• 한국기계가공학회지
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• 제21권3호
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• pp.29-35
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• 2022

When a vehicle is driven off a road surface, the deformations of the road surface and tire are combined. Consequently, the dynamic behavior of wheel movement becomes difficult to predict and control. Herein, we propose a tire test bed to capture the dynamic behavior of tires moving on sand and soil. Based on this study, it is discovered that the slip rate can be controlled, and the vertical force can be measured using a load cell. The test results show that this test bed can be useful for capturing the dynamic behavior of the tire and validating dynamic simulations. In fact, the tire test bed developed in this study can be used to verify the results of computer simulations. In addition, it can be used for basic experiments pertaining to the speed control of unmanned autonomous vehicles.

• 제어로봇시스템학회논문지
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• 제14권10호
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• pp.1062-1072
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• 2008

When mobile robots perform the mission in the rough terrain, the traversability depended on the terrain characteristic is useful information. In the traversabilities, wheel-terrain maximum friction coefficient can indicate the index to control wheel-terrain traction force or whether mobile robots to go or not. This paper proposes estimating wheel-terrain maximum friction coefficient. The existing method to estimate the maximum friction coefficient is limited in flat terrain or relatively easy driving knowing wheel absolute velocity. But this algorithm is applicable in rough terrain where a lot of slip occurred not knowing wheel absolute velocity. This algorithm applies the tire-friction model to each wheel to express the behavior of wheel friction and classifies slip-friction characteristic into 3 major cases. In each case, the specific algorithm to estimate the maximum friction coefficient is applied. To test the proposed algorithm's feasibility, test bed(ROBHAZ-6WHEEL) simulations are performed. And then the experiment to estimate the maximum friction coefficient of the test bed is performed. To compare the estimated value with the real, we measure the real maximum friction coefficient. As a result of the experiment, the proposed algorithm has high accuracy in estimating the maximum friction coefficient.

• 상하수도학회지
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• 제13권1호
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• pp.43-50
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• 1999

In spite of low energy requirement, and operation and construction cost, biofilters with soil beds have not been operated efficiently. Because of excess moisture in winter and rainy periods, saturated pores in the bed prevent passage and sorption of odorous compounds. Sometimes this results in septic conditions that release previously sorbed and oxidized sulfur. Therefore, an economical and effective alternative needs to be developed. The objectives of this study were to confirm applicability of the granular scrap tires with compost for treating odorous gas as well as to obtain optimum design parameters for proposed system. In lab-scaled test, multiple stage reactors had lower headloss than a single stage reactor and less headloss was occurred for the gas with higher moisture content. For practical purpose, pilot-scaled reactor was operated to remove odor from septic tank, manure and animal wastewater treatment plant and composting machine. According to the results of pilot scaled test, $H_2S$ can be always removed completely and ammonia/amine can be removed excellently when proper moisture content is provided. The results from lab and pilot test showed that granular scrap tire could be replaced with soil as supporting material for biofilter showed excellent drainage because of its ability to reject moisture.

• 대한환경공학회지
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• 제30권5호
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• pp.507-516
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• 2008

폐타이어 담체 유 무에 따른 질소 제거 효과와 담체를 충진한 유동상 생물막 공정의 질소제거 특성을 알아보고자 실험을 수행하였다. 하수처리장 유입하수를 이용해 폐타이어 담체 유 무에 따른 질소 제거 정도는 실험실 규모 회분식 실험을 이용하고, 온도가 질소제거에 미치는 영향은 담체를 15% 충진한 파일럿 규모 유동상 생물막 공정을 약 370일 동안 장시간 운전을 통해 알아보았다. 폐타이어 담체 유 무에 따른 질산화율은 3.4 및 1.7 mg NH$_4^+$-N/g Mixed-Liquor Volatile Suspended Solid(MLVSS)$\cdot$hr로 담체를 투입한 경우 질소 제거가 더 효과적이었다. 온도범위가 9$\sim$10$^{\circ}C$에서 20$\sim$24$^{\circ}C$로 증가하였을 때 총 질소제거효율은 53 $\pm$ 8%에서 76 $\pm$ 5%까지 증가하였다. 온도가 9$\sim$10$^{\circ}C$, 10$\sim$20$^{\circ}C$, 20$\sim$24$^{\circ}C$에서 질산화율은 0.8 $\pm$ 0.5, 3.1 $\pm$ 1.9, 3.4 $\pm$ 2.1 mg NH$_4^+$-N/g MLVSS$\cdot$hr로, 탈질율은 0.6 $\pm$ 0.2, 1.1 $\pm$ 0.6, 1.4 $\pm$ 0.6 mg NO$_3^-$-N/g MLVSS$\cdot$hr로 나타났으며, 전체미생물 중 부착미생물은 17 $\pm$ 7, 20 $\pm$ 6, 22 $\pm$ 6%로 온도가 증가함에 따라 증가하는 경향을 나타내었다. 미생물 총괄활성도는 온도가 9$\sim$10$^{\circ}C$에서 20$\sim$24$^{\circ}C$으로 증가함에 따라 혐기조, 무산소조, 호기조에서 22, 20, 15% 증가하였고 질산화 미생물인 Nitrosomonas와 Nitrobacter 활성분율도 증가하였다.