• 전기학회논문지P
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• 제58권2호
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• pp.130-135
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• 2009

In recent years, researches on rotary inverted pendulum control systems have been significantly focused due their highly nonlinear dynamics and complicated geometric structures. This paper presents a novel control approach for such systems by means of similarity transformation theory. At first, we represent nonlinear system dynamics to the controllability-formed state space model including a time-varying parameter vector. We establish the state-feedback control configuration based on the transformed model and derive an adaptive control law for adjusting desired characteristic equation. Numerical analysis is achieved to evaluate our control method and demonstrate its superiority by comparing it to the traditional control strategy. Furthermore, real-time control experiment is carried out to test its practical reliability.

• 설비공학논문집
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• 제23권9호
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• pp.620-626
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• 2011

The purpose of this study is to evaluate a simulation model of a stacking guidance system (SGS) with a roller guide applicable to the mobile harbor. The study used a small-scale model (1/20) made of wood with rollers in order to compare the dynamic analysis with experiment results. The law of similarity was applied for the validation of the scaled model. In order to construct a more realistic simulation model, the damping coefficient of the dynamic model was adjusted to 0.5 Ns/mm for the wood-to-wood contact condition based on the experimental results. Using this validated model, dynamic simulations were also carried out for containers of 20, 30, and 40 tons. The results showed that the reaction force of the roller guide was increased from 74.7 kN to 91.2 kN as the weight of container increased. For the design of a roller guide for SGS, the results obtained in this study can be used to reduce the reaction force by employing a rubber roller or a highly damped rotational joint.

• 한국농공학회논문집
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• 제59권2호
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• pp.49-55
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• 2017

Recently climate change and urbananization have been increased surface runoff, resulting in flooding. Retention basins have been constructed to control urban flooding by reducing peak flow rate. Recently, the retention basin plays a role in controlling combined sewer overflows (CSOs) as well as urban flooding. In this study, the retention basin with a rotatable bucket was suggested and scale down experiments was performed for the optimum design of the retention basin. Scaled down model was produced using a 3D printer after it was designed as law of similarity. Two times for operating a rotary bucket is required to sweep out the sediments deposited on the bottom of the basin. Optimized dimensions for the retention basin were width of 5 m, height of 5 m, bucket radius of 0.5 m, and bottom slope of 5.0 %. It can be concluded that the results obtained from this study can be used to design the retention basin with a rotatable bucket which does not require energy to operate.

• 가정과삶의질연구
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• 제18권3호통권47호
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• pp.129-146
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• 2000

The purpose of this study was to investigation the variables that affected the generational transmission of household work form mothers to their married daughter. The subjects were 415 married daughters and their mothers living in Seoul and metropolitan areas. Statistical techniques used for this study included descriptive statistics and multiple regression analysis. The results of this study were as follows : First, married daughters; value of household work was significantly affected by total periods of marriage of daughters, daughter's perceived similarity to their mothers' household work. Second, married daughters' preference for household work was significantly affected by mother's occupation (managerialㆍprofessional), mother's perceived similarity, daughter's experience of living with mother-in-law, daughter's sex-role attitude, and daughter's perceived similarity. Third, married daughters' ability to do household work was significantly affected by total periods of marriage for mothers, mother's perceived similarity, and daughter's perceived similarity. Fourth, married daughters' standard of household work was significantly affected by mother's perceived similarity, daughter's occupation (techniciansㆍclerk), daughter's monthly income, and daughter's perceived similarity. Fifth, married daughters' usage level of home equipments was significantly affected by mother's birth order, mother's education, mother's occupation (managerialㆍprofessional), daughter's birth order, daughter's education, and daughter's monthly income. Sixth, Mother related variables had greater power than daughter related ones in explaining daughters' values and preference for household work value and preferences and usage of home equipments. In conclusion, married daughter's consciousness and performance of household work were significantly influenced by their mothers. It was especially so in daughter's usage level of hoe equipments. Accordingly, the results of this study support the existence of generational transmission of household work from mothers to their married daughters with regard to its consciousness and performance. Findings of this study have implications for counsellors, practitioners and educators.

• 소음진동
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• 제9권5호
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• pp.955-965
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• 1999

Centrifugal fans are widely used and the noise generated by the these machines causes one of the most serious problems. In general, the centrifugal fan noise is often dominated by tones at BPF(blade passage frequency) and its higher harmonics. This is a consequence of the strong interaction between the flow discharged form the impeller and the cutoff in the casing. However, only a few researches have been carried out on predicting the noise because of the difficulty in obtaining detailed information about the flow field and casing effects on noise radiation. The objective of this study is to understand the generation mechanism of sound and to develop a prediction method for the unsteady flow field and the acoustic pressure field of a centrifugal fan. We assume that the impeller rotates with a constant angular velocity and the flow field of the impeller is incompressible and inviscid. So, a discrete vortex method (DVM) is used to model the centrifugal by the unsteady Bernoulli equation. Lowson's method is used to predict the acoustic source. A centrifugal impeller and wedge introduced by Weidemann are used in the numerical calculation and the results are compared with the experimental data. Reasonable results are obtained not only for the peak frequencies but also for the amplitudes of the tonal sound.

• Journal of Multimedia Information System
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• 제4권3호
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• pp.107-114
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• 2017

As to talk about computer aided 3D modeling, it can be conformed to the popular aesthetics based theory of heightening the organizing useful visual information. This thesis heightens the formativeness of the 3D modeling from the angle of the Gestalt psychology and attempts a finding of a method as also explains among the grouping laws of Gestalt. They are the definitions and the special features of 'The Law of Proximity', 'The Law of Similarity', 'The Law of Closure', 'The Law of Continuity', etc. And, through a logical, theoretical analysis, the relationships between such laws are found out. And the case examples of the uses of such laws in the 3D animation character designs and the situation in which such laws are applied to the things in the actual lives are analyzed. If it is intended to improve the formativeness of the 3D model forms, the rules of the simplicity, the safety, and the symmetry must be pursued according to the visual recognitions of the human beings. Because the actual objects are seen and touched, other than the visual pursuits by the human beings, the functionalities and the practicalities of the objects must be considered.

• 한국해양공학회지
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• 제15권3호
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• pp.134-141
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• 2001

An experimental method to investigate the dynamic characteristics of buoys in extreme environmental condition is established. Because the buoy model requires a resonable size for accurate experiment, the test condition in model basin that satisfies the similarity law is hardly compatible with capability of test facilities. It is suggested that the linear wave component that is unable to satisfy similarity is separated with others. The model experiment is carried out with mitigated condition for the linear wave components while others including wave drift, current and wind are keeping the similarities. Then, the result can be extrapolated to give the dynamic behavior of buoys n extreme condition because linear wave component is solely responsibly to oscillatory buoy motion and other environmental components are applied as a initial tension. The similarity for current and wind conditions is viewed as equivalence of restoring forces. The validity of proposed method is examined with different types of standard ocean buoys and it indicates that the linearity of measured characteristics is assured with a limitation of resonable distance between test and estimated wave conditions.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 춘계학술대회 논문집
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• pp.208-215
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• 2001

An experimental method to investigate the dynamic charasteristics of buoys in extreme environmental condition is established. Because the buoy model requires a resonable size for accurate experiment, the test condition in model basin that satisfies the similarity law is hardly met with capability of test facilities. It is suggested that the linear wave component that is unable to satisy similarity is separated with others. The model experiment can be carried out with mitigated condition for the linear wave components while others including wave drift, current and wind are keeping the similarities. Then the result is extrapolated to give the dynamic behavior of buoys in extreme condition because linear wave component is soley responsible to oscillatory buoy motion and other environmental components are applied as a initial tension. the similarity for current and wind conditions is viewed as equivalence of restoring forces. the validity of proposed method is examined with different types of standard ocean buoys and it indicates that the linearity of measured characteristics is assured with a limitation of resonable distance between test and estimated wave conditions.

• 전기학회논문지
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• 제61권4호
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• pp.606-611
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• 2012

The similarity, analogy and equivalence between the phenomenon due to electric and magnetic dipoles have been discussed in the open literature for different situations. Here we are presenting the numerical proof of the trajectory of leakage electric field due to a semi-infinite electric dipole layer in the external periphery and the electric field in the space between oppositely charged surfaces. The result is also valid for the fringing electric field of a parallel plate capacitor. The result is also proved to be a dual of Amp$\grave{e}$re's law in the electrostatics due to a semi-infinite electric dipole layer.

• 복식
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• 제66권1호
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• pp.28-41
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• 2016

This paper is aimed at intensively examining the scope of legal protection for fashion designs under the Design Protection Act of Korea. For this purpose, this looked into how the Act defines the concept of design, its requirements, and the prerequisites for acquiring design rights. The study also reviewed statutory interpretations over the judgment of the identity and similarity of designs. For more practical and substantial discussions, this research utilized cases and precedents, which had relevant legal principles. This study also figured out how both the requirements for a design definition - such as merchantability, configuration, visibility, and aesthetics - and the prerequisites for acquiring design rights - like industrial applicability, novelty, and creativity - are interpreted and utilized in actual circumstances. The authors expressed their opinions regarding the criteria of judging the identity and similarity of designs, based on a study of previous cases. Previous rulings show that aesthetics of the exterior design is used as the criteria for determining whether a design is same or similar. So, two designs, which have different specific details, are deemed same or similar, if both designs show similarity in the dominant elements. This is because both designs will produce similar aesthetic qualities. However, if the dominant elements of a design are part of the public domain, and the specific details characterize the design, the latter has to be evaluated in the process. This paper examined scope of legal protection for fashion designs using relevant precedents. The study may serve as academic materials that lead to the establishment of rightful ownership in creative activities.