• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.681-685
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• 2004

A media-feeding (or media-transport) system is a key component in daily consumer systems such as printers, copiers and ATM's. The role of the media-transport system is to feed a medium, which is usually in the form of a thin film, to the main process in a uniform and repeatable manner. Even small slippage between the media and the feeding rollers could significantly degrade the performance of the entire system. The slippage between the medium and the feeding rollers is determined by many parameters which include the friction coefficient between the feeding rollers and the medium material, the angular velocity of the feeding rollers, and the normal force applied by feeding rollers on the medium. This paper investigates the effect of the normal force and the angular velocity of feeding rollers on the slippage of the medium. Authors have constructed a test bed for experiments, which consists of a feeding module and various measuring devices. Using regular paper as media being fed, the authors experimentally measured the slippage of the medium under various normal forces and angular velocities of driving feeding roller. Also the authors developed a novel two-dimensional simulation model for the media-transport system. The paper medium is modeled as a set of multiple rigid bodies interconnected by revolute joints and rotational springs and dampers. Simulations were executed using a multi-body dynamic analysis tool called RecurDy $n^{ⓡ}$. The slippage obtained by the simulation is compared to experimental results.ults.

• Clinical and Experimental Pediatrics
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• v.53 no.11
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• pp.931-935
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• 2010

Juvenile idiopathic arthritis (JIA) is comprised of a heterogeneous group of several disease subtypes that are characterized by the onset of arthritis before the age of 16 years and has symptoms lasting at least 6 weeks. The previous classification of JIA included seven different categories, whereas its current classification was compiled by the International League of the Association for Rheumatology, and replaced the previous terms of "juvenile chronic arthritis" and "juvenile rheumatoid arthritis," which were used in Europe or North America, respectively, with the single nomenclature of JIA. As mentioned above, JIA is defined as arthritis of unknown etiology that manifests itself before the age of 16 years and persists for at least 6 weeks, while excluding other known conditions. The clinical symptoms of JIA can be quite variable. Several symptoms that are characteristic of arthritis are not necessarily diagnostic of JIA and may have multiple etiologies that can be differentiated with careful examination of patient history. The disease may develop over days or sometimes weeks, thereby making the diagnosis difficult at the time of presentation. To make a clinical diagnosis of JIA, the first step is to exclude arthritis with known etiologies. Of note, late treatment due to excessive delay of diagnosis can cause severe damage to joints and other organs and impair skeletal maturation. Therefore, early detection of JIA is critical to ensure prompt treatment and to prevent long-term complications including the likelihood of disability in childhood.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.1
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• pp.114-122
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• 2001

Leg weakness in pigs is one of the most serious problems in the pig industry. Leg weakness is responsible for an increase in the rate of culling of breeding pigs, which results in economic loss in the pig industry. Many researchers have investigated the cause of leg weakness, and that of osteochondrosis, in pigs, as well as in other mammals. For evaluating leg weakness, subjective scoring criteria have been applied, but the scoring systems varied widely. Subjective scoring systems have also been used in evaluating osteochondrosis lesions in leg joints. The lesions were scored optically, radiographically and histologically. Leg weakness and osteochondrosis are to some extent heritable traits. The heritability of leg weakness and joint lesion scores was found to range from 0.01 to 0.42. Leg weakness and osteochondrosis are associated with production traits (lean percentage and back fat depth). Nutritional aspects of leg weakness and osteochondrosis have also been extensively studied. Although the energy level of the diet may affect leg weakness and osteochondrosis, other nutritional factors seem to have very little effect. Confinement conditions also have an effect on leg weakness and osteochondrosis. Although studied extensively, the cause and etiology of leg weakness and osteochondrosis remain uncertain. It could be that there are multiple causes of leg weakness.

• Computers and Concrete
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• v.22 no.3
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• pp.305-317
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• 2018

Steel reinforced Engineered Cementitious Composite (ECC) components have been proposed for seismic structural applications, for example in coupling beams, infill panels, joints, columns, and flexural members. The development of strain in the steel reinforcement of cementitious components has been shown to vary based on both the steel reinforcement ratio and the applied deformation history. Strain in the steel reinforcement of reinforced ECC components is an important structural response metric because ultimate failure is often by fracture of the steel reinforcement. A recently proposed bond-slip model has been successfully calibrated to cyclically tested reinforced ECC beams wherein the deformation history contained monotonically increasing cycles. This paper reports simulations of two-dimensional finite element models of reinforced ECC beams to determine the appropriateness and significance of altering a phenomenological bond-slip model based on the applied deformation history. The numerical simulations with various values of post-peak bond-slip softening stiffness are compared to experimental results. Varying the post-peak bond-slip softening stiffness had little effect on the cracking patterns and hysteretic response of the reinforced ECC flexural models tested, which consisted of two different steel reinforcement ratios subjected to two different deformation histories. Varying the post-peak bond-slip softening stiffness did, however, affect the magnitude of strain and the length of reinforcing bar that strain-hardened. Overall, a numerical model with a constant bond-slip model represented well various responses in reinforced ECC beams with multiple steel reinforcement ratios subjected to different deformation histories.

• Journal of Korean Foot and Ankle Society
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• v.14 no.2
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• pp.173-176
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• 2010

Synovial chondromatosis is a benign lesion forming multiple round cartilagenous nodules or osseous loose bodies in joint cavity. Predilection sites are known as knee, hip and elbow joints. However, the involvement of ankle joint was rarely reported in the literature. Moreover, extraarticular chondromatosis in synovial sheath or bursa of extremities is extremely rare. We present a case of synovial chondromatosis of the left ankle joint and flexor hallucis longus tendon sheath.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.205-208
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• 2008

Steel-embedded composite piers can enhance the resistance of core concrete by confinement of the steel elements and also can strengthen the stability of the embedded steel elements by concrete parts, so that the resistance of the composite members and seismic requirements can be provided without increasing section dimensions and self-weight. While modular composite piers with single segment do not need prestressing, precast segment composite piers with multiple segments need to have prestressing to prevent excessive cracking at the joints. Initial stresses and deformation by the introduced prestress are changed by long-term properties of concrete and need to be considered in the design. This paper deals with the prestress losses by the measurement of load cells, strains of reinforcements, concrete and embedded steel tubes.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2002.11a
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• pp.487-489
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• 2002

Recently, mobility and accessibility occurs for the elder and the handicapped in the aging problem. In this paper, we analyze the dynamics of slide-up seat, which helps to care the handicapped passenger in and out the automobile when we enjoy trip with the families including the elder and handicapped. We check the trajectories of slide-up seat inside and outside car to protect its corrosion and the stress at the joints of mechanical structure. Those can be helped to keep the safety and accuracy of the multiple dynamic systems for precision quality assurance in mass production.

• The Journal of the Korean dental association
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• v.55 no.10
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• pp.706-714
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• 2017

Background Synocial chondromatosis(SC), a proliferative disorder of the synovial membrane. The etiology or cause of SC remains unclear. SC usually occurs in large articular joints such as knee, hip, elbow, and ankle. SC of the TMJ is very rare. It is a benign disease that mainly affects unilateral side. It can form cartilagenous and calcified loose bodies of various sizes and cause abnormal function of TMJ. Case Report In this paper, we report two cases of SC in the upper joint space of the left TMJ. One complained that "Sometimes the left jaw joint feels disoriented" and the other had no symptoms. CT scan and MRI showed left TMJ space widening, multiple tiny calcified mass. After clinical and radiographic analysis, we performed surgical removal of the lesion under genereal anesthesia. In the histologic examination, synovial chondromatosis was diagnosed in both patients. Conclusions We report two cases of synovial chondromatosis in the upper joint space of the left TMJ. We performed surgical removal of the lesion. The two patients showed good prognosis without recurrence or pain up to date.

• Clinical and Experimental Pediatrics
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• v.45 no.12
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• pp.1601-1605
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• 2002

Henoch-Sh${\ddot{o}}$nlein Purpura(HSP) is an immuologically mediated systemic vasculitis of small blood vessels affecting predominantly the skin, gastrointestinal tract, joints, and kidneys. Clinical neurological manifestations such as headaches, behavioral changes, mental changes, seizures, and visual loss are described, but neurological complication are rare during the course of HSP. We experienced a case of an 8 year-old male with HSP who presented with seizures. Magnetic resonance imaging(MRI) showed multiple high signal intensity in both cortical and subcortical areas of frontal and parieto-occipital lobes and magnetic resonance(MR) angiogram showed stenosis of cerebral arteries, compatible with MRI and MR angiogram findings of cerebral vasculitis. We report this case with related literature.

• Journal of Power System Engineering
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• v.16 no.4
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• pp.12-16
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• 2012

In this paper, the equations of motions for planar multibody dynamics are established for considering the parallel programming based on GPU. Cartesian coordinates are used to formulate the equations of motion and implicit integration method called HHT-alpha is employed. Open chain multibody system is considered for computer simulation. CUDA toolkit is employed for establishing the GPU parallel programming. The exactness of the analysis is verified from the comparison with ADAMS. The results from parallel computing based on GPU are compared with the results from the sequential programming based on CPU in terms of calculation time. The multiple pendulum with bodies and joints is employed for the computer simulation. In the pendulum system that has 290 bodies, the parallel program indicates an improved efficiency of about 25.5 second(15.5% improvement). It is noted that the larger the size of system is, the time efficiency is better.