• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.8
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• pp.693-700
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• 2007

We can predict spatial acoustic pressure distribution on the plane of interest by using acoustic holography. However, the information embedded in the distribution plot is usually much more than what we need: for example, source locations and their overall propagation pattern. One possible candidate to solve the problem is complex envelope analysis. Complex envelope analysis extracts slowly-varying envelope signal from a band signal. We have attempted to extend this method to space domain so that we can have spatial information that we need. We have to modulate two dimensional data for obtaining spatial envelope. Although spatial modulation basically follows the same concept that is used in time domain, the algorithm for the spatial modulation turns out to be different from temporal modulation. We briefly describe temporal complex envelope analysis and extend it to spatial envelope of 2-D acoustic field by introducing geometric transformation. In the end, the results of applying the spatial envelope to the holography are envisaged and verified.

• Advances in aircraft and spacecraft science
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• v.2 no.4
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• pp.427-443
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• 2015

The present paper is the follow-on of a former work in which the influence of the gas-surface interaction models was evaluated on the aerodynamic coefficients of an aero-space-plane and on a section of its wing. The models by Maxwell and by Cercignani-Lampis-Lord were compared by means of Direct Simulation Monte Carlo (DSMC) codes. In that paper the diffusive, fully accommodated, semi-specular and specular accommodation coefficients were considered. The results pointed out that the influence of the interaction models, considering the above mentioned accommodation coefficients, is pretty strong while the Cercignani-Lampis-Lord and the Maxwell models are practically equivalent. In the present paper, the comparison of the same models is carried out considering the dependence of the accommodation coefficients on the angle of incidence (or partial accommodation coefficients). More specifically, the normal and the tangential momentum partial accommodation coefficients, obtained experimentally by Knetchel and Pitts, have been implemented. Computer tests on a NACA-0012 airfoil have been carried out by the DSMC code DS2V-64 bits. The airfoil, of 2 m chord, has been tested both in clean and flapped configurations. The simulated conditions were those at an altitude of 100 km where the airfoil is in transitional regime. The results confirmed that the two interaction models are practically equivalent and verified that the use of the Knetchel and Pitts coefficients involves results very close to those computed considering a diffusive, fully accommodated interaction both in clean and flapped configurations.

• Structural Engineering and Mechanics
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• v.44 no.1
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• pp.15-34
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• 2012

In the present paper, an improved high-order theory is used for bending analysis of soft-core sandwich plates. Third-order plate assumptions are used for face sheets and quadratic and cubic functions are assumed for transverse and in-plane displacements of the orthotropic soft core. Continuity conditions for transverse shear stresses at the interfaces as well as the conditions of zero transverse shear stresses on the upper and lower surfaces of the plate are satisfied. Also, transverse flexibility and transverse normal strain and stress of the orthotropic core are considered. The equations of motion and boundary conditions are derived by principle of minimum potential energy. Analytical solution for bending analysis of simply supported sandwich plates under various transverse loads are presented using Navier's solution. Comparison of the present results with those of the three-dimensional theory of elasticity and some plate theories in the literature confirms the accuracy of the proposed theory.

• Steel and Composite Structures
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• v.28 no.6
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• pp.709-718
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• 2018

Masonry walls are sometimes removed in buildings to either make new passages or increase the usable space. This may change the loading paths in the structure, and require new beams to transfer the loads which are carried by the masonry walls that are to be removed. One possible method of creating such new beams is to attach steel plates onto part of the existing walls to form a steel plate-masonry composite (SPMC) beam, leading to a new structure with part of the masonry wall supported by a new SPMC beam. This paper presents an experimental investigation into the interaction between the SPMC beam and the masonry wall above. Five SPMC beams supporting a masonry wall were tested to study the influence of parameters including the height-to-span ratio of the masonry wall, height of the beam and thickness of the steel plates. The test results, including failure mode, load-carrying capacity, load-deflection curves and strain distribution, are presented and discussed. It is found that for developing better arching effect in the masonry wall the ratio of the in-plane flexural stiffness of the masonry wall to the flexural stiffness of the SPMC beam must be between 2.8 and 7.1.

• Journal of the Korean Chemical Society
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• v.7 no.4
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• pp.293-298
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• 1963

The crystal structure of ethylenediamine dihydrochloride has been determined by the two-dimensional Patterson methods and refined by two-dimensional Fourier syntheses. The unit cell dimensions are a = 4.44${\pm}$0.02, b = 6.88${\pm}$0.02, c = 9.97${\pm}$0.02 ${\AA}$, ${\beta}$ = 92${\pm}$$1^{\circ}$. The space group is $P2_1_{/c}$. The carbon and nitrogen atoms in the ethylenediamine itself lie on one plane and its structure has a trans-form with a centre of symmetry in it, and C-C distance of 1.54 ${\AA}$, C-N distance of 1.48${\AA}$ and C-C-N bond angle of $109.07^{\circ}$. The molecules are linked by N-H${\cdots}$Cl hydrogen bonds with distance of 3.14, 3.16 and 3.22 ${\AA}$ forming three dimensional network. The values of reliability factor for F(okl), F(hol) and F(hko) are 0.11, 0.10 and 0.09 respectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.1
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• pp.231-236
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• 2017

The space harmonics generated by a plane-wave incident upon a multi-layered dielectric grating can undergo strong resonance scattering variations known as GMR(guided-mode resonance). To clarify these effects, we examine the field propagation and dispersion curve inside the grating region by using a rigorous equivalent transmission-line theory(RETT). The results show that, at the peak of a scattering resonance, the reflected mode is almost identical to a leaky wave that can be supported by the grating structure. Thus, we confirm and generalize previous research that has occurred GMR effect associated with the free-resonant character of leaky waves at multi-layered dielectric gratings. Quantitative simulation results illustrating the behavior of typical gratings are given, and the special case of normal incidence is discussed for TM mode.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.92-95
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• 1999

The design problem of the control system is the ability to synthesize controller that achieve robust stability and robust performance. The paper explains the Finite Inclusions Theorem (FIT) by the procedure namely FIT synthesis. It is developed for synthesizing robustly stabilizing controller for parametrically uncertain system. The fundamental problem in the study of parametrically uncertain system is to determine whether or not all the polynomials in a given family of characteristic polynomials is Hurwitz i.e., all their roots lie in the open left-half plane. By FIT it can prove a polynomial is Hurwitz from only approximate knowledge of the polynomial's phase at finitely many points along the imaginary axis. An example shows the simplicity of using the FIT synthesis to directly search for robust controller of parametrically uncertain system by way of solving a sequence of systems of linear inequalities. The systems of inequalities are solved via the projection method which is an elegantly simple technique fur solving (finite or infinite) systems of convex inequalities in an arbitrary Hilbert space. Results from example show that the controller synthesized by FIT synthesis is better than by H$\sub$$\infty$/ synthesis with parametrically uncertain system as well as satisfied the objectives for a considerably larger range of uncertainty.

• Archives of Pharmacal Research
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• v.2 no.2
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• pp.99-110
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• 1979

The crystal structure of sulfapyridine, $C_{11}H_{11}N_{3}O_{2}S$, has been determined by X-ray diffraction method. The compound crystallizees in the monoclinic space group C2/c with a = 12, 80(4), b= 11.72(4), $c= 15.36(5){\AA}, {\beta}= 94(3)^{\circ}$and Z = 8. A total of 1133 observed reflections were collected by the Weissenberg method with CuKaradiation. Structure was solved by the heavy atom method and refined by isostropic block-diagonal least-squares method to the R value of 0.14. The nitrogen in the pyridine ring of sulfapyridine is associated with an extra-annular hydrogen. The C (benzene ring) S-N-C (pyridine ring) group adopts the gauche form with a fonformational angle of $71^{\circ}$. The benzene ring are inclined at angle of $84^{\circ}.to the pyridine ring plane. Sulfapyridine shows three different hydrogen bonding in the crystal. They are two N-H...O hydrogen bonds with the distance of 2.90 and 2.98${\AA}$ respectively, and on N-H...N with the distance of 3.06 ${\AA}$.

• Journal of Power System Engineering
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• v.19 no.4
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• pp.43-49
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• 2015

This study has been analyzed and investigated the possibility for the substitution of a heat source with the application of PTC(Positive Temperature Coefficient Heater) in a food drying machine. And this experiment was conducted to measure temperatures at the upper part of the vessel and the heat sink. And the structure has the many holes plane connected with the external air in the upper part of similar volumetric vessel, and attached to the PTC heater (3sets) of total consumption electricity of 120[W] in Al radiant heat structure and the small fan (2sets) in the suitable space of the lower part. Consequently, it was found that at the most conditions of food drying test with the seven holes(5mm) under the control temperature $62^{\circ}C$, the optimum drying condition formatted and the optimum time range especially appeared from 6,500 second to 7,000 second in case of drying test on banana sample.

• Journal of Chest Surgery
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• v.22 no.1
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• pp.170-175
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• 1989

Eleven cases of pulmonary resection had been performed for pulmonary aspergilloma in the department of thoracic and cardiovascular surgery, School of Medicine, Kyungpook National University from August 1984 to July 1988. The patients were consisted of six males and five females and were evenly distributed from third decade to sixth decade. Hemoptysis was usually presenting symptom [72.2%] and the variable was the interval between symptom onset to surgical resection, which was ranged from few months to several years In the plane chest films, intracavitary fungus balls were noted in five cases [5/11] and upper lobe involvements were seven cases [7/11]. Aspergillus fumigatus was identified preoperatively in three cases among the eight cases of sputum culture. Mean preoperative FVC and FEV 1.0 values were in normal range. Eleven pulmonary resections were done by eight lobectomies, two segmentectomies and one pneumonectomy. The lesion was superimposed upon old tuberculosis in eight patients, in one upon bronchiectasis and in two upon tuberculous bronchiectasis. Five complications appeared postoperatively which included ARDS [1 case] bleeding [2 cases], persistent air leak[1 case], and dead space [1 case].