• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.6
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• pp.673-679
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• 2012

Vehicle rollover is a serious kind of accident, particularly for sport utility vehicles, and its occurrence can be minimized by utilizing active rollover prevention systems. The performance of these protection systems is very sensitive to vehicle inertial parameters such as the vehicle's mass and center of mass. These parameters vary with the number of passengers and in different load situations. In this paper, a unified method for vehicle mass estimation is proposed that takes into account the available driving conditions. Three estimation algorithms are developed based on longitudinal, lateral, and vertical vehicle motion, respectively. Then, the three algorithms are combined to extract information on the vehicle's mass during arbitrary vehicle maneuvering. The performance of the proposed vehicle mass estimation method is demonstrated through real-time experiments.

• Archives of Craniofacial Surgery
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• v.11 no.1
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• pp.65-68
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• 2010

Purpose: Dermoid cysts are benign neoplasms that are derived from both ectoderm and mesoderm. Approximately 7 percent of all dermoid cysts occur in the head and neck, as most common sites are the lateral ends of the eyebrows, the midline in the nasal root and neck. Rarely they can be found in the frontal sinus, temporal bone, maxilla and the floor of the mouth. Dermoid cysts in the temporal fossa are extremely rare. We experienced a characteristic dermoid cyst that occupied the temporal fossa. Methods: A 16-year-old man had a progressive enlarging mass on the left eyebrow. Computerized tomographic scan showed a bulging mass in the temporal fossa, and it had the density similar to that of fat. The size of the mass was $3{\times}3{\times}2cm$, and it was composed of high density of fat with clear margin. There was no bony invasion, but the mass was fixed on bone. Results: We performed the surgery through coronal incision under general anesthesia. Because the mass was closely connected with temporal fat pads, we removed this mass with some portion of temporal fat pads, avoiding damage to the facial nerve. The postoperative course was ordinary without complication. Conclusion: The reports about dermoid cyst on the temporal fossa is uncommon. However, if there is a mass in the temporal fossa which has the density similar to that of fat in CT scan, we should consider the possibility of dermoid cyst. We suggest that excision through coronal incision with bewaring temporal fat pad can induce good result.

• Journal of the Korean Society of Radiology
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• v.18 no.4
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• pp.345-353
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• 2024

The purpose of this study was to suggest an appropriate collimation size and central X-ray incidence point by analyzing the correlation between the collimation size used in lumbar lateral examination and factors affecting the collimation size. the lumbar lateral examination results of 148 patients suitable for the purpose of this study were analyzed. The measurement method was to set the total horizontal width shown in the image to the size of the irradiation field(collimation) used during the examination. The distance connected vertically from the end of the dorsal field to the apophyseal joint of the third lumbar vertebra(AJD), the distance from the dorsal end of the image field to the center of the body of the third lumbar vertebra(BD), and the distance from the end of the dorsal field of the image to the center of the pedicle of the third lumbar vertebra(PD). The distance was measured. For comparative analysis of the mean values of dependent variables according to gender, age, height, weight, and body mass index, the mean values were compared using the independent samples t test and one-way ANOVA. For post hoc analysis, duncan was used. The correlation between independent and dependent variables was analyzed using Pearson correlation analysis. In this study, statistical significance was set at a p value of 0.05 or lower. The average value of the collimation size during the lumbar spine lateral examination was 252.45 mm, AJD was 102.11 mm, BD was 141.17 mm, and PD was 119.73 mm. The mean values of collimation size, AJD, BD, and PD were larger in men than in women, but statistical significance for the difference in mean values by gender was found only in BD (p<0.05). There was a slight difference in the mean value of each group according to age, but there was no statistical significance (p>0.05). The collimation size and mean values of AJD, BD, and PD according to height, weight, and body mass index differed depending on the independent variables, and the differences were all statistically significant (p<0.05). As a result of the correlation analysis, field size and AJD, BD, and PD showed no correlation with gender and age, a weak positive correlation with height, and a medium positive correlation with weight and body mass index. The results of this study showed that CS was correlated with height, weight, and BMI during lumbar lateral examination. If the entrance point of the central X-ray is moved to the appophyseal joint by considering weight and BMI when adjusting the collimation size in clinical practice, it is expected that the collimation size can be reduced bu about 5%.

• Journal of Korean Neurosurgical Society
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• v.42 no.4
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• pp.311-316
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• 2007

Objective : The objective of this study is to investigate the safety, surgical efficacy, and advantages of a polyaxial screw-rod system for posterior occipitocervicothoracic arthrodesis. Methods : Charts and radiographs of 32 patients who underwent posterior cervical fixation between October 2004 and February 2006 were retrospectively reviewed. Posterior cervical polyaxial screw-rod fixation was applied on the cervical spine and/or upper thoracic spine. The surgical indication was fracture or dislocation in 18, C1-2 ligamentous injury with trauma in 5, atlantoaxial instability by rheumatoid arthritis (RA) or diffuse idiopathic skeletal hyperostosis (DISH) in 4, cervical spondylosis with myelopathy in 4, and spinal metastatic tumor in 1. The patients were followed up and evaluated based on their clinical status and radiographs at 1, 3, 6 months and 1 year after surgery. Results : A total of 189 screws were implanted in 32 patients. Fixation was carried out over an average of 3.3 spinal segment (range, 2 to 7). The mean follow-up interval was 20.2 months. This system allowed for screw placement in the occiput, C1 lateral mass, C2 pars, C3-7 lateral masses, as well as the lower cervical and upper thoracic pedicles. Satisfactory bony fusion and reduction were achieved and confirmed in postoperative flexion-extension lateral radiographs and computed tomography (CT) scans in all cases. Revision surgery was required in two cases due to deep wound infection. One case needed a skin graft due to necrotic change. There was one case of kyphotic change due to adjacent segmental degeneration. There were no other complications, such as cord or vertebral artery injury, cerebrospinal fluid leak, screw malposition or back-out, or implant failure, and there were no cases of postoperative radiculopathy due to foraminal stenosis. Conclusion : Posterior cervical stabilization with a polyaxial screw-rod system is a safe and reliable technique that appears to offer several advantages over existing methods. Further biomechanical testings and clinical experiences are needed in order to determine the true benefits of this procedure.

• Journal of Acupuncture Research
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• v.30 no.5
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• pp.185-192
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• 2013

Objectives : Weight loss and loss of appetite in amyotrophic lateral sclerosis patients are common symptoms, these are associated with survival as well as nutritional condition. The changes in weight and appetite were reported after treatment using Megestrol acetate and Korean medical treatments. Methods : Amyotrophic lateral sclerosis patient with weight loss and loss of appetite were treated by administering megestrol acetate a known anti-malignant tumor agent and Korean medical treatments such as acupuncture, pharmacopuncture and herbal medicine. The changes in weight and appetite were checked using body mass index(BMI) and simplified nutritional appetite questionnaire(SNAQ). Results : There was a more than 17 kg increase in weight. BMI increased from 15.94 $kg/m^2$ to 21.97 $kg/m^2$ and SNAQ score increased from 7 to 16. Owing to several side effects, Megestrol acetate was stopped after which only Korean medical treatments were provided. After which the lasting effects in BMI and appetite could be seen. Conclusion : There are few studies on weight loss and loss of appetite in ALS patients. Using only megestrol acetate can cause several considerable side effects. Which respect to this, the findings in this study could open up new clinical guideline possibilities.

• Journal of Korean Foot and Ankle Society
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• v.19 no.4
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• pp.188-192
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• 2015

Purpose: The purpose of this study is to provide Korean data on heel pad thickness according to age, gender, underlying disease, occupation, and body mass index (BMI). Materials and Methods: A retrospective study was conducted on 670 patients who underwent foot lateral plain radiography and magnetic resonance imaging (MRI) between January 2010 and July 2014. Through measurements of heel pad thickness, the usefulness and accuracy of foot lateral plain radiography was evaluated, and the mean Korean heel pad thickness in the weight-bearing and non-weight-bearing conditions was also evaluated according to age, gender, underlying disease, occupation, and BMI. Results: The 670 subjects with a mean age of 44 years (range, 12 to 84 years) consisted of 420 males and 250 females. The difference in heel pad thickness between non-weight-bearing foot lateral plain radiography and MRI was 0.69 mm. The heel pad thickness did not show a significant difference with age (p=0.08) and the presence of diabetes (p=0.09). With the increase in the Tegner score, the thickness of the heel pad increased (p=0.035), and subjects with a higher BMI had a thicker heel pad (p=0.03). The compressibility of the heel pad thickness showed no correlation with gender, diabetes, and Tegner score. Compressibility also increased with the increase in age and body weight. Conclusion: The mean Korean heel pad thickness measured through non-weight-bearing foot lateral plain radiography was 18.79 mm. The heel pad thickness increased with increasing BMI; however, age and diabetes did not show significant correlation. The compressibility of heel pad increased with the increase in age.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.931-942
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• 1999

This paper develops a 3 DOF vehicle model which includes lateral, roll and yaw motion to study a 4WS vehicle. The model is used for the simulation of a 4WS vehicle behavior, and to derive a control algorithm for rear wheel steering. This paper uses a feedforward plus feedback control scheme to compute a rear wheel steering angle. The feedforward control scheme for computing the first rear wheel steering angle uses a gain which is acquired by multiplying a proper value on a gain to maintain a zero sideslip angle. The feedback control scheme for computing the second rear wheel steering angle uses fuzzy logic and model following control scheme. A linear 2 DOF model is used as a reference model for model following control, and is derived from the developed 3 DOF model by neglecting sprung mass roll motion. A reference state variable is yaw rate, and is computed using the linear 2 DOF model. J-turn and lane change maneuver simulation are performed to show the effectiveness of the developed control scheme. The simulation results show that the 4WS vehicle with the developed control scheme has much better performance in yaw rate, lateral acceleration, roll angle, and sideslip angle than the 2WS vehicle. Also, the results show that the performance of the developed control is close to the one of an optimal control which assumes all states are perfect.

• Journal of Trauma and Injury
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• v.25 no.4
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• pp.241-246
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• 2012

Purpose: The objective of this study was to investigate the appropriateness of the cross table lateral cervical X-ray used in the emergency department for severely traumatized Korean patients. Methods: Patients visiting our institution from May 2011 to May 2012, who had injury severity score (ISS) > 15 and who received a cervical X-ray in the emergency department, were included in this study. Data including demographics, ISS score, GCS score, and place where the x-ray was taken were collected to evaluate their relationship with appropriate coverage of the cervical X-ray. The appropriateness of a cervical cross lateral view X-ray was evaluated using exposure of the basion, and the opisthion, as well as the distal level of exposure. Results: Fifty-two patients were included in this study. The identification rate of the basion was 79.2%, and the identification rate of the opisthion was 88.7%. Complete exposure of C7/T1 was accomplished in 3.8% of the patients. The ISS was higher for X-ray taken in the trauma bay, but the range of exposure showed no difference between the places where the X-rays taken. Patients who had exposure of C 5/6 or more had lower body weight and body mass index (BMI) compared with unexposed patients. Conclusion: In severely traumatized Korean patients, the adequacy of the cross table lateral cervical X-ray was inappropriate in most cases. No difference was observed in the exposure range between the places where the X-rays were taken, and patients with less exposure showed higher body weight and higher BMI.

• Geomechanics and Engineering
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• v.16 no.6
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• pp.643-654
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• 2018

Tunnel excavation leads to a disturbance on the initial stress balance of surrounding soils, which causes convergences around the tunnel and settlements at the ground surface. Considering the effective impact of settlements on the structures at the surface, it is necessary to estimate them, especially in urban areas. In the present study, ground settlements due to the excavation of East-West Line 7 of the Tehran Metro (EWL7) and the Abuzar tunnels are evaluated and the effect of the lateral earth pressure coefficient ($K_0$) on their extension is investigated. The excavation of the tunnels was performed by TBMs (Tunnel Boring Machines). The coefficient of lateral earth pressure ($K_0$) is one of the most important geotechnical parameters for tunnel design and is greatly influenced by the geological characteristics of the surrounding soil mass along the tunnel route. The real (in-situ) settlements of the ground surface were measured experimentally using leveling methods along the studied tunnels and the results were compared with evaluated settlements obtained from both semi-empirical and numerical methods (using the finite difference software FLAC3D). The comparisons permitted to show that the adopted numerical models can effectively be used to predict settlements induced by a tunnel excavation. Then a numerical parametric study was conducted to show the influence of the $K_0$ values on the ground settlements. Numerical investigations also showed that the shapes of settlement trough of the studied tunnels, in a transverse section, are not similar because of their different diameters and depths of the tunnels.

• Journal of Chest Surgery
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• v.51 no.2
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• pp.156-158
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• 2018

Cervicothoracic thymic cysts are rare and difficult to diagnose preoperatively. We report a case of a cervicothoracic thymic cyst presenting as a lateral neck mass and mimicking a laryngocele in a 3-year-old boy and its definitive management.