• Journal of Korean Society of Rural Planning
• /
• v.29 no.4
• /
• pp.175-182
• /
• 2023

The purpose of this study, the trend of renewable energy, domestic and foreign renewable energy policies, and the flow of the legal system related to renewable energy location were identified, and a location analysis using public data was studied when solar energy was located. First, renewable energy is leading to energy conversion by reducing the proportion of existing fossil fuel-centered energy sources in the global trend and increasing the proportion of renewable energy, an eco-friendly energy source, and changing the institutional and market structure. Second, large-scale solar energy power plants are installed and operated in rural areas where there is no change in insolation and land prices are cheaper than in urban areas where there are many changes in insolation due to surrounding high-rise buildings and street trees. Third, if a preliminary location review is conducted using public data at this time, it will be easy to identify the optimal location for area and size calculation. Fourth, the solar energy location functional area was studied in area A, and the total area of the target area was 624.5km², with 392.7km² and 62.9% of the avoidance area where solar power cannot be located.

• East Asian Economic Review
• /
• v.27 no.3
• /
• pp.179-211
• /
• 2023

This paper investigates the relationship between the spread of COVID-19 and time preference. In contrast to previous studies that compared time preferences before and during the pandemic, this study estimates time preferences during the COVID-19 period using eight surveys conducted over two years. Additionally, a regression analysis was conducted on the number of new COVID-19 cases and the time elapsed since the outbreak, with estimated time preference as the dependent variable. Despite a small sample size, statistically significant results were obtained, showing that as the number of new cases increased, time preference also increased. However, this effect diminished over time and disappeared by the end of 2021 in Japan. This may be due to the public's growing familiarity with the risks of COVID-19 and the availability of vaccines and treatments. Despite a significant increase in new cases in 2022, time preference was lower than immediately after the outbreak, and this was reflected in private investments. Immediately after the outbreak of COVID-19, private investments decreased by 12% compared to the previous year, but the investments are returning in 2022 despite the surge in the number of cases. The trend of time preference explains the trend of Japanese private investments very well.

• Journal of Preventive Medicine and Public Health
• /
• v.57 no.5
• /
• pp.421-434
• /
• 2024

Objectives: Schizophrenia is an organic disease and a severe mental disorder with a relatively high risk of relapse. The rising rate of schizophrenia relapse has motivated researchers and academics to innovate and develop interventions aimed at relapse prevention. This bibliometric study sought to examine the publication trends in schizophrenia relapse prevention from 1973 to 2023, assess the contribution of international collaborations across various journals, identify the most influential authors and articles, and forecast future developments in this field. Methods: The study included 683 articles obtained from the Scopus database, analyzed using VOSviewer software, and visualized with Tableau. Results: Reports of schizophrenia relapse prevention strategies have increased significantly over the last 3 decades. However, fluctuations persist, as evidenced by the annual number of publications ranging from 25 to 40 within the past 5 years. Nevertheless, this increasing trend underscores the sustained interest in this area of research. Regarding contribution size, the United States produced the largest volume of publications on this subject. John M. Kane authored the most articles, while Stefan Leucht exhibited the highest h-index. Frequently used keywords in this field include "relapse AND schizophrenia" AND "prevention." Conclusions: These results represent an important reference for determining the current state of research on schizophrenia relapse prevention and future research directions.

• Journal of Preventive Medicine and Public Health
• /
• v.43 no.1
• /
• pp.1-8
• /
• 2010

Objectives: This study was performed to investigate if organochlorine pesticides (OCPs) were associated with metabolic syndrome and insulin resistance among non-diabetes. Methods: Among subjects who participated in a community-based health survey, 50 non-diabetic subjects with metabolic syndrome and 50 normal controls were selected. Insulin resistance was measured by the homeostasis model assessment (HOMA-IR). Eight OCPs were selected. Results: After adjusting for confounders except for body mass index (BMI), beta-hexachlorocyclohexane ($\beta$-HCH) and heptachlor epoxide were positively associated with metabolic syndrome. Odds ratios across tertiles of $\beta$-HCH and heptachlor epoxide were 1.0, 3.2 and 4.4, and 1.0, 4.0 and 6.0, respectively (p for trend = 0.01 and <0.01). After additional adjustment for body mass index (BMI), heptachlor epoxide still showed an increasing trend with adjusted odds ratios of 1.0, 4.1, and 4.6 (p for trend = 0.10). When the five components of metabolic syndrome (with the definition of high fasting glucose ($\geq$ 100 mg/dL) were separately analyzed, all components were positively, but not significantly, associated with heptachlor epoxide. As the serum concentration of heptachlor epoxide increased, HOMA-IR increased significantly in subjects with metabolic syndrome even after adjusting for BMI (p value <0.05 and <0.01). Conclusions: Despite the small sample size, this study suggests that the background exposure to some OCPs may be associated with metabolic syndrome.

• Journal of the Korean Data and Information Science Society
• /
• v.20 no.6
• /
• pp.1103-1118
• /
• 2009

When we wish to estimate the mean or total of a finite population, the numbering of the population units is of importance. In this paper, we have proposed two methods for estimating the mean or total of a population having a linear trend, for the case when the reciprocal of the sampling fraction is an even number and the sample size is an odd number. The first method involves drawing a sample by using a method which is a generalization of Singh et al's (1968) modified systematic sampling, and using interpolation in determining the estimator. The second method involves selecting a sample by modified systematic sampling, and estimating the population parameters by the regression estimation method. Under the criterion of the expected mean square error based on Cochran's (1946) infinite superpopulation model, the proposed methods have been compared with existing methods. We have also made a comparison between the two proposed methods.

• Structural Engineering and Mechanics
• /
• v.66 no.6
• /
• pp.677-691
• /
• 2018

Reliability assessment of complex structures using simulation methods is time-consuming. Thus, surrogate models are usually employed to reduce computational cost. AK-MCS is a surrogate-based Active learning method combining Kriging and Monte-Carlo Simulation for structural reliability analysis. This paper proposes three modifications of the AK-MCS method to reduce the number of calls to the performance function. The first modification is related to the definition of an initial Design of Experiments (DoE). In the original AK-MCS method, an initial DoE is created by a random selection of samples among the Monte Carlo population. Therefore, samples in the failure region have fewer chances to be selected, because a small number of samples are usually located in the failure region compared to the safe region. The proposed method in this paper is based on a uniform selection of samples in the predefined domain, so more samples may be selected from the failure region. Another important parameter in the AK-MCS method is the size of the initial DoE. The algorithm may not predict the exact limit state surface with an insufficient number of initial samples. Thus, the second modification of the AK-MCS method is proposed to overcome this problem. The third modification is relevant to the type of regression trend in the AK-MCS method. The original AK-MCS method uses an ordinary Kriging model, so the regression part of Kriging model is an unknown constant value. In this paper, the effect of regression trend in the AK-MCS method is investigated for a benchmark problem, and it is shown that the appropriate choice of regression type could reduce the number of calls to the performance function. A stepwise approach is also presented to select a suitable trend of the Kriging model. The numerical results show the effectiveness of the proposed modifications.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.17 no.3
• /
• pp.3815-3832
• /
• 1975

This study was made to investigate various engineering properties of earth materials resulting from their changes in density and moisture content. The results obtained in this study are summarized as follows: 1. The finner the grain size is, the bigger the Optimum Moisture Content(OMC) is, showing a linear relationship between percent passing of NO. 200 Sieve (n) and OMC(Wo) which can be represented by the equation Wo=0.186n+8.3 2. There is a linear relationship of inverse proportion between OMC and Maximum Dry Density (MDD) which can be represented by the equation ${\gamma}$d=2.167-0.026Wo 3. There is an exponential curve relationship between void ratio (es) and MDD whose equation can be expressed ${\gamma}$d=2.67e-0.4550.9), indicating that as MDD increases, void ratio decreases. 4. The coefficent of permeability increases in proportion to decrease of the MDD and this increase trend is more obvious in coarse material than in fine material, and more obvious in cohesionless soil than in cohesive soil. 5. Even in the same density, the coefficient of permeability is smaller in wet than in dry from the Optimum Moisture Content. 6. Showing that unconfined compressive strength increases in proportion to dry density increase, in unsaturated state the compacted in dry has bigger strength value than the compacted in wet. On the other hand, in saturated state, the compacted in dry has a trend to be smaller than the compacted in wet. 7. Even in the same density, unconfined compressive strength increases in proportion to cohesion, however, when in small density and in saturated state, this relationship are rejected. 8. In unsaturated state, cohesion force is bigger in dry than in wet from OMC. In saturated state, on the other hand, it is directly praportional to density. 9. Cohesion force decreases in proportion to compaction rate decrease. And this trend is more evident in coarse matorial than in fine material. 10. Internal friction angle of soil is not influenced evidently on the changes of moisture content and compaction rate in unsaturated state, On the other hand in saturated state it is influenced density. 11. Cohesion force is directly proportional to unconfined compressive strength(qu), indicating that it has approximately 35 percent of qu in unsaturated state and approximately 70 percent of qu in saturated state.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.33 no.4
• /
• pp.209-217
• /
• 2007

Melanin plays an important role in protecting human skin from UV radiation and determines the race and skin color. Melanin is also major target for developing skin-whitening cosmeceuticals. Recently, as the market size of skin-whitening cosmeceuticals has rapidly expanded, related researches and developments are also focused on maximizing the safety and efficacy. Also, patents of skin-whitening materials have been increasing steadily for ensuring the competitive power. Patent also shows the research trend of industry and institutes. In this review, we analyze the trend of research and development based on the patent application of skin-whitening cosmeceuticals.

• The Korean Journal of Applied Statistics
• /
• v.13 no.2
• /
• pp.457-476
• /
• 2000

In this study, we have proposed a sampling method and an estimation method for efficiently estimating the mean of a population which has a linear trend. These methods involve drawing a sample by the so-called "centered balanced systematic sampling", which is an extension of systematic sampling, and then estimating the population mean with an adjusted estimator, not with the sample mean itself. We used the concept of interpolation in determining the adjusted estimator.\Ve compared the efficiency of the proposed estimator with those of the estimators from existing methods, under the expected mean square error criterion based on the infinite superpopulation model introduced by Cochran(1946). The proposed method is for use in the case when the sample size n(2 5) is an odd number and k(the reciprocal of the sampling fraction) is an even number. A good result was also obtained in an example using computer simulation. simulation.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.2
• /
• pp.791-793
• /
• 2013

Colorectal cancer is one of the most common cancers. The aim of this study is determination its trends in Kerman province and individual cities separately until year 2016. This analytical and modeling study was based of cancer registry data of Kerman University of Medical Sciences, collected during 2001-2010. Among 20,351 cancer case, 792 were colorectal cancer cases in age group 18-93 years with a mean of 59.4 and standard deviation of 15.1. By applying time series and data trends, incidences were predicted until 2016 for the province and each city, with adjustment for population size. In colorectal cases, 413 (52%) were male, and 379 (48%) were female. The annual increasing rate in Kerman province overall was and can be expected to be 6%, and in the cities of the province Rafsanjan, Bardsir, Bam, Kerman, Baft, Sirjan, Jiroft, Kahnuj and Manujan had an increasing range from 5 to 14% by the year 2016. But in Ravar, Zarand and Shahrbabak reduction in rates of at least 2% could be predicted. The time series showed that the trend of colorectal cancer in female will increase 15% and in male 7% by year 2016. Given the trend of this cancer is increasing so that resources will be consumed in the treatment of the patients, efforts shoudlbe focused on prevention and early diagnosis of the disease. Screening could have an important role leading to improved survival.