Daejeon University is a private university located in Daejeon, South Korea. The current president is Lim Yong-Cheol. About 230 instructors are employed. The university also operates 4 Oriental medicine hospitals, two in Daejeon City and two others in Chungju and Chunan. Wikipedia.
Noh D.K.,Daejeon University |
Kang K.,Hanyang University
Journal of Computer and System Sciences | Year: 2011
Solar power can extend the lifetime of wireless sensor networks (WSNs), but it is a very variable energy source. In many applications for WSNs, however, it is often preferred to operate at a constant quality level rather than to change application behavior frequently. Therefore, a solar-powered node is required adaptation to a highly varying energy supply. Reconciling a varying supply with a fixed demand requires a good prediction of that supply, so that demand can be regulated accordingly. We describe two energy allocation schemes, based on time-slots, which aim at optimum use of the periodically harvested solar energy, while minimizing the variability in energy allocation. The simpler scheme is designed for resource-constrained sensors; and a more accurate approach is designed for sensors with a larger energy budget. Each of these schemes uses a probabilistic model based on previous observation of harvested solar energy. This model takes account of long-term trends as well as temporary fluctuations of right levels. Finally, this node-level energy optimization naturally leads to the improvement of the network-wide performance such as latency and throughput. The experimental results on our testbeds and simulations show it clearly. © 2010 Elsevier Inc.
Lee S.W.,Kyung Hee University |
Yu S.-Y.,Kyung Hee University |
Seo K.H.,Kyung Hee University |
Kim E.S.,Daejeon University |
Kwak H.W.,Kyung Hee University
Retina | Year: 2014
PURPOSE: To investigate diurnal variations in choroidal thickness (CT) in relation to various factors in healthy Korean subjects using spectral-domain optical coherence tomography. METHODS: A prospective study was conducted on 100 healthy volunteers who each underwent measurements of CT in the same subfoveal area using an enhanced depth imaging technique with spectral-domain optical coherence tomography at 8 AM, 11 AM, 2 PM, and 5 PM. Possible correlations between the diurnal variation of CT and other factors, such as sex, axial length (AL), baseline CT (8 AM), blood pressure, and intraocular pressure, were evaluated. RESULTS: One hundred volunteers with a mean age of 30.1 years were scanned. A significant pattern of diurnal variation was observed, with a mean CT of 278.28 ± 91.78 μm at 8 AM, 271.57 ± 89.08 μm at 11 AM, 266.39 ± 86.18 μm at 2 PM, and 264.92 ± 87.10 μm at 5 PM in a right eye. Right eye and left eye had a similar trend of diurnal cycle. Based on sex, AL, and baseline CT, the pattern of diurnal variation was greater and the amplitude significantly was greater in men, AL ≤ 24 mm and baseline CT ≥ 300 μm (men vs. women: P = 0.048, AL ≤ 24 mm vs. AL > 24 mm: P = 0.036, baseline CT ≥ 300 μm vs. baseline CT < 200 μm: P = 0.002, baseline CT ≥ 300 μm vs. 200 μm ≤ baseline CT < 300 μm: P = 0.008). There were no significant correlations between the diurnal variation of CT and systolic blood pressure, diastolic blood pressure, or intraocular pressure. CONCLUSION: In men as well as in those with a shorter AL and thick baseline CT, a greater pattern of diurnal variation with significantly greater amplitude was observed. Copyright © by Ophthalmic Communications Society, Inc.
Kim S.-K.,Daejeon University
Multimedia Tools and Applications | Year: 2013
Given an unstructured point set, we use an MLS (moving least-squares) approximation to estimate the local curvatures and their derivatives at a point by means of an approximating surface. Then, we compute neighbor information using a Delaunay tessellation. Ridge and valley points can then be detected as zero-crossings, and connected using curvature directions. We demonstrate our method on several large point-sampled models, rendered by point-splatting, on which the ridge and valley lines are rendered with line width determined from curvatures. © 2012 Springer Science+Business Media, LLC.
Namgung U.,Daejeon University
Cells Tissues Organs | Year: 2014
After peripheral nerve injury, Schwann cells are released from the degenerating nerve, dedifferentiated, and then actively participate in axonal regeneration. Dedifferentiated Schwann cells, together with macrophages, are involved in eliminating myelin debris, forming bands of Büngner that provide pathways for regenerating axons, and redifferentiating for remyelination. Activation of Erk1/2 and c-Jun was shown to induce stepwise repair programs in Schwann cells, indicating that plastic changes in Schwann cell activity contribute to interaction with axons for regeneration. Schwann cell β1 integrin was identified to mediate the Cdc2-vimentin pathway and further connect to adaptor molecules in the growth cone of regenerating axons through the binding of extracellular matrix (ECM) proteins. Timely interaction between Schwann cells and the axon (S-A) is critical to achieving efficient axonal regeneration because the delay in S-A interaction results in retarded nerve repair and chronic nerve damage. By comparing with the role of Schwann cells in developing nerves, this review is focused on cellular and molecular aspects of Schwann cell interaction with axons at the early stages of regeneration. © 2015 S. Karger AG, Basel.
Eom J.H.,Daejeon University
International Journal of Security and its Applications | Year: 2012
In this paper, we designed a document security checkpoint for inspecting leakage of sensitive documents including military information from the internal to the outside network. Our designed model checks all documents when they are downloaded, sent, and printed. The model consists of four modules: authentication module, access control module, misuse monitor module, and tracking module. The authentication module checks the insider's information and after which allows an insider to log on to the system. The access control module authorizes an insider to do operations (read, write) according to his role and security level. The pattern monitor module watches an insider's abnormal access on documents as comparing the insider's actual process to current process profile in database. The tracking module traces documents sent outside and verifies fabrication of documents. The document security checkpoint prevents indiscriminate access to documents and it does not allow access to documents unrelated to the insider's duty and security level. Even though the document is illegally leaked by an insider, it can be tracked by watermarking techniques in tracking module.