• Title/Summary/Keyword: literature evidence

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FG-based computational fracture of frequency up-conversion for bistablity of rotating shell: An effective numerical scheme

  • Hussain, Muzamal
    • Advances in concrete construction
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    • v.13 no.5
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    • pp.367-376
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    • 2022
  • Theoretical study of vibration distinctiveness of rotating cylindrical are examined for three volume fraction laws viz.: polynomial, exponential and trigonometric. These laws control functionally graded material composition in the shell radius direction. Functionally graded materials are controlled from two or more materials. In practice functionally graded material comprised of two constituent materials is used to form a cylindrical shell. For the current shell problem stainless steel and nickel are used for the shell structure. A functionally graded cylindrical shell is sanctioned into two types by interchanging order of constituent materials from inner and outer side for Type I and Type II cylindrical shell arrangement. Fabric composition of a functionally graded material in a shell thickness direction is controlled by volume fraction law. Variation of power law exponent brings change in frequency values. Influence of this physical change is investigated to evade future complications. This procedure is capable to cater any boundary condition by changing the axial wave number. But for simplicity, numerical results have been evaluated for clamped- simply supported rotating cylindrical shells. It has been observed from these results that shell frequency is bifurcated into two parts: one is related to the backward wave and other with forward wave. It is concluded that the value of backward frequency is some bit higher than that forward frequency. Influence of volume fraction laws have been examined on shell frequencies. Backward and forward frequency curves for a volume fraction law are upper than those related to two other volume fraction laws. The results generated furnish the evidence regarding applicability of present shell model and also verified by earlier published literature.

Evaluation of time-dependent deflections on balanced cantilever bridges

  • Rincon, Luis F.;Viviescas, Alvaro;Osorio, Edison;Riveros-Jerez, Carlos A.;Lozano-Galant, Jose Antonio
    • Computers and Concrete
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    • v.28 no.5
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    • pp.487-495
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    • 2021
  • The use of prestressed concrete box girder bridges built by segmentally balanced cantilevers has bloomed in the last decades due to its significant structural and construction advantages in complex topographies. In Colombia, this typology is the most common solution for structures with spans ranging of 80-200 m. Despite its popularity, excessive deflections in bridges worldwide evidenced that time-dependent effects were underestimated. This problem has led to the constant updating of the creep and shrinkage models in international code standards. Differences observed between design processes of box girder bridges of the Colombian code and Eurocode, led to the need for a validation of in-service status of these structures. This study analyzes the long-term behavior of the Tablazo bridge with data scarcity. The measured leveling of this structure is compared with a finite-element model that consider the most widely used creep and shrinkage models in the literature. Finally, an adjusted model evidence excessive deflection on the bridge after six years. Monitoring of this bridge typology in Colombia and updating of the current design code is recommended.

Elastic shell model: Effect of Young's Modulus on the vibration of double-walled CNTs

  • Hussain, Muzamal;Asghar, Sehar;Khadimallah, Mohamed Amine;Ayed, Hamdi;Banoqitah, Essam Mohammed;Loukil, Hassen;Ali, Imam;Mahmoud, S.R.;Tounsi, Abdelouahed
    • Advances in concrete construction
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    • v.13 no.6
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    • pp.471-479
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    • 2022
  • In this paper, vibrational attributes of double-walled carbon nanotubes (CNTs) has been studied based upon nonlocal elastic shell theory. The implication of small scale is being perceived by establishing nonlocal Love shell model. The wave propagation approach has been operated to frame the governing equations as eigen value system. The comparison of local and nonlocal model has been overtly explored by means of scaling parameter. An appropriate selection of material properties and nonlocal parameter has been considered. The influence of changing mechanical parameter Young's modulus has been studied in detail. The dominance of end condition via nonlocal parameter is explained graphically. The results generated furnish the evidence regarding applicability of nonlocal shell model and also verified by earlier published literature.

The Relationship Between Capital Structure and Firm Performance: New Evidence from Pakistan

  • ISLAM, Zia ul;IQBAL, Muhammad Mazhar
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.2
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    • pp.81-92
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    • 2022
  • The necessity for a theoretical explanation of the negative association between capital structure and company performance is identified in this study. By focusing on accounting metrics of business performance, this study is the first to investigate the moderating effects of firm size between these variables using logical reasoning. Due to the possibility of endogeneity, this study applies a two-step system GMM approach with data from 285 non-financial enterprises from PSX over a 21-year period. For robustness, we employed pooled OLS, fixed effect, and two-step difference GMM. Our data show that leverage has a detrimental impact on business performance, with size acting as a moderator in the same direction. Our analysis empirically supports some studies while refuting others due to inconsistent results in the literature, but no study has theoretically justified their negative link. We believe that because larger companies have more and easier access to capital markets, they focus primarily on the amount of return, even if the investment is inefficient in terms of the rate of return, but small businesses do not. As a result of this thinking, firm managers' performance suffers as a result of leverage.

A systematic review of treatment and outcomes in patients with mandibular coronoid process hyperplasia

  • Parmentier, Griet I.L.;Nys, Margaux;Verstraete, Laurence;Politis, Constantinus
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.48 no.3
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    • pp.133-148
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    • 2022
  • Treatment of mandibular coronoid process hyperplasia (MCPH) has been described and explored in the literature. This systematic review aims to provide a comprehensive overview of the surgical and non-surgical treatment options for MCPH in pediatric and adult populations. Three databases were searched for treatment of MCPH patients (MEDLINE, Embase, and Web of Science). Two reviewers selected case reports and case series based on titles and abstracts. Finally, 55 studies reporting a total of 127 cases were included for qualitative synthesis and data extraction. The mean age at symptom onset was 15.6 years, while the mean age at diagnosis was 23.5 years. Of the included cases, 83.7% were male, and the condition was bilateral in more than 81% of the cases. Coronoidectomy was performed in 82.7% of the included cases, while coronoidotomy was performed in 3.9% of the cases. In 85.0% of the surgically treated cases, the approach was intraoral. The mean maximal intraoperative mouth opening was 38.1 mm compared with 16.5 mm at diagnosis. The mean maximal postoperative mouth opening was 35.3 mm, and the mean follow-up period was 16.3 months. Maximum mouth opening was achieved intraoperatively, and non-surgical treatment after surgery aims to reduce the risk of relapse. Additional research with a higher level of evidence is necessary to confirm these findings.

The Implementation of Smart Factories: Empirical Evidence from Korean Small and Medium-Sized Enterprises (스마트팩토리 도입 영향요인에 관한 실증연구: 우리나라 중소제조기업을 중심으로)

  • Chung, Jiyoon
    • Asia-Pacific Journal of Business
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    • v.13 no.2
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    • pp.79-94
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    • 2022
  • Purpose - The purpose of this study is to examine firm-level attributes related to Korean manufacturing small and medium-sized enterprises' (SMEs') decisions to implement smart factories. Design/methodology/approach - This study uses the provided by the Ministry of SMEs and Startups of Korea and the Korea Federation of SMEs. Manufacturing SMEs' decisions to implement smart factories in 2018-2019 were analyzed using multinomial logit and ordered logit models. Findings - The findings of this study suggest that firms' decisions to implement smart factories were positively related to firm size, R&D intensity, international market scope, and transactional relationships with customers. However, smart factory implementation decisions were not related to firm age and CEO gender. Research implications or Originality - This study illuminates firm-level attributes that may drive organizational innovation in the era of Industry 4.0 and thus contributes to the innovation adoption literature. This study also contributes to growing research on smart factories by analyzing the actual, progressive decisions to implement smart factories, as opposed to perceived intentions to implement them.

Factors for Better Adoption of Information Security on Custom-Made Software at SMEs: A Systematic Review and Framework

  • Fatimah Alghamdi;Moutasm Tamimi;Nermin Hamza
    • International Journal of Computer Science & Network Security
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    • v.23 no.2
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    • pp.65-78
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    • 2023
  • Investigations on information security factors re- main elusive at small and medium enterprises (SMEs), es- specially for custom-made software solutions. This article aims to investigate, classify, adopt factors from recent literature addressing information security resources. SMEs al- ready have information security in place, but they are not easy to adopt through the negotiation processes between the in-house software development companies and custom-made software clients at SMEs. This article proposes a strategic framework for implementing the process of adoption of the information security factors at SMEs after conducting a systematic snapshot approach for investigating and classifying the resources. The systematic snapshot was conducted using a search strategy with inclusion and exclusion criteria to retain 128 final reviewed papers from a large number of papers within the period of 2001-2022. These papers were analyzed based on a classification schema including management, organizational, development, and environmental categories in software development lifecycle (SDLC) phases in order to define new security factors. The reviewed articles addressed research gaps, trends, and common covered evidence-based decisions based on the findings of the systematic mapping. Hence, this paper boosts the broader cooperation between in-house software development companies and their clients to elicit, customize, and adopt the factors based on clients' demands.

A Literature Review of Clinical Studies on Korean Medicine Treatment on Tension-type Headache: Focused on Domestic Case Reports (긴장형 두통의 한의학적 치료에 대한 임상연구 동향 분석 : 국내 증례보고를 중심으로)

  • Jun Hyeok Choi;Hae Chang Jung;Haemo Park
    • Journal of Society of Preventive Korean Medicine
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    • v.27 no.1
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    • pp.53-68
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    • 2023
  • Objectives : This study was conducted to analyze the Korean Medicine treatment on Tension-type Headache (TTH) in Korean clinical studies. Methods : Articles were searched from four Korean databases(KISS, RISS, OASIS, ScienceON). Study type, publication year, demographic information of participants, intervention type and details, outcome measurements and treatment results of selected articles were analyzed. Results : 17 articles were selected among those published until January 15th 2023. 'Cheonghyulgangki-tang', acupuncture at 'GV20', moxibustion at 'CV12', pharmacopunture at 'GB20', 'ByeolGab' were most frequently used in treatment on TTH. 'Numeric Rating Scale(NRS)' and 'Visual Analog Scale(VAS)' were most frequently used in outcome measurements. All of the articles exhibited that Korean Medicine treatments improved symptoms of TTH. Conclusion : This study showed that various Korean Medicine treatments for TTH were effective. This finding could be used in clinical practice and build the basis for the direction of clinical practice guidelines in future, Nevertheless, this study has few limitations. Further systematic reviews and meta analyses of randomized controlled trials are required for more evidence on Korean Medicine.

A Study on the Korean Translation of the Shishimilu (한글본 석실비록(石室祕錄) 연구)

  • Park Hun-pyeong
    • Journal of Korean Medical classics
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    • v.36 no.3
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    • pp.1-13
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    • 2023
  • Objectives :The Shishimilu is a clinical treatise, published in 1687 by Qing period doctor, Chensiduo. The purpose of this study is to report the newly discovered Korean translation to the academic world and discuss its significance. Methods : The newly discovered Korean translated version was examined in detail focusing on bibliography and content items. In addition, the time of introduction of the Shishimilu to Joseon was studied philologically. Results : 1. The time of completion was during the period of the Korean Empire. 2. The original text was faithfully translated. 3. The book was rearranged from the original document to make it easier to apply in clinical practice. 4. Experiences of Joseon medicine were reflected, mainly prescriptions. 5. According to documentary evidence, the Shishimilu was first introduced to Korea only in the late 19th century, and was widely distributed during the Japanese colonial period. Conclusions : he Korean translated version of the Shishimilu was the earliest among known Korean translations of Chinese medical texts, and while faithfully translating the original text, the compilation was rearranged to make it easier to apply clinically. In addition, the experience of Joseon medicine was reflected mostly in prescriptions. It could be determined that if contents of the Shishimilu appear in Korean literature whose writing period is unknown, it can be historically verified to have been written after the late 19th century.

A Literature Review on Acupuncture and Transcutaneous Electrical Nerve Stimulation for Tinnitus - Focusing on Autonomic Nervous System - (침, 경피전기자극의 이명 치료에 대한 문헌 고찰 - 자율신경을 중심으로 -)

  • Hye-Yeon Ko;Eun-Kyung Lee;Min-Hee Kim
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.36 no.3
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    • pp.12-26
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    • 2023
  • Objectives : The purpose of this study is to analyze the acupuncture and transcutaneous electrical nerve stimulation(TENS) for tinnitus to identify the trend, effectiveness and mechanism. Methods : Research studies related to objectives were gathered through Pubmed, RISS, KISS, KCI, OASIS with keywords such as 'Tinnitus', 'Autonomic', 'ANS', 'HRV', 'acupuncture', 'transcutaneous' and analyzed. Results : 4 studies were included. Acupuncture was used in 1 study and TENS was used in 3 studies. Tinnitus handicap inventory(THI), fMRI and 'heart rate and blood pressure' were used in 1 study each and heart rate variability(HRV) was used in 3 studies as evaluation tools. Each treatment showed a significant effect. Conclusions : Our findings indicate that acupuncture and TENS could be a potential therapy for tinnitus, however additional well designed RCT are required to establish high level of evidence.