• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2011.04a
• /
• pp.731-732
• /
• 2011

This paper shows a whole noise quality checking system for the new developed 6th speed automatic transmission manufactured in USA. Due to demand for manufacturing of the high NVH quality transmissions in the mass product line, some special checking system called EOL is adapted. This EOL system is using vibration analysis technologies. Through adapting vibration analysis technologies and functions likewise RMS, Crest Factor, Harmonics, Peak, Band, and Order tracking, various noise problems caused by wear, nick, and deformations could be successfully detected and predicted. Therefore, automatic transmissions manufactured in the USA could get high NVH quality.

• Applied Chemistry for Engineering
• /
• v.19 no.2
• /
• pp.137-144
• /
• 2008

In these days, there has been increased focus on global warming and the exhaustion of resources caused by the heavy consumption of fossil resources. In order to resolve these problems, biomass is increasingly gaining international attention as a source of renewable energy. Biodiesel fuel produced by the transesterification of vegetable oils and animal fats is expected to be one of the eco-friendly biomass based alternatives to petrodiesel. This article reviews some of the research for effective of biodiesel production.

• 한국금형공학회:학술대회논문집
• /
• 2008.06a
• /
• pp.89-94
• /
• 2008

The injection molding process is a predominant method for producing plastic parts. In order to maximize productivity and molding quality in a injection mold, it is important that each cavity in a multi-cavity injection mold is identical. This requires that cavity dimensions should be identical and delivery system of melt to each cavity have to be the same. Despite the geometrically balanced layout in multi-cavity injection mold more than 4 cavities, it has been observed that the filling in each cavity results in imbalances. Most of cases, this phenomenon of filling imbalances have a bad effect on dimension accuracy, warpage, molding appearance and strength of molding parts. In this study, experiment were conducted to investigate the effect of filling imbalances on the molding quality(surface gloss, shrinkage, tensile strength) in the multy-cavity injection mold.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2007.04a
• /
• pp.89-92
• /
• 2007

Since 1960s, advanced constructions have introduced warranty contract which is warranted to quality and performance for need of owner in determined term to ensure the quality of construction. However, the interior of a country encounter another problem result from Defects Liability what indefiniteness of defects standard, excess responsibility period, social recognition of be identical fraudulent work and defects, and contract with ascendancy of owners. etc, so builders concerned more excess defects liability than the quality of construction. The purpose of this study is to analysis of warranty contract in order to solve the problem such as stated above.

• Journal of Welding and Joining
• /
• v.31 no.4
• /
• pp.28-33
• /
• 2013

The effects of laser welding beam quality is very large. However, not an analysing case was found for the difference on the plasma emission signal during laser welding according to the beam quality. Therefore, in this study, we compared and evaluated penetration and signal change according to the beam quality at the a similar wavelength band by using a fiber laser and Nd:YAG laser. In addition, we took high speed videography in order to make sure that FFT analysis reflects the actual motion period of keyhole and found the period of video analysis and FFT mostly matched. As a result, it is expected to secure higher reliability than evaluating signal intensity when appling FFT to monitoring.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2000.10a
• /
• pp.519-524
• /
• 2000

The goal of this research is the establishment of a connection of an existing water quality model to GIS. The water quality model investigated was the Water Quality Analysis Simulation Program (WASP5), while the actual linkage was performed using object-oriented programming. The runoff and the non-point source loadings into the Channel were determined using a grid-based model developed in GIS. Afterwards, scripts were written in the ArcView programming language, Avenue, in order for ArcView to perform the following tasks : 1) write the input file informations, 2) format the input information into the proper WASP5 file, 3) execute the WASP5 subprogram for modeling.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2003.05a
• /
• pp.342-352
• /
• 2003

Idle NVH characteristics are one of the most important aspects among the vehicle performances. Vehicle developers are devoted to improve vehicle interior noise and steering wheel and seat vibrations. In order to improve the idle quality, noise and vibration transfer path should be carefully evaluated. Also, effects of various components related to the idle performance should be confirmed. A general procedure for improving the idle qualify is described in detail. The relationship among cylinder pressure characteristics, crankshaft rotational speed variation, and vehicle vibrations is also investigated. Influences of drive shaft, torque converter, air conditioning system, vehicle structure including engine mount system, and idle control parameters on the vehicle idle quality are studied. Weak points of typical vehicles on the idle qualify are identified. Some of improvement measures are proposed and verified.

• Journal of Aerospace System Engineering
• /
• v.2 no.1
• /
• pp.22-27
• /
• 2008

It is anticipated that quality assurance for the Ka band Communication Payload System(COPS) development program of the Communication, Ocean & Meteorological Satellite(COMS) may be a core technical factor to be concerned in order to avoid any failure, and to assure its performance during the mission lifetime in space. Those can be managed and verified and assessed by performing the Quality Assurance (QA) and risk management which helps to prevent and reduce the critical fails. This paper introduces the Product Assurance (PA) system and procedures for Ka band Communication Payload System which was established and performed during the Qualification Model (QM) manufacturing phase. In this paper, we present detailed process for the products manufactured by local companies according to PA procedures operated through whole phases from design to test of equipment. Also this paper shows Quality Assurance (QA) procedures and detailed their processes for assured the product quality manufactured by local companies.

• Proceedings of the IEEK Conference
• /
• 2002.07c
• /
• pp.1495-1498
• /
• 2002

The constrained average method is one of dither methods which combines edge emphasis and grayscale rendition to provide legibility of textual region and proper quality of continuous tone region. How-ever, image quality of continuous tone region is insufficient compared to other dither methods, such as ordered dither methods or the error diffusion method. The constrained average method uses a uniform distribution function to decide number of lit pixels related to the average intensity in a picture area. However, actual distribution of continuous tone region is closer to the Laplacian distribution or triangle distribution. In this paper, we introduce various probability distributions and the actual luminance distribution to decide the threshold value of the constrained average method in order to improve image quality of dithered image.

• Journal of Industrial Technology
• /
• v.32 no.A
• /
• pp.57-64
• /
• 2012

In order to examine the tailorability of advanced sewage treatment of a separated sewer pipe, we observed the quality of leaked water in a reactor. A2C affiliation and MBR affiliation decreased by over 78% in cases of BOD, COD, and SS. SBR affiliation decreased by 79.1% in a case of T-N. Overall, the efficiency of T-N on the above affiliations was low. SS had the high efficiency in MBR affiliation. In the end, examination of water quality improvement showed that the quality was improved from 20% to 90%; hence, it is expected that this treatment can protect the water resources of the Hongcheon River and makes it easier to use the water of the river.