• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.17-28
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• 2009

There are many limitations in dealing with rapidly changing traffic demand in urban cities. Thus recently, traffic operation and management skills are more emphasized rather than the expansion of traffic facilities. In particular, in the interrupted flow formed by signalized intersections, it is quite important to give optimal signal timing to each intersection with consideration of progression. However, as fixed signal times per direction can affect passing capacity in signalized intersections, the present four-signal phase including a left-turn signal has many limitations, including reduction of directional road capacity when traffic demand is increases dramatically during peak hours. Because of this problem, lots of studies about internal metering techniques for oversaturated signal control skills have progressed but these techniques are not used widely due to the absence of detectors for queue sensing in real-time signal control systems. In this research, a new methodology called the "restrictive left-turn signal control", which is already used at the intersection above Samsung subway station, is suggested in order to reduce control delay of urban arterial roads. The restrictive left-turn signal control allows a driver to make a U-turn and then a right turn instead of turning left in that intersection. With this change, the restrictive left-turn signal control can contribute to increased intersection capacity by reducing the number of signal phases and maximizing the through phase time. However, road structure and traffic conditions at the target intersections should be considered before the adoption of the proposed signal control.

• Journal of Animal Environmental Science
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• v.13 no.3
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• pp.195-200
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• 2007

Management of odors is essential to swine industry in the Republic of Korea. This study was conducted to evaluate the odor removal efficiency of biofilter ducting systems. Rice straw and auto clave concrete(ALC) were used as filter medium. The ventilation fans(5 units, diameter: 500 mm) at the side wall of a growing pig housing were connected to a biofilter using a duct. The size of a biofilter is $2.5{\times}2{\times}1.2(W{\times}L{\times}H)$. The air velocities at the 300 mm above rice straw and ALC were 0.77 and 0.56 m/s, respectively. Ammonia concentration at the outlet of rice straw and ALC media were 2 and 3 ppm, respectively. Dust concentrations were also measured. The dust concentrations of rice straw and ALC were 93, $32\;mg/m^3$, respectively. There was no significant difference between filter mediums in terms of carbon dioxide concentrations(rice straw: 320, ALC: 270 mg/l). The concentration of hydrogen sulfide was stable over the experimentation. The actual concentrations of hydrogen sulfide were 4, 3 and 3 ppm at the days of 7, 21 and 36, respectively. These results suggest that biofilter ducting systems may remove odors from pig house effectively.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.3
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• pp.1-8
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• 2007

PDiabetic neuropathy is one of the most common diabetes related complications including diabetic nephropathy and retinopahty. In clinical practices, nerve conduction velocity (NCV) has been used as a standard method for diagnosing diabetic neuropathy. However, it applies maximum current of 100mA to nerves causing stress and pain to patients. In this study, as a non-invasive method, $TcpO_2$ was utilized to investigate the difference and relationship between $TcpO_2$ and $SpO_2$ of normal and diabetic neuropathy subjects. In addition, a new method of diagnosing diabetic neuropathy using $TcpO_2$ is suggested. 50 normal subjects and 50 diabetic patients with neuropathy diagnosed by NCV participated in this study. Parameters used in this study were $TcpO_2$, $TcpCO_2$, and $SpO_2$. As a result of the $TcpO_2$ measurements, statistical significances were found from $TcpO_2$ of hands and feet from normal and patients group(p<0.01). $SpO_2$ measured from index finger of normal and patient groups showed no statistical significance(p>0.05). On the other hand, $SpO_2$ measured from great toes of normal and patient groups showed statistical significance(p<0.01). Correlation coefficient between $SpO_2$ of finger and $TcpO_2$ of hand was 0.400 (p<0.01) and $SpO_2$ of toe and $TcpO_2$ of foot was 0.471(p<0.01). Both correlation values were statistically significant. Sensitivities and specificities of the $TcpO_2$ method were found to be 66 % and 92 %, respectively. If the suggested $TcpO_2$ method is used periodically, prevention and early diagnosis of diabetic neuropathy would be possible.