• Title/Summary/Keyword: Scale-model

Search Result 8,303, Processing Time 0.04 seconds

The Effect of Preoperative Three Dimensional Modeling and Simulation on Outcome of Intracranial Aneursym Surgery

  • Erkin Ozgiray;Bugra Husemoglu;Celal Cinar;Elif Bolat;Nevhis Akinturk;Huseyin Biceroglu;Ceren Kizmazoglu
    • Journal of Korean Neurosurgical Society
    • /
    • v.67 no.2
    • /
    • pp.166-176
    • /
    • 2024
  • Objective : Three-dimensional (3D) printing in vascular surgery is trending and is useful for the visualisation of intracranial aneurysms for both surgeons and trainees. The 3D models give the surgeon time to practice before hand and plan the surgery accordingly. The aim of this study was to examine the effect of preoperative planning with 3D printing models of aneurysms in terms of surgical time and patient outcomes. Methods : Forty patients were prospectively enrolled in this study and divided into two groups : groups I and II. In group I, only the angiograms were studied before surgery. Solid 3D modelling was performed only for group II before the operation and was studied accordingly. All surgeries were performed by the same senior vascular neurosurgeon. Demographic data, surgical data, both preoperative and postoperative modified Rankin scale (mRS) scores, and Glasgow outcome scores (GOS) were evaluated. Results : The average time of surgery was shorter in group II, and the difference was statistically significant between the two groups (p<0.001). However, no major differences were found for the GOS, hospitalisation time, or mRS. Conclusion : This study is the first prospective study of the utility of 3D aneurysm models. We show that 3D models are useful in surgery preparation. In the near future, these models will be used widely to educate trainees and pre-plan surgical options for senior surgeons.

Voice Activity Detection Method Using Psycho-Acoustic Model Based on Speech Energy Maximization in Noisy Environments (잡음 환경에서 심리음향모델 기반 음성 에너지 최대화를 이용한 음성 검출 방법)

  • Choi, Gab-Keun;Kim, Soon-Hyob
    • The Journal of the Acoustical Society of Korea
    • /
    • v.28 no.5
    • /
    • pp.447-453
    • /
    • 2009
  • This paper introduces the method for detect voices and exact end point at low SNR by maximizing voice energy. Conventional VAD (Voice Activity Detection) algorithm estimates noise level so it tends to detect the end point inaccurately. Moreover, because it uses relatively long analysis range for reflecting temporal change of noise, computing load too high for application. In this paper, the SEM-VAD (Speech Energy Maximization-Voice Activity Detection) method which uses psycho-acoustical bark scale filter banks to maximize voice energy within frames is introduced. Stable threshold values are obtained at various noise environments (SNR 15 dB, 10 dB, 5 dB, 0 dB). At the test for voice detection in car noisy environment, PHR (Pause Hit Rate) was 100%accurate at every noise environment, and FAR (False Alarm Rate) shows 0% at SNR15 dB and 10 dB, 5.6% at SNR5 dB and 9.5% at SNR0 dB.

Assessment of Questionnaire of Physical Activity at Workplace Based on the Social Cognitive Theory (PAWPQ-SCT): A Psychometric Study in Iranian Gas Refinery Workers

  • Kamel Ghobadi;AhmadAli Eslami;Asiyeh Pirzadeh;Seyed Mohammad Mazloomi;Fatemeh Hosseini
    • Safety and Health at Work
    • /
    • v.14 no.4
    • /
    • pp.358-367
    • /
    • 2023
  • Background: This study aimed to develop and assess the psychometric features of the Physical Activity at Workplace Questionnaire (PAWPQ) based on the Social Cognitive Theory (SCT) to evaluate employees' physical activity (PA) behaviors at the workplace. Methods: This psychometric cross-sectional study was conducted on 455 employees working in one of the gas refineries in Iran. The participants were selected using the proportional stratified sampling method in 2019. The data collection tools were a demographic information questionnaire, the short form of the International Physical Activity Questionnaire (IPAQ), and a questionnaire developed based on the SCT, whose psychometric features were confirmed in terms of validity and reliability. Data were analyzed using SPSS22 and AMOS20 software. Results: The first version of PAWPQ-SCT had 74 items. After evaluating content and face validity, nine items were removed. The results of the content validity index (0.98), content validity ratio (0.86), and impact score (3.62) were acceptable for the whole instrument. In exploratory factor analysis, after removing seven items-58-item final version of the scale-six factors could explain 73.54% of the total variance. The results of structural equation modeling showed the acceptable fit of the model into the data (RMSEA = 0.052, CFI = 0.917, NFI = 0.878, TLI = 0.905, IFI = 0.917, CMIN/DF = 2.818). Cronbach's alpha coefficient and Intraclass Correlation were 0.90 and 0.86, respectively. Conclusion: This study confirmed that the psychometric features of the 58-item final version of PAWPQSCT constructs were acceptable in a sample of Iranian employees. This questionnaire can be used as a valid and reliable tool to evaluate Iranian employees' PA behaviors and develop effective educational interventions for workers and managers.

Prediction of ocean surface current: Research status, challenges, and opportunities. A review

  • Ittaka Aldini;Adhistya E. Permanasari;Risanuri Hidayat;Andri Ramdhan
    • Ocean Systems Engineering
    • /
    • v.14 no.1
    • /
    • pp.85-99
    • /
    • 2024
  • Ocean surface currents have an essential role in the Earth's climate system and significantly impact the marine ecosystem, weather patterns, and human activities. However, predicting ocean surface currents remains challenging due to the complexity and variability of the oceanic processes involved. This review article provides an overview of the current research status, challenges, and opportunities in the prediction of ocean surface currents. We discuss the various observational and modelling approaches used to study ocean surface currents, including satellite remote sensing, in situ measurements, and numerical models. We also highlight the major challenges facing the prediction of ocean surface currents, such as data assimilation, model-observation integration, and the representation of sub-grid scale processes. In this article, we suggest that future research should focus on developing advanced modeling techniques, such as machine learning, and the integration of multiple observational platforms to improve the accuracy and skill of ocean surface current predictions. We also emphasize the need to address the limitations of observing instruments, such as delays in receiving data, versioning errors, missing data, and undocumented data processing techniques. Improving data availability and quality will be essential for enhancing the accuracy of predictions. The future research should focus on developing methods for effective bias correction, a series of data preprocessing procedures, and utilizing combined models and xAI models to incorporate data from various sources. Advancements in predicting ocean surface currents will benefit various applications such as maritime operations, climate studies, and ecosystem management.

The Effect of Market Structure on the Performance of China's Banking Industry: Focusing on the Differences between Nation-Owned Banks and Joint-Stock Banks (개혁개방 이후 중국 은행산업의 구조와 성과: 국유은행과 주식제 은행의 차이를 중심으로)

  • Ze-Hui Liu;Dong-Ook Choi
    • Asia-Pacific Journal of Business
    • /
    • v.14 no.4
    • /
    • pp.431-444
    • /
    • 2023
  • Purpose - This study applies the traditional Structure-Conduct-Performance (SCP) model from industrial organization theory to investigate the relationship between market structure and performance in China's banking industry. Design/methodology/approach - For analysis, financial data from the People's Bank of China's "China Financial Stability Report" and financial reports of 6 state-owned banks and 11 joint-stock banks for the period 2010 to 2021 were collected to create a balanced panel dataset. The study employs panel fixed-effects regression analysis to assess the impact of changes in market structure and ownership structure on performance variables including return on asset, profitability, costs, and non-performing loan ratios. Findings - Empirical findings highlight significant differences in the effects of market structure between state-owned and joint-stock banks. Notably, increased market competition positively correlates with higher profits for state-owned banks and with lower costs for joint-stock banks. Research implications or Originality - State-owned banks demonstrate larger scale and stability, yet they struggle to respond effectively to market shifts. Conversely, joint-stock banks face challenges in raising profitability against competitive pressures. Additionally, the study emphasizes the importance for Chinese banks to strengthen risk management due to the increase of non-performing loans with competition. The results provide insights into reform policies for Chinese banks regarding the involvement of private sector in the context of market liberalization process in China.

Improvement and application of SWMM-ING for carbon reduction in green infrastructure (그린인프라시설의 탄소저감을 위한 SWMM-ING 개선 및 적용성 평가)

  • Young Jun Lee;Chaeyoung Lee
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.37 no.6
    • /
    • pp.335-345
    • /
    • 2023
  • In Korea, as part of the Green New Deal project toward a carbon-neutral society, it is necessary to build a climate-resilient urban environment to green the city, space, and living infrastructure. To this end, SWMM-ING was improved and the model was modified to analyze the carbon reduction effect. In addition, I plan to select target watersheds where urbanization is rapidly progressing and evaluate runoff, non-point pollution, and carbon reduction effects to conduct cost estimation and optimal design review for domestic rainwater circulation green infrastructure. In this study, green infrastructure facilities were selected using SWMM-ING. Various scenarios were presented considering the surface area and annual cost of each green infrastructure facility, and The results show that the scenario derived through the APL2 method was selected as the optimal scenario. In this optimal scenario, a total facility area of 190,517.5 m2 was applied to 7 out of 30 subwatersheds to achieve the target reduction. The target reduction amount was calculated a 23.50 % reduction in runoff and a 26.99 % reduction in pollutant load. Additionally, the annual carbon absorption was analyzed and found to be 385,521 kg/year. I aim to achieve additional carbon reduction effects by achieving the goal of reducing runoff and non-point pollution sources and analyzing annual carbon absorption. Moreover, considering the scale-up of these interventions across the basin, it is believed that an objective assessment of economic viability can be conducted.

Current Status and Sustainable Development Strategies of Traditional Korean Medicine Official Development Assistance (ODA) in Global Health (국제보건에서 한의약 공적개발원조의 현재와 지속가능한 발전전략)

  • Yeeun Hwang;Seunghyeon Lee;Hyungwoo Kim;Hyoju Nam;Seungun Lee;Yousang Baik;Han Chae
    • The Journal of Korean Medicine
    • /
    • v.45 no.1
    • /
    • pp.257-270
    • /
    • 2024
  • Objectives: Korea has a unique history of being both a recipient and a donor of Official Development Assistance (ODA), and the international community expects Korea to contribute to the development of developing countries by utilizing this experience. Traditional Korean medicine (TKM) seeks to contribute to global health, however the concept of ODA has been unclear and there has been no clear strategy and sustainable initiatives. Methods: This study examines the concept of ODA and its application in global health, including business objectives, scale, evaluation principles, and development strategies. Additionally, we reviewed the current status of Traditional Korean medicine globalization projects and conducted a SWOT analysis of the internal and external environment of the TKM sector. Based on these findings, we redefined the concept of ODA for TKM and proposed suggestions for its development. Results: The current study identified key ideas for TKM ODA. It should prioritize the improvement of primary healthcare in recipient countries, aligning with the international evaluation criteria of the SDGs. Secondly, TKM's 70 years of experience can be leveraged to enhance both the competence and economic benefits of recipient countries' medical systems. Based on these concepts, a TKM ODA development model was proposed, comprising two core visions, three development strategies and goals, and six core values. Conclusion: This study systematically examined the TKM in global health and suggested sustainable development strategies for TKM ODA. Through its expansion, TKM could contribute to the advancement of global traditional medicine and its overall engagement in healthcare.

Analysis of University Cafeteria Safety Based on Pathfinder Simulation

  • Zechen Zhang;Jaewook Lee;Hasung Kong
    • International Journal of Internet, Broadcasting and Communication
    • /
    • v.16 no.2
    • /
    • pp.209-217
    • /
    • 2024
  • Recent years have seen a notable increase in fire incidents in university cafeterias, yet the social attention to these occurrences remains limited. Despite quick responses to these incidents preventing loss of life, the need for large-scale evacuation in such high foot traffic areas can cause significant disruptions, economic losses, and panic among students. The potential for stampedes and unpredictable damage during inadequate evacuations underscores the importance of fire safety and evacuation research in these settings. Previous studies have explored evacuation models in various university environments, emphasizing the influence of environmental conditions, personal characteristics, and behavioral patterns on evacuation efficiency. However, research specifically focusing on university cafeterias is scarce. This paper addresses this gap by employing Pathfinder software to analyze fire spread and evacuation safety in a university cafeteria. Pathfinder, an advanced emergency evacuation assessment system, offers realistic 3D simulations, crucial for intuitive and scientific evacuation analysis. The studied cafeteria, encompassing three floors and various functional areas, often exceeds a capacity of 1500 people, primarily students, during peak times. The study includes constructing a model of the cafeteria in Pathfinder and analyzing evacuation scenarios under different fire outbreak conditions on each floor. The paper sets standard safe evacuation criteria (ASET > RSET) and formulates three distinct evacuation scenarios, considering different fire outbreak locations and initial evacuation times on each floor. The simulation results reveal the impact of the fire's location and the evacuation preparation time on the overall evacuation process, highlighting that fires on higher floors or longer evacuation preparation times tend to reduce overall evacuation time.In conclusion, the study emphasizes a multifaceted approach to improve evacuation safety and efficiency in educational settings. Recommendations include expanding staircase widths, optimizing evacuation routes, conducting regular drills, strengthening command during evacuations, and upgrading emergency facilities. The use of information and communication technology for managing emergencies is also suggested. These measures collectively form a comprehensive framework for ensuring safety in educational institutions during fire emergencies.

A Case Study on Near-Cloud Turbulence around the Mesoscale Convective System in the Korean Peninsula (한반도에서 발생한 중규모 대류계의 구름 주변 난류 발생 메커니즘 사례 연구)

  • Sung-Il Yang;Ju Heon Lee;Jung-Hoon Kim
    • Atmosphere
    • /
    • v.34 no.2
    • /
    • pp.153-176
    • /
    • 2024
  • At 0843 UTC 30 May 2021, a commercial aircraft encountered severe turbulence at z = 11.5 km associated with the rapid development of Mesoscale Convective System (MCS) in the Gyeonggi Bay of Korea. To investigate the generation mechanisms of Near-Cloud Turbulence (NCT) near the MCS, Weather Research and Forecasting model was used to reproduce key features at multiple-scales with four nested domains (the finest ∆x = 0.2 km) and 112 hybrid vertical layers. Simulated subgrid-scale turbulent kinetic energy (SGS TKE) was located in three different regions of the MCS. First, the simulated NCT with non-zero SGS TKE at z = 11.5 km at 0835 UTC was collocated with the reported NCT. Cloud-induced flow deformation and entrainment process on the downstream of the overshooting top triggered convective instability and subsequent SGS TKE. Second, at z = 16.5 km at 0820 UTC, the localized SGS TKE was found 4 km above the overshooting cloud top. It was attributed to breaking down of vertically propagating convectively-induced gravity wave at background critical level. Lastly, SGS TKE was simulated at z = 11.5 km at 0930 UTC during the dissipating stage of MCS. Upper-level anticyclonic outflow of MCS intensified the environmental westerlies, developing strong vertical wind shear on the northeastern quadrant of the dissipating MCS. Three different generation mechanisms suggest the avoidance guidance for the possible NCT events near the entire period of the MCS in the heavy air traffic area around Incheon International Airport in Korea.

Evaluation of Problems in Tourism Systems and Their Evolutionary Status Based on Self-Organization Theory

  • Enhou Zu;Haoming Wen;Minghung Shu;Chih-Lung Yu
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.18 no.6
    • /
    • pp.1500-1517
    • /
    • 2024
  • With the rapid development of the tourism economy, large-scale construction of tourist attractions to achieve resource utilization and ensure the healthy development of the tourism industry has become a hot topic. However, there are still issues with resource utilization and coordinated management in the economic development of the tourism industry, which in turn affects the coordinated development of the tourism industry economy. Therefore, this study utilizes self-organization theory to explore the structure, organizational mechanism, conditional driving force of evolution, and evolutionary operation mechanism of the tourism system, analyze the current tourism situation in Hunan Province and related regions, and construct a self-organization evolution model of the tourism system. The result shows that the cumulative variance contribution rate of tourism areas in Hunan Province is 78.8%, with Zhangjiajie having the highest industrial management factors and tourism resource levels in the province, with 1.6 and 3.2 respectively. Hunan Province has abundant tourism resources but overall uneven development, with a comprehensive score of -1.03. Therefore, it is necessary to leverage the coordination advantages of various departments and industries to promote sustainable and healthy development of tourism areas. The self-organizing evolution of the tourism system not only discovers the current problems of the tourism industry, but also provides theoretical support and mechanism suggestions for the tourism system.