• Title/Summary/Keyword: period change

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Comparative Analysis of Radiative Flux Based on Satellite over Arctic (북극해 지역의 위성 기반 복사 에너지 산출물의 비교 분석)

  • Seo, Minji;Lee, Eunkyung;Lee, Kyeong-sang;Choi, Sungwon;Jin, Donghyun;Seong, Noh-hun;Han, Hyeon-gyeong;Kim, Hyun-Cheol;Han, Kyung-soo
    • Korean Journal of Remote Sensing
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    • v.34 no.6_2
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    • pp.1193-1202
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    • 2018
  • It is important to quantitatively analyze the energy budget for understanding of long-term climate change in Arctic. High-quality and long-term radiative parameters are needed to understand the energy budget. Since most of radiative flux components based on satellite are provide for a short period, several data must be used together. It is important to acquaint differences between data to link for conjunction with several data. In this study, we investigated the comparative analysis of Arctic radiative flux product such as CERES and GEWEX to provide basic information for data linkage and analysis of changes in Arctic climate. As a result, GEWEX was underestimated the radiative variables, and it difference between the two data was about $3{\sim}25W/m^2$. In addition, the difference in high-latitude and sea ice regions have increased. In case of comparing with monthly means, the other variables except for longwave downward flux represent high difference of $9.26{\sim}26.71W/m^2$ in spring-summer season. The results of this study can be used standard data for blending and selecting GEWEX and CERES radiative flux data due to recognition of characteristics according to ice-ocean area, season, and regions.

Optimal Design of a Coil for Improved Heating Efficiency of Electric Induction Boiler (전기유도보일러의 발열효율개선을 위한 권선최적설계)

  • Kim, Youn-Hyun;Kim, Sol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.3
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    • pp.476-482
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    • 2019
  • Regulatory protocols such as the Convention on Climate Change and the regulation of greenhouse gas emissions act as catalysts for the development of high-efficiency energy equipment and the efficient use of energy. Among the fields where energy consumption is high, the electric heating equipment is not efficient. The electric boiler mainly uses a method of circulating water by contacting the heater. When the existing electric boiler is used, the water minerals are contacted with the high-temperature heater to be carbonized and adsorbed, thereby promoting the corrosion of the heater and lowering the efficiency of the heater. For this reason, an electric induction boiler, which has high energy efficiency and is applied to an induction heating system that can uniformly heat the object to be heated rather than conduction or convection heating, is in the limelight. This method induces a boiler pipe And it is recognized as an alternative that can solve the problem that occurs when heating is performed by direct heating. Despite the fact that research on induction heating has been conducted for a relatively long period of time, there have been few studies on the electrothermal technology using induction heating. Therefore, in this paper, to improve the heat efficiency of electric induction boiler, the influence of the cross sectional area, number of windings and winding layers is analyzed by finite element method through parametric study method. The method of finding the design point which maximizes the total loss is proposed by the alternating winding design method which can maximize the heat generation by analyzing copper and iron losses.

Development and Effect Analysis of Pregnancy Recognition Improvement Program (임신 인식 개선 프로그램 개발 및 효과 분석)

  • Kim, Jungae;Kim, Ju-ok
    • The Journal of the Convergence on Culture Technology
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    • v.4 no.4
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    • pp.77-87
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    • 2018
  • The study was a mixed design study that analyzed the effects of developing and applying a program to improve pregnancy recognition for severe low fertility. The study period was from April 1, 2018, to October 26, 2018, and the participants included 16 women of 19~21 age who lived in M City and M Gun. The process of program development is based on Dorothy Johnson 's theory of behavior system to induce change of perception, and reference literature review and national policy report. The program developed through the literature was finally developed by examining the experts panel discussion after deriving causes and alternatives for low fertility from 25 fertility women. The contents of program consist of three areas. Quantitative research results were analyzed using Shapiro Wilk and Wilcoxon sign rank using SPSS 18.0, and qualitative research results were analyzed using focus group. As a result of study, the perception of pregnancy increased significantly (P<0.01) with statistical significance as pre-experimental (M=3.21, SD=.342), post-experimental (M=4.46, SD=.398) and the result of content analysis appeared three themes as , , . In conclusion, the program was effective in improving the recognition of pregnancy for young women.

Disaster risk predicted by the Topographic Position and Landforms Analysis of Mountainous Watersheds (산지유역의 지형위치 및 지형분석을 통한 재해 위험도 예측)

  • Oh, Chae-Yeon;Jun, Kye-Won
    • Journal of Korean Society of Disaster and Security
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    • v.11 no.2
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    • pp.1-8
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    • 2018
  • Extreme climate phenomena are occurring around the world caused by global climate change. The heavy rains exceeds the previous record of highest rainfall. In particular, as flash floods generate heavy rainfall on the mountains over a relatively a short period of time, the likelihood of landslides increases. Gangwon region is especially suffered by landslide damages, because the most of the part is mountainous, steep, and having shallow soil. Therefore, in this study, is to predict the risk of disasters by applying topographic classification techniques and landslide risk prediction techniques to mountain watersheds. Classify the hazardous area by calculating the topographic position index (TPI) as a topographic classification technique. The SINMAP method, one of the earth rock predictors, was used to predict possible areas of a landslide. Using the SINMAP method, we predicted the area where the mountainous disaster can occur. As a result, the topographic classification technique classified more than 63% of the total watershed into open slope and upper slope. In the SINMAP analysis, about 58% of the total watershed was analyzed as a hazard area. Due to recent developments, measures to reduce mountain disasters are urgently needed. Stability measures should be established for hazard zone.

Mineralogical Changes of Oyster Shells by Calcination: A Comparative Study with Limestone (소성에 따른 굴패각의 광물학적 특성변화: 석회석과의 비교 연구)

  • Lee, Jin Won;Choi, Seung-Hyun;Kim, Seok-Hwi;Cha, Wang Seog;Kim, Kangjoo;Moon, Bo-Kyung
    • Economic and Environmental Geology
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    • v.51 no.6
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    • pp.485-492
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    • 2018
  • About 300 thousand tones of oyster shells are produced annually and, thus, their massive recycling methods are required. Recently, a method, utilizing them as wet desulfurization materials after removal of organic matters and changing $CaCO_3$ phase into CaO through calcination, is under consideration. This study investigates the mineralogical changes (specific surface area, phase changes, surface state, etc.) of oyster shells by calcination and their characteristics were compared with those of limestone. Uncalcined oyster shells showed the higher specific surface area than limestone because the former are composed of platy and columnar structures. In contrast, investigated limestone showed a dense structure. The phase change of oyster shells occurred at lower temperature than that of limestone. The specific surface area of oyster shell decreased significantly after calcination while limestone depicted a drastic increase. Small amount of Na contained in oyster shell was suggested as the cause of this phenomenon; in that, it acted as a flux causing melting and sintering of oyster materials at lower temperature. Because of this, an additional phenomenon was observed that a part of shell materials remained untransformed even at higher calcination temperature and after longer treatment period due to the sintered surface, which covers the rest parts. Further studies investigating the effect of this phenomena from the perspective of desulfurization is required.

Reaction Characteristics of Phytoplankton Before and After the Yellow Dust Event in Taean Peninsula and Yellow Dust Impact Assessment (태안반도주변에서 춘계 황사 전·후 식물플랑크톤 반응특성과 황사분진 영향평가)

  • Yoo, Man Ho;Youn, Seok Hyun;Oh, Hyun Ju;Choi, Joong Ki
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.7
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    • pp.898-906
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    • 2018
  • To investigate the effect of yellow dust on phytoplankton, a field survey and physiological experiments were carried out in the waters near Taean Peninsula from April 22 to 26, 2006, when yellow dust occurred. Phytoplankton populations during the yellow dust period were in the range of $26{\sim}290{\times}10^3cells{\cdot}L^{-1}$, a somewhat low standing crop. An increase in diatoms (a main taxonomic group), especially benthic diatoms such as Paralia sulcate, a typical species for active mixed sea water areas, was also remarkable. In addition, the Chl-a concentration after yellow dust exceeded the Chl-a concentration change range according to the tide before yellow dust. As the concentration of yellow sand increased in a yellow sand treatment experiment, primary productivity decreased, and the maximum assimilation number showed the same tendency. In the 48h culture experiment, primary productivity of the test group was lower than that of the control group at the early stage (T0) of yellow sand treatment, but after 48 hours (T48), the test group showed higher primary productivity than the control group. In particular, the primary productivity of the test group significantly increased to 321 % after 48 hours. Therefore, strong physical environment accompanied by yellow dust may temporarily inhibit the growth of phytoplankton in the waters adjacent to China in the early stage of yellow dust, but the formation of stable water mass has also been identified as a potential factor promoting the growth of phytoplankton.

Understanding Forest Status of the Korean Peninsula in 1910: A Focus on Digitization of Joseonimyabunpodo (The Korean Peninsula Forest Distribution Map) (1910년 한반도 산림의 이해: 조선임야분포도의 수치화를 중심으로)

  • Bae, Jae Soo;Kim, Eun-Sook
    • Journal of Korean Society of Forest Science
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    • v.108 no.3
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    • pp.418-428
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    • 2019
  • The purpose of this study was to analyze and clarify the forest information shown in the Korean Peninsula Forest Distribution Map (KPFDM) printed in 1910. First, the background, process, results, and reliability of the Forest Survey Project (1910), which is the basis of the KPFDM, were evaluated. Next, the information of the KPFDM, preserved as a paper map, was digitized to show forest status and forest type. The results of the analysis can be summarized as follows: Analyzing the Korean peninsula of the 1910 period in terms of the present South and North Korean regions, stocked forests were found to be more widely distributed (73%) in the northern region. The southern region largely consisted of deforested areas, with young-growth trees and unstocked forests making up 80% of all forests there. The northern region had abundant natural forests, with 80% of the forests in Yanggang-do, which currently includes Mt. Baekdu and the Hyesan area, composed of stocked forests. Pinus densiflora was found about 2.7 times more often in the southern region than in the northern region. Large numbers of coniferous trees excluding Pinus densiflora were found in the northern region. In particular, 53% of the forests and 72% of the stocking land in the southern region were composed of Pinus densiflora.

Designing the Record Management Functions for Record Content Using Advantages of Cloud Storage (클라우드 저장소 장점을 활용한 기록 콘텐츠 관리기능 설계)

  • Yim, Jin-Hee
    • Journal of Korean Society of Archives and Records Management
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    • v.19 no.3
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    • pp.271-292
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    • 2019
  • Recently, the central administrative agency changed its business management system to cloud-based On-nara 2.0. To transfer and manage the records of the cloud business management system, the National Archives Service has developed and distributed a cloud-based records management system. It serves as an opportunity to maximize the benefits of cloud computing and redesign the records management to be more effective and efficient. The process and method of electronic record management can be transformed through digital technologies. First, we can change the transfer method for electronic records. When the business and the records management systems share the same cloud storage, it is possible to transfer the content files between the two systems without moving the contents files physically, thus copying only the metadata and reducing the cost and the risk of integrity damage. Second, the strategy for allocating storage space for contents can be conceived. Assuming that the cloud storage is shared by the business and the record management systems, it is advantageous to distinguish the storage location based on the retention period of the content files. Third, systems that access content files, such as records creation, records management, and information disclosure systems, can share the cloud storage and minimize the duplication of content files.

Effects of dietary vitamin levels on physiological responses, blood profiles, and reproductive performance in gestating sows

  • Jeong, Jae Hark;Hong, Jin Su;Han, Tae Hee;Fang, Lin Hu;Chung, Woo Lim;Kim, Yoo Yong
    • Journal of Animal Science and Technology
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    • v.61 no.5
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    • pp.294-303
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    • 2019
  • This study was performed to evaluate the effects of dietary vitamin levels on physiological responses, blood profiles, and reproductive performance in gestating sows. A total of 52 F1 multiparous sows ($Yorkshire{\times}Landrace$) with an average body weight of $223.5{\pm}31.7kg$, an average parity of $6.4{\pm}2.7$, and an average backfat thickness of $18.5{\pm}4.9mm$ were divided into four treatment groups considering body weight, backfat thickness, and parity in a completely randomized design with 13 replicates. The treatments were 100% (V1), 300% (V3), 600% (V6) and 900% (V9) of the National Research Council (NRC) Nutrient Requirements of Swine. The gestation diet was formulated based on corn-soybean meal (SBM) and contained 3,265 kcal of metabolizable energy (ME)/kg and 12.00% crude protein. During the lactation period, all sows were fed the same commercial lactation diet. There was no significant difference in body weight of gestating sows. However backfat thickness tended to increase when higher levels of vitamins were provided to gestating sows (p < 0.10). When high levels of dietary vitamins were provided, the body weight change of lactating sows increased (p < 0.01). When sows were fed higher levels of vitamins, the feed intake of lactating sows tended to decrease (p = 0.06). There were no treatment differences in the number of total born, born alive, stillbirth piglets, or the body weight of piglets according to different dietary vitamin level. As dietary vitamin level increased, the serum concentration of $25(OH)D_3$ in sows at 90 days of gestation linearly increased (p < 0.01). Furthermore, the serum vitamin E level of gestating sows was linearly increased with increasing dietary vitamin level (p < 0.05). The current NRC vitamin requirements are sufficient for gestating sows and higher levels of vitamins in the gestation diet did not show any beneficial effects for gestating and lactating sows.

Spatial and Temporal Distribution of Fish Communities with Rainfall in Jungrang Stream (강우에 따른 중랑천 어류군집의 시공간적 분포 특성)

  • Lee, Seung-Hyun;Jeong, Hyun-Gi;Shin, Hyun-Seon;Kim, Jin-young;Pak, Sangsuk;Shin, Yuna;Moon, Jeong-Suk;Lee, Su-Woong;Lee, Jae-Kwan
    • Korean Journal of Ecology and Environment
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    • v.51 no.4
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    • pp.354-364
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    • 2018
  • In this study, we surveyed the fish community at the four sites(St. 1, 3, 5, 7) in Jungrang Stream from 2008 to 2016. We found 37 species grouped into nine families. There were three exotic species; Cyprinus carpio, Carassius cuvieri and Micropterus salmoides after rainfall. Dominant species was Zacco platypus (57.3%) and subdominant species was Carassius auratus(10.4%) in a community. The water quality, surveyed at the six sites(St. 1, 2, 3, 4, 5, 6), based on eight factors(Water temperature, pH, DO, BOD, SS, EC, TN and TP), largely varied depending on each site and period. Minimum values in four factors(BOD, EC, TN and TP) were observed in rainy season, indicating an ionic and nutrient dilution of stream water by precipitation. In contrast, a maximum value in SS was occurred in rainy season at St. 2 and St. 5. The precipitation, Maximum value observed in July ($497.5{\pm}297.2mm$), minimum value in January ($12.9{\pm}8.6mm$). In July and August, the precipitation was divided into before and after the rainfall season in Jungrang stream. Using cluster analysis three fish sites (St. 1, 3, 5) were identified as significantly influence 11 fish species; Hemiculter eigenmanni, Squalidus japonicus coreanus, Hemibarbus labeo, Gnathopogon strigatus, Pungtungia herzi, Rhynchocypris oxycephalus, Pseudogobio esocinus, Pseudorasbora parva, Cyprinus carpio, Carassius auratus and Zacco platypus by rainfall.