• International Journal of Aeronautical and Space Sciences
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• v.11 no.2
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• pp.87-97
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• 2010

A fault tolerant satellite attitude control scheme with a modified iterative learning law is proposed for dealing with actuator faults. The actuator fault is modeled to reflect the degradation of actuation effectiveness, and the solar array-induced disturbance is considered as an external disturbance. To estimate the magnitudes of the actuator fault and the external disturbance, a modified iterative learning law using only the information associated with the state error is applied. Stability analysis is performed to obtain the gain matrices of the modified iterative learning law using the Lyapunov theorem. The proposed fault tolerant control scheme is applied to the rest-to-rest maneuver of a large satellite system, and numerical simulations are performed to verify the performance of the proposed scheme.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.844-847
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• 1996

This paper describes the servo position control for the 2-axis positioning table the servo controller consists of conventional feedback loops, disturbance observer. To reduce the contour error, which occurs in the multi-dimensions machines, cross-coupled controller(CCC) is suggested. A weak point of the CCC is their low effectiveness in dealing with arbitrary nonlinear contour such as circles and parabolas. This paper introduces a new nonlinear CCC that is based on control gains that vary during the contour movement The gains of CCC and adjusted in real time according to the shape of nonlinear contour. The feedback controller based on the disturbance observer compensated for external disturbance, plant uncertainty and bad effectiveness by friction model. Suggested servo controller which improve the contouring accuracy, apply to the 2-axis system. Simulation results on 2-axis table verify the effectiveness of the proposed servo controller.

• Korean Journal of Veterinary Research
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• v.16 no.2
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• pp.165-171
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• 1976

Experimental approaches on the effectiveness of thimerosal to control growth of Nosema apis (Zander, 1909) were carried out in the rearing honey bees. The rearing honey bees were artificially infected with various levels of spore isolated from local honey bees. The results obtained were summarized as follows: 1. In the experiments of therapeutic chemicals for Nosema disease, 0.01% and 0.02% thimerosal of sucrose-honey mixture was the most effective agent but the each concentration of amprolium, furazolidone, hygiene, sulfadimethoxine and terramycin did not show the any effects 2. It showed very high therapeutic effectiveness (over than 90%) that the treatment of three times every other day after the treatment of three times consecutive every day with 0.01% thimerosal, or the treatment of three times consecutive every day with 0.02% thimerosal. 3. When 0.02% thimerosal was administered three times consecutive every day to honey bees at the 4th day before artificial inoculation of N. apis, it showed very high degree (100%) of prevalence control effectiveness, and it also showed high degree (over than 90%) in administration at the 7th day before, and over than 80% at the 10th day before. Then authors found that thimerosal has the prevalence control effectiveness as well as the treatment effectiveness. 4. In the rearing honey bee colony, 0.02% thimerosal showed the high degree (over than 80%) of therapeutic effectiveness with the various levels which contained from the light decree of infection to the severe degree of it.

• International Journal of Aeronautical and Space Sciences
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• v.14 no.2
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• pp.152-161
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• 2013

This paper presents a control effectiveness analysis of the hawkmoth Manduca sexta. A multibody dynamic model of the insect that considers the time-varying inertia of two flapping wings is established, based on measurement data from the real hawkmoth. A six-degree-of-freedom (6-DOF) multibody flight dynamics simulation environment is used to analyze the effectiveness of the control variables defined in a wing kinematics function. The aerodynamics from complex wing flapping motions is estimated by a blade element approach, including translational and rotational force coefficients derived from relevant experimental studies. Control characteristics of flight dynamics with respect to the changes of three angular degrees of freedom (stroke positional, feathering, and deviation angle) of the wing kinematics are investigated. Results show that the symmetric (asymmetric) wing kinematics change of each wing only affects the longitudinal (lateral) flight forces and moments, which implies that the longitudinal and lateral flight controls are decoupled. However, there are coupling effects within each plane of motion. In the longitudinal plane, pitch and forward/backward motion controls are coupled; in the lateral plane, roll and side-translation motion controls are coupled.

• Journal of Preventive Veterinary Medicine
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• v.42 no.4
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• pp.163-170
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• 2018

The cost-effectiveness of foot-and-mouth disease (FMD) control strategies was evaluated using a simulation model fitted to the 2010/11 FMD epidemic in the city of Andong, Republic of Korea. Seven FMD-control strategies were evaluated with respect to the direct cost of a FMD-control strategy, such as slaughtering, movement restriction, and vaccination. All the strategies included pre-emptive slaughtering, movement restriction, and vaccination, but the levels of each control option were different. The simulated median cost of the baseline FMD-control strategy (three kilometers of pre-emptive slaughtering area, 100 days of movement restriction and vaccination of all FMD-susceptible animals in the study area) was estimated to be USD 99.7 million. When a five kilometer vaccination area was applied (with the other control measures being the same as the baseline strategy), the simulated median cost was reduced to USD 81.1 million from USD 99.7. The simulated median costs were USD 107.6 million for a five kilometer radius slaughtering area and USD 168.8 million for 60 days of movement restriction. The FMD-control strategy cost decreased with increasing number of farms depopulated per day. The probability of passive surveillance being effective or the probability of the successful implementation of movement restrictions were increased. Cost-effectiveness analysis is a suitable tool for evaluating the financial consequences of FMD-control strategies by comparing the cost of control strategies for a specific area.

• Journal of Korean Academy of Nursing Administration
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• v.8 no.3
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• pp.457-474
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• 2002

Purpose : The purpose of this study was to construct the Organizational Effectiveness Model that explains and predicts the effectiveness of a nursing unit from the organizational-behavioral perspective. Furthermore, this study arms to develop a comprehensive organizational effectiveness model. Method : The subjects of this study consist of two groups: 455 nurses and 538 patients. Staff nurses who were employed and twenty patients from each ward in four university hospitals located in Seoul, Pusan and Kyungki were involved. Data were collected from October 4th to October 14th in 2000 by self-report questionnaire. Data were analyzed by the SAS for the general characteristics of the subjects, descriptive statistics, test for the reliability and correlations. Fitness of the hypothetical model were tested using Lisral 8.12(a) program. Result : With the findings from this study, duration of employment and the locus of control among the characteristics of the nurses, job enrichment among the characteristics of nursing job were direct or indirect predictors of the organizational effectiveness of the nursing units. Group dynamics in the nursing units and the characteristics of organizational behavior were mediating variables for the organizational effectiveness of the nursing units, and affect directly and indirectly on the individual outcome and group outcome to the great extends. Conclusion : Therefore, nursing managers ought to develop career ladder program and based job enrichment program in order to improve the organizational effectiveness of the nursing units. Additionally, programs to improve organizational effectiveness via improve group dynamics and characteristics of the organizational behaviors should be developed.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.04a
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• pp.387-393
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• 2001

Installing vibration control devices in the structure rises as a solution instead of increasing structural strength considering construction cost. Especially, viscoelastic dampers show excellent vibration control performance at low cost and are easy to install in existing structures compared with other control devices. Therefore, cost-effectiveness of structure with viscoelastic dampers needs to be evaluated. Previous cost-effectiveness evaluation method for the seismically isolated structure(Koh et al., 1999;2000)is applied on the building structure with viscoelastic dampers, which combines optimal design and cost-effectiveness evaluation for seismically isolated structures based on minimum life-cycle cost concept. Input ground motion is modeled in the form of spectral density function to take into account acceleration and site coefficients. Damping of the viscoelastic damper is considered by modal strain energy method. Stiffness of shear building and shear area of viscoelastic damper are adopted as design variables for optimization. For the estimation of failure probability, transfer function of the structure with viscoelastic damper for spectral analysis is derived from the equation of motion. Results reveal that cost-effectiveness of the structure with viscoelastic dampers is relatively high in how seismic region and stiff soil condition.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.87-91
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• 2005

A conceptual design for the movable roll vane system is done for the roll stability control of KSLV-I. The control effectiveness of the roll vanes is estimated using the numerical simulation. The hinge location is selected to minimize the torque requirement at the maximum dynamic pressure condition, and the maximum torque of 3.0 kN-m is found to be required to actuate the roll vanes for the entire range of operation. An electro-mechanical actuator system which is composed of a DC motor, the speed reducers, the battery package and the controller is designed using the given requirements, the maximum torque of 3.0 kN-m, the maximum deflection angle of 25 deg. and the maximum angular velocity of 30 deg/sec. More detailed design to make more compact and highly efficient system will be done in the future.

• Smart Structures and Systems
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• v.6 no.1
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• pp.57-72
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• 2010

This paper presents the most significant results obtained within a broad-ranging experimental program aiming to evaluate both the effectiveness and the robustness of a Base Isolation (BIS) and a Tuned Mass Damper (TMD) combined control strategy (BI & TMD). Following a brief description of the experimental model set-up and the adopted kinematic scaling technique, this paper describes the identification procedures carried out to characterize the system''s model. The dynamic response of a small-scale model to recorded earthquake excitations, which has been scaled by using the Buckingham pi-theorem, are later presented and discussed. Finally, the effectiveness and robustness of the combined control strategy is evaluated by comparing the model's dynamic response. In particular, reduction in relative displacements and absolute accelerations due to the application of different mass damping systems is investigated.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.23 no.3
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• pp.5-11
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• 1978

Since 1970, herbicides have been widely used in the crop production, especially in paddy field in Korea. In 1978, both preemergence and postemergence type herbicides are applied in the approximately 70% of total paddy field and 15% of upland to control weeds. Most herbicides control annual weeds effectively, but perennials have been problems in the paddy field. Under upland conditions, effectiveness of herbicides varies depending on many environmental conditions (soil moisture, soil physical properties, temperature, etc.) as well as uniform application of appropriate amounts of herbicides. In Korea, many research works have been concentrated on the screening of new herbicides in terms of herbicide effectiveness and yield or phytotoxicity of crops, and especially on the paddy field. However, physiological aspects of herbicidal action in plant and interaction of herbicides with the environments have not been studied approximately. Therefore, researches on the uptake of herbicides and the influence of herbicides on the physiological phenomena such as photosynthesis, respiration, nutrient uptake etc., to control troublesome perennial weeds in the paddy field are needed in future. Also some researches are needed to improve effectiveness of herbicirdes under upland conditions.