• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.9
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• pp.913-919
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• 2008

Dynamic characteristics of a wrist power transmission of an industrial robot are studied. The wrist power transmission has complex structure characteristics, because it is composed with several shafts and gear system. We used an analytical method to investigate the dynamic characteristics. An analytical model is a rigid model which is composed with masses and springs. Both bearing and gear contact model represent equivalent stiffness springs which are determined by the experiment. In order to investigate the dynamic tendency of the robot wrist power transmission, we simulate the analytical model. There is a dynamic analysis tool which is called the RecurDyn. To verify the analytic results, we experiment a signal analysis which is an overall noise level of the robot. By the parametric study of the element of the robot, we study an improvement method of dynamic characteristics.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.6 s.99
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• pp.680-686
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• 2005

This paper introduces the robust design of an intake system using transmission loss and the frequency weighting function. First, transmission loss is measured to evaluate the performance of the noise reduction for the intake system. The robust design parameters of the intake system are extracted by adapting a cost function with the Taguchi method. Subsequently, the frequency weighting function is developed by the subjective evaluation in which 6 special engineers were participated. Finally, the comparison between the proposed frequency weighted optimal design and unweighted optimal design for the transmission loss as the part is performed. Here, the overall levels of the transmission loss according to the methods are presented to validate the effectiveness of the proposed methodology.

• The Journal of Korea Robotics Society
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• v.4 no.1
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• pp.68-73
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• 2009

The UPnP is middleware architecture that supports dynamic distributed computing environment. It has many good features for possible use as middleware in robot system integration. There is a need for bulky binary data transmission between distributed robot S/W components. Since the UPnP utilizes SOAP protocol for message transmission, however, it is not efficient to send bulky binary data. In order to overcome this weak point, this paper proposes UPnP-MTOM, MTOM (Message Transmission Optimization Mechanism) implementation over UPnP, as an efficient way for bulky binary data transmission with UPnP messages. This paper presents our implementation method and experimental results of the UPnP-MTOM implementation.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.6
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• pp.55-60
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• 2004

Most vehicles having automatic transmission system use fixed standard shift map to provide automatic transmission for driver. In this case, driver who operates vehicle may be complaint with the fixed transmission pattern being different from the driver's intention. In this paper, therefore, to infer the driver's intention module for learning the driver's intention with related input variables using soft computing method is proposed. After inference, the standard shift map will be shifted according to a certain parameter decided from the proposed module for providing proper shift pattern. The efficiency of the proposed module is evaluated by the data acquired from real time driving.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.21-29
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• 2020

This paper presents an effective single image haze removal using edge-preserving and adaptive transmission estimation to enhance the visibility of outdoor images vulnerable to weather and environmental conditions with computational complexity reduction. The conventional methods involve the time-consuming refinement process. The proposed transmission estimation however does not require the refinement, since it preserves the edges effectively, which selects one between the pixel-based dark channel and the patch-based dark channel in the vicinity of edges. Moreover, we propose an adaptive transmission estimation to improve the visual quality particularly in bright areas like sky. Experimental results with various hazy images represent that the proposed method is superior to the conventional methods in both subjective visual quality and computational complexity. The proposed method can be adopted to compose a haze removal module for realtime devices such as mobile devices, digital cameras, autonomous vehicles, and so on as well as PCs that have enough processing resources.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.172-174
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• 2002

This paper proposes a new methodology for adequacy evaluation of composite power system considering an ambiguity of overload of transmission lines. Nodal arrival powers under considering an ambiguity of overload of transmission lines can be evaluated using the proposed method. Fuzzy set theory has been used in order to consider the permission level of overload of transmission lines. The problem of adequacy evaluation has been formulated using fuzzy linear programing. The effectiveness of the proposed method considering permissible overload of transmission lines has been demonstrated on the IEEE RTS.

• Journal of Ocean Engineering and Technology
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• v.20 no.6 s.73
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• pp.82-87
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• 2006

Numerical analysis is performed on the wave transmission coefficient of various crown widths of the double-submerged breakwater and the triple-submerged breakwater, varying the distance between submerged breakwaters. The finite element method is used, and the fluid motion is considered as linearized two-dimensional potential flow. In case of the double- and triple-submerged breakwaters, as the width of submerged breakwater increases, the minimum wave transmission coefficient decreases and the wave period at which the minimum wave transmission coefficient occurs moves to a longer wave period the distance between submerged breakwaters at which the minimum wave transmission coefficient occurs becomes larger.

• Current Optics and Photonics
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• v.3 no.6
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• pp.496-501
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• 2019

We propose a method to eliminate the noise of a disordered medium optical transmission matrix. Gaussian noise exists whenever light passes through the medium, during the measurement of the transmission matrix and thus cannot be ignored. Experiments and comparison of noise eliminating before and after are performed to illustrate the effectiveness and advance presented by our method. After noise elimination, the results of focusing and imaging are better than the effect before noise elimination, and the measurement of the transmission matrix is more consistent with the theoretical analysis as well.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.8
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• pp.752-758
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• 2013

The effect of external leakage on the acoustic performance of Helmholtz resonators is experimentally and numerically investigated. The transmission loss of the Helmholtz resonator with a circular perforated hole is measured by using an impedance tube setup. The experimental results are then compared with one-dimensional analytical and three-dimensional numerical results. As the size of the hole increases, the peak of the transmission loss shifts to higher frequency, especially for the holes on the cavity. While the transmission loss is almost independent of the location of the hole on the cavity, the impact of the hole location on the neck on the transmission loss is not negligible. The results show that one-dimensional analytical method can predict the overall trends, whereas three-dimensional numerical method is necessary for more accurate predictions.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.309-314
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• 2007

Optimal layer sequencing of a multi-layered acoustical foam is solved to maximize its sound transmission loss. A foam consisting of air and poroelastic layers can be optimized when a limited amount of a poroelastic material is allowed. By formulating the sound transmission loss maximization problem as a one dimensional topology optimization problem, optimal layer sequencing and thickness were systematically found for several frequencies. For optimization, the transmission losses of air and poroelastic layers were calculated by the transfer matrix derived from Biot's theory. By interpolating five intrinsic parameters among several poroelastic material parameters, dear air-poroelastic layer distributions were obtained; no filtering or post-processing was necessary. The optimized foam layouts by the proposed method were shown to differ depending on the frequency of interest.