• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.3
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• pp.330-338
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• 2016

Impregnation of shear-thickening fluid(STF) into high-strength fabrics makes a considerable improvement on the ballistic performance of fabric armors. Understanding dissipation augmentation due to shear thickening effects on yarn-yarn and yarn-projectile friction is of great importance in liquid armor research. This paper takes a shearthickening effect into account in numerical simulations by using a velocity-dependent friction model. Impact simulations were performed to validate the friction model as well as to evaluate the ballistic performance of STF-fabrics. Impact simulations on neat fabrics were also conducted to provide baseline results for comparison.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.1
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• pp.129-136
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• 2017

This paper aims to establish a guideline for ridership capacity of different rail vehicles for military passengers. Previous guideline is limited only to a Mungungwha(hauled by diesel locomotive) vehicle, but this paper expands the limitation to ITX- Saemaeul and urban rail vehicles classified to Electric Motivated Unit(EMU). The guideline considers both with and without personal armor conditions, and based on repetitive ridership experiments. The experiments are designed under considerations of the required number of soldiers for the sample spaces of the different rail vehicles. Moreover, the design tries to establish a concept of optimal capacity additionally to a traditional limiting ridership capacity. In order to do this, ridership comfort is questioned to participant soldiers repetitively over the experiments and all answers of them are surveyed as a results of it. The results of the experiments presented by this paper can be referenced to establish a new guideline on ridership capacity for Korean army.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.11
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• pp.1016-1021
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• 2008

The development of the first wall whose major function is to withstand high neutron and heat fluxes is a critical path to fusion power. The materials database and the fabrication technology are being developed for design, construction and safety operation of the fusion reactor. The first wall was designed to consist of the plasma facing armor, the heat sink layer and the supporting plates. and Porous materials are of significant interest due to their wide applications in catalysis, separation, lightweight structural materials. In this study, the characteristics of the sintering process of SiC ceramic, $SiC_f$/SiC composite and porous $C_f$/SiC composite have been introduced order to study of the fusion blanket materials and heat-exchange pannel.

• Journal of the military operations research society of Korea
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• v.22 no.1
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• pp.67-80
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• 1996

Artificial Intelligence(AI) techniques and Object-Oriented(OO) techniques contribute to the simulation modeling of the complex systems. AI techniques are suitable to model human reasoning in the simulation. While OO techniques have advantages of re-usability, maintainability and extendability of the software. Thus, in this paper, we design a knowledge-based object-oriented simulation model, particularly for the logistics analysis of military armor vehicles. The simulation model consists of three modules i.e., scenario, simulation mechanism, and inference engine. The model is designed within the OO paradigm and implemented by using the C++ language. An example case of using the model for the logistic analysis is included.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.113-118
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• 2002

Wave overtopping is one of the most important hydraulic responses of breakwater because it significantly affects its functional efficiency, the safety of transit and mooring on the rear side, wave transmission in the sheltered area, rear side armor stones and to some extent, the structural safety itself. The hydrodynamic characteristics of low crest breakwater by the overtopping rate can be summarized as follows: 1. It is better to use maximum overtopping rate than to use mean overtopping rate for design of coastal structures. 2. Maximum overtopping rate was increase with wave steepness (between 0.01 and 0.02). 3. Overtopping rate is decreased when relation length of berm was over wave length.

• Advanced Composite Materials
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• v.17 no.2
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• pp.111-124
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• 2008

The effect of temperature on natural frequency and damping is investigated in two different composite materials, Kevlar 29 fiber woven and polyethylene cloth, used especially to design ballistic armor. A damping monitoring method is used experimentally to measure the frequency response curve and it is also modeled numerically using a finite element program. The natural frequencies of a material, or a system, are a function of its elastic properties, dimensions and mass. This concept is used to calculate theoretical vibration modes of the composites. The damping properties in terms of the damping factor are determined by the half-power bandwidth technique. Numerically analyzed and experimentally measured time response curves are compared. It is seen that polymer matrix composites have temperature dependent mechanical properties. This relationship is functional and they have different effects against temperature.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.443-445
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• 2008

Determination of allowable overtopping rate for coastal structure is a key point to determine the application of background of coastal structure while considering safety and economic efficiency. Thus, the accurate estimation of overtopping rate against coastal structure is essential. In general, estimation of overtopping against the coastal structure is based on an empirical formula or hydraulic experiment. In this study, we investigate the behavior of overtopping for rubble mound coastal structure with rubble armor stone and wave dissipating block using hydraulics experiment, and domestic or foreign design standard.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1781-1786
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• 2003

This research develops a robot as the device which constructs underwater harbour. This construction is to build a breakwater, which is dangerous and difficult. The hydraulic parallel mechanism-typed robot is developed to mechanize the construction by operating of a stoneworker (or diver) through a joystick. The six-dof robot is able to carry 2-3 tons' heavy stone and put it on the surface of breakwater. This paper presents the mechanical design of a miniature robot, its control and application for the breakwater construction.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.2
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• pp.109-120
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• 2017

A discounted cost model for preventive maintenance of armor units of rubble-mound breakwaters is mathematically derived by combining the deterioration model based on a discrete-time stochastic process of shock occurrence with the cost model of renewal process together. The discounted cost model of condition-based maintenance proposed in this paper can take into account the nonlinearity of cumulative damage process as well as the discounting effect of cost. By comparing the present results with the previous other results, the verification is carried out satisfactorily. In addition, it is known from the sensitivity analysis on variables related to the model that the more often preventive maintenance should be implemented, the more crucial the level of importance of system is. However, the tendency is shown in reverse as the interest rate is increased. Meanwhile, the present model has been applied to the armor units of rubble-mound breakwaters. The parameters of damage intensity function have been estimated through the time-dependent prediction of the expected cumulative damage level obtained from the sample path method. In particular, it is confirmed that the shock occurrences can be considered to be a discrete-time stochastic process by investigating the effects of uncertainty of the shock occurrences on the expected cumulative damage level with homogeneous Poisson process and doubly stochastic Poisson process that are the continuous-time stochastic processes. It can be also seen that the stochastic process of cumulative damage would depend directly on the design conditions, thus the preventive maintenance would be varied due to those. Finally, the optimal periods and scale for the preventive maintenance of armor units of rubble-mound breakwaters can be quantitatively determined with the failure limits, the levels of importance of structure, and the interest rates.

• Journal of the Korean Society of Costume
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• v.61 no.8
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• pp.100-113
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• 2011

The earlier notion of feminism regarding gender equality was changed into that of Postfeminism because of gender differences. The idea of Postfeminism has been present since the 1980s but has been influenced by modern culture theories such as Postmodernism, Poststructuralism, Theory of Power and Discourse and Psychoanalysis. Various features of Postfeminism are found in the medieval warrior images of contemporary fashion. Warrior costumes were men's exclusive property in the medieval ages, but as it is introduced as women's wear in the 21st century, it shows us new fashion images which are constructed by gender deconstruction, differences and pastiche. In this regard, the purpose of this study is to examine a key characteristic of Postfeminism fashion. An article described the historical costumes of medieval warriors and refocused on the development processes of feminism and then conducted an analysis on formative characteristics and Postfeminism tendencies in contemporary women's wear from 2000 to 2011. The results were that materials such as metallic and flexible materials, monotonic and red colors and detailed patterns of armor were used to display forms of exaggeration and restraint. These elements fully and correctly expressed the image of a medieval warrior woman in contemporary fashion. Postfeminism fashion is constructed with feminine power, gendered identity, sensual elegance and a postmodern body. Postfeminism is the contemporary cultural icon and is continuously influencing modern fashion design in the 21st century in a positive and powerful way.