• Title/Summary/Keyword: Passive Type

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ROLE OF PASSIVE SAFETY FEATURES IN PREVENTION AND MITIGATION OF SEVERE PLANT CONDITIONS IN INDIAN ADVANCED HEAVY WATER REACTOR

  • Jain, Vikas;Nayak, A.K.;Dhiman, M.;Kulkarni, P.P.;Vijayan, P.K.;Vaze, K.K.
    • Nuclear Engineering and Technology
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    • v.45 no.5
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    • pp.625-636
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    • 2013
  • Pressing demands of economic competitiveness, the need for large-scale deployment, minimizing the need of human intervention, and experience from the past events and incidents at operating reactors have guided the evolution and innovations in reactor technologies. Indian innovative reactor 'AHWR' is a pressure-tube type natural circulation based boiling water reactor that is designed to meet such requirements, which essentially reflect the needs of next generation reactors. The reactor employs various passive features to prevent and mitigate accidental conditions, like a slightly negative void reactivity coefficient, passive poison injection to scram the reactor in event of failure of the wired shutdown systems, a large elevated pool of water as a heat sink inside the containment, passive decay heat removal based on natural circulation and passive valves, passive ECC injection, etc. It is designed to meet the fundamental safety requirements of safe shutdown, safe decay heat removal and confinement of activity with no impact in public domain, and hence, no need for emergency planning under all conceivable scenarios. This paper examines the role of the various passive safety systems in prevention and mitigation of severe plant conditions that may arise in event of multiple failures. For the purpose of demonstration of the effectiveness of its passive features, postulated scenarios on the lines of three major severe accidents in the history of nuclear power reactors are considered, namely; the Three Mile Island (TMI), Chernobyl and Fukushima accidents. Severe plant conditions along the lines of these scenarios are postulated to the extent conceivable in the reactor under consideration and analyzed using best estimate system thermal-hydraulics code RELAP5/Mod3.2. It is found that the various passive systems incorporated enable the reactor to tolerate the postulated accident conditions without causing severe plant conditions and core degradation.

A Study on Automobile Information Search Activity According to Urban Housewives' Life Style (도?주부의 Life Style에 따른 승용차 정보탐색활동에 관한연구)

  • 양남희
    • Journal of Families and Better Life
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    • v.11 no.2
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    • pp.13-29
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    • 1993
  • The Purpopse of this study are to classify the lifestyles of urban housewives with automobiles living in Gwangju to see their relationship between lifestyle and demographic social and econo-mic variables and to see the relationship between lifestyle and prepurchase information search activity. For these purpose a survey was conducted using questionaires on 410 The data was collected from March 8 to March 20 1993 and analyzed by factor analysis cluster analysis Duncan test {{{{ chi ^2 }} }}- t e s t a nd ANOVA. The findings are classified into 7 types: enjoyable convenience type (15.6%) conservative sound and thrifty type(17.3%) rationative type (13.2%) thrifty life type (11.0%) passive-inactive type(8.3%) fashion-pursuity type(12.9%) 2) The lifestyles of he respondents showed significant difference according to their age education level employment status. length marriage consumer education and type of housing. 3) The lifestyles of the respondents showed a difference only automobile attitude While showing no significant difference by automobile size information sources of automobile priority of automobile attitude and time spent in searching information The lifestyle of respondents showed a difference by automobile price size quality secuity warranty service and maintenance cost. 4) Among the lifestyle patterns of the respondents the passive-inactive type and rationative typ were positive about all the prepurchase information activity of automobile.

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Satisfaction, Reliability, and Word-of-Mouth Intention for Online Information According to Cosmetic Consumer Information Search Types

  • Shin, Saeyoung
    • Journal of Fashion Business
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    • v.23 no.6
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    • pp.49-63
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    • 2019
  • The purpose of this study was to determine the satisfaction, trust and word-of-mouth intention of online information according to the type of information search by female cosmetics consumers in their 20's to 40's. For this study, online and offline surveys were conducted by 307 people. Factor, correlation, and multiple regression analysis were used to analyze the data. The main results are summarized as follows. First, the cosmetic consumer's information search types were identified as active, playful, and economic information search types. Second, the results of examinations on the effect of consumer information search types on satisfaction, reliability, and word-of-mouth intention of the online information searches showed that the active information search type had a positive effect on satisfaction, reliability, and word-of-mouth intention. The economic information search type had a positive effect on satisfaction. The active information search type was confirmed to have high satisfaction, reliability, and word-of-mouth intention for the provided information and thus, the acceptance of the provided information was high. The playful information search type was divided into continuous, habitual, and independent information search and a tendency to assign a low value to consumer information was confirmed. The economic information search type showed high satisfaction with the information obtained by searching, but also a passive attitude toward trust or word-of-mouth intention and was categorized as a passive search type. Online information search is a communication channel with a great influence that can provide various benefits to cosmetic consumers.

The Design of Long-life and High-efficiency Passive LED Drivers using LC Parallel Resonance (LC 병렬공진을 이용한 고효율 장수명 LED 구동회로 설계)

  • Lee, Eun-Soo;Choi, Bo-Hwan;Cheon, Jun-Pil;Kim, Bong-Cheol;Rim, Chun-Taek
    • The Transactions of the Korean Institute of Power Electronics
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    • v.18 no.4
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    • pp.397-402
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    • 2013
  • This paper proposes a new passive type LED driver which satisfies the standard of power factor (PF) and total harmonic distortion (THD). The proposed passive LED driver also has high-efficiency and long-life time characteristics compared to active LED driver which is composed of op-amp, switches and so on. By using just passive components such as inductor, capacitor, and diode, it has resolved extremely short-life time and low-efficiency problems of previous LED drivers. It has achieved PF of 0.99, THD of 16.4 %, and the total efficiency of 95 %. The proposed passive LED driver is fully analyzed and verified by simulations and experiments, which results are in good agreement each other.

Why Smartphone Users are Not Using Mobile Banking: Focusing on the Difference between Passive Resistance and Active Resistance (스마트폰 사용자가 모바일뱅킹을 사용하지 않는 이유: 소극적 저항과 적극적 저항의 차이를 중심으로)

  • Kim, Jongki;Kim, Jiyun
    • The Journal of Information Systems
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    • v.27 no.3
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    • pp.81-102
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    • 2018
  • Purpose The purpose of this study is to investigate the reason why smartphone users do not use mobile banking based on Status Quo Bias and to find out whether there is a difference between passive resistance and active resistance. Design/methodology/approach This study made a design of the research model based on Status Quo Bias. SPSS 23.0 and SmartPLS 2.0 were used for the analysis. Multiple group analysis was performed to identify differences between groups. Findings According to the empirical analysis result, this study confirmed that inertia and perceived risk affected smartphone users who do not use mobile banking. According to the type of resistance, the active resistance group(64.2%) was more than the passive resistance group(35.8%), and it was confirmed that there was a difference in the reasons for not using mobile banking between passive and active resistance group. That is, the greatest difference between passive and active resistance groups was found to be perceived risk, which is an assessment of risk.

A study on Life Style and Clothing Involvement of Elderly Women (노년기 여성의 라이프 스타일과 의복관여에 관한 연구)

  • 이은실;이명희
    • Journal of the Korean Society of Costume
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    • v.25
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    • pp.233-247
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    • 1995
  • The objectives of this study were to classify the contents of clothing involvement, to group elderly women into life style types. A method of this study was face to face re-search and questionnaire. Questionnaire was comprised of four sections : 18 Likert type items of clothing involvement measure ; 26 Likert type items of life style measure ; 3 items of clothing purchase measure ; and 3 demographic variables. Samples were 215 elderly women(60∼79 years of age) in Seoul, Korea. The data were analyzed using factor analy-sis, cluster analysis, one-way ANOVA, Dun-can's multiple range test,χ2 test. The results of the study were the follow-ings. 1. Four factors of clothing involvement derived by factor analysis : F.1 'clothing pleasure'; F.2 'clothing symbolism' ; F.3 'perceived risk in clothing purchase' ; F.4 'clothing interest'. 2. Four factors of life style derived by factor analysis : F.1 'active-leisure';F.2 'confidence oriented';F.3 'appearance interest';F.4 'house-work interest and community conciousness'. Three types of life style were defined by the cluster analysis of the 4 factors : T.1 'passive stag-nation'; T.3'outside activity'. 3. There were significant differences in clothing involvement factors according to life style types. Outside activity type perceived 'clothing pleasure' highest level among 3 life style types. Outside activity type and house-work and positive living type perceived 'cloth-ing symbolism' and 'clothing interest' higher level than did passive stagnation types. 4. Elderly women high in educational level were more distributed in outside activity type and the low in educational level in passive stagnation types. 5. There were significant relationships be-tween life style types and source of a clothing allowance, clothing purchase frequency, and a companion of dress store.

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Numerical Study on the Cooling Characteristics of a Passive-Type PEMFC Stack (수동공기공급형 고분자 전해질 연료전지 스택에서의 냉각특성에 대한 전산해석 연구)

  • Lee, Jae-Hyuk;Kim, Bo-Sung;Lee, Yong-Taek;Kim, Yong-Chan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.8
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    • pp.767-774
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    • 2010
  • In a passive-type PEMFC stack, axial fans operate to supply both oxidant and coolant to cathode side of the stack. It is possible to make a simple system because the passive-type PEMFC stack does not require additional cooling equipment. However, the performance of a cooling system in which water is used as a coolant is better than that of the air-cooling system. To ensure system reliability, it is essential to make cooling system effective by adopting an optimal stack design. In this study, a numerical investigation has been carried out to identify an optimum cooling strategy. Various channel configurations were applied to the test section. The passive-type PEMFC was tested by varying airflow rate distribution at the cathode side and external heat transfer coefficient of the stack. The best cooling performance was achieved when a channel with thick ribs was used, and the overheating at the center of the stack was reduced when a case in which airflow was concentrated at the middle of the stack was used.

Development of the Passive-Active Vibration Absorber Using Piezoelectric Actuators (수동-능동 압전형 진동흡수장치의 개발)

  • Kwak, Myung-Hoon;Heo, Seok;Kwak, Moon-K
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.05a
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    • pp.308-312
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    • 2001
  • This research is concerned with development of the passive-active vibration absorber using piezoelectric actuators. This active-passive isolation system consists of 4-pairs of PZT actuators bonded on accordion type of mounting bracket and a spring-damper located in center. Hence, the active system is connected in parallel to the passive system. In this paper, we discuss the dynamic characteristics of the addressed system. Based on the series of experiment, it is found that the proposed system can cope with the external disturbances. The controller design is currently under investigation.

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Design and Analysis of a Passive-type Self-bearing Step Motor (수동형 셀프-베어링 스텝모터의 설계 및 성능해석)

  • Kwak, Ho-Seong;Choi, Dong-Hoon;Kim, Seung-Jong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.415-420
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    • 2006
  • This paper introduces a new self-bearing motor which combines a homopolar step motor and a passive magnetic bearing. Compared with conventional self-bearing motors which are mostly based on the theory of active magnetic bearings and therefore have some difficulties in design of the complicated flux distribution and control of the levitation force and the torque independently, the proposed self-bearing motor has a very simple and novel structure and operating principle. for the levitation, it works just like passive magnetic bearings which use the repulsive force between permanent magnets. On the other hand, its rotation principle is quite similar to that of a conventional homopolar step motor. In this paper, we introduce the basic structure and the operating principle in detail, and show some results of FEM analysis to predict the performance of the proposed self-bearing motor and further, to get the optimal design parameters.

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Passive Force Acting on the Kicker Block Used to Support a Raker in Soft and Weathered Soil (연약지반과 풍화토지반에서 경사고임대 지지블록의 수동토압 산정)

  • Kim, Tae Hyung;Park, Lee Keun;Kim, Tae O;Jin, Hyun Sik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.37 no.5
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    • pp.801-813
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    • 2017
  • Passive force acting on the kicker block used to support a raker is different dependent on soil's type. The passive force incorporating a factor of safety is considered for design of the retaining wall. However, an actual passive force developing on the kicker block is overestimated and it may lead to an unsafe design. In this study, the actual passive forces acting on the kicker block in soil ground are evaluated using 3-D Finite Element Program, PLAXIS. Soft and weathered soils are selected as a soil ground. The relation curves between horizontal displacement and actual passive force of the kicker block for each soil ground are obtained through numerical analyses. From the curves, the actual passive forces are determined as a yielding point, which are about 55.5% and 66% of Rankine's passive forces in soft and weathered soils, respectively.