• The Journal of Korean society of community based occupational therapy
• /
• v.5 no.2
• /
• pp.43-55
• /
• 2015

Objective : This study was a meta-analysis of previous studies to examine the integration of related factors depression University students of Korea, and to determine the relative importance among the relevant factors based on it. Methods : 2000-2014 papers posted on the National Science and Technology Information Center (NDSL), Nurimedia (DBpia), Academic Research Information Service (RISS), Korea Research Information(KISS), provide the text of the Library of Congress were collected using the service. The Key words a 'University Student', 'Depression', 'Depression Factors' was used. Used the Down & Black level, evidence-based checklist was developed by the research (1998) (checklist) had analyzed the selected document metadata to assess the quality. Results : 47-studies selected research groups are divided into five factors(self-esteem, suicidal ideation, positive thinking, stresses, Internet and smartphone addiction). Using meta-analysis, we analyzed the effect sizes, statistical heterogeneity and publication amenities. As a result, the self-esteem of the five factors were not found heterogeneity. Effect size is a self-esteem and suicidal ideation "large effect size", positive thinking and stress "medium effect size", internet and smart phone addiction"small effect size". Conclusion : Self-esteem and suicidal ideation are among the factors associated with depression in University students of Korea was found that the most relevant. It identified the factors associated with depression in college students, and could utilized as basis for the prevention of depression.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.4D
• /
• pp.351-360
• /
• 2010

In 2010, the number of registered vehicles reached almost at 17.48 millions in Korea. This dramatic increase of vehicles influenced to increase the number of traffic accidents which is one of the serious social problems and also to soar the personal and economic losses in Korea. Through this research, an enhanced intersection hazard prediction model by combining Genetic Algorithm and Artificial Neural Network will be developed in order to obtain the important data for developing the countermeasures of traffic accidents and eventually to reduce the traffic accidents in Korea. Firstly, this research has investigated the influencing factors of road geometric features on the traffic volume of each approaching for the intersections where traffic accidents and congestions frequently take place and, a linear regression model of traffic accidents and traffic conflicts were developed by examining the relationship between traffic accidents and traffic conflicts through the statistical significance tests. Secondly, this research also developed an intersection hazard prediction model by combining Genetic Algorithm and Artificial Neural Network through applying the intersection traffic volume, the road geometric features and the specific variables of traffic conflicts. Lastly, this research found out that the developed model is better than the existed forecasting models in terms of the reliability and accuracy by comparing the actual number of traffic accidents and the predicted number of accidents from the developed model. In conclusion, it is expect that the cost/effectiveness of any traffic safety improvement projects can be maximized if this developed intersection hazard prediction model by combining Genetic Algorithm and Artificial Neural Network use practically at field in the future.

• Journal of Educational Research in Mathematics
• /
• v.21 no.4
• /
• pp.327-344
• /
• 2011

This study is the first step for us toward improving high school students' capability of statistical inferences, such as obtaining and interpreting the confidence interval on the population mean that is currently learned in high school. We suggest 5 underlying concepts of 'discretion of contingency and inevitability', 'discretion of induction and deduction', 'likelihood principle', 'variability of a statistic' and 'statistical model', those are necessary to appreciate statistical inferences as a reliable arguing tools in spite of its occasional erroneous conclusions. We assume those 5 concepts above are to be gradually developing in their school periods and Korean mathematics textbooks of grades 1-12 were analyzed. Followings were found. For the right choice of solving methodology of the given problem, no elementary textbook but a few high school textbooks describe its difference between the contingent circumstance and the inevitable one. Formal definitions of population and sample are not introduced until high school grades, so that the developments of critical thoughts on the reliability of inductive reasoning could not be observed. On the contrary of it, strong emphasis lies on the calculation stuff of the sample data without any inference on the population prospective based upon the sample. Instead of the representative properties of a random sample, more emphasis lies on how to get a random sample. As a result of it, the fact that 'the random variability of the value of a statistic which is calculated from the sample ought to be inherited from the randomness of the sample' could neither be noticed nor be explained as well. No comparative descriptions on the statistical inferences against the mathematical(deductive) reasoning were found. Few explanations on the likelihood principle and its probabilistic applications in accordance with students' cognitive developmental growth were found. It was hard to find the explanation of a random variability of statistics and on the existence of its sampling distribution. It is worthwhile to explain it because, nevertheless obtaining the sampling distribution of a particular statistic, like a sample mean, is a very difficult job, mere noticing its existence may cause a drastic change of understanding in a statistical inference.

• Journal of Korean Society of Transportation
• /
• v.27 no.6
• /
• pp.69-77
• /
• 2009

The maximum and mean acceleration rates of vehicles estimated from the stopping conditions at signalized intersections provided an important clue to analyze traffic accident investigation when there was a dispute about legal liability such as first entering vehicle at the intersection, etc. This paper provided the maximum and mean acceleration rates of vehicles reflecting current traffic conditions in Korea through field studies. The mean acceleration rates of vehicles at stopline were measured up to 50m at the intervals of 5m. Results showed that the mean acceleration rate for bus was found to be $1.011^m/s^2{\sim}1.314^m/s^2$(0.1g~0.13g), and for passenger car was $1.548^m/s^2{\sim}1.818^m/s^2$(0.16g~0.19g). Statistical test results indicated that the observed differences from vehicle types and vehicle positions were statistically significant for the all ranges tested. It is expected that the accuracy of accident investigation practice will be improved by applying the acceleration rate values presented in this paper.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.12 no.6
• /
• pp.116-126
• /
• 2013

Weather factor to affect driver's driving environment are due to changes in weather conditions is caused rainfall, snowfall, fog etc and the reducing of road capacity and because deteriorating weather could be affect the headway and vehicle speed and the decrease in lane caused by an accident occurs that was analyzed that bad weather occur congestion greater than on the clear day. Bad weather to reduce of the driver's visibility was analysed the sensitive to changes in travel speed and traffic accident to appears high characteristics according to weather conditions on the expressway(higher speed) than general road. As a result, visibility have been determined to be important factor in changes of the highway traffic flow characteristics. Therefore, in this study, we selected traffic volume and travle speed that have a major impact on high-speed expressway basic segments as importance effect factor and we selected to subject of analysis among the Metropolitan Expressway that it could be obtained certain level of traffic volume data and we studied the changing of expressway traffic flow due to change visibility after the collecting of meteorological and traffic data. In order to perform this study, data collection and analysis methods were established through the existing literature and we had selected level of visibility of the expressway and we had performed the statistical verification. Finally, we had calculated the rate of change of expressway traffic flow characteristics due to visibility and we had come up with a way to apply at capacity and service level analysis.

• The Journal of the Korea Contents Association
• /
• v.19 no.7
• /
• pp.402-411
• /
• 2019

The purpose of this study is to determine critical assessments and core competencies, and to determine the competence and discipline of self-assessment. We surveyed 511 students who graduated from 12 universities. Self-efficacy 24 items were measured on a 5-point scale, 8 core competencies and 52 detailed competencies were self - assessed from 0 to a maximum of 10 points. The higher the score, the higher the self - evaluation competency level. Statistical analysis was performed using SPSS 20.0 Ver., And a statistical significance level of 0.05 was considered. The self - evaluation competency level was the highest at 6.7 points in the clinical dentistry area, and the lowest at the evidence - based decision area of 5.7 points. Self-regulation was found to be positively related to the self-evaluation core competence level among self-efficacy sub-factors. As the students' self-efficacy affects subjective academic achievement and self-evaluation, it is necessary to develop and apply relevant programs to enhance critical thinking in curriculum, apply problem-based learning method, improve self-efficacy and leadership, It should be possible to cultivate.

• Journal of the Korea Institute of Building Construction
• /
• v.24 no.1
• /
• pp.97-108
• /
• 2024

This research delves into the escalating concerns of accidents and fatalities in the construction industry over the recent five-year period, focusing on the development of a Safety Perception Model to augment safety measures. Given the rising percentage of elderly workers and the concurrent drop in productivity within the sector, there is a pronounced need for leveraging Fourth Industrial Revolution technologies to bolster safety protocols. The study comprises an in-depth analysis of statistical data regarding construction-related fatalities, aiming to shed light on prevailing safety challenges. Central to this investigation is the formulation of a Safety Perception Model tailored for small-scale construction projects. This model facilitates the quantification of safety risks by evaluating safety grades across construction sites. Utilizing the DWM1000 module, among an array of wireless communication technologies, the model enables the real-time tracking of worker locations and the assessment of safety levels on-site. Furthermore, the deployment of a safety management system allows for the evaluation of risk levels associated with individual workers. Aggregating these data points, the Safety Climate Index(SCLI) is calculated to depict the daily, weekly, and monthly safety climate of the site, thereby offering insights into the effectiveness of implemented safety measures and identifying areas for continuous improvement. This study is anticipated to significantly contribute to the systematic enhancement of safety and the prevention of accidents on construction sites, fostering an environment of improved productivity and strengthened safety culture through the application of the Safety Perception Model.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.43 no.6
• /
• pp.785-791
• /
• 2023

Risk management is essential for preventing accidents arising from uncertainties in TBM tunnel projects, especially concerning managing the risk of TBM tunnel collapse, which can cause extensive damage from the tunnel face to the ground surface. In addition, prioritizing risks is necessary to allocate resources efficiently within time and cost constraints. Therefore, this study aimed to establish a TBM risk database through case studies of TBM accidents and determine a risk priority for TBM tunnel collapse using the Bayes theorem. The database consisted of 87 cases, dealing with three accidents and five geological sources. Applying the Bayes theorem to the database, it was found that fault zones and weak ground significantly increased the probability of tunnel collapse, while the other sources showed low correlations with collapse. Therefore, the risk priority for TBM tunnel collapse, considering geological sources, is as follows: 1) Fault zone, 2) Weak ground, 3) Mixed ground, 4) High in-situ stress, and 5) Expansive ground. In practice, the derived risk priority can serve as a valuable reference for risk management, enhancing the safety and efficiency of TBM construction. It provides guidance for developing appropriate countermeasure plans and allocating resources effectively to mitigate the risk of TBM tunnel collapse.

• Journal of Educational Research in Mathematics
• /
• v.15 no.2
• /
• pp.177-196
• /
• 2005

In the Korean curriculum, students learn the concept of sample, sampling and other concepts related to sample and sampling, when they have reached the 10th grade of high school. But before the 10th grade, they have an activity about data collection, data analysis and the formulation of conclusion. We then investigated and analyzed the informal knowledge of students before they receive formal instructions. The results enabled the identification of the maximum response rate for each question that each student agreed or disagreed with. In particular, it didn't agree with how students consider the characteristic of population in the process of sampling, and the students agreed on a sampling process without considering the characteristic of the population or the components that consist the population. It showed that 5th grade students didn't investigate the data connected with sampling, and didn't understand the validity of sample survey process. While, 6th grade students equally understood sample size, sampling process, the reliance of data acquired through sample survey that applied to the source of judgment. But in details, it revealed that student had a misconception, or stayed at a subjective judgment level. The significant point is that many high school students didn't adequately understood a sample size with sampling. Though statistics instruction has traditionally been delayed until upper secondary education, this inquiry convinced us that this delay is unnecessary.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.1
• /
• pp.195-202
• /
• 2014

The newly updated Rail Safety Act is required to build a comprehensive railway safety management system with corresponding accreditation regulations for the purpose of safe railway operations. However, such efforts would not be enough to achieve a successful safety-performance solely without being in place of an appropriate level of safety cultures in an organization. No research was taken place to propose a safety culture maturity model and its estimate procedures in Korean railway industries. The research reviews a variety of safety maturity models applied in many other industries and the process of conducting surveys in order to propose a framework of railway safety maturity estimates, with a set of railway safety elements. This research is expected to contribute in diagnosing weak areas and finding their appropriate treatment, along with in placing the railway safety certificate program from 2014.