• Journal of Institute of Control, Robotics and Systems
• /
• v.10 no.10
• /
• pp.899-906
• /
• 2004

In this paper, fault tolerant algorithm is presented for a servo manipulator system. For fault tolerance of a servo manipulator system, reconfiguration algorithm accommodating a motor's failure has been presented. The algorithm considers a transport's degree of freedoms as redundant joints of a servo manipulator. The reconfiguration algorithm recovers the end effector's motion in spite of one motor's failure A modified pseudo inverse redistribution method has been proposed for the reconfiguration algorithm. Numerical examples and hardware tests have been presented to verify the proposed methods.

• Journal of Power System Engineering
• /
• v.19 no.4
• /
• pp.24-29
• /
• 2015

This paper designs a looper-tension controller for strip top-tail parts in hot strip finishing mills. A three-degree linear model of the looper-tension system is derived by a Taylor's linearization method, where the actuator's dynamics are ignored because of their fast responses. A feedforward shaping controller for the strip top part and a feedforward model reference controller for the strip tail part are respectively designed, they are combined with an ILQ(Inverse Linear Quadratic optimal control) feedback controller for the strip middle part. It is shown from by a computer simulation that the proposed controller is very effective to the strip top-tail parts including the middle part.

• 한국연소학회:학술대회논문집
• /
• 2003.12a
• /
• pp.19-26
• /
• 2003

Experimental measurements of flame structure and soot characteristics were performed for ethene inverse diffusion flames (IDF). IDF has been considered as the excellent flow field to study the incipient soot because soot particle do not experience the oxidation process. In this study, LIF image clarified the reaction zone of IDF with OH signal and PAH distribution. laser light scattering technique also identified the being of soot particle. To address the degree of soot maturing, C/H ratio and morphology of soot sample were investigated. From these measurements, the effect of flow residence time and temperature on soot inception could be suggested, and more details on soot characteristic in the IDF was determined according to fuel dilution and flame condition. The fuel dilution results in a decrease of temperature and enhancement of residence time, but the critical dilution mole fraction is existed for temperature not to effect on soot growth. Also, the soot inception evolved on the specific temperature and its morphology are independent of the fuel dilution ratio of fuel.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.20 no.3
• /
• pp.322-328
• /
• 2011

This paper presents inverse kinematics and workspace analysis of a planar three degree-of-freedom (DOF) parallel manipulator. Furthermore, optimization problem of the manipulator is presented. The manipulator adopts PRR (Prismatic-Revolute-Revolute) mechanism and the prismatic actuators are fixed to the base. This leads to a reduction of the inertia of the moving links and hence enables it to move with high speed. The actuators are linear electric motors. First, the mechanism based on the geometry of the manipulator is introduced. Second, a workspace analysis is performed. Finally, design optimization is carried out to have large workspace. The proposed approach can be applied to the design optimization of various three DOF parallel manipulators in order to maximize their workspace. The performance of mechanism is improved and satisfies the requirements of workspace to align micro-components.

• Journal of the Korean Society for Precision Engineering
• /
• v.10 no.2
• /
• pp.170-177
• /
• 1993

In robotic arc welding, the roll (rotation) of the torch about its direction vector does not have any effect on the welding operation. Thus we could use this redundant degree of greedom for the motion control of the robot manipulator. This paper presents an algorithm for the pseudo- inverse kinematic motion control of the 6-axis robot, which utilizes the above mentioned redunancy. The prototype welding operation and the tool path are also graphically simulated. Since the proposed algorithm requires only the position and normal vector of the weldine as an input data, it is useful for the CAD-based off-line programming of the arc welding robot. In addition, it also has the advantages of the redundant manipulator motion control, like singularity avoidance and collision free motion planning, when compared with the other motion control method based on the direct inverse kinematics.

• Journal of the Korean Society of Radiology
• /
• v.13 no.7
• /
• pp.901-907
• /
• 2019

The aim of this study is to evaluate the ability of target localizations of Leksell GammaPlan(LGP) in Gamma Knife Subthalamotomy(or Pallidotomy, Thalamotomy) of functional diseases. To evaluate the accuracy of LGP's location settings, the difference Δr of the target coordinates calculated by LGP (or LSP) and author's algorithm was reviewed for 10 patients who underwent Deep Brain Stimulation(DBS) surgery. Δr ranged from 0.0244663 mm to 0.107961 mm. The average of Δr was 0.054398 mm. Transformation matrix between stereotactic space and brain atlas space was calculated using PseudoInverse or Singular Value Decomposition of Mathematica to determine the positional relationship between two coordinate systems. Despite the precise frame positioning, the misalignment of yaw from -3.44739 degree to 1.82243 degree, pitch from -4.57212 degree to 0.692063 degree, and rolls from -6.38239 degree to 7.21426 degree appeared. In conclusion, a simple in-house algorithm was used to test the accuracy for location settings of LGP(or LSP) in Gamma Knife platform and the possibility for Gamma Knife Subthalamotomy. The functional diseases can be treated with Gamma Knife Radiosurgery with safety and efficacy. In the future, the proposed algorithm for target localizations' QA will be a great contributor to movement disorders' treatment of several Gamma Knife Centers.

• Journal of the Korean Geotechnical Society
• /
• v.15 no.4
• /
• pp.153-166
• /
• 1999

Since the reliability of results by the existing analyzing method is low, in the case of for excavation performed in urban area whose stability is of great importance, construction control based on field monitoring is always necessary. But the field monitoring reflects only the behavior of construction process that has already been carried out, and it has limitations in predicting the behavior of the expected construction process, which is practically more important for construction control. In this study, construction control system for excavation which can predict the behavior of the expected processes during construction with high degree of accuracy, is developed by adopting inverse analysis. The inverse analied applied field monitoring results to excavation analysis can improve the reliability of predicted results. The developed system uses an elasto-plastic soil spring model for the excavation analysis and the minimization of least squared errors between measured displacements and calculated displacements for the inverse analysis. All the required processes for construction control can be performed as an integrated work within the system reflecting real time application and user's convenience. Their applicabilitis are confirmed by two case studies.

• Journal of Korean Academy of Nursing
• /
• v.13 no.1
• /
• pp.42-53
• /
• 1983

The purpose of this study is to help the care of patient and to his family through comparison of the level of anxiety which between the family of admitted patient and the family without in patient, and to his family through comparison of the level of anxiety which between the family of admitted patient and the family without inpatient and exclude the factors which raised the level of anxiety in them. The experimental group in this study were samples of 200 patient's family selected by random sampling in H. University hospital located in Seoul (Department of patient were internal medicine, surgery, pediatrics and neuropsychiatry). The control group were samples of 70 family without inpatient selected by random sampling in Seoul. The data were collected through STAI (State-Trait Anxiety Inventory) by Spielberger (1970) for measurement to level of state and trait anxiety from April 1st to April 15th in 1982. The contents of data analysis by EDPS included the difference of level of anxiety between experimental and control group, correlationship between general characteristics of experimental group and level of anxiety, and correlation of trait and state anxiety in experimental group. The Findings of this study were as follows: 1) Level of anxiety of experimental group is higher than control group. 2) In the correlation between general characteristics and level of anxiety of experimental group, there were no significant difference which revealed in correlation with age of family member, family life cycle, marital status, the relation between patient and family member, the degree of symptom, number of admission, admission or nonadmission of medical insurance, number of family member, and division of disease to level of anxiety However, according to the sex of family member, hospitalization period, a monthly income of family, the degree of confidence toward medical team, religion of family, academic background of family, a tendency of significant differences to level of anxiety were seen. To put them in the concrete, they were as follow; a) Level of. anxiety on female family member is higher than male in experimental group. b) Admission period of patient is positively related to the level of anxiety of patient's family. c) The degree of confidence of patient's family toward medical team is in inverse proportion to the level of anxiety. d) A monthly income of patient's family is in inverse proportion to the level of anxiety. e) Levlt of anxiety of believer in patient's family is lower than unbeliever. f) The academical background of patient's family is in inverse proportion to the level of anxiety g) Level of state anxiety of patient's family at the time of admission is positively related to the level of trait anxiety.

• Journal of Korean Library and Information Science Society
• /
• v.42 no.4
• /
• pp.311-330
• /
• 2011

This study examined whether there is a correlation between the degree of the financial independence and the establishment and operation of public libraries in 25 local governments in Seoul. It was revealed that there is an inverse correlation between them. According to the results, differently than expected, the local governments with low degree of financial independence generally built and operate more public libraries and assign more library budgets than the local governments with high degree of financial independence. It can be concluded that the local governments with low degree of financial independence show more interest in building and operating public libraries.

• Journal of radiological science and technology
• /
• v.2 no.1
• /
• pp.23-29
• /
• 1979

Roentgenographic film has to be handled with greatest care during removal from the packing, loading of the cassettes and loading of the hanger. In the case of prior to or after exposed film is handled with mechanical pressure in darkroom, the most common phenomena are desensitization or sensitization on roentgenographic film. In order to observe these defect occurring on, it, the author studied on change of the densities where the mechanical pressure reached to the roentgenographic film. 1. The optimal minimum and maximum densities in routine chest x-ray film are from 0.25 to 1.47 2. The dependence of the desensitization occurring on film upon the bent degree of film is in the portion to bent degree over $10^{\circ}$ 3. Appearances of the desensitization on film by the curved degree of film is inverse proportion to it's degree below intervals of 3cm. 4. The more unexposed film is bent with nail tip and is pressured with palm, the more desensitization it was appeared upon film size and pressure weight. 5. The most serious area of desensitization produced by many types of mechanical pressure is in the portion of lung apex and outside lung fields. 6. The tendency of desensitization due to mechanical pressure on unexposed film is more serious than sensitization on exposed film in the view of radiologic diagnosis.