• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.11 no.3
• /
• pp.102-109
• /
• 2002

The fatigue crack growth under mixed mode condition has been discussed within the scope of linear fracture mechanics such as maximum tangential stress, maximum tangential principal stress and minimum strain energy density. The purpose of this study is to investigate the characteristics of fatigue test crack growth in 304 stainless steel under mixed node. The fatigue test results carried out by using inclined pre-crack specimens was compared to both of the theoretical predictions of the criteria, maximum tangential stress and stain energy density. As difference from theoretical analysis, the transition region from mixed mode to mode I appeared in the fatigue test. There is deep relationship between the angle of slanted pre-crack and transition. Therefore, as applying the different stress intensity factor to each node I+II and mode I, the directions and rates of fatigue crack growth are evaluated more accurately under mixed mode.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.21 no.6
• /
• pp.21-31
• /
• 2017

In the present study, theoretical and numerical analyses have been carried out to investigate the detailed flow characteristics during the mode transition. The theoretical analysis rearranged the knowledge of gasdynamics and the previous studies, and the numerical analysis has conducted to solve the 2D unsteady compressible Navier-Stokes equations with a fully implicit finite volume scheme. To validate the numerical analysis, the experiment was compared with it. The total temperature at the inlet of isolator and the hydrogen fuel equivalent ratio were changed to investigate their effects on the mode transition phenomenon. As the results, the numerical analysis reproduced well the experiment qualitatively, the increment in the hydrogen fuel equivalent ratio induced the scram-mode to ram-mode transition which is discontinuous with a non-allowable region, and the variation in the total temperature changed the boundary of the mode transition.

• Journal of Aerospace System Engineering
• /
• v.1 no.2
• /
• pp.6-12
• /
• 2007

Flight modes of automatic flight control system for light general aviation flight deck. Garmin G1000, were realized using Stateflow. In developing aircraft, it is difficult to verify the operational flight program in particular branch statement because developer can not see any visual logical steam. So, Stateflow has been used to visualize logical stream, transition from one flight mode to another flight mode. The performance was approved by applying flight mode transition conditions of G1000 to proposed transition system that is composed of states, switches, events, data and transition conditions. DURMI-II was used as 6-DOF simulation model.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.18 no.1
• /
• pp.39-44
• /
• 2010

A method is presented of dynamic determination of mode transition probability for IMM in order to improve the accuracy performance of maneuvering target tracking for air traffic control surveillance processing system under multiple radar environment. It is shown that dynamic determination of mode transition probability based on the time intervals between the data input from multiple radars gives the optimized performance in terms of position estimation accuracy.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.10 no.3
• /
• pp.100-107
• /
• 2011

To evaluate the wear characteristics of very thin ceramic coated layer, it is very important to investigate its wear process in great detail. An effective method for investigating the wear of a thin layer is the observation of wear process in microscopic detail, using in-situ system. In this study, based on the SEM Tribosystem as in-situ system, the microscopic wear mode of TiN coatings was investigated in repeated sliding. Consequently, four modes were revealed for TiN coatings: Ploughing, powder formation, flake formation and coating delimitation. Sc(Severity of contact) can clarify transition condition of those microscopic wear modes.

• Current Optics and Photonics
• /
• v.5 no.3
• /
• pp.243-249
• /
• 2021

In this paper, the sensing characteristics of a double cladding fiber (DCF) long-period fiber grating (LPFG) to the surrounding refractive index (SRI) are studied. The outer cladding of the DCF plays the role of the overlay, thus, the mode transition (MT) phenomenon of DCF can be induced by etching the outer cladding radius instead of coating overlays. The response characteristics of the effective refractive index (ERI) of the cladding mode to the outer cladding radius are analyzed. It is found that in the MT range, the change rate of ERIs of cladding modes is relatively larger than that for other ranges. Further, based on the features of the mode transition region (MTR), the phase-matching curve of the 11^th cladding mode is investigated, and the response of the DCF-LPFG to the SRI is characterized by the change of wavelength intervals between the dual peaks under different outer cladding radii. The numerical simulation results show that the SRI sensitivity is greatly improved, which is available to 3484.0 nm/RIU with the fitting degree 0.998 in the SRI range of 1.33-1.37. The proposed DCF-LPFG can provide new theoretical support for designing the DCF-LPFG refractive index sensor with excellent performances of sensitivity, linearity and structure.

• Journal of Fisheries and Marine Sciences Education
• /
• v.22 no.2
• /
• pp.165-179
• /
• 2010

The purpose of this study was to analyze career behaviors(job exploration, job hunting) of the need mode in the women's second labor market transition. To obtain this objective 501 women, who quitted their job in 780 women randomly sampling completed questionnaire. To analyze data, $x^2$, ANOVA were executed. Research results were explained, there were no difference career behaviors, experience of career counseling, experience of career education, aspiration of career behaviors by the need mode in the women's second labor market transition. But, there were difference motivation of labor market entry, career barriers, preference of occupations, level of job competence of career behaviors by the need mode in the women's second labor market transition. The implications of the results on women's second labor market transition of developing career education and counseling programs were discussed and finally suggestions for further study were made.

• Proceedings of the KIPE Conference
• /
• 2016.07a
• /
• pp.173-174
• /
• 2016

This paper proposes a comparison of Voltage Oriented Control (VOC) and Direct Power Control (DPC) under command mode transition for PMSG Wind Turbines (WT). Based on a neutral point clamped three level back to back type Voltage Source Converter (VSC), proposed control scheme automatically control the generated output power to satisfy a grid requirement from the hierarchical wind farm controller. Automatic command mode transition based on the dc-link voltage error provides a command mode changing between grid command and MPPT mode. It is confirmed through PLECS simulations in Matlab. Simulation result shows that proposed control scheme of VOC and DPC achieves a much shorter transient time of generated output power than the conventional control scheme of MPPT with optimal torque control and VOC under a step response. The proposed control scheme makes it possible to provide a good dynamic performance for PMSG wind turbines in order to generate a high quality output power.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1225-1228
• /
• 2004

We have studied the Polymer Stabilized Continuous Director Rotation (PSCDR) mode to solve the thermal shock problem which is core and main problem in CDR mode. The cell filled 95wt. % R2301 FLC and 5wt. % UCL-001 polymer is applied a low DC voltage only near the phase transition temperature from cholesteric to chiral smectic C phase transition to get defect-free alignment. In the previous work, we also confirmed layer deformation induced by an applied DC field only near the phase transition temperature from Ch to $SmC^{\ast}$. Results of layer structure, and characteristics of electro-optical properties between CDR and PSCDR mode will be discussed in this paper. We are also in progress to finalize the layer structures compared between CDR and PSCDR mode by x-ray measurements.

• Journal of Welding and Joining
• /
• v.15 no.1
• /
• pp.109-115
• /
• 1997

The arc stability and the metal transfer mode of high deposition GMA welding were investigated using various compositions of shielding gas with two types of filler, ie solid wire and metal cored wire. As for a solid wire, the transfer mode changed from axial spray to rotational spray with increasing wire feed rate (welding current) and the transition current was different with the gas composition. The gas composition also affected the apparent stability of rotating arc. As for a metal cored wire, on the other hand, no transition occurred and thus spray transfer mode could be applied with the welding current over 500A (deposition rate over 300g/min). Looking for the development of high deposition GMA welding process, above results were discussed in two different ways, one is to elevate the transition current, the other is to stabilize the rotational transfer mode.