Synchronization Technologies for OFDM on the System of Satellite Communication

Satellite communications is an important component of the the world's communication networks and has become an indispensable means of communication in modern society. Wireless communication technology Based on orthogonal frequency division multiplexing (OFDM) is in rapid development. OFDM can provide high-capacity information transmission and Solve the issue of wireless Channel performance variation when the channel of high-speed data transmission in the mobile terminal, which greatly improve the quality of transmission channel. OFDM technology has the character of anti-multipath fading, high spectral efficiency, and so on, which is suitable for satellite communications with high-speed transmission in the wireless environment. In order to achieve a real sense of the OFDM system, synchronization is a critical issue.

At first, the current satellite communications and the development of OFDM technology are introduced in this paper, which is the research background of the subject. Some problems in the satellite communications and the necessary of OFDM technology applied for satellite communications are discussed.Second, the importance of the satellite communication channel in the analysis and designing of communication systems is discussed. The characteristics of satellite channels and the propagation characteristics described in detail. The probability density function of the satellite channels as well as the satellite channel model is analyzed.OFDM system and its synchronization technology are studied, the basic principles of OFDM are introduced and OFDM system model is given. The OFDM synchronization and synchronization technology are focused on the basis of analysis the factors of Synchronization in a variety of non-ideal. Various synchronization methods and improved synchronization algorithm of satellite communications based OFDM are analyzed on the basis of channel model and the corresponding results of computer simulation are given.At last, low-orbit satellite communication system is introduced, and the mode of satellite channels in the theoretical analysis is further simplified. On the analysis of low-orbit satellites, the effects of low signal to noise ratio and Doppler frequency shift Focus on considered. Synchronization of carrier frequency under the low signal to noise ratio of low-orbit satellites is analyzed in this paper, including the degradation of the capture performance under low signal to noise ratio and the design of loop carrier.
More about Satellite communications please visit: Information Technology Science

Organic Structure Probes and Studies Modern Interior Space

Today's society has been large-scale industrial production from the machine to the era of knowledge economy era, Chaos Theory, Phenomenology and symbiotic way of thinking in different aspects of objective and rational to the spirit and challenge Anthropocentrism, mechanical materialism by the sublimation of uncertainty to the complex and ever-changing organic synthesis.In the design of architectural space, organic thinking has never been a new, Wright proposed the theory of organic architecture, organic form of Gaudi architecture made attempts, Kisho Kurokawa more symbiotic with its philosophy, so that a comprehensive theory of organic development. Function in the beyond, and to go beyond the simple people-centered development of a sound, the interior space of the organic structure was established on the grounds. Interior space of the aesthetic orientation of the organic structure is diversified.

Contemporary architectural creation around the world, we can see that more and more interior space into the design of the idea of organic, even though very few people claim to be organic interior designers, but we can not deny the impact of the ideological role of organic. Spatial form and follow a straight line no longer advocate the design, but bold organic form; designed not only to emphasize the concept of self, but seek harmonious integration into the environment; design pattern is no longer the lingua franca of international style, but the search for geographical features, emphasize here and now; so on and so forth, are all in line with the organic philosophy.Representative of the organic concept is not a style, but more style, and it gave birth to the idea of ecological aesthetics, this is a new, beyond the form or function on a purely aesthetic form, a contact is the most the oldest living forms and the most distant prospect of the future survival of the survival of the aesthetic situation.

In this background, the interior space and the environment, and urban space, indoor space and the relationship between human beings has become the focus of thinking about the object, the modern architecture of the static and pure geometric point of view, must be changed from time to time.

The Bathroom Space Design of Based upon Universal Design

Universal design of products and environmental is non-adaptive and specific, can be used by as many people as possible and the best condition is used by all people. Universal design includes the principles of a barrier-free design and architectural design of the elderly. This design is benefit not only to the disabled, the elderly , but also to the healthy. It is truly reflects the "people-oriented" ideas, reflected the ethics of science and technology of and social responsibility. The ideal of universal design can be used for all products, this ideal state of the elderly for the barrier-free design and architectural design guidelines for the direction of development. This thesis discussion the residential design of sanitary facilities based on the current and future aging of China's population situation worsening, as well as the trend of the housing industry. The three elements of universal design in the architectural design are human being, and building construction, as well as interactive and interdependent relationship.

This thesis to meet the aging society, sanitary facilities and space for study, to universal design theory as a guide, combined with ergonomics, gerontology, psychology and other related knowledge, systematic analysis of the elderly, physical, psychological characteristics and rest patterns . By empirical research on the existing bathroom space for the elderly in the design and use of existing in-depth study of issues in order to seek appropriate measures and means of rational solution is proposed to enhance the subjective well-being of older people as the goal of design ideas. After the results of the analysis, the thesis is proposed space bathroom design principles of universal design and design methods and the elderly and human-scale projection and amendments carried out.

More information please visit Technology Science or http://www.latest-science-articles.com

A Study of Government Administration and Supervision of Construction Quality

This dissertation has systematically studied the organization systems, mechanism, actions, phases of government supervision, and main part administration and supervision. The main contents are summarized as follows:Organizational systems and mechanism. For organizational systems, this dissertation, based on the theories of systems engineering, management, economics and government regulation, exposes eight traits of government management and supervision, including systematic character, objective inherence, legislation character, social character, market, economic character, service character and international character.

Resource From:
A Study of Government Administration and Supervision of Construction Quality

A Study on Capital Management of Forest Ecological Compensation in China

Based on the great development of China the fact that the forest ecological compensation has become a key policy of national economy and social development. With using as a reference the past research results, the paper makes a comparatively comprehensive study on the capital management problems such as the sources, expenditures, effects, supervision and assessment of forest ecological compensation for the project of natural forest reservation.
Resource From:
A Study on Capital Management of Forest Ecological Compensation in China

The Research on the Governance-oriented Audit Model

The 21st century is the times of the corporate governance. Currently,no matter the academic research on modern company system or the arrange of company correlation work, is aiming at the corporate governance. In post-Enron era, there are more and more attentions to corporate governance and financial frauds, which have brought a great influence on the development of auditing.
Resource from:The Research on the Governance-oriented Audit Model

Research on D0A Estimation Algorithm in Smart Antenna

In smart antenna systems, digital signal process technologies are used to produce spatial and directional beam to aim the main beam at the coming direction of user signal of interest with the side lobe aiming at the coming direction of signal of interference user so that the signals of the user of interest are made use of with great efficiency while the interference signals are eliminated or restrained.
Resource From:Research on D0A Estimation Algorithm in Smart Antenna

Theoretical and Empirical Research on Legal Protection of Investor

On the basis of the legal protection of investors, the paper looks for mechanisms and channels to increase the degree of protection of shareholders, and confirms the propositions using countries' data.
Resource From: Theoretical and Empirical Research on Legal Protection of Investor

Clinical Significance of ATP-tumor Chemosensitivity Assay (ATP-TCA) in Chemotherapy of Advanced Breast Cancer

Objective:1. To study whether ATP chemosensitivity assay(ATP-TCA) test can direct clinical chemotherapy.2. ATP in vitro method to explore whether there is any experimental drugs to reduce toxicity.Methods:1. 56 cases of patients with non-surgical advanced breast cancer patients were tested by the ATP-TCA as the research group; The other 56 cases of patients with non-surgical advanced breast cancer patients weren’t tested by the ATP-TCA as the control group. Compare two group’s clinical outcome after six cycles’(one cycle for twenty-one days) chemotherapy.2. The two groups in the first 2 cycles (1 cycle 21d) after treatment compared toxicity .Results:1. The overall response rate of the research group was 86%(48/56) ,the control group was 49%(27/56). The research group shows better than the control group in alleviating symptoms, decreasing tumor size ,cutting down tumor markers of breast cancer such as CEA、CA15-3 and so on. In the research group,more than one year survival period was 83%(46/56);Correspondingly,th control group is 61%(34/56).The research group is more significantly than the control group in Clinical effect (P<0.05).2. Study group and control group toxicity of mainly bone marrow suppression, gastrointestinal reactions, alopecia and mucositis. Reaction in which the digestive tract was significantly (P<0.05), and bone marrow suppression, alopecia and mucositis was no significant difference.Conclusions: 1. The ATP—TCA has preferable value to direct the chemotherapy of advanced breast cancer,which can prolong the survival period , which can improve the clinic curative effect.2. ATP in vitro tumor cell culture + sensitivity test of advanced breast cancer chemotherapy drug can avoid the use of ineffective drugs toxicity.

The Effect of Ketamine on the Learning and Memory Function of the Sprague-Dawley Rat's Offspring

Objective:To study the effects of ketamine general anesthesia during gestationperiod on the learning and memory functions of Sprague-Dawley rat,s offspring.

Method:Thirty pregnant Sprague-Dawley (SD) rats were randomly divided into ketamine group and Control group,fifteen in each group. Ketamine was injected intravenously to the rats in the ketmine group for 2 hours, While ketmine was replaced with eaqual volume physiological saline solution for the rats in the control group.The learning and memory functions of the offspring rats were tested by Morris water maze test at different postnatal time intervals,20 days and 30 days respectively.The morphological changes of hippocampus tissue were analyzed under electrical microscope for the offspring rats. At the same time, the expression of the immediate early genes, c-fos and c-jun, were checked by RT-PCR.

Result:The latent period of the offspring rats in ketamine group was longer than that in the control group at 20 days and 30 days postnatly. The latent period of the second times of the offspring rats in ketamine group was significantly longer than that in the control group at 30 days postnatly (p<0.05). The hippocampus tissue of the offspring rat,s in the ketmine group was significantly damaged. The expression of the immediate early genes, c-fos and c-jun, appeared in both the offspring of the two groups and their gray value were equal.

Conclusion:Ketmine general anesthesia during gestationperiod could cause learning and memory functional injury to the offspring rats.It is related to the neuronal damage in the hippocampal tissue caused by ketmine.

The Rap-style Bone Stress Stimulator on Accelerating Fracture Healing

Background: Fracture healing is regulated by the local mechanical environmen, and can be significantly promoted by proper stress. A rap-style bone stress stimulator had been developed based on this principle by our group, and had obtained the national invention patent.

Objective: To explore the effect of the rap-style bone stress stimulator on accelerating fracture healing.

Methods:Ten male grey goats of the same species were randomly collected. All the goats were performed with bilateral tibial transverse osteotomy and plate fixation, the right tibias undewent stress stimulation as the experimental group, the left didn't as the self-control group. Study factor treatment was started at the first day post operation and persevered for 12 weeks. Radiographs were taken for each tibia at the first day and the end of every four weeks after surgery. All animals were killed at the 12th weekend, bilateral complete tibias were obtained for three-point bending mechanical test and torsion test, the data was processed by SPSS V13.0. After the biomechanical tests, histological sections of the callus tissue were stained by HE and Masson method to assess the level of maturity.Results: All the animals had healed, and no reaction had been seen. The quality and quantity of callus of the experimental group was better than that of the control group by observing X-ray at the same time point. The results of Biomechanical tests suggested that three-point bending static rigidity, maximum load and torsional static rigidity of callus of the experimental group were significantly higher than that of the control group(P=0.000). The histomorphometry tests pointed out that the callus of the experimental group was more mature than that of the control group.

Conclusion: Fracture healing should be promoted significantly by the rap-style bone stress stimulator, and the basis for the next clinical trials could be provided by this study.