• 제목/요약/키워드: Chain drive

검색결과 54건 처리시간 0.028초

고효율 전자기형 정원창 구동 트랜스듀서의 설계 (Design of electromagnetic type transducer to drive round window with high efficiency)

  • 이장우;김동욱;김명남;조진호
    • 센서학회지
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    • 제19권6호
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    • pp.449-455
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    • 2010
  • Implantable middle ear hearing devices(IMEHDs) have being actively studied to overcome the problems of conventional hearing aids. Vibration transducer, an output devices of IMEHDs, is attached on the ossicular chain and transmits mechanical vibration to cochlea. This approach allows us to hear more clear sound because mechanical vibration is effective to transfer high frequency acoustics, but occurs some problems such as fatigue accumulation to ossicular chian and reduction of vibration displacement caused by mass loading effect. Recently, many studies for the round window stimulation are announced, because it does not cause such problems. It have been studied by older transducers designed for attaching on ossicular chain. In this paper, we proposed a new electromagnetic transducer which consists of two magnets, three coils and a vibration membrane. The magnet assembly, magnet coupled in opposite direction, were placed in the center of three coils, and the optimum length of each coil generating maximum vibrational force was calculated by finite element analysis(FEA). The transducer was implemented as the calculated length of each coil, and measured vibration displacement. From the results, it is verified the vibration displacement can be improved by optimizing the length of coils.

차량 탑재형 고소작업대의 사고분석을 통한 안전대책 고찰 (Review of Safety Measures through Analysis of Accidents on the Vehicle-mounted MEWP(mobile elevated work platforms))

  • 이준호
    • 한국건설안전학회 논문집
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    • 제1권1호
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    • pp.47-56
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    • 2018
  • 본 논문에서는 고소작업에 가장 널리 사용되고 있는 차량 탑승형 고소작업대의 재해사례분석을 통해 예방대책을 제안하였다. 높은 위치에서의 고소작업은 사고가 발생한 경우 치명적인 인명사고로 이어지기 때문에 이에 대한 안전 대책이 더욱 절실하다. 이에 고소작업 중 발생하는 여러 가지 유형의 사고에 대한 원인을 분석하여 유형별 안전대책을 제시하고, 나아가 사고를 줄일 수 있도록 관련법규의 제정 또는 개정안을 제안하였다. 본 논문에서는 고소작업대의 사고유형을 크게 4가지로 분류하였다. 첫째 와이어로프 구동시스템 불량, 둘째 허용 작업반경 초과로 인한 전도 및 붐 파손, 셋째 턴테이블 불량, 넷째 아우트리거 불량으로서, 가 유형별 사고사례를 분석하고 안전대책을 제시하고, 현행 규정상 고소작업대의 운전 조종에 관한 아무런 규정이 없어서 고소작업대의 운전 조종에 관한 교육 및 자격증 신설을 제시하였다. 그리고 증가하고 있는 안전사고의 예방을 위해 고소작업대의 안전인증 및 안전검사 기준을 강화하는 정책에 발맞추어 법규 개정을 위한 기초자료를 제시하고자 하였다. 본 연구 결과가 실무에 적용된다면 고소작업대로 인한 사고를 크게 줄일 수 있을 것으로 기대된다.

Research on Development Strategy of China Ice-Snow Sports Tourism Industry Based on SWOT-AHP Model-Case Study on Zhangjiakou

  • Chen, Wenjie;Zhou, Pan;Bae, Kihyung
    • International Journal of Contents
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    • 제16권2호
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    • pp.92-101
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    • 2020
  • Industrial integration is the innovative embodiment of regional economic theory. The promotion of industrial integration is conducive to improving the scale effect and spillover effect of the industry. Also, it has the power to radiate, drive, and lead the innovation and development of the whole industrial cluster. The purpose of this paper was to identify the most suitable development pattern of the ice-snow sports tourism industry in Zhangjiakou, one of the host cities of the 2022 Winter Olympics. This study combs the characteristics of the development of the ice-snow sports industry, and analyzes the current situation of the industry in Zhangjiakou based on the SWOT-AHP method. This paper argues that the integrated industry is the most suitable development pattern for the promotion of the ice-snow culture industry in Zhangjiakou. The following content will present effective countermeasures to accelerate the development of the ice-snow culture industry integration in Zhangjiakou from three aspects: industrial resource integration, industrial chain layout, and scientific and technological innovation. The IT live simulation technique facilitates identifying some vital elements during the data collection.

PGSFR 제어봉집합체 낙하성능시험 (Drop Performance Test of Control Rod Assembly for Prototype Gen-IV Sodium-cooled Fast Reactor)

  • 이영규;김회웅;이재한;구경회;김종범;김성균
    • 한국압력기기공학회 논문집
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    • 제12권1호
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    • pp.134-140
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    • 2016
  • The Control Rod Assembly (CRA) controls the reactor power by adjusting its position in the reactor core during normal operation and should be quickly inserted into the reactor core by free drop under scram condition to shut down chain reactions. Therefore, the drop time of the CRA is one of important factors for the safety of the nuclear reactor and must be experimentally verified. This study presents the drop performance test of the CRA which has been conceptually designed for the Proto-type Generation IV Sodium-cooled Fast Reactor. During the test, the CRA was free dropped from a height of 1 m under different flow rate conditions and its drop time was measured. The results showed that the drop time of the CRA increased as the flow rate increased; the average drop times of the CRA were approximately 1.527 seconds, 1.599 seconds and 1.676 seconds at 0%, 100% and 200% of design flow rates, respectively.

Does Big Data Matter to Value Creation? : 오라클(Oracle) 솔루션을 중심으로 (Does Big Data Matter to Value Creation? : Based on Oracle Solution Case)

  • 김용희;유응준;강미선;최정일
    • 한국IT서비스학회지
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    • 제11권3호
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    • pp.39-48
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    • 2012
  • It is essential that firm makes a rational and scientific decision making and creates a news value for the future direction. To do so, many firms attempt to collect meaningful data and find the filtered and refined implication for the better customer relationship and the active market drive through the various analytic tools. Among the possible IT solutions, utilization of 'Big Data' is becoming more attractive and necessary in such a way that it would help firms obtain the systemized and demanding information and facilitate their decision making process to keep up with the market needs. In this paper, it introduces the concepts and development of 'Big Data' recognized as a IT resource and solution under the rapidly changing firm environment. This study also presents the several firm cases using Big Data' and the Oracle's total data management and analytic solutions in order to support the application of 'Big Data'. Finally this paper provides a holistic viewpoint and realistic approach on use of 'Big Data' to create a new value.

벤처·중소 ICT 기업의 디지털 생태계에서의 글로벌 경쟁력 요인 연구 (A Study of the Competitive Factors of ICT Venture and SMEs in the Global Digital Ecosystem)

  • 이계수;윤현덕
    • 한국IT서비스학회지
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    • 제15권1호
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    • pp.1-18
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    • 2016
  • Recently, in the bio-field success stories of ventures through a biosimilar technology is being excavated. but the growth of ICT industry has been stagnant since reaching a boom in the dissemination of early high-speed internet in 2000s. The purpose of this study is to explore the factors of change of business model and business strategy of ICT ventures and SMEs with the evolution of the digital ecosystem, and to drive the factors to be competitive on the global value chain. The researcher selected an entreprenuership, market-innovation orientation, technology-innovation orientation, and Administration-innovation orientation as internal factors influencing the global competence and healthiness of the ecosystem as external factors. The researcher applied samples of 94 ICT Venture and SMEs to a research model, and adopted 5 hypotheses. The researcher believes that only a few hypotheses were adopted because it takes time for overall innovation orientation of ICT Venture and SMEs to result in the real global competence as the their innovation orientation is still on the level of domestic market. And the researcher also thinks that only healthiness of the ecosystem affected management performances because the companies' performances of the last 3 years were so weak that the correlation between innovation orientation of each company and the performances were not big enough.

Determining the Relationship between the Effective Factors of Strategic Behavior: A Case Study for Social Insurance Company of Tehran

  • Kazemi, Arsalan;Javanmard, Habibollah;Mohammadi, Ramona
    • Asian Journal of Business Environment
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    • 제7권1호
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    • pp.5-12
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    • 2017
  • Purpose - In order to achieve the organizational objectives, the behavior of the employees and their collaboration with management should be taken into account. It has been shown that strategic behavior depends on a number of different factors. The aim of this article was determining the relationship between factors related to the strategic behavior. Research design, data, and methodology - Accordingly, a conceptual model was developed and tested in the form of a survey. Participants of the study were the employees working in the social Insurance company of Tehran. Data was collected using a questionnaire conducted among managers and the staff. A correlation model was used for data analysis by employing the SPSS software. Results - The findings showed there was a relationship between employees' engagement and the strategic behavior. Conclusions - Our research has demonstrated the effect of employees' engagement on the strategic-driven behavior, emphasizing the role of employees' engagement in health-care service firms. Although previous service research has focused on the factors that drive employees' performance, it seems that most of this research has been inspired by the idea of the service profit chain, focusing on the effect of employees' satisfaction on performance.

Sorting Cut Roses with Color Image Processing and Neural Network

  • Bae, Yeong Hwan;Seo, Hyong Seog;Choi, Khy Hong
    • Agricultural and Biosystems Engineering
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    • 제1권2호
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    • pp.100-105
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    • 2000
  • Quality sorting of cut flowers is very essential to increase the value of products. There are many factors that determine the quality of cut flowers such as length, thickness, and straightness of stem, and color and maturity of bud. Among these factors, the straightness of stem and the maturity of bud are generally considered to be more difficult to evaluate. A prototype grading and sorting machine for cut flowers was developed and tested for a rose variety. The machine consisted of a chain-drive feed mechanism, a pneumatic discharge system, and a grading system utilizing color image processing and neural network. Artificial neural network algorithm was utilized to grade cut roses based on the straightness of stem and maturity of bud. Test results showed 89% agreement with human expert for the straightness of stem and 90% agreement for the maturity of bud. Average processing time for evaluating straightness of the stem and maturity of the bud were 1.01 and 0.44 second, respectively. Application of neural network eliminated difficulties in determining criteria of each grade category while maintaining similar level of classification error.

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정공 및 전자 전달체의 기능기를 가진 공중합체를 사용한 단층형 유기 발광소자의 특성에 관한 연구 (Studies on the Characteristics of Single-Layered Organic EL Device Using a Copolymer Having Hole and Electron Transporting Moieties)

  • 이창호;김승욱;오세용
    • 폴리머
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    • 제26권4호
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    • pp.543-550
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    • 2002
  • 곁사슬에 정공 및 전자 전달체로 triphenylamine moiety와 triazine moiety를 갖는 새로운 공중합체를 합성하였다. ITO/공중합체와 발광물질 (DCM, coumarin 6, DPvBi)/Al으로 구성되는 단층형 유기 EL 소자는 정공 전달 단위체와 전자 전달 단위체 비율이 6:4와 방광물질의 함유량이 30 wt%일 때 최고의 외부 양자 효율을 나타내었다. 특히 위에서 제작한 유기 EL 소자는 각각 발광물질에 상응하는 빨강 (620 nm), 초록 (520 nm)과 파랑색 (450 nm)의 빛을 발광하였다. 최고 휘도는 DC 12V에서 ITO/공중합체 (6:4)와 DCM (30 wt%)/Al으로 구성되는 소자를 구동하였을 때 500 cd/$m^2$이었다.

Sensor Fault Detection, Localization, and System Reconfiguration with a Sliding Mode Observer and Adaptive Threshold of PMSM

  • Abderrezak, Aibeche;Madjid, Kidouche
    • Journal of Power Electronics
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    • 제16권3호
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    • pp.1012-1024
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    • 2016
  • This study deals with an on-line software fault detection, localization, and system reconfiguration method for electrical system drives composed of three-phase AC/DC/AC converters and three-phase permanent magnet synchronous machine (PMSM) drives. Current sensor failure (outage), speed/position sensor loss (disconnection), and damaged DC-link voltage sensor are considered faults. The occurrence of these faults in PMSM drive systems degrades system performance and affects the safety, maintenance, and service continuity of the electrical system drives. The proposed method is based on the monitoring signals of "abc" currents, DC-link voltage, and rotor speed/position using a measurement chain. The listed signals are analyzed and evaluated with the generated residuals and threshold values obtained from a Sliding Mode Current-Speed-DC-link Voltage Observer (SMCSVO) to acquire an on-line fault decision. The novelty of the method is the faults diagnosis algorithm that combines the use of SMCSVO and adaptive thresholds; thus, the number of false alarms is reduced, and the reliability and robustness of the fault detection system are guaranteed. Furthermore, the proposed algorithm's performance is experimentally analyzed and tested in real time using a dSPACE DS 1104 digital signal processor board.