• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.394-398
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• 2005

This study aimed to develop a novel anaerobic two-stage process converting food waste to $H_2$ and $CH_2$. The anaerobic two-stage process was devised by combining hydrogen fermentation with methane fermentation. At the high loading rate of 12.3 kg $Vs/m^3/d$, it could remove 72.5%of VS and convert $VS_{removed}$ to $H_2$ (28.2%) and $CH_4$ (69.9%) on COD basis in 8 days.

• Journal of the Korea Society of Computer and Information
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• v.26 no.9
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• pp.49-55
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• 2021

In this paper, an enhanced 2-stage vehicle license plate detection scheme using object segmentation is proposed to detect accurately the rotated license plates due to the inclined photographing angles in real-road situations. With the previous 3-stage vehicle license plate detection pipeline model, the detection accuracy is likely decreased as the license plates are declined. To resolve this problem, we propose an enhanced 2-stage model by replacing the frontal two processing stages which are for detecting vehicle area and vehicle license plate respectively in only rectangular shapes in the previous 3-stage model with one step to detect vehicle license plate in arbitrarily shapes using object segmentation. According to the comparison results in terms of the detection accuracy of the proposed 2-stage scheme and the previous 3-stage pipeline model against the rotated license plates, the accuracy of the proposed 2-stage scheme is improved by up to about 20% even though the detection process is simplified.

• Korean Journal of Chemical Engineering
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• v.35 no.11
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• pp.2150-2156
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• 2018

We suggest a systematic method for obtaining the optimal compression ratio in the multi-stage closed-loop compression process of carbon dioxide. Instead of adopting the compression ratio of 3 to 4 by convention, we propose a novel approach based on mathematical analysis and simulation. The mathematical analysis prescribes that the geometric mean is a better initial value than the existing empirical value in identifying the optimal compression ratio. In addition, the optimization problem considers the initial installation cost as well as the energy required for the operation. We find that it is best to use the fifth stage in the general closed-loop type carbon dioxide multi-stage compression process.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.288-291
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• 2006

Piercing or blanking process is widely used to manufacture most of lead frame parts, but it is difficult to analyze the real process by the actual shape through progressive dies. In this paper several stages in progressive punching are modeled by 2D and 3D configurations using $DEFORM^{TM}$ 2D/ 3D code. During the progressive stage some state variables and deformed configurations are analyzed in each model. There are three stages in the process, the deformations at each stage are cumulative. The advantages and disadvantages of these two type modeling are discussed and analyzed. The experiments are performed as a working material copper alloy through manufactured die. Computed results in load by two types are compared to experiments.

• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.610-614
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• 2004

The objective of this study was to remove organics and color in livestock wastewater using coagulation and Fenton oxidation process. After coagulation process as $1^{st}$ treatment, organics in $1^{st}$ treatment water were removed by using OH radical produced in Fenton oxidation process. Removal efficiencies of $COD_{Mn}$ and color were 87.2% and 95.7% separately. At that time, the ratio of $Fe^{2+}/H_2O_2$ was 0.8~1.0, and range of reaction pH was effective at the pH of 3.5~3.8. The Reaction time of 120min more than 60min or 90min was sufficient in Fenton process. Removal efficiency of organics was higher two- or multi-stage treatment than one-stage treatment.

• Korean Journal of Health Education and Promotion
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• v.22 no.1
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• pp.103-115
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• 2005

The Purpose of this study was to identify the process of change, decisional balance and self-efficacy corresponding to the stages of change in exercise behavior based on the Transtheoretical Model(TTM) in obese adolescents. A random sample of 517 obese adolescents was recruited in Pusan. The data were collected from June 15 to 30, 2004. The research instruments were Stages of Change for Exercise Behavior, Process of Change, Decisional Balance, and Self-Efficacy. The data were analyzed by descriptive statistics and ANOVA using SPSS WIN 10.0 program. The results of this study were as follows 1. The subjects were distributed in each stage of exercise behavior: There were 255 subjects($49.3\%$) in the contemplation stage, 131 subjects($25.3\%$) in the preparation stage, 52 subjects($10.1\%$) in the maintenance stage, 41 subjects($7.9\%$) in the action stage, and 38 subjects($7.4\%$) in the precontemplation stage. 2. Analysis of variance showed that cognitive process (F=13.57, p=.000), behavioral process(F=17.23, p=.000), decisional balance pros(F=11.95, p=.000), and self efficacy(F=12.52, p=.000) were significantly associated with the stages of exercise behavior change, but decisional balance cons(F=2.87, p=.023) was not significantly associated with the stages of exercise behavior change. This study can provide useful information for developing effective exercise behavior program considering obese adolescents' stages of change according t'.t the TTM.

• Journal of Korea Planning Association
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• v.54 no.1
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• pp.40-51
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• 2019

The ultimate aim of this study is to diagnose the process stage and look at the step change of transition process to see how the step changes. Therefore, in this study, cluster analysis was conducted by examining four types of commercial characteristics such as Retail Homogeneity, Share of Neighbourhood store, Share of chain store, and Share of cafe & Western food store. Through the cluster analysis, three types have been identified. Type1 is the first step which can explain the time before gentrification occurs and when the ratio of neighborhood facilities is the highest. Type2 is the second step that can explain boutique stage where the gentrification occurs. At this time, the ratio of Cafes & Western food restaurant increased and the proportion of neighborhood shops decreased. And Type3, third step is when the mature gentrification occurs. In the analysis of the transition period, it is necessary to monitor the change of the industry in the period from the first stage to the second stage. In the transition period from the second stage to the third stage, It is necessary to constantly monitor such factors as the increase of shops.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.107-116
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• 2013

This algorithm suggests a method in which a minimum spanning tree can be obtained fast by reducing the number of an algorithm execution. The suggested algorithm performs a select-and-delete process. In the select process, firstly, it performs Borůvka's first stage for all the vertices of a graph. Then it re-performs Borůvka's first stage for specific vertices and reduces the population of the edges. In the delete process, it deletes the maximum weight edge if any cycle occurs between the 3 edges of the edges with the reduced population. After, among the remaining edges, applying the valency concept, it gets rid of maximum weight edges. Finally, it eliminates the maximum weight edges if a cycle happens among the vertices with a big valency. The select-and-delete algorithm was applied to 9 various graphs and was evaluated its applicability. The suggested select process is believed to be the vest way to choose the edges, since it showed that it chose less number of big edges from 6 graphs, and only from 3 graphs, comparing to the number of edges that is to be performed when using MST algorithm. When applied the delete process to Kruskal algorithm, the number of performances by Kruskal was less in 6 graphs, but 1 more in each 3 graph. Also, when using the suggested delete process, 1 graph performed only the 1st stage, 5 graphs till 2nd stage, and the remaining till 3rd stage. Finally, the select-and-delete algorithm showed its least number of performances among the MST algorithms.

• Korean Journal of Health Education and Promotion
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• v.23 no.1
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• pp.63-75
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• 2006

Objective: This study was performed to identify the related factors of change affecting the stage of change, on the assumption that there are various stages of change in the exercise behavior of workers. Method: The subjects of the study consisted of 138 workers of 10 workplaces located in Daejeon City, and data collected by using questionnaires were analyzed with SPSS/WIN 11.5 program. Results: The subjects were distributed in the stage of exercise behavior change as follows: precontemplation stage(10.9%), contemplation stage(22.5%), preparation stage(41.3%), action stage(8.7%), and maintenance stage(16.7%). Of the process of change depending on the stage of exercise behavior change, the consciousness raising(F=11.50, p=.00), dramatic relief(F=2.82, p=.02) showed significant difference in the cognitive process, and the counter conditioning(F=4.56, p=.00), reinforcement management(F=4.64, p=.00), self-liberation(F=9.46, p=.00), and stimulus control(F=13.28, p=.00) showed significant difference in the behavioral process. For decision-making depending on the stage of exercise behavior change, both the pros of decision-making(F=9.23, p=.00) and the cons of decision-making(F=2.45, p=.04) showed significant difference. Self-efficacy depending on the stage of exercise behavior change showed significant difference as F=11.50, p=.00. The related factors of change affecting the stage of exercise behavior change were the pros of decision-making, the cons of decision-making, and self-efficacy including 34.1% R-square. Conclusion: In order to change the exercise behavior of workers positively, they need to be stimulated to use the cognitive and behavioral process in the process of change properly, and to be induced to make a decision positively. And also exercise programs suitable to various characteristics of each worker as well as those of workplaces to enhance self-efficacy need to be applied after being devised. Through the further longitudinal research, it is necessary to analyze the various aspects, such as groups to select, to maintain, to stop or give up the exercise, and to avoid the change, and to study how the related factors of change affect diversity like the above.

• Journal of Educational Research in Mathematics
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• v.16 no.4
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• pp.345-366
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• 2006

In this study, we investigated the methods of using the Cabri3D program for education of problem solving in school mathematics. Cabri3D is the program that can represent 3-dimensional figures and explore these in dynamic method. By using this program, we can see mathematical relations in space or mathematical properties in 3-dimensional figures vidually. We conducted classroom activity exploring Cabri3D with 15 pre-service leachers in 2006. In this process, we collected practical examples that can assist four stages of problem solving. Through the analysis of these examples, we concluded that Cabri3D is useful instrument to enhance problem solving ability and suggested it's educational usage as follows. In the stage of understanding the problem, it can be used to serve visual understanding and intuitive belief on the meaning of the problem, mathematical relations or properties in 3-dimensional figures. In the stage of devising a plan, it can be used to extend students's 2-dimensional thinking to 3-dimensional thinking by analogy. In the stage of carrying out the plan, it can be used to help the process to lead deductive thinking. In the stage of looking back at the work, it can be used to assist the process applying present work's result or method to another problem, checking the work, new problem posing.