• Title/Summary/Keyword: school characteristics

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Effects of Ramp Type-Common Electrode Bias on Reset Discharge Characteristics in AC-PDP

  • Park, Choon-Sang;Cho, Byung-Gwon;Tae, Heung-Sik
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1258-1261
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    • 2005
  • The ramp type bias voltage applied to the common electrode during a reset-period is newly proposed to lower the background luminance and to improve the address discharge characteristics in AC-PDP. The positive ramp bias voltage is applied during the ramp-up period, whereas the negative ramp bias voltage is applied during the ramp-down period. The effects of the voltage slopes in both the positive and negative ramp bias voltages on the background luminance and address voltage characteristics are examined intensively. It is observed that the optimized positive and negative ramp bias voltages applied to the common electrode during the ramp-period can lower the background luminance and also enhance the address discharge characteristics of the AC-PDP.

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The Optimal Design of SAW Filters with Arbitrary Frequency Characteristics (임의의 주파수 특성을 갖는 표면음파 필터의 최적 설계)

  • Park, Seog-Hong;Son, Yeong-Chan;Yu, Sang-Dae
    • Journal of Sensor Science and Technology
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    • v.5 no.4
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    • pp.81-87
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    • 1996
  • This paper presents the optimal design method of SAW filters with arbitrary frequency characteristics. The design program using the unconstrained nonlinear optimization method and FFT algorithm is developed for optimal design of SAW filters with arbitrary frequency characteristics. As a design example, a SAW TV IF filter with asymmetric-amplitude and nonlinear-phase frequency characteristics is designed.

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A study on the Electric Characteristics of Polyimide Ultra Thin through LB-Method (Langumir-Blodgett법으로 제작된 polyimide 超薄膜(초박막)의 전기적특성(電氣的特性))

  • Park, Sang-Hyun;Yun, Sung-Do;Cheong, Hak-Su;Kook, Sang-Hoon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1992.11a
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    • pp.63-66
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    • 1992
  • Using an aromatic system, we made a ultra thin insulator through LB-method. We measured and wrote down afternating currant characteristics of ultraviolet rays extincting-spectrum and I.R extincting-spectrum. We surveyed the thickness of a film through X-ray diffracting method and certified about $4{\AA}$ by the layer. Measuring the characteristics of direct current voltage and electric current with this sample, we produced its conductivity and discovered that this sample had a god insulating performance. Addition to this, we measured the characteristics of voltage and electric current, and the temperature dependency of conductivity in a high voltage system and with these results tried to interpret a mechanism of conduction.

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Analysis on Fault Current Limiting Characteristics of Flux-Lock Type SFCL Using Magnetic Flux Application Circuit (자기인가회로를 이용한 자속구속형 초전도한류기의 고장전류제한 특성 분석)

  • Go, Ju-Chan;Lim, Seung-Taek;Lim, Sung-Hun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.30 no.1
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    • pp.37-41
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    • 2017
  • In this paper, the fault current limiting characteristics of the flux-lock type SFCL (superconducting fault current limiter) using magnetic application circuit were analyzed. The flux-lock type SFCL has the structure to install the magnetic application circuit, which can increase the resistance of HTSC ($high-T_C$ superconducting element comprising) the SFCL. To analyze the fault current limiting effect of the flux-lock type SFCL through the magnetic flux application circuit, the flux-lock type SFCL either with the magnetic flux circuit or without the magnetic flux circuit was constructed and the fault current limiting characteristics of the SFCL were compared each other through the short-circuit tests.

A Study on the Lubrication Characteristics of Spool Valve with Spiral Groove (스파이럴 그루브가 가공된 스풀밸브의 윤활 특성 연구)

  • Hong, Sung-Ho;Son, Sang-Ik;Kim, Kyung-Woong
    • Tribology and Lubricants
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    • v.28 no.6
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    • pp.303-314
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    • 2012
  • In this research, spool valves with spiral grooves are suggested and their lubrication characteristics are investigated by numerical analysis. The three-dimensional flow field is obtained by solving the Navier-Stokes equations in dimensionless form, so that the performance variables such as lateral force, friction force and volume flow rate are determined. Also, the lubrication characteristics of spool valves with spiral grooves are compared with those with typical grooves under variable working conditions. It is shown that spool valves with spiral grooves can get better performance in aspect of mitigation of uneven pressure distribution surrounding spool. Moreover, it is found that the minimum distance between spool edges and grooves, the type of spiral groove, and the groove angle have noticeable effect on the lubrication characteristics.

Electrical Characteristics of NVM Devices Using SPC Substrate (SPC 기판을 사용한 NVM 소자의 전기적 특성)

  • Hwang, In-Chan;Lee, Jeoung-In;Yi, J.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.60-61
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    • 2007
  • In this paper, the p-channel poly Si thin-film transistors (Poly-Si TFT's) using formed by solid phase crystallization (SPC) on glass substrate were fabricated. And we propose an ONO(Oxide-Nitride-Oxide) multilayer as the gate insulator for poly-Si TFT's to indicate non-volatile memory (NVM) effect. Poly-Si TFT is investigated by measuring the electrical properties of poly-Si films, such as I-V characteristics, on/off current ratio. NVM characteristics is showed by measuring the threshold voltage change of TFT through I-V characteristics.

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Photocurrent Characteristics of Gate/Body-Tied MOSFET-Type Photodetector with High Sensitivity

  • Jang, Juneyoung;Choi, Pyung;Lyu, Hong-Kun;Shin, Jang-Kyoo
    • Journal of Sensor Science and Technology
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    • v.31 no.1
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    • pp.1-5
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    • 2022
  • In this paper, the photocurrent characteristics of gate/body-tied (GBT) metal-oxide semiconductor field-effect transistor (MOSFET)-type photodetector with high sensitivity in the 408 nm - 941 nm range are presented. High sensitivity is important for photodetectors, which are used in several scientific and industrial applications. Owing to its inherent amplifying characteristics, the GBT MOSFET-type photodetector exhibits high sensitivity. The presented GBT MOSFET-type photodetector was designed and fabricated via a standard 0.18 ㎛ complementary metal-oxide-semiconductor (CMOS) process, and its characteristics were analyzed. The photodetector was analyzed with respect to its width to length (W/L) ratio, bias voltage, and incident-light wavelength. It was confirmed experimentally that the presented GBT MOSFET-type photodetector has over 100 times higher sensitivity than a PN-junction photodiode with the same area in the 408 nm - 941 nm range.

The Impact of Environment Characteristics on Perceived Value and Visit Intention in Franchise Coffee Shops (프랜차이즈 커피전문점의 환경 특성이 지각된 가치와 방문의도에 미치는 영향)

  • Park, Heung-jin;Lee, Yong-Ki;Lee, Jung-Won
    • The Korean Journal of Franchise Management
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    • v.6 no.2
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    • pp.105-122
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    • 2015
  • This study was to investigate the impact of environment characteristics on perceived value and visit intention in franchise coffee shops. And, the study was to examine the mediating role of perceived value in the relationship between environment characteristics and visit intention. The data were collected from 212 coffee shop users and analyzed with SPSS and AMOS.. The findings are as follows. First, price, service, and atmosphere have a significant effect on the defined hedonic value but menu does not. Second, price and service have a significant effect on utilitarian value but menu and atmosphere do not. Finally, both hedonic value and utilitarian value have a significant effect on visit intention.

Adolescent Consumers' Attitudes toward TV Advertisements on and Purchasing Behaviors of the Sport Beverages (청소년 소비자의 스포츠 음료에 대한 TV 광도 수용태도와 구매 행동)

  • Kim, Shin-Ae;Cho, Jae-Soon
    • Korean Journal of Human Ecology
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    • v.4 no.1
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    • pp.51-61
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    • 1995
  • The purpose of this study was to find out the characteristics of the adolescent consumers related to the attitudes toward TV advertisements on and purchasing behaviors of the sport beverages, and to test the role of the atitudes toward TV advertisements between the consumer characteristics and the purchasing behaviors of the sport beverages. The qusetionnaire method was utilized to 549 female and male junior and senior high school students in urban and rural areas. The results showed that the attitudes toward TV advertisement on sport beverage was related to the residentiae years in school, whom to buy, level of interests in sports, and level of knowledges of the beverages; purchasing behaviors of the sport beverages, whom to buy, gender, level of knowledges of the beverages, size of the allowance, and the residentiae years in school. The attitudes toward TV advertisements seemed to the intervenning role between the consumer characteristics and the purchasing behaviors among adolescent consumers.

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Design of a Luenberger Observer-based Current Sensorless Multi-loop Control for Boost Converters

  • Li, Xutao;Chen, Minjie;Shinohara, Hirofumi;Yoshihara, Tsutomu
    • IEIE Transactions on Smart Processing and Computing
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    • v.5 no.1
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    • pp.22-28
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    • 2016
  • Multi-loop control of a boost converter needs a current-sensing circuit to detect the inductor current. Current sensorless multi-loop control reduces the cost, size and weight of the converter. The Luenberger observer (LO) is widely used to estimate the inductor current for current sensorless control of a switching converter. However, the design of the LO-based sensorless multi-loop control has not been well presented, so far. In this paper, a closed-loop characteristics evaluation method is proposed to design an LO-based current sensorless multi-loop control for boost converters. Simulations show evaluations of the closed-loop characteristics. Practical experiments on a digital processor confirm the simulations.