• The Journal of the Korea institute of electronic communication sciences
• /
• v.18 no.5
• /
• pp.761-768
• /
• 2023

In the 4th Industrial Revolution, AI(Artificial Intelligence) and IoT(Internet of Things) technologies are being applied to across various fields, with particularly prominence in asset management, disaster management, and meteorological observation. In these fields, it is necessary to accurately determine the real-time and precise tracking of the object's location and status, and to collect various data even in situations that are difficult to detect with existing sensors. In order to address these demands, the use of GNSS(Global Navigation Satellite System) is essential, and this technology enables the efficient management of assets, disaster prevent and response, and accurate weather forecasting. In this paper, we provide the investigated results for the latest trends in the application of GNSS in the fields of asset management, disaster management, and weather observation, among various fields incorporating AI and IoT and analyze them.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.6
• /
• pp.807-812
• /
• 2023

This study examines the training effectiveness of airsoft guns that look and operate like real guns. Airsoft guns were developed in Japan in the late 1970s and are now popular for leisure sports and training, especially in countries where gun ownership is permitted. In particular, Taiwan has been promoting airsoft gun games to train citizen soldiers, and military leaders such as the United States have also utilized airsoft guns for live fire combat training and combat troops' live fire training. However, due to strict usage regulations and the perception that it is a toy, it is underutilized in Korea despite being a good training tool. Therefore, this study will prove the effectiveness of airsoft guns and improve the military's combat capabilities through practical training using airsoft guns. In addition, it will improve the negative perception of airsoft guns and foster a new sports industry.

• Journal of Advanced Navigation Technology
• /
• v.27 no.6
• /
• pp.877-883
• /
• 2023

For safe operation of ships and management of marine fisheries farms, the data set that extracts the boundaries of marine fisheries farms can provide information on obstacles in the vessel's navigation path in advance by examining whether it matches the fishing ground permit area. In addition, it can be used to determine whether fish farms are operating to compensate for damage caused by marine accidents, and the relevant local government can use it to manage fishing grounds. It is also highly utilized as basic data to identify obstacles for safe navigation of ships. In this study, Sentinel-2 satellite image data from the European Space Agency (ESA) was used to extract the boundaries of fish farms. From the video image, the fish farm's status data by cycle was divided into five zones: Busan-Ulsan area, Geoje-Changwon area, Goseong-Tongyeong area, and Namhae-Sacheon area. Through the image highlighting process, the farm boundary data and meta data were processed and extracted.

• Tribology and Lubricants
• /
• v.40 no.1
• /
• pp.8-16
• /
• 2024

This study conducts numerical modeling and eigen-analysis of a rod-fastened rotor, which is mainly used in aircraft gas turbine engines in which multiple disks are in contact through curvic coupling. Nayak's theory is adopted to calculate surface parameters measured from the tooth profile of the curvic coupling gear. Surface parameters are important design parameters for predicting the stiffness between contact surfaces. Based on the calculated surface parameters, elastoplastic contact analysis is performed according to the interference between two surfaces based on the Greenwood-Williamson model. The equivalent bending stiffness is predicted based on the shape and elastoplastic contact stiffness of the curvic coupling. An equation of motion of the rod-fastened rotor, including the bending stiffness of the curvic coupling, is developed. Methods for applying the bending stiffness of a curvic coupling to the equation of motion and for modeling the equation of motion of a rotor that includes both inner and outer rotors are introduced. Rotordynamic analysis is performed through one-dimensional finite element analysis, and each element is modeled based on Timoshenko beam theory. Changes in bending stiffness and the resultant critical speed change in accordance with the rod fastening force are predicted, and the corresponding mode shapes are analyzed.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.34 no.4
• /
• pp.681-691
• /
• 2024

In recent decades, research and development in the field of industrial robotics, such as an unmanned ground vehicle (UGV) and an unmanned aerial vehicle (UAV), has been significant progress. In these advancements, it is important to use middleware, which facilitates communication and data management between different applications, and various industrial communication middleware protocols have been released. The robot operating system (ROS) is the most widely adopted as the main platform for robot system development among the communication middleware protocols. However, the ROS is known to be vulnerable to various cyber attacks, such as eavesdropping on communications and injecting malicious messages, because it was initially designed without security considerations. In response, numerous studies have proposed countermeasures to ROS vulnerabilities. In particular, some work has been proposed on generating ROS datasets for intrusion detection systems (IDS), but there is a lack of research in this area. In this paper, in order to contribute to improving the performance of ROS IDSs, we propose a new type of attack scenario that can occur in the ROS and build ROS attack datasets collected from a real robot system and make it available as an open dataset.

• Journal of Korean Society for Quality Management
• /
• v.52 no.2
• /
• pp.275-286
• /
• 2024

Purpose: The spare part cost is one of the most important cost factors with which construct Life Cycle Cost. The LCSP(Life Cycle Sustainment Plan) Guidebook issued by Korea Ministry of Defense, however, suggests a simple equation to estimate the spare part cost using maintenance task frequencies and each part cost. Therefore, following the cost estimation method in the LCSP Guidebook may lead to an improper cost estimation result since both the hierarchical structure of the weapon system and the part discard rate are not considered. The purpose of this study is to develop a new life cycle cost estimation method for spare parts of weapon system during its life cycle. Methods: In this study, the detailed cost structure of spare parts is provided. Also a new spare part cost estimation methods for the each cost element are proposed, considering the hierarchical structure of weapon system and the part discard rate. And the proposed spare cost estimation methods are applied to K system for a case study. Results: Based on the case study of K system, the spare part cost estimation method, proposed by this study, shows that it can complement the estimation method suggested by the LCSP Guidebook. It also shows that it is applicable to the weapon systems for Korea armed forces. Conclusion: The proposed life cycle cost estimation method for spare parts has an advantage of estimating the spare part cost more accurately. It is expected to be useful in analyzing the procurement alternatives objectively and making up the Korea armed forces budget effectively.

• The Korean Journal of Air & Space Law and Policy
• /
• v.20 no.1
• /
• pp.87-107
• /
• 2005

Land Remote Sensing' is defined as the science (and to some extent, art) of acquiring information about the Earth's surface without actually being in contact with it. Narrowly speaking, this is done by sensing and recording reflected or emitted energy and processing, analyzing, and applying that information. Remote sensing technology was initially developed with certain purposes in mind ie. military and environmental observation. However, after 1970s, as these high-technologies were taught to private industries, remote sensing began to be more commercialized. Recently, we are witnessing a 0.61-meter high-resolution satellite image on a free market. While privatization of land remote sensing has enabled one to use this information for disaster prevention, map creation, resource exploration and more, it can also create serious threat to a sensed nation's national security, if such high resolution images fall into a hostile group ie. terrorists. The United States, a leading nation for land remote sensing technology, has been preparing and developing legislative control measures against the remote sensing industry, and has successfully created various policies to do so. Through the National Oceanic and Atmospheric Administration's authority under the Land Remote Sensing Policy Act, the US can restrict sensing and recording of resolution of 0.5 meter or better, and prohibit distributing/circulating any images for the first 24 hours. In 1994, Presidential Decision Directive 23 ordered a 'Shutter Control' policy that details heightened level of restriction from sensing to commercializing such sensitive data. The Directive 23 was even more strengthened in 2003 when the Congress passed US Commercial Remote Sensing Policy. These policies allow Secretary of Defense and Secretary of State to set up guidelines in authorizing land remote sensing, and to limit sensing and distributing satellite images in the name of the national security - US government can use the civilian remote sensing systems when needed for the national security purpose. The fact that the world's leading aerospace technology country acknowledged the magnitude of land remote sensing in the context of national security, and it has made and is making much effort to create necessary legislative measures to control the powerful technology gives much suggestions to our divided Korean peninsula. We, too, must continue working on the Korea National Space Development Act and laws to develop the necessary policies to ensure not only the development of space industry, but also to ensure the national security.

• The Korean Journal of Air & Space Law and Policy
• /
• v.35 no.3
• /
• pp.151-208
• /
• 2020

Japan's two outer space-related laws were promulgated on November 16, 2016. There are the Act on Launching of Spacecraft, etc. and Control of Spacecraft (Act No. 76 of 2016, Space Activities Act) and the Act on Securing Proper Handling of Satellite Remote Sensing Records (Act No.77 of 2016, Remote Sensing Records Act). Japan's Space Activities Act states that a person who launches a satellite from the territory of Japan, or from a ship or airplane registered in Japan, must obtain permission from the Prime Minister prior to the launch. To obtain the permission, the person must have a certificate for a rocket design and for radio equipment at a launching facility. In addition, the ability to launch a rocket safely and the purpose for the satellite launch must be evaluated. Managing a satellite from Japan also requires permission from the government. A person who launches a rocket must have insurance for any potential damage arising from accidents, and the government is to supplement the potential compensation to allow for damage that cannot be covered by private insurance. The purpose of this paper reviews regulations of launch services and management of satellites in the Japan's Space Activities Act. It also offers some implications and suggestions for regulations of launching of spacecraft and management or operation of satellites.

• The Korean Journal of Air & Space Law and Policy
• /
• v.28 no.2
• /
• pp.183-221
• /
• 2013

While in the early stages of space activities only a few states engaged in the use of outer space, as is well known, commercial space activities have grown dramatically in recent years. Both states, state institutions, and international governmental organizations as well as many private enterprises are engaged in such commercial use of outer space by now. This development is not reflected in the present state of space law. The existing international instruments of space law were developed and finalized before this development and thus only provide very few and sometimes unfitting provisions for the commercial use of outer space and particularly the use by private enterprises. Law formulated in an era when the word "privatization" had not even been coined cannot contain potential problems caused by the increasing commercialization of outer space. For the promotion and further development of such commercial use of outer space it is necessary to clarify and establish the legal framework for such use, because participants will need this information for their future investments in this field. The purpose of this paper is to research and make an analysis of the contents and international regulation of international space commerce, which is rapidly proliferating and to review the process of improvement on national legislations relating to the commercialization of outer space in a few main space advanced countries to make the sustainable progress of commercial space activities project in international society. The legal implications of matters such as international commercial launch services, the liability aspects of such services, intellectual property rights, insurance, product liability insurance and materials processing could one day will be subject to regulated by international space law as well as domestic law. In fact, the question of commercialization is linked to the question of sharing benefits of space activities, and this currently is an agenda item in the Legal Subcommittee of UN COPUOS. Most of developed countries have enacted the national legislation for commercial space activities relating to the development of our space as follows : The National Aeronautic and Space Act of 1958 and the Commercial Space Act of 1998 in the United States, Outer Space Act of 1986 in England, Establishment Act of National Space Center of 1961 in France, Canadian Space Agency Act of 1990 in Canada, Space Basic Act of 2008 in Japan, and Law on Space Activity of 1993 in Russia. Becides there are currently three national legislations relating to space development and commercial space activities in Korea as follows : Aerospace Industry Development Promotion Act of 1987, Outer Space Development Promotion Act of 2005, Outer Space Damage Compensation Act of 2008. Commercial space great promise for the utilization and expansion of human outer space activities but aspring commercial actors must recognize that foreign policy, as well as obligations to the international community as a whole, ensure that commercial space activities will not operate in a legal and regulatory vacuum. As commercial space matures the law and accompanying regulation will most certainly evolve and choose to become participants in the inevitable evolution of law and regulation.

• Management & Information Systems Review
• /
• v.39 no.2
• /
• pp.77-94
• /
• 2020

While the importance of the service industry has increased at the national economy level, the service rate and job satisfaction of the flight attendants in the aviation service industry are not high. In this regard, this study aims to recognize what factors can reduce their job stress in the emotional work environment, and how job stress affects their attitude and job performance. More specifically, the current study tries to investigate how flight attendants' positive psychological status affect their job stress, organizational commitment, and knowledge sharing in the aspect of job performance. The main five constructs in these interrelationships include the flight attendants' positive psychological capital, leader-member exchange(LMX), job stress, organizational commitment, and knowledge sharing. This study conducted a quantitative research with 390 questionnaire for flight attendants, and analyzed the data using SPSS/PC version 20.0 and structural equation modeling program of AMOS 20.0. The findings show that the favorable leader-member exchange relationship between flight attendants plays a significant role in lowering job stress, while high job stress has a negative effect on organizational commitment and knowledge sharing. The result also shows that personal positive psychological capital acts as a trigger to influence other factors. Therefore, this study suggests that it is essential for airlines not only to promote an organizational system to support the flight attendants' emotional work but also to maintain a positive psychological state for securing competitive human resources.