• Title/Summary/Keyword: tunnel convergence

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Effect of Manual Acupuncture for Mild-to-Moderate Carpal Tunnel Syndrome: A Systematic Review

  • Huh, Jeong Ho;Jeong, Hye In;Kim, Kyeong Han
    • Journal of Pharmacopuncture
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    • v.24 no.4
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    • pp.153-164
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    • 2021
  • Objectives: Despite the low cost and high accessibility of manual acupuncture (MA) treatments for the carpal tunnel syndrome (CTS), this intervention has not been uniformly evaluated in systematic reviews (SR), and no SR has evaluated MA monotherapy for CTS. This review was conducted to summarize the findings and undertake a quality assessment of randomized controlled trials (RCTs) of acupuncture treatment methods for mild-to-moderate CTS to identify clinical evidence for the use of MA in CTS. Methods: We searched five databases for articles on relevant RCTs that were published until June 2021 without imposing specific restrictions, such as age or sex, on CTS patients. RCTs that evaluated MA were included without any restriction on comparator interventions. Measurement tools for evaluating pain reduction and functional improvement or for evaluating efficacy using electrophysiological indicators were included as outcome measures. Results: We included seven RCTs, of which three studies reported both post-treatment improvement effects and statistical significance using p-values for all outcomes. Five studies reported statistically significant intergroup differences (p-values for all outcomes) in posttreatment improvement. None of the studies reported severe adverse effects of MA. In all of the RCTs, the reporting rates of the 2c, 2a, and 6a items of STRICTA 2010 were 14%, 29%, and 29%, respectively. PC7 (Daereung) was used to treat CTS in all of the included studies. Conclusion: MA can be used for CTS treatment without serious adverse effects. PC7 was the most commonly used acupoint. In order to ensure objective and reliable reporting, accurate standardization of acupuncture treatment methods acupoint terms should be undertaken in future RCTs.

A study on the optimal reinforced zone of a small sectional shield TBM tunnel in difficult ground (특수지반 구간의 소단면 쉴드 TBM 터널 굴착 시 최적 보강영역 연구)

  • Kang, Byung-Yun;Park, Hyung-Keun;Cha, Jae-Hoon;Kim, Young-Jin
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.21 no.6
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    • pp.735-747
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    • 2019
  • Due to the lack of ground space by urbanization, the demand of utility tunnels for laying social facilities is increasing. During the construction of a utility tunnel in downtown area using a shield TBM, various problems may occur when difficult ground is encountered such as mixed ground and cobbly ground. Thus, in this study, using MIDAS GTS NX (Ver. 280), a numerical analysis was performed on characteristics of difficult ground, reinforced area, depth of cover and groundwater level to analyze the optimal ground reinforced area according to combination of parameters. As a result, it was difficult to secure stability in unconstrained excavation cases on both the mixed ground and the cobbly ground. However, when ground reinforcement grouting as much as 2.0D is applied, convergence occurred within the allowable limit, except for mixed ground with a depth of cover 30 m. In addition, excessive leakage occurred during excavation of both the mixed ground and the cobbly layers. It was able to secure stability after applying waterproof grouting.

A Study on the Assessment of Safety Factor of Tunnels (터널의 안전율 평가 기법에 관한 연구)

  • 박종원;박연준;유광호;이상돈
    • Tunnel and Underground Space
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    • v.14 no.5
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    • pp.327-338
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    • 2004
  • The purpose of this research is to establish a concept of the factor of safety of tunnels which is a quantitative estimate of the stability of tunnels. Based on this concept, a numerical technique which calculates the factor of safety of tunnels was developed. To obtain the safety factor of a tunnel, the strength reduction technique in which a series of analyses are repeated with reduced ground strength until the tunnel collapses were employed. With this technique, the failure plane, as well as the factor of safety, can be obtained without prescribing the trial failure plane. Analyses were conducted with FLA $C^{2D}$(ver3.3), a geotechnical analysis program which is based on the finite difference method. From the result, the location of plastic zones, the maximum convergence and the maximum stress generated in the support system were also analyzed. The result shows that factors of safety are higher for the 1st and 2nd rock classes, and lower for the lower rock classes. Furthermore, factor of safety is higher when $K_{0}$ =0.5 compared to at in case of $K_{0}$ =2.0. Through this research, it is found that the factor of safety defined in this research can be used as a good quantitative index representing the stability of tunnels. Also, close examination of the results can help adjustment of the quantity and location of additional supports.s.

A risk management system applicable to NATM tunnels: methodology development and application (NATM 터널의 리스크 관리 시스템 개발 및 현장적용)

  • Chung, Heeyoung;Lee, Kang-Hyun;Kim, Byung-Kyu;Lee, In-Mo;Choi, Hangseok
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.22 no.2
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    • pp.155-170
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    • 2020
  • In this paper, a risk management system applicable to NATM tunneling projects is proposed. After investigating case histories in NATM tunnel collapse, this paper analyzes the potential risk factors and their corresponding risk events during NATM tunnel construction. The risk factors are categorized into three groups: geological, design and construction risk factors. The risk events are also categorized into four types: excessive deformation, excessive deformation with subsidence, collapse inside tunnels, and collapse inside tunnels with subsidence. The paper identifies risk scenarios in consideration of the risk factors and proposes a risk analysis/evaluation method for the NATM tunnel risk scenarios. Based on the evaluation results, the optimal mitigation measure to handle the risk events is suggested. In order to effectively facilitate a series of risk management processes, it is necessary to develop a risk register and a management ledger for risk mitigation measures that are customized to NATM tunnels. Lastly, the risk management for an actual NATM tunnel construction site is performed to verify the validity of the proposed system.

Effect on self-enhancement of deep-learning inference by repeated training of false detection cases in tunnel accident image detection (터널 내 돌발상황 오탐지 영상의 반복 학습을 통한 딥러닝 추론 성능의 자가 성장 효과)

  • Lee, Kyu Beom;Shin, Hyu Soung
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.21 no.3
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    • pp.419-432
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    • 2019
  • Most of deep learning model training was proceeded by supervised learning, which is to train labeling data composed by inputs and corresponding outputs. Labeling data was directly generated manually, so labeling accuracy of data is relatively high. However, it requires heavy efforts in securing data because of cost and time. Additionally, the main goal of supervised learning is to improve detection performance for 'True Positive' data but not to reduce occurrence of 'False Positive' data. In this paper, the occurrence of unpredictable 'False Positive' appears by trained modes with labeling data and 'True Positive' data in monitoring of deep learning-based CCTV accident detection system, which is under operation at a tunnel monitoring center. Those types of 'False Positive' to 'fire' or 'person' objects were frequently taking place for lights of working vehicle, reflecting sunlight at tunnel entrance, long black feature which occurs to the part of lane or car, etc. To solve this problem, a deep learning model was developed by simultaneously training the 'False Positive' data generated in the field and the labeling data. As a result, in comparison with the model that was trained only by the existing labeling data, the re-inference performance with respect to the labeling data was improved. In addition, re-inference of the 'False Positive' data shows that the number of 'False Positive' for the persons were more reduced in case of training model including many 'False Positive' data. By training of the 'False Positive' data, the capability of field application of the deep learning model was improved automatically.

Comparison analysis of before and after use of periodontal instruments on strength and agility of hands (치주기구사용 전·후의 손의 근력 및 민첩성 비교분석)

  • Yoo, DooHan;Kyung, So-jin;Back, Eun-jeong;Oh, Hyeon-hoei;Won, Sol-hee;Jang, Sol;Chae, Na-ri;Kang, Kyung-hee
    • Journal of the Korea Convergence Society
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    • v.10 no.12
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    • pp.117-122
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    • 2019
  • This study aimed to provide the basic data for the prevention of carpal tunnel syndrome by measuring and comparatively analyzing the changes in muscular strength, grasping force, and agility of hands before/after practice, targeting the dental hygiene students taking the scaling practice course. Targeting total 15 students(4th-year) of Dental Hygienics who had no problems with anatomical structure, muscular strength, grasping force, and senses of hands, the muscular strength, grasping force, and agility of hands were measured before/after the scaling practice. The collected data was processed by using the PASW Statistics 18.0(SPSS) Program. In the results of this study, the muscular strength and grasping force of hands were decreased after the practice compared to the ones before the practice. The agility of hands was increased after the practice compared to the one before the practice. Based on such results of this study, it would be necessary to avoid such exhausting hand gestures for scaling, and also to develop the preventive exercise to build up the strength of hands like stretching before/after scaling.

A Numerical Study on the NATM Tunnel Reinforcement using Centrifuge Model Experimental value (실험값을 이용한 NATM 터널의 보강효과에 관한 수치 해석적 연구)

  • Huh, Kyung-Han;Kim, Nak-Seok
    • Journal of the Korean Society of Hazard Mitigation
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    • v.4 no.2 s.13
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    • pp.13-18
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    • 2004
  • In this study, in the first place, parameters primarily influencing displacement and stress were constructed by using the Finite Difference Method; then using those parameters, the result of crown displacement and convergence among the existing, experimental values of a centrifuge model were compared with the result of numerical analysis; and then considering the stress and time effect of lining installation, parameters according to the difference of stiffness were studied. In the result of this study, it found out that rough, ground reinforcement effect manifests itself when reinforcement propert of the grouting of the big scale steel pipe through 3-D analysis is E= 4,000tf/m2 which of the stiffness of the original ground.

A fundamental study on the ventilation analysis method for the network-type tunnel - focused on the none hardy-cross method (네트워크형 터널의 환기해석 방법에 대한 기초연구-비 Hardy-Cross 방법을 중심으로)

  • Kim, Hyo-Gyu;Choi, Pan-Gyu;Ryu, Ji-Oh;Lee, Chang-Woo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.18 no.3
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    • pp.291-303
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    • 2016
  • Recently, various forms of diverging sections in tunnels have been designed as the demand for underground passageway in urban areas increases. Therefore, the complexity of the ventilation system in tunnels with diverging sections requires a ventilation analysis method different from the conventional method for the straight tunnels. None of the domestic and foreign tunnel ventilation design standards specifies the method for the ventilation network analysis, and the numerical analysis methods have been most widely used. This paper aims at reviewing the ventilation network analytical method applicable as the design standard. The proposed method is based on the characteristic equations rather than the numerical analysis. Thanks to the advantages of easy application, the Hardy-Cross method has been widely applied in the fields of mine ventilation and tunnel ventilation. However, limitations with the cutting errors in the Taylor series expansion and the convergence problem mainly caused by the mesh selection algorithm have been reported. Therefore, this paper examines the applicability of the ventilation analysis method for network-type tunnels with the gradient method that can analyze flow rate and pressure simultaneously without the configuration of mesh. A simple ventilation analysis method for network-type tunnels is proposed.

Deformation of segment lining and behavior characteristics of inner steel lining under external loads (외부 하중에 따른 세그먼트 라이닝 변형과 보강용 내부 강재 라이닝의 거동 특성)

  • Gyeong-Ju Yi;Ki-Il Song
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.26 no.3
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    • pp.255-280
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    • 2024
  • If there are concerns about the stability of segment lining due to section deficiency or large deformation in shield TBM tunnel, reinforcement can be done through ground grouting outside the tunnel or by using steel plate reinforcement, ring beam reinforcement, or inner double layer lining inside the tunnel. Traditional analyses of shield TBM tunnels have been conducted using a continuum method that does not consider the segmented nature of segment lining. This study investigates the reinforcement mechanism for double layer reinforced sections with internal steel linings. By improving the modeling of segment lining, this study applies Break-joint mode (BJM), which considers the segmented characteristics of segment lining, to analyze the deformation characteristics of double layer reinforced sections. The results indicate that the existing concrete segment lining functioned similarly to ground reinforcement around the tunnel, rather than distribution the load. In general, both the BJM model considering the segmentation of segment lining and the continuum rigid method were similar deformation shapes and stress distributions of the lining under load. However, in terms of deformation, when the load strength exceeded the threshold, the deformation patterns of the two models differed.

A Study on the In-Situ Measurement of the Deformation and the Back Calculation of the Load in the Mine Roadway Over-Stressed Rocks (중지압 운반 갱도내 변형계측 및 하중역산에 관한 연구)

  • Cho, Young-Soo;Kim, Hong-Woo;Shin, Hee-Soon;Chung, So-Keul;Lee, Hi-Keun
    • Tunnel and Underground Space
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    • v.3 no.1
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    • pp.40-49
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    • 1993
  • In this study, the indirect estimation method of the support load which is based upon the integrated measuring technique suggested by Kovari was applied to the calculation of support load in the mine roadway. Four test supports were installed in the area where they had to be replaed. Two of those were GI-130 rigid supports and the others were U-26 yieldable supports. The vibrating wire strain gages which were attached inpairs on the steel arch support were used to provide an accurate measurement. Bending moments and normal forces obtained from strain gage pairs were used to calculate the support load. This method was also verified by laboratory bending tests. The results obtained from the back-calculction method showed relatively good agreement with the measured convergence for each crossection.

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