• Journal of Biomedical Engineering Research
• /
• v.28 no.1
• /
• pp.102-107
• /
• 2007

In molecular imaging studies via magnetic resonance imaging, in vivo cell tracking is an important issue for the observation of cell therapy or disease behavior. High resolution imaging and longitudinal study are necessary to track the cell movement. Since the field inhomogeneity extends over several voxels, we have performed the numerical analysis using the sub-voxel method dividing a voxel of MR image into several elements and the information about the field inhomogeneity distribution around the micro-beads. We imbedded ferrite-composite micro-beads with the size of $20-150{\mu}m$ in the subject substituted for cells to induce local field distortion. In the phantom imaging with the isotropic voxel size of $200{\mu}m^3$, we could confirm the feasibility of sub-voxel tracking in a 3.0 T MRI.

• Journal of Technologic Dentistry
• /
• v.29 no.2
• /
• pp.163-171
• /
• 2007

The purpose of this study is comprehension for relationships between job stress and mental health for dental technicians in performing their duties. and this study can make use of opportunity of accumulation of data on dental technician's health care and work environment in future. Job stress for dental technicians served in general hospital dental laboratory were more highly effected than in local dental laboratory. and this result was statistically reliable. There were no meaningful differences in mental health between dental technician in dental laboratory in dental climic dental laboratory and commercial dental laboratory. and this result was not statistically reliable. The analysis of this study could be used by preliminary data to further research of relationships between job stress and mental health for dental technicians in the future. This study was made progress partially under limited members of dental technician in Seoul. so future studies are suggested that the more advanced total figure study for whole dental technicians in Korea.

• BMB Reports
• /
• v.41 no.5
• /
• pp.353-357
• /
• 2008

LRR family proteins play important roles in a variety of physiological processes. To facilitate their production and crystallization, we have invented a novel method termed "Hybrid LRR Technique". Using this technique, the first crystal structures of three TLR family proteins could be determined. In this review, design principles and application of the technique to protein crystallization will be summarized. For crystallization of TLRs, hagfish VLR receptors were chosen as the fusion partners and the TLR and the VLR fragments were fused at the conserved LxxLxLxxN motif to minimize local structural incompatibility. TLR-VLR hybridization did not disturb structures and functions of the target TLR proteins. The Hybrid LRR Technique is a general technique that can be applied to structural studies of other LRR proteins. It may also have broader application in biochemical and medical application of LRR proteins by modifying them without compromising their structural integrity.

• Journal of Biomedical Engineering Research
• /
• v.10 no.2
• /
• pp.191-194
• /
• 1989

A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network.

• Journal of Biomedical Engineering Research
• /
• v.16 no.1
• /
• pp.33-42
• /
• 1995

A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filters representing global features is proposed in this network.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.10a
• /
• pp.260-263
• /
• 2005

In this study, we analyzed the plantar shear stress and pressure of diabetic foot patients during walking by using in-shoe local shear force and plantar pressure measurement system. Twelve normal subjects and three diabetic foot patients with diabetic neuropathy in lateral heel were participated in this study. The center of pressure in diabetic foot patients moved more medially and directed toward 1st, 2nd metatarsal heads and hallux during late stance period, making pressure at the medial heel and 2nd metatarsal head significantly higher than in the normal. Shear stress at the heel were changed significantly in early stance and the magnitude of shear stresses in each metatarsal head were also changed. Further studies would be very helpful to design foot orthoses in patients with diabetic neuropathy or other diseases.

• Medical Lasers
• /
• v.10 no.3
• /
• pp.185-188
• /
• 2021

Onychomycosis is the most common disease of the nail, with a worldwide prevalence of 5.5%. It causes local pain, paresthesia, and cosmetic problems and decreases the patients' quality of life. Conventional treatments include the administration of topical and systemic agents. However, factors such as subungual hyperkeratosis and biofilm formation may affect the efficacy of these treatments. Moreover, side effects associated with systemic agents are a major concern for patients. Therefore, various novel treatments are being developed; among them, photodynamic therapy (PDT) and Nd:YAG laser are promising, and several studies have demonstrated the efficacy and safety of PDT and laser therapy. Here, we report the efficacy and tolerability of PDT combined with 1064-nm Nd:YAG laser therapy and topical efinaconazole for the treatment of three patients with refractory onychomycosis.

• Advances in concrete construction
• /
• v.17 no.4
• /
• pp.187-210
• /
• 2024

Cantilever structures demonstrate diverse nonlocal effects, resulting in either stiffness hardening or dynamic softening behaviors, as various studies have indicated. This research delves into the free and forced vibration analysis of rotating nanoscale cylindrical beams and tubes under external dynamic stress, aiming to thoroughly explore the nonlocal impact from both angles. Utilizing Euler-Bernoulli and Reddy beam theories, in conjunction with higher-order tube theory and Hamilton's principle, nonlocal governing equations are derived with precise boundary conditions for both local and nonlocal behaviors. The study specifically examines two-dimensional functionally graded materials (2D-FGM), characterized by axially functionally graded (AFG) and radial porosity distributions. The resulting partial differential equations are solved using the generalized differential quadrature element method (GDQEM) and Newmark-beta procedures to acquire time-dependent results. This investigation underscores the significant influence of boundary conditions when nonlocal forces act on cantilever structures.

• Journal of Digital Convergence
• /
• v.12 no.12
• /
• pp.571-580
• /
• 2014

Korea's water supply efficiency is low, due to weak industrial structure, such as small scale, regional disparities in the management and services, unreasonable problem in a use and management of interregional water resources. This study investigated changes in the productivity of Jeollabuk-do local water supply service by using analysis of efficiency by data envelopment analysis and Malmquist Index Analysis. As a result, 6 office is showed that the value of scale efficiency is 1 and productivity index per gun in mainly seemed below average. Therefore these offices should strive to increase their productivity. This study is differentiated from earlier studies in the aspect of measuring change of productivity by not only DEA but also Malmquist productivity analysis. Therefore it will contribute to increase productivity of water supply in Jeollabuk-do.

• Korean Journal of Radiology
• /
• v.24 no.7
• /
• pp.640-646
• /
• 2023

Objective: Prospective studies on postoperative residual breast tissue (RBT) after robotic-assisted nipple-sparing mastectomy (R-NSM) for breast cancer are limited. RBT presents an unknown risk of local recurrence or the development of new cancer after curative or risk-reducing mastectomies. This study investigated the technical feasibility of using magnetic resonance imaging (MRI) to evaluate RBT after R-NSM in women with breast cancer. Materials and Methods: In this prospective pilot study, 105 patients, who underwent R-NSM for breast cancer at Changhua Christian Hospital between March 2017 and May 2022, were subjected to postoperative breast MRI to evaluate the presence and location of RBT. The postoperative MRI scans of 43 patients (age, 47.8 ± 8.5 years), with existing preoperative MRI scans, were evaluated for the presence and location of RBT. In total, 54 R-NSM procedures were performed. In parallel, we reviewed the literature on RBT after nipple-sparing mastectomy, considering its prevalence. Results: RBT was detected in 7 (13.0%) of the 54 mastectomies (6 of the 48 therapeutic mastectomies and 1 of the 6 prophylactic mastectomies). The most common location for RBT was behind the nipple-areolar complex (5 of 7 [71.4%]). Another RBT was found in the upper inner quadrant (2 of 7 [28.6%]). Among the six patients who underwent RBT after therapeutic mastectomies, one patient developed a local recurrence of the skin flap. The other five patients with RBT after therapeutic mastectomies remained disease-free. Conclusion: R-NSM, a surgical innovation, does not seem to increase the prevalence of RBT, and breast MRI showed feasibility as a noninvasive imaging tool for evaluating the presence and location of RBT.