Evaluation scheme for the design of high power single mode vertical-cavity surface-emitting lasers

A very simple and efficient evaluation procedure is suggested for the design of high power single mode VCSELs by reviewing the physical mechanisms that governs mode transition and simplifying the computation steps. In addition, the new structures are proposed and tested following the suggested evaluation procedure. As a result, the proposed design exhibits much better stability of the fundamental mode over a current range wider than the conventional one.Comment: 6 pages, submitted to "optics express

Size-dependent mechanical properties of molybdenum nanopillars

We report the deformation behavior of single crystalline molybdenum nanopillars in uniaxial compression, which exhibits a strong size effect called the “smaller is stronger” phenomenon. We show that higher strengths arise from the increase in the yield strength rather than through postyield strain hardening. We find the yield strength at nanoscale to depend strongly on sample size and not on the initial dislocation density, a finding strikingly different from that of the bulk metal

Does Logarithm Transformation of Microarray Data Affect Ranking Order of Differentially Expressed Genes?

A common practice in microarray analysis is to transform the microarray raw data (light intensity) by a logarithmic transformation, and the justification for this transformation is to make the distribution more symmetric and Gaussian-like. Since this transformation is not universally practiced in all microarray analysis, we examined whether the discrepancy of this treatment of raw data affect the "high level" analysis result. In particular, whether the differentially expressed genes as obtained by $t$-test, regularized t-test, or logistic regression have altered rank orders due to presence or absence of the transformation. We show that as much as 20%--40% of significant genes are "discordant" (significant only in one form of the data and not in both), depending on the test being used and the threshold value for claiming significance. The t-test is more likely to be affected by logarithmic transformation than logistic regression, and regularized $t$-test more affected than t-test. On the other hand, the very top ranking genes (e.g. up to top 20--50 genes, depending on the test) are not affected by the logarithmic transformation.Comment: submitted to IEEE/EMBS Conference'0

Making the Global Visible: Charting the Uneven Development of Global Monsters in Bong Joon-Ho’s \u3cem\u3eOkja\u3c/em\u3e and Nacho Vigalondo’s \u3cem\u3eColossal\u3c/em\u3e

In her essay, “Making the Global Visible: Charting the Uneven Development of Global Monsters in Bong Joon-Ho’s Okja and Nacho Vigalondo’s Colossal,” Ju Young Jin examines the entanglement of the global and the monstrous in two recent films that position Korea on the cusp between Cold War politics and global capitalism: Bong Joon-Ho’s Okja and Nacho Vigalondo’s Colossal. The Korean filmmaker Bong Joon-Ho and Spanish filmmaker Nacho Vigalondo offer viewers films that challenge conventional notions of monster by fusing it with a coming-of-age plot of the female protagonist that takes place on a global scale, which contests the bildungsroman form that valorizes the nation-state in tracing a person’s growth and social integration. By using the critical frameworks of postcolonial bildungsroman and Kaiju (Japanese monster films such as Godzilla) genre, I highlight how these films stage the broader tensions and radical discontinuities of globalization informed by the complex Korea-US relationship. My term “global monsters” is meant to refer, on one hand, to the discursive act of charting the uneven development and mobility of the monsters shown in the two films and, on the other hand, to the indexical act of making visible the process and force of globalization. Exploring the entanglement of the global and the monsters in the two films then is tantamount to delineating an abstract space of globalization and radical discontinuities therein writ large

Effective indenter radius and frame compliance in instrumented indentation testing using a spherical indenter

We introduce a novel method to correct for imperfect indenter geometry and frame compliance in instrumented indentation testing with a spherical indenter. Effective radii were measured directly from residual indentation marks at various contact depths (ratio of contact depth to indenter radius between 0.1 and 0.9) and were determined as a function of contact depth. Frame compliance was found to depend on contact depth especially at small indentation depths, which is successfully explained using the concept of an extended frame boundary. Improved representative stress-strain values as well as hardness and elastic modulus were obtained over the entire contact depth