• 한국기계가공학회지
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• 제20권9호
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• pp.35-41
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• 2021

A rotor is a crucial component in various mechanical assemblies. Additionally, high-speed and high-efficiency components are required in the automotive industry, manufacturing industry, and turbine systems. In particular, the failure of high-speed rotating bearings has catastrophic effects on auxiliary systems. Therefore, bearing reliability and fault diagnosis are essential for bearing maintenance. In this work, we performed failure mode and effect analysis on bearing rotors and determined that corrosion is the most critical failure type. Furthermore, we conducted experiments to extract vibration characteristic data and preprocess the vibration data through principle component analysis. Finally, we applied a machine learning algorithm called support vector machine to diagnose the failure and observed a classification performance of 98%.

• 한국산업융합학회 논문집
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• 제24권5호
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• pp.641-644
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• 2021

Wearable devices and IoT are being utilized in various fields, where all systems are developing in the direction of multi-functionality, low power consumption, and high speed. In this paper, we propose a DC -DC Step-down C onverter for IoT smart devices. The proposed DC -DC Step-down converter is composed of a control block of the power supply stage. It also consists of an overheat protection circuit, under-voltage protection circuit, an overvoltage protection circuit, a soft start circuit, a reference voltage circuit, a lamp generator, an error amplifier, and a hysteresis comparator. The proposed DC-DC converter was designed and fabricated using a Magnachip / Hynix 180nm CMOS process, 1-poly 6-metal, the measured results showed a good match with the simulation results.

• 한국산업융합학회 논문집
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• 제22권3호
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• pp.281-292
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• 2019

This paper proposed a new technology to control a path forging parts in limited narrow space of manufacturing process automation for smart factory. In the motion control, we adapted the obstacle avoidance technology based on ultrasonic sensors. The new motion control performance test for a mobile robot is experimented in narrow space environments. The travelling path control is performed by a fuzzy control logic. which plays a role for selecting an appropriate behavior in accordance with the situation in the vicinity of the mobile robot. Ultrasonic sensors installed at the front face of the mobile robot are used. In order to update the current position and heading angle of the mobile robot, a new approch is adapted. The reliability is illustrated by simulation and experiments.

• 한국산업융합학회 논문집
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• 제22권2호
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• pp.137-146
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• 2019

This study proposed a new technique to control of mobile robot based on voice command for (Human-Robot Cooperative operation in manufacturing precess). High performance voice recognition and control system was designed In this paper for smart factory. robust voice recognition is essential for a robot to communicate with people. One of the main problems with voice recognition robots is that robots inevitably effects real environment including with noises. The noise is captured with strong power by the microphones, because the noise sources are closed to the microphones. The signal-to-noise ratio of input voice becomes quite low. However, it is possible to estimate the noise by using information on the robot's own motions and postures, because a type of motion/gesture produces almost the same pattern of noise every time it is performed. In this paper, we describe an robust voice recognition system which can robustly recognize voice by adults and students in noisy environments. It is illustrated by experiments the voice recognition performance of mobile robot placed in a real noisy environment.

• 한국산업융합학회 논문집
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• 제26권3호
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• pp.509-515
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• 2023

This study examind the product quality characteristics and industrial application of arrowroot powder added Yanggaeng before its industrial application. Several preliminary experiments were conducted by applying manufacturing conditions and varying the amount of arrowroot powder(1%, 2%, 3%, 4%) added to produce Yanggaeng recipes that can be sold commercially. The moisture content of the produce Yanggaeng was low due to the manufacturing standards, but it showed a significant increase with an increase in the ratio, which was similar to the results of other studies on Yanggaeng. The solubility, particale size distribution, and pH also showed a significant increasing trend. The hardness of arrowroot powder added Yanggaeng decreased with an increase in the amount of arrowroot powder, while springiness, gumminess, and chewiness increased with the addition of arrowroot powder. In terms of color, arrowroot powder showed a dark color, which was well suited to white bean paste and could also be used with black bean paste without any problem. These results were due to the manufacturing ratio being adjusted to meet commercial sales standards, resulting in a lower amount of water being used, and the characteristics of arrowroot powder being applied as they were.

• 경영과학
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• 제16권1호
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• pp.157-171
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• 1999

In a increasingly competitive marketplace, the manufacturing companies have no choice but looking for ways to improve productivity to sustain their competitiveness and survive in the industry. Recently cellular manufacturing has been under discussion as an option to be easily implemented without burdensome capital investment. The objective of cellular manufacturing is to realize many aspects of efficiencies associated with mass production in the less repetitive job-shop production systems. The very first step for cellular manufacturing is to group the sets of parts having similar processing requirements into part families, and the equipment needed to process a particular part family into machine cells. The underlying problem to determine the part and machine assignments to each manufacturing cell is called the cell formation. The purpose of this study is to develop a clustering algorithm based on the neural network approach which overcomes the drawbacks of ART1 algorithm for cell formation problems. In this paper, a generalized learning vector quantization(GLVQ) algorithm was devised in order to transform a 0/1 part-machine assignment matrix into the matrix with diagonal blocks in such a way to increase clustering performance. Furthermore, an assignment problem model and a rearrangement procedure has been embedded to increase efficiency. The performance of the proposed algorithm has been evaluated using data sets adopted by prior studies on cell formation. The proposed algorithm dominates almost all the cell formation reported so far, based on the grouping index($\alpha$ = 0.2). Among 27 cell formation problems investigated, the result by the proposed algorithm was superior in 11, equal 15, and inferior only in 1.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.401-402
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• 2012

• 대한지리학회지
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• 제21권
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• pp.38-52
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• 1980

이 글에서는 다음의 내용을 다루었다. 1. 공업의 개황 2. 공업의 입지변동 3. 업종별 입지 변동 4. 입지 변동의 요인

• 자원ㆍ환경경제연구
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• 제18권2호
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• pp.241-277
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• 2009

본 연구의 목적은 한국과 중국 제조업의 기술효율성과 생산성, 환경을 포함한 기술효율성과 생산성 그리고 황산화물($SO_x$) 저감의 잠재가격을 측정해 보고자 함이다. 2000~2004년간 환경을 포함한 경우와 불포함한 경우에 중국의 기술효율이 한국 제조업의 기술효율보다 높았다. 대부분 개별 중국 제조업의 기술효율이 한국 제조업의 기술효율보다 높았다. 환경을 제외한 일반적 생산성 변화를 기준으로 한국 제조업의 연간 증가율은 1.13%였으나 중국은 2.73% 수준이다. 그러나 $SO_x$ 저감을 고려한 연간 생산성 변화는 오히려 한국이 2.41%로서 중국의 1.58%보다 높았다. $SO_x$ 잠재가격으로 추정한 한계저감비용은 한국 제조업이 오염 1단위 저감에 평균 1.4731단위 생산액 감소가 필요한 반면 중국 제조업은 매우 적은 평균 0.0049단위 생산액 감소로 추정되었다. 한국 제조업은 기술효율성과 생산성이 높은 업종으로 특화하고 오염처리비용에서 효율을 유지하는 노력이 필요하다.

• Asian Journal of Business Environment
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• 제14권2호
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• pp.19-30
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• 2024

Purpose: This research article investigates the intricate relationship between economic growth and employment in the Korean agri-food industry. Research design, data and methodology: Drawing on Okun's law, which proposes a negative correlation between economic growth and unemployment, the study explores the applicability of this law to different sectors. By focusing on the agri-food industry, the study examines the impact of economic growth on both full-time and temporary employment. Results: The findings highlight the industry's role as a buffer, absorbing workers from other sectors, particularly manufacturing. Moreover, the study reveals that temporary employment is more sensitive to economic growth fluctuations compared to full-time employment. Conclusions: The research emphasizes the importance of implementing employment programs that support transitioning workers in the agri-food industry, facilitating knowledge and skill transfer to ensure sustained employment. Furthermore, it recommends government and company support for temporary employment during buffering periods to ensure safe job transitions. This study provides valuable evidence to understand the nuanced relationship between economic growth and employment in the Korean agri-food industry.