• 한국정밀공학회지
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• 제20권8호
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• pp.101-107
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• 2003

A new mechanical probe for 3-D feature measurement on coordinate measuring machines (CMMs) is presented. The probe is composed of the contact stylus and the three-component force sensor. With the stylus mounted on the force sensor, the probe can not only measure 3-D features, but also detect contact force acting on the stylus tip. Furthermore, the probing direction and the actual contact position can be determined by the relationship among three components of contact force to be detected. In this paper, transformation matrix representing the relationship between the external force acting on the stylus tip and the output voltages of measurement gauges is derived and calibrated. The prototype of probe is developed and its availability is investigated through the experimental setup for calibration test of the probe. A series of experimental results show that the proposed probe can be an effective means of improving the accuracy of touch probing on CMM.

• 전기학회논문지
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• 제62권1호
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• pp.43-48
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• 2013

In this paper, magnetic buoyancy force on nonmagnetic solid object submerged in magnetic liquid was simulated and measured. For the evaluation of the force, a multi-physics approach of hydrostatic equilibrium considering magnetic body force as well as gravity is presented. The magnetic body force should be regarded as an additional forcing term in the momentum equation of hydrodynamics. It is also shown that the virtual air-gap based Kelvin's force formula is a useful method for the calculation of force distribution in the magnetic liquid. The experimental result which was performed by a load-cell measurement system agreed quantitatively well with the numerical one.

• 한국정밀공학회지
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• 제19권6호
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• pp.43-50
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• 2002

In the design of structure, the forces acting on tai structure are key parameter fur noise and vibration control. However, in the complex structure, the forces at the injection point on the structure cannot be measured directly. So, it is necessary to find out Indirect force evaluation method. In this paper, forces have been measured with In-situ vibration responses and system information. And, three existing techniques of indirect force measurement, vita. direct inverse. principal component analysis and regularization have been compared. This paper shows that multi-vibration responses are essential for talc precise estimation of the forces. To check these conditions, rotary compressor is adopted as test sample, because it is very difficult to measure the injection forces from internal excitation to shell. It alas also been obtained that relatively higher force is transmitted through three welding paths to the compressor shell. It shows a good agreement between direct and indirect force evaluation with curvature shell and plate.

• Environmental Analysis Health and Toxicology
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• 제23권1호
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• pp.47-51
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• 2008

The toxicity of environmental pollutants was measured between a image of the surface topography in HeLa cells using atomic force microscopy for the possibility of toxic effect measurement and environmental monitoring. A image of the surface topography by AFM were estimated as toxic endpoints. The surface topography by AFM was observed a change of the cell surface in the environmental pollutants, but the standard of the measurement requires for the dose-effect degree. The overall results indicate that the possibility of measurement using AFM were confirmed a dose-effect degree related toxic effects, but it requres correlation between more various biomarker and AFM's measurements if the possibility of the toxic effect measurement was established.

• International Journal of Railway
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• 제8권1호
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• pp.1-4
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• 2015

An accurate measurement of the train-track interaction forces is important for track performance evaluation. In the field calibration test as a wheel load measurement process, the calibration system creates a different boundary condition in comparison with that in the train wheel passage. This study aims to evaluate a reliability of the field calibration test in the process of wheel load measurement. Finite element models were developed to compare the deformed shapes, bending moment and shear force profiles on the rail section. The analysis results revealed that the deformed shapes and their associated bending moment profiles on the rail are significantly different in two numerical simulations of the calibration test and the train wheel load passage. However, the shear stress profile on the rail section of the strain gauge installation in the field was almost identical, which may imply that the current calibration test is sufficiently reliable.

• 한국기계가공학회지
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• 제6권2호
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• pp.22-27
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• 2007

In this study, the two methods of stiffness measurement(Spring constant) of cantilever were proposed for quantitative measurement in Atomic Force Microscopy(AFM). As the 1st method for the measurement of stiffness, the probe method, which is used in the measurement of the semiconductor mechanical and electrical properties, was applied to the measurement of the cantilever. Experiments by the probe method were performed finding the resistance value of cantilever. As the results, the resistance was measured differently along with the dimension and the thickness of cantilever that determined the stiffness(spring constant) of the lever. As the 2nd method, the vibration characteristics(Dunkerley expression) is used to obtain the stiffness of the complex structure which is combined by AFM cantilever and the standard cantilever. We measured the resonant frequency from the complex structure using the micro stages and stereo microscope. As the results, we confirmed that the vibration characteristics(Dunkerley expression) is effected the micro complex structure of AFM cantilever.

• 한국철도학회논문집
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• 제10권6호
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• pp.806-811
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• 2007

탈선은 차륜 플렌지가 레일에 접촉할 때 발생하는 횡방향의 힘이 커져 차륜이 레일을 이탈하는 현상이다. 탈선 또는 주행안전도를 평가하는 대표적인 기준은 탈선계수이다. 차륜에 스트레인게이지를 부착하여 탈선계수를 측정하는 기존방법은 대단히 복잡하고 측정의 실패확률도 높으며, 고도의 측정기술과 고가의 비용이 요구되고 있다. 따라서 안전성확인이 필요한 그 시점에 즉시 확인하지 못하고 있어 안전확보에 어려움을 겪고 있다. 본 논문에서는 차륜과 레일간의 접촉력인 윤중과 횡압을 쉽게 측정할 수 있는 방안을 집중적으로 연구하였으며, 가속도과 변위의 거동만으로 탈선 가능성을 예측할 수 있는 새로운 탈선계수 측정방법을 제시하였다.

• 대한기계학회논문집A
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• 제27권12호
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• pp.2079-2084
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• 2003

In biological cell manipulation, manual thrust or penetration of an injection pipette into an embryo cell is currently performed by a skilled operator, relying on visual feedback information only. Accurately measuring cellular forces is a requirement for minimally invasive cell injections. Moreover, the cellular force sensing is essential in investigating the biophysical properties for cell injury and membrane modeling studies. This paper presents cellular force measurements for the force feedback-based biomanipulation. Cellular force measurement system using piezoelectric polymer sensor is implemented to measure the penetration force of a zebrafish egg cell. First, measurement system setup and calibration are described. Second, the force feedback-based biomanipulation is experimentally carried out. Experimental results show that it successfully supplies real-time cellular force feedback to the operator at tens of uN and thus plays a main role in improving the reliability of biological cell injection tasks.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.717-718
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• 2010

• 한국정밀공학회지
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• 제19권3호
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• pp.13-18
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• 2002