• Journal of Magnetics
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• v.17 no.2
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• pp.158-162
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• 2012

Although 3.0T magnetic resonance imaging (MRI) has the advantages of a higher signal to noise ratio (SNR) and contrast than 1.5T MRI, there are limitations on the contrast between white and grey matter because of the long T1 recovery time when T1 images are obtained using the Spin Echo Technique. To overcome this, T1 weighted images are obtained occasionally using the inversion recovery (IR) technique, which employs a relatively long TR. The aim of this study was to determine the optimal TI in a brain examination when a T1 weighted image is obtained using the IR technique. Eight participants (male: 7, female: 1, average age: $34{\pm}14.11$) with a normal diagnosis were targeted from February 18, 2012 to February 27, 2012, and the contrast between white and grey matter as well as the contrast to noise ratio (CNRs) in each participant were measured. The CNRs of white matter and grey matter were highest at TI = 600, 650, 750, 900, 1050 and 1100 ms when the TR was 1100, 1400, 1700, 2000, 2300 and 2600 ms, respectively. Therefore, as the TIs were $44.425{\pm}0.877%$ of the TRs in the TR range of 1400-2300 ms, the optimal T1 weighted images that describe the contrast between white and grey matter can be obtained if the TIs are compensated for with $44.425{\pm}0.877%$ of the TRs in the time of setting TIs.

• Science of Emotion and Sensibility
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• v.20 no.4
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• pp.113-126
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• 2017

The purpose of the study was to find grey matter (GM) and white matter (WM) volume reduction in the brain reward system among patients with alcohol dependency. This study investigated regional GM and WM in chronic alcoholic patients, focusing primarily on the reward system, including principal components of the mesocorticolimbic reward circuit as well as cortical areas with modulating and oversight functions. Sixteen abstinent long-term chronic alcoholic men and demographically matched 16 healthy control men participated in the study. Morphometric analysis was performed on magnetic resonance brain scans using voxel-based morphometry (VBM)-diffeomorphic Anatomical Registration through Exponentiated Liealgebra (DARTEL). We derived GM and WM volumes from total brain and cortical and subcortical reward-related structures. Morphometric analyses that revealed the total volume of GM and WM was reduced and cerebrospinal fluid (CSF) was increased in the alcohol group compared to control group. The pronounced volume reduction in the reward system was observed in the GM and WM of the nucleus accumbens (NAc), GM of the amygdala, GM and WM of the hippocampus, WM of the thalamus, GM and WM of the insula, GM of the dorsolateral prefrontal cortex (DLPFC), GM of the orbitofrontal cortex (OFC), GM of the cingulate cortex (CC), GM and WM of the parahippocampal gyrus in the alcohol group. We identified volume reductions in WM as well as GM of reward system in the patients with alcohol dependency. These structural deficits in the reward system elucidate underlying impairment in the emotional and cognitive processing in alcoholism.

• Investigative Magnetic Resonance Imaging
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• v.4 no.2
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• pp.128-135
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• 2000

Purpose : The aim of this study is to develope the Magnetic Resonance Spectroscopy(MRS) data processing S/W which plays an important role as a diagnostic tool in clinical field. Materials and methods : Post-processing software of MRS based on graphical user interface(GUI) under windows operating system of personal computer(PC) was developed using MATLAB(Mathwork, U.S.A.). This tool contains many functions to increase the quality of spectrum data such as DC correction, zero filling, line broadening, Gauss-Lorentzian filtering, phase correction, etc. And we obtained the normal human brain $^1H$ MRS data from parietal white matter, basal ganglia and occipital grey matter region using 1.5T Gyroscan ACS-NT R6 (philips, Amsterdam, Netherland) MRS package. The analysis of the MRS peaks were performed by obtaining the ratio of peak area. Results : The peak ratios of NAA/Cr, Cho/Cr, MI/Cr for the different MRS machines have a little different values. But these peak ratios were not significantly different between different echo time MRS peak ratios in the same machine (p<0.05). Conclusion : MRS post-processing S/W based on GUI using PC was developed and applied to the analysis of normal human brain $^1H$ MRS. This independent MRS processing job increases the performance and throughput of patient scan of main console. Finally, we suggest that the database for normal in-yivo human MRS data should be obtained before clinical applications.

• Advances in Energy Research
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• v.7 no.1
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• pp.35-52
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• 2020

The paper proposes a hybrid approach of artificial bee colony (ABC) and grey wolf optimizer (GWO) algorithm for multi-objective and multidimensional engine optimization of a converted plug-in hybrid electric vehicle. The proposed strategy is used to optimize all emissions along with brake specific fuel consumption (FC) for converted parallel operated diesel plug-in hybrid electric vehicle (PHEV). All emissions particulate matter (PM), nitrogen oxide (NOx), carbon monoxide (CO) and hydrocarbon (HC) are considered as optimization parameters with weighted factors. 70 hp engine data of NOx, PM, HC, CO and FC obtained from Oak Ridge National Laboratory is used for the study. The algorithm is initialized with feasible solutions followed by the employee bee phase of artificial bee colony algorithm to provide exploitation. Onlooker and scout bee phase is replaced by GWO algorithm to provide exploration. MATLAB program is used for simulation. Hybrid ABC-GWO algorithm developed is tested extensively for various values of speeds and torque. The optimization performance and its environmental impact are discussed in detail. The optimization results obtained are verified by real data engine maps. It is also compared with modified ABC and GWO algorithm for checking the effectiveness of proposed algorithm. Hybrid ABC-GWO offers combine benefits of ABC and GWO by reducing computational load and complexity with less computation time providing a balance of exploitation and exploration and passes repeatability towards use for real-time optimization.

• The Korean Journal of Petroleum Geology
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• v.12 no.1
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• pp.1-8
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• 2006

Jiaolai Basin is the Cretaceous continental sedimentary basin developed in Shandong Province of China. It is interpreted as a pull-apart basin which is filled with fluvio-lacustrine sediments and volcanic rocks. The sedimentary strata are divided into three formations: Laiyang Formation, Qingshan Formation and Wangshi Formation in ascending order. Laiyang Formation of the early Cretaceous consists of conglomerate, sandstone and shale, which are grey, black or red in color, respectively. Qingshan Formation of early Cretaceous includes various kinds of volcanic rocks. Late Cretaceous Wangshi Formation consists of red conglomerate, sandstone and shale. Various types of oil shows are observed on many outcrops in the basin such as asphalt filing fissures, oil smelling, rocks wetted with oil. However, commercial oil discovery was not made. Laiyang Formation is the richest in terms of organic matter contents. Some grey or black shales of Laiyang Formation contain more than 1% of organic matter. Kerogens of some layers mainly consist of amorphous organic matter or pollen. Thermal maturity of the organic matter reached main oil generation zone and hydrocarbon genetic potential is fairly good. According to such geochemical data, some layers of Laiyang Formation can act as hydrocarbon source rocks.

• Journal of Veterinary Clinics
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• v.21 no.2
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• pp.177-180
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• 2004

Lower motor neuron signs of hind limbs, anus and bladder were identified by history taking and physical examination in the 6.8 year-old mongrel dog and 2.6 year-old Cocker spaniel. The Cocker spaniel, also showed gradual cranial migration of neurologic deficit including respiratory paralysis. On plain radiography and myelography, intervertebral disc extrusion between L2 and L3, the infiltration of contrast medium into the spinal cord and cord swelling were found in the mongrel dog, and infiltration of contrast medium like hollowness of cord parenchyma was observed in the Cocker spaniel. On the basis of clinical signs and radiographic findings, they were diagnosed tentatively as acute myelomalacia. The Cocker spaniel died of respiratory paralysis on the following day. Decompressive surgery was performed on the mongrel dog and the extensive necrosis and hemorrhage were found at surgery. It was euthanized with the owner's consent because of the perceived poor prognosis. Histopathologic examination after autopsy confirmed acute diffuse hemorrhagic myelomalacia with the swelling and the inflammation of axon, showing hemorrhagic changes in the white matter and the grey matter.

• Investigative Magnetic Resonance Imaging
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• v.18 no.2
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• pp.167-170
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• 2014

The medial longitudinal fasciculus (MLF) is myelinated composite tract, lying near the midline, ventral to periaqueductal grey matter that plays a key role in coordinating eye movements. A lesion of the MLF results in an ipsilateral adduction deficit and a contralateral abducting nystagmus, referred to as an internuclear ophthalmoparesis. The blended tract with adjacent white matter in pons and midbrain is indistinguishable on brain imaging such as CT and MRI. Until now, to the best of our knowledge, MLF is not delineated on in vivo MRI. We present a case showing the whole connecting courses of MLF lesion on MRI in a patient with inflammatory demyelinating disorder.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10b
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• pp.466-468
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• 2001

의료 영상 처리 기술은 질병의 진단 및 치료를 위한 계획이나 방법을 결정하는데 있어 매우 중요한 역할을 하고 있으며 의료 영상 시스템과 같은 활용 분야에서는 질병이 있는 환자의 자동 진단을 위한 연구도 활발하게 이루어지고 있다. 여기서는 뇌 MR영상에서의 질병을 자동 진단할 수 있는 방법에 관한 연구를 한다. 뇌 MR영상에서의 질병 진단을 위한 단계로서 필수적으로 이루어져야 하는 단계가 비정상 영역의 추출 단계이다. 이 논문에서는 뇌의 질병 진단에 사용할 수 있는 자료를 제공하기 위한 전처리 단계로서 질병이 있는 환자의 뇌 영상에서 비정상적인 영역 추출 방법을 제안한다. 일반적으로 비정상적인 영역의 명암간 분포는 회백질 영역의 분포와 유사하나 두께 차이로서 구분이 가능하다. 여기서는 이 정보를 활용하여 정상인의 뇌영상에 대해서 회백질의 평균 두께 분포를 구하여 테스트로 입력되어지는 영상에서 회백질의 평균 두께 이상의 영역만을 남김으로서 질병이 있는 환자의 뇌 영상에서 비정상적인 영역을 추출할 수 있음을 보인다. 또한 추출되어진 비정상 영역에 대해서 진단에 필요한 인자를 자동으로 측정하였고 뇌경색, 뇌종양 환자를 포함한 63명의 뇌 MR 영상 시리즈에 대해서 실험하여 비교적 정확한 추출결과를 유도할 수 있었음을 확인하였다.

• Nuclear Engineering and Technology
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• v.53 no.11
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• pp.3772-3783
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• 2021

This work proposes a new efficient meta-heuristic optimization algorithm called Gamma Ray Interactions Based Optimization (GRIBO). The algorithm mimics different energy loss processes of a gamma-ray photon during its passage through a matter. The proposed novel algorithm has been applied to search for the global minima of 30 standard benchmark functions. The paper also considers solving real optimization problem in the field of nuclear engineering, radioisotope identification. The results are compared with those obtained by the Particle Swarm Optimization, Genetic Algorithm, Gravitational Search Algorithm and Grey Wolf Optimizer algorithms. The comparisons indicate that the GRIBO algorithm is able to provide very competitive results compared to other well-known meta-heuristics.

• Korean Journal of Veterinary Research
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• v.25 no.2
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• pp.103-112
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• 1985

A total of 1-0 colostrum-deprived pigs (1 or 2-day-old) and 6 pigs (35-day-old), which had been raised by natural maternal nursing, were used to study the pathogenicity of the porcine enteroviruses by the intracerebral and intramuscular routes of inoculation, which the enterovirus were isolated from the diseased pigs in Korea. The porcine enteroviruses produced an identical polioencephalomyelitis in colostrum-deprived pigs and 35-day-old pigs, which manifested clinical signs and histopathological changes. Clinically it was characterized by incoordination, rise in rectal temperature, ataxia, flaccid paralysis in all the experimental groups. Histopathologically, the lesions were present in both grey and white matter at all levels of central nervous system, though usually more severe in the grey matter. These changes were characterized by meningeal infiltration, degeneration of nerve cells, neuronophagia, diffuse and focal gliosis, glial nodules and perivascular lymphocytic infiltrations. Ganglionitis of the dorsal root ganglia was frequently observed. On the basis of the clinical and histopathological changes mentioned above, it was concluded that porcine enteroviruses isolated in Korea were pathogenic strains which could produce polioencephalomyelitis in pigs. The most severe Jisease was prcduced by the inoculation of both enterovirus and hog cholera vaccine in the 35-day-old pigs at a time when colostral immunity presumably was low. The porcine enterovirus infections seemed to be associated with certain stress factor such as hog cholera vaccine in or immediately following the weanling period.