• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.6
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• pp.488-496
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• 2015

This paper proposes a framework to determine the routes of multiple unmanned aerial vehicles (UAVs) to conduct multiple tasks in different locations considering the survivability of the vehicles. The routing problem can be formulated as the vehicle routing problem (VRP) with different cost matrices representing the trade-off between the safety of the UAVs and the mission completion time. The threat level for a UAV at a certain location was modeled considering the detection probability and the shoot-down probability. The minimal-cost path connecting two locations considering the threat level and the flight distance was obtained using the Dijkstra algorithm in hexagonal cells. A case study for determining the optimal routes for a persistent multi-UAVs surveillance and reconnaissance missions given multiple enemy bases was conducted and its results were discussed.

• Korean Chemical Engineering Research
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• v.62 no.2
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• pp.153-162
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• 2024

Securing safety in the maritime danger zone around the launch site before a launch is a fundamental requirement. If maritime safety is not ensured, the launch is halted or postponed. However, challenges have arisen in the process of securing public safety at sea due to factors such as the increasing population engaged in water leisure activities. These challenges include unauthorized entry of vessels into controlled areas, unauthorized access by water leisure activity participants, and non-compliance with regulations. In this paper, we employed the Delphi/Analytic Hierarchy Process to survey 22 experts, including professionals in launch vehicle development and launch site operation, to identify 10 factors posing threats to maritime public safety. Additionally, we identified five issues that need improvement for ensuring maritime safety. This study verified the consistency of expert opinions and conducted an analysis of importance and prioritization, objectively confirming the necessity for amendments to relevant laws or the enactment of new laws concerning the establishment and control of danger zones around launch sites.

• Composites Research
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• v.21 no.5
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• pp.23-30
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• 2008

Stab threats using sharp edged or pointed Instruments could be easily encountered by police officers or soldiers. In this study, the shear thickening fluids (STF) was impregnated into Kevlar fabrics to improve the stab protection and the resistance of STF impregnated Kevlar fabrics was experimentally investigated. The puncture and cut resistance were tested using a drop test machine withspike and knife indenters fabricated based on the National Institute of Justice (NIJ) standard. The STF was filled with spherical $SiO_2$ particles having an average diameter of 100nm, 300nm, and 500nm. The effect of particle size on puncture and cut resistance of STF impregnated Kevlar fabrics was also investigated. The measured impact load histories showed that STF impregnation into fabric leads to withstand higher peak loads than that of neat fabrics under spike test. The test results showed that Kevlar impregnated with STF exhibit remarkable improvements in puncture resistance while it is slightly influential on the cut resistance. Specifically, particle size is the one of the dominant factors controlling fabric resistance to puncture under spike impact test.

• Journal of the Korean Geotechnical Society
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• v.39 no.10
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• pp.49-55
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• 2023

The discovery of lunar ice in the lunar polar region has fueled international interest in in situ resource utilization (ISRU) and the construction of lunar habitats. Unlike Earth's atmosphere, the Moon presents unique challenges, including frequent meteoroid impacts, direct exposure to space radiation, and extreme temperature variations. To safeguard lunar habitats from these threats, the construction of a protective shield is essential. Lunar regolith, as a construction material, offers distinct advantages, reducing transportation costs and ensuring a sustainable supply of raw materials. Moreover, it streamlines manufacturing, integration schedules, and enables easy repairs and modifications without Earth resupply. Adjusting the shield's thickness within the habitat's structural limits remains feasible as lunar conditions evolve. Although extensive research on protective shields using lunar regolith has been conducted, unresolved conflicts persist regarding shield requirements. This study conducts a comprehensive analysis of the primary lunar threats and suggests a minimum shield thickness of 2 m using lunar regolith. Furthermore, it outlines the necessary technology for the rapid construction of such protective shields.

• The Korean Journal of Air & Space Law and Policy
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• v.31 no.1
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• pp.145-167
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• 2016

UN Security Council is entitled to power for determining the existence of the threat to the peace. Specifying the provisions adopted in accordance with the chapter 7 of the UN Charter, its resolution is deemed as document confirming its decision about the threat to the peace. In general, resolutions adopted by the Security Council acting under Chapter VII of the Charter, are considered binding, in accordance with Article 25 of the Charter. Regarding to the terms of the Resolutions to be interpreted, the word "decide" is used as to the suspension of the ballistic missile program, the word "demand" is used as to the stopping of the the launch of ballistic missile, and the word "demand" is used as to return to the missile test moratorium. These provisions may be deemed to determining specific obligations to be imposed upon the States in accordance with the 1967 Outer Space Treaty. On the other hand, the Resolutions may be limited to the decision, not leading to a sort of international legislation, the main purpose of which is to provide a legal basis for international sanctions against Northe Korea. North Korea missile test case has reminded us of continuing discussion about whether the decision of the Security Council lacks the legislative authority due to its decision process. Furthermore, having regard to the outer space and space activities, the outer space law regime would be not compatible with the Security Council decision process in that the former presupposes the agreement among all States parties, while the latter based upon the agreement between Council member States. Therefore, it is premature to consider the Security Council decision as becoming the lex specialis of the space law regime.

• The Korean Journal of Air & Space Law and Policy
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• v.29 no.2
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• pp.205-237
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• 2014

Last 50 years there were a lot of space subjects launched by space activities of many states and these activities also had created tremendous, significant space debris contaminating the environment of outer space. The large number of space debris which are surrounding the earth have the serious possibilities of destroying a satellite or causing huge threat to the space vehicles. For example, Chinese anti-satellite missile test was conducted by China on January 11, 2007. As a consequence a Chinese weather satellite was destroyed by a kinetic kill vehicle traveling with a speed of 8 km/s in the opposite direction. Anti-satellite missile tests like this,contribute to the formation of enormous orbital space debris which can remain in orbit for many years and could interfere with future space activity (Kessler Syndrome). The test is the largest recorded creation of space debris in history with at least 2,317 pieces of trackable size (golf ball size and larger) and an estimated 150,000 debris particles and more. Several nations responded negatively to the test and highlighted the serious consequences of engaging in the militarization of space. The timing and occasion aroused the suspicion of its demonstration of anti-satellite (ASAT) capabilities following the Chinese test of an ASAT system in 2007 destroying a satellite but creating significant space debris. Therefore this breakup seemed to serve as a momentum of the UN Space Debris Mitigation Guidelines and the background of the EU initiatives for the International Code of Conduct for Outer Space Activities. The UN Space Debris Mitigation Guidelines thus adopted contain many technical elements that all the States involved in the outer space activities are expected to observe to produce least space debris from the moment of design of their launchers and satellites until the end of satellite life. Although the norms are on the voluntary basis which is normal in the current international space law environment where any attempt to formulate binding international rules has to face opposition and sometimes unnecessary screening from many corners of numerous countries. Nevertheless, because of common concerns of space-faring countries, the Guidelines could be adopted smoothly and are believed faithfully followed by most countries. It is a rare success story of international cooperation in the area of outer space. The EU has proposed an International Code of Conduct for Outer Space Activities as a transparency and confidence-building measure. It is designed to enhance the safety, security and sustainability of activities in outer space. The purpose of the Code to reduce the space debris, to allow exchange of the information on the space activities, and to protect the space objects through safety and security. Of the space issues, the space debris reduction and the space traffic management require some urgent attention. But the current legal instruments of the outer space do not have any binding rules to be applied thereto despite the incresing activities on the outer space. We need to start somewhere sometime soon before it's too late with the chaotic situation. In this article, with a view point of this problem, focused on the the Chinese test of an ASAT system in 2007 destroying a satellite but creating significant space debris and tried to analyse the issues of space debris reduction.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.1
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• pp.261-284
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• 2018

The current international legal system does not provide a safeguard against the militarization and the weaponization of outer space. Although the term "peaceful use of outer space" in the 1967 Outer Space Treaty(OST) appears in official government statements or in multilateral space treaties, it is still without an authoritative definition in reviewing national practices. The ambiguous ban on weapons in Article IV of the OST allows countries to loophole on the deployment of other weapons other than nuclear weapons. Meanwhile "Draft Treaty on the Prevention of the Placement of Weapon in Outer Space and of the Threat or Use of Force against Outer Space Objects(PPWT)" to Conference on Disarmament (CD) commissioned by the UN General Assembly's Special Session jointly submitted by China and Russia in 2008 and later revised in 2014, attempting to define and prohibit the proliferation of weapons in outer space and provided definitions of prohibited weapons, are opposed by the US on the grounds that currently there is no arms race in outer space. Some experts support a hard law approach in which binding laws aimed at ultimately creating integrated and binding legal instruments in all aspects of the use of outer space should be adopted to regulate the military use of space. However as a temporary measure the soft law guidelines should be developed for the non liquiet, a situation where there is no applicable law. The soft law could be used to create support for the declaration of the treaties and to create international customary law. For example, the 1963 Declaration of Legal Principles Governing the Activities of States in the Exploration and Use of Outer Space that regulates the activities of the state in the exploration and use of the universe, and the 1992 Principles Relevant to the Use of Nuclear Power Sources in Outer Space will illustrated. While substantial portions of the former was codified later in the 1967 OST, the latter which, although written in somewhat mandatory terms, have been consistently complied with by states, have arguably become part of customary international law. On November 12, 1974, the General Assembly reaffirmed that the development of international law may be reflected inter alia, by declarations and resolutions of the General Assembly which may to that extent be taken into consideration by the International Court of Justice.

• Convergence Security Journal
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• v.22 no.3
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• pp.19-24
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• 2022

Metaverse is a compound word of the English words 'meta', meaning 'virtual' and 'transcendence', and 'universe' meaning the universe. dimensional virtual world. Metaverse is a concept that has evolved one step further than virtual reality (VR, a cutting-edge technology that enables people to experience life-like experiences in a virtual world created by a computer). It has the characteristic of being able to engage in social and cultural activities similar to reality. However, there are many security issues related to this, and cybersecurity vulnerabilities may occur. This paper analyzes cybersecurity threats that may occur in the metaverse environment and checks vulnerabilities.

• Composites Research
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• v.23 no.6
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• pp.14-18
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• 2010

Among the factors that threaten spacecraft, Micrometeoroid and Orbital Space Debris(MMOD) cause damage to spacecraft and impact velocity is about 8~70km/s. Nowadays, various Whipple Shield are studied and applied to protect spacecraft. As the materials used to Shielding System, aluminum is usually used but composite is also used increasingly. So this study compared characteristics of hypervelocity impact of Aluminum and composites through finite element analysis. The Projectile was a spherical shape using Aluminum 2017-T4, and aluminum plate was using Aluminum 6061-T6, CFRP plate was using T300/5208. Initial impact velocity of projectile was 1km/s. As a result, kinematic energy of projectile decreased to about 64J and about 63J for aluminum plate and CFRP plate, respectively after impact. Although both results is almost same about the absorption of impact energy, you can think the CFRP has good ballistic characteristic, because CFRP is lighter about 1.7 times compared with density of aluminum.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.2
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• pp.247-276
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• 2017

The protection of space asset has been new major cause of space militarization. For such purpose, it has been officially announced that a policy of deterring and denying any adversaries from accessing the outer space. Space militarization is to be conversed into a new concept of space weaponization. The USA has announced its policy of space weaponization, while China and Russia have not revealed their plan or policy. Latter States, however, have proposed a draft treaty limiting the deployment of warfare in the outer space. The terms of the Outer Space Treaty, reflecting three significant United Nations General Assembly resolutions from the 1960s, support the position that ground rules must be observed in the exploration and the use of outer space, particularly in the absence of specific space law rules. Yet the combination (and culmination) of these two approaches to the legal regulation of outer space-specific rules as and when agreed by the international community and the translation of principles developed for terrestrial regulation to outer space-still leaves much room for uncertainty and exploitation for military and strategic purposes. As space weaponization may contribute to deterring the use of weapon, it may be not against the UN Charter Article 2(4). If space weaponization might generate the space debris such that the outer space is no more available for exploration and use, it is against the proportionality principle and discrimination principle enshrined in the laws of the war. But, if the limitation upon the kind and use of space weaponization is agreed among the States, then the space weaponization may not be against the laws of the war, and be considered permissible within the rationale of limited war.