• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.705-713
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• 2021

Because the cage assembly serves as the launch platform, an accurate aim is essential to ensure shooting accuracy for the target. On the other hand, the abnormal rotation of the cage due to the directional errors of the K-MLRS has continuously caused quality problems. The quality problem of weapon systems may have a negative impact on the military's power loss. In this study, improvement plans were derived by examining the defects and analyzing the directional errors of the K-MLRS launcher. In addition, all possible causes of directional errors were derived from the flow diagram for cage directionality. Based on the results, the defense design through the software program was intended to prevent the loss of direction. Through this study, the signal error of the resolver was improved by preventing unspecific signals in the data. Furthermore, the directional judgment method was improved to minimize the impact of data distortion. Lastly, directional storage and verification methods were improved so that data for the cage rotation direction would not be affected by errors. For the design improvement method, the reliability was verified through the system applicability. This study is expected to be a reference for failure analysis and design for similar weapon systems in the future.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.2
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• pp.138-147
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• 2009

In this paper, improved direct torque control(DTC) system for five-phase squirrel-cage induction motor(IM) is proposed. Due to the additional degrees of freedom, five-phase 1M drives present unique characteristics. Also five-phase motor drives possess many other advantages compared with the traditional three-phase motor drive system, such as reducing an amplitude of torque pulsation and increasing the reliability. The DTC method is advantageous when it is applied to the five-phase IM, because the five-phase inverter provides 32 space vectors in comparison to 8 space voltage vectors into the three-phase inverter. However, five-phase motor has structural drawback of 3rd space-harmonics current component, it is necessary to controlled 3rd harmonic current. So to control 3rd harmonic current and enhance dynamic characteristics of five-phase squirrel-cage IM drive, modified DTC method should be demanded. The characteristics and dynamic performance of traditional five-phase DTC are analyzed and new DTC for five-phase IM is presented. A more precise flux and torque control algorithm for the drives can be suggested and explained For presenting the superior performance of the proposed direct torque control, experimental results are presented using a 32-[bit] fixed point TMS320F2812 digital signal processor with 2.2[kW] induction motor.

• Journal of Advanced Marine Engineering and Technology
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• v.8 no.1
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• pp.72-84
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• 1984

In this paper, the characteristics relating to the stator voltage control of a small three phase squirrel cage induction motor by means of symmetrically trggered triacs instead of antiparallel SCR's is described. A complete model of the system with 220V, $3{\phi}$, 1HP motor and triac gate control circuit has been designed and tested in the laboratory, and the experimental results are compared with the numerical values. As a result of the above investigation, it is found that the range of induction motor speed control by stator voltage control is narrow.

• Magazine of the Korea Concrete Institute
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• v.14 no.5
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• pp.15-20
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• 2002

갱폼이라 함은 주로 고층 아파트에서와 같이 평면상 상ㆍ하부 동일 단면 구조물에서 외부벽체 거푸집과 거푸집 설치ㆍ해체작업 및 미장ㆍ치장(견출) 작업발판용 케이지(cage)를 일체로 제작하여 사용하는 대형 거푸집을 말한다. 여기서 케이지는 갱폼에서 외부벽체 거푸집 부분을 제외한 부분으로 거푸집 설치ㆍ해체작업, 후속 미장, 치장(견출) 등 작업을 안전하게 수행하는데 필요한 작업발판, 안전난간 등으로 구성되어 갱폼 거푸집에 결합된 부분이며, 상부 케이지는 갱품 케이지의 4단 작업발판 중 거푸집 설치ㆍ해체작업용으로 사용되는 상부 2단 작업발판 구성 부분이고, 하부 케이지는 미장ㆍ치장(견출) 작업용으로 사용되는 하부 2단 작업발판 구성 부분을 말한다.(중략)

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.571-575
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• 1986

The squirrel-cage induction motor can be characterized as a nonlinear and multi-input, multi-output system, and has the unmeasurable states which are the rotor currents. In this paper, the time-delayed output feedback method is applied to the speed control of induction motor driven by the current-controlled PWM inverter and its performance is investigated by using the computer simulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.7
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• pp.916-923
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• 2014

This paper proposes a low-cost switched-mode rectifier (SMR) for a small-scale wind turbine with a permanent magnet synchronous generator (PMSG) system. Also, a sensorless Fuzzy MPPT control is realized by the proposed system. In the PMSG system with the SMR, the synchronous impedance can be replaced as the input inductor of a boost converter. Moreover, the sensorless MPPT control using the Fuzzy technique is carried out by the duty-ratio regulation of the SMR. The relation between the generating power and the duty-ratio is ruled by the chain rule. The wind turbine model is implemented by the squirrel cage induction motor and generated the variable torque when the generator speed is varied. To verify the performance of the proposed system, simulation and experimental results are executed.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.13 no.1
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• pp.45-53
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• 2018

Objectives: This report aimed to provide an introduction to the analysis of the Biolinkage System. Methods: During diagnosis, the Biolinkage System was first classified into Type I & Type II according to the Patric's Test and the Pelvic Twist Analysis; the two types were then sub-classified into Step I, II, III according to the Thompson's sacrum test, Patrick's test, Scapular Fixation Test, and Pelvic Twist Analysis. During treatment, the sacrum-axis-temporomandibular joints were used in Step I, the hip joint-fourth cervical or scapular-occiput were used in Step II, and lastly the thoracic cage is used in Step III. Conclusions: The Biolinkage System is useful in the examination of somatic dysfunction.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.726-728
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• 2003

A linear induction motor conveyance system with longitudinal and transverse rails is manufactured. which is controlled by programmable logic controller(PLC). The linear induction motor has a cage-type secondary and the total number of the installed primaries is 10. Four secondaries are installed on the below surface of the moving carrier. In this paper, the developed conveyance system is introduced and its PLC control characteristics for the longitudial and transverse moving directions are presented.

• Journal of fish pathology
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• v.35 no.1
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• pp.1-25
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• 2022

The aquaculture industry has developed rapidly over the last three decades and is an important industry that supplies over 15% of humans' animal protein intake; therefore, there is a need to increase production to meet the continuous demand. The fish cage farms on the southern coast (Kyengsangnam-do and Jeollanam-do) of Korea are critical resources in aquaculture because they account for approximately 90% of the national total fish cage farms by water area ratio. However, the current aquaculture environment is being gradually affected by climate change, which is a global issue, and its effects are expected to intensify in the future. Therefore, it is urgently imperative to accurately evaluate the effects of climate change on South Korean aquaculture industries and to develop social and national strategies to minimize damage to the fishing industry. The damage to fish farmed in cage farms on the southern coast is increasing annually and the leading causes are high and low water temperature and red tides, which are directly or indirectly related to climate change. At present, global warming can provide opportunities for aquaculture industrialization of fish or other novel species, with economic implications. However, despite such opportunities, the influx of new species can also cause problems such as ecological disturbances, increase in the reproduction frequency of microalgae such as red tide, increase in disease incidence, and occurrence and periods of high water temperatures in summer. The scale of farmed fish mortality is increasing due to the complex effects of these factors. Increased damages due to fish mortality not only have severe economic impacts on the aquaculture industry, but the social costs of responding to the damage and follow-up measures also increase. various active responses can reduce the mortality damage in fish farms such as improving the management skills in aquaculture, improved species breeding, efficient food management, disease prevention, proactive responses, and system-wide improvements. This review article analyzes the large-scale mortality cases occurring in fish cage farms on the southern coast of Korea and proposes measures to mitigate mortality and enhance responses to such scenarios.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1045_1046
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• 2009

This paper presents an active and reactive power compensator for the wind power system with squirrel-cage induction generator. The developed system is able to continuously compensate the active and reactive power. The 3-phase inverter operates for the compensation of reactive power, while the DC/DC converter with super-capacitors operates for the compensation of active power. The proposed compensator can be expected that developed system may be used to compensated the abrupt power variation due to sudden change of wind speed or sudden power-drop by tower effect. It can be also applied for the distributed generation and the Micro-Grid.