Solving Survival Gridworld Problem Using Hybrid Policy Modified Q-Based Reinforcement

Montero, Vince Jebryl,Jung, Woo-Young,Jeong, Yong-Jin Institute of Korean Electrical and Electronics Eng 2019 전기전자학회논문지 Vol.23 No.4

This paper explores a model-free value-based approach for solving survival gridworld problem. Survival gridworld problem opens up a challenge involving taking risks to gain better rewards. Classic value-based approach in model-free reinforcement learning assumes minimal risk decisions. The proposed method involves a hybrid on-policy and off-policy updates to experience roll-outs using a modified Q-based update equation that introduces a parametric linear rectifier and motivational discount. The significance of this approach is it allows model-free training of agents that take into account risk factors and motivated exploration to gain better path decisions. Experimentations suggest that the proposed method achieved better exploration and path selection resulting to higher episode scores than classic off-policy and on-policy Q-based updates.

Development of License Plate Recognition on Complex Scene with Plate-Style Classification and Confidence Scoring Based on KNN

MONTERO, Vince Jebryl,JEONG, Yong-Jin Institute of Electronics, Information and Communic 2018 IEICE transactions on information and systems Vol.101e.d No.12

Isolation and Molecular Characterization of Xylella fastidiosa from Coffee Plants in Costa Rica

Mauricio Montero-Astua,Carlos Chacon-Diaz,Estela Aguilar,Carlos Mario Rodriguez,Laura Garita,William Villalobos,Lisela Moreira,John S. Hartung,Carmen Rivera 한국미생물학회 2008 The journal of microbiology Vol.46 No.5

Coffee plants exhibiting a range of symptoms including mild to severe curling of leaf margins, chlorosis and deformation of leaves, stunting of plants, shortening of internodes, and dieback of branches have been reported since 1995 in several regions of Costa Rica’s Central Valley. The symptoms are referred to by coffee producers in Costa Rica as “crespera” disease and have been associated with the presence of the bacterium Xylella fastidiosa. Coffee plants determined to be infected by the bacterium by enzyme linked immunosorbent assay (ELISA), were used for both transmission electron microscopy (TEM) and for isolation of the bacterium in PW broth or agar. Petioles examined by TEM contained rod-shaped bacteria inside the xylem vessels. The bacteria measured 0.3 to 0.5 μm in width and 1.5 to 3.0 μm in length, and had rippled cell walls 10 to 40 nm in thickness, typical of X. fastidiosa. Small, circular, dome-shaped colonies were observed 7 to 26 days after plating of plant extracts on PW agar. The colonies were comprised of Gram-negative rods of variable length and a characteristic slight longitudinal bending. TEM of the isolated bacteria showed characteristic rippled cell walls, similar to those observed in plant tissue. ELISA and PCR with specific primer pairs 272-1-int/272-2-int and RST31/RST33 confirmed the identity of the isolated bacteria as X. fastidiosa. RFLP analysis of the amplification products revealed diversity within X. fastidiosa strains from Costa Rica and suggest closer genetic proximity to strains from the United States of America than to other coffee or citrus strains from Brazil.

Vitamin D Insufficiency and Asthma Severity in Adults From Costa Rica

Felicia Montero-Arias,Giovanni Sedó-Mejía,Allan Ramos-Esquivel 대한천식알레르기학회 2013 Allergy, Asthma & Immunology Research Vol.5 No.5

Purpose: Non-classical actions of vitamin D as a cytokine are related to the immunopathology of asthma. Few studies have examined vitamin D levels and asthma severity in adults. The aim of this research was to assess the relationship between vitamin D levels, atopy markers, pulmonary function, and asthma severity. Methods: We analyzed 25-hydroxyvitamin D levels in serum collected from 121 asthmatic adults from Costa Rica to investigate the association between vitamin D levels (categorized as sufficient, ≥30 ng/mL, or insufficient, <30 ng/mL), allergic rhinitis, total IgE and peripheral blood eosinophils (as markers of atopy), asthma severity, baseline forced expiratory volume in 1 second (FEV1), and forced vital capacity (FVC). Univariate and multivariate analyses were performed to assess these relationships. Results: When the population was stratified by vitamin D status, 91% of asthmatic patients with vitamin D levels below 20 ng/mL (n=36) and 74% of patients with vitamin D levels between 20 and 30 ng/mL (n=73) had severe asthma versus 50% of those with vitamin D sufficiency (n=12; P=0.02). Vitamin D insufficiency was associated with a higher risk of severe asthma (odds ratio [OR], 5.04; 95% Confidence interval [CI], 1.23-20.72; P=0.02). High vitamin D levels were associated with a lower risk of hospitalization or emergency department visit during the last year (OR, 0.90; 95% CI, 0.84-0.98; P=0.04). Although there appeared to be a direct relationship between vitamin D levels and FEV1 (regression coefficient=0.48; r2=0.03), it did not reach statistical significance (P=0.07). Conclusions: Our findings suggest that vitamin D insufficiency is common among our cohort of asthmatic adults. Lower vitamin D levels are associated with asthma severity.

Solving Survival Gridworld Problem Using Hybrid Policy Modified Q-Based Reinforcement

Vince Jebryl Montero,Woo-Young Jung,Yong-Jin Jeong 한국전기전자학회 2019 전기전자학회논문지 Vol.23 No.4

This paper explores a model-free value-based approach for solving survival gridworld problem. Survival gridworld problem opens up a challenge involving taking risks to gain better rewards. Classic value-based approach in model-free reinforcement learning assumes minimal risk decisions. The proposed method involves a hybrid on-policy and off-policy updates to experience roll-outs using a modified Q-based update equation that introduces a parametric linear rectifier and motivational discount. The significance of this approach is it allows model-free training of agents that take into account risk factors and motivated exploration to gain better path decisions. Experimentations suggest that the proposed method achieved better exploration and path selection resulting to higher episode scores than classic off-policy and on-policy Q-based updates.

Case Reports : Primary fallopian tube carcinoma co-existing with pregnancy: A case report

( Agnes P. Montero Fenix ),( Nephtali N. Gorgonio ) 대한산부인과학회 2011 Journal of Womens Medicine Vol.4 No.2

Primary fallopian tube carcinoma is the rarest of all gynecologic cancers and usually occurs in postmenopausal women. Thus, its presence in pregnancy is extremely remote. A 31-year-old term primigravid with a history of right lower quadrant pain, diagnosed with dermoid focus on imaging was admitted due to ruptured membranes and delivered a live and healthy infant. Intraoperatively, the right fimbria was dilated and fimbriectomy was performed which revealed papillary serous cyst adenocarcinoma. There was no residual disease on re-exploration. She was classified as International Federation of Gynecologists and Obstetricians stage IA. No adjuvant chemotherapy was given. The incidence of primary fallopian tube carcinoma co-existing with pregnancy is extremely low. This article review is possibly the first reported case of primary fallopian tube carcinoma co-existing with pregnancy, locally.

Optimization of a four-bar mechanism cyclic pitch control for a vertical axis wind turbine

Mariana Montenegro-Montero,Gustavo Richmond-Navarro,Pedro Casanova-Tret 한국풍공학회 2022 Wind and Structures, An International Journal (WAS Vol.35 No.2

In this paper, the issue of pitch control in a vertical axis wind turbine was tackled. Programming the Actuator Cylinder model in MATLAB, a theoretical optimum pitch solution was found and then a classic four-bar mechanism was adapted to that theoretical solution to achieve a simple and elegant control of the pitch in the turbine. A simulation using the mechanism worked to find the optimum pitch cycles, where it was found that the mechanism would, in fact, increase the efficiency of the VAWT, by at least 11% and in the best case, over 35%. Another aspect that is studied is the possibility of selfstart of the turbine by only changing the pitch on the blades. This analysis, however, proved that a further individual pitch control must be used to surpass the cogging torque. All analyses conducted were done for a specific wind turbine that is 2 m2 in the swept area.

A Finite Element-Based Methodology for the Thermo-mechanical Analysis of Early Age Behavior in Concrete Structures

H. Cifuentes,F. Montero-Chacón,J. Galán,J. Cabezas,A. Martínez-De la Concha 한국콘크리트학회 2019 International Journal of Concrete Structures and M Vol.13 No.6

This paper presents a general procedure based on fracture mechanics models in order to analyze the level of crack-ing and structural safety in reinforced concrete elements at early ages, depending on the stripping time. Our proce-dure involves the development of a thermo-mechanical numerical model based on the finite element method that accounts for the change in the mechanical properties of concrete with time. Moreover, fracture mechanisms are analyzed by means of a material damage model, which is characterized via specific experimental results obtained for standard specimens and notched beams under three-point bending testing. The loading conditions are both thermal and mechanical, and are obtained from the hydration process for a given concrete dosage. The presented methodol-ogy allows for the determination of the optimal stripping time, whereas it helps assessing the analysis of the cracking and the stress states of the elements under consideration. A practical application, namely the analysis of a retaining wall, is used to validate our methodology, showing its suitability in engineering practice.

Large superconformal near-horizons from M-theory

Kelekci, Ö,.,Lozano, Y.,Montero, J.,Ó,Colgá,in, E.,Park, M. American Physical Society 2016 Physical review. D Vol.93 No.8

<P>We report on a classification of supersymmetric solutions to 11D supergravity with SO(2, 2) x SO(3) isometry, which are AdS/CFT dual to 2D CFTs with N = (0, 4) supersymmetry. We recover the Maldacena, Strominger, Witten near-horizon with small superconformal symmetry and identify a class of AdS(3) x S-2 x S-2 x CY2 geometries with emergent large superconformal symmetry. This exhausts known compact geometries. Compactification of M-theory on CY2 results in a vacuum of 7D supergravity with large superconformal symmetry, providing a candidate near-horizon for an extremal black hole and a potential new setting to address microstates.</P>

Proposal for a gingival shade guide based on in vivo spectrophotometric measurements

Cristina Gomez Polo,Javier Montero,Ana Maria Martin Casado 대한치과보철학회 2019 The Journal of Advanced Prosthodontics Vol.11 No.5

PURPOSE. The purpose of this study was to propose and assess a shade guide for pink gingival aesthetics using a Spanish population sample. MATERIALS AND METHODS. The L*, C*, h, a* and b* coordinates of 259 participants were measured using a spectrophotometer in 3 standardized points along the attached gingiva of the maxillary central incisors. A hierarchical clustering analysis was applied to obtain separate solutions regarding the number of shade tabs. For each of the solutions obtained, color differences (ΔE*) were calculated using the CIELab and CIEDE2000 formulas, and the proposed shade guide was selected considering (1) the color differences between tabs and (2) the coverage error of each of the solutions. RESULTS. The proposed shade guide consisted of 8 gingival shade tabs and achieved CIELab and CIEDE2000 coverage errors of less than the respective 50:50% acceptability thresholds (ΔE*=4.6 units and ΔE00=4.1). The coordinates for the various gingival shade tabs were as follows: Tab 1: L*43.3, a*21.9, b*12.3 (1.6); Tab 2: L*42.9, a*34.1, b*19.1; Tab 3: L*46.5, a*25.8, b*10.9; Tab 4: L*46.5, a*27.3, b*15.1; Tab 5: L*49.6, a*23.5, b*16.8; Tab 6: L*51.5, a*19.7, b*13.6; Tab 7: L*55.9, a*22.0, b* 15.0; and Tab 8: L*56.0, a*19.9, b*18.8. CONCLUSION. The CIELab and CIEDE2000 coverage errors for the 8 shade tabs of the proposed gingival shade guide were significantly lower than those of other guides. Therefore, despite the limitations of this study, the proposed guide is more appropriate for matching gingival shade in the Spanish general population.