• 제어로봇시스템학회논문지
• /
• 제20권9호
• /
• pp.900-907
• /
• 2014

This paper proposes a MPC (Model Predictive Control) method for the torque and flux controls of induction motor. The proposed MPC method selects the optimized voltage vector for the matrix converter control using the predictive modeling equation of the induction motor and cost function. Hence, the reference voltage vector that minimizes the cost function of the torque and flux error within the control period is selected and applied to the actual system. As a result, it is possible to perform the torque and flux control of induction motor using only the MPC controller without a PI (Proportional-Integral) or hysteresis controller. Even though the proposed control algorithm is more complicated and has lots of computations compared with the conventional MPC, it can perform torque ripple reduction by synthesizing voltage vectors of various magnitude. This feature provides the reduction of amount of calculations and the improvement of the control performance through the adjustment of the number of the unit vectors n. The proposed control method is validated through the PSIM simulation.

• 식물조직배양학회지
• /
• 제26권2호
• /
• pp.71-76
• /
• 1999

약배양에 대한 반응이 비교적ㆍ높은 것으로 알려진 고추의 두 품종 계룡산재래와 밀양재래의 약을 2,4-D와 kinetin이 각각 0.1 mg/L씩 첨가된 배지에 치상한 후 4$^{\circ}C$와 32$^{\circ}C$의 온도 전처리가 소포자배 발생에 미치는 영향을 조사하였다. 소포자배의 발생은 사용한 두 품종 중 밀양재래에서 높았다. 고온처리는 저온처리에 비해 소포자 배의 발생이 많았고 캘러스의 발생은 거의 없었으며 발생한 배는 동일 배지에서 또는 호르몬이 없는 배지에 옮겼을 때 대부분이 정상적인 유식물로 발달하였다. 저온처리에서는 캘러스의 발생이 많았고 발생한 배는 대부분이 비정상적으로 발달하였다. 소포자배 발생에 효과적인 고온처리 기간은 밀양재래에서는 3일, 계룡산재래에서는 6일이었다. 고추의 약배양 시 고온처리는 소포자배의 유기뿐만 아니라 유기된 배의 생장에도 중요한 영향을 미치는 것으로 나타났다.

• 한국동물학회지
• /
• 제31권3호
• /
• pp.157-164
• /
• 1988

SCK종양세포에 온열처리와 여러가지 sulihydryl-reacting agents을 처리하여 stress protein의 합성을 유도하고, 그 양상을 검토해 봄으로서 stress proteins의 합성유도와 denatured protein의 생성과의 관계를 고찰하였다. 세포에 cycloximid와 더불어 Zn또는 ME를 처리한 경우에는 stress protein의 합성이 일어나지 않았으나,온열처리 또는 IAA를 처리한 경우에는 stress protein의 합성이 유도되었다. 이 결과로 미루어 볼 때,stress protein의 유도 경로에는 두 가지가 있어서 새로운 단백질의 합성이 필요한 경로와 새로운 단백질의 합성과는 무관한 경로가 있는 것으로 추정할 수 있었다. 결국, 본 실험에서 사용한 stress들이 기존의 mature protein을 denature시키거나 (온열처리 또는 IAA),새로 합성된 immature protein을 denatur시키는 것,(Zn 또는 ME)으로 알려져 있으므로,stress에 의한 abnormal protein의 출현이 stress proteins의 합성을 유도하는 tigger의 구실을 하는 것으로 생각된다. 이 밖에 여러 가지 stress가 동시에 작용할 경우, 세포는 보다 강한 stress에 대해서 stress protein을 합성하여 대치하게 되는 것으로 생각된다.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제34권3호
• /
• pp.173-179
• /
• 2012

Purpose: This study was to determine the effects of surgical induction of anterior disc displacement (ADD) on the distribution of glycosaminoglycan (GAG) and collagen fiber arrangement in the rabbit temporomandibular joint (TMJ) tissues including articular cartilage of condyle, disc, retrodiscal tissue, and articular eminence. Methods: We used van Gieson staining and Alcian blue critical electrolyte concentration (CEC) method to observe change of collagen fibers on disc and to measure GAG up to 10 weeks in TMJ tissues after surgical induction of ADD on 25 rabbits. Results: CEC measurements for GAG showed 0.3 M, 0.4 M, 0.6 M, and 0.8 M at 1 week, 2 weeks, 3, 4, and 8 weeks, 10 weeks, respectively. This result indicated that GAGs shifted to highly sulphated ones as time passed. Disruption of collagen fiber arrangement in the disk occurred at 10 days and aggravated at 3 weeks. Conclusion: Our study showed degenerative osteoarthritis changes in rabbit TMJ following surgical induction of ADD up to 10-week period.

• 신재생에너지
• /
• 제10권3호
• /
• pp.14-21
• /
• 2014

As the world supply of fossil fuel sources decreases, the need for efficient energy consevation and develping green energy technologies becomes critical. Because of the high cost of the foundation for large turbines and optional high wind speed (over 12 m/s), it is very difficult to be located at inland city. For the solution above mentioned problem, we have been experimented about that not only using the adaption of wind power system on buildings for improving turbine efficiency, but also applying a wound rotor type induction generator for a small wind turbine.In this research, we try to find out the wind direction and wind speed those were measured every 1 min., during operation period, using the anemometers which consist of horizontally spinning cups on a vertical post. Performance testing for small wind turbine generating system was carried out by using the induction motor and invertor. Finally, we measured the power of 1 kW wind turbine system with the clamp meter and a voltmeter.

• 전력전자학회논문지
• /
• 제7권3호
• /
• pp.297-302
• /
• 2002

유도전동기의 직접 토크 제어방식은 구조가 간단하여 구현이 용이하고, 빠른 토크 응답성을 갖는 것을 특징으로 견인용 유도전동기의 추동시스템 등에 그 응용분야를 넓혀가고 있다. 그러나 히스테리시스 제어기를 사용하여 출력전압을 결정하는 기존의 직접 토크 제어방식에서는 인버터의 스위칭 주파수가 히스테리시스 밴드 폭과 운전조건에 따라 가변하고 토크맥동이 발생하는 문제점이 있다. 따라서 본 논문에서는 인버터의 스위칭 주파수를 일정하게 유지하고 저속 및 고속 운전영역에서 전동기의 토크 및 고정자 전류 맥등을 저감하기 위한 목적으로 고정자 자속 제어개념과 공간전압벡터 P%에 의한 새로운 직접 토크 제어방식을 제안하였다. 시뮬레이션과 실험을 통해 제안한 알고리즘의 타당성을 입증하였다.

• 한국지능시스템학회논문지
• /
• 제14권7호
• /
• pp.878-882
• /
• 2004

본 논문에서는 유도전동기 고장진단을 위하여 계층적인 하이브리드 뉴럴네트웍을 제안하였다. 시스템의 입출력 데이터에 근거하여 패턴을 분류할 때 단계별 변환 및 분류 기법을 이용하였다. 제안된 방법에서는 실험에 측정된 전류값을 주기별로 주성분분석(PCA) 기법을 이용하여 입력차원을 축소한 후 이를 조건부 FCM으로 방사기저함수의 초기치를 최적화하는데 사용하였다. 이는 주성분분석이 가지는 특성을 이용하여 데이터의 특징을 나누었으며 이를 뉴럴네트웍의 학습 기능을 이용하여 고장검출 모델의 최종 성능을 개선하는 것이다. 이를 실제 계측된 유도전동기 데이터를 이용하여 실험한 결과 제안된 방법의 성능이 기존의 방법들에 비하여 우수함을 알 수 있었다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제50권5호
• /
• pp.238-245
• /
• 2001

During an AC motor's start-up accelerating period, a large amount of current is required to reach to the rating speed. This is called in-rush current. This peak in-rush current can be more than about several times the operating or steady-state current in the full load rating of the motor. In-rush current is present in both and electronic ballasts. The main area of concern is the tripping of circuit breaker and fuses which can affect electrical system components From this, we can see that the electrical power controllers will be rather concerned, since they have to supply the actual current necessary to start the motor. This paper presents a new method to reducing in-rush current and energy saving of the single-phase induction motor used in air-conditioner. It can be obtained that proposed system is low cost and small size as compared with other controller. Experiments are focused on a capacitor starting single-phase induction motor. The optimal power saving and in-rush current limiting by phase angle control are verified by experimental results. Also, auxiliary winding was controlled by electronic starting switch.

• The Journal of Asian Finance, Economics and Business
• /
• 제4권3호
• /
• pp.45-56
• /
• 2017

Considerable research has been done on the issue of succession in family businesses. However the process of induction, of preparing the members of the next generation for joining the family business has not been examined in detail. This paper attempts to analyse the relevance of three critical factors - 'quality of relations', 'willingness of the inductee' and 'the ability to manage tensions harmoniously' - to the induction process and the progress of the business. It focuses on the Indian context, specifically in the Small and medium Enterprise (SME) area. Qualitative research has been carried out. The Case Study method is used and data has been gathered from two families (including two branches of one family), using frequent unstructured interviews, over a period of five years. It is concluded that positive impact on business, family and the inductee depends to a large extent on the quality of relations, willingness of the inductee and the ability of both the inductor and inductee to handle and manage the tensions. Thus the findings of the study extend current understanding about succession drivers to the specific context of eastern cultural and developing economy represented by the Indian family businesses in the small and medium enterprise sector.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제5권1호
• /
• pp.1-12
• /
• 2002

Ecophysiologically diapause represents a syndrome of physiological and biochemical characteristics, all of which ensure survival during a long period of dormancy. Since, silkworm enters diapause as embryo at the early embryonic stage, the duration of egg life depends on the duration of embryonic diapause. The nature of diapause in silkworm, Bombyx mori, is primarily determined by genetic characters and endocrinologicnl mechanisms, mediated by environmental factors such as temperature and photoperiod. Hibernating potency value besides nucleic acid and carbohydrate metabolism, production and utilization of sorbitol are also equally responsible for induction, initiation, determination, maintenance and termination of diapause. Embryonic diapause in Bombyx moir, induced by active secretion of sub-oesophageal ganglion is attributed to hormonal system and metabolic adjustment, which serves to bring about a new physiological state. Metabolic conversion of trehalose to glycogen at induction, glycogen to sorbitol at initiation and sorbitol to glycogen at termination of diapause is correlated and in each metabolic shift a key enzyme becomes active in response to hormonal and environmental stimulation. An attempt has been made in this review article to discuss briefly the nature of embryonic diapause, influence of various factors on diapause nature, hormonal mechanism of diapause besides biochemical composition of egg, nucleic acid and carbohydrate metabolism, production and utilization of sorbitol in relation to induction, determination, maintenance, initiation and termination of diapause in the silkworm, Bombyx mori.