• Analytical Science and Technology
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• v.21 no.6
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• pp.562-568
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• 2008

A novel two-dimensional cadmium(II)-nickel(II) bimetallic host clathrate, $[Cd{NH_2CH_2CH_2OH}_2Ni(CN)_4]{\cdot}3C_6H_5NH_2{\cdot}H_2O$, 1, has been synthesized and structurally characterized by X-ray single crystallographic method. The clathrate 1 crystallizes in the monoclinic system, space group $P2_1/c$ with a = 14.370(3), b = 7.728(1), c = 28.172(4) ${\AA}$, ${\beta}=97.58(1)^{\circ}$, V = 3101.1(9) ${\AA}^3$, Z = 4. The host framework of the clathrate 1 is built of the cyanide bridges between octahedral Cd(II) atom and square planar Ni(II) atom. The octahedral Cd atoms ligated by two 2-aminoethanol molecules and four cyanide ligands bridged with square planar Ni atoms. The Ni atoms bridges to four Cd atoms via cyanides is made up of puckered quadrangles of composition $\{CdNi(CN)_2\}_2$, all edges are shared. This cyanide bridges form an infinite two-dimensional host networks stacking along b axis. 2-Aminoethanol ligands bond to Cd atom through N atom as a monodentate ligand in the axial position and four cyanides take an equatorial plane with all in trans-configurations. The aniline guest molecules and water molecules are located in between the host layer sheets, respectively.

• Journal of Positioning, Navigation, and Timing
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• v.2 no.1
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• pp.81-89
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• 2013

Many of the current visual odometry algorithms suffer from some extreme limitations such as requiring a high amount of computation time, complex algorithms, and not working in urban environments. In this paper, we present an approach that can solve all the above problems using a single camera. Using a planar motion assumption and Ackermann's principle of motion, we construct the vehicle's motion model as a circular planar motion (2DOF). Then, we adopt a 1-point method to improve the Ransac algorithm and the relative motion estimation. In the Ransac algorithm, we use a 1-point method to generate the hypothesis and then adopt the Levenberg-Marquardt method to minimize the geometric error function and verify inliers. In motion estimation, we combine the 1-point method with a simple least-square minimization solution to handle cases in which only a few feature points are present. The 1-point method is the key to speed up our visual odometry application to real-time systems. Finally, a Bundle Adjustment algorithm is adopted to refine the pose estimation. The results on real datasets in urban dynamic environments demonstrate the effectiveness of our proposed algorithm.

• Journal of IKEEE
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• v.16 no.3
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• pp.173-176
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• 2012

This paper introduces a novel horn antenna for circular polarization using a planar-type radiator. This antenna can be divided to two parts, microstrip antenna and square horn. The microstrip antenna has the role of feeder and polarizer of the horn antenna, and it is designed to stacked type having metal spacer for high gain, high isolation and wideband characteristic. Using the proposed antenna structure, the horn antenna needs not additional structure such as feeder and polarizer, and the size of it can be considerably reduced. The horn antenna has typical gain of 8dBi and 3-dB axial-ratio bandwidth around 4.9%.This antenna can widely used for various antenna system for mobile and satellite communication using circular polarization expecially in high frequency band.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.7
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• pp.72-76
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• 2008

In this paper, the several printed square loop antennas which modified monopole antennas are proposed. The proposed antennas are reduced about 20% physical size of antenna and miniaturized reactance value of impedance due to fold center part of the loop. They obtained omni-directional radiation patterns with broad bandwidth and feed method used coplanar waveguide to composed single planar. The proposed antenna bandwidth is about 900MHz($2.63{\sim}3.56GHz]$) resonance frequency on $VSWR{\le}2$. it can be sufficiency of S-DMB band.

• Bulletin of the Korean Chemical Society
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• v.7 no.2
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• pp.129-136
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• 1986

The dipole moments for some coordination compounds with organic ligands have been calculated adopting the molecuar orbitals obtained from EHT calculation with modified technique. Adopting the molecular orbitals with the modified technique, the calculated dipole moments for all the coordination compounds with organic ligands give closer agreements with experimental values than those using the molecular orbitals obtained from EHT calculation. The calculated dipole moments suggest that $(C_2H_5)_2SO,\;(C_6H_5)_2SO,\;and\;(C_6H_5)_2SeO$ may have a trigonal planar structure and $(C_6H_5)_3AsO,\;and\;(C_6H_5)_3PBCl_3$ a square planar structure and $(C_2H_5)_2OZrCl_4$ may be distorted markedly. This work may also indicate that the modified technique is superior to the EHT calculation as far as the dipole moment calculation is concerned.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.5
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• pp.287-296
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• 2020

The present study aims to improve the accuracy of the maneuvering simulations based on captive model test results. To derive the hydrodynamic coefficients in a self-propelled condition, a mathematical maneuvering model using a whole vehicle model was established. Captive model tests were carried out using the Vertical Planar Motion Mechanism (VPMM) equipment. A motor controller was used to control the constant propeller revolution rate during pure motion tests. The resistance tests, self-propulsion tests, static drift tests, and VPMM tests were performed in the towing tank of Seoul National University. When the vertical drift angle changes, the gravity load on the sensors were changed. The hydrodynamic forces were deduced by subtracting the gravity load from the measured forces. The hydrodynamic coefficients were calculated using the least-square method. The simulation of the turning circle test was compared with the free-running model test result, and the error of the turning radius was 8.3 % compared to the free-running model test.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.408-413
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• 2004

Numerical and experimental investigation were car-ried out to clarify the flow structure of underexpanded jet from a square nozzle. The square nozzle rep-resents one of the clustered combustors of a linear aerospike engine. From the numerical results, the three-dimensional shock wave of the underexpanded square jet was found to be composed of two shocks. One is the intercepting shock which corresponds to the shock observed in two-dimensional planar jet. The other is the recompression shock divided into two types. The expansion fans coming from the nozzle edges interact with each other at the comers of the nozzle exit, and overexpanded regions are generated. Therefore one of the two recompression shocks is formed at the comers of the nozzle exit behind the overexpanded regions. As the jet goes downstream, the overexpanded regions grow larger to coalesce at the symmetry planes. Then, the other type of the recompression shock is generated. The three-dimensional shock structure formed by the intercepting shock and the recompression shocks dominates the expansion of the jet boundary. The shock detection algorithm us-ing CFD results was developed to reveal the relation between the shock waves and the jet boundary, and it was found that the cross-sectional jet shape becomes cross-shape. The key features observed in the numerical investigation were verified by the experimental results. The shock structure at the diagonal plane was in good agreement with the experimental schlieren images. Moreover, the cross-sections visualized by the Mie scattering method confirmed that the cross-section of the jet becomes cross-shape.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.11
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• pp.93-98
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• 2003

In this paper, we designed a printed square loop antenna for operating of PCS and IMT2000 band. The proposed antenna has omni-directional radiation patterns with broad bandwidth, similar to the conventional antenna, to easy feed on composing single planar. We obtain an ideal impedance matching and increase bandwidth. An antenna bandwidth is about 150MHz(1.74∼l.89〔GHz〕) at 1$^{st}$ resonance frequency and 290MHz(1.95∼2.24GHz) at 2$^{nd}$ resonance frequency on VSWR(equation omitted)1.5, and then we can obtain not only 1.73∼l.87 〔GHz〕 PCS band but also 1.92∼2.17 (GHz) IMT2000 band. band.

• Journal of the Korean Chemical Society
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• v.22 no.5
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• pp.295-303
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• 1978

The dipole moments for octahedral [Co(III)-$O_3N_3$], tetrahedral [M(II)-$O_2N_2$] and square planar [M(II)-$O_2N_2$] types complexes are calculated by the expansion method for spherical harmonics using the valence basis sets for the central metal ion and the single basis set orbital ($2p_z$) for ligands. The calculated dipole moments for these complexes are in agreement with the experimental values.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.9 no.3
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• pp.206-212
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• 2009

This paper presents an optimized integrated task planning and control approach for manipulating a nonholonomic robot by mobile manipulators. Then, we derive a kinematics model and a mobility of the mobile manipulator(M2) platform considering it as the combined system of the manipulator and the mobile robot. to improve task execution efficiency utilizing the redundancy, optimal trajectory of the mobile manipulator(M2) platform are maintained while it is moving to a new task point. A cost function for optimality can be defined as a combination of the square errors of the desired and actual configurations of the mobile robot and of the task robot. In the combination of the two square errors, a newly defined mobility of a mobile robot is utilized as a weighting index. With the aid of the gradient method, the cost function is minimized, so the path trajectory that the M2 platform generates is optimized. The simulation results of the 2 ink planar nonholonomic M2 platform are given to show the effectiveness of the proposed algorithm.