• Journal of Communications and Networks
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• v.16 no.4
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• pp.421-429
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• 2014

We consider the problem of scheduling communications in wireless sensor networks (WSNs) to ensure battery preservation through the use of the sleeping mode of sensors.We propose a communication protocol for 1-hop WSNs and extend it to multi-hop WSNs through the use of a 1-hop clustering algorithm.We propose to schedule communications in each cluster in a virtual communication ring so as to avoid collisions. Since clusters are cliques, only one sensor can speak or listen in a cluster at a time, and all sensors need to speak in each of their clusters at least once to realize the communication protocol. We model this situation as a mathematical program.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.4 s.19
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• pp.1-8
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• 2005

In this study, a numerical model combined by a river model and an inland model developed to simulated a flood event. The river model describing an inundation in a river solves the two-dimensional Saint Venant equations with a finite difference method. The inland model based on the ILLUDAS describes the conveyance capacity of a storm sewer system. The combined model is applied to a real situation. The model simulates reasonably the real flood event occurred in a river and inland simultaneously.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.79-86
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• 2018

Although the intrinsic characteristics of DNA molecules and carbon nanotubes (CNT) are well known, fabrication methods and physical characteristics of CNT-embedded DNA thin films are rarely investigated. We report the construction and characterization of carboxyl (-COOH) group-modified multi-walled carbon nanotube (MWCNT-COOH)-embedded DNA and cetyltrimethyl-ammonium chloride-modified DNA (DNA-CTMA) composite thin films. Here, we examine the structural, compositional, chemical, spectroscopic, and electrical characteristics of DNA and DNA-CTMA thin films consisting of various concentrations of MWCNT-COOH. The MWCNT-COOH-embedded DNA and DNA-CTMA composite thin films may offer a platform for developing novel optoelectronics, energy harvesting, and sensing applications in physical, chemical, and biological sciences.

• Proceedings of the Korean Society for Language and Information Conference
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• 1995.02a
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• pp.261-266
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• 1995

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.898-899
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• 2005

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.1
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• pp.363-365
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• 2015

Background: Kidney cancer is the third most frequent urologic cancer in Lebanon after prostate and bladder cancer, accounting for 1.5% of all diagnosed cancers. In this paper, we report the histologic characteristics and distribution of kidney cancer, never described in Lebanon or the Middle East. Materials and Methods: Pathology results of operated kidney cancer were collected during a two year period (2010-2011) from two different Lebanese hospitals (Hotel-Dieu de France University Hospital and Saint Joseph Hospital). A total of 124 reports were reviewed and analyzed according to WHO classification of 2009. Results: The 124 patients diagnosed with kidney cancer had a median age of 62.4 [18-86], 75% being men and 25% women. Some 71 % of the lesions were renal cell carcinoma (RCC), 25.8% had a urothelial histology, 1.6% were lymphomas and 1.6% were metastases to the kidney. Patients having RCC had a median age of 60.3 [18-85], 77.3% were men and 22.7% women. Of the RCCs, 59.1% were clear cell carcinoma, 22.7% papillary, 11.4% chromophobic, 3.4% rom the collecting ducts of Bellini and 3.4% were not otherwise classified. Conclusions: Histological distribution of Lebanese kidney cancer seems unusual when compared to the literature. The percentage of urothelial renal pelvis tumors is strikingly high. Moreover, clear cell carcinoma accounts for only 59.1% of RCCS in contrast to the 75% described elsewhere, while papillary carcinoma represents more than 22.7% compared to 10%.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1899-1902
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• 2016

Background: Despite the fact that testicular cancer is a major health issue with its increasing incidence, very few studies have described its characteristics in the Middle East, particularly in Lebanon. Materials and Methods: We report in this paper a retrospective pilot study of the characteristics of testicular cancer in Lebanon. The demographic, epidemiologic and survival characteristics of 178 patients diagnosed between 1990 and 2015 at an oncology clinic affiliated to Hotel Dieu de France Hospital were analyzed. Results: The mean age at diagnosis was $32{\pm}10years$. The most prevalent testicular tumor was the germ cell type (GCT) (95.2%) of which non-seminomatous tumors (NST) were the commonest (64.7%). Most of our patients were diagnosed at an early stage. Lymph node spread affected most commonly the retroperitoneal region and distant visceral metastases occurred in 14.6%. All patients underwent orchiectomy with 67% receiving adjuvant treatment, mainly chemotherapy. After a median follow up of 2,248 days (75.9 months) 16 patients were reported dead. Two, five and ten-year overall survival rates were 96%, 94% and 89% respectively. The median overall survival rate was not reached. Conclusions: Despite being part of the developing world, demographic, epidemiologic and survival analyses of testicular cancer reported in our study are in line with those reported from developed countries and would allow us to extrapolate management plans from these populations.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.2
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• pp.149-156
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• 2011

In this paper, a methodology is proposed to improve the stress prediction of plates via Saint Venant's principle. According to Saint Venant's principle, the stress resultants can be used to describe linear elastic problems. Many engineering problems have been analyzed by Euler-Bernoulli beam(E-B) and/or Kirchhoff-Love(K-L) plate models. These models are asymptotically correct, and therefore, their accuracy is mathematically guaranteed for thin plates or slender beams. By post-processing their solutions, one can improve the stresses and displacements via Saint Venant's principle. The improved in-plane and out-of-plane displacements are obtained by adding the perturbed deflection and integrating the transverse shear strains. The perturbed deflection is calculated by applying the equivalence of stress resultants before and after post-processing(or Saint Venant's principle). Accuracy and efficiency of the proposed methodology is verified by comparing the solutions obtained with the elasticity solutions for orthotropic beams.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.431-431
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• 2011

Graphene, two dimensional sheet of sp2-hybridized carbon, has attracted an enormous amount of interest due to excellent electrical, chemical and mechanical properties for the application of transparent conducting films, clean energy devices, field-effect transistors, optoelectronic devices and chemical sensors. Especially, graphene is promising candidate to detect the gas molecules and biomolecules due to the large specific surface area and signal-to-noise ratios. Despite of importance to the disease diagnosis, there are a few reports to demonstrate the graphene- and rGO-FET for biological sensors and the sensing mechanism are not fully understood. Here we describe scalable and facile fabrication of rGO-FET with the capability of label-free, ultrasensitive electrical detection of a cancer biomarker, prostate specific antigen/${\alpha}1$-antichymotrypsin (PSA-ACT) complex, in which the ultrathin rGO sensing channel was simply formed by a uniform self-assembly of two-dimensional rGO nanosheets on aminated pattern generated by inkjet printing. Sensing characteristics of rGO-FET immunosensor showed the highly precise, reliable, and linear shift in the Dirac point with the analyte concentration of PSA-ACT complex and extremely low detection limit as low as 1 fg/ml. We further analyzed the charge doping mechanism, which is the change in the charge carrier in the rGO channel varying by the concentration of biomolecules. Amenability of solution-based scalable fabrication and extremely high performance may enable rGO-FET device as a versatile multiplexed diagnostic biosensor for disease biomarkers.

• Journal of Korean Neurosurgical Society
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• v.46 no.3
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• pp.205-209
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• 2009

Objective : This study was conducted to investigate the correlation between the degrees of injury on brain magnetic resonance imaging (MRI) and the time interval to recovery of consciousness in patients with diffuse axonal injury. Methods : From January 2004 to December 2008, 25 patients with diffuse axonal injury were treated at our hospital. We retrospectively investigated the patients' medical records and radiological findings. We divided the patients into three groups according to the grade of MRI finding : grade I, small scattered lesions on the white matter of the cerebral hemisphere; grade II, focal lesions on the corpus callosum; and grade III, additional focal lesions on the brain stem. Result : Seven patients belonged to the grade I group; 10 to the grade II group; and 8 to the grade III group. The mean Glasgow Coma Scale (GCS) score of all patients at the time of admission was 7.28. Recovery of consciousness was observed in 23 of the 25 patients; the remaining two patients never regained consciousness. The time interval to recovery of consciousness (awake status) ranged from 1 day to 125 days (mean 22.1 days) : grade I group patients, within approximately 1 week (mean 3.7 days); grade II group patients, within approximately 2 weeks (mean 12.5 days); and grade III group patients, within approximately 2 months (mean 59.5 days). Conclusion : Our study results suggest a correlation between the mean time interval to recovery of consciousness in patients with diffuse axonal injuries and the degrees of brain injuries seen on MRI. Patients with grade I and II diffuse axonal injuries recovered consciousness within 2 weeks, while patients with grade III injuries required approximately 2 months.