• Korean Journal of Remote Sensing
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• v.30 no.2
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• pp.315-329
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• 2014

In order to analyze the Land Surface Temperature (LST) in metropolitan area including Seoul, Landsat and MODIS land surface temperature, Automatic Weather Station (AWS) temperature, digital elevation model and landuse are used. Analysis method among the Landsat and MODIS LST and AWS temperature is basic statistics using by correlation coefficient, root-mean-square error and linear regression etc. Statistics of Landsat and MODIS LST are a correlation coefficient of 0.32 and Root Mean Squared Error (RMSE) of 4.61 K, respectively. And statistics of Landsat and MODIS LST and AWS temperature have the correlations of 0.83 and 0.96 and the RMSE of 3.28 K and 2.25 K, respectively. Landsat and MODIS LST have relatively high correlation with AWS temperature, and the slope of the linear regression function have 0.45 (Landsat) and 1.02 (MODIS), respectively. Especially, Landsat 5 has lower correlation about 0.5 or less in entire station, but Landsat 8 have a higher correlation of 0.5 or more despite of lower match point than other satellites. Landsat 7 have highly correlation of more than 0.8 in the center of Seoul. Correlation between satellite LSTs and AWS temperature with landuse (urban and rural) have 0.8 or higher. Landsat LST have correlation of 0.84 and RMSE of more than 3.1 K, while MODIS LST have correlation of more than 0.96 and RMSE of 2.6 K. Consequently, the difference between the LSTs by two satellites have due to the difference in the optical observation and detection the radiation generated by the difference in the area resolution.

• Journal of the Korean Data and Information Science Society
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• v.28 no.1
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• pp.21-28
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• 2017

This study aims to identify individual and familial factors associated with youth sexual experience by using the nationally representative sample data in South Korea. Specifically, we select 68,043 students in middle and high schools participating in the 2015 Korea Youth Risk Behavior Web-based Survey. Considering the complex survey design, we conduct a descriptive analysis and multiple logistic regression for sexual experience. The main results identify factors on sexual experience such as age, type of school, stress level, drinking, smoking, economic status, and cohabiting parents. In particular, the drinking and smoking behaviors are positively associated with sexual experience and the youth living with neither parent is more likely to have a sexual experience than those who lived two parents. In conclusion, the plan of sex education should consider the risk factors and the quality of sex education should be enhanced in order to build more appropriate sexual culture and behaviors among the youth.

• Journal of the Korean Data and Information Science Society
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• v.28 no.6
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• pp.1427-1435
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• 2017

The smart farm is a remarkable system because it utilizes information and communication technologies in agriculture to bring high productivity and excellent qualities of crops. It automatically measures the growth environment of the crops and accumulates huge amounts of environmental information in real time growing in smart farms using multi-variable control of environmental factors. The statistical model using the collected big data will be helpful for decision making in order to control optimal growth environment of crops in smart farms. Using data collected from a smart farm of tomato, we carried out multiple regression analysis to determine the relationship between yield and environmental factors and to predict yield of tomato. In this study, appropriate parameter modification was made for environmental factors considering tomato growth. Using these new factors, we fit the model and derived the optimal environmental factors that affect the yields of tomato. Based on this, we could predict the yields of tomato. It is expected that growth environment can be controlled to improve tomato productivities by using statistical model.

• Korea journal of population studies
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• v.6 no.1
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• pp.43-69
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• 1983

This study was conducted to make the life tables from specific causes of death in Korea. Both "Life tables of Korea in l978-79" and "the statistics on causes of death statistics in 1980" issued by Economic Planning Board were used as source of data for this study. Among the 58, 187 death certificates reported to the concerned authorities, 39, 801 causes were drawn for the purpose of this study. As a result, it is revealed that two thirds of men in Korea died from these 10 major causes of death. The summarized results are as follows: 1. According to recent statistics, 10 major causes of death in 1980 were shown in the order of 1) malignant neoplasms, 2) cerebrovascular disease, 3) accidents and adverse effects, 4)hypertensive disease, 5) ischaemic heart disease and heart attack, 6) chronic liver disease and cirrhosis, 7) tuberculosis, 8) pneumonia, bronchitis, emphysema and asthma, 9) suicide, 10) diabetes mellitis. 2. The major causes of death in Korea were very similar to those of developed countries such as West Germany, Denmark and Japan. This means that our pattern of death causes is almost approaching to that of developed countries. 3. Our crude death rate in 1980 was on the line of 6.6 per 1, 000 people. This is very low level, compared with 12.1 in West Germany and 10.0 in Denmark, however, our age sepcific death rate was on the verge of doubled level in each age category as to that of West Germany, Denmark and Japan. The fact tells us that our death rate is very high yet, especially in young and prime adult age, and the proportion of the aged is quite low. 4. Average ages of people died from malignant neoplasms, cerebro vascular diseases and hypertensive diseases were 63.1, 66.6, 67.3 respectively, however, that of accidents and adverse effect was only 42.5. This shows that accidents occur indifferently from age. 5. In the curve of eventual death probability, the curve of malignant neoplasms was the highest of all curves before 60 in age. However, the probability curve of eventually dying from accidents and adverse effects tends to decline with age. 6. In this study five life tables from major causes of death (four leading causes of death and of tuberculosis) were constructed for 1979. These life tables are reflecting accurately the effects of age distribution on the specific cause of death. In the surviving curje of these tables we can see that the curve of accidents is adversely related to age. While curves of neoplasms, hypertension and tuberculosis are not diminishing before 40 in age, they are going sharply downward after 50 in age.ard after 50 in age.

• Journal of the Korean Data and Information Science Society
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• v.26 no.6
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• pp.1175-1188
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• 2015

The Ministry of Education of Korea announced the university structural reform plans which reduces 160,000 of the university entrance quota during 10 years from January 2014. Because the reduction plans of entrance quota influence regional economy as well as students and universities, naive evidence of the Ministry of Education of Korea is disappointed. In this research, we forecast the total number of the university entrance exam candidate by 2032 including not only third grade high school students but also repeaters according to the 16 metropolises and provinces in Korea. We also forecast the regional university recruiting rate using the forecasts of the total number of the university entrance exam candidates. However, we can not make more realistic results because we can not apply the inter-regional movement of students to the forecast. In order to handle this limitation, we first estimated the rank of the whole 7,277 departments of all universities in Korea and assigned the quotas according to the estimated rank for each departments and then we calculated the local university recruiting rate. The estimated the university recruiting rates of 16 metropolises and provinces can provide more noticeable results of characteristics and problems than that of nationwide.

• Journal of Communications and Networks
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• v.14 no.4
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• pp.374-384
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• 2012

Utilizing artificial noise (AN) is a good means to guarantee security against eavesdropping in a multi-inputmulti-output system, where the AN is designed to lie in the null space of the legitimate receiver's channel direction information (CDI). However, imperfect CDI will lead to noise leakage at the legitimate receiver and cause significant loss in the achievable secrecy rate. In this paper, we consider a delayed feedback system, and investigate the impact of delayed CDI on security by using a transmit beamforming and AN scheme. By exploiting the Gauss-Markov fading spectrum to model the feedback delay, we derive a closed-form expression of the upper bound on the secrecy rate loss, where $N_t$ = 2. For a moderate number of antennas where $N_t$ > 2, two special cases, based on the first-order statistics of the noise leakage and large number theory, are explored to approximate the respective upper bounds. In addition, to maintain a constant signal-to-interferenceplus-noise ratio degradation, we analyze the corresponding delay constraint. Furthermore, based on the obtained closed-form expression of the lower bound on the achievable secrecy rate, we investigate an optimal power allocation strategy between the information signal and the AN. The analytical and numerical results obtained based on first-order statistics can be regarded as a good approximation of the capacity that can be achieved at the legitimate receiver with a certain number of antennas, $N_t$. In addition, for a given delay, we show that optimal power allocation is not sensitive to the number of antennas in a high signal-to-noise ratio regime. The simulation results further indicate that the achievable secrecy rate with optimal power allocation can be improved significantly as compared to that with fixed power allocation. In addition, as the delay increases, the ratio of power allocated to the AN should be decreased to reduce the secrecy rate degradation.

• Journal of Digital Convergence
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• v.18 no.10
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• pp.33-39
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• 2020

In order to cope with traffic accidents efficiently, the maximum number of traffic accidents, deaths and serious injuries that can occur during the day should be presented quantitatively. In order to examine the characteristics of traffic accidents in different regions, it was divided into the Seoul metropolitan area, Chungcheong area, Gyeongbuk area, Honam area, and Gyeongnam area and was suitable for the generalized extreme value distribution (GEV). The parameters of the GEV distribution were estimated by the L-moments, and the Anderson-Darling test and the Cramer-von Mises test confirmed the suitability of the distribution. According to the analysis, the maximum number of traffic accidents that can occur once every 50 years is 401 in the Seoul metropolitan area, 168 in the South Gyeongsang region, 455 in the North Gyeongsang region, 136 in the Chungcheong region and 205 in the South Jeolla region. Compared to the Seoul metropolitan area, which has a large population and car registration, the number of traffic accidents is relatively high due to the large area, mountainous areas, and logistics movement caused by the industrial complex.

• Industry Promotion Research
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• v.9 no.2
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• pp.13-22
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• 2024

The purpose of this study is to derive passenger trends and change rates for each airline and identify directionality and synchronization phenomenon. Data by each airlines was collected from the National Statistics Forum of Statistics Korea, and we used a total of 156 monthly data from January 2011 to December 2023. In this study, the rate of change was calculated for domestic Full Service Carriers (Korean Air, Asiana Airlines) and Low Cost Carriers (Jeju Air, Jin Air, T'way, foreign airlines). As a result of the analysis, the correlation was found to be high for KOREA in that order: Asiana, Korean Air, Jeju Air, T'way, Jin Air, foreign airlines. The rate of increase was highest in that order: T'way, Jin Air, Jeju Air, foreign airlines, Asiana, Korean Air. In the Scatter analysis, Asiana and Korean Air showed a very strong synchronization with KOREA. In addition, Jeju Air, T'way, Jin Air and foreign airlines also showed the same direction toward KOREA to a certain degree. In the Box-Box Plot analysis, it was determined that each airline experienced a number of unusual sudden fluctuations due to the outbreak of COVID-19. Passengers have a wider range of choices due to the emergence of Low Cost Carriers, and as a result, expectations for airline service are increasing. Airlines will need to make appropriate environmental improvements to satisfy these needs for corporate development.

• Journal of Korea Technology Innovation Society
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• v.14 no.1
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• pp.1-21
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• 2011

Technical change and technological innovation have become major drivers of economic progress in the knowledge oriented economies where growth, productivity, and competitiveness are increasingly based on improved technologies, novel products, upgraded processes or customized services. The creation of new knowledge, modifying or improving existent knowledge, or imitation of others, has become central to economic development. New discoveries, state-of-the-art information gathering procedures, or successful problem solving routines are often at he core of these innovations. Despite the generally acknowledged importance of science in many high-tech areas of major economic relevance, there is few science-related statistics to be found in high-profile international benchmarking reports. This paper aims to provide an answer by advancing our understanding of the possibilities of indicators quantifying linkages between science and technology. Central are the concepts of innovation capability and science/technology interface, which are used to assemble a wide range of empirical studies and quantitative indicators to summarize their possibilities and limitations for producing comparative statistics. For the purpose of the study, we extracted the US patents by Korean assignees or inventors, scientific papers cited in the patents in order to analyze the characteristics of linkage of scientific knowledge flows. The review focuses on indicators dealing with flows of written or codified information, and indicators of inventiveness that capture the non-codifiable tacit knowledge dimension. General conclusions will be drawn with a view towards further developments in the foreseeable future, suggesting new avenues for the design and implementation of patent-based and inventor-based relationships between scientific research and technical development within the context of regional or national systems of innovation.

• Journal of the Korean Data and Information Science Society
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• v.26 no.6
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• pp.1397-1407
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• 2015

Individual phenotype is mostly influenced by genetic factors as well as the effects of environmental factors. Therefore, adjustment of environmental factors are needed in order to see more clearly the effects of genetic factors that we are interested in gene screening study related to Hanwoo's economic trait. The purpose of this study is to propose new statistical model that was adjusted environmental factor and identify adjustment effect in a superior gene marker screening study for producing high quality Hanwoo. First, statistical model including both genetic factor and environmental factor establishes and adjusted value of economic trait find by removing effect of environmental factor such as age, breeding farm. Finally, we identify superior gene marker combination and compare accuracy by applying MDR to data of before and after adjustment. Economic trait is used C18:1, SFA, MUFA, MS, CWT, BFT and SNP marker is used 6 markers of LPL that were identified as more excellent SNP marker than the others among 49 markers through fatty acid composition and economic trait performance test.