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Search Results: 1 - 10 of 168258 matches for " Kwang B Lee "
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Developing Mobile Collaborative Learning Applications for Mobile Users
Kwang B Lee
International Journal of Interactive Mobile Technologies (iJIM) , 2011, DOI: 10.3991/ijim.v5i4.1823
Abstract: With the rapid growth wireless communication technologies, the number of mobile applications have been developing. One of them is approached for mobile learning area since it is unique in its own way and offers learning opportunities anywhere and anytime. Mobile collaborative learning (MCL) is a small group learning application based on mobile devices. MCL is a new exciting research area in which students can earn knowledge about a topic and concept via communicating with others by a mobile device. This paper introduces describes the theoretical and technical foundations for designing and developing an effective MCL environment. Also, the paper describes a new approach for building the MCL application towards mobile technology. The prototype will be constructed using Android operating system with suggesting necessary infrastructure and middleware. Finally, the paper include the result of a usability test to find valuable hidden facilitating issues to efficiently access and obtain the class contents in collaborative learning environment.
Hydrogen Peroxide Alleviates Hypoxia during Imbibition and Germination of Bean Seeds (Phaseolus vulgaris L.)  [PDF]
C. B. Rajashekar, Kwang-Hyun Baek
American Journal of Plant Sciences (AJPS) , 2014, DOI: 10.4236/ajps.2014.524373
Abstract: Bean seeds (Phaseolus vulgaris L. cv. Tendergreen) were imbibed in water to examine the effects of hypoxia during imbibition and subsequent germination. Hypoxic conditions occurred when seeds were imbibed in water for 24 h or longer and resulted in severe reduction of hypocotyl elongation and stem growth during subsequent germination under non-limiting oxygen conditions. Under continued hypoxic conditions, bean seeds failed to germinate, however, this was reversed in the presence of hydrogen peroxide (20 mM) in the medium. Furthermore, imbibition of seeds in the presence of hydrogen peroxide overcame the adverse hypoxic effects on hypocotyl elongation and stem growth. Exogenous hydrogen peroxide increased the dissolved oxygen levels in the germinating medium, and catalase and transition metal ions such as Fe2+, Cu2+ and Mn2 helped to facilitate the production of oxygen from hydrogen peroxide. In these catalysts, catalase played a major role in the decomposition of hydrogen peroxide as demonstrated by the use of a catalase inhibitor, 3-amino-1, 2, 4-triazole, which reversed the positive effects produced by hydrogen peroxide on germination of seeds under hypoxic conditions. The results show that imbibition is sensitive to oxygen deficits which affect subsequent hypocotyl growth and seedling performance. The adverse effects of hypoxia on germination of bean seeds can be overcome by exogenous hydrogen peroxide.
Three-level anterior cervical discectomy and fusion in elderly patients with wedge shaped tricortical autologous graft: A consecutive prospective series
Lee Suk,Oh Kwang,Yoon Kwang,Lee Sung
Indian Journal of Orthopaedics , 2008,
Abstract: Background: Treatment of multilevel cervical spondylotic myelopathy/radiculopathy is a matter of debate, more so in elderly patients due to compromised physiology. We evaluated the clinical and radiological results of cervical fusion, using wedge-shaped tricortical autologous iliac graft and Orion plate for three-level anterior cervical discectomy in elderly patients. Materials and Methods: Twelve elderly patients with mean age of 69.7 years (65-76 years) were treated between April 2000 and March 2005, for three-level anterior cervical discectomy and fusion, using wedge-shaped tricortical autologous iliac graft and Orion plate. Outcome was recorded clinically according to Odom′s criteria and radiologically in terms of correction of lordosis angle and intervertebral disc height span at the time of bony union. The mean follow-up was 29.8 months (12-58 months). Results: All the patients had a complete recovery of clinical symptoms after surgery. Postoperative score according to Odom′s criteria was excellent in six patients and good in remaining six. Bony union was achieved in all the patients with average union time of 12 weeks (8-20 weeks). The mean of sum of three segment graft height collapse was 2.50 mm (SD = 2.47). The average angle of lordosis was corrected from 18.2° (SD = 2.59°) preoperatively to 24.9° (SD = 4.54°) at the final follow-up. This improvement in the radiological findings is statistically significant (P < 0.05). Conclusion: Cervical fusion with wedge-shaped tricortical autologous iliac graft and Orion plate for three-level anterior cervical discectomy is an acceptable technique in elderly patients. It gives satisfactory results in terms of clinical outcome, predictable early solid bony union, and maintenance of disc space height along with restoration of cervical lordosis.
Estimating higher order perturbative coefficients using Borel transform
Kwang Sik Jeong,Taekoon Lee
Physics , 2002, DOI: 10.1016/S0370-2693(02)02976-3
Abstract: A new method of estimating higher order perturbative coefficients is discussed. It exploits the rapid, asymptotic growth of perturbative coefficients and the information on the singularities in the complex Borel plane. A comparison with other methods is made in several Quantum Chromodynamics (QCD) expansions.
Building the process-drug–side effect network to discover the relationship between biological Processes and side effects
Lee Sejoon,Lee Kwang H,Song Min,Lee Doheon
BMC Bioinformatics , 2011, DOI: 10.1186/1471-2105-12-s2-s2
Abstract: Background Side effects are unwanted responses to drug treatment and are important resources for human phenotype information. The recent development of a database on side effects, the side effect resource (SIDER), is a first step in documenting the relationship between drugs and their side effects. It is, however, insufficient to simply find the association of drugs with biological processes; that relationship is crucial because drugs that influence biological processes can have an impact on phenotype. Therefore, knowing which processes respond to drugs that influence the phenotype will enable more effective and systematic study of the effect of drugs on phenotype. To the best of our knowledge, the relationship between biological processes and side effects of drugs has not yet been systematically researched. Methods We propose 3 steps for systematically searching relationships between drugs and biological processes: enrichment scores (ES) calculations, t-score calculation, and threshold-based filtering. Subsequently, the side effect-related biological processes are found by merging the drug-biological process network and the drug-side effect network. Evaluation is conducted in 2 ways: first, by discerning the number of biological processes discovered by our method that co-occur with Gene Ontology (GO) terms in relation to effects extracted from PubMed records using a text-mining technique and second, determining whether there is improvement in performance by limiting response processes by drugs sharing the same side effect to frequent ones alone. Results The multi-level network (the process-drug-side effect network) was built by merging the drug-biological process network and the drug-side effect network. We generated a network of 74 drugs-168 side effects-2209 biological process relation resources. The preliminary results showed that the process-drug-side effect network was able to find meaningful relationships between biological processes and side effects in an efficient manner. Conclusions We propose a novel process-drug-side effect network for discovering the relationship between biological processes and side effects. By exploring the relationship between drugs and phenotypes through a multi-level network, the mechanisms underlying the effect of specific drugs on the human body may be understood.
Plasma Post Oxidation of Plasma Nitrocarburized SKD 61 Steel

Insup Lee,Kwang-Ho Jeong,

材料科学技术学报 , 2008,
PINK1 positively regulates IL-1β-mediated signaling through Tollip and IRAK1 modulation
Lee Hyun Jung,Chung Kwang Chul
Journal of Neuroinflammation , 2012, DOI: 10.1186/1742-2094-9-271
Abstract: Background Parkinson disease (PD) is characterized by a slow, progressive degeneration of dopaminergic neurons in the substantianigra. The cause of neuronal loss in PD is not well understood, but several genetic loci, including PTEN-induced putative kinase 1 (PINK1), have been linked to early-onset autosomal recessive forms of familial PD. Neuroinflammation greatly contributes to PD neuronal degeneration and pathogenesis. IL-1 is one of the principal cytokines that regulates various immune and inflammatory responses via the activation of the transcription factors NF-κB and activating protein-1. Despite the close relationship between PD and neuroinflammation, the functional roles of PD-linked genes during inflammatory processes remain poorly understood. Methods To explore the functional roles of PINK1 in response to IL-1β stimulation, HEK293 cells, mouse embryonic fibroblasts derived from PINK1-null (PINK1 / ) and control (PINK1+/+) mice, and 293 IL-1RI cells stably expressing type 1 IL-1 receptor were used. Immunoprecipitation and western blot analysis were performed to detect protein–protein interaction and protein ubiquitination. To confirm the effect of PINK1 on NF-κB activation, NF-κB-dependent firefly luciferase reporter assay was conducted. Results PINK1 specifically binds two components of the IL-1-mediated signaling cascade, Toll-interacting protein (Tollip) and IL-1 receptor-associated kinase 1 (IRAK1). The association of PINK1 with Tollip, a negative regulator of IL-1β signaling, increases upon IL-1β stimulation, which then facilitates the dissociation of Tollip from IRAK1 as well as the assembly of the IRAK1–TNF receptor-associated factor 6 (TRAF6) complex. PINK1 also enhances Lys63-linked polyubiquitination of IRAK1, an essential modification of recruitment of NF-κB essential modulator and subsequent IκB kinase activation, and increases formation of the intermediate signalosome including IRAK1, TRAF6, and transforming growth factor-β activated kinase 1. Furthermore, PINK1 stimulates IL-1β-induced NF-κB activity via suppression of Tollip inhibitory action. Conclusions These results suggest that PINK1 upregulates IL-1β-mediated signaling through the functional modulation of Tollip and IRAK1. These results further suggest that PINK1 stimulates the ubiquitination of proximal molecules and increases signalosome formation in the IL-1β-mediated signaling pathway. The present study therefore supports the idea of the close relationship between neuroinflammation and PD.
Global Stability of a Host-Vector Model for Pine Wilt Disease with Nonlinear Incidence Rate
Kwang Sung Lee,Abid Ali Lashari
Abstract and Applied Analysis , 2014, DOI: 10.1155/2014/219173
Abstract: Based on classical epidemic models, this paper considers a deterministic epidemic model for the spread of the pine wilt disease which has vector mediated transmission. The analysis of the model shows that its dynamics are completely determined by the basic reproduction number . Using a Lyapunov function and a LaSalle's invariant set theorem, we proved the global asymptotical stability of the disease-free equilibrium. We find that if , the disease free equilibrium is globally asymptotically stable, and the disease will be eliminated. If , a unique endemic equilibrium exists and is shown to be globally asymptotically stable, under certain restrictions on the parameter values, using the geometric approach method for global stability, due to Li and Muldowney and the disease persists at the endemic equilibrium state if it initially exists. 1. Introduction Pine wilt disease (PWD) is caused by the pinewood nematode Bursaphelenchus xylophilus Nickle, which is vectored by the Japanese pine sawyer beetle Monochamus alternatus. The first epidemic of PWD was recorded in 1905 in Japan [1]. Since PWD was found in Japan, the pinewood nematode has spread to Korea, Taiwan, and China and has devastated pine forests in East Asia. Furthermore, it was also found in Portugal in 1999 [2]. The greatest losses to pine wilt have occurred in Japan. During the 20th century, the disease spread through highly susceptible Japanese black (P. thunbergiana) and Japanese red (P. densiflora) pine forests with devastating impact. Iowa, Illinois, Missouri, Kentucky, eastern Kansas, and southeastern Nebraska have experienced heavy losses of Scots pine. Thus, PWD has become the most serious threat to forest worldwide [3]. Mathematical modeling is useful in understanding the process of transmission of a disease, and determining the different factors that influence the spread of the disease. In this way, different control strategies can be developed to limit the spread of infection. Lately, some mathematical models have been formulated on pest-tree dynamics, such as PWD transmission model which was investigated by Lee and Kim [4] and Shi and Song [5]. The incidence rate of the transmission of the disease plays an important role in the study of mathematical epidemiology. In classical epidemiological models, the incidence rate is assumed to be bilinear given by , where is the probability of transmission per contact rate, is susceptible, and is infective populations, respectively. However, actual data and evidence observed for many diseases show that dynamics of disease transmission are not always
Effect on Defect in N or F-Doped Ferromagnetic Zn1-xCuxO: First-Principles Study  [PDF]
Byung-Sub Kang, Kwang-Pyo Chae, Haeng-Ki Lee
Materials Sciences and Applications (MSA) , 2014, DOI: 10.4236/msa.2014.514102
Abstract: We investigated the electronic and magnetic properties for O or Zn defect of (Cu, N) or (Cu, F)-co- doped ZnO with the concentration of 2.77% - 8.33% by using the first-principles calculations. The ferromagnetic coupling of Cu atoms in (Cu, N)-codoped ZnO can be attributed to the hole-mediated double-exchange through the strong 2p-3d coupling between Cu and neighboring O (or N) atoms. The ferromagnetism in Cu-doped ZnO is controllable by changing the carrier density. The Cu magnetic moment in low Cu concentration (2.77%) is increased by the N-doping, while for the F-doping it decreases. For two Cu atoms of Zn0.9445Cu0.0555O with O vacancy, the antiferromagnetic state is more energetically favorable than the ferromagnetic state.
Integrated Testing Environment of Instructor Station for SMART Simulator  [PDF]
Joon Ku Lee, Geun Ok Park, Keung Koo Kim, Woo Seok Huh, Kwang Young Sohn
Open Journal of Modelling and Simulation (OJMSi) , 2015, DOI: 10.4236/ojmsi.2015.32004
Abstract: SMART is the reactor that has been researched for many years by KAERI in order to provide the small-mid scale of power for typically seawater desalination. Now Korea Atomic Energy Research Institute (KAERI) has issued Standard Safety Analysis Report (SSAR) and acquired Standard Design Approval (SDA) for SMART. In order to conduct the design verification and validation for license, the integrated simulation test environment that is composed of 1) the system specific simulation codes formerly developed in the name of Nuclear Plant Analyzer (NPA) including NSSS and BOP simulation, 2) Instructor Station (IS), 3) Supervisory Control and Data Acquisition (SCADA), 4) operator and instructor Human Machine Interface (HMI), and 5) soft-controller has been considered as an important area for operator training and system validation. These sub-components has been designed and implemented for verifying and validating the SMART design and training of operators and for generating the backup data for licensing. This paper introduces the structure of integrated simulation test environment for SMART, explains the efforts to assist system-specific simulation code interface, and also addresses the effort for implementing and optimizing the test environment by maintaining its own simulation functionality and performance in order to review the simulation results efficiently.
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