• Journal of the Korean Chemical Society
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• v.53 no.5
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• pp.491-498
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• 2009

The critical micelle concentration (CMC) and the counter ion binding constant (B) for the mixed micellizations of DBS (sodium dodecylbenzenesulfonate) with Brij 30 (polyoxyethylene(4) lauryl ether) and Brij 35 (polyoxyethylene (23) lauryl ehter) at 25 ${^{\circ}C}$ in pure water and in aqueous solutions of n-butanol were determined as a function of $\alpha$1 (the overall mole fraction of DBS) by the use of electric conductivity method. Various thermodynamic parameters (Xi, $\gamma$i, Ci, aiM, $\beta$, and ${\Delta}H_{mix}$) were calculated and compared for each mixed surfactant system by means of the equations derived from the nonideal mixed micellar model. There sults show that the molecules of DBS interact more strongly with Brij 35 than Brij 30 and that the DBS/Brij35 mixed system has greater negative deviation from the ideal mixed micellar model than the DBS/Brij 30mixed system.

• Nuclear Engineering and Technology
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• v.49 no.1
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• pp.148-164
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• 2017

The focus on the issues surrounding spent nuclear fuel and lifetime extension of old nuclear power plants continues to grow nowadays. A transparent decision-making process to identify the best suitable nuclear fuel cycle (NFC) is considered to be the key task in the current situation. Through this study, an attempt is made to develop an equilibrium model for the NFC to calculate the material flows based on 1 TWh of electricity production, and to perform integrated multicriteria decision-making method analyses via the analytic hierarchy process technique for order of preference by similarity to ideal solution, preference ranking organization method for enrichment evaluation, and multiattribute utility theory methods. This comparative study is aimed at screening and ranking the three selected NFC options against five aspects: sustainability, environmental friendliness, economics, proliferation resistance, and technical feasibility. The selected fuel cycle options include pressurized water reactor (PWR) once-through cycle, PWR mixed oxide cycle, or pyroprocessing sodium-cooled fast reactor cycle. A sensitivity analysis was performed to prove the robustness of the results and explore the influence of criteria on the obtained ranking. As a result of the comparative analysis, the pyroprocessing sodium-cooled fast reactor cycle is determined to be the most competitive option among the NFC scenarios.

• The Korean Journal of Applied Statistics
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• v.27 no.4
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• pp.523-541
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• 2014

We apply a Bayesian estimation procedure to the analysis of roll call voting records on 2,389 bills processed during the 18th Korean National Assembly. The analysis of roll calls yields useful tools for to combining the measurement of legislative preference with the models of legislative behavior. The current Bayesian procedure is extremely exible, applicable to any legislative setting, irrespective of the extremism of the legislator's voting history or the number of roll calls available for analysis. It can be applied to any legislative settings, providing a useful solution to many statistical problems inherent in the analysis of roll call voting records. We rst estimate the ideal points of all members of the 18th National Assembly and their condence intervals. Subsequently, using the estimated ideal points, we examine the factional disparity within each major party using the estimated ideal points. Our results clearly suggest that there exists a meaningful ideological spectrum within each party. We also show how the Bayesian procedure can easily be extended to accommodate theoretically interesting theoretical models of legislative behavior. More specically, we demonstrate how the estimated posterior probabilities can be used for identifying pivotal legislators.

• Journal of Korea Water Resources Association
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• v.52 no.5
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• pp.337-347
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• 2019

This study proposes the framework to select the representative general circulation model (GCM) for climate change projection. The grid-based results of GCMs were transformed to all considered meteorological stations using inverse distance weighted (IDW) method and its results were compared to the observed precipitation. Six quantile mapping methods and random forest method were used to correct the bias between GCM's and the observation data. Thus, the empirical quantile which belongs to non-parameteric transformation method was selected as a best bias correction method by comparing the measures of performance indicators. Then, one of the multi-criteria decision techniques, TOPSIS (Technique for Order of Preference by Ideal Solution), was used to find the representative GCM using the performances of four GCMs after the bias correction using empirical quantile method. As a result, GISS-E2-R was the best and followed by MIROC5, CSIRO-Mk3-6-0, and CCSM4. Because these results are limited several GCMs, different results will be expected if more GCM data considered.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.4
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• pp.397-414
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• 2003

The performance of one-particle stochastic Lagrangian models for passive tracer dispersion are evaluated against measurements in horizontally-homogeneous neutrally-stratified atmospheric surface layer. State-of-the-technology models as well as classical Langevin models, all in class of well mixed models are numerically implemented for inter-model comparison study. Model results (far-downstream asymptotic behavior and vertical profiles of the time averaged concentrations, concentration fluxes, and concentration fluctuations) are compared with the reported measurements. The results are: 1) the far-downstream asymptotic trends of all models except Reynolds model agree well with Garger and Zhukov's measurements. 2) profiles of the average concentrations and vertical concentration fluxes by all models except Reynolds model show good agreement with Raupach and Legg's experimental data. Reynolds model produces horizontal concentration flux profiles most close to measurements, yet all other models fail severely. 3) With temporally correlated emissions, one-particle models seems to simulate fairly the concentration fluctuations induced by plume meandering, when the statistical random noises are removed from the calculated concentration fluctuations. Analytical expression for the statistical random noise of one-particle model is presented. This study finds no indication that recent models of most delicate theoretical background are superior to the simple Langevin model in accuracy and numerical performance at well.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.1
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• pp.19-28
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• 2000

The purposes of this study are two folds: a) to introduce conjoint choice model to research the choice behavior of theme park users, and b) to suggest the strategies to strengthen the competitiveness of theme parks. The major four theme parks in Seoul metropolitan areas were selected as study areas. A leading polling agency was employed to select 432 respondents by probability sampling and to conduct face-to-face interview. Both alternative generating and choice set generating fractional factorial design were conducted simultaneously to meet the necessary and sufficient conditions for calibration of the conjoint choice model. Dummy coding was used to represent the attribute levels, and the alternative-specific model was calibrated. The goodness-of-fit of the model was quite satisfactory($\rho$$^2$=0.47950), and most parameters values had to expected sign and magnitude. Car was preferred transport mode to shuttle bus for visiting theme parks ; however the most ideal attribute levels only were estimated significantly. Most attribute levels of shuttle bus were estimated significantly except the Dream Land, which is the least attractive park among study areas. Simulation results showed that the shuttle bus was a mode worth providing to switch the current car dominant visiting pattern of theme parks, which will be one the effective strategies to attract more patrons, especially for potential users adjacent to parks. Several ideals were suggested for future researches, in terms of utilization of more general utility function and new base alternative, and inclusion of more salient attributes such as constraints in the model.

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.4
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• pp.565-576
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• 2013

This study investigated 1) the effects of mountain climbing motivation on the desired mountain climbing wear benefits, and 2) the desired effects of mountain climbing wear benefits on clothing usage behavior. Data were collected via a questionnaire administered to 498 consumers who make at least one mountain climbing wear purchase for personal use. All items were evaluated on a 5-point Likert scale, and SPSS 20.0 and Amos 7.0 were used for data analysis. Confirmatory factor analysis for the research variables were performed and three factors of mountain climbing motivation (social interaction, health improvement, and mental rejuvenation), four factors of mountain climbing wear benefits sought (ostentation, ideal healthy figure, conformity, and functions), and two factors regarding clothing usage behavior (sportswear usage and daily wear usage) were identified. The results from the model test were as follows: 1) Mountain climbing motivation was found to vary depending on the mountain climbing wear benefits sought. Social interaction had a positive effect on all 4 factors of mountain climbing wear benefits sought. Health improvement was the only motivating factor for consumers who sought the benefit of functions; however, the functions benefit was not found to be a consideration for consumers who climbed for mental rejuvenation. 2) Mountain climbing wear usage was affected by mountain climbing wear benefits sought. The benefits for conformity and functions had a positive effect on sportswear usage and daily wear usage; however, the ideal healthy figure only affected daily wear usage. The twofold usage of mountain climbing wear reflects a cultural trend toward the usage of mountain climbing wear as daily wear; however, consumers show this twofold usage to conform successfully to mainstream society and not to pursue the ideal healthy figure.

• The korean journal of orthodontics
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• v.24 no.2
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• pp.479-508
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• 1994

This study was designed to investigate the reciprocal movement which was derived form application of active torque in ideal archwire by computer-aided three-dimensional finite element analysis of maxillary teeth and surrounding periodontal ligament composed of 2617 elements and 3725 nodes. Ideal archwire model was also made using the beam elements and the contact between the wire and the bracket slot was made using the gap element. In this study non-linear elastic behaviors of contact between the wire and the bracket slot were considered on. We put the active torque between the lateral and cenral incisor and between the second premolar and the first molar with/without cinch-back. The results were expressed by quantitative and visible ways. The findings of this study were as follows: 1. Reciprocal actions to active torque were complex system consisting of a combination of counter-torque, bucco-lingual linear displacement and tipping, rotation of the teeth, occluso-gingival linear displacement. 2. When active anterior crown labial torque was applied, crown labial tippings of the lateral were the greatest, and those of the central incisor was the next, Crown lingual tippings of the canine and the first premolar, mesial rotations and extrusion of the lateral and distal rotations and intrusion of the canine occurred. When anterior torque with the cinch-back was applied, amount of crown labial tippings of the lateral and central incisor were reduced. Amount of crown lingual tipping of the canine and the first premolar were increased. Mesial tippings and mesial rotations of the second molar occurred. 3. When active posterior crown lingual torque was applied, crown lingual tippings of the first moalr were the greatest, and crown labial tippings of the second premolar and the first premolar were the next, the crown lingual tipping of the second molar were a little. Mesial rotations of the second premolar occurred but those of the first premolar didn't occurred.

• Korean Journal of Social Welfare
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• v.69 no.3
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• pp.289-315
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• 2017

Debate on basic income expanded worldwide as well as in South Korea. However, the expansion of these discussion has led to vigorous arguments for and against the various claims of basic income. In order to introduce basic income in Korea, discussing on the picture of Korean welfare state which includes basic income is important. In this study, 'Ideal Model of Korean Basic Income (and Welfare State)'is discussed and theoretically constructed using fuzzy-set ideal type approach, and feasible paths in realizing Korean basic income are suggested. This study attempts to contribute to a practical discussion on taking feasible and reasonable path to realize full basic income in Korean welfare state.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11C
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• pp.1498-1509
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• 2004

In this paper, we evaluate the performance of a noncoherent OOK (On-Off Keying) UWB (Ultra Wide Band) system based on power detection with noise power calibration and noise power windowing for ubiquitous sensor network applications in typical indoor wireless channels. Utilizing noise power calibration and noise power windowing, the current noise information can be initially or adaptively provided to determine suitable detection threshold value for signal demodulation. Simulation results show that the noncoherent OOK UWB system using noise power calibration achieves good BER (Bit Error Rate) performance which is favorably comparable to that of the system using the ideal adaptive threshold, while maintaining simple receiver structure. However, despite the serious loss of the data transmission rate, the performance improvement by noise power windowing is not so remarkable. furthermore, these performance results are similarly maintained in BEE 802.15 Task Group 3a UWB indoor channel model, and it is also revealed that the BER performance can be significantly improved by increasing the pulse repetition rate.