• Title/Summary/Keyword: comparative assessment

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Experimental and analytical study of a new seismic isolation device under a column

  • Benshuai Liang;Guangtai Zhang;Mingyang Wang;Jinpeng Zhang;Jianhu Wang
    • Earthquakes and Structures
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    • v.24 no.6
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    • pp.415-428
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    • 2023
  • Low-cost techniques with seismic isolation performance and excellent resilience need to be explored in the case of rural low-rise buildings because of the limited buying power of rural residents. As an inexpensive and eco-friendly isolation bearing, scrap tire pads (STPs) have the issue of poor resilience. Thus, a seismic isolation system under a column (SISC) integrated with STP needs to be designed for the seismic protection of low-rise rural buildings. The SISC, which is based on a simple exterior design, maintains excellent seismic performance, while the mechanical behavior of the internal STP provides elastic resilience. The horizontal behaviors of the SISC are studied through load tests, and its mechanical properties and the intrinsic mechanism of the reset ability are discussed. Results indicate that the average residual displacement ratio was 24.59%, and the reset capability was enhanced. Comparative experimental and finite element analysis results also show that the load-displacement relationship of the SISC was essentially consistent. The dynamic characteristics of isolated and fixed-base buildings were compared by numerical assessment of the response control effects, and the SISC was found to have great seismic isolation performance. SISC can be used as a low-cost base isolation device for rural buildings in developing countries.

Adaptive Extraction Method for Phase Foreground Region in Laser Interferometry of Gear

  • Xian Wang;Yichao Zhao;Chaoyang Ju;Chaoyong Zhang
    • Current Optics and Photonics
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    • v.7 no.4
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    • pp.387-397
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    • 2023
  • Tooth surface shape error is an important parameter in gear accuracy evaluation. When tooth surface shape error is measured by laser interferometry, the gear interferogram is highly distorted and the gray level distribution is not uniform. Therefore, it is important for gear interferometry to extract the foreground region from the gear interference fringe image directly and accurately. This paper presents an approach for foreground extraction in gear interference images by leveraging the sinusoidal variation characteristics shown by the interference fringes. A gray level mask with an adaptive threshold is established to capture the relevant features, while a local variance evaluation function is employed to analyze the fluctuation state of the interference image and derive a repair mask. By combining these masks, the foreground region is directly extracted. Comparative evaluations using qualitative and quantitative assessment methods are performed to compare the proposed algorithm with both reference results and traditional approaches. The experimental findings reveal a remarkable degree of matching between the algorithm and the reference results. As a result, this method shows great potential for widespread application in the foreground extraction of gear interference images.

Narrative Review of the Association between Cervical Region Treatment and Facial Paralysis

  • Young-Jun Kim;Hye-Ri Jo;So-Rim Kim;Dong-Guk Shin;Da-Won Lee;Yeon-Sun Lee
    • Journal of Acupuncture Research
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    • v.40 no.4
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    • pp.319-328
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    • 2023
  • Facial nerve palsy refers to sudden, unilateral lower motor neuron facial paralysis. This study aimed to determine the importance of neck treatment in the treatment of facial paralysis. A literature search was performed on six online databases and other sources until January 15, 2023. A total of 426 papers were retrieved. After excluding duplicated and inconsistent papers, papers not including cervical treatment, and experimental papers on animals, two papers were finally selected. The type of treatment method, therapeutic effects, assessment of the risk of bias in randomized controlled trials, and non-randomized controlled trials and side effects were evaluated. Chiropractic, manual therapy, facial meridian massage, and acupotomy were applied to the face and cervical spine region. The results showed that each treatment had a significant therapeutic effect through evaluation index measurement methods, such as the visual analog scale and Yanagihara's unweighted regional grading system. This study demonstrated the importance of the cervical spine area in the treatment of facial paralysis. However, this study has many limitations. Thus, high-quality randomized controlled comparative studies on the treatment of the cervical spine area only or studies that include cervical spine area treatment as an interventional treatment while performing oriental or comprehensive treatment are needed.

Comparative Evaluation of Egg Quality in Response to Temperature Variability: From Farm to Table Exposure Scenarios

  • Ji-Hoon An;Youngmin Hwang;Sumin Hwang;Hyojin Kwon;Hyelim Gu;Kihwan Park;Changsun Choi
    • Food Science of Animal Resources
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    • v.43 no.6
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    • pp.1002-1016
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    • 2023
  • This study aimed to develop appropriate temperature management practices and provide scientific evidence to support the development of sell-by-date guidance for eggs. Washed and unwashed eggs were subjected to storage under six different scenarios, and both types of eggs were stored at temperatures up to 35℃ to evaluate the sell-by-date. Despite temperature fluctuations or continuous storage at 30℃ for 5 days, subsequent storage at 10℃ resulted in significantly higher Haugh unit and yolk index on day 15. These results indicate that refrigerating eggs from retail sales until consumption is effective for egg quality management, despite the exposure of up to 35℃ during distribution. In terms of sell-by-date evaluation, washed eggs retained class B quality for an additional 37 days beyond the recommended sell-by-date at 15℃, which is above the regulated storage temperature. However, unwashed eggs maintained class B quality for approximately 20 days at 30℃-35℃, emphasizing the need for sell-by-date guidelines for unwashed eggs. This study is the first to provide appropriate egg-handling practices based on the actual distribution environment in Korea.

Pregabalin versus Gabapentin Efficacy in the Management of Neuropathic Pain Associated with Failed Back Surgery Syndrome

  • Laith Thamer Al-Ameri;Mohammed Emad Shukri;Ekhlas Khalid Hameed;Ahmed Abed Marzook
    • Journal of Korean Neurosurgical Society
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    • v.67 no.2
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    • pp.202-208
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    • 2024
  • Objective : Failed back surgery syndrome (FBSS) is a common long-term complication following spine surgeries characterized by chronic persistent pain; different strategies of management were employed to deal with it. This clinical trial aims to compare the efficacy of Pregabalin and Gabapentin in the management of this condition. Methods : A double-blind, randomized, comparative study (clinical trial registry NCT05324761 on 11th April 2022) with two parallel arms with Pregabalin and Gabapentin were used in arms one and two, respectively. Visual analog scale was used for basal and endpoint assessment of pain. T-test and analysis of covariance were used to deal with different variables. A pairwise test was used to compare pairs of means. Results : Of 66 patients referred to the trial, 64 were eligible, with 60 patients completing the 30 days trial. Both pregabalin and gabapentin effectively reduce pain, with significant p-values of 0.001 for each group. However, the pregabalin group was superior to gabapentin in pain reduction (p=0.001). Gender was an insignificant factor (p=0.574 and p=0.445 for the pregabalin and gabapentin groups, respectively, with a non-significant reduction (p=0.393) for both groups in total. Location of stenosis before surgery and type of surgery performed show non-significant effect on pain reduction for both groups. Conclusion : Both pregabalin and gabapentin effectively and safely relieve neuropathic pain associated with FBSS; pregabalin was significantly more effective irrespective of the patients' gender.

Probabilistic earthquake risk consideration of existing precast industrial buildings through loss curves

  • Ali Yesilyurt;Seyhan O. Akcan;Oguzhan Cetindemir;A. Can Zulfikar
    • Geomechanics and Engineering
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    • v.37 no.6
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    • pp.565-576
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    • 2024
  • In this study, the earthquake risk assessment of single-story RC precast buildings in Turkey was carried out using loss curves. In this regard, Kocaeli, a seismically active city in the Marmara region, and this building class, which is preferred intensively, were considered. Quality and period parameters were defined based on structural and geometric properties. Depending on these parameters, nine main sub-classes were defined to represent the building stock in the region. First, considering the mean fragility curves and four different central damage ratio models, vulnerability curves for each sub-class were computed as a function of spectral acceleration. Then, probabilistic seismic hazard analyses were performed for stiff and soft soil conditions for different earthquake probabilities of exceedance in 50 years. In the last step, 90 loss curves were derived based on vulnerability and hazard results. Within the scope of the study, the comparative parametric evaluations for three different earthquake intensity levels showed that the structural damage ratio values for nine sub-classes changed significantly. In addition, the quality parameter was found to be more effective on a structure's damage state than the period parameter. It is evident that since loss curves allow direct loss ratio calculation for any hazard level without needing seismic hazard and damage analysis, they are considered essential tools in rapid earthquake risk estimation and mitigation initiatives.

In-Vitro Model Design of Mitral Valve Regurgitation and Comparative Study of Quantification between PISA and 4D flow MRI (승모판 역류 In-Vitro 모델을 활용한 초음파 및 4D flow MRI 기반 혈류 정량화 비교연구)

  • Juyeon Lee;Minseong Kwon;Hyungkyu Huh
    • Journal of the Korean Society of Visualization
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    • v.22 no.1
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    • pp.40-48
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    • 2024
  • This study presents an in-vitro model designed to simulate mitral valve regurgitation, aiming to compare the quantification results between Proximal Isovelocity Surface Area(PISA) and 4D Flow MRI on both fixed and valve annulus tracking(VAT) views. The in-vitro model replicates the dynamic conditions of the mitral valve in a pulsatile environment, utilizing a piston pump set at 60 bpm. Through systematic experiments and analysis, the study evaluates the accuracy and effectiveness of PISA and 4D Flow MRI in assessing regurgitation severity, considering both fixed and valve annulus tracking. The displacement length measured in echo closely resembled that of optical measurements, making it advantageous for structural analysis. VAT-4D flow MRI exhibited the smallest deviation from actual flow rate values, establishing it as most accurate method for quantitative regurgitation assessment.

Comparative Assessment of Typical Year Dataset based on POA Irradiance (태양광 패널 일사량에 기반한 대표연도 데이터 비교 평가)

  • Changyeol Yun;Boyoung Kim;Changki Kim;Hyungoo Kim;Yongheack Kang;Yongil Kim
    • New & Renewable Energy
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    • v.20 no.1
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    • pp.102-109
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    • 2024
  • The Typical Meteorological Year (TMY) dataset compiles 12 months of data that best represent long-term climate patterns, focusing on global horizontal irradiance and other weather-related variables. However, the irradiance measured on the plane of the array (POA) shows certain distinct distribution characteristics compared with the irradiance in the TMY dataset, and this may introduce some biases. Our research recalculated POA irradiance using both the Isotropic and DIRINT models, generating an updated dataset that was tailored to POA characteristics. Our analysis showed a 28% change in the selection of typical meteorological months, an 8% increase in average irradiance, and a 40% reduction in the range of irradiance values, thus indicating a significant shift in irradiance distribution patterns. This research aims to inform stakeholders about accurate use of TMY datasets in potential decision-making. These findings underscore the necessity of creating a typical dataset by using the time series of POA irradiance, which represents the orientation in which PV panels will be deployed.

Assessment of Odor Issues and Technologies in Wonju Traditional Market

  • Benish ZAHRA;Young-Jin SO
    • Journal of Wellbeing Management and Applied Psychology
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    • v.7 no.4
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    • pp.21-28
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    • 2024
  • This study investigates the sources and characteristics of odor pollutants, focusing on total volatile organic compounds (TVOCs), hydrogen sulfide, and ammonia in traditional markets. The objective is to assess the impact of these odors on market environments and evaluate the effectiveness of new odor-reducing techniques. Research design, data, and methodology: Conducted in Wonju Traditional Market, the research employed a longitudinal design to analyze odor concentrations over time through continuous monitoring at five strategically established points. Measurements were taken continuously for five minutes at one-minute intervals using the AOMS-1000 odor-measuring equipment. The study also applied a sewage odor-reducing substance spraying device designed to minimize unpleasant odors. Data was collected in the summer of 2022 and again in the summer of 2023, allowing for a comparative analysis of odor levels before and after implementing the odor-reducing technique. Results: Findings revealed significant concentrations of TVOCs, hydrogen sulfide, and ammonia, with a notable reduction in pollutants following the introduction of the odor-reducing device. Conclusions: This study highlights the importance of effective odor management in traditional markets. It recommends the adoption of advanced technologies such as biofilters, electrostatic precipitators, and photocatalytic purification systems to better control odor emissions. Implementing these solutions can significantly enhance the shopping experience for consumers.

Assessment of environmental fatigue in nuclear power plants: A comparative analysis of the effects of plasticity correction

  • Tae-Song Han;Hee-Jin Kim;Nam-Su Huh;Hyeong-Yeon Lee;Changheui Jang
    • Nuclear Engineering and Technology
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    • v.56 no.9
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    • pp.3764-3774
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    • 2024
  • In accordance with Regulatory Guide 1.207, Rev.1, fatigue assessments must be conducted considering the influence of primary coolant environment in nuclear reactors. Environmental fatigue, resulting from corrosion in the primary coolant, is evaluated in air fatigue life assessments through the application of an environmental fatigue correction factor. This environmental fatigue correction factor depends on sulfur content, operating temperature, dissolved oxygen, and strain rate. It remains constant for sulfur content, operating temperature, and dissolved oxygen, while strain rate introduces potential errors based on the analysis method. The current fatigue evaluation procedure for air, following ASME B&PV Code Sec.III, NB-3200, employs elastic analysis with a simplified elastic-plastic correction factor(Ke). However, Ke factor is considered excessively conservative, prompting less conservative alternatives proposed by JSME, RCC-M, ASME Code Case N-779. This study applied both ASME Ke and JSME Ke for fatigue evaluations considering environmental effects. Additionally, fatigue assessments accounting for elastic-plastic effects were conducted using Neuber and Glinka methods, compared with actual experiments. The analysis systematically examined changes in fatigue life and the environmental fatigue correction factor due to plastic effects in environmental fatigue evaluations.