• Title/Summary/Keyword: 지속시간 추세분석

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An iodine database establishment and iodine intake in Korean adults: Based on the 1998~2014 Korea National Health and Nutrition Examination Survey (요오드 DB 구축 및 한국 성인의 요오드 섭취 추이 분석 : 1998~2014 국민건강영양 조사 데이터를 이용하여)

  • Ko, Yu Mi;Kwon, Yong Seok;Park, Yoo Kyoung
    • Journal of Nutrition and Health
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    • v.50 no.6
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    • pp.624-644
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    • 2017
  • Purpose: This study analyzed iodine intake by establishing an iodine database of general Korean foods eaten by Korean adults based on the data from the 1998 ~ 2014 KNHANES (Korea National Health and Nutrition Examination Survey). Methods: Data on 56,818 subjects aged 19 years and older were obtained from health behavior interviews and a 24-hour dietary recall survey. Iodine intake of subjects was analyzed according to general characteristics, dietary lifestyle, food groups, and cooking method. Results: An iodine database was established for 312 food items. The mean iodine intake of Korean adults decreased from $641.6{\mu}g$ in 1998 to $236.2{\mu}g$ in 2014 per day. Iodine intake of women was higher than that of men. For age distribution, those aged 30 ~ 49 years constituted more than 39 ~ 46% of subjects by survey year. Regarding iodine intake according to dietary lifestyle, the highest iodine intake was 29.4 ~ 34.4% for lunch while that of breakfast decreased. The highest iodine contribution by food group was seaweed such as kelp, sea mustard, and laver. Conclusion: The results of this study indicate that iodine intake of Korean adults has been decreasing, and iodine intake is associated with the prevalence of thyroid disease. This study provides basic data for the estimation of iodine intake in Korean adults.

Additional CSP calculation method considering Human Error (휴먼에러를 고려한 추가 CSP 산정 방안)

  • Baek, Sung-Il;Ha, Yun-chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.1
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    • pp.759-767
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    • 2021
  • Most weapons systems that are Force Integration are expensive equipment that reflects the latest technology, and the operation and maintenance cost is increasing continuously. Factors that efficiently operate and maintain these weapon systems include maintenance plans, economic costs, and repair part requirements. Among them, predicting the repair parts requirements during the life cycle in advance is an important way to increase operation and maintenance cost efficiency and operating availability. The start of requirement analysis for repair parts is a calculation of the CSP (CSP: Concurrent Spare parts, CSP hereafter) that is distributed when the weapon system is deployed. The CSP is an essential component of achieving the operating availability during this period because the weapon system aims to successfully perform a given operation mission without resupply for an initial set period. In the present study, the CSP calculation method was analyzed, reflecting the failure rate and operating time of items, but the analyzed CSP was aimed at preparing for technical failure, but in the initial operating environment, it is limited in coping with unexpected failures caused by human error. The failure is not included in the scope of free maintenance and is a serious factor in making the weapon system inoperable during the initial operation period. To prevent the inoperable status of a weapon system, CSP that considers human error is required in the initial operating environment, and the calculation criteria and measures are proposed.

Recovery of Mass Changes in Antarctic Ice-Sheet based on the Regional Climate Model, RACMO (RACMO 기후 모델에 기반한 남극 빙상 질량 변동의 재현)

  • Eom, Jooyoung;Rim, Hyoungrea
    • Economic and Environmental Geology
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    • v.53 no.2
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    • pp.147-157
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    • 2020
  • Mass change in the Antarctic Ice Sheet(AIS) is the most important indicator of changes in Earth's climate system including global mean sea level rise that are largely affected by ongoing global warming. In this study, AIS mass variations are examined with satellite gravity data and outputs from a regional climate model. The analysis of gravity data shows that along the coastal region the Western AIS has experienced a continuous and significant ice loss while a slight increasing in the Eastern AIS during the study period (2002.08-2016.08). The temporal and spatial variations in ice mass changes are recovered by a regional climate model, but the recovered amplitudes are much smaller than those of observations. This under-estimation is remarkably resolved by modifying a base flow field for the ice discharge. The recovered estimates based on the ice-flow field can explain about 97% of the rate of mass change in observations before 2009. This implies that changes in ice flow dynamics along the coast line plays a pivotal role in regulating long-term budget of ice mass in AIS.

The Characteristics analysis of a Flux-lock Type Fault Current Limiter according to the Winding Directions for Power Grid (전력계통 적용을 위한 결선방향에 따른 자속구속형 한류기의 특성 분석)

  • Lee, Mi-Yong;Park, Jeong-Min
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.11
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    • pp.5879-5884
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    • 2013
  • With the rapid industrialization and economical development, the electricity demands of the industrial facilities and densely populated large cities are continuing to increase in Korea. The increase in the power consumption requires the extension of power facilities, but it is difficult to secure spaces for equipment installation in the limited space of urban areas. In addition, the 154 kV or 345 kV transmission systems in Korea has a short transmission distance, and are connected to one another in network structures that ensure the high reliability and stability of power supply. This structure reduces the impedance during the fault in power system, and increases the magnitude of in the short circuit fault current. The superconducting fault current limiter (SFCL) was devised to effectively address these existing problems. The SFCL is a new-concept eco-friendly protective device that ensures fast operation and recovery time for the fault current and does not need additional fault detection devices. Therefore, many studies are being conducted around the world. In this paper, based on the wiring method the initial fault current characteristics, current limiting characteristics, according to the incident angle and the change in inductance current limiting characteristics were analyzed in a multifaceted methods.

Trends and Socio-Economic Factors Impacting on Married Couples' Childlessness Among Korean Provinces : 1990~2010 (무자녀율 변화 추세 및 변화에 영향을 미치는 사회·경제적 요인에 관한 연구: 1990~2010)

  • Kim, Han-Gon
    • The Journal of the Korea Contents Association
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    • v.14 no.12
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    • pp.959-972
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    • 2014
  • This study aims to describe childlessness trends and examine the factors impacting on the childlessness of married couples among Korean provinces between 1990 and 2010. The results are as follows: There have been differences in childlessness rates among provinces and over time as well. Furthermore, social development, transportation, women's status, and economic development have statistically significant positive impacts on ASMCR. It turns out that age-specific marital childlessness rate is rather accurate measurement than general marital childlessness rate in terms of exploring the factors influencing on the childlessness among Korean provinces. Korea's government policy to aid the married couples who are suffering from in-fecundity is strongly recommended to maintain its policy and extend its subjects in order to increase married couples' fertility rate. Furthermore, campaigns to change married couples' recognition and attitudes from unfavorable against childbearing to favorable toward childbearing so that the married couples would be willing to have childbearing in terms of fertility rate increase.

Seasonal Trend of Elevation Effect on Daily Air Temperature in Korea (일별 국지기온 결정에 미치는 관측지점 표고영향의 계절변동)

  • 윤진일;최재연;안재훈
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.3 no.2
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    • pp.96-104
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    • 2001
  • Usage of ecosystem models has been extended to landscape scales for understanding the effects of environmental factors on natural and agro-ecosystems and for serving as their management decision tools. Accurate prediction of spatial variation in daily temperature is required for most ecosystem models to be applied to landscape scales. There are relatively few empirical evaluations of landscape-scale temperature prediction techniques in mountainous terrain such as Korean Peninsula. We derived a periodic function of seasonal lapse rate fluctuation from analysis of elevation effects on daily temperatures. Observed daily maximum and minimum temperature data at 63 standard stations in 1999 were regressed to the latitude, longitude, distance from the nearest coastline and altitude of the stations, and the optimum models with $r^2$ of 0.65 and above were selected. Partial regression coefficients for the altitude variable were plotted against day of year, and a numerical formula was determined for simulating the seasonal trend of daily lapse rate, i.e., partial regression coefficients. The formula in conjunction with an inverse distance weighted interpolation scheme was applied to predict daily temperatures at 267 sites, where observation data are available, on randomly selected dates for winter, spring and summer in 2000. The estimation errors were smaller and more consistent than the inverse distance weighting plus mean annual lapse rate scheme. We conclude that this method is simple and accurate enough to be used as an operational temperature interpolation scheme at landscape scale in Korea and should be applicable to elsewhere.

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A Study on the Urban Inundation Flooding Forecasting According to the Water Level Conditions (내수위 조건에 따른 도시내수침수 예보에 관한 연구)

  • Choo, Tai-ho;Choo, Yean-moon;Jeon, Hae-seong;Gwon, Chang-heon;Lee, Jae-gyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.4
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    • pp.545-550
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    • 2019
  • The frequency of natural disasters and the scale of damage are increasing due to the abnormal weather phenomenon occurring all over the world. As a result, as the hydrological aspect of the urban watershed changes, the increase in impervious area leads to serious domestic flood damage due to increased rainfall. In order to minimize the damage of life and property, domestic flooding prediction system is needed. In this study, we developed a flood nomogram capable of predicting flooding only by rainfall intensity and duration. This study suggests a method to set the internal water immersion alarm criterion by analyzing the characteristics of the flooding damage in the flooded area in the metropolitan area where flooding is highly possible and the risk of flooding is high. In addition, based on the manhole and the pipe, the water level was set as follows under the four conditions. 1) When manhole overflows, 2) when manhole is full, 3) when 70% of the pipe is reached, and 4) when 60% of the pipe is reached. Therefore, it can be used as a criterion and a predictive measure to cope with the pre-preparation before the flooding starts, through the rainfall that causes the flooding and the flooding damage.

An Study on the Correlation between Sound Characteristics and Sasang Constitution by CSL (CSL을 통한 음향특성과 사상체질간의 상관성 연구)

  • Shin, Mi-ran;Kim, Dal-lae
    • Journal of Sasang Constitutional Medicine
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    • v.11 no.1
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    • pp.137-157
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    • 1999
  • The purpose of this study is to help classifying Sasang Constitution through correlation with sound characteristic. This study was done it under the suppose that Sasang Constitution has correlation with sound spectrogram. The following result were obtained about correlation between sound spectrogram and Sasang Constitution by comparison and analysis 1. Soeumin answered his voice low tone, smooth and quiet in the survey. Soyangin answered his voice high, clear, fast and speaking random. Taeumin answered his voice low, thick and muddy. 2. Taeyangin was significantly slow compared with the others in the time of reading composition. Taeyangin was significantly slow compared with the others in Formant frequency 1. Taeyangin was significantly discriminated from Soeumin in Formant frequency 5. Taeyangin was significantly low compared with the others in Bandwidth 2. Soeumln was significantly low compared with Taeyangin in Pitch Maximum and Pitch Maximum-Pitch Minimum. Taeyangin was significantly high compared with the others in Energy mean. 3. In list of specification, the discrimination rate was higher than that by lists of 13 in the results of Multi-dimensional 4-class minimum-distance. The discrimination rate of three disposition except Soyangin was higher than that of four disposition in the results of One way ANOVA and Analysis of dis crimination in SPSS/PC+. In CART, the estimate rate of Sasang Constitution discrimination was higher than any other method. It is considered that there is a correlation between sound spectrogram and Sasang constitution according to the results. And method of Sasang constitution classification through sound spectrogram analysis can be one method as assistant for the objectification of Sasang constitution classification.

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A Study on the Application Effect of Central-Grid PV System at a Streetlamp using RETScreen - A Case Study of Gwangjin-gu - (RETScreen을 이용한 가로등의 계통연계형 태양광시스템 적용 효과 분석 - 서울시 광진구를 중심으로 -)

  • Kang, Seongmin;Choi, Bong-Seok;Kim, Seungjin;Mun, Hyo-dong;Lee, Jeongwoo;Park, Nyun-Bae;Jeon, Eui-Chan
    • Journal of Climate Change Research
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    • v.5 no.1
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    • pp.1-12
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    • 2014
  • With continued economic growth, Korea has seen an increase in the nighttime activities of its citizens as hours of activity have extended into night. There is an increasing trend in energy consumption related to citizens' nighttime activities. In order to analyze ideas for an efficient replacement of the power consumption of streetlights and for profit generation by applying grid-type solar systems, this study used an RETScreen model. Through energy analysis and cost analysis, the application benefit and viability of grid-type solar street light systems were analyzed. With analysis result of a total weekly power generation of 114 kWh via a grid-connected solar streetlight system, it was shown that the net present value of a grid-connected solar street light system is 155,362 KRW, which would mean a payback period of about 5.2 years, and as such, it was shown that profit could be generated after about 6 years. In addition, if the grid-connected solar power generation system proposed by this study is to be applied, it was shown that 401,935 KRW in profit could be generated after the 20-year useful life set for the solar system. In addition, the sensitivity analysis was performed taking into account the price fluctuations of SMP, maintenance. As a result, a payback period has increased by 1~2 years, and there were no significant differences. Because the most important factor that affect the economic analysis is the cost of supply certification of renewable energy, a stable sales and acquisition of this certification are very important. the Seoul-type Feed in Tariff(FIT) connected to other institutions will enable steady sales by confirming to purchase the certification for 12 years. Therefore, if those issues mentioned above are properly reflected, Central-grid PV system project will be able to perform well in the face of unfavorable condition of solar PV installation.

Change of Flora of Damaged Land in Juwangsan National Park for Five Years (2010~2014) (주왕산국립공원 내 훼손지의 5년간(2010~2014년) 식물상 변화)

  • You, Juhan;Kim, Mijin
    • Journal of Environmental Impact Assessment
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    • v.25 no.4
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    • pp.233-247
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    • 2016
  • The purpose of this study is to offer the basic data for management of National Park by surveying and analysing the change of flora of damaged lands in Juwangsan National Park, Korea. In cause of occurring the damaged lands, site-1 was the vegetation damage by stamping, the removing Gwangamsa of site-2, 3, 4 and the removing Naewon village of site-5, 6, 7. Whole sites are caused by the artificial disturbance and interference. The numbers of flora were summarized as 135 taxa including 52 families, 109 genera, 116 species, 2 subspecies and 17 varieties in whole sites. The status of flora by sites, site-6 is the largest number of 52 taxa, site-1 is the lowest of 23 taxa. The rare plant is 1 taxa, 4 taxa of endemic plants, 10 taxa of specific plants by floristic region, 9 taxa of naturalized plants and 1 taxa of invasive alien plant. In the results of analysis about the change of coverage ratio, for this shrub layer, site-7 was changed to the most $0%{\rightarrow}50%$, and the herb layer, site-5 was changed to the most $75%{\rightarrow}95%$. In case of the change of species numbers, most sites tended to increase in the sites introduced different species or generated by the growth. It is contemplated that is similar to the restoration with the surrounding natural vegetation that is in progress is a transition occurs with the passage of time. In the dominant species, the shrub layer is Fraxinus sieboldiana, Lespedeza bicolor, Rhus javanica, Lespedezamaximowiczii, Salix koreensis and Zelkova serrata, and Miscanthus sinensis var. purpurascens, Oplismenus undulatifolius, Artemisia princeps, Bothriochloa ischaemum and Erigeron annuus of herb layer. In the results of analysing Naturalized Index(NI) and Urbanized Index(UI), NI was increased or decreased this phenomenon with the lapse of time, UI was the most increase. In particular, the increase in UI is due to the transition process, the pioneering plant, naturalized plant was imported to continue.