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Frequency doubling of mode-locked frequencytunable CO laser emission in high quality 17-mm long ZnGeP2 nonlinear optical crystal was studied. The internal efficiency of frequency doubling exceeded 25%, which was obtained by stabilization of mode-locking regime and increasing peak power of pump radiation in the scheme "master oscillator -power amplifier". A feasibility of difference frequency conversion of both fundamental and first overtone CO laser lines to cover ∼ 4.0 -5.0 μm spectral range and a possibility of getting spectral range of ∼ 1.25 -10 μm by mixing of all CO laser lines were estimated. Internal efficiency of SHG in ZnGeP2 crystal versus pump energy when the nonlinear crystal after focal plate. CO Laser transition 9→8 P(10) (λ ≈ 5.274 μm)

Analytical expressions (formulas) for normalizing constants in closed queueing networks with different classes of customers are presented and discussed in this article.

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This paper describes a new approach for dynamic code analysis. It combines dynamic symbolic execution and static code analysis with fuzzing to increase efficiency of each component. During fuzzing we recover indirect function calls and pass that information to the static analysis engine. This improves static path detection in the control flow graph of a program. Detected paths are used in dynamic symbolic execution to construct inputs which will cover new paths during execution. These inputs are used by the fuzzing tool to improve testcase generation and increase code coverage. The proposed approach can be used for classic fuzzing when the main goal is achieving high code coverage. As well it can be used for targeted analysis of paths and code fragments in the program. In this case the fuzzing tool accepts a set of programs addresses with potential defects and passes them to the static analysis engine. The engine constructs all paths connecting program entry point to the given addresses. Finally, dynamic symbolic execution is used to construct the set of inputs, which will cover these paths. Experimental results have shown that the proposed method can effectively detect different program defects.