• Journal of Institute of Control, Robotics and Systems
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• v.17 no.2
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• pp.131-134
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• 2011

In this study, we propose an optimal design and new fabrication method for a slim tactile sensor. Slim tactile sensor can detect 3-axial forces and has suitable flexibility for intelligent robot fingers. To amplify the contact signal, a unique table-shaped structure was attempted. A new layer-by-layer fabrication process for polymer micromachining that can make a 3D structure by using a sacrificial layer was proposed. A table-shaped epoxy sensing plate with four legs was built on top of a flexible polymer substrate. The plate can convert an applied force to a concentrated stress. Normal and shear forces can be detected by combining responses from metal strain gauges embedded in the polymer substrate. The optimal positions of the strain gauges are determined using the strain distribution obtained from finite element analysis.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.267-271
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• 2000

The local heat transfer rate of an axisymmetric submerged air jet impinging on normal to a heated flat plate was investigated experimentally with varying solidity of mesh screen. The mean velocity and turbulent Intensity profiles of streamwise velocity component were measured using a hot-wire anemometry. The temperature distribution on the heated flat surface was measured with thermocouples. The screen installed in front of the nozzle exit(behind of 35mm) modify the jet flow structure and local heat transfer characteristics. For higher solidity screen, turbulence intensity at core lesion is high and increases the local heat transfer rate at nozzle-to-plate spacings(L/D<6). For larger nozzle-to-plate spacings(L/D>6), however, the turbulent Intensities of all screens tested in this study approach to an asymptotic curve, but the small mean velocity at the core region reduces the local heat transfer rate for high solidity screens.

• Journal of the Korean Society of Safety
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• v.25 no.3
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• pp.15-21
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• 2010

A differential case equipped with LSD(limited slip differential) has several advantages over a normal type for rear wheel drive vehicles. Specially, the torque distribution can be done between left and right drive wheel in the state of limited slip differential. Also although LSD types are very various according to operating type, medium and torque distribution, a multi-clutch type is generally applied to rear wheel drive vehicles. So, this study presents the analysis of design parameters for development of a friction plate for multi-clutch type LSD using vehicle road test, the simulation of analytical model and the development of vehicle dynamics model by a benchmark product. According to this investigation, the design parameters which are pre-load of coil spring, friction plate and contact area quantity, friction coefficient and TBR(torque bias ratio) for a friction plate are derived from experiment and simulation and consequently, vehicle dynamics model has been constructed for the development of friction plate for multi-clutch type LSD.

• Journal of Veterinary Clinics
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• v.17 no.1
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• pp.76-82
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• 2000

This study was undertaken to find out the effect of persimmon leaves on histopathological changes of cadmium toxicity in mice. Seventy two BALB/c mice of male were divided into a control group(A) and five experimental groups (B, C, D, E, F) : group A received tap water and basal diet, group B received tap water and diet supplemented with 3% persimmon leaves alone, group C received basal diet and 300 ppm cadmium, group D, E and F received basal diet supplemented with 1, 3% and 7% persimmon leaves and 300 ppm cadmium respectively. Cadmium dissolved in tap water was used, and the persimmon leaves were mixed with feed. All mice were dissected on the 84th day. Pathological changes in liver, kidney, cortical osseous tissue of femoral shaft, bone trabecular of femur, and epiphyseal cartilage plate of femur were observed. Group B showed no significant changes as the control group. But group C showed the unclearness of specific cells in liver, the loss of architecture and necrosis of hepatocyte, degeneration and necrosis of renal convoluted tubules, desquamation and vacuolization of the greater part of the renal tubular epithelium, marked thinning of the cortical osseous tissue in femoral shaft, reduction of cancellous bone volume and decreaswe of trabecular number, and marked thinning of epiphyseal cartilage plate in femur. On the other hand, persimmon leaves-treated group showed a little convalescent changes an maintained their normal architectures in liver, kidney, cortical osseous tissue of femoral shaft, bone trabecular of femur, and epiphyseal cartilage plate of femur.

• Journal of Biomedical Engineering Research
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• v.21 no.4
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• pp.385-390
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• 2000

The alignment of the prosthetics is very important in an amputee's gait. In the present study. a static prosthesis-alignment device was developed. It consisted of a force plate with four load cells, a laser beam controlled by a step motor, and a control part programmed by PCBASIC. Using the static prosthesis-alignment device, we measured the distance between the load line and various joints of 24 normal volunteers in three standing postures. such as neutral, forward leaning, and backward leaning. Only neutral postures were evaluated on four trans-tibial amputees. The load line for the normal person's neutral position located anterior to the ankle, the knee, and the greater trochanter, but posterior to the shoulder joint. Forward and backward leaning of the normal person resulted in a significant anterior and posterior movements of the load line, respectively. The load line for the amputated side of the trans-tibial amputee also located anterior to the ankle, the extremity prostheses, providing a good relative locations of the load line with respect to various joints.

• The Korean Journal of Pain
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• v.32 no.4
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• pp.256-263
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• 2019

Background: Antinociceptive anti-inflammatory drugs have many adverse effects. The goal of this investigation is to study the probable anti-inflammatory and analgesic effects of verapamil and N-acetylcysteine (NAC) in experimental rats. Methods: Adult male Wistar rats were randomly divided into 4 groups in the antinociceptive study, each containing 6 rats; the normal control group, which received saline (1 mL/kg); the diclofenac group, which received diclofenac sodium (5 mg/kg); the NAC group, which received NAC (125 mg/kg); and the verapamil group, which received verapamil (8 mg/kg). In the anti-inflammatory study, 5 groups were used, the 4 previous groups with the addition of an edema control group, received saline and were subjected to formalin test. Hot plate latency time was recorded for antinociceptive evaluation. Paw edema thickness and biochemical parameters were recorded for anti-inflammatory evaluation. Results: Administration of NAC showed significant prolongation of hot plate latency time at 1 hour when compared to the control group while verapamil showed a significant prolongation of hot plate latency time at 1 and 2 hours when compared to the control group and NAC group values. Administration of NAC and verapamil significantly decreased paw edema thickness at 2, 4, and 8 hours when compared to edema control values. Regarding biochemical markers, NAC and verapamil significantly decreased serum nitric oxide synthase, C-reactive protein, and cyclooxygenase-2 levels compared to the edema control value. In accordance, a marked improvement of histopathological findings was observed with both drugs. Conclusions: NAC and verapamil have antinociceptive and anti-inflammatory effects comparable to diclofenac sodium.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.3
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• pp.370-375
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• 2008

Sagittal split ramus osteotomy (SSRO) is widely used in treatment of dentofacial deformities. But, many complications can occur including unfavorable fractures during osteotomy. To prevent these complications, it is necessary to understand comprehensively the anatomy of the mandiular ramus. The purpose of this study was to evaluate the morphology of the madibular ramus in manibular prognathism patients by computed tomography comparing with normal control group. The study group consisted of 33 skeletal class III patients (20 males, 13 females) and the control group consisted of the 52 patients without dentofacial deformities (32 males, 20 females). The mean age of study group was 22.0-year old, and that of control group was 37.1-year. For the CT examination, following scan parameters was used: 1mm slice thickness, 0.5 second scan time, 120kV and 100mA/s. The axial scans of the head were made parallel to the mandibular occlusal plane. The anteroposterior length of the ramus, the distance from anterior border of the ramus to lingula, the relative distance from the anterior border of the ramus to lingula compared to the anteroposterior length of the ramus, the thickness of anterior and posterior cortical plate, the thickness of medial cortical plate of the ramus at lingula level, the thickness of cancellous bone of the ramus at lingula level were measured. The skeletal class III mandibular prognathism patients exhibited shorter anteroposterior length of the ramus, thicker anterior and posterior cortical plate, thinner mediolateral cancellous bone thickness. The lingula has a relative stable anteroposterior position in ramus in all groups. There was higher possibility of fusion of medial and lateral cortical plate at lingula level in the mandibular prognathism group. In conclusion, the mandibular prognathism patients have narrow rami with scanty cancellous bone, which means that careful preoperative examination including CT scan can prevent undesirable fractures during osteotomy.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.7
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• pp.3-10
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• 2018

Steel fiber reinforced concrete can improve the resistance to cracking by adding steel fibers when mixing concrete. It can reduce the temperature and shrinkage cracks, and its flexural performance can be improved by increasing the effective moment of inertia. In this study, the deck-plate was used to replace the concrete form and reinforcing bars, and the steel fiber reinforced concrete was used to control the shrinkage and temperature cracks, and improve the flexural performance of the slab. Total 9 slab specimens were tested for analyzing the structural performance and serviceability. As a results, flexural capacity of the slab with deck-plate was evaluated to be superior to that of the normal reinforced concrete slab specimens with the same tensile reinforcement. The steel fiber reinforced concrete was found to have about 8% flexural capacity increase depending on the steel fiber content $15.7kg/m^3$. Also, in terms of flexural stiffness, the specimens using steel fiber reinforced concrete for the same parameters were evaluated to have a stiffness increase of about 30% compared with the case of using ordinary concrete. Especially, it was found that the stiffness of the test results was significantly higher than the analytical result because the increase of the tensile strength of the steel fiber reinforced concrete is not reflected in the current structural code.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.8
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• pp.89-96
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• 2017

This Paper proposes a vehicle detection system and a license plate recognition system from CCTV images installed on public roads. Since the environment of this system acquires the image in the general road environment, the stable condition applied to the existing vehicle entry / exit system is not given, and the input image is distorted and the resolution is irregular. At the same time, the viewing angle of the input image is more wide, so that the computation load is high and the recognition accuracy of the plate is likely to be lowered. In this paper, we propose an improved method to detect and recognize a license plate without a separate input control devices. The vehicle and license plate were detected based on the HOG feature descriptor, and the characters inside the license plate were recognized using the k-NN algorithm. Experimental environment was set up for the roads more than 45m away from the CCTV, Experiments were carried out on an entry vehicle capable of visually identifying license plate and Experimental results show good results of the proposed method.

• Computers and Concrete
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• v.29 no.2
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• pp.81-92
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• 2022

The influence of normal stress perpendicular to the potential shear plane was always neglected in existing researches, which may lead to a serious deviation of the shear strength of concrete members in practice designs and numerical analyses. In this study, a series of experimental studies are carried out in this paper, which serves to investigate the shear behavior of concrete under compression shear loading. Based on the test results, a three-phase shear failure model for cohesive elements are developed, which is able to take into consideration the influence of normal stress on the shear strength of concrete. To identify the accuracy and applicability of the proposed model, numerical models of a double-noted concrete plate are developed and compared with experimental results. Results show that the proposed constitutive model is able to take into consideration the influence of normal stress on the shear strength of concrete materials, and is effective and accurate for describing the complex fracture of concrete, especially the failure modes under compression shear loadings.