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We tested the hypothesis that exposure of healthy volunteers to concentrated ambient particles (CAPS) is associated with an influx of inflammatory cells into the lower respiratory tract. Thirty-eight volunteers were exposed to either filtered air or particles concentrated from the immediate environment of the Environmental Protection Agency (EPA) Human(More)
RATIONALE Exposure to ozone causes a decrease in spirometric lung function and an increase in airway inflammation in healthy young adults at concentrations as low as 0.08 ppm, close to the National Ambient Air Quality Standard for ground level ozone. OBJECTIVES To test whether airway effects occur below the current ozone standard and if they are more(More)
| We propose a new framework for the link assignment (i.e., topological design) problem that arises from the use of inter-satellite links (ISL's) in Low-Earth Orbit (LEO) satellite networks. In the proposed framework, we model a LEO satellite network as a Finite State Automaton (FSA) where each state corresponds to an equal-length interval in the system(More)
A dynamic single-path mathematical model was developed that is capable of analyzing detailed deposition patterns of inhaled particles in human lungs. Weibel's symmetric lung morphology was adopted as the basic lung structure, and detailed transport processes were evaluated numerically using the fully implicit procedure. Deposition efficiencies by specific(More)
Detailed regional deposition of inhaled particles was investigated in young adults (n = 11) by use of a serial bolus aerosol delivery technique. A small bolus (45 ml half-width) of monodisperse aerosols [1-, 3-, and 5-microns particle diameter (Dp)] was delivered sequentially to a specific volumetric depth of the lung (100-500 ml in 50-ml increments), while(More)
The Caller Identiication System is a security system designed to strengthen the security measures already present in the SNU(Seoul National University) local area network. It is a system made up of two main components and they are (1) an Extended TCP Wrapper(ETCPW) and (2) a Caller Identiication Server(CIS). The Extended TCP Wrapper(ETCPW) is, as its name(More)
We investigate a topological design and routing problem for Low-Earth Orbit (LEO) satellite communication networks where each satellite can have a limited number of direct inter-satellite links (ISL's) to a subset of satellites within its line-of-sight. First, we model LEO satellite network as a FSA (Finite State Automaton) using satellite constellation(More)
  • Chong S Kim
  • 2009
The deposition dose and site of inhaled particles within the lung are the key determinants in health risk assessment of particulate pollutants. Accurate dose estimation, however, is a formidable task because aerosol transport and deposition in the lung are governed by many factors whose precise workings are often not fully understood. In vivo human data(More)
Ultrafine particles (< 0.10 microm in diameter) are present in great number in polluted urban air, thus posing a potential health risk. In this study, the total deposition fraction (TDF) of ultrafine aerosols with a narrow size distribution (number median diameter NMD = 0.04-0.1 microm and geometric standard deviation sigma(g) = approximately 1.3) was(More)
The evaporative and hygroscopic effects and deposition of isotonic and hypertonic saline droplets have been simulated from the mouth to the first four generations of the tracheobronchial tree under laminar-transitional-turbulent inspiratory flow conditions. Specifically, the local water vapor transport, droplet evaporation rate, and deposition fractions are(More)