Extra Parts Research Articles

Utilizing Deep Learning for Defect Inspection in Hand Tool Assembly.

The integrity of product assembly in the precision assembly industry significantly influences the quality of the final products. During the assembly process, products may acquire assembly defects due to personnel oversight. A severe assembly defect could impair the product's normal function and potentially cause loss of life or property for the user. For workpiece defect inspection, there is limited discussion on the simultaneous detection of the primary kinds of assembly anomaly (missing parts, misplaced parts, foreign objects, and extra parts). However, these assembly anomalies account for most customer complaints in the traditional hand tool industry. This is because no equipment can comprehensively inspect major assembly defects, and inspections rely solely on professionals using simple tools and their own experience. Thus, this study proposes an automated visual inspection system to achieve defect inspection in hand tool assembly. This study samples the work-in-process from three assembly stations in the ratchet wrench assembly process; an investigation of 28 common assembly defect types is presented, covering the 4 kinds of assembly anomaly in the assembly operation; also, this study captures sample images of various assembly defects for the experiments. First, the captured images are filtered to eliminate surface reflection noise from the workpiece; then, a circular mask is given at the assembly position to extract the ROI area; next, the filtered ROI images are used to create a defect-type label set using manual annotation; after this, the R-CNN series network models are applied to object feature extraction and classification; finally, they are compared with other object detection models to identify which inspection model has the better performance. The experimental results show that, if each station uses the best model for defect inspection, it can effectively detect and classify defects. The average defect detection rate (1-β) of each station is 92.64%, the average misjudgment rate (α) is 6.68%, and the average correct classification rate (CR) is 88.03%.

Information Capsule: A New Approach for Summarizing Medical Information.

The diversities of medical information resources and health information needs in recent years have caused another form of summarization and abstract writing to appear in the information capsule (IC) versus various types of abstracts. The present study was conducted with the aim to analyze the current IC, giving a unique definition and a standard structure for the development of an IC, and how it can be represented and implemented. This study was conducted in three phases in the form of a qualitative study. In the first phase, a library review study was done on the relevant websites and international databases, such as PubMed, Science Direct, Web of Sciences, Google Scholar, ProQuest, and Embase. In the second phase, the results of the previous stage were discussed with a panel of experts. In the third phase, a suggested frame for an IC was stated. A specific structure was suggested for IC so that, in addition to having parts of similar cases, they had extra parts. The suggested frame includes title, name of the IC writers and reviewers, question or goals, design or methods, setting, patient or community of the study, result, commentary, citation, topic, picture, and tag and can be used in different fields. Due to the importance of IC in summarizing information, our suggested structure should be used in other fields and be subject to trial and error.

Design of a multi-epitope vaccine against brucellosis fused to IgG-fc by an immunoinformatics approach.

Brucella, a type of intracellular Gram-negative bacterium, has unique features and acts as a zoonotic pathogen. It can lead to abortion and infertility in animals. Eliminating brucellosis becomes very challenging once it spreads among both humans and animals, putting a heavy burden on livestock and people worldwide. Given the increasing spread of brucellosis, it is crucial to develop improved vaccines for susceptible animals to reduce the disease's impact. In this study, we effectively used an immunoinformatics approach with advanced computer software to carefully identify and analyze important antigenic parts of Brucella abortus. Subsequently, we skillfully designed chimeric peptides to enhance the vaccine's strength and effectiveness. We used computer programs to find four important parts of the Brucella bacteria that our immune system recognizes. Then, we carefully looked for eight parts that are recognized by a type of white blood cell called cytotoxic T cells, six parts recognized by T helper cells, and four parts recognized by B cells. We connected these parts together using a special link, creating a strong new vaccine. To make the vaccine even better, we added some extra parts called molecular adjuvants. These included something called human β-defensins 3 (hBD-3) that we found in a database, and another part that helps the immune system called PADRE. We attached these extra parts to the beginning of the vaccine. In a new and clever way, we made the vaccine even stronger by attaching a part from a mouse's immune system to the end of it. This created a new kind of vaccine called MEV-Fc. We used advanced computer methods to study how well the MEV-Fc vaccine interacts with certain receptors in the body (TLR-2 and TLR-4). In the end, Immunosimulation predictions showed that the MEV-Fc vaccine can make the immune system respond strongly, both in terms of cells and antibodies. In summary, our results provide novel insights for the development of Brucella vaccines. Although further laboratory experiments are required to assess its protective effect.

An inexpensive semi-automated sample processing pipeline for cell-free RNA extraction.

Despite advances in automated liquid handling and microfluidics, preparing samples for RNA sequencing at scale generally requires expensive equipment, which is beyond the reach of many academic laboratories. Manual sample preparation remains a slow, expensive and error-prone process. Here, we describe a low-cost, semi-automated pipeline to extract cell-free RNA using one of two commercially available, inexpensive and open-source robotic systems: the Opentrons OT1.0 or OT2.0. Like many RNA isolation protocols, ours can be decomposed into three subparts: RNA extraction, DNA digestion and RNA cleaning and concentration. RT-qPCR data using a synthetic spike-in confirms comparable RNA quality to the gold standard, manual sample processing. The semi-automated pipeline also shows improvement in sample throughput (+12×), time spent (-11×), cost (-3×) and biohazardous waste produced (-4×) compared with its manual counterpart. This protocol enables cell-free RNA extraction from 96 samples simultaneously in 4.5 h; in practice, this dramatically improves the time to results, as we recently demonstrated. Importantly, any laboratory already has most of the parts required (manual pipette and corresponding tips and kits for RNA isolation, cleaning and concentration) to build a semi-automated sample processing pipeline of their own and would only need to purchase or three-dimensionally print a few extra parts (US$5.5 K-12 K in total). This pipeline is also generalizable for many nucleic acid extraction applications, thereby increasing the scale of studies, which can be performed in small research laboratories.

Improving attention network to realize joint extraction for the construction of equipment knowledge graph

In the context of promoting autonomous decision, intelligent interaction, and concept recognition of the equipment, constructing an equipment Knowledge Graph (KG) is the key technology to facilitate this. In this article, we propose a method that combines design rules and automatic extraction to construct equipment KG from equipment manuals. We define that equipment KG is scheme-based and depicts scheme in the form of KG triples (a.k.a design rules, scheme layer of KG, or concept KG). Our contributions include designing an initial concept KG for the equipment domain and improving the BERT (Bidirectional Encoder Representations from Transformers) model to jointly extract knowledge from texts to enrich the KG. The BERT model was improved from internal calculations so that joint extraction could be achieved directly without extra additional parts. We applied our model to a standard dataset “SemEval2010 Task 8” and achieved the F1 score of 89.55 which demonstrates its rationality. We also established a dataset called “Equipment Manuals Corpus for KG” based on the concept KG and applied the joint model in the dataset to extract knowledge. The result was visualized in the form of a graph.

LEXICAL AND GRAMMATICAL FEATURES OF CORPORATE CHRISTMAS AND NEW YEAR’S GREETINGS IN GERMAN AND RUSSIAN CULTURES

The article focuses on the text type greeting in German and Russian languages. It aims at identifying lexical and grammatical means of corporate greeting in German language culture. The study is novel in that it discusses contemporary corporate greetings in German and in Russian as a part of the language politeness. The methods used in the study include continuous sampling method, lexical and semantical analysis, and comparison. The greetings under discussion consist of three obligatory (address, wishes and signature) and two extra parts (introduction and gratitude). The introduction aims at establishing of festive mood and can have a quote in German greetings. In Russian congratulations, the introduction is rare, in certain cases it is replaced with congratulation on a holiday. The reason why in German texts there is no congratulation is the fact that the congratulation is written on a card which has pre-printed greeting. There are semantical differences between Russian and German wishes. The Russians tend to express wishes for the whole upcoming year. They are about job and private life of an addressee. The Germans focus their wishes on Christmas, and an addressee is supposed to spend it in a quiet company of relatives and friends. The wishes on New Year’s Day are similar to Russian ones. The difference in wishes partly would raise from the difference in calendars: While the Germans celebrate Christmas right after working days, the Russians have it at the end of a series of days-off at the beginning of January.

Condition monitoring of induction motor-vibration analysis technique

Condition Based Monitoring maintenance implies that a precautionary job should be executed at a convinced state of hardware. Such technique stands to be considerably additional cost effective than complete letdown of equipment. When racing to disappointment, an impromptu interference to creation is instigated. Likewise, an inadvertent blow-back may happen, leading to costly consequences. Extra parts or spare parts stock must be kept to replace in case of failure of parts. Booked preventive support results typically in repairing, fixing or supplanting parts, driving in an upkeep that is too exorbitant and ineffective in forestalling breakdowns. To further develop accessibility, the framework is upgraded for higher constancy and the necessity for support is restricted. Maintenance is likewise being completed in a most viable way, furthermore, in an arranged approach. Finally, some condition markers are checking to notice decay and recognize disappointments. This task is focused on the examination of Industrial Induction Motor and distinguishing conceivable condition pointers dependent on vibration estimations and investigation.

Flexure Variable Stiffness Actuators

Series elastic actuators (SEAs) and variable elastic actuators (VSAs) provide shock resistance, energy storage, and stable force control. However, they usually require extra springs, mechanical parts, and transmissions, increasing size, weight, number of moving parts, and reducing the mechanical efficiency. In particular, this mechanical complexity is one of the significant challenges in the design of wearable and scalable force feedback devices. In this article, flexure variable stiffness actuators (F‐VSAs), which combine kinematic transmission, elasticity, and stiffness modulation via a network of folding patterns using flexure hinges, are presented. Thus, F‐VSAs allow the creation of robots benefiting from the advantages of SEAs and VSAs without hindering form factor or mechanical efficiency. To illustrate the design strategy of F‐VSAs, a 4‐design‐of‐freedom (DoF) robot that provides stiffness and force output is presented. An analytical model that estimates the inherent stiffness and the end‐effector force output for any given configuration of the folding pattern is proposed. Finally, stiffness modulation and force control of the robot are implemented and good agreement with the predictions from the model is observed. Thus, this novel design strategy allows the creation of compact and scalable robots with stiffness and force output for wearable, rehabilitation, and haptic applications.

Secured Authentication and Key Sharing Using Encrypted Negative Password in IoT Devices

State hoarding is an important consideration in systems that use a mystery word request, which is now the most widely used check mechanism for removing security issues. In this study, we present a perplexing word check structure that is expected to provide safe riddle word handling and might potentially be integrated into existing explanation frameworks. They received a clear puzzle enunciation from a client who had astounded out a cryptographic hash work in our sequence of events. The hashed puzzle verbalization is adjusted into a negative problem key at that time. Finally, using a symmetric-key figure, the negative puzzle enigma is combined into an Encoded Negative Enigma state (e.g., AES). In expansion development security, multi-cycle encryption might be used. Avoiding passwords from ENPs is difficult due to cryptographic hash work and symmetric encryption. There are also stores of monitoring ENPs for a particular plain appear up that the ENP might oblige enquire table trap and supplies more solid mystery key security below word reference trap. It's thought that the ENP doesn't appear to have any extra parts (such as salt). Apart from that, the ENP may at the very least deny pre-calculation ambushes. The ENP is the most basic key, including symmetrickey figures, cryptographic hash work, and negative mystery words, all without the requirement for any more information beyond the simple mystery express.

Decreasing e-waste through reliability enhancement encouraged by performance-based contracting

PurposeIn the last 20 years, e-waste has become a serious issue resulting from an overwhelming amount of electronics consumption. However, there has been limited research on how to decrease such waste in a structured manner. Toward study was to use a simulation methodology to investigate the dynamics of upfront investment in reliability enhancement promoted by performance-based contracting (PBC), based on the number of spare parts and duration of the contract.Design/methodology/approachThe present research first details the relevant mathematical equations and uses game theory to demonstrate the utility for supplier and buyer relationships. Next, the effects of reliability enhancement, spare partsPBC are analyzed using a BlockSim simulation model.FindingsThe results indicate strong relationships among system design cost, reliability, availability and service cost. The authors found that investment in reliability increases system availability while reducing total service costs. Furthermore, increasing the spare parts inventory was determined to have less influence on the readiness of highly reliable systems. The findings support the notion that PBC reduces e-waste by increasing system availability, incentivizing upfront investment in reliability growth.Research limitations/implicationsRecognition of these findings in the context of buyer–supplier relationships will help managers better understand the value of upfront reliability investment, reducing maintenance, repair and overhaul requirements, avoiding the need to plan for extra spare parts and minimizing volume and the resulting e-waste.Practical implicationsThis study also clarifies the uncertainty associated with upfront investment and provides potential incentives for suppliers.Originality/valueThe main contribution of this study is its use of PBC for e-waste reduction, highlighting the effects of upfront investment in reliability enhancement. The authors applied a game theory model to illustrate the relationship between incentives and upfront investment and demonstrate how increased levels of spare parts can be counterproductive to achieving readiness, reducing inventory and consequent e-waste.

El desarrollo de la noción de “mitad” en niños de dos comunidades shipibo-konibo de Ucayali

This research aims to identify and describe developmental levels of the notion of “half” in a group of children from two Shipibo-Konibo native communities of the Ucayali region, in the Peruvian Amazon rainforest. Fourteen students aged between 7 and 16 participated, six from Bethel community and eight from Bena Jema community. The community of Bethel is located approximately 6 hours by river from the city of Pucallpa, while Bena Jema is located within Pucallpa’s boundaries, in the Yarinacocha district. All participants were assessed using Jean Piaget’s clinical-critical method, with two tasks. In the first task, focusing on discrete quantities: different sets of cards with the picture of a fish were presented sequentially, some with an even number of units and some with an odd number. Participants were asked to choose and present back half of each set. In the second task, focusing on continuous quantities: participants were asked to choose and present half of a single raw spaghetti, which they needed to break with their hands. If the resulting pieces were unequal, they were asked to break them again and redistribute the results. Students from Bena Jema community were assessed with both tasks, while students from Bethel community were assessed only with the discrete quantities task. The results showed four developmental levels in the discrete quantities task. In the first level, participants took any one of two parts of the set to be “half”, without checking if they were equal or whether putting them back together reconstituted the original whole. In the second level, participants took any one of two equal parts to be "half", but were inconsistent and accepted the possibility of the parts being unequal. In the third level, participants only took any one of two equal parts to be “half” but had difficulties splitting odd-numbered sets, including sets with fewer elements than the even-numbered ones they had previously split correctly. In the fourth level, the task was solved successfully with both even-numbered and odd-numbered sets. For the continuous quantities task, three levels were found. In the first level, any one of two raw spaghetti pieces was taken to be “half”, without checking their evenness. In the second level, participants took any two equal pieces of the raw spaghetti to be “half”, but without checking whether putting them back together reconstituted the original whole, with no extra parts remaining. In the third level, participants took any one of two equal pieces to be “half”, checking whether putting them back together reconstituted the original whole. These results are consistent with reports from previous research assessing the notion of “half” in Western contexts. Results support universality in the development of the notion of “half”, but show a delay in the participants’ level of acquisition, taking Peru’s national curriculum as reference. This study is a contribution to the understanding of the development of the notion of “half” in indigenous children living in Amazonian native communities, and shows the relevance of the Piagetian clinical-critical interview in these sociocultural contexts. The implications of these findings are discussed in relation to the universality of logical-mathematical knowledge, as well as the need to rethink the timing and manner in which the notion of “half” appears in the curriculum. https://doi.org/10.16888/interd.2022.39.2.17

A Compact 4×4 Filtering Microstrip Patch Antenna Array With Dolph-Chebyshev Power Distribution

This paper proposes a compact 4×4 filtering microstrip patch antenna array with Dolph-Chebyshev distribution implemented by multilayer structure. The proposed antenna array features good filtering performance but contains no extra filtering parts in the feeding or the radiating element. The whole antenna array consists of four 1×4 antenna subarrays, each subarray is composed of four patch antennas which are coupled-fed by a single microstrip line. Inside the desired passband, by properly choosing the coupling area along the microstrip line, the patches are induced in-phase currents therefore achieving the excellent radiation characteristics. On the other hand, the four patches can’t be properly excited outside the passband which would enable radiation suppression performance. In order to implement a 4×4 filtering microstrip patch antenna array with low sidelobe level (SLL), four subarrays are combined and fed by Dolphy-Chebyshev excitation method. Finally, the proposed antenna array is implemented, fabricated and measured. The maximum measured gain in the passband is 14.7 dBi, and the radiation suppression outside the passband is better than 25 dB.

Integrating helicoid channels for passive control of fiber alignment in direct-write 3D printing

3D printing of fiber-reinforced composites has been receiving increasing attention as an efficient additive approach enabling lightweight, functional, and high-performance components required for industrial applications. The properties of fiber composites significantly depend on internal microstructures, including fiber orientation, distribution, and degree of alignment. Although multiple strategies have been introduced for controlling the fiber composites microstructures, these strategies are mostly active approaches relying on additional control of mechatronics parts, external forces, or intentionally introduced unstable flows inside narrow nozzles. These methods suffer from higher risk of nozzle clogging and requiring extra parts in 3D printing. Here, we introduce helicoid channels into extrusion system as a passive approach to control the fiber alignment without any additional moving parts in direct-write 3D printing. The helicoid channels automatically guide the composite inks and align fibers before flowing into narrow nozzle space, avoiding clogging and improving printability. The analyses indicate that both helicoid surface to volume ratio and helix angle affect the pre-alignment of fibers, leading to tunable mechanical properties of printed fiber-reinforced composites with increased stiffness and strength up to 77.6% and 47.8%, respectively.

The long sixth finger illusion: The representation of the supernumerary finger is not a copy and can be felt with varying lengths

We can have a distorted perception of our body, instantly induced with multisensory illusions, anaesthesia or Virtual Reality, and recent studies show we can also feel extra body parts. Newport and colleagues (Newport et al., 2016) created an illusion that induces the feeling of having a sixth finger on one's hand, for a brief moment. By changing the paradigm with a double back and forth stroking, we were able to extend the duration of this illusion (Cadete & Longo, 2020), which can reflect an endured representation of a supernumerary finger. This innovation allowed us to test one specific distortion in the supernumerary finger: length. Patients with supernumerary phantom limb syndrome feel like they have an extra limb, as if one of their limbs was duplicated (Staub et al., 2006), resembling the same size and shape of the existing one. It is unclear from existing studies whether a supernumerary limb is represented as a copy of the existing limb, or if it is represented independently, with its own features. We therefore aimed to investigate whether the properties of the supernumerary sixth finger could be altered, independently of the actual little finger. Hence, we tested whether we can embody a sixth finger with double the size of the average little finger, and half its size. Participants reported feeling a long and a short sixth finger, and gave visual judgements on the felt length of the supernumerary finger, that matched the condition length. Overall, the results show that the supernumerary sixth finger is not a mere copy of the little finger but is represented independently, with distinct features from the existing finger. Moreover, the representation of the supernumerary finger is flexible, allowing the embodiment of a long or a short sixth finger.

Optimisation of maintenance in delivery systems for cytostatic medicines

BackgroundThe real-world application of maintenance in organisations brings together a number of maintenance policies in order to achieve the desired availability, efficiency and profitability. However, the literature mostly chooses a single maintenance policy, and so the decision process is not suited to the real conditions in the company to which it is applied. Our study takes a combination of maintenance policies as alternatives, and so conforms to the actual practice of maintenance in organisations. Furthermore, it introduces the possibility of including extra spare parts, or outsourcing maintenance policies. Although the selection of maintenance policies has been applied to many kinds of business and of machine, there is almost no instance of its application to hospitals, and it has never been applied to delivery systems for cytostatic drugs.MethodsThe model uses the fuzzy Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), which is recognised as being highly suitable for solving group decision-making problems in a fuzzy environment. Fuzzy set theory is also considered to be more proficient than crisp numbers for handling the ambiguity, imprecisions, data scarcity, and uncertainty inherent in decisions made by human beings. The judgements required were obtained from a decision group comprising the heads of facilities maintenance, maintenance of medical equipment, health and safety at work, environment, and programming-admission. The group also included care staff; specifically, the heads of the main clinical services, and the medical supervisors. The model includes original criteria, such as Quality of health care, which measures impact on care as a function of mean availability of each alternative. It also considers Impact on hospital management via the criteria: Working environment in the organisation and Impact on health care; the former criterion measures equality among care services in the hospital, while the latter assesses the effect on regional health cover. The model was built using real data obtained from a state hospital in Spain. The model can also be easily applied to other national and international healthcare organisations, providing weights specific to the criteria. These are produced by a decision group from each healthcare organisation and the alternatives are updated in accordance with what is considered important in each hospital.ResultsThe results obtained from the model recommend changing the alternative that is currently in use, Corrective and Preventive Maintenance, to Corrective and Preventive Maintenance plus two spare hoods. This alternative would lead to an availability of 1 (the highest possible) in the systems for preparing personalised cytotoxic drugs, and so the quality of service is therefore very high. Additionally, it could offer services to all the users of the hospital, and also offer cover in the preparation of cytotoxic medicines to other hospitals in the catchment area.ConclusionsThe results suggest the possibility that improvements to the support and logistical systems, which include maintenance, traditionally held to have no effect on quality of care, may be key to improving care quality, but also in reducing risk to patients, care and non-care staff, and the environment.

Issues related to an attempt to recreate the geometry of a non-standard spur gear

Modern machine manufacturers are making the design and technology of their products more and more complicated. This is to protect against a frequently used practice at customers, i.e. making extra parts on your own. This is because entrepreneurs often cannot afford to order expensive original spare parts and - using reverse engineering - prepare working drawings and commission the components to be made in their own machine park or externally from local suppliers. However, the matter is more complex in the case of gears, which so far have been designed on the basis of the selection of standard geometric parameters. A small modification of one or more of these parameters is enough and it becomes very difficult to recreate the geometry of such a gear. This paper presents the issues related to the reverse engineering of a spur involute gear with very non-standard parameters m = 4.98, α = 26.325 °, x = 0.0695, y = 0.795, c* = 0.383. Further metrological steps were proposed that should be taken to correctly identify at least the fact that the test object is not a part produced by standard modular tools (Fellows cutter, Maag rack cutter, worm cutter, etc.). The work also includes short graphical analyzes of the recreated geometry.

Pushing the capture limit of thermionic gun linacs

Although accelerator technology has matured sufficiently, state-of-the-art X-ray linacs for radiotherapy and cargo-scanning capture merely 30-50% of the electrons from a thermionic cathode, requiring a higher cathode current and leaving uncaptured electrons to cause problems due to back bombardment, shortening of cathode life, etc. Any solution to increase capture should be effective, simple, reliable, compact, and low cost in order to be adopted by industry. To address this, we present the design of a 6 MeV high capture efficiency S-band electron linac that captures 90% of the initial DC beam. This linac does not require any extra parts that would increase the cost as the high efficiency is achieved via a low-field-amplitude in the first bunching cell to decrease the number of backstreaming electrons, to velocity bunch the electron beam, and recapture backstreaming electrons. Under the low field amplitude, any electrons launched at decelerating phases travel backward with low speeds, thus most of them can catch the next RF cycle, and get re-accelerated/recaptured. As the electron speed is low, the cell length is also shorter than existing linacs. Such a short field is achieved by the use of asymmetric cells with differential coupling to the side-coupled cells. Our novel design has implications for all commercial high current thermionic gun linacs for increasing beam current and increasing cathode lifetime.

Noise‐based logic locking scheme against signal probability skew analysis

Due to integrated circuit (IC) production chain globalisation, several new threats such as hardware trojans, counterfeiting and overproduction are threatening the IC industry. So logic locking is deployed to hinder these security threats. In this technique, an IC is locked, and its functionality is retrieved when the right key is loaded onto it. We propose ‘noise-based’ logic locking, consisting of two separate compliment blocks, which function in three states. By flipping a signal once in the circuit, these modules add corruption to the circuit, whereas either flipping the same signal twice or not flipping leads to the correct functionality. Thus, a low probability skew with a low corruption in the output is obtained by utilisation of these flipping states. We have improved SAT attack resiliency based on time by 17% for a locking block with 14 primary inputs in comparison with the well-known anti-SAT. The area overhead is less in comparison with other schemes, in which extra dummy parts or obfuscation elements are added to their circuit. Also, more crucially, our locking blocks are immune to SPS attack solely. After executing various attacks, retrieved circuits indicate improved overall resiliency against automatic test pattern generation based and approximate guided removal attacks as well.

Assessment of carotid arteries and brain matter in patients with isolated abnormal tortuosities and those combined with occlusion by computed tomography angiography

Rationale: The prevalence of malformation of internal carotid arteries (ICA) in the population amounts to 46%. In 4 to 16% of the cases, it is associated with clinical manifestations of cerebrovascular insufficiency. Hemodynamic changes in the abnormal arterial vasculature and neurological symptoms are the main indications for surgical intervention. Computed tomography (CT) angiography has shown its high information value in the assessment of ICA occlusions; however, its informativity in the diagnosis of ICA malformations has not been established.Aim: To assess ICA and brain matter in the patients with abnormal tortuosities, both isolated and combined with occlusion, by CT angiography.Materials and methods: We performed a retrospective analysis of medical files of 58 inpatients, who underwent ultrasound examination and CT angiography of extra and intracranial parts of brachycephalic arteries with 256 slice multidetector computer scanner (Philips iCT). CT angiography included native imaging, and contrast-enhanced arterial and venous phases. We assessed the impact of ICA abnormalities on the degree of brain matter lesions in patients with isolated ICA malformations (n=27) and with combination of ICA malformations with its occlusion (n=31).Results: In the group of the patients with isolated ICA malformations, there were no brain focal lesions in 14, small vessel focal lesions and single liquor cysts in 9, and areas and zones of cystic and glial abnormalities in 4. The most frequent in this group were S-like and C-like malformations, together with 2 saccular aneurysms (one of them true and one false). In the group of patients with combination of abnormal ICA tortuosities and occlusions, there were areas and zones of cystic and glial abnormalities in 7, various degrees of small vessel disease and few liquor cysts in 18, and no abnormal brain matter foci in 6. No ICA malformations in combination with true or false aneurysms were found. The patients with combination of ICA malformations and stenosis, the signs of chronic brain ischemia were more advanced, compared to those in the patients with isolated ICA malformations (p=0.012).Conclusion: CT angiography is a highly informative method for the assessment of carotid arteries and brain matter in patients with ICA malformations. The combination with ICA malformations and occlusion is associated with more advanced lesions of brain matter.

A scenario-based optimization model for planning and redesigning the sale and after-sales services closed-loop supply chain

In today’s competitive world, the quality of after-sales services plays a significant role in customer satisfaction and customer retention. Some after-sales activities require spare parts and owing to the importance of customer satisfaction, the needed spare parts must be supplied until the end of the warranty period. In this study, a mixed-integer linear optimization model is presented to redesign and plan the sale and after-sales services supply chain that addresses the challenges of supplying spare parts after the production is stopped due to demand reduction. Three different options are considered for supplying spare parts, including production/procurement of extra parts while the product is being produced, remanufacturing, and procurement of parts just in time they are needed. Considering the challenges of supplying spare parts for after-sales services based on the product’s life cycle is one contribution of this paper. Also, this paper addresses the uncertainties associated with different parameters through Mulvey’s scenario-based optimization approach. Applicability of the model is investigated using a numerical example from the literature. The results indicate that the production/procurement of extra parts and remanufacturing are preferred to the third option. Moreover, remanufacturing is recommended when the remanufacturing cost is less than 23% of the production cost.