• Title/Summary/Keyword: Internal Balance

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A Study on the Proper Number of Banks of Parallel Operation of Transformer in Large-scale Power Plants Using the High Temperature Fuel Cell Considering the Internal Failure (내부고장을 고려한 고온형 연료전지 대규모 발전단지의 병렬운전 변압기 적정 뱅크수에 관한 연구)

  • Chong, Young-Whan;Chai, Hui-Seok;Sung, In-Je;Kim, Jae-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.3
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    • pp.26-31
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    • 2014
  • High temperature fuel cell system, such as molten carbonate fuel cells(MCFC) and solid oxide fuel cells(SOFC), are capable of operating at MW rated power output. The power output change of high temperature fuel cell imposes the thermal and mechanical stresses on the fuel cell stack. To minimize the thermal-mechanical stresses on the stack and increase the systems reliability, we should divide the power plant configuration to several banks. However, the improvement of reliability in fuel cell power plant system causes an increase of the investment cost, for example, replacement costs, labor costs, and so on. For this reason - the balance between investment and reliability improvement - many studies about the appropriate level of investment have been conducted. In this paper, we evaluate the cost for operation and installation, the benefit for electric energy and thermal energy sales, and the system reliability for several cases : these cases relate with the bank configuration.

A Literature Study on Five Type Personality (Wutairen) in China: characteristic, treatment and prevention (중국 오태인 체질이론의 문헌연구: 체질 특성과 치료, 양생법)

  • Cui, Zhen-Yang;Gwak, Si-Ra;Joo, Jong-Cheon
    • Journal of Sasang Constitutional Medicine
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    • v.30 no.1
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    • pp.14-23
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    • 2018
  • Objectives Because of growing interest in personalized medicine, constitutional medicine also becomes more important. Constitutional medicine has already developed in many countries. In this study, we tried to investigate five type personality (Wutairen), a kind of Chinese constitutional medicine. Methods We did a research on five type personality using CNKI (http://www.cnki.net) up to Jan 15, 2018. Total 204 papers were searched with the keyword "Wutairen". We excluded 170 papers away from the subject or clinically studied. As a result, 34 papers were selected and analyzed. Results and Conclusions Five type personality (Wutairen) originated from Huangdi Neijing-Lingshu. There are 5 types: greater Yin person (Taiyin), lesser Yin person (Shaoyin), greater Yang person (Taiyang), lesser Yang person (Shaoyang) and Yin-yang balanced person. These are classified according to Yin-Yang content. Each type has different characteristic, treatment and prevention. Five type personality theory considers internal factors more important than external factors. Also, it considers the balance of Yin-Yang important.

Design of a New Harmonic Noise Frequency Filtering Down-Converter in InGaP/GaAs HBT Process

  • Wang, Cong;Yoon, Jae-Ho;Kim, Nam-Young
    • Journal of electromagnetic engineering and science
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    • v.9 no.2
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    • pp.98-104
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    • 2009
  • An InGaP/GaAs MMIC LC VCO designed with Harmonic Noise Frequency Filtering(HNFF) technique is presented. In this VCO, internal inductance is found to lower the phase noise, based on an analytic understanding of phase noise. This VCO directly drives the on-chip double balanced mixer to convert RF carrier to IF frequency through local oscillator. Furthermore, final power performance is improved by output amplifier. This paper presents the design for a 1.721 GHz enhanced LC VCO, high power double balance mixer, and output amplifier that have been designed to optimize low phase noise and high output power. The presented asymmetric inductance tank(AIT) VCO exhibited a phase noise of -133.96 dBc/Hz at 1 MHz offset and a tuning range from 1.46 GHz to 1.721 GHz. In measurement, on-chip down-converter shows a third-order input intercept point(IIP3) of 12.55 dBm, a third-order output intercept point(OIP3) of 21.45 dBm, an RF return loss of -31 dB, and an IF return loss of -26 dB. The RF-IF isolation is -57 dB. Also, a conversion gain is 8.9 dB through output amplifier. The total on-chip down-converter is implanted in 2.56${\times}$1.07 mm$^2$ of chip area.

The study on the Re - design of Banking Business using the Information Technology (정보처리기술을 이용한 은행업무의 재설계에 관한 연구)

  • Lee, Sun-Cheol;Cheon, Jeong-Rak
    • Asia pacific journal of information systems
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    • v.6 no.1
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    • pp.125-163
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    • 1996
  • Since the bank managers were accustomed to be under the goverment policy and control so far, all what they had to do were just to follow the government policy and wait for customers. These usual practices resultedin neglection of concerns for innovation and competitive power. However, it currently happens the change of business environment such as the liberalization of interest rates and the open finance market policy. Thus, it is necessary for the bank managers to have a concern on that situation for the improvement of profitability through productivity and cost-down. The bank managers are trying to set out an innovation strategy to cope with this situation. An innovation strategy should be based on its own characteristics of banking business. The banking business is different from those of other business because it deals with intangible services rather than material goods and thus, the bank managers have to be more sensitive to the customers. There also exists an inefficiency of internal process due to too many repetition of 'check and balance'. Thus, We set out the five principles and six selected tasks in order to settle down an inefficiency and to redesign a bank operation process.

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Nutritional Management in Patients with Chronic Obstructive Pulmonary Disease (만성폐쇄성폐질환 환자의 영양관리)

  • Lee, Kwan-Ho
    • Journal of Yeungnam Medical Science
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    • v.21 no.2
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    • pp.133-142
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    • 2004
  • Chronic obstructive pulmonary disease(COPD) is characterized by a not entirely reversible limitation in the airflow. An airflow limitation is progressive and associated with an abnormal inflammatory response of the lung to gases and harmful particles. In COPD, the weight loss is commonly observed and there is a negative impact on the respiratory as well as skeletal muscle function. The pathophysiological mechanisms that result in weight loss in COPD are not fully understood. However, the mechanisms of weight loss in COPD may be the result of an increased energy expenditure unbalanced by an adequate dietary intake. The commonly occurring weight loss and muscle wasting in COPD patients adversely affect the respiratory and peripheral muscle function, the exercise capacity, the health status, and even the survival rates. Therefore, it is very valuable to include management strategies that the increase energy balance in order to increase the weight and fat free mass. A Better understanding of the molecular and cellular pathological mechanisms of COPD can improve the many new directions for both the basic and clinical investigations. The Nutritional supply is an important components of a multidisciplinary pulmonary rehabilitation program. Future studies combining an exercise program, the role of anabolic steroids, nutritional individualization, a more targeted nutritional therapy, and the development of new drugs including anti-cytokines is needed for the effective management of COPD.

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A Review of Factors in Elderly Health-Promotion Behaviors (노인의 건강증진 행위와 관련된 변수분석)

  • Jeon, Jae-Kyun;Mun, Mi-Suk
    • The Journal of Korean Physical Therapy
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    • v.13 no.1
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    • pp.107-114
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    • 2001
  • Recently the number of elderly have been increasing at a rapid pace in Korea. Accompanying this aged society are numerous health problems. Whit this in mind health-promotion behaviors such as physical activity. good nutrition and stress management are vitally important to the elderly in reducing the risk of Health problems, maintaining health and improving the overall quality of life. Health promotion programs for the elderly must be developed. The purpose of th is study was to determine influential cognitive factors on health-promotion behaviors and the effects of previously implemented Health promotion programs. For this, previous studies were reviewed and analyzed. The results were as follows. 1. Cognitive factors on health-promotion behaviors were internal locus of control, perceived health status, self-efficacy, concerns about health, social support, attending social activities. 2. Components of health promotion programs were exercise and health education. Exercise was performed in most programs. The effects of exercise programs were improved flexibility, muscle strength. balance, cardiopulmonary function and elevated ability of daily living, perceived health status, quality of lift and a decrease depression. The results strongly suggest that complex health promotion programs should be developed. Health promotion programs need to include exercise, health education, health counseling and social activities. We have to consider cognitive factors on health-promotion behaviors.

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Optimum Welding Position between Shell and Cylinder based on SEA (SEA를 이용한 셸과 실린더의 최적 용접 조건)

  • 이장우;양보석;안병하
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.5
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    • pp.370-376
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    • 2004
  • The overall aim of this paper is to determine coupling loss factor of welding point between shell and cylinder using loss factor and structural loss factor. For this purpose, two kinds of loss factor were adopted. One is loss factor of each sub structure, another is structural loss factor based on the complex welded or assembled structure. Using these two parameters, it ispossible to derive the coupling loss factor which represent characteristic condition of SEA theory. Coupling loss factor of conjunction in complex structure was expressed as power balance equation. The derived equation for a coupling loss factor has been simplified on the assumption of one way (uni-directional) power flow between multi-sub structures. Using these conditions, it is possible to find the equation of coupling loss factor expressed as above two loss factors. To check the effectiveness of above equation, this paper used two-stage application. The first approach was application between simple cylinder and shell. The next was adopted rotary compressor. Rotary compressor has three main conjunctions between shell and internal vibration part. This equation was applied to find out the optimum welding point with respect to reduce the noise propagation. It shows the effective tool to evaluate the coupling loss factor in complex structure

Study on the Dynamic Torsional Instability of a Thin Beam (비틀림 하중을 받는 얇은 빔의 동적 불안정성에 관한 연구)

  • 박진선;주재만;박철희
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1995.10a
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    • pp.185-190
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    • 1995
  • In recent years, many researcher have been interested in the stability of a thin beam. Among them, Pai and Nayfeh[1] had investigated the nonplanar motion of the cantilever beam under lateral base excitation and chaotic motion, but this study is associated with internal resonance, i.e. one to one resonance. Also Cusumano[2] had made an experiment on a thin beam, called Elastica, under bending loads. In this experiment, he had shown that there exists out-of-plane motion, involving the bending and the torsional mode. Pak et al.[3] verified the validity of Cusumano's experimental works theoretically and defined the existence of Non-Local Mode(NLM), which is came out due to the instability of torsional mode and the corresponding aspect of motions by using the Normal Modes. Lee[4] studied on a thin beam under bending loads and investigated the routes to chaos by using forcing amplitude as a control parameter. In this paper, we are interested in the motion of a thin beam under torsional loads. Here the form of force based on the natural forcing function is used. Consequently, it is found that small torsional loads result in instability and in case that the forcing amplitude is increasing gradually, the motion appears in the form of dynamic double potential well, finally leads to complex motion. This phenomenon is investigated through the poincare map and time response. We also check that Harmonic Balance Method(H.B.M.) is a suitable tool to calculate the bifurcated modes.

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A Study on the Changes of Urinary Hormonal Excretion and Renal Function During Three-shift Nursing Practice (일일 3교대 간호활동시 호르몬분비 및 신장기능의 변화에 관한 연구 -간호학생을 대상으로-)

  • 김명애
    • Journal of Korean Academy of Nursing
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    • v.16 no.3
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    • pp.78-96
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    • 1986
  • The sympathico-adrenergic system and the hypophyseal-adrenocortical system mediates the regulation of the internal milieu. And the kidneys regulate both water and electrolyte balance of the body fluid. The kidneys are the sites of production of renin which participate indirectly in maintaining renin. angiotensin-aldosterone system. These system de-serve special attention in the context of adjustment the effects on the body function. And so, maximal exercise and work load are associated with home-osthetic function. The nurses working in the hospital have been complained of fatigue and stress by frequent duty changes and overload. In order to define this, the possible changes of hormonal excretion during three-shift nursing practice were investigated. Urine samples were collected at pre-duty and post-duty, and were measured with chemical assay and radioimmunoassay in 30 nursing students, in nursing practice and 43 nursing students, in studying. The results obtained were as follows. 1. In nursing practice, urinary norepinephrine concentration showed a marked increase during day duty, urinary cortisol concentration showed a marked increase during evening duty, and urinary renin concentration was increased in night duty, 2. Corrected ratio of urinary sodium excreted by the urinary excretion of creatinin (UNa/UCr) and UCl/UCr showed a marked decrease during night duty. Nursing practice did not affect on the UK/UCr and urinary concentrating ability. From these results, it is suggested that further studies the define the effects on some physiological function of the three-shift nursing practice against circadian rhythm are needed for better working condition of nurses.

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The Characteristics of Fatigue Cracks Emanating from Micro Hole Defects Located Opposite Position of the Shaft Cross Section (축 단면 내 대칭 위치의 미소 원공 결함에서 발생한 피로균열 특징)

  • Song, Sam-Hong;Bae, Jun-Su;Ahn, Il-Hyuk
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.211-216
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    • 2001
  • The components with the circular cross section have the symmetric combination parts for rotating balance and the crack emanates from the symmetric combination parts. The symmetric cracks from symmetric combination parts make a decrease in the component fatigue life more than single crack. In this study, to estimate the behavior of symmetric cracks, the fatigue test was performed using rotary bending tester on the specimen with a symmetric defects in circular cross section. The material used in this study is Ni-Cr-Mo steel alloy. Under the same stress, the result from the rotary bending fatigue test turned out that the symmetric cracks made a decrease in the fatigue life by 35% more than single crack and the relation between log a and cycle ratio $N/N_f$ obtained linearly.

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