• Journal of Korea Society of Industrial Information Systems
• /
• v.11 no.2
• /
• pp.40-47
• /
• 2006

The learning control develops controllers that learn to improve their performance at executing a given task, based on experience performing this specific task. In a previous work the authors presented an iterative precision of linear decentralized learning control based on p-integrated teaming method for the vertical dynamic multiple systems. This paper develops an indirect decentralized learning control based on adaptive control method. The original motivation of the loaming control field was learning in robots doing repetitive tasks such as on a]1 assembly line. This paper starts with decentralized discrete time systems, and progresses to the robot application, modeling the robot as a time varying linear system in the neighborhood of the nominal trajectory, and using the usual robot controllers that are decentralized, treating each link as if it is independent of any coupling with other links. Error wave propagation method will show up in the numerical simulation for five-bar linkage as a vertical dynamic robot. The methods of learning system are shown up for the iterative precision of each link at each time step in repetition domain. Those can be helped to apply to the vertical multiple dynamic systems for precision quality assurance in the industrial robots and medical equipments.

• Journal of People, Plants, and Environment
• /
• v.23 no.1
• /
• pp.67-75
• /
• 2020

The purpose of this study was to develop an effective horticultural activity program for the vocational rehabilitation of people with mental disabilities. The subjects of this study were seven persons with mental disabilities in the vocational rehabilitation team of a public health center located in G city, Gyeongsangbuk-do. A total of 10 horticultural programs were held from October 10 to December 11, 2018. Five programs were selected among those that were easy for the persons with mental illness to handle and their preference was high. In each session, the same task was repeated 10 times and finally changes in hand functions and working speed were measured. As a result, the assembly task of the Purdue Pegboard test was 23.6 (SD = 10.5) before the program, 26.6 (SD = 11.5) after planting, 27.7 (SD = 12.2) after wrapping pots, and 28.0 (SD = 13.9) after making mini flower baskets, 26.9 (SD = 12.0) after wrapping a single flower, and 29.1 (SD = 11.9) after making corsages. There was a significant difference between the five programs (p = .016). As a result of measuring the time taken to produce the same 10 products, the average planting time was 9.9 (SD = 4.0) minutes in the first class and 6.0 (SD = 2.3) minutes in the second class (p = .018), and making mini flower baskets was reduced from 35.2 (SD = 10.1) minutes to 21.0 (SD = 7.7) minutes (p = .018), wrapping a single flower from 23.3 (SD = 7.9) minutes to 16.2 (SD = 7.3) minutes (p = .043), and making corsages from 53.6 (SD = 15.9) to 40.8 (SD = 16.8) minutes (p = .043). The working time was significantly shortened in the second class compared to the first class. The class for wrapping pots was shortened from 52.7 (SD = 11.7) to 49.6 (SD = 17.8) minutes, but there was no significant difference (p = .398).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2013.04a
• /
• pp.835-841
• /
• 2013

Modern solid-state gyroscopes (HRG) with hemispherical resonators from high-purity quartz glass and special surface superfinishing and ultrathin gold coating become the best instruments for precise-grade inertial reference units (IRU) targeting long-term space missions. Designing of these sensors could be a notable contribution into development of Korea as a space nation. In participial, 40mm diameter thin-shell resonator from high-purity fused quartz, fabricated as a single-piece with its supporting stem has been designed, machined, etched, tuned, tested, and delivered by STM Co. (ATS of Ukraine) several years ago; an extremely-high Q-factor (upto 10~20 millions) has been shown. Understanding of the best way how to match such a unique sensor with inner glass assembly of the gyro means how to use the high potential in a maximal extent; and this has become the urgent task. Inner quartz glass assembly has a very thin indium (In) layer soldered the resonator and its silica base (case), but effects of internal resonances between operational modal pair of the shell-cup and its side (parasitic) modes can notable degrade the potential of the sensor as a whole, instead of so low level of resonator's intrinsic losses. Unfortunately, there are special combinations of dimensions of the parts (so-called, "resonant sizes"), when intensive losses of energy occurs. The authors proposed to use the length of stem's fixture as an additional design parameter to avoid such cases. So-called, a cyclic scheme of finite element method (FEM) and ANSYS software were employed to estimate different combinations of gyro assembly parameters. This variant has no mismatches of numerical origin due to FEM's discrete mesh. The optimum length and dangerous "resonant lengths" have been found. The special attention has been paid to analyses of 3D effects in a cup-stem transient zone, including determination of a difference between the positions of geometrical Pole of the resonant hemisphere and of its "dynamical Pole", i.e., its real zone of oscillation node. Boundary effects between the shell (cup) and 3D short "beams" (inner and outer stems) have been ranged. The results of the numerical experiments have been compared with the classic model of a quasi-hemispherical shell band with inextensional midsurface, and the solution using Rayleigh's functions of the $1^{st}$ and $2^{nd}$ kinds. To guarantee the truth of the recommended sizes to a designer of the real device, the analytical and FEM results have been compared with experimental data for a party of real resonators. The consistency of the results obtained by different means has been shown with errors less than 5%. The results notably differ from the data published earlier by different researchers.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1458-1463
• /
• 2004

Tracking is one of the most important pre-required task for many application such as human-computer interaction through gesture and face recognition, motion analysis, visual servoing, augment reality, industrial assembly and robot obstacle avoidance. Recently, 3D information of object is required in realtime for many aforementioned applications. 3D tracking is difficult problem to solve because during the image formation process of the camera, explicit 3D information about objects in the scene is lost. Recently, many vision system use stereo camera especially for 3D tracking. The 3D feature based tracking(3DFBT) which is on of the 3D tracking system using stereo vision have many advantage compare to other tracking methods. If we assumed the correspondence problem which is one of the subproblem of 3DFBT is solved, the accuracy of tracking depends on the accuracy of camera calibration. However, The existing calibration method based on accurate camera model so that modelling error and weakness to lens distortion are embedded. Therefore, this thesis proposes 3D feature based tracking method using SVM which is used to solve reconstruction problem.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.13 no.2
• /
• pp.55-62
• /
• 1999

In order to perform a elaborate task like as assembly, manufacturing and so forth of components, tracking control on the trajectory of power coming in contact with a target as well as tracking control on the movement course trajectory of end-effector is indispensable. In this paper, to bring under robust ard accurate control of auto-equipnent systems which disturbance, parameter alteration of system, uncertainty ard so forth exist, neural network controller called dynamic neural processor(DNP) is designed. Also, the learning architecture to compute inverse kinematic coordinates transfonnations in the manirclator of auto-equipnent systems is developed ard the example that DNP can be used is explained The architocture and learning algorithm of the proposed dynamic neural network, the DNP, are described and computer simllations are provided to demonstrate the effectiveness of the proposed learning method using the DNP.he DNP.

• Journal of Information Technology Services
• /
• v.12 no.1
• /
• pp.131-141
• /
• 2013

Matters related to the right to be forgotten started the dispute Europe to introduce it first when Data Protection Directive established in 1995 proceeded revision. Relating to this, diverse disputes proceed on responding to personal information protection and internet laws in our nation. Especially as our National Assembly submitted the law regarding the promotion of information and communication network use and protection of information and amendment of copyright, it is necessary to look into the movement on introduction of law of right to be forgotten closely in detail. EU which attempted the institutionalization for the first time, relating to review of General Data Protection Regulation, proposed opinions such as the necessity to define subjects of personal information concretely and specifically and or protection target and balanced consideration on freedom of expression which is constitutional value. In the case of our nation, there was legislation attempt to introduce the regulation but it was limited in the form of fallen effectiveness without concrete and detailed review on internet law. To solve such problems, it is necessary to look into issues and matters to be considered required to accept right to be forgotten closely and discuss possibility of introducing right to be forgotten, conflicts between fundamental rights becoming issue, effect of goal achievement of personal information protection through the system introduction, and other rational acceptance method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.05a
• /
• pp.607-612
• /
• 2004

Disc brake noise continues to be a major concern throughout the automotive industry despite efforts to reduce its occurrence. Eliminating vibrations during braking is an important task for both vehicle passenger comfort and reducing the overall environmental noise levels. There are several classes of disc brake noise, the major ones being squeal, judder, groan, and moan. In this study, analytical model for moan noise of rear disk brake is investigated. Modeling of the disc brake assembly to take account of the effect of different geometrical and contact parameters is studied through the use of multi-body model. The contact stiffness of the caliper and torque member plays an important role in controlling brake vibration. Therefore, a suitable material pair at the caliper/body contact has been made. An ADAMS model of a rear disc brake system was integrated with a flexible suspension trailng arm from MSC/NASTRAN. A fully non-linear dynamic simulatin of brake system behavior, containing rigid and flexible bodies, was performed for a Prescribed set of operating conditions. Simulation results were validated using data from vehicle experimental testing.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.7
• /
• pp.3213-3230
• /
• 2016

Sensor node (SN) is a crucial part in any remote monitoring system. It is a device designed to monitor the particular changes taking place in its environs. Wireless sensor network (WSN) is a system formed by the set of wirelessly connected SNs placed at different geographical locations within a target region. Precise placement of SNs is appreciated, as it affects the efficiency and effectiveness of any WSN. The manual placement of SNs is only feasible for small scale regions. The task of SN placement becomes tedious, when the size of a target region is extremely large and manually unreachable. In this research article, an automated mechanism for fast and precise deployment of SNs in a large scale target region has been proposed. It uses an assembly of rotating cannons to launch the SNs from a moving carrier helicopter. The entire system is synchronized such that the launched SNs accurately land on the pre-computed desired locations (DLs). Simulation results show that the proposed model offers a simple, time efficient and effective technique to place SNs in a large scale target region.

• Korean Journal of Child Studies
• /
• v.13 no.1
• /
• pp.65-79
• /
• 1992

The present study investigated perception of social authority by children and adolescents removed from illegally built shacks 181 children and adolescents from illegally built shacks and 200 comparative respondants of middle socioeconomic status were investigated. Perception of the social authority figures was classified by 5 categories(self, family member, neighbor, teacher and peer. social authority, collective member) in terms of contactable possibility and psychological distance. The data were analyzed by Hest. The results showed that (1) compared with their middle class peers(M group) children and adolescents from illegally built shacks(S group) perceived social authority figures positively, while they perceived their own family members less favorably. (2) The S group regarded their teachers as more valuable and able than M group. (3) The S group perceived social authority figures, i. e., statemen. polices. national assembly members. public servants and enterprisers, less favorably than their family members. (4) There were main effects of the age and sex variables of respondants. (5) There was an interaction effects between the age. sex and SES variables and was also interation effect between age. sex and task variables in cognition for the social authority figures. There was also an interaction effect between age and SES variables in perception for the personal traits of the social authority figures.

• Journal of Power Electronics
• /
• v.5 no.3
• /
• pp.198-205
• /
• 2005

The mechanical system of a drive can often be modeled as a two- or three-mass-system. The load is coupled to the driving motor by a shaft able to perform torsion oscillations. For the automatic tuning of the control, it is necessary to know the mathematical description of the system and the corresponding parameters. As the manpower and setup-time necessary during the commissioning of electrical drives are major cost factors, the development of self-operating identification strategies is a task worth pursuing. This paper presents an identification method which can be utilized for the assisted commissioning of electrical drives. The shaft assembly can be approximated as a two-mass non-rigid mechanical system with four parameters that have to be identified. The mathematical background for an identification procedure is developed and some important implementation issues are addressed. In order to avoid the excitation of the system with its natural resonance frequency, the frequency response can be obtained by exciting the system with a Pseudo Random Binary Signal (PRBS) and using the cross correlation function (CCF) and the auto correlation function (ACF). The reference torque is used as stimulation and the response is the mechanical speed. To determine the parameters, especially in advanced control schemes, a numerical algorithm with excellent convergence characteristics has also been used that can be implemented together with the proposed measurement procedure in order to assist the drive commissioning or to achieve an automatic setting of the control parameters. Simulations and experiments validate the efficiency and reliability of the identification procedure.