• Journal of Advanced Navigation Technology
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• v.21 no.2
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• pp.193-199
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• 2017

In the paper, a dual band-notched monopole antenna is proposed for 2.4 GHz WLAN (2.4 ~ 2.484 GHz) and UWB (3.1 ~ 10.6 GHz) applications. The 3.5 GHz WiMAX band notched characteristic is achived by a pair of L-shaped slots instead of the previous U-shaped slot on the center of the radiating patch, whereas the 7.5 GHz band notched characteristic is achived by C-shaped strip resonator placed near to the microstrip feed line. The measured impedance bandwidth (${\mid}S_{11}{\mid}{\leq}-10dB$) is 8.62 GHz (2.38 ~ 11 GHz) which is sufficient to cover 2.4 GHz WLAN and UWB band, while measured band-notched bandwidths for 3.5 GHz WiMAX and 7.5 GHz bnad are 1.13 GHz (3.15 ~ 4.28 GHz) and 800 MHz (7.2 ~ 8 GHz) respectively. In particular, it has been observed that antenna has a good omnidirectional radiation patterns and higher gain of 2.51 ~ 6.81 dBi over the entire frequency band of interest.

• Journal of the Korea Concrete Institute
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• v.29 no.2
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• pp.169-177
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• 2017

Rather than causing damage from heat, blast, and radiation of a regular nuclear weapon, recently, it is predicted that North Korea has been inventing high altitude electromagnetic pulse (HEMP) missile in order to incapacitate electronic equipment. HEMP shielding facility is used for military purpose today. Despite the electromagnetic shielding effects from high quality compression plates, problems may include such as the possibility of electromagnetic influx resulting in the welding of the compression plates, and difficulties and high cost of construction. Therefore, in this study, a high electrical conducting material was added to the concrete experimental subject to ensure the shielding effect through electromagnetic waves to for the concrete structure, instead of building a shielding facility separately for the structure. Also, among the experimental subjects, 100 ${\mu}m$ of Iron-Aluminum alloy metal spraying coat was applied to two types with the highest shielding effect, and to two types with the lowest shielding effect. The result of the experiment indicates that experimental subjects added with a high electrical conductivity material did not meet the minimum shielding criteria of MIL-STD-118-125-1 standard, but all the experimental material applied to the metal spraying coating satisfied the minimum shielding criteria. In conclusion, it is considered that 100 µm of Iron-Aluminum alloy metal spraying coat contains high efficiency in the HEMP shielding.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.6
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• pp.761-768
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• 2013

New warheads are designed and developed to be highly lethal when used as part of ballistic missile payloads. There are many trades associated with the design of a central warhead core, mainly dealing with the projectiles or penetrators. Obviously, a payload-type configuration is very susceptible to kills from one projectile because of the high impacts required for bomblet or submunition payloads. Based on these requirements, the optimum kill vehicle configuration will have the smallest mass and relative velocity that will kill all the submunitions. The designs of the penetrator shape and size are directly related to the space and weight of the warhead. The shape, size, L/D, penetrator material, and manner in which they are inserted inside the surrounding explosive segments are critical in achieving successful penetrator design. The AUTODYN-3D code was used to study the effect of penetrator penetration. The objective of numerical analysis was to determine the penetration characteristics of the penetrator produced by hypervelocity impacts under different initial conditions such as initial velocity, shape, and L/D of the penetrator.

• Korea and Global Affairs
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• v.1 no.2
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• pp.171-208
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• 2017

This paper is to analyze the type characteristics and prospects of the North Korean nuclear strategy. To this end, the paper is composed of 5 chapters titled introduction; the concept and type of nuclear strategy; the nuclear capabilities of North Korea and the declarative nuclear strategy; the operational characteristics and prospects of the North Korean nuclear strategy; and conclusion. Recently, the deployment of nuclear weapons and the enhancement of nuclear capabilities in North Korea have raised serious problems in our security and military preparedness. Nuclear strategy means military strategy related to the organization, deployment and operation of nuclear weapons. The study of North Korea's nuclear strategy begins with a very realistic assumption that the nuclear arsenal of North Korea has been substantiated. It is a measure based on North Korea's nuclear arsenal that our defense authorities present the concepts of preemptive attack, missile defense, and mass retaliation as countermeasures against the North Korean nuclear issue and are in the process of introducing and deploying them. The declared nuclear declaration strategy of the DPRK is summarized as: (1)Nuclear deterrence and retaliation strategy under the (North Korea's) Nuclear Weapons Act, (2)Nuclear preemptive aggression, (3)The principle of 'no first use' of nuclear weapons in the 7th Congress. And the intentions and operational characteristics of the North Korean nuclear strategy are as follows: (1)Avoiding blame through imitation of existing nuclear state practices, (2)Favoring of nuclear strategy through declarative nuclear strategy, (3)Non-settlement of nuclear strategy due to gap between nuclear capability and nuclear posture. North Korea has declared itself a nuclear-weapon state through the revised Constitution(2012.7), the Line of 'Construction of the Nuclear Armed Forces and the Economy'(2013.3), and the Nuclear Weapons Act(2013.4). However, the status of "nuclear nations" can only be granted by the NPT, which is already a closed system. Realistically, a robust ROK-US alliance and close US-ROK cooperation are crucial to curbing and overcoming the North Korean nuclear threat we face. On this basis, it is essential not only to deter North Korea's nuclear attacks, but also to establish and implement our own short-term, middle-term and long-term political and military countermeasures for North Korea's denuclearization and disarmament.

• The Korean Journal of Air & Space Law and Policy
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• v.26 no.2
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• pp.203-237
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• 2011

Since USSR successfully launched its satellite "Sputnik"in 1957, many countries including US and USSR began military use of space, and engaged in arms race in space, which is against spirit and ideals of peaceful use of space as common heritage of mankind stipulated in many treaties such as Outer Space Treaty. With worsening Cold War between East and Western Bloc, this military use of space and arms race in space has been intensifying. Regarding the ideals of peaceful use of space, it is interpreted that military use of space is possible unless it does not have the purpose of aggression. The military use of space may have diverse forms such as attacking satellites in space, or attacking from satellites, making use of present and future technologies available which should include the use of nuclear and kinetic/hyper-speed weapons, laser, particle beams, near explosion, disturbance weapons in different directions (i.e., surface to space, space to space, and space to surface). Arms control is being implemented by the efforts of many countries in different formalities including legislature of international treaties under the auspices of UNCOPUOS and prohibition of weapons of mass destruction. Taking outstanding examples aiming at arms control by international community, there are confidence building measures (CBM), strengthening implementation of existing treaties, partial ban of nuclear tests, countryand regional approach, comprehensive approach and measures having legally binding force. While U.S. has surpassed other countries concerned in the area of military useof space, it withdrew from OST in early 2000s, thereby raising concern of international community. It requires concerted efforts of cooperationand implementation by international society to make sure peace of mankind and environmental conservation through arms control in space. Observing de facto possession of nuclear weapons by North Korea following series of nuclear tests and launching satellites, and efforts of launching rockets by South Korea, it is strongly needed for both countries to take part in arms control efforts by international community.

• Maritime Security
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• v.7 no.1
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• pp.31-60
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• 2023

This study proposes a new convergence weapon system that combines the covert placement and detection abilities of a self-propelled mobile mine with the rapid tracking and attack abilities of supercavitating rocket torpedoes. This innovative system has been designed to counter North Korea's new underwater weapon, 'Haeil'. The concept behind this convergence weapon system is to maximize the strengths and minimize the weaknesses of each weapon type. Self-propelled mobile mines, typically placed discreetly on the seabed or in the water, are designed to explode when a vessel or submarine passes near them. They are generally used to defend or control specific areas, like traditional sea mines, and can effectively limit enemy movement and guide them in a desired direction. The advantage that self-propelled mines have over traditional sea mines is their ability to move independently, ensuring the survivability of the platform responsible for placing the sea mines. This allows the mines to be discreetly placed even deeper into enemy lines, significantly reducing the time and cost of mine placement while ensuring the safety of the deployed platforms. However, to cause substantial damage to a target, the mine needs to detonate when the target is very close - typically within a few yards. This makes the timing of the explosion crucial. On the other hand, supercavitating rocket torpedoes are capable of traveling at groundbreaking speeds, many times faster than conventional torpedoes. This rapid movement leaves little room for the target to evade, a significant advantage. However, this comes with notable drawbacks - short range, high noise levels, and guidance issues. The high noise levels and short range is a serious disadvantage that can expose the platform that launched the torpedo. This research proposes the use of a convergence weapon system that leverages the strengths of both weapons while compensating for their weaknesses. This strategy can overcome the limitations of traditional underwater kill-chains, offering swift and precise responses. By adapting the weapon acquisition criteria from the Defense force development Service Order, the effectiveness of the proposed system was independently analyzed and proven in terms of underwater defense sustainability, survivability, and cost-efficiency. Furthermore, the utility of this system was demonstrated through simulated scenarios, revealing its potential to play a critical role in future underwater kill-chain scenarios. However, realizing this system presents significant technical challenges and requires further research.