• Title/Summary/Keyword: Unbalance control

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Prediction of Internal Tube Bundle Failure in High Pressure Feedwater Heater for a Power Generation Boiler by the Operating Record Monitoring (운전기록 모니터링에 의한 발전보일러용 고압 급수가열기 내부 튜브의 파손예측)

  • Kim, Kyeong-seob;Yoo, Hoseon
    • Plant Journal
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    • v.15 no.2
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    • pp.56-61
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    • 2019
  • In this study, the failure analysis of the internal tube occurred in the high pressure feedwater heater for power generation boiler of 500 MW supercritical pressure coal fired power plant was investigated. I suggested a prediction model that can diagnose internal tube failure by changing the position of level control valve on the shell side and the suction flow rate of the boiler feedwater pump. The suggested prediction model is demonstrated through additional cases of feedwater system unbalance. The simultaneous comparison of the shell side level control valve position and the suction flow rate of the boiler feedwater pump compared to the normal operating state value, even in the case of the high pressure feedwater heater for the power boiler, It can be a powerful prediction diagnosis.

A Comparative Study of Eastern and Western Nursing for Pyrexia Patient (발열환자의 동.서 간호 비교고찰)

  • Kung, Hyun-Sook;Kim, Won-Ock;Lee, Jung-Min
    • Journal of East-West Nursing Research
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    • v.1 no.1
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    • pp.40-49
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    • 1997
  • This study was done for understanding the desirable direction of eastern and western nursing by comparing the nursing practice for the Pyrexia patient occuring most commonly. Body temperature usually maintains around $37^{\circ}C$ owing to the thermoregulatory center but pyrexia is caused by exogenous pyrogen like infection, cancer or disturbances in body's homeostatic heat balance. Pyrexia is defined that body temperature rise above $37.2^{\circ}C$. It has chill phase, course of the fever, termination accompanied various symptoms. Oriental medicine explains that pyrexia comes from Yang's(陽) abundance and Yin's(陰) lack. Pyrexia mainly happens when body constitution is in bad condition by Six Dirty's(六陰) affection to Wi Area (偉分). It also occurs because of unbalance between Qi (氣) and Yin(陰) caused by the lack in Seven Emotions, labor, food. The Sanghanron(傷寒論), explains that pyrexia is categorized exogenous fever like Poong Han(風寒), Poong Yul(風熱), Sup Yul(濕熱) and endogenous fever due to the Qi and blood deficiency. Explained above, even though pyrexia has different meaning in oriental medicine and western medicine, but this study have compared the oriental and western medicine assuming that pyrexia is rise of body temperature. From this point of view, oriental and western nursing shows the similarity in the field of 1) use of antipyretic to control the body temperature 2) rest and comfort 3) watering 4) nutrition and case study was executed in nursing practice. From the above study, western nursing has superiority in decreasing the patient's risen body temperature using antipyretic and ice bag. But in case of empty heat, oriental nursing which recommends the patient's body keep warm and prevent the use of ice bag as the first step and helps patient's sweating by drinking of hot water was comparatively effective. In conclusion, it is desirable that oriental nursing emphasizing the supportive nursing and western nursing should be harmonized according to the status of pyrexia patient and it is needed to study the nursing method appropriate in our culture.

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Design and Implementation of Multifunction 2-Channel Receiver for 3 Dimensional Phased Array Radar (3차원 위상배열 레이다용 다기능 2채널 수신기 설계 및 제작)

  • 강승민;양진모;송재원
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.9
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    • pp.1-12
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    • 1998
  • We have implemented receiver for a 3 Dimensional Phased-Array Radar detecting the azimuth angle, the altitude, the range of a target on real time. This system consists of high frequency module, which protects receiver and controls sensitivity, intermediate frequency module, monopulse detector, IQ phase detector, AGC controller. A two-channel receiver with same function is implemented for increasing accuracy of target altitude data by amplitude comparison monopulse method. The TSS sensitivity of the receiver is -98dBm. The bandwidth of the receiver is 500 MHz. We can control the system gain manually by 100 dB when be AGC off. The gain and phase unbalance of two channels is 5 dB and 30 degree, respectively. The image rejection rate of the IQ detector is 30 dB. We used duroid substrate and package- type device.

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The Average Power Algorithm of Active Power Filters for Asymmetrical Three-Phase Three-Wire Power System (비대칭 3상 3선 전원 시스템을 위한 능동전력필터의 평균전력 알고리즘)

  • 정영국;김우용;임영철
    • The Transactions of the Korean Institute of Power Electronics
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    • v.6 no.6
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    • pp.514-524
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    • 2001
  • Conventional average power theory has been used to design and control active power filters But compensating reference currents of active power filters calculated by conventional average power theory are definitively influenced by three phase source voltage conditions such as unbalance or distortion. This paper presents a new average power algorithm for active power filters which can detect symmetrically equally active or fundamental reactive currents in each phase based on decomposition of fundamental reactive component and harmonics under unbalanced power conditions. The effectiveness of the proposed algorithm is demonstrated by MATLAB/SIMULINK simulation and experimental results for a three wire distribution system with 15% unbalanced source voltages.

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The Development of Integrated Power Quality Diagnosis System for Power System (전력계통 전력품질 통합진단시스템 개발)

  • Kwak, N.H.;Jeon, Y.S.;Park, S.H.;Lee, I.M.;Park, H.C.
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.277-279
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    • 2005
  • Recently, due to the increase of power conversion devices and nonlinear loads with the development of information, communication and control technologies, the instantaneous minute interruption factors such as voltage & current harmonics, surge occurring frequency, instantaneous voltage variation, voltage unbalance, flicker etc. have greatly threatened the power quality, and the deterioration of electric power facilities and the functional error of controllers are increasing. As such an instantaneous minute interruption appears to be small and local, accurate evaluation with measurement is difficult and total analysis system is required through a wide range of power quality effect analysis such as the simultaneous measurement on various power supply phenomena and the analysis on the interrelation with system loads. Most of conventional power quality diagnosis equipments have beer developed and applied, which were able to measure the stability rate of frequency, the stability rate of voltage, the electricity-failure duration etc, However, they were insufficient to analyze the system present situation, understand the cause of the failure occurred by the problem of power quality and analyze out the phenomena. Accordingly, this study will address the development of the system for a wide range of power quality diagnosis over the present level, the system for supporting the determination such as the analysis on risk factors, failure mode and impact, the system for harmonic evaluation based on international standards(IEC 61000 Series) and the total power quality diagnosis network & system with the extension and openness as a local and national-scale broadband power quality diagnosis system.

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The Comparative Study on the Myofascial Pain Syndrome vs. Twelve-Meridian Muscle System and the Interpretation through Yook Kyoung Theory (근막통증후군(筋膜痛症侯群)과 십이경근(十二經筋)의 비교(比較) 고찰(考察) 및 육경이론(六經理論)에 따른 해석(解釋))

  • Lee, Bong-Hyo;Lee, Yoon-Kyoung;Lee, Kyung-Min;Lim, Seong-Chul;Jung, Tae-Young;Seo, Jung-Chul;Yang, Chae-Ha;Choi, Seong-Hun
    • Journal of Acupuncture Research
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    • v.24 no.5
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    • pp.33-41
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    • 2007
  • Objectives : In oriental medicine, many researchers have studied Myofascial Pain Syndrome and Twelve-Meridian Muscle system in correlation with the orthodox form of muscular anatomy. In this study, the authors compared Myofascial Pain Syndrome with Twelve-Meridian Muscle system and interpreted Myofascial Pain Syndrome through Yook Kyoung theory to reveal the similarity between Myofascial Pain Syndrome and Twelve-Meridian Muscle system, as well as to suggest another useful therapeutics. Methods : The authors investigated several literatures related with Myofascial Pain Syndrome, Twelve-Meridian Muscle system and Yook Kyoung theory. Conclusions : 1. Myofascial Pain Syndrome and Twelve-Meridian Muscle system have many similar features in their theory, concept, physiological function, pathological symptom, therapeutic principal, etc., also have some different features. 2. Myofascial Pain Syndrome is thought to be induced by the unbalance between the upregulated-Kwelum energy and the downregulated-Soyang energy in a viewpoint of Yook Kyoung theory, therefore, it is requisite to control the unbalanced energy between Kwelum and Soyang.

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Cervical stabilization exercise using the Sling system (슬링(Sling) 시스템을 이용한 경부 안정화 운동)

  • Kwon, Jae-Hoak;Cho, Mi-Ju;Park, Min-Chull;Kim, Suhn-Yeop
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.8 no.2
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    • pp.57-71
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    • 2002
  • Cervical pain is a rapid increase that is owing to a flexion-extension whiplash injury, unappropriated posture, chronical repetition injury from abdominal position of head and neck, excessive repeating work, chronical deficiency of excercise. Because of that is bring about muscle unbalance, tightness of cervical extensor muscle, weakness of cervical deep flexor muscles, instability of cervical region and reduction of proprioceptive sensor. Recent the role of muscle is more emphasized for preservation of sine stabilization. And cognition of integrated muscular system, importance for the operation and relation is increased to maintain stability of the motor system and pertinent function. Therefore we are going to introduce the sling exercise and stabilization exercise method for advanced efficient of cervical and upper limb and for the muscle strengthening to importance cervical stabilization through neurological program as control the reaction of cervical stabilization. Sling exercise therapy(SET) concept consists of a system of diagnosis and treatment. The system of diagnosis involves testing the muscle's tolerance through progressive loading in open and close kinetic chains. The SET system contains elements such as relaxation, increasing the range of movement, traction, training the stabilizing musculature, sensory-motor exercises, training in open and close kinetic chains, dynamic training of the mobilizing musculature, cardiovascular exercise, group exercise, personal exercise at home Sensory-motor training is an essential element of the SET concept. The emphasis is on closed kinetic chain exercise on an unstable surface, there by achieving optimum stimulation of the sensory-motor apparatus.

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Selection of substitute medium of cotton seed pomace on the oyster mushroom for bottle cultivation (느타리버섯 병재배 면실박 대체배지 선발)

  • Kim, Jeong-Han;Ha, Tae-Moon;Ju, Young-Cheol
    • Journal of Mushroom
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    • v.3 no.3
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    • pp.105-108
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    • 2005
  • Main materials used as media for oyster mushroom cultivation are pine sawdust, beet pulp, cotton seed pomace. Increases in the price and the unbalance of demand and supply of cotton seed pomace was often damage to oyster mushroom cultivation farm, so we investigated agricultural by-product to replace the cotton seed pomace for bottle cultivation of oyster mushroom. Treatment of coconut oil meal or coconut pomace delayed incubation period about 3 days compared with cotton seed waste treatment(control), but yield and income index showed similar to each other in three treatment. Consequently coconut oil meal and coconut pomace could select for cotton seed pomace substitute.

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Effect of Harmonic Generation and Countermeasures (고조파발생에 따른 영향과 대책 연구)

  • Baek, Dong-Hyun
    • Fire Science and Engineering
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    • v.29 no.6
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    • pp.91-97
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    • 2015
  • Skyscrapers, large business buildings, and IT consumers use many appliances, and the electrical power stems can cause fires by overheating. This can result in damaged capacitors, lost data, rising ground potential, and communication obstacles from linear or nonlinear high frequency. To make sure of that we investigated 7 spots of a building, among which 6-spots were fair but the other one needed high frequency control. Spots 3, 6, and 7 needed diagnostic workup, and spots 2, 3, and 5 considered 5 high frequency currents. A phase is all of good but the high frequency current is greater than the standard level except for spot 1. As a result, a zigzag transformer or active filter needs to be installed, and the efficiency needs to be upgraded by investigating load unbalance factors and power factors.

A study on the Healing Mechanism of Herbal Medicine, Oryoungsan (오령산의 작용기전(作用機轉)에 대한 고찰(考察))

  • Nam, Hyoung-sin;Cho, Chung-sik;Kim, Chul-jung
    • Journal of Haehwa Medicine
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    • v.10 no.1
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    • pp.157-166
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    • 2001
  • Oryoungsan which first recorded in Sanghanron, the clinical medical book consists of treating acute febrile disease according to its change, is one of the frequently used oriental medicines. these days, it has been prescribed in symptoms accompanied by edema mostly. therefore it is easy to consider it as a type of diuretics. In Sanghanron it was originally used in the symptoms of perspiration, decreased urine volume, thirsty, flatulence. these symptoms indicate loss of body fluid and the prescription which orders "taking warm water sufficiently" supports this. On this background, it is supposed that Oryoungsan treats dehydration after providing water and electrolytes. To consider that herbal medicines consisted of Oryoungsan make electrolytes go out of the body, The healing mechanism of dehydration doesn't meet this. Because Oryoungsan was used in condition of fever or in similar condition, it is more resonable to understand that restoration of increasing blood flow to the subcutaneous venous plexus regulating body temperature in febrile condition into body circulation, resulting into maintaining main blood volume and into treating decreased urine volume and thirsty is Oryoungsan's function in the dehydration or febrile condition. That is, symptoms are decreased or disappeared through restoring unbalance of internal body fluid. The other target is pain controls, especially chronic headache, facial pain and trigeminal neuralgia. it is suggested that the function of pain control of Oryoungsan is related to 5-HT(5-hydroxytrypamine), nerve transmitter in the endogenous analgesic system. Moreover it is also suggested that Oryoungsan is relate to 5-HT, considering the fact that gastroparesis, a symptom of cyclic vomiting syndrome treated with 5-HT1D receptor agonist is similar to the 'bi', symptoms appeared in the Oryoungsan-related disease.

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