• Journal of the Korean Society for Railway
• /
• v.9 no.6 s.37
• /
• pp.652-656
• /
• 2006

Constant load model is widely used for an electric train to perform the static analysis of AT (Auto Transformer) feeding systems. In this model, the train will be considered as a constant load model when it drives or as a constant source model when it applies regenerative brake. However there must be some constraints imposed on the pantagraph voltage in actual operations. These constraints are established for the reason of protecting the feeding facilities from excessive rise of regenerative braking voltage or guaranteeing the minimum traction power of train. In normal operating situation, the pantagraph voltage of the train should be maintained within these limits. Keeping these facts in minds, we suggest new methods or analyzing AT feeding systems using the constant power models with the conditions of voltage constraints. The simulation results from a sample system using the proposed method illustrate both the states of system variables and the supply-demand relation of power among the trains and the systems very clearly, so it is believed that the proposed method yields more accurate results than conventional methods do. The proposed methods are believed to contribute to the assessment of TCR-TSC for compensating reactive powers too.

• Journal of Animal Environmental Science
• /
• v.4 no.2
• /
• pp.105-111
• /
• 1998

The study was conducted to analyze the directions of domestic production and import of livestock machinery and to propose their direction of development. The results of this study are as follows ; 1. Most of livestock machinery for feeding and watering systems are manufactured by a domestic skill. But their performances and know-how are behind those of the advanced countries. 2. The know-how and ratios of the market share of feeding systems for pigs are evaluated high, but researches of total automatic systems for them are very insufficient. 3. Feeding and milking systems for milk-cow are in the conditions of a weak technologies, which should be studied in the future.

• Journal of Mechanical Science and Technology
• /
• v.19 no.spc1
• /
• pp.403-410
• /
• 2005

Many daily appliances for examples copiers, printers and ATMs contain the media transport system (MTS) and the slippage between the medium in the MTS deteriorates the performance quality of the whole system. The slippage of the medium in the MTS is affected by many parameters including the friction coefficient between the feeding rollers and the medium, the velocity of the feeding rollers, and the normal force exerted on the medium by feeding rollers. This paper focuses on the effect of the normal force on the slippage while the medium is being fed. For this purpose, we developed a two-dimensional simulation model for a paper feeding system. Using the simulation model, we calculated the slippage of the paper for different normal forces. We have also constructed a testbed of the paper feeding system to verify the simulation results. Experimental results are compared with the simulation results.

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.1322-1327
• /
• 2004

There are some previous studies that utilize constant impedance models or constant current models for electric trains to perform the static analysis of AT feeding systems. These mentioned models have some merits of linear systems but yield erroneous results because of the innate restraints of the models since linear models cannot represent the features of constant power in inverter-driven trains. From these reasons, it is suitable that the train be considered as a constant load model when it drives or as a constant source model when it applies regenerative brake. However, excessive rise of regenerative voltage during the braking may damage the vehicle itself and the feeding systems so the voltage must be restricted below a certain value. Keeping these facts in minds, we suggest new methods of analyzing AT feeding systems using the constant power models with the conditions of voltage constraints. The simulation results from a sample system using the proposed method illustrate both the states of system variables and the supply-demand relation of power among the trains and the systems very clearly, so it is believed that the proposed method yields more accurate results than conventional methods do.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.2
• /
• pp.283-300
• /
• 2004

Currently commercial dry sows are housed in individual stalls and subject to restricted feeding. These sows often show stereotypic behaviours which increase their maintenance energy requirement. Group housing is desirable to improve animal welfare and public perception. However, under restricted feeding systems, group-housed dry sows are also aggressive. The feed intake of these sows is variable, depending on their social rank, which results in different milk production and variable piglet performance. These problems can be solved by ad libitum feeding systems, but the large capacity of intake by dry sows will not allow this feeding system to be practical as high feeding level during pregnancy can reduce reproduction performance of sows. Current research indicates that feeding high fibre diets to dry sows enables sows to be fed ad libitum, but the effect of dietary fibre on feed intake and nutrient utilisation is dependent on the quality of fibre sources. Most research has focused on sugar beet pulp, straw, lucerne meal and by-products, but there is a need to identify and evaluate some widely available and cheap fibre materials and feed grains for developing the best strategy to control nutrient intake of dry sows while feeding ad libitum.

• Asian-Australasian Journal of Animal Sciences
• /
• v.6 no.1
• /
• pp.91-97
• /
• 1993

This experiment was carried out to examine the effects of urea-treated rice straw feeding on the growth performance of crossbred Holstein heifers under different feeding conditions. In the first experiment, the animals were given diets having 2 levels of TDN and CP and 3 levels of crude fiber (22, 30 and 36%) which were formulated with urea-treated rice straw and concentrates. Daily weight gain of heifers was not different between 22% and 30% CF diets, but the reduction of TDN or CP level to 90% of the requirements decreased the weight gain. Fiber content of 36% also reduced the body weight gain. The reduction of TDN significantly reduced DM intake and increased feed conversion ratio. Feed cost per kg weight gain was significantly increased by an increase in CF to 36%. In the second experiment, separate feeding and total mixing feeding were compared. There were no significant differences between the two feeding systems in body weight gain although the possibility of superiority in SF to TMF remained. DM intake was not affected by the feeding system, but 30% CF diet gave higher DM intake. Feed cost per kg weight gain was lower in the 30% CF diet.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.11a
• /
• pp.596-599
• /
• 2004

The media transport systems, such as printers, copiers, facsimile, ATMs, cameras, etc., have been widely used and being developed rapidly. In the development of those systems, the media feeding mechanism is an important key technology for the design and development of the media transport systems. In this paper, a multi-degree of freedom sheet model with dynamic contact conditions is presented to understand the mechanism of sticking and jamming. A sheet is modelled as a cantilever beam and the feeding velocity is assumed to be constant. The relation between the feeding velocity and the coefficient of friction for guaranteeing stable feeding is presented. Simulations are performed for a horizontal linear guide and a oblique linear guide, calculating the contact force and contact states of mass points.

• Asian-Australasian Journal of Animal Sciences
• /
• v.10 no.3
• /
• pp.253-259
• /
• 1997

Holstein Friesian and Jersey crossbreds are being widely introduced in the state of Gujarat in India. This paper evaluates feeding practices at farm level and examines whether the crossbreds fit into the existing mixed farm systems. Over a period of four years milk-offtake and feeds offered were recorded for 1331 cows at fortnightly intervals. The breed and the amount of concentrates fed contributed most to the variation in milk offtake. The introduction of crossbred cattle has a major impact on smallholder mixed farming systems. Crossbreds produced, on average, 1.8 times more milk than Desi, Gir, and Kankrej cows. They were fed 1.4 times more concentrates, and about 1.2 times more green and dry feeds than local cows. The major limiting constraint is the quality of the roughages offered. Farmers with crossbreds try to adjust their feeding of concentrates according to the needs of their cows. On tribal farms, local cows produced less milk than on non-tribal farms, whereas crossbreds produced the same amount of milk on both tribal and non-tribal farms. Crossbreds fit into the farming systems of both tribal and non-tribal farmers. The differences in agro-climatic characteristics between different areas in Gujarat were not reflected in differences in milk offtakes.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.1466-1472
• /
• 2007

State estimation is to estimate the values of the states that minimize the error between the real states and the measured states, which are usually hampered by noise. It exploits the redundant data and the equality constraints achieved from the power systems. In the electric railway feeding systems, especially, the measured states may have significant level of noise in comparison with the commercial power systems. Since the meters - the sources of the data that include vehicles - are distributed in the long distance along the railroad, they are vulnerable to the signal interference. In this paper we have studied the application of state estimation method to the AT feeding systems and shown that this method can increase the reliability of the measured data.

• Proceedings of the KSR Conference
• /
• 1999.11a
• /
• pp.344-351
• /
• 1999

The safe operation of electro railways is greatly dependant on its protective systems. The system so-called Fault Protection Wire(FW) is now widely adapted to protect in AT feeding systems. It is connected between the feeder and trolley circuit to return the fault current to autotransfonmers at substation. This paper computed the distribution of fault currents at FW in the system and also evaluated the safety from electric shock when ground fault or flashover occur in the feeding system. The results show FW is useful to protect power supply network from fault in electric railways