• Journal of Energy Engineering
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• v.5 no.2
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• pp.160-169
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• 1996

Parametric studies are conducted for optimizing the integration design between gas turbine compressor and air separation unit (ASU) of integrated gasification combined cycle power plant. The present study adopts the ASU of double-distillation column process, from which integration conditions with compressor such as the heat exchanger condition between air and nitrogen, the amount and the pressure of extracted air are defined and mathematically formulated. The performance variations of the compressor integrated with ASU are analyzed by combining streamline curvature method and pressure loss models, and the predicted results are compared with the performance test results of actual compressors to verify the prediction accuracy. Using the present performance prediction method, the effects of pinch-point temperature difference (PTD) in the heat exchanger, the amount and the pressure of extracted air on compressor performances are quantitatively examined. As the extraction air amount or the PTD is increased, the pressure ratio and the power consumption of compressor are increased. The compressor efficiency deteriorates as the increase of the flow rate of air extracted at higher pressure level while improving at lower pressure air extraction. Furthermore, through the characteristic curve between generalized inlet condition and efficiency of compressor, optimal integration condition is presented to maximize the compressor efficiency.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.30 no.2
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• pp.118-123
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• 2019

Background and Objectives Voice evaluation is classified into subjective tests such as auditory perception and self-measurement, and objective tests such as acoustic and aerodynamic analysis. When evaluating dysphonia, subjective and objective test results do not always match. The purpose of this study was to analyze the relationship between subjective and objective evaluation in patients with dysphonia and to identify meaningful parameters by disease. Materials and Method The total of 322 patients who visited voice clinic from May 2017 to May 2018 were included in this study. Laryngeal lesions were identified using stroboscopy. Pearson correlation test was performed to analyse correlation between subjective tests including GRBAS scale and voice handicap index, and objective tests including jitter, shimmer, noise to harmonic ratio (NHR), cepstral peak prominence (CPP), maximal phonation time (MPT), mean flow rate, and subglottic pressure. Results In vocal nodule and sulcus vocalis, among GRBAS system, grade and breathiness showed good correlation with CPP, and roughness showed good correlation with jitter or shimmer. In unilateral vocal cord paralysis (UVCP), grade and breathiness showed a very good correlation with CPP, and also good correlation with jitter, shimmer, NHR, and MPT. Also asthenia showed good correlation with CPP and MPT. Vocal polyp has a limited association with other diseases. Conclusion In patients with dysphonia, grade and breathiness showed good correlation with CPP, jitter, and shimmer, and reflect the state of voice change well especially in UVCP, CPP, and MPT.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.27 no.1
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• pp.25-29
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• 2016

Background and Objectives : The clinical reports for the treatment of vocal fold scar and sulcus vocalis are limited, also there is no best one for the treatment of them. This study is to evaluate the effect of Injection laryngoplasty (IL) for the treatment of vocal fold scar and sulcus vocalis. Materials and Methods : from January 2013 to May 2015, the Nineteen patients who were diagnosed as vocal fold scar, sulcus and atrophy, and underwent IL, were engaged in this study. Clinical information and voice parameters were analyzed by retrospective chart review. Pre and post voice parameters were compared. Results : Subgroups of diagnosis were classified into sulcus vocalis for 12 patients, vocal fold scar for 5, and atrophy for 2. IL was performed under local anesthesia through cricothyroid membrane except one patient. Atesense$^{(R)}$, Radiessess$^{(R)}$, and Rofilan$^{(R)}$ were used as injected materials in 9, 9, and 1 patients respectively. Maximal phonation time (p=0.0124), dynamic range (p=0.0028), pitch range (p=0.0141), voice handicap index (p=0.028), glottal closure (p=0.0229), and mucosal wave (p=0.0132) had significant improvement for post-IL voice assessment than Pre-IL. While GRBAS, Mean flow rate, Jitter, Shimmer, Harmony to Noise ratio didn't have improvement. Conclusion : IL is a feasible option for the treatment of glottis incompetence with normally mobile vocal folds such as sulcus vocalis and vocal fold scar.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.557-565
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• 2010

Recently, regulations on toxic compounds in aquatic environment have been strengthened in korea due to the increasing public awareness of the water quality. Typically, these regulations include introduction of emerging toxic compounds and stricter effluent limitations for the already regulated compounds. However, too strict regulations may cause excessive burden on the industry. Therefore it is also important to assess the economic impacts when the new effluent limitation guidelines are introduced. The estimation of the additional cost for the wastewater dischargers to meet the new guidelines are based on the selected treatment technology to handle the hazardous substances and the regulatory levels for effluent limitations. To explore the procedures for cost estimation in enforcing new effluent limitations, a case study was performed specially for 1,4-dichlorobenzene. The pollutants of concern are surveyed for different industrial categories and various treatment technologies. For a given pollutant, the general performances of the treatment technologies are surveyed and a representative technology is selected. For a given technology, the capital cost and annual Operation and Maintenance (O&M) cost was calculated. The calculation of baseline costs to operate ordinary treatment technologies is also important. The ratio between the cost for introducing new treatment process and the baseline cost required for conventional technology was used to evaluate the economic impact on the industry. For 1,4-dichlorobenzene, steam stripping and activated carbon processes were selected as the specific treatment technologies. The cost effects to the regulation of the compound were found to be 6.4% and 14.5% increase in capital cost and O&M cost, respectively, at the flow rate over $2,000m^3/d$ for the categories of synthetic resin and other plastics manufacturing industry. For the case of petrochemical basic compounds manufacturing industry, the cost increases were 5.8% and 12.4%, respectively. It was suggested that cost effect analysis to evaluate the economic impacts of new effluent limitations on the industry is crucial to establish more balanced and reasonable effluent limitations to manage the industrial wastewater containing emerging toxic compounds in the wastewater.

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.286-293
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• 1998

Two methods were used to enhance the adsorption capacity of activated carbons. One is to impregnate activated carbons with chemical compounds which have a good affinity for $CO_2$. The other is to activate by heat-treating after impregnation with KOH on activated carbons(AC). The chemical compounds impregnated on AC were alkali metal, alkaline earth metal, and transition metal chlorides. The adsorption capacity of $CO_2$ on AC impregnated with these metals was less than that of pure AC. These compounds have not the chemical affinity for $CO_2$ and obstruct the micropore of AC. The experiment of breakthrough for $CO_2$ on AC impregnated with KOH showed the increase of the adsorbed amount of $CO_2$ in influent gases containing water vapor. This means that KOH adsorbes $CO_2$ gas. However, the adsorbents impregnated with KOH had not the reproducibility because of the production of $K_2CO_3$ by the reaction of KOH with $CO_2$. The amount of $CO_2$ adsorbed on the heat-treated AC at $800^{\circ}C$ increased with the amount of impregnation. The adsorption capacity of $CO_2$ was the largest when the ratio of weight of KOH to AC equal to 4. The isosteric heat of adsorption was calculated by the equation of Clausius-Clapeyron form adsorption capacity data of $CO_2$ for the temperature change. In addition, the characteristics of $CO_2$ breakthrough curve were surveyed for the change of flow rate and concentration.

• Analytical Science and Technology
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• v.5 no.4
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• pp.389-399
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• 1992

Liquid Chromatographic behavior of Pd(II) in Isonitrosoethylacetoacetate lmine, $Pd(IEAA-NR)_2$ (R=H, $CH_3$, $C_2H_5$, $n-C_3H_7$, $C_6H_5-CH_2$, $n-C_4H_9$) chelates were investigated by reversed-phase HPLC on Micropak MCH-5 column using methanol/water as mobile phase. The optimum conditions for the separation of $Pd(IEAA-NR)_2$ chelates were examined with respect to the effect of the flow rate, sample solvent, mobile phase strength and column temperature. It wass found that metal chelates were properly eluted in an acceptable range of capacity factor value($0{\leq}log\;k^{\prime}{\leq}1$). The dependence of the logarithm of capacity factor(k') on the volume fraction of water in the binary mobile phase was examined. Also, the dependence of k' on the liquid-liquid extration distribution ratio($D_c$) in methanol-water/n-alkane extration system was investigated. Both kinds of dependence are linear, which susggests that the retention of the electroneutral metal chelate is largely due to the solvophobic effect. Standard adsorption enthalpy changes (${\Delta}H^{\circ}$) and standard adsorption entropy changes (${\Delta}S^{\circ}$) of Pd(II) Isonitrosoethylacetoacetate imine chelates on Micropak MCH-5 column were calculated by measuring capacity factor with changing temperature of the column.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.6
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• pp.25-40
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• 2015

Korean tourist areas are designated/managed in accordance with the Tourism Promotion Act. Since Taejongdae was designated as a tourist area in 1969, a total of 230 tourist areas have been designated/built/operated. It has been 46 years since the first tourist area was designated. According to the Tourism Area Life Cycle by Butler, it is estimated that the flow of the life cycle will be reflected in ups and downs over time. Thus, this study aimed to provide basic data for suggesting the direction of changes and development of the future tourist areas after analyzing the life cycle stage of domestic tourist areas, by applying the Tourism Area Life Cycle by Butler. The research method was based on the tourist areas by year, the number of visitors, and data of the target to derive the change transition curve, obtained by dividing the life cycle stages of the tourist areas based on the visitor rate of change. In the analysis results, more than 1/3 of domestic tourist areas are reaching the stagnation/decline stage, and tourist areas such as hot springs and seaside/beach resources show a particularly high ratio of stagnation/decline. The tourist areas that already have reached the stagnation/decline stage will need to analyze the causes for the decline, seek for resolution measures, and introduce new innovative elements. Even though the results of this study are not sufficient to be used as an absolute standard to decide the life cycle stage of domestic tourist areas, it is considered to be adequate for phenomenologically understanding the life cycle stage of Korean tourist areas. Based on this study, the causes for the stagnation/decline of tourist areas can be revealed while it can be also used as basic research to establish revitalization measures for tourist areas by introducing new innovation.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.741-746
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• 2015

Purpose: To investigate the influence of exogenous p53 upregulated modulator of apoptosis (PUMA) expression on cell proliferation and apoptosis in human non-small cell lung cancer A549 cells and transplanted tumor cell growth in nude mice. Materials and Methods: A549 cells were divided into the following groups: control, non-carrier (NC), PUMA (transfected with pCEP4-(HA) 2-PUMA plasmid), DDP ($10{\mu}g/mL$ cisplatin treatment) and PUMA+DDP (transfected with pCEP4-(HA)2-PUMA plasmid and $10{\mu}g/mL$ cisplatin treatment). The MTT method was used to detect the cell survival rate. Cell apoptosis rates were measured by flow cytometry, and PUMA, Bax and Bcl-2 protein expression levels were measured by Western blotting. Results: Compared to the control group, the PUMA, DDP and PUMA+DDP groups all had significantly decreased A549 cell proliferation (p<0.01), with the largest reduction in the PUMA+DDP group. Conversely, the apoptosis rates of the three groups were significantly increased (P<0.01), and the PUMA and DDP treatments were synergistic. Moreover, Bax protein levels significantly increased (p<0.01), while Bcl-2 protein levels significantly decreased (p<0.01). Finally, both the volume and the weights of transplanted tumors were significantly reduced (p<0.01), and the inhibition ratio of the PUMA+DDP group was significantly higher than in the single DDP or PUMA groups. Conclusions: Exogenous PUMA effectively inhibited lung cancer A549 cell proliferation and transplanted tumor growth by increasing Bax protein levels and reducing Bcl-2 protein levels.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.1
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• pp.71-78
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• 2018

Transportation is gradually changing into the era of V2X and autonomous cars. Accurate judgement of traffic conditions is an important indicator of route choice or autonomous driving. There are many ways to use probes car such as taxis, as a way to identify accurate traffic conditions. These methods may vary depending on the characteristics of the probe vehicle, and there is a problem with the cost. The V2X vehicle can solve these problems and collect traffic information in real time. If all vehicles are of V2X vehicle, these issues are expected to be resolved briefly. However, if the communication information of a V2X vehicle is represented by a traffic representative in a traffic with only V2X, the traffic information of some V2X vehicles will be able to collect traffic information. To accomplish this, a virtual network and transport were created and various scenarios were performed through SUMO simulations. It has been analyzed that 3-5 % of V2 vehicles are capable of representative the road traffic characteristics. In the future, various follow-up studies are planned.

• Journal of the Korean Ceramic Society
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• v.39 no.6
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• pp.582-588
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• 2002

IrO$_2$-RuO$_2$ films were deposited on plasma sprayed TiO$_2$ buffer layer above Ti metal by sol-gel and dip-coating method. Organic vehicle (ethyl cellulose and $\alpha$-terpineol) and glass frit were added to improve adherence of the coatings. Taguchi method and L$_{18}$ (2$^1$$\times$3$^{7}$ ) orthogonal arrays were evalvated in terms of current density to determine the optimal combination of levels of factors that best satisfy the bigger is better quality characteristic. The observed conditions were as fellows: ethyl cellulose (100 cp), drying temperature and time (17$0^{\circ}C$,20 min), heat treatment temperature and time (75$0^{\circ}C$,10 min), the weight ratio of IrO$_2$-RuO/powders to glass frit (99:5), final heat treatment time (120 min) and flow rate of air (5 sccm), respectively. ANOVA analysis suggested that the influence of the factors within $\alpha$= 0.1 was significant with a 90% confidence level.