• Title/Summary/Keyword: Squirrel

Search Result 256, Processing Time 0.027 seconds

A Case Report of Bordetella Bronchiseptica Infection in Squirrel Monkey(Saimiri sciureus) (다람쥐 원숭이의 Bordetella bronchiseptica 감염 예)

  • 배유찬;윤순식;이희수;진영화
    • Journal of Veterinary Clinics
    • /
    • v.20 no.4
    • /
    • pp.493-495
    • /
    • 2003
  • A dead, female, 3 years old, squirrel monkey (Saimiri sciureus) was submitted and examined. Before death the monkey has showed lethargy, recumbency and inappetence since November 14, 2001 and died in November 17. Grossly much fibrin was deposited on the pleura of right lung, pericardium, and diaphragm(pleural part). And reddening of right lung was seen. Histopathologically lung showed severe fibrinous pleuritis, severe edema, thrombosis, and focal necrosis in parenchyma. Also much fibrin and mononuclear cells were deposited on the pericardium. In bacterial culture on the pleura and parenchyma of lung, and pericardium, B. bronchiseptica was isolated. Therefore we confirmed this case as the fatal case by B. bronchiseptica in squirrel monkey.

Comparison of Torque-Speed Curve according to the Changes in Cross-Sectional Area and Shape of Squirrel Cage Rotor of Induction Motor (농형 유도전동기의 회전자 형상과 단면적 변화에 따른 토크-스피드 곡선 비교)

  • Lee, Jin Seok;Lee, Ha Jeong;Park, Gwan Soo
    • Journal of the Korean Magnetics Society
    • /
    • v.26 no.2
    • /
    • pp.67-69
    • /
    • 2016
  • Recently, cost of rare-earth magnets has been raised, because rare-earth magnets are monopolized and the export is also regulated in China. For this reason, the induction motor is operated without the rare-earth magnets. The efficient development of induction motor is more important for economical scheme. A torque of the induction motor is computed and the correlation between dimension and resistance of the squirrel cage rotor is investigated. Also, the correlation between leakage reactance and torque was analyzed with respect to the same dimension of rotor with different shapes. Therefore, this paper proposes the method of improvement for squirrel cage rotor.

Analysis of Starting Torque and Speed Characteristics for Squirrel Cage Induction Motor According to Material Properties of Rotor Slot

  • Kim, Young Sun
    • Transactions on Electrical and Electronic Materials
    • /
    • v.16 no.6
    • /
    • pp.328-333
    • /
    • 2015
  • Squirrel cage induction motors have mostly been used for their small capacity because the starting torque is smaller than the starting current during start-up. However, as more and more mid-to-large capacity motors are developed, the demands for improvements in performance characteristics have also increased. In this study, the starting characteristics of squirrel cage induction motors were analyzed based on the rotor materials and shapes using a finite element method to provide design data suitable for different use purposes and capacities. We further completed analysis by combining electromagnetic equations deduced from Maxwell’s equations and the circuit equations of stators and rotors. A moving coordinator was introduced to rotate the rotor during the analysis, and the torques calculated via the finite element method were combined with the motion equations to calculate the position and angular velocity of the rotors at the next time, thereby analyzing the transient characteristics. The analysis results of the transient characteristics were applied to a 3-phase 4-pole 5-hp induction motor to calculate the starting torque, speed, and rotation angle of the rotors. In the reference model, the materials and shapes of the rotor slot were changed to copper and silicon copper and a deep slot, shallow slot, and long-neck-shaped slot.

Fininte Element Analysis of Squirrel-cage Induction Motor Taking into account the End-ring (엔드링을 고려한 농형 유도전동기의 2차원 유한요소해석)

  • Ha, Gyeong-Ho;Hong, Jeong-Pyo;Kim, Gyu-Tak;Im, Tae-Bin
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.48 no.2
    • /
    • pp.49-55
    • /
    • 1999
  • This paper proposes an efficient 2D Finite Element Method(FEM) taking into account the end-ring of three phase squirrel-cage induction motors. The parameters of the squirrel-cage induction motor such as conductivity of secondary conductor have an effect on the characteristics of a motor. Especially, if the characteristic analysis is done without considering the end-ring, the good results can not be obtained. Therefore, we calculated a new resistivity of the secondary conductor including the end-ring's resistance to apply the 2D FEM. Then, the performances of the motors are analyzed by using the new resistivity of secondary conductor which contains the end-ring resistivity. The validity of the proposed method is verified by comparing the numerical results with experimental ones.

  • PDF

SQUIRREL SEARCH PID CONTROLLER ALGORITHM BASED ACTIVE QUEUE MANAGEMENT TECHNIQUE FOR TCP COMMUNICATION NETWORKS

  • Keerthipati.Kumar;R.A. KARTHIKA
    • International Journal of Computer Science & Network Security
    • /
    • v.23 no.4
    • /
    • pp.123-133
    • /
    • 2023
  • Active queue management (AQM) is a leading congestion control system, which can keep smaller queuing delay, less packet loss with better network utilization and throughput by intentionally dropping the packets at the intermediate hubs in TCP/IP (transmission control protocol/Internet protocol) networks. To accelerate the responsiveness of AQM framework, proportional-integral-differential (PID) controllers are utilized. In spite of its simplicity, it can effectively take care of a range of complex problems; however it is a lot complicated to track down optimal PID parameters with conventional procedures. A few new strategies have been grown as of late to adjust the PID controller parameters. Therefore, in this paper, we have developed a Squirrel search based PID controller to dynamically find its controller gain parameters for AQM. The controller gain parameters are decided based on minimizing the integrated-absolute error (IAE) in order to ensure less packet loss, high link utilization and a stable queue length in favor of TCP networks.

A Study of Ku on the costume of the variant races dynasty in China-based on Khitai, Mongols and Manchus costume- (중국 민왕조 복식에서 에 관한 연구)

  • 정복남
    • Journal of the Korean Society of Costume
    • /
    • v.26
    • /
    • pp.163-173
    • /
    • 1995
  • The purpose of this study is to investigate the Ku which was worn by nomadic tribes which was Khitai, Mongols and Manchus. The results of this study can be summarized as follows. 1. The fur clothes were very important clothes that nomadic tribes put on in order to protect them against the cold. The Ku was an outfit for protection against the cold. It was made of ani-mal fur and its style was tight sleeve and long dress. 2. The Ku was worn in all social classes including emperor, nobles and the masses in ancient China and Asia dynasty. After the nomadic tribes estabilished dynasty in China the style of Ku was changed. All kinds of animal fur was used to make the Ku but the volume of fur, kinds and colors were classified severely by their social position. In Khitai dynasty the Ku was worn in same style. But the emperor wore the Ku of silver marten. The noble class wore the Ku of purple, black and blue marten and silver squirrel skin. The masses wore the Ku of the other colors marten, sheep, squirrel and dessert fox skin. In Mongol dynasty, the emperor wore the Ku of purple marten, silver squirrel, silver fox and black fox skin. The nobles wore the Ku of the other colors marten and squirrel. The masses wore the Ku of degraded animal fur. Before the Manchus estabilished the varient races dynasty in China, the rich man preferred the Ku of marten, squirrel, fox, goat furs. But the poorman preferred the Ku of cow, horses, pig, sheep, cat, dog, snake and deer skin. After the manchus conquered the China, the manners of dress were changed. Generally the fur did not appear in right side of garment, but high quality or noble fur appeared outside. Sometimes the inside or outside of Ku was made of silk fabrics and sleeves, neck-band was made of the high quality fur.

  • PDF

Morphological Characteristics of Siberian Flying Squirrel (Pteromys volans): Sexual Dimorphism and Camparison of Morphological Characteristics in Different Latitudes (하늘다람쥐(Pteromys volans)의 형태적 특성: 성적이형성 및 위도에 따른 형태학적 특성 비교)

  • Kim, Junsoo;Jeon, Jonghoon;Lee, Woo-Shin;Kim, Jong-U
    • Journal of Korean Society of Forest Science
    • /
    • v.108 no.1
    • /
    • pp.133-137
    • /
    • 2019
  • This study was conducted to clarify the morphological characteristics of Siberian flying squirrel (Pteromys volans). We investigated 6 morphological characteristics from April, 2014 to March 2016 at Mt. Baekwoon, Wonju, Gangwon province. We found that Siberian flying squirrel showed female-biased sexual dimorphism. This result would be related to reproductive strategy of the species which female nurse offspring alone. As results of comparison of morphological characteristics from Korea, Finland and Japan, both body weight and head-body length appeared heavier and longer from high-latitude to low-latitude. This result suggest that morphological difference between different latitudes would be related with climate and habitat environment. The more researches would be needed with other morphological characteristics of Siberian flying squirrel.

Study on the Operating Characteristics of Double Fed Induction Generator Connected AC network (계통 연계형 권선형 유도발전기의 동작특성 연구)

  • Kim, Chan-Ki;Han, Sang-Yul;Choo, Jin-Boo
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.11 no.3
    • /
    • pp.247-257
    • /
    • 2006
  • This paper shows the comparison of operating characteristics between squirrel cage induction generator and DFIG(Double Fed Induction Generator). Because squirrel cage induction generator consume the reactive power due to magnetizing reactance, the capacitor is need to compensate the reactive power. Otherwise, two back-to-back PWM voltage-fed inverters connected between the stator and the rotor allow sub/super synchronous operation with low distortion currents. In this paper, the response characteristics of squirrel cage induction generator and DFIG, were analyzed and investigated using PSCAD/EMTDC.

A Study on the outside rotor type double squirrel cage Induction motor (외측회전형 이중 농형 유도전동기에 관한 연구)

  • 김현수;배철오;안병원
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.27 no.6
    • /
    • pp.776-782
    • /
    • 2003
  • This paper describes a newly developed double squirrel cage induction motor in which the rotor is located outside the stator. The outside rotor type brushless dc motor has been used for VTR's head drum and PC's cooling fan, but this kind of induction motor has not been developed yet. The parameters of outside rotor type induction motor were measured from the locked rotor test and no load test. It is possible to determine the parameters which are presented in the steady-state equivalent-circuit of the outside rotor type induction motor. Load test of induction motor was carried out using a dynamometer. For the characteristics of torque, efficiency, power factor and output. the developed double squirrel cage induction motor is compared with the ordinary induction motor It is believed that the results of this paper can be used for the development of the outside rotor type induction motor.

Parameters Estimation Characteristics of Five-Phase Squirrel-Cage Induction Motor within Over Current Load (과전류 부하에서 5상 농형 유도전동기의 정수 특성)

  • Kim, Min-Huei
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.29 no.7
    • /
    • pp.38-46
    • /
    • 2015
  • This paper propose a variable parameter estimations for variable over current load of five-phase squirrel-cage induction motor(IM) to servo control system. In order to high performance control of AC motor using a field oriented control(FOC) and direct torque control(DTC) algorithm, there are required precise motor parameters for slip calculation, flux observer, controller gain, torque command of current components, rotor position, speed estimation, and so on. We are suggest a analyzed estimation results of the motor parameters that developing five-phase squirrel-cage IM have a stator of concentrated winding for experimental within variable over current load at rated input frequency. There are results of stator winding measurement, no-load test, locked-rotor test, variable over current load test, and estimated parameters of equivalent circuits using manufactured experimental apparatus by IEEE Standard Test Procedure for Polyphase Induction Motors and Generators 112-2004.