• Environmental Engineering Research
• /
• v.20 no.3
• /
• pp.260-267
• /
• 2015

The $PM_{10}$, $SO_2$ and $NO_2$ mass concentrations were obtained over five years from monitoring stations across Nanchong, a southwest city in China. Changes in urban air quality over time, as well as the factors influencing that change, were evaluated based on air pollutant concentrations, the Air Pollution Index (API), and the Comprehensive Pollution Index (P). The results showed that the total annual mean $PM_{10}$, $SO_2$ and $NO_2$ concentrations over the five years studied were $61.1{\pm}1.1$, $45.0{\pm}3.9$ and $34.9{\pm}4.9{\mu}g{\cdot}m^{-3}$, respectively. The annual mean concentrations displayed a generally decreasing trend; lower than the annual mean second-level air quality limit. Meanwhile, the annual mean API values were in a small range of 52-53, the air quality levels were grade II, and P values were 1.06-1.21 less than the slight level ($P{\leq}1.31$). Total monthly mean $PM_{10}$, $SO_2$, $NO_2$ concentrations, and API and P values were consistently higher in winter and spring than during autumn and summer. The results of a correlation analysis showed that temperature and pressure were the major meteorological factors influencing pollution levels. Pollution sources included industrial coal and straw burning, automobiles exhaust and road dust, fireworks, and dust storms.

• Journal of Digital Convergence
• /
• v.18 no.5
• /
• pp.33-41
• /
• 2020

The purpose of this study was to analyze research papers related to the without disabilities university students' perceptions toward the university students with the disabilities. An open questionnaire survey was conducted on a total of 141 students. The results of this study are as follows. First, two researchers, university professors as the first author, and survey method had the most. Also topics were mostly about perception, attitude, community, and integration. Independent and intermediary variables were gender, department or major, grade, experience, and inclusive education. Second, general university students were perceived as 'great', and the words 'help' and 'need' also showed high frequencies. The results of this study suggest that the study applies various educational supports and experiences for improving the awareness of students with disabilities.

• The Journal of the Petrological Society of Korea
• /
• v.5 no.2
• /
• pp.168-187
• /
• 1996

In the study area Uanggunbong-Samgunri area), Precambrian metamorphic complex, (Taebacksan gneiss complex, Hyundong gneiss complex, and Taebacksan schist complex) had undergone three different regional metamorphisms at least before Paleozoic. The Paleozoic sediments in the study area also had undergone three different metamorphisms at least. The first is low pressure type regional metamorphism, the second is low pressure type contact metamorphism due to the intrusion of Chunyang granite, and the last is medium pressure type metamorphism caused by thrust in south of Janggunbong area. The first metamorphism formed the prevailing metamorphic zones in the Paleozoic metasediments and the metamorphic grade of the first regional metamorphism increases from the chloritoid zone, through the staurolite zone, garnet zone, staurolite+biotite zone, and to the andalusite+biotite zone. The second metamorphism affected both Pre-Cambrian and Paleozoic metasediments located close to the Chunyang granite. The effect of the contact metamorphism is restricted to the very narrow zone around the granite. The third metamorphism that produced kyanite, is restricted to the very narrow region near the thrust fault in the south of Janggunbong with an E-W trend.

• Education of Primary School Mathematics
• /
• v.22 no.4
• /
• pp.239-259
• /
• 2019

The 2015 revised mathematics curriculum specified software education as a mandatory curriculum amid a trend in which the software environment was extended to daily life due to the fourth industrial revolution. It also calls for a paradigm shift in lessons that incorporate learning and evaluation by specifying a process-oriented assessment. This study focused on addition and subtraction classes based on computational thinking skills that integrate mathematics learning and evaluation. Two fourth grade classes of elementary schools in Seoul were selected to conduct a pre- and post- test of metacognition and mathematics achievement through quantitative research. Also, a mixed study was conducted to analyze students' activities and opinions in parallel. The results of the study confirmed that the computational thinking-based classes, which incorporate mathematics learning and evaluation, had a positive effect on the metacognition of elementary school students and the improvement of their achievement scores. In addition to those identified in this study, further studies on other factors are proposed.

• Journal of Elementary Mathematics Education in Korea
• /
• v.22 no.2
• /
• pp.115-142
• /
• 2018

This research analyzed domestic researches on early algebra education which are published in six major mathematics education journals in Korea. The purpose of this work is to grasp trends of early algebra education in Korea and to draw up future tasks. From 2000 to 2017, 89 papers which are related to early algebra education published in 6 journals. The 89 papers were categorized by research period, academic journals, research topics, and research subjects. As a result, the number of researches on early algebra education in Korea has increased since 2000. Although early algebra education belongs to the field of elementary mathematics education, lots of papers were published in other math education journals than in the math education journals for elementary school mathematics. Most research focused on proportional reasoning across the algebraic content area. The majority of the research subjects were students, especially upper-grade students of elementary school. Based on the results of this study, some implications for early algebra education in Korea were suggested.

• Korean Medical Education Review
• /
• v.25 no.3
• /
• pp.243-257
• /
• 2023

This study aimed to analyze trends in research on depression among medical students in Korea and to conduct a meta-analysis to determine the average correlation coefficients between depression and related variables. In total, 38 quantitative studies (four theses and 34 journal articles) published between January 1995 and February 2023 were analyzed according to publication year, subjects, analysis methods, and measurement tools. Among them, 15 studies that provided numerical information on the relationships between depression and variables such as self-esteem, social support, grade point average (GPA), stress, and academic stress were selected for meta-analysis. The main findings of this study were as follows. First, quantitative research on depression among medical students began in earnest in 2009, and cross-sectional studies targeting first-year and second-year medical students were the most prevalent. Furthermore, the most commonly used analysis method was difference testing, and the Beck Depression Inventory was the most frequently used measurement tool. Second, the mean correlation coefficients between depression and stress, self-esteem, social support, academic stress, and GPA were 0.534, 0.532, 0.465, 0.390, and 0.102, respectively. The results for self-esteem, stress, and academic stress showed substantial heterogeneity, while those for social support and GPA showed little heterogeneity. These findings suggest that educational interventions, such as social support improvement programs, are necessary to prevent depression among medical students.

• Journal of Elementary Mathematics Education in Korea
• /
• v.12 no.2
• /
• pp.165-183
• /
• 2008

This study is to help to understand the influence of exchange writing activity in the elementary mathematics on students' mathematical communication skill. Various technical activities had been implemented during the classes and the ideas from those activities had been interpreted into writings in the final stage of the classes. Those writings, then, were distributed to other students or teachers in order to devise a teaching model for exchange writing, which is to be applied to the 3rd grade classes and to identify the influence on the in mathematical communication skill. From this study, we could get such conclusions as follows: First, there was considerable difference between experimental group practicing exchange writing and control group engaging in normal learning activities in the progress of their mathematical communication skill (group discussion), writing skill and expressivity when examining their average communication skill using t-method. Similar trend had been witnessed when self-evaluating their mathematical communication skill. Second, when it comes to the mathematical tendency, experimental group showed a higher tendency in positiveness compared to the control group. Therefore, we might conclude that the exchange writing has a positive influence on the students' mathematical tendency, especially on their curiosity or interest in teaming, willingness to study and their comprehension of its importance.

• Korean Journal of Ecology and Environment
• /
• v.33 no.1 s.89
• /
• pp.51-60
• /
• 2000

In order to understand the trend and assessment of water pollution, seasonal water quality was determined in the main river and the tributaries from midstream to downstream of the Kum River from March 1998 to June 1999. Among environmental factors, the variation of nitrogen, phosphorus and chlorophyll-a was distinctive on an aspect of increase and decrease relatively to others, and particularly the impact of inorganic N ${\cdot}$ P inflowing into the main river was observed to be more significant at the Kapchon, Mihochon and Soksongchon among the tributaries. Water quality was highly related to hydrologic factor, and it was more deteriorated when water discharge maintains for a long time below normal flow or relatively at low condition of minimum and drought flow. These phenomena were remarkablee from December to March of the next year. $NH_4$ and SRP were decreased dramatically flowing toward the lower part of the river and chl-a was increased exponentially. While, the variations of $NO_3$ and $BOD_5$ were regular from midstream to downstream and there was no significant difference between the stations. Limiting nutrient for Phytoplankton growth seemed to be P than N because the ratio of TN/TP or DIN/SRP was relatively high as 42 or 544 in the main river, respectively. The main river and tributaries were ranked to be third grade, based on the assessment of BOD as an indirect indicator of organics, but particularly Kapchon was ranked to be over fifth grade. In addition, the inflow of high N ${\cdot}$ P nutrients from tributaries including Kapchon and Mihochon seemed to be major factor of the development of water pollution of the Kum River. On the other hand, persistent bloom of phytoplankton in lower part of the river was observed. As a conclusion, management of water quality for main source of pollution is urgent.

• Korean Journal of Social Welfare
• /
• v.60 no.3
• /
• pp.31-58
• /
• 2008

This study examines applying the elderly poverty labor hypothesis and skill-biased technological change hypothesis to labor force participation rate(LFPR) of older males in Korea. These hypotheses have hardly been examined on the this group. The analysis is based on the data "Summary of economically active population($1965{\sim}2007$)", "Population projection($1965{\sim}2007$)", "Report on wage structure survey($1993{\sim}2005$)" and "Korea Labor and Income Panel Study($1998{\sim}2006$)". The method employed for this study is logistic regression. The main results from this analysis are summarized in five points. Firstly, Korean older males' LFPR have been increasing since 1965 when industrialization was expanding at full steam. This trend has been different from the decreasing trend of industrialized countries. The second finding is that poor older males' LFPR is, on the average, 5.2% higher than that of non-poor older males from 1998 to 2005. The third result is that the non-elderly man has been increasingly positioned at higher grade occupations, while the elderly man has been held at lower grade occupations. The fourth is that labor demand for highly educated workers has exceeded the increased labor supply of the group, while the demand for low educated workers has decreased far beyond the declined labor supply. As a result, college premium has increased from 139% in 1993 to 157.8% in 2005. The final main implication of this study is that the industrialization theory and modernization hypothesis still holds for the LFPR of Korean older males. However, the elderly affluence hypothesis of the LFPR of older males are hardly persuasive in explaining Korean phenomenon. Especially, we find that the elderly poverty is the main mechanism in determining the Korean LFPR in old ages. This supports the elderly poverty labor hypothesis presented in this study. Skill-biased technological change hypothesis partially explains the LFPR of older man. However, we believe that other factors; human capital specially high school education rather than university education and skill required in less skill biased occupations or the poverty; also have taken effect.

• Land and Housing Review
• /
• v.10 no.4
• /
• pp.41-50
• /
• 2019

This study was started to study the buffer zone of Daejeon metropolitan city in order to study the policy and environment for the suitability evaluation of the use of green buffer zone. The target of the study was selected as the buffer zone of western buffer, which is frequently used in the Daejeon Metropolitan City, and a preliminary index was selected to evaluate the suitability of the green buffer zone. AHP analysis was conducted to increase the reliability of the preliminary indicators and the weight was analyzed by questionnaires to experts and practitioners. In addition, based on the existing statistical data, we rebuilt the green buffer zone and investigated the current condition, and compared and analyzed the green buffer zone and the places where they did not. The results are as follow. First, unlike the statute interpretation that construction can not be done in buffered green spaces, green buffer zones have been utilized in various ways. However, the lack of advanced citizen consciousness of the residents, the responsibility of the responsible person, and the problem of the management office alone are causing problems. Second, according to the results of AHP questionnaire analysis, functional and stability among the appropriateness indexes of green buffer zone utilization were evaluated highly. Park accessibility and utilization potential also weighed somewhat, and it was judged that the epochal trend was more important in the use of green buffer zones. Third, analysis of the status of Western green buffer zones in Daejeon showed that the utilization rate was more than half. This suggests the necessity of judging the appropriateness of the application of the green buffer zone effectively due to the change of the perception of the green buffer zone of the residents. Fourth, as a result of comparing and analyzing the site where the site is used and the site where it is not, it is found that it is used within a range that does not greatly affect each index. However, as the stability has decreased, we have decided that the utilization method is most damaging to the green zone, and we should strive to improve the stability in future. Finally, the analysis of a red clay road and a red clay road sites decreased from Class I of stability to Grade II. However, the fall figure showed a difference between the 13 % drop rate of the target location and the 5% decline rate of utilization. The difference was analyzed as the difference of width of a red clay road. This can be regarded as one of the ways of damaging the green zone to the minimum extent, which is a great advantage in selecting the future utilization plan.