• Journal of Animal Environmental Science
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• v.2 no.1
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• pp.1-11
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• 1996

This study was conducted to analyze the present status and the levels of mechanization and automation for raising, feeding, water supply, propagation, health management, ventilation and heat control, data analysis, and etc, and to establish the guide of the future study on development of the optimum production system models of swine facility from the results of this analysis. The scheme of the future study on the development of the optimum production system model of swine facility was established as follows : 1. A Korean and environmental control type slatted windowless swine housing model would be developed according to the following basis : \circled1 Boars, gilts and sows, delivery sows should be raised individually and piglets, growing pigs, and finishing pigs should be raised in group. \circled2 The arrangement of furrowing house were two rows of furrowing crates facing the center aisle. 2. The environmental control system and waste management system that are suitable to Korean and environmental control type slatted windowless swine housing model would be developed. 3. An electronic identification device would be developed. 4. The automatic individual wet feeding system by electronic identification device and computers would be developed. 5. The individual management system would be developed, which could manage individually the breeding pigs by the electronic identification device. 6. An expert system would be developed, which could manage the health and data base of pigs.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.1-7
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• 2007

Generally, an electric railroad feeding system has many problems due to the different characteristics in contrast with a load of general three-phase AC electric power system. One of them is harmonics problem caused by the switching device existing in the feeding system, and moreover, the time-varying dynamic loads of rail way is inherently another cause to increase this harmonics problem. In Korea power systems, the electric railroad feeding system is directly supplied from the substation of KEPCO. Therefore, if voltages fluctuation or unbalanced voltages are created by the voltage and current distortion or voltage drop during operation, it affects directly the source of supply. The trainloads of electric railway system have non-periodic but iterative harmonic characteristics as operating condition, because the electric characteristic of the electric railroad feeding system is changed by physical conditions of the each trainload. According to the traditional study, the estimation of harmonics has been performed by deterministic way using the steady state data at the specific time. This method is easy to analyze harmonics, but it has limits in some cases which needs an assessment of dynamic load and reliability. Therefore, this paper proposes the probabilistic estimation method, moments matching method(MW) in order to overcome the drawback of deterministic method. In this paper, distributions for each harmonics are convolved to obtain the moments and cumulants of TDD(Total Demand Distortion), and this can be generalized for any number of trains. For the case study, the electric railway system of LAT(Intra Airport Transit) in Incheon International Airport is modeled using PSCAD/EMTDC dynamic simulator. The raw data of harmonics for the moments matching method is acquired from simulation of the LAT model.

• Design & Manufacturing
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• v.16 no.4
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• pp.52-59
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• 2022

Currently, Korea is an aging society and is expected to become a super-aged society in about four years. X-ray devices are widely used for early diagnosis in hospitals, and many X-ray technologies are being developed. The development of X-ray device technology is important, but it is also important to increase the reliability of the device through accurate data management. Sensor nodes such as temperature, voltage, and current of the diagnosis device may malfunction or transmit inaccurate data due to various causes such as failure or power outage. Therefore, in this study, the temperature, tube voltage, and tube current data related to each sensor and detection circuit of the diagnostic X-ray imaging device were measured and analyzed. Based on QC data, device failure prediction and diagnosis algorithms were designed and performed. The fault diagnosis algorithm can configure a simulator capable of setting user parameter values, displaying sensor output graphs, and displaying signs of sensor abnormalities, and can check the detection results when each sensor is operating normally and when the sensor is abnormal. It is judged that efficient device management and diagnosis is possible because it monitors abnormal data values (temperature, voltage, current) in real time and automatically diagnoses failures by feeding back the abnormal values detected at each stage. Although this algorithm cannot predict all failures related to temperature, voltage, and current of diagnostic X-ray imaging devices, it can detect temperature rise, bouncing values, device physical limits, input/output values, and radiation-related anomalies. exposure. If a value exceeding the maximum variation value of each data occurs, it is judged that it will be possible to check and respond in preparation for device failure. If a device's sensor fails, unexpected accidents may occur, increasing costs and risks, and regular maintenance cannot cope with all errors or failures. Therefore, since real-time maintenance through continuous data monitoring is possible, reliability improvement, maintenance cost reduction, and efficient management of equipment are expected to be possible.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.7
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• pp.1045-1052
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• 2013

In this study we deal with design procedures for the flywheel energy storage system that has the capacity to store the regenerative energy produced from the railway vehicles. The flywheel energy storage system (FESS) stores the regenerative electrical energy into the high speed rotational flywheel, by conversion the electrical energy into the mechanical rotational energy. Thus the FESS is composed of the energy conversion components, such as the motor and generator, mechanical support components, such as the rotational rotor, the magnetic bearings to support the rotor, and the digital controller to control the air gap between the rotor and the magnetic bearings. In this paper the design procedures for the rotor operating at the rigid mode and the magnetic bearings to support the rotational rotor without contact are presented.

• Culinary science and hospitality research
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• v.14 no.1
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• pp.94-106
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• 2008

This study is conducted to explore the cooks' recognition of culinary environment of school feeding among the cooks working for elementary schools, middle schools, and high schools in the Ulsan district. A total of 200 samples were distributed and 185 samples were collected; among them, 182 valid samples were selected for research. Answers were processed by SPSS 12.0. after data coding. As for factor analysis of culinary environment, three factors were extracted, which are general environment, human environment, and facilities equipment environment. It was found that general environment included ventilation(31.5%), temperature (29.0%), humidity(22.1%) in the order of importance; human environment covered cooperation among cooks (28.1%), the number of cooks(25.7%), and professionalism of cooks in the order of importance; facility equipment environment contained the design and layout of facilities and equipment(29.3%), various safety facilities, and safety device(23.3%) in the order of importance. However, a measure for improving work environment, number of cooks, deterioration of equipment, etc. should be considered.

• Journal of Welding and Joining
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• v.19 no.5
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• pp.481-485
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• 2001

Laser cladding processing allows rapid transfer of heat to the material being processed with minimum conduction into base metal. The effect of $CO_2$ laser cladding with high viscosity mixed powders was investigated. High viscosity mixed powder consists of bronze powder and flux that is used at a high temperature condition. The mixed powder has a high viscosity that it can be easily pasted over a curved or slope substrate. The device for mixed powder was designed and manufactured. It consists of the high viscosity mixed powder feeding system, the preheating system and the shielding gas system which prevents the clad layer from being oxidized. The results of experiment indicated that the feed rate of high viscosity mixed powder was important for later cladding with mixed powder feeding. The high viscosity mixed powder and substrate must be preheated to prevent porosity from breaking at the clad layer. The experimental result shows that the high viscosity mixed can be applied for laser cladding process.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.4
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• pp.77-84
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• 2003

The properties of a machine tool greatly affect machining quality since a machine tool has large variance in its features. Machine tool makers want to find best machining condition with the one that they have built. Machine builders need to develop test specimen since it helps finding characteristics of machine tools when the machining properties of the specimen are analyzed. This paper develops test specimen to identify features of the main spindle, the feeding device, and the frame of a machine tool. The specimen is machined with a high speed machine and the features of the machine are analyzed with test items. They are surface roughness, overshoot in axial movement, errors in circular movement, feeding with small movement and compensational error. This work can improve usability for a machine tool in machining practice.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.4
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• pp.50-55
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• 2008

CNC wire bending machines are used in industries to make a type variety of wire products such as long links. The machines have a long arm device to rotate in order to remove forming errors by flexibility of wire. Generally, the machines which constructed servo motors in the arm have the rotating range of the arm under 360 degree because the servo motors connect with fixed control devices on frame by many cables. The rotating angle under 360 degree limits working speed and forming geometry. Therefore this study developed a gear train to drive a parts in arm and to be independent on arm rotation movement. The developed gear train can transfer four movements to four components in arm and is consists parallel of four pairs of satellite gear trains. This study constructed the CNC wire bending machine with the developed gear train and verified that the gear train could drive internal components independently on arm rotation.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1858-1863
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• 2003

The properties of a machine tool greatly affect machining quality since a machine tool has large variance in its features. Machine tool makers want to find best machining condition with the one that they have built. Machine builders need to develop test specimen since it helps finding characteristics of machine tools when the machining properties of the specimen are analyzed. This paper develops test specimen to identify features of the main spindle, the feeding device, and the frame of a machine tool. The specimen is machined with a high speed machine and the features of the machine are analyzed with test items. They are surface roughness, overshoot in axial movement, errors in circular movement, feeding with small movement, and compensational error. This work can improve usability for a machine tool in machining practice.

• Journal of Korea Soil Environment Society
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• v.3 no.3
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• pp.109-116
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• 1998

Treatability tests of a soil washing device were performed for the remediation of eil-contaminated soil. The contaminant-containing soil with water was first fed into a oc-current screw conveyor and then into a counter-current washer. Surfactant was introduced into the washer and feeding soil was continuously separated on the basis of #40 mesh at the same time. A washing efficiency of 97.9% was achieved by the the soil washing device optimized.