• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.5
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• pp.423-429
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• 2014

Passive attitude stabilization methods using the permanent magnet combined with hysteresis damper and the gravity gradient boom have been widely used for the attitude determination and control of cube satellite, due to its advantage of system simplicity. In this paper, on-orbit thermal characteristics of the cube satellite considering the attitude profiles obtained from the above passive attitude stabilization methods have been investigated through on-orbit thermal analysis. In addition, the effectiveness of the various thermal coatings on the panel for the communication antenna installation has been verified.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.3
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• pp.161-168
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• 2008

The deployable space structure is necessary to minimize the satellite volume and launch cost. For the deployment, passive deployment mechanism has widely been used to attenuate a latch shock induced when the structure is just fully deployed. To reduce the latch shock, viscous damper is applied to the passive deployment mechanism and it can control the deployment speed of the structure. In this paper, dynamic analysis of the deployable space structure using the passive deployment mechanism with the viscous damper has been performed. The viscous damping values have been optimized through numerical simulation. The satellite's attitude influenced by pyro activation for the release of the structure has also been investigated.

• Journal of Aerospace System Engineering
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• v.7 no.1
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• pp.44-49
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• 2013

Passive attitude stabilization method has been widely used for attitude determination and control of cube satellite due to its advantage of system simplicity. In this paper, permanent magnet stabilization method for application of cube satellite attitude control has been introduced and its performance with and without hysteresis damper system has been investigated through a numerical simulation. The simulation results indicate that the permanent magnet stabilization combined with hysteresis damper shows much higher stabilization performance than the system without damper system.

• Journal of Aerospace System Engineering
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• v.7 no.3
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• pp.26-32
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• 2013

Passive attitude stabilization method has been widely usde for attitude determination and control of cube satellite due to its advantage of system simplicity. The permanent magnet installed on the cube satellite passively controls the attitude of the satellite such that the satellite is aligned with the earth magnetic field. In this paper, on-orbit thermal behavior of the cube satellite with the permanent magnet attitude stabilization method has been investigated through on-orbit thermal analysis. THe orbit profile obtained from the aforementioned attitude control method has been reflected in the analysis. The analysis results indicate that the thermal design proposed in this study is effective for satisfying the temperature requirements of the commericial mission equipments.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.1
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• pp.82-90
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• 2014

In this paper, the effect of Lorentz force on the stability of attitude orientation of a charged spacecraft moving in an elliptic orbit in the geomagnetic field is considered. Euler equations are used to derive the equations of attitude motion of a charged spacecraft. The equilibrium positions and its stability are investigated separately in the pitch, roll and yaw directions. In each direction, we use the Lorentz force to identify an attitude stabilization parameter. The analytical methods confirm that we can use the Lorentz force as a stabilization method. The charge-to-mass ratio is the main key of control, in addition to the components of the radius vector of the charged center of the spacecraft, relative to the center of mass of the spacecraft. The numerical results determine stable and unstable equilibrium positions. Therefore, in order to generate optimum charge, which may stabilize the attitude motion of a spacecraft, the amount of charge on the surface of spacecraft will need to be monitored for passive control.

• The Korean Journal of Food And Nutrition
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• v.22 no.2
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• pp.177-184
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• 2009

The study investigated the eating lifestyles of female consumers and whether they influenced weight control behavior. The findings of the study can be summarized as follows. First, the eating lifestyles of the subjects were presented four types: 'active eating life pursuit type', 'safe economical type', 'gourmet type' and 'passive negligence type'. In general, most cases were of the 'passive negligence type'. Second, weight control behavior was analyzed according to eating lifestyle. The results of the analysis indicated that the female consumers of the 'active eating life pursuit type' and 'safe economy type' had high behavior levels in each aspect of weight control attitude, subjective regulation, perceived behavior control, and behavior intention. Third, the 'gourmet type', with a strong preference for taste, and the 'passive negligence type', with fewer eating considerations in general, showed weaker attitudes towards weight control and the recognition of pressure from people around them. As such, the level of consideration for food or eating was correlated with weight control. These findings impliedy that the more active, safer, and economical women are in their general eating style, the stronger they perceive weight control issues.

• Journal of Astronomy and Space Sciences
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• v.8 no.1
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• pp.85-98
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• 1991

Geomagnetism was used to control the attitude of the small scientific satellite at low altitude in sun-synchronous orbit. First, we analyzed the telemetry data. The rotation state of the satellite, can be known from the magnitude and variations of the magnetic field which is measured from the 3 axis magnetometer. In axisymmetric case, it is possible to control the attitude of the satellite by changing the rotation velocity of each 3 axis. The algorithm and the program were developed to calculate the supply time of the current operating the magnetorquer. This attitude control can be applied when the satellite is in tumbling motion and after passive control is attained by the Gravity gradient boom.

• Journal of the Korean housing association
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• v.22 no.6
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• pp.31-42
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• 2011

The purpose of the study was to investigate the characteristics of energy use behaviors and energy saving consciousness of multi-family housing residents. The energy referred to in this study includes electric energy, heating energy and water usage. This study was conducted from a survey carried out in Seoul and Gyeonggi-do. The results of the study are as follows: First, among the survey questions, the only positive energy saving behaviors shown by the occupants was turning off the lights and the television, and in the use of kitchen appliances; it could therefore be concluded that, in general, energy saving attitude and consciousness were not sufficient to reduce energy consumption. Second, the results showed high mean scores for the behaviors which were easy to control, such as turning off lights and televisions, and low mean scores for the behaviors which required extra effort to completely cut off electricity energy such as pulling out the plugs of electronic appliances. Third, it was found that the occupants generally showed the tendency to save heating energy. However, in cases where the occupants were required to continuously and directly experience indoor temperatures, they expressed passive attitudes toward saving energy. Fourth, they showed wasteful attitudes toward water usage by leaving the tap running when taking showers and washing their faces. Fifth, while they showed a strong energy saving consciousness, they also showed a passive attitude about putting this into practice; there was therefore some gap between attitude and behavior. Lastly, among the socio-demographic factors, age and family lifecycle were very important factors affecting energy use and energy saving consciousness.

• Journal of Mechanical Science and Technology
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• v.14 no.8
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• pp.807-815
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• 2000

In this paper, modified discrete time preview control algorithms for active and semi-active suspension systems are derived based on a simple mathematical 4 DOF half-car model. The discrete time preview control laws for ride comfort are employed in the simulation. The algorithms for MIMO system contain control strategies reacting against body forces that occur at cornering, accelerating, braking, or under payload, in addition to road disturbances. Matlab simulation results for the discrete time case are compared with those for the continuous time case and the appropriateness of the discrete time algorithms are verified by the of simulation results. Passive, active, and semi-active system responses to a sinusoidal input and an asphalt road input are analysed and evaluated. The simulation results show the extent of performance degradation due to numerical errors related to the length of the sampling time and time delay.

• Journal of the Korean Society of Costume
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• v.48
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• pp.37-52
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• 1999

The purpose of this study was to find out the clothing-consumption propensity(CCP) and to classify consumption types in CCP and to classify consumption types in CCP and to compare the classfied groups on their consumer characteristics among Korean female X-generation. The survey method was conducted for this study. The subjects are 477 Koran femal X-generation whose age ranges from 18 to 29 and who reside in Seoul and its adjoined areas. The span of the survey was February through March in 1998. the results were analyzed by using of SPSS/PC+package. 1. The clothing consumption motives among the female X-generation were the sensuous satisfaction for posession motive the were practical necessity of the purcahse successively in order. The clothing consumption attitude were the practical electicism the effective value the favorable attitude on low price goods toward sale items and the self-control over their consumption. 2. According to the CCP consumers were classified into five groups: electice and practical group ostentatious and extravagant group passive and economical group sensuous and practical group and sale-fond group. The respective group showed significant difference in the nine factors of the CCP. 3. Consumtion type group had significantly difference in lifestyle among consumer factor and materialistic propensity influence of economic recession follow consumption among social influence factors.