• Title/Summary/Keyword: Migration rate

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Study of the Migration Rate of L-menthol into Cigarette Pack and Delivery Rate to Cigarette Smoke (포갑 내에서 L-menthol의 이동과 연중 이행 효과에 관한 연구)

  • 김병구;김시몽;양범호;제병권;이규서
    • Journal of the Korean Society of Tobacco Science
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    • v.24 no.1
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    • pp.46-52
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    • 2002
  • This study was carried out to investigate the transfer rate of I-menthol constituent into cigarette case and delivery rate to cigarette smoke. Test sample was used a light-type standard brand cigarette made in Korea. I-Menthol contents was measured according to A.O.A.C(1990) method by G.C and smoking conditions was a puff volume of 35$m\ell$ and 2.0s duration, taken once per minute to filter tipping paper plus 3mmwith 20 cigarettes. Migration rate of menthol into cigarette case had an interrelation with triacetin contents into filter and 6% triacetin level was most suitable. I-Menthol transferred to filter part from tobacco sheet by 20.2% in one month after cigarette manufacture, and the transfer was continued subsequently. Maximum menthol transfer in five months was 4.1% to foils and other packing materials and the loss outside of cigarette pack was also 3.9% below. The migration balance of menthol into cigarette pack and the delivery to cigarette smoke were the optimum condition when menthol was added at the ration of 30% in filter to 70% in the other parts into cigarette.

EFFECTS OF UNIFORM SHEAR STRESS ON THE MIGRATION OF VASCULAR ENDOTHELIAL CELL (균일한 전단응력에 의한 혈관내피세포의 운동성 변화)

  • Shin, Jennifer H.;Song, Suk-Hyun
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1404-1408
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    • 2008
  • The migration and proliferation of vascular endothelial cells (VEC), which play an important role in vascular remodeling, are known to be regulated by hemodynamic forces in the blood vessels. When shear stresses of 2, 6, 15 dynes/$cm^2$ are applied on mouse micro-VEC in vitro, cells surprisingly migrate against the flow direction at all conditions. While higher flow rate imposes more resistance against the cells, reducing their migration speed, the horizontal component of the velocity parallel to the flow increases with the flow rate, indicating the higher alignment of cells in the direction parallel to the flow at a higher shear stress. In addition, cells exhibit substrate stiffness and calcium dependent migration behavior, which can be explained by polarized remodeling in the mechanosensitive pathway under shear stress.

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Improvement of Migration Lifetime by Dual-sized Grain Structure in 1% Si-Al Metal Line (이중 결정립 구조 1%Si-Al 금속선에 의한 Migration 수명의 개선)

  • 김영철;김철주
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.6
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    • pp.1-7
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    • 1993
  • After the 1%S-Al metal is deposited, a thin oxide is formed thereon. Then, a single charged Argon(Ar$^{+}$) is ion implanted into the oxide layer, thereby causing the metal grain in the upper surface of the metal layer to become amorphous. Consequently, the grain size will be reduced and the rough surface of the metal layer flattened. However, the remainder of the metal layer beneath the upper surface thereof will still exhibit large grain size and low resistance, because the Argon ion is only implanted to characterized by a dual-sized grain structure which served to reduce interlayer stress, thereby decreasing the rate of stress migration, and to lower the resistivity of the metal line, thereby enhancing the electromigration characteristic thereof. Experiments have shown that the metal line exhibits a metal migration rate which is approximately 700% less than the control group and a standard deviation which is approximately 200% less than these group.p.

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Development of system of Population projection and driving variation on demography for Korea using R (R를 활용한 인구변동요인 산정과 인구추계 시스템 개발)

  • Oh, Jinho
    • The Korean Journal of Applied Statistics
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    • v.33 no.4
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    • pp.421-437
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    • 2020
  • This paper implemented a method to predict the fertility rate, mortality rate, and international migration rate using the R program, which has been widely used in recent years, that calculates population projection by substituting the results into the Leslie matrix. In particular, the generalization log gamma model for the fertility rate by Kaneko (2003), LC-ER model for mortality rate by Li et al. (2013), and functional data model for international migration rates proposed by Ramsay and Silverman (2005) and Hyndman and Booth (2008), Hyndman et al. (2013) can be directly demonstrated with R programs. Demography and bayesPop have been introduced as a representative demographic package implemented in R; however, it can be analyzed only for data uploaded to Human Mortality Database (HMD) and Human Fertility Database (HFD) with data changes and modifications requiring application of other data. In particular, in Korea, there is a limitation in applying this package because it is provided only for short-term data in HMD. This paper introduces an R program that can reflect this situation and the different patterns of low fertility, aging, migration of domestic and foreigners in Korea, and derives a population projection for the year 2117.

The Effect of Flow Rate on the Process of Immiscible Displacement in Porous Media (다공성 매체 내 비혼성 대체 과정에서 주입 유량이 거동 양상에 미치는 영향)

  • Park, Gyuryeong;Kim, Seon-ok;Lee, Minhee;Wang, Sookyun
    • Journal of Soil and Groundwater Environment
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    • v.23 no.1
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    • pp.1-13
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    • 2018
  • A series of experiments using transparent micromodels with an artificial pore network etched on glass plates was performed to investigate the effects of flow rate on the migration and distribution of resident wetting porewater (deionized water) and injecting non-wetting fluid (n-hexane). Multicolored images transformed from real RGB images were used to distinguish n-hexane from porewater and pore structure. Hexane flooding followed by immiscible displacement with porewater, migration through capillary fingering, preferential flow and bypassing were observed during injection experiments. The areal displacement efficiency increases as the injection of n-hexane continues until the equilibrium reaches. Experimental results showed that the areal displacement efficiency at equilibrium increases as the flow rate increases. Close observation reveals that preferential flowpaths through larger pore bodies and throats and clusters of entrapped porewater were frequently created at lower flow rate. At higher flow rate, randomly oriented forward and lateral flowpaths of n-hexane displaces more porewater at an efficiency close to stable displacement. It may resulted from that the pore pressure of n-hexane, at higher flow rate, increases fast enough to overcome capillary pressure acting on smaller pore throats as well larger ones. Experimental results in this study may provide fundamental information on migration and distribution of immiscible fluids in subsurface porous media.

Population Projections for Busan Using a Biregional Cohort-Component Method (이지역 코호트-요인법을 이용한 부산광역시 장래 인구 추계)

  • Cho, Dae-Heon;Lee, Sang-Il
    • Journal of the Korean Geographical Society
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    • v.46 no.2
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    • pp.212-232
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    • 2011
  • The main objective of this study is to establish a population projection method based on the biregional cohort-component method and to apply it to population projections for Busan. Some drawbacks of using the net migration cohort-component method in a regional or local level population projection are demonstrated. A biregional cohort-component method, a variant of the interregional cohort-component method, is established as an alternative where in-migration and out-migration are separately considered and then are combined to produce a projection for the migration component. Predicated on the established method, population projections for Busan are undertaken for the period of 2005~2030 under three different scenarios. Considerably different projection results are obtained between the net migration and biregional methods; among others, the trend of population decline is more severe in the former than in the latter. An investigation of the temporal trend of the projected population shows that the proposed method is highly reasonable. In conclusion, the proposed method based on the biregional cohort-component method seems not only to be theoretically more robust than the net migration cohort-component method but also to be very effective in the real world application.

Effect of Moisture Migration in Concrete with Hating Rate on Concrete Spalling (가열속도에 따른 콘크리트 내부의 수분이동이 폭렬발생에 미치는 영향)

  • Choe, Gyeong-Cheol;Kim, Gyu-Yong;Nam, Jeong-Soo;Kim, Hong-Seop;Yoon, Min-Ho;Hwang, Ui-Chul
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.05a
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    • pp.246-247
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    • 2017
  • In this study, it reviewed the effect of moisture migration in concrete with heating rate on concrete spalling. Concrete specimens with compressive strength 30MPa and 110MPa are used and its size is □100×100×h200mm. And, two kinds of heating rate are set such as IS0 834 and 1℃/min. As a result, in the concrete specimen exposed to ISO 834 standard heating condition, moisture could migrate through pore network and surface concrete pieces fall out by generating moisture clog near the surface in 110MPa concrete specimen. Meanwhile, In the case of concrete specimens exposed to 1℃/min. heating condition, it is appeared that moisture could not migrate because temperature is distributed uniformly. Therefore, surface spalling is not occurred with low heating rate. However, in the case of 110MPa concrete specimen is exploded even though it heated by low heating rate.

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Relationship between Retirement Migration and Economic Development of Rural Communities in Korea (은퇴인구 유입과 지역경제 활성화와의 관련성 분석)

  • Yoon, Soon-Duck;Park, Gong-Ju
    • The Korean Journal of Community Living Science
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    • v.18 no.3
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    • pp.455-467
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    • 2007
  • Recently, there has been a gradual growth of retired in-migrants in high-amenity, rural areas in Korea. However, little has known about that the retirement migration is a blessing or a blight for a local economy in Korea. Therefore, in this study, we intend to explore the relationship between retirement migration and economic development of rural communities in Korea. For this purpose, we used the 1995 and 2000 census data and annual regional statistics for 138 counties in Korea. Based on the previous empirical studies, economic development was measured by 3 indicators such as GRDP (Gross Regional Domestic Product), job creation in the wholesale and retail sector, and the increase of local tax. Also, cross-tab, scatter plot, and correlation were analyzed using the SPSS Windows Program. The finding are as follows: First, from 1995 to 2000, nearly 11 percent of rural counties showed 10 percent and over increase of in-migration rate among retirees. Second, correlation statistics showed a close relationship between retirement in-migrant flows and economic resurgence. In particular, retirement in-migration rates were significantly tied to the job creation of the wholesale and retail sector (r=.19, p<.05) as well as car ownership rate (r=.58, p<.001) resulting in the increase of local tax. However, there was non-significantly positive correlation between retirement in-migrant flows and GRDP change (r=.13). Knowledge of these relationships will be important to policy-makers and for understanding the role that retirement in-migration play in stimulating economic growth of rural communities in Korea.

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Analysis of the Factors Affecting on Internal Population Migration in Seoul Metropolitan Area (수도권 도시유형별 내부 인구이동 영향요인 분석)

  • Kim, Sang-Won;Lee, Hoon-Rae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.9
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    • pp.737-744
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    • 2016
  • Seoul Metropolitan Area has been changed by fierce internal migration during the last several decades. To determine the regional structure, we analyzed the in-and-out migration pattern and main factors affecting the intense of mobility. The migration within metropolitan city and province shows that in Seoul, Songpa and Dobong Gu gained a large population, in Incheon, Namdong Gu experienced a huge population influx, and in Gyeonggi Province, Hwasung, Yongin and Paju city gained a great population. In Seongnam, Suwon city lost a lot of population. These population gains and losses came from mainly residential redevelopment projects in the metropolitan city and new land development projects in Gyeonggi Province. The main factors affecting the intense of mobility diverse from city characters. In central type cities, house price gets the more population influx. In job-housing balanced cities, total income growth rate, housing supply rate and roads cause in-migration. In bed-town type cities, the increase of housing supply rate and parks increase the population. In suburban type cities, business density, housing supply rate, housing, subway station number and educational facilities increase population from outside the city. So, we have to prepare more detailed urban and housing policy responses.

Food Selection of the Abalone, Haliotis discus hannai on Various Diets

  • Kang, Kyoung-Ho;Hwang, Sung-Il;Zhang, Zhi-Feng;Kim, Jae-Min;Kim, Young-Hun
    • The Korean Journal of Malacology
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    • v.19 no.2
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    • pp.89-93
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    • 2003
  • In this study, the food selection of abalone, Haliotis discus hannai, on four various diets, Ulva pertusa, Laminaria japonica, Navicula spp., and artificial diet, was investigated. The abalones in Ulva pertusa and Navicula spp groups had the higher migration rate than the others. The artificial group had the lowest migration rate. As to the growth, Ulva pertusa group had the highest daily increment and the growth rate, which is 120.7 ${\mu}$m and 2.41%. The value of Navicula spp. group is 102.0 ${\mu}$m and 2.04% and that of Laminaria japonica group is 88.7 ${\mu}$m and 1.77%. The lowest one is 81.7 ${\mu}$m and 1.63%, which appeared at the artificial diet group. We suggest that, when breeding Haliotis discus hannai and the diets which is easy to be ingested and digested, as well as contains much nutrient content, should be used. If the artificial diet is used, it should contain low concentration of flesh-eating content.

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