• The Korean Journal of Nuclear Medicine
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• v.38 no.2
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• pp.171-174
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• 2004

Angiogenesis, the formation of new capillaries from existing vessels, increases oxygenation and nutrient supply to ischemic tissue and allows tumor growth and metastasis. As such, angiogenesis targeting provides a novel approach for cancer treatment with easier drug delivery and less drug resistance. Therapeutic anti-angiogenesis has shown impressive effects in animal tumor models and are now entering clinical trials. However, the successful clinical introduction of this new therapeutic approach requires diagnostic tools that can reliably measure angiogenesis in a noninvasive and repetitive manner. Molecular imaging is emerging as an exciting new discipline that deals with imaging of disease on a cellular or genetic level. Angiogenesis imaging is an important area for molecular imaging research, and the use of radiotracers offers a particularly promising technique for its development. While current perfusion and metabolism radiotracers can provide useful information related to tissue vascularity, recent endeavors are focused on the development of novel radioprobes that specifically and directly target angiogenic vessels. Presently available proges include RGD sequence containing peptides that target ${\alpha}_v\;{\beta}_3$ integrin, endothelial growth factors such as VEGF or FGF, metalloptoteinase inhibitors, and specific antiangiogenic drugs. It is now clear that nuclear medicine techniques have a remarkable potential for angiogenesis imaging, and efforts are currently continuing to develop new radioprobes with superior imaging properties. With future identification of novel targets, design of better probes, and improvements in instrumentation, radiotracer angiogenesis imaging promises to play an increasingly important role in the diagnostic evaluation and treatment of cancer and other angiogenesis related diseases.

• Nuclear Engineering and Technology
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• v.47 no.2
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• pp.196-203
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• 2015

The aim of this work is to demonstrate a method for exciting and receiving torsional and longitudinal mode guided waves with an electromagnetic acoustic transducer (EMAT) ring array. First of all, a three-dimensional guided wave simulator is developed in order to numerically analyze the propagation of the guided wave. The finite difference time domain method is used for the simulator. Second, two guided wave testing systems using an EMAT ring array are provided: one is for torsional mode (T-mode) guided wave and the other is for longitudinal mode (L-mode). The EMATs used in the both systems are the same in design. A method to generate and receive the T- and L-mode guided waves with the same EMAT is proposed. Finally, experimental and numerical results are compared and discussed. The results of experiments and simulation agree well, showing the potential of the EMAT ring array as a mode controllable guided wave transmitter and receiver.

• Carbon letters
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• v.15 no.2
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• pp.77-88
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• 2014

Double walled carbon nanotubes (DWCNTs) are considered an ideal model for studying the coupling interactions between different concentric shells in multi-walled CNTs. Due to their intrinsic coaxial structures they are mechanically, thermally, and structurally more stable than single walled CNTs. Geometrically, owing to the buffer-like function of the outer tubes in DWCNTs, the inner tubes exhibit exciting transport and optical properties that lend them promise in the fabrication of field-effect transistors, stable field emitters, and lithium ion batteries. In addition, by utilizing the outer tube chemistry, DWCNTs can be useful for anchoring semiconducting quantum dots and also as effective multifunctional fillers in producing tough, conductive transparent polymer films. The inner tubes meanwhile preserve their excitonic transitions. This article reviews the synthesis of DWCNTs, their electronic structure, transport, and mechanical properties, and their potential uses.

• Biomedical Science Letters
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• v.11 no.2
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• pp.89-101
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• 2005

Obesity is increasing worldwide and has become a major health burden in Western societies affecting every third American and every fifth European. Obesity makes a major contribution to morbidity and mortality, predisposing individuals to cardiovascular disease and diabetes. Many new substances are currently being investigated for their usefulness in the pharmacotherapy of obesity. Most anti-obesity drugs can be divided into four groups: those that reduce food intake; those that alter metabolism; those that increase thermogenesis; and those that regulate hormone involved in feeding behavior. In this article we review these and other agents available in various countries for the treatment of obesity. Perhaps more importantly, we have focussed on areas of potential productivity in the future. Over the last 5 or so years, this impetus in obesity research has provided us with exciting new drugs targets involved in the regulation of feeding behavior and cellular mechanism involved in energy expenditure. Recent development in the quest for control of human obesity include the discovery of hormones, neuropeptides, receptors and transcription factors involved in feeding behavior, metabolic rate and adipocyte development. For developing new, perhaps even more specific pharmacological agents, further research is needed to understand the individual different genetic and physiological basis of obesity. It remains the hope of research scientists that in the not too distant future we shall see a new class of anti-obesity drugs arising logically from the molecular biology revolutions.

• Korean Journal of Biological Psychiatry
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• v.18 no.4
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• pp.217-224
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• 2011

Subsyndromal bipolar symptoms are common during maintenance treatment and appear to be associated with relapse into an episode of the same polarity. This implies subsyndromal symptoms are an important problem in recurrent bipolar disorder and require more additive and infallible therapeutic intervention. Undetected, untreated subsyndromal states lead patients to have poor prognosis and quality of life. The combination of a long undetected illness and significant psychosocial impairment renders early identification and intervention vital for the treatment of bipolar disorders. Methods for early identification includes finding prodromes, using screening tools such as the HCL-32 (Hypomania Checklist-32) and the BSDS (bipolar spectrum diagnostic scale). Various augmentation treatment methods would be needed to reduce subsyndromal symptoms, especially, psychosocial treatment has the potential to help patients address the multiple psychosocial problems associated with this chronic illness. To overcome difficulties of diagnosing subsyndromal disorder and to treat it appropriately, a staging system was suggested by some researchers. It assumes that earlier stages have better prognosis and require simpler therapeutic regimens. Staging may assist in treatment planning and prognosis of bipolar disorder, and emphasize the importance of early intervention. Further research is required in this exciting and novel area.

• Tuberculosis and Respiratory Diseases
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• v.40 no.2
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• pp.91-97
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• 1993

Pulmonary surfactant is a lipoprotein complex composed primarily of phospholipid and lung specific apoproteins that reduces surface tension in the alveolus and maintains alveolar stability at low lung volume. Adult respiratory distress syndrome still carries a very high morbidity and mortality. The surfactant system is vital to the maintenance of proper lung function, any type of surfactant deficiency, whether primary or secondary, will contribute significantly to the development of pulmonary pathophysiology. Various mechanisms in adult respiratory distress syndrome may be responsible for such alterations in the surfactant system. Surfactant replacement is now an established treatment for neonatal respiratory distress syndrome, reducing both incidence of complications and mortality. With the current knowledge of surfactant physiology and the pathophysiology of the adult respiratory distress syndrome exogenous surfactant treatment or stimulation of endogenous surfactant synthesis and secretion will prove to be beneficial in preventing and treating the adult respiratory distress syndrome. The study of clinical surfactant therapy for adult respiratory distress syndrome is just beginnig and this can be viewed as an area with exciting potential. As soon as surfactant preparations become more widely available trials should begin to define the role of surfactant treatment in the adult respiratory distress syndrome as an adjunct to available treatment techniques.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.1
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• pp.13-19
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• 2001

This paper deals with decentralized control scheme and its application to multi-machine power systems. Decentralized control scheme has several practical advantages, because power system has geographically distributed characteristics. In this paper, decentralized observer-based optimal Power System Stabilizer(PSS) and Thyristor-Controlled Series Capacitor(TCST) controller are designed and tested in WSCC 9 bus system with one TCSC installed. Simulation results show that the proposed decentralized controller has satisfactory performances comparable to the centralized controller. In addition, using modal analysis, this paper shows that the proposed decentralized controller significantly affects only one pair of eigenvalues which have high participation with each generator, while slightly affects other eigenvalues. This result indicates that the application of the decentralized control scheme to enhance power system dynamic stability via excitation control have potential advantages because each low-damped mode occurs dominantly by each decentralized subsystem.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.1
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• pp.60-67
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• 2004

In this paper, a rectangular ring microstrip patch antenna has been analyzed by using desegmentation method and evaluation impedance matrices from Green's functions fur rectangular segment and desegmentation method for analysis of planar electro-magnetic structures is discussed. As the rectangular ring cavity could be seen as a structure subtracted a small rectangular cavity from a large one, the overall impedance matrix was obtained by applying a multiport connection method to the individual impedance matrices expressed as a term of Green's function fer rectangular segment. The electromagnetic fields can be solved from a vector potential which is satisfied it's eight boundary conditions. The electric field distribution at each edges was expressed as a histogram table with exciting modes. These results can be used to analyze the operational modes for a rectangular ring microstrip antennas.

• The KIPS Transactions:PartD
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• v.16D no.1
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• pp.139-144
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• 2009

Neural network is a very exciting and generic framework to develop almost all ranges of machine learning technologies and its potential is far beyond its current capabilities. Among other characteristics, neural network acts as associative memory obtained from the values structurally stored in synaptic inherent structure. Due to innate complexity of neural networks system, in its practical implementation and maintenance, multifaceted problems are known to be unavoidable. In this paper, we present design and implementation details of GUI software which can be valuable tool to maintain and develop neural networks. It has capability of displaying every state of synaptic weights with network nodal relation in each learning step.

• Journal of Ocean Engineering and Technology
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• v.27 no.5
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• pp.43-50
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• 2013

In the present investigation, the hydrodynamic characteristics of a vertically floating hollow cylinder in regular waves have been studied. The potential theory for solving the diffraction and radiation problem was employed by assuming that the heave response motion was linear. By using the matched eigenfunction expansion method, the characteristics of the exciting forces, hydrodynamic coefficients, and heave motion responses were investigated with various system parameters such as the radius and draft of a hollow cylinder. In the present analytical model, two resonances are identified: the system resonance of a hollow cylinder and the piston-mode resonance in the confined inner fluid region. The piston resonance mode is especially important in the motion response of a hollow circular cylinder. In many cases, the heave response at the piston resonance mode is large, and its resonant frequency can be predicted using the empirical formula of Fukuda (1977). The present design tool can be applied to analyze the motion response of a spar offshore structure with a moon pool.