• The korean journal of orthodontics
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• v.51 no.6
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• pp.419-427
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• 2021

Objective: The purpose of this study was to evaluate the esthetic preference for various Korean silhouette profiles. Methods: The Korean average male and female profiles were modified by changing the lower facial height and anteroposterior lip position to produce nine types of profiles. In order to test intrarater reliability, the average profile was copied once more to be included for evaluation. A questionnaire containing 10 profiles for each sex, each of which had to be rated for preference on a numerical rating scale from 0 to 10, was administered to 30 adult orthodontic patients, 30 dental students, 30 orthodontists, and 30 dentists excluding orthodontists. The data were statistically analyzed using the intraclass correlation coefficient (ICC), independent t-test, and one-way ANOVA. Results: The ICC of overall intrarater reliability was 0.629. For several profiles, significantly higher scores were given to male profiles than to female profiles (p < 0.05). However, no significant differences were found in the scores for all profiles among the four rater groups. Among the short profiles, a significantly higher score was given to the retruded profile, and among the vertically average and long profiles, a significantly higher score was given to the horizontally average profile (p < 0.001). Among all the profiles, significantly lower scores were given to the protruded profile (p < 0.001). Conclusions: This study revealed good overall intrarater reliability, with several types of male profiles being esthetically preferred over female profiles. Moreover, while retruded and horizontally average profiles were generally preferred, protruded profiles were not.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.2
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• pp.1-11
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• 2021

Salt and pepper is a type of impulse noise. It may appear due to an error in the image transmission process and image storage memory. This noise changes the pixel value at any position in the image to 0 (in case of pepper noise) or 255 (in case of salt noise). In this paper, we present an algorithm for SAP noise reduction. The proposed method consists of three steps. In the first step, the location of the SAP noise is detected, and in the second step, the pixel value of the detected location is restored using a weighted average of the surrounding pixel values. In the last step, a reliability matrix around the reconstructed pixels is constructed, and additional correction is performed with a weighted average using this. As a result of the experiment, the proposed method appears to have similar or higher objective and subjective image quality than previous methods for almost all SAP noise ratios.

• Journal of Korean Academy of Nursing
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• v.17 no.1
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• pp.44-51
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• 1987

The purpose of this study is to identify the leadership and subordination of hospital nurses: to determine the leadership and subordination by nurses' characteristics, which are age, educational background, career, and position of nurses. 279 staff nurses, 13 charge nurses, 32 head nurses and 16 nurse supervisors were participated in this study during the period from Dec. 5 to Dec. 20, 1986. Subjects were instructed to rate at one of five points likert type scale on the 26 items of leadership and subordination. The reliability of the items (Cronbach's α) were 0.63∼0.84. Among the total 26 items, 8 items on authority, 4 items on human relation, 9 items on committment of position and 5items on committment of job were summed to cummulative scores in each category. As a result of data analysis nurses who perceive positive on authority are 68.6% and positive on human relation are 67.9%. The perception of authority is different by age, Career and position of nurses. (P<0.05). And nurses who perceive positive on committment of position are 84.7% and positive on committment of job are 62.1%. The perception of committment for position is different by age, career and position of nurses (P <0.05), and committment of job is different by age and position. (P<0.05).

• Journal of Electrical Engineering and Technology
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• v.11 no.1
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• pp.29-37
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• 2016

Fast and accurate fault diagnosis of the position sensor is of great significance to ensure the reliability as well as sensor fault tolerant operation of the Switched Reluctance Wind Generator (SRWG). This paper presents a fault diagnostic scheme for a SRWG based on the residual between the estimated rotor position and the actual output of the position sensor. Extreme Learning Machine (ELM), which could build a nonlinear mapping among flux linkage, current and rotor position, is utilized to design an assembled estimator for the rotor position detection. The data for building the ELM based assembled position estimator is derived from the magnetization curves which are obtained from Finite Element Analysis (FEA) of an SRWG with the structure of 8 stator poles and 6 rotor poles. The effectiveness and accuracy of the proposed fault diagnosis method are verified by simulation at various operating conditions. The results provide a feasible theoretical and technical basis for the effective condition monitoring and predictive maintenance of SRWG.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.850-853
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• 2011

The position indicator for cryogenic valves used in space launch vehicle should have high reliability and accuracy. Because the valves operate in cryogenic environment, the position indicator has to measure the valve status independently of the environmental factor, such as moisture and external contamination. We have developed the position indicator using a permanent magnet and reed switches to satisfy these requirements. We analyzed the characteristics of a permanent magnet and reed switches, then selected the appropriate components for cryogenic temperature. The shape and position of components were also considered to measure the open/close information of valve accurately Finally, the position indicator was applied to the valve prototype model, and verified the feasibility of design parameters.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.774-779
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• 1998

For the speed control of motors, the position or speed sensors are necessary to obtain the position information of the rotor. Specially, SRM(Switched Reluctance Motor) needs an accurate rotor position data because both the rotor and the stator have a salient pole structure. High functional sensors like resolver or encoder are expensive and have complex connecting lines to the controller so the pure signals are apt to be mixed with noised. In the sight of SRM drives, the high temperature, heavy dust, and the EMI surroundings reduce the reliability of speed and position sensors. Therefore, the speed and position sensorless control algorithms using observer have been accepted widely. In this paper An adaptive sliding observer is described to control the SRM without speed or position sensors. The adaptive sliding observer is set on the basis of variable structure control theory. The sliding surface is constructed by current error terms and this surface guarantees the errors converge to "zero". The stability of observer is affirmed by Lyapunov stability analysis and popov's hyper stability theory.ty theory.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.226-231
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• 2011

This research was done to prove the optimal position to detect a train reader when using a multiple fusion sensor. The experiment was done using four Train installed RFID Readers located on the train. These readers were read by sensors installed at intervals of 50 meters on the up and down sections of the Line 8, from Amsa station to Moran station. We analyze errors in the recognition range according to the Tag's number of recognition due to RFID of train speed, and propose a method of estimation for an accurate estimation of the position of train At this the Least-Squares Method is applied to judge the position of train accurately from the error because of Tag's number of recognition and RFID of train speed. also It is verified through simulation.

• Structural Engineering and Mechanics
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• v.41 no.2
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• pp.299-312
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• 2012

Stiffened coupled shear walls (SCSW) are under axial load resulting from their weight and this axial load affects the behavior of walls because of their excessive height. In this paper, based on the continuum approach, the optimal position of the stiffening beam on the stiffened coupled shear walls is investigated considering the effect of uniformly distributed axial loads. Moreover, the effect of the height of stiffened coupled shear walls on the optimal position of the stiffening beam has been studied with and without considering the axial force effect. A computer program has been developed in MATLAB and numerical examples have been solved to demonstrate the reliability of this method. The effects of the various flexural rigidities of the stiffening beam on the internal forces and the lateral deflection of the structure considering axial force effect have also been investigated.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.371-372
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• 2016

In this paper, the encoder of the hybrid type which can use a single position sensor in order to overcome the use of multiple signal lines and the reliability reduction for the location information acquisition caused by using a plurality of position detectors to acquire the position information of the rotor offer. Encoder of the proposed method was the replacement location information generating function by the plurality of sensors to the Capture function of the shape and the microcomputer of the encoder plate. Capture of the DSP function was verified through experiments using the in order to verify the validity of the detection by the proposed method and the hybrid encoder position prototyping, a means.

• Journal of Power Electronics
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• v.15 no.6
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• pp.1559-1566
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• 2015

The brushless DC motor (BLDCM) has many advantages. As a result, it is widely used in electric vehicle (EV) drive systems. To improve the reliability of the motor control system, a position sensorless control strategy based on a sliding mode observer (SMO) is proposed. The global fast terminal sliding mode observer (GFTSMO) is proposed to enhance the control performance of the SMO control system. The advantages of the linear sliding mode and the nonsingular terminal sliding mode (NTSM) are combined in the control strategy. The convergence speed of the system state is enhanced. The motor commutation point is obtained with the observation of the back EMF, and the instantaneous torque value of the motor is calculated. Therefore, the position sensorless control of the BLDCM is realized. Experimental results show that the proposed control strategy can improve the convergence speed, dynamic characteristics and robustness of the system.