• Journal of the Korean Mathematical Society
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• v.13 no.1
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• pp.15-18
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• 1976

• Communications of the Korean Mathematical Society
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• v.12 no.2
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• pp.287-291
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• 1997

Assume $H_i : R_+ \times R_+ \to R_+ (i = 1, 2)$ are monotonically increasing (in both variables), homogeneous mapping for which $H_1(tu, tv) = t^p(H_1(u, v) (p > 0)$ and $H_2(u, v)^{t^q} (q \leq 1)$ hold for $t, u, v \geq 0$. Using an idea from the paper of Baker, Lawrence and Zorzitto [2], the superstability problems of the functional inequalities $\Vert f(x+y) - f(x)f(y) \Vert \leq H_i (\Vert x \Vert, \Vert y \Vert)$ shall be investigated.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.157-157
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• 2003

수평 전기로에서 CdIn2Te4 다결정을 용융법으로 합성하고 Bridgman법으로 tetragonal structure의 c축에 평행한 CdIn2Te4 단결정을 성장시켰다. c축에 평행한 시료의 광흡수와 광전류 spectra를 293K에서 10K까지 측정하였다. 광흡수 spectra에 의해 band gap Eg(T)는 varshni공식에 따라 계산한 결과 1.4753eV-(7.78$\times$$10^{-3}$eV/K)T$^2$/(T+2155K)임을 확인하였다. Hall 효과는 van der Pauw 방법에 의해 측정되었으며, 온도에 의존하는 운반자 농도와 이동도는 293K에서 각각 9.01$\times$$10^{16}$ /㎤, 219 $\textrm{cm}^2$/V.S였다. 광전류 스펙트럼으로부터 Hamilton matrix(Hopfield quasicubic mode)법으로 계산한 결과 crystal field splitting $\Delta$cr값이 0.2704 eV이며 spin-orbit $\Delta$so 값은 0,1465 eV임을 확인하였다. 10K일 때 광전류 봉우리들은 n=1일때 Al-, Bl-와 Cl-exciton 봉우리임을 알았다.

• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.2
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• pp.201-203
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• 2008

A field study on self trap cropping system in controlling tukra mealy bug Maconellicoccus hirsutus Green) incidence on mulberry (Morus spp.; V-1 variety; $3'{\times}3'$ spacing) gardens was undertaken in selected sericulture farmers' mulberry gardens of Pydeti village (Parigi Mandal, Anantapur District, Andhra Pradesh, India). The study was conducted for three years (2004, 2005 and 2006). Four treatments (T0; control/no treatment, T1; self trap cropping rows with 10 row interval, T2; self trap cropping rows with 10 row interval and treating these rows only with 0.5% neem oil emulsion and T3; self trap cropping rows with 10 rows intervals and treating all the mulberry rows including self trap cropping rows with 0.5% neem oil emulsion) were considered. The results indicated that the incidence increased in T0 and T1 while the same suppressed in T2 and T3. The suppression (%) of tukra incidence between T2 and T3 was not significant. Hence, T2 only was recommended to farmers as its economical viable practice. The results are discussed based on the importance of tukra, its suppression and cost of treatment.

• Communications of the Korean Mathematical Society
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• v.35 no.1
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• pp.1-12
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• 2020

A pathos block line cut-vertex graph of a tree T, written P BL_c(T), is a graph whose vertices are the blocks, cut-vertices, and paths of a pathos of T, with two vertices of P BL_c(T) adjacent whenever the corresponding blocks of T have a vertex in common or the edge lies on the corresponding path of the pathos or one corresponds to a block B_i of T and the other corresponds to a cut-vertex c_j of T such that c_j is in B_i; two distinct pathos vertices P_m and P_n of P BL_c(T) are adjacent whenever the corresponding paths of the pathos P_m(v_i, v_j) and P_n(v_k, v_l) have a common vertex. We study the properties of P BL_c(T) and present the characterization of graphs whose P BL_c(T) are planar; outerplanar; maximal outerplanar; minimally nonouterplanar; eulerian; and hamiltonian. We further show that for any tree T, the crossing number of P BL_c(T) can never be one.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.6
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• pp.244-252
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• 2004

A stoichiometric mixture of evaporating materials for $CuInSe_2$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $_CuInSe2$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (HWE) system. The source and substrate temperatures were $620^{\circ}C$ and $410^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $CuInSe_2$ single crystal thin films measured with Hall effect by van der Pauw method are $9.62\times10^{16}/\textrm{cm}^3$, 296 $\textrm{cm}^2$/Vㆍs at 293 K, respectively. The temperature dependence of the energy band gap of the $CuInSe_2$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g$(T) = 1.1851 eV -($8.99\times10^{-4} eV/K)T^2$(T + 153 K). The crystal field and the spin-orbit splitting energies for the valence band of the CuInSe$_2$ have been estimated to be 0.0087 eV and 0.2329 eV at 10 K, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the Δso definitely exists in the $\Gamma$6 states of the valence band of the $CuInSe_2$. The three photocurrent peaks observed at 10 K are ascribed to the $A_1-, B_1$-와 $C_1$-exciton peaks for n = 1.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.349-354
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• 2004

Predictive growth model of Vibrio parahaemolyticus in modified surimi-based imitation crab broth was investigated. Growth curves of V. parahaemolyticus were obtained by measuring cell concentration in culture broth under different conditions ($Initial\;cell\;level,\;1{\times}10^{2},\;1{\times}10^{3},\;and\;1{\times}10^{4}\;colony\;forming\;unit\;(CFU)/mL$; temperature, 15, 25 37, and $40^{\circ}C$; pH 6, 7, and 8) and applying them to Gompertz model. Microbial growth indicators, maximum specific growth rate (k), lag time (LT), and generation time (GT), were calculated from Gompertz model. Maximum specific growth rate (k) of V. parahaemolyticus increased with increasing temperature, reaching maximum rate at $37^{\circ}C$. LT and GT were also the shortest at $37^{\circ}C$. pH and initial cell number did not influence k, LT, and GT values significantly (p>0.05). Polynomial model, $k=a{\cdot}\exp(-0.5{\cdot}((T-T_{max}/b)^{2}+((pH-pH_{max)/c^{2}))$, and square root model, ${\sqrt{k}\;0.06(T-9.55)[1-\exp(0.07(T-49.98))]$, were developed to express combination effects of temperature and pH under each initial cell number using Gauss-Newton Algorism of Sigma plot 7.0 (SPSS Inc.). Relative coefficients between experimental k and k Predicted by polynomial model were 0.966, 0.979, and 0.965, respectively, at initial cell numbers of $1{\times}10^{2},\;1{\times}10^{3},\;and\;1{\times}10^{4}CFU/mL$, while that between experimental k and k Predicted by square root model was 0.977. Results revealed growth of V. parahaemolyticus was mainly affected by temperature, and square root model showing effect of temperature was more credible than polynomial model for prediction of V. parahaemolyticus growth.

• Tuberculosis and Respiratory Diseases
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• v.46 no.6
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• pp.803-810
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• 1999

Background : The patient's work of breathing(WOBp) during assisted ventilation may vary according to many factors including ventilatory demand of the patients and applied ventilatory setting by the physician. Pressure-controlled ventilation(PCV) which delivers gas with decelerating flow may better meet patients' demand to improve patient-ventilator synchrony compared with volume-controlled ventilation(VCV) with constant flow. This study was conducted to compare the difference in WOBp in two assisted modes of ventilation, PCV and VCV with constant flow. Methods : Ten patients with respiratory failure were included in this study. Initially, the patients were placed on VCV with constant flow at low tidal volume($V_{T,\;LOW}$)(6-8 ml/kg) or high tidal volume($V_{T,\;HIGH}$)(10-12 ml/kg). After a 15 minute stabilization period, VCV with constant flow was switched to PCV and pressure was adjusted to maintain the same tidal volume($V_T$) received on VCV. Other ventilator settings were kept constant. Before changing the ventilatory mode, WOBp, $V_T$, minute ventilation($V_E$), respiratory rate(RR), peak airway pressure (Ppeak), peak inspiratory flow rate(PIFR) and pressure-time product(PTP) were measured. Results : The mean $V_E$ and RR were not different between PCV and VCV during the study period. The Ppeak was significantly lower in PCV than in VCV during $V_{T,\;HIGH}$. HIGH ventilation(p<0.05). PIFR was significantly higher in PCV than in VCV at both $V_T$ (p<0.05). During $V_{T,\;LOW}$ ventilation, WOBp and PTP in PCV($0.80{\pm}0.37\;J/min$, $164.5{\pm}74.4\;cmH_2O.S$) were significantly lower than in VCV($1.06{\pm}0.39J/mm$, $256.4{\pm}107.5\;cmH_2O.S$)(p<0.05). During $V_{T,\;HIGH}$ ventilation, WOBp and PTP in PCV($0.33{\pm}0.14\;J/min$, $65.7{\pm}26.3\;cmH_2O.S$) were also significantly lower than in VCV($0.40{\pm}0.14\;J/min$, $83.4{\pm}35.1\;cmH_2O.S$)(p<0.05). Conclusion : During assisted ventilation, PCV with decelerating flow was more effective in reducing WOBp than VCV with constant flow. But since individual variability was shown, further studies are needed to confirm these results.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.4
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• pp.67-74
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• 2018

Thermoelectric thin film modules were fabricated by electroplating p-type $Sb_2Te_3$and n-type $Bi_2Te_3$ thin film legs with the same thickness of $20{\mu}m$ and different diameters of $100{\mu}m$, $300{\mu}m$, and $500{\mu}m$, respectively. The output voltage and output power of thin film modules were measured and compared as a function of the leg diameter. The modules processed with thin film legs of $100{\mu}m$, $300{\mu}m$, and $500{\mu}m$-diameter exhibited open circuit voltages of 365 mV at ${\Delta}T=36.7K$, 142 mV at ${\Delta}T=37.5K$, and 53 mV at ${\Delta}T=36.1K$, respectively. Maximum output powers of $845{\mu}W$ at ${\Delta}T=36.7K$, $631{\mu}W$ at ${\Delta}T=37.5K$, and $276{\mu}W$ at ${\Delta}T=36.1K$ were obtained for the modules fabricated with the thin film legs of $100{\mu}m$, $300{\mu}m$, and $500{\mu}m$-diameter, respectively.

• The Korean Journal of Ceramics
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• v.4 no.1
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• pp.37-42
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• 1998

The barrier heights and carrier densities of ZnO varistors with various compositions were estimated using C-V, J-V and $\rho$-T relations. The barrier heights obtained from C-V and J-V plots were 0.73~5.98 eV and 0.25~2.70 eV, respectively. The carrier densities estimated from C-V plots were ~$10^{18}cm^{-3}$. Acceptable values of the barrier heights and the carrier densities were obtained from $\rho$-1/T curves and the capacitances at zero bias; 0.6~0.8 eV for the barrier heights and ~$10^{17}cm^{-3}$ for carrier densities. Addition of cobalt increased the barrier height and the carrier density, while chromium slightly lowered both of them.