• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.742-749
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• 2009

The use of cone-beam computed tomography(CBCT) has been proposed for guiding the delivery of radiation therapy. A kilovoltage imaging system capable of radiography, fluoroscopy, and cone-beam computed tomography(CT) has been integrated with a medical linear accelerator. A standard clinical linear accelerator, operating in arc therapy mode, and an amorphous-silicon (a-Si) with an on-board electronic portal imager can be used to treat palliative patient and verify the patient's position prior to treatment. On-board CBCT images are used to generate patient geometric models to assist patient setup. The image data can also, potentially, be used for dose reconstruction in combination with the fluence maps from treatment plan. In this study, the accuracy of Hounsfield Units of CBCT images as well as the accuracy of dose calculations based on CBCT images of a phantom and compared the results with those of using CT simulator images. Phantom and patient studies were carried out to evaluate the achievable accuracy in using CBCT and CT stimulator for dose calculation. Relative electron density as a function of HU was obtained for both planning CT stimulator and CBCT using a Catphan-600 (The Phantom Laboratory, USA) calibration phantom. A clinical treatment planning system was employed for CT stimulator and CBCT based dose calculations and subsequent comparisons. The dosimetric consequence as the result of HU variation in CBCT was evaluated by comparing MU/cCy. The differences were about 2.7% (3-4MU/100cGy) in phantom and 2.5% (1-3MU/100cGy) in patients. The difference in HU values in Catphan was small. However, the magnitude of scatter and artifacts in CBCT images are affected by limitation of detector's FOV and patient's involuntary motions. CBCT images included scatters and artifacts due to In addition to guide the patient setup process, CBCT data acquired prior to the treatment be used to recalculate or verify the treatment plan based on the patient anatomy of the treatment area. And the CBCT has potential to become a very useful tool for on-line ART.)

• Journal of Veterinary Clinics
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• v.31 no.2
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• pp.152-155
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• 2014

An 11-year-old castrated Schnauzer presented with paraplegia for the last two weeks, initially developed pelvic limb ataxia 6 months ago and left pelvic limb paresis 3 months ago. On neurological examination, paraplegia and postural reaction deficits were noted in the pelvic limbs with no deep pain sensation, and the dog showed exaggerated spinal reflexes and involuntary urination. Magnetic resonance (MR) images of thoracolumbar spinal cord were obtained with a 0.3 Tesla magnet. A mass with a broad base to the dorsal and left dural margins was identified at the level of L2, causing marked spinal cord compression. The mass showed isointensity to the spinal cord on T1-weighted (T1W) precontrast images, hyperintensity on T2-weighted images, marked homogeneous contrast enhancement with well-defined margins and the "dural tail" sign on T1W postcontrast images. An intradural-extramedullay tumor was considered, most likely, meningioma was highly suggestive. Left-sided hemilaminectomy and dorsal laminectomy were performed. An intradural mass partially adherent to dura mater was compressing the spinal cord, and the mass was completely removed with the attached dura mater. A histopathologic diagnosis of angiomatous subtype meningioma was made.

• Korean Journal of Psychosomatic Medicine
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• v.5 no.2
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• pp.143-150
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• 1997

This study was performed to evaluate the characteristics of smoking behavior and the effects of smoking on clinical symptoms and level of serum prolactin in schizophrenic patients. Methods : 76 male schizophrenic patients answered the questionnaire about the characteristics of smoking patterns. And patients were assessed by brief psychiatric rating scale(BPRS), positive and negative syndrome scle(PANSS), Hamilton rating scale for depression(HAM-D), assessment for involuntary movement scale(AIMS) and symptom checklist 90 R(SCL-90-R). Serum prolactin levels were measured by enzymeimmunoassay. Results: 1) The frequences of drinking coffee were significantly higher in smokers. The reasons for smoking were to relieve tension, to avoid boredom, due to habit and to do with friends. 80.1% of smokers tried quitting, but smoking was relapsed due to craving and withdrawal symptoms. 2) No significant difference was seen in mean neuropeltic doses, scores of PANSS and AIMS. But as for BPRS, scores of anxiety/depression subscale were significanly lower in smokers. Scores of HAM-D and scores of interpersonal sensitivity and phobia among SCL-90-R were significantly lower. 3) Levels of serum prolactin were significanlty lower in smokers. Conclusion : These findings suggest that in schisophrenia smoking relieves anxiety and depression subjectively But decreased prolactin levels may suggest that the possibility of increased dopamine in CNS.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.3
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• pp.287-295
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• 2016

Involuntary physical activity induced by the avoidance of electrical shock leads to improved endurance exercise capacity in animals. However, it remains unknown whether voluntary stand-up physical activity (SPA) without forced simulating factors improves endurance exercise capacity in animals. We examined the effects of SPA on body weight, cardiac function, and endurance exercise capacity for 12 weeks. Twelve male Sprague-Dawley rats (aged 8 weeks, n=6 per group) were randomly assigned to a control group (CON) or a voluntary SPA group. The rats were induced to perform voluntary SPA (lifting a load equal to their body weight), while the food height (18.0 cm) in cages was increased progressively by 3.5 every 4 weeks until it reached 28.5 cm for 12 weeks. The SPA group showed a lower body weight compared to the CON group, but voluntary SPA did not affect the skeletal muscle and heart weights, food intake, and echocardiography results. Although the SPA group showed higher grip strength, running time, and distance compared to the CON group, the level of irisin, corticosterone, genetic expression of mitochondrial biogenesis, and nuclei numbers were not affected. These findings show that voluntary SPA without any forced stimuli in rats can effectively reduce body weight and enhance endurance exercise capacity, suggesting that it may be an important alternative strategy to enhance endurance exercise capacity.

• Journal of Distribution Research
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• v.17 no.5
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• pp.39-57
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• 2012

The unabated influx of micro businesses has turned the Korean retailing market to a rat race, which causes severe financial distress for micro business owners due to heavy competition. The woes of these micro business owner's are exacerbated by the presence of large scale distributors such as Super Supermarket(SSM) and large discount stores. In summary, the Korean retail market is overburdened an uneconomically viable. Retailing has low barriers to entry which attracts unskilled labor or those with little capital. These start-ups have low opportunity costs since they would make low wages elsewhere in the economy. Thus, these owners are content with relatively low returns on their investment. These 'subsistence ventures' are maintained for economical viability rather than economic growth. These 'subsistence ventures' intensifies competition among small-scale businesses. The presence of large retail corporations also aggravates the situation. The recent stagnation of the economy has worsened the retail market in Korea. The overwhelming competition solidifies the coarse structural system and the prolonged economic sluggishness has increased the risk of insolvency for micro business owners. As the economy continues to stagnate, the imminent risk in retailing market will rise up to surface threatening economic stability. More systematic inflows and outflows of retailers are required in order to redress this structural problem. It has been empirically shown that the self-employment rate is high in Korea compared to other OECD countries. To draw the comparison of self-employment rate by industry, Korea shows high rates among transportation, whole sale, retail, education, lodging, and restaurants. In the case of the transportation and education service sectors, this high rate can be explained by the idiosyncratic nature of Korean culture. In the transportation sector, political policies favor private cap service and private freight carriers. In the education service sector, Koreans put particular emphasis on education that leads to many private institutions that outnumber other OECD countries. For these singular reasons, Korea maintains high micro business, self-employed rates particularly in retailing. A comparable nation is Japan, with its similar social, economic, cultural environment among OECD countries. Unlike Korea, Japan has much lower rates of micro business which continues to decrease. Also Korean retailers are much more destitute than Japanese. The fundamental problem of Korean retailing is the involuntary exit of these 'subsistence ventures,' micro businesses with low margins, in which a small drop in demand can lead to financial difficulties for the owner. This problem will be exacerbated when Korean babyboomers retire and join the micro business ventures. The first priority in order to cope with the severity of oversupply in retailing is to provide better opportunities for the potential self-employers. There should be viable alternatives to subsistent ventures. Strengthening the retirement program, scrutiny of exit process, reconfiguration of policy funds are the recommendations.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.1159-1166
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• 2009

The use of cone-beam computed tomography(CBCT) has been proposed for guiding the delivery of radiation therapy. A kilovoltage imaging system capable of radiography, fluoroscopy, and cone-beam computed tomography(CT) has been integrated with a medical linear accelerator. A standard clinical linear accelerator, operating in arc therapy mode, and an amorphous-silicon (a-Si) with an on-board electronic portal imager can be used to treat palliative patient and verify the patient's position prior to treatment. On-board CBCT images are used to generate patient geometric models to assist patient setup. The image data can also, potentially, be used for dose reconstruction in combination with the fluence maps from treatment plan. In this study, the accuracy of Hounsfield Units of CBCT images as well as the accuracy of dose calculations based on CBCT images of a phantom and compared the results with those of using CT simulator images. Phantom and patient studies were carried out to evaluate the achievable accuracy in using CBCT and CT stimulator for dose calculation. Relative electron density as a function of HU was obtained for both planning CT stimulator and CBCT using a Catphan-600 (The Phantom Laboratory, USA) calibration phantom. A clinical treatment planning system was employed for CT stimulator and CBCT based dose calculations and subsequent comparisons. The dosimetric consequence as the result of HU variation in CBCT was evaluated by comparing MU/cCy. The differences were about 2.7% (3-4MU/100cGy) in phantom and 2.5% (1-3MU/100cGy) in patients. The difference in HU values in Catphan was small. However, the magnitude of scatter and artifacts in CBCT images are affected by limitation of detector's FOV and patient's involuntary motions. CBCT images included scatters and artifacts due to In addition to guide the patient setup process, CBCT data acquired prior to the treatment be used to recalculate or verify the treatment plan based on the patient anatomy of the treatment area. And the CBCT has potential to become a very useful tool for on-line ART.)

• Journal of radiological science and technology
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• v.39 no.2
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• pp.149-156
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• 2016

Measurement of cardiac blood flow using the magnetic resonance imaging has been limited due to breathing and involuntary movements of the heart. The present study attempted to improve the accuracy of cardiac blood flow testing through phase contrast magnetic resonance imaging by presenting the adequate breathing method and imaging variables by comparing the measurement values of cardiac blood flow. Each was evaluated by comparing the breath hold retrospective 1NEX and non breath hold retrospective 1-3NEX in the ascending aorta and descending aorta. As a result, the average blood flow amount/velocity of the breath hold retrosepctive 1NEX method in the ascending aorta were $96.17{\pm}19.12ml/sec$, $17.04{\pm}4.12cm/sec$ respectively, which demonstrates a statistically significant difference(p<0.05) with the non-breath hold retrospective method 1NEX of $72.31{\pm}13.27ml$ and $12.32{\pm}3.85$. On the other hand, the average 2NEX blood flow and mean flow velocity is $101.90{\pm}24.09$, $16.84{\pm}4.32$, 3NEX $103.06{\pm}25.49$, $16.88{\pm}4.19$ did not show statistically significant differences(p>0.05).The average blood flow amount/ velocity of the breath hold retrospective 1NEX method in the descending aorta were $76.68{\pm}19.72ml/s$, and $22.23{\pm}4.8$, which did not demonstrate a significant difference in comparison to non-breath hold retrospective method 1-3 NEX. Therefore, the non breath hold retrospective method does not significantly differ in terms of cardiac blood flow in comparison with the breath hold retrospective method in accordance with the increase of NEX, so pediatric patients or patients who are not able to breathe well must have the diagnostic value of their cardiac blood flow tests improved.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.1
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• pp.34-42
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• 1997

Enuresis is repeated involuntary or intentional voiding of urine into bed or clothes over age 5. Though it would be a self-remitting disorder, it could be serious problem in emotional and socio-adaptational aspects. The author reviewed the enuretic patients of Child & Adolescence psychiatric section in Chungnam National University Hospital during past 3 years. 46(4.9%) of 936 patients were diagnosed as enuresis in DSM-Ⅳ. The author evaluated their comorbidity by the data of diagnostic review made in two psychiatrists, and emotional aspects(self-concept, anxiety, depression) through the self-rating scales (Piers-Harris children’ self concept scales, RCMAS, state-trait anxiety inventory for children, child’s depresson inventory). Thirty(65.2%) of the 46 enuretic patients had additional diagnoses such as attention deficit hyperactive disorder, mental retardation, encopresis, oppositional defiant disorder, depression, anxiety disorder, autism, somatoform disorder, tic disorder, obsessive-compulsive disorder, sleep disorder, etc. Sixteen enuretic patients had at least one comorbid disorder. Eleven patients had two, and three patients had more than three. Fourteen of 46 enuretic patients were evaluated through self-rating scales of self-concept, anxiety and depression. But we couldn’t obtain meaningful results. Maybe it was due to the small sample size(N＝14) and the influence of the comorbid disorders. Finally, it was an impressive evidence that there exist many comorbid disorders in enuresis(esp. attention deifict/hyperactive disorder). In emotional aspects, the author thought that further evaluation should be needed for more meaningful results.

• Investigative Magnetic Resonance Imaging
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• v.12 no.2
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• pp.123-130
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• 2008

Purpose : Motion effects in parallel magnetic resonance imaging (MRI) are investigated. Parallel MRI is known to be robust to motion due to its reduced acquisition time. However, if there are some involuntary motions such as heart or respiratory motions involved during the acquisition of the parallel MRI, motion artifacts would be even worse than those in conventional (non-parallel) MRI. In this paper, we defined several types of motions, and their effects in parallel MRI are investigated in comparisons with conventional MRI. Materials and Methods : In order to investigate motion effects in parallel MRI, 5 types of motions are considered. Type-1 and 2 are periodic motions with different amplitudes and periods. Type-3 and 4 are segment-based linear motions, where they are stationary during the segment. Type-5 is a uniform random motion. For the simulation, Cartesian and spiral grid based parallel and non-parallel (conventional) MRI are used. Results : Based on the motions defined, moving artifacts in the parallel and non-parallel MRI are investigated. From the simulation, non-parallel MRI shows smaller root mean square error (RMSE) values than the parallel MRI for the periodic (type-1 and 2) motions. Parallel MRI shows less motion artifacts for linear(type-3 and 4) motions where motions are reduced with shorter acquisition time. Similar motion artifacts are observed for the random motion (type-5). Conclusion : In this paper, we simulate the motion effects in parallel MRI. Parallel MRI is effective in the reduction of motion artifacts when motion is reduced by the shorter acquisition time. However, conventional MRI shows better image quality than the parallel MRI when fast periodic motions are involved.

• Childhood Kidney Diseases
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• v.12 no.1
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• pp.78-87
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• 2008

Purpose: Recently, the conception and cognition that enuresis was resolved spontaneously, have changed. We reviewed the attitudes of the primary care physicians who make diagnose and treat nocturnal enuresis. Methods: From January 2006 to February 2007, a total of 293 primary care physicians in Daegu city participated in this survey. Questionnaires included questions about physicians' opinions on the appropriated age for diagnosis of enuresis, the likely causes of enuresis, etc. Physicians are grouped in two according to whether enuresis is major field of their subspecialty; the pediatrician & urologist group and the other physician group. Results: 59.2% of pediatricians and urologists thought that enuresis is defined as the nightly involuntary release of urine by children of the age of 5 to 6, while 49.6% of other physicians did. For the causes of enuresis, most of clinicians checked "yes" to the question that "Under-developed bladder and nerve" and "Emotional problems". In the patient's behavioral reactions related to enuresis, "Lack of concentration in home and school" and "Frequent urination" were most responded. Attendance to the education program of enuresis in last five years and willing to participate in education program was statistically different among pediatricians-urologists and other physicians. Regarding the treatment of enuresis, most physicians used imiprarnin widely, but pediatricians and urologists preferred desmopressin. Alarm was the last one in treatment modality. Conclusion: This study revealed that pediatricians and urologists are attending more to the educational places and knowing much about the recent information on enuresis when compared to other primary care physicians, regarding the diagnostic age and treatment modality of enuresis. The education of enuresis for primary physicians is more needed.