• Title/Summary/Keyword: Impact Safety

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A study on the hydrodynamic forces acting on a GT 4,000 tonnage fishery training vessel in the proximity of semi-circle bank wall (반원 형상의 측벽 부근을 항행하는 4,000톤급 어업실습선에 미치는 유체력에 관한 연구)

  • Chun-Ki LEE;Kyung-Jin RYU;Yoo-Won LEE;Su-Hyung KIM
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.59 no.4
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    • pp.336-343
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    • 2023
  • The aging fishery training vessels from the past have mostly been decommissioned, and many universities are introducing state-of-the-art large fishery training vessels. The purpose of these training vessels is to train marine professionals and above all, safety to prevent marine accidents should be of utmost priority as many students embark on the vessel. This study estimated the impact of the hydrodynamic interaction forces acting on the model vessel (fishery training vessel) from the bank when the vessel pass near the semi-circle bank wall in various conditions through the numerical calculation, especially concerning maneuvering motions of the vessel. For estimation, variables were mainly set as the size of the semi-circle shape, the lateral distance between the bank and the model vessel, and the depth near the bank. As a result, it was estimated that, in order for the model vessel to safely pass the semi-circle bank wall at a speed of 4 knots, the water depth to the vessel draft ratio should be 1.5 or more (approximately 8 m of water depth), and the lateral distance from the semi-circle bank wall should be 0.4 times the model vessel's length (Lpp) or more (a distance of 34 m or more). Under these conditions, it was expected that the model vessel would pass without significantly being affected by the bank wall.

A Study on the Influencing Factors of Falling Disaster in Small and Medium-sized Construction Sites (중소형 건설현장의 추락재해 영향요인 분석 연구)

  • Lee, Ji-Yeob;Lee, Jae-Hyeon;Son, Seunghyun;Kim, Ji-Myong;Son, Kiyoung
    • Journal of the Korea Institute of Building Construction
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    • v.23 no.6
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    • pp.821-830
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    • 2023
  • This research aims to identify risk factors for fall accidents at small and medium-sized construction sites through a comprehensive regression analysis. Initially, the study involved collecting a decade's worth of fall accident data from these sites. A t-test confirmed a significant variation in the treatment duration following fall accidents between two distinct groups: small and medium-sized versus large construction sites. Subsequently, a regression analysis was conducted to establish a model highlighting the risk factors associated with safety accidents. The factors influencing fall accidents were determined to be, in descending order of impact, the time of the accident, the day of the accident, and the occupational classification. The findings from this study are expected to serve as foundational data for enhancing policies and conducting statistical analyses tailored to construction site sizes. They also provide crucial information for future research on risk quantification at small and medium-sized construction sites.

Growth hormone treatment for children with mucopolysaccharidosis I or II

  • Minji Im;Chiwoo Kim;Juyoung Sung;Insung Kim;Ji-Hoon Hwang;Min-Sun Kim;Sung Yoon Cho
    • Journal of Genetic Medicine
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    • v.20 no.2
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    • pp.60-69
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    • 2023
  • Purpose: Despite enzyme replacement therapy (ERT) and/or allogeneic hematopoietic stem cell transplantation, individuals with mucopolysaccharidosis (MPS) I or II often experience significant growth deficiencies. This study aimed to assess the safety and efficacy of recombinant human growth hormone (hGH) treatment in children diagnosed with MPS I or II. Materials and Methods: A total of nine pediatric patients-four with MPS I and five with MPS II-underwent treatment with ERT and hGH at Samsung Medical Center. Results: The mean hGH dose administered was 0.26±0.03 mg/kg/week. In the MPS I group, three patients showed an increase in height Z-score from -4.09±0.83 to -3.68±0.43 after 1 year of hGH treatment, and to -3.10±0.72 by the end of the hGH regimen. In the MPS II group, while the height Z-score of four patients decreased according to standard growth charts, it improved from 1.61±1.79 to 2.71±1.68 based on the disease-specific growth chart through hGH treatment. Two patients discontinued hGH treatment due to lack of efficacy after 22 and 6 months each of treatment, respectively. No new-onset neurological symptoms or necessity for prosthetic or orthopedic surgery were reported during hGH treatment. Conclusion: This study provides insights into the impact of hGH on MPS patients, demonstrating its potential to reverse growth deceleration in some cases. Further research is needed to explore the long-term effects of hGH on changes in body composition, muscle strength, and bone health in this population.

Analysis of the Impact of Transmission Towers on the Performance of RF Scanners for Drone Detection (드론탐지용 RF스캐너의 성능에 송전탑이 미치는 영향 분석)

  • Moon-Hee Lee;Jeong-Ju Bang
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.23 no.1
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    • pp.112-122
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    • 2024
  • Recently, as unmanned aerial vehicle technology such as drones has developed, there are many environmental, social and economic benefits, but if there is malicious intent against important national facilities such as airports, public institutions, power plants, and the military, it can seriously affect national safety and people's lives. It can cause damage. To respond to these drone threats, attempts are being made to introduce detection equipment such as RF scanners. In particular, power transmission towers installed in substations, power plants, and Korea's power system can affect detection performance if the transmission tower is located in the RF scanner detection path. In the experiment, a commercial drone was used to measure the signal intensity emitted from the drone and confirm the attenuation rate. The average and maximum attenuation rates showed similar trends in the 2.4 GHz and 5.8 GHz bands, and were also affected by the density of the structure.

Computing machinery techniques for performance prediction of TBM using rock geomechanical data in sedimentary and volcanic formations

  • Hanan Samadi;Arsalan Mahmoodzadeh;Shtwai Alsubai;Abdullah Alqahtani;Abed Alanazi;Ahmed Babeker Elhag
    • Geomechanics and Engineering
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    • v.37 no.3
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    • pp.223-241
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    • 2024
  • Evaluating the performance of Tunnel Boring Machines (TBMs) stands as a pivotal juncture in the domain of hard rock mechanized tunneling, essential for achieving both a dependable construction timeline and utilization rate. In this investigation, three advanced artificial neural networks namely, gated recurrent unit (GRU), back propagation neural network (BPNN), and simple recurrent neural network (SRNN) were crafted to prognosticate TBM-rate of penetration (ROP). Drawing from a dataset comprising 1125 data points amassed during the construction of the Alborze Service Tunnel, the study commenced. Initially, five geomechanical parameters were scrutinized for their impact on TBM-ROP efficiency. Subsequent statistical analyses narrowed down the effective parameters to three, including uniaxial compressive strength (UCS), peak slope index (PSI), and Brazilian tensile strength (BTS). Among the methodologies employed, GRU emerged as the most robust model, demonstrating exceptional predictive prowess for TBM-ROP with staggering accuracy metrics on the testing subset (R2 = 0.87, NRMSE = 6.76E-04, MAD = 2.85E-05). The proposed models present viable solutions for analogous ground and TBM tunneling scenarios, particularly beneficial in routes predominantly composed of volcanic and sedimentary rock formations. Leveraging forecasted parameters holds the promise of enhancing both machine efficiency and construction safety within TBM tunneling endeavors.

Study on Establishing Comprehensive Management Measures to Ensure Stability of Existing Metro when Constructing Ground Structures Adjacent to Subway (지하철 인접 지상구조물 설치시 기존 지하철 안정성 확보 위한 종합관리대책 수립 연구)

  • Jae-Hong Lim;Guk-Hwan Cho
    • Tunnel and Underground Space
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    • v.34 no.3
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    • pp.196-207
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    • 2024
  • In this study, a comprehensive management plan was proposed to ensure the stability of the existing subway when constructing ground structures adjacent to the subway. In the first step, the measurement inspection cycle is selected through proximity evaluation, in the second step, the stability of existing subway and station structures such as displacement and stress is reviewed through 3D numerical analysis considering the construction stage and groundwater influence, and in the third stage, the safety of train operation was reviewed by examining the track stability, and based on the numerical analysis results in the fourth stage, the displacement concentration section was selected as an intensive management section and it was proposed that intensive measurement management be performed.

Prospects of Cumulative Installed Power Capacity of Domestic Offshore Wind Projects for K-RE100 (K-RE100 이행에 필요한 국내해상풍력단지 누적 설치량 전망 연구)

  • Hong Goo Kang;Byung Ha Kim;Hun Jo Kim;Chang Jo Yang;Hae Chang Jeong
    • New & Renewable Energy
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    • v.20 no.2
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    • pp.44-54
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    • 2024
  • The objective of this study was to contribute to domestic offshore wind farms by reasonably predicting the expected completion time and installed power generation capacity of offshore wind projects in South Korea. Offshore wind power is drastically regarded as a core tool for clean energy transition and industrial decarbonization in the fight against the climate crisis globally. Especially in South Korea offshore wind power is the main tool in partaking in RE100 and K-RE100, and the Korean government aims to install 14.9 GW of offshore wind farms by 2030. However, this seems to have been significantly delayed due to the complex process of obtaining permits for offshore wind power in Korea. Thus, a reasonable prediction of power generation and a timeline for the final construction are imperative. To establish the delay time for permit licenses, classified location factors were included into site analysis. These factors comprised reviews of transmission and military operability, environmental impact assessment, maritime traffic safety examination, wind resource assessment and an analysis of current offshore wind projects. According to the analysis, the majority of offshore wind projects currently being developed in Korea are predicted to be delayed by 3-5 years as they are among the criteria included in key discussion points for obtaining permits. The cumulative installed power capacity and annual power generation after construction are expected to be 37 GW and 97 TWh respectively.

Preclinical Evidence and Underlying Mechanisms of Polygonum multiflorum and Its Chemical Constituents Against Cognitive Impairments and Alzheimer's Disease

  • Jihyun Cha;Ji Hwan Yun;Ji Hye Choi;Jae Ho Lee;Byung Tae Choi;Hwa Kyoung Shin
    • Journal of Pharmacopuncture
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    • v.27 no.2
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    • pp.70-81
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    • 2024
  • Objectives: Cognitive impairments, ranging from mild to severe, adversely affect daily functioning, quality of life, and work capacity. Despite significant efforts in the past decade, more than 200 promising drug candidates have failed in clinical trials. Herbal remedies are gaining interest as potential treatments for dementia due to their long history and safety, making them valuable for drug development. This review aimed to examine the mechanisms behind the effect of Polygonum multiflorum on cognitive function. Methods: This study focused primarily on the effects of Polygonum multiflorum and its chemical constituents on cognitive behavioral outcomes including the Morris water maze, the passive avoidance test, and the Y maze, as well as pathogenic targets of cognitive impairment and Alzheimer's disease (AD) like amyloid deposition, amyloid precursor protein, tau hyperphosphorylation, and cognitive decline. Additionally, a thorough evaluation of the mechanisms behind Polygonum multiflorum's impact on cognitive function was conducted. We reviewed the most recent data from preclinical research done on experimental models, particularly looking at Polygonum multiflorum's effects on cognitive decline and AD. Results: According to recent research, Poligonum multiflorum and its bioactive components, stilbene, and emodin, influence cognitive behavioral results and regulate the pathological target of cognitive impairment and AD. Their mechanisms of action include reducing oxidative and mitochondrial damage, regulating neuroinflammation, halting apoptosis, and promoting increased neurogenesis and synaptogenesis. Conclusion: This review serves as a comprehensive compilation of current experiments on AD and other cognitive impairment models related to the therapeutic effects of Polygonum multiflorum. We believe that these findings can serve as a basis for future clinical trials and have potential applications in the treatment of human neurological disorders.

Herbal Medicine for Sarcopenia: A Systematic Review of Randomized Controlled Trials (근감소증에 대한 한약 치료 : 체계적 문헌 고찰)

  • Se-eun Chun;Soo-hyung Lee;Yong-jeen Shin;Sun-ho Shin
    • The Journal of Internal Korean Medicine
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    • v.44 no.6
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    • pp.1118-1138
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    • 2023
  • Objectives: Sarcopenia is an age-associated skeletal muscle disorder that can profoundly impact the health of elderly people. However, the efficacy of herbal medicine in sarcopenia is uncertain. This review aims to investigate evidence of the effect of herbal medicine on sarcopenia. Methods: We systematically searched 12 electronic databases for relevant randomized controlled trials (RCTs). Only trials that met the inclusion criteria were selected, and the characteristics of the included studies were extracted and synthesized in a narrative manner. The quality of the included studies was assessed using Cochrane's Risk of Bias (RoB) 2.0 tool. Results: 7 RCTs involving 672 participants with sarcopenia met the inclusion criteria. The intervention combining herbal medicine and conventional treatment (i.e., exercise, nutritional support) had a significant therapeutic effect compared with the conventional treatment, showing improvement in muscle strength (i.e., grip strength), muscle mass (i.e., appendicular skeletal muscle mass index), and physical function (i.e., gait speed, short physical performance battery, and timed up and go test). However, the methodological quality of the included RCTs was relatively low due to their high RoB, making it difficult to evaluate the efficacy of herbal medicine in sarcopenia. In terms of safety, several adverse events were reported. Conclusion: This review suggests that herbal medicine has a positive effect on muscle strength, muscle mass, and physical performance in elderly patients with sarcopenia, but there is a clear need for further research in this area.

Application of analytic hierarchy process technique for selecting a hydrothermal energy site (수열에너지 입지 선정을 위한 계층화분석법의 적용)

  • Joohyun Ahn;Suwan Park;Changhyun Oh
    • Journal of Korean Society of Water and Wastewater
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    • v.38 no.2
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    • pp.69-81
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    • 2024
  • In this study, an evaluation system that can be used to evaluate the feasibility of developing and supplying hydrothermal energy for the operation of large-scale complex facilities was developed. To this end, this study derived factors to be considered when selecting a location for the use of hydrothermal energy using raw water from multi-purpose dams and regional water supply systems through literature survey and expert interviews. The evaluation indicators derived from this study are divided into four sectors: hydrothermal energy utilization factors, location factors, planning factors, and disaster safety factors, and are composed of 10 mid-level indicators and 34 detailed planning indicators. The relative importance of all factors was derived using the Analytic Hierarchy Process (AHP) technique, and the developed evaluation indicators and relative importance were applied to four multi-purpose dam regions in the country. As a result, it was found that in the development and use of hydrothermal energy utilizing regional raw water supply line the urban planning conditions of the supply site can have a greater impact on the location selection results than the hydrothermal energy development itself. Due to the characteristics of the evaluation indicators developed in this study and their nature as comprehensive indicators, it is believed that the results should be applied to determine the overall adequacy of site selection in the early stages of hydrothermal energy development. In the future, it is believed that it will be necessary to analyze the problems in supplying and operating hydrothermal energy using raw water from multi-purpose dams and regional water resources. Based on the analysis the evaluation system developed in this study is expected to be improved and supplemented.