Storage and Retrieval of Thermal Light in Warm Atomic Vapor

We report slowed propagation and storage and retrieval of thermal light in warm rubidium vapor using the effect of electromagnetically-induced transparency (EIT). We first demonstrate slowed-propagation of the probe thermal light beam through an EIT medium by measuring the second-order correlation function of the light field using the Hanbury-Brown$-$Twiss interferometer. We also report an experimental study on the effect of the EIT slow-light medium on the temporal coherence of thermal light. Finally, we demonstrate the storage and retrieval of thermal light beam in the EIT medium. The direct measurement of the photon number statistics of the retrieved light field shows that the photon number statistics is preserved during the storage and retrieval process.Comment: 4 pages, 4 figure

Reversing the Weak Quantum Measurement for a Photonic Qubit

We demonstrate the conditional reversal of a weak (partial-collapse) quantum measurement on a photonic qubit. The weak quantum measurement causes a nonunitary transformation of a qubit which is subsequently reversed to the original state after a successful reversing operation. Both the weak measurement and the reversal operation are implemented linear optically. The state recovery fidelity, determined by quantum process tomography, is shown to be over 94% for partial-collapse strength up to 0.9. We also experimentally study information gain due to the weak measurement and discuss the role of the reversing operation as an information erasure

CARBON CAPTURE AND STORAGE(CCS) RESEARCH COLLABORATION TRENDS USING NETWORK ANALYSIS OF SCI PAPERS

Climate change has become one of the most important global agenda, and nations worldwide are taking actions to resolve the issue and contribute to the new climate change regime. In the case of South Korea, the new goal of reducing greenhouse gas emission to 37% below BAU(Business-As- Usual) was set. As a means to achieve this goal, the Korean government is actively investing in highly effective greenhouse reduction technologies such as solar cell, fuel cell, bioenergy, secondary battery, power IT, and CCS(Carbon Capture and Storage). This paper investigates the overall trend of CCS research by examining international CCS research collaboration characteristics through network analysis of SCI papers; collaboration network of Korea is analyzed in further detail. Such analysis helps understand the status of international research in the field of CCS, especially that of Korea

Topology-aware Piecewise Linearization of the AC Power Flow through Generative Modeling

Effective power flow modeling critically affects the ability to efficiently solve large-scale grid optimization problems, especially those with topology-related decision variables. In this work, we put forth a generative modeling approach to obtain a piecewise linear (PWL) approximation of AC power flow by training a simple neural network model from actual data samples. By using the ReLU activation, the NN models can produce a PWL mapping from the input voltage magnitudes and angles to the output power flow and injection. Our proposed generative PWL model uniquely accounts for the nonlinear and topology-related couplings of power flow models, and thus it can greatly improve the accuracy and consistency of output power variables. Most importantly, it enables to reformulate the nonlinear power flow and line status-related constraints into mixed-integer linear ones, such that one can efficiently solve grid topology optimization tasks like the AC optimal transmission switching (OTS) problem. Numerical tests using the IEEE 14- and 118-bus test systems have demonstrated the modeling accuracy of the proposed PWL approximation using a generative approach, as well as its ability in enabling competitive OTS solutions at very low computation order

The Reduplication Process of Balantak Language: A Minority Austronesian Language of Eastern Sulawesi

Indonesia has many local languages. One of the local languages used in Indonesia is Balantak language. It is used by people who live in 5 (five) sub-districts in Banggai Regency, Central Sulawesi. In Balantak language, there are a number of words which are formed by using reduplication. Reduplication is found in many languages but is quite diverse as a process and in its. Due to reduplicated words in Balantak language, the writers are interested in analyzing the problem statement about: What are the forms of reduplicated words in Balantak language? Reduplication is the repetition of an entire word or part of the word. According to Haspelmath and Sims (2010), reduplications are a very common morphological operation, whereby part of the base orthe complete base is copied and attached to the base (either preceding or following it). In Balantak language both forms of reduplication are found full reduplication and partial reduplication, and each form consists of various kind of words

A Routing Path Construction Method for Key Dissemination Messages in Sensor Networks

Authentication is an important security mechanism for detecting forged messages in a sensor network. Each cluster head (CH) in dynamic key distribution schemes forwards a key dissemination message that contains encrypted authentication keys within its cluster to next-hop nodes for the purpose of authentication. The forwarding path of the key dissemination message strongly affects the number of nodes to which the authentication keys in the message are actually distributed. We propose a routing method for the key dissemination messages to increase the number of nodes that obtain the authentication keys. In the proposed method, each node selects next-hop nodes to which the key dissemination message will be forwarded based on secret key indexes, the distance to the sink node, and the energy consumption of its neighbor nodes. The experimental results show that the proposed method can increase by 50–70% the number of nodes to which authentication keys in each cluster are distributed compared to geographic and energy-aware routing (GEAR). In addition, the proposed method can detect false reports earlier by using the distributed authentication keys, and it consumes less energy than GEAR when the false traffic ratio (FTR) is ≥10%

Dependence of GCRs influx on the Solar North-South Asymmetry

We investigate the dependence of the amount of the observed galactic cosmic ray (GCR) influx on the solar North-South asymmetry using the neutron count rates obtained from four stations and sunspot data in archives spanning six solar cycles from 1953 to 2008. We find that the observed GCR influxes at Moscow, Kiel, Climax and Huancayo stations are more suppressed when the solar activity in the southern hemisphere is dominant compared with when the solar activity in the northern hemisphere is dominant. Its reduction rates at four stations are all larger than those of the suppression due to other factors including the solar polarity effect on the GCR influx. We perform the student's t-test to see how significant these suppressions are. It is found that suppressions due to the solar North-South asymmetry as well as the solar polarity are significant and yet the suppressions associated with the former are larger and more significant.Comment: 17 pages, 3figures, accepted to JAST

On some Gronwall type inequalities with iterated integrals

The main objective of the present paper is to establish some new Gronwall type inequalities involving iterated integrals