In view of the problems of difficult establishment of effective displacement system and poor effect of water drive in Chang 8 reservoir of C335 area of JY oilfield, the reservoir development effect was evaluated comprehensively by reservoir pressure change, water drive law and effect characteristics. On this basis, combining with reservoir engineering and numerical simulation, this article formulated reasonable exploitation policy. The optimum injection⁃production ratio was 2.0, the flow pressure was 6.0 MPa, and the production rate was 0.7%. Finally, by comparing and forecasting the three schemes, the comprehensive scheme was the best.

A new image encryption method based on rotation transformation and chaos theory was proposed, which used chaos function to generate random phase mask (chaotic random phase mask). In the proposed technique, the image was encrypted using gyrator transform and two chaotic random phase masks. In the proposed method, the image was encrypted by using rotation transform and two chaotic random phase masks, and the chaotic random phase mask was generated by using three chaotic functions: Logistic map, Tent map and Kaplan⁃Yorke map. The computer simulations were presented to verify the validity of the proposed technique. By calculating the mean square deviation, the robustness of the blind decryption algorithm based on the seed value of rotation angle and chaotic random phase was evaluated, and the optical implementation scheme of encryption and decryption technology was given.

In this paper, a new watermarking scheme based on Chaos for image authentication and tamper detection is proposed. This scheme can detect any modification to the image and determine the specific location of the modification. In order to improve the security of the proposed scheme, two chaotic maps are used. Because the chaotic map is sensitive to the initial value, the corresponding position relationship between the pixels in the watermarking image and the watermarking is disturbed, which makes the watermarking scheme resist forgery attack. In this scheme, the initial value of the chaotic map is used as the secret key, and the effectiveness of the proposed scheme is checked through a series of attacks. The experimental results show that the scheme is not only safe and reliable, but also can achieve high tamper detection and location accuracy under different attacks.

Voice forgery is detected by digital audio watermarking and pattern recovery techniques. The three methods used by digital watermarking mode for speech signal forgery detection are replacement, insertion and deletion. If some changes are made to the speech signal, the watermark mode will also change, and the mode recovery can be used to measure or detect whether the speech signal has been modified or forged. The proposed method uses the cyclic pattern embedding to overcome synchronizing problems of previous detection techniques. In addition, pattern recovery enhances the robustness to compression. This method has been tested and verified using six recording devices, which was used for collecting verbal data. The speech signals were sampled at the rate of 8 kHz and digitized at 16 bits resolution. Randomly chosen regions were substituted, removed, and compressed in MP3 at the rate of 16 kbps as well as in CELP at the rate of 11.5 kbps. The experiment shows the perfect detection for three kinds of forgeries and it proved the validity of the proposed method.

Aiming at the reservoir characteristics of strong reservoir heterogeneity, circulation way widely distributed and poor water flooding effect in X oilfield of yanchang, a kind of nano⁃microsphere oil displacement agent WQ⁃3 was systhesized. The microstructure, swelling property, viscoelasticity and shear resistance performance were evaluated through the indoor experiments. The core⁃flow experiment was used to evaluate the performance of the regulator in heterogeneous core. The results showed that nano⁃microsphere WQ⁃3 are spherical nanoparticles with good roundness and the average particle size is 404.92 nm. At 80 ℃ in simulated formation water, the expansion ratio of the nano⁃microspheres after 24 h of water absorption is 34.96 g/g. Nano⁃microsphere WQ⁃3 has obvious viscoelastic properties after water absorption, showing the properties of soft solids. At high shear rate, nano⁃sphere WQ⁃3 system has better shear resistance; the injection pressure rises rapidly and the oil recovery increased as high as 14.25% of the injection of WQ⁃3 system.

A color image encryption method is proposed. The method uses discrete fractional random transform (DFRNT) and Arnold transform (AT) to encrypt in the luminance hue saturation color space. A color image is converted from the standard red-green-blue (RGB) space to luminance hue saturation space . The luminance component is encrypted by a method DFRNT transform, which encrypts the pixel value and the pixel position simultaneously. The hue and saturation components are encrypted using an Arnold scrambling method that scrambling pixels. Compared with the traditional double-random-phase encoding, the DFRNT encryption method can save storage space of the encryption key. At the same time, it is as safe as the traditional dual random phase coding. The fractional order of the DFRNT, the random matrix and the iteration numbers of Arnold transform are used as the encryption keys of the algorithm. The performance of the cryptographic algorithm is analyzed against the variation in fractional order, the change of Arnold transform iteration number, known-plaintext attack, noise addition and occlusion of the encrypted image. The test results show the feasibility and effectiveness of the scheme.

In previous image watermarking methods, an encoded host image and a watermark image are usually directly added.Therefore, the two images have cross-talk in the decryption step.In order to eliminate this effect，a new method based on digital holography interferometry is proposed,in which all the image pixels of the two sets of holograms resulted from two hidden images are rearranged and integrated into one set of composite holograms with a random scattering matrix (RSM)．In decryption the use of this matrix can ensure the exact retrieval of each hologram，and then the perfect reconstruction of each image without cross-talk noise can be achieved．In the decryption process, the use of RSM can ensure the accurate recovery of each holographic image, so as to achieve a perfect reconstruction of no crosstalk noise in each image. The computer simulation is performed using phase-shift interference and double random phase encoding techniques to verify the feasibility of the method , its robustness to occlusion and additional noise.this method is suitable for 2D and 3D images, and the additional RSM can also provide a higher level of security as a key.

Welding robots have a wide range of applications in manufacturing industries. There are usually many welded joints in the welding task, and a reasonable welding path passes through these welded joints has a significant impact on the welding efficiency. Traditional manual path planning techniques can handle a small number of welded joints effectively, but when the number of welded joints is large, it is difficult to obtain the optimal path. The traditional manual path planning method is also time consuming and inefficient, and cannot guarantee optimality. Genetic algorithmparticle swarm optimization (GA-PSO) is based on the advantages of genetic algorithm (GA) and particle swarm optimization (PSO) to solve the welding robot path planning problem. The simulation results indicate that the algorithm has strong searching ability and practicality and is suitable for welding robot path planning.

A new technique combining spatial domain and frequency domain is proposed, which can provide more watermarks in the condition of reducing the distortion of watermark image. The watermark is divided into two parts: the spatial domain and the frequency domain, and embedded into the spatial domain and the frequency domain according to the user's needs or the importance of the data respectively. Experimental results provide the comparisons when different sized watermarks are embedded into the grayscale image. The proposed combinational image watermarking possesses the following advantages. More watermark data can be embedded into the host image, so that the capacity is increased. The watermark is divided into two parts in spatial domain and frequency domain makes the degree of protection double. The splitting strategy can be designed to be more complex in order to make the embedded watermark unrecoverable. In addition, in order to enhance the robustness, a random permutation of the watermark is used to combat the attacks of signal processing such as image crops.

The mobile robot can sense the surrounding environment，and can plan the path to reach the target point in real time， among which the obstacle avoidance problem is the focus of the research. A control scheme for path planning transformation of mobile robot in obstacle avoidance without detailed environmental information is designed.In this scheme，the robot can according to the motion tracking mode，obstacle avoidance model and robot state gradually approaching the target，using the Matlab simulation experiment in any shape obstacles as far as possible. The obstacle experiment verifies the effectiveness of the adaptive path planning control scheme is proposed.

      In view of the phenomena of using the same standard comprehensive evaluation to all students in the current university, not considering the difference of individual special ability of the students, and avoiding to produce the phenomenon of high grade and low ability of the students, the rough set theory and the average evaluation method were used to find out the weak link of students' ability and to enhance students' ability of different quantization. The experiments showed that the students' comprehensive ability could be evaluated by the rough set theory, which also provided theoretical basis for the students to improve their comprehensive quality and ability.

A new video watermarking algorithm based on the 1D DFT (one-dimensional discrete Fourier transform) and Radon transform was proposed in this paper. The 1D DFT for a video sequence generates an ideal domain. The frames with highest frequency were chosen to embed the watermark in the Radon transform domain. The performance of the proposed algorithm is evaluated by video compression standard H.264 with three different bit rates; geometric attacks such as rotation, translation, and aspectratio; and other attacks like frame drop, frame swap, spatial filtering, noise addition, lighting were conducted. The results show that the algorithm is robust to the attack. One of the most important advantages of this video watermarking algorithm is its simplicity and practicality.

This paper presents a control strategy of obstacle avoidance for nonfully constrainedmobilerobots in unknown environment.The avoidance of unexpected obstacles is consideredin a reactive way by following the contour of the obstacles.The robot backwardsmotions are avoided and the robot heading is always in the direction of thegoal point facilitating the obstacle handling. The stability of obstacle avoidance is analyzed under the reasonable conditions. Finally, the goodperformance and the feasibility of this approach are shown through several experimental results.

Disassembly modeling and planning are meaningful for the reuse and recycling of obsolete and discarded products. However, the existing disassembly methods pay little or no attention to impact of resources constraints for disassembly problem. According to the characteristics of lot sizing disassembly optimization problem with multiresource constraints, a mathematical model was established to solve disassembly optimization problems with multi-resource capacity constraints. The model aims at maximizing the profit of disassembly. The CPLEX software is used to solve the model. In order to approve the effectiveness of the proposed model, several randomly generated problem instances are used, the experimental results approved the effectiveness of the proposed model for the lot sizing disassembly optimization problem.

The increasing demand for more efficient high power supplies have forced to draw attention towards high frequency isolated threephase DCDC converter. Herein, a high frequency isolated threephase DCDC converter was studied, which can be used in the applications that require very low voltage conversion ratio, isolation, good regulation against load and line disturbances, and fast dynamic response. In this paper, modeling, control and design of highfrequency isolated threephase DCDC converter is carried out under asymmetrical control with fixed frequency operation and its steady state analysis is presented according to the description of the operation stages of the converter. A 750 W/5 V/150 A prototype model of proposed DCDC converter is built and tested under different operating conditions. Based on experimental results under the control method, performances of proposed converter have been investigated in view of low voltage high current applications.

n view of the digital archives of IP network encountered problems in the design process, this paper puts forward a design method of IP network in the design of digital archives based on the campus network, with the consideration of the overall planning, route planning, capacity design, equipment design, design for reliability, scalability design, and business planning of digital archives of the campus network. The designed network in this paper has been applied on the construction of College Party school digital archives of IP network, and the network performance has been tested. The results showed that the performance of the network could meet the new business development needs of party school of university digital archives.

HZSM-5 was loaded on the cordierite monolithic, and the effect of porous size of the carrier, solid content in slurry, solvent and binder on the loaded amount and loaded quality has been studied. The results show that the big channel, high solid content and the addition of ethanol solvent could increase the loaded amount of the active components in each immobilization process, yet the loaded quality of HZSM5/monolithic catalyst was decreased. While silica sol could significantly increas ethe loaded quality of HZSM5 on monolithic. In conversion of methanol to gasoline, HZSM-5/ monolithic catalyst exhibited high methanol conversion, and oil yield could reach 30.53% at 380 ℃.

A new asymmetric public key digital watermarking algorithm for still images was presented. The private key was embedded into the watermark, the public key was used to decrypt and detect. The results show that the attacker removed watermark without adequate information of the public key and private key. The image would be geometric deformation, and could obtain information of attacks from the image geometric distortion.