• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.19-22
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• 2004

Two-dimensional modeling studies using TOUGHREACT were conducted to investigate the coupling between flow and transport developed as a consequence of differences in density, dissolution/ precipitation, and medium heterogeneity. The model includes equilibrium reactions for aqueous species, kinetic reactions between tile solid phases and aqueous constituents, and full coupling of porosity and permeability changes resulting from precipitation and dissolution reactions in porous media. Generally, the evolutions in the concentrations of the aqueous phase are intimately related to the reaction-front dynamics. Plugging of the medium contributed to significant transients in patterns of flow and mass transport.

• Journal of Chest Surgery
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• v.17 no.1
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• pp.140-143
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• 1984

We have experienced 30 patients of tuberculous chest wall abscess which was surgically treated at Kyung Hee University hospital during 6 years from Jan, 1978 to Dec, 1983. We analyze 30 cases of clinical findings and surgically treated, and 20 cases of chest X-rays are available. The results of this sturdy are as follows: 1.Sex ratio ; Male: Female = 1:1.72. 2.Chief complaints are fluctuated mass with or without tenderness or pain and pus from wound. 3.Out of 20 cases of chest x-rays revealed 8 cases of osteolytic lesion, 11 cases of soft tissue swelling, 5 cases of pleural changes and 4 cases of negative findings. 4.We resected partially 43 ribs of 30 patients [average: 1.43 resected] in tuberculous chest wall abscess. 5.Operative methods of tuberculous chest wall abscess were partial resection of destructed or denuded periosteum of ribs and curettage of its surrounding tissues in operative field.

• Journal of Chest Surgery
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• v.18 no.3
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• pp.470-473
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• 1985

We performed clinical analysis about 20 cases of pulmonary parenchymal and intrabronchial hamartoma in Korea by literatures of the Korean Journal of Thoracic and Cardiovascular Surgical Society during 8 years from September 1976 to September 1984 and in addition to our hospital experienced 4 cases of pulmonary parenchymal hamartoma during same periods. 1] There were no cases below second decades. 2] Patients of pulmonary parenchymal hamartoma were asymptomatic, but patients of intrabronchial hamartoma were symptomatic [dyspnea & frequent upper respiratory tract infections]. 3] Pulmonary parenchymal hamartoma were confirmed by removal of mass, but intrabronchial hamartoma were confirmed by bronchoscopic biopsy. 4] There were no malignant changes in both type of pulmonary hamartoma.

• Journal of Biosystems Engineering
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• v.21 no.3
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• pp.293-305
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• 1996

Effects on the tractor vibrations of tread, wheelbase and axle load distribution were analyzed by using mathematical models of tractor and random road surface. A 4 degrees of freedom tractor model was developed to predict the bounce, pitch and roll motions of tractor. The front axle which is constrained to roll with respect to tractor body was also included in the model. A random road profile was generated and used as an excitation input to the tractor. Output vibrations of the model were predicted and analyzed by a computer simulation method. In general, longer tread tends to reduce rolling and longer wheelbase does bouncing and pitching motions. Tractor vibrations were minimum when the ratio of front to rear axle loads was in the range of 30:70-35:65. Sensitivity analysis showed that rolling and pitching motions most sensitively varied with changes in tread and wheelbase while bouncing motion did with the location of mass center.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.11a
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• pp.144-147
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• 2003

It is important to understand the process of technology diffusion among end users for effectively implementing adoption and coping with frequent changes in the environment. Previous studies indicate that information and communication technology (ICT) adoption is affected by innovation influence such as usefulness, ease of use and self-efficacy. Most of these studies, however, bypassed imitation influence such as subjective norms, word-of-mouth, and advertising, specifically, interactive innovation having critical mass in technology acceptance research. Thus, this study investigates imitation influence in individual adoption of mobile communication technology, more specifically, mobile phones, using Mahaian's diffusion model in individual ICT adoption.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.515-518
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• 2003

Mathematical models can be used to evaluate the effects of operational alternatives of dam on the downstream aquatic environment. An unsteady, one-dimensional water quality model, CE-QUAL-RIVI was calibrated and validated in Geum river as a sub model for the realtime water management system in the basin. The main usage of the model within the system is to predict the effects of flow regulation by Daecheong Dam on the downstream water quality. The validated model was then used to simulate dynamic water quality changes at several key stations responding to different scenarios of reservoir releases under a hypothetical spill condition. The model showed fairly good performance in the simulation of hydrodynamic and mass transport processes under highly unsteady conditions.

• Geomechanics and Engineering
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• v.8 no.3
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• pp.377-390
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• 2015

The governing equations of wave propagation in one dimension of elastic continuum materials are investigated by taking the influence of the initial stress into account. After a short review of the theory of elastic wave propagation in a rock mass with an initial stress, results indicate that the initial stress differentially influences P-wave and S-wave propagation. For example, when the initial stress is homogeneous, for the P-wave, the initial stress only affects the magnitude of the elastic coefficients, but for the S-wave, the initial stress not only influences the elastic coefficients but also changes the governing equation of wave propagation. In addition, the P-wave and S-wave velocities were measured for granite samples at a low initial stress state; the results indicate that the seismic velocities increase with the initial stress. The analysis of the previous data of seismic velocities and elastic coefficients in rocks under ultra-high hydrostatic initial stress are also investigated.

• Journal of the Korean Society of Combustion
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• v.23 no.1
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• pp.44-54
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• 2018

Heat and mass balance process modeling has been conducted for a coal-firing power plant to be used as a testbed facility for development of various plant systems and equipment. As the material and design of the boiler tube bundle and fuel conversion to the biomass have become major concerns, the process modeling is required to incorporate those features in its calculation. The simulation cases for two different generation load show the satisfying results compared to the operational data from the actual system. Based on the established process conditions, the hypothetical case using wood pellet has also been simulated. Additional calculations for the tube bundle has been conducted regarding the changes in the tube material and design.

• Journal of Nutrition and Health
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• v.30 no.2
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• pp.177-186
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• 1997

To evaluate the effectiveness of nutritional supplements for cancer patients, the study was performed in 30 cncer patients, receiving chemotherapy. Patients were randomly divided into two groups -15 patients for the nutritionally supplemented group and 15 patients for the control group. Patients of the supplemented group were nutritionally supported with a commercial product for 9 weeks. Nutritional status of the patients was detrmined by dietary intake data, anthropometric measurements and hematological analysis at the beginning and after 3, 6 and 9 weeks of supplemental priod. Mean daily intake levels of energy, protein, calcium, phosphorus, thiamin, riboflavin, niacin and asorbic acid for the supplemented group were significantly higher than those of control group. Significant increase in mid-arm circumference, triceps skinfold thickness and arm fat area were observed in supplemented group during the study period. However, the changes of body weight, body mass index and arm muscle area were not significantly increased. Serum transferrin level improved slightly by nutritioal support, but serum albumin levle did not change significantly. There data show that nutritional status of cancer patients receiving chemotherapy can be improved by utritional supplementation for 9 weeks.

• Journal of Korean Neurosurgical Society
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• v.57 no.6
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• pp.487-490
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• 2015

We report a 10-year-old boy with supratentorial cortical ependymoma that rapidly grew in the course of 3 years. He suffered generalized seizures when he was 5 years old; MRI showed a small cortical lesion in the right postcentral gyrus. MRI performed 2 years later revealed no changes. For the next 3 years he was free of seizures. However, at the age of 10 he again suffered generalized seizures and MRI disclosed a large parietal tumor. It was resected totally and he remains free of neurological deficits. The histopathological diagnosis was ependymoma. Pediatric supratentorial cortical ependymomas are extremely rare. We recommend including cortical ependymoma as a differential diagnosis in pediatric patients with cortical mass lesions presenting with seizures and careful follow-up even in the absence of symptoms because these tumors may progress.