• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.9-17
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• 2018

Heterogeneous high performance computing systems are gaining acceptance as the environments for computational scientific simulations of various application fields. Those computing systems, however, have been mostly used with the legacy consoles, resulting in the severe decrement of accessibility and usability of heterogeneous computing assets. To solve this problem, this paper presents the design and implementation of web-based computational science simulation management program. The proposed program provides fundamental primitives including user authentication, data management, physical/virtual computing resource management, job management, etc. that can be used to manage different kinds of simulations efficiently, and also offers highly extensible feature through a modular plug-in architecture. We also present the best practical examples of applications (e.g., scientific simulation education and bio-medical) to confirm our program's effectiveness.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.185-188
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• 2008

This paper introduces the Bootstrap method for statistical analysis of noise and vibration spectrum in aeronautic and space fields. Generally, all components of a launch vehicle and its payloads are subjected to high intensive noise and vibration environment during the lift-off phase and the ascent phase through Mach =1 and Max Q. In order to verify their survivabilities against these severe vibroacoustic environments during qualification tests and acceptance tests, it is most important to estimate the proper upper limits of the environmental condition. Although NASA has typically utilized the Normal Tolerance Limit method in deriving these levels, the reference[1] says that the Bootstrap can be also an alternative method to estimate the maximum expected environments. In this paper, a general procedure of the Bootstrap method is summarized, and it is applied to analyze acceleration power spectral density functions, which were measured during acoustic test on the upper stage of KSLV-I.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.7
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• pp.659-666
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• 2016

Magnetic disturbance is one of the main factors that deteriorate the accuracy of orientation estimation methods based on inertial/magnetic sensor signals. This paper proposes a parallel Kalman filter(KF) that explicitly detects magnetic disturbances and thus can accurately estimate 3D orientation in magnetically disturbed environments. Due to the parallel nature of the proposed KF, even severe magnetic disturbances only affect yaw estimation, while roll and pitch values remain accurate. Consequently, the proposed KF can be effectively used in various applications that involve magnetically inhomogeneous environments, such as robots, ships, and planes.

• Journal of Communications and Networks
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• v.13 no.6
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• pp.583-590
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• 2011

Full-mesh IPSec tunnels pass through a black ("unsecure") network (B-NET) to any red ("secure") networks (RNETs). These are needed in military environments, because they enable dynamically changing R-NETs to be reached from a BNET. A dynamically reconfiguring security policy database (SPD) is very difficult to manage, since the R-NETs are mobile. This paper proposes advertisement process technologies in association with the tunnel gateway's protocol that sends 'hello' and 'prefix advertisement (ADV)' packets periodically to a multicast IP address to solve mobility and security issues. We focus on the tunnel gateway's security policy (SP) adaptation protocol that enables R-NETs to adapt to mobile environments and allows them to renew services rapidly soon after their redeployment. The prefix ADV process enables tunnel gateways to gather information associated with the dynamic changes of prefixes and the tunnel gateway's status (that is, 'down'/restart). Finally, we observe two different types of performance results. First, we explore the effects of different levels of R-NET movements on SP adaptation latency. Next, we derive the other SP adaptation latency. This can suffer from dynamic deployments of tunnel gateways, during which the protocol data traffic associated with the prefix ADV protocol data unit is expected to be severe, especially when a certain tunnel gateway restarts.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.4
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• pp.401-409
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• 2007

Because of the various excellent characteristics of cast basalt materials. such as, anti-corrosion, anti-wearing, good hardness. high chemical stability, of which steel may not possess, the steel-basalt composite pipes are used in severe environments for compensating the defects of steel. However. without sufficient mechanical investigation prior to application. the basalt liners in steel-basalt composite pipes may be cracked and broken or the basalt liners are omitted from steel pipes in applications. In these cases, the merits of basalt materials may disappear and the basalt liners may not play their good roles as expected. Therefore, it is required that mechanical behavior of steel-basalt composite pipes and surrounding environments be fully examined before installation. The limit of bending moment with which steel-basalt composite pipe may safely endure is calculated and the limit curvature of the composite pipe in the safe range is presented in this paper. The temperature distributions and the thermal stresses are also computed and the limit difference of temperatures between inner and outer side of composite pipe is given together.

• Smart Media Journal
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• v.6 no.2
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• pp.9-14
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• 2017

A packet loss in wireless environments causes a severe degradation of video quality in video communications. In this paper, a novel video error concealment algorithm is presented by combining boundary errors and a block reliability measure. The block reliability measure decides the reliability of a block by checking residual errors of a block. In the proposed approach, a motion vector of a missing unreliable block in an inter coded frame is obtained initially based on the motion vector of the same block in the reference frame. Furthermore, if the block in the reference frame is unreliable according to the reliability measure, a new motion vector is decided based on block boundary errors around the initial motion vector. According to our simulations, the proposed approach shows promising results for error concealment in error-prone wireless environments.

• The Journal of Korea Robotics Society
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• v.16 no.3
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• pp.199-206
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• 2021

The robot is an effective means to perform repetitive tasks quickly and accurately. It could be more effective in dangerous environments where human is difficult to access. The construction site is a dangerous environment with a high possibility of industrial accidents where heavy work is frequently carried out at a high place. In particular, an accident in the construction site is highly likely to lead to a severe disaster. Of course, various technologies are being developed to monitor the safety of workers in construction sites and prevent accidents, but there is a limit to eliminate the risk of accidents. Therefore, it is necessary to make efforts to replace workers exposed to dangerous environments with equipment or robots that could be controlled remotely in a more active way. In this study, Remote Precise Installation System was proposed to replace the workers exposed to the risk of accident at a high place during the bridge construction. Also, the conceptual design and analytical reviews of this system were carried out. Suppose Remote Precise Installation System is developed according to the derived concept and the target performance. In that case, this system is expected to be applied as a technology that can effectively replace the workers at the bridge construction site.

• Corrosion Science and Technology
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• v.20 no.1
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• pp.7-14
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• 2021

PosMAC^® is a brand of Zn-Mg-Al hot-dip coated steel sheet developed by POSCO. PosMAC^® can form dense surface oxides in corrosive environments, providing advanced corrosion resistance compared to traditional Zn coatings such as GI and GA. PosMAC^® 3.0 is available for construction and solar energy systems in severe outdoor environments. PosMAC^®1.5 has better surface quality. It is suitable for automotive and home appliances. Compared to GI and GA, PosMAC^® shows significantly less weight reduction due to corrosion, even with a lower coating thickness. Thin coating of PosMAC^® provides advanced quality and productivity in arc welding applications due to its less generation of Zn fume and spatters. In repeated friction tests, PosMAC^® showed lower surface friction coefficient than conventional coatings such as GA, GI, and lubricant film coated GA. Industrial demand for PosMAC^® steel is expected to increase in the near future due to benefits of anti-corrosion and robust application performance of PosMAC^® steel.

• Korean Journal of Childcare and Education
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• v.8 no.2
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• pp.5-26
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• 2012

The purpose of the study was to review the literature with the following three themes : 1) the necessity and benefits of inclusion for young children with severe disabilities, 2) the solutions to overcome the concerns for the inclusion of young children with severe disabilities, and 3) the implication for the inclusion of young children with disabilities in Korea. The results of the study indicated that it was necessary to support pre-service and in-service early childhood education teachers to be professional educators who can create the most effective inclusive educational environments. As well, the results showed that teachers, parents, and relevant professionals need to use various strategies to activate inclusive education for young children with severe disabilities. Based on the review, the study provided the instructional strategies and educational implications for the effective inclusion of young children with severe disabilities.

• The Journal of Korean Academic Society of Nursing Education
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• v.27 no.4
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• pp.423-435
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• 2021

Purpose: The purpose of this study is to identify the educational needs of a severe trauma treatment simulation program based on mixed reality which combines element of both virtual reality and augmented reality. Methods: Focus group interviews were conducted with ten military hospital nurses on February 4 and 5, 2021. The collected data were analyzed using a qualitative content analysis. As a framework for data analysis, the educational needs were clustered into the following four categories: teaching contents, teaching methods, teaching evaluation, and teaching environment. Results: The educational needs for each category that emerged were as follows: three subcategories including "realistic education reflecting actual clinical practice" and "motivating education" for teaching contents; five subcategories including "team-based education," "repeated education that acts as embodied learning," and "stepwise education" for teaching methods; six subcategories including "debriefing through video conferences," "team evaluation and evaluator in charge of the team," "combination of knowledge and practice evaluation" for teaching evaluation; six subcategories including "securing safety," "similar settings to real clinical environments," "securing of convenience and accessibility for learners," and "operating as continuing education" for teaching environment. Conclusion: The findings of this study can provide a guide for the development and operation of a severe trauma treatment simulation program based on mixed reality. Moreover, it suggests that research to identify the educational needs of various learners should be conducted.