• Journal of Institute of Control, Robotics and Systems
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• v.22 no.6
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• pp.435-444
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• 2016

James C. Maxwell published a paper titled "On Governors" in the Proceedings of the Royal Society of London in 1868. However, this paper was ignored for about 80 years due to unreadability of the paper itself. In 1948, Norbert Wiener revived this paper and identified it as the first significant control theory paper, which gave Maxwell his due as the first contributor to this theory. The purpose of this article is to provide historical information on the origin of stability analysis through Maxwell's paper, and to revisit the key idea of the paper in view of the present stability theory with clear explanations. This article includes a proof and some illustrative figures of governors that were not shown in the original publication.

• Korean Journal of Veterinary Service
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• v.33 no.2
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• pp.157-165
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• 2010

A survey of canine heartworm infections among 83 dogs (Male 42, Female 41) of pet dogs in Ulsan area was performed from March to July 2009 using antigen test. Of 83 dogs, 6 dogs (7.2%) were infected with the Dirofilaria immitis, and 5 dogs (6%) were detected to have microfilaria in the peripheral blood. The infection according to the age of 4~5, 6~7, 7 over years were 7.4%, 12.5%, and 10.5%, Also, A survey of canine heartworm infections among 23 dogs (Male 15, Female 8) of hunting dogs in Ulsan area was performed from July 2008 using antigen test. Of 23 dogs, 11 dogs (47.8%) were infected with the D. immitis, and 6 dogs (26.1%) were detected to have microfilaria in the peripheral blood. The infection according to the age of under 1, 2-3, 4-5, 6-7 over years were 12.5%, 40%, 85.7% and 66.7%, respectively.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.513-518
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• 2001

This research has been performed to estimate the hunting motion hysteresis of railway passenger cars. An old and a new car with almost same structure are chosen as analysis models. To solve effectively a set of simultaneous equations of motion strongly coupled with creep relations, shooting algorithm in which the nonlinear relations are regarded as a two-point boundary value problem is adopted. The bifurcation theory is applied to the dynamic analysis to distinguish differences between linear and nonlinear critical speeds by variation of parameters. It is found that there are some factors and their operation area to make nonlinear critical speed respond to them more sensitivity than linear critical speed. Full-scale roller rig tests are carried out for the validation of the numerical results. Finally, it is concluded that the wear of wheel profile and the stiffness discontinuities of wheelset suspension caused by deterioration have to be considered in the analysis to predict hysteresis of critical speed precisely.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.2
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• pp.409-425
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• 2015

In this paper, we employ a dynamics modeling method for investigating a multi-body dynamics system of semi-submersible autonomous underwater vehicles consisting of a towing vehicle operated near the water surface, a tow cable, and a towfish. The towfish, which is towed by a marine cable for the purposes of exploration or mine hunting, is modeled with a Six-Degree-of-Freedom (6-DOF) equation of motion that reflects its hydrodynamics characteristics. The towing cable, which can experience large displacements and deformations, is modeled using an absolute nodal coordinate formulation. To reflect the hydrodynamic characteristics of the cable during motion, the hydrodynamic force due to added mass and the drag force are imposed. To verify the completeness of the modeling, a few simple numerical simulations were conducted, and the results confirm the physical plausibility of the model.

• International Journal of Railway
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• v.3 no.3
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• pp.90-94
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• 2010

In this paper, driving functions of the Korea High-speed Trains were decomposed based on systems engineering architecture. In order to analyze the driving function, various systems engineering tools and methods were used. Moreover, interfaces of decomposed driving functions were analyzed to figure out purposes of the driving functions. Through activity modeling of driving function of the Korea High-Speed Trains, main functions were derived when starting, speeding and stopping. When the high speed train is speeding, pre-departure checks and wheel slide prevention are essential driving activities for the safety and when the high speed train runs high speed, maintaining driving stability by monitoring bogie hunting and monitoring drivers' safe operation by vigilance systems is important. Furthermore, when the train is braking, the driver should checks brake and suspensions as safety actions.

• Journal of the Korea Furniture Society
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• v.19 no.4
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• pp.300-306
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• 2008

Nepal is rich country in terms of its vast array of biological diversity. The relationship between local communities and the biological diversity in Nepal is a very entangle one, whereby two-thirds of our population are heavily dependent upon the biodiversity for their survival. The destruction of biodiversity signifies the destruction of people's livelihoods and survival. Biodiversity and genetic resources conservation has been a most significant part of the Nepalese society due to its socio-economic and cultural importance and provides the human race trees for timber, fuel, food, industrial raw materials, pharmaceuticals, beverages and environmental stabilization. Threats to biodiversity at global level is of greater concern, specially, human activities are the greatest factor currently affecting biodiversity, through the use of natural resources by industry, agriculture, hunting, and energy generation.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1159-1161
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• 2003

Gidra speaking people living in Wonnie area of western province in Papua New Guinea are traditionally dependent on hunting and gathering. Sago is the main staple food and the vegetation consists of rain forest (Bua) and trees with savannah grass (Yap). The population density is very low and the people are very little affected by modernization. This study is an attempt to look at the people-resource interaction in the area for the past thirty years based on aerial photographs and various satellite data. The study showed the trends of yap versus bua distribution as well as the location of garden and Sago grove areas, which is important for studying the livelihood of the people.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.3
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• pp.137-143
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• 1996

The propulsion marine diesel engine has been widely applied with a mechanical-hydraulic governor to control the ship speed for long time. But it was recently very difficult for the mechanical-hydraullic governor to control the speed of engine under the condition of low speed and low load because of jiggling and hunting by rough fluctuation of rotating torque. To solve these problems of control systems, the performance improvement of mechanical-hydraulic governor is required. In this paper, in order to analyze the speed stability of control systems, the influence of parameters of the engine dead time, gain, damping ratio was discussed on the view of control engineering. The performance improvement of a conventional mechanical hydraulic governor is confirmed to be possible by fuzzy control scheme.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1435-1440
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• 2008

High-speed train under development is a type of EMU(electric multiple units). Since power sources like motors and gears are distributed in the high-speed EMU, the high-speed EMU generates vibration and sound more than the articulated high-speed train. Vibration of vehicle, vibration between rails and wheels, hunting of bogie and snake motion reduce ride comfort. In this paper, to decrease the vibration of the articulated high-speed train, improvements were presented using an analytical model and a simulation model. The simulation model of the high-speed EMU was designed on the basis of the korean high-speed train and the design parameters for ride comfort were showed and the dynamic characteristics of the vehicle was understood. To consider the characteristics of the vehicle suspension, the analytical model was designed and the simulation model was verified with it.

• Acta Via Serica
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• v.6 no.2
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• pp.21-36
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• 2021

This paper discusses textile motifs depicted in the hunting panels inside the late Sasanian larger grotto at Taq-i Bustan. Scholars of Iranian art have referred to these rock reliefs in order to trace the origin of Sasanian textile decorations and their exportation in the whole medieval Eurasian continent. This however does not seem to be the case. In fact, the textile motifs reproduced at Taq-i Bustan could be a good term of comparison only for late Sasanian textile production. Moreover, nothing like this has appeared in previous Sasanian rock reliefs. For this reason, the present paper argues that some of those motifs could actually be importations from Central Asia where reproductions of textiles embellished with those motifs were very popular. Islamic written sources on Taq-i Bustan rock reliefs could be very useful to support some ideas expressed in this paper.