• Title/Summary/Keyword: high quality factor

Search Result 1,923, Processing Time 0.028 seconds

A High Performance Solenoid-Type MEMS Inductor

  • Seonho Seok;Chul Nam;Park, Wonseo;Kukjin Chun
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • v.1 no.3
    • /
    • pp.182-188
    • /
    • 2001
  • A solenoid-type MEMS inductor with a quality factor over 10 at 2 GHz has been developed using an electroplating technique. The integrated spiral inductor has a low Q factor due to substrate loss and skin effects. It also occupies a large area compared to the solenoid-type inductor. The direction of flux of the solenoid-type inductor is parallel to the substrate, which can lower the substrate loss and other interference with integrated passive components. To estimate the characteristics of the proposed inductor over a high frequency range, the 3D FEM (Finite Element Method) simulation is used by using the HFSS at the Ansoft corporation. The electroplated solenoid-type inductor is fabricated on a glass substrate step by step by using photolithography and copper electroplating. The fabrication process to improve the quality factor of the inductor is also developed. The achieved inductance varies within a range from 0.5 nH to 2.8 nH, and the maximum Q factor is over 10.

  • PDF

The Factorial Structure Analysis of the Criteria on Clothing Selection (의복선택기준에 관한 요인구조분석 -서울시내 주부를 중심으로-)

  • Park Eun Joo;Lee Eun Young
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.6 no.2
    • /
    • pp.49-55
    • /
    • 1982
  • The purpose of this study was to analyze the factorial structure of the criteria on clothing selection. Data were obtained from 219 housewives in Seoul. 95 likert type questions were selected from the existing questionnaires and from the open end questions. The items were analyzed for discriminating power, followed by the factor analysis. 57 items were subjected to the principal component analysis with orthogonal rotation after extraction of 5 major factors. 47 items were found to be significantly loaded to at least one of the five factors. The factors had the following characteristics: Factor I. The persons scoring high on this factor would invest time and energy in their clothes to achieve their image and individuality. They were interested in clothes, appearance and fashion. Factor II. The persons scoring high on this factor were more concerned about the practicality of clothing, such as ease-of-care, comfort, texture and quality of fabric. They would not select the clothes which soiled easily and would not perform as expected. Factor III. High scores on this factor were associated with the eagerness to get the cloth-ing value for the money. They would make a long plan to buy an expensive clothing and choose a unique clothing regardless of fashion. Factor IV. A high score on this factor was suggestive of modesty. They were willing to buy inconspicuous clothes, such as dark or muted colors, small prints and conservative styles. Factor V. High scores on this factor were characterized by the desire for conformity and approval of their friends. This result may be used to develop an instrument to measure the criteria on clothing selection of consumer.

  • PDF

A Study on the Perception Level and Proper Management of Indoor Air Quality Recognition in Elderly Care Hospital Workers

  • Choi, Mi-Suk
    • Journal of the Korea Society of Computer and Information
    • /
    • v.24 no.11
    • /
    • pp.171-178
    • /
    • 2019
  • In this paper, we proposed a plan for a indoor air quality management in elderly care hospital by measuring the indoor air quality level of elderly care hospital and conducting a survey the workers' awareness of indoor air quality. The measurement items were Temperature, Humidity, CO2, CO, PM10, VOC and were taken on April 26, 2019. The survey found that the lower the satisfaction level with indoor air quality, the better outdoor air quality and odor items were analyzed to be the lowest among the indoor environmental factors. When the satisfaction level of indoor air quality is high, the satisfaction level of indoor environment factor is high. The result of the multiple response analysis was "lack of ventilation" and the regression analysis was the lower the "relevance of indoor air quality" category. To provide the best indoor air quality environment for elderly care hospital workers the installation of additional ventilation equipment to remove odors, the increase in the number of natural ventilation and the designation of regular ventilation personnel will be necessary. By establishing such a plan, it is possible to provide indoor air quality environment to provide the best services for elderly care hospital workers.

An Experimental Study on the Effects of High temperature Hysteresis on Concrete Strength Development (고온이력이 콘크리트의 강도발현에 미치는 영향에 관한 실험적 연구)

  • Kim, Hak-Young;Min, Hong-Jun;Jang, Hyung-Jun;Gong, Min-Ho;An, Moo-Young;Jung, Sang-Jin
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2006.05b
    • /
    • pp.433-436
    • /
    • 2006
  • This study is basic experiment for estimating influence of strength by curing temperature of concrete's heat of hydration and estimate relationship of compressive strength development by initial curing temperature factor, and then asume temperature factor which influence compressive strength development and for showing basic document of quality control. According to the result of managerial test pieces by the curing temperature factor high-curing temperature shows high strength on 3 day compare with low curing-temperature, shows higher strength than the piece of high curing temperature.

  • PDF

An Experimental Study on the Characteristics of Strength in Mortar under High Temperature conditions in an Early Age (초기 고온이력을 받은 시멘트 모르타르의 강도 특성에 관한 실험적 연구)

  • Kim Young Joo;Kim Han Sik;Gong Min Ho;Kim Je Sub;Lee Young Do;Jung Sang Jin
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2005.05b
    • /
    • pp.517-520
    • /
    • 2005
  • This study is basic experiment for estimating influence of strength by curing temperature of concrete's heat of hydration and estimate relationship of compressive strength development by initial curing temperature factor, and then asume temperature factor which influence compressive strength development and for showing basic document of quality control. According to the result of cement mortar by the curing temperature factor high-curing temperature shows high strength on 3 day compare with low curing-temperature, shows higher strength than the piece of high curing temperature.

  • PDF

An Experimental Study on the Characteristics of Strength in Mortar under High Temperature conditions in an Early Age (모르터 압축강도 특성에 영향을 미치는 고온이력에 관한 실험적 연구)

  • Kim Young Joo;Gong Min Ho;Song In Myung;Yang Dong Il;Paik Min Su;Jung Sang Jin
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2004.11a
    • /
    • pp.703-706
    • /
    • 2004
  • This study is basic experiment for estimating influence of strength by curing temperature of concrete's heat of hydration and estimate relationship of compressive strength development by initial curing temperature factor, and then asume temperature factor which influence compressive strength development and for showing basic document of quality control. According to the result of cement mortar by the curing temperature factor high-curing temperature shows high strength on 3 day compare with low curing-temperature, shows higher strength than the piece of high curing temperature.

  • PDF

Single-Stage Double-Buck Topologies with High Power Factor

  • Pires, Vitor Fernao;Silva, Jose Fernando
    • Journal of Power Electronics
    • /
    • v.11 no.5
    • /
    • pp.655-661
    • /
    • 2011
  • This paper presents two topologies for single-stage single-phase double-buck type PFC converters, designed to operate at high power factor, near sinusoidal input currents and adjustable output voltage. Unlike the known buck type PFC topologies, in which the output voltage is always lower than the maximum input voltage, the proposed converters can operate at output voltages higher than the ac input peak voltage. A reduced number of switches on the main path of the current are another characteristic of the two proposed topologies. To shape the input line currents, a fast and robust controller based on a sliding mode approach is proposed. This active non-linear control strategy, applied to these converters allows high quality input currents. A Proportional Integral (PI) controller is adopted to regulate the output voltage of the converters. This external voltage controller modulates the amplitude of the sinusoidal input current references. The performances of the presented rectifiers are verified with experimental results.

Using Analytic Network Process to Construct Evaluation Indicators of Knowledge Sharing Effectiveness in Taiwan's High-tech Industries

  • Liu, Pang-Lo;Tsai, Chih-Hung
    • International Journal of Quality Innovation
    • /
    • v.9 no.2
    • /
    • pp.99-117
    • /
    • 2008
  • High-tech industry has been the principal economic source for Taiwan in recent years. The characteristics of high-tech industries in Taiwan are changeable product markets, short product life cycles and high company attrition rate. In the globalization trend, the high-tech industry has gradually increased corporate competitiveness and reached the goal of sustainable operations through knowledge management, knowledge sharing and new product research and development. Firms have aggressively strengthened and integrated their internal and external resources and enhanced knowledge sharing to increase industry operational performance. Effectively strengthening the knowledge management operation and performance evaluation of knowledge sharing in Taiwan's high-tech industry has become a critical issue. In the selection of knowledge sharing Key Performance Indicators (KPI), this research divided the knowledge sharing indicators into representative strategic indicators such as organizational knowledge learning, organizational knowledge resources, organizational information capacity and organizational knowledge performance through screening using Factor Analysis. The characteristics of the constructs were interdependent. This research calculated and adjusted the correlation among the key performance knowledge sharing indicators using ANP and determined the relative weight of knowledge sharing.

Factors Influencing the Quality of E-learning Contents Provided by the Universities at the Learners' Perspectives (학습자의 측면에서 본 대학 e-러닝 콘텐츠의 질에 영향을 미치는 요인 분석)

  • Jang, Sun-Young;Roh, Seak-Zoon
    • Journal of Internet Computing and Services
    • /
    • v.10 no.3
    • /
    • pp.159-172
    • /
    • 2009
  • The purposes of this study were to identify factors affecting the quality of universities' e-learning contents from the perspectives of learners and to find out specific solutions for improving them. To achieve these goals, research questions were established as follows: 1) What factors were influencing the quality of universities' e-learning contents, and how were learners perceived about each factor(by its importance and satisfaction)? 2) Were there any differences on the learners' perceptions about each factor(by its importance and satisfaction)? 3) What were any specific ways to enhance the quality of universities' e-learning contents? The participants were of 543 university students who took at least one e-learning course and were living in the metropolitan areas(Seoul, Incheon, Gyeonggi). The survey questionnaire was consisted of 38 items developed through the literature review. To analyze the data collected, factor analysis and paired-sample t-test were conducted. The results were as follows: Five identified factors influencing the quality of universities' e-learning contents from the perspectives of learners were instructional strategies, learning contents, usability, evaluation/feedback, and interface design, and all identified factors were statistically significant differences among the learners' perceptions of its importance and satisfaction. The analysis results of importance-satisfaction matrix by each factor showed that 1) learning contents was the factor that current status should be at least continuously maintained, 2) usability, instructional strategies, and evaluation/feedback were the factors that learners' satisfactions still need to be increased although those importances were not relatively high, and 3) interface factor was important, while learners' satisfaction toward it was not much high so that solutions to increase the satisfaction need to be immediately considered. Based on the results, several suggestions to enhance universities' e-learning contents from the learners' perspectives were also recommended.

  • PDF

A Study on the Assessment Factors for Car Audio Sound Quaility (자동차용 오디오의 실내음질 평가인자에 관한 연구)

  • 오양기;한명호
    • Journal of KSNVE
    • /
    • v.9 no.5
    • /
    • pp.991-997
    • /
    • 1999
  • It is getting higher the demand on a good sound in a car. Like some other sensory qualities, achieving a good sound is still treated as a black-box followed by the individual taste of tuning engineers. This study aims to define the attributes of a good car audio sound and the assessment factors affecting the sound quality. With a variety of surveys on professional listening groups and car audio installers, 26 most frequently used vocabularies are selected as typical presentations of car audio sound quality. After repetitions of listening tests with deliberately selected test CD, pre-recorded 15 different digital car-recordings, headphones replay system, and three different listening groups, it is proved that there are at least 5 different assessment factors which significantly affect the car audio sound quality. They are high fidelity, spectral balance, tonal accuracy, sound stage and acoustic fault.

  • PDF