`One Man´s Gain Is Another Man´s Loss´? Interim Report on the Consequences of Emigration for Those Staying at Home in the 18th Century

Research on historical migration has so far focused on the impact of immigration on recipient areas. Although several researchers have already pointed out this bias, no studies have been conducted on the impact of emigration from the early German Empire on the affected areas. In this study, the southern German territories affected by emigration to Hungary in the 18th century are examined. Through some examples, the paper seeks to assess potential source groups and provide a preliminary picture of impacts. In conclusion, further research needs to be carried out through intensive resource exploration, covering individuals, smaller communities along with distinct provinces and regions.

Kajian Hambur Balik Akustik Dari Tukik Penyu Lekang (Lepidochelys olivacea) Melalui Pengukuran Secara Terkontrol Pada Frekuensi 200 kHz

Turtles are marine reptiles that are protected because of their endangered population. The Convention on International Trade in Endangered of Wild Flora and Fauna (CITES) stipulates seven species of sea turtles in the world into Appendix I as endangered, protected and not exploited in any form. The number of hatchlings that managed to reach the sea is currently difficult to know, one method that can be used to detect the presence of hatchlings in nature is by using the acoustic method. This study aims to analyze the backscatter characteristics of the turtle hatchlings and to determine the relationship between backscattering and body length of the turtle hatchlings. The benefits of this research are expected to be able to provide information about the value of backscatter and the relationship to the body length of hatchlings that can be used as a basis for estimating the stock or abundance of hatchlings in nature. This research was conducted in the waters of the Tapak Padri pond, Bengkulu City. The research implementation takes about 3 months, from August to October 2020. Acoustic data processing is carried out at the Marine Acoustic and Resource Exploration Laboratory, Marine Department, FMIPA, Sriwijaya University, Palembang. The results obtained are that the average value of TS ranges from -52.74 to -48.45 dB for hatchlings length of 7-9.3 cm. Based on the regression equation, the coefficient of determination (R2) obtained is 0.57, so it is known that the total length affects the target strength value by 57% and 43% is influenced by other factors. it can be concluded that there is a relationship between the total length of the hatchlings with the TS value of the hatchlings or the total length has an influence on the magnitude of the TS value in the hatchlings.

The Forward Modeling for Surface-borehole Observation Responses of Polarized Target

Surface-hole induced polarization method is a typical deep resource exploration technology, which plays an important role in the mineral survey. The traditional surface-hole induced polarization method is mainly to observe a single polarized secondary field. At present, the time spectrum observation of polarization fields is becoming more and more popular, which greatly enriches the interpretation technology of induced polarization data. In this work, the time spectrum induced polarization method is expounded, the decay polarization fields were numerical calculated and analyzed for the typical 2-dimensional geoelectric model. The results show that for a single polarized target, the time spectrum obtained from different azimuth observation responses are basically the same, which can effectively reflect the time-varying characteristics of the polarized fields. The observation responses of polarized target at different depths can still reflect the time spectrum of decay fields. The main change of the observed response of the polarized target closer to the borehole is the response amplitude. The conclusions and simulations of this study can provide working mode for relevant research and reference for similar work.

Who Owns Space?

Space mining is no longer a figment of fringe science fiction. Due to the recent passage of the Space Resource Exploration and Utilization Act of 2015 (SREU Act), U.S. domestic space companies now have a semblance of legislative backing to launch commercial resource acquisition ventures in space. Previously, such companies floundered as capital from investors was reasonably sparse. Uncertainty created by the previously untested Outer Space Treaty (OST) perpetuated worry surrounding the existence of private property rights in space. With the passage of the recent SREU Act, many domestic worries were dismissed by the definitive granting of commercial property rights to U.S. citizens, yet equally many worries continue to surround the legitimacy of the SREU Act itself, as certain legal experts both inside and outside the U.S. argue the Act to be a violation of U.S. international obligations. In contrast to the OST, the SREU Act explicitly grants Americans the right to hold and obtain material resources from celestial bodies such as asteroids and minor planets. This paper examines the implications of such a legal gray area by examining the extent to which select clauses of the OST may or may not conflict with such definitive legislation. Ultimately, it is concluded that the issue is far from settled, as the existence of celestial property rights may not presently be as clear as investors might hope.

Reliable and Energy-Efficient Routing Scheme for Underwater Wireless Sensor Networks (UWSNs)

Despite the fact that the ocean plays a role in everything from the air we breathe to daily weather and climate patterns, we know very little about our ocean. Underwater wireless sensor network (UWSN) is one of the options helping us to discover some domains such as natural assets and underwater resource exploration. However, the acoustic signal is the only suitable option in underwater communication in the absence of radio waves, which face a number of challenges under this environment. To overcome these issues, many routing schemes are introduced by researchers though energy consumption is still a challenge in underwater communication. To overcome the issue of rapid energy consumption, a reliable and energy-efficient routing method is introduced that avoids the redundant forwarding of data; hence, it achieves energy efficiency and eventually prolongs the network lifetime. Simulation results support the claim that the proposed scheme achieves energy efficiency along higher delivery ratio by reducing the data transmission error rate during the routing decisions.

Fast Least-Squares Reverse Time Migration of OBN Down-Going Multiples

Nowadays the ocean bottom node (OBN) acquisition is widely used in oil and gas resource exploration and seismic monitoring. Conventional imaging algorithms of OBN data mainly focus on the processing of up-going primaries and down-going first-order multiples. Up-going multiples and higher-order down-going multiples are generally regarded as noise and should be eliminated or ignored in conventional migration methods. However, multiples carry abundant information about subsurface structures where primaries cannot achieve. To take full advantage of multiples, we propose a migration method using OBN down-going all-order multiples. And then the least-squares optimization algorithm is used to suppress crosstalks. Finally, a phase-encoding-based migration algorithm is developed to cut down the computational cost by blending several common receiver gathers together using random time delays and polarity reversals. Numerical experiments on the complex Marmousi model illustrate that the developed approach can enlarge the imaging area evidently, reduce the computational cost effectively, and enhance the image quality by suppressing crosstalks and improving the resolution.