• Korean Journal of Optics and Photonics
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• v.6 no.2
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• pp.165-171
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• 1995

Infrared-Radio frequency double resonance (IRRFDR) and Infrared-Microwave double resonance (IRMWDR) spectroscopy have been used to probe a level of A symmetry for $CD_{3}$OH. Double resonance spectra of $CD_{3}$OH have been investigated over the range of 940 to 1020 $cm ^{-1}$ . Twenty K-type doublet transitions have been observed in both the radio frequency region, which covers 50 MHz to 1 GHz, and the microwave region, which covers 8 GHz to 12 GHz. The results propose new assignments of infrared (IR) absorption transitions and far-infrared (FIR) laser emission lines. These involve torsional excited levels and CO stretch states. Measurements of the A state splitting have permitted the determination of the asymmetry splitting parameters $S^{o}$(n, K) and $^{co}$ (n, K) for (n, K)=(0.3) and (1.3)

• 한국전산유체공학회:학술대회논문집
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• 1997.10a
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• pp.99-105
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• 1997

A finite-difference method based on conservative supra characteristic method type upwind flux difference splitting has been developed to study the nonequilibrium chemically reacting inviscid flow. For nonequilibrium air, NS-1 species equations were strongly coupled with flowfield equations through convection and species production terms. Inviscid nonequilibrium chemically reacting air mixture flows over Blunt-body were solved to demonstrate the capability of the current method. At low altitude flight conditions the nonequilibrium air models predicted almost the same temperature, density and pressure behind the shock as equilibrium flow: however, at high altitudes they showed substantial differences due to nonequilibrium chemistry effect. The new nonequilibrium chemically reacting upwind flux difference splitting mettled can be extended to viscous flow and multi-dimensional flow conditions.

• Computers and Concrete
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• v.3 no.2_3
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• pp.91-102
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• 2006

To place concrete overlays has become a standard application in the strengthening and rehabilitation of concrete structures such as bridges, tunnels, parking decks and industrial buildings. In general, connectors are used to ensure a monolithic behavior of the two concrete layers. Within the framework of the development of a new connector wedge splitting tests and shear tests were performed, in addition nonlinear finite element analyses were applied to investigate the load transfer behavior of the connectors for different prototypes. The numerical simulation results were compared to experimental data. The computed load-displacement curve demonstrates good correspondence with the curves obtained in the experiments, and the experimental crack patterns are reasonably simulated by the computed crack propagation. Both numerical and experimental investigations on the wedge splitting test and on the shear test served as basis for the development of new type of connectors.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.49-51
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• 2003

This test data informs to compare components from different manufactured coupler type. On the point of reliability, less than 1x8 output branching number, fuse type coupler was more stable than PLC type coupler. But more than 1x8 output branching number, PLC type coupler was more stable. This test data showed critical branching point, on the point of reliability.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.04a
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• pp.19-24
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• 1994

Four types of horizontal joint were tested to investigate the difference with regards to the compressive behavior and strength. These include wedge-type joints (i)with and (ii)without transverse reinforcement against splitting failure of the panel concrete, and wedge-type joints (iii)with different widths of joint concrete (6cm vs 8cm) and (iv)closed platform joint. It was shown that the compressive strength of wedge-type joint is about 10% higher than that of closed-type (platform) joint. But the effect of transverse reinforcement and joint concrete widths on the strength of the joints turned out be negligible. Also, the moduli of elasticity in panel and joint are compared and the equivalent moduli of the whole wall are derived.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.1
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• pp.9-15
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• 2013

This paper presents a uniform analytical model by energy method and Fourier series expansion to analyze detent force in uneven magnetic field for permanent magnet linear synchronous motor (PMLSM). The model reveals that detent force in long-primary type is mainly influenced by non-ideal distribution of permanent magnet magnetic motive force, while nounified air-gap permeance makes a great impact on detent force of short-primary type. Hence, magnetic field similarity of motor design techniques referring rotary counterpart are adopted. For long-primary type novel method of splitting edge magnets is proposed to reduce end effects force, and optimal widths of edge tooth in short-primary type also verify the effectiveness of magnetic field similarity. The experimental results validate finite element analysis results.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.2
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• pp.447-457
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• 1995

The subjects of this study consisted of 75 patients with 83 condylar fractures, who were admitted to Chonbuk National University Hospital from Jan. 1988 to Oct. 1995. The purpose of this study was to compare the imagings of conventional radiograms with those of computed tomograms and to aid in the diagnosis of condylar fractures. Also the author evaluated the usefulness of 3-dimensional reconstructive imaging in condylar fractures. The obtained results were as follows: 1. The condylar fractures were observed mainly between 2nd and 4th decades, but there was no significant difference of incidence between decades. The incidence of condyalr fractures by fracture site was subcondyalr(44.6％), condylar head(36.1％), condylar neck(19.3％) in orders. 12 of 30 condylar head fractures were sagittal splitting fractures. 2. According to the relationship of condylar head to articular fossa, the incidence of condylar fractures was higher in Type II and Type m. And the incidence of subcondylar fractures was higher in Type I classified by Mclennan. But there was no significant difference of incidence between Types. 3. The more the fracture fragments were displaced, the easier the fracture patterns were detected in conventional radiograms. The computed tomograms were also useful in the diagnosis of sagittal splitting fractures which were displaced mesially. 4. The 3-dimensional reconstructive imaging were useful in the evaluation of the fracture patterns, but they were not useful when the size of fragment and the degree of displacement were small.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.9
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• pp.2944-2952
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• 1996

In this paper the CSCM type upwind flux difference splitting Navier-Stokes method has been applied to study the ARL-SL19 transoni $c^ersonic compressor cascade flow. First, the general characteristics of baseline cascade flow were analyzed. At freestream Mach n.1.612 and exit/inlet pressure ratio 2.15, the results from current laminar flow were compared well in suction surface with the experiment; however, not well in pressure surface. Second, numerical study of the transoni $c^ersonic compressor cascade flow demonstrated the effectiveness of a passive control by the various size cavities. A cavity under the shock foot point at the suction surface of the blades was used as a passive control. The passive control of shock-boundary layer interaction by a cavity reduced total pressure losses. The effect of cavity length and depth was studied. The total pressure loss was reduced by about 10% and the isentropic efficiency was improved slightly. The effect of cavity depth in current study(d/l = 0.05, 0.02) was not found strong. Further adequate turbulence modeling and TVD schemes would help to capture the shock more accurately and increase the effectiveness of the current shock-boundary layer interaction study using upwind flux difference splitting computational methods.thods.

• Korean Journal of Materials Research
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• v.32 no.2
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• pp.98-106
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• 2022

Metal-organic frameworks (MOFs) are widely used in various fields because they make it easy to control porous structures according to combinations of metal ions and organic linkers. In addition, ZIF (zeolitic imidazolate framework), a type of MOF, is made up of transition metal ions such as Co²⁺ or Zn²⁺ and linkers such as imidazole or imidazole derivatives. ZIF-67, composed of Co²⁺ and 2-methyl imidazole, exhibits both chemical stability and catalytic activity. Recently, due to increasing need for energy technology and carbon-neutral policies, catalysis applications have attracted tremendous research attention. Moreover, demand is increasing for material development in the electrocatalytic water splitting and metal-air battery fields; there is also a need for bifunctional catalysts capable of both oxidation/reduction reactions. This review summarizes recent progress of bifunctional catalysts for electrocatalytic water splitting and metal-air batteries using ZIF-67. In particular, the field is classified into areas of thermal decomposition, introduction of heterogeneous elements, and complex formation with carbon-based materials or polyacrylonitrile. This review also focuses on synthetic methods and performance evaluation.

• Geomechanics and Engineering
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• v.24 no.1
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• pp.81-89
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• 2021

Uniaxial compression tests were conducted on sandstone-CGFB composite samples with different interface angles, and their strength, acoustic emission (AE), and failure characteristics were investigated. Three macro-failure patterns were identified: the splitting failure accompanied by local spalling failure in CGFB (Type-I), the mixed failure with small sliding failure along with the interface and Type-I failure (Type-II), and the sliding failure along with the interface (Type-III). With an increase of interface angle β measured horizontally, the macro-failure pattern changed from Type-I to Type-II, and then to Type-III, and the uniaxial compressive strength and elastic modulus generally decreased. Due to the small sliding failure along with the interface in the composite sample with β of 45°, AE events underwent fluctuations in peak values at the later post-peak failure stage. The composite samples with β of 60° occurred Type-III failure before the completion of initial compaction stage, and the post-peak stress-time curve initially exhibited a slow decrease, followed by a steep linear drop with peaks in AE events.