• Title/Summary/Keyword: academic failure

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Does the prosthesis weight matter? 3D finite element analysis of a fixed implant-supported prosthesis at different weights and implant numbers

  • Tribst, Joao Paulo Mendes;Dal Piva, Amanda Maria de Oliveira;Borges, Alexandre Luiz Souto;Rodrigues, Vinicius Aneas;Bottino, Marco Antonio;Kleverlaan, Cornelis Johannes
    • The Journal of Advanced Prosthodontics
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    • v.12 no.2
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    • pp.67-74
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    • 2020
  • PURPOSE. This study evaluated the influence of prosthesis weight and number of implants on the bone tissue microstrain. MATERIALS AND METHODS. Fifteen (15) fixed full-arch implant-supported prosthesis designs were created using a modeling software with different numbers of implants (4, 6, or 8) and prosthesis weights (10, 15, 20, 40, or 60 g). Each solid was imported to the computer aided engineering software and tetrahedral elements formed the mesh. The material properties were assigned to each solid with isotropic and homogeneous behavior. The friction coefficient was set as 0.3 between all the metallic interfaces, 0.65 for the cortical bone-implant interface, and 0.77 for the cancellous bone-implant interface. The standard earth gravity was defined along the Z-axis and the bone was fixed. The resulting equivalent strain was assumed as failure criteria. RESULTS. The prosthesis weight was related to the bone strain. The more implants installed, the less the amount of strain generated in the bone. The most critical situation was the use of a 60 g prosthesis supported by 4 implants with the largest calculated magnitude of 39.9 mm/mm, thereby suggesting that there was no group able to induce bone remodeling simply due to the prosthesis weight. CONCLUSION. Heavier prostheses under the effect of gravity force are related to more strain being generated around the implants. Installing more implants to support the prosthesis enables attenuating the effects observed in the bone. The simulated prostheses were not able to generate harmful values of peri-implant bone strain.

The Analysis on Research in the Korean Journal of Rehabilitation Nursing (재활간호학회지 논문 분석 - 창간호부터 2004년까지 -)

  • Lim, Nan-Young;Kim, Jeong-Hwa;Cho, Bok-Hee;So, Hee-Young;Park, Song-Ja;Cho, Nam-Ok;Yoo, Kyung-Hee
    • The Korean Journal of Rehabilitation Nursing
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    • v.8 no.2
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    • pp.119-128
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    • 2005
  • Purpose: The purpose of this study was to analyze research in the Korean Journal of Rehabilitation Nursing and to suggest further perspective for rehabilitation nursing research. Method: In this study we reviewed the contents of 134 articles published in this journal from its beginning year 1998 to 2004. Results: The majority of subjects were adult patients. The type of disease were Cerebrovascular Accident, Neuromuscular disease, Cancer patients, Urogenital disease such as Chronic Renal Failure, Spinal cord injury. Domain of research almost was client, type of research were survey(34.3%), quasi experimental study(20.9%), correlation study(19.4%). Nursing intervention of experimental study was exercise(39.0%), education(17.1%). Place of data collection was hospital (58.2%), position of researcher was professor(67.2%), method of data collection was questionnaire(50.7%). Conclusion: There has been a lack of written consent, child rehabilitation, measurement tool development, qualitative research. More studies about rehabilitation nursing are needed to extend the role and fields for professional nursing.

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Case Study on AUTOSAR Software Functional Safety Mechanism Design: Shift-by-Wire System (AUTOSAR 소프트웨어 기능안전 메커니즘 설계 사례연구: Shift-by-Wire 시스템)

  • Kum, Daehyun;Kwon, Soohyeon;Lee, Jaeseong;Lee, Seonghun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.16 no.6
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    • pp.267-276
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    • 2021
  • The automotive industry and academic research have been continuously conducting research on standardization such as AUTOSAR (AUTomotive Open System ARchitecture) and ISO26262 to solve problems such as safety and efficiency caused by the complexity of electric/electronic architecture of automotive. AUTOSAR is an automotive standard software platform that has a layered structure independent of MCU (Micro Controller Unit) hardware, and improves product reliability through software modularity and reusability. And, ISO26262, an international standard for automotive functional safety and suggests a method to minimize errors in automotive ECU (Electronic Control Unit)s by defining the development process and results for the entire life cycle of automotive electrical/electronic systems. These design methods are variously applied in representative automotive safety-critical systems. However, since the functional and safety requirements are different according to the characteristics of the safety-critical system, it is essential to research the AUTOSAR functional safety design method specialized for each application domain. In this paper, a software functional safety mechanism design method using AUTOSAR is proposed, and a new failure management framework is proposed to ensure the high reliability of the product. The AUTOSAR functional safety mechanism consists of memory partitioning protection, timing monitoring protection, and end-to-end protection. The fault management framework is composed of several safety SWCs to maintain the minimum function and performance even if a fault occurs during the operation of a safety-critical system. Finally, the proposed method is applied to the Shift-by-Wire system design to prove the validity of the proposed method.

Simulation Modeling for Production Scheduling under Make-To-Order Production Environment : Focusing on the Flat Glass Production Environment (주문생산 방식의 생산계획 수립을 위한 시뮬레이션 모델 설계 : 판유리 제조 공정을 중심으로)

  • Choi, Yong-Hee;Hwang, Seung-June
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.42 no.1
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    • pp.64-73
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    • 2019
  • The manufacturing companies under Make-To-Order (MTO) production environment face highly variable requirements of the customers. It makes them difficult to establish preemptive production strategy through inventory management and demand forecasting. Therefore, the ability to establish an optimal production schedule that incorporates the various requirements of the customers is emphasized as the key success factor. In this study, we suggest a process of designing the simulation model for establishing production schedule and apply this model to the case of a flat glass processing company. The flat glass manufacturing industry is under MTO production environment. Academic research of flat glass industry is focused on minimizing the waste in the cutting process. In addition, in the practical view, the flat glass manufacturing companies tend to establish the production schedule based on the intuition of production manager and it results in failure of meeting the due date. Based on these findings, the case study aims to present the process of drawing up a production schedule through simulation modeling. The actual data of Korean flat glass processing company were used to make a monthly production schedule. To do this, five scenarios based on dispatching rules are considered and each scenario is evaluated by three key performance indicators for delivery compliance. We used B2MML (Business To Manufacturing Markup Language) schema for integrating manufacturing systems and simulations are carried out by using SIMIO simulation software. The results provide the basis for determining a suitable production schedule from the production manager's perspective.

What Factors Make the Delay of the Information System Project Implementation? (무엇이 정보시스템 프로젝트 일정을 지연시키는가?)

  • Seoung, Byung Ook;Park, Sang Cheol;Koh, Joon
    • Knowledge Management Research
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    • v.22 no.1
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    • pp.1-19
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    • 2021
  • Large-scaled hospital information system projects are often delayed than originally planned. Regarding project management, it is necessary to examine main factors triggering the schedule delay and to analyze the causality of such delay. This study tries to find the delay factors and causal relationship between them based on the case of the hospital information system development project by using the grounded theory method. It turned out that 'unrealistic scheduling' affects overall schedule delays like domino phenomenon, and 'poor analysis of existing systems' leads to poor quality of work analysis while 'poor subsystem integrated interface' triggers poor design quality. This study found out the factors affecting the delay of a project, analyzing cause-and-effect relationships between them in the academic side. From the practical view, it shows a solution to minimize delays in the project schedule for each of SI companies, hospitals and project managers.

Can Panax ginseng help control cytokine storm in COVID-19?

  • Choi, Jong Hee;Lee, Young Hyun;Kwon, Tae Woo;Ko, Seong-Gyu;Nah, Seung-Yeol;Cho, Ik-Hyun
    • Journal of Ginseng Research
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    • v.46 no.3
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    • pp.337-347
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    • 2022
  • Coronavirus disease 2019 (COVID-19) is currently a pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). COVID-19 are directly associated with hyper-activation of innate immune response that excessively produce pro-inflammatory cytokines and induce cytokine storm, leading to multi-organ-failure and significant morbidity/mortality. Currently, several antiviral drugs such as Paxlovid (nirmatrelvir and ritonavir) and molnupiravir are authorized to treat mild to moderate COVID-19, however, there are still no drugs that can specifically fight against challenges of SARS-CoV-2 variants. Panax ginseng, a medicinal plant widely used for treating various conditions, might be appropriate for this need due to its anti-inflammatory/cytokine/viral activities, fewer side effects, and cost efficiency. To review Panax ginseng and its pharmacologically active-ingredients as potential phytopharmaceuticals for treating cytokine storm of COVID-19, articles that reporting its positive effects on the cytokine production were searched from academic databases. Experimental/clinical evidences for the effectiveness of Panax ginseng and its active-ingredients in preventing or mitigating cytokine storm, especially for the cascade of cytokine storm, suggest that they might be beneficial as an adjunct treatment for cytokine storm of COVID-19. This review may provide a new approach to discover specific medications using Panax ginseng to control cytokine storm of COVID-19.

A Scientometric and Meta-analysis of Rail Infrastructure in Nigeria

  • Awodele, Imoleayo Abraham;Mewomo, Modupe Cecilia
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.960-966
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    • 2022
  • Mobility is an essential human need. Human survival and societal interaction depend on the ability to move people and goods. Efficient mobility systems are essential facilitators of economic development. Cities could not exist and global trade could not occur without systems to transport people and goods cheaply and efficiently. Rail has been considered as one of the important components of the transportation infrastructure required to service and improve the performance and productivity of an economy. In Nigeria, the rail infrastructure built by the colonial master several decades ago has been left in a state of total deterioration. This long neglect was occasioned by the failure of the government to pay adequate attention to infrastructure development. There is a vital and urgent need for rail infrastructure development in Nigeria. This study presents a systematic review of the evolution of rail, the current nature of railway infrastructure delivery in Nigeria, and offers possible suggestions on how to achieve an effective and sustainable rail infrastructure delivery in Nigeria. A thorough literature search of academic databases was conducted on current research trends on the subject of railway infrastructure by systematically reviewing selected published articles from reputable research domains. The analysis of the selected articles revealed the following among others (1) the existing railway infrastructure is in a state of mess and not sustainable, and (2), Government's investment/commitment in rail infrastructure seems inadequate compared to what is obtainable in other developed countries. Rail infrastructure development cannot be left to the Federal government of Nigeria to solve on its own; collaboration and participation are required. Government as a matter of priority should devote considerable attention to the development of rail infrastructure to harness the economic potential and transformation that sustainable rail infrastructural projects will provide.

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The Dynamic Effects of Customer Satisfaction on Firm's Profitability and Value (기업의 수익성과 가치에 미치는 고객만족의 동태적 영향)

  • Yi, Youjae;Cha, Kyoung Cheon;Lee, Cheonglim
    • Asia Marketing Journal
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    • v.10 no.1
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    • pp.1-23
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    • 2008
  • It is natural that firms would like to increase their profits and value through customer satisfaction (CS). It is therefore important for the academic and practical purposes to investigate the relationship between CS and firm's performance. Previous studies about this relationship have examined mainly the current effect of CS on firm's performance. According to the research that many marketing activities have dynamic effects over time, however, the dynamic effect of CS on firm's performance needs to be tested. Failure to assess the dynamic effects might lead to the underestimation of the impact of CS. This study thus attempts to investigate the dynamic effects of CS on firm's profitability and value by panel data analysis. The results show that CS has dynamic effects on firm's profitability and value. There was a significant improvement in model fit compared with the model examining the current effects only. On the other hand, it was difficult to interpret the estimation results of the alternative model incorporating two lagged variables of CS, and there was also a multicollinearity problem.

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Influence of size-anatomy of the maxillary central incisor on the biomechanical performance of post-and-core restoration with different ferrule heights

  • Domingo Santos Pantaleon;Joao Paulo Mendes Tribst;Franklin Garcia-Godoy
    • The Journal of Advanced Prosthodontics
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    • v.16 no.2
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    • pp.77-90
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    • 2024
  • PURPOSE. The study aims to investigate the influence of the ferrule effect and types of posts on the stress distribution in three morphological types of the maxillary central incisor. MATERIALS AND METHODS. Nine models were created for 3 maxillary central incisor morphology types: "Fat" type - crown 12.5 mm, root 13 mm, and buccolingual cervical diameter 7.5 mm, "Medium" type - crown 11 mm, root 14 mm, and buccolingual cervical diameter 6.5 mm, and "Slim" type - crown 9.5 mm, root 15 mm, and buccolingual cervical diameter 5.5 mm. Each model received an anatomical castable post-and-core or glass-fiber post with resin composite core and three ferrule heights (nonexistent, 1 mm, and 2 mm). Then, a load of 14 N was applied at the cingulum with a 45° slope to the long axis of the tooth. The Maximum Principal Stress and the Minimum Principal Stress were calculated in the root dentin, crown, and core. RESULTS. Higher tensile and compression stress values were observed in root dentin using the metallic post compared to the fiber post, being higher in the slim type maxillary central incisor than in the medium and fat types. Concerning the three anatomical types of maxillary central incisors, the slim type without ferrule height in mm presented the highest tensile stress in the dentin, for both types of metal and fiber posts. CONCLUSION. Post system and tooth morphology were able to modify the biomechanical response of restored endodontically-treated incisors, showing the importance of personalized dental treatment for each case.

The Effect of Internal Control Weaknesses on Book-Tax Difference (내부회계관리제도의 취약점이 회계이익과 과세소득의 차이에 미치는 영향)

  • Yu, Soon-Mi;Park, Sang-Bong
    • Management & Information Systems Review
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    • v.30 no.3
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    • pp.169-190
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    • 2011
  • Recent academic studies have investigated book-tax differences as an indicator of earnings management. Tax accounting texts claim that the differences between pre-tax financial reporting earnings and taxable income can provide information about current earnings, and the large differences between book and taxable incomes are an indicator of low-quality financial reporting earnings. This study investigates the effect of internal control system over book and tax difference using the KOSPI and KOSDAQ firms from 2006 to 2008. The empirical findings are consistent with a weakness of internal control system being associated with higher book-tax difference. That means a firm which has material weakness in the internal control system allows for more malpractice. In addition to this, If the managers tries to the efficient tax decrease strategy, book-tax difference can be large. Which in turn leads us to observe a positive relation between the weakness of internal control system and intensity of book-tax difference. Overall, we interpret this evidence as indicating that the failure of the internal control system can effect not only investors and creditors but also tax authorities. And It emphasizes that a more effective internal control system linked with sound corporate governance.

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