• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.240-241
• /
• 2005

In this paper, Latin Hypercube Sampling based the neural network model for the electrical characteristics of $HfO_2$ thin films grown by metal organic molecular beam epitaxy was investigated. The accumulation capacitance and the hysteresis index are extracted to be the main responses to examine the characteristics of $HfO_2$ thin films. X-ray diffraction was used to analyze the characteristic variation for the different process conditions. The initial weights and biases are selected by Latin Hypercube Sampling method. This modeling methodology can allow us to optimize the process recipes and improve the manufacturability.

• Clinical Endoscopy
• /
• v.56 no.5
• /
• pp.613-622
• /
• 2023

Background/Aims: Endoscopic submucosal dissection (ESD) is currently considered the first-line treatment for the eradication of superficial neoplasms of the esophagus in Eastern countries. However, in the West, particularly in Latin America, the experience with esophageal ESD is still limited because of the high technical complexity required for its execution. This study aimed to present the results of the clinical application of ESD to manage superficial esophageal neoplasms in a Latin American center in over 100 consecutive cases. Methods: This retrospective study included consecutive patients who underwent endoscopic ESD for superficial esophageal neoplasms between 2009 and 2022. The following clinical outcomes were assessed: en bloc, complete, and curative resection rates, local recurrence, adverse events, and procedure-related mortality. Results: Esophageal ESD was performed mainly for squamous cell carcinoma (66.6%), high-grade intraepithelial neoplasia (17.1%), and adenocarcinoma (11.4%). En bloc and complete resection rates were 96.2% and 81.0%, respectively. The curative resection rate was 64.8%. Adverse events occurred in six cases (5.7%). Endoscopic follow-up was performed for an average period of 29.7 months. Conclusions: ESD performed by trained operators is feasible, safe, and clinically effective for managing superficial neoplastic lesions of the esophagus in Latin America.

• Iberoamérica
• /
• v.22 no.2
• /
• pp.25-57
• /
• 2020

Eduardo Galeano is a left-wing intellectual who led the criticism and accusations of dictatorship and social absurdity in Latin America. It digs into the truth of hidden history that has not been revealed in official history. He values the memory of history to stop repetition of the unfortunate history of the past. The main research topic of this study, 『The Book of Embraces』, is also an extension of such work. Most of the stories in this work depend on the writer's memory. There is no coherence or integration in the content of the story, and the length of the text is not constant, so it is extremely informal and fragmented. This is a strategy to formally reveal the illogical and irrational reality of Latin America. He analyzes the problems of the separation system prevalent in Latin American society from various perspectives. It separates me and the others as well as the past and the present. It makes the memory of history void and paralyzes the consciousness of history. These systems are fixed for convenient governance. In this situation, the pattern of violence becomes more explicit and broad. The anxiety and fear of the Latin American public become commonplace. It is a reality of enduring daily life without hope. Galeano finds this enduring force in historical memory. He believes that when the past and the present meet and embrace, a new history of the future can be encountered. Galeano does not just criticize reality or cynical attitude but also suggests hope for the future.

• Iberoamérica
• /
• v.21 no.2
• /
• pp.83-114
• /
• 2019

Now Venezuela is the most attentional country in Latin America not only in our country but also all world. Unfortunately, the current crisis is a danger that threatening the venezuelan people's right to live, so most of the news is negative. Some analysts in Korea insist that everything is the result of invasion by US imperialism, others say it is a state of default due to excessive populism. The others also described as a power game of the powers of the world by the new Cold War. But most essential thing is that Sovereign of Venezuela, Venezuelan people are marginalized in this process. Venezuela's crisis seems to have been both a combination of internal and external factors, but internal factors been a main cause. The internal factors are the dictatorship and corruption of crony capitalism of nepotism which are considered historical ailments in Latin America. Chávez criticized the oligarchy, but paradoxically, the Chávezian or current ruling forces became another oligarchy. Unfortunately, Western powers such as the United States and the EU and Venezuela's current ruling powers are at an extreme confrontation, so can be seen using cliff-edge tactics. The best solution is the free and peaceful reelection of the president. After the patriarchal winter, which spring will come the Venezuelan people must decide.

• Korean Architects
• /
• s.506
• /
• pp.40-44
• /
• 2011

• Korean Architects
• /
• s.507
• /
• pp.46-50
• /
• 2011

• Journal of the Korean Wood Science and Technology
• /
• v.11 no.4
• /
• pp.5-106
• /
• 1983

• Korean Journal of Computational Design and Engineering
• /
• v.16 no.6
• /
• pp.397-406
• /
• 2011

Since tolerance allocation in a mobile phone camera manufacturing process greatly affects production cost and reliability of optical performance, a systematic design methodology for allocating optimal tolerances is required. In this study, we proposed the tolerance optimization procedure for determining tolerances that minimize production cost while satisfying the reliability constraints on important optical performance indices. We employed Latin hypercube sampling for evaluating the reliabilities of optical performance and a function-based sequential approximate optimization technique that can reduce computational burden and well handle numerical noise in the tolerance optimization process. Using the suggested tolerance optimization approach, the optimal production cost was decreased by 30.3 % compared to the initial cost while satisfying the two constraints on the reliabilities of optical performance.

• The KSFM Journal of Fluid Machinery
• /
• v.12 no.3
• /
• pp.7-12
• /
• 2009

In this paper, shape optimization based on three-dimensional flow analysis has been performed for impeller design of centrifugal compressor. To evaluate the objective function of an isentropic efficiency, Reynolds-averaged Navier-Stokes equations are solved with SST (Shear Stress Transport) turbulence model. The governing equations are discretized by finite volume approximations. The optimization techniques based on the radial basis neural network method are used for the optimization. Latin hypercube sampling as design of experiments is used to generate thirty design points within design space. Sequential quadratic programming is used to search the optimal point based on the radial basis neural network model. Four geometrical variables concerning impeller shape are selected as design variables. The results show that the isentropic efficiency is enhanced effectively from the shape optimization by the radial basis neural network method.

• Smart Structures and Systems
• /
• v.12 no.6
• /
• pp.641-659
• /
• 2013

In this paper is studied the influence of the uncertain mass distribution over the floors on the choice of the optimal parameters of a hybrid control system for tall buildings subjected to wind load. In particular, an optimization procedure is developed for the robust design of a hybrid control system that is based on an enhanced Monte Carlo simulation technique and the genetic algorithm. The large computational effort inherent in the use of a MC-based procedure is reduced by the employment of the Latin Hypercube Sampling. With reference to a tall building modeled as a multi degrees of freedom system, several numerical analyses are carried out varying the parameters influencing the floors' masses, like the coefficient of variation of the distribution and the correlation between the floors' masses. The procedure allows to obtain optimal designs of the control system that are robust with respect to the uncertainties on the distribution of the dead and live loads.