• 제목/요약/키워드: Drawn model

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척수손상인의 적응과정에 관한 근거이론적 접근 (A Ground Theory Approach to the Adaptation Process of the Spinal Cord Injured Persons)

  • 송충숙
    • 동서간호학연구지
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    • 제22권2호
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    • pp.158-169
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    • 2016
  • Purpose: This study is a qualitative research on the adaptation of the spinal cord injury after fortuitous the accident. Methods: The subjects are fifteen spinal cord injuries. As a study method, this author employed Grounded theory, one of the qualitative research methods. For data analysis, the procedures of Grounded theory methodology was adopted, and then the data collection were collected for six months from March to September 2009. Concerning the frequence of interviewing, each participants went through individual interviewing twice at least and up to four times if necessary. Results: As a result of open coding, total thirty six concepts and twenty categories were drawn. To synthesize these categories, they came to choose 'Going into the new self-made spinal cord injury' as a nuclear category. Typological analysis based on the result of the paradigm model divided them into a reality-avoiding, passive coping, reality-maintaining, reality-overcoming, and self-fulfillment type. Conclusion: As a result of this study, family support to those with spinal cord disability is an important factor for their motive for rehabilitation and adjustment, spinal disabilities were accepted to mostly the disabilities in relations with colleagues. Thus it is necessary to give them a nursing intervention through disability group for successful adjustment to life with disability.

통합 제조 시스템 설계 : 공정 계획과 AGV 경로 설계의 통합 접근 (Integrated Manufacturing Systems Design : Integrated Approach to Process Plan Selection and AGV Guidepath Design)

  • 서윤호
    • 대한산업공학회지
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    • 제20권3호
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    • pp.151-166
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    • 1994
  • The manufacturing environment on which this research is focused is an FMS in which AGVs are used for material handling and each part type has one or more process plans. The research aims at developing a methodology whereby, given a part and volume mix for production during any production session, the best set of process plans including one plan per part type is selected and the best unidirectional AGV guidepath can be dynamically reconfigured in response to changes in parts and lot sizes combination. For the integrated PPS/FGD problem in which two functions of process plan selection (PPS) and flexible AGV guidepath design (FGD) are integrated, a zero-one integer programming model is developed. The integrated problem is decomposed into two subproblems, process plan selection given a directed AGV layout and AGV guidepath design with a fixed process plan per part type. A heuristic algorithm that alternately and iteratively solves these two subproblems is developed. The effectiveness of the heuristic algorithm is tested by solving various randomly generated sample problems and comparing the heuristic solutions with those obtained by an exact procedure. From the test results, the following conclusions are drawn: 1) For a reasonable size problem, the heuristic is very effective. 2) By integrating the two functions of PPS and FGD, a remarkable benefit in total production time for a given part and volume mix is gained.

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VALVELSS 압전펌프 진동 해석 및 특성 (Vibration analysis of characteristics and valveless Type Piezoelectric micro-pump)

  • 임종남;오진헌;임기조;김현후
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.185-185
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    • 2009
  • Micropump is very useful component in micro/nano fluidics and bioMEMS applications. Using the flexural vibration mode of PZT bar, a piezopump is successfully made. The PZT bar is polarized with thickness direction. The proposed structure for the piezo-pump consists of an input and an output port, piezoelectric ceramic actuator, actuator support, diaphragm. The traveling flexural wave along the bar is obtained by dividing two standing waves which are temporally and spatially phase shifted by 90 degrees from each other. Fluid is drawn into a forming chamber, eventually the forming chamber closes trapping the fluid therein. The finite elements analysis on the proposed pump model is carried out to verify its operation principle and design by the commercial FEM software. Components of piezopump were made, assembled, and tested to validate the concepts of the proposed pump and confirm the simulation results. The performance of the proposed piezopump the highest pressure level of 83.4kHz.

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수간호사의 윤리적 리더십이 간호사의 직무만족에 미치는 영향: 정서적 몰입의 매개효과 (Influence of Head Nurses' Ethical Leadership on Job Satisfaction among Staff Nurses: Mediating Effect of Affective Commitment)

  • 정민
    • 간호행정학회지
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    • 제22권5호
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    • pp.553-561
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    • 2016
  • Purpose: This study was conducted to identify the mediating effect of affective commitment on the relationship between ethical leadership and job satisfaction. Methods: Participants were 216 nurses drawn from three general hospitals in C city. Data were analyzed using descriptive analysis, t-test, ANOVA, Pearson correlation coefficient, and multiple regression. Results: The findings from multiple regression were as follows. First, people orientation, ethical guidance of ethical leadership factors showed significant positive effects on affective commitment. Second, people orientation, ethical guidance of ethical leadership factors showed significant positive effects on job satisfaction. Finally, when ethical leadership factors and affective commitment were entered into the regression model at the same time, ethical leadership factors showed no significant effects on job satisfaction, however, affective commitment showed a significant effect and so affective commitment had a mediating effect between ethical leadership and job satisfaction. Conclusion: Results of this study indicate that affective commitment with an effect on the relationship between ethical leadership and job satisfaction plays a full mediating role. Thus, developing ethical leadership training programs for head nurses would likely increase the affective commitment and job satisfaction of staff nurses.

데이터마이닝을 이용한 DDoS 예측 모델링 (DDoS Prediction Modeling Using Data Mining)

  • 김종민;정병수
    • 융합보안논문지
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    • 제16권2호
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    • pp.63-70
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    • 2016
  • 최근 인터넷 등 정보통신 기술의 발달로 인해 언제 어디서나 인터넷을 이용할 수 있는 환경이 구축 되었으며, 이로 인한 사이버위협은 다양한 경로를 통해 시도되고 있다. 본 연구에서는 사이버위협 중 지속적으로 증가 추세인 DDoS 예측 모델링하기 위해 이벤트 데이터를 근거로 하여 통계적 기법을 통해 DDoS 위험지수 예측식을 도출하였고, 도출된 위험지수를 정량화하였다. 제시된 위험지수를 활용하여 DDoS 위협에 대해 사전 대응정책을 세움으로써 피해를 최소화시킬 수 있는 객관적이고 효율적인 예측 모델이 될 것으로 기대한다.

전산유체해석을 이용한 다양한 요철 형상에 대한 고압터빈 노즐 냉각유로 최적화 및 냉각 성능 비교 (DESIGN OPTIMIZATION AND PERFORMANCE ANALYSIS OF INTERNAL COOLING PASSAGE WITH VARIOUS TYPE OF RIB TURBULATOR FOR HIGH PRESSURE TURBINE NOZZLE)

  • 이상아;이동호;강영석;이관중;김규홍
    • 한국전산유체공학회지
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    • 제19권4호
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    • pp.14-19
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    • 2014
  • This study conducts shape optimization of rib turbulator on the internal cooling passage that has triangular cross-section of high pressure turbine nozzle. During optimization, various types of rib turbulator including angled, V-shaped, A-shaped and angled rib with intersecting rib are considered. Each type of rib turbulator is parameterized with attack angle(s), rib height, spacing ratio and bending/intersecting location. For optimization, Design of Experiment (DOE) and Kriging surrogate model are used to utilize computational resource more efficiently and Genetic Algorithm (GA) is used to search the optimum points. As a result, Pareto front of each type of rib turbulator with friction factor that relates to pressure drop in cooling passage and spatially averaged Nusselt number that relates to heat transfer on the wall is drawn and optimum points on the Pareto front are suggested.

기상 환원제를 사용하는 선택적 환원촉매에서 유동혼합 개선에 관한 연구 (A STUDY ON FLOW MIXING IMPROVEMENT OF SELECTIVE CATALYTIC REDUCTION USING GASEOUS REDUCTANT)

  • 고상철;이범호;조승환;이상헌;홍성태;이대엽
    • 한국전산유체공학회지
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    • 제15권1호
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    • pp.56-63
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    • 2010
  • Since emission regulations for vehicles have become more stringent, SCR technology has drawn a strong attention in order to reduce NOx emissions. Optimal design of a reductant injection nozzle and a multi-hole plate located between the cone and catalyst is critical in that the uniform distribution of reductant is necessary to maximize the NOx conversion efficiency and minimize the slip of reductant in SCR. In this work, an LPG fuel(C3H8 in vapor state) was used as a reductant for LPG vehicles. A Realizable k-$\varepsilon$ model is used for turbulence, and SCR body is defined as porous media with inertia and viscous resistances measured in this work. Effect of the number of nozzle holes on the flow mixing index was analyzed, which revealed that a four hole nozzle shows the best performance in terms of uniformity of flow. An installment of a multi-hole plate at the entrance of catalyst was evaluated with flow mixing index, uniformity of flow, and pressure drop. A multi-hole plate with gradual hole diameter change in three steps showed the best uniformity of flow within the conditions suggested in this work.

화장장시설에 관한 입지갈등 관리모형 구축 (Management Model-Buildings of Location Conflict on Crematory Facilities)

  • 이만형;이중훈;권혁일
    • 한국시스템다이내믹스연구
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    • 제8권1호
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    • pp.67-95
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    • 2007
  • This paper focuses on prototype management models of location conflict concerned with crematory facilities in Korea. Using causal loops and stock-flow diagrams, it examines behavioral patterns of key variables, which would contribute to developing objective evaluation criteria. After a series of simulation works, the paper finds that the top priority should be given to how to improve neighboring residents' perception, ahead of specific compensation issues. Otherwise, they are open to vicious cycles or impasse. Juxtaposing individual cases together, Pusan and Cheongju examples which experienced the extreme confrontation in the initial stage could succeed in resolving crematory location conflict, especially between local residents and the public authorities, as the latter has repeatedly guaranteed to the former higher standards of participation. The opposite was almost true for Seoul and Ulsan cases, both of which were drawn into a crematory location whirlpool, incrementally losing resident's participation base. These results imply that the proposed management models would enhance mutual understanding among major stake-holders in relatively a shorter time, not to mention the overall cost.

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An Efficient and Stable Congestion Control Scheme with Neighbor Feedback for Cluster Wireless Sensor Networks

  • Hu, Xi;Guo, Wei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권9호
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    • pp.4342-4366
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    • 2016
  • Congestion control in Cluster Wireless Sensor Networks (CWSNs) has drawn widespread attention and research interests. The increasing number of nodes and scale of networks cause more complex congestion control and management. Active Queue Management (AQM) is one of the major congestion control approaches in CWSNs, and Random Early Detection (RED) algorithm is commonly used to achieve high utilization in AQM. However, traditional RED algorithm depends exclusively on source-side control, which is insufficient to maintain efficiency and state stability. Specifically, when congestion occurs, deficiency of feedback will hinder the instability of the system. In this paper, we adopt the Additive-Increase Multiplicative-Decrease (AIMD) adjustment scheme and propose an improved RED algorithm by using neighbor feedback and scheduling scheme. The congestion control model is presented, which is a linear system with a non-linear feedback, and modeled by Lur'e type system. In the context of delayed Lur'e dynamical network, we adopt the concept of cluster synchronization and show that the congestion controlled system is able to achieve cluster synchronization. Sufficient conditions are derived by applying Lyapunov-Krasovskii functionals. Numerical examples are investigated to validate the effectiveness of the congestion control algorithm and the stability of the network.

Design of a Bimorph Piezoelectric Energy Harvester for Railway Monitoring

  • Li, Jingcheng;Jang, Shinae;Tang, Jiong
    • 비파괴검사학회지
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    • 제32권6호
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    • pp.661-668
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    • 2012
  • Wireless sensor network is one of prospective methods for railway monitoring due to the long-term operation and low-maintenance performances. How to supply power to the wireless sensor nodes has drawn much attention recently. In railway monitoring, the idea of converting ambient vibration energy from vibration of railway track induced by passing trains to electric energy has made it a potential way for powering the wireless sensor nodes. In this paper, a bimorph cantilever piezoelectric energy harvester was designed based on a single degree-of-freedom model. Experimental test was also performed to validate the design. The first natural frequency of the bimorph piezoelectric energy harvester was decreased from 117.1 Hz to 65.2 Hz by adding 4 gram tip mass to the free end of the 8.6 gram energy harvester. In addition, the power generation of the piezoelectric energy harvester with 4 gram tip mass at resonant frequency was increased from 0.14 mW to 0.74 mW from $2.06m/s^2$ base excitation compared to stand-alone piezoelectric energy harvester without tip mass.