• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2529-2534
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• 2003

A quadruped walking robot has a superior adaptablility as well as highly adaptable mobility in various environments. These special advantages are outstanding in the mobile robot group. In this work, we introduce the method for omni-directional gait and rotational gait which is the generalized control algorithm to perform any direction commands. In addition, to improve the stability of quadruped walking robot, we performed the optimization between walking angle and sequence of feet. The proposed ideas are applied to the actual design of MRWALLSPECT III(Multifunctional Robot for Wall inSpection version 3) that is designed to inspect of the large surface of industrial utilities. By implementing the proposed idea on the robot, it’s effectiveness is experimentally confirmed.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2529-2532
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• 2003

The quality of agricultural products is represented a degree of freshness and a special qualify that has a close relation to commercial value. To grade tomatoes, it used to nondestructive equipment of a charge-coupled device(CCD) camera and near-infrared(NIR) spectrum analysis method. The NIR spectrum analysis method is used to determine internal qualities such as a brix and an acidity. The CCD camera is used to measure external qualities like color and a size of tomatoes. This paper explaines the structure and movement of the automatic grade system and applies the algorithm for deformed tomtatoes and characteristics of tomatoes through image processing to the grade system.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2521-2529
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• 2018

This paper deals with a sampled-data tracking control problem for the Takagi-Sugeno fuzzy system with external disturbances. We derive a stability condition guaranteeing both asymptotic stability and H-infinity tracking performance by employing a newly proposed time-dependent line-integral fuzzy Lyapunov-Krasovskii functional. A new integral inequality is also introduced, by which the proposed stability condition is formulated in terms of linear matrix inequalities. Finally, the effectiveness of the proposed method is demonstrated through a simulation example.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2529-2533
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• 1999

This paper proposes a modified hysteresis current control method based on space vector modulation. The proposed method differs from former works in that it uses effective voltage vectors instead of zero vectors while not significantly increasing the circuit complexity. The circuit uses outer band that is slightly wider than the usual current limit band (inner band) to detect the phase of current command and thereby the region information. The comparator output signals associated with the inner and outer band are used to determine the proper voltage vector that minimizes the current error and number of switching, with simple logic circuitry. The utilization of effective voltage vector is of particular importance when the ac-side emf is relatively large. Both the simulation and experiment show that the proposed method is more effective than the conventional one that uses zero vectors, in reducing the number of switching over a range of ac-side emf variation.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2527-2529
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• 1998

Measurement equipment, which consists of He-Ne laser, objective lens, CCD camera and position sensitive detector, was developed for the dynamic response of micromirror. This equipment can measure the tilting direction and angle, the rise time and frequency response of micromirror to the input signal. It was found that the rise time of the micromirror was less than 10${\mu}m$ and the resonant frequency was about 25kHz.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2524-2529
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• 2008

The thermal system like a combustion chamber is believed to experience a significant instability problem with vibration in case that the thermal energy or the acoustic energy are transformed into a different form through a relevant path. This study deals with a numerically- predicted, Thermoacoustic instability in a Rijke tube by using a non-linear model for a heat source. The heating part where the energy transformation occurs actively is modeled after simulating two-dimensional cylinder case with constant surface temperature, and a nonlinear model that accounts for the transfer function of magnitude- and phase-characteristics is properly implemented so as to be dependent on the pulsation strength in the tube. The heat source model is observed to result in equivalent Thermoacoustic instabilities in the Rijke tube except low flow-rate cases in which the natural convection is dominant.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.9
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• pp.2529-2549
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• 2023

For effectively lowering down the risk of cyber threating, the zero-trust architecture (ZTA) has been gradually deployed to the fields of smart city, Internet of Things, and cloud computing. The main concept of ZTA is to maintain a distrustful attitude towards all devices, identities, and communication requests, which only offering the minimum access and validity. Unfortunately, adopting the most secure and complex multifactor authentication has brought enterprise and employee a troublesome and unfriendly burden. Thus, authors aim to incorporate machine learning technology to build an employee behavior analysis ZTA. The new framework is characterized by the ability of adjusting the difficulty of identity verification through the user behavioral patterns and the risk degree of the resource. In particular, three key factors, including one-time password, face feature, and authorization code, have been applied to design the adaptive multifactor continuous authentication system. Simulations have demonstrated that the new work can eliminate the necessity of maintaining a heavy authentication and ensure an employee-friendly experience.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2529-2539
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• 2013

The Korean construction industry has led the miraculous economic boost of Korea by providing solid domestic infrastructures such as highway, roads, and airports. It also played a critical role in global construction market and eaned more than 500 billions dollars in terms of their accumulated international orders. However, domestic construction market has significantly decreased in recent years due to the domestic political environments and global economic crisis. Therefore, the importance of international construction market cannot be more emphasized to the Korean construction market in order for the sustainable growth. There has been, however, little research in the area of identifying required competency elements for the Korean construction industry to stay successful in the global market. The main purpose of this study is to identify elements of core competency to increase global competitiveness for Korean construction industry. Core global construction competency elements were derived from the internal and external environmental analyses along with the extensive literature review, expert interviews and a survey. This study utilized the Importance-Performance Analysis (IPA) and a gap analysis in providing insights on the status competitiveness of the Korean construction industry in terms of required global core competency elements. The analysis shows that project management and financial management are the main areas for improvements required to engineering contractors while construction contractors need to take a more balanced approach among technical, project management, and financial management in order to increase their global competencies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.223-231
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• 2017

The purpose of this study was to determine the relationships among sexual attitudes, autonomy, and harassment experience and to find out how each factor affects the sexual attitudes of college students. The subjects were 236 college students in D city. The data were collected from September 3 - 8, in 2015 using a structured questionnaire. The data were analyzed using the SPSS WIN 18.0 program. For data analysis, a Mann-Whitney U-test, Kruskal-Wallis test, Pearson's correlation coefficients, and multiple regression analysis were carried out. The results are as follows. First, the average scores of sexual attitude, sexual autonomy, and sexual harassment experience were 4.01, 1.95, and 0.95 points, respectively. Second, the individual characteristics in sexual attitude were significantly different in gender (U=2124.50, p=0.000) and department (U=5741.00, p=0.026), sexual autonomy were considerably different in gender (U=2529.50, p=0.001) and satisfaction with personal relationships ($X^2=9.46$, p=0.009), and sexual harassment experience were significantly different in the department (U=5604.00, p=0.007). Third, a positive relationship was observed between the sexual attitudes and sexual autonomy (r=0.517, p<0.01). Sexual autonomy was found to influence the sexual attitudes (${\beta}=0.46$, p<.001). These results highlight the need to develop sex education programs in various situations for college students and that sex education should be implemented constantly.

• Design & Manufacturing
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• v.8 no.2
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• pp.1-6
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• 2014

The narrow-pitched connectors are of interest for small-scale devices such as smart phones because of theirs caling. We conducted an injection molding analysis and a warp analysis for 0.3mm and 0.5mm pitch FPC connectors. We obtained a volumetric shrinkage of 4.344%, a clamping force of 0.2529 tonne, a maximum injection pressure of 76.3 MPa as optimized molding conditions for the 0.3mm pitch FPC connector. We found that, compared with the traditional injection molding technique, the injection molding for narrow-pitched connectors comes with distinct features like low clamping force, high injection molding pressure, and narrow gate size. Adding to the optimization analysis, the deflection of 0.5mm pitch FPC connector was analyzed as well. A maximum deflection of 0.053mm was calculated, which the actual deflection of 0.062mm was compared to. The results deduced a relative error of 17%. We conclude that the deflection analysis along with the optimization analysis can be used as an effective tool to predict the behavior of narrow-pitch connectors although the relative error may need to improve.