• Title/Summary/Keyword: and passivity

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Equivalent Circuit Model of RF passive components based on its simulated frequency response data (EM Solver 의 주파수 응답 데이터를 이용한 RF 수동 소자의 등가회로 모델링에 관한 연구)

  • Oh, Sang-Bae;Ko, Jae-Hyeong;Han, Hyeong-Seok;Kim, Hyeong-Seok
    • 한국정보통신설비학회:학술대회논문집
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    • 2007.08a
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    • pp.27-30
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    • 2007
  • This paper deals with an equivalent circuit model for RF passive components. Rational functions are obtained from the frequency responses of EM simulation by using Foster canonical partial fraction expressions. The Vector Fitting(VF) and the Adaptive Frequency Sampling(AFS) scheme are also implemented to obtain the rational functions. A passivity enforcement algorithm is applied to ensure the stability of the equivalent circuit model. In order to verify the schemes, S parameters of the equivalent circuit model is compared to those of EM simulation in case of the microstrip line structure with 3 slots in ground.

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Design of an improved PID controller for DC/DC boost pourer converter with inductor resistance under load variation (부하변동과 인덕터 저항을 고려한 DC/DC 승압 컨버터의 개선된 PID 제어기 설계)

  • Kim, In-Hyuk;Jeong, Goo-Jong;Son, Young-Ik
    • Proceedings of the IEEK Conference
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    • 2009.05a
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    • pp.85-87
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    • 2009
  • This paper presents a new PID controller for a DC/DC boost converter model that has a parasitic inductor resistance. In order to maintain the robust output regulation property under load variations the proposed controller is designed by using an additional state variable developed via a parallel-damped passivity-based control approach. Simulation results using Matlab/Simulink SimPowerSystems compare the performances of the proposed controller with a conventional PI controller for reference step changes and load uncertainties.

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The Study of Corrosion of Heat Exchanger Tube for Absorption Refrigeration Machine (흡수식냉동기용 열교환기 세관의 부식에 관한 연구)

  • 임우조;정기철;윤병두
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2002.05a
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    • pp.147-152
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    • 2002
  • This paper was studied on corrosion of heat exchanger tube for absorption refrigeration machine. In the 62 % lithium bromide solution at $60^{\circ}C$, polarization test of Cu, Al-brass, 10 % cupro nickel(90-10 % Cu-Ni) and 30 % cupronickel(70-30 % Cu-Ni) tube was carried out. And polarization behavior, polarization resistance characteristics, open circuit potential, anodic polarization of heat exchanger tube for absorption refrigeration machine were considered. The main results are as following: The open circuit potential of Al-brass tube becomes less noble than that of Cu tube, corrosion current density of that becomes lower than Cu tube. The open circuit potential of cupronickel tube is more noble than that of Cu tube, corrosion current density of that is controlled than Cu tube. The passivation critical current of 30 % Cu-Ni tube is lower than that of 10 % Cu-Ni tube, potential of passive region of that is more wide than 10 % Cu-Ni tube.

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Variable Configuration Tracked Mobile Robot for Demining Operations (지뢰제거작업을 위한 가변 형상 무한궤도형 주행 로봇)

  • Jeong, Hae-Kwan;Kim, Sang-Do;Lee, Cheong-Hee;Kwak, Yoon-Keun
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.804-809
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    • 2004
  • This paper introduces a link-type tracked vehicle which is developed for demining operations. The vehicle consists of three parts - front frame, rear frame and body. The front frame is connected to the rear frame by a rotational passive adaptation mechanism which is a driving mechanism of the vehicle. Additionally, the demining system which is adaptable to mobile robot is developed to clear small Anti-Personnel(AP) mines with inexplosive method. In other words, assembled rakes unearth mines by their opposite rotation to the direction of the robot. Finally, the motions of demining rakes and design parameters of the demining system are analyzed.

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A Qualitative Study of Interpretations of Grandmothers' Childrearing Experiences (손자녀 양육지원 경험에 대한 할머니들의 해석에 관한 질적 연구)

  • An, Heelan;Kim, Seonmi
    • Journal of Family Resource Management and Policy Review
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    • v.19 no.1
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    • pp.93-109
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    • 2015
  • This study explores interpretations of grandmothers' experiences rearing their grandchildren. For this study, 13 participants provided in-depth interview data, which was analyzed according to Spradely's ethnographic method. Based on the pattern of interpretations, nine concepts were classified into three categories: (i) repentance (compulsive decisions, passivity of the childrearing activity, non-compensation); (ii) sorrow (restrictions on everyday life, renunciation of occupational careers, worsened health); and (iii) satisfaction (decreased isolation in old age, proof of existence for their children, intimacy development with their grandchild). The results of this study show that grandmothers have a higher appreciation for the benefits of relational compensation than for personal cost. Some practical implications are suggested to improve family welfare.

Formation of Resilience in the Context of Volunteer Activities Using Information and Communications Technology

  • Lazarenko, NataLiia;Sabat, Nataliia;Sabat, Nadiia;Sylenko, Nadiia;Rundong, Wang;Duchenko, Anna;Shuppe, Liudmyla
    • International Journal of Computer Science & Network Security
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    • v.22 no.6
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    • pp.374-381
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    • 2022
  • The article identifies and theoretically substantiates the trends of national resilience in the context of establishing the security of the country and its civilizational subjectivity. The strategy of development of the pedagogical university in the conditions of European integration into the European educational and scientific space based on certain characterological features of the personality of the volunteer in the context of allocation of personal resilience is developed. The analysis of both external and internal challenges and threats to the civilization of the country needs to be understood in the context of economic, socio-political, legal, military-political, spiritual-cultural, educational-scientific and network-information resilience. The concepts of "national resilience" and "national security" are quite close - at first glance, even identical. However, a deeper understanding clarifies the differences: national security is a state of protection of the country identity and its very existence, the realization of its national interests. In turn, resilience is a fairly effective strategy and a fundamental guarantee of national security. At the same time, it is extremely important to understand that both national security as a state and national resilience as a strategy are only means of achieving and developing a strong and humanistic civilizational subjectivity of the country. After all, such subjectivity opens for citizens the opportunity for development, dignified self-realization and a proper life. The restructuring of the volunteer's motivational sphere is due to the dominance of such leading motives, which are focused mainly on maintaining and restoring health, which leads to distorted meaningful life goals: isolation, alienation, passivity, inertia, reduced activity, limited communication, etc. The characteristics of relatively stable human behavior include several primary and secondary properties. The primary (relevant) properties include patience, trust, hope, faith, confidence, determination, perseverance, and love; the secondary - punctuality, neatness, obedience, honesty, loyalty, justice, diligence, thrift, accuracy, conscientiousness, obligation, etc. The restructuring of the volunteer's motivational sphere is due to the dominance of such leading motives, which are focused mainly on maintaining and restoring health, which leads to distorted meaningful life goals: isolation, alienation, passivity, inertia, reduced activity, limited communication, etc. The characteristics of relatively stable human behavior include several primary and secondary properties. The primary (relevant) properties include patience, trust, hope, faith, confidence, determination, perseverance, and love; the secondary - punctuality, neatness, obedience, honesty, loyalty, justice, diligence, thrift, accuracy, conscientiousness, obligation, etc. The use of information and communication technologies in volunteering will contribute to the formation of resilience traits in the structure of personality formation. Directly to the personal traits of resilience should be included methodological competencies, which include methodological knowledge, skills and abilities (ability to define ultimate and intermediate goals, plan, conduct and analyze knowledge, establish and implement interdisciplinary links with disciplines of medical-psychological-pedagogical cycles, etc.). All these competencies form the professional resilience of the volunteer.

Apparatus on Corrosion Protection and Marine Corrosion of Ship (선박의 해양 부식과 부식방지 장치)

  • Kim, Seong-Jong
    • Journal of Surface Science and Engineering
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    • v.44 no.3
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    • pp.105-116
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    • 2011
  • Ships and offshore structures are exposed to harsh marine environments, and maintenance and repair are becoming increasingly important to the industry and the economy. The major corrosion phenomenons of metals and alloys in marine environment are pitting corrosion, stress corrosion cracking, crevice corrosion, fatigue corrosion, cavitation-erosion and etc. due to the effect of chloride ions and is quite serious. Methods of protection against corrosion can generally be divided into two groups: anodic protection and cathodic protection. Anodic protection is limited to the passivity characteristics of a material in its environment, while cathodic protection can apply methods such as sacrificial anode cathodic protection and impressed current cathodic protection. Sacrificial anode methods using Al and Zn alloys are widely used for marine structures and vessels intended for use in seawater. Impressed current cathodic protection methods are also widely used in marine environments, but tend to generate problems related to hydrogen embrittlement caused by hydrogen gas generation. Therefore, it is important to the proper maintenance and operation of the various corrosion protection systems for ship in the harsh marine environment.

Effects of Solidification Modes on the Pit Initiation and Propagation in Austenitic Stainless Steel Weld Metals (오스테나이트계 스테인리스강 용착금속의 응고모드가 공식 생성 및 성장에 미치는 영향 x Effects of Solidification Modes on the Pit Initiation and Propagation in Austenitic Stainless Steel Weld Metals)

  • 최한신;김규영;이창희
    • Journal of Welding and Joining
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    • v.16 no.6
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    • pp.59-68
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    • 1998
  • In this study, effects of solidification modes (primary $\delta$-ferrite, primary ${\gamma}$-austenite) on the pit initiation and propagation in the 304L and 316L austenitic stainless steel weld metals were investigated. The solidification mode of weld metal was controlled by the addition of nitrogen to Ar shielding gas. Through the electrochemical experiments (potentiodynamic anodic polarization and potentiostatic time-current transient test) and metallographic examination (microstructure and elemental distribution), the following results were obtained. The more the volume content of nitrogen in the shielding gas were, the lower critical current density for passivity was observed. In comparison with weldments solidified through the primary $\delta$-ferrite solidification mode and the primary ${\gamma}$-solidification mode, the former showed higher critical pitting potential and a longer incubation time for stable pit initiation than the latter. However, in the pit propagation stage the former exhibited a faster dissolution rate than the latter. These results were believed to ee related to the distribution of alloying elements such as Cr, Mo, Ni and S.

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Corrosion Mechanism and Bond-Strength Study on Galvanized Steel in Concrete Environment

  • Kouril, M.;Pokorny, P.;Stoulil, J.
    • Corrosion Science and Technology
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    • v.16 no.2
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    • pp.69-75
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    • 2017
  • Zinc coating on carbon steels give the higher corrosion resistance in chloride containing environments and in carbonated concrete. However, hydrogen evolution accompanies the corrosion of zinc in the initial activity in fresh concrete, which can lead to the formation of a porous structure at the reinforcement -concrete interface, which can potentially reduce the bond-strength of the reinforcement with concrete. The present study examines the mechanism of the corrosion of hot-dip galvanized steel in detail, as in the model pore solutions and real concrete. Calcium ion plays an important role in the corrosion mechanism, as it prevents the formation of passive layers on zinc at an elevated alkalinity. The corrosion rate of galvanized steel decreases in accordance with the exposure time; however, the reason for this is not the zinc transition into passivity, but the consumption of the less corrosion-resistant phases of hot-dip galvanizing in the concrete environment. The results on the electrochemical tests have been confirmed by the bond-strength test for the reinforcement of concrete and by evaluating the porosity of the cement adjacent to the reinforcement.

Validation of an Instrument to Measure Exercise of Self-Care Agency and its Predictors (자가간호역량의 행사 측정도구의 타당성 및 예측요인 조사)

  • 소향숙;이은숙
    • Journal of Korean Academy of Nursing
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    • v.19 no.3
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    • pp.273-284
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    • 1989
  • The aim of this investigation was to delineate concepts contributing to the Exercise of Self-Care Agency (E.S.C.A.) Scale developed by Kearney & Fleischer (1979) and to test its construct validity and its predictors. The results are summarized as follows ; 1. By means of principal factor analysis and maximal likelihood factor analysis upon data generated from 280 undergraduate students, the factors of Concern about Health Knowledge, self-Concept, Information - Seeking Behavior, Decision -making and Responsibility, Self-esteem, and Passivity emerged. The total percent of variance explained by the 6 factors was 75.1% 2. To assess factor independence and instrument homogeneity, correlations among the 6 factors were computed. The correlations ranged from .24 to .46 indicating that the factors and the items were not too similar or redundant. 3. Test-retest reliability of the total scale is r=.70. Cronbach's $\alpha$ coefficient for internal consistency of the total scale is .86 and that of the factors ranged from .750 to .661 (only factor 6 .497). 4. In additional analysis of the Exercise of Self-Care Agency Scale in relationship to Multiple Health Locus of Control, Family Environmental Scale, and Cornell Medical Index using stepwise multiple regression, the Internal Health Locus of Control Score predicted 21.8%(F=53.34, p=.0001), Family Environmental Score 8.3%(F=22.59, P=.0001), Modified Cornell Medical Index Score 5.4%(F=15.74, P=.0001) of the score of the E.S.C.A.

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