• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.252-255
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• 2005

The operation of a gas-turbine engine gradually deteriorates the performance of its main components and often generates the defects of its components. The GPA method has been usually used for the diagnosis of the deterioration. In this study, the diagnostic code of the engine performance using the thermodynamic sensitivity between the sensed parameters and the health parameters has been developed without an application of the commercial program. The single performance deterioration of the turbo-shaft engine for SUAV has been estimated with this code.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.835-843
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• 2010

The objectives of this study were to investigate the effect of fermentation medium on the hydroxyl radical scavenging activity of exopolysaccharides from Inonotus obliquus by response surface methodology (RSM). A two-level fractional factorial design was used to evaluate the effect of different components of the medium. Corn flour, peptone, and $KH_2PO_4$ were important factors significantly affecting hydroxyl radical scavenging activity. These selected variables were subsequently optimized using path of steepest ascent (descent), a central composite design, and response surface analysis. The optimal medium composition was (% w/v): corn flour 5.30, peptone 0.32, $KH_2PO_4$ 0.26, $MgSO_4$ 0.02, and $CaCl_2$ 0.01. Under the optimal condition, the hydroxyl radical scavenging rate (49.4%) was much higher than that using either basal fermentation medium (10.2%) and single variable optimization of fermentation medium (35.5%). The main monosaccharides components of the RSM optimized polysaccharides are rhamnose, arabinose, xylose, mannose, glucose, and galactose with molar proportion at 1.45%, 3.63%, 2.17%, 15.94%, 50.00%, and 26.81%.

• Journal of Distribution Science
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• v.16 no.10
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• pp.47-54
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• 2018

Purpose - The main purpose of the study is to investigate the antecedents of repurchase intention on foreign brand products by Chinese and Indian millennial customers. In addition to this, this study also examines mediating effect of 'CSR' on the relationship between the antecedents and repurchase intention. Research design, data, and methodology - Responses from 202 Chinese university students and 209 Indian university students were finally analyzed. To test the proposed relationships, path analyses, mediation analyses and multi-group analysis were conducted. Results - In China, only brand image had positive effects on repurchase intention. CSR played mediating role between manufacturer's country image and repurchase intention. In India, comparatively, economic factor, manufacturer's country image and brand image had positive effects on repurchase intention. CSR played mediating role between all four antecedents and repurchase intention. Conclusion - This study showed different results of repurchase intentions of Millennial consumers in China and India because cultural and political systems of two countries were so different. So foreign firms should apply customized and differentiated marketing strategies to each country.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.7
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• pp.682-687
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• 2011

Calibration mirror mechanism has been widely used for on-board calibration with black body. The calibration mirror is deployed to reflect the radiation energy from the black body to the image sensor for calibrating the sensor system. After the calibration, the calibration mirror is stowed not to hide a main optical path. It also has a fail-safe function which can stow the mirror by just removing the input power of motor when the calibration mirror is stopped at certain position during the calibration. In the present work, the operation concept, design, torque analysis and functional test results of the calibration mirror mechanism with the aforementioned function have been introduced and investigated.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.9
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• pp.916-924
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• 2008

In this paper dynamic modeling parameters were estimated using a frequency domain estimation method. A systematic flight test method was employed using preprogrammed multistep excitation of the swashplate control input. In addition when one axis is excited, the autopilot is engaged in the other axis, thereby obtaining high-quality flight data. A dynamic model was derived for a small scale unmanned helicopter (CNUHELI-020, developed by Chungnam National University) equipped with a Bell-Hiller stabilizer bar. Six degree of freedom equations of motion were derived using the total forces and moments acting on the small scale helicopter. The dynamics of the main rotor is simplified by the first order tip-path plane, and the aerodynamic effects of fuselage, tail rotor, engine, and horizontal/vertical stabilizer were considered. Trim analysis and linearized model were used as a basic model for the parameter estimation. Doublet and multistep inputs are used to excite dynamic motions of the helicopter. The system and input matrices were estimated in the frequency domain using the equation error method in order to match the data of flight test with those of the dynamic modeling. The dynamic modeling and the flight test show similar time responses, which validates the consequence of analytic modeling and the procedures of parameter estimation.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.5
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• pp.279-290
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• 2020

This study examines how economic preparation for later life directly influences life after retirement. As people's life cycle is gradually getting longer, preparation for the later time with less economic activity after retirement is becoming more important. Thus, this study analyzes the factors influencing life after retirement. Data comes from the Korean Retirement and Income Study (KReIS) surveyed carried out by the National Pension Research Institute in 2015. The analysis includes Cronbach's alpha, Pearson Product Moment Correlation Coefficient and Sobel Test. This study confirms that voluntary retirement has a positive influence on life satisfaction. Results are in line with previous research about the relationship between voluntary retirement and retired life. When a person retires voluntarily, financial preparation can be made in advance for retirement. In case of involuntary retirement, people may experience a sense of loss in personal standing and financial difficulties due to the unexpected situation. Especially, early retirement from the main workplace leads to unstable later life. The study's policy recommendation, in particular, calls on government and businesses to agree on social responsibility for helping employees to retire in the predictable retirement time and, thus, enabling the retiree to decide all aspects of the path after retirement.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.7
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• pp.403-412
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• 2020

The main purpose of this paper is to explore how green supply chain management (GSCM) and its evaluative factors have affected green supply chain management practice and performance in industrial zone. This study proposes a structural equation model of the relationships among four factors: internal awareness (IA); suppliers' pressure (SP); customers' awareness (CA); and regulations pressure (RP) and their effect on GSCM practice (PA) and GSCM performance (PE). We used a survey questionnaire to elicit perceptions/opinions about GSCM from three level of managers of 322 companies in Bac Ninh Province's industrial zones, Vietnam. PLS-SEM 3.0 software was applied to analyze and verify the gathered data, and the proposed hypothesis model. The results of path analysis show that internal awareness and customers' awareness are positively related to the GSCM practice and GSCM performance. However, suppliers' pressure and regulations pressure just impacted on GSCM practice. As a result, the testing of the relationship between GSCM practice and GSCM performance has been verified and supported. The findings of this study can help manager of companies in industrial zone understand the structure of GSCM, associate with the green supply chain management practice and green supply chain management performance, and be successful in green management organizations.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.132-132
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• 2009

To achieve the commercialization of PEM fuel cell, the durability problem must be solved. Recently, many researchers have focused on this durability problem and degradation studies about membrane and electrode have been reported. But durability characteristics of gas diffusion layer is not much reported yet. Durability of GDL is very important to maintain the performance of PEM fuel cell because the main function of GDL is a path of fuel and water and the GDL degradation causes the loss of the GDL function. In this study, the degradation of GDL, especially, the mechanical degradation process was investigated with the leaching test. The effect of water dissolution was observed through the test and the amount of GDL degradation was measured with various measurement methods such as weight measurement, static contact angle measurement, scanning electron microscope. After 2,000 hours test, the GDL showed structural damage and loss of hydrophobicity.

• Fire Science and Engineering
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• v.22 no.5
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• pp.137-147
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• 2008

This study has investigated fire safety rules related with traditional temples and main fire causes and cases to traditional temples among traditional wooden buildings so has analyzed fire vulnerability, and through a field probe of three traditional temples in Eunpyeonggu Seoul which have cultural properties, has analyzed geographical conditions, going out path spot reaching time required of a fire brigade, fire protection system, fire prevention administration and security system, factors of fire vulnerability, and has presented about fire safety plans of traditional temples.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.8
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• pp.788-795
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• 2011

In this paper, we present the requirements specification to develop the small ring laser gyroscope(RLG) which is applicable to the medium-grade inertial navigation system(INS) widely used as a main navigation system. To this end, first we analyse the performance specifications of RLG which is needed to configure the medium-grade INS and then we present the design results of RLG to meet the performance specifications, based on the overseas technology survey and the theoretical analysis. It is also shown in this paper what technology is required to develop a small RLG.