Abstract-This paper presents an efficient algorithm for loss minimization by using an automatic switching operation in largescale distribution systems. Simulated annealing is particularly well suited for a large combinatorial optimization problem since it can avoid local minima by accepting improvements in cost. However, it often requires a meaningful cooling schedule and a special strategy, which makes use of the property of distribution systems in finding the optimal solution. In this paper, we augment the cost function with the operation condition of distribution systems, improve the perturbation mechanism with system topology, and use the polynomial-time cooling schedule, which is based on the statistical calculation during the search. The validity and effectiveness of the proposed methodology is demonstrated in the Korea Electric Power Corporation's distribution system.

The flexibility and self-healing properties of animal cell surface membranes are well known. These properties have been best exploited in various micrurgical studies on living cells (2, 3), especially in amoebae (7, 20). During nuclear transplantation in amoebae, the hole in the membrane through which a nucleus passes can have a diameter of 20-30 μm, and yet such holes are quickly sealed, although some cytoplasm usually escapes during the transfer. While enucleating amoebae in previous studies, we found that if a very small portion of a nucleus was pushed through the membrane and exposed to the external medium, the amoeba expelled such a nucleus on its own accord. When this happened, a new membrane appeared to form around the embedded portion of the nucleus and no visible loss of cytoplasm occurred during nuclear extrusion. In the present study, we examined amoebae that were at different stages of expelling partially exposed nuclei, to follow the sequence of events during the apparent new membrane formation. Unexpectedly, we found that a new membrane is not formed around the nucleus from inside but a hole is sealed primarily by a constriction of the existing membrane, and that cytoplasmic filaments are responsible for the prevention of the loss of cytoplasm.

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Low-temperature fabrication of thin-film dielectrics is essential for various applications including flexible/stretchable electronics, monolithic threedimensional integrated circuits, and large-area sensors/displays. Silicon dioxide is one of the most extensively used dielectric materials, but conventional deposition methods such as plasma-enhanced chemical vapor deposition and atomic layer deposition require relatively high temperatures. In this study, a high-quality SiO 2 thin film was fabricated at low temperatures below 150 °C using sputtering and hydrogen plasma treatment. The sputtered SiO 2 thin film exhibited low leakage current (3 × 10 −7 A/cm 2 at 3 MV/cm) and a high breakdown field (11.33 MV/ cm). After hydrogen plasma treatment was carried out under optimized conditions, the interface trap density between Si and sputtered SiO 2 was minimized to 7 × 10 11 cm −2 eV −1 , which is comparable to the corresponding value for thermally grown SiO 2 . The results of X-ray photoelectron spectroscopy and secondary-ion mass spectroscopy confirmed that the hydrogen treatment effectively passivates dangling bonds and reduces the portion of oxygen-deficient species.

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We report broadband optical parametric generation (OPG) in a single periodically poled lithium niobate crystal with a picosecond pump pulse at a fixed wavelength. We also demonstrate efficient optical parametric amplification of a broadband seed pulse within the quasi-phase-matched OPG band. The broad parametric gain band is attributed to group-velocity matching and degeneracy between the signal and idler, and the broad spectral width of the pumping source.

Nanosecond pulsed laser energy and thermal field evolution during second harmonic generation in periodically poled Li Nb O 3 crystals