• 로봇학회논문지
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• 제18권1호
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• pp.53-58
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• 2023

In general, in order to operate an autonomous underwater vehicle (AUV) in an underwater environment, a navigation system such as a Doppler Log (DVL) using a Doppler phenomenon of ultrasonic waves is used for speed and direction estimation. However, most of the ultrasonic sensors in underwater is large for long-distance sensing and the cost is very high. In this study, not only canal neuromast on the fish's lateral lines but also superficial neuromast are studied on the simulation to obtain pressure values for each pressure sensor, and the obtained pressure data is supervised using spherical CNN. To this end, through supervised learning using pressure data obtained from a pressure sensor attached to an underwater vehicle, we can estimate the speed and angle of the underwater vehicle in a quasi-static underwater environment and propose a method for a non-ultrasonic based navigation system.

• Journal of Chest Surgery
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• 제10권2호
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• pp.195-204
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• 1977

Dynamic lung compliance was measured in healthy ten young[mean age, 26 years] male and five young[mean age, 25 years] female. Lung volume was integrated of the rate of flow signal which was obtained by using pneumotachograph and differential pressure transducer[PM 5, Statham]. Intrapleural pressure was measured as that of intraesophagel pressure. Esophageal ballon, 15. 5cm in length, 4ml of luminal capacity and made of thin latex, was connected to the polyethylene tube that had 12-14 side holes and was of 1.5mm of ID. Transpulmonary pressure was traced by means of differential pressure transducer[PM 131, Statham] to which connected the esophageal balloon catheter and connection tube from mouth piece. Lung volume and transpulmonary pressure were photographed by cathode ray oscilloscope camera while the subjects were breathing spontaneously. Dynamic lung compliance loop was displayed on single trace monitor and subtraction was performed for the quasi-static hysteresis. Dynamic lung compliance was measured, 1. by plotting the pressure-volume relationship 2. from the subtracted pressure-volume loop. Results were as follows. 1. Dynamic lung compliances measured by plotting of healthy young male and female were $0.202{\pm}0.06$ and $0.190{\pm}0.023L/cm$ $H_2O$ respectively. 2. When measured from subtraction loop, dynamic lung compliance for male and female were $0.327{\pm}0.107$, and $0.27{\pm}0.06L/cm$ $H_2O$ respectively. 3. Dynamic chest wall and total respiratory system compliance were also measured. 4. Dynamic lung compliance by plotting appeared to be essentially same when compared to that of static compliance reported previously from our laboratory, however, that obtained from subtraction loop revealed higher values than the compliances obtained by plotting and that of static compliance.

• Geomechanics and Engineering
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• 제13권2호
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• pp.301-318
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• 2017

Based on the existing research results, a three-dimensional failure mechanism of tunnel face was constructed. The dynamic seismic effect was taken into account on the basis of quasi-static method, and the nonlinear Mohr-Coulomb failure criterion was introduced into the limit analysis by using the tangent technique. The collapse pressure along with the failure scope of tunnel face was obtained through nonlinear limit analysis. Results show that nonlinear coefficient and initial cohesion have a significant impact on the collapse pressure and failure zone. However, horizontal seismic coefficient and vertical seismic proportional coefficient merely affect the collapse pressure and the location of failure surface. And their influences on the volume and height of failure mechanism are not obvious. By virtue of reliability theory, the influences of horizontal and vertical seismic forces on supporting pressure were discussed. Meanwhile, safety factors and supporting pressures with respect to 3 different safety levels are also obtained, which may provide references to seismic design of tunnels.

• 대한정형도수물리치료학회지
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• 제22권1호
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• pp.65-70
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• 2016

Background: To determine the correlation Between forward head posture and plantar pressor in a McKenzie Exercise. Methods: This study had a cross-sectional design. There are included 20 participants with forward head posture. We measured the craniovertebral angle (CVA), cranial rotation angle (CRA) by image obtained digital camera and the plantar pressure, static balance using Gait Analyzer each before and after McKenzie Exercise. Results: There was negative correlation between CVA and CRA (p<.05). There was negative correlation between CVA and fore foot(p<.05). There was positive correlation between CRA and both fore foot (p<.05). There was negative correlation between CVA and static balance(p<.05). There was positive correlation between CRA and static balance (p<.05). Conclusions: There is a correlation between the change a mount of forward head position and plantar pressure in the McKenzie Exercise.

• 대한물리치료과학회지
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• 제12권3호
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• pp.35-45
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• 2005

The purpose of this study was to measure the static foot pressure distribution of children between forefoot and rearfoot, and the percentage of static pressure were measured from 1256 normal children in a primary school by the TPScan(Triple Pod Scan) systemCommercial system). The measurement were performed while standing with their comfortable state using the TPScan system. The static pressure distribution between forefoot and rearfoot was analyzed by paired t-test. The results were as follows: 1. The Pes cavus and Pes planus of students was 4.936%. 2. The Pes cavus were 42 children(3.343%) and Pes planus was 20 children(1.592%). 3. The Pes planus were seen in 42 of 1256 children with Grade I in 11 feet (26.2%), Grade II in 24(57.1%), Grade III in 6(57.1%), Grade IV in zero. 4. Pes planus and Pes cavus were significantly difference in foot pressure between forefoot and rearfoot(P<0.05). The future study needs detailed research and comparison with various variance between theses before and after correction.

• 제어로봇시스템학회논문지
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• 제11권5호
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• pp.451-456
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• 2005

This paper describes three kinds of experiments and analysis of their results related to human tactile sensitivity using an integrated tactile display system. The device can provide vibration, normal pressure and lateral slip/stretch which are important physical quantities to sense texture. We have tried to find out the efficient method of stimulating, limitation of surface discrimination by kinesthetic farce feedback and the effectiveness of the combination of kinesthetic force and tactile feedback. Seven kinds of different stimulating methods were carried out and they are single or combination of the kinesthetic force, normal static pressure, vibration, active/passive shear and moving wave. Both prototype specimen and stimulus using tactile display were provided to all examinees and they were allowed to answer the most similar sample. The experimental results show that static pressure is proper stimulus for the display of micro shape of the surface and vibrating stimulus is more effective for the display of fine surface. And the sensitivities of active touch and passive touch are compared. Since kinesthetic force feedback is appropriate to display shape and stiffness of an object, but roughness display has a limitation of resolution, the concurrent providing methods of kinesthetic and tactile feedback are applied to simulate physical properties during touching an object.

• 동력기계공학회지
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• 제9권3호
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• pp.33-38
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• 2005

The aerodynamic performance of a cross-flow fan is strongly influenced by the various design factors of a rear-guider and a stabilizer. The purpose of this paper is to investigate the effects of a rear-guider and a stabilizer on the aerodynamic performance of a cross-flow fan. The design factors considered in this paper are a rear-guider clearance, a stabilizer clearance, and a stabilizer setup angle, respectively. This experiment was carried out with a constant revolution number of 700 rpm in a cross-flow fan installed in the fan tester. The static pressure, flowrate, torque, and revolution number were measured in this paper. Also, the pressure coefficient and the efficiency were analysed according to the various assembly conditions using a stabilizer setup angle, a stabilizer clearance, and a rear-guider clearance in the indoor room air-conditioner.

• Geomechanics and Engineering
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• 제10권5호
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• pp.657-676
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• 2016

In this paper, the active lateral earth pressure is evaluated using the stress characteristics or slip line method. The lateral earth pressure is expressed as the lateral earth pressure coefficients due to the surcharge, the unit weight and cohesion of the backfill soil. Seismic horizontal and vertical pseudo-static coefficients are used to consider the seismic effects. The equilibrium equations along the characteristics lines are solved by the finite difference method. The slope of the ground surface, the wall angle and the adhesion and friction angle of the soil-wall interface are also considered in the analysis. A computer code is provided for the analysis. The code is capable of solving the characteristics network, determining active lateral earth pressure distribution and calculating active lateral earth pressure coefficients. Closed-form solutions are provided for the lateral earth pressure coefficients due to the surcharge and cohesion. The results of this study have a good agreement with other reported results. The effects of the geometry of the retaining wall, the soil and soil-wall interface parameters are evaluated. Non-dimensional graphs are presented for the active lateral earth pressure coefficients.

• 한국기계가공학회지
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• 제18권11호
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• pp.83-88
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• 2019

In this study, the high-temperature high-pressure vessel was successfully manufactured, which can be used to store pressurized air and to increase the temperature for the mix performance test of high-temperature high-pressure air with coolant (e.g., water). In this research, static structure analysis and transient thermal analysis were performed using the commercial software Midas NFX 2015 R1. Based on the results, the optimized pressure vessel design was carried out. As a result of the optimized design, the minimum stress and minimum weight were found at 120 mm of the vessel thickness, and the optimized pressure vessel was verified. Finally, through manufacture and performance test (e.g., the non-destructive inspection and hydraulic pressure test), the reliability and safety were validated for the designed pressure vessel.

• 한국정밀공학회지
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• 제17권4호
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• pp.148-154
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• 2000

In this study, the static and the dynamic characteristics of the load-sensitive hydraulic pump control systems of a hydraulic excavator were analyzed using the developed analysis tool. The results were compared with the experimental ones. To improve the static performance of the system, the system parameter effects on the controllable region and the pump pressure variation were studied. The parameters enhancing dynamic characteristics were also considered.