A DOE based approach for the design of RBF artificial neural networks applied to prediction of surface roughness in AISI 52100 hardened Steel turning

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Sub-Optimal Orbital Maneuvers for Artificial Satellites

The determination of a specific orbit and the procedure to calculate orbital maneuvers of artificial satellites are problems of extreme importance in the study of orbital mechanics. Therefore, the transferring problem of a spaceship from one orbit to another, and the attention due to this subject has in increased during the last years. Many applications can be found in several space activities, for example, to put a satellite in a geostationary orbit, to change the position of a spaceship, to maintain a specific satellite's orbit, in the design of an interplanetary mission, and others. The Brazilian Satellite SCD-1 (Data Collecting Satellite) will be used as example in this paper. It is the first satellite developed entirely in Brazil, and it remains in operation to this date. SCD-1 was designed, developed, built, and tested by Brazilian scientists, engineers, and technicians working at INPE (National Institute for Space Research, and in Brazilian Industries. During the lifetime, it might be necessary do some complementary maneuvers, being this one either an orbital transferring, or just to make periodical corrections. The purpose of transferring problem is to change the position, velocity and the satellite's mass to a new pre determined state. This transfer can be totally linked (in the case of "Rendezvous") or partially free (free time, free final velocity, etc). In the global case, the direction, the orientation and the magnitude of the thrust to be applied must be chosen, respecting the equipment's limit. In order to make this transferring, either sub-optimal or optimal maneuvers may be used. In the present study, only the sub-optimal will be shown. Hence, this method will simplify the direction of thrust application, to allow a fast calculation that may be used in real time, with a very fast processing. The thrust application direction to be applied will be assumed small and constant, and the purpose of this paper is to find the time interval that the thrust is applied. This paper is basically divided into three parts: during the first one the sub-optimal maneuver is explained and detailed, the second presents the Satellite SCD-1, and finally the last part shows the results using the sub-optimal maneuver applied to the Brazilian Satellite.

Wear Particle Classifier System Based on an Artificial Neural Network

This paper describes a method of identifying morphological attributes that classify wear particles in relation to the wear process from which they originate and permit the automatic identification without human expertise. The method is based on the use of Multi Layer Perceptron (MLP) for analysis of specific types of microscopic wear particles. The classification of the wear particles was performed according to their morphological attributes of size and aspect ratio, among others. (C) 2010 Journal of Mechanical Engineering. All rights reserved.

Artificial neural networks and clustering techniques applied in the reconfiguration of distribution systems

One objective of the feeder reconfiguration problem in distribution systems is to minimize the power losses for a specific load. For this problem, mathematical modeling is a nonlinear mixed integer problem that is generally hard to solve. This paper proposes an algorithm based on artificial neural network theory. In this context, clustering techniques to determine the best training set for a single neural network with generalization ability are also presented. The proposed methodology was employed for solving two electrical systems and presented good results. Moreover, the methodology can be employed for large-scale systems in real-time environment.

Artificial neural networks for load flow and external equivalents studies

In this paper an artificial neural network (ANN) based methodology is proposed for (a) solving the basic load flow, (b) solving the load flow considering the reactive power limits of generation (PV) buses, (c) determining a good quality load flow starting point for ill-conditioned systems, and (d) computing static external equivalent circuits. An analysis of the input data required as well as the ANN architecture is presented. A multilayer perceptron trained with the Levenberg-Marquardt second order method is used. The proposed methodology was tested with the IEEE 30- and 57-bus, and an ill-conditioned 11-bus system. Normal operating conditions (base case) and several contingency situations including different load and generation scenarios have been considered. Simulation results show the excellent performance of the ANN for solving problems (a)-(d). (C) 2010 Elsevier B.V. All rights reserved.

Intelig��ncia artificial e teoria de resolu����o de problemas

Este artigo �� uma tentativa de delinear as principais caracter��sticas da pesquisa numa nova ��rea de estudos a chamada Intelig��ncia Artificial (AI). Os itens 1 e 2 constituem um r��pido hist��rico da AI e seus pressupostos b��sicos. O item 3 trata da teoria de resolu����o de problemas, desenvolvida por A. Newell e H. Simon. O item 4 procura mostrar a relev��ncia da AI para a Filosofia, em especial para a filosofia da Mente e para a Teoria do Conhecimento.

Robots, intencionalidade e intelig��ncia artificial

O artigo aborda problemas filos��ficos relativos �� natureza da intencionalidade e da representa����o mental. A primeira parte apresenta um breve hist��rico dos problemas, percorrendo rapidamente alguns epis��dios da filosofia cl��ssica e da filosofia contempor��nea. A segunda parte examina o Chinese Room Argument (Argumento do Quarto do Chin��s) formulado por J. Searle. A terceira parte desenvolve alguns argumentos visando mostrar a inadequa����o do modelo funcionalista de mente na constru����o de robots. A conclus��o (quarta parte) aponta algumas alternativas ao modelo funcionalista tradicional, como, por exemplo, o conexionismo.

Umidifica����o e aquecimento do g��s inalado durante ventila����o artificial com baixo fluxo e fluxo m��nimo de gases frescos

JUSTIFICATIVA E OBJETIVOS: em pacientes sob intuba����o traqueal ou traqueostomia, a umidifica����o e o aquecimento do g��s inalado s��o necess��rios para a preven����o de les��es no sistema respirat��rio, conseq��entes ao contato do g��s frio e seco com as vias a��reas. O objetivo da pesquisa foi avaliar o efeito do sistema respirat��rio circular com absorvedor de di��xido de carbono do aparelho de anestesia C��cero da Dr��ger, quanto �� capacidade de aquecimento e umidifica����o dos gases inalados, utilizando-se fluxo baixo (1 L.min-1) ou m��nimo (0,5 L.min-1) de gases frescos. M��TODO: O estudo aleat��rio foi realizado em 24 pacientes, estado f��sico ASA I, com idades entre 18 e 65 anos, submetidos �� anestesia geral, utilizando-se a Esta����o de Trabalho C��cero da Dr��ger (Alemanha), para realiza����o de cirurgias abdominais, os quais foram distribu��dos aleatoriamente em dois grupos: grupo de Baixo Fluxo (BF), no qual foi administrado 0,5 L.min-1 de oxig��nio e 0,5 L.min-1 de ��xido nitroso e fluxo m��nimo (FM), administrando-se somente oxig��nio a 0,5 L.min-1. Os atributos estudados foram temperatura, umidade relativa e absoluta da sala de opera����o e do g��s no sistema inspirat��rio. RESULTADOS: Os valores da temperatura, umidade relativa e umidade absoluta no sistema inspirat��rio na sa��da do aparelho de anestesia e junto ao tubo traqueal n��o apresentaram diferen��a significante entre os grupos, mas aumentaram ao longo do tempo nos dois grupos (BF e FM), havendo influ��ncia da temperatura da sala de opera����o sobre a temperatura do g��s inalado, nos dois grupos estudados. N��veis de umidade e temperatura pr��ximos dos ideais foram alcan��ados, nos dois grupos, a partir de 90 minutos. CONCLUS��ES: N��o h�� diferen��a significante da umidade e temperatura do g��s inalado utilizando-se baixo fluxo e fluxo m��nimo de gases frescos.

Artificial oocyte activation using calcium ionophore in ICSI cycles with spermatozoa from different sources

The present study evaluated the effect of artificial oocyte activation (AOA) with calcium ionophore A23187 oil intracytoplasmic sperm injection (ICSI) cycles using spermatozoa from different sources. The 314 cycles evaluated were divided into three groups according to sperm origin, the ejaculated group (n = 92), the epididymal group (n = 82). and the testicular roup (n = 140). Each group was further split into experimental subgroups, depending oil whether or no AOA was performed. In additions the cycles of women younger than 36 years were evaluated separately. For each experimental group, ICSI outcomes were compared between subgroups. No significant difference was observed between subgroups for all sperm origin groups. When evaluating only the cycles of women younger than 36 years of age, AOA increased the percentage of high-quality embryos (74.5 versus 53.0%. P = 0.011) and the implantation rate (19.3 versus 10.5%, P = 0.0025) when it was used with ejaculated spermatozoa, and the percentage of high-quality embryos (64.4 versus 50.3%, P = 0.006) when epididymal spermatozoa were used. These results may suggest that both sperm maturity and oocyte quality play a role in oocyte activation. However. this study is to be continued to confirm these findings.

Artificial oocyte activation with calcium ionophore A23187 in intracytoplasmic sperm injection cycles using surgically retrieved spermatozoa

Objective: To evaluate the effect of artificial oocyte activation (AOA) on intracytoplasmic sperm injection (ICSI) cycles using surgically retrieved sperm.Design: Laboratory study.Setting: Fertility/assisted fertilization center.Patient(s): Couples undergoing surgical sperm retrieval for ICSI (n = 204).Intervention(s): Application of calcium ionophore A23187 for AOA.Main Outcome Measure(s): Cycles were divided into experimental groups according to the origin of the sperm used for injection and the type of azoospermia: [1] testicular sperm aspiration in nonobstructive-azoospermic patients (TESA-NOA group, n = 58), [2] TESA in obstructive-azoospermic patients (TESA-OA group, n = 48), [3] and percutaneous epididymal sperm aspiration in obstructive-azoospermic patients (PESA-OA, n = 98). For each experimental group, cycles where AOA was applied (subgroup: activation) were compared with cycles in which AOA was not applied (Subgroup: control). The fertilization, high-quality embryo, implantation, and pregnancy rates were compared among the subgroups.Result(s): For patients undergoing TESA, AOA did not improve ICSI outcomes for either type of azoospermia. However, for cases in which the injected sperm were retrieved from the epididymis, a statistically significantly increased rate of high-quality embryos was observed with AOA.Conclusion(s): Artificial oocyte activation may improve ICSI outcomes in azoospermic patients when epididymal, but not testicular spermatozoa, are injected. (Fertil Steril (R) 2009;92:131-6. (C)2009 by American Society for Reproductive Medicine.)

Factors affecting conception rates following artificial insemination or embryo transfer in lactating holstein cows

The objective of this study was to evaluate the factors that may affect conception rates (CR) following artificial insemination (AI) or embryo transfer (ET) in lactating Holstein cows. Estrous cycling cows producing 33.1 +/- 7.2 kg of milk/d received PGF(2 alpha) injections and were assigned randomly to 1 of 2 groups (AI or ET). Cows detected in estrus (n = 387) between 48 and 96 h after the PGF2a injection received AI (n = 227) 12 h after detection of estrus or ET (n = 160) 6 to 8 d later (1 fresh embryo, grade 1 or 2, produced from nonlactating cows). Pregnancy was diagnosed at 28 and 42 d after estrus, and embryonic loss occurred when a cow was pregnant on d 28 but not pregnant on d 42. Ovulation, conception, and embryonic loss were analyzed by a logistic model to evaluate the effects of covariates [days in milk (DIM), milk yield, body temperature (BT) at d 7 and 14 post-AI, and serum concentration of progesterone (P4) at d 7 and 14 post-AI] on the probability of success. The first analysis included all cows that were detected in estrus. The CR of AI and ET were different on d 28 (AI, 32.6% vs. ET, 49.4%) and 42 (AI, 29.1% vs. ET, 38.8%) and were negatively influenced by high BT (d 7) and DIM. The second analysis included only cows with a corpus luteum on d 7. Ovulation rate was 84.8% and was only negatively affected by DIM. Conception rates of AI and ET were different on d 28 (AI, 37.9% vs. ET, 59.4%) and 42 (AI, 33.8% vs. ET, 46.6%) and were negatively influenced by high BT (d 7). The third analysis included only ovulating cows that were 7 d postestrus. Conception rates of AI and ET were different on d 28 (AI, 37.5% vs. ET, 63.2%) and 42 (AI, 31.7% vs. ET, 51.7%) and were negatively influenced by high BT (d 7). There was a positive effect of serum concentration of P4 and a negative effect of milk production on the probability of conception for the AI group but not for the ET group. The fourth analysis was embryonic loss (AI, 10.8% vs. ET, 21.5%). The transfer of fresh embryos is an important tool to increase the probability of conception of lactating Holstein cows because it can bypass the negative effects of milk production and low P4 on the early embryo. The superiority of ET vs. AI is more evident in high-producing cows. High BT measured on d 7 had a negative effect on CR and embryonic retention.

Conception rate in Holstein cows treated with GnRH or hCG on the fifth day post artificial insemination during summer

Vacas da ra��a Holandesas em lacta����o (n=158) aos 213��112 dias de lacta����o e produ����o de 26��9kg leite/dia, foram aleatoriamente distribu��das em tr��s grupos: controle (GC, n=52, salina); GnRH (GG, n=55, 100mcg de gonadorelina); e hCG (GH, n=51, 2500UI de hCG) aplicado no dia 5 ap��s a insemina����o artificial (IA). A temperatura retal foi verificada no momento da IA, e as amostras de sangue coletadas nos dias 5, 7 e 12 ap��s a IA. A concep����o foi determinada entre os dias 42 e 49 ap��s IA. As concentra����es s��ricas de progesterona (P4 - ng/ml, m��dia��EPM) para GC, GG, e GH foram, respectivamente: no dia 5: 2,7��0,4, 2,5��0,4 e 3,2��0,4; no dia 7: 4,8��0,4, 4,2��0,4 e 5,7��0,5; e no dia 12 ap��s a IA: 5,2��0,4, 6,9��0,4 e 8,5��0,5. O aumento proporcional na concentra����o s��rica de P4 entre os dias 5 e 7 ap��s IA (GC: 178%, GG: 168%, e GH: 178%) sugere que os tratamentos n��o induziram efeito luteotr��pico no corpo l��teo (CL) existente. O aumento na P4 s��rica entre os dias 7 e 12 nos animais tratados com GnRH ou hCG (GG: 164% e GH: 149%, P<0,01) em rela����o aos animais controle (GC: 18%, P=0,31), sugere a indu����o de novo CL. Os tratamentos com GnRH ou hCG aumentaram as taxas de concep����o nas vacas com temperatura retal abaixo de 39,7��C (GC: 10,1%, n=26; GG: 36,8%, n=27 e GH: 32,8%, n=21), mas n��o em vacas com temperatura retal acima de 39,7��C (15,2% n=26; 17,8%, n=28 e 24,4%, n=30). Os resultados sugerem que a alta temperatura corporal pode mascarar os efeitos positivos do tratamento com GnRH ou hCG no dia 5 ap��s a IA, na concep����o.

M��s de pari����o, condi����o corporal e resposta ao protocolo de insemina����o artificial em tempo fixo em vacas de corte prim��paras

No experimento I, foi avaliada a altera����o da condi����o corporal (CC) pr�� e p��s-parto em 155 novilhas inseminadas para parir de setembro a dezembro. A CC foi avaliada mensalmente no pr�� e p��s-parto, de junho a fevereiro. No experimento II, 538 vacas prim��paras foram sincronizadas com o protocolo de insemina����o artificial em tempo fixo (IATF) que usou estradiol junto ao dispositivo intravaginal de progesterona (CIDR��). As taxas de ciclicidade, sincroniza����o e concep����o foram avaliadas por ultra-som. No experimento I, os animais que pariram primeiro tiveram maior (P<0,001) redu����o na CC p��s-parto. No experimento II, foi observado maior CC (P<0,0001) nos animais com menor n��mero de dias p��s-parto, maior (P<0,05) taxa de sincroniza����o nas vacas de melhor CC e aumento (P<0,0001) na taxa de concep����o proporcional ao aumento na CC (incremento m��dio na concep����o de seis pontos percentuais para cada 0,25 ponto na CC). N��o se deve antecipar a pari����o de novilhas de corte quando se pretende realizar IATF no in��cio da esta����o de monta subseq��ente.

Indu����o �� ovula����o pelo uso de LHRH an��logo e fertiliza����o artificial em r��-touro (Rana catesbeiana)

Este trabalho teve por objetivo aperfei��oar a t��cnica de reprodu����o induzida existente para r��-touro, com o intuito de aumentar a taxa de fecundidade e viabilizar seu uso pelo produtor. As doses hormonais para a indu����o da ovula����o e espermia����o seguiram as propostas de FALCON e CULLEY (1995) e ALONSO (1997); entretanto, a t��cnica de fertiliza����o artificial foi adaptada da metodologia para reprodu����o artificial de peixes com ovos n��o-aderentes (WOYNAROVICH e HORV��TH, 1983). A t��cnica proposta apresenta as seguintes etapas: I) sincroniza����o da ovula����o e da espermia����o, por meio de horm��nio liberador de gonadotropina ((Des-Gli10, D-His(Bzl)6, Pro-NHEt9)-LHRH)); II) extra����o dos ��vulos de cada f��mea (1 a 2 minutos); III) fertiliza����o dos ��vulos (2 minutos) com l��quido esperm��tico dilu��do em 100 mL de ��gua; IV) hidrata����o dos ovos em 10 a 20 litros de ��gua; e V) incuba����o dos ovos em quadros de tela de 1x 0,70 m, com malha de 1 mm. As taxas de fertiliza����o obtidas com as modifica����es propostas foram superiores a 60%. Ressalta-se ainda que a t��cnica propiciou a obten����o, a partir de um mesmo animal, de v��rias desovas, sendo que cada f��mea pode ovular em intervalos de, aproximadamente, 45 dias.

Strategies to improve fertility in Bos indicus postpubertal heifers and nonlactating cows submitted to fixed-time artificial insemination

Two experiments were designed to evaluate strategies to increase fertility of Bos indicus postpubertal heifers and nonlactating cows submitted to a fixed-time artificial insemination (TAI) protocol consisting of an intravaginal device containing 1.9 g of progesterone (CIDR) insertion + estradiol benzoate on Day 0, CIDR withdrawal + estradiol cypionate on Day 9, and TAI on Day 11. In Experiment 1, heifers (n = 1153) received a new or an 18-d previously used CIDR and, on Day 9, prostaglandin F(2 alpha) (PGF(2 alpha)) + 0, 200, or 300 IU equine chorionic gonadotropin (eCG). Heifers treated with a new CIDR had greater (least squares means +/- SEM) serum concentration of progesterone on Day 9 (3.06 +/- 0.09 ng/mL vs. 2.53 +/- 0.09 ng/mL; P < 0.05) and a smaller follicle at TAI (11.61 +/- 0.11 nim vs. 12.05 +/- 0.12 mm; P < 0.05). Heifers with smaller follicles at TAI had lesser serum progesterone, concentrations on Day 18 and reduced rates of ovulation, conception, and pregnancy (P < 0.05). Treatment with eCG improved (P < 0.05) follicle diameter at TAI (11.50 +/- 0.10 mm, 11.90 +/- 0.11 mm, and 12.00 +/- 0.10 mm, for 0, 100, and 200 IU, respectively), serum progesterone concentration on Day 18 (2.77 +/- 0.11 ng/mL, 3.81 +/- 0.11 ng/mL, and 4.87 +/- 0.11 ng/mL), and rates of ovulation (83.8%, 88.5%, and 94.3%) and pregnancy (41.3%, 47.0%, and 46.7%). In Experiment 2, nonlactating Nelore cows (n = 702) received PGF(2 alpha) treatment on Days 7 or 9 and, on Day 9, 0 or 300 IU cCG. Cows receiving PGF(2 alpha) on Day 7 had lesser serum progesterone concentrations on Day 9 (3.05 +/- 0.21 ng/mL vs. 4.58 +/- 0.21 ng/mL; P < 0.05), a larger follicle at TAI (11.54 +/- 0.21 mm vs. 10.84 +/- 0.21 mm; P < 0.05), and improved (P < 0.05) rates of ovulation (85.4% vs. 77.0%), conception (60.9% vs. 47.2%), and pregnancy (52.0% vs. 36.4%). Treatment with eCG improved (P < 0.05) serum progesterone concentration on Day 18 (3.24 +/- 0.14 ng/mL vs. 4.55 +/- 0.14 ng/mL) and the rates of ovulation (72.4% vs. 90.0%) and pregnancy (37.5% vs. 50.8%). In conclusion, giving PGF(2 alpha) earlier in the protocol in nonlactating cows and eCG treatment in postpubertal heifers and nonlactating cows improved fertility in response to a TAI (progesterone + estradiol) protocol. (C) 2009 Elsevier B.V. All rights reserved.