• Journal of Digital Convergence
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• v.12 no.5
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• pp.139-148
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• 2014

In recent years, computational models using parametric estimation method have been developed and used widely for efficient cost analysis. In this research, by applying experienced data from Guidance and Control Systems in Missile System field, the cost analysis for engineering model and commercial computational model(Price H, HL, M, S) are conducted and its result is analysed, so that the difference between two models and its grounds are apprehended. Comparing the calibrated value of computational model based on the data base of similar equipment and the cost from the engineering estimation, the two results are very close. It means that the credibility of data is enhanced through calibration. Also, for cost analysis of similar components in the future, the method for calibration of the computational models is also examined. When estimating development cost in this research, although many parts have been estimated through uncertain elements, the reliability could have been enhanced by applying computational model which secures objectivity. It is a very reasonable estimation method by utilizing calibration of the computational models based on existing accumulated development data.

• Geomechanics and Engineering
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• v.30 no.1
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• pp.93-105
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• 2022

With the exploitation of natural resources in China, underground resource extraction and underground space development, as well as other engineering activities are increasing, resulting in the creation of many defective rocks. In this paper, uniaxial compression tests were performed on rocks with double holes and fractures at different angles using particle flow code (PFC2D) numerical simulations and laboratory experiments. The failure behavior and mechanical properties of rock samples with holes and fractures at different angles were analyzed. The failure modes of rock with defects at different angles were identified. The fracture propagation and stress evolution characteristics of rock with fractures at different angles were determined. The results reveal that compared to intact rocks, the peak stress, elastic modulus, peak strain, initiation stress, and damage stress of fractured rocks with different fracture angles around holes are lower. As the fracture angle increases, the gap in mechanical properties between the defective rock and the intact rock gradually decreased. In the force chain diagram, the compressive stress concentration range of the combined defect of cracks and holes starts to decrease, and the model is gradually destroyed as the tensile stress range gradually increases. When the peak stress is reached, the acoustic emission energy is highest and the rock undergoes brittle damage. Through a comparative study using laboratory tests, the results of laboratory real rocks and numerical simulation experiments were verified and the macroscopic failure characteristics of the real and simulated rocks were determined to be similar. This study can help us correctly understand the mechanical properties of rocks with defects and provide theoretical guidance for practical rock engineering.

• Journal of the Korean Society of School Health
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• v.8 no.2
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• pp.293-303
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• 1995

Health has occupied a position of importance in the human history, whether it be in the East or in the West, and it is a subject in which people have been constantly interested. The concept of health has changed continuously as the society has developed, industrialized and become more structured. The perception of health concept can be an esential factor which is to determine the health behaviors. This study is a descriptive inquiry done to identity high school students' perception of health and what they do as health behaviors. The subject consisted of 503 voctional high school seniors, 129 boys and 374 girls, from a school located in An-san Si, kyong-gi Do. The instruments used for this study were open-ended questionnaires and data were collected by having the students fill out the questionnaires which took 10 minutes, in their first class, April 6, 1995. The collected materials were classified and recorded on the cards according to each question using the terms which students had written. After putting statements which had common meanings together, the representative categories were labelled. The results obtained are as follows. 1. Categorizing and labelling of health concepts What high school students descripted as health concepts were classified as the absence of illness, physical comfort, strong physical strength and physique, not having a deformity, resisting power, self control mental-rest(or psychological comfort), wholesome ideas, self-control, harmony in body and in mind, maintenace of daily life, pleasant life, good friends, peaceful family life and realizing objectives. 2. Categorizing and labelling of health behaviors These were classified as preventive life, good dietary habits and regimen, maintenance of clean body, exercises, preventing obesity, rest, environmental balance or control of environment, limit one's tastes, making use of leisure, peaceful mind, sound thought and regular living habits. The result indicates that the health concepts were positive and included not only absence of illness but also harmony in body and in mind and pleasant life; health behaviors which had high frequency were good dietary habits and regimen, exercises and sound thought. It is hoped that these findings well serve as practical references for teachers when they counsel with, and provide the students with guidance programs which include health care.

• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.307-313
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• 2018

In this study, analyzed the effect of the introduction and operation of internal control system of a company on accounting information usefulness in a rapidly changing business environment. In order to conduct this study, we studied a comprehensive analysis on the usefulness of internal control and accounting information, and applied the research model to the purpose of this study. In this study, we analyzed the degree of the relationship between variables based on the discretionary accruals of the modified Jones model using the internal control evaluation index based on the components of the internal control system for China. In the empirical analysis, analyzed that the operation of internal control has a negative influence on discretionary accruals, which is a substitute for usability of accounting information. In addition, the risk management factors of the internal control system have a negative correlation with the usefulness of accounting information. The results of this study suggest that it is possible to present the positive function of internal control system to many firms where the introduction and operation of internal control is important, and to provide useful guidance in the study of the relationship between the operation of internal control and discretionary accruals for foreign company.

• Geomechanics and Engineering
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• v.28 no.4
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• pp.335-346
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• 2022

Buckling failure is a typical slope instability mode that should be paid more attention to. It is difficult to provide systematic guidance for the monitoring and management of such slopes due to unclear mechanism. Here we examine buckling failure as the potential instability mode for a slope above a railway tunnel in southwest China. A comprehensive model test system was developed that can be used to conduct buckling failure experiments. The displacement, stress, and strain of the slope were monitored to document the evolution of buckling failure during the experiment. Monitoring data reveal the deformation and stress characteristics of the slope with different slipping mass thicknesses and under different top loads. The test results show that the slipping mass is the main subject of the top load and is the key object of monitoring. Displacement and stress precede buckling failure, so maybe useful predictors of impending failure. However, the response of the stress variation is earlier than displacement variation during the failure process. It is also necessary to monitor the bedrock near the slip face because its stress evolution plays an important role in the early prediction of instability. The position near the slope foot is most prone to buckling failure, so it should be closely monitored.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.11.1-11.8
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• 2020

Background: The purpose of this study is to compare the skeletal stability of two-jaw surgery via surgery-first approach with conventional two-jaw surgery in facial asymmetry patients by measuring the skeletal changes after surgery from a three-dimensional analysis. From January 2010 to January 2014, 40 patients with facial asymmetry who underwent two-jaw surgery in Pusan National University Hospital were included in this study. They were classified into experimental group (n = 20) who underwent two-jaw surgery via surgery-first approach and control group (n = 20) who underwent conventional two-jaw surgery. After selection of 24 landmarks and the construction of horizontal and sagittal, coronal reference planes, changes in 10 linear measurements and 2 angular measurements were compared between the surgery-first approach and conventional groups in the preoperative, immediate postoperative, and postoperative periods. The paired t test and Student t test were used for statistical analysis. The mean and standard deviation of the measurement were calculated for the experimental and control groups. Results: The statistical analysis showed that changes in skeletal measurements were similar between the surgery-first approach and conventional groups, according to each period. However, U1-SRP measurement showed statistically significant changes in surgery-first approach groups at postsurgical change (T1 to T2). Also, the mean treatment duration in the treatment group was 15.9 ± 5.48 months whereas that in the control group was 32.9 ± 14.05 months. Conclusion: In facial asymmetry patients, similar results were observed in the postoperative skeletal stability when 2-jaw surgery via surgery-first approach was compared with conventional 2-jaw surgery. However, significant lateral deviation of upper incisor midline was observed. In addition, a shorter average treatment duration was observed. To stabilize the unstable occlusion after surgery, increased wearing of the stent and proactive rubber guidance will be needed.

• The Korean Journal of Pain
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• v.19 no.2
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• pp.168-174
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• 2006

Background: Several biochemical mediators, such as substance P, calcitonin gene-related peptide (CGRP) and prostaglandin $E_2$, have been demonstrated to be involved in herniated or degenerated disc-induced radiculopathy. The authors tested the hypothesis that these mediators would existed in the epidural space of humans. Methods: Thirty nine patients were divided into two groups; 27 patients, who were diagnosed with spinal stenosis (stenosis group), and 12 scheduled for epidural anesthesia, without a history of back pain (control group). Under fluoroscopic guidance, an epidural catheter was introduced through the caudal space and placed into the anterior and posterior spaces, up to and around the epidural adhesive area, in the stenosis group. In the control group, the catheter was placed into the posterior epidural space through the L3⁣-4 or L4⁣-5 intervertebral space. Epidural irrigation was performed with 10 ml of saline, via an epidural catheter. Aspirated lavage fluid was collected, and the concentrations of biochemical mediators (substance P, CGRP and prostaglandin $E_2$) measured using an enzyme immunoassay kit. Results: Substance P, CGRP and prostaglandin $E_2$ were detected in all the epidural lavage fluids from both groups. The concentrations of substance P and prostaglandin $E_2$ in the stenosis group were higher than those of the control (P < 0.05). However, there was no difference in the CGRP levels between the two groups. In the stenosis group, the concentrations of these three mediators in the anterior epidural space were no different to those in the posterior space. Conclusions: These results suggest that biochemical mediators, such as substance P and prostaglandin $E_2$, in the epidural space might be partly involved in pain mechanism associated with spinal stenosis.

• Journal of the Korean Society of School Health
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• v.29 no.1
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• pp.11-21
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• 2016

Purpose: The purposes of this study were to check the obesity of middle and high school students in the nation and identify factors influencing their obesity. Methods: The present study is a secondary analysis research that obtained permission to use the primitive data of 10th (2014) Online Survey on Adolescents' Health Behaviors by the Korea Centers for Disease Control and Prevention and analyzed the primitive data according to the purposes. Results: The findings show that the BMI of middle and high school students in the nation was $20.7kg/m^2$ with the obesity and non-obesity group recording $27.0kg/m^2$ and $19.9kg/m^2$, respectively. Factors influencing the obesity of adolescents include gender, grade, educational background of parent, school grades for the last 12 months, satisfaction with sleep, fast food consumption, ramen consumption, intense and muscle exercise three times a week or more, subjective sense of health, stress, suicidal ideation, and hours of Internet usage per week. Conclusion: For the management of adolescent obesity, there is a need for obesity management programs taking the characteristics of male students into consideration. The possibilities of obesity grow according to the grades, which means that both the teachers and parents should offer more guidance on weight control in upper grades. The adjustment of adolescent obesity requires psychological health management including stress and suicidal ideation as well as diet control and exercise. It is also needed to apply a stepwise obesity management program according to the hours of internet usage and dependence on the internet

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.8
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• pp.859-866
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• 2009

The article discusses an issue of estimating the airspeed of an autonomous flying vehicle. Airspeed is the difference between ground speed and wind speed. It is desirable to know any two among the three speeds for navigation, guidance and control of an autonomous vehicle. For example, ground speed and position are used to guide a vehicle to a target point and wind speed and airspeed are used to maximize flight performance such as a gliding range. However, the target vehicle has not an airspeed sensor but a ground speed sensor (GPS/INS). So airspeed or wind speed has to be estimated. Here, airspeed is to be estimated. A vehicle's dynamics and its dynamic parameters are used to estimate airspeed with attitude and angular speed measurements. Kalman filter is used for the estimation. There are also two major sources arousing a robust estimation problem; wind speed and altitude. Wind speed and direction depend on weather conditions. Altitude changes as a vehicle glides down to the ground. For one reference altitude, multiple model Kalman filters are pre-designed based on several reference airspeeds. We call this group of filters as a cluster. Filters of a cluster are activated simultaneously and probabilities are calculated for each filter. The probability indicates how much a filter matches with measurements. The final airspeed estimate is calculated by summing all estimates multiplied by probabilities. As a vehicle glides down to the ground, other clusters that have been designed based on other reference altitudes are activated. Some numerical simulations verify that the proposed method is effective to estimate airspeed.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.9 no.1
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• pp.53-63
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• 2003

This study was analyzed the effects of blood-activating and stasis-eliminating herbs on anti-tumor and hematogenic metastasis. The metastasis and recurrence of tumor was the basis of yudok(yudu) on remained tumor cell and stagnation of blood, thermotoxo, phlegm, asthenia of healthy enerngy, stagnation of vital energy. Malignant tumor is caused by carcinogen and go through the progress of initiation, promotion, progression, it is closely related with Eohyul$(y{\grave{u}}xi {\breve{e}})$. Symptoms of blood stasis disease are purplish tongue, mass, fixed stabbing pain, ecchymosis of nail, hypodermic petechia, dermal thesaurismosis, melena, ecchymoma, disturbance of circulation. Effects on the therapy of activating blood circulation and congestion are anti-tumor, anti-coagulation, anti-hemolysis, anti-solution, anti-inflammation, anti-infection, control of blood circulations, control of connective tissue metabolism and control of immunity. They can directly kill the cancer cells entering the blood circulation, inhibit the formation of tumor embody and reduce the blood hyperviscosity. It is suggested that these herbs can be used to prevent and treat blood metastasis of cancer under the guidance of syndrome differentiation.