• Title/Summary/Keyword: Tool failure

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Implementation of the Feed and Swaddle Technique as a Non-Pharmacological Strategy to Conduct Brain Magnetic Resonance Imaging in Very Low Birth Weight Infants

  • Yoo, Yeong Myong;Park, Ji Eun;Park, Moon Sung;Lee, Jang Hoon
    • Neonatal Medicine
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    • v.28 no.3
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    • pp.108-115
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    • 2021
  • Purpose: Magnetic resonance imaging (MRI) is a useful tool for evaluating brain injury and maturation in preterm infants and often requires sedation to acquire images of sufficient quality. Infant sedation is often associated with adverse events, despite extreme precautions. In this study, the swaddling technique was investigated as an alternative non-pharmacological strategy to obtain brain MRIs of sufficient quality. Methods: We applied the feed and swaddle technique during routine brain MRI as a quality improvement project and compared its morbidity with that of sedation in a historic age-matched group. Seventy-nine very low birth weight infants in the neonatal intensive care unit of Ajou University Hospital (Suwon, Korea) were enrolled. Thirty-two (40.5%) infants were in the feed and swaddling group, and 47 (59.5%) were in the sedation group. Results: The morbidity associated with the cardiopulmonary system (swaddling group vs. sedation group: 53.13% [n=17] vs. 63.83% [n=30], P=0.723) and central nervous system (40.63% [n=13] vs. 29.79% [n=14], P=0.217) were not significantly different between groups. The MRI failure rate was not significantly different (swaddling group vs. sedation group: 12.5% [n=4] vs. 4.3% [n=2], P=0.174). The MRI scanning time was longer in the swaddling group than in the sedation group (76.5±20.3 minutes vs. 61.5±13.6 minutes, P=0.001). Cardiopulmonary adverse events were significantly less common in the swaddling group than in the sedation group (3.13% [n=1] vs. 34.04% [n=16], P=0.002). Conclusion: The success rate of MRI was comparable between the swaddling technique and sedation. Furthermore, despite the drawback of prolonged scan time, cardiopulmonary adverse events are fewer with swaddling than with sedative agents. Therefore, swaddling can be an alternative to sedation or anesthesia when performing neonatal MRI scans.

A Study on the Wireless Sensor Network Routing Method and Fault Node Detection for Production Line (생산라인에 적용을 위한 무선 센서 네트워크 라우팅방식 및 고장노드 검출에 대한 연구)

  • Park, Jeong?Hyeon;Seo, Chang-Jun
    • Journal of IKEEE
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    • v.22 no.4
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    • pp.1104-1108
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    • 2018
  • IIoT applies IoT to industrial sites to monitor factors such as production, manufacturing, and safety, and it is a solution that allows the worker to easily manage the site. An important technology element in this IIoT is a technology that collects information on industrial sites and delivers reliable information to managers using sensors. Therefore, general industrial sites use wired network methods such as Ethernet and RS485 to deliver information. However, there are limitations to the problem of infrastructure costs and to the wide range of line constructions in network deployment. Therefore, in this paper, the network of IEEE 802.15.4 Ad-Hoc wireless sensors is deployed on production lines with machine tools. In addition, we describe the routing method considering machine tool layout and sensor node failure detection algorithm.

The Evaluation of Structural Safety of Impeller Using FEM Simulation (FEM 시뮬레이션을 이용한 임펠러의 구조 안전성 평가)

  • Jung, Jong Yun
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.43 no.4
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    • pp.41-47
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    • 2020
  • As modern industries are highly being developed, it is required that mechanical parts have to be manufactured with a high precision. In order to have precise parts, error-free designs have to be done before manufacturing with accuracy. For this intention being fulfilled, a mechanical analysis is essential for design proof. Nowadays, FEM simulation is a popular tool for verifying a machine design. In this paper, an impeller, being utilized in a compressor or an oil mixer as an actuator, is studied for an evaluation. The purpose of this study is to present a safety of an impeller for a proof of its mechanical stability. A static analysis for stress, strain, and deformation within a regular usage is examined. This simulation test shows 357.26×106 Pa for maximum equivalent stress and 0.207mm for total deformation. A fatigue test is carried to provide durability and its result shows that minimum safety factor is 3.2889, which guarantees that it runs without a fatigue failure in 106 cycles. The natural frequencies for the impeller is ranged from 228.09Hz to 1,253.6Hz for the 1st to the 6th mode. Total deformations at these natural frequencies are shown from 6.84mm to 12.631mm. Furthermore, Campbell diagram reveals that a critical speed is not found throughout regular rotational speeds. From the test results for the analysis, this paper concludes that the suggested impeller is proved for its mechanical safety and good to utilize at industries.

Comparative genome characterization of Leptospira interrogans from mild and severe leptospirosis patients

  • Anuntakarun, Songtham;Sawaswong, Vorthon;Jitvaropas, Rungrat;Praianantathavorn, Kesmanee;Poomipak, Witthaya;Suputtamongkol, Yupin;Chirathaworn, Chintana;Payungporn, Sunchai
    • Genomics & Informatics
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    • v.19 no.3
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    • pp.31.1-31.9
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    • 2021
  • Leptospirosis is a zoonotic disease caused by spirochetes from the genus Leptospira. In Thailand, Leptospira interrogans is a major cause of leptospirosis. Leptospirosis patients present with a wide range of clinical manifestations from asymptomatic, mild infections to severe illness involving organ failure. For better understanding the difference between Leptospira isolates causing mild and severe leptospirosis, illumina sequencing was used to sequence genomic DNA in both serotypes. DNA of Leptospira isolated from two patients, one with mild and another with severe symptoms, were included in this study. The paired-end reads were removed adapters and trimmed with Q30 score using Trimmomatic. Trimmed reads were constructed to contigs and scaffolds using SPAdes. Cross-contamination of scaffolds was evaluated by ContEst16s. Prokka tool for bacterial annotation was used to annotate sequences from both Leptospira isolates. Predicted amino acid sequences from Prokka were searched in EggNOG and David gene ontology database to characterize gene ontology. In addition, Leptospira from mild and severe patients, that passed the criteria e-value < 10e-5 from blastP against virulence factor database, were used to analyze with Venn diagram. From this study, we found 13 and 12 genes that were unique in the isolates from mild and severe patients, respectively. The 12 genes in the severe isolate might be virulence factor genes that affect disease severity. However, these genes should be validated in further study.

An experimental and numerical investigation on fatigue of composite and metal aircraft structures

  • Pitta, Siddharth;Rojas, Jose I.;Roure, Francesc;Crespo, Daniel;Wahab, Magd Abdel
    • Steel and Composite Structures
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    • v.43 no.1
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    • pp.19-30
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    • 2022
  • The static strength and fatigue crack resistance of the aircraft skin structures depend on the materials used and joint type. Most of the commercial aircraft's skin panel structures are made from aluminium alloy and carbon fibre reinforced epoxy. In this study, the fatigue resistance of four joint configurations (metal/metal, metal/composite, composite/composite and composite/metal) with riveted, adhesive bonded, and hybrid joining techniques are investigated with experiments and finite element analysis. The fatigue tests were tension-tension because of the typical nature of the loads on aircraft skin panels susceptible of experimenting fatigue. Experiment results suggest that the fatigue life of hybrid joints is superior to adhesive bonded joints, and these in turn much better than conventional riveted joints. Thanks to the fact that, for hybrid joints, the adhesive bond provides better load distribution and ensures load-carrying capacity in the event of premature adhesive failure while rivets induce compressive residual stresses in the joint. Results from FE tool ABAQUS analysis for adhesive bonded and hybrid joints agrees with the experiments. From the analysis, the energy release rate for adhesive bonded joints is higher than that of hybrid joints in both opening (mode I) and shear direction (mode II). Most joints show higher energy release rate in mode II. This indicates that the joints experience fatigue crack in the shear direction, which is responsible for crack opening.

A Comparison of the Crack Plane Equilibrium Model for Elastic-Plastic Fracture Analysis with the Irwin's Plastic Zone Corrected LEFM (탄소성 파괴해석을 위한 크랙 평면 평형모형과 항복 선형 파괴역학과의 비교에 관한 연구)

  • Lee, Kyu-Yong;Smith, F.W.
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.20 no.1
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    • pp.30-36
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    • 1984
  • It is well known that the application of linear elastic fracture mechanics is inadequate to solve the large deformation fracture failures which occurr in ductile manner because of the large scale yielding due to the severe stress concentration in the region adjacent to the crack tip. The authors have been evolved a fracture model, the crack plane equilibrium model, for this kinds of elastic-plastic fracture problems in the previous report. In this report, the crack plane equilibrium model was compared with the Irwin's plastic zone corrected linear elastic fracture mechanics through theoretical comparisons and experimental results to examine the validity of the crack plane equilibrium model as an available tool for nonlinear fracture analysis. Through this study, the main results were reached as follows; Irwin's plastic zone corrected linear elastic fracture mechanics could be applicable only for small scale yielding problems as expected while the crack plane equilibrium model valid as a fracture model for large deformation fracture failure. However, the followings should be considered for the more precise evaluations of CPE model; 1) It is necessary to test more specimens which contain small cracks in the range of 2a/W<0.1. 2) It is important to detect the crack initiation point during the fracture test for determining an accurate fracture load. 3) Effects of specimen thickness in the fracture process zone should be examined.

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Fracture Mechanical Characterization of Bi-material Interface for the Prediction of Load Bearing Capacity of Composite-Steel Bonded Joints (복합재료-탄소강 접착제 결합 조인트의 하중지지 능력 예측을 위한 이종 재료 접합 계면의 파괴 역학적 분석)

  • Kim, Won-Seok;Shin, Kum-Chel;Lee, Jung-Ju
    • Composites Research
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    • v.19 no.4
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    • pp.15-22
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    • 2006
  • One of the primary factors limiting the application of composite-metal adhesively bonded joints in structural design is the lack of a good evaluation tool for the interfacial strength to predict the load bearing capacity of boned joints. In this paper composite-steel adhesion strength is evaluated in terms of stress intensity factor and fracture toughness of the interface corner. The load bearing capacity of double lap joints, fabricated by co-cured bonding of composite-steel adherends has been determined using fracture mechanical analysis. Bi-material interface comer stress singularity and its order are presented. Finally stress intensities and fracture toughness of the wedge shape bi-material interface corner are determined. Double lap joint failure locus and its mixed mode crack propagation criterion on $K_1-K_{11}$ plane have been developed by tension tests with different bond lengths.

What explains the failure of Google in the Korean market? The Impact of Multicultural PR Strategy

  • Kim, Hyejung;Woo, Wonseok;Kang, Hyoung-goo
    • Asia Marketing Journal
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    • v.14 no.4
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    • pp.35-56
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    • 2013
  • The era of globalization provides us with both opportunities and threats. The success of a multinational corporation depends largely on its ability to adapt itself to new market environment. We believe that understanding and implementing multicultural PR strategy can be a key to the multinational corporations' success in foreign markets. We argue in this paper that even a global iconic company such as Google needs to focus on how to understand local consumers' needs and preferences before formulating and implementing PR strategy. Having a global hit product or service is not sufficient enough to be successful in some foreign markets. It is especially more evident in the industries where companies deal with individual consumers, and perceptions and sentiments play a large role in their purchase decisions. The objective of this research is to find out the relationship between multicultural PR strategy and business performance. Therefore, our main hypothesis is; better implementation of multicultural PR strategy by a multinational corporation will result in higher performance in the foreign markets. To prove the relationship between multicultural PR strategy and performance, we designed a framework that uses Rudan's (2004) five rules for multicultural PR strategy. It is a contribution to the business academics as there are very few studies that directly focus on and analyze the multicultural aspects of a multinational company's PR strategy. Through our research, we found strong evidence that there is a positive relationship between the level and effectiveness of a company's multicultural PR strategy and its performance in the foreign markets. This offers some meaningful implications to the managers of the multinational corporations and those who are considering going into a foreign market for the first time. We also suggested a way of measuring the implementation of multicultural PR strategy. By applying five rules for multicultural PR strategy to Google's PR activities, it allowed us to convert qualitative information into quantitative data. This kind of tool can be helpful for multinational corporations that want to evaluate their own PR activities.

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Damage identification in a wrought iron railway bridge using the inverse analysis of the static stress response under rail traffic loading

  • Sidali Iglouli;Nadir Boumechra;Karim Hamdaoui
    • Smart Structures and Systems
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    • v.32 no.3
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    • pp.153-166
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    • 2023
  • Health monitoring of civil infrastructures, in particular, old bridges that are still in service, has become more than necessary, given the risk that a possible degradation or failure of these infrastructures can induce on the safety of users in addition to the resulting commercial and economic impact. Bridge integrity assessment has attracted significant research efforts over the past forty years with the aim of developing new damage identification methods applicable to real structures. The bridge of Ouled Mimoun (Tlemcen, Algeria) is one of the oldest railway structure in the country. It was built in 1889. This bridge, which is too low with respect to the level of the road, has suffered multiple shocks from various machines that caused considerable damage to its central part. The present work aims to analyze the stability of this bridge by identifying damages and evaluating the damage rate in different parts of the structure on the basis of a finite element model. The applied method is based on an inverse analysis of the normal stress responses that were calculated from the corresponding recorded strains, during the passage of a real train, by means of a set of strain gauges placed on certain elements of the bridge. The results obtained from the inverse analysis made it possible to successfully locate areas that were really damaged and to estimate the damage rate. These results were also used to detect an excessive rigidity in certain elements due to the presence of plates, which were neglected in the numerical reference model. In the case of the continuous bridge monitoring, this developed method will be a very powerful tool as a smart health monitoring system, allowing engineers to take in time decisions in the event of bridge damage.

A Study on Expected Dispute Arbitration in Supply Chain ESG Management: Focusing on the cases of POSCO and NAVER (공급망 ESG 관리에서 예상되는 분쟁 중재에 관한 연구 - 포스코와 네이버 사례를 중심으로 -)

  • Lee, Geonwoo;Lee, Jungeun;Lee, Hunjong
    • Journal of Arbitration Studies
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    • v.34 no.1
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    • pp.75-101
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    • 2024
  • "ESG management" guides companies to prioritize corporate social responsibility and sustainable development as key management objectives, going beyond mere financial performance pursuits. This approach involves creating a sustainable and robust supply chain by urging companies, acting as 'supply chain managers', to implement ESG management practices alongside their 'supply chain partners'. The domestic business community has been quick to respond to this trend, recognizing that failure to adhere to ESG standards set by organizations such as the EU and SEC could lead to severe repercussions, including exclusion from international trade and reputational damage. POSCO and NAVER, two leading Korean companies, are at the forefront of practicing ESG management effectively. They have both produced and publicly disclosed ESG management reports, showcasing their success in enhancing supply chain ESG management. However, as supply chain managers enforce ESG-related obligations on their suppliers, the likelihood of disputes between the parties may increase. In scenarios where supply chain ESG management leads to conflicts between supply chain managers and suppliers, commercial arbitration emerges as a viable solution for dispute resolution. This method offers several advantages, including the arbitrators' expertise, time and cost efficiency, the binding nature of decisions akin to a court's final judgment, international recognition under the New York Convention, confidentiality, and ample opportunity for parties to be heard. Our analysis focuses on the emerging disputes between supply chain managers and suppliers within the context of supply chain ESG management, particularly examining the cases of POSCO and NAVER. By categorizing the expected types of disputes and assessing the appropriateness of commercial arbitration for their resolution, we highlight the effectiveness of this approach. Furthermore, we propose leveraging the Korean Commercial Arbitration Board's role to enhance the use of arbitration in resolving supply chain ESG disputes, underscoring its potential as a strategic tool for maintaining sustainable and harmonious supply chain relationships.