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A novel reinforcement-learning-based dual-control methodology adaptive neural network (NN) controller is developed to deliver a desired tracking performance for a class of complex feedback nonlinear discrete-time systems, which consists of a second-order nonlinear discrete-time system in nonstrict feedback form and an affine nonlinear discrete-time system, in the presence of bounded and unknown disturbances. For example, the exhaust gas recirculation (EGR) operation of a spark ignition (SI) engine is modeled by using such a complex nonlinear discrete-time system. A dual-controller approach is undertaken where primary adaptive critic NN controller is designed for the nonstrict feedback nonlinear discrete-time system whereas the secondary one for the affine nonlinear discrete-time system but the controllers together offer the desired performance. The primary adaptive critic NN controller includes an NN observer for estimating the states and output, an NN critic, and two action NNs for generating virtual control and actual control inputs for the nonstrict feedback nonlinear discrete-time system, whereas an additional critic NN and an action NN are included for the affine nonlinear discrete-time system by assuming the state availability. All NN weights adapt online towards minimization of a certain performance index, utilizing gradient--descent-based rule. Using Lyapunov theory, the uniformly ultimate boundedness (UUB) of the closed-loop tracking error, weight estimates, and observer estimates are shown. The adaptive critic NN controller performance is evaluated on an SI engine operating with high EGR levels where the controller objective is to reduce cyclic dispersion in heat release while minimizing fuel intake. Simulation and experimental results indicate that engine out emissions drop significantly at 20% EGR due to reduction in dispersion in heat release thus verifying the dual-control approach. Index Terms--Adaptive critic design, near-optimal control, nonstrict feedback nonlinear discrete-time system, output feedback control, separation principle.

Background: Sexual dimorphism is widespread in insects. The certain specialized structures may be used as weapons in male-male combats or as ornaments to enhance mating opportunities. Results: We report striking swollen first tarsal segments in two families, four genera and six species of scorpionflies from the Middle Jurassic Yanliao Biota of Northeastern China. Swollen tarsal segments are restricted to male specimens and to hind leg tarsi. The geometric morphometric analyses reveal that the degree of swelling within the orthophlebiid species possessing swollen first metatarsal segments is species-specific, which can be used as a diagnostic character for taxonomic and phylogenetic studies. Conclusions: The new findings indicate that swollen first metatarsal segments are relatively common in the family Orthophlebiidae during the Middle Jurassic. The tarsal swellings are considered to be sexually dimorphic, potentially associated with sexually display by males and/or camouflage of a "nuptial gift" in the mating process. [ABSTRACT FROM AUTHOR]

A new genus and species of Labenopimplinae (Ichneumonidae), Heteropimpla megista Li, Shih, Kopylov & Ren gen. et sp. nov., is erected based on a specimen in mid-Cretaceous Myanmar (Burmese) amber. A key to genera of Labenopimplinae is provided. In addition, a new species, Amplicella abbreviata Li, Shih, Kopylov & Ren (Tanychorinae) from the Lower Cretaceous Yixian Formation is described. Geometric morphometric analysis (GMA) was applied to study forewing venation of 24 Cretaceous species of Ichneumonidae and the results are presented for the first time. The GMA results not only confirm the taxonomic position of new taxa and relationships among these genera consistent with subfamily classifications, but also clarify the methodological differences between classical taxonomy and the GMA. [ABSTRACT FROM AUTHOR]

The presence of all three classes of pathogens (viral, protozoan and bacterial) as well as indicator microbes at a non-point source recreational beach is assessed. The analysis of the various microbes under different targeted environmental conditions has included the evaluation of the sources of microbial contaminants and pathogens and the effectiveness of various analytical methods for microbe detection.

Interferometric SAR analysis with a time series of images obtained from satellite has been proven to be a useful monitoring scheme for geomorphological changes, particularly related to the vertical dimension. The success of this technique relies on the coherence between the images. This imposes severe challenges for applications in vegetated areas. In this study, the landslide process of a site located in Liugui, southern Taiwan, is investigated by a time series of SAR images collected from ALOS PALSAR and Sentinel 1A. This landslide monitoring site is heavily vegetated. From the Persistent Scattering (PS) analysis, ALOS PALSAR presented more extracted points. The wavelength of the band may be a decisive factor. The time series of ALOS images spans across the deadliest typhoon impacted Taiwan in recorded history, Typhoon Morakot on 8 August 2009. It is clear that there are more PS points extracted from the time series after the event as compared to before Typhoon Morakot. This is largely explained by the increase in the amount of bare earth after the disaster. From the interferometric SAR analysis, the development of headward erosion could be observed. Although the number of PS points is limited, the understanding of erosion and landslide progress in the area could still be improved while integrating with the digital elevation model collected with airborne lidar, historic aerial photos, and images collected with UAS (Unmanned Aviation Systems). Together with the in situ measurements, the colluvium depth ranges from 2 - 40 m in the area. The surface instability is expected to persist. [ABSTRACT FROM AUTHOR]

Water depth and the topography under water provide important information for near shore human activities. With the intensification of international territory concerns, bathymetric mapping is also gaining attention. Optical satellite imagery is an efficient tool for estimating shallow water depth as compared to the traditional field surveying because of its wide coverage area. On the other hand, the existence of cloud and haze contaminates the spectral signatures, which introduces errors to the depth data retrieved. In this research, the contaminated pixels are treated as a mixture of water and cloud. Linear Spectral Unmixing (LSU) procedure is applied for estimating the cloud abundance in mixed pixels. The cloud component is then removed with a linear function and the "purified" water component used for depth retrieval. In this research, water depth is estimated with two methods, namely, artificial neural network (ANN) and physical model. The former demands in-situ bathymetric samples for training, the latter requires site information of inherent optical properties (IOPs) and apparent optical properties (AOPs). The experiments reveal that retrieving depth with ANN generates better results than the physical model, but with a few extremely large errors. As for mixed pixels, the error of depth estimation becomes higher as cloud abundance increases. The precision of depth retrieval is higher for mixed pixels at the reef flat level (within 10 m in depth) than those in the lagoon (about 20 m in depth), and the precision generally agrees with those retrieved from water pixels without cloud or haze. [ABSTRACT FROM AUTHOR]

Experiences with natural disasters have intensified recent efforts to enhance cooperation mechanisms among official disaster management institutions to community participation. These experiences reveal a need to enhance rapid mapping technical assistance to be developed and shared among young scientists through a summer school. However, the question arose of how effective this summer school to be used as a tool to increase scientists' understanding and capacity. This study sought to evaluate the extent to which human resource capacity building can be effectively implemented. The methods used for this evaluation is through observations, questionnaires and a weighted scoring based on knowledge, skills and attitudes' criteria. The results indicate a significant improvement in knowledge (94.56%), skills (82%) and attitudes (85.20%) among the participants. Even though there are still gaps in participants' skills, the summer school was found to be an effective way to train the young scientists for rapid mapping. [ABSTRACT FROM AUTHOR]

National vertical data are mostly referenced to a tidal level of one or more tidal stations. The Keelung tidal station has been serving as the reference tidal station of the Taiwan National Height Datum for more than one century; all orthometric height in Taiwan is zeroed to the mean sea level (MSL) of an astronomical period of this station. A monument of the Taiwan height origin was established nearby, but due to construction, the height origin was relocated to the newly built National Museum of Marine Science and Technology in Badouzi. This article documents the search for an improved definition of the tidal reference for height origin in Taiwan. The selection criteria identified include geological stability; sufficient depth of water; limited influence from nontidal effects, such as passing vessels; and proximity to the monument of height origin. As part of the preliminary assessment, a tidal station was established at the nearby Cheng-Bin fishery port. The authors performed tidal comparisons of observations collected from the Keelung, Cheng-Bin, and nearby Longdong (to the east) and Taipei Harbor (to the west) stations. In addition to the harmonic analysis, tidal levels of different definitions were computed to determine the potential influence resulting from the change of reference tidal station to the national height datum. From concurrent observations over 3 months, from September 5 to December 17, 2013, the amplitude and phase of significant tidal components were found to be similar between the Keelung and Cheng- Bin stations, whereas the Longdong and Taipei Harbor stations presented larger deviations. The differences between MSL calculations were significant. Although the deviation between the national vertical datum zero and the tidal level was noted in previous studies, the Cheng-Bin station showed relatively smaller changes. Although defining height system with geoid and sea surface topography preserves a more physical and geometric definition of height, a MSL-based definition with a group of coordinated tidal stations may serve as a more reliable scheme for the transitional period. [ABSTRACT FROM AUTHOR]

Bathymetric LiDAR utilizes a green laser capable of penetrating water and surveying seafloor topography. The intensity of the echo identified as the seafloor carries information about the substrate type. However, besides the reflectance characteristics of the substrate, there are also other influencing factors, including those from the LiDAR system and the environment. The data collected in the 2010 Dongsha atoll bathymetric LiDAR mission is processed and analyzed in this study. The corrections for environmental factors, mainly contributed from the water column that is presented as the inherent optical parameters of water are retrieved from the recorded green laser waveform. Those from the system, such as deviations between the signal receptors or between laser beam angles to each interface, are eliminated with data from IMU (Inertial Measurement Unit), scanner controlling mechanisms, etc. The resulting reflectance from each flight line is compared in the overlap area. The reflectance of the west side strip is subtracted from that of the east side strip. The reflectance is scaled between zero and one. While the mean of the differences is -0.0037, the standard deviation is 0.0436 for the flight line with a flight height of 400 m. The mean and standard deviation are -0.0058 and 0.0272, respectively, with flight height of 300 m. When interpolating the reflectance from the 300 m flight altitude dataset into a surface after subtracting the point measurement from the 400 m flight altitude, the mean and standard deviations are -0.0215 and 0.0382, respectively. This indicates that the consistency among flight lines of the same flight altitude is higher than those from different flight altitudes. A WorldView-2 (WV-2) image is compared with the LiDAR reflectance, and after atmospheric correction, the green band reflectance from WV-2 showed high similarities between the two image types. However, in the deep water region the one derived from LiDAR has much more information content. [ABSTRACT FROM AUTHOR]

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The digital elevation products produced by the Shuttle Radar Topography Mission (SRTM) are disseminated with different resolutions. This study investigates the differences in information content between different resolutions. Three 1° cells are selected to represent flat area, moderate terrain, and mountain ranges. All of these cells are located in the continental territory of the United States. The theory of information loss caused by the sampling density is shown with the increasing deviation from the reference in the experiment. The error resulting from bilinear interpolation is also assessed. The experimental result also indicates that if the 1-arcsecond SRTM, digital elevation model (DEM) is released for global coverage, the height accuracy would be improved over the 3-arcsecond product. [ABSTRACT FROM AUTHOR]

ABSTRACT Dongsha Atoll is a coral reef located in the South China Sea. The surrounding area is characterized by dangerous shoals. Historic shipwrecks mark past human activities. Due to the shallow water and risky navigational conditions in the area, a sonar survey with platforms on the water surface was not feasible. Airborne bathymetric LiDAR, which utilizes green laser for measurement, however, is a proven convenient method for studying shipwrecks around the atoll, particularly in shallow-water areas. At a point density of about 3.5 m by 3.5 m, four shipwrecks were identified. The bathymetric measurements allow not only the length of the shipwreck to be estimated, but also its height above the sea floor. The full waveform record of the laser reflection also provided information to separate the wreckage from its surroundings. This provides an excellent working environment for marine archaeological analysis, as not only the location, but also the depth and geomorphological information can be assessed in an integrated setting. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Three new species, Exilaulacus advenus sp. nov. , Exilaulacus eximius sp. nov. and Electrofoenops exaltatus sp. nov. in two genera of Aulacidae, are described and figured based on three well-preserved specimens from the mid-Cretaceous Myanmar (Burmese) amber. Forewings of four described fossil species of Aulacidae and the three new species are studied by using the Geometric Morphometric Analyses (GMA) to further confirm their taxonomic classifications. [ABSTRACT FROM AUTHOR]

Airborne lidar systems are equipped with a scanning mechanism that produces a swath of 3D coordinated points to form a cloud in each flight strip. The scanning is perpendicular to the direction of flight. The density of the point cloud is one of the major quality measures for the data collected with such systems. Point density, shade (occlusion of the laser beam) and penetration rate are major factors to be considered in the flight design. For practical operations, flight missions may be designed with overlaps ranging from 5 to 50%. Aside from the percentage overlap, the field of view is another important parameter for flight design. An evaluation scheme to assess the percentage overlap between flight strips and the selection of the field of view is proposed in this study. The influences of overlap and field of view are also demonstrated with real data gathered by an airborne lidar system. [ABSTRACT FROM AUTHOR]

A novel reinforcement-learning-based output adaptive neural network (NN) controller, which is also referred to as the adaptive-critic NN controller, is developed to deliver the desired tracking performance for a class of nonlinear discrete-time systems expressed in nonstrict feedback form in the presence of bounded and unknown disturbances. The adaptive-critic NN controller consists of an observer, a critic, and two action NNs. The observer estimates the states and output, and the two action NNs provide virtual and actual control inputs to the nonlinear discrete-time system. The critic approximates a certain strategic utility function, and the action NNs minimize the strategic utility function and control inputs. All NN weights adapt online toward minimization of a performance index, utilizing the gradient- descent-based rule, in contrast with iteration-based adaptive-critic schemes. Lyapunov functions are used to show the stability of the closed-loop tracking error, weights, and observer estimates. Separation and certainty equivalence principles, persistency of excitation condition, and linearity in the unknown parameter assumption are not needed. Experimental results on a spark ignition (SI) engine operating lean at an equivalence ratio of 0.75 show a significant (25%) reduction in cyclic dispersion in heat release with control, while the average fuel input changes by less than 1% compared with the uncontrolled case. Consequently, oxides of nitrogen (NOx) drop by 30%, and unburned hydrocarbons drop by 16% with control. Overall, NOx's are reduced by over 80% compared with stoichiometric levels. [ABSTRACT FROM AUTHOR]

Ecosystem-based adaptation to climate change impacts, such as shoreline retreat, has been promoted at the international, national, and even local levels. However, among scientists, opinions about how to implement it in spatial-planning practices are varied. Science-based environmental factors, human wellbeing, and sustainable development can be strengthened by developing spatial-planning-based ecosystem adaptations (SPBEAs). Therefore, this article aims to assess how the SPBEA model can be developed within an area prone to shoreline retreat. A coastal area of the Sayung subdistrict in Central Java, Indonesia, was selected as a study area because it has experienced a massive shoreline retreat. A multicriteria analysis (MCA) method was employed for developing the model by using the geographic information system (GIS) technique of analysis, divided into three steps: the fishpond zone determination, which involved the analytical hierarchy process (AHP) method in the process of model development; the fishpond site determination; SPBEA fishpond site development. The results show that the SPBEA model is the best practice solution for combatting shoreline retreat because of tidal waves and/or sea-level rise. The spatial site management should empower the coastal protection zone and the sustainable fishpond zone by implementing a silvofishery approach. [ABSTRACT FROM AUTHOR]

The Chi-Chi earthquake of 1999 in Central Taiwan caused significant vertical uplift and ignited a dynamic fluvial erosion system in the Taan River. In order to understand the geomorphologic changes in the Taan River after the Chi-Chi earthquake, this study uses multi-temporal aerial photos to produce orthoimages and surface models to derive regional three dimensional movements from 2001 - 2009. The Particle Image Velocimetry (PIV) technique is applied to identify the horizontal movements from both orthoimages and digital surface models (DSMs). While PIV can provide estimates for the channel change direction and magnitude; vertical analysis such as river incision rate derivation could be performed using the height difference between multi-temporal surface models. The results from these two approaches are then integrated for river geomorphological interpretation. It is observed that the proposed scheme is capable of identifying three river evolution stages from the extracted movements in the Taan case. These stages are: years 2001 to 2003, 2004 to 2006, and 2007 to 2009, respectively. The total incision between 2001 and 2009 is about 10 m. This study demonstrates that both PIV and DSM subtraction are effective in river geomorphological change identification. The integration of these two approaches could provide more information when observing the evolution of river morphology. [ABSTRACT FROM AUTHOR]

Thrombin exists in two allosteric forms, slow (S) and fast (F), that recognize natural substrates and inhibitors with significantly different affinities. Because under physiologic conditions the two forms are almost equally populated, investigation of thrombin function must address the contribution from the S and F forms and the molecular origin of their differential recognition of ligands. Using a panel of 79 Ala mutants, we have mapped for the first time the epitopes of thrombin recognizing a macromolecular ligand, hirudin, in the S and F forms. Hirudin binding is a relevant model for the interaction of thrombin with fibrinogen and PAR1 and is likewise influenced by the allosteric S→F transition. The epitopes are nearly identical and encompass two hot spots, one in exosite I and the other in the Na+ site at the opposite end of the protein. The higher affinity of the F form is due to the preferential interaction of hirudin with Lys-36, Leu-65, Thr-74, and Arg-75 in exosite I; Gly-193 in the oxyanion hole; and Asp-221 and Asp-222 in the Na+ site. Remarkably, no correlation is found between the energetic and structural involvements of thrombin residues in hirudin recognition, which invites caution in the analysis of protein-protein interactions in general. [ABSTRACT FROM AUTHOR]

The geomorphology of Taiwan is characterized by marked changes in terrain, geological fractures, and frequent natural disasters. Because of sustained economic growth, urbanization and land development, the land cover in Taiwan has undergone frequent use changes. Among the various technologies for monitoring changes in land cover, remote sensing technologies, such as LiDAR, are efficient tools for collecting a broad range of spectral and spatial data. Two types of airborne LiDAR systems exist; full-waveform (FW) LiDAR and traditional discrete-echo LiDAR. Because reflected waveforms are affected by the land object material type and properties, the waveform features can be applied to analyze the characteristics specifically associated with land-cover classification (LCC). Five types of land cover that characterize the volcanic Guishan Island were investigated. The automatic LCC method was used to elucidate the spectral, geomorphometric and textural characteristics. Interpretation keys accompanied by additional information were extracted from the FW LiDAR data for subsequent statistical and separation analyses. The results show that the Gabor texture and geomorphometric features, such as the normalized digital surface model (nDSM) and slopes can enhance the overall LCC accuracy to higher than 90%. Moreover, both the producer and user accuracy can be higher than 92% for forest and built-up types using amplitude and pulse width. Although the wave-form characteristics did not perform as well as anticipated due to the waveform data sampling rate, the data provides suitable training samples for testing the waveform feature effects. [ABSTRACT FROM AUTHOR]

Residue Asp-189 plays an important dual role in thrombin: it defines the primary specificity for Arg side chains and participates indirectly in the coordination of Na+. The former role is shared by other proteases with trypsin-like specificity, whereas the latter is unique to Na+-activated proteases in blood coagulation and the complement system. Replacement of Asp-189 with Ala, Ash, Glu, and Ser drastically reduces the specificity toward substrates carrying Arg or Lys at P1, whereas it has little or no effect toward the hydrolysis of substrates carrying Phe at P1. These findings confirm the important role of Asp-189 in substrate recognition by trypsinlike proteases. The substitutions also affect significantly and unexpectedly the monovalent cation specificity of the enzyme. The Ala and Asn mutations abrogate monovalent cation binding, whereas the Ser and Glu mutations change the monovalent cation preference from Na+ to the smaller cation Li+ or to the larger cation Rb+, respectively. The observation that a single amino acid substitution can alter the monovalent cation specificity of thrombin from Na+ (Asp-189) to Li+ (Ser-189) or Rb+ (Glu-189) is unprecedented in the realm of monovalent cation-activated enzymes. [ABSTRACT FROM AUTHOR]