• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.84-87
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• 1999

This paper presents a preform design method that combines the analytic method and inference of known knowledge with neural network. The analytic method is a finite element method that is used to simulate backward extrusion with pre-defined process parameters. The multi-layer network and back-propagation algorithm are utilized to learn the training examples from the simulation results. The design procedures are utilized to learn the training examples from the simulation results. The design procedures are two methods the first the neural network infer the deformed shape from the pre-defined processes parameters. The other the network infer the processes parameters from deformed shape. Especially the latest method is very useful to design the preform From the desired feature it is possible to determine the processes parameters such as friction stroke and tooling geometry. The proposed method is useful for shop floor to decide the processes parameters and preform shapes for producing sound product.

• Structural Engineering and Mechanics
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• 제70권6호
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• pp.661-669
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• 2019

Buckling analysis of shape memory alloy (SMA) rectangular plates subjected to uniform and linearly distributed inplane loads is the main objective in the present paper. Brinson's model is developed to express the constitutive characteristics of SMA plate. Using the classical plate theory and variational approach, stability equations are derived. In addition to external inplane mechanical loads, the plate is subjected to the pre-stresses caused by the recovery stresses that are generated during martensitic phase transformation. Ritz method is used for solving the governing stability equations. Finally, the effects of conditions on the edges, thickness, aspect ratio, temperature and pre-strains on the critical buckling loads of SMA plate are investigated in details.

• 동의생리병리학회지
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• 제23권2호
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• pp.301-307
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• 2009

In korean society, the chronic life style diseases are increasing. It is caused by the approach of the aged society and the highly increasing income. Accordingly the preventive side of the health promotion and management is very important. In the oriental medicine, the general disease pre-estimate and the management program are necessary. On this point, the sign forecast is very significant in connection with the disease pre-estimate in the preventive disease management side. The sign forecast according to the human shape type diagnosis is mainly the sign of the super-early stage, The difference of the shape type has the difference of the special affinity about the disease. Accordingly we can find the sign forecast from the latent disease in the early stage. In NAE-GYEONG(內經), the theory of "five body form's type" can be pre-estimated the latent tendency and the clue of the disease and the growing tendency of disease in relation to the Differentiation of Syndrome, In the disease pre-estimate side, the graspe and management of the sign forecast from the latent disease will be the part of the new development.

• 한국공간구조학회논문집
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• 제7권1호
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• pp.79-85
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• 2007

FRP를 이용한 보강법 중에서도 기존에 일반적으로 행해진 보강법은 Plate 또는 Sheet의 형태로 콘크리트 표면에 부착하여 추가적인 강도를 발현하도록 하는 것이다. 그러나 조기 박락파괴, 부착면의 정리, 보강 단부의 앵커시공, 부착면에 대한 내화처리 등의 어려움이 많다. 이러한 문제점들에 대한 방안으로 막대(Rod) 형태인 CFRP-Rod를 보강모체에 홈을 파고 매립하는 NSMR(Near Surface Mounted Reinforcement)공법이 제안되었고, CFRP-Rod의 보강량, 길이, 간격 등의 변수에 의한 휨보강 능력의 평가에 대한 연구가 이루어져왔다. 그러나 구조물에서 CFRP-Rod의 보강은 어느 정도의 하중이 보강부위에 계속 재하된 상태로 보강이 이루어지게 되므로 본 연구에서는 보강전에 가해지는 선하중(Pre-loading)의 크기를 주요변수로 선하중의 크기에 따른 구조물의 거동 특성을 분석하고자 하였고, 선하중의 크기의 결정은 무보강 시험체의 공칭모멘트와의 비로 결정하였다.

• 한국재료학회지
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• 제13권1호
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• pp.64-68
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• 2003

The 1.6 vol% and 2.5 vol% TiNi/6061Al composites were fabricated by permanent mold casting for investigating the effect of heat treatment on tensile strength for composites. The tensile strength without T6 treatment at 293 K was increased with increasing the volume fraction of TiNi fiber and at 363 K the higher the pre-strain, the higher the tensile strength. The tensile strength of the composite with $T_{6}$ treatment at 293 K was found to increase with increasing both the amount of pre-strain and the volume fraction of TiNi fiber and was higher than that without $T_{6}$ treatment. It should be noted that the tensile strength 2.5vol%TiNi/6061Al composites rolled at a 38% reduction ratio was the maximum value of 298 MPa. The tensile strength of composites decreased with increasing the reduction ratio over 38% because of the rupture of TiNi fiber.

• 대한두개안면성형외과학회지
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• 제20권6호
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• pp.405-407
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• 2019

Due to the variety in the shape of dysmorphic cartilage, tragus reconstruction is one of the most challenging goals in otoplasty. The authors describe a method to reconstruct a prominent tragus in a simple way suitable for accounting for the size, shape, and location of the remaining ear. We present a case of tragus deformity in an 11-year-old female patient after a previous excision of pretragal skin tags. There was a small remnant of the deeply located dystopic cartilage in a horizontal orientation. The dystopic cartilage was used to reconstruct the tragus using a chondrocutaneous transposition flap. Only a small portion of the pre-existing cartilage was used to create a chondrocutaneous transposition flap that supplemented the portion of cartilage during tragus reconstruction. The result was a new tragus that showed acceptable improvement in shape, location, and projection. Patients with a small portion of pre-existing cartilage near the tragal wall may benefit from the use of this method for tragus reconstruction.

• 국제강구조저널
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• 제18권4호
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• pp.1325-1335
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• 2018

This study dealt with investigating the seismic performance of the smart and shape memory alloy (SMA) and magnets plus rubber-spring (MRS) dampers and their effects on the seismic resistance of multiple-span simply supported bridges. The rubber springs in the MRS dampers were pre-compressed. For this aim, a set of experimental works was performed together with developing nonlinear analytical models to investigate dynamic responses of the bridges subjected to earthquakes. Fragility analysis and probabilistic assessment were conducted to assess the seismic performance for the overall bridge system. Fragility curves were then generated for each model and were compared with those of as-built. Results showed dampers could increase the seismic capacity of bridges. Furthermore, from system fragility curves, use of damper models reduced the seismic vulnerability in comparison to the as-built bridge model. Although the SMA damper showed the best seismic performance, the MRS damper was the most appropriate one for the bridge in that the combination of magnetic friction and pre-compressed rubber springs was cheaper than the shape memory alloy, and had the similar capability of the damper.

• Structural Engineering and Mechanics
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• 제72권5호
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• pp.617-629
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• 2019

Based on the finite element method of traditional straight Euler-Bernoulli beams and the coupled relations between linear displacement and angular displacement of a pre-twisted Euler-Bernoulli beam, the shape functions and stiffness matrix are deduced. Firstly, the stiffness of pre-twisted Euler-Bernoulli beam is developed based on the traditional straight Euler-Bernoulli beam. Then, a new finite element model is proposed based on the displacement general solution of a pre-twisted Euler-Bernoulli beam. Finally, comparison analyses are made among the proposed Euler-Bernoulli model, the new numerical model based on displacement general solution and the ANSYS solution by Beam188 element based on infinite approach. The results show that developed numerical models are available for the pre-twisted Euler-Bernoulli beam, and which provide more accurate finite element model for the numerical analysis. The effects of pre-twisted angle and flexural stiffness ratio on the mechanical property are investigated.

• 한국유체기계학회 논문집
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• 제20권1호
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• pp.21-28
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• 2017

Optimization process of pre-swirl nozzle geometry was conducted to improve the discharge coefficient of pre-swirl system by using CFD. The optimization of pre-swirl nozzle shape covered the converging angle and the location of the converging nozzle. Optimization process included Optimal Latin Hyper-cube Design method to get the experimental points and the Kriging method to create the response surface which gives candidate points. The process was finished when the difference between the predicted value and CFD value of candidate point was less than 0.1 %. This paper compared the Reference model, Initial model which is the first model of optimization and Optimized model to study flow characteristics. Finally, the discharge coefficient of Optimized model is improved about 17 % to the Reference model.

• Human Ecology Research
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• 제61권1호
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• pp.73-90
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• 2023

This study aimed to identify ways to implement pre-parent education for adolescents in regular classes at school. This was achieved by investigating whether the contents of the 2015 revised curriculum high-school technology and home economics textbooks reflected the goals of pre-parent education. The main texts and activities of chapters with 'preparing for parenthood' in the title from 12 high-school technology and home economics education textbooks were analyzed with respect to the three pre-parent education goals of developing perceptions and attitudes toward parenthood, learning parenting knowledge and skills, and reinforcing parental capacity. The results were as follows. First, textbook contents and activities reflected the three goals of pre-parent education in a balanced manner. Second, both the contents and activities of textbooks tried to motivate students to perceive parenthood and parenting through reflection on their relationship with their own parents. Third, because the textbooks encouraged students to consider parenthood and parenting, they acknowledged the importance of undertaking pre-parent education to reinforce their parental capacities. Using such textbooks in regular technology and home economics classes is expected to provide students with an opportunity to consider parenthood and shape their perceptions and attitudes accordingly, thereby allowing adolescents to prepare themselves for parenthood and become good parents.