• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.9
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• pp.734-745
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• 2017

The navigation system of lunar lander are composed of various navigation sensors which have a complementary characteristics such as inertial measurement unit, star tracker, altimeter, velocimeter, and camera for terrain relative navigation to achieve the precision and autonomous navigation capability. The required performance of sensors has to be determined according to the landing scenario and mission requirement. In this paper, the specifications of navigation sensors are investigated through covariance analysis. The reference error model with 77 state vector and measurement model are derived for covariance analysis. The mission requirement is categorized as precision exploration with 90m($3{\sigma}$ ) landing accuracy and area exploration with 6km($3{\sigma}$ ), and the landing scenario is divided into PDI(Powered descent initiation) and DOI(Deorbit initiation) scenario according to the beginning of autonomous navigation. The required specifications of the navigation sensors are derived by analyzing the performance according to the sensor combination and landing scenario.

• International Journal of Computer Science & Network Security
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• v.22 no.8
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• pp.97-104
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• 2022

European integration processes have acted as a catalyst for the emergence of a new type of educational environment, which is characterized by competent flexibility of specialists. Therefore, the article focuses on professional training of teachers in the context of European integration processes using information technology and the search for innovative methods of training specialists. One of the educational priorities in Europe is to create a new model of a teacher who has an academic education, knows innovative methods, is able to perform functions and tasks efficiently and professionally, adequately, quickly and correctly respond to changes and innovations. The tasks facing education in the European dimension are formulated. The main trends in the education of teachers in modern Europe are described: the need to deepen and expand subject training programs in pedagogical institutions of Higher Education, which will allow autonomy of activity, awareness of responsibility for independent creative decisions, create favorable conditions for the development of professionalism through the use of Information Technology and the search for innovative methods of training specialists. At the present stage, various models of teacher training are being developed based on the University and practical concept using information technology and searching for innovative methods of training specialists. On this basis, two different theories of perception of teacher education were formed: as preparation of teachers for work throughout their professional career; as preparation for the first years of professional work, which is periodically repeated in the process of continuous professional training and improvement. Among the advantages that the use of Information Technology and the search for innovative methods of training specialists to implement the learning process, it is worth mentioning the following: simultaneous use of several channels of perception of the student or student in the learning process, thanks to which the integration of information processed by different sensory organs is achieved; the ability to simulate complex real experiments; visualization of abstract information by dynamic representation of processes, etc.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.1 s.41
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• pp.25-32
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• 2005

Seismic load is distributed to modes of a structure through the modal participation factor(MPF). The modal participation factor is essential to analyze structural response under earthquake load. MPF of a real structure differs from that of analytical mathematical model due to the error induced from analytical assumptions and during the construction. In this study, an identification method is proposed to calculate the 1st MPF of real structure based on $H^{\infty}$ optimal model reduction. The MPF is obtained from the relationship between observability and controllability matrices realized from system identification and those of a prototype 2-degree state space model. The proposed method is verified thorough numerical examples.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.1
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• pp.73-96
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• 2013

ICAO's Universal Safety Oversight Audit Programme (USOAP) was initially launched in January 1995, in response to widespread concerns about the adequacy of aviation safety oversight around the world. The recent reduction in aircraft accidents and effective role that is evaluated on the basis of these results, and in 2013 the existing 'snapshot approach' to 'regular monitoring system (USOAP-Continuous Monitoring Approach)' was converted to. ICAO aviation safety assessment of the state in today's international community 'aviation safety credibility' as objective indicators to judge the enormous impact on the aviation industry, the state is not satisfactory, especially if the results of the evaluation and expansion of code-share airline ban, reduced international air transit passengers, including premium increases business and economic penalties should. In addition, ICAO implementation of the existing laws and regulations(Prescriptive Approach), but based on the Risk-based prevention model, Proactive Approach introduced the concept of aviation safety system, including international aviation safety policy has been to switch paradigms. This new ICAO international aviation safety policy also applies to the Government of the Republic of Korea in line with the aviation safey policies have changed. In particular, the systematic implementation of safety management for the existing laws and regulations in the center of the safety oversight system of risk-based introduction of the concept of proactive safety management, and According to international standards ICAO aviation service providers operate their own Safety Management System was set out in Aviation Law ever. In addition, the aviation safety is at the center of the field of the safety of aircraft operations and maintenance for the promotion is promoting various safety policies. This new paradigm shift in the international aviation safety policy in line with our state in the international community with the most exemplary aviation safety system firmly established itself as a model, the Government will strengthen the competitiveness of our aviation plans to support. To do this, the government, airlines, aviation officials try all the practical effect would be expected.

• Journal of the Korean Society of Safety
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• v.18 no.4
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• pp.169-175
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• 2003

In this paper, and estimation method for estimating the states of underwater vehicle systems with external unknown disturbance is proposed. First, the dynamics of underwater vehicle are induced by Taylor series expansion in the vertical plane and horizontal plane, respectively. For constructing the system model, the external efforts, i.e., the sea surface disturbances, the current, wave and etc., are regarded as external unknown disturbances. Thus the disturbance is added as external input into state-space form of underwater vehicle system. To estimate the state of systems with unknown disturbance, a disturbance observer which does not effected the external unknown input is proposed, and the existence condition for the observer is given. Finally, the effectiveness of the proposed disturbance observer for robust control of underwater vehicle systems is verified by using numerical simulation.

• 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 Korea Institute of Building Construction
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• v.10 no.4
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• pp.31-39
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• 2010

As the linear scheduling method has been used since the Empire State Building linear schedule in 1929, it is being applied in various fields, such as construction and manufacturing. When addressing concurrent critical paths occurring in a linear construction schedule, empirical researches have stressed resource management, which should be applied for optimizing workflow, ensuring flexible work productivity and continuous resource allocation. However, work relationships have been usually overlooked in making the linear schedule from an existing network schedule. Therefore, this research analyzes the previous researches related to the linear scheduling model, and then proposes a method that can be applied for adopting the relationships of a network schedule to the linear schedule. To this end, this research considers the work relationships occurring in changing a network schedule into a linear schedule, and then confirms the activities movement phenomenon of linear schedule due to workspace change, such as physical floors change. As a result, this research can be used as a basic research in order to develop a system generating a linear schedule from a network schedule.

• The Journal of the Korea Contents Association
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• v.19 no.6
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• pp.236-248
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• 2019

Green belts can help to set boundary for city growth, provide ecological protection system and enhance the resilience of Beijing. During the implementation period of the current overall city planning of Beijing, the proportion of green space varies much among the sub-districts, villages and towns involved in the two green belts in the research. With this as starting point, by researching the correlations of 'city system factors' and 'planning policy factors' with the change in the scale of green space, the paper discussed the influential factors of implementing the planning of green space of Beijing, and conducted quantitative research, with such possible influential factors classified into 'city system factors' and 'planning policy factors'. Through multiple linear regression model, the paper tested the correlations of city system factors and planning policy factors (independent variable) with the increment in the construction land in green belts (dependent variable). Through influence to population aggregation and the expansion force of construction land, city system factors such as mountain land and water, house rent of unit area, accessibility of public transport and the newly-defined state-owned construction land generate correlation with the change in the scale of construction land in green belts.

• The Korean Journal of Pain
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• v.21 no.2
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• pp.112-118
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• 2008

Background: This study was conducted to quantitatively analyze proteins associated with the calcitonin gene-related peptide (CGRP) in cerebrospinal fluid (CSF) that was obtained from a rat model of chronic neuropathic pain following administration of intrathecal $CGRP_{8-37}$. Methods: Male Sprague-Dawley rats (100-150 g, 5-6 wks) were divided into two groups, sham controls and neuropathic pain models. At the time of operation for neuropathic pain model, an intrathecal catheter was threaded through the intrathecal space. At 1 or 2 wks after the operation (maximum pain state), a test dose of 1, 5, 10, or 50 nM of $CGRP_{8-37}$ was injected into the intrathecal catheter and the CSF was then aspirated. Conventional proteomics to evaluate the CSF were then performed using high resolution 2-D, gel electrophoresis followed by computational image analysis and protein identification by mass spectrometry. Results: Treatment with $CGRP_{8-37}$ effectively alleviated mechanical allodynia in a dose dependent manner. The most effective response was obtained when a dose of 50 nM was administered, but significant differences were obtained following administration of only 5 nM $CGRP_{8-37}$. Furthermore, the results of the proteomic analysis were consistent with the experimental results. Specially we detected 30 differentially expressed spots in 7 images when 2-D gel electrophoresis was conducted. The intensity of 6 of these spots (spot number: 20 and 26-30) was found decrease the $CGRP_{8-37}$ dose increased; therefore, these spots were evaluated by mass spectrometry. This analysis identified 2 different proteins, CGRP (spot numbers: 26-30) and neurotensin-related peptide (spot number: 20). Conclusions: The results of this study suggest that CGRP plays a role in chronic central neuropathic pain and is a major target of chronic neuropathic pain management.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.2
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• pp.163-169
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• 1998

In this paper, we design an optimal model following ${\mu}-$synthesis control system for fuel-injection of diesel engine which has robust performance and satisfactory command tracking performance in spite of uncertainties of the system. To do this, we give gain and dynamics parameters to the weighting functions and apply genetic algorithm with reference model to the optimal determination of the weighting functions that are given by the D-K iteration method which can design ${\mu}-$synthesis controller in the state space. These weighting functions are optimized simultaneously in the search domain which guarantees the robust performance of the system. The ${\mu}-$synthesis control system for fuel-injection designed by the above method has not only the robust performance but also a better command tracking performance than those of the ${\mu}-$synthesis control system designed by trial-and-error method. The effectiveness of this ${\mu}-$synthesis control system for fuel-injection is verified by computer simulation.