• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.05a
• /
• pp.1443-1448
• /
• 2006

The reduction of the vehicle interior noise has been the main interest of NVH engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. In particular, the HVAC sound among the vehicle interior noise has been reflected sensitively in the side of psychology. Even though the HVAC noise is not louder than overall noise level, it clearly affects subjective perception in the way of making a diver become nervous or annoyed. Therefore, these days a vehicle engineer takes aim at developing sound quality as well as reduction of noise. In this paper, we acquired noises in the HVAC from many vehicles. Through the objective and subjective sound quality evaluation with acquiring noises caused by the vehicle HVAC system, the simple and multiple regression models were obtained for the subjective evaluation 'Pleasant' using the sound quality metrics. The regression procedure also allows you to produce diagnostic statistics to evaluate the regression estimates including appropriation and accuracy. Furthermore, the neural network model were obtained using three inputs(loudness, sharpness and roughness) of the sound quality metrics and one output(subjective 'Pleasant'). And then the models were compared with correlations between sound quality index outputs and hearing test results for 'Pleasant'. As a result of application of the sound quality index, the neural network was verified with the largest correlation of the sound quality index.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.3
• /
• pp.41-50
• /
• 2021

While artificial intelligence is rapidly replacing human jobs, the art field where human creativity is important is considered an exception. There are currently several AI mastering services in the field of mastering music, a profession at the border between art and technology. In general, the quality of AI mastering is considered to be inferior to the work of a human professional mastering engineer. In this paper, acoustic analysis, listening experiments, and expert interviews were conducted to compare AI and human experts. In the acoustic analysis, In the analysis of audio, there was no significant difference between the results of professional mastering engineers and the results of artificial intelligence. In the listening experiment, the non-musicians could not distinguish between the sound quality of the professional mastering engineer's work and the artificial intelligence work. The group of musicians showed a preference for a specific sound source, but the preference for a specific mastering did not appear significantly. In an expert interview, In expert interviews, respondents answered that there was no significant difference in quality between the two mastering services, and the biggest difference was the communication method between the mastering service provider and the user. In addition, as data increases, it is expected that artificial intelligence mastering will achieve rapid quality improvement and further improvement in communication.

• Electronics and Telecommunications Trends
• /
• v.35 no.1
• /
• pp.60-70
• /
• 2020

Artificial intelligence (AI) is expected to bring about a wide range of changes in the industry, based on the assessment that it is the most innovative technology in the last three decades. The manufacturing field is an area in which various artificial intelligence technologies are being applied, and through accumulated data analysis, an optimal operation method can be presented to improve the productivity of manufacturing processes. In addition, AI technologies are being used throughout all areas of manufacturing, including product design, engineering, improvement of working environments, detection of anomalies in facilities, and quality control. This makes it possible to easily design and engineer products with a fast pace and provides an efficient working and training environment for workers. Also, abnormal situations related to quality deterioration can be identified, and autonomous operation of facilities without human intervention is made possible. In this paper, AI technologies used in smart factories, such as the trends in generative product design, smart workbench and real-sense interaction guide technology for work and training, anomaly detection technology for quality control, and intelligent manufacturing facility technology for autonomous production, are analyzed.

• Journal of the Korean Professional Engineers Association
• /
• v.15 no.1
• /
• pp.46-50
• /
• 1982

Following rapid industrial development and urbanization in Korea, there is a need for the Government to implement effective control of pollution and to undertake specific schemes in areas where pollution of the environment is severe. In response to this need, Government of Korea prepare Han River Basin Environmental Master Plan Project for water, air, solid waste to cover environmental protection of the Han River Basin. The Project area is approximately 27,000 sq. Km extending over Seoul, Kyunggi, Kwangwon, Chungbuk Province. The total population of Master Plan Project area is approximately 11.6 million, or one-third of the total population of Korea. There are about 8,000 industries, including those located in 16 industrial complexes, in the project area. The scope of work and terms of reference are the following: (1) A Summary of existing land use and forecasts for changes in land use by the year 2,000. (2) Emission inventories for air, waste water, and solid wastes. (3) Forecasts of future population growth patterns and pollution loadings. (4) Identification of specific projects needs to reduce pollution levels and satisfy the environmental quality standards. (5) A Program of enforcement to include (i) self monitoring, and (ii) governmental inspections and surveillance. (6) A program for quality improvement and quality assurance of environmental measurements. (7) Reports summarizing all data collected analyzed during the study. (8) Conceptual design and feasibility studies, including cost estimates, for needed pollution control projects. (9) A financial plan for future detailed design and construction of public facilities, for financial incentives to industry, and for user charges for industrial use of public treatment of disposal works.

• Journal of the Korean Professional Engineers Association
• /
• v.18 no.2
• /
• pp.16-22
• /
• 1985

This study was carried out to evaluate the quality of soybean sprouts grown under three different sources of light. The soybean was germinated under light through blue (251 ux), red (751 ux) and white (50 to 200 lux) polyethylene films at 25$^{\circ}C$ for 10hr./day. Vitamin C, chlorophyll, cellulose and total protein contents were determined and texture was evaluated by tasting soybean sprouts soup. protein pattern in the soybean sprouts were investigated using polyacrylamide gel electrophoresis. Vitamin C, chlorophyll and cellulose contents were increased by white light intensity. The texture of the sprouts grown under white light (50 lux, 100 lux) was better than darkness, but fought under 200 lux. Vitamin C contents of soybean sprouts grown under various sources of light (in order of light : blue > white > red) were higher than theses of ones grown in the darkness. Biosynthesis of chlorophyll was not correlated to Vitamin C content. Total protein contents of cotyledon was not changed significantly under light irradiation. But the soybean sprouts grown under different quality of light, hypocotyl was higher than those grown darkness. (37% and 20% higher for blue light and white light) Densitometric tracing of disc polyacrylamide gel electrophoretic patterns showed that protein of hypocotyl under white light had more high molecular weight protein.

• IE interfaces
• /
• v.21 no.2
• /
• pp.221-228
• /
• 2008

The injection molding process is able to produce high precision manufactures as a single process with fast speed. However, the prices of both the mold and the molding machine are expensive, and the single process is very complex and difficult to compose of the exact relationship between the process setting conditions and the product quality. Therefore, the quality of a molded product often depends on a skillful engineer's operations in the design of both parts and molds. In this paper, the relationship between the process conditions and the defectiveness is built for better manufactures under settings of the appropriate parameters, and so it can reduce the setup time in the injection molding process. Quality Function Deployment (QFD) provides severe defectiveness factors along with the related process parameters. Also, neural networks estimate the relationship between defective factors and process setting parameters, and lead to reduce the defectiveness of molded parts.

• Journal of KIISE:Information Networking
• /
• v.37 no.6
• /
• pp.494-498
• /
• 2010

Performance requirements of a system are usually closely related to the quality of service provided by the system. The call success rate of a mobile communication system is, for example, directly linked with the quality of call service. Therefore, meeting the performance requirements is one of the critical issues during the operation of services as well as in system development. In this paper, we present a testing method for evaluating the call success rate of a mobile communication system by using interval estimation. Also we analyze the criterion used in the evaluation of the quality of 3G mobile communication services which was recently performed by Korea Communications Commission and then discuss the problems.

• Journal of the Society of Naval Architects of Korea
• /
• v.37 no.3
• /
• pp.78-89
• /
• 2000

The quality of a product/system is getting more important concept nowadays. 'Performance', as one of the quality characteristics, means how well a product carries out its given functions and is the most adjacent characteristics to the customer satisfaction. To an engineer, however, who deals with large structures such as ships, 'Safety' is actually getting more important because of its direct relationship with failures of a product/system itself and human injuries when an accident occurs. In this study, therefore, we consider both performance and safety recognized the most important elements in dealing with structures and present a quality analysis method based on customer requirements by using QFD for performance analysis and FMEA for safety analysis respectively. Applying these methods to the hatchway of a bulk carrier, we could find 8 and 12 important parts based on performance and safety respectively. Among these, only 7 parts were pointed out commonly critical. From these, we can suggest that designers should pay more attention to these 7 parts and thus give a high priority of concerns to them when trying to improve the quality of system.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.38 no.4
• /
• pp.155-167
• /
• 1996

동일한 하천의 용전산소량(DO)을 예측하는 경우에도 사용하는 재포기계수$(K^2)$는 계산하는 공식에 따라 커다란 차이를 나타매며, 부적합한 공식의 사용에 의한 $(K^2)$의 계산은 하천의 수질관리 정책결정에 지장을 초래하므로 현장사정에 적합한 공식의 개발이 필요하다. 이러한 공식의 개발은 많은 현장측정 자료를 사용하도록 신뢰성이 높으나 현장측정은 소요되는 비용에 제약을 받기 때문에 신뢰성과 경제성을 동시에 고려한 표본의 크기의 적정규모를 산정하는 것이 필요하다. 본 연구에서는 Monte Carlo 방법에 의해 통계적으로 수출된 $(K^2)$를 사용해서, 주어진 자료에 의해 개발된 공식을 사용할 때 야기되는 오차가 $(K^2)$개수의 증가에 따라 얼마나 감소하는지를 널리 사용되는 공식 중에 Owen공식과 Churchill공식을 New Jersey에 있는 Passaic River에 적용시켜 검토하였다. 표본의 크기가 10에서 20으로 증가할 때 오차가 크게 감소하였으며 20을 넘어 증가시켰을 때에는 오차의 감소폭이 미미하였다. 초차의 감호형태와 단위측정당 소요되는 비용을 고려할 때 약 20정도의 표본의 크기가 적정수준의 규모에 판단된다. 이러한 적용사례의 결과는 회귀모델의 이론적 계산결과에 의한 오차 감소와 흡사하여 본 연구결과는 여러 가지(K2)공식과 광범위한 하천의 조건에 적용이 가능할 것이며, 본 연구에서 사용한 적정표본의 크기 산정방법은 회귀분석에 의해 실험식을 개발하는 다른 분야에도 적용이 가능하다.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.20 no.11
• /
• pp.995-1000
• /
• 2010

With the development of the auto industry, the automobile manufacturers demand to shorten development period and reduce the cost. Compared with the traditional method, applying the virtual prototype is more economical. This paper presents a method for parameters sensitivity analysis and optimizing the performance of vehicle noise and vibration. The existing design processes were repeatedly analyzed with a focus on vehicle performance to decide the design parameters of dimension, thickness, mounting type of body and chassis systems in the vehicle development period. This paper describes the prediction technique of vehicle performance using L18 orthogonal array layout, quality deviation analysis and parameter sensitivity analysis for robust design. This paper analyzed the performance correlation equation through the frequency and sensitivity database according to a design factor change. The new concept is that the performance prediction is possible without repeated activities of test and analysis. This paper described the parameter analysis applications such as bush dynamic stiffness and bush void direction of rear suspension. Design engineer could efficiently decide the design variable using parameter analysis database in early design stage. These improvements can reduce man hour and test development period as well as to achieve stable NVH performance.