• 환경영향평가
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• 제21권4호
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• pp.567-572
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• 2012

This paper suggests the set-up plan of the assessment scope in road noise considering road characteristics with the prediction model of road noise. The RLS90 prediction model with some assumptions is used to establish the assessment scope of road noise. The main contents of the applied assumptions are smooth drive of cars, flat region, location of all noise sources in one lane, drive in design speed, and set-up of assessment scope according to traffic volume and car speed. The information of traffic volume to predict road noise is obtained by the distribution of small cars and full-sized cars in road. In this study, the total traffic volume in road is computed by adding the number of small cars to the conversion number of small cars, which means the number of small cars making the same noise as one full-sized car. The prediction result of road noise with the influence factor of traffic volume, car speed, distance between road and receiver is presented. The resultant assessment scope of road noise is obtained by combining road noise prediction data with the set-up standard of road noise assessment scope.

• 드라이브 ㆍ 컨트롤
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• 제11권3호
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• pp.14-21
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• 2014

The goal of this study drifter is to understand the operating mechanism of a drifter and to suggest a reliable analysis model which can be used for evaluating the drifter's performance from the viewpoint of impact frequency and energy. For this, the working principle of drifter and functions of its main components were analyzed, and a simulation model was developed based on the analysis. The model was validated using experimental tests on a test-bench. A comparative study of simulation and experimental results indicated that the suggested model accurately represents the real drifter system in terms of impact frequency and impact energy per blow.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권6호
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• pp.286-290
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• 2003

The high temperature superconducting bulk can be used as the bearing of induction motors. This paper presents the fabrication and test results of an induction motor with superconducting bearings using HTS bulks. The bearing had eight hexahedron type YBCO bulks. Height, width and thickness of the HTS bulk were 30mm, 30mm and 10mm, respectively. Single phase induction motor was used to drive the shaft made of aluminum and the rotor of a conventional induction motor. To estimate the performance of the HTS bulk magnetic bearing, no load test, load test and Impact test were carried out. Load tests were performed by using air resistance caused by the shaft-mounted thin cylinder with buckets. Impact tests by axial direction and vertical direction impact showed that the vibration of the shaft gradually decayed. The induction motor with HTS bulk magnetic bearing rotated silently and smoothly throughout the tests. According to the test results, conventional bearings can be replaced with superconducting magnetic bearings made of HTS bulks.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.172-178
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• 1993

This paper deals with the modeling and experiment of a robot system for force/impact control performance. The basic model is composed of a direct drive motor, servo amplifier, link, force sensor and environments. Based on the developed model, the stability of the whole system was analyzed via root locus method. For the force control, integral force compensation with velocity feedback method shows the best performance of all the explicit force control strategies. In dealing with impact, PID position control and the explicit force control method were implemented. Instead of add more damping to the robot system by velocity feedback, we developed a new passive damping method and it was also applied to enhance the damping characteristic of the system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.843-847
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• 2007

The unbalanced mass of a high precision rotor deteriorates mechanical performance of the rotor. The geometrical center of a rotor generally corresponds to the rotational axis of the rotor. However, this alignment carried out with a stationary rotor does not guarantee the dynamic rotor balance. There have been a number of schemes for the correction of the imbalance published for decades especially in the hard drive industry where the issues are directly affecting manufacturing costs and product performances. Realizing the significance of the problem, the present work tries to refine one of the methods that works by applying external impact during a rotor spins. A systematic way to apply the external impact to a rotating rotor has been introduced to minimize imbalance correction process time.

• 한국정보시스템학회지:정보시스템연구
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• 제25권4호
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• pp.37-61
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• 2016

Purpose This study examines firms at various industries to identify key organizational characteristics that positively drive the evaluation of cloud computing. In addition, this study tests the impact of one's evaluation has on the adoption and integration of cloud computing within their respective firm. Design/methodology/approach A total of 172 responses from various firms currently using cloud computing service were analyzed using the structural equation modeling(SEM). Findings Results show that organizational Needs(Mobility and Job Relevance), Perceived Factors(Relative Advantages and Cost Savings), and Organizational Readiness(Technical Knowledge, Financial Supports, and Managerial Supports) have a significant impact on cloud computing evaluation; and evaluation influences its adoption, and integration. However, two variables(IT Performance Gaps and Compatibility) have no significant impact on cloud computing evaluation. Finally, Evolutional Leadership has a significant moderating effect within the relationship among variables in the process of cloud computing implementation.

• 한국소음진동공학회논문집
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• 제17권8호
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• pp.720-725
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• 2007

The unbalanced mass of a high precision rotor deteriorates mechanical performance of the rotor. The geometrical center of a rotor generally corresponds to the rotational axis of the rotor. However, this alignment carried out with a stationary rotor does not guarantee the dynamic rotor balance. There have been a number of schemes for the correction of the unbalance published for decades especially in the hard drive industry where the issues are directly affecting manufacturing costs and product performances. Realizing the significance of the problem, the present work tries to refine one of the methods that works by applying external impact during a rotor spins. A systematic way to apply the external impact to a rotating rotor has been introduced to minimize unbalance correction process time.

• 한국자동차공학회논문집
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• 제18권2호
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• pp.104-113
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• 2010

Domestic insurance claims were statistically investigated to analyze the elderly driver's accident patterns and injury types in side impact crashes. Medical treatment records and accident vehicle damage photos have been surveyed for 5,419 cases. The results of our statistical analysis showed that the thorax injury risk of the elderly drive group is 8.8 and 4.0 times higher than that of the young and middle age group respectively. Diagnosis showed that most thorax injuries were caused by rib fracture. The head injury risk of the elderly female driver group seemed to be higher than that of the younger female driver group, however, statistical test has not been conducted because of the lack of number of samples for elderly female accident.

• 산업경영시스템학회지
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• 제24권69호
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• pp.65-73
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• 2001

The objective of this study is to evaluate the vibration attenuation effects of the different type of gloves and drilling mode while operating a light-weighted powered hand drill. For the experimental design, five different kinds of glove(barehanded cotton partly coated anti-vibration, and open-finger vibration glove) two types of push force level(100N and 200N) and two types of drilling mode(impact and non-impulsive) were considered. Six healthy male subjects were employed to drive screws into a vertically mounted marble plate with a powered hand drill in a randomly ordered experimental conditions. The findings of this study are summarized as follows; (1) It was found that the best combination of overall BMS transmissibility was using impact drilling mode with anti-vibration glove among evaluated experimental conditions (2) The wearing open finger vibration glove in mid-frequency level and anti-vibration glove with impact drill in high-frequency were the best in the result from mean corrected transmissibility equation of ISO 10819.

• 드라이브 ㆍ 컨트롤
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• 제19권3호
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• pp.1-8
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• 2022

In this paper, the design of automatic impact force control mechanism of hydraulic breaker was studied. The control mechanism uses the change of piston upper chamber pressure, when the hydraulic breaker impacts various strength rock. The piston stroke is controlled by rock strength sensing valve, piston stroke switching valve, and piston control valve. It is imperative to denote the area of each valve section, the spring constant of the spring. It provides convenience to users by automatically adjusting the appropriate striking force, according to the strength of the rock. Additionally, by increasing work productivity, it can contribute to reducing greenhouse gas emissions due to fuel efficiency reduction.