• Structural Engineering and Mechanics
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• v.76 no.3
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• pp.337-354
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• 2020

Reinforced concrete beam-column (RCBC) joints of laterally loaded unbraced frames are sometimes controlled by their shear behavior. This behavior relies on multiple and interdependent complex mechanisms. There are already several studies on the influence of some parameters on the shear strength of reinforced concrete joints. However, there are no studies methodically tackling all the most relevant parameters and quantifying their influence on the overall joint behavior, not just on its shear strength. Hence, considering the prohibitive cost of a comprehensive parametric experimental investigation, a nonlinear finite element analysis (NLFEA) was undertaken to identify the key factors affecting the shear behavior of such joints and quantify their influence. The paper presents and discusses the models employed in this NLFEA and the procedure used to deduce the joint behavior from the NLFEA results. Three alternative, or complementary, quantities related to shear are considered when comparing results, namely, the maximum shear stress supported by the joint, the secant shear stiffness at maximum shear stress and the secant shear stiffness in service conditions. Depending on which of these is considered, the lower or higher the relevance of each of the six parameters investigated: transverse reinforcement in the joint, intermediate longitudinal bars and diagonal bars in the column, concrete strength, column axial load and confining elements in transverse direction.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.4
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• pp.75-86
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• 1996

A fatigue life prediction program for multiple planar surface cracks in finite plates and T-fillet joints, based on linear elastic fracture mechanics was developed. This prediction technique include the crack coalescence, mutual interation and the stress intensity concentration effect in welded joints. Total of 44 cases were compared with lida's and Vosikovsky's experimental results and it was found that the present method was a reasonable tool for the predictioin of fatigue life.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.6
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• pp.90-96
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• 2011

In this study, the characteristic of fractured portion and shape on solder joints were investigated according to the thermal shock test for Automotive Application Component using Sn-3.0Ag-0.5Cu solder, which has a outstanding property as Lead-free solder. The value of pull and shear strength was decreased in principle after 432 cycles thermal shock test. In addition, fracture mode was verified by using EDS and SEM to observe fractured shape on the solder joints before and after thermal shock. In before thermal shock test, the fracture mode revealed typically solder layer's fracture mode. In after thermal shock test, we identified multiple fracture mode of the ductile and brittle fracture. Even though same composition of solder was used to experimental for estimating. the fracture mode varied on the fracture portion's height and the directional angles of shear strength. In conclusion, we identified that mechanical strength was affected on the solder layer's fracture mode.

• Journal of Korean Foot and Ankle Society
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• v.11 no.1
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• pp.107-110
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• 2007

Synovial chondromatosis is an uncommon non-neoplastic condition of the joints, forming multiple cartilaginous nodules in the synovium. The lesion usually tends to involve large joints, and the occurrence in the small joint of foot is very rare. We would like to report a case of synovial chondromatosis which was confused with Freiberg infarction in the 1st metatarsophalangeal joint of the foot.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.11 s.170
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• pp.2058-2066
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• 1999

The present paper proposes a new dynamic analysis method for multi-span Timoshenko beam structures supported by joints with damping subject to moving loads. An exact dynamic element matrix method is adopted to model Timoshenko beam structures. A generalized modal analysis method is applied to derive response formulae for beam structures subject to moving loads. The proposed method offers an exact and closed form solution. Two numerical examples are provided for validating and illustrating the proposed method. In the first numerical example, a single span beam with multiple moving loads is considered. A dynamic analysis on a multi-span beam under a moving load is considered as the second example, in which the flexibility and damping of supporting joints are taken into account. The numerical study proves that the proposed method is useful for the vibration analysis of multi-span beam-hype structures by moving loads.

• Journal of the Semiconductor & Display Technology
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• v.21 no.4
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• pp.126-131
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• 2022

The number of joint disease patients is increasing every year. Currently, the most CPM(Continuous Passive Motion) equipment uses expensive imported equipment, and one CPM equipment is designed to be used only in one joint, medical personnel or hospitals who are the main users of the medical equipment need to have several types of CPMs for joint rehabilitation. To solve this problem, this paper designed a multifunctional joint medical equipment that enables rehabilitation of knee, shoulder, and elbow joints in one CPM equipment and includes general, intensive, and adaptive exercise functions for effective treatment according to the patient's condition. The patient's condition was diagnosed using a load cell and a current sensor. In this paper, effective rehabilitation methods were presented and high reliability and precision of medical equipment was confirmed through experiments using potentiometer, encoder, and PI controller.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.15 no.1
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• pp.308-314
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• 2002

Multiple epiphyseal dysplasia is an uncommon disorder, which was first described by Fairbank in 1935, characterized by irregularity in development of the epiphysis that manifests itself as late appearance and mottling of the ossification centers, knobby joints, stubby digits and minimal shortness of stature. It is typically transmitted as an autosomal dominant trait though recessive forms have been described. The diagnosis is established on the basis of the positive roentgenographic findings in combination with the absence of biochemical abnormalities. We report a case of multiple epiphyseal dysplasia, which was improved by herbal medication.

• Steel and Composite Structures
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• v.35 no.6
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• pp.799-813
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• 2020

Fatigue cracks of rib-to-deck (RD) joints have been frequently observed in the orthotropic steel decks (OSD) using conventional U-ribs (CU). Thickened edge U-rib (TEU) is proposed to enhance the fatigue strength of RD joints, and its effectiveness has been proved through fatigue tests. In-depth full-scale tests are further carried out to investigate both the fatigue strength and fractography of RD joints. Based on the test result, the mean fatigue strength of TEU specimens is 21% and 17% higher than that of CU specimens in terms of nominal and hot spot stress, respectively. Meanwhile, the development of fatigue cracks has been measured using the strain gauges installed along the welded joint. It is found that such the crack remains almost in semi-elliptical shape during the initiation and propagation. For the further application of TEUs, the design curve under the specific survival rate is required for the RD joints using TEUs. Since the fatigue strength of welded joints is highly scattered, the design curves derived by using the limited test data only are not reliable enough to be used as the reference. On this ground, an experiment-numerical hybrid approach is employed. Basing on the fatigue test, a probabilistic assessment model has been established to predict the fatigue strength of RD joints. In the model, the randomness in material properties, initial flaws and local geometries has been taken into consideration. The multiple-site initiation and coalescence of fatigue cracks are also considered to improve the accuracy. Validation of the model has been rigorously conducted using the test data. By extending the validated model, large-scale databases of fatigue life could be generated in a short period. Through the regression analysis on the generated database, design curves of the RD joint have been derived under the 95% survival rate. As the result, FAT 85 and FAT 110 curves with the power index m of 2.89 are recommended in the fatigue evaluation on the RD joint using TEUs in terms of nominal stress and hot spot stress respectively. Meanwhile, FAT 70 and FAT 90 curves with m of 2.92 are suggested in the evaluation on the RD joint using CUs in terms of nominal stress and hot spot stress, respectively.

• Journal of Korean Public Health Nursing
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• v.15 no.1
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• pp.111-124
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• 2001

This study was conducted to identify the characteristics of pain, self-esteem, perceived health status, and self-efficacy and its influencing factors in patients with chronic arthritis. The data were obtained from 104 patients with chronic arthritis registered in one university hospital in Seoul, from May to August, 2000. For analysing the data, SAS program was used for t-test, ANOVA, Scheffe test, Pearson correlation, and stepwise multiple regression. The results were as follows: 1. The variables which showed significant difference with pain were sex, number of painful joints. 2. The variables which showed significant difference with perceived health status were age, diagnosis. number of painful joints. 3. The variables which showed significant difference with self-efficacy were duration of disease, number of painful joints. quality of sleeping. 4. Moderate negative correlation were observed between pain and perceived health status, self-efficacy, and low positive correlation was observed between self-esteem and perceived health status. Also self-esteem revealed moderate positive correlation with self-efficacy, and moderate positive correlation was observed perceived health status and self-efficacy. 5. The predictors to explain self-efficacy were number of painful joints, self-esteem, duration of disease, duration of exercise and pain. These predictors explained $36.05\%$ of variance of self-efficacy. In conclusion, the nursing intervention to improve self-efficacy for chronic arthritis patients focused not only physiological symptoms such as pain. but also psychosocial factors such as self-esteem.

• The Korean Journal of Nuclear Medicine
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• v.25 no.1
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• pp.87-94
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• 1991

To evaluate the diagnostic usefulness of quantitative sacroiliac joint scintigraphy and its clinical significance in the ankylosing spondylitis, we measured SIS ratio (Sacroiliac Joint/Sacrum Uptake ratio) by region of interest method in 52 patients with ankylosing spondylitis. As compared with radiological grade, SIS ratio was significantly elevated in the early stage of ankylosing spondylitis and returned to normal range in the late stage. Scintigraphic finding of focal uptakes of radiotracer at multiple spinal apophyseal joints was characteristic and proximal large joints were more involved than distal joints. The incidence and extent of the arthropathy revealed by scnitigraphy exceeded that which was clinically evident, and scintigraphy was more sensitive to detect symptomatic lesion than radiography. Therefore, it is suggested that bone scan is useful for the early diagnosis and the assessment of clinical activity of involved joints of ankylosing spondylitis.