• Title/Summary/Keyword: Overload Control

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Development of Current-based Compact Digital Protective Relay for Induction Motor Protection (중용량 전동기보호를 위한 전류형 디지털 보호계전기 개발)

  • Jung, Jong-Jin;Kim, Joong-Pyo;Shin, Jong-Han;Park, Jang-Soo
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.140-142
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    • 2005
  • This paper describes the current- based compact digital motor protective relay for low and high voltage induction motors, which are widely used in industrial and commercial power systems. The existing protective relays for motor protection had only overload, short circuit, reverse phase, open circuit and grounding protective elements, and measurement, start/stop control function. But in present day, for automation system, various functions are required, especially motor management and sequence control function and more. To meet these requirements, we developed an economic current-based compact digital motor protective relay which had various function to control, manage and monitor the induction motor.

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Setup Procedure of Dump Valve for Full-Scale Airframe Test (전기체 구조시험의 덤프밸브 조절절차 개발;)

  • Kim, Sung-Chan;Kim, Sung-Jun;Hwang, In-Hee
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1252-1257
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    • 2003
  • This paper present a procedure of meter-out flow control method for dump valve in full-scale airframe test. Emergency stop, which results in dump state, can be happened during full-scale airframe test by several causes. Because servo valve can't control hydraulics actuator in the dump state, pressure in cylinder chamber may rise abruptly and overload can be acted to the test article. In this paper, the procedure and technology of orifice setting are investigated to protect the test article from unexpected loads by dump. The test results show that the presented methods decrease peak loads and improve unloading characteristics of hydraulic actuators in the dump state.

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- A Study on Stressors, Locus of Control, and Distress of Employed Wives - (취업부인의 스트레스원, 내외통제성 및 디스트레스에 관한 연구)

  • 고은숙
    • Journal of the Korean Home Economics Association
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    • v.31 no.1
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    • pp.45-60
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    • 1993
  • The purpose of this study is evaluate by using ready prepared question-naires consist of items including perceived stressors. locus of control and distress to classify the different characteristics due to occupations and ages. The sampling groups ranges from 20 generations to 50 generations employed wives living with husband and children dwelling in Seoul. Finally, the sampling data used in this study are the number of 412. The major findings are as follows; (1) All employed wives feel less perceived stressors but more perceived stressors for insufficient understanding of their childrens, overload of housework, willingness of stop of employment by their parents of both families, economic expenditures, and various problems in work places. (2) There appear signigicant differences for perceived stressors and mental and physical distress due to the occupations and the ages of employed wives. Otherwise the locus of control appear clear differences due to the ages only. The more perceived stressors and mental and physical distress appear for laborious and service occupation than professional and administrative occupation. (3) The variables related to physical distress and mental distress are occupation, age, martial status and work allocation of housework, relationship childrens and relationship kinship.

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Development of a Double-blades Road Cutter with Automatic Cutting and Load Sensing Control Technology (자동 절단과 부하 감응 제어 기술을 적용한 양날 도로절단기 개발)

  • Myoung Kook Seo;Myeong Cheol Kang;Jong Ho Park;Young Jin Kim
    • Journal of Drive and Control
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    • v.21 no.1
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    • pp.53-58
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    • 2024
  • With the recent development of intelligence and automation technologies for construction machinery, the demand for safety and efficiency of road-cutting operations has continued to increase. In response to this, a double-blade road cutter has been developed that can automatically cut roads. However, a double-blade road cutter has a load difference between the two blades due to the ground and wear conditions of the cutting blades. The difference in load between the two blades distorts the direction of travel of the cutter. In this study, a vision sensor-based driving guide technology was developed to correct the driving path of road cutters. In addition, we developed a load-sensing technology that detects blade loads in real-time and controls driving speed in the event of overload.

PULMONARY EDEMA INDUCED BY BOSMINE SOAKED GAUZE IN ORTHOGNATHIC SURGER (악교정 수술시 보스민 거즈에 의해 나타난 폐부종 증례보고)

  • Kim, Jae-Gyung;Kim, Yong-Kwan;You, Jun-Young;Joo, Jin-Churl;Lee, Chang-Sun
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.20 no.2
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    • pp.148-151
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    • 1998
  • There are many vessels in oral and maxillofacial region. Therefore blood oozing is a frequent findings in this area when operation takes place. Beacuse of this, most oral and maxillofacial surgeons as well as operators of this region usually use bosmine soaked gauze for oozing control during operation. Theoretically overdose of systemic epiniephrine(bosmine) may lead to pulmonary edema due to secondary systemic volume overload. For this reason, oral and maxillofacial surgeons should give more attention to the use of bosmine soaked gauze. In spite of this possibility, epinephrine induced pulmonary edema using bosmine soaked gauze has not been reported. We experienced one case of pulmonary edema which was induced by epinephrine overdose by bosmine soaked gauze that has not been diluted by mistake in preparing bosmine soaked gauze. The authuors report a case with review of literature.

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A Study on Auxiliary Control Safety Apparatus for RCD Trip on Electric Arc and Spark Disasters - Using by Power Semiconductor Switching Device - (아크 및 스파크 재해에 대한 누전차단기 트립을 위한 보조제어 전기안전장치에 관한 연구 - 전력용 반도체 스위칭 소자 적용 및 응용 -)

  • Kwak, Dong-Kurl;Shin, Mi-Young;Jung, Do-Young
    • Fire Science and Engineering
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    • v.20 no.1 s.61
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    • pp.71-76
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    • 2006
  • The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The occurrence factor of the fire is electric arc or spark accompanied with electrical faults. Residual Current Protective Device(RCD) of high sensitivity type used at low voltage wiring cuts off earth leakage and overload, but the RCD can't cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied low voltage distribution panel are prescribed to rated breaking time about 30[ms](KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To be improved on such problem, this paper is proposed to a auxiliary control apparatus for RCD trip on electric arc or spark due to electrical fire. Some experimental results of the proposed apparatus is confirmed to the validity of the analytical results.

Study on the Safety Assurance for the Temporary Structures (가설구조물 안전성 확보 방안 연구)

  • Lee, Jung Seok;Moon, Seong Oh;Youn, Ye Bin;Lim, Nam Gi;Oh, Tae Keun
    • Journal of the Korean Society of Safety
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    • v.33 no.1
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    • pp.73-80
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    • 2018
  • According to the statistics publication of KOSHA, more than half of serious accidents at the construction sites were related to the temporary works and/or the temporary structures such as scaffoldings, shores, earth retaining walls, etc. The structural failures are occurred because of the overload acting on the structures or lack of performance of the one or more members of the structures. For the prevention of the collapse accidents relating to the temporary structures at the construction sites, we have to control construction processes not to occur the overload and also to control the performance and quality of each member of the temporary structures. MOLIT has amended the "Construction Technology Promotion Act" on Jan. 7th, 2015 to ensure the structural safety of the temporary structures. According to the Act, the designers of the construction design projects should check the structural integrity of the structures including the temporary structures and the construction companies have to let 'the Relative Professionals' confirm the structural integrity of temporary structures, the shores(${\geq}5m$ high) and the scaffolds(${\geq}31m$ high), before construction. Also, MOLIT has amended the "Regulation for Construction Technology Promotion Act" on Jul. 4th, 2016 for quality management and testing of temporary equipments. According th this regulation, the construction companies and supervisors should manage and test the temporary equipments before using them. In this paper, the standard drawings of the shores(< 5 m high) and the scaffolds(< 31 m high) and the amended "Business Guideline for Quality Management of Construction Work" are presented. As the result of this study, MOLIT noticed the amended "Business Guideline for Quality Management of Construction Work" on Jul. 1st, 2017.

Endoplasmic Reticulum Signaling for Recombinant-protein Production (재조합 단백질 생산을 위한 소포체 신호전달)

  • Goo, Tae-Won;Yun, Eun-Young;Kang, Seok-Woo;Kwon, Ki-Sang;Kwon, O-Yu
    • Journal of Life Science
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    • v.17 no.6 s.86
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    • pp.847-858
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    • 2007
  • The endoplasmic reticulum (ER) is an important intracellular organelle for folding and maturation of newly synthesized transmembrane and secretory proteins. The ER provides stringent quality control systems to ensure that only correctly folded proteins exit the ER and unfolded or misfolded proteins are retained and ultimately degraded. The ER has evolved stress response both signaling pathways the unfolded protein response (UPR) to cope with the accmulation of unfolded or misfolded proteins and ER overload response (EOR). Accumulating evidence suggests that, in addition to responsibility for protein processing, ER is also an important signaling compartment and a sensor of cellular stress. In this respect, production of bio-functional recombinant-proteins requires efficient functioning of the ER secretory pathway in host cells. This review briefly summarizes our understanding of the ER signaling developed in the recent years to help of the secretion capacities of recombinant cells.

Development of electric safety control system for incapable operation of ELB and MCB using the low voltage distribution line (저압 배전선로의 누전 및 배선용 차단기의 오동작 방지를 위한 전기안전 제어장치 개발)

  • Kwak, Dong-Kurl;Shin, Mi-Young;Jung, Do-Young;Kim, Hyo-Jin;Baek, Seong-Hyun;Choi, Byung-Seub
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.371-372
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    • 2007
  • The major causes of electrical fire are classified to short circuit fault, overload fault, electric leakage and electric contact failure. The occurrence factor of the fire is electric arc or spark accompanied with electrical faults. Residual Current Protective Device (RCD), that is Earth Leakage Circuit Breaker(ELB) and Molded_case Circuit Breaker (MCB), of high sensitivity type used at low voltage wiring cuts off earth leakage and overload, but the RCD can't cut off electric arc or spark to be a major factor of electrical fire. As the RCDs which are applied low voltage distribution panel are prescribed to rated breaking time about 30[ms] (KS C 4613), the RCDs can't perceive to the periodic electric arc or spark of more short wavelength level. To be improved on such problem, this research development is proposed to a auxiliary control apparatus for RCD trip on electric arc or spark due to electrical fire. Some experimental results of the proposed apparatus is confirmed to the validity of the analytical results.

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The Capacity Increase Scheme for Cellular based LPWA (Low Power Wade Area) IoT (이동통신 기반 LPWA (Low Power Wade Area) IoT를 위한 용량 증대 방안)

  • Park, Bok-Nyong;Jung, Il-Do
    • Journal of Internet of Things and Convergence
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    • v.8 no.4
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    • pp.17-23
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    • 2022
  • NB-IoT and LTE Cat.M1 based on LPWA(Low Power Wide Area) are commercialized and serviced by mobile carriers. As the demand for IoT devices is increased, the number of subscribers to these services is also increasing. In the beginning of service, there was no issue that eNB capacity for NB-IoT and LTE Cat.M1. However, as the number of subscribers increases, there is an issue that the eNB capacity for these service is insufficient. Active UE capacity issue may cause overload by continuous increase and temporary increase. In this paper, we propose a solution to solve the problem of LTE RRC(Radio Resource Control) Active UE capacity shortage and base station overload caused by the increase of NB-IoT and LTE Cat.M1 UE in same eNB. The proposed solution can increase a cell capacity without cell division and additional eNB, and can also improve the service quality of these UEs.