• Title/Summary/Keyword: Loss and damage

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Strain energy release rates in the curved spar wingskin joints with pre-embedded delaminations

  • P.K. Mishra;A.K. Pradhan;M.K. Pandit ;S.K. Panda
    • Structural Engineering and Mechanics
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    • v.87 no.1
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    • pp.47-56
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    • 2023
  • Any pre-existed delamination defect present during manufacturing or induce during service loading conditions in the wingskin adherend invariably shows a greater loss of structural integrity of the spar wingskin joint (SWJ). In the present study, inter-laminar delamination propagation at the critical location of the SWJ has been carried out using contact and multi-point constraint finite elements available with commercial FE software (ANSYS APDL). Strain energy release rates (SERR) based on virtual crack closure technique have been computed for evaluation of the opening (Mode-I), sliding (Mode-II) and cross sliding (Mode-III) modes of delamination by sequential release of multi point constraint elements. The variations of different modes of SERR are observed to be significant by considering varied delamination lengths, material properties of adherends and radius of curvature of the SWJ panel. The SERR rates are seen to be much different at the two pre-embedded delamination ends. This shows dissimilar delamination propagation rates. The maximum is seen to occur in the delamination front in the unstiffened region of the wingskin. The curvature geometry and material anisotropy of SWJ adherends significantly influences the SERR values. Increase in the SERR values are observed with decrease in the radius of curvature of wingskin panel, keeping its width unchanged. SWJs made with flat FRP composite adherends have superior resistance to delamination damage propagation than curved composite laminated SWJ panels. SWJ made with Boron/Epoxy (B/E) material shows greater resistance to the delamination propagation.

Physicochemical and textural properties of thawed pork by vacuum tumbling (진공 텀블링을 이용한 해동 돈육의 이화학적 및 조직학적 특성)

  • Su-Jin Park;Won-Ho Hong;Seung-Min Oh;Chang-Hee Cho;Jiyeon Chun
    • Food Science and Preservation
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    • v.31 no.3
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    • pp.423-432
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    • 2024
  • In this study, a vacuum tumbler with 4 impellers (DVT) was designed and applied for thawing frozen pork (vacuum -60 kPa, jacket 35℃, 1 rpm). Quality characteristics of the thawed pork were compared with those of industrially thawed meat by natural air at room temperature (NAT) and imported vacuum tumbler (IVT). The thawing time for frozen pork (303.36 kg) using DVT (165 min) was much shorter than that of NAT (4,200 min). DVT-thawed pork had lower drip loss (0.85%) than NAT (2.08%). DVT-thawed pork showed a pH of 5.92, a total bacterial count of 1.96±0.02 log CFU/g and no coliforms. Deteriorations in fat (TBARS 0.31±0.01 MDA mg/kg) and protein (VBN 5.67±1.98 mg%) in DVT-thawed pork were significantly lower than those of NAT (p<0.05). DVT-thawed pork had a high water-holding capacity (WHC, 97.5%). The hardness (34.59±0.46 N) and chewiness (188.21±0.17) of cooked DVT-thawed pork were about 5-6 times lower than those of NTA. Microstructure (SEM) showed myofibrillar damage in NAT-thawed pork, whereas dense myofibrillar structure was observed in DVT-thawed pork. DVT was better or similar to IVT in all evaluation parameters. The designed DVT is expected to be used as an efficient thawing method in terms of processing time and yield and to produce thawed meat with high WHC, soft texture, and low spoilage by minimizing tissue damage.

A Study of Emergency Plan Making Programs for Personnel Handling Accident Precaution Chemicals (사고대비물질 취급자를 위한 비상대응계획 작성 프로그램 연구)

  • Kim, Sung Bum;Cho, Mun Sik;Park, Choon Hwa;Yoon, Yi;Hwang, Kyung Sup;Yang, Sang Yong
    • Journal of Korean Society of societal Security
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    • v.3 no.2
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    • pp.27-32
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    • 2010
  • Emergency preparedness plan (EPP) is the systematic management of activities that involve a material degree of risk of loss or other damage to the surroundings (people, property and environment), and the boundary of accident recovery plan (ARP). The main purpose of the program is to provide a safety management system to each facility in order to enable to prevent accident and to control accident immediately. The EPP includes not only typical safety-related documentations such as material safety data sheet (MSDS), standard operation procedure (SOP), emergency response plan(ERP). EPP is established basis of the preliminary safety analysis involving risk identification, assessment and prevention plans. The program is also helpful for government or related agencies to control a number of accidents in small-scale companies in the whole country.

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Animal Models of Demyelination and 1H-Magnetic Resonance Spectroscopy (탈수초화 동물 모델과 1H 자기공명분광영상)

  • Cho, Han Byul;Lee, Suji;Park, Shinwon;Kang, Ilhyang;Ma, Jiyoung;Jeong, Hyeonseok S.;Kim, Jieun E.;Yoon, Sujung;Lyoo, In Kyoon;Lim, Soo Mee;Kim, Jungyoon
    • Korean Journal of Biological Psychiatry
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    • v.24 no.1
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    • pp.1-9
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    • 2017
  • The proton magnetic resonance spectroscopy ($^1H-MRS$) is a tool used to detect concentrations of brain metabolites such as N-acetyl aspartate, choline, creatine, glutamate, and gamma-amino butyric acid (GABA). It has been widely used because it does not require additional devices other than the conventional magnetic resonance scanner and coils. Demyelination, or the neuronal damage due to loss of myelin sheath, is one of the common pathologic processes in many diseases including multiple sclerosis, leukodystrophy, encephalomyelitis, and other forms of autoimmune diseases. Rodent models mimicking human demyelinating diseases have been induced by using virus (e.g., Theiler's murine encephalomyelitis virus) or toxins (e.g., cuprizon or lysophosphatidyl choline). This review is an overview of the MRS findings on brain metabolites in demyelination with a specific focus on rodent models.

A Study on the application simplified traffic signal system at the intersection of the city back road (도시 이면도로 교차로의 간이 교통신호시스템 적용연구)

  • Oh, Eun-Yeol
    • Journal of the Korea Convergence Society
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    • v.9 no.10
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    • pp.37-44
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    • 2018
  • In this thesis, the traffic signal system is generally applied to the intersection of urban side streets, where blind spots and cramped areas are high risk of accidents, contributing to the prevention of accidents and smooth traffic communication. Therefore, the purpose of the system is to prevent accidents and facilitate traffic communication by providing a light traffic signal at street intersections in busy cities. Also, this study is a universal application of traffic angle to vehicles without the need for a separate terminal installation, and the provision of traffic signals in cities In addition, it is thought that the narrow loss of life on the road can serve as a catalyst to help optimize its function as a signal system that can minimize damage.

Design and Implementation of Modified Web Contents Detection System (웹 컨텐츠 변경 탐지 시스템의 설계 및 구현)

  • 김영선;장덕철
    • Journal of Korea Multimedia Society
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    • v.7 no.1
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    • pp.91-97
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    • 2004
  • As the electronic commercial transaction is being transacted by contents which can get an illegal intrusion from the outside, we sincerely require security for them. We must consider a protection countermeasure about intrusion from protection of the passive form to protection intrusion of the active one. So the security is required against hackers illegality intrusion into the contents. As soon as the intrusion happens about the contents, the tools providing the monitor of contents are required to minimize the damage to the systems. Modified web contents detection system in this paper prevents the loss of resources and manpower required through individually monitoring on the web. Also, this paper offers rapid support of security that it analyzes the weakness of contents security of the web environment and the cause of the problem with the leakage of information. So this system has the pur pose of protecting the weakness of contents security and the leakage of information.

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The Role of Lumbar Drainage to Prevent Shunt-Dependent Hydrocephalus after Coil Embolization for Aneurysmal Subarachnoid Hemorrhage in Good-Grade Patients

  • Yong, Cho-In;Hwang, Sung-Kyun;Kim, Sung-Hak
    • Journal of Korean Neurosurgical Society
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    • v.48 no.6
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    • pp.480-484
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    • 2010
  • Objective : To evaluate the role of lumbar drainage in the prevention of shunt-dependent hydrocephalus after treatment of ruptured intracranial aneurysms by coil embolization in good-grade patients. Methods : One-hundred-thirty consecutive patients with aneurysmal subarachnoid hemorrhage in good-grade patients (Hunt & Hess grades I-III), who were treated by coil embolization between August 2004 and April 2010 were retrospectively evaluated. Poor-grade patients (Hunt & Hess grades IV and V), a history of head trauma preceding the development of headache, negative angiograms, primary subarachnoid hemorrhage (SAH), and loss to follow-up were excluded from the study. We assessed the effects on lumbar drainage on the risk of shunt-dependent hydrocephalus related to coil embolization in patients with ruptured intracranial aneurysms. Results : One-hundred-twenty-six patients (96.9%) did not develop shunt-dependent hydrocephalus. The 2 patients (1.5%) who developed acute hydrocephalus treated with temporary external ventricular drainage did not require permanent shunt diversion. Overall, 4 patients (3.1%) required permanent shunt diversion; acute hydrocephalus developed in 2 patients (50%). There was no morbidity or mortality amongst the patients who underwent a permanent shunt procedure. Conclusion : Coil embolization of ruptured intracranial aneurysms may be associated with a lower risk for developing shunt-dependent hydrocephalus, possibly by active management of lumbar drainage, which may reflect less damage for cisternal anatomy than surgical clipping. Coil embolization might have an effect the long-term outcome and decision-making for ruptured intracranial aneurysms.

A Design of Certificate Management Method for Secure Access Control in IoT-based Cloud Convergence Environment (IoT기반 클라우드 융합환경에서 안전한 접근제어를 위한 인증서 관리기법 설계)

  • Park, Jung-Oh
    • Journal of Convergence for Information Technology
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    • v.10 no.7
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    • pp.7-13
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    • 2020
  • IoT which is the core IT of the 4th industrial revolution, is providing various services from users in the conversion with other industries. The IoT convergence technology is leading the communication paradigm of communication environment in accordance with the increase of convenience for users. However, it is urgently needed to establish the security measures for the rapidly-developing IoT convergence technology. As IoT is closely related to digital ethics and personal information protection, other industries should establish the measures for coping with threatening elements in accordance with the introduction of IoT. In case when security incidents occur, there could be diverse problems such as information leakage, damage to image, monetary loss, and casualty. Thus, this paper suggests a certificate management technique for safe control over access in IoT-based Cloud convergence environment. This thesis designed the device/user registration, message communication protocol, and device renewal/management technique. On top of performing the analysis on safety in accordance with attack technique and vulnerability, in the results of conducting the evaluation of efficiency compared to the existing PKI-based certificate management technique, it showed about 32% decreased value.

Comparison of Liquefactive Hazard Map Regarding with Geotechnical Information and Spatial Interpolation Target (공간보간 대상 및 지반정보에 따른 액상화 재해도 비교)

  • Song, Seong-wan;Hwang, Bumsik;Cho, Wanjei
    • Journal of the Korean Geotechnical Society
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    • v.38 no.1
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    • pp.5-15
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    • 2022
  • Due to the Pohang earthquakes in 2017, concerns are increasing that Korea is no longer safe from liquefaction, and needs the research to take proper measures for liquefaction. Liquefaction is defined as the loss of shear strength of the ground. In order to solve this problem, many studies, such as composing a liquefaction hazard map using Liquefaction Potential Index (LPI), have been conducted. However, domestic researches on the comparative analysis of liquefaction prediction results are not sufficient. Therefore, in this study, liquefaction hazard maps were composed using the standard penetration test results, shear wave velocity values, and cone penetration test results. After that, the precision was determined by comparing the calculated LPI using the geotechnical information and predicted LPI via spatial interpolation target. Based on the analysis results, the predicted LPI value using geotechnical information is more precise than using calculated LPI value.

The Limitation of Air Carriers' Cargo and Baggage Liability in International Aviation Law: With Reference to the U.S. Courts' Decisions (국제항공법상 화물.수하물에 대한 운송인의 책임상한제도 - 미국의 판례 분석을 중심으로 -)

  • Moon, Joon-Jo
    • The Korean Journal of Air & Space Law and Policy
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    • v.22 no.2
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    • pp.109-133
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    • 2007
  • The legal labyrinth through which we have just walked is one in which even a highly proficient lawyer could easily become lost. Warsaw Convention's original objective of uniformity of private international aviation liability law has been eroded as the world community ha attempted again to address perceived problems. Efforts to create simplicity and certainty of recovery actually may have created less of both. In any particular case, the issue of which international convention, intercarrier agreement or national law to apply will likely be inconsistent with other decisions. The law has evolved faster for some nations, and slower for others. Under the Warsaw Convention of 1929, strict liability is imposed on the air carrier for damage, loss, or destruction of cargo, luggage, or goods sustained either: (1) during carriage in air, which is comprised of the period during which cargo is 'in charge of the carrier (a) within an aerodrome, (b) on board the aircraft, or (c) in any place if the aircraft lands outside an aerodrome; or (2) as a result of delay. By 2007, 151 nations had ratified the original Warsaw Convention, 136 nations had ratified the Hague Protocol, 84 had ratified the Guadalajara Protocol, and 53 nations had ratified Montreal Protocol No.4, all of which have entered into force. In November 2003, the Montreal Convention of 1999 entered into force. Several airlines have embraced the Montreal Agreement or the IATA Intercarrier Agreements. Only seven nations had ratified the moribund Guatemala City Protocol. Meanwhile, the highly influential U.S. Second Circuit has rendered an opinion that no treaty on the subject was in force at all unless both affected nations had ratified the identical convention, leaving some cases to fall between the cracks into the arena of common law. Moreover, in the United States, a surface transportation movement prior or subsequent to the air movement may, depending upon the facts, be subject to Warsaw, or to common law. At present, International private air law regime can be described as a "situation of utter chaos" in which "even legal advisers and judges are confused." The net result of this barnacle-like layering of international and domestic rules, standards, agreements, and criteria in the elimination of legal simplicity and the substitution in its stead of complexity and commercial uncertainty, which manifestly can not inure to the efficient and economical flow of world trade. All this makes a strong case for universal ratification of the Montreal Convention, which will supersede the Warsaw Convention and its various reformulations. Now that the Montreal Convention has entered into force, the insurance community may press the airlines to embrace it, which in turn may encourage the world's governments to ratify it. Under the Montreal Convention, the common law defence is available to the carrier even when it was not the sole cause of the loss or damage, again making way for the application of comparative fault principle. Hopefully, the recent entry into force of the Montreal Convention of 1999 will re-establish the international legal uniformity the Warsaw Convention of 1929 sought to achieve, though far a transitional period at least, the courts of different nations will be applying different legal regimes.

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