• Journal of Korean Society on Water Environment
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• v.23 no.4
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• pp.474-481
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• 2007

With population growth, industrialization, and urbanization within the watershed, the hydrologic response changed dramatically, resulting in increases in peak flow with lesser time to peak and total runoff with shortened time of concentration. Infiltration is directly affected by initial soil moisture condition, which is a key element to determine runoff. Influence of the initial soil moisture condition on hydrograph analysis should be evaluated to assess land use change impacts on runoff and non-point source pollution characteristics. The Long-Term Hydrologic Impact Assessment (L-THIA) model has been widely used for the estimation of the direct runoff worldwide. The L-THIA model was applied to the Little Eagle Creek (LEC) watershed and Its estimated direct runoff values were compared with the BFLOW filtered direct runoff values by other researchers. The $R^2$ value Was 0.68 and the Nash-Sutcliffe coefficient value was 0.64. Also, the L-THIA estimates were compared with those separated using optimized $BFI_{max}$ value for the Eckhardt filter. The $R^2$ value and the Nash-Sutcliffe coefficient value were 0.66 and 0.63, respectively. Although these higher statistics could indicate that the L-THIA model is good in estimating the direct runoff reasonably well, the Antecedent Moisture Condition (AMC) was not adjusted in that study, which might be responsible for mismatches in peak flow between the L-THIA estimated and the measured peak values. In this study, the L-THIA model was run with AMC adjustment for direct runoff estimation. The $R^2$ value was 0.80 and the Nash-Sutcliffe coefficient value was 0.78 for the comparison of L-THIA simulated direct runoff with the filtered direct runoff. However there was 42.44% differences in the L-THIA estimated direct runoff and filtered direct runoff. This can be explained in that about 80% of the simulation period is classified as 'AMC I' condition, which caused lower CN values and lower direct runoff estimation. Thus, the coefficients of the equation to adjust CN II to CN I and CN III depending on AMC condition were modified to minimize adjustments impacts on runoff estimation. The $R^2$ and the Nash-Sutcliffe coefficient values increase, 0.80 and 0.80 respectively. The difference in the estimated and filtered direct runoff decreased from 42.44% to 7.99%. The results obtained in this study indicate the AMC needs to be considered for accurate direct runoff estimation using the L-THIA model. Also, more researches are needed for realistic adjustment of the AMC in the L-THIA model.

• Journal of Preventive Medicine and Public Health
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• v.39 no.4
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• pp.317-324
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• 2006

Objectives: This study was conducted to estimate the unbiased smoking prevalence and its standard errors among adolescents in a large city in Korea, by design-based analysis. Methods: All the students in Daegu city were stratified by grade, gender and region, and then schools as primary sampling units (PSU) were selected by probability proportional to size (PPS) sampling. One or two classes were sampled randomly from each grade, from 5th grade in elementary schools to the 3rd grade in high schools. The students anonymously completed a standardized self-administered questionnaire from October to December 2004. The total number of respondents was 8,480 in the final analysis, excluding the third graders in the general high schools because of incomplete sampling. The sampling weight was calculated for each student after post-stratification adjustment, with adjustment being made for the missing cases. The data were analyzed with Stata 8.0 with consideration of PSU, weighting and the strata variables. Results: The smoking prevalence (%) and standard errors for male students from the fifth grade in elementary schools to the second grade in high schools were $0.93{\pm}0.47,\;1.83{\pm}0.74,\;3.16{\pm}1.00,\;5.12{\pm}1.02,\;10.86{\pm}1.13,\;15.63{\pm}2.44\;and\;17.96{\pm}2.67$, and those for the female students were $0.28{\pm}0.28,\;1.17{\pm}0.73,\;3.13{\pm}0.60,\;1.45{\pm}0.58,\;3.94{\pm}0.92,\;8.75{\pm}1.86\;and\;10.04{\pm}1.70$, sequentially. Conclusions: The smoking prevalence from this study was much higher than those from the other conventional studies conducted in Korea. The point estimates and standard errors from the design-based analysis were different from those of the model-based analysis. These findings suggest the importance of design-based analysis to estimate unbiased prevalence and standard errors in complex survey data and this method is recommended to apply to future surveys for determining the smoking prevalence for specific population.

• Journal of Korean Classical Literature and Education
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• no.37
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• pp.111-149
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• 2018

This story is written by Shin Kwang-han who is a famous scholar and writer in Josun Dynasty. The most notable feature of this story is the love between a man and a dead woman. The protagonist has failed the test to be a national official for several years, because of the corruption and unfairness of the leaders of his society. He is very upset, but then changes his mind in order to become an officer. One day he meets a dead woman. He saves her life from death, and falls in love with her. Finally he marries her and attains a high position. Till now, all the aspects of this story have been extensively researched from a number of different perspectives. However the narrative structure of this story has not been discussed much. This story belongs to Jungi-novel, a kind of old story style which includes fantasy. The studies on this story have mostly been carried out to find the different features in comparison with other works of the same style. Further, we could not understand its own specific meaning structure. This study aims to find the narrative structure of this story. It was recognized by researchers that Shin's stories talk about his life and his perspective of the world. Further, I will try to show how he expresses his thoughts, emotion and life through this story. First, to obtain a satisfactory result through this study, I will find a way to resolve several problems that have become the center of the controversy. Afterward, the conflict and resolution the hero's relation to the world will be identified in every paragraph. Through these efforts, we will have a new point of the view about the narrative structure of this story and the intent expressed by the writer through its structure.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.321-327
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• 2019

Purpose: To evaluate an effect of additional firing process after sintering of monolithic zirconia crown on marginal and internal fit through three-dimensional analysis. Materials and methods: Ten monolithic zirconia crowns were fabricated using titanium abutment model. Monolithic zirconia crowns were designed, milled, and sintered as a control group, and additional firing with coloring was performed as a test group. Three dimensional analysis were performed by using triple-scan protocol, and cross-section analysis on mesio-distal and disto-lingual section was evaluated to measure marginal and internal fitness. Then, three-dimensional surface difference on between two groups was evaluated (${\alpha}=.05$). Results: There was statistically significant difference between the control group ($32.0{\pm}24.3{\mu}m$) and the test group ($17.0{\pm}10.8{\mu}m$) in the mesial axial wall (P < .02) and the control group ($60.2{\pm}24.3{\mu}m$) and the test group ($71.8{\pm}21.5{\mu}m$) in the distal axial wall (P < .01). There was no statistically significant difference at the remaining point. Conclusion: There was no statistical significance on the deviation of inner surface of crown according to firing number, and the results of both group were considered clinically acceptable.

• Bulletin of the Korean Chemical Society
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• v.7 no.5
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• pp.367-371
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• 1986

Dynamic and equilibrium properties of n-alkane chains immersed in solvent molecules have been investigated by a molecular dynamics method. The n-alkane chain is assumed to be a chain of elements (CH$_2$) interconnected by bonds having a fixed bond length and bond angle, but each bond of the chain is allowed to execute hindered internal rotation. We studied the effect of the number of the chain elements (N$_c$ = 10, 15 and 20) on the equilibrium properties of the system, e.g., the pair correlation functions between a chain element and solvent molecules, g$_{cs}$(r), and between the chain elements, g$_{cc}$(r), and the configurational properties such as the mean-square end-to-end distance < R$^2$ >, the mean-square radius of gyration < S$^2$ >, and the eigenvalues of the moment-of-inertia tensor < S$_i^2$ > / < S$^2$ > (i = 1, 2 and 3). We also studied the dynamic properties of the system, e.g., the autocorrelation function C(A;t) where A = R$^2$(t), = S$^2$(t), or = ${\vec{V}}(t)({\vec{V}}$ = velocity of the center of mass), and the diffusion coefficient D. The g$_{cs}$(r)'s are almost equal irrespective of the change of Nc while g$_{cc}$(r) becomes larger as N$_c$ increases; The MD computed configurational properties < R$^2$2 > and < S$^2$ > were found to be a little different from the values calculated from the statistical equations of < R$^2$ > and < S$^2$ >, it may be due to the fact that our model for the MD simulations includes a long-range volume effect. From the < S$_i^2$ > / < S$^2$ >, it is found that the chain molecule has a nearly spherical shape irrespective of the variation of N$_c$. For the dynamic properties we found that the C(R$^2$;t) and C(S$^2$;t) of lower N$_c$ decay faster than those of higher N$_c$, while the C($\vec V$;t) of the center of mass in the chain is weakly dependent on the N$_c$. The center of mass diffusion coefficient D$_c$ decreases as N$_c$ increases while the end point diffusion coefficient D$_e$ is nearly equal irrespective of the change of N$_c$.

• Journal of Korea Foundry Society
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• v.42 no.2
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• pp.83-93
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• 2022

Throughout this research course, we have analyzed the financial situation of more than 2,700 companies using credit evaluation disclosures from 2017 to 2019. The population was gathered based on the certification of Ppuri companies and Ppuri Expertise companies through the Korea National Ppuri Industry Center, accompanied by the NICE credit evaluation index. For the first time in Korea, we wanted to look at growth, profitability, and stability through financial analysis of the Ppuri industry. Through an indepth analysis, we identified operating income (rate), net income (rate), asset size, and debt ratio, along with three years of Ppuri company workers and total sales fluctuations, and looked at the financial structure per capita. In addition, financial status per person was compared by dividing Ppuri companies into six groups by employee size. Groups were 10 or fewer people, 11 to 20 people, 21 to 50 people, 51 to 200 people, 201-300 people, and 300 or more people; single individual companies were excluded for research convenience. Overall, the financial situation of Ppuri companies was judged to be in a very bad downturn, and financial indicators deteriorated over the course of the three years of investigation. In particular, the smaller the number of employees, the greater the financial fluctuations were and the worse the situations were. Among Ppuri companies, the casting industry, which is the technical starting point for the value chain of the industry, was found to also be in a very bad state, with continued workforce declines, total assets and sales reductions at severe levels, and operating income (rate) and net income (rate) also very poor. This is why we need a suitable and feasible policy direction, something that is difficult but must be allowed to develop.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.4
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• pp.87-94
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• 2022

This paper researched a study to find a combination of acquisition scores for 9 dart throws, which is the minimum number of dart tactile throws in 501 point dart games. The maximum score that can be obtained by throwing once in a dart game is 60 points, which can end the perfect dart game with 60 points eight times according to 60×8+21×1=501, and if you earn 21 points once, you can finish the game with 9 throws. This is called 9-dart finish. As such, only 18 and 14 studies on the combination of scores that can obtain 501 points with 9 throws are known, and no studies have been conducted applying the exhaustive search algorithm. This paper proposed a division branch-and-bound algorithm as a method of simplifying the O(2ⁿ) exponential time performance complexity of the typical branch-and-bound method of a exhaustive search method, to polynomial time complexity. The proposed method limited the level to 8, jumped to a quotient level of 501/60, and backtracked to explore only possible score combinations in the previous level. The possible score combinations of the nine perfect games found with the proposed algorithm were 90(101 cases).

• The Journal of the Acoustical Society of Korea
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• v.42 no.2
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• pp.124-132
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• 2023

When the building becomes high, the number of households increases and they are adjacent to the elevator. So, frequency of use of elevators will increase. Elevator noise is bound to increase in the future. However, there are currently no legal standards for elevator noise or measurement and evaluation methods that can clearly measure elevator noise in Korea. Although some methods for measuring elevator noise are presented in KS F ISO 16032, this standard is not a standard established for elevator noise. It is a standard that integrates the overall measurement method of building equipment and equipment, and the position of the microphone is selected by the experimenter during measurement. Elevator noise is characterized by a low sound pressure level as the noise in the mid-low frequency band is important. However, even today, complaints from residents about elevator noise are increasing. In this study, the position of the microphone that can most sensitively pick up the elevator noise when measuring the elevator noise was studied. According to the distance from the wall and the height from the floor, a total of 9 microphone positions were measured and analyzed. As a result of the experiment, it was confirmed that the elevator noise has a very high influence in the 63 Hz band. The measured value at the center point was identified as a factor that lowered the overall elevator noise level value.

• Therapeutic Science for Rehabilitation
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• v.12 no.2
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• pp.43-53
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• 2023

Objective : In this study, the rehabilitation motivation evaluation tool for stroke patients was identified, and the characteristics of the evaluation tool were analyzed to analyze the conceptual framework and characteristics used in the composition of the evaluation contents. Methods : From 2000 to May 2022, documents registered in major domestic and foreign databases (PubMed, NDSL, Medline, and EMbase) were searched and selected according to the selection and exclusion criteria. The evaluation tools used in the selected documents were analyzed, and the characteristics of this evaluation tool were analyzed. Results : A total of 30 documents were selected, and they were classified into a total of five rehabilitation motivation evaluation tools. The most widely used in Korea was the measurement tool for rehabilitation motivation for the disabled, and the most widely used overseas was the intrinsic motivation inventory. Three evaluation tools constructed the evaluation contents based on the self-determination theory, and two constructed the evaluation contents through expert agreement. The number of evaluation items and 8 to 45 items were varied, and the evaluation scale was also used in various ways from 4 to 7 point scale. Conclusion : It was possible to identify the evaluation tools mainly used for the evaluation of rehabilitation motivation, and to identify the main conceptual framework based on the development of the rehabilitation motivation evaluation tool. The results of this study are expected to be used as basic data for research on the development of rehabilitation motivation evaluation tools for stroke patients in the future.

• Journal of Environmental Health Sciences
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• v.48 no.1
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• pp.1-8
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• 2022

Objectives: The purpose of this study is to reveal the circumstances under which the cases of harm to health caused by humidifier disinfectant were neglected and show the points where the number of victims and the degree of damage could have been reduced. In addition, it attempts to describe how damage management proceeded immediately after the incident and actually exacerbated the damage. Finally, it explores the unfortunate aspects of the recent trial. By doing so, it attempts to take this as an opportunity to consider whether a tragic event such as the humidifier disinfectant incident could occur in the future. Methods: This study collected and analyzed data on chemical material characteristics related to humidifier disinfectants, data on health effect characteristics, data on related laws and regulations from the Ministry of Environment, data related to the damage investigation by the Korea Environmental Industry and Technology Institute, and current contents. Results: The lack of related systems and laws is the area where the greatest responsibility for the cause of the humidifier disinfectant disaster falls, so it is difficult for the government to escape this responsibility. Establishing a dedicated department to identify the prevalence of certain diseases within the functions of the Health Insurance Review and Assessment Service to monitor health can greatly contribute to the prevention and management of diseases through early detection and management of group outbreaks caused by harmful factors. Humidifier disinfectant damage relief should have been expanded earlier beyond HDLI (humidifier disinfectant lung injury) to include non-specific diseases such as asthma, pneumonia, and interstitial pneumonia. The scope of relief benefits should have also been expanded earlier to include the payment of disability benefits. Fortunately, with the 2020 revision of the Special Act, the conditions for estimating causal relations were eased and individual screening systems such as health impact assessment were reorganized along with the introduction of a rapid screening system. Conclusions: The management system for chemical substances in a country is clearly of paramount importance, and the ministry in charge must have a response system in case of damage to health effects. Administration that looks at the victims' situation from their point of view is needed, and technical countermeasures are required to quickly recognize the prevalence of certain diseases.