nucleate boiling. As the oscillation of liquid slugs and vapor plugs was very speedy, the flow pattern changed from the capillary slug flow to a pseudo slug flow near the annular flow. The flow of short vapor-liquid slug-train units was the flow pattern in the adiabatic section. In the condensing section, it was the oscillation of liquid slugs and vapor plugs and the circulation of working fluid. The oscillation flow in the loop type OCHP was more active than that in the non-loop type OCHP due to the circulation of working fluid in the OCHP. When the turn number of the OCHP was increased, the oscillation and circulation of working fluid was more active as well as forming the oscillation wave of long liquid slugs and vapor plugs in the OCHP. The oscillation flow of R-142b as the working fluid was more active than that of ethanol and the high efficiency of the heat transfer performance of R -142b was achieved.

The Kinematic Analysis of the Hand spring forward and Salto forward straight with 3/2 Turn on the Vault (도마 손 짚고 몸펴 앞 공중 돌아 540도 비틀기의 운동학적 분석)

  • Yeo, Hong-Chul;Yoon, Hee-Joong;Ryu, Ji-Seon;Jung, Chul-Jung
    • Korean Journal of Applied Biomechanics
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    • v.13 no.3
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    • pp.47-65
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    • 2003
  • The purpose of this study was to investigate the differences of the kinematical and the kinetical factors that calculated from preflight to postflight of salto forward straight 3/2 turn motion between skitters and less-skitters. four S-VHS video cameras operating at 60Hz were used to record the performances. five elite male gymnasts were participated in this study as subjects. three-dimensional coordinates of 20 body landmarks during each trial were collected using a Direct Linear Transformation method. The digitized body landmarks were smoothed using a Butterworth second order with low pass digital filter and a cutoff frequency of 10Hz. 1. A skitter, got a high score for performance, showed shorter time and faster horizontal velocity than a less-skitter at the board contact. also, a skitter extended quickly his knee and hip joint after contacting board for preflight phase. 2. A skitter revealed faster time and horizontal velocity the vault from taking off board than a less-skiller. A skitter took a long time and high distance to get the vertical peak compared with a less-skiller. 3. For the second phase, a skitter, who executes the most optimal motions among the subjects, displayed a long flight time, a high height, and a far flight distance as well as maintaining consistent horizontal speed even at the peak of post flight. On the other side, a less-scorer displayed a slow vertical velocity, distance and a short time at the point of take-off from vault as well as low height at the peak of post flight.

Characteristic analysis of the current type high frequency resonant DC - DC converter (전류형 고주파 공진 DC-DC 컨버터의 특성해석)

  • 황계호;남승식;김동희;심광열;안항목
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.17 no.1
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    • pp.86-93
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    • 2003
  • This paper describes that the resonant tank type DC-DC converter consist of reactor and capacitor resonant tank circuit for increased the output current. This circuit configuration is composed of the resonant tank circuit used resonant capacitor and reactor and the capacitor connected in switch are a common using by resonance capacitor and ZVS(Zero Voltage Switching) capacitor. Therefore, the proposed converter can reduce a switching losses, noise, and voltage stress at turn-on and turn-on and has an advantage which is able to operating safely in load short, because DC reactor is connected with resonance reactor in order to supply a fixed current with low ripple from DC power supply. The analysis of proposed circuit uses normalized parameters and characteristic estimation is generally described the proposed circuit with the characteristics of power and output voltage etc. Also, design is based on the characteristic estmations in each step. Hence, We conform a rightfulness theoretical analysis by comparing a theoretical values and experimental values obtained from experiment.

Intelligent interface using hand gestures recognition based on artificial intelligence (인공지능 기반 손 체스처 인식 정보를 활용한 지능형 인터페이스)

  • Hangjun Cho;Junwoo Yoo;Eun Soo Kim;Young Jae Lee
    • Journal of Platform Technology
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    • v.11 no.1
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    • pp.38-51
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    • 2023
  • We propose an intelligent interface algorithm using hand gesture recognition information based on artificial intelligence. This method is functionally an interface that recognizes various motions quickly and intelligently by using MediaPipe and artificial intelligence techniques such as KNN, LSTM, and CNN to track and recognize user hand gestures. To evaluate the performance of the proposed algorithm, it is applied to a self-made 2D top-view racing game and robot control. As a result of applying the algorithm, it was possible to control various movements of the virtual object in the game in detail and robustly. And the result of applying the algorithm to the robot control in the real world, it was possible to control movement, stop, left turn, and right turn. In addition, by controlling the main character of the game and the robot in the real world at the same time, the optimized motion was implemented as an intelligent interface for controlling the coexistence space of virtual and real world. The proposed algorithm enables sophisticated control according to natural and intuitive characteristics using the body and fine movement recognition of fingers, and has the advantage of being skilled in a short period of time, so it can be used as basic data for developing intelligent user interfaces.

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