In this study, we investigated the effect of annealing conditions on the ferromagnetic resonance(FMR) of yttrium iron garnet (Y3Fe5O12, YIG) thin film prepared on gadolinium gallium garnet (Gd3Ga5O12, GGG) substrate. The YIG thin films were grown by rf magnetron sputtering at room temperature and were annealed at various temperatures from 700 to 1000 ˚C. FMR characteristics of the YIG thin films were investigated with a coplanar waveguide FMR measurement system in a frequency range from 5 to 20 GHz. X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) were used to characterize the phase formation, crystal structure and composition of the YIG thin films. Field dependent magnetization curves at room temperature were obtained by using a vibrating sample magnetometer(VSM). The FMR measurements revealed that the resonance magnetic field was highly dependent on the annealing condition: the lowest FMR linewidth can be observed for the 800 ˚C annealed sample, which agrees with the VSM results. We also found that the Fe and O composition changes during the annealing process play important roles in the observed magnetic properties.

Muscular dystrophy is a hereditary musculoskeletal disorder caused by a mutation in the dystrophin gene. Duchenne muscular dystrophy (DMD) is one of the most common, and progresses relatively faster than other muscular dystrophies. It is characterized by progressive myofiber degeneration, muscle weakness and ultimately ambulatory loss. Since it is an X-linked recessive inheritance, DMD is mostly expressed in males and rarely expressed or less severe in females. The most effective measurement tool for DMD is magnetic resonance imaging (MRI), which allows non-invasive examination of longitudinal measurement. It can detect progressive decline of skeletal muscle size by measuring a maximal cross-sectional area of skeletal muscle. Additionally, other techniques in MRI, like T2-weighted imaging, assess muscle damage, including inflammation, by detecting changes in T2 relaxation time. Current MRI techniques even allow quantification of metabolic differences between affected and non-affected muscles in DMD. There is no current cure, but physical therapist can improve their quality of life by maintaining muscle strength and function, especially if treatment (and other forms of medical intervention) begins in the early stages of the disease.

The spinal cord is highly complex, consisting of a specialized neural network that comprised both neuronal and non-neuronal cells. Any kind of injury and/or insult to the spinal cord leads to a series of damaging events resulting in motor and/or sensory deficits below the level of injury. As a result, muscle paralysis (or paresis) leading to muscle atrophy or shrinking of the muscle along with changes in muscle fiber type, and contractile properties have been observed. Traditionally, histology had been used as a gold standard to characterize spinal cord injury (SCI)-induced adaptation in spinal cord and skeletal muscle. However, histology measurements is invasive and cannot be used for longitudinal analysis. Therefore, the use of conventional magnetic resonance imaging (MRI) is promoted to be used as an alternative non-invasive method, which allows the repeated measurements over time and secures the safety against radiation by using radiofrequency pulse. Currently, many of pathological changes and adaptations occurring after SCI can be measured by MRI methods, specifically 3-dimensional MRI with the advanced diffusion tensor imaging technique. Both techniques have shown to be sensitive in measuring morphological and structural changes in skeletal muscle and the spinal cord.

목 적 : 3.0T 자기 공명 영상에서 강자성 임플란트로 인해 발생한 자화감수성 인공음영에 대한 시퀀스별 WARP기법의 적정한 VAT(view angle tilting)값을 알아보았다. 대상 및 방법 : 자화감수성 인공음영(susceptibility artifact image)이 head용 워터 팬텀영상의 왜곡정도를 평가하기 위하여 head용 워터 팬텀에 강자성 임플란트(ferromagnetic implant)인 금속 와이어를 부착하여 영상을 획득하였다. 진행하였고(VAT(view angle tilting)) Warp를 사용하였다. 사용된 장비는 3.0T MRI system(MAGNETOM Skyra, Siemens, Munich, Germany)이었으며 20ch head/neck coil을 사용하여 TSE T2, TSE T1, FLAIR, Turbo IR T1 시퀀스에 WARP를 적용하여 VAT를 0~100% 범위내에서 10%씩 변화하여 각각 24개의 axial 영상을 얻었다. TSE T2 영상변수는 TR/TE 4410ms/79ms, Matrix 512×291이었으며, TSE T1 영상변수는 TR/TE 693ms/10ms, Matrix 512×291이었으며, Turbo IR T1 영상변수는 TR/TE 2000ms/9.5ms, Matrix 384×307이었으며, FLAIR 영상변수는 TR/TE 9000ms/96ms, Matrix 384×180이었다. 시퀀스별로 slice thickness 4mm, slice gap 0.4mm, NEX 1, bandwidth는 500Hz 였다. 정량평가는 팬텀영상의 대부분을 ROI로 설정 하여 표준편차를 구하였다. 정성 평가는 팬텀 영상 내에 dark area크기, image blurring 정도를 5점 척도로 하여 영상의 변화가 없는 경우 1점, 영상의 질이 약간 우수한 경우 2점, 보통 3점, 우수한 경우 4점, 매우 우수한 경우 5점으로 숙련된 방사선사 3명이 관찰 후 평가하였다. 결 과 : 정량분석으로 TSE T2와 TSE T1의 표준편차(SD)는 VAT 10%에서 VAT 적용전보다 많은 감소를 보였으며, VAT가 증가 할수록 감소하는 경향을 나타냈다. 그러나 IR 계열의 FLAIR와 Turbo IR T1은 WARP의 적용에 따른 영상차이가 없었다. 변동계수는 모든 시퀀스에서 30%이하였다. 또한 VAT 변화에 따라 영상의 위치변화도 나타났다. 정성분석으로 TSE T2는 VAT가 30~60%일 때 우수한 것으로 나타났고, TSE T1은 VAT가 10~70%일 때 우수한 것으로 나타났다. FLAIR와 Turbo IR T1은 WARP사용에 따른 영상의 변화가 없었다 결 론 : WARP는 TSE T2와 TSE T1의 자화감수성 인공음영을 줄이는데는 매우 효과적인 영상기법이었다. 그러나 WARP는 VAT를 증가시키면 image blurring도 증가함으로 VAT값을 최소화해서 사용 되어져야 할 것으로 사료된다.

Ischemic stroke is the most common type of stroke in humans. The purpose of this study was to evaluate the diagnostic value of magnetic resonance imaging (MRI) in a canine model of stroke. Ischemic stroke was induced by using prepared autologous thrombus. The dogs were placed in lateral recumbency on the operation table and the cervical area of each dog was sterilized by using alcohol. After making a cervical incision, the common carotid artery and internal carotid artery (a branch of the common carotid artery that supplies an anterior part of the brain) were exposed. A 200 μL injection of the autologous thrombus prepared 24 hr prior to surgery was delivered with a 20 gauge venous catheter through an internal carotid artery. After successful delivery of the autologous thrombus, the venous catheter was removed, and the cervical incision was sutured. Neurologic signs including generalized seizures, tetraparesis, and altered mental status, were observed in all 3 dogs after induction of ischemic stroke and the signs manifested immediately after awakening from anesthesia. T1- and T2-weighted images and fluid-attenuated inversion recovery (FLAIR) images of the brain were acquired 1 day before and 1 day after surgery. On the day following ischemic stroke induction, MRI revealed multifocal lesions in the cerebral cortex and subcortex such as T1 hypointensity, T2 hyperintensity, FLAIR hyperintensity, and diffusion-weighted hyperintensity in all 3 dogs. Upon postmortem examination, ischemic lesions were found to be consistent with the MRI findings and they were unstained with 2% triphenyltetrazolium chloride. Histologic features of the earliest neuronal changes such as cytoplasmic eosinophilia with pyknotic nuclei were identified. Neuropil spongiosis and perivascular cuffing were also prominently observed at the infarcted area. The present study demonstrated the features of MRI and histopathologic findings in canine ischemic stroke models.

In this study, we investigated localized surface plasmon resonance and the related coupling phenomena with respect to various geometric parameters of Ag nanoparticles, including the size and inter-particle distance. The plasmon resonances of Ag nanoparticles were studied using three-dimensional finite difference time domain(FDTD) calculations. From the FDTD calculations, we discovered the existence of a symmetric and an anti-symmetric plasmon coupling modes in the coupled Ag nanoparticles. The dependence of the resonance wavelength with respect to the inter-particle distance was also investigated, revealing that the anti-symmetric mode is more closely correlated with the inter-particle distance of the Ag nanoparticles than the symmetric mode. We also found that higher order resonance modes are appeared in the extinction spectrum for closely spaced Ag nanoparticles. Plasmon resonance calculations for the Ag particles coated with a SiO2 layer showed enhanced plasmon coupling due to the strengthened plasmon resonance, suggesting that the inter-particle distance of the Ag nanoparticles can be estimated by measuring the transmission and absorption spectra with the plasmon resonance of symmetric and anti-symmetric localized surface plasmons.

PURPOSES: The dynamic modulus can be determined by applying the various theories from the Impact Resonance Testing(IRT) Method. The objective of this paper is to determine the best theory to produce the dynamic modulus that has the lowest error as the dynamic modulus data obtained from these theories(Complex Wave equation Resonance Method related to either the transmissibility loss or not, Dynamic Stiffness Resonance Method) compared to the results for dynamic modulus determined by using the Universal Testing Machine. The ultimate object is to develop the predictive model for the dynamic modulus of a Linear Visco-Elastic specimen by using the Complex Wave equation Resonance Method(CWRM) came up for an existing study(S. O. Oyadiji; 1985) and the Optimization. METHODS: At the destructive test which uses the Universal Testing Machine, the dynamic modulus results along with the frequency can be used for determining the sigmoidal master curve function related to the reduced frequency by applying Time-Temperature Superposition Principle. RESULTS: The constant to be solved from Eq. (11) is a value of 14.13. The reduced dynamic modulus obtained from the IRT considering the loss factor related to the impact transmissibility has RMSE of 367.7MPa, MPE of 3.7%. When the predictive dynamic modulus model was applied to determine the master curve, the predictive model has RMSE of 583.5MPa, MPE of 3.5% compared to the destructive test results for the dynamic modulus. CONCLUSIONS: Because we considered that the results obtained from the destructive test had the most highest source credibility in this study, the dynamic modulus data obtained respectively from DSRM, CWRM were compared to the results obtained from the destructive test by using th IRT. At the result, the reduced dynamic modulus derived from DSRM has the most lowest error.

PURPOSES: The dynamic modulus for a specimen can be determined by using either the non-destructed or destructed testing method. The Impact Resonance Testing (IRT) is the one of the non-destructed testing methods. The MTS has proved the source credibility and has the disadvantages which indicate the expensive equipment to operate and need a lot of manpower to manufacture the specimens because of the low repeatability with an experiment. To overcome these shortcomings from MTS, the objective of this paper is to compare the dynamic modulus obtained from IRT with MTS result and prove the source credibility. METHODS: The dynamic modulus obtained from IRT could be determined by using the Resonance Frequency (RF) from the Frequency Response Function (FRF) that derived from the Fourier Transform based on the Frequency Analysis of the Digital Signal Processing (DSP)(S. O. Oyadigi; 1985). The RF values are verified from the Coherence Function (CF). To estimate the error, the Root Mean Squared Error (RMSE) method could be used. RESULTS : The dynamic modulus data obtained from IRT have the maximum error of 8%, and RMSE of 2,000MPa compared to the dynamic modulus measured by the Dynamic Modulus Testing (DMT) of MTS testing machine.. CONCLUSIONS: The IRT testing method needs the prediction model of the dynamic modulus for a Linear Visco-Elastic (LVE) specimen to improve the suitability.

As an offshore wind power turbine is bigger, a new-type supporting structure is required reduce any probability of risk such as its buckling failure. In this study, we analyzed free oscillation of ICH RC wind power tower based on the design sections in the previous study. Also, we checked the safety by resonance between designed ICH RC wind power towers and various commercial wind power turbines. The eigenvalue analysis results showed that the designed ICH RC wind power towers were free from the resonance by turbines.

This study were to perform for verifying the activation areas in the human's brain during mastication by using functional-MRI (f-MRI) device on the basis of hypothesis regarding anatomical-physiological parts of brain processing the information of motor and sensory function, and to perform further more for a providing basic provisional foundation about diagnosis, treatment and prognosis of abnormal occlusion as applying functional MRI. Generally healthy 10 volunteers who have a normal occlusion were selected. The half of members of volunteers was female. Age distributions were approximately alike. Before taking a f-MRI, sufficient practice was carried out as strict standards and made volunteers be not sensible to sweet taste of gum through chewing gum for 30 minutes before taking a f-MRI. Functional images for all volunteers were firstly obtained, and then anatomical images were next. The functional images consisted of echo-planar image volumes which were sensitive to BOLD (blood oxygenation level-dependent) contrast in axial orientation. The volume covered the whole brain with a 64×64 matrix and 42 slices. Images with 64 volumes were acquired under periodic mastication. The orofacial sensorimotor cortex was primary responsible cerebral part during mastication and insula. And also supplementary motor area and cerebellum in brain were intimately connected with mastication. Other numerous anatomical parts of brain were activated in each volunteer during mastication, but there was no statistical significance in this experiment. Differences according to gender and age were no significance in this study. The f-MRI device showed the accurate and detailed image in activation area of brain through valuable device. It suggested that f-MRI might be helpful to establish the basis of funtional standard occlusion depend on activation area of brain.

본 논문의 목적은 우리가 춤을 추고 감상하는 방식을 메를로-퐁티의 현상학을 기반으로 살펴 보고, 그의 몸 지각론을 바탕으로 춤 현상에서의 몸의 의미를 알아보는 것이다. 또한 우리가 춤 을 추고 춤을 보는 이유와 그럼으로써 춤이 존재하는 의미를 메를로-퐁티의 존재론을 바탕으로 설명하는 것이다. 이는 향후 연구에서 들뢰즈의 감각론으로 이어지는 시발점이 될 수 있을 것이다. 메를로-퐁티는 전기 연구에서 몸-주체를 내세우며 몸 지각과 우리 몸이 실제로 몸을 담고 경 험하고 있는 생활세계의 근원성을 주장하였다. 춤 공연 현장에서의 지각하는 몸은 메를로-퐁티 가 말하는 몸의 능동성, 행동하며 세계로 열려나가는 몸, 주객의 교환 관계 등을 집약적으로 경험한다. 이를 통해 메를로-퐁티는 후기의 연구에서 지각, 나아가 감각의 통일을 이야기한다. 감각 사 이의 교차를 이야기하는 이중 감각의 예에서, 봄과 만짐, 즉 감각 사이의 소통, 그리고 감각들 간의 공명 관계로써 그것들을 모두 아우르는‘하나의 감각’,‘살’, 들뢰즈의 용어로‘리듬’을 설 명한다. 몸의‘살아있음’, 그 생명력을 그 자체로 가시화하는 예술은 바로 춤이라고 할 수 있다. 본 연구는 춤의 존재론을 현상학적으로 규명해보고자 했다는 데 의의가 있다.

Micro speakers are used to reproduce sound in small electric and information and communications devices, such as cellular phones, PMPs, and MP3 players. The acoustical properties and sound quality, which are changed due to the decreased size of the speaker, are often adjusted varying the type and thickness of the diaphragm. The most widely used diaphragm material is thin polymer. It was previously reported by the author of this paper that the resonance frequency of a micro speaker is changed by the type and thickness of a polymer diaphragm. In this paper, the frequency response near the resonance frequency of a micro speaker was studied as functions of the type and thickness of the polymer diaphragm. While Rmax and RDC were affected by the type and thickness, an analysis of the electrical impedance curve revealed that Ro(= Rmax/RDC) and δf were not changed. Thus, QTS which was function of Ro, δf, and the resonance frequency, is only related to the resonance frequency. The increase of the resonance frequency led to a proportional rise of QTS. The change of the frequency response near the resonance frequency was not dependent on the type or thickness of the polymer diaphragm, but was affected by the resonance frequency.

The purpose of the study was to improve of performance for Magnetic Resonance Imaging (MRI) examination in the department of radiology. It was performed DMAIC (Define, Measure, Analyze, Improve, and Control). In the stage of definition, The fifth kinds of CTQ (critical to quality) by the kindness, the waiting time, the examination explanation, the waiting time and the waiting environment were selected by voice of customer. In the stage of measurement, the performed examinations and the reservation waiting time were measured each 1.77 and 1.69 sigma. In the stage of analysis, the potential key causes were determined the limited working hours and the difference of examination time of various entries. In the stage of improvement, MRI were performed with the operating system of 24 hours examination and the optimization of the difference of examination time by among of 30 minutes, 40 minutes, 50 minutes. Finally, the number of examinations and reserved waiting days were measured by each 3.17 and 1.71 sigma in the control stage.

Information technology devices, such as cellular phones, MP3s and so on, due to restrictions of space, require thin and small micro-speakers to generate sound. The reduction of the size of micro-speakers has resulted in the decrease of sound quality, due to such factors as frequency range and sound pressure level. In this study, the acoustical properties of oval microspeakers has been studied as a function of pattern shape on the diaphragm. The other conditions of micro-speakers, except for the pattern, was not changed. When the pattern is present on the diaphragm and the shape of pattern was a whirlwind, the resonance frequency was reduced due to the decrease of tensile strength of diaphragm. The patterns presented in the semi-minor axis of diaphragm did not effect a change of resonance frequency. However, increasing the number of patterns in the semimajor axis of diaphragm became a reason for the decrease of resonance frequency on edge side. When the depth of pattern on edge side was increased, the resonance frequency was decreased due to reduction of geometrical stiffness. If the height of edge and dome were increased, the resonance frequency and geometrical stiffness rapidly increased. After reaching the maximum values, they began to decrease with the continuous increase of height.

Since today’s digital culture deepens the tendency toward city-centric and mechanic-centric areas while individual communication is carried out mainly to be comfortable and efficient through convenient operation and management of technical civilization, it is getting difficult to experience the lingering impression derived from simplicity and timelessness of nature. As technology is rapidly developing, people tend to satisfy indirectly through visual sensation and to stay in passive lifestyle concentrating on intended transfer of culture that significantly different from the actual nature.The era of the absence of impression, sensible spirit, dialogues appealing to deep human nature, and trustful relationships implemented by sustainable ethos are possibly completed and healed by the soul of sound transcending time and space. It is necessary, in terms of succession, to identify, emphasize, and research the genre of art refreshing our age and society. We especially need to emphasize the important of the value of artistic sublimation of life and literary elements relieving human emotion and harmonizing everyday life through poetic rhythms, the source of resonance that has us recognized the culmination of representation, the beauty of scenery.Therefore, this study described there has been a rhythmical harmonization echoing to the spirit of traditional culture that inspires the soul of sound through works, concerning the role of "the human being of soul blending with the earth and heaven"between nature and human while enjoying the culture of digital era. There are several works having the spirit of sound and culture, bringing actual changes in life by adapting contemporary cultural expressions to traditional formats, and refreshing everyday life by repetitive reciting unconsciously with metric delights. In contemporary poetry of Korea, those expressions containing the soul of sound through rhythm and rhyme of transformed tradition are enjoyed and will be enjoyed by ordinary people as a form of resonance. In the present study, analysis and examination were conducted with the works of Kim Sowal who sublimated destruction and solitude in harmonization and creation by concentrating sprit, Manhae Han Yonghun who chanted the mysterious life and universe expressed by the sound of streams flowing in poetic thoughts, Yoon Dongjoo who reflected and implemented ethos by conversing with the sound of rain and wind, Kim Youngrang who sang the melody of life through the sound and the art of drums, Cheong Jiyong who recited the sound of hometown recalling nostalgic emotion of Korean, Midang Seo Jeongjoo who intoned the sound of Manpasikjuk, the flute inspiring the mystery of myth and music, and the sound of Hapjukseon from wind, and Hwang Donggye who mastered poetic transition sympathizing the process to experience the soul of sound mysteriously though lyrical poems.Further studies will be expected to continue based on this study that identified the direction of contemporary poetry and cultural historical value through the works of art that integrated the soul of sound into the aesthetics of expression.