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.
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.
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.
Choi C.,Daejeon University |
Hu N.,Daejeon University
Bioresource Technology | Year: 2013
In this study, tetrachloroaurate as an electron acceptor of a microbial fuel cell (MFC) has been studied to discover the parameters that affect the cost-effective recovery of gold. The modeling and equations for calculating the maximum actual efficiency and electrochemical impedance spectroscopic internal resistance of the MFC were also developed. The maximum power density (Pmax) of 6.58W/m2 with a fill factor of 0.717 was achieved for 60mL volumes of 2000ppm Au(III) catholyte and 12.2mM acetate anolyte, respectively. The Pmax can also be predicted simply by measuring Rint by EIS. Additionally, the maximum actual MFC efficiency of about 57% was achieved, and the recovery efficiency of Au and the remaining concentration reached 99.89±0.00% and 0.22±0.00ppm, respectively, for an Au(III) concentration of 200ppm. The anodic concentration polarization quenching of the MFC strongly supports a mediator mechanism for the electron transfer from the microorganism to the anode. © 2013 Elsevier Ltd.
Choi C.,Daejeon University |
Cui Y.,Daejeon University
Bioresource Technology | Year: 2012
A cost-effective microbial fuel cell (MFC) system was developed in order to recover silver metal from silver ion containing wastewaters. After 8h reaction, silver metal recovery efficiencies as high as 99.91±0.00%-98.26±0.01% were achieved. The initial concentrations were from 50ppm to 200ppm with a load resistor of 1000Omega;. In the batch-fed cathode and continuous-fed anode system with an initial silver concentration of 200ppm, discharge curves display the production of both silver metal and electric energy at a rate of 69.9kg silver per KWh energy output. The maximum power of about 4.25W/m 2, maximum voltage of 0.749V, maximum current density of 5.67A/m 2, and a fill factor of 0.626 were achieved at 1000ppm initial silver ion concentration. © 2011 Elsevier Ltd.
Wang Z.,Daejeon University |
Lim B.,Daejeon University |
Choi C.,Daejeon University
Bioresource Technology | Year: 2011
In this study, removal of Hg 2+ as an electron acceptor of a microbial fuel cell (MFC) was successfully achieved. The initial pH affected the removal efficiency of Hg 2+ from electrochemical and chemical reactions. The effluent Hg concentrations for initial Hg 2+ concentration of 50mg/L after a 5-h reaction were 3.08±0.07, 4.21±0.34, 4.84±0.00, and 5.25±0.36mg/L for initial pH of 2, 3, 4, and 4.8, respectively. For 10-h reaction, the effluent Hg concentration was in the range of 0.44-0.69mg/L, for different initial Hg 2+ concentrations (25, 50, and 100mg/L). Lower initial pH and higher Hg 2+ concentration resulted in larger maximum power density. A maximum power density of 433.1mW/m 2 was achieved from 100mg/L Hg 2+ at pH 2. © 2011 Elsevier Ltd.
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.
Daejeon University | Date: 2012-12-27
Provided is a composition for preventing or treating oxidative brain injury and brain dysfunction including an extract of Astragali Radix and Salvia Miltiorrhizae Radix as an active ingredient, the composition having a highly outstanding preventive or therapeutic effect in animal models simulating brain-tissue damage and brain dysfunction induced by acute and long-term excessive stress generated in actual clinical practice, which is effectively usable as a therapeutic agent thereof.
Daejeon University | Date: 2015-05-20
Provided is a preparation method of an anti-tumor composition having a cancer cell proliferation-suppressing effect containing Cynanchi atrati Radix extracts obtained by solvent-extracting Cynanchi atrati Radix, which is a medicinal herb having the cancer cell proliferation-suppressing effect. The Cynanchi atrati Radix extracts may have a melanoma-specific cancer cell proliferation-suppressing effect, thereby making it possible to provide an anti-tumor composition for preventing and treating malignant melanoma.