• Korean Chemical Engineering Research
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• v.55 no.4
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• pp.561-566
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• 2017

Butt-fusion welding process is used to join the polymeric pipes. Recently, some researchers suggest the curved surface to enhance a welding quality. We investigated how curved welding surface affects heat and flow behaviors of polymer melt during the process in 2D axisymmetric domain with finite element method, and discussed the effect to the welding quality. In this study, we considered HDPE pipes. In heat soak stage, curved phase interface between the melt and solid is shown along the shape of welding surface. In jointing stage, squeezing flow is generated between curved welding surface and phase interface. The low shear rate in fusion domain reduces the alignment of polymer to the perpendicular direction of pipes, and then this phenomenon is expected to help to enhance the welding quality.

• The Korean Journal of Pain
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• v.19 no.2
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• pp.223-227
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• 2006

Complex regional pain syndrome (CRPS) is clinically characterized by pain, abnormal regulation of blood flow and sweating, edema of skin and subcutaneous tissues, sensory and motor disturbances, and trophic changes of the skin. A 21-year-old man was suffering from pain and swelling in his right hand and forearm. His arm had been in splints for 3 weeks following an extension injury of the right fingers and wrist, with the pain having developed 2 weeks after the splinting. He was treated with various nerve blocks including continuous epidural infusion, thoracic sympathetic block and peripheral nerve blocks, and squeezing his edematous region under general anesthesia as well as intravenous lidocaine and ketamine infusions. However, all of the performed treatments had no effect on the patient's pain or hand swelling. As a next line therapy, spinal cord stimulation should be considered because of intractable severe pain and swelling to almost all other modalities of therapy. We therefore performed an early intervention of spinal cord stimulation for the patient with refractory CRPS type I 5 months after the onset of pain and have got an excellent result.

• Transactions of Materials Processing
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• v.16 no.8
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• pp.603-613
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• 2007

This paper is concerned with joining of thin metal sheets by single stroke clinching process. This method has been used in sheet metal work as it is a simple process and offers the possibility of joining similar-dissimilar thin sheet metals. Clinching generates a joint by overlapping metal sheets deforming plastically by punching and squeezing sequence. AA 5754 aluminum alloy of 0.5 mm thick sheets have been selected as a modal material and the process has been simulated under different process conditions and the results have been analyzed in terms of the quality of clinch joints which are influenced mainly by tool geometries. The rigid-plastic finite element method is applied to analyses in this paper. Analysis is focused mainly on investigation of deformation and material flow patterns influenced by major geometrical parameters such as die diameter, die depth, groove width, and groove corner radius, respectively. To evaluate the quality of clinch joints, four controlling or evaluation parameters have been chosen and they are bottom, neck thickness of bottom and top sheets, and undercut thickness, respectively. It has been concluded from the simulation results that the die geometries such as die depth and diameters are the most decisive process parameters influencing on the quality of clinch joints, and the bottom thickness is the most important evaluation parameter to determine if the quality of clinch joints satisfies the demand for industrial application.

• Structural Engineering and Mechanics
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• v.75 no.5
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• pp.529-540
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• 2020

The mechanical properties of timber construction have drawn more attention after the 2013 Lushan earthquake. A strong desire to preserve this ancient architectural styles has sprung up in recent years, especially for residential buildings of the mountainous areas. In the column-and-tie timber construction, continuous-tenon joints are the most common structural form to connect the chuanfang (similar to the beam in conventional structures) and the column. To study the cyclic performance of the continuous-tenon joints in column-and-tie timber construction, the reversed lateral cyclic loading tests were carried out on three 3/4 scale specimens with different section heights of the chuanfang. The mechanical behavior was assessed by studying the ultimate bending capacity, deformation ductility and energy dissipation capacity. Test results showed that the slippage of chuanfang occurred when the specimens entered the plastic stage, and the slippage degree increased with the increase of the section height of chuanfang. An obvious plastic deformation of the chuanfang occurred due to the mutual squeezing between the column and chuanfang. A significant pinching was observed on the bending moment-rotation curves, and it was more pronounced as the section height of chuanfang increased. The further numerical investigations showed that the flexural capacity and initial stiffness of the continuous-tenon joints increased with the increase of friction coefficient between the chuanfang and the column, and a more obvious increasing of bending moment occurred after the material yielding. The compressive strength perpendicular to grain of the material played a more significant role in the ultimate bending capacity of continuous-tenon joints than the compressive strength parallel to grain.

• Health Policy and Management
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• v.21 no.2
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• pp.249-262
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• 2011

Since May 1st in 2008, the products of ginkgo biloba extract have had to be used with the patient's out-of-pocket payment due to reimbursement restriction guidelines. This study aims to analyze the policy effects of reimbursement restriction on pharmaceutical expenditures using interrupted time series(ITS) analysis. We retrieved monthly NHI claims data for the period between May, 2005 and December 2009. The ingredients identified as a substitute for ginkgo biloba have similar indications based on the similar pharmacological activities. The effects of changes in reimbursement scope were evaluated both for all relevant pharmaceuticals within the same therapeutic class and for 2 separate groups : ginkgo biloba's and its substitutes. According to the study results, restrictions on reimbursement scope resulted in savings of the drug expenditures in the targeted therapeutic class. Direct restriction on ginkgo biloba was associated with a decrease in expenditure level by 60.1% and changes in trend from an average increase rate of 1.4% to an average decrease rate of 1.5% for the therapeutic class, with a dramatic decrease in expenditure level(-191.5%) for ginkgo biloba itself, but with an increased expenditure level(+50.1%) and changes in trend from an average increase rate of 2.0% to an average decrease rate of 1.0% for the substitute group. Further policy to restrict nicergoline was associated with additional decrease in expenditure level for the therapeutic class. Additionally, we could identify the balloon effect - a new policy squeezing one part results in bulging out elsewhere. After the restriction of ginkgo biloba, the utilization of and expenditures on its substitutes increased significantly. In conclusion, we demonstrated that consecutively introduced policies effectively reduced overall expenditures on the therapeutic class of interest. Some ingredients played as a substitute while others did not. Further studies need to be conducted to identify which factors determine a substitute.

• Korean journal of food and cookery science
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• v.16 no.5
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• pp.410-415
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• 2000

This study was performed to study tile organophosphorus pesticides residues removal effect of rice and Korean cabbage. Four organophosphorus pesticides(EPN, diazinon, fenithrithion, phenthoate) were artificially added to rice and Korean cabbage. Then they were washed with water and cooked differently to analyze the amount of pesticides residues reduced. The result of the study were as following; 1. The removal rate of pesticides residue on rice was 15.5∼35.4% an[ the amount of washing water was more influential in removal rate than number of washing. 2. The removal rate of pesticides residues through cooking processes after rice washing was 72.1∼77.8%. 3. The removal rate of pesticides residues through washing and cooking processes on the Korean cabbage were 18.4∼41.0%, 22.8∼92.7%. 4. As the amount of washing water of Korean cabbage increase, pesticides removal effect was higher. 5. Squeezing out the washed water from the cabbage increased pesticides removal rate.

• Journal of the Korean Society for Railway
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• v.19 no.2
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• pp.109-116
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• 2016

The market share of high-speed railway vehicles is increasing across the world. A high-performance impact energy absorption factor is essential to satisfy the safety standards of railway vehicles. A deformed tube assembly is a typical energy absorption factor in railway vehicles. The tube assembly comprises a deformed tube and a press-fitting punch, its performance depends on the absorption energy characteristics in the plastic zone of the tube. In this study, a deformed tube assembly of a railway vehicle is designed that can absorb a maximum impact energy of 200kJ under plastic deformation. Slab method and finite element analysis are used to estimate the reaction force of the punch in the initial stage, the performance of the designed tube assembly is confirmed experimentally.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.171-184
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• 2007

Chemical admixture stabilization has been extensively used in both shallow and deep stabilization in order to improve inherent properties of the soil such as strength and deformation behavior. An increment in strength, a reduction in compressibility, an improvement of the swelling or squeezing characteristics and increasing the durability of soil are the main aims of the admixtures for soil stabilization. Recently, the various advanced cement stabilizer mixing technique was developed. Advanced cement stabilizer mixing technique is environmentally-friendly and has an excellent mixing property and outstanding mixing speed. In this study, to develop the rural road pavement technology using cement stabilizer, compaction and unconfined compression test were performed with various mixing ratio and two types of soil(clay and silty soil). And the freezing/thaw test and bending strength test performed to develop suitable cement stabilizer material for stabilization of rural road. Based on the test results, the liquid types of cement stabilizer material and silty soil mixture are most suitable for rural road construction and although the mixing ratio is low, cement stabilizer mixture is effective for durability of rural road surface layer.

• Advances in concrete construction
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• v.11 no.5
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• pp.357-365
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• 2021

High deformable concrete (HDC) elements have compressive strength rates equal to conventional concrete and have got a high compressive strain at about 20% to 50%. These types of concrete elements as prefabricated parts have an abundance of applications in the construction industry which is the most used in the construction of tunnels in squeezing grounds, tunnel passwords from fault zones or swelling soils as soft supports. HDC elements after reaching to compressive yield stress, in nonlinear behavior have hardening combined with increasing strain and compressive strength. The main aim of this laboratory and numerical research is to construct concrete elements with the above properties so the compressive stress-strain behavior of different concrete elements with four categories of mix designs have been discussed and finally one of them has been defined as HDC element mix design. Furthermore, two columns with and without implementing of HDC elements have been made and stress-strain curves of them have been investigated experimentally. An analysis model is presented for columns using finite element method adopted by ABAQUS. The results obtained from the ABAQUS finite element method are compared with experimental data. The main comparison is made for stress-strain curve. The stress-strain curves from the finite element method agree well with experimental results. The results show that the dimension of the HDC samples is significant in the stress-strain behavior. The use of the element greatly increases energy absorption and ductility.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.29 no.2
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• pp.84-91
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• 2020

Regeneration of interdental papilla damaged by periodontal disease is a very challenging task. So far, many dentists have devised and introduced great surgical methods. Comparing the pros and cons of the methods introduced so far, I came up with the best way to regenerate interdental papilla. Temporarily creating space between narrow interdental papilla, which cannot be solved by periodontal surgery alone, was a great help for connective tissue graft(CTG). The CTG was performed using a microblade, and only one vertical incision was performed off the gingival margin, and the graft was performed by inserting the grafts through here. Along with the orthodontic treatment, the area between the narrow interdental papilla was widened to make it easier for the CTG was carried out. After a period of maintenance, I was able to gather the teeth again with orthodontic force and regenerate the interdental papilla. I named this method ELSA (Enlargement of space-Labial graft-Squeezing-for Augmentation of papilla) technique.