• Title/Summary/Keyword: mass sensing

Search Result 210, Processing Time 0.026 seconds

Fabrication and Characterization of Silicon Devices for Flow Measurement (II) (흐름측정용 실리콘 소자의 제작 및 특성 평가 (II))

  • Ju, B.K.;Ko, C.G.;Kim, C.J.;Tchah, K.H.;Oh, M.H.
    • Journal of Sensor Science and Technology
    • /
    • v.3 no.1
    • /
    • pp.12-18
    • /
    • 1994
  • In this study, we fabricated and characterized a calorimetric-type flow sensing element using a micromachined silicon substrate. The cooling and heating effects resulted from the gas flow were measured by two temperature sensors located at both sides of the heating resistor, and the insulator diaphragm was employed as a substrate in order to improve thermal isolation. The sensor generated $0{\sim}378.4mV$ output signal under 10V bridge-applied voltage when the nitrogen gas was passed on the sensor surface having a mass flow rate of $0{\sim}0.25grs/min$, and reached to the stable operating condition within 10 seconds.

  • PDF

Analysis of Tropospheric Carbon Monoxide using MOPITT data

  • Lee, Sang-Hee;Park, Gi-Hyuk;Lim, Hyo-Suk;Lee, Joo-Hee
    • Proceedings of the KSRS Conference
    • /
    • 2002.10a
    • /
    • pp.373-377
    • /
    • 2002
  • The Measurement of Pollution in the Troposphere (MOPITT) instrument is an eight-channel gas correlation radiometer launched on the Earth Observing System (EOS) Terra spacecraft in 1999. Its main objectives are to measure carbon monoxide (CO) and methane (CH4) concentrations in the troposphere. This work analyzes tropospheric carbon monoxide distributions using MOPITT data in East Asia and compared ozone distributions. In general, seasonal CO variations are characterized by a spring peak and decreased in the summer. Also, this work revealed that the seasonal cycles of CO are spring maximum and summer minimum with averaged concentrations ranging from 118ppbv to 170ppbv. The CO monthly means show a similar profiles to those of O3. This fact clearly indicates that the high concentration of CO in spring is caused by two possible causes: the photochemical CO production in the troposphere, transport of the CO in the northeast Asia. The CO and O3 seasonal cycles in northeast Asia are influenced extensively by the seasonal exchange of the different types of air mass due to the Asian monsoon. The continental air masses contain high concentrations of O3 and CO due to higher continental background concentrations and sometimes due to the contribution of regional pollution. In summer the transport pattern is reversed. The Pacific marine air masses prevail over Korea, so that the marine air masses bring low concentrations of CO and O3, which tend to give the apparent minimum in summer.

  • PDF

A Development of Device for Measurement of Vertical Ground Reaction Force(II) (수직 반작용력 측정 장치 개발(II))

  • Park, Jin
    • Korean Journal of Applied Biomechanics
    • /
    • v.13 no.3
    • /
    • pp.341-354
    • /
    • 2003
  • The purpose of this study was to develop the uniaxial force plate system which is measured by the vertical force. The VGRF(vertical ground reaction force) 1.0 was composed of 2 bath digital scales, 2 indicaters, and analyzing software. This system was newly renovated to VGRF 2,0 which are 2 industrial digital scales, 2 adjustable indicators, and enforced analyzing software. Changes of the new system were as follows. First, the height of the plate was 75% lower than before. Second, sensing ability of the load cell was changed from 90 - 0.05kg to 300 - 0.1kg. Third, the speed of data processing was changed from 17 per second to 60 per second. Fourth, analyzing software was enforced to develop and calculate the data. For the test of the system, two different types(bare foot, high-heeled shoes) gait was adopted. highly skilled female walker(23yrs, height 165cm, body mass 46.8kg) participated for the experimental study. During the dynamic performance(gait analysis), the data of each load cell were very similar to the previous studies. Specifically, bare foot walking had less vertical force than high-heeled shoes. Consequently, VGRF 2.0 can sense the general dynamic movements as well as static load conditions.

A STUDY ON THE CORRELATION BETWEEN GROUND SUBSIDENCE AREA NEAR ABANDONED UNDERGROUND COAL MINE AND GEOPHYSICAL PROSPECTING DATA USING GIS

  • Kim Ki-Dong;Choi Jong-Kuk;Won Joong-Sun
    • Proceedings of the KSRS Conference
    • /
    • 2005.10a
    • /
    • pp.325-328
    • /
    • 2005
  • To estimate presumptive local ground subsidence area near Abandoned Under ground Coal Mine(AUCM) at Samcheok city in Korea, the geological properties of existing ground subsidence area and the geophysical prospecting data were analyzed using GIS. The electrical resistivity survey and seismic reflection survey database were constructed from investigation reports and factors which are related with ground subsidence such as geological map, topological map, land use map, lineament map, groundwater level, RMR (Rock Mass Rating), mining tunnel map and slope database were constructed also to make a comparative study of each parameters. As a result of the spatial analysis of existing ground subsidence area, 9 major factors causing ground subsidence were extracted and a connection between the structure of underground and the ground subsidence was determined from the analysis of geophysical prospecting data. The estimation of presumptive ground subsidence area was performed using the correlation between the result from neural network analysis of 9 factors and the scrutiny of geophysical prospecting data.

  • PDF

Quantification of Oxygen Transfer in Test Tubes by Integrated Optical Sensing

  • Wittmann, Christoph;Schutz, Verena;John, Gernot;Heinzle, Elmar
    • Journal of Microbiology and Biotechnology
    • /
    • v.14 no.5
    • /
    • pp.991-995
    • /
    • 2004
  • Immobilized sensor spots were applied for online measurement of dissolved $O_2$, in test tubes. Oxygen transport was quantified at varied shaking frequency and filling volumes. The k$_{L}$ a increased with increasing shaking frequency and decreasing filling volume. In non-baffled tubes the maximum $k_{L}a$ value was $70h^{-1}$, equivalent to a maximum $O_2$ transfer capacity of 15mMh^{-1}$. Monitoring of the hydrodynamic profile revealed that the liquid bulk rotated inside the tube with an inclined liquid surface, whereby the angle between the surface and tube wall increased with increasing shaking frequency. The $k_{L}a$ clearly correlated to the surface area. Placement of four baffles into the tubes improved the oxygen transfer up to 3-fold. The highest increase in $k_{L}a$ was observed at high filling volume and high shaking frequency. The maximum $k_{L}a$ in baffled tubes was $100 h^{-1}$.

Silver nanowire-containing wearable thermogenic smart textiles with washing stability

  • Dhanawansha, Kosala B.;Senadeera, Rohan;Gunathilake, Samodha S.;Dassanayake, Buddhika S.
    • Advances in nano research
    • /
    • v.9 no.2
    • /
    • pp.123-131
    • /
    • 2020
  • Conventional fabrics that have modified in to conductive fabrics using conductive nanomaterials have novel applications in different fields. These of fabrics can be used as heat generators with the help of the Joule heating mechanism, which is applicable in thermal therapy and to maintain the warmth in cold weather conditions in a wearable manner. A modified fabric can also be used as a sensor for body temperature measurements using the variation of resistance with respect to the body temperature deviations. In this study, polyol synthesized silver nanowires (Ag NWs) are incorporated to commercially available cotton fabrics by using drop casting method to modify the fabric as a thermogenic temperature sensor. The variation of sheet resistance of the fabrics with respect to the incorporated mass of Ag NWs was measured by four probe technique while the bulk resistance variation with respect to the temperature was measured using a standard ohm meter. Heat generation profiles of the fabrics were investigated using thermo graphic camera. Electrically conductive fabrics, fabricated by incorporating 30 mg of Ag NWs in 25 ㎠ area of cotton fabric can be heated up to a maximum steady state temperature of 45℃, using a commercially available 9 V battery.

Lessons from FIFE on Scaling of Surface Fluxes at Gwangneung Forest Site (광릉 산림지의 지표 플럭스 스케일링에 관한 FIFE로부터의 교훈)

  • Hong Jinkyu;Lee Dongho;Kim Joon
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.7 no.1
    • /
    • pp.4-14
    • /
    • 2005
  • CarboKorea and HydroKorea are the domestic projects aiming to improve our understanding of carbon and water cycles in a typical Korean forest located in a complex terrain with a watershed connected to large rivers. The ultimate goal is to provide a nowcasting of these cycles for the whole Peninsula. The basic strategy to achieve such goal is through the inter- and multi-disciplinary studies that synthesize the in-situ field observation, modeling and remote sensing technology. The challenge is the fact that natural ecosystems are nonlinear and heterogeneous with a wide range of spatio-temporal scales causing the variations of mass and energy exchanges from a leaf to landscape scales. Our paradigm now shifts from temporal variation at a point to spatial patterns and from spatial homogeneity to complexity of water and carbon at multiple scales. Yet, a large portion of our knowledge about land-atmosphere interactions has been established based on tower observations, indicating that the development of scaling logics holds the key to the success of CarboKorea and HydroKorea. Here, we review the pioneering work of FIFE (First ISLSCP Field Experiment) on scaling issues in a temperate grassland and discuss the lessons from it for the application to Gwangneung forest site.

Principle of Sensor Systems by using a Quartz Crystal and Their Applications (수정진동자를 이용한 센서시스템의 원리와 응용)

  • Kim, Jong-Min;Chang, Sang-Mok;Kim, Woo-Sik
    • Korean Chemical Engineering Research
    • /
    • v.47 no.6
    • /
    • pp.655-668
    • /
    • 2009
  • The principle and applications of quartz crystal sensors based on the three basic concepts for mass, viscosity, and viscoelastic changes are reviewed. In the general discussion the basic principle of quartz crystal and realization of a resonant frequency-resonant resistance diagram are described in detail. As examples of their applications, gas sensing with a carbon-coated quartz crystal, determination of the blood coagulation factor, an electrochemical analysis and crystallization analysis are reported. The possibility of developing new biosensors and chemical sensors is discussed on the basis of these results.

A Noise Re-radiation Calibration Technique in Interferometric Synthetic Aperture Radiometer for Sub-Y-type Array at Ka-Band

  • Seo Seungwon;Kim Sunghyun;Choi Junho;Park Hyuk;Lee Hojin;Kim Yonghoon;Kang Gumsil
    • Proceedings of the KSRS Conference
    • /
    • 2004.10a
    • /
    • pp.577-580
    • /
    • 2004
  • To overcome with large size noise source distribution network design difficulty in interferometric radiometer system, especially for sub-Y-type array, a new on-board calibration technique using noise re-radiation is proposed in this paper. The suggested calibration technique is using noise re-radiation effect of center antenna after noise source injection from matched load. This approach is especially proper to sub-Y-type array interferometric synthetic aperture radiometer in mm-wave frequency band. Compared with noise injection network of a conventional synthetic aperture radiometer, the system mass, volume, and hardware complexity is reduced and cost-effective. Only one internal noise source, matched load, is used for injection using noise re-radiation technique a small set of sub-Y receiver channels is calibrated. Detailed calibration scenario is discussed and simulation results about noise re­radiation effect are presented.

  • PDF

Virtual Sensor Verification Using Neural Network Theory of the Quadruped Robot (보행로봇의 신경망 이론을 이용한 가상센서 검증)

  • Ko, Kwang-Jin;Kim, Wan-Soo;Yu, Seung-Nam;Han, Chang-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.33 no.11
    • /
    • pp.1326-1331
    • /
    • 2009
  • The sensor data measured by the legged robot are used to recognize the physical environment or information that controls the robot's posture. Therefore, a robot's ambulation can be advanced with the use of such sensing information. For the precise control of a robot, highly accurate sensor data are required, but most sensors are expensive and are exposed to excessive load operation in the field. The seriousness of these problems will be seen if the prototype's practicality and mass productivity, which are closely related to the unit cost of production and maintenance, will be considered. In this paper, the use of a virtual sensor technology was suggested to address the aforementioned problems, and various ways of applying the theory to a walking robot obtained through training with an actual sensor, and of various hardware information, were presented. Finally, the possibility of the replacement of the ground reaction force sensor of legged robot was verified.