• Title/Summary/Keyword: Margin of Safety

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A study on hull girder shear strength in bulk carriers for CSR and Harmonized CSR (CSR-BC와 Harmonized CSR-BC의 선체 전단 응력에 대한 비교 고찰)

  • Park, Jong Min;Lee, Kyu Ho;Lee, Sang Bok;Shin, Sung-Kwang
    • Special Issue of the Society of Naval Architects of Korea
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    • 2015.09a
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    • pp.46-49
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    • 2015
  • Common Structural Rules (CSR) about bulk carriers and double-hull oil tankers of International Association of Classification Societies (IACS) has been applied to ships contracted for construction since April 2006. By unifying each society's rules, the difference of opinion in the between shipyard and ship owners, classification was reduced, and CSR has been evaluated by rules the safety structure more enhanced. However, The CSR about the bulk carriers and double hull oil tankers, important design content standards, such as the local scantling calculation, static/dynamic load case and corrosion margin and etc., are different. Therefore in order to combine the CSR, the Harmonized CSR for bulk carriers and double hull oil tankers (H-CSR) was issued on 1, January, 2014, and will be apply to ships contracted for construction after 1st July 2015. It is necessary to verify the H-CSR to optimize the structural arrangement because effective date is not far off. In this study, we compared the impact by rule change for the hull girder shear strength of bulk carriers between CSR and H-CSR in respect of the yielding and buckling strength.

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A Study on the Pharmacological Actions of Lycaconitine, an Alkaloid of Radix Jingyu with Emphasis on Toxicologic Aspects (진구성분 Lycaconitine의 약리작용(藥理作用)에 관한 연구(硏究))

  • Lee, Jang-Nag
    • Korean Journal of Veterinary Research
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    • v.2 no.2
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    • pp.29-31
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    • 1962
  • Although Lycaconitine, one of the alkaloids of Radix Jingyu, had been identified in 1884, its use in practice has not been known probably because of our limited knowledge on pharmacologic actions of the drug. Recently repellent efficacy of Lycaconitine against Korean cattle ticks and goat ticks was demonstrated. Obviously, there in a need to investigate toxicologic aspects of Lycaconitine before its widespread use for the control of animal ticks can be attempted. As will be reported in this paper, Lycaconitine Shows a wide margin of safety in the concentration applied as cattle or goat tick repellent.

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Load bearing capacity reduction of concrete structures due to reinforcement corrosion

  • Chen, Hua-Peng;Nepal, Jaya
    • Structural Engineering and Mechanics
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    • v.75 no.4
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    • pp.455-464
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    • 2020
  • Reinforcement corrosion is one of the major problems in the durability of reinforced concrete structures exposed to aggressive environments. Deterioration caused by reinforcement corrosion reduces the durability and the safety margin of concrete structures, causing excessive costs in managing these structures safely. This paper aims to investigate the effects of reinforcement corrosion on the load bearing capacity deterioration of the corroded reinforced concrete structures. A new analytical method is proposed to predict the crack growth of cover concrete and evaluate the residual strength of concrete structures with corroded reinforcement failing in bond. The structural performance indicators, such as concrete crack growth and flexural strength deterioration rate, are assumed to be a stochastic process for lifetime distribution modelling of structural performance deterioration over time during the life cycle. The Weibull life evolution model is employed for analysing lifetime reliability and estimating remaining useful life of the corroded concrete structures. The results for the worked example show that the proposed approach can provide a reliable method for lifetime performance assessment of the corroded reinforced concrete structures.

Desmoplastic Fibroma of the Cranium in a Young Man

  • Lee, Sungjoon;Jung, Sung-Mook;Cho, Byung-Kyu;Kim, Hoon
    • Journal of Korean Neurosurgical Society
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    • v.52 no.6
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    • pp.561-563
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    • 2012
  • Desmoplastic fibroma, which develops predominantly in long bones and the mandible, is a rare and benign but locally aggressive tumor. Desmoplastic fibroma of the cranium is extremely rare. We report a case of desmoplastic fibroma of the frontal bone in a young man. Because of its locally aggressive behavior, complete surgical excision with a safety margin is essential.

Retrofit Design of Damaged Prestressed Concrete Cylinder Pipes

  • Lee, Yongjei;Lee, Eun-Taik
    • International Journal of Concrete Structures and Materials
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    • v.7 no.4
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    • pp.265-271
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    • 2013
  • Prestressed concrete cylindrical pipe (PCCP) has been widely used for the distribution of water in communal, industrial, and agricultural systems for a long time. However, as it deteriorates, structural failures have been experienced. Replacing the entire existing PCCP with partial damages is not an economical method. Currently, as a cost effective repairing method, a new approach using fiber reinforced polymer (FRP) has been applied. A new design procedure of this method was proposed considering various kinds of loading condition. However, it is not easy to apply this method for design purpose due to its complex procedures. The objective of this study is to provide a new design criteria and process for PCCP rehabilitation with FRP. Through this method, the appropriate quantities of FRP layers will be decided after examining of limit states of deteriorated PCCP. For this purpose, two deterioration conditions are assumed; fully deteriorated and partially deteriorated. Different limit states for each case are applied to decide the quantities of attached FRP. The concept of "margin of safety" is used to judge whether the design results are within the optimal ranges to satisfy all limit states.

A recurrent case of extraocular sebaceous carcinoma with distant organ metastasis

  • Kwon, Byeong Soo;Chung, Eui Han;Kim, Jin Woo
    • Archives of Craniofacial Surgery
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    • v.22 no.1
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    • pp.56-61
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    • 2021
  • Sebaceous carcinoma (SC) is a rare tumor, accounting for approximately 0.7% of skin cancers. SC can be classified as ocular SC (OSC) or extraocular SC (EOSC) depending on its location. Because EOSC accompanied by metastases is rare, there is a paucity of data about EOSC accompanied by metastasis. This study presents a case of an aggressive EOSC of the scalp with lymph node metastases. The patient underwent wide local excision of the primary tumor with a 1 cm safety margin and bilateral radical lymph node dissection. However, recurrence was observed 1 month after surgery. Radiation therapy and resection were performed for the recurrent tumor. However, distant metastases to both lungs eventually occurred. Here, we describe a rare recurrent case of EOSC of the scalp with distant organ metastasis with a review of the literature.

Studies on Starting Transient in Solid Rockets

  • V.R. Sanal Kumar;Kim, Heuy-Dong
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2003.10a
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    • pp.6-10
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    • 2003
  • Accurate description of starting transient history allows and justifies the use of small margin of safety for the engine parts, resulting in high motor mass ratio in addition to satisfying the control and guidance requirements of the vehicle. Studies have been carried out for the prediction and reduction of ignition peak and pressure-rise rate during the starting transient of solid rocket motors. Numerical studies have been carried out using a two dimensional Navier-Stokes solver. It has been inferred through the parametric studies that, in the case of solid rocket motors with uniform port, high ignition peak is observed at high spread rate and low pressure-rise rate. In the case of the port with sudden expansion configuration, high ignition peak is observed at relatively high average spread rate and high-pressure rise rate. These studies are expected to aid the designer in reducing the ignition peak by altering the propellant properties or igniter characteristics without sacrificing the motor performance.

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Inhibition of Rebar Corrosion by Carbonate and Molybdate Anions

  • Tan, Y.T.;Wijesinghe, S.L.;Blackwood, D.J.
    • Corrosion Science and Technology
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    • v.16 no.4
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    • pp.167-174
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    • 2017
  • Bicarbonate/carbonate and molybdate anions have been characterized for their inhibitive effect on pitting corrosion of carbon steel in simulated concrete pore solution by using electrochemical tests such as electrochemical impedance (EIS) and linear polarization (LP). It was revealed that bicarbonate/carbonate has a weak inhibitive effect on pitting corrosion that is approximately one order of magnitude lower compared to hydroxide. Molybdate is effective against pitting corrosion induced by the concentration of chloride as low as 113 mM and can increase the pitting potential of a previously pitted sample to the oxygen evolution potential by the concentration of molybdate as much as 14.6 mM only. The formation of a $CaMoO_4$ film on the surface hinders the reduction of dissolved oxygen on the steel surface, reducing corrosion potential and increasing the safety margin between corrosion potential and pitting potential further. In addition, pore-plugging by $FeMoO_4$ as a type of salt film within pits increases the likelihood of repassivation.

Survey on Current Situations of Geriatric Patients' Medication and Drug Interactions Based on Prescriptions (노인환자들의 복약실태와 처방전상의 약물상호작용 검토)

  • 최용순;손의동
    • YAKHAK HOEJI
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    • v.47 no.6
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    • pp.390-397
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    • 2003
  • It is common that geriatric patients are on several medications at the same time. With this situation on hand, this study has collected prescriptions of individual geriatric patient and investigated possible drug interactions. In order to minimize the drug interactions and protect those patients from adverse reactions of medication, the gradual implementation and management of the medication history of each individual patient, the establishment of medication counseling system on medicines particularly in need of obligatory advice, the use of an inspection system on drug interactions at the time of prescription, and the implementation of a patient monitoring system on the drugs with narrow margin of safety at hospitals.

Considerations for submucosal midazolam administration in combination with oral and inhaled medications for sedation of pediatric dental patients

  • Baek, Kwanwoo
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.15 no.2
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    • pp.47-52
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    • 2015
  • Sedation allows patients to maintain their airway independently and respond appropriately to physical stimulation and verbal command while maintaining a minimum depressed level of consciousness. Drugs commonly used for sedation of pediatric dental patients include a combination of chloral hydrate, hydroxyzine, and nitrous oxide-oxygen. Midazolam is a benzodiazepine and currently one of the most commonly used intravenous sedative agents. It can be easily titrated to provide a wide range of sedation, from conscious sedation to deep sedation, and exhibits a wide safety margin without severe respiratory and circulatory depression. At an appropriate dose, it also decreases patient anxiety and induces amnesia. We found that the submucosal administration of midazolam combined with chloral hydrate provided increased sedative effects and decreased the postoperative vomiting response compared with conventional chloral hydrate administration, with no significant difference in physiological responses. The depth of sedation can be titrated using this technique.