• Bulletin of the Society of Naval Architects of Korea
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• v.26 no.4
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• pp.81-93
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• 1989

The present study attempts to develop the theoretical model for the damage estimation of offshore tubular members which are subjected to the accidental impact loads due to collision, falling objects and so on. For the reasons of the simplicity of the problem being considered, however, this paper postulates that the accidental load can be approximated to be the quasi-static one, in which dynamic effects are negelcted. Based upon the theoretical and experimental results which are obtained from the present study as well as the existing literature, the load-displacement relations taking the interaction effect between the local denting and the global bending deformation into account are presented in the explicit form when the concentrated lateral load acts on the tubular member whose end condition is supposed to be rotation ally free and axially restrained, in which membrane forces develop. Thus, the practical estimation of damage deformation for the local denting and the global bending damage of tubular members against the accidental loads is possible and also the collision absorption capability of the member can be calculated by performing the integration of the area below the given load-displacement curves, provided that all the energy is dissipated to the deforming the member itself.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.10
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• pp.883-893
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• 2018

The inflow of Labor Migrants has been grown up to 600,000 people until now with the adoption of Employment Permit System (EPS) in 2004 until now. However the institutional support lack to ensure their rights and improve their conditions. This is because of their consideration ad temporary labors in South Korean society and labor forces rather than the objects of integration. As a result, the legal status and rights of migrant workers are criticized for their utilization rather than human rights, and human rights protection is insufficient. To this context, this paper analyzed the 19th presidential election pledge of the four political parties (Democratic Party, the Liberty Korea Party, Bareun Party and Justice Party) the majority of the Korean National Assembly, and predicted how the policies of migrant workers would evolve. The study found that there were two political parties that did not mention policies for migrant workers, and the remaining two parties also maintained their current policies. This is probably the biggest reason to recognize migrant workers as temporary residents. However, they should also be aware of the fact, that migrant workers are the members of the Korean society and are the owners of human rights that should be guaranteed, and should consider the policy directions to live with them.

• International Journal of Quality Innovation
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• v.8 no.3
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• pp.81-112
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• 2007

In the competitive global market, firms have to keep profit from innovation activities. A firm makes profits by offering products or services at a lower cost than its competitors or by offering differentiated products at premium prices that more than compensate for the extra cost of differentiation. The IC Package and Testing technology industries were the first high technological industry to build in Taiwan. The Package and Testing industries in Taiwan adopted competitive innovation activities to become stronger. In our study, we want to know how innovation activities influence a firm operating in the IC Package and Testing industries. Our study used a questionnaire and Likert five-point scale to survey the innovation activities, customer and feedback in innovation performance in the IC Package and Testing industry. The wafer level chip size packing technology in our study indicates the innovation activities. Because we need to compare the difference between the wafer level chip size packing technology and wire bonding technology to recognize innovation and how the innovator and customer were influenced. Our conclusions are described below: (1) When the innovator adopts innovation activities that can be maintained using experiments and knowledge, using machine and decision variables more quickly will produce success; (2) Innovators should adopt innovation activities that focus on customers that use knowledge and experimentation, training time and cost. If an innovation forces customers to spend much time and cost to learn new technology or applications, the innovation will not be adopted; (3) Innovators that create innovation performance higher than his customers must also consider the impact upon their customers. We have to remind innovator to focus on why their customers have a different level of evolution in the same innovation activities.

• Journal of Ocean Engineering and Technology
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• v.30 no.2
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• pp.91-99
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• 2016

The global demand for oil and natural gas has increased, and resource development is moving to the deep sea. Floating and flexible offshore structures such as semi-submersible, spar, and FPSO structures have been widely used. The major equipment of floating structures is always exposed to waves, currents, and other marine environmental factors, which cause structural damage. Moreover, flexible risers are susceptible to an exciting force due to the motion of the floating body. The inline and transverse responses from the three-dimensional behavior of a floating structure occur because of various forces. Typical risers are made of steel pipe and applied in the oil and gas development field, but flexible materials such as polyethylene are suitable for OTEC risers. Consequently, the optimal design of a flexible offshore plant requires a dynamic behavior analysis of slender bodies made of the different materials commonly used for offshore flexible risers. In this study, a three-dimensional motion measurement device was used to analyze the displacements of riser models induced by external force factors, and forced oscillation of a riser was linked to forced oscillation under a steady flow and regular wave condition.

• Journal of Digital Convergence
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• v.11 no.12
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• pp.41-47
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• 2013

In circumstances that case studies of management strategy for the domestic media company were rare, this study was performed case analysis of CJ E&M, representative new media/contents company in Korea. An evolutionary perspective is applied to diversification of the business and the external environmental analysis/resource based view are applied to capability evaluation since the inauguration as analysis frameworks. Unlike other media companies, CJ E&M have increased synergies of scale through horizontal, vertical diversification and superior contents strategies. furthermore, there are many advantages of enthusiasm of the leadership, expertise, high human configuration, creative corporate culture, effective contents portfolio. However, it is necessary to note that too much emphasis on competition and the performance of the organization may make organizational atmosphere rigid and weaken the global competitiveness.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.1
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• pp.21-28
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• 1994

This paper discusses the block method on cable stayed bridge. The block method is one of the structural analysis methods, and it calculates the sectional forces and the displacements by combining results of several sub-structural system after analyzing each divided structure by means of finite element method. The block method has two branches, one is based on the force method and the other is based on the displacement method. We can select one of two methods by considering structural stability of divided structures. The conclusion gives some thoughts about cable stayed bridge analysis using this block method. Those are as follows. First, the results of analysis on divided structural system are consistent with those of analysis on global structural system. Second. saving memory volume of computer, we can analyze the complicated multi-cable stayed bridge on personal computer.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.1
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• pp.55-62
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• 2017

The SRP (Solar Radiation Pressure) model has always been an issue in the dynamic GPS (Global Positioning System) orbit determination. The widely used CODE (Center for Orbit Determination in Europe) model and its variants have nine parameters to estimate the solar radiation pressure from the Sun and to absorb the remaining forces. However, these parameters show a very high correlation with each other and, therefore, only several of them are estimated at most of the IGS (International GNSS Service) analysis centers. In this study, we attempted to numerically verify the correlation between the parameters. For this purpose, a bi-directional, multi-step numerical integrator was developed. The correlation between the SRP parameters was analyzed in terms of post-fit residuals of the orbit. The integrated orbit was fitted to the IGS final orbit as external observations. On top of the parametric analysis of the SRP parameters, we also verified the capabilities of orbit prediction at later time epochs. As a secondary criterion for orbit quality, the positional discontinuity of the daily arcs was also analyzed. The resulting post-fit RMSE (Root-Mean-Squared Error) shows a level of 4.8 mm on average and there is no significant difference between block types. Since the once-per-revolution parameters in the Y-axis are highly correlated with those in the B-axis, the periodic terms in the D- and Y-axis are constrained to zero in order to resolve the correlations. The 6-hr predicted orbit based on the previous day yields about 3 cm or less compared to the IGS final orbit for a week, and reaches up to 6 cm for 24 hours (except for one day). The mean positional discontinuity at the boundary of two 1-day arcs is on the level of 1.4 cm for all non-eclipsing satellites. The developed orbit integrator shows a high performance in statistics of RMSE and positional discontinuity, as well as the separations of the dynamic parameters. In further research, additional verification of the reference frame for the estimated orbit using SLR is necessary to confirm the consistency of the orbit frames.

• Smart Structures and Systems
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• v.21 no.4
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• pp.479-491
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• 2018

Shape memory alloys (SMA) exhibit superelasticity which refers to the capability of entirely recovering large deformation upon removal of applied forces and dissipating input energy during the cyclic loading reversals when the environment is above the austenite finish temperature. This property is increasingly favored by the earthquake engineering community, which is currently developing resilient structures with prompt recovery and affordable repair cost after earthquakes. Compared with the other SMAs, NiTi SMAs are widely deemed as the most promising candidate in earthquake engineering. This paper contributes to evaluate the seismic performance of properly designed concentrically braced frames (CBFs) equipped with NiTi SMA braces under earthquake ground motions corresponding to frequently-occurred, design-basis and maximum-considered earthquakes. An ad hoc seismic design approach that was previously developed for structures with idealized SMAs was introduced to size the building members, by explicitly considering the strain hardening characteristics of NiTi SMA particularly. The design procedure was conducted to compliant with a suite of ground motions associated with the hazard level of design-basis earthquake. A total of four six-story CBFs were designed by setting different ductility demands for SMA braces while designating with a same interstory drift target for the structural systems. The analytical results show that all the designed frames successfully met the prescribed seismic performance objectives, including targeted maximum interstory drift, uniform deformation demand over building height, eliminated residual deformation, controlled floor acceleration, and slight damage in the main frame. In addition, this study indicates that the strain hardening behavior does not necessarily impose undesirable impact on the global seismic performance of CBFs with SMA braces.

• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.307-315
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• 2017

This study aims to propose a methodology for future strategies of the Korean petrochemical industry. Instead of using static models or trade related statistical analysis, we derived emerging issues of the Korean petrochemical industry through survey in accordance with the STEPPER analysis. The participants of the survey were limited to leading experts of the field, such as businessmen, researchers and professors. Also, I observed whether the current driving forces are suitable in analyzing the future. Furthermore, emerging trends and emerging issues as far as 2040 were also extracted through horizon scanning and expert interviews. Through this study, three factors, which are the global oil prices, economic prospects, and core material development, have been confirmed. In the future, I believe that not only petrochemical industry, but also other industries such as steel, autos, shipbuilding and so on, can be studied for future scenarios and strategies as well.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.29 no.1
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• pp.39-55
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• 1993

Modal Analysis is the process of characterizing the dynamic properties of an elastic structure by identifying its modes of vibration. A mode of vibration is a global property of an elastic structure. That is, a mode has a specific natural frequency and damping factor which can be identified from response data at practically any point on a structure, and it has a characteristic mode shape which identifies the mode spatially over the entire structure. Modal testing is able to be performed on structural and mechanical structure in an effort to learn more about their elastic behavior. Once the dynamic properties of a structure are known its behavior can be predicted and therefore controlled or corrected. Resonant frequencies, damping factors and mode shape data can be used directly by a mechanical designer to pin point weak spots in a structure design, or this data can also be used to confirm or synthesize equations of motion for the elastic structure. These differential equations can be used to simulate structural response to know input forces and to examine the effects of pertubations in the distributed mass, stiffness and damping properties of the structure in more detail. In this paper the measurement of transfer functions in digital form, and the application of digital parameter identification techniques to identify modal parameters from the measured transfer function data are discussed. It is first shown that the transfer matrix, which is a complete dynamic model of an elastic plate structure can be written in terms of the structural modes of vibration. This special mathematical form allows one to identify the complete dynamics of the structure from a much reduced set of test data, and is the essence of the modal approach to identifying the dynamics of a structure. Finally, the application of transfer function models and identification techniques for obtaining modal parameters from the transfer function data are discussed. Characteristics on vibration response of elastic plate structure obtained from the dynamic analysis by Finite Element Method are compared with results of modal analysis.