Daegu Health College

Daegu, South Korea

Daegu Health College

Daegu, South Korea

Daegu Health College provides medical training to aspiring professionals in Daegu metropolitan city, South Korea. The current president is Nam Seong-hui . About 100 instructors are employed. Wikipedia.


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Rooh G.,Kyungpook National University | Kim H.J.,Kyungpook National University | Kim S.,Daegu Health College
IEEE Transactions on Nuclear Science | Year: 2010

In this work, we present the crystal growth and scintillation properties of our newly developed scintillation crystal, Cs2 LiCeCl6, for a γ-ray spectroscopy. This scintillation crystal is grown by using the vertical Bridgman method. The crystal of this material belongs to the elpasolite family characterized by a cubic structure and potentially can be easily grown in large volumes. Under the X-ray excitation, cerium emission band is observed to peak at 385 nm and 405 nm. An energy resolution (full width at half maximum over the peak position) of 5.5 % was observed for the 662 keV full absorption peak. We measured an absolute light yield of 22 000 photons/MeV of absorbed γ-ray energy. The crystal shows three main scintillation decay time components of 101 ns (42%), 557 ns (35%) and 2.9 μs (23%). This material is highly hygroscopic and special attention was paid during data taking and handling processes. We believe that the Cs2 LiCeCl6 crystal can be a promising material for medical imaging and radiation detection. Moreover due to the presence of Li ions, this scintillation crystal can also be a possible candidate for thermal neutron detection. © 2010 IEEE.


Patent
Samsung and Daegu Health College | Date: 2015-11-12

A wearable electronic device is provided. The wearable electronic device includes a frame, a body section connected with the frame, a display module mounted on the body section and configured to output an image, and a guide section configured to change a position of the display module in relation to the frame. The wearable electronic device may be variously implemented according to various embodiments.


Kim W.-G.,Daegu Health College | Choe H.-C.,Chosun University
Thin Solid Films | Year: 2011

The purpose of this study was to investigate the surface characteristics of hydroxyapatite (HA)/titanium (Ti) composite layer on the Ti-35Ta-xZr alloy surface by radio frequency (RF) and direct current (DC) sputtering for dental application. The magnetron sputtered deposition for the HA was performed in the RF mode and for the Ti in the DC mode. Microstructures of the alloys were examined by optical microscopy (OM) and x-ray diffractometer (XRD). Surface characteristics of coated film was investigated by field-emission scanning electron microscope (FE-SEM) equipped with an energy dispersive x-ray spectrometer (EDS), and XRD. Microstructures of the Ti-35Ta-xZr alloys were changed from α″ phase to β phase, and changed from a needle-like structure to an equiaxed structure with increasing Zr content. From the results of polarization behavior in the Ti-35Ta-15Zr alloy, HA/Ti composite layer showed the good corrosion resistance compared to Ti single layer. The results of alternating current (AC) impedance test indicated that the presence of ha coating acted as a stable barrier in increasing the corrosion resistance. © 2011 Elsevier B.V.


Kim W.-G.,Daegu Health College | Choe H.-C.,Chosun University
Applied Surface Science | Year: 2012

Electrochemical characteristics of a titanium nitride (TiN)-coated/ nanotube-formed Ti-Ta-Zr alloy for biomaterials have been researched by using the magnetic sputter and electrochemical methods. Ti-30Ta-xZr (x = 3, 7 and 15 wt%) alloys were prepared by arc melting and heat treated for 24 h at 1000 °C in an argon atmosphere and then water quenching. The formation of oxide nanotubes was achieved by anodizing a Ti-30Ta-xZr alloy in H 3PO 4 electrolytes containing small amounts of fluoride ions at room temperature. Anodization was carried out using a scanning potentiostat, and all experiments were conducted at room temperature. The microstructure and morphology of nanotube arrays were characterized by optical microscopy (OM), field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). The TiN coatings were obtained by the radio-frequency (RF) magnetron sputtering technique. The depositions were performed from pure Ti targets on Ti-30Ta-xZr alloys substrates. The corrosion properties of the specimens were examined using potentiodynamic test in a 0.9% NaCl solution by using potentiostat. The microstructures of Ti-30Ta-xZr alloys were changed from an equiaxed to a needle-like structure with increasing Zr content. The interspace between the nanotubes was approximately 20, 80 and 200 nm for Zr contents of 3, 7 and 15 wt%, respectively. The corrosion resistance of the TiN-coated on the anodized Ti-30Ta-xZr alloys was higher than that of the untreated Ti alloys, indicating a better protective effect. © 2011 Elsevier B.V. All rights reserved.


Choi J.R.,Daegu Health College | Maamache M.,Ferhat Abbas University Setif
Frontiers of Physics | Year: 2014

Quantum characteristics of a charged particle traveling under the influence of an external time-dependent magnetic field in ionized plasma are investigated using the invariant operator method. The Hamiltonian that gives the radial part of the classical equation of motion for the charged particle is dependent on time. The corresponding invariant operator that satisfies Liouville-von Neumann equation is constructed using fundamental relations. The exact radial wave functions are derived by taking advantage of the eigenstates of the invariant operator. Quantum properties of the system is studied using these wave functions. Especially, the time behavior of the radial component of the quantized energy is addressed in detail. © 2014 Choi and Maamache.


Menouar S.,Ferhat Abbas University Setif | Choi J.R.,Daegu Health College
Annals of Physics | Year: 2015

Quantum characteristics of a charged particle subjected to a singular oscillator potential under an external magnetic field is investigated via SU (1,1) Lie algebraic approach together with the invariant operator and the unitary transformation methods. The system we managed is somewhat complicated since we considered not only the time-variation of the effective mass of the system but also the dependence of the external magnetic field on time in an arbitrary fashion. In this case, the system is a kind of time-dependent Hamiltonian systems which require more delicate treatment when we study it. The complete wave functions are obtained without relying on the methods of perturbation and/or approximation, and the global phases of the system are identified. To promote the understanding of our development, we applied it to a particular case, assuming that the effective mass slowly varies with time under a time-dependent magnetic field. © 2014 Elsevier Inc.


Choi J.R.,Daegu Health College
Physics of the Dark Universe | Year: 2013

Quantum behavior of scalar fields and vacuum energy density in inflationary universe are investigated using SU(1,1) Lie algebraic approach. Wave functions describing the evolution of scalar fields thought to have driven cosmic inflation are identified in several possible quantum states at the early stage of the universe, such as the Fock state, the Glauber coherent state, and SU(1,1) coherent states. In particular, we focus in this research on two important classes of SU(1,1) coherent states, so-called the even and odd coherent states and the Perelomov coherent state. It is shown in spatially flat universe driven by a single scalar field that the probability densities in all these states have converged to the origin (φ? == 0, where φ? is the scalar field) as time goes by. This outcome implies that the vacuum energy density characterized by the scalar field dissipates with time. The probability density in the matter-dominated era converged more rapidly than that in the radiation-dominated era. Hence, we can confirm that the progress of dissipation for vacuum energy density became faster as the matter era began after the end of the early dominance of radiation. This consequence is, indeed, well agree with the results of our previous researches in cosmology (for example, see [Chin. Phys. C 35 (2011) 233] and references there in). © 2013 Jeong Ryeol Choi.


Choi J.R.,Daegu Health College
Laser Physics Letters | Year: 2013

The properties of thermal radiation fields in linear media which have time-dependent parameters are investigated on the basis of the invariant operator method. For quantum mechanical description of the electromagnetic waves whose amplitude and/or frequency vary with time, we introduce a quadratic invariant operator that is constructed according to its exact definition. The density operator of the system, being considered signal plus noise, is obtained via maximization of the entropy. The expectation values of the energy operator, the Hamiltonian, and the invariant operator are obtained in the thermal state and their thermal behaviours are illustrated in detail. It is shown that the fluctuations of the electric and the magnetic fields do not depend on signal plus noise and dissipate with time due to the conductivity in media. Our theory of wave propagation in time-varying media is applied to describe the biophoton signal in order to promote the understanding of our developments. © 2013 Astro Ltd.


Choi J.R.,Daegu Health College
Results in Physics | Year: 2013

Quantum energies for Caldirola-Kanai Hamiltonian systems with and without a singular perturbation are investigated in coherent states on the basis of invariant operator theory. Our results are compared with those of several different approaches from various angles. Further, the advantages of our method over that adopted in the previous researches are addressed in detail. © 2013 Elsevier Ltd.V.


Choi J.R.,Daegu Health College
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

Recently, Pedrosa and Rosas [Phys. Rev. Lett. 103, 010402 (2009)] investigated the quantum states of an electromagnetic field in time-dependent linear media using a Hermitian linear invariant. The wave function obtained by them is represented in terms of an arbitrary weight function g(λ l). Since the type of wave function varies depending on the choice of g(λ l) in their problem, it may be a difficult task to construct a coherent state that resembles the classical state from their theory. We suggest, on the basis of a non-Hermitian linear invariant, another quantum state that is a kind of coherent state. The expectation value of canonical variables in this alternate state follows an exact classical trajectory. For a simple case in which the time dependence of the parameters ε(t), μ(t), and σ(t) disappears, we showed that the quantum energy expectation value in the alternate quantum state recovers exactly to the classical energy in the limit h{stroke} → 0. This alternate state leads to the correspondence between the quantum and the classical behaviors of physical observables in a high-energy limit. ©2010 The American Physical Society.

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