• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.390-401
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• 2010

In this paper, we wish to develop suitable TPM Model (C-TPM) in Korea's medium and small enterprises. TPM technique was informed well and there are a lot of success instances but there was problem that is not fitness in medium and small enterprises. In this study, we propose C-TPM model in medium and small enterprises by examining TPM success example variously. This model construction constructed based on medium and small enterprises field supervision and experience, and verification of model is assignment late.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.2 s.173
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• pp.347-354
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• 2000

This paper presents performance characteristics of a semi-active suspension featuring continuously variable ER (electro-rheological) dampers. These are evaluated through the field test of a passeng er car. Four ER dampers (two for front and two for rear part) are manufactured and their field-dependent damping properties are experimentally investigated. The damping force responses to step input fields are also identified by employing small size of high voltage amplifiers which are made adaptable to the field test. A skyhook controller considering the vertical, pitch and roll motions is formulated and incorporated with a car to be tested. The field test is then undertaken in order to evaluate both comfortability and steering stability showing bump, dive and squat responses.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.3 s.73
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• pp.233-238
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• 2006

In this paper, mixed mode magneto-rheological(MR) damper, which is applicable for vibration control of a small scale multi-story structure, is devised. First, the schematic configurations of the shear, flow, and mixed mode MR dampers are described with design constraints and then the analytical models to predict the field-dependent damping forces are derived for each type. Second, an appropriate size of the mixed mode MR damper is manufactured and its field-dependent damping characteristics are evaluated in time domain. Finally, the performance of the manufactured MR damper which is semi-actively applied to a small scale building excited by earthquake load, is numerically evaluated.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.193-206
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• 2022

Several algorithms for nuclear power plant (NPP) break event detection, isolation, localization, and size estimation are proposed. A break event can be promptly detected and isolated after its occurrence by simultaneously monitoring changes in the sensing readings and by employing an interquartile range-based isolation scheme. By considering the multi-sensor data block of a break to be rank-one, it can be located as the position whose lead field vector is most orthogonal to the noise subspace of that data block using the Multiple Signal Classification (MUSIC) algorithm. Owing to the flexibility of deep neural networks in selecting the best regression model for the available data, we can estimate the break size using multiple-sensor recordings of the break regardless of the sensor types. The efficacy of the proposed algorithms was evaluated using the data generated by Maanshan NPP simulator. The experimental results demonstrated that the MUSIC method could distinguish two near breaks. However, if the two breaks were close and of small sizes, the MUSIC method might wrongly locate them. The break sizes estimated by the proposed deep learning model were close to their actual values, but relative errors of more than 8% were seen while estimating small breaks' sizes.

• Journal of agriculture & life science
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• v.44 no.5
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• pp.101-107
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• 2010

The objective of this study was to assess the statistics and associated criteria for field-scale model used to simulate nutrient concentrations in paddy field. CREAMS-PADDY, a modified version of the field-scale CREAMS model, simulates the hydrologic, sediment, and nutrient cycles in paddy fields was applied in this study. The model was calibrated and validated using data from study rice paddy fields in Republic of Korea. The calibration statistics include mean and the minimum-maximum range associated with a "temporal window" that spans a period of several days. Because nutrient concentrations in paddy filed are typically sampled infrequently (on a weekly basis, at best) and represent only an instant in time, it is not reasonable to expect any model to simulate a daily average concentration equal to an observed value on a particular day. The 5-day window and related calibration statistics were applied in this study and the applicability of this concept was tested for field-scale water quality model. As a result of calibration and validation, the ponded water nutrient concentration values showed only small changes except the fertilization period. Because of the small changes in ponded water concentration, the size of 5-day window was too small to capture the observed values. Further study is required to establish the 5-day window calibration method for field-scale water quality modeling.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.8
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• pp.131-139
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• 1995

In this study, small size stacker Crane for automatic ware house and interface circuit is designed and manufactured. IBM-PC is used as a controller. At 50kg$_{f}$ load, optimal motion velocity is 20 mm/min for X and Y axis and 12 mm/min for Z axis. Position fesolution is 0.005 mm and repeatability is .+-. 0.025 mm. Through characteristic experiment, effectiveness of the designed and manufactured stacker crane. PC control program, and design of interface circuit and construction of control system are shown. From these results, the developed stacker crane can be apply to FMS(Flexible Manufacturing System) and FA(Factory Automation) of industrial field.d.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.11
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• pp.1634-1640
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• 2012

This paper develops the high-efficiency drive system of the small-size electric vehicles (EVs) driven by the brushed dc motors. A power circuit for driving the dc motor is designed with the H-bridge circuit and buck converter by considering both the efficiency and cost. In order to change smoothly the rotating direction of dc motor driven by the proposed power circuit, an operating sequence for both the field current and the armature voltage according to an accelerator pedal angle is suggested. Through the simulation studies and experimental results with the low-cost 8-bit AVR, the performances of the proposed methods are verified.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.450-451
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• 2010

In this paper, the low-cost drive circuit of dc motor for a multipurpose small-size electric vehicle is developed. In order to change smoothly the rotating direction of dc motor for traction, the operating sequence of both the field current and the armature voltage according to the angle of a pedal of vehicle is suggested. The simulation study is carrier out to verify the proposed method, and the control system is implemented with 8-bit AVR.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.329-332
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• 2002

Recently, most machineries have been small size and mobile type. Then the motors used in this field are developed in micro size such as about 2mm in diameter. The structure of this motor is similar to a general brushless DC motor but because of small sige there is no position sensor such as hall sensor. In this paper, we propose synchronous driving and control method for micro brushless DC motor without position sensor. We design and manufacture this controller and perform experiment to show the effectiveness of the proposed method.

• Journal of the korean Society of Automotive Engineers
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• v.6 no.4
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• pp.54-61
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• 1984

Numerical calculation of the flow field past a passenger car was carried out by using a panel method with a small computer of 5Mbyte memory size. The shape of car body was simplified and reconstructed by 2180 panels on which a constant strength sink (or source) was distributed. The separation of flow from the surface and the wake flow were not considered in the calculation because of the computer memory limitation. All of the results of calculation were presented by using a 3-dimensional computer graphics. In spite of small memory size of computer, generally good agreements were obtained, except the separated region, from the comparison of pressure distribution between numerical analysis and wind tunnel experiment with 1/5 scaled model.