• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.4
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• pp.42-47
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• 2008

The power control system of Smart UAV is similar to the propeller pitch governing concept of turboprop aircraft. The pilot adjusts the engine power directly and the pitch governor controls the propeller pitch to maintain the propeller rotational speed. The electronic engine controller(EEC) of PW206C engine developed for helicopter is not fit for the power control concept of Smart UAV, and therefore the manual back-up system of PW206C engine is used for the engine power control of Smart UAV. Engine performance estimation program is used to predict the control range of power lever angle(PLA) according to the variation of engine output shaft speed, flight altitude and flight speed. These data provide a guide for the PLA control in manual mode operation.

• Journal of Distribution Science
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• v.18 no.10
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• pp.39-52
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• 2020

Purpose: This study aims to find out the relationship between the impact of Korean crew on airline service quality in the global aviation market, which is the representative of the face-to-face sales and can help in the face-to-face market of aviation services. Research design, data: The survey was conducted for about a month from March 1 to April 6, 2020, and a total of 300 copies were used in the analysis of the results. To verify the hypothesis, data was analyzed using the statistical package program SPSS 18.0, and frequency analysis, exploratory factor analysis, correlation analysis, and multiple regression analysis were performed. Results: It is a study on the sales of face-to-face service of crews of global airlines. Non-verbal elements in airline service face-to-face sales have been shown to have a significant impact on service quality. Conclusions: In the face-to-face service sales of global airlines, communication has been shown to affect service quality. A face-to-face sale using mother tongue means important. The better the flight attendant's linguistic face-to-face selling ability, the more positive on the airline's quality of service. It suggests that the communication skills of managers in the aviation service market are important for repurchase.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.222-226
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• 2006

The purpose of this study is to analyze both the design and off design performance simulation of the PW206C turbo shaft engine used in the development of the smart UAV (Unmanned Ariel Vehicle) by KARI(Korean Aerospace Research Institute). Its mainly aims to investigate performance behavior at the un-installed and installed conditions. The ways employed to be able to analyze the performance extensively were mainly carried out by comparison of performance simulation results from both the commercial program 'GASTURB 9' using compressor maps generated by Genetic algorithms (GAs) or Scaling Method, and the engine manufacturer's program 'EEPP'. Off-design performance analysis was performed through matching of both mass flow and work between engine components. The set of performance simulations of the developed analytical models was performed by a commercial program package (GASTURB 9) that provides great flexibility in the choice of independent variables of the overall system. The results from the simulations are used to compare turbo shaft engine (PW206C) performance data obtained by the EEPP. At un-installed condition, it was found that the results with the compressor map generated by GAs were relatively agreed well than those with the compressor map generated by the Scaling Method. The performance calculation results using the compressor map generated by GAs were compared at un-installed condition and installed conditions with ECS-off and ECS-Max in variation of altitude, gas generator speed and flight speed.

• The Journal of the Korea Contents Association
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• v.14 no.3
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• pp.401-413
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• 2014

The principal objective of this study is to examine the relationship between the emotional intelligence and customer orientation in airline service context. Moreover, this study was designed to test the moderating effect of social support to provide fundamental and practical data for airline industry. In this study, 2 hypotheses based on literature reviews were employed. A questionnaire was also developed based on previous studies. A convenience sample of 233 flight attendants was surveyed and a total of 214 usable questionnaires were analyzed. Then the data and hypotheses were examined using multiple regression analysis using SPSS 18.0. The results are as follows. Firstly, emotional intelligence was divided into 'self-emotional appraisal', 'other's emotional appraisal', 'regulation of emotion' and 'use of emotion' according to the literature review. Analysis showed that emotional intelligence has partial effect on customer orientation accordingly. Secondly, social support has partial moderating effects between emotional intelligence and customer orientation. Continuous and systematic training program which build up team work should be conducted to administer 'emotional intelligence'.

• 한국전산유체공학회:학술대회논문집
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• 2000.10a
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• pp.123-128
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• 2000

Orthostatic stress in human cardiovascular system following spaceflight remains a critical problem in the current lifercience space program. The study presented in this paper is part of an ongoing effort to use mathematical models to investigate the effects of gravitational stresses on the cardiovascular system of normals and microgravity adapted individuals. We employ a twelve compartment lumped parameter representation of the hemodynamic system coupled to set-point models of the arterial baroreflex and the cardiopulmonary reflex to investigate the transient response of heart rate to orthostatic stress. We simulate current hypotheses concerning the mechanisms underlying postspaceflight orthostatic intolerance over a range of physiologically reasonable values and compare the simulations to astronaut stand-test data pre-and postflight.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.8
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• pp.365-370
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• 2005

Microwave diagnostics have been widely utilized to measure the important parameters of high temperature and high density plasmas. Reflectometry is known as a promising microwave diagnostic which has a number of merits to measure electron density profiles. In the KSTAR device, X-mode FM reflectometry is planned to measure the plasma density profiles. FM reflectometry is required to extract phase information on raw mixer IF signals, thereby obtaining time-of-flight of reflectometry signals. It is known that the data analysis method is crucial to determine the performance of FM reflectometry In fact, there are several analysis programs which have been utilized in various FM systems. Since each program was developed for a specific device, however, it is difficult to directly apply it to a different reactor like the KSTAR device. It is necessary, therefore, to develop a data analysis program for the KSTAR FM reflectometry. In this paper, complex digital demodulation (CDM) and wavelet transformation are examined in terms of the performance of density profile reconstruction. For the comparison of both methods, FM reflectometry signals are generated on the basis of assumed profiles and the interaction of the X-mode wave and the plasma. In order to see how well both methods work under various conditions, three types of profiles are assumed and noise effects are included. As a result, both methods work well under the condition of gentle density gradient and small noise level. As density gradient becomes steeper and noise level gets higher. the reconstruction performance of wavelet is better than that of CDM.

• Journal of Digital Convergence
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• v.18 no.4
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• pp.211-219
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• 2020

The purpose of the study is to identify the structural equation modeling among work-life balance(WLB), organizational commitment, subjective career success, and turnover intentions. The study data came from 199 respondents, as flight attendants working for large domestic airlines. The research tested structural equation modeling by utilizing the SPSS20.0 and AMOS20.0 statistical program. As the results, the study found that WLB would have a negative impact on organizational immersion, and secondly, the hypothesis that WLB has a positive impact on the subjective career success of the flight attendants. Third, the hypothesis that the organization immersion of the flight attendants would have a positive impact on subjective career success, and fourth, the hypothesis that organizational immersion has a negative impact on the turnover. However, fifth, the hypothesis that subjective career success would have a negative impact on turnover was dismissed. Finally, the hypothesis that WLB would have a positive impact on turnover was adopted. Based on the results of this analysis, the research presents highly significant theoretical and practical implications.

• Journal of Biosystems Engineering
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• v.37 no.3
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• pp.192-200
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• 2012

Purpose: Aerial application of chemicals with an agricultural helicopter allows for precise and timely spraying and reduces working labor and pollution. An attitude controller for an agricultural helicopter would be helpful to aerial application operator. The objectives of this paper are to determine the transfer function models and to estimate the handling qualities of a bare-airframe model helicopter. Methods: Transfer functions of a model unmanned helicopter were estimated by using NAVFIT and DERIVID modules of the $CIFER^{(R)}$ program to the time history data of frequency sweep flight tests. Control inputs of the transfer functions were elevator, aileron, rudder and collective pitch stick positions and the outputs were resulting on-axis movements of the fuselage. Results: Minimum realization of the transfer functions for pitch rate output to elevator control input and roll rate output to aileron control input produced second order transfer functions with undamped natural frequencies around 3.0 Hz and damping ratios of 0.139 and 0.530, respectively. The equivalent time delays of the transfer functions ranged from 0.16 to 0.44 second. Sensitivity analysis of the proposed parameters allowed derivation of minimal realization of the transfer functions. Conclusions: Handling quality of the model helicopter was addressed based on the eigenvalues of the transfer functions, corresponding undamped natural frequencies with damping ratios. The equivalent time delays of the lateral-directional motion ranged from 0.16 to 0.44 second, longer than the 0.1 to 0.15 second requirement for well-controlled typical manned aerial vehicles.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.347-350
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• 2004

A space radiation analysis has been used to evaluate an ability of electronic equipment boxes or spacecrafts to endure various radiation effects, so it helps design thicknesses of structure and allocate components to meet the radiation requirements. A comparison study of space radiation dose analysis programs SPENVIS Sectoring Tool (SST) and SIGMA II is conducted through some structure cases, simple sphere shell, box and representative satellite configurations. The results and a discussion of comparison will be given. A general comparison will be shown for understanding those programs. The both programs use the same strategy, solid angle sectoring with ray-tracing method to produce an approximate dose at points in representative simple and complex models of spacecraft structures. Also the particle environment data corresponding to mission specification and radiation transport data are used as input data. But there are distinctions between them. The specification of geometry model and its input scheme, the assignment of dose point and the numbers, the prerequisite programs and ways of representing results will be discussed. SST is a web-based interactive program for sectoring analysis of complex geometries. It may be useful for a preliminary dose assessment with user-friendly interfaces and a package approach. SIGMA II is able to obtain from RSICC (Radiation Safety Information Computational Center) as a FOR-TRAN 77 source code. It may be suitable for either parametric preliminary design or detailed final design, e.g. a manned flight or radiation-sensitive component configuration design. It needs some debugs, recompiling and a tedious work to make geometrical quadric surfaces for actual spacecraft configuration, and has poor documentation. It is recommend to vist RSICC homepage and GEANT4/SSAT homepage.

• Journal of the Korea Convergence Society
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• v.6 no.4
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• pp.55-64
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• 2015

The purpose of this study is to analyze the relationship between the safety, working condition and the organizational commitment among crews members of airline companies in Korea. The data were collected from 230 employees of the a private airline company who gave their informed consent and completed a self-reported questionnaire in November, 2014. A structural equation model was established. The fitness of the hypothetical model was adequate (${\chi}^2=88.424$, df=48, RMR=0.044, GFI=0.940, CFI=0.964, NFI=0.926, IFI=0.965). Analysis of the hypothetical model demonstrated that effects of safety, working condition were significantly correlated with organizational justice and organizational commitment. The results of this study indicate that it is necessary to develop a safety program and working condition to encourage better organizational commitment of the pilot, leading to a brighter future for domestic airline business.