• Journal of Advanced Marine Engineering and Technology
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• v.30 no.3
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• pp.438-443
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• 2006

The probe type sensor using strain gauges was used to track a container box's seam in this paper. A strain gauge has a property which the specific resistance is changed by varying of the sectional area and length when tensile and compressive stresses are generated at the strain gauge. We designed the automatic seam tracking device by attaching the probe type strain gauge sensor, motor driving slide, encorder to check the moving distance and interface card connected MPU upside the speed controllable carriage. The folded work piece for a container box is made to examine whether the device can track the seam automatically or not. Seam tracking experiments were done by changing the carriage moving speed at 300. 400. 500. 600[mm/min] each as the voltage of side track was 2.5[V]. We compared and analyzed the sampling data which is obtained by output voltage of strain gauge sensor and rotary encorder pulse every 100 [m/s]. The welding experiments were performed by using $CO_2$ welding machine about the carriage moving speed that has good seam tracking condition in the seam tracking experiments above. And we compared the seam tracking status.

• Journal of Ocean Engineering and Technology
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• v.30 no.6
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• pp.468-473
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• 2016

This paper focuses on the estimation of local ice loads exerted from ship-ice interaction processes. The Korean IBRV ARAON was used to perform field ice trials during her 2015 Arctic voyage. During ARAON's general ice transit, a total of 72 channels of data from both strain gauges on the inner hull plates and those installed on the transverse frames of the ARAON's bow section structures were analyzed to calculate the local ice loads. The local ice loads estimated from the analysis of the shear strain data measured on the side frames were compared to those from the hull plate pressures.

• Steel and Composite Structures
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• v.28 no.1
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• pp.1-11
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• 2018

In this paper, local ratcheting behavior of 1045 steel plates with circular cutout was investigated. Experimental tests were carried out by a Zwick/Roell HB 100 servo hydraulic machine. In order to measure the local strain at notch root, a data acquisition system with strain gauge was used. Various notch diameters and distances of strain gauges mounted from the notch root were found influential in the magnitude of local ratcheting strain. It was found that the local maximum principal stress plays a crucial role in increasing the local plastic deformation. Numerical simulation was done by ABAQUS software using nonlinear isotropic/kinematic hardening model. Material parameters of hardening model were attained from several stabilized cycles of flat specimens subjected to symmetric strain cycles. The nonlinear kinematic hardening model along with the Neuber's rule was employed to assess local ratcheting at the notch root of steel plates. The results of the numerical simulations agreed closely with those measured values in this study. Both ratcheting progress and mean stress relaxation occurred simultaneously at the notch root.

• Journal of KIBIM
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• v.10 no.2
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• pp.21-28
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• 2020

As the number of aging bridges increases, more studies are being conducted on developing effective and reliable methods for the assessment and maintenance of bridges. With the advancement in new sensing systems and data learning techniques through AI technology, there is growing interests in how to evaluate bridges using these advanced techniques. This paper presents a CNN(Convolution Neural Network) deep learning based technique for evaluating the damage existence and for estimating the damage location in PSC bridges using static strain data. Simulation studies were conducted to investigate the proposed method with error analysis. Damage was simulated as the reduction in the stiffness of a finite element. A data learning model was constructed by applying the CNN technique as a type of deep learning. The damage status and its location were estimated using data set built through simulation. It was assumed that the strain gauges were installed in a regular interval under the PSC bridge girders. In order to increase the accuracy in evaluating damage, the squared error between the intact and measured strains are computed and applied for training the data model. Considering the damage occurring near the supports, the results of error analysis were compared according to whether strain data near the supports were included.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.3
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• pp.322-330
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• 2005

Statement of problem. In distal extension removable partial denture, the preservation of health of abutment teeth is very important, but abutment teeth are subjected to unfavorable stress. Purpose. The purpose of this study was to investigate the biomechanical effects of mandibular removable partial dentures with various prosthetic designs using strain gauge analysis. Material and methods. Artificial teeth of both canines were anchored bilaterally in a mandibular edentulous model made of resin. Bilateral distal extension removable partial dentures with splinted and unsplinted abutments were fabricated. Group 1 : Clasp-retained mandibular removable partial denture with unsplinted abuhnents Group 2 : Clasp-retained mandibular removable partial denture with splinted abutments by 6-unit bridge Group 3 : Bar-retained mandibular removable partial denture Strain gauges were bonded on the labial plate of the mandibular resin model, approximately 2 mm close to the abutments. Two vertical experimental loadings (100N and 200N) were applied subsequently via two miniature load cells that were placed at mandibular first molar regions. Strain measurements were performed and simultaneously monitored from a computer connected to data acquisition system. For within-group evaluations, t-test was used to compare the strain values and for between-group comparisons, a one-way analysis of variance (ANOVA) was used and Duncan test was used as post hoc comparisons. Results. Strain values increased as the applied load increased from 100N to 200N for all groups (p<.05). The strain values of group 1 and 2 were tensile under loadings. In contrast, strain values of group 3 were compressive in nature. Under 100N loading, group 1 showed higher strain values than group 3 in absolute quantity (p<.05). Under 200N loading, group 3 showed higher strain values than group 1 and 2 in absolute quantity (p<.05). Group 1 showed higher strain values than group 2 (p<.05). Conclusion. Splinting of two isolated abutments by bridge reduced the peri-abutment strain in comparison with unsplinted abutments. Strain of bar-retained removable partial denture increased much more as applied load increased, but was compressive in nature.

• The Journal of Advanced Prosthodontics
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• v.3 no.1
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• pp.1-9
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• 2011

PURPOSE. This study investigated the strain of implants using a chewing simulator with strain gauges in mandibular implant-supported fixed prostheses under various dynamic loads. MATERIALS AND METHODS. Three implant-supported 5-unit fixed prostheses were fabricated with three different occlusion types (Group I: Canine protected occlusion, Group II: Unilaterally balanced occlusion, Group III: Bilaterally balanced occlusion). Two strain gauges were attached to each implant abutment. The programmed dynamic loads (0 - 300 N) were applied using a chewing simulator (MTS 858 Mini Bionix II systems, MTS systems corp., Minn, USA) and the strains were monitored. The statistical analyses were performed using the paired t-test and the ANOVA. RESULTS. The mean strain values (MSV) for the working sides were 151.83 ${\mu}{\varepsilon}$, 176.23 ${\mu}{\varepsilon}$, and 131.07 ${\mu}{\varepsilon}$ for Group I, Group II, and Group III, respectively. There was a significant difference between Group II and Group III (P < .05). Also, the MSV for non-working side were 58.29 ${\mu}{\varepsilon}$, 72.64 ${\mu}{\varepsilon}$, and 98.93 ${\mu}{\varepsilon}$ for Group I, Group II, and Group III, respectively. One was significantly different from the others with a 95% confidence interval (P < .05). CONCLUSION. The MSV for the working side of Groups I and II were significantly different from that for the non-working side (Group I: t = 7.58, Group II: t = 6.25). The MSV for the working side of Group II showed significantly larger than that of Group III (P < .01). Lastly, the MSV for the non-working side of Group III showed significantly larger than those of Group I or Group II (P < .01).

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.276-280
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• 1993

An articulated, multifinger mechanical hand can carry out grasping and manipulation operations on objects of different type and shape. In this paper the architecture of the mechanical hand is presented. Joints are driven by two antagonist tendons. Strain gauges are used to derive tendon tensions, and located in the palm of the hand. Angular defection of the joints is measured by Hall effect sensors attached to the joints. A multiprocessor-based architecture for controlling the hand is illustrated.

• The Journal of Engineering Geology
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• v.8 no.3
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• pp.215-224
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• 1998

In this study, total strain was measured by LVDTs and local strains on the surface of specimens were measured by strain gauges. And axi-symmetrically elastoplastic FEM analyses was carried out for cylindrical specimens. Considering the influence of the restraint induced by the loading platen, in the case of H/D=1, the strain distribution on the side of a specimen is obviously affected by the condition of platen contact. Furthermore, it is clear that the larger H/D ratio becomes, the smaller the influence to the strain distribution is. For the smooth contact condition, the strain on the side is not influenced by the stiffness of the specimen, the shape and the scale effect, the strain distribution coincides with the nominal total strain. Whereas, in the case of rough contact condition, the strain distribution is remarkably affected. It is made clear that strain responses of hard rock specimens may more sensitive than these of soft rock specimens as a results of interaction between loading platens and specimen and the uniaxial strength of specimens may strongly depends on this interaction and stress-strain relation is affected by the contact condition.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.11 s.116
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• pp.1172-1178
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• 2006

Measurement of blade strain with sensors directly installed on the blade has one critical issue, how to send the sensor signal to the ground. Strain-gauges have been dominantly used to directly measure stress of a blade and either a slip ring or a telemetry system has to be used to send measured signal to the ground. However, both systems have many inherent problems and sometimes very severe limitations to be practically used. In this paper, new on-line strain monitoring method using. FBG(Fiber Bragg Grating) sensors and a beam coupler is introduced. Measurement of rotor stress using FBG sensors is nothing new, but unlike other system which installs all necessary instruments on the rotor and use telemetry system to send data to the ground, this system makes use of light's unique characteristic - light travels through space. In this new approach, single optical fiber with many FBG sensors is installed on the blade and all other necessary instruments can be installed at ground thereby giving tremendous advantages over slip ring or telemetry system. A reference sensor is also introduced to compensate the beam coupler's transmission loss change due to rotation. The suggested system's good performance is demonstrated with experiments.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.538-541
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• 2006

PSC(Prestressed Concrete) box girder bridges have been widely applied in Korea. A number of these bridges have been built by the segmental construction method in the longitudinal direction and(or) vertically along the cross-sectional depth with MSS(Moving Scaffolding System). An actual 2-span continuous PSC box girder bridge of Kyeongbu high speed railway was selected and instrumented with 96 vibrating wire embedded type strain gauges and 2 thermocouples. The long-term behavior of the bridge was monitored through two major points located at mid-span of the first span and at the internal support. Data collection started just after the casting of the first segment (U section). Concrete strain and temperature data were gathered regularly by a data logger (CR10) during 600 days under and after construction. According to this measurement, the parabolic longitudinal strain distribution in the top slab at mid-span is shown. And also, the same distribution at the interior support is shown. The compressive strains at the cantilever region are larger than at the web position and the internal part in the top slab. Strain difference largely happened during the early construction period.