• Journal of the Korean Chemical Society
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• v.25 no.2
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• pp.61-66
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• 1981

A method for calculation of the contribution of $\pi$ bonding molecular orbitals to the dipole moments for octahedral [M(III)$A_3B_3$] type complexes has been developed [M(III) = Ti(III), V(III), Cr(III), Fe(III) or Co(III); A = O or N; B = N, S or Cl]. The contribution of ${\pi}$ bonding molecular orbitals to the dipole moments is found to be smaller than that of ${\sigma}$ bonding molecular orbitals but this contribution may not be negligible even for chelate complexes in which delocalization of ${\pi}$ electron is assumed. The calculated dipole moments (u = $u_{\sigma}$ + $u_{\pi}$) are closer to the experimental values than those for the case where only ${\sigma}$ bonds are assumed to be formed.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.2
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• pp.100-105
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• 2010

In this paper, a FM radio receiver integrated circuit has been developed based on $0.5{\mu}m$ CMOS process for Zero-Crossing FM demodulator over the 88MHz to 108MHz band. The receiver is designed with the low-IF architecture, and includes Low Noise Amplifier(LNA), Down-Conversion Mixer, Phase Locked Loop(PLL), IF LPF, and a comparator. The measured results of the LNA and Mixer show that the conversion gain of 23.2 dB, the input PldB of -14 dBm, and the noise figure of 15 dB. The measured analog block of the LPF and comparator show the voltage gain of over 89 dB, and the IF LPF can configure the passband from 600KHz to 1.3MHz with 100KHz step through the internal control register banks. The designed FM radio receiver operates at 4.5V with the total current consumption of 15.3mA, so the total power consumption is about 68.85mW. The commercial FM radio has been successfully received.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.63-71
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• 2009

In order to improve flame retardancy, the halogen free organic melamine phosphate(M-P) flame retardant was synthesized from melamine and phosphoric acid by the reaction of precipitation. The ignition test was carried out preparing hybrid flame retardant compound($H_bFRC$) consisting of organic M-P and inorganic Mg$(OH)_2$ as a flame retardant in the polyolefin resins. The flame retardancy and mechanical properties of flame retardant aluminum composite panel($H_bFRC$-ACP) were performed to investigate the possibility of the composite material, which was contained M-P, as a inner core for $H_bFRC$-ACP. For this study, the results of ignition test indicate that a char formation and drip suppressing effect, and combustion time reduced as the content of M-P increased. The limited oxygen index(LOI) values were measured 17.4vol% and 31.5vol% for LDPE only and $H_bFRC$-3(M-P content: 15wt%), respectively. And it was verified that the $H_bFRC$-3 was needed more oxygen quantity with the increase of M-P content when it combustion. Also, the results from thermogravimetric analysis were observed endothermic peak at $350^{\circ}C$ and $550^{\circ}C$, it was confirmed predominant thermal stability though the wide temperature range by the mixture of M-P and Mg$(OH)_2$. The LDPE-ACP (using only LDPE as a inner core), $35.13kW/m^2$ of heat release rate(HRR) and 13.43MJ/m2 of total heat release(THR) were measured while the $H_bFRC$-ACP, $10.44kW/m^2$ of HRR and 1.84MJ/m2 of THR were measured by results of cone calorimeter test. In case of $H_bFRC$-ACP, the average gas emission amount of CO and $CO_2$ could be decreased down to 25% and 20%, respectively, in comparison with LDPE-ACP. The mechanical properties such as tensile strength, bending strength and adhesion strength of $H_bFRC$-ACP were revealed slightly high values $54N/mm^2$, $152N/mm^2$ and 120N/25mm, respectively, compared with LDPE-ACP. It was confirmed that flame retardancy was improved with the synergy effect because of char formation by M-P and hydrolysis by Mg$(OH)_2$. The result of this study suggest that $H_bFRC$ can be applied for an adequate halogen free flame retardant composite material as a inner core for ACP.

• Journal of Korean Society of Forest Science
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• v.83 no.3
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• pp.400-409
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• 1994

To investigate the noise attenuation effects of various vegetation configurations, noise levels on 6 study sites along relatively heavy traffic roads were measured. The differences between noise level measures at 1m and 10m spots from the road range from 10 to 15dB depending upon the attributes of the vegetation. When flat grass land was set to control plot, the maximum noise attenuation at 10m spot was measured at the densely planted shrubs with 5dB difference. The areas on upward slope from the road showed the least attenuation effects. Based on the study results, an appropriate setting for low level residential area noise buffer belt would be densely planted shrubs with at least 3m width and 2m height. To be effective, 3m width soft areas covered with grasses are needed at the front and behind sides of the belt. More than 15dB of the noise level caused by the road traffic would be attenuated with the prescription.

• Journal of the Korean Home Economics Association
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• v.20 no.4
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• pp.1-12
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• 1982

This study was to investigate the changes of shape of the lower limb surface, the rate of the measurement of expansion and contraction and correlation coefficient between variables caused by hip joint and knee joint movements. The results of the investigation are as follows; 1. According to the development figure of shell when the leg was raised $45^{\circ}$forward($M_{2}$), total length of F.L shortened while B.L lengthened. This result is contarary to $M_{3}$raising the leg $15^{\circ}$ backward. In both $M_{2}$, $M_{3}$movements, the rate of expansion and contraction to the course direction was insignificant. When hip joint was bent $15^{\circ}$ with knee joint $120^{\circ}$bent ($M_{4}$) and hip joint was bent $30^{\circ}$ with knee joint $90^{\circ}$ bent($M_{5}$), upper section of back hip expanded while the front hip section contracted slightly. In the Movement of sitting on the chair($M_{6}$), abdomen, front hip section and upper thight section contracted to the wale direction remarkably while the back hip section expanded conspicuously. 2. According to the rate of expansion and contraction of skin (surface) by the somatometry. In $M_{2}$, C.F.L. upper and middle thight girth contracted and B.L, C.L, L.L expanded. This fact is contarary to M3. In M4, M5, C.F.L showed remarkable contraction and C.B.L expanded remarkably. In $M_{6}$, C.B.L contracted most of all the items measured and knee girth, F.L, L.L, C.B.L, hip girth expanded conspicuously. 3. According to the correlation coefficient between variables. In various movements, the correlation among girth items commonly showed a high or middle grade, the correlation among length items also commonly showed a low grade and that girth and length items showed a very low grade commonly. Waist girth, hip grith, F.L, B.L, L.L items showed that there were significant correlation.

• The Plant Pathology Journal
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• v.25 no.4
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• pp.361-368
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• 2009

The efficacy of the combination of Burkholderia cepacia B23 with 0.75% chitosan and 3% calcium chloride ($CaCl_2$) as a biocontrol treatment of anthracnose disease of papaya caused by Colletotrichum gloeosporioides, was evaluated during storage. The growth of B. cepacia B23 in papaya wounds and on fruit surfaces was not affected in presence of chitosan and $CaCl_2$ or combination throughout the storage period. The combination of B. cepacia B23 with chitosan-$CaCl_2$ was more effective in controlling the disease than either B. cepacia B23 or chitosan or other combination treatments both in inoculated and naturally infected fruits. Combining B. cepacia B23 with chitosan-$CaCl_2$ gave the complete control of anthracnose infection in artificially inoculated fruits stored at $14^{\circ}C$ and 95% RH for 18 days, which was similar to that obtained with fungicide $benocide^{(R)}$. Moreover, this combination offered a greater control by reducing 99% disease severity in naturally infected fruits at the end of 14 days storage at $14^{\circ}C$ and 95% RH and six days post ripening at $28\pm2^{\circ}C$, which was superior to that found with $benocide^{(R)}$ or other treatments tested. Thus, postharvest application of B. cepacia B23 with chitosan-$CaCl_2$ as enhancers represents a promising alternative to synthetic fungicides for the control of anthracnose in papaya during storage.

• Bulletin of the Korean Mathematical Society
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• v.45 no.2
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• pp.321-338
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• 2008

Let $\bar{M}$ be a smoothly bounded pseudoconvex complex manifold with a family of almost complex structures $\{L^{\tau}\}_{{\tau}{\in}I}$, $0{\in}I$, which extend smoothly up to bM, the boundary of M, and assume that there is ${\lambda}{\in}C^{\infty}$(bM) which is strictly subharmonic with respect to the structure $L^0|_{bM}$ in any direction where the Levi-form vanishes on bM. We obtain explicit estimates for the $\bar{\partial}$-Neumann problem in Sobolev spaces both in space and parameter variables. Also we get a similar result when $\bar{M}$ is strongly pseudoconvex.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.421-422
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• 2008

In this paper, CMOS RF front-end circuits for an L1/L5 dual-band global positioning system (GPS)/Galileo receiver are designed in $0.13\;{\mu}m$ CMOS technology. The RF front-end circuits are composed of an RF single-to-differential low noise amplifier, an RF polyphase filter, two down-conversion mixers, two transimpedance amplifiers, a IF polyphase filter, four de-coupling capacitors. The CMOS RF front-end circuits provide gains of 43 dB and 44 dB, noise figures of 4 dB and 3 dB and consume 3.6 mW and 4.8 mW from 1.2 V supply voltage for L1 and L5, respectively.

• Communications of the Korean Mathematical Society
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• v.38 no.4
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• pp.1281-1298
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• 2023

Let (M^2m, 𝜑, g) be a B-manifold. In this paper, we introduce a new class of metric on (M^2m, 𝜑, g), obtained by a non-conformal deformation of the metric g, called a generalized Berger-type deformed metric. First we investigate the Levi-Civita connection of this metric. Secondly we characterize the Riemannian curvature, the sectional curvature and the scalar curvature. Finally, we study the proper biharmonicity of the identity map and of a curve on M with respect to a generalized Berger-type deformed metric.

• Speech Sciences
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• v.15 no.2
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• pp.119-129
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• 2008

The purpose of this study were to develop short form versions of MacArthur-Bates Communicative Development Inventories - Korean and to discuss clinical implications. Two short versions were developed: one for $9\sim17$ month-olds(including 69 words and 17 object manipulation skills) and the other for $18\sim35$ month-olds (including 128 words and 5 grammatical items). Short versions seemed to be representative of full versions and showed developmental validity. Short versions showed concomitant validity with SELSI which is a standardized test for Korean children under 37 month-olds. Norm tables for words and criteria for object manipulation and grammaticality are also provided. M-B CDI-K short versions could be used as a preliminary screening tool to identify Korean children with language impairment economically and efficiently. Cautions using short versions of M-B CDI-K are discussed.