• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.1
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• pp.1-5
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• 1998

This study presents intelligent deburring system which can transfer the exper's skill to deburring robot through neural network. The expert's skill is expressed as associate mapping between the characteristics of the burr and human expert's action. Under the fundamental idea that the state of the deburring process can be extracted via the visual sense of the human, we employ vision system for the perception and identification of the changing burr. From the demonstration of human experts, force data are measured and fitted impedance model. Finally the characteristics of the burr and coressponding force are associated by the neural network which is trained through many demonstrations. The proposed method is verified in the deburring process of welding burr.

• Journal of the Korean Physical Society
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• v.80
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• pp.1035-1041
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• 2022

Nondestructive nano-characterization methods were reviewed with respect to technical aspect and practicability. Micro-photoluminescence, cathodoluminscence and Raman spectroscopy with mapping modes were investigated as optical characterization tools, while electron backscatter diffraction and piezoresponse force microscopy were introduced as monitoring techniques for the crystallographic and electromechanical properties. Especially, the spatial resolution of the data acquisition and analysis was carefully inspected in the representative semiconducting nanomaterial systems. Some of efforts to overcome the limit of these characterizations were also taken into consideration.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.597-597
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• 2013

The resistive switching behaviors of Pt nanodisk on Nb-doped SrTiO3 single-crystal have been studied with conductive atomic force microscopy in ultra-high vacuum. The nanometer sizes of Pt disks were formed by using self-assembled patterns of silica nanospheres on Nb-doped SrTiO3 single-crystal semiconductor film using the Langmuir-Blodgett, followed by the metal deposition with e-beam evaporation. The conductance images shows the spatial mapping of the current flowing from the TiN coated AFM probe to Pt nanodisk surface on Nb：STO single-crystal substrate, that was simultaneously obtained with topography. The bipolar resistive switching behaviors of Pt nanodisk on Nb：STO single-crystal junctions was observed. By measuring the current-voltage spectroscopy after the forming process, we found that switching behavior depends on the charging and discharging of interface trap state that exhibit the high resistive state (HRS) and low resistive state (LRS), respectively. The results suggest that the bipolar resistive switching of Pt/Nb:STO single-crystal junctions can be performed without the electrochemical redox reaction between tip and sample with the potential application of nanometer scale resistive switching devices.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.792-795
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• 1996

In TIG welding of pipe, back bead size monitoring is important for weld quality assurance. Many researches have been performed on estimation of the back bead size by heat conduction analysis. However numerical conduction model based on many uncertain thermal parameters causes remarkable errors and thermomechanical phenomena in molten pool can not be considered. In this paper, filler wire feeding force in addition to weld current, wire feedrate, torch travel speed and orbital position angle is monitored to estimate back bead size in orbital TIG welding. Monitored welding process variables are fed into an artificial neural network estimator which has been trained with the monitored process variables (input patterns) and actual back bead size (output patterns). Experimental verification of the proposed estimation method was performed. The predicted results are in a good agreement with the actual back bead shape. The results are quite promising in that estimation of invisible back bead shape can be achieved by analyzing the welding parameters without any conventional NDT of welds.

• Wind and Structures
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• v.39 no.1
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• pp.47-69
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• 2024

Pounding of structures may result in considerable damages, to the extent of total failure during severe lateral loading events (e.g., earthquakes and wind). With the new generation of tall buildings in densely occupied locations, wind-induced pounding becomes of higher risk due to such structures' large deflections. This paper aims to develop mathematical formulations to determine the maximum pounding force when two adjacent structures come into contact. The study will first investigate wind-induced pounding forces of two equal-height structures with similar dynamic properties. The wind loads will be extracted from the Large Eddy Simulation models and applied to a Finite Element Method model to determine deflections and pounding forces. A Genetic Algorithm is lastly utilized to optimize fitting parameters used to correlate the maximum pounding force to the governing structural parameters. The results of the wind-induced pounding show that structures with a higher natural frequency will produce lower maximum pounding forces than those of the same structure with a lower natural frequency. In addition, taller structures are more susceptible to stronger pounding forces at closer separation distances. It was also found that the complexity of the mathematical formula from optimization depends on achieving a more accurate mapping for the trained database.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.419-427
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• 2021

Due to the effects of climate change and the reduction of the labor force due to COVID-19, the crop yield, harvest time, and cultivated area are rapidly changing every year. In order to respond flexibly to this situation, attempts to apply smart farm technology based on ICT (Information and Communication Technology) to individual farms are increasing. On the other hand, various stakeholders are trying to predict the yield of crops using artificial intelligence and IoT technology, but accurate prediction is difficult due to the lack of learning data. In this study, in order to overcome the data collection problem limited to a specific institution, a smart farmer service technology based on community mapping was developed in which farmers directly participate, input and share accurate data to predict production. In the process, analysis was performed on napa cabbage, which is a vegetable with a large price change compared to production.

• Bulletin of the Society of Naval Architects of Korea
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• v.14 no.3
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• pp.13-22
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• 1977

The hydrodynamic forces acting on a forced oscillating 2-dimensional cylinder on a free surface of a fluid of a finite depth are calculated by distributing singularities on the immersed body surface. And the Haskind-Newman relation in a fluid of a finite depth is derived. The wave exciting force of the cylinder to an oscillation is also calculated by using the above relation. The method is applied to a circular cylinder swaying in a water of finite depth, and then, to a rectangular cylinder heaving, swaying, and rolling. The results of above cases give a good agreement with those by earlier investigators such as Bai, Keil, and Yeung. Also, this method is applied to a Lewis form cylinder with a half beam-to-draft ratio of 1.0 and a sectional area coefficient of 0.941, and to a bulbous section cylinder which is hard to represent by a mapping function. The results reveal that the hydrodynamic forces in heave increase as the depth of a water decrease, but in sway or roll, the tendency of the hydrodynamic forces is difficult to say in a few words. The exciting force to heave for a bulbous section cylinder becomes zero at two frequencies. The added mass moment of inertia for roll is seemed to mainly depend on the sectional shape than the water depth.

• Archives of design research
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• v.16 no.2
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• pp.415-424
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• 2003

People store information not only in their Drain but also material things. Norman called it knowledge in the world. The general way to store the information is to paste labels. 4 burner gas range force user to make conceptual model between burner and switch to see labels. but those are cognitive stress. Norman suggested spatial analogies for natural mapping between display and control. However the way of his methods in spatial analogies was not compatible with kitchen atmosphere. To solve those problems 1 suggested color coding . This study hypothesized that the mapping between burner and switch is realized by color coding. To testy the hypothesis 1 compared A group using general gas range with B group using color coded gas range. The result showed difference between A and B in accuracy ( F (1, 38) = 17.892, p < 0.01) and response time ( F (1, 38) = 6.726 p < 0.05). The result of this test is to certify that color coding affect peoples by presenting the difference accuracy and response time. As result this study presents that color coding can be compatible the product having importance to certify in the design process.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.525-536
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• 2004

The objective of this study was to identify the quantitative traits loci(QTL) for meat quality traits in pigs. Three-generation resource population was constructed from a cross between Korean native boars and Landrace sows. The resource population including founders, $F_1$ and $F_2$ was genotyped for 23 microsatellite markers on chromosome 7. The sex average total length of linkage map on chromosome 7 was estimated 154.6 cM. Meat quality traits including meat pH, meat color, drip loss, shear force, heating loss, crude fat, crude protein, crude ash and water content in muscle were collected from $F_2$ animals. For the QTL mapping, we used $F_2$ QTL Analysis Servlet of QTL express for web-based QTL mapping tools(http://qtl.cap.ed.ac.uk/). The QTLs for CIE-a and CIE-b on SSC7 were significantly detected at 1% and 5% chromosome-wide level, respectively.

• Steel and Composite Structures
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• v.47 no.1
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• pp.91-102
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• 2023

To study the evaluation standard and control limit of mortar filling layer void length, in this paper, the train sub-model was developed by MATLAB and the track-bridge sub-model considering the mortar filling layer void was established by ANSYS. The two sub-models were assembled into a train-track-bridge coupling dynamic model through the wheel-rail contact relationship, and the validity was corroborated by the coupling dynamic model with the literature model. Considering the randomness of fastening stiffness, mortar elastic modulus, length of mortar filling layer void, and pier settlement, the test points were designed by the Box-Behnken method based on Design-Expert software. The coupled dynamic model was calculated, and the support vector regression (SVR) nonlinear mapping model of the wheel-rail system was established. The learning, prediction, and verification were carried out. Finally, the reliable probability of the amplification coefficient distribution of the response index of the train and structure in different ranges was obtained based on the SVR nonlinear mapping model and Latin hypercube sampling method. The limit of the length of the mortar filling layer void was, thus, obtained. The results show that the SVR nonlinear mapping model developed in this paper has a high fitting accuracy of 0.993, and the computational efficiency is significantly improved by 99.86%. It can be used to calculate the dynamic response of the wheel-rail system. The length of the mortar filling layer void significantly affects the wheel-rail vertical force, wheel weight load reduction ratio, rail vertical displacement, and track plate vertical displacement. The dynamic response of the track structure has a more significant effect on the limit value of the length of the mortar filling layer void than the dynamic response of the vehicle, and the rail vertical displacement is the most obvious. At 250 km/h - 350 km/h train running speed, the limit values of grade I, II, and III of the lengths of the mortar filling layer void are 3.932 m, 4.337 m, and 4.766 m, respectively. The results can provide some reference for the long-term service performance reliability of the ballastless track-bridge system of HRS.