• The KIPS Transactions:PartA
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• v.16A no.1
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• pp.35-42
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• 2009

This paper proposes a new coverage algorithm for intelligent robot. Many algorithms for improving the performance of coverage have been focused on minimizing the total coverage completion time. However, if one does not have enough time to finish the whole coverage, the optimal path could be different. To tackle this problem, we propose a new coverage algorithm, which we call MaxCoverage algorithm, for covering maximal area within the deadline. The MaxCoverage algorithm decides the navigation flow by greedy algorithm for Set Covering Problem. The experimental results show that the MaxCoverage algorithm performs better than other algorithms for random deadlines.

• Geomechanics and Engineering
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• v.34 no.5
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• pp.481-489
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• 2023

Drained cyclic triaxial tests were conducted on a saturated sand to examine its deformation characteristics under either axial or lateral cyclic loading condition. To apply lateral cyclic loading, the cell pressure was cycled while maintaining a constant vertical stress. The strain accumulations and flow direction in the soil were presented and discussed considering various initial stress ratios (η₀), cyclic stress amplitudes and cyclic stress paths. The results indicate that axial strain accumulation shows an exponential increase with the maximum stress ratio (η^max). The initial deviatoric stress has comparable effects with lateral cyclic stress amplitude on the accumulated axial strain. In contrast, the accumulated volumetric strain is directly proportional to the lateral cyclic stress amplitude but not much affected by η₀ values. Due to the anisotropy of the soil, the accumulated axial and lateral bulging strains are greater in lateral cyclic loading when compared to axial cyclic loading even though η^max is the same. It is also found that η^max affects soil's lateral deformation and increasing the ratio could change the lateral deformation from contraction to bulging. The flow direction depends on η^max in the sand under lateral cyclic loading, regardless of η₀ values and the cyclic stress amplitudes, and a large η^max could lead to great deviatoric strain but a little volumetric strain accumulation.

• Journal of the Korea Society of Computer and Information
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• v.19 no.4
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• pp.91-99
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• 2014

TThis paper suggests an heuristic polynomial time algorithm to solve the optimal solution for QAP (quadratic assignment problem). While Hungarian algorithm is most commonly used for a linear assignment, there is no polynomial time algorithm for the QAP. The proposed algorithm derives a grid type layout among unit distances of a distance matrix. And, we apply max-flow/min-distance approach to assign this grid type layout in such a descending order way that the largest flow is matched to the smallest unit distance from flow matrix. Evidences from implementation results of the proposed algorithm on various numerical grid type QAP examples show that a solution to the QAP could be obtained by a polynomial algorithm.

• ETRI Journal
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• v.35 no.2
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• pp.311-320
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• 2013

In most spectral clustering approaches, the Gaussian kernel-based similarity measure is used to construct the affinity matrix. However, such a similarity measure does not work well on a dataset with a nonlinear and elongated structure. In this paper, we present a new similarity measure to deal with the nonlinearity issue. The maximum flow between data points is computed as the new similarity, which can satisfy the requirement for similarity in the clustering method. Additionally, the new similarity carries the global and local relations between data. We apply it to spectral clustering and compare the proposed similarity measure with other state-of-the-art methods on both synthetic and real-world data. The experiment results show the superiority of the new similarity: 1) The max-flow-based similarity measure can significantly improve the performance of spectral clustering; 2) It is robust and not sensitive to the parameters.

• Journal of Chest Surgery
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• v.30 no.1
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• pp.11-16
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• 1997

The Increasing use of coronary perfusates for the protection of the human heart during ischemic cardiac arrest has placed great emphasis on the need for a rational and safe formulation. For the purpose of this study isolated rat hearts were connected to retrograde nonworking perfusion system proposed by Langendorff, and then perfused for 20 minutes by coronary infusates of magnesium concentration of 1.66 m Mol per liter(group A, n: 10) or 15mMo1 per liter(group B, n: 10). After 20 minutes perfusion, cold cardioplegic solution (modified St. Thomas'Hospital solution) was infused for 2 minutes, and prepared within 4$^{\circ}C$ Krebs-Henseleit solution. Finally, 20 minutes of cononay reprsfuslon was reestablished after I hour of cold ischemic cardiac arrest. Hemodynamic parameters (heart rate, left ventricular pressure, $\pm$ dp/dt max. and coronany flow) and enzymes assay (creatine phosphokinase, lactic dehydrogenase and flutamic oxaloacetic transaminase) were performed each other at whic rat heart was perfused for 20 minutes and reperfused for 20 minutes thereafter. There were significant differences in the recovery rate of heart rate, systolic left ventricular pressure, + dp/dt max, and coronary flow and reperfusion-perfusion ratio of creatine phosphokinase(P < 0.05). But, there were no signicant differences in the recovery rate of dp/dt max, and reperfunion-perfusion ratio of lactic dehydrogenase and glutamic oxaloacetic acid (P > 0.05).

• Journal of The Korea Institute of Healthcare Architecture
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• v.13 no.3
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• pp.7-14
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• 2007

The concept and spatial composition of office have endlessly changed according to social trend. And according to social change, members of office, namely, concept of organization has been changed. Presently, our society finds and needs appearance of office suitable for our society. According to a concept of ecological environment and a concept laying stress on human, various trials have been performed but still, stress of salaried men is treated as social issue. By having connection between psychological healing theory of Max $L{\ddot{\bar{u}}}scher$ and spatial expression elements (content : refuge, self-esteem : prospect, confidence : flow, liberty : void) as a theory, we discussed possibility of aesthetic office landscape could be developed to a type of office which could control emotion that can be a cause of stress and we intended to examine limitation and possibility through case analysis.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.8 no.11
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• pp.79-83
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• 1985

This paper is to develop four heuristic algorithms for $n/m/D/F/F_{max}$. A study present numerical example for (H1) algorithm. Among the sequence generated, the best sequence is J2, J1, J6, J7, J4, J3, J5 and makespan is 528. The optimal makespan of this numerical example can be found as 528 as also, and the worst value of heuristic solution is only 7.2 % away from it.

• Journal of Mechanical Science and Technology
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• v.20 no.9
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• pp.1492-1501
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• 2006

A transportation system of single wafer has been developed to be applied to semiconductor manufacturing process of the next generation. In this study, the experimental apparatus consists of two kinds of track, one is for propelling a wafer, so called control track, the other is for generating an air film to transfer a wafer, so called transfer track. The wafer transportation speed has been evaluated by the numerical and the experimental methods for three types of nozzle position a..ay (i.e., the front-, face- and rear-array) in an air levitation system. Test facility for 300mm wafer has been equipped with two control tracks and one transfer track of 1500mm length from the starting point to the stopping point. From the present results, it is found that the experimental values of the wafer transportation speed are well in agreement with the computed ones. Namely, the computed values of the maximum wafer transportation speed $V_{max}$ are slightly higher than the experimental ones by about $15{\times}20%$. The disparities in $V_{max}$ between the numerical and the experimental results become smaller as the air velocity increases. Also, at the same air flow rate, the order of wafer transportation speeds is : $V_{max}$ for the front-array > $V_{max}$ for the face-array > $V_{max}$ for the rear-array. However, the face-array is rather more stable than any other type of nozzle array to ensure safe transportation of a wafer.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.3
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• pp.115-120
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• 2017

Moving techniques is made up the physical moving status of the flow distinction modulus (FDM) and stream distinction modulus (SDM) on the shudder moving shape. Condition of the distinction modulus by the shudder moving shape is organized the dangle moving system. As to define the physical moving of special signal on the matter, we compared a shudder value of the flow distinction modulus on the flow state. The concept of stream distinction modulus is analyzed the reference of stream distinction signal and stream distinction signal by the stream state. For detecting a variation of the FDM-SDM of the maximum-minimum and average in terms of the moving shape, and shudder moving value that is a shudder value of the top variation of the $Top-{\varepsilon}$ MAX-MIN-AVG with $(-0.817){\pm}0.15$ units, that is a shudder value of the peripheral variation of the $Per-{\varepsilon}$ MAX-MIN-AVG with $(-2.53){\pm}(-0.11)$ units, that is a shudder value of the limbus variation of the $Lim-{\varepsilon}$ MAX-MIN-AVG with $(-0.29){\pm}0.03$ units, that is a shudder value of the center variation of the $Cen-{\varepsilon}$ MAX-MIN-AVG with $(-0.09){\pm}(-0.01)$ units. The dangle moving will be to assess at the capacity of the physical moving shape for the control degree of distinction modulus on the FDM-SDM that is showed the flow and stream shape by the distinction modulus system. Dangle distinction system is adjusted of a shape by the special moving and is included a shudder data of dangle moving modulus.

• Wind and Structures
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• v.7 no.5
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• pp.317-332
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• 2004

Wind tunnel experiments were conducted under highly turbulent and disturbed flow conditions over a solid/perforated plate with a long splitter plate in its plane of symmetry. The effect of varied level of perforation of the normal plate on fluctuating velocities and fluctuating pressures measured across and along the separation bubble was studied. The different perforation levels of the normal plate; that is 0%, 10%, 20%, 30%, 40% and 50% are studied. The Reynolds number based on step height was varied from $4{\times}10^3$ to $1.2{\times}10^4$. The shape and size of the bubble vary with different perforation level of the normal plate that is to say the bubble is reduced both in height and length up to 30% perforation level. For higher perforation of the normal plate, bubble is completely swept out. The peak turbulence value occurs around 0.7 to 0.8 times the reattachment length. The turbulence intensity values are highest for the case of solid normal plate (bleed air is absent) and are lowest for the case of 50% perforation of the normal plate (bleed air is maximum in the present study). From the analysis of data it is observed that $\sqrt{\overline{u^{{\prime}2}}}/(\sqrt{\overline{u^{{\prime}2}}})_{max}$, (the ratio of RMS velocity fluctuation to maximum RMS velocity fluctuation), is uniquely related with dimensionless distance y/Y', (the ratio of distance normal to splitter plate to the distance where RMS velocity fluctuation is half its maximum value) for all the perforated normal plates. It is interesting to note that for 50% perforation of the normal plate, the RMS pressure fluctuation in the flow field gets reduced to around 60% as compared to that for solid normal plate. Analysis of the results show that the ratio [$C^{\prime}_p$ max/$-C_{pb}(1-{\eta})$], where $C^{\prime}_p$ max is the maximum coefficient of fluctuating pressure, $C_{pb}$ is the coefficient of base pressure and ${\eta}$ is the perforation level (ratio of open to total area), for surface RMS pressure fluctuation levels seems to be constant and has value of about 0.22. Similar analysis show that the ratio $[C^{\prime}_p$ max/$-C_{pb}(1-{\eta})]$ for flow field RMS pressure fluctuation levels seems to be constant and has a value of about 0.32.