• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.268-275
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• 2006

Excavation works of cylindrical shafts and tunnels for the construction of a variety of infrastructures have been frequently going on in the urban areas. When ground excavations of cylindrical shafts and shallow tunnels proceed in the ground condition of high water level and silt particle component, ground water drawdown involving soil particle migration causes loosening of ground around tunnels and shafts, causes settlement and deformation of ground. Damages due to ground sinking and differential settlement can occur in the adjacent ground and structures. The extent and possibility of damage relevant to ground water drawdown and soil particle migration can't be so precisely expected in advance that we will face terrible damages in case of minor carefulness. This paper introduces two examples of construction management where using incremental deformation graph of inclinometer, we noticed the possibility of soil migration due to ground water drawdown in the excavation process of vertical shaft and shallow tunnel, analysed a series of measurement data in coupled connection, properly prepared countermeasures, so came into safe and successful completion of excavation work without terrible damages. The effort of this article aims to improve and develop the technique of design and construction in the coming projects having similar ground condition and supporting method.

• 동의생리병리학회지
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• 제23권2호
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• pp.480-487
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• 2009

Atherosclerosis, slow progressing inflammatory lesion in arteries, is one of the major causes of cardiovascular diseases. As mortality due to cardiovascular disease keeps increasing in Korea, researches on pathological mechanism of atherosclerosis may be beneficial in fighting against cardiovascular diseases. It is known that migration and MMP-9 secretion of Vascular Smooth Muscle Cell(VSMC) play a significant part in pathogenesis of atherosclerosis, although detailed mechanism of entire process is not clarified. We investigated whether the seeds of Trichosanthes kirilowii maxim (TS), inhibit migration and MMP-9 production of HASMC(human aortic SMC), which were induced by TNF-${\alpha}$ treatment. Migration assay showed that TS inhibited the migration of HASMC induced by TNF-${\alpha}$, in dose dependent manner. Also by Zymography MMP-9 production of HASMC was found to be reduced by TS, both in time and in dose dependent manner. Western blotting results suggest TS suppress activity of MAPkinases.

• Tribology and Lubricants
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• 제15권4호
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• pp.335-342
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• 1999

Corrosion of the disk has been an ongoing concern for the manufacturers of hard disk drives. With the advent of magnetoresistive (MR) head, very low levels of corrosion and contamination become more critical since the raised defects and corrosion products on the disk surface-anything that heats the MR sensor due to the contact-can distort the output signal of the head. This phenomenon is called as thermal asperity. In this paper, the effect of corrosion as a form of Co migration on the occurrence of thermal asperity in MR drives was investigated. The corrosion test at high temperature (60$^{\circ}C$) and high relative humidity (80%) was emphasized in this study and the testing results at ambient condition were compared. The corrosion on the disks was characterized as the amount of Co ion migration using an ion chromatography (IC) and a time-of-flight secondary ion mass spectroscopy (TOF-SIMS). It is proved that corrosion on the disk surface after storage testing is closely correlated to the amount of Co ions migration from the magnetic layer to disk surfaces and higher Co migration causes more thermal asperities in the drive. In order to reduce Co migration, several methods such as burnishing process and structure of the carbon overcoat were investigated. It is found that the hydrogenated carbon overcoat shows the least Co migration among different types of overcoat layer. However, the most effective way to reduce Co migration is the application of Cr layer between the overcoat and the magnetic alloy layer.

• 한국재료학회지
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• 제15권1호
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• pp.54-60
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• 2005

Recently a lots of problems have observed in high densified and high integrated electronic components. One of them is ion migration phenomena, which induce the electrical short of electrical circuit. ion migration phenomena has been observed in the field of exposing the specific environment and using for a long tin e. This study was evaluated the generation time of ion migration and was investigated properly test method through water drop test and high temperature high humidity test. Also we observed direct causes and confirmed generation mechanism of dendritic growth as we reproduced the ion migration phenomena. We utilized PCB(printed circuit board) having a comb pattern as follows 0.5, 1.0, 2.0 mm pattern distance. Cu, SnPb and Au were electroplated on the comb pattern. 6.5 V and 15 V were applied in the comb pattern and then we measured the electrical short time causing by ion migration. In these results, we examined a difference of ion migration time depending on pattern materials, applied voltage and pattern spacing of PCB conductor.

• 농촌지도와개발
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• 제18권1호
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• pp.1-33
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• 2011

In-migration has long been recognized as on important factor in rural development. Its impact can be expected to increase even further as the elderly population continues to grow. Recently with the retirement of baby boomers, postretirement moves have become increasingly important issue in rural Korea. Because the consequences of rural in-migration are often most pronounced at the local or regional level, rural planners are among the many scholars and practitioners seeking to understand the patterns and consequences of in-migration. At the same time, however, planners have sometimes overlooked basic research on the causes and determinants of mobility, and on the relationships between retirement migration and other socioeconomic processes. The papers aims to explore the reviews of rural in-migration studies and its practical implications, providing an interdisciplinary review of the most important studies published between 1990-2009. Through the literature review of in-migration, this study suggests that main arguments for rural in-imgration studies such as rural populations, counterurbanization, rural businesses incubator and rural amenity be emphasized to vitalize and diversify rural economies.

• Asia Pacific Journal of Business Review
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• 제4권2호
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• pp.23-33
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• 2020

Uzbekistan has been gradually integrating into the world economy since gaining its independence back in 1991. The need to integrate stems from the desire to advance the national economy and social well-being of population through importing advanced technologies or stimulating exports. However, opening up the country also meant exposure to increase in the mobility of its human capital. As a result, Uzbekistan has witnessed labor migration in and out of the country in the past couple of decades, driven by various causes, which is having inevitable social and economic implications for the country. Intensifying processes in contemporary international labor market make migration as a mechanism, which has a back-to-back impact onto and from economic development of a country. From developing countries' perspective, international labor migration is an instrument for reducing tension in national labor markets, decreasing high rates of unemployment and expanding sources of income. From developed countries' perspective, international labor migration helps solve demographic problems like decreasing number of population, aging of population and shortage of labor force. Thus, this processes turned into a mechanism or a system, which is not possible to ignore. Uzbekistan, in particular, is increasing its participation in the international labor market due to its high rates of population growth and young population.

• Toxicological Research
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• 제9권2호
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• pp.207-215
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• 1993

Lead is an environmental toxicant that causes a marked deficit in cognative development in infants and children. Damage to the hippocampus has been linked to the lead-induced deficit in the learning process. The present study examined the effects of lead on the development of hippocampal neurons in vitro. Hippocampal neurons were incubated with various concentrations in lead acetate (1nM to 30 nM) for 72 hrs from 4 h after plating, and the percentage of living neurons bearing neurites, neurite outgrowth and migration of multipolar neurons in culture were determined.

• Parasites, Hosts and Diseases
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• 제58권3호
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• pp.217-227
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• 2020

Trichomonas vaginalis causes inflammation of the prostate and has been detected in tissues of prostate cancers (PCa), prostatitis and benign prostatic hyperplasia. Obesity is a risk factor for PCa and causes a chronic subclinical inflammation. This chronic inflammation further exacerbates adipose tissue inflammation as results of migration and activation of macrophages. Macrophages are the most abundant immune cells in the PCa microenvironment. M2 macrophages, known as Tumor-Associated Macrophages, are involved in increasing cancer malignancy. In this study, conditioned medium (TCM) of PCa cells infected with live trichomonads contained chemokines that stimulated migration of the mouse preadipocytes (3T3-L1 cells). Conditioned medium of adipocytes incubated with TCM (ATCM) contained Th2 cytokines (IL-4, IL-13). Macrophage migration was stimulated by ATCM. In macrophages treated with ATCM, expression of M2 markers increased, while M1 markers decreased. Therefore, it is suggested that ATCM induces polarization of M0 to M2 macrophages. In addition, conditioned medium from the macrophages incubated with ATCM stimulates the proliferation and invasiveness of PCa. Our findings suggest that interaction between inflamed PCa treated with T. vaginalis and adipocytes causes M2 macrophage polarization, so contributing to the progression of PCa.

• 한국포장학회지
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• 제12권2호
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• pp.91-96
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• 2006

The widespread use of packaging materials on food packages sometimes causes off-flavor and deterioration in the food by migration of packaging materials which consist of mainly plastic materials and printing ink solvents. Even though migration of the residual packaging materials does not generally cause safety problems in the contained food, it certainly can generate off-flavor and finally deteriorate quality of the finished product. In highly consumer-oriented markets, quality of the finished product is gaining more importance economically, so profound and thorough study about migration into food to maintain the fine quality of the end product becomes an importance issue. Studies have been conducted about migration of various packaging materials and the chemical reactions between the food components and the materials used for food packaging (Brody, 1989; Mcneal and Breder, 1987; Lawson, G and Lawson, C, 1996). Several of these studies have measured partition coefficient values (Kp) between packaging materials and various food samples and involved finding factors that affected the partitioning behavior of packaging materials into the contained food. However, to enable prediction of partitioning, data are still needed on the relation of packaging material chemical structure and properties to partitioning behavior, and on the partitioning behavior of various food ingredients and the total food compositions.

• 전기전자학회논문지
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• 제26권2호
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• pp.329-332
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• 2022

본 논문에서는 ferroelectric(HfO₂)구조가 적용된 3D NAND flash memory의 parameter에 따른 lateral charge migration의 retention과 V_th를 분석하였다. P_s가 클수록 Program 시 ferroelectric에서 가능한 최대 polarization이 크기 때문에 초기 V_th는 P_s 25µC/cm² 보다 P_s 70µC/cm²에서 약 1.04V차이로 커진다. 또한 Program 이후 trap된 전자는 시간이 지남에 따라서 lateral charge migration이 발생한다. Program 이후 gate에 전압을 가하지 않고 ferroelectric은 polarization을 유지하기 때문에 P_s와 크게 관계없이 P_r이 클수록 polarization이 커지고 lateral charge migration에 의한 ∆V_th는 P_r 5µC/cm² 보다 P_r 50µC/cm²에서 약 1.54V차이로 작아진다.