• The Korean Journal of Pain
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• 제19권2호
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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.

• 소성∙가공
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• 제16권8호
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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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• 제75권5호
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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.

• 보건행정학회지
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• 제21권2호
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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.

• 한국식품조리과학회지
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• 제16권5호
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• pp.410-415
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• 2000

본 실험의 목적은 우리나라 상용식품인 쌀과 배추의 세척과 가열에 의한 유기인계 농약의 제거효과를 보기 위한 것으로 유기인계 농약 중 diazinon, fenithrithion, phenthoate, EPN 인위적으로 부착하여 세척과 가열과정의 변화에 의한 저감 효과를 실험한 결과는 다음과 같다. 1. 쌀의 세척에 의한 농약의 제거율은 15.5∼35.4%이었으며, 제거효과는 세척회수보다 물의 양의 영향력이 더 높았다. 2. 쌀을 세척한 후 취반과정을 거치면 농약의 제거율은 72.1∼77.8%이었다. 3. 배추의 세척, 가열과정에 의한 농약의 제거율은 각각 18.4∼41.0%, 22.8∼82.7%이었다. 4. 배추는 쌀과 같이 세척과 가열시 물의 양이 많을수록 제거효과가 높았다. 5. 우리나라의 요리 방법인 나물 무침시 배추를 삶아서 꼭 짜서 수분이 제거되면 농약의 잔존량은 더욱 낮아진다.

• 한국철도학회논문집
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• 제19권2호
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• pp.109-116
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• 2016

고속철도 차량의 시장 점유율은 전 세계적으로 확대되고 있다. 고성능 충격 에너지 흡수 요소는 철도차량의 안전 기준을 충족하는 것이 필수 요소이다. 변형 튜브 조립체는 철도 차량에 대한 전형적인 에너지 흡수 요소이다. 그것은 변형 튜브와 압입 펀치로 구성되어 있으며 튜브 조립체의 성능은 튜브의 소성 영역에서 흡수 에너지 특성에 의존한다. 본 논문의 변형 튜브에서 흡수하는 소성변형 에너지는 200kJ의 철도차량 충돌 에너지를 흡수하도록 설계되어 있다. 슬래브 법과 유한 요소해석을 사용하여 초기 단계에서 펀치의 반력은 예측되며 설계된 튜브 조립체의 성능은 실험으로 확인되었다.

• 한국도로학회논문집
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• 제9권4호
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• pp.171-184
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• 2007

화학적 첨가제를 이용한 안정처리는 지반의 강도증가 및 변형발생을 제어하기 위한 방법으로 깊은 심도까지 광범위하게 적용되어 지고 있다. 화학적 안정처리의 기본목적은 지반의 강도증가, 압축성 감소, 팽창특성 등을 개선하여 지반의 내구성을 증가시키는 것이며, 최근 들어 환경친화적이며 혼합체의 특성 및 혼합속도를 효율적으로 개선한 다양한 형태의 진보적인 시멘트 혼화재가 개발되고 있다. 본 연구에서는 농어촌도로(농도)의 효율적인 포장공법 개발을 위하여 시멘트혼화재를 활용하는 방안을 연구하였으며, 혼화재 종류 및 배합비에 따른 다짐시험, 일축압축강도시험, 동결융해시험 및 휨강도시험을 실시하였다. 본 연구결과에 따르면, 실트질 원지반토가 점토지반에 비해 강도증가 및 동결융해특성이 우수하며, 액상형 시멘트 혼화재가 분말형태 보다 효과적인 것으로 나타났다. 또한 저배합에서도 고강도의 품질을 발휘하여 농어촌도로 표층 내구성 저하를 개선할 수 있을 것으로 판단된다.

• Advances in concrete construction
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• 제11권5호
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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.

• 대한심미치과학회지
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• 제29권2호
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• pp.84-91
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• 2020

치주질환으로 손상된 치간유두의 재생은 아주 도전적인 과제이다. 지금까지 많은 치과의사들이 훌륭한 수술적인 방법을 고안하여 소개하였다. 지금까지 소개된 술식들을 순서대로 비교해보고 장단점을 비교해 치간유두를 재생을 위한 최적의 방법을 고안해보았다. 치주수술만으로 해결하기 어려운 좁은 치간유두 사이의 공간을 부분교정치료를 통하여 공간을 일시적으로 만들어 주는 것이 치은이식을 위해 큰 도움이 되었다. 치은이식은 마이크로 블레이드를 이용하여 박리를 시행하고 치은경계부에서 떨어진 수직절개를 하나만 시행해 여기를 통해 추가적인 박리와 이식편을 넣어서 치은이식을 시행하였다. 이렇게 교정치료를 동반하여 좁은 치간유두 사이의 폭을 벌려서 치은이식이 더 용이한 상태로 만들어 치은이식을 진행하고, 치은이 성숙한 뒤 교정력으로 다시 치아사이를 모아주는 술식(ELSA technique)을 통해 치간유두 재생을 할 수 있었다.

• Geomechanics and Engineering
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• 제34권6호
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• pp.637-648
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• 2023

When an earth pressure balance (EPB) shield machine bores a tunnel in gravelly sand stratum, the excavated natural soil is normally transformed using foam and water to reduce cutter wear and the risk of direct muck squeezing out of the screw conveyor (i.e., muck spewing). Understanding the undrained shear behavior of conditioned soils under pressure is a potential perspective for optimizing the earth pressure balance shield tunnelling strategies. Owing to the unconventional properties of conditioned soil, a pressurized vane shear apparatus was utilized to investigate the undrained shear behavior of foam-conditioned gravelly sands under normal pressure. The results showed that the shear stress-displacement curves exhibited strain-softening behavior only when the initial void ratio (e₀) of the foam-conditioned sand was less than the maximum void ratio (e_max) of the unconditioned sand. The peak and residual strength increased with an increase in normal pressure and a decrease in foam injection ratio. A unique relation between the void ratio and the shear strength in the residual stage was observed in the e-ln(τ) space. When e₀ was greater than e_max, the fluid-like specimens had quite low strengths. Besides, the stick-slip behavior, characterized by the variation coefficient of measured shear stress in the residual stage, was more evident under lower pressure but it appeared to be independent of the foam injection. A comparison between the results of pressurized vane shear tests and those of slump tests indicated that the slump test has its limitations to characterize the chamber muck fluidity and build the optimal conditioning parameters.