• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.793-798
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• 2003

The purpose of this study is to investigate the setting properties of polystyrene mortars using waste expanded polystyrene(EPS) solution-based binders. The binders for polystyrene mortars are made by mixing crosslinking agent with waste EPS solutions which prepared by dissolving EPS in styrene. Polystyrene mortars are prepared with various EPS concentrations of EPS solutions and crosslinking agent contents, subjected to a dry curing, and tested for working life, peak exotherm temperature and 10h-length change. From the test results, the working lives of polystyrene mortars are shortened with raising EPS concentration of EPS solution and crosslinking agent content. Low-shrinkage or non-shrinkage of polystyrene mortars should be accomplished by adjusting EPS concentration of EPS solution and crosslinking agent content.

• Journal of Communications and Networks
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• 제16권6호
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• pp.583-591
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• 2014

In wireless communications, knowledge of the signal-to-noise ratio is required in diverse communication applications. In this paper, we derive the variance of the maximum likelihood estimator in the data-aided and non-data-aided schemes for determining the optimal shrinkage factor. The shrinkage factor is usually the constant that is multiplied by the unbiased estimate and it increases the bias slightly while considerably decreasing the variance so that the overall mean squared error decreases. The closed-form biased estimators for binary-phase-shift-keying and quadrature phase-shift-keying systems are then obtained. Simulation results show that the mean squared error of the proposed method is lower than that of the maximum likelihood method for low and moderate signal-to-noise ratio conditions.

• 품질경영학회지
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• 제30권2호
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• pp.86-98
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• 2002

Defining the relationship between the quality of injection molded parts and the process condition is very complicate because of lots of factor are involved and each factor has a non-linearity. With the development of CAE(Computer Aided Engineering) technology, the estimation of volumetric shrinkage of injection mold parts is possible by computer simulation even though restricted application. In this research, Neural Network applied for finding optimal processing condition. The percent of volumetric shrinkage compared on each case and show neural network can be successfully applied selecting optimum condition not only within factor level but also between factor level.

• 산업경영시스템학회지
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• 제25권2호
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• pp.71-76
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• 2002

Defining the relationship between the quality of Injection molded parts and the process condition is very complicate because of lots of factors are involved and each factor has a non-linearity. With the development of CAE(Computer Aided Engineering) technology, the estimation of volumetric shrinkage of injection mold parts is possible by computer simulation in spite of restricted application. In this research, the Taguchi method md Neural Network are applied for finding optimal processing condition. The percent of volumetric shrinkage is compared on each case and shows neural network can be successfully applied.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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• pp.318-320
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• 2013

The spherical bead manufactured by rapidly cooling process shows high density of 3.64g/㎤, high unit volume weight of 2.6kg/l, and high solid volume of 71%. When it applies to the grouter, it is possible to obtain even high fluidity with only a small amount. This study, focusing the grouter using a rapidly-cooled electric arc furnace oxidizing slag(RC-EAFS), deals with the properties of flow and setting time in fresh state, compressive strength and length variation at 1, 3, 7 and 28 curing day in hardened state. As the results, even though the grouter with RC-EAFS shows comparative low strength, it will be possible to development the competitive product due to the properties of increasing flow and low cost.

• Design & Manufacturing
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• 제14권4호
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• pp.52-57
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• 2020

In this study attempted to prevent defects due to blow holes among defects of sand casting products. It was intended to reduce the defect rate by reducing the blow hole of the inner surface. Currently, expectations and requirements for the quality level of non-ferrous aluminum casting in the casting industry are increasing. In addition, the shape is complex and the shrinkage precision is required. Among them, the test prototype is expensive to manufacture the mold, and the production time is also long, and the product is manufactured by sand casting. At this time, the highest defect rates are defects caused by shrinkage defects, surface defects, and blow holes.. At this study, the manufacturing time was shortened by using the shape of the fluid movement path in advance. Also, it is possible to reduce defects due to blow holes.

• Clinics in Shoulder and Elbow
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• 제1권1호
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• pp.40-45
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• 1998

Multidirectional instability of the shoulder joint is an unusual entity which is not yet well understood. Traditionally recommended treatment is non-operative, but recently arthroscopic treatment has been performed. This is a retrospective review of 20 patients who had multidirectional instability, who had been treated with arthroscopic capsular shift(7 cases), and arthroscopic treatment using Ho:YAG laser(l3 cases) at Department of Orthopaedic Surgery, Chungnam National University Hospital from July, 1988to February, 1997. Results of this study were as follows: 1. In five patients who were treated with arthroscopic anterior capsular shift only, all cases had redislocation of the shoulder joint. But there was no redislocation in two patients who were treated with arthroscopic anterior and posterior capsular shift. 2. ln three patients who were treated with laser-assisted capsular shift only, all cases had redislocation of the shoulder joint. But there was only one redislocation in ten patients treated with laser-assisted capsular shrinkage and capsular plication. Ho: Y AG laser has been found to be a safe and efficacious adjunct to many arthroscopic shoulder procedures. We had satisfactory results by combining a transglenoid capsular shift with laser-assisted capsular shrinkage. Arthroscopic laser-assisted capsular shrinkage and capsular plication is a one of recommendable treatment options in multidirectional instability of the shoulder joint.

• 한국구조물진단유지관리공학회 논문집
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• 제18권5호
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• pp.19-26
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• 2014

콘크리트 방호벽 및 중앙분리대는 교량의 부속시설이지만, 슬립폼 시공과 넓은 비표면적으로 인해 초기재령 균열이 발생하기 쉽다. 본 연구에서는 대형 교량의 방호벽과 중앙분리대 콘크리트의 외관조사 및 비파괴실험을 수행하여 균열의 원인과 발생 균열의 패턴을 분석하였다. 이를 위해 시공기간을 고려하여, 건조수축, 수화열 해석이 수행되었으며, 현장의 환경조건을 고려하여 소성수축 특성을 평가하였다. 평가결과 대상구조물의 균열 원인은 철근위치에 따른 소성침하균열, 소성수축 및 건조수축에 의한 복부균열, 재료분리에 따른 상부균열로 추정할 수 있었다. 또한 균열원인과 발생 패턴을 도식화하였으며, 시공 및 재료분야에서 균열제어대책을 제안하였다. 해상위 교량에 설치하는 중앙분리대 및 방호벽 콘크리트는 환경조건 (풍속, 온도, 습도)에 매우 민감하여 초기재령균열이 쉽게 발생하므로 재료선택 및 시공방법에 신중을 기해야 한다.

• 대한기관식도과학회지
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• 제14권2호
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• pp.31-37
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• 2008

Background and Objectives: In most cases of benign neck cysts, surgical excision has been considered as treatment of choice. However, sometimes complete excision is very difficult, and recurrences has been occured due to insufficient surgery frequently. In this point of view, non-surgical treatment has been attempted with sclerosing agents such as picibanil(OK-432). In this study, we evaluated the efficacy of picibanil sclerotherapy for benign neck cysts. Materials and methods: We retrospectively reviewed 53 patients(27 males, 26 females) who had undergone sclerotherapy with picibanil for benign neck cysts such as ranula, lymphangioma, thyroglossal duct cyst and branchial cyst. Information was gathered with respected to age, sex, number of injections, side effect and outcome of treatment. All patients were treated with intralesional aspiration of cystic contents and injection of picibanil, and followed on neck ultrasonography or neck CT. Results: 53 patients received sonoguided sclerotherapy using picibanil(OK-432). 31 patients(41.3%) showed total shrinkage, near total shrinkage(more than 90% of volume) in 7 patients(9.3%), marked shrinkage(more than 70%) in 5 patients(6.6%) and partial shrinkage(less than 70%) in 17 patients. 15 patients(20%) reaveled no response and 8 patients showed recurrences with repeated sclerotherapy. The side effects of therapy were observed by symptoms such as fever, localized pain and odynophagia. However, these complications disappeared after several days in all cases. Conclusions: We recognized that picibanil(OK-432) sclerotherapy for benign neck cyst is a safe and effective procedures as a primary treatment before considering surgery.

• The Korean Journal of Pain
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• 제18권1호
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• pp.56-59
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• 2005

The most effective treatment methods for a herniated lumbar disc remain questionable. This report follows the patients course, from the onset of pain through the completion of the non-surgical treatment, and shows that a lumbar herniated disc, with radiculopathy, can be successfully treated with a non-surgical approach. This report discusses the possible explanations for disc resorption: retraction into the intervertebral space, dehydration/shrinkage and resorption due to an inflammatory reaction. A non-surgical approach can be an effective treatment option for a herniated lumbar disc.