Efficient SAR Azimuth Ambiguity Reduction in Coastal Waters Using a Simple Rotation Matrix: The Case Study of the Northern Coast of Jeju Island

Azimuth ambiguities, or ghosts on SAR images, represent one of the main obstacles for SAR applications involving coastal monitoring activities such as ship detection. While most previous methods based on azimuth antenna pattern and direct filtering are effective for azimuth ambiguity suppression, they may not be effective for fast cruising small ships. This paper proposes a unique approach for the reduction of azimuth ambiguities or ghosts in SAR single-look complex (SLC) images using a simple rotation matrix. It exploits the fact that the signal powers of azimuth ambiguities are concentrated on narrow bands, while those of vessels or other true ground targets are dispersed over broad bands. Through sub-aperture processing and simple axis rotation, it is possible to concentrate the dispersed energy of vessels onto a single axis while the ghost signal powers are dispersed onto three different axes. Then, the azimuth ambiguities can be easily suppressed by a simple calculation of weighted sum and difference, while preserving vessels. Applied results achieved by processing TerrSAR-X SLC images are provided and discussed. An optimum weight of 0.5 was determined by Receiver Operating Characteristic (ROC) analysis. Capabilities of ship detection from the test image were significantly improved by removing 93% of false alarms. Application results demonstrate its high performance of ghost suppression. This method can be employed as a pre-processing tool of SAR images for ship detection in coastal waters.

Multi-wavelength achromatic bifocal metalenses with controllable polarization-dependent functions for switchable focusing intensity

In this paper, bifocal metalens are designed through simultaneously controlling two polarization-dependent functions, which can respectively focus x-polarized and y-polarized light into different positions, and the relative intensity between two foci can be continuously tuned through a simple rotation of the incident linear polarization direction. The proposed metalenses are composed of rectangle nanopillars with spatially varying widths and lengths, which provide distinct propagating phases under two orthogonal polarizations. Therefore, there exists a freedom of degree to achieve two polarization-dependent focusing functions. More importantly, these nanopillars possess the excellent dispersion engineering, and provide an effective way for the realization of achromatic bifocal metalenses. After powerful optimizations, two achromatic bifocal metalenses are constructed and further demonstrated numerically. The x-polarized and y-polarized components are focused into different positions under different working wavelengths. Simulated results agree well with our designs. The approach here is expected to find optical applications in micro-manipulation, optical communication and multicolor display.

COMBINED USE OF TURNOVER AND PIVOT FLAP FOR DOUBLE LAYER CLOSURE OF POSTAURICULAR FISTULA

ABSTRACT Repair of post auricular stula are challenging owing to scarred tissue and poor blood supply in this area. Various techniques including locoregional ap cover and cavity obliteration have been utilized to repair this complicated problem. In our report, we introduce a novel technique using a double layer closure utilising local skin ap successful lasting results. Two young adults of age 18 Male and 21 year female. Size of stulas were ranging from 1x2 and 2x2 cm respectively in size. Once the stulous tract was excised two aps were planned for double layer closure of stula. First ap for inner lining was turnover ap. Then another local pivot ap is planned to cover the secondary defect or the raw area. It can be either simple rotation ap as in rst case or Limberg type local transposition nd defect (2 case) ap. Both stulas were healed well. KEYWORDS : Fistula , Post auricular, Flap Closure

Two-Qubit Bloch Sphere

Three unit spheres were used to represent the two-qubit pure states. The three spheres are named the base sphere, entanglement sphere, and fiber sphere. The base sphere and entanglement sphere represent the reduced density matrix of the base qubit and the non-local entanglement measure, concurrence, while the fiber sphere represents the fiber qubit via a simple rotation under a local single-qubit unitary operation; however, in an entangled bipartite state, the fiber sphere has no information on the reduced density matrix of the fiber qubit. When the bipartite state becomes separable, the base and fiber spheres seamlessly become the single-qubit Bloch spheres of each qubit. Since either qubit can be chosen as the base qubit, two alternative sets of these three spheres are available, where each set fully represents the bipartite pure state, and each set has information of the reduced density matrix of its base qubit. Comparing this model to the two Bloch balls representing the reduced density matrices of the two qubits, each Bloch ball corresponds to two unit spheres in our model, namely, the base and entanglement spheres. The concurrence–coherence complementarity is explicitly shown on the entanglement sphere via a single angle.

THE STUDY OF MARKET TIMING IMPLEMENTATION IN INDONESIAN STOCK MARKET

This study is intended to discuss about implementation of market timing as an investment alternative strategic in Indonesian Stock Market. Market timing is procedure for changing portfolio asset allocation to deal with changes in business cycle. The market timing indicator used in this study is interest rate of Bank Indonesia. The active portfolio consist of IHSG and bond for simple rotation strategy. Sector rotation strategy consist of cyclical and non cyclical sector index. The dissecting cycle analyse by two methods, Hamilton Filter and indicator change assumptions. The secondary data used in this study have a span of time from January 2005 - December 2017. The result showed that active strategies produced better performance than passive strategy, and sector rotation were the best performance among other alternative strategies. Optimal performance of simple rotation occurs when change of variable BI rate by ±2% and optimal performance of sector rotation occurs when change of variable BI rate by ±4%. Keywords—Hamilton Filter; Market Timing; Sector Rotation; Simple Rotation AbstrakPenelitian ini bertujuan untuk membahas tentang penerapan market timing sebagai tindakan strategi investasi aktif di pasar modal Indonesia. Market timing merupakan prosedur perubahan alokasi aset portfolio untuk menghadapi perubahan siklus bisnis di suatu negara. Indikator market timing yang digunakan dalam penelitian ini adalah suku bunga acuan Bank Indonesia. Portfolio aktif terdiri dari IHSG dan obligasi untuk strategi aktif rotasi sederhana dan indeks sektor siklikal dan non siklikal untuk rotasi sektoral. Pemilahan siklus dilakukan dengan dua metode yaitu Hamilton Filter dan asumsi perubahan variabel indikator. Seluruh data sekunder yang digunakan dalam penelitian ini memiliki rentang waktu dari Januari 2005 - Desember 2017. Hasil penelitian menunjukkan bahwa strategi aktif menghasilkan kinerja lebih baik relatif terhadap strategi pasif, dan strategi rotasi sektoral secara keseluruhan lebih baik dibandingkan dengan alternatif strategi lain. Strategi rotasi sederhana optimal pada penggunaan asumsi perubahan variabel ±25 bps (basis point) dan strategi rotasi sektoral optimal pada penggunaan asumsi perubahan variabel ±100 bps (basis point). Kata kunci— Hamilton Filter, Market Timing, Rotasi Sederhana, Rotasi Sektoral

Calix[6]arene-based atropoisomeric pseudo[2]rotaxanes

Some examples of atropoisomeric pseudorotaxanes in which the isomerism arises by the different conformations adopted by the wheel are reported here. Upon threading hexahexyloxycalix[6]arene 1 with ammonium axles 2 + or 3 + , bearing biphenyl or trifluoromethylbenzyl moieties, respectively, two atropoisomeric pseudorotaxanes were formed in which the calix[6]-wheel 1 adopts the 1,2,3-alternate and cone conformations. The interconversion between them cannot be obtained by simple rotation around the ArCH2Ar bonds of the calixarene wheel, which is blocked by the presence of the axle inside its cavity. Therefore, it can only be obtained through a mechanism of de-threading/re-threading of the axle. In all the examined cases, the 1,2,3-alternate and cone atropoisomers are, respectively, the kinetic and the thermodynamic ones.

Symmetrical Ball Check-Valve Based Rotation-Sensitive Pump

In this work an electromagnetically actuated membrane pump, which allows flow reversion with a simple rotation of its valve system, is presented as a proof of concept. The valve system combines two symmetrical ball check-valves (SBCV), fabricated using laser machining techniques on PMMA (poly-methyl methacrylate) and PDMS (polydimethylsiloxane). The best efficiencies were achieved using glass balls within the SBCVs. This configuration provides flow rates from 0.2 to 6.0 ml/min with pressures up to 7 kPa. We also present a model which allows simulating the pumping behavior qualitatively, including the reversion after the rotation. The main advantages of the presented pump are wide range flow rates, low driving voltage (below 30 V), same pressure and flow rate in both direct and reverse pumping modes, and easily scalable to both bigger and smaller dimensions.

GPS Satellite State Vector Determination in ECI Coordinate System using the Civil Navigation Message

A closed form of an algorithm to determine a Global Positioning System (GPS) satellite's position, velocity and acceleration is proposed, and an Earth Centred Earth Fixed (ECEF) to Earth Centred Inertial (ECI) transformation result using the Civil Navigation (CNAV) message is presented in this paper. To obtain the closed form of the GPS satellite velocity and acceleration determination algorithm using the CNAV, we analytically differentiated the IS-GPS-200F position determination function. The calculated data are transformed from the International Terrestrial Reference Frame (ITRF) to the Geocentric Celestial Reference Frame (GCRF) using an equinox-based transform algorithm that is defined in the IAU-2000 resolution system using the Earth Orientation Parameter (EOP) data. To verify the correctness of the proposed velocity and acceleration determination algorithm, the analytical results are compared to the numerical result. The equinox-based transformation result is compared to simple rotation about the z-axis, which does not use the EOP. The results show that by using the proposed algorithm and the equinox-based transformation together, the user can obtain more accurate navigation data in the ECI frame.