• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.420-424
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• 2008

The new MOV(motor-operated valve) diagnostic system MOVIDS(MOV intelligent diagnostic system) was developed. Its remote diagnostic methods with high accuracy have improved the applicability. This enables the diagnostic tests and the evaluations of many MOVs not only at the valves but also in remote places like MCCs(motor control centers). The remote diagnostic ability of the new system reduces the cost and the man power for diagnosing MOVs and eliminates the danger of the toxic or radioactive environments to which workers might be exposed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.413-415
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• 2008

In this paper, the new algorithm which eliminates structural noise and extracts the impact signature from the measured vibration signal is developed. We studied how the transient vibration signal due to the impact is distorted while propagating through the structure. Also the characteristics of noise generated by flow and the mechanical components are analyzed. The developed method is verified in the model plenum and the flow system in the laboratory. Results show the significant improvement in the sensitivity and accuracy.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.416-419
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• 2008

In order to ensure the safety, the performance evaluation of the safety-related components in a nuclear power plant such as air-operated valves. In this paper, the diagnostic system(MOVIDS $A^+$) for the performance of air-operated valves was developed. For this purpose, the characteristics of their operation and the methods of the diagnostic tests were reviewed. The setup and diagnostic functions of the system were mentioned. Its applicability was validated through the diagnostic tests of air-operated valves in nuclear power plants. This diagnostic system is now applied in nuclear power plants for performance tests.

• Korean Journal of Computational Design and Engineering
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• v.5 no.3
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• pp.224-231
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• 2000

In order to satisfy customers'various needs in the market, manufacturing companies tend to add similar variants to an existing product model. This variety causes immense growth of product configuration and makes data management uncontrollable. In order to resolve this problem, we propose a method to efficiently represent the variants in a single schema of product structure and configuration and manage the product configuration. First of all, the product structure which adopts the concept of features and options is suggested. Second, the method to represent option specifications which restricts option configurations is proposed. Finally, the prototype module, which inspects if a product configuration violates the option specifications, is introduced.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.330-331
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• 2014

A mathematical model is suggested for diagnosis on a reciprocating pump. To the end, kinematic, thermodynamic and fluidic analyses are carried out for a simplified reciprocating pump model. The pressure inside the cylinder is expressed as a function of the rotation angle of a crank axle. The mathematical model consists of one cylinder with suction and discharge valves and an accumulator. The effect of valve leakage on the discharge angle is investigated. The discharge angle difference between normal state and leakage state increases with the leakage extent.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.417-419
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• 1998

In a large diesel engine actuator position servo system, it is impossible to isolate an actuator fault from a load torque with conventional fault detection isolation (FDI) schemes because they are propagated through a channel. This paper deals with a parity equation based residual generation to isolate them in the system. The actuator fault is modelled by a multiplicative type fault that can be characterized as discrepancies between the nominal and actual plant parameters, whereas the load torque is modelled by an additive disturbance. The transformation implemented in the residual generator should be determined on-line to achieve the isolation. Simulation studies show the practical applicability of the FDI scheme.

• Korean Journal of Computational Design and Engineering
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• v.8 no.2
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• pp.101-108
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• 2003

Presented in this paper is the development of an product cost estimation system at the product design stage. The efficient cost estimation function at the design stage is essential for the cost reduction activities through the entire product life cycle. For this purpose, it is necessary to establish a systematic working procedure, and to develop information system for managing a great deal of production and product-related data required for the cost estimation. The developed system has the capability of estimating a cost of assembly type products as well as unit-item type products. As proposed system is based on the variant approach, it can be used easily at an early design stage without the need for detail design information. Also, this system is integrated with legacy PDM (Product Data Management) and ERP (Enterprise Resource Planning) system for fast. accurate and easy product cost estimation. The estimated cost includes material cost, overhead cost as well as labor cost.

• Water Engineering Research
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• v.3 no.3
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• pp.195-202
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• 2002

The mean is generally used as a point estimator in water-quality data. Unfortunately, the nonnormal and skewed distributions of data hinder the direct application of the mean, which is inappropriate statistics in this case. The use of robust statistics such as L, M, and R-estimators are recommended and become more efficient. The median (L-estimator), the biweight (M-estimator), and the Hodges-Lehmann method (R-estimator) are briefly introduced and applied in this paper. From the actual data analyses, it is known that the median does not guarantee robustness for a small number of data sets, and robust measures of location or the arithmetic mean without outliers are highly recommended if the distribution has tails or outliers. Care must be taken to measure the location because water quality level within a water body can change depending on the selected point estimator.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.809-814
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• 2000

이 연구의 목적은 비침투적으로 펌프의 유량을 알아내고, 이를 이용하여 펌프의 성능을 감시하는데 있다. 그리고 운전중인 펌프의 상태를 감시함으로써 펌프의 결함을 진단하는데 있다. 위 목적을 달성하기 위하여 본 연구에서는 비침투적으로 측정이 가능한 변수인 모터 토크와 회전속도를 이용하여 펌프의 성능을 예측할 때 필수석인 유량을 알아내는 Simulator를 개발하였다. 유량의 변화를 감시함으로써 펌프의 성능 변화를 감시하는 일반적인 방법을 적용하면 펌프의 성능을 효율적이며 경제적으로 감시를 하는데 이용할 수 있다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.2
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• pp.72-78
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• 2020

Demand for cosmetics with functionality and eco-friendliness has increased dramatically due to recent aging, well-being trends, and increased interest in beauty. Cosmetics production in 2014 was 8,970.4 billion won, an increase of about 50% compared to 6,014.6 billion won in 2010. In the midst of this, similar companies in intense competition are pursuing differentiated strategies and innovation activities to solve quality, price and delivery problems. In particular, cosmetics packaging work is getting more difficult due to the increasing bill of materials (BOM) and difficult assembly methods. Therefore, in this study, the following problems were identified and suggestions for the improvement of the packaging Many research laboratories such as biotechnology, chemistry, and pharmaceuticals, which are undergoing various studies, are equipped with ready-made laboratory safety equipments such as bio-safety workbenches, aseptic bases, and exhaust workbenches. However, most researchers are disadvantaged in using existing safety equipment. This is because existing safety equipment can not take into account all of the unique characteristics of the research. For this reason, researchers are demanding the development of customized safety equipment that is well suited to their research needs. process of Company C, which is facing difficult situation to respond to the customer 's delivery due to the 52 - hour work week. First, we used the stopwatch to find the difficulty process in the packaging process and show ways to improve it. Second, to improve the efficiency of line balancing in the packaging process, we integrate processes, improve work methods, and perform simple automation. As a result, the prepare loss for replacement was reduced by 1 minute from 5 minutes, resulting in a 23% increase in productivity from 112 ea./hour to 137ea./ hour per person. At this time, the LOB of the packaging process was improved from 70% to 82% by operating one more production line through one person per line, total 9 people saving.