• Bulletin of the Korean Chemical Society
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• v.3 no.2
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• pp.37-44
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• 1982

In this work we have studied the multilayer stepwise adsorption of gases on solid adsorbents based on the previously developed theory. It is shown that stepwise adsorption isotherms emerge from our theory if an ad hoc adsorption regarding the degree of occupation for each successive layer is abolished and the effect of lateral intermolecular interactions among adsorbate molecules is included. In addition to these the effect of vertical interactions has also been taken into consideration. It seems that the vertical interaction plays a role in deciding the shape and the position of steps in resulting isotherms. It is evident from this research that it is the lateral interaction that is responsible for stepwise adsorption as long as the adsorbent surface is uniform and temperature is sufficiently low.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.2B
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• pp.125-136
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• 2002

It is very important to acquire the synchronization in a intercell asynchronous WCDMA system, and it is carried out through the three-step cell search process. The cell search can operate in a stepwise parallel manner, where each step works in pipelined operation, to reduce the cell search time. In case that the execution time is set to be the same in each step, excessive accumulations will be caused in both step 1 and step 3, because step 2 should take at least one frame for its processing. In general, the effect of post-detection integration becomes saturated as the number of the accumulations increases. Therefore, the stepwise parallel scheme does not give much enhancement. In this paper, the performance of the stepwise parallel processing for cell search in WCDMA system is analyzed over Rayleigh fading channels. Through the analysis, the effect of cell search parameters such as the number of accumulations in each step and the power ratio allocated among channels is investigated. In addition, the performance of the stepwise parallel cell search is improved by adjusting the execution time appropriately for each step and is compared with that of the conventional stepwise serial processing.

• KSBB Journal
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• v.14 no.6
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• pp.639-642
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• 1999

Optimization of the chitosanoligosaccharide production was studied with chitosanase. The optimum conditions for the enzymic reaction have been determined. Enzyme stability was maintained above 90% after 6 days at pH 5.0. The optimum initial reaction rate was appeared in 1.0% of chitosan solution. The production yield of chitosanoligosaccharides was over at 0.4%~2.0% of chitosan. At 4.0% of chitosan solution, however, the production yield was decreased to 64.6%. To increase the yield, stepwise addition of substrate into the reactor was investigated. In this case, the yield was increased from 64.6% to 83.2% and the final concentrations of chitosanoligosaccharide was 12.26 mg/mL. By TLC analysis, most of the chitosanoligosaccharides produced were 3-5 mers.

• PNF and Movement
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• v.16 no.3
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• pp.307-315
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• 2018

Purpose: The purpose of this study was to demonstrate the effects of a stepwise proprioceptive neuromuscular facilitation (PNF) pattern therapy in weightbearing positions on the balance and walking functions of a patient with subacute stroke. Methods: The patient was a 78-year-old man with right post-stroke hemiparesis who had decreased balance and gait function. During the baseline and withdrawal phases, no intervention was applied; however, in the intervention phase, the patient received a stepwise PNF pattern therapy in weight-bearing positions. Results: During the intervention phase, the LOS improved by 296.51% (from $2482.13mm^2$ to $626mm^2$), and walking speed improved by 18.70% (from 0.75 m/s to 0.64 m/s). The LOS and 10MWT values appeared to be clinically significantly improved after the intervention. In addition, the scores of the BBS and ABC scales improved by 100% (from 36 points to 18 points) and 56.52% (from 720 points to 460 points), respectively. Conclusion: These findings suggest that a stepwise PNF pattern therapy may be helpful in enhancing the balance and walking function of a patient with subacute stroke. Further studies are required to validate the results of this study.

• Asia-Pacific Journal of Atmospheric Sciences
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• v.54 no.4
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• pp.611-622
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• 2018

Observed climate data are processed under the assumption that their time series are stationary, as in multi-step temperature and precipitation prediction, which usually leads to low prediction accuracy. If a climate system model is based on a single prediction model, the prediction results contain significant uncertainty. In order to overcome this drawback, this study uses a method that integrates ensemble prediction and a stepwise regression model based on a mean-valued generation function. In addition, it utilizes empirical mode decomposition (EMD), which is a new method of handling time series. First, a non-stationary time series is decomposed into a series of intrinsic mode functions (IMFs), which are stationary and multi-scale. Then, a different prediction model is constructed for each component of the IMF using numerical ensemble prediction combined with stepwise regression analysis. Finally, the results are fit to a linear regression model, and a short-term climate prediction system is established using the Visual Studio development platform. The model is validated using temperature data from February 1957 to 2005 from 88 weather stations in Guangxi, China. The results show that compared to single-model prediction methods, the EMD and ensemble prediction model is more effective for forecasting climate change and abrupt climate shifts when using historical data for multi-step prediction.

• Journal of Korean Society for Quality Management
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• v.48 no.1
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• pp.51-68
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• 2020

Purpose: The primary objective of this research is to develop the optimal operating conditions as well as their associated design spaces for a Cryogenic Submerged Arc Welding(SAW) process by improving its quality and productivity simultaneously. Methods: In order to investigate functional relationships among quality characteristics and their associated control factors of an SAW process, a stepwise design of experiment(DoE) method is proposed in this paper. Based on the DoE results, not only a multi-dimensional design space but also a safe operating space and normal acceptable range(NAR) by integrating statistical confidence intervals were demonstrated. In addition, the optimal operating conditions within the proposed NAR can be obtained by a robust optimal design method. Results: This study provides a customized stepwise DoE method (i.e., a sequential set of DoE such as a factorial design and a central composite design) for Cryogenic SAW process and its statistical analysis results. DoE results can then provide both the main and interaction effects of input control factors and the functional relationships between the input factors and their associated output responses. Maximizing both the product quality with high impact strength and the productivity with minimum processing times simultaneously in a case study, we proposed a design space which can provide both acceptable productivity and quality levels and NARs of input control factors. In order to confirm the optimal factor settings and the proposed NARs, validation experiments were performed. Conclusion: This research may provide significant contributions and applications to many SAW problems by preparing a standardization of the functional relationship between the input factors and their associated output response. Moreover, the proposed design space based on DoE and NAR methods can simultaneously consider a number of quality characteristics including tradeoff between productivity and quality levels.

• Journal of Korean Academy of Nursing
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• v.31 no.4
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• pp.561-570
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• 2001

Purpose: This study was conducted to detect the correlations and the main factors influencing depression, life satisfaction, burden, defenition of suffering, meaning of life, and suffering. Method: The samples were composed of 160 cancer patients who were or outpatients of four hospitals in Seoul. The reliability of the 6 instruments was tested with Cronbach's alpha which ranged from .62 to .90. The data was analyzed using a SAS program for descriptive statistics, Pearson correlation coefficients, and stepwise multiple regression. Results: The results were as follows: 1. The scores on the suffering scale ranged from 132 to 40 with a mean of 87.3 (SD 17.5). 2. There were significant correlations between all the predictive variables and even the amounts of suffering (r=.27-.84, p〈.05). 3. Stepwise multiple regression analysis showed that depression was the main predictor of suffering, and accounted for 71.6% of the variance. In addition burden accounted for 4.6% of the variance in suffering. The two variables combined to account for 76.2% of the variance in suffering. Conclusion: In conclusion and depression, burden were identified as important variables in explaining the suffering of patients with cancer.

• Journal of Korea Multimedia Society
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• v.25 no.5
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• pp.670-675
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• 2022

This study proposes an improved binarization method to improve image recognition rate. The research goal is to minimize the information loss that occurs during the binarization process, and to transform the object of the original image that cannot be determined through the transformation process into an image that can be judged. The proposed method uses a stepwise segmentation method of an image and divides blocks using prime numbers. Also, within one block, a trapezoidal type of fuzzy is applied. The fuzzy trapezoid is binarized by dividing the brightness histogram area into three parts according to the degree of membership. As a result of the experiment, information loss was minimized in general images. In addition, it was found that the converted binarized image expressed the object better than the original image in the special image in which the brightness region was tilted to one side.

• The Korean Journal of Applied Statistics
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• v.10 no.1
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• pp.137-149
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• 1997

In this paper we propose a logdensity estimation based on a Fourier expansion. The basis functions consisting of trigonometric functions are determinded by stepwise addition and deletion and the Bayes Information Criterion, where the maximum likelihood method is used to estimate the parameters. Numericla examples using real data and simulated data are provided to show the performance of proposed method.

• YAKHAK HOEJI
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• v.37 no.6
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• pp.555-560
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• 1993

Methyl 3-[(phenylsulfonyl)methyl]-1, 4, 8-trimethoxy-2-naphthoate(7) preparad by 3 steps was condensed with 5-ethyl-2-cyclohexen-1-one(8) to afford the teracyclic aromatic ring system compound 10, which was stepwise converted into the precursor of 11-Deoxy-$\beta$-rhodomycinone by means of various functional groups transformation.