Distinct Higher Order Research Articles

Lasing Characteristics of GaN-Based Photonic Quasi-Crystal Surface Emitting Lasers Operated at Higher Order Γ Mode

In this study, GaN-based photonic quasi-crystal surface emitting lasers (PQCSELs) operated at different Γ band-edge modes were fabricated and investigated. The photonic quasi-crystal patterns were defined by utilizing electron-beam lithography and inductively coupled plasma etching. Distinctive higher order Γ band-edge lasing modes were identified in the GaN PQCSELs. The threshold energy density and lasing wavelength for the S3 band-edge mode were 4.6 mJ/cm2 and 394.2 nm, respectively. The decreasing tendency of the threshold energy of PQCSEL was observed while the designed lasing mode moved from the higher Γ band to the lower Γ band. Numerical results showed that the S3 mode had the lower threshold and the threshold gain would be largely varied by tuning the ratio of air hole radius/lattice constant ( r / a ). Based on calculations and experiments, PQCSELs show the opportunity to realize lower threshold lasers than typical PC laser for specific value of r / a and appropriate higher order band-edge modes.

Post-LDAC Reflections of ROTC Cadets: Relationship to Leadership and Performance

In the United States Reserve Officer Training Program, cadets attend a month-long camp, where they are evaluated on leadership ability. The purpose of this study was to assess the experiences of cadets upon their return. Through semistructured interviews, with 25 cadets, 3 distinct higher order themes emerged: (a) perceived difficulty of the Leadership Development and Assessment Course, (b) psychological skills required for success, and (c) social climate experienced. Furthermore, upon completion of general inductive analysis, cadets’ responses were compared to their leadership score, thereby highlighting how salient aspects of leadership manifest themselves through cadets’ behaviors and performances.

The Construct Validity of Higher Order Structure-of-Intellect Abilities in a Battery of Tests Emphasizing the Product of Transformations: A Confirmatory Maximum Likelihood Factor Analysis

Within the context of a causal modeling system involving use of Joreskog's confirmatory maximum likelihood factor analysis in conjunction with the LISREL IV computer program devised by Joreskog and Sorbom an evaluation was made of the construct validity underlying the higher order factor structure of a given correlation matrix of 46 structure-of-intellect (SOI) tests emphasizing the product of transformations. The tenability of four alternative factor models was examined relative to their accounting for the intercorrelations among the 46 tests that had been hypothesized to represent first-order abilities involving one kind of operation, one type of content, and one form of product. The major elements of each of the three postulated dimensions of the SOI model (the five operations, the five contents, and the six products) were defined as the 16 possible third-order factors. The following conclusions resulted: (a) the five third-order SOI factors comprising operations of cognition, convergent production, divergent production, memory, and evaluation do not appear to be highly differentiated (with the cognition and convergent production factors being substantially correlated); (b) the two third-order factors of symbolic and semantic content are relatively discrete; (c) the third-order product factor involving the ability to complete tasks requiring hypothesized transformations is an identifiable construct; and (d) evidence of the construct validity of the third-order factors in the SOI test battery analyzed appears to be at best only equivocal. The predominance of tests intended to reflect the product of transformations (32 out of 46) very possibly created inflated levels of intercorrelations among SOI tests that prevented the emergence of distinct higher order dimensions. New confirmatory maximum likelihood factor analyses of correlational matrices derived from SOI tests in which a careful balance has been achieved in the representation of hypothesized third-order factors across the three basic dimensions of the SOI model are expected to demonstrate differentiability among the higher order constructs.