• Journal of the Korea Computer Industry Society
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• v.10 no.5
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• pp.221-226
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• 2009

The closed system's internal rigid body particle rotation motion can be distinguished by a main body that becomes the core of the rotation and the particles that are subjected to the rotation. The instance of particles becoming bounded to the main body as a holonomic system, has till now, been well defined and formulated in the study of Kinetics, and the structure of the formulas relate well to reality. However, when the structure is non-holonomic it deviates from these existing equations. The purpose of this research is to categorize the differences between a holonomic system and a non-holonomic system when rotating, through devices. With a special emphasis on the real phenomenon of the non-holonomic system which will be formulated in the form of a model or computer simulation. With these formulas, the center of mass shift in a closed rotating motion system and confined motion of external friction will be adequately expressed, so that it may be applied to computer graphics motions methods.

• Journal of the Korean Chemical Society
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• v.34 no.6
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• pp.509-516
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• 1990

1H-nmr chemical shifts and lineshapes of amino-protons of acetamide (AA) in n-alcohols were determined. The chemical shifts are discussed by the Reichardt's solvent polarity parameter, E$_{T}$(30). The following relationship between $\delta$obs and E$_{T}$(30) was obtained. ${\delta}_{obs}$ = ${\delta}_{o}$ ＋ aE$_{T}$ (30) ＋ b[E$_{T}$(30)]$^2$ where ${\delta}_{o}$ is the chemical shift of the solute in gaseous state or at $E_{T}$(30) = 0, a is a characteristic constant for the protons of AA in n-alcohol solutions and b is a constant for the solute (AA)-solvent (n-alcohols) interaction. The barrier of the hindered rotation about the N-C(O) bond in AA was obtained by analysis of the lineshapes of the amino-protons in AA. The behavior of the internal rotation as well as chemical shifts of the amino-protons in AA has been found to be closely related to the $E_{T}$(30) of n-alcohols.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.6
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• pp.469-477
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• 2003

This paper proposes a Carrier-Rotation (CR) PWM technique that is a new solution for the voltage unbalancing problem of flying capacitors in the Flying Capacitor Multi-level Inverter (FCMI). The proposed technique equalizes the utilization of phase leg voltage redundancies corresponding to the charging and the discharging state of individual flying capacitors during each switching period of all the switches. Therefore, the charging and the discharging quantity of flying capacitors are equal, which makes the average variation of flying capacitor voltages become zero and keeps their voltage stable during minimum specified period. It also has the reduced harmonic contents of output voltage and the same switch utilization since all the carrier signals are in phase and the switching frequency of each switch is identical. The proposed technique is analyzed precisely in flying capacitor 3-level inverter and then it has expanded to the FCMI (N-level, N>3). Experimental results on the laboratory prototype flying capacitor 3-level inverter confirm the validity of the proposed technique.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.3
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• pp.267-274
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• 2009

Recently, UAVs (Unmanned Aerial Vehicles) are expected much as the Unmanned Systems for various missions. These missions are often based on the Vision System. Especially, missions such as surveillance and pursuit have a process which is carried on through the transmitted vision data from the UAV. In case of small UAVs, monocular vision is often used to consider weights and expenses. Research of missions performance using the monocular vision is continued but, actually, ground and target model have difference in distance from the UAV. So, 3D distance measurement is still incorrect. In this study, Mean-Shift Algorithm, Optical Flow and Subspace Method are posed to estimate the relative depth. Mean-Shift Algorithm is used for target tracking and determining Region of Interest (ROI). Optical Flow includes image motion information using pixel intensity. After that, Subspace Method computes the translation and rotation of image and estimates the relative depth. Finally, we present the results of this study using images obtained from the UAV experiments.

• Clinics in Shoulder and Elbow
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• v.10 no.1
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• pp.33-41
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• 2007

Purpose: The purpose of this study was to prove the effectiveness of the open medial (glenoid-based) anterior-inferior capsular shift in patients with multidirectional shoulder instability. Materials and Methods: We reviewed 19 patients treated by medial anterior-inferior capsular shift for multidirectional shoulder instability from March, 1998 to December, 2003. 15 patients of them have experienced recurrent dislocation. 8 patients(42%) showed bilateral laxity and 11 patients(58%) generalized ligamentous laxity, and 2 patients(10.5%) voluntary subluxation. An average follow-up was 24 months (range : $9{\sim}32$ months). Results: Pain improved in 18 patients of all. There was an average loss of 10 degree of external rotation, but no limitation of activity of daily living. There was no redislocation and subluxation, but two patients had some apprehension in sports activity. With Rowe score, the result was excellent or good in all patients. There were hematoma and local skin problem in 1 patient, but all had healed up. Conclusion: Medial anterior-inferior capsular shift in multidirectional shoulder instability provided satisfactory results in pain relief, patient's satisfactions and stability of glenohumeral joint. Though some of them have anterior gleniod deformities and large Hill-Sachs lesions, we could get good stabilities.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.2
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• pp.153-163
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• 2004

The control objective in hard disk drives is to move head as fast as possible to target track and position the head over the center of target track in the presence of external disturbances. The external shock or disk clamping error in manufacturing process causes the disk center to deviate from the disk rotation center. The disk shift acts on the control system as disturbance and degrades severely the performance of disk drives. In this paper, we present a new controller that compensates for the periodic disturbances very fast. The disturbance compensator is arranged in parallel with the state feedback controller. To avoid the interference with the state feedback controller, the compensator creates compensation signal without the feedback of system output until steady state. The pulse type controller is included additionally for improving the transient performance due to initial state. Finally, in order to demonstrate the superior performance of the proposed compensator. we present some experimental results using a commercially available disk drive.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.450-453
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• 2004

A tactile stimulator array using stacked PZT is fabricated and evaluated in this paper. The purpose of this research is the development of a tactile stimulator to represent the obstacle information for the visually disabled. As a first step of this research, we investigate the physiological characteristics of tactile stimuli and design a tactile stimulator based on the investigated results. Also we evaluated a fabricated tactile stimulator. The prototype of tactile stimulator which has 2$\times$2 tactor elements with 3mm spacing is fabricated using stacked PZT actuator. In order to evaluate the characteristics of this tactile stimulator, physiological experiments are carried out. In the experiment, the threshold of tactile stimulus intensity within a frequency range of 5-500Hz at various stimulus amplitudes are investigated. According to the obtained experimental result, the input signal of tactile stimulator for the effective transfer of obstacle information is determined. Also physiological experiments of multi-stimuli recognition such as shift and rotation are carried out

• Clinics in Shoulder and Elbow
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• v.7 no.1
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• pp.1-4
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• 2004

As the multidirection and posterior instabilities of the shoulder are not only uncommon but responds well to conservative treatment, the shoulder instabilities which requires surgical treatment are traumatic anterior type in most cases, Although various surgical procedures had been used in the past, Bankart procedure is the standard surgical method as a primary procedure in traumatic anterior instability, Nevertheless there has been changes in the techniques of Bankart procedure in order to minimize decrease of external rotation and effectively address capsular laxilty, Capsular shift might be needed if there remains excessive capsular laxity of the inferior capsule after repair of the Bankart lesion, Large bony Bankart lesion should be fixed if possible and severe glenoid rim erosion requires extracapsular bone block after repair of the capsule. Although a few surgical procedures are described for the management of Hill-Sachs lesion in special circumstances, Hill-Sachs lesion does not usually need to be addressed.

• Journal of Korea Multimedia Society
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• v.7 no.12
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• pp.1639-1649
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• 2004

In this paper, a method for detection of forged signatures based on spectral analysis of directional gradient density function and a weighted fuzzy classifier is proposed. The well defined outline of an incoming signature image is extracted in a preprocessing stage which includes noise reduction, automatic thresholding, image restoration and erosion process. The directional gradient density function derived from extracted signature outline is highly related to the overall shape of signature image, and thus its frequency spectrum is used as a feature set. With this spectral feature set, having a property to be invariant in size, shift, and rotation, a weighted fuzzy classifier is evaluated for the verification of freehand and random forgeries. Experiments show that less than 5% averaged error rate can be achieved on a database of 500 signature samples.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.913-916
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• 1998

In this paper, to provide the robustness of character recognition, we propose a recognition method using the dilated boundary curve feature which has the invariance characteristics for the shift, scale, and rotation changes of character pattern. And its some characteristics and effectieness are evaluated through the experiments for both the english alphabets and the numeral digits. The feature vector is represented by the fourier descriptor for a boundary curve of the dilated character pattern which is generated by the circular mask dilation method, and is used for a nearest neighbort classifier(NNC) or a nearest neighbor mean classifier(NNMC). These the processing time and the recognition rate, and take also the robustness of recognition for both some internal noise and partial corruption of an image pattern.