• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.5
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• pp.173-181
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• 2015

A stoichiometric mixture of evaporating materials for $BaIn_2S_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $BaIn_2S_4$ 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 $420^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by double crystal X-ray diffraction (DCXD). The carrier density and mobility of $BaIn_2S_4$ single crystal thin films measured from Hall effect by van der Pauw method are $6.13{\times}10^{17}cm^{-3}$ and $222cm^2/v{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $BaIn_2S_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=3.0581eV-(3.9511{\times}10^{-3}eV/K)T^2/(T+536K)$. The crystal field and the spin-orbit splitting energies for the valence band of the $BaIn_2S_4$ have been estimated to be 182.7 meV and 42.6 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $BaIn_2S_4/GaAs$ epilayer. The three photocurrent peaks observed at 10 K are ascribed to the $A_1$-, $B_1$-exciton for n = 1 and $C_{24}$-exciton peaks for n = 24.

• Management & Information Systems Review
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• v.29 no.4
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• pp.245-266
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• 2010

So far the study on college graduates has been concentrated on employment and wages. But if college graduates get a job, this study want expanding to the study of the suitability of their level to the job or the job satisfaction. For this study, structural equation model was built up to verify the influencing factors on the job suitability and job satisfaction of college graduates by using data of '2007 Graduates Occupational Mobility Survey(GOMS)'. To put it concretely, job suitability and job satisfaction were analysed based on the leading factors such as vocational value of graduates and the participation of employment supporting program in university. Analyses showed that the vocational value has a positive influence on the job suitability and the job satisfaction as well as the participation of employment support program. And the participation of employment supporting program influenced positively on the job satisfaction and the job suitability while in work. Besides we found that the job suitability has a positive impact on the job satisfaction. These confirmed that the vocational value while in school is very important and plays an important role in the job suitability and the job satisfaction with their jobs while in work. Also those who have a higher vocational value take part in the various employment supporting programs and experience the job satisfaction and the job suitability while in work. Therefore we found that the various employment supporting programs play an important role for the graduates. Accordingly, the school authorities and job centers have to strengthen the value education for the enrolled student to plant a vocational value and improve and reinforce the employment supporting program in university.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.1 s.4
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• pp.45-52
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• 2004

There are many cities installing ITS(Intelligent Transportation Systems) and running TMC(Trafnc Management Center) to improve mobility and safety of roadway transportation by providing roadway information to drivers. There are many devices in ITS which collect real-time traffic data. We can obtain many valuable traffic data from the devices. But it's impossible to avoid missing traffic data for many reasons such as roadway condition, adversary weather, communication shutdown and problems of the devices itself. We couldn't do any secondary process such as travel time forecasting and other transportation related research due to the missing data. If we use the traffic data to produce AADT and DHV, essential data in roadway planning and design, We might get skewed data that could make big loss. Therefore, He study have explored some imputation techniques such as heuristic methods, regression model, EM algorithm and time-series analysis for the missing traffic volume data using some evaluating indices such as MAPE, RMSE, and Inequality coefficient. We could get the best result from time-series model generating 5.0$\%$, 0.03 and 110 as MAPE, Inequality coefficient and RMSE, respectively. Other techniques produce a little different results, but the results were very encouraging.

• KDI Journal of Economic Policy
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• v.12 no.3
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• pp.125-151
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• 1990

This paper reviews the economic liberalization experiences of the Southern Cone countries and draws some lessons from their experiences. The Southern Cone countries-Chile, Argentina and Uruguay-followed the different sequences in liberalization. Chile implemented the fiscal reform and the following comprehensive trade reform in the beginning of liberalization, but capital controls were maintained until 1979. Argentina and Uruguay placed more emphasis on the financial reform with the goods market reformed afterwards, but the fiscal sector was never reformed in Argentina. Since the serious inflation plagued the Southern Cone countries, they combined the economic liberalization scheme with the economic stabilization programmes which are based on the monetarist model. Although economic situations in the Southern Cone countries are quite different from those of Korea, we can learn many lessons from their experiences. First, the monetary and fiscal policies should consist of strict financial discipline to bring in the stable domestic inflation. Without the domestic stabilization, the financial liberalization could disturb the domestic economy as the capital inflows in particular generate a real exchange rate appreciation. Second, the monetary approach which is based on the full purchasing power parity and perfect capital mobility make stabilization as simple as a matter of the appropriate exchange rate policy and the proper rate of domestic credit creation. The unsuccessful experiences with monetarist stabilization in the Southern Cone countries suggest that the monetarist model cannot make real exchange rate and real interest rate stable with the trade and financial reform. Third, both the theory and practice have not yet provided a precise solution on the optimal sequencing and speed of the goods and financial market. Nonetheless, it seems desirable to keep the real exchange rate and the real interest rate stable by gradually opening up the current account and then the capital account.

• IMMUNE NETWORK
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• v.3 no.1
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• pp.38-46
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• 2003

Background: Platelet-activating factor (PAF) induces nuclear factor $(NF)-{\kappa}B$ activation and angiogenesis and increases tumor growth and pulmonary tumor metastasis in vivo. The role of $NF-{\kappa}B$ activation in PAF-induced angiogenesis in a mouse model of Matrigel implantation, and in PAF-mediated pulmonary tumor metastasis were investigated. Methods: Angiogenesis using Matrigel and experimental pulmonary tumor metastasis were tested in a mouse model. Electrophoretic mobility shift assay was done for the assessment of $NF-{\kappa}B$ translocation to the nucleus. Expression of angiogenic factors, such as tumor necrosis factor $(TNF)-{\alpha}$, interleukin $(IL)-1{\alpha}$, basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF) were tested by RT-PCR and ELISA. Results: PAF induced a dose- and time-dependent angiogenic response. PAF-induced angiogenesis was significantly blocked by PAF antagonist, CV6209, and inhibitors of $NF-{\kappa}B$ expression or action, including antisense oligonucleotides to p65 subunit of $NF-{\kappa}B$ (p65 AS) and antioxidants such as ${\alpha}$-tocopherol and N-acetyl-L-cysteine. In vitro, PAF activated the transcription factor, $NF-{\kappa}B$ and induced mRNA expression of $TNF-{\alpha}$, $IL-1{\alpha}$, bFGF, VEGF, and its receptor, KDR. The PAF-induced expression of the above mentioned factors was inhibited by p65 AS or antioxidants. Also, protein synthesis of VEGF was increased by PAF and inhibited by p65 AS or antioxidants. The angiogenic effect of PAF was blocked when anti-VEGF antibodies was treated or antibodies against $TNF-{\alpha}$, $IL-1{\alpha}$, and bFGF was co-administrated, but not by antibodies against $TNF-{\alpha}$, $IL-1{\alpha}$, and bFGF each alone. PAF-augmented pulmonary tumor metastasis was inhibited by p65 AS or antioxidants. Conclusion: These data indicate that PAF increases angiogenesis and pulmonary tumor metastasis through $NF-{\kappa}B$ activation and expression of $NF-{\kappa}B$-dependent angiogenic factors.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.1
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• pp.91-105
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• 2016

Carbon Nanotube Field-Effect Transistors (CNTFETs) have been studied as candidates for post Si CMOS owing to the better electrostatic control and high mobility. To enhance the immunity against short - channel effects (SCEs), the novel channel and gate engineered architectures have been proposed to improve CNTFETs performance. This work presents a comprehensive study of the influence of channel and gate engineering on the CNTFET switching, high frequency and circuit level performance of carbon nanotube field-effect transistors (CNTFETs). At device level, the effects of channel and gate engineering on the switching and high frequency characteristics for CNTFET have been theoretically investigated by using a quantum kinetic model. This model is based on two-dimensional non-equilibrium Green's functions (NEGF) solved self - consistently with Poisson's equations. It is revealed that hetero - material - gate and lightly doped drain and source CNTFET (HMG - LDDS - CNTFET) structure can significantly reduce leakage current, enhance control ability of the gate on channel, improve the switching speed, and is more suitable for use in low power, high frequency circuits. At circuit level, using the HSPICE with look - up table(LUT) based Verilog - A models, the impact of the channel and gate engineering on basic digital circuits (inverter, static random access memory cell) have been investigated systematically. The performance parameters of circuits have been calculated and the optimum metal gate workfunction combinations of ${\Phi}_{M1}/{\Phi}_{M2}$ have been concluded in terms of power consumption, average delay, stability, energy consumption and power - delay product (PDP). In addition, we discuss and compare the CNTFET-based circuit designs of various logic gates, including ternary and binary logic. Simulation results indicate that LDDS - HMG - CNTFET circuits with ternary logic gate design have significantly better performance in comparison with other structures.

• Molecules and Cells
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• v.38 no.3
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• pp.259-266
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• 2015

The regulation of flowering time has crucial implications for plant fitness. MicroRNA156 (miR156) represses the floral transition in Arabidopsis thaliana, but the mechanisms regulating its transcription remain unclear. Here, we show that two AGAMOUS-like proteins, AGL15 and AGL18, act as positive regulators of the expression of MIR156. Small RNA northern blot analysis revealed a significant decrease in the levels of mature miR156 in agl15 agl18 double mutants, but not in the single mutants, suggesting that AGL15 and AGL18 co-regulate miR156 expression. Histochemical analysis further indicated that the double mutants showed a reduction in MIR156 promoter strength. The double mutants also showed reduced abundance of pri-miR156a and pri-miR156c, two of the primary transcripts from MIR156 genes. Electrophoretic mobility shift assays demonstrated that AGL15 directly associated with the CArG motifs in the MIR156a/c promoters. AGL18 did not show binding affinity to the CArG motifs, but pull-down and yeast two-hybrid assays showed that AGL18 forms a heterodimer with AGL15. GFP reporter assays and bimolecular fluorescence complementation (BiFC) showed that AGL15 and AGL18 co-localize in the nucleus and confirmed their in vivo interaction. Overexpression of miR156 did not affect the levels of AGL15 and AGL18 transcripts. Taking these data together, we present a model for the transcriptional regulation of MIR156. In this model, AGL15 and AGL18 may form a complex along with other proteins, and bind to the CArG motifs of the promoters of MIR156 to activate the MIR156 expression.

• Korean Journal of Environmental Agriculture
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• v.12 no.3
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• pp.209-218
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• 1993

The behaviour of insectcide ethoprophos (O-ethyl S,S-propyl phosphorodithioate) in soil was investigated. In a laboratory study, the degradation of ethoprophos in soil followed first-order reaction kinetics. The half-life of the insecticide in the soil incubated with 10, 18 and $25^{\circ}C$ was 12.4, 5.5 and 2.5 days, respectively. Arrhenius activation energy was 73.8 KJ/mole. The half-life was 46.4, 17.6 and 6.9 day in the soil with 7, 14 and 19% of soil water content, respectively. The moisture dependence B value in empirical equation was 1.67. The adsorption isotherm for ethoprophos in the soil agreed with freundlich equation. The adsorption distribution coefficient (Kd) was 0.27. In a field study prepared in autumn with undisturbed soil column in a mini-lysimeter system, ethoprophos residues were largely distributed in the top $0{\sim}2cm$ soil layer and moved down to the top 6cm soil layer. Persistence of ethoprophos in field soil was correlated with variation in weather pattern during the period of experiments. The half-life of ethoprophos treated at March and October was about 17 and 5 days, respectively. The ethoprophos woil was degraded up to 90% at 37day after the both treatment. In persistence and mobility of ethoprophos in field soil, the observed data were reasonably corresponded with predicted data by some computer model of pesticide behaviour.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.7
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• pp.504-515
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• 2012

Groundwater is widely used as drinking water supplies around the world. However, microbial contamination of groundwater is a serious environmental problem that degrades drinking water quality and poses a great threat to human health. Among the pathogenic microorganisms such as viruses, bacteria, and protozoa, viruses are not readily removed during transport through soils, having high mobility in groundwater environment due to their smaller size compared to bacteria and protozoa. Studies regarding the fate and transport of viruses in soils and aquifers are necessary to determine the vulnerability of groundwater to microbial contamination and to secure safe drinking water sources. Also, these studies provide important information to establish the regulations and policies related to public health. This review paper presented the field and laboratory studies conducted for the fate and transport of viruses in subsurface environments. Also, the paper provided the factors affecting the fate and transport of viruses, the characteristics of bacteriophages used for virus studies, and virus transport model/colloid filtration theory. Based on this review work, future researches should be performed actively to set up the viral protection zone for the protection of groundwater from viral contamination sources. Especially, the researches should be focused on the development of mathematical models to calculate the setback distance and travel time for the viral protection zone along with the accumulation of information related to the model parameters.

• Korean Journal of Construction Engineering and Management
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• v.16 no.6
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• pp.3-11
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• 2015

The current real estate market is in a state that is considerably shrink due to the recession and long-term reduction of trading. In response, the government recently announced an innovative way for the middle-class residential housing and it is taking the lead to activate the real estate market. Meanwhile, the domestic housing market is entering a transition period, including structural changes of household structure, changes from joeonse to rent increasingly. Also single-member households will rise steeply, so that makes the high demand of small houses. In addition, the domestic construction industry is interested in new technology called Modular building. The Modular construction is an off-site construction system that shorten construction period, eco-friendly building technology and mobility etc, which can be used in various field. Overall, there are two major issues of the current market, one is the change of the real estate market, and the other is the modular construction. This study will propose modular business model in the rental market through the analysis the profitability of the modular business scenarios and IRR analysis.