• Journal of Navigation and Port Research
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• v.42 no.6
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• pp.427-436
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• 2018

In this study, experimental and numerical analysis were performed on the survivability of a long pipe-type buoy structure in waves. The buoy structure is an articulated tower consisting of an upper structure, buoyancy module, and gravity anchor with long pipes forming the base frame. A series of experiment were performed in the ocean engineering basin of KRISO with the scaled model of 1/ 22 to evaluate the survivability of the buoy structure at West Sea in South Korea. Survival condition was considered as the wave of 50 year return period. Additional experiments were performed to investigate the effects of current and wave period. The factors considered for the evaluation of the buoy's survival were the pitch angle of the structure, anchor reaction force, and the number of submergence of the upper structure. Numerical simulations were carried out with the OrcaFlex, the commercial program for the mooring analysis, with the aim of performing mutual validation with the experimental results. Based on the evaluation, the behavior characteristics of the buoy structure were first examined according to the tidal conditions. The changes were investigated for the pitch angle and anchor reaction force at HAT and LAT conditions, and the results directly compared with those obtained from numerical simulation. Secondly, the response characteristics of the buoy structure were studied depending on the wave period and the presence of current velocity. Third, the number of submergence through video analysis was compared with the simulation results in relation to the submergence of the upper structure. Finally, the simulation results for structural responses which were not directly measured in the experiment were presented, and the structural safety discussed in the survival waves. Through a series of survivability evaluation studies, the behavior characteristics of the buoy structure were examined in survival waves. The vulnerability and utility of the buoy structure were investigated through the sensitivity studies of waves, current, and tides.

• Korean Security Journal
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• no.33
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• pp.197-228
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• 2012

The private security industry in Korea has rapidly proliferated. While the industry has grown quickly, though, private security officers have recently been implicated in incidents involving violence, demonstrating an urgent need for systematic reform and regulation of private security practices in Korea. Due to its quasi-public service character, the industry also risks losing the public's favor if it is not quickly disciplined and brought under legitimate government regulation: the industry needs professional standards for conduct and qualification for employment of security officers. This paper shares insights for the reform of the Korean private security industry through a study of the licensing and training requirements for private security businesses in the United States, mainly focusing on the Private Security Officer Employment Authorization Act (hereinafter the PSOEAA) and the California system. According to the PSOEAA, aspiring security officers shall submit to a criminal background check (a check of the applicants' criminal records). Applicants' criminal records should include not only felony convictions but also any other moral turpitude offenses (involving dishonesty, false statement, and information on pending cases). The PSOEAA also allows businesses to do background checks of their employees every twelve months, enabling the employers to make sure that their employees remain qualified for their security jobs during their employment. It also must be mentioned that the state of California, for effective management of its private security sector, has established a professional government authority, the Bureau of Security and Investigative Services, a tacit recognition that the private security industry needs to be thoroughly, professionally, and actively managed by a professional government authority. The American system provides a workable model for the Korean private security industry. First, this paper argues that the Korean private security industry should implement a more strict criminal background check system similar to that required by the PSOEAA. Second, it recommends that an independent professional government authority be established to oversee and enforce regulation of Korea's private security industry. Finally, this article suggests that education and training course be implemented to provide both diverse training as well as specialization and phasing.