• Title/Summary/Keyword: damage models

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Motion Analysis of Light Buoys Combined with 7 Nautical Mile Self-Contained Lantern (7마일 등명기를 결합한 경량화 등부표의 운동 해석)

  • Son, Bo-Hun;Ko, Seok-Won;Yang, Jae-Hyoung;Jeong, Se-Min
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.5
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    • pp.628-636
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    • 2018
  • Because large buoys are mainly made of steel, they are heavy and vulnerable to corrosion by sea water. This makes buoy installation and maintenance difficult. Moreover, vessel collision accidents with buoys and damage to vessels due to the material of buoys (e.g., steel) are reported every year. Recently, light buoys adopting eco-friendly and lightweight materials have come into the spotlight in order to solve the previously-mentioned problems. In Korea, a new lightweight buoy with a 7-Nautical Mile lantern adopting expanded polypropylene (EPP) and aluminum to create a buoyant body and tower structure, respectively, was developed in 2017. When these light buoys are operated in the ocean, the visibility and angle of light from the lantern installed on the light buoys changes, which may cause them to function improperly. Therefore, research on the performance of light buoys is needed since the weight distribution and motion characteristics of these new buoys differ from conventional models. In this study, stability estimation and motion analyses for newly-developed buoys under various environmental conditions considering a mooring line were carried out using ANSYS AQWA. Numerical simulations for the estimation of wind and current loads were performed using commercial CFD software, Siemens STAR-CCM+, to increase the accuracy of motion analysis. By comparing the estimated maximum significant motions of the light buoys, it was found that waves and currents were more influential in the motion of the buoys. And, the estimated motions of the buoys became larger as the sea state became worser, which might be the reason that the peak frequencies of the wave spectra got closer to those of the buoys.

Potential Role of Hedgehog Signaling in Radiation-induced Liver Fibrosis (방사선에 의한 간섬유증에서 헤지호그의 잠재적 역할)

  • Wang, Sihyung;Jung, Youngmi
    • Journal of Life Science
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    • v.23 no.5
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    • pp.710-720
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    • 2013
  • Radiotherapy is commonly used in treating many kinds of cancers which cannot be cured by other therapeutic strategies. However, radiotherapy also induces the damages on the normal tissues. Radiation-induced fibrosis is frequently observed in the patients undergoing radiotherapy, and becomes a major obstacle in the treatment of intrahepatic cancer. Hedgehog (Hh) that is an essential in the liver formation during embryogenesis is not detected in the healthy liver, but activated and modulates the repair process in damaged livers in adult. The expression of Hh increases with the degree of liver damage, regulating the proliferation of hepatic progenitors and hepatic stellate cells (HSC). In addition, Hh induces epithelial-to-mesencymal transition (EMT) and activation of myofibroblasts. In the irradiated livers, up-regulated expression of Hh signaling was associated with proliferation of progenitors, EMT induction, and increased fibrosis. Female-specific expression of Hh leaded to the expansion of progenitors and the accumulation of collagen in the irradiated livers of female mice, indicating that gender disparity in Hh expression may be related with radiation-susceptibility in female. Hence, Hh signaling becomes a novel object of studies for fibrogenesis induced by radiation. However, the absence of the established experimental animal models showing the similar physiopathology with human liver diseases and fibrosis-favorable microenvironment hamper the studies for the radiation-induced fibrosis, providing a few descriptive results. Therefore, further research on the association of Hh with radiation-induced fibrosis can identify the cell and tissue-specific effects of Hh and provides the basic knowledge for underlying mechanisms, contributing to developing therapies for preventing the radiation-induced fibrosis.

Anti-inflammatory Effects of Inhalation of Injured Starfish Extracts on Formaldehyde Exposure (손상된 불가사리 추출물 흡입이 포름알데히드 노출에 의한 항염증 작용에 미치는 효과)

  • Hwang, Kyung Hee;Chang, Su Chan;Park, Jong Seok;Wahid, Fazli;Kim, You Young
    • Journal of Life Science
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    • v.23 no.4
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    • pp.501-509
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    • 2013
  • Formaldehyde (FA) is widely used in industries, and it is an indoor and outdoor pollutant. Exposure to FA may cause inflammation and respiratory oxidative stress. Studies have demonstrated that FA can cause cancer in animal models. During the regeneration process of injured starfish (Asterina pectinifera), several changes have been observed in the expression of cytokines. In particular, higher TGF-${\beta}1$ expression has been detected in arm cut starfish extract after eight days. The current study was designed to elucidate the in-vitro and the in-vivo pharmacological effects of starfish extract on FA exposure. We investigated the protective effects of intact starfish extract and arm cut starfish extract on an IMR-90 cell line and on mouse lung injury in response to FA exposure. In the presence of FA, inhalation of the arm cut starfish extract was associated with more promising cell proliferation, TNF-${\alpha}$, NF-${\kappa}B$ decrement, and $I{\kappa}-B{\alpha}$ increment. In the experimental group, the pulmonary structure of the arm cut starfish extract-treated group in the presence of FA exposure was similar to the control group, whereas the FA exposure group showed damage to the pulmonary structure. Moreover, the arm cut starfish extracts was more effective than the intact starfish extracts in terms of the expression of TNF-${\alpha}$, NF-${\kappa}B$, $I{\kappa}-B{\alpha}$, and surfactant protein A. The results obtained in this study demonstrate that arm cut starfish extracts are more effective in protecting pulmonary structure and function against FA exposure than intact starfish extracts.

Legal Relations of the Contract of International Carriage of Goods by Air (국제항공화물운송계약(國際航空貨物運送契約)의 법률관계(法律關係) -화주(貨主)의 권리의무(權利義務)를 중심(中心)으로-)

  • Lee, Kang-Bin
    • The Korean Journal of Air & Space Law and Policy
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    • v.1
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    • pp.193-222
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    • 1989
  • The purpose of this study is to review the rights and duties of cargo owners, the party to the contract of international carriage of goods by air under the Warsaw Convention System and the IATA conditions. It is generally known that air freight is the most-cost mode of transportation. However, should there be considerations of total distribution cost, the use of air freight leads exporters to be advantageous in physical distribution. The Warsaw Convention System defined and limited the rights and duties of cargo owners and air carriers paticipating in the international carriage of goods, but it does not regulate every aspect of air transportation. Therefore, the unregulated parts are governed by national laws and by individual contracts of carriage. The International Air Transport Association(lATA), a worldwide organization of airlines, has formulated model conditions of contract for the carriage of cargo. These models are not uniformly followed but they serve as a basis for many of the individual standard form of contracts prepared by air carriers. The contract of air carriage of goods is a contract of adhesion, 'the consignor recognizing and accepting the conditions laid down by the carrier'. There are consignors and carriers as the parties to the contract of international carriage of goods. In addition to his basic right, implied in Warsaw Convention Article 18 and 19, to require devery of the goods in good condition and at the date agreed upon, the consignor has the right to dispose the goods in the course of the journey up to the moment when the consignee is entitled to require delivery. If it is impossible to carry out the orders of the consignor, the carrier must so inform him forthwith. The right conferred on the consignor ceases at the moment when that of the consignee begins in accordance with Warsaw Convention Article 13. Nevertheless, if the consignee declines to accept the air waybill or the goods, or if he cannot be communicated with, the consignor resumes his right of disposition. Unless it is otherwise agreed, it is the duty of the carrier to give notice to the consignee as soon as the goods arrive. The consignee is entitled, on arrival of the goods at the place of destination, to require the carrier to hand over to him the air waybill and to deliver the goods to him, on payment of the charges due and on complying with the conditions of carriage set out in the air waybill. The air waybill is supposed to be made out by the consignor. If the carrier makes it out, he is deemed, subject to proof to the contrary, to have done so on behalf of the consignor, whether there is one air waybill or several, each must be made out in three original parts. The first is for the carrier, the second is for the consignee, and the the third is handed to the consignor when the shipment has been accepted. The consignor is responsible for the correctness of the particulars and statement concerning the cargo appearing in the air waybill. Each of the original parts of the air waybill has evidential value and possession of his part is a condition for the exercise by the consignor or consignee of his rights under the contract of carriage. Hague Protocol set forth in Article 9 that nothing in this. Convention prevents the issue of a negotiable air waybill, but Montreal Additional Protocol No. 4 deleted this article. All charges applicable to a shipment are payable in cash at the time of acceptance thereof by the carrier in case of a prepaid shipment or at the time of delivery thereof by the carrier in case of a collect shipment. The carrier shall have lien the cargo for unpaid charges and, in the event of non-payment thereof, shall have the right to dispose of the cargo at public or private sale and pay itself out of the proceeds of such sale any and all such amounts. In conclusion, the Warsaw Convention System has the character of ambiguity in various respects, not only in the part of the forms of documents but also in conditions of contract. Accordingly, the following propositions might be considered: (1) If the carrier does not obey the orders of the consignor for the disposition of the goods without proper reasons, he will be liable strictly for any damage which may be caused thereby to the cargo owner. The special agreement and carrier's conditions of carriage which limit unreasonably the consignor's right of disposition of the goods will be nullified. (2) The instrument of the Warsaw Convention System which is not yet in force(Montreal Additional Protocol No. 4) would considerably simplfy the processing and keeping of computerized records of the carriage. Until this instrument enters into force, the airlines will be faced with practical problems preventing them to substitute computerized data processing techniques for the formal issuance of the documents. Accordingly, Montreal Additional Protocol No. 4 should become effective as soon as posisble. From a practical point of view in the international trade, the issuance of negotiable air waybill should be permitted for the security of the bank.

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Change Detection of land-surface Environment in Gongju Areas Using Spatial Relationships between Land-surface Change and Geo-spatial Information (지표변화와 지리공간정보의 연관성 분석을 통한 공주지역 지표환경 변화 분석)

  • Jang Dong-Ho
    • Journal of the Korean Geographical Society
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    • v.40 no.3 s.108
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    • pp.296-309
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    • 2005
  • In this study, we investigated the change of future land-surface and relationships of land-surface change with geo-spatial information, using a Bayesian prediction model based on a likelihood ratio function, for analysing the land-surface change of the Gongju area. We classified the land-surface satellite images, and then extracted the changing area using a way of post classification comparison. land-surface information related to the land-surface change is constructed in a GIS environment, and the map of land-surface change prediction is made using the likelihood ratio function. As the results of this study, the thematic maps which definitely influence land-surface change of rural or urban areas are elevation, water system, population density, roads, population moving, the number of establishments, land price, etc. Also, thematic maps which definitely influence the land-surface change of forests areas are elevation, slope, population density, population moving, land price, etc. As a result of land-surface change analysis, center proliferation of old and new downtown is composed near Gum-river, and the downtown area will spread around the local roads and interchange areas in the urban area. In case of agricultural areas, a small tributary of Gum-river or an area of local roads which are attached with adjacent areas showed the high probability of change. Most of the forest areas are located in southeast and from this result we can guess why the wide chestnut-tree cultivation complex is located in these areas and the capability of forest damage is very high. As a result of validation using a prediction rate curve, a capability of prediction of urban area is $80\%$, agriculture area is $55\%$, forest area is $40\%$ in higher $10\%$ of possibility which the land-surface change would occur. This integration model is unsatisfactory to Predict the forest area in the study area and thus as a future work, it is necessary to apply new thematic maps or prediction models In conclusion, we can expect that this way can be one of the most essential land-surface change studies in a few years.

Topographic Factors Computation in Island: A Comparison of Different Open Source GIS Programs (오픈소스 GIS 프로그램의 지형인자 계산 비교: 도서지역 경사도와 지형습윤지수 중심으로)

  • Lee, Bora;Lee, Ho-Sang;Lee, Gwang-Soo
    • Korean Journal of Remote Sensing
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    • v.37 no.5_1
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    • pp.903-916
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    • 2021
  • An area's topography refers to the shape of the earth's surface, described by its elevation, slope, and aspect, among other features. The topographical conditions determine energy flowsthat move water and energy from higher to lower elevations, such as how much solar energy will be received and how much wind or rain will affect it. Another common factor, the topographic wetness index (TWI), is a calculation in digital elevation models of the tendency to accumulate water per slope and unit area, and is one of the most widely referenced hydrologic topographic factors, which helps explain the location of forest vegetation. Analyses of topographical factors can be calculated using a geographic information system (GIS) program based on digital elevation model (DEM) data. Recently, a large number of free open source software (FOSS) GIS programs are available and developed for researchers, industries, and governments. FOSS GIS programs provide opportunitiesfor flexible algorithms customized forspecific user needs. The majority of biodiversity in island areas exists at about 20% higher elevations than in land ecosystems, playing an important role in ecological processes and therefore of high ecological value. However, island areas are vulnerable to disturbances and damage, such as through climate change, environmental pollution, development, and human intervention, and lacks systematic investigation due to geographical limitations (e.g. remoteness; difficulty to access). More than 4,000 of Korea's islands are within a few hours of its coast, and 88% are uninhabited, with 52% of them forested. The forest ecosystems of islands have fewer encounters with human interaction than on land, and therefore most of the topographical conditions are formed naturally and affected more directly by weather conditions or the environment. Therefore, the analysis of forest topography in island areas can be done more precisely than on its land counterparts, and therefore has become a major focus of attention in Korea. This study is focused on calculating the performance of different topographical factors using FOSS GIS programs. The test area is the island forests in Korea's south and the DEM of the target area was processed with GRASS GIS and SAGA GIS. The final slopes and TWI maps were produced as comparisons of the differences between topographic factor calculations of each respective FOSS GIS program. Finally, the merits of each FOSS GIS program used to calculate the topographic factors is discussed.

Atorvastatin and Fluvastatin Can Reduce IL-1β-induced Inflammatory Responses in Human Keratinocytes (Atorvastatin 그리고 fluvastatin 약물의 IL-1β-유도 염증반응 억제 효과)

  • Choe, Yeong-In;Moon, Kyoung Mi;Yoo, Jae Cheal;Byun, June-Ho;Hwang, Sun-Chul;Moon, Dong Kyu;Woo, Dong Kyun
    • Journal of Life Science
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    • v.31 no.4
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    • pp.418-424
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    • 2021
  • Skin inflammation (dermatitis) is caused by varying skin damage due to ultraviolet radiation and microbial infection. Currently prescribed drugs for dermatitis include anti-histamine and steroid drug classes that soothe inflammation. However, incorrect or prolonged use of steroids can cause weakening of skin barriers as well as osteoporosis. Therefore, treating dermatitis with a drug that has minimal side effects is important. Statins, also known as 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, are cholesterol-lowering drugs that have been widely treated for hyperlipidemia and cardiovascular diseases. Interestingly, recent studies have shown the anti-inflammatory effects of statins in both experimental and clinical models for of osteoarthritis. This study investigated the possible anti-inflammatory effects of atorvastatin and fluvastatin in human keratinocytes (HaCaT cells), which are crucial components of skin barriers. Stimulation of HaCaT cells with IL-1β increased the expression of the COX2 protein, a major player of inflammatory responses. However, this induction of the COX2 protein was downregulated by pretreatments with atorvastatin and fluvastatin. Treatment with IL-1ß-induced the upregulation of other inflammatory genes (such as iNOS and MMP-1) and these expressions were similarly lowered by these two statin drug treatments. Taken together, these results indicated that atorvastatin and fluvastatin can reduce IL-1β-induced inflammatory responses in HaCaT cells. In conclusion, the findings suggest that atorvastatin and fluvastatin can be potential modulators for ameliorating skin inflammation.

Development of 3D Impulse Calculation Technique for Falling Down of Trees (수목 도복의 3D 충격량 산출 기법 개발)

  • Kim, Chae-Won;Kim, Choong-Sik
    • Journal of the Korean Institute of Landscape Architecture
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    • v.51 no.2
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    • pp.1-11
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    • 2023
  • This study intended to develop a technique for quantitatively and 3-dimensionally predicting the potential failure zone and impulse that may occur when trees are fall down. The main outcomes of this study are as follows. First, this study established the potential failure zone and impulse calculation formula in order to quantitatively calculate the risks generated when trees are fallen down. When estimating the potential failure zone, the calculation was performed by magnifying the height of trees by 1.5 times, reflecting the likelihood of trees falling down and slipping. With regard to the slope of a tree, the range of 360° centered on the root collar was set in the case of trees that grow upright and the range of 180° from the inclined direction was set in the case of trees that grow inclined. The angular momentum was calculated by reflecting the rotational motion from the root collar when the trees fell down, and the impulse was calculated by converting it into the linear momentum. Second, the program to calculate a potential failure zone and impulse was developed using Rhino3D and Grasshopper. This study created the 3-dimensional models of the shapes for topography, buildings, and trees using the Rhino3D, thereby connecting them to Grasshopper to construct the spatial information. The algorithm was programmed using the calculation formula in the stage of risk calculation. This calculation considered the information on the trees' growth such as the height, inclination, and weight of trees and the surrounding environment including adjacent trees, damage targets, and analysis ranges. In the stage of risk inquiry, the calculation results were visualized into a three-dimensional model by summarizing them. For instance, the risk degrees were classified into various colors to efficiently determine the dangerous trees and dangerous areas.

Impact Assessment of Agricultural Reservoir on Streamflow Simulation Using Semi-distributed Hydrologic Model (준분포형 모형을 이용한 농업용 저수지가 안성천 유역의 유출모의에 미치는 영향 평가)

  • Kim, Bo Kyung;Kim, Byung Sik;Kwon, Hyun Han
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.1B
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    • pp.11-22
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    • 2009
  • Long-term rainfall-runoff modeling is a key element in the Earth's hydrological cycle, and associated with many different aspects such as dam design, drought management, river management flow, reservoir management for water supply, water right permission or coordinate, water quality prediction. In this regard, hydrologists have used the hydrologic models for design criteria, water resources assessment, planning and management as a main tool. Most of rainfall-runoff studies, however, were not carefully performed in terms of considering reservoir effects. In particular, the downstream where is severely affected by reservoir was poorly dealt in modeling rainfall-runoff process. Moreover, the effects can considerably affect overall the rainfallrunoff process. An objective of this study, thus, is to evaluate the impact of reservoir operation on rainfall-runoff process. The proposed approach is applied to Anseong watershed, where is in a mixed rural/urban setting of the area and in Korea, and has been experienced by flood damage due to heavy rainfall. It has been greatly paid attention to the agricultural reservoirs in terms of flood protection in Korea. To further investigate the reservoir effects, a comprehensive assessment for the results are discussed. Results of simulations that included reservoir in the model showed the effect of storage appeared in spring and autumn when rainfall was not concentrated. In periods of heavy rainfall, however, downstream runoff increased in simulations that do not consider reservoir factor. Flow duration curve showed that changes in streamflow depending upon the presence or absence of reservoir factor were particularly noticeable in ninety-five day flow and low flow.

Tokamak plasma disruption precursor onset time study based on semi-supervised anomaly detection

  • X.K. Ai;W. Zheng;M. Zhang;D.L. Chen;C.S. Shen;B.H. Guo;B.J. Xiao;Y. Zhong;N.C. Wang;Z.J. Yang;Z.P. Chen;Z.Y. Chen;Y.H. Ding;Y. Pan
    • Nuclear Engineering and Technology
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    • v.56 no.4
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    • pp.1501-1512
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    • 2024
  • Plasma disruption in tokamak experiments is a challenging issue that causes damage to the device. Reliable prediction methods are needed, but the lack of full understanding of plasma disruption limits the effectiveness of physics-driven methods. Data-driven methods based on supervised learning are commonly used, and they rely on labelled training data. However, manual labelling of disruption precursors is a time-consuming and challenging task, as some precursors are difficult to accurately identify. The mainstream labelling methods assume that the precursor onset occurs at a fixed time before disruption, which leads to mislabeled samples and suboptimal prediction performance. In this paper, we present disruption prediction methods based on anomaly detection to address these issues, demonstrating good prediction performance on J-TEXT and EAST. By evaluating precursor onset times using different anomaly detection algorithms, it is found that labelling methods can be improved since the onset times of different shots are not necessarily the same. The study optimizes precursor labelling using the onset times inferred by the anomaly detection predictor and test the optimized labels on supervised learning disruption predictors. The results on J-TEXT and EAST show that the models trained on the optimized labels outperform those trained on fixed onset time labels.