Reliability and barrier assessment of series–parallel systems subject to cascading failures

2020 ◽  
Vol 234 (3) ◽  
pp. 455-469 ◽  
Author(s):  
Lin Xie ◽  
Mary Ann Lundteigen ◽  
Yiliu Liu
Keyword(s):  
Block Diagram ◽  
Parallel Systems ◽  
The Other ◽  
Cascading Failures ◽  
Practical Case ◽  
Aggregation Method ◽  
Safety Barriers ◽  
Parallel Structures ◽  
In Series ◽  
Technical Systems

Cascading failures can occur in many technical systems where the components are organized as in series–parallel structures. The failures in these systems may propagate from one component to the other, not only within the same parallel sub-structure but also between different sub-structures. This article presents a recursive aggregation method based on the extended models of reliability block diagram, for analyzing the impacts of cascading failures on the reliability of series–parallel systems. Based on the reliability analysis, the effects of safety barriers on preventing cascading failures are studied, and the importance of safety barriers at different locations is evaluated. One simple example of three components and one practical case from an oil production system are presented. The findings in these case studies illustrate how system designers and safety managers can identify the effective and reasonable ways of installing safety barriers by using the proposed approaches, for the mitigation of cascading failures in series–parallel technical systems.

VII.–The Effect of the Transport of Heat on the Rate of Evaporation of Small Droplets I. Evaporation into a Large Excess of a Gas

1962 ◽  
Vol 66 (2) ◽  
pp. 65-80
Author(s):  
P. G. Wright
Keyword(s):  
Gaseous Phase ◽  
The Other ◽  
Total Resistance ◽  
Large Excess ◽  
Stationary Growth ◽  
In Series ◽  
Finite Period ◽  
Rate Of Evaporation ◽  
Latent Heat Of Vaporization ◽  
Algebraic Formulation

SynopsisBeginning with fundamental results obtained by Mason for the effect of self-cooling on the evaporation of drops, and by Fuchs for the diffusional retardation of evaporation for small droplets of any radius, explicit expressions for the effect of the transport of heat on the rate of quasi-stationary growth or evaporation, are discussed.The simplest algebraic formulation of the results lends itself to interpretation as expressing a resistance to evaporation, the total resistance being the sum of four resistances in series. Two of these resistances, one to diffusion and one to the conduction of heat, are offered by the gaseous phase in bulk; and there are two corresponding resistances at the interface. Corrections are formulated for the effect of the heating of the droplet by radiation. These corrections may be expressed as a (finite) resistance in parallel with the other two resistances to the transfer of heat. Simplified equations are obtained for the evaporation of a liquid whose latent heat of vaporization is very large.Some remarks are made on the formation of a monodisperse aerosol by the growth of smaller droplets. Integrated expressions are obtained for particular cases of the evaporation of a droplet over a finite period of time.

scholarly journals A CLINICAL CASE OF REMOVING A RESIDUAL FOREIGN BODY FROM THE LEFT SUPRACLAVICULAR REGION

2017 ◽  
Vol 4 (3) ◽  
pp. 120-122
Author(s):  
V.V. Boyko ◽  
V.V. Makarov ◽  
A.L. Sochnieva ◽  
V.V. Kritsak
Keyword(s):  
Surgical Treatment ◽  
Foreign Body ◽  
Soft Tissue ◽  
Clinical Case ◽  
Foreign Bodies ◽  
Soft Tissues ◽  
Life Quality ◽  
The Other ◽  
Practical Case ◽  
The One

Boyko V.V., Makarov V.V., Sochnieva A.L., Kritsak V.V.Residual foreign bodies in soft tissues are one of the main causes of chronical infection lesions and decrease in life quality. Surgical treatment is the most common way to relieve the patient from a foreign body. Often there is a question whether to remove a foreign body? On the one hand, all foreign bodies that are in the human body must be removed. On the other hand, in the absence of symptoms, the risk of surgery performed for the purpose of removal exceeds the risk associated with finding the foreign body. We would like to describe a practical case of removing a foreign body (Kirschner`s wires) from the left supraclavicular region. The young patient lived with a fragment of Kirschner's wire left after the osteosynthesis of the fractured clavicle for 5 years. Surgery to remove the residual foreign body was successful. On the 7th postoperative day the patient was discharged from the hospital under the supervision of surgeons at the place of residence.Key words: foreign body in soft tissue, Kirschner`s wire, surgical treatment. КЛІНІЧНИЙ ВИПАДОК ВИДАЛЕННЯ ЗАЛИШКОВ СТОРОННЬОГО ТІЛА З ЛІВОЇ НАДКЛЮЧИЧНОЇ ОБЛАСТІБойко В.В., Макаров В.В., Сочнева А.Л.,  Крицак В.В.Залишкові чужорідні тіла м'яких тканин залишаються однією з основних причин виникнення вогнища хронічної інфекції та зниження рівня якості життя. Хірургічне лікування основний спосіб позбавити хворого від наявності чужорідного агента. Часто виникає питання чи видаляти чужорідне тіло. З одного боку, усі сторонні тіла, що знаходяться в тілі людини, підлягають видаленню, з іншого боку при відсутності симптомів ризик операції, проводимої з метою видалення, перевищує ризик, пов'язаний з перебуванням чужорідного тіла. Ми хотіли б поділитися випадком видалення залишкового стороннього тіла (спиці Кіршнера) лівої надключичної ділянки із власної практики. Молода пацієнтка прожила з уламком спиці Кіршнера, залишеної після металлоостеосинтезу поламаної ключиці протягом 5 років. Операція з видалення залишкового стороннього тіла пройшла успішно. На 7 післяопераційну добу пацієнтка була виписана зі стаціонару під спостереження хірурги за місцем проживання.Ключові слова: чужорідне тіло м'яких тканин, спиця Кіршнера, хірургічне лікування. кЛИНИЧЕСКИЙ СЛУЧАЙ УДАЛЕНИЯ ОСТАТКОВ ИНОРОДНОГО ТЕЛА ИЗ ЛЕВОЙ ПОДКЛЮЧИЧНОЙ ОБЛАСТИ Бойко В.В., Макаров В.В., Сочнева А.Л.,  Крицак В.В.Остаточные инородные тела мягких тканей остаются одной из основных причин возникновения очага хронической инфекции и снижения уровня качества жизни. Хирургическое лечение основной способ избавить больного от наличия чужеродного агента. Часто возникает вопрос удалять ли инородное тело? С одной стороны, все инородные тела, находящиеся в теле человека, подлежат удалению, с другой стороны при отсутствии симптомов риск операции, производимой с целью удаления, превышает риск, связанный с нахождением инородного тела. Мы хотели бы поделится случаем удаления остаточного инородного тела (спицы Киршнера) левой надключичной области из собственной практики. Молодая пациентка прожила с обломком спицы Киршнера, оставленной после металлоостеосинтеза поломанной ключицы в течении 5 лет. Операция по удалению остаточного инородного тела прошла успешно. На 7 послеоперационные сутки пациентка была выписана из стационара под наблюдение хирурги по месту жительства.Ключевые слова: инородное тело мягких тканей, спица Киршнера, оперативное лечение.

The Frequency of Pericardial Effusions in Bacterial Meningitis

PEDIATRICS ◽  
1979 ◽  
Vol 63 (5) ◽  
pp. 764-770
Author(s):  
W. Pennock Laird ◽  
John D. Nelson ◽  
F. Douglas Huffines
Keyword(s):  
Risk Factors ◽  
Bacterial Meningitis ◽  
Antibiotic Therapy ◽  
Significant Risk ◽  
Literature Survey ◽  
The Other ◽  
Purulent Pericarditis ◽  
Pericardial Effusions ◽  
In Series ◽  
A Prospective Study

Because of our experience with four cases of purulent pericarditis complicating bacterial meningitis during a 13-month period, we performed a prospective study to determine the frequency of this complication. Echocardiograms were done on 100 patients with bacterial meningitis. Small or moderate pericardial effusions were detected in 19 patients, but none had symptoms or signs related to the effusion. Pericardiocentesis was done in one infant; all the other effusions resolved spontaneously. Patients with effusion were significantly younger than those without this complication, but no other significant risk factors were identified. A literature survey indicated that symptomatic pericarditis occurs in fewer than 1% of patients with meningitis. Conversely, in series of cases of purulent pericarditis, associated meningitis was reported in 12% of patients. We concluded that pericardial infection is common in patients with meningitis but that it is usually of no clinical significance and resolves with antibiotic therapy.

The Algorithmic Aspects of Creating and Using Wireless Sensor Network Key Spaces Based on Combinatorial Block Diagrams

Vestnik MEI ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 108-118
Author(s):  
Aleksandr B. Frolov ◽  
◽  
Natalya P. Kochetova ◽  
Anton O. Klyagin ◽  
Dmitriy Yu. Temnikov ◽  
...  
Keyword(s):  
Wireless Sensor Network ◽  
Sensor Network ◽  
Block Diagram ◽  
The Other ◽  
Wireless Sensor ◽  
Algorithmic Approach ◽  
Network Nodes ◽  
Rule Sets ◽  
Independent Calculation ◽  
Do So

Algorithmic approach principles relating to development and use of wireless sensor network (WSS) key spaces are formulated based on an analysis of the keys management peculiarities. The formulated principles, which meet certain requirements for the WSS key spaces, have been elaborated proceeding from the assumption that their structure corresponds to one of the varieties of combinatorial block diagrams: cyclic or acyclic projective plane, linear or quadratic transversal block diagrams. Owing to the WSS having a distributed configuration, it becomes possible to avoid the need to construct a combinatorial block diagram in full scope, and the required blocks are computed, whenever necessary, in scaling the network (in adding new nodes) or when determining, in a decentralized manner, the switching parameters of specific nodes. To do so, it is necessary to have algorithms for computing the blocks of the combinatorial block diagram (as the sets of key numbers allocated to a given node) and dual blocks (as the sets of the numbers of nodes to which keys are assigned with the numbers coinciding with the numbers of dual blocks), as well as algorithms for solving derived problems: computing of the key numbers common to two nodes and the number of the node that has a common key with one of two nodes and, possibly, another key with the other one. These problems are solved by using the numbering of elements, blocks and dual blocks in accordance with the proposed duality rule: sets of elements and dual blocks are in one-to-one correspondence by numbering; the dual block with a specified number contains the numbers of blocks containing elements with this number. Distributed (independent) calculation of blocks is carried out on the basis of algebraic identifiers computed by block numbers. In addition to the possible absence of a physical connection between the nodes, the inadmissibility of using separate (compromised) keys is taken into account, and the incomplete furnishing of the network nodes with keys, as well as the incompleteness of the system implementation as a whole. Algorithms for computing the switching parameters of two nodes in designing the WSS and an algorithm for computer modeling of the calculation of such parameters during the WSS operation subject to the specified constraints and in using any of the above types of combinatorial block diagrams are presented.

The diffusion of load from a stiffener into an infinite elastic sheet

1957 ◽  
Vol 239 (1218) ◽  
pp. 296-310 ◽  
Keyword(s):  
Mixed Boundary ◽  
Functional Differential Equations ◽  
Mixed Boundary Conditions ◽  
Limited Range ◽  
The Other ◽  
Shear Stresses ◽  
Variable Theory ◽  
Elastic Sheet ◽  
Complex Variable Theory ◽  
In Series

The use of complex variable theory to express problems in generalized plane stress is well known, but methods of finding particular solutions are available for only a limited range of problems. This paper and its sequel will develop a new technique, reducing certain problems with mixed boundary conditions to second order functional differential equations, whose solutions can be found in series form. Exact solutions are given to three fundamental problems of the diffusion of load in an infinite two-dimensional elastic sheet to which a semi-infinite elastic stiffener is continuously attached throughout its length. The first problem has a load applied to the end of the stiffener, with its line of action along the stiffener and its reactions at infinity. In the other two problems the stiffener end is unloaded but a uniform tension is applied to the sheet at infinity, in one case parallel to the stiffener, in the other perpendicular to it. Expressions for the load in the stiffener and for the direct and shear stresses in the sheet are found and plotted in non-dimensional form.

Reliability and non-reliability studies of Poisson variables in series and parallel systems

2012 ◽  
Vol 218 (9) ◽  
pp. 5112-5120 ◽  
Author(s):  
Pushpa L. Gupta ◽  
Ramesh C. Gupta ◽  
Seng-Huat Ong ◽  
H.M. Srivastava
Keyword(s):  
Parallel Systems ◽  
In Series

Larval development of ovine Neostrongylus linearis in four experimentally infected mollusc species

1994 ◽  
Vol 68 (3) ◽  
pp. 207-210 ◽  
Author(s):  
M.Y. Manga-González ◽  
M.P. Morrondo-Pelayo
Keyword(s):  
Post Infection ◽  
The Other ◽  
Snail Species ◽  
Intermediate Hosts ◽  
Cepaea Nemoralis ◽  
In Series ◽  
Mollusc Species ◽  
Higher Temperature ◽  
The One ◽  
First Time

AbstractDevelopment of Neostrongylus linearis larvae was studied in the snail intermediate hosts Oestophora (Oestophora) barbula, Oestophorella buvinieri, Cepaea nemoralis and Helix (Cryptomphalus) aspersa. The molluscs of each species, all adults, were divided into groups of 40 for infection purposes. The infection doses for the first two snail species were 90 and 50 first stage larvae (L1) of N. linearis, respectively. For C. nemoralis two batches were tested: one with 200 L1 kept at 19°C and the other with 250 L1 at a temperature of 21°C. The same was done with Helix (C.) aspersa with 200 L1 at a temperature of 21°C, on the one hand and 300 L1 at 24°C on the other. One or two molluscs of each species were killed in series from the 6th day post-infection (p.i.) until the 44th. Percentage values for total larvae (1, 2 and 3) and L3 were higher with the lower dose for C. nemoralis, whilst the same was true with the higher dose in Helix (C.) aspersa. In both cases, the higher temperature appeared to contribute to cycle acceleration. Using one way analysis of variance, statistically significant differences were detected between the species of molluscs tested concerning percentages of L1 which penetrated, total larvae and L3. According to our results, the decreasing order of susceptibility of these species of molluscs as experimental intermediate hosts of N. linearis is: O. buvinieri, Oestophora (O.) barbula, C. nemoralis and Helix (C.) aspersa. It is the first time that Oestophora (O.) barbula and Oestophorella buvinieri have been named as experimental intermediate hosts of N. linearis.

Approaches to Predicting the Vertical Transmissibility of a Suspension Seat With a Seated Subject

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Jun Wu ◽  
Meihuan Wang ◽  
Yi Qiu
Keyword(s):  
High Frequency ◽  
Dynamic Stiffness ◽  
The Other ◽  
Human Model ◽  
Apparent Mass ◽  
Frequency Range ◽  
Air Suspension ◽  
In Series ◽  
Inert Mass ◽  
Good Agreement

Abstract In this paper, four methods were put forward to predict the transmissibility of an air suspension seat with a seated subject. For characterizing the dynamics of the suspension seat, two of the methods were based on developing a model of the air suspension seat and calibrating the parameters using the transmissibilities of the suspension and complete seat respectively with an inert mass from the experiment. The other two methods substituted the detailed modeling of the seat by two dynamic stiffness connecting in series calculated from two same transmissibilities measured in the experiment. For characterizing the biodynamics of the human body, two of the methods took advantage of the normalized apparent mass from published papers to take the place of the human model, while the other two methods made use of one measured seat transmissibility with a subject to deduce the apparent masses of all the subjects. Good agreement was illustrated between the experiment and model prediction for all the four methods. In addition, it also exhibited that a large discrepancy can be resulted in, especially in the high-frequency range, if the seat model was substituted by one integrated dynamic stiffness.

Sign in / Sign up

Export Citation Format

Share Document