• 제목/요약/키워드: Compressed chip

검색결과 31건 처리시간 0.029초

환경 친화적인 세미드라이 선삭가공 특성 (Characteristics of Environment-friendly Semi-dry Turning)

  • 이종항;오종석
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 1997년도 추계학술대회 논문집
    • /
    • pp.385-388
    • /
    • 1997
  • As the environmental regulations become stricter, new machining technologies are being developed which takes envi ronmenta 1 aspects into account . Since cut t ing oi I has some impact on environment. many researches are being carried out to minimize the use of cutting oi I. The methods for minimizing cutting oil usage includes the following techniques: I ) Cooling of tools and work piece. 2) Useage of compressed cooling air for the removal of chip. 3) Minimal useage of environment-friendly vegetable cutt:ngoiI for lubrication between chip and tools. Since the turning machine is continuous, tools are under constant thermal load and tool wear increases as the lubricative performance degrades. Also surface roughnesses have a direct influence on turning. In order to examine the characteristics of turningmachining, this work investigates experimentally the degree of tool wear and characteristics of surface roughness in relation to machining conditions, supply methods, and cooling methods.

  • PDF

On-Off 솔레노이드 엑츄에이터의 특성 연구 (A Study of On-Off Solenoid Actuator)

  • 전용식;김동수;임기조
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2007년도 제38회 하계학술대회
    • /
    • pp.154-155
    • /
    • 2007
  • Put Recently, development of micro valves that operate by compressed air has received significant attention in the fields of the micro fluid chip for medical applications or production lines of semi-conduct chip for electronic goods. Especially it is required that high-speed responsibility and lower power in optimal design of these micro valves. The primary objective of this study is to compare the optimally designed Solenoid Valve with the actually produced one which can highly improve the efficiency by providing optimal current according to mechanical load.

  • PDF

Micro On-Off Valve 해석에 의한 최적 설계 (The optimal design by Micro On-Off Valve analysis)

  • 김동수;박상운;고창섭
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2005년도 추계학술대회 논문집
    • /
    • pp.285-290
    • /
    • 2005
  • Micro On-Off valves are currently recognized as the core technology in the fields of the micro fluid chip fur medical applications and production lines of semi-conduct chip. Micro valves that operate by compressed air need the high-speed responsibility, repeatability, the absorbability and the uniform pressure by the poppet. In this study, Micro On-Off valves that posses the high-speed responsibility and the high rate of flow have designed and analyzed through the law of equivalent magnetic circuit and Finite Element Method (FEM) respectively. In case of poppet, Flow field characteristic was analyzed by the variation of poppet and it was able to display flow field by changing the location of the poppet. Also, we verified possibility of the design through the static and dynamic pressure and the 3D distribution curve of the force by working the front poppet.

  • PDF

Low Computational FFT-based Fine Acquisition Technique for BOC Signals

  • Kim, Jeong-Hoon;Kim, Binhee;Kong, Seung-Hyun
    • Journal of Positioning, Navigation, and Timing
    • /
    • 제11권1호
    • /
    • pp.11-21
    • /
    • 2022
  • Fast Fourier transform (FFT)-based parallel acquisition techniques with reduced computational complexity have been widely used for the acquisition of binary phase shift keying (BPSK) global positioning system (GPS) signals. In this paper, we propose a low computational FFT-based fine acquisition technique, for binary offset carrier (BOC) modulated BPSK signals, that depending on the subcarrier-to-code chip rate ratio (SCR) selectively utilizes the computationally efficient frequency-domain realization of the BPSK-like technique and two-dimensional compressed correlator (BOC-TDCC) technique in the first stage in order to achieve a fast coarse acquisition and accomplishes a fine acquisition in the second stage. It is analyzed and demonstrated that the proposed technique requires much smaller mean fine acquisition computation (MFAC) than the conventional FFT-based BOC acquisition techniques. The proposed technique is one of the first techniques that achieves a fast FFT-based fine acquisition of BOC signals with a slight loss of detection probability. Therefore, the proposed technique is beneficial for the receivers to make a quick position fix when there are plenty of strong (i.e., line-of-sight) GNSS satellites to be searched.

Dynamic Rank Subsetting with Data Compression

  • Hong, Seokin
    • 한국컴퓨터정보학회논문지
    • /
    • 제25권4호
    • /
    • pp.1-9
    • /
    • 2020
  • 본 논문에서는 데이터 압축을 통해 메모리 시스템의 에너지 효율 및 성능을 향상시키는 동적랭크 서브세팅 기법 (Dynamic Rank Subsetting, DRAS)을 제안한다. DRAS 기법은 하나의 메모리 랭크 (Rank)를 두 개의 서브랭크 (Sub-rank)로 동작되도록 하여, 데이터가 절반 크기로 압축될 경우 압축된 데이터를 하나의 서브랭크에만 저장한다. 이를 통해 DRAS 기법은 압축된 데이터에 대한 읽기 및 쓰기 동작의 메모리 대역폭을 두 배로 높일 수 있고, 동적 전력 소모도 절반으로 감소시킬 수 있다. 만약 데이터가 절반 크기로 압축되지 않는다면 기존 메모리 시스템에서와 같이 데이터를 두 서브랭크에 저장한다. 따라서 DRAS 기법은 데이터가 압축되지 않는 경우에 대해서는 기존 메모리 시스템 수준의 메모리 대역폭과 전력 효율성을 보장한다. 메모리 시뮬레이터를 사용한 실험 평가를 통해 DRAS 기법이 컴퓨터 시스템 성능을 평균 12% 향상시키고 메모리 시스템의 전력소모를 평균 24% 감소시킬 수 있음을 보인다.

Design of a Beam-coupling System for a Chip-integrated Spectrometer with a Discrete Linear Waveguide

  • Liu, Zhiying;Jiang, Xin;Li, Mingyu
    • Current Optics and Photonics
    • /
    • 제4권3호
    • /
    • pp.229-237
    • /
    • 2020
  • In this study, a beam-coupling system is designed to improve the coupling efficiency of achip-integrated spectrometer when the waveguide is arranged in a linear and discrete manner. In the proposed system the beam is shaped to be anti-Gaussian, to deposit adequate energy in the edge waveguides. The beam is discretely coupled to the corresponding waveguide by a microlens array, to improve the coupling efficiency, and is compressed by a toroidal lens to match the linear discrete waveguides. Based on the findings of this study, the coupling efficiency of the spectrometer is shown to increase by a factor of 2.57. Accordingly, this study provides a reference basis for the improvement of the coupling efficiency of other similar spectrometers.

랩온어칩 내부 미세유동제어를 위한 새로운 유동제어기법 (A New Flow Control Technique for Handling Infinitesimal Flows Inside a Lab-On-a-Chip)

  • 한수동;김국배;이상준
    • 대한기계학회논문집B
    • /
    • 제30권2호
    • /
    • pp.110-116
    • /
    • 2006
  • A syringe pump or a device using high electric voltage has been used for controlling flows inside a LOC (lab-on-a-chip). Compared to LOC, however, these microfluidic devices are large and heavy that they are burdensome for a portable ${\mu}-TAS$ (micro total analysis system). In this study, a new flow control technique employing pressure regulators and pressure chambers was developed. This technique utilizes compressed air to control the micro-scale flow inside a LOC, instead of a mechanical actuator or an electric power supply. The pressure regulator controls the output air pressure by adjusting the variable resistor attached. We checked the feasibility of this system by measuring the flow rate inside a capillary tube of $100{\mu}m$ diameter in the Re numbers ranged from 0.5 to 50. In addition, the performance of this flow control system was compared with that of a conventional syringe pump. The developed flow control system was found to show superior performance, compared with the syringe pump. It maintains automatically the: air pressure inside a pressure chamber whether the flow inside the capillary tube is on or off. Since the flow rate is nearly proportional to the resistance, we can control flow in multiple microchannels precisely. However, the syringe pump shows large variation of flow rate when the fluid flow is blocked in the microchannel.

다구찌 실험계획법을 이용한 드라이 선삭가공의 최적 가공조건 선정 (Selection of Optimum Machining Condition of Dry fuming Using Taguchi Method)

  • 송춘삼;김준현;김주현
    • 한국공작기계학회:학술대회논문집
    • /
    • 한국공작기계학회 2003년도 추계학술대회
    • /
    • pp.19-24
    • /
    • 2003
  • Recently, various efforts to make more speedy and precision machine tool to improve productivity and also various efforts to solve environmental problem are going on, so that dry cutting in manufacturing industry, which needs environmental conscious design and development of manufacturing technique, is becoming a very important assignment to solve. Because dry cutting does not use cutting fluid, we need other methods that can be used instead of cutting fluid, which does cooling, lubricating, chip washing, and anti-corrosion. Especially, because turning is a continuous work, the consideration of tool life and surface roughness due to continuous heat and poor lubrication is important. The purposes of this paper are the consideration of how well the compressed air can work instead of cutting fluid, and also the development of the method to select the optimum machining condition by the minimum numbers of experiments through the Taguchi method.

  • PDF

건조 선삭의 최적 가공 조건 (Optimal Machining Condition of Drying Turning)

  • 장승순;이정익
    • 한국기계기술학회지
    • /
    • 제13권4호
    • /
    • pp.49-55
    • /
    • 2011
  • Recently, various efforts to make more speedy and precision machine tool to improve productivity and also various efforts to solve environmental problem are going on, so that dry cutting in manufacturing industry, which needs environmental conscious design and development of manufacturing technique, is becoming a very important assignment to solve. Because dry cutting does not use cutting fluid, we need other methods that can be used instead of cutting fluid, which does cooling, lubricating, chip washing, and anti-corrosion. Especially, because turning is a continuous work, the consideration of tool life and surface roughness due to continuous heat and poor lubrication is important. The purposes of this paper are the consideration of how well the compressed air can work instead of cutting fluid, and also the development of the method to select the optimum machining condition by the minimum numbers of experiments through the Taguchi method.

2채널 영상 스트리밍 기술을 적용한 차량용 전. 후방 무선 영상 모니터링 시스템 (Applying a Two-channel Video Streaming Technology Front and Rear Vehicle Wireless Video Monitoring System)

  • 나희수;원영진;윤중근;이상민;안명일;김동현;문종훈
    • 전자공학회논문지
    • /
    • 제51권12호
    • /
    • pp.210-216
    • /
    • 2014
  • 본 논문은 승용 및 화물 차량의 주차 시, 사각지대에 의해 발생할 수 있는 위험요소를 차량의 전방, 후방에 장착된 카메라를 이용하여, 위험 요소 발견 시 신속히 상황을 대처할 수 있도록 운전자를 도와주는 차량용 전. 후방 영상 모니터링 시스템의 개발을 제안하였다. 임베디드 시스템(embedded system) 환경에서 두 개의 고해상도 영상 데이터를 TCP/IP 기반 네트워크로 전송하는 방법으로 하나의 SoC(System on Chip)와 두 개의 고해상도 CMOS(Complementary metal-oxide-semiconductor) 영상 센서를 사용 하였다. 영상 데이터를 TCP/IP 네트워크 기반으로 전송하기 위해서 두 개의 카메라에서 입력 받은 영상을 H.264 포맷으로 압축한 뒤에 실시간 전송 규약(Real-time Transport Protocol)을 이용해서 영상 데이터를 무선(Wi-Fi)으로 전송하였다. 무선 환경에서 발생할 수 있는 전송손실, 전송지연, 전송제한 등을 감안하여 H.264로 압축된 두 개의 영상 데이터의 비트레이트를 조절하여, 무선(Wi-Fi) 환경에서 최적의 전송 조건을 갖추기 위한 시스템을 구현하여 실험하였다.