The objective of this Thesis is to design a scan lens for a long wave infrared laser marking system. The system is comprised of a laser source emitting a collimated beam coupled with a 14mm aperture dual axis galvanometer scanning system capable of scanning a range ± 11° (mechanical). Multiple scan lens options will be considered. Each scan lens will be optimized to maximize peak irradiance and operate at, or near, the diffraction limit over a 210x110 mm 'plus' shaped field. Unintended distortion evident in some lens designs and will be compensated for by developing equations that allowed the proprietary imaging algorithm to adjust the angle of the scanning mirror appropriately to achieve an undistorted image. The accuracy of the distortion correction will be within 1% of the shortest image dimension. Commercially available scan lenses are designed for generic scanning systems with no apriori knowledge of the imaging model and are typically available in arbitrary focal length increments. As a result, use of off the shelf scan lenses result in sub-optimal performance. This thesis presents background information on galvanometer based scanning systems followed by a review of classical scan lenses. The imaging application and systems constraints for the marking system are defined. The steps taken to design and optimize a conventional, aspheric, and F-Theta scan lens are described, and their performances are compared with respect to the design requirements. The Conventional scan lens coupled with a distortion correction equation was found to offer the best performance to cost ratio and was deemed the most appropriate lens for the marking system.

In the process of continuous scaling improvement under a single system-on-chip which contains millions of logic gates, testability of the design becomes more and more important and thus multiple scan tree test architecture can effectively reduce test time and test data simultaneously. In the current two-dimensional structure of the system-level chip, the interconnect has become one of the main factors in delay and power consumption, and thus optimizing interconnect becomes a very important topic. Especially, three-dimensional ICs, stacked multiple chips vertically by through-silicon-via technique, can be effective in reducing the length of the interconnects, power consumption and offering features of heterogeneous IC integration. In this research study, we consider three-dimensional chips in both respects of wire length and the scan output limits, and propose the test synthesis algorithm of multiple scan trees to reduce test cost for three dimensional integrated circuits.

About the investigation method of the present situation of coral reef at present, the main choice is scuba diving investigation no matter domestic and foreign countries. Take the coral reef of physical examination in Taiwan as example, divers use transects as basic methods to calculate the coverage rate of coral reef and characteristic of the seabed environment and to survey specific fish and quantity of the invertebrate in order to judge the influence that the human activity causes to the coral reef. In above-mentioned methods can really make full and accurate investigation to the coral reef of monitor area, so the method has already been adopted and walked for many years by the domestic and international relevant organization. But its shortcomings are slower investigating speed and lack accurate fixed position methods, and the divers also have hiding danger. However, some characteristics of side-scan sonar system just can mend the weak points of them. For the speed of investigating, our side-scan sonar's survey range can reach the belt area of hundred meters wide in both route sides, so it can substantially improve the speed of investigating. For the accuracy of fixed position, the side-scan sonar system match to GPS can obtain certain longitude and latitude of targets¡]the precision about 10 m¡^. So, this research is using side-scan sonar system to survey the seabed around LIU-CHIEU YU¡]the survey area about 2.6 km2¡^, the steps contain: mapping the distribute condition¡]sand, mud and rock¡^of seabed bottom, then identifying growing coral reef of rocky area, final assessing its feasibility by the process and result of survey. The ultimate purpose is an attempt to provide a new method for coral reef survey. The result of study shows: the seabed bottom around LIU-CHIEU YÜ can be divided into several parts by the difference of acoustics reflectivity. Among them, coral reef covers maximum area, and the area can reach to 1,133,670m2¡]46.4% of effective survey area¡^. In the part of identifying growing coral reef in the acoustics image, this study compares with optics images of TOV and acoustics images of side-scan sonar to establish the characteristics of growing coral reef in the acoustics image. Among them, the tree-like corals have some characteristics about high backscatter, individual risings, tree-like figures and acoustics shadows, unregulated reflection surfaces and complicated color tones in the reflection surface, but the cover-form reefs do not have tree-like figures and acoustics shadows. Then, using the above-mentioned characteristics to identify survey area seabed shows¡GThe cover area of growing coral reef is 547,438 m2¡]22.4% of effective survey area¡^, and the growing coral reef distributes in the southwest, southern and eastern sea area of LIU-CHIEU YÜ. And the optics images of the TOV shows the growth state of growing coral reef in the southeast sea area is superior to the southwest sea area, Finally, assessed by the process and result of this research, basically it is feasible to map the distribute condition of growing coral reef by side-scan sonar system.

Huffman coding is a good method for statistically compressing test data with high compression rates. Unfortunately, the on-­‐chip decoder to decompress that encoded test data after it is loaded onto the chip may be too complex. With limited die area, the decoder complexity becomes a drawback. This makes Huffman coding not ideal for use in scan data compression. Selectively encoding test data using Huffman coding can provide similarly high compression rates while reducing the complexity of the decoder. A smaller and less complex decoder makes Alternate Huffman Coding a viable option for compressing and decompressing scan test data. / text

Thesis (M.S.)--Rochester Institute of Technology, 1981. / Typescript. Includes bibliographical references (leaves 64-65).

Testing a PCB assembly can be very time consuming due to its complexity andcompactness. Tests are desired to be consistent and test coverage should be as highas possible, which is perfect for automated testing software.This thesis intends to develop computer controlled tests of faulty PCB assembliesusing boundary scan, which is meant to quickly locate the error so that an analysisengineer can evaluate it and prevent it from happening in future versions of theproduct. Boundary scan is even able to test the inner circuitry.Testing with boundary scan has been around for quite some time, but in recentyears it has shown to be truly valuable and time saving, due to the increasingcomplexity of PCB assemblies. The conclusions reached in this study are promisingfor future tests and development of PCBs using boundary scan, which has shownto be quite the powerful tool.

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No description available.

L'ondulation pli est un défaut majeur qui peut apparaître dans certains matériaux composites tels que le CFRP. Des mesures de vitesse et atténuation ultrasonore permettent la détection, mais pas l'identification, de l'ondulation pli. Dans la présente étude, il est démontré que pour identifier cette ondulation pli, il est important de prendre en compte la déviation du faisceau ultrasonore. Deux méthodes différentes, A²Scan et C²Scan, permettent de détecter et mesurer cette déviation. D'une part, de l'écart produit un comportement asymétrique dans les réponses obtenues à des angles d'incidence oblique. Ce phénomène se manifeste à travers l'étude des domaines d'angles d'incidence, qui peuvent normalement être superposés. D'autre part, la technique de C²Scan permet la mesure de la déviation du champ acoustique transmis. Dans les deux cas, l'étude de la déviation induite révèle sa sensibilité à la présence d'ondulation plis. Ces méthodes ont été validées expérimentalement et leur utilisation potentielle, en fonction de l'épaisseur de la pièce, ainsi que sont industrialisation par ultrasons laser sont discutées. / Ply waviness is a major defect, which can appear in certain composite materials such as CFRP. Attenuation and ultrasound velocity measurements allow the detection, but not the identification, of ply waviness. In the present study it is shown that in order to identify this ply waviness, it is important to take the deviation of the ultrasonic beam into account. Two different methods,A²Scan et C²Scan , allowing such deviations to be detected are proposed. On the one hand, the deviation produces an asymmetrical behaviour in the responses obtained at oblique incidence angles. This phenomenon is revealed through the study of incidence angle ranges, which can normally be superimposed. On the other hand, the double scanning technique allows the deviation of the energy maxima of the transmitted acoustic field to be determined. In both cases, the study of induced deviation reveals that it is sensitive to the presence of ply waviness. These methods have been experimentally validated and their potential use, depending on the thickness of the workpiece and industrialization by laser ultrasonic means are discussed.

<p>The boundary scan standard which has been in existence since the early nineties is widely used to test printed circuit boards (PCB). It is primarily aimed at providing increased physical test access to surface mounted devices on printed circuit boards (PCB). Using boundary scan avoids using functional testing and In-circuit-techniques like '<em>bed of nails</em>' for structurally testing PCBs as increasing densities and complexities made opting for them a herculean task. Though the standard has had a revolutionizing effect on board testing conducted during the development and production phases, there is a lack of a standardized mechanism to allow IEEE 1149.1 to be used in a system post installation. This has led to problems typically encountered during field test runs, like the issue of high number of No-Fault-Found (NFF), being left unaddressed. The solution lies in conducting a structural test after a given module has already been installed in the system. This can be done by embedding the programmability features of the boundary scan test mechanism into the Unit under test (UUT) thereby enabling the UUT to conduct boundary scan based self tests without the need of external stimuli. In this thesis, a test and debug framework, which aims to use boundary-scan in post system-installation, is the subject of a study and subsequent enhancement. The framework allows embedding much of the test vector deployment and debug mechanism onto the Unit under test (UUT) to enable its remote testing and debug. The framework mainly consists of a prototype board which, along with the UUT, comprise the 'embedded system'. The following document is a description of the phased development of above said framework and its intended usage in the field.</p>