• Natural Product Sciences
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• v.17 no.1
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• pp.38-44
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• 2011

The quality inspections items such as loss on drying, total ash, and acid-insoluble ash contents in herbal medicines, have a correlation with external sources of pollution, but are not themselves hazardous factors. Z-scores for standard normal distribution were used to investigate herbal medicines requiring quality control, which exceeds the regulatory limits of quality inspection. In total, 7,773 samples were analyzed based on plant parts. For the loss on drying, the numbers of items of herbal medicines requiring quality control are like these; 15 items for above-ground parts and 5 items for underground parts. For the total ash, 21 items for above-ground parts and 4 items for underground parts. For the acid-insoluble ash, 8 items for above-ground parts and 1 item for underground parts.

• The Magazine of the IEIE
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• v.21 no.11
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• pp.75-85
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• 1994

Safety and Reliability assessments of Avionics Parts must be conducted essentially in the step of disign and manufacture as it constitutes a major field of aircraft critical operation. Recently Avionics parts fabrication techniques are continuously developing by applying digital techniques. Airborne computer is being adopted on an aircraft for flight is being adopted on an aircraft for flight safety augmentation and simplification of controls including reduction of human error. Therefore inspection and evaluation procedures should be developed in order to accomodate such trends. The number of avionics parts is approximitely 72% of total TSO parts, so it is expected high added-values through manufactures of TSO parts in aircraft industries. Particuarly avionics parts must be manufacturered with our own technology to be used in Mid-class aircraft which will be developed soon. Along with this, preparation of Certification Procedures is essential for Avionics Parts.

• Journal of Korean Society for Quality Management
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• v.41 no.3
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• pp.475-486
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• 2013

Purpose: In this study, we propose the evaluation criteria and method for selecting intensive management items which, in order to improve the parts management.1) Methods: Parts management such as MIL-STD-3018, SD-19, SD-22 is used for devising the proposed evaluation criteria and method of selecting intensive management items. Especially, proposed evaluation criteria is customized by using AHP method. Results: We approved the importance of evaluation criteria for selecting intensive management items using AHP method. In production step, the parts problem record, the parts reliability, the supplier reliability, DMSM S1). In development step, the parts problem record, a counterfeit, the parts reliability, MTTF2). Conclusion: The evaluation criteria and method for selecting intensive management items which is applicable to the domestic weapon acquisition environment is proposed.

• Analytical Science and Technology
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• v.30 no.3
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• pp.130-137
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• 2017

The leaves (Mori Folium; MF), branches (Mori Ramulus; MR), and root bark (Mori Cortex Radicis; MCR) of the mulberry tree have been used as therapeutic herbs for centuries. Existing analytical methods were developed specifically for different parts of the tree and cannot be applied to samples containing a mixture of tree parts. Such method specialization is time-consuming and requires separate identification and quality control of each tree part. This report describes an HPLC method for the simultaneous quality control and discrimination of MF, MR, and MCR using four marker compounds: rutin, kuwanon G, oxyresveratrol, and morusin. An Optimapak $C_{18}$ column ($4.6{\times}250mm$, $5{\mu}m$) was used with a gradient elution of 0.1 % formic acid in water and acetonitrile. The flow rate was 1.0 mL/min and the detection wavelength was 270 nm. In quantitative analyses of the three parts, rutin (0.11 % w/w) was detected only in MF. The oxyresveratrol content (0.12 % w/w) was highest in MR. Kuwanon G (0.33 % w/w) and morusin (0.18 % w/w) were higher in MCR than in other parts. The HPLC method given herein can be used to simultaneously classify and quantify three herbal medicines from the mulberry tree.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1543-1548
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• 2010

Powder metallurgy processes are used to form Net-Shape products and have been widely used in the production of automobile parts to improve its manufacture productivity. Powder-forging technology is being developed rapidly because of its economic merits and because of the possibility of reducing the weight of automobile parts by replacing steel parts with aluminum ones, in particular while manufacturing automotive parts. In the powder-forging process, the products manufactured by powder metallurgy are forged in order to remove any pores inside them. Powderforging technology can help expand the applications of powder metallurgy; this is possible because powder-forging technology enables the minimization of flashes, reduction of the number of stages, and possible grain refinement. At present, powder forging is widely used for manufacturing primary mechanical parts as in combination with the technology of powder forging of aluminum alloy pistons.

• The KSFM Journal of Fluid Machinery
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• v.18 no.3
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• pp.46-52
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• 2015

Pump-turbine system is widely used by the hydropower industry for stabilizing the electrical grid in the vast growing economy of most developed countries. This study only investigates the Fluid-structure Interaction (FSI) analysis of the pump-turbine system at various operating conditions. The FSI analysis can show how reliable each component of the system is by providing the engineer with a better understanding of high stress and deformation points, which could reduce the lifespan of the pump-turbine. Pump-turbine components are categorized in two parts, pressurized static parts and movable stressed parts. The fixed parts include the spiral casing, top and bottom cover, stay vane and draft tube. The movable parts include guide vanes and impeller blades. Fine hexahedral numerical grids were used for CFD calculation and fine tetrahedral grids were used for structural analysis with imported load solution mapping greater than 90 %. The maximum equivalent stress are much smaller than the material yield stress, and the maximum equivalent stress showed an increasing tendency with the varying of operating conditions from partial to excessive at both modes. In addition, the total deformation of all the operating conditions showed a small magnitude, which have quite small influence on the structural stability. It can be conjectured that this system can be safely implemented.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.161-167
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• 2020

In the process of cutting large aircraft parts, the tool may be abnormally worn or damaged due to various factors such as mechanical vibration, disturbances such as chips, and physical properties of the workpiece, which may result in deterioration of the surface quality of the workpiece. Because workpieces used for large aircrafts parts are expensive and require strict processing quality, a maintenance plan is required to minimize the deterioration of the workpiece quality that can be caused by unexpected abnormalities of the tool and take maintenance measures at an earlier stage that does not adversely affect the machining. In this paper, we propose a method to indirectly monitor the tool condition that can affect the machining quality of large aircraft parts through real-time monitoring of the current signal applied to the spindle motor during machining by comparing whether the monitored current shows an abnormal pattern during actual machining by using this as a reference pattern. First, 30 types of tools are used for machining large aircraft parts, and three tools with relatively frequent breakages among these tools were selected as monitoring targets by reflecting the opinions of processing experts in the field. Second, when creating the CNC machining program, the M code, which is a CNC auxiliary function, is inserted at the starting and ending positions of the tool to be monitored using the editing tool, so that monitoring start and end times can be notified. Third, the monitoring program was run with the M code signal notified from the CNC controller by using the DAQ (Data Acquisition) device, and the machine learning algorithms for detecting abnormality of the current signal received in real time could be used to determine whether there was an abnormality. Fourth, through the implementation of the prototype system, the feasibility of the method proposed in this paper was shown and verified through an actual example.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.3
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• pp.102-107
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• 2000

This study describes computer-aided design system for stepped asymmetric forgings. To establish the appropriate process sequence, an integrated approach based on a rule-base system was accomplished. This system has four modules, which are undercut prevention module, shape cognition module, 3D modelling module and corner/fillet correction module. These modules can be used independently or at all. The proposed shape cognition method could be widely used in forging design of asymmetric parts.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1994.06a
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• pp.185-189
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• 1994

The key factor of quality in precision metal forming is to meet the requirements of parts size and shape. Particular problem of unflatness occurs frequently. This study focuses on figuring out the cause of unflatness. To predict the amount of unflatness after ejection from tool, equivalent temperature method is used. This method, temperature equivalent to the final stress value is calculated, and it is applied as the boundary condition of the linear static analysis. The final of formed part is used as the geometry model of the static analysis.

• The Journal of the Acoustical Society of Korea
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• v.16 no.6
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• pp.76-84
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• 1997

Loose parts monitoring system(LPMS), which is used to detect metallic loose parts in the nuclear power plant, plays an important role in safe and reliable operation of the plant. To prevent from the damage due to the loose parts, most domestic nuclear power plants are using, or planning to use LPMS. However, these LPMS's, which are all invented from overseas and thereby depend on the oversea technologies, are very expensive, and are known to be inefficient to diagnose loose parts due to the lack of fundamental know-how of LPMS. Therefore, the main purpose of this paper is to propose and to realize a new loose parts localization algorithm which is simple and efficient enough even for the inexperienced operators to diagnose loose parts accurately and promptly. Considering practical nuclear power plant circumstances, some simulations for estimating the loose parts location have been done. The results show that the proposed method, called a modified circle intersection method, performs high resolved loose parts localization with 3.4% of error.