• Current Optics and Photonics
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• v.3 no.1
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• pp.54-65
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• 2019

To develop a biomarker predicting tumor treatment efficacy is helpful to reduce time, medical expenditure, and efforts in oncology therapy. In clinics, microvessel density using immunohistochemistry has been proposed as an indicator that correlates with both tumor size and metastasis of cancer. In the preclinical study, we hypothesized that vascular morphometrics using optical coherence tomography angiography (OCTA) could be potential indicators to estimate the treatment efficacy of breast cancer. To verify this hypothesis, a 13762-MAT-B-III rat breast tumor was grown in a dorsal skinfold window chamber which was applied to a nude mouse, and the change in vascular morphology was longitudinally monitored during tumor growth and metronomic cyclophosphamide treatment. Based on the daily OCTA maximum intensity projection map, multiple vessel parameters (vessel skeleton density, vessel diameter index, fractal dimension, and lacunarity) were compared with the tumor size in no tumor, treated tumor, and untreated tumor cases. Although each case has only one animal, we found that the vessel skeleton density (VSD), vessel diameter index and fractal dimension (FD) tended to be positively correlated with tumor size while lacunarity showed a partially negative correlation. Moreover, we observed that the changes in the VSD and FD are prior to the morphological change of the tumor. This feasibility study would be helpful in evaluating the tumor vascular response to treatment in preclinical settings.

• Communications of the Korean Mathematical Society
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• v.32 no.3
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• pp.553-563
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• 2017

Different topological dimensions related to the pseudo-prime spectrum of topological modules are studied. An example of topological modules is introduced. Also, we give a result about Noetherianness of the pseudo-prime spectrum of topological modules.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1115-1117
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• 2005

This paper describes the three dimension model and simulation results of a thermal actuator based on polyMUMPs process, known as thermal multimorph actuator. The device has potential application in micro-transducers such as atomic force microscope (AFM) tip and scanning tunneling microscope (STM) tip. This device made of a multi-layer materials stack together with consisted of polysilicon, $SiO_2$ and gold. A mask layout design, three dimension model and simulation results are reported and discussed.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.253-254
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• 2002

Based on 3-D surface morphology measurements of C.G. irons, the fractal analyses were made on relationship between dry sliding surface morphology and the fractal dimension. It is revealed that the values of fractal dimensions ($D_f$) of sliding surfaces are in the range between 1-2, which are closely related to the surface morphologies. With the increase in depths of grooves or pits, the $D_f$ values increase. At the same time, the increases in densities of the grooves also cause the $D_f$ values to increase. At last, relationship among $D_f$ and friction coefficient as well as wear rate is discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.957-960
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• 2006

In this paper, we studied the location estimation algorithm of a spatial 3 dimension which extend the location estimation algorithm of a plane 2 dimension in 2.45GHz band RTLS(Real time location system). We used TDOA scheme which need not a time of transmission information of the tag and estimated 3 dimension coordinates. Also, estimated intersection of hyperbolic curve to X, Y coordinate of the tag at 2D coordinates searching area, $300m\times300m$ and LOS propagation environments. And, we estimated Z coordinate ultimately using X, Y coordinate. The location estimation algorithm of a spatial 3 dimension satisfies the RTLS specification requirement, 3m radius accuracy. From the result, we confirm that the location of tag which similar to actual coordinate in the case to an ideal received offset. However, we verified that the location of tag which escapes from a radius 3m within error range when received offset increased. Therefore, as the future work we are consider enhanced location accuracy of a spatial 3 dimension in RTLS system which using the decrease scheme of reader offset or the discriminate scheme of the estimation location.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.2
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• pp.129-135
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• 2015

The objective grading system for the facial palsy is needed. In this study, the facial palsy grading system was developed with combination of three dimensional image processing and Nottingham scale. The developed system is composed of 4 parts; measurement part, image processing part, computational part, facial palsy evaluation & display part. Two web cam were used to get images. The 8 marker on face were recognized at image processing part. The absolute three dimensional positions of markers were calculated at computational part. Finally, Nottingham scale was calculated and displayed at facial palsy evaluation & display part. The effects of measurement method and position of subject on Nottingham scale were tested. The markers were measured with 2-dimension and 3-dimension. The subject was look at the camera with $0^{\circ}$ and $11^{\circ}$ rotation. The change of Scale was large in the case of $11^{\circ}$ rotation with 2-dimension measurement. So, the developed system with 3-dimension measurement is robust to the orientation change of subject. The developed system showed the robustness of grading error originated from subject posture.

• Bulletin of the Korean Mathematical Society
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• v.42 no.3
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• pp.433-441
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• 2005

The concepts linearly independent elements and u-linearly independent elements in an N-group G where N is a near-ring, were introduced and studied. A few important results in the theory of vector spaces were generalized to N-groups.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.2
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• pp.45-51
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• 2000

This study proposes that analysis and evaluation method of time series ultrasonic signal using the chaotic feature extrac-tion for degradation extent. Features extracted from time series data using the chaotic time series signal analyze quantitatively material degradation extent. For this purpose analysis objective in this study if fractal dimension lyapunov exponent and strange attractor on hyperspace. The lyapunov exponent is a measure of the rate at which nearby trajectories in phase space diverge. Chaotic trajectories have at least one positive lyapunov exponent. The fractal dimension appears as a metric space such as the phase space trajectory of a dynamical syste, In experiment fractal(correlation) dimensions and lyapunov experiments showed values of mean 3.837-4.211 and 0.054-0.078 in case of degradation material The proposed chaotic feature extraction in this study can enhances ultrasonic pattern recognition results from degrada-tion signals.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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• pp.195-200
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• 2007

We analyzed a sequence of multi-stage automatic cold forging processes composed of four axisymmetric processes followed by a non-axisymmetric process using rigid-plastic finite element based forging simulators. The forging sequence selected for an example involves a piercing process and a heading process accompanying folding or overlapping, which all make it difficult to simulate the processes. To reduce computational time and to enhance the solution reliability, only the non-symmetric process was analyzed by the three-dimensional approach after the axisymmetric processes were analyzed by the two-dimensional approach. It has been emphsized that this capability is very helpful in simulating the multi-stage automatic forging processes which are next to axisymmetric.

• Communications of the Korean Mathematical Society
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• v.38 no.3
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• pp.649-661
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• 2023

Let 𝓜 be a stable Serre subcategory of the category of R-modules. We introduce the concept of 𝓜-minimax R-modules and investigate the local-global principle for generalized local cohomology modules that concerns to the 𝓜-minimaxness. We also provide the 𝓜-finiteness dimension f^𝓜_I (M, N) of M, N relative to I which is an extension the finiteness dimension f_I (N) of a finitely generated R-module N relative to I.