• Title/Summary/Keyword: dampening

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연안 항행안전 위험시설 정보 취득 및 활용 기법

  • Yang, Chan-Su
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2009.10a
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    • pp.73-74
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    • 2009
  • This study attempts to establish a system extracting and monitoring cultural grounds of seaweeds (lavers, brown seaweeds and seaweed fulvescens) and abalone on the basis of both KOMPSAT-2 and Terrasar-X data. The study areas are located in the northwest and southwest coast of South Korea, famous for coastal cultural grounds. The northwest site is in a high tidal range area (on the average, 6.1 m in Asan Bay) and has laver cultural grounds for the most. An semi-automatic detection system of laver facilities is described and assessed for spaceborne optic images. On the other hand, the southwest cost is most famous for seaweeds. Aquaculture facilities, which cover extensive portions of this area, can be subdivided into three major groups: brown seaweeds, capsosiphon fulvescens and abalone farms. The study is based on interpretation of optic and SAR satellite data and a detailed image analysis procedure is described here. On May 25 and June 2, 2008 the TerraSAR-X radar satellite took some images of the area. SAR data are unique for mapping those farms. In case of abalone farms, the backscatters from surrounding dykes allows for recognition and separation of abalone ponds from all other water-covered surfaces. But identification of seaweeds such as laver, brown seaweeds and seaweed fulvescens depends on the dampening effect due to the presence of the facilities and is a complex task because objects that resemble seaweeds frequently occur, particularly in low wind or tidal conditions. Lastly, fusion of SAR and optic spatial images is tested to enhance the detection of aquaculture facilities by using the panchromatic image with spatial resolution 1 meter and the corresponding multi-spectral, with spatial resolution 4 meters and 4 spectrum bands, from KOMPSAT-2. The mapping accuracy achieved for farms will be estimated and discussed after field verification of preliminary results.

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Nonlinear finite element modeling of the self-centering steel moment connection with cushion flexural damper

  • Ali Nazeri;Reza Vahdani;Mohammad Ali Kafi
    • Structural Engineering and Mechanics
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    • v.87 no.2
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    • pp.151-164
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    • 2023
  • The latest earthquake's costly repairs and economic disruption were brought on by excessive residual drift. Self-centering systems are one of the most efficient ways in the current generation of seismic resistance system to get rid of and reduce residual drift. The mechanics and behavior of the self-centering system in response to seismic forces were impacted by a number of important factors. The amount of post-tensioning (PT) force, which is often employed for the standing posture after an earthquake, is the first important component. The energy dissipater element is another one that has a significant impact on how the self-centering system behaves. Using the damper as a replaceable and affordable tool and fuse in self-centering frames has been recommended to boost energy absorption and dampening of structural systems during earthquakes. In this research, the self-centering steel moment frame connections are equipped with cushion flexural dampers (CFDs) as an energy dissipator system to increase energy absorption, post-yielding stiffness, and ease replacement after an earthquake. Also, it has been carefully considered how to reduce permanent deformations in the self-centering steel moment frames exposed to seismic loads while maintaining adequate stiffness, strength, and ductility. After confirming the FE model's findings with an earlier experimental PT connection, the behavior of the self-centering connection using CFD has been surveyed in this study. The FE modeling takes into account strands preloading as well as geometric and material nonlinearities. In addition to contact and sliding phenomena, gap opening and closing actions are included in the models. According to the findings, self-centering moment-resisting frames (SF-MRF) combined with CFD enhance post-yielding stiffness and energy absorption with the least amount of permeant deformation in a certain CFD thickness. The obtained findings demonstrate that the effective energy dissipation ratio (β), is increased to 0.25% while also lowering the residual drift to less than 0.5%. Also, this enhancement in the self-centering connection with CFD's seismic performance was attained with a respectable moment capacity to beam plastic moment capacity ratio.

Effect of Phlorotannins Isolated from the Ethyl Acetate Fraction of Ecklonia stolonifera on Peritoneal Macrophage Polarization (복강대식세포의 염증성 표현형에 대한 곰피(Ecklonia stolonifera) 유래 Phlorotannins의 효과)

  • Choi, Min-Woo;Choi, Jun-Hyeong;Kim, Hyeung-Rak;Kim, Jae-Il
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.48 no.4
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    • pp.439-446
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    • 2015
  • Inflammation is a protective response to infection or injury. However, prolonged inflammation can contribute to the pathogenesis of many diseases, such as cancer, diabetes, arthritis, atherosclerosis, and Alzheimer's disease. Recent studies have shown that activated macrophages, inflammatory effector cells, can react to tissue insults in a polarized manner, in which their phenotypes are polarized into two major subtypes, categorized as M1 or M2. Classical M1 activation involves the production of pro-inflammatory cytokines, such as interleukin (IL)-6 and tumor necrosis factor (TNF)-${\alpha}$, and free radicals, while M2 or alternative activation is an anti-inflammatory phenotype involved in homeostatic processes, such as wound healing, debris scavenging, and the dampening of inflammation via the production of very low levels of pro-inflammatory cytokines and high levels of anti-inflammatory mediators, including IL-10. As part of our ongoing effort to isolate anti-inflammatory compounds from seaweeds, we investigated the effects of phlorotannins isolated from the brown alga Ecklonia stolonifera on macrophage polarization. Mouse peritoneal macrophages were treated with various concentrations of the extracts, and real-time RT-PCR analyses were performed to examine the expression of polarization markers: IL-$1{\beta}$, IL-6, and TNF-${\alpha}$ for M1 and arginase-1, peroxisome proliferator-activated receptor (PPAR)-${\gamma}$, found inflammatory zone-1 (Fizz-1), chitinase 3-like 3 (Ym1), and$Kr{\ddot{u}}ppel$-like factor 4 (Klf-4) for M2. The pretreatment of cells with eckol, dieckol, and phlorofucofuroeckol-A (PFF-A), isolated from the ethyl acetate fraction of E. stolonifera ethanolic extract, potentiated the anti-inflammatory M2 phenotype of the macrophages. These results indicate that phlorotannins derived from E. stolonifera can be used to enrich macrophages with markers of the M2 anti-inflammatory state.

A Study on the Impact of Oil Price Volatility on Korean Macro Economic Activities : An EGARCH and VECM Approach (국제유가의 변동성이 한국 거시경제에 미치는 영향 분석 : EGARCH 및 VECM 모형의 응용)

  • Kim, Sang-Su
    • Journal of Distribution Science
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    • v.11 no.10
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    • pp.73-79
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    • 2013
  • Purpose - This study examines the impact of oil price volatility on economic activities in Korea. The new millennium has seen a deregulation in the crude oil market, which invited immense capital inflow into Korea. It has also raised oil price levels and volatility. Drawing on the recent theoretical literature that emphasizes the role of volatility, this paper attends to the asymmetric changes in economic growth in response to the oil price movement. This study further examines several key macroeconomic variables, such as interest rate, production, and inflation. We come to the conclusion that oil price volatility can, in some part, explain the structural changes. Research design, data, and methodology - We use two methodological frameworks in this study. First, in regards to the oil price uncertainty, we use an Exponential-GARCH (Exponential Generalized Autoregressive Conditional Heteroskedasticity: EGARCH) model estimate to elucidate the asymmetric effect of oil price shock on the conditional oil price volatility. Second, along with the estimation of the conditional volatility by the EGARCH model, we use the estimates in a VECM (Vector Error Correction Model). The study thus examines the dynamic impacts of oil price volatility on industrial production, price levels, and monetary policy responses. We also approximate the monetary policy function by the yield of monetary stabilization bond. The data collected for the study ranges from 1990: M1 to 2013: M7. In the VECM analysis section, the time span is split into two sub-periods; one from 1990 to 1999, and another from 2000 to 2013, due to the U.S. CFTC (Commodity Futures Trading Commission) deregulation on the crude oil futures that became effective in 2000. This paper intends to probe the relationship between oil price uncertainty and macroeconomic variables since the structural change in the oil market became effective. Results and Conclusions - The dynamic impulse response functions obtained from the VECM show a prolonged dampening effect of oil price volatility shock on the industrial production across all sub-periods. We also find that inflation measured by CPI rises by one standard deviation shock in response to oil price uncertainty, and lasts for the ensuing period. In addition, the impulse response functions allude that South Korea practices an expansionary monetary policy in response to oil price shocks, which stems from oil price uncertainty. Moreover, a comparison of the results of the dynamic impulse response functions from the two sub-periods suggests that the dynamic relationships have strengthened since 2000. Specifically, the results are most drastic in terms of industrial production; the impact of oil price volatility shocks has more than doubled from the year 2000 onwards. These results again indicate that the relationships between crude oil price uncertainty and Korean macroeconomic activities have been strengthened since the year2000, which resulted in a structural change in the crude oil market due to the deregulation of the crude oil futures.

The Role of the Insulin-like Growth Factor System during the Periimplantation Period (착상기 Insulin-like Growth Factor System의 역할)

  • 이철영
    • Journal of Embryo Transfer
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    • v.12 no.3
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    • pp.229-246
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    • 1997
  • Implantation is a most important biological process during pregnancy whereby conceptus establishes its survival as well as maintenance of pregnancy. During the periimplantation period, both uterine endometriurn and conceptus synthesize and secrete a host of growth factors and cytokines which mediate the actions of estrogen and /or progesterone and also exert their steroid-independent actions. Growth factors expressed by the materno-conceptal unit en masse have important roles in cell migration, stimulation or inhibition of cell proliferation, cellular differentiation, maintenance of pregnancy and materno-conceptal communications in an autorcrine /paracrine manner. The present review focuses on the role of the intrauterine IGF system during periimplantation conceptus development. The IGF system comprises of IGF- I and IGF- II ligands, types I and II IGF receptors and six or more IGF-binding proteins(IGFBPs). IGFs and IGFBPs are expressed and secreted by uterine endometrium with tissue, pregnancy stage and species specificities under the influence of estrogen, progesterone and other growth factor(s). Conceptus also synthesizes components of the IGF system beginning from a period between 2-cell and blastocyst stages. Maternal IGFs are utilized by both maternal and conceptal tissues; conceptus-derived growth factors are believed to be taken up primarily by conceptus. IGFs enhance the development of both maternal and conceptal compartments in a wide range of biological processes. They stimulate proliferation and differentiation of endometrial cells and placental precursor cells including decidual transformation from stromal cells, placental formation and the synthesis of some steroid and protein hormones by differentiated endometrial cells or placenta. It is also well-documented in a number of experimental settings that both IGFs stimulate preimplantation embryo development. In slight contrast to these, prenatal mice carrying a null mutation of IGF and /or IGF receptor gene do not exhibit any apparent growth retardation until after implantation. Reason (s) for this discrepancy between the knock-out result and the in vitro ones, however, is not known. IGFBPs, in general, are believed to inhibit IGF action within the materno-conceptal unit, thereby allowing endometrial stromal cell differentiation as well as dampening ex cessive placental invasion into maternal tissue. There is evidence, however, indicating that IGFBP can enhance IGF action depending on environrnental conditions perhaps by directioning IGF ligand to the target cell. There is also a third possibility that certain IGFBPs and their proteolytic fragments may have their own biological activities independent of the IGF. In addition to IGFBPs, IGFBP proteases including those found within the uterine tissue or lumen are thought to enhance IGF bioavailability by degrading their substrates without affecting their bound ligand. In this regard, preliminary results in early pregnant pigs suggest that a partially characterized IGFBP protease activity in uterine luminal fluid enhances intrauterine IGF bioavailability during conceptus morphological development. In summary, a number of in vitro results indicate that IGFs stimulates the development of the rnaterno-conceptal unit during the periimplantation period. IGFBPs appear to inhibit IGF action by sequestering their ligands, whereas IGFBP proteases are thought to enhance intrauterine bioavailability of IGFs. Much is remaining to be clarified, however, regarding the roles of the individual IGF system components. These include in vivo evidence for the role of IGFs in early conceptus development, identification of IGF-regulated genes and their functions, specific roles for individual IGFBPs, identification and characterization of IGFBP proteases. The intrauterine IGF club house thus will be paying a lot of attention to forthcoming results in above and other areas, with its door wide-open!

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A Study on the Feasibility of the Espionage Charges for the Industrial Technology Divulgence (산업기술의 해외유출행위에 대한 간첩죄 처벌 타당성 연구)

  • Kim, Hang-Gon;Lee, Chang-Moo
    • Korean Security Journal
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    • no.57
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    • pp.253-275
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    • 2018
  • Economic security emerged as a strong element of national security. Nations around the world are exerting their efforts to collect economic intelligence to serve their national interest while making added efforts to uncover industrial espionage and arrest industrial spies in defensive aspect. Cases in point are the enactment of "Economic Espionage Act(1996)" of the U.S. and the "Act on Prevention of Divulgence and Protection of Industrial Technology(2006)"of Korea. Korea is trying to punish industrial spying on the same level as espionage that poses national security threat by revising Criminal Code. It is necessary to review whether the move to toughen the punishment of industrial spying from "up to 15 years in prison and/or up to 1.5 billion won in fine" to "minimum seven years of imprisonment, life imprisonment or death penalty" is appropriate. Advanced nations regulate industrial spying with a special act on economy although they have applied espionage act not to "enemy states" but to "foreign countries" in the first place. Likewise, preventing industrial spying by applying espionage act through the revision of criminal code poses a risk of undermining the autonomy of industry sector by excessive influence of state power. Furthermore, the penalty of minimum imprisonment of seven years, life imprisonment or death penalty with the application of espionage act under the criminal code is an legal application by stretching of the law, posing a risk of dampening healthy economic activities. Therefore, revising and applying relevant economic laws such as aforementioned 'Act on Prevention of Divulgence and Protection of Industrial Technology(2006)' is thought to be desirable to achieve the goal of protecting industrial technologies.

Ruminal pH pattern, fermentation characteristics and related bacteria in response to dietary live yeast (Saccharomyces cerevisiae) supplementation in beef cattle

  • Zhang, Xiangfei;Dong, Xianwen;Wanapat, Metha;Shah, Ali Mujtaba;Luo, Xiaolin;Peng, Quanhui;Kang, Kun;Hu, Rui;Guan, Jiuqiang;Wang, Zhisheng
    • Animal Bioscience
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    • v.35 no.2
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    • pp.184-195
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    • 2022
  • Objective: In this study we aimed to evaluate the effect of dietary live yeast supplementation on ruminal pH pattern, fermentation characteristics and associated bacteria in beef cattle. Methods: This work comprised of in vitro and in vivo experiments. In vitro fermentation was conducted by incubating 0%, 0.05%, 0.075%, 0.1%, 0.125%, and 0.15% active dried yeast (Saccharomyces cerevisiae, ADY) with total mixed ration substrate to determine its dose effect. According to in vitro results, 0.1% ADY inclusion level was assigned in in vivo study for continuously monitoring ruminal fermentation characteristics and microbes. Six ruminally cannulated steers were randomly assigned to 2 treatments (Control and ADY supplementation) as two-period crossover design (30-day). Blood samples were harvested before-feeding and rumen fluid was sampled at 0, 3, 6, 9, and 12 h post-feeding on 30 d. Results: After 24 h in vitro fermentation, pH and gas production were increased at 0.1% ADY where ammonia nitrogen and microbial crude protein also displayed lowest and peak values, respectively. Acetate, butyrate and total volatile fatty acids concentrations heightened with increasing ADY doses and plateaued at high levels, while acetate to propionate ratio was decreased accordingly. In in vivo study, ruminal pH was increased with ADY supplementation that also elevated acetate and propionate. Conversely, ADY reduced lactate level by dampening Streptococcus bovis and inducing greater Selenomonas ruminantium and Megasphaera elsdenii populations involved in lactate utilization. The serum urea nitrogen decreased, whereas glucose, albumin and total protein concentrations were increased with ADY supplementation. Conclusion: The results demonstrated dietary ADY improved ruminal fermentation dose-dependently. The ruminal lactate reduction through modification of lactate metabolic bacteria could be an important reason for rumen pH stabilization induced by ADY. ADY supplementation offered a complementary probiotics strategy in improving gluconeogenesis and nitrogen metabolism of beef cattle, potentially resulted from optimized rumen pH and fermentation.

A study on the activation plan of domestic franchise companies third party logistics (국내 프랜차이즈 기업의 제3자 물류 활성화에 관한 연구 : 본아이에프 사례 중심으로)

  • Cho, Jun-ho;Lee, Sang-Youn
    • The Journal of Industrial Distribution & Business
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    • v.2 no.2
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    • pp.15-24
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    • 2011
  • Modern enterprises should concentrate their efforts on continuous improvements in focusing their development in the core areas of business and to reduce their expenses and to enhance the quality of service for customers. The enterprises should focus on their core business while outsourcing the non-core areas of business to external specialists for the purpose of reducing cost. In South Korea, the enterprises are becoming increasingly interested in outsourcing their logistics function, especially in using IT technologies to the 3PL. The underlying reason for this trend is because the logistics costs of Korean businesses are much higher than that of other advanced countries. This higher logistic costs weakens the price competitiveness of Korean companies in the overseas export markets and even dampening the balance of international trade. Domestically, the higher logistics costs have the effect of raising prices in the local markets and thus affecting the local economy. Therefore a solution is urgently needed to save the logistics costs for the Korean companies in the interest of increasing national competitiveness. Outsourcing to the 3PL is becoming an attraction solution to this problem. Thanks to the increasing supply of professional logistics companies, many of the enterprises are switching to the Third Party Logistics. Nevertheless the enterprises do not yet utilize the integrated third-party logistics services on a full scale. This study analyzes present conditions and problems of the domestic third-party logistics market and suggests directions for future development. To solve the problems in the domestic third-party logistics market, four actions are recommended. First there should be new supporting policies in the laws and regulations and a system for small and medium sized companies to grow. Solutions to structural problems such as abnormal multilevel merchandising, illegal operation of private cars, and freight dumping should be implemented concurrently. Furthermore, standards for new companies entry into the market should be enhanced to allow only the competitive distribution companies to enter the market. Second, development of variety of educational programs is needed through establishing human-resource development system and specialized formal educational institution focused on this market. Third, the third party distribution companies, which seek long-term relationships with the owners of goods, should endeavor to strengthen their communications capability. Fourth, adoption of high-tech distribution system and the advent of U-Logistics, making use of RFID is urgent. This study has the limitation of objectivity because it does not include various comparative case studies about companies relating to the Third Party Logistics and domestic franchise companies. However, this study is significant to the extent that it analyzes the general present conditions and the problems of domestic Third Party Logistics and suggests recommendations for revitalization of Third Party Logistics. For future studies, analyzing the successful cases of international third party logistics companies' empirical data and studying the application into domestic franchise companies would improve the objectivity of the results. This would assist the domestic third party logistics companies not only to perform excellent domestic logistics function but also to enter into the global market for international logistics.

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