• International Journal of Ocean System Engineering
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• v.1 no.2
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• pp.60-67
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• 2011

This paper presents an in-situ correction method to compensate for the position error of an autonomous underwater vehicle (AUV) near the sea floor. AUVs generally have an inertial navigation system assisted with auxiliary navigational sensors. Since the inertial navigation system shows drift in position without the bottom reflection of a Doppler velocity log, external acoustic positioning systems, such as an ultra short baseline (USBL), are needed to set the position without surfacing the AUV. The main concept of the correction method is as follows: when the AUV arrives near the sea floor, the vehicle moves around horizontally in a circular mode, while the USBL transceiver installed on a surface vessel measures the AUV's position. After acquiring one data set, a least-square curve fitting method is adopted to find the center of the AUV's circular motion, which is transferred to the AUV via an acoustic telemetry modem (ATM). The proposed method is robust for the outlier of USBL, and it is independent of the time delay for the data transfer of the USBL position with the ATM. The proposed method also reduces the intrinsic position error of the USBL, and is applicable to the in-situ calibration as well as the initialization of the AUVs' position. Monte Carlo simulation was conducted to verify the effectiveness of the method.

• Journal of the Korea Fashion and Costume Design Association
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• v.19 no.3
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• pp.207-218
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• 2017

This study evaluates the difference in visual images according to changes in waist position and pants style. The researcher made twelve stimuli-combination of four pants styles (classic, baggy, skinny, bell-bottom) and three waist positions (0cm, -3cm, -5cm). The test involved 48 female college students. The stimuli were made using the i-Designer computer program. The panels tested the screen images of all manikins wearing pants. A 7-point scale was used to evaluate each image. For the data analysis, the ANOVA and Duncan-test were applied along with an SPSS program. The results of this study are as follows. The visual evaluations by pants style and waist position are composed of seven factors (attractiveness, attention, hip, activity, height, waist, abdomen). Among these factors, attractiveness is evaluated to be the most important factor. The mutual agreement of the visual effect (according to pants style and waist position) was indicated as four factors of attractiveness, attention, waist, and abdomen. The height factor is evaluated to be the most important factor by change in regards to waist position. The 0cm waist position of three styles (classic, baggy, bell-bottom) were evaluated positively in elongated height whereas the -3cm, -5cm waist position of the skinny style was evaluated positively in elongated height. The mutual agreements of visual effect (according to pants style and waist position) were not indicated.

• Journal of the Korean Applied Science and Technology
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• v.35 no.1
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• pp.36-42
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• 2018

This study was to investigate the difference of muscle activities in trunk, upper arm, and shoulder during push-up exercise based on 3 types of different arm position(posterior position, PP; normal position, NP; and anterior position, AP) and to provide effective push-up arm position for each muscle development. Fifteen healthy males(age, $21.5{\pm}0.5years$; height, $172.7{\pm}1.0cm$; body mass, $70.5{\pm}1.3kg$; shoulder width, $42.3{\pm}0.6cm$; and BMI, $23.6{\pm}0.5kg/m^2$) participated in this study. PP, NP, and AP of the arm were used to conduct push-up exercise and 8 muscles(deltoideus p. acromialis: DA; pectoralis minor: PMI; pectoralis major: PMA; serratus anterior: SA; biceps brachii: BB; triceps brachii: TB; latissimus dorsi: LD; and infraspinatus: IS) of right side were selected to measure muscle activities. Total 9 counts of push-up exercise were conducted and EMG data signals of 5-time(from $3^{th}$ to $7^{th}$) push-up movement were used for measuring muscle activities. PP push-up exercise showed that there was a significantly higher muscle activity of DA, PMI, PMA, SA, BB, LD, and IS(p<.05) and AP push-up exercise showed a significantly higher TB activity(p<.05). It would be suggested that different arm position evokes various muscle activities when conducting push-up exercise. PP would be the best push-up arm position for inducing various trunk, upper arm, and shoulder muscle activities compared to NP and AP.

• The Journal of Advanced Prosthodontics
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• v.15 no.3
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• pp.126-135
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• 2023

PURPOSE. The aim of this study was to evaluate the reliability of implant stability measuring devices depending on the location of the implant and the position of the patient. MATERIALS AND METHODS. Six implants were installed in different dentate sextants of six artificial bone models. Implant stability was measured in three conditions of the bone model (without mounting on a phantom head, mounted on a phantom head in supine position, and mounted on a phantom head in upright position). A resonance frequency analysis device (Osstell) and two damping capacity analysis devices (Periotest and Anycheck) were used to measure implant stability. The values measured outside the phantom head were treated as controls, and the values inside the phantom head were compared using an independent t-test. RESULTS. Osstell showed different results in two of the six divisions in both the supine and upright positions compared to outside of the mouth (P < .05). Periotest showed different results in all six parts in the supine position and in five parts in the upright position compared to outside of the mouth (P < .05). While Anycheck showed different results in five areas in the supine position compared to outside of the mouth, it showed different results in only one area in the upright position (P < .05). CONCLUSION. In the difficult implant position for the operator to access, the implant stability measuring devices show less reliability. The accessibility of implant is greatly affected in the order of Osstell, Anycheck, and Periotest.

• Journal of Power Electronics
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• v.4 no.1
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• pp.28-38
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• 2004

In this paper, the position control of a detuned indirect field oriented control (IFOC) induction motor drive is studied. A proposed Simple-Neuro-Controllers (SNCs) are designed and analyzed to achieve high-dynamic performance both in the position command tracking and load regulation characteristics for robotic applications. The proposed SNCs are trained on-line based on the back propagation algorithm with a modified error function. Four SNCs are developed for position, speed and ｄ-ｑ axes stator currents respectively. Also, a synchronous proportional plus integral-derivative (PI-D) two-degree-of-freedom (2DOF) position controller and PI-D speed controller are designed for an ideal IFOC induction motor drive with the desired dynamic response. The performance of the proposed SNCs and synchronous PI-D 2DOF position controllers for detuned field oriented induction motor servo drive is investigated. Simulation results show that the proposed SNCs controllers provide high-performance dynamic characteristics which are robust with regard to motor parameter variations and external load disturbance. Furthermore, comparing the SNC position controller with the synchronous PI-D 2DOF position controller demonstrates the superiority of the proposed SNCs controllers due to attain a robust control performance for IFOC induction motor servo drive system.

• The Journal of Korean Physical Therapy
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• v.26 no.1
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• pp.27-32
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• 2014

Purpose: The purpose of the study was to comparison of trunk muscle activity during static standing position and standing position on therapeutic climbing wall of adult. Methods: Study subject is arbitrarily classified into 10 of experimental group and 10 control group among 20 of adult. Trunk activity measured as rectus abdominalis, external oblique, internal oblique, erector spinae. Control group maintains that center of gravity of trunk pass the front of shoulder, pelvis, knee and ankle on stable surface with putting legs apart more than shoulder width. Experimental group had static exercise on 4 by 3 meter, 90 degree of Therapeutic climbing wall. Starting position is that putting arms and legs apart more than shoulder width. In order to compare the effect of it between the groups, independent t-test was used. Results: According to the test result, significant difference between among rectus abdominalis, erector spinae the experimental groups. And external oblique, internal oblique muscle atvity is no significant difference experimental groups between among the control groups was observed. Conclusion: Trunk muscle activation is activated to standing position on the Therapeutic Climbing Wall more than static standing position.

• Physical Therapy Rehabilitation Science
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• v.1 no.1
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• pp.28-32
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• 2012

Objective: The purpose of this study is to compare chronic low back pain patients' pain provocation position so as to identify the relevance with lumbar stabilizing muscles atrophy and pain provocation position. Design: Cross-sectional study. Methods: Fifty five chronic low back pain patients were participated in this study. Subjects were eligible for study participation if they were 35-55 years old and had experienced low back pain for more than 3 months. Subjects were questioned about pain and pain provocation test were done. And then they were inspected their cross sectional area (CSA) of lumbar muscles (erector spinae, iliopsoas, and multifidus) by using computed tomography. Analyze the relevance through the result data with painful area, aspect of pain and pain provocation position. Results: CSA of erector spinae showed significant decrease on ipsilateral extension position (p<0.05). Iliopsoas muscle showed significant decrease on contralateral position (p<0.05). Multifidus showed significant decrease on the position of contralateral extension and contralateral flexion (p<0.05). Conclusions: Based on the results of our study, it may be possible to evaluate muscle atrophy by assessing causing position.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.3
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• pp.246-252
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• 2004

This paper presents a position sensorless control system of Switched Reluctance Motor (SRM) using neural network. The control of SRM depends on the commutation of the stator phases in synchronism with the rotor position. The position sensing requirement increases the overall cost and complexity. In this paper, the current-flux-rotor position lookup table based position sensorless operation of SRM is presented. Neural network is used to construct the current-flux-rotor position lookup table, and is trained by sufficient experimental data. Experimental results for a 1-hp SRM is presented for the verification of the proposed sensorless algorithm.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.8 s.101
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• pp.954-961
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• 2005

This paper is concerned with the implementation of auto-tuning positive position feedback controller using a digital signal processor and microcontroller. The main advantage of the positive position feedback controller is that it can control a natural mode of interest by tuning the filter frequency of the positive position feedback controller to the natural frequency of the target mode. However, the positive position feedback controller loses its advantage when mistuned. In this paper, the fast fourier transform algorithm is implemented on the microcontroller whereas the positive position feedback controller is implemented on the digital signal processor. After calculating the frequency which affects the vibrations of structure most, the result is transferred to the digital signal processor. The digital signal processor updates the information on the frequency to be controlled so that it can cope with both internal and external changes. The proposed scheme was installed and tested using a beam equipped with piezoceramic sensor and actuator. The experimental results show that the auto-tuning positive position feedback controller proposed in this paper can suppress vibrations even when the target structure undergoes structural change thus validating the approach.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.2
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• pp.169-176
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• 2012

GPS(Global Positioning System) is widely used for the position estimation of an aerial vehicle. However, GPS may not be available due to hostile jamming or strategic reasons. A vision-based position estimation method can be effective if GPS does not work properly. In mountainous areas without any man-made landmark, a horizon is a good feature for estimating the position of an aerial vehicle. In this paper, we present a new method to estimate the position of the aerial vehicle equipped with a forward-looking infrared camera. It is assumed that INS(Inertial Navigation System) provides the attitudes of an aerial vehicle and a camera. The horizon extracted from an infrared image is compared with horizon models generated from DEM(Digital Elevation Map). Because of a narrow field of view of the camera, two images with a different camera view are utilized to estimate a position. The algorithm is tested using real infrared images acquired on the ground. The experimental results show that the method can be used for estimating the position of an aerial vehicle.