• Journal of the Korean Society for Precision Engineering
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• v.24 no.3 s.192
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• pp.117-123
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• 2007

This paper describes a three-probe system that can be used to measure the parallelism and straightness of a pair of rails simultaneously. The parallelism is measured using a modified reversal method, while the straightness is measured using a sequential two-point method. The measurement algorithms were analyzed numerically using a pair of functionally defined rails to validate the three-probe system. Tests were also performed on a pair of straightedge rails with a length of 250 mm and a maximum straightness deviation of $0.05{\mu}m$, as certified by the supplier. The experimental results demonstrated that the parallelism-measurement algorithm had a cancellation effect on the probe stage motion error. They also confirmed that the proposed system could measure the slope of a pair of rails about $0.06{\mu}rad$. Therefore, by combining this technique with a sequential differential method to measure the straightness of the rails simultaneously, the surface profiles could be determined accurately and eliminate the stage error. The measured straightness deviation of each straight edge was less than $0.05{\mu}m$, consistent with the certified value.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.303-306
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• 2001

Using THz time-domain spectroscopy (THz-TDS), the power absorption and the real conductivity of silica sand are measured terahertz frequency range. It is impossible to measure the characterization of the silica sand by simple electrical measurements using mechanical contacts, e.g., Hail effect or four-point probe measurements. However, the THz-TDS technique can measure not only electrical but also optical characterization of the sample. Also this technique can measure frequency dependent results. Especially, the real conductivity was increased according to THz frequency this is unusual material compare with metal and semiconductor materials; the measured real conductivity are not followed by the simple Drude theory.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.51-55
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• 2004

In this study, the levelling and the GPS levelling were carried out with 6 points in 2km${\times}$2km area and the results were analysed. As a result of this research, we had to observe more than 15 minutes to get the height accuracy of 10mm by single frequency GPS receiver in relative surveying. We could not get more better accuracy than 10mm. we could get the height accuracy of within 10mm from observing only more than 5 minutes by double frequency GPS receiver, and of within about 3mm from observing more than 10 minutes. When the number of fixed points is within 3, the level net adjustment result is very close to the one of direct levelling survey. When the number of fixed points is 3, the less the area of triangle the better the adjustment result, and the case of including measure point has more better accuracy than that of non-including measure point.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.52-54
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• 2003

Measurement is used to improve software process and to help calculating software quality. It makes software project to be control and help producing software. Measuring software scale becomes important target in software development. LOC is used to measure the size intentioned aspect and function point is used to measure the function intentioned aspect. This paper discusses measurement method using function point, which fullows proposed rule, and degree of GUI (Graphical User Interface) accesses achieved by applying this measurement to web page. Applying proposed rules to web pages (specially that use much GUI such as shopping mall or auction site), there is advantage that calculate site changes on numerical value by measuring GUI degree when do site administration or update.

• IE interfaces
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• v.17 no.spc
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• pp.79-89
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• 2004

Supply Chain (SC) can balance demands with supply activities as executing Supply Chain Planning (SCP). The fluctuated demands, however, will break the balance between demand and supply. It means that the present SCP is useless in responding the changed demands. Thus it is necessary for SCP to be updated with changed demands. We call this procedure as Supply Chain Replanning. However, the existing measures for SC can not deal with the balance between supply and demand so that they can not detect effectively the timing of replanning. For this reason, a new performance measure, Balancing Point, is developed using momentum, a concept of Physics. It can treat the balance between supply and demand. Also, a replanning method based on Balancing Point is proposed. The proposed method is more effective than the existing replanning method, periodic replanning method and net inventory method.

• International Journal of Control, Automation, and Systems
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• v.4 no.1
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• pp.42-52
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• 2006

In order to utilize hydrodynamic drag force on articulated robots moving in an underwater environment, an optimum motion planning procedure is proposed. The drag force acting on cylindrical underwater arms is modeled and a directional drag measure is defined as a quantitative measure of reaction force in a specific direction in a workspace. A repetitive trajectory planning method is formulated from the general point-to-point trajectory planning method. In order to globally optimize the parameters of repetitive trajectories under inequality constraints, a 2-level optimization scheme is proposed, which adopts the genetic algorithm (GA) as the 1st level optimization and sequential quadratic programming (SQP) as the 2nd level optimization. To verify the validity of the proposed method, optimization examples of periodic motion planning with the simple two-link planner robot are also presented in this paper.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.91-95
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• 1997

ESPI(Electronic Speckle Pattern Interferometry) is new optical measuring method to be able to measure the surface deformations of engineering components and materials in industrial areas. Conventional measuring method of surface deformation such as the strain gauge have many demerits because it is contact and point-to-point measuring one. But ESPI that is non-contact, whole field measuring method can overcome previous disadvantages. The speckle pattern to be formed with interference phenomena of scattering light from rough surfaces illuminated by laser light have phase information of surface In this study we used this interference phenomena and the phase shifting method to measure the in- plane deformation, together with the use of digital equipment to process the information contained in the speckle pattern and to display consequent inter ferograms. Finally we obtained good agreement between the experimenta results and those of FEM..

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.721-726
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• 2008

Community Noise has been great concerned in public. A road traffic noise has affected too much damage on quiet living environment. In this paper, About measured from the measure point noise and the noise signal processing techniques applied to the occurrence of the noise source with a path to reach this measure point to the measured data to determine signal processor for Complex Cepstrum Analysis of how to apply for research.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.4
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• pp.479-484
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• 2003

In this paper, film thickness and temperature distribution are measured in EHL point contact at high slip ratios. Infrared temperature mapping with two band pass fillers. proposed by Ausherman (1976). is used to measure temperature distribution. And the optical interferornetric method with two filters (red and green filters) is used to measure film thickness. Result of experiment showed that temperature rising at film and ball surface occurred very dramatically in Dimple zone. As slip velocity, slip ratio and load increased, size of Dimple and temperature rising became more large In addition, Position and shape of Dimple we changed by slip ratios, and increasing of Dimple size decreased traction coefficient. In short, it is appointed that the Dimple phenomenon be developed by the effect of viscosity wedge.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.371-374
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• 2004

The ultimate purpose of Supply Chain Management (SCM) is maximizing the profits of the overall Supply Chain (SC) through increasing customer satisfaction and decreasing operating cost. It can be successfully accomplished only when SC system balances demands with supply activities coordinated by aggregate planning, mid-term level of Supply Chain Planning(SCP). However, the existing measures to mainly estimate the specific function of SCM are not enough to evaluate the state of SC with respect to the balance between supply and demand in operating. To solve this problem, we develop a new SC performance measure, Balancing Point, using momentum concept. a fundamental knowledge of physics. Momentum concept can explain the relation among objects so that it can consider the balance between supply and demand in SC operating. The developed measure can not only consider the current state of the SC system but also take planned but not executed supply activities and upcoming demands into account. Therefore, using Balancing point, we can be aware of the unbalanced state of SC in advance.