• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.4
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• pp.1223-1247
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• 2012

The need for securing Wireless Sensor Networks (WSNs) is essential especially in mission critical fields such as military and medical applications. Security techniques that are used to secure any network depend on the security requirements that should be achieved to protect the network from different types of attacks. Furthermore, the characteristics of wireless networks should be taken into consideration when applying security techniques to these networks. In this paper, energy efficient Security Model for Tree-based Routing protocols (SMTR) is proposed. In SMTR, different attacks that could face any tree-based routing protocol in WSNs are studied to design a security reference model that achieves authentication and data integrity using either Message Authentication Code (MAC) or Digital Signature (DS) techniques. The SMTR communication and processing costs are mathematically analyzed. Moreover, SMTR evaluation is performed by firstly, evaluating several MAC and DS techniques by applying them to tree-based routing protocol and assess their efficiency in terms of their power requirements. Secondly, the results of this assessment are utilized to evaluate SMTR phases in terms of energy saving, packet delivery success ratio and network life time.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.7
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• pp.654-661
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• 2015

Stairs are the most popular obstacles in buildings and factories. To enlarge the application areas of a field robotic platform, stair-climbing is very important mission. One important reason why a stair-climbing is difficult is that stairs are various in sizes. To achieve autonomous climbing of various-sized stairs, dynamic modeling is essential. In this research, an inverse dynamic modeling is performed to enable an autonomous stair climbing. Stair-climbing robotic platform with flip locomotion, named FilpBot, is analyzed. The FlipBot platform has advantages of robust stair-climbing of various sizes with constant speed, but the autonomous operation is not yet capable. Based on external constraints and the postures of the robot, inverse dynamic models are derived. The models are switched by the constraints and postures to analyze the continuous motion during stair-climbing. The constraints are changed according to the stair size, therefore the analysis results are different each other. The results of the inverse dynamic modeling are going to be used in motor design and autonomous control of the robotic platform.

• Clinical and Experimental Pediatrics
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• v.63 no.12
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• pp.477-482
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• 2020

The childhood obesity pandemic has emerged as an important public health problem in many countries. Obese children are likely to become obese adults, and adult obesity is associated with an increased risk of morbidity. Therefore, controlling the childhood obesity epidemic has become a top public health priority worldwide. The current coronavirus disease 2019 (COVID-19) pandemic may significantly impede this important mission and constitute an unprecedented tragedy in the global battle against childhood obesity. This manuscript presents evidence that the COVID-19 pandemic will aggravate the childhood obesity epidemic and lead to significant weight gain in school children by creating an unprecedented obesogenic environment. Within the last few months, many countries took uncompromising measures in response to the COVID-19 pandemic, including school closures and quarantine. While these steps are often necessary to ensure infection control, they may have a significant negative effect on children's mental and physical health. Physical, nutritional, and psychosocial factors that promote obesity in children during this special situation complementarily contribute to an unprecedented obesogenic environment. Large-scale quarantine and home confinement will impose new and unfamiliar stressors on children, thereby worsening the childhood obesity epidemic. Most importantly, adverse childhood events resulting from a predicted increase in domestic violence within the next few months will significantly contribute to this concern. The scenario presented in this review is of paramount public health importance and must be considered during future pandemic planning. Involved stakeholders, including governments, schools, and families, must make all possible efforts to minimize the impact of the COVID-19 epidemic on childhood obesity.

• Journal of Korea Multimedia Society
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• v.24 no.1
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• pp.146-154
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• 2021

Conspicuous consumption is often investigated in Korea and consumers purchase a product to publicly display economic power or social status. The existing studies argue that brand loyalty and luxury brand preferences escalate conspicuous consumption, and it is important to identify different visual perception to understand irrational consumers' behavior. Car emblem as brands' visual identity represents the brand's image, mission and message. Irrational consumers thus are expected have different visual perception to the emblem or logo. To understand the impact of irrational consumer behavior on visual perception, this study explored how brand loyalty and luxury brand preferences impact on the visual perception of car emblems between Korean domestic brand and imported brand. This study used eye tracking technology to measure the respondents' attention on an emblem of the cars. Eye tracking tools analyze fixations and measure the attention on a specific area of interests (AOI). This study explored the maintaining time and frequency on AOI, as well as explored the size of pupil to identify the respondents' attention on the AOI. In this experiment, the logos of domestic cars (i.e., Hyundai and Kia) and foreign cars (i.e., Mercedes-Benz and BMW) were swapped to see how irrational consumer behavior impact on visual perception of car emblem.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.3
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• pp.441-450
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• 2022

The introduction of autonomous underwater gliders (AUGs) specifically addresses the reduction of operational costs that were previously prohibited with conventional autonomous underwater vehicles (AUVs) using a "scaling-down" design philosophy by utilizing the characteristics of autonomous drifters to far extend operation duration and coverage. Long-duration, wide-area missions raise the cost and complexity of in-water testing for novel approaches to autonomous mission planning. As a result, a simulator that supports the rapid design, development, and testing of autonomy solutions across a wide range using software-in-the-loop simulation at faster-than-real-time speeds becomes critical. This paper describes a faster-than-real-time AUG simulator that can support high-resolution bathymetry for a wide variety of ocean environments, including ocean currents, various sensors, and vehicle dynamics. On top of the de facto standard ROS-Gazebo framework and open-sourced underwater vehicle simulation packages, features specific to AUGs for ocean mapping are developed. For vehicle dynamics, the next-generation hybrid autonomous underwater gliders (Hybrid-AUGs) operate with both the buoyancy engine and the thrusters to improve navigation for bathymetry mappings, e.g., line trajectory, are is implemented since because it can also describe conventional AUGs without the thrusters. The simulation results are validated with experiments while operating at 120 times faster than the real-time.

• Journal of Research and Publication Ethics
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• v.5 no.1
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• pp.19-27
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• 2024

Purpose: To prevent and respond to youth sexual problems that are becoming more serious with digital development, this study sought to develop a sex education program that applies gamification as an effective method for youth who are digital natives. Research design, data and methodology: To develop a sex education program for teenagers, elements of gamification were considered based on Dick and Kerry's teaching system design model. The learning content reflected UNESCO's 'Comprehensive Sex Education Guidelines'. In addition, it was designed to enable students to learn about ethics and morals from a social and emotional aspect. Results: A four-session distance learning sex education program was developed for first-year high school students. To learn about gender sensitivity, sexual relationships, sexuality, and healthy sexual behavior, we developed a story that reflects the mission and quest for sex education. It included leaderboards, time limits, and levels, and also utilized mechanics such as points and items. Edutech tools include video content, Google Sheets, Zoom, Padlet, and Mentimeter. Conclusions: This study aims to improve learning effectiveness, satisfaction, and immersion by developing a sex education program for youth using gamification that promotes active learner participation and motivation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.10
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• pp.868-874
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• 2015

Thrust variation is an essential parameter in a space mission such as landing on an atmosphereless planet or docking a spacecraft. In order to achieve the thrust variation control, using throttleable injector is a representative and general method. A dual-manifold injector, one of throttleable injectors, was used to control mass flow rate. Five kinds of injectors were designed and investigated in order to compare the spray characteristics of the dual-manifold injector with various tangential entries. Spray angles and patterns were measured to determine external flow characteristics and film thicknesses were measured in order to investigate the internal flow patterns.

• Information Systems Review
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• v.9 no.1
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• pp.283-309
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• 2007

This case study reviews procedures of the implementation of a strategic performance management system for the KITECH(Korea Institute of Industrial Technology). The purpose of the study is to provide government funding research institutions with cautious considerations when the institutions want to setup performance systems.. KITHCH's strategic performance management system is based on BSC and has following characteristics: 1. KITHCH has spent more than a year in order to obtain the personnel's agreements on mission, strategies and goals. 2. They have focused a mission and strategy focused performance system so that KPIs are as much aligned as possible with strategies. 3. They have developed the system using both top-down and bottom-up frames. The weights for KPIs were formulated with the bottom-up procedure. This study results possible effective factors for successful implementation of a strategic performance management system for research institutions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.4
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• pp.332-337
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• 2018

This paper presents the design optimization of fuel sensor location used to measure remained fuel amount in aircraft conformal fuel tank. The conformal fuel tank is utilized to expand the mission range in airplane, and the sensor location is a critical design variable determining the measurement accuracy. In this work, the sensor location is optimized to minimize unmeasurable fuel amount due to non-contact between fuel and sensor. The simplified model is prepared from the conformal fuel tank CATIA model, and the unmeasurable fuel amount is calculated. Then, the optimization is performed using MATLAB optimization solver. The optimized sensor location is validated by comparing with the location obtained using parametric study.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.836-842
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• 2009

On April 14, 2008, National Human Rights Commission of Korea's recommendation led to severe argument that hiring qualification of religious school. it shall not be an unlawful employment practice for a school, college, university, or other educational institution or institution of learning to hire and employ employees of a particular religion if such organizations is, in whole or in substantial part, owned, supported, controlled, or managed by a particular religion or by a particular religious corporation, association, or society, or if the curriculum of such organizations is directed toward the propagation of a particular religion. An employer is a "religious organization" entitled to the exemption. So If the employer is a school, its history and mission, the religion of the faculty and students, and the religious focus of the curriculum must be examined. Consequently it is possible for religious educational institution to reject specific religionist.