• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1868-1870
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• 2006

Neural network is used in many fields of control systems, but input-output patterns of a control system are not easy to be obtained and by using as single feedback neural network controller. And also it is difficult to get a satisfied performance when the changes of rapid load and disturbance are applied. To resolve those problems, this paper proposes a new algorithm which is the neural network controller. The new algorithm uses the neural network instead of activation function to control object at the output node. Therefore, control object is composed of neural network controller unifying activation function, and it supplies the error back propagation path to calculate the error at the output node. As a result, the input-output pattern problem of the controller which is resigned by the simple structure of neural network is solved, and real-time learning can be possible in general back propagation algorithm. Application of the new algorithm of neural network controller gives excellent performance for initial and tracking response and it shows the robust performance for rapid load change and disturbance. The proposed control algorithm is implemented on a high speed DSP, TMS320C32, for the speed of 3-phase induction motor. Enhanced performance is shown in the test of the speed control.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.2
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• pp.186-193
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• 2014

This paper presents characteristic analysis of underwater bearing for canned type electric water pump. Characteristic analysis of underwater bearing was performed using self-developed performance tester, which capable of torque change, noise change, motor speed change and abrasion loss test with respect to temperature change of underwater bearing. The performance tester can be monitored in real time by designing the control unit using the Labview program. The performance experiment was performed through comparison of the silicon carbide (SIC) and the carbon bearing. From the experiment results, performance of SIC bearing was better than carbon bearing at the abrasion and temperature experiment.

• Child Health Nursing Research
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• v.12 no.2
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• pp.260-267
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• 2006

Purpose: This pilot study was to develop Korean version of CDI(The Child Development Inventory) and assess the validation and reliability on K-CDI. Method: The K-CDI is assessed by parent-report method that has designed to screen children developmental functioning on 12 months to 6.5 years of age /or older children who are judged to be functioning in the one to six-year range. The inventory assesses areas of child development in the social, self-help, motor, language, letter and number skills. also, it includes various symptoms and behavior problems that young children may have. Participants were 130 children and their mothers who has lived in Seoul or Gyounggi-Do. Data was analyzed on the ratio of item response, Pearson's correlation, and Cronbach alpha. Results: 270 items with 8 sub-developmental realms were confirmed the reliabilities and validity on Korean children. Total 300 items were selected for restandardization. There was a significant correlation between the score of Social Maturity Scale and K-CDI. The corrlation coefficient alpha was .98. Conclusion: This study indicated that CDI is applicable in the clinical and early childhood educational setting for developmental assessment in Korea.

• Journal of the Korean Society of Safety
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• v.24 no.3
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• pp.59-64
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• 2009

This study was conducted in order to investigate prevalence of musculoskeletal disorders(MSDs) for farmers. The study was based on self-reporting questionnaire. The MSDs prevalence was ascertained by using three criteria, which are known as NIOSH criteria 1, 2 and 3. The results showed that the prevalences of MSDs in at least one body site by criteria 1, 2 and 3 were 96.4%, 66.7% and 26.2%, respectively. The MSDs prevalences for the shoulder by criterion 1 was the highest, followed by the lower back, neck, while the rates for the hip, feet and fingers were relatively low. Farmers' age, types of corps, working hours/day, length of service and length of service in current corps were not significant on the MSDs prevalences, except that types of corps and length of service in current corps were significant on the MSDs prevalences by criterion 2(p

• Korean Parent-Child Health Journal
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• v.16 no.1
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• pp.17-26
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• 2013

Purpose: This study was to examine the mother's knowledge of premature development and rearing and their education needs in order to provide information to develop an education program for premature mothers. Methods: The study participants was 73 mothers of premature infants. Knowledge on premature infant's development and rearing was measured by measurement tools developed by previous research. The education needs about development and rearing were measured by self-report questionnaire. The data were analyzed using descriptive statistics, t-Test, ANOVA using SPSS 20.0. Results: The score of knowledge on development was 59.3 out of 100. The category of knowledge on language development was rated the highest, and motor development category was the lowest. The score of knowledge on rearing was 77.8 out of 100. The knowledge on bathing category was rated the highest and defecation category was the lowest. The growth education needs for premature infant development was the highest education needs of premature infant development. The method for developmental improvement was the highest education needs of premature infant rearing. Conclusion: The results showed that premature infant mothers have less knowledge on premature development than premature rearing, also mothers were interested in development and there were many needs on premature infant's development.

• Journal of the Korean Society for Heat Treatment
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• v.22 no.6
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• pp.339-344
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• 2009

Recently, Laser surface treatment technologies have been used to improve wear charactenitics and fatigue resistance of metal molding. When the laser beam is irradiated on the surface and laser speed is appropriate, the laser focal position is rapidly heated and the thermal energy of surface penetrates the material after irradiation, finally imbuing it with a new mechanical characteristic by the process of self-quenching. This research estimates the material characteristic after efficient and functional surface treatment using HPDL, which is more efficient than the existing CW Nd:YAG laser heat source. To estimate this, microstructural changes and hardness characteristics of three parts (the surface treatment part, heat affect zone, and parental material) are observed with the change of laser beam speed and surface temperature. Moreover, the depth of the hardened area is observed with the change of the laser beam speed and temperature. From the results of the experiments, it has been shown that the maximum hardness is approximately 788Hv when the heat treatment temperature and the travel speed are $1150^{\circ}$ and 2 mm/sec, respectively.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.9
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• pp.768-776
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• 2000

A robust high-speed motion controller is proposed. The proposed controller consists of the proximate time optimal servomechai는 (PTOD) for high-speed motion, disturbance observer (DOB) for robustness, friction compensator, and saturation handling element, In the proposed controller, DOB basically provides the chance to apply PTOS to non-double integrator systems by drastically reducing disturbances as well as unwanted signals due to difference between real system and the double integrator model. But, in DOB-based systems, if control input is saturated due to control input PTOS and/or DOB, overall system stability cannot be guaranteed. To solve this problem, ribust stability, when the control input is saturated. Eventually, a simple saturation handling element is inserted to maintain internal stability of overall system. Also, we explain the our two saturation handling methods, Additional Saturation Element (ASE_ and Self Adjusting Saturation (SAS), are the equivalent solutions of the saturation problem to maintain internal stability. The stability and performance of the proposed controller are verified through numerical simulations and experiments using a precision linear motor system.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.331-334
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• 2002

In this paper, we present two types of vision algorithm that mobile robot has CCD camera. for obstacle avoidance. This is simple algorithm that compare with grey level from input images. Also, The mobile robot depend on image processing and move command from PC host. we has been studied self controlled mobile robot system with CCD camera. This system consists of digital signal processor, step motor, RF module and CCD camera. we used wireless RF module for movable command transmitting between robot and host PC. This robot go straight until recognize obstacle from input image that preprocessed by edge detection, converting, thresholding. And it could avoid the obstacle when recognize obstacle by line histogram intensity. Host PC measurement wave from various line histogram each 20 Pixel. This histogram Is ( x , y ) value of pixel. For example, first line histogram intensity wave from ( 0, 0 ) to ( 0, 197 ) and last wave from ( 280, 0 ) to ( 280, 197 ). So we find uniform wave region and nonuniform wave region. The period of uniform wave is obstacle region. we guess that algorithm is very useful about moving robot for obstacle avoidance.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.221-224
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• 2010

Recently, due to the enormous cost for sending a satellite into an orbit, small and more reliable satellites have been more demanded. An introduction of new binders(HTPB, GAP) and new oxidizers made great improvements of the large thrust modulation. In order to make cost reduction, one prefers to the low melting temperature thermoplastic propellant reforming the manufacturing process dramatically. Solid propellant rockets have been had a problem of the injection accuracy into orbit, but PBS(Post Boost Stage) using a liquid mono-propellant improves the injection accuracy. This paper also gives the direction of the advanced nozzle materials and the motor case.

• Journal of the Korean Institute of Intelligent Systems
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• v.7 no.5
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• pp.46-50
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• 1997

In fuzzy logic control, static fuzzy rules cannot cope with significant changes of parameters of plants or environment. To solve this prohlem, self-organizing fuzzy control. neural-network-hased fuzzy logic control and so on have heen introduced so far. However, dynamically changed fuzzy rules of these schemes may make a fuzzy logic controller Fall into dangerous situations because the changed fuzzy rules may he incomplete or inconsistent. This paper proposes a new adaptive filzzy logic control scheme using a predictivc neural network. Although some parameters of a controlled plant or environment are changed, proposed fuzzy logic controller changes its decision outputs adaptively and robustly using unchanged initial fuzzy rules and the predictive errors generated hy the predictive neural network by on-line learning. Experimental results with a D<' servo-motor position control problem show that propnsed cnntrol scheme is very useful in the viewpoint of adaptability.