• Title/Summary/Keyword: Tunnel in use

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Effects of Wearing a Microcurrent Wrist Guard on Pain Scale, Range of Motion, and Muscle Strength in Elderly Women with Carpal Tunnel Syndrome (미세전류 손목 보호대 착용이 손목터널증후군 노인 여성의 통증 척도, 관절가동범위 및 근력에 미치는 영향)

  • Hyesun Park;Jinhee Park;Jooyong Kim
    • Journal of Fashion Business
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    • v.27 no.5
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    • pp.1-12
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    • 2023
  • The purpose of this study was to investigate impact of wearing low-level current wrist guards on pain scale, range of motion (ROM), and muscle strength in elderly women with Carpal Tunnel Syndrome (CTS). Subjects were 12 elderly women aged between 65 and 85 years who were diagnosed with CTS symptoms. Measurements included grip strength and wrist ROM. Wrist ROM was assessed through flexion and dorsiflexion. Wrist guards were worn. After two weeks, pain level was assessed using the Visual Analogue Scale (VAS). Results showed a significant reduction in VAS score in the MES group after stimulation, whereas there was no difference in the control group. However, there was no significant difference in ROM between the MES group and the control group. Grip strength increased in the MES group after two weeks (p ≤ 0.001). In conclusion, clinical trials suggest that MES wrist guards might be provided as an adjunctive treatment method for CTS patients. This study provides foundational data for the design and use of auxiliary devices such as gloves in the field of MES research for pain reduction, ROM improvement, and muscle strength enhancement resulting from CTS.

Effects of Catgut -Embedding Therapy in Patients with Carpal Tunnel Syndrome: a Retrospective Pilot Study

  • You, Kyung-Gon;Kwon, Young-Dal
    • The Journal of Korean Medicine
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    • v.36 no.2
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    • pp.43-49
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    • 2015
  • Objectives: We evaluated the effect of the traditional Korean medical therapy of catgut-embedding therapy in patients with carpal tunnel syndrome (CTS). Methods: Thirteen patients(20 hands) with CTS underwent catgut-embedding therapy once per week for a total of 1-4 sessions. We measured the time to tingling in the fingers on performing Phalen's test. We also had patients use a visual analog scale (VAS) to indicate the severity of tingling. We also asked about the awakening time at night due to pain and tingling. We controlled the treatment as being limited to four sessions. Even if a patient had not been treated for four sessions, we ended the patient's treatment if symptoms resolved. Results: Patients who received catgut-embedding therapy showed significant improvements in the clinical symptoms of CTS. After treatment, in a total of 19 hands, the status of fourteen was changed from positive to negative in Phalen's test and the average of tingling occurrence time in that test was delayed. Among the 20 hands, the VAS in eight hands changed to zero and the average of VAS score decreased. Furthermore, in nine patients, four could sleep well without the use of a splint. Conclusions: Patients undergoing this traditional Korean medical therapy showed alleviation of finger tingling after even a single treatment. We thus concluded that this traditional Korean catgut-embedding therapy, may be effective for treating CTS. However, to confirm the effects of catgut-embedding therapy on CTS, further tests are required, including under the defined, strict conditions of a randomized controlled trial.

The Mixed Charging Method with Low-velocity Explosives and Normal Explosives in Tunnel Blasting (터널 발파에서의 저폭속폭약과 일반폭약의 혼용장약법)

  • Kang, Dae-Woo;Ahn, Bong-Do
    • Tunnel and Underground Space
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    • v.20 no.4
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    • pp.252-259
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    • 2010
  • In urban tunnels, namely, in case there are residents in the near distance, we normally use non-vibration and ambient vibration which are not blasting methods because it’ impossible to meet the blasting vibration regulation with only normal explosives. However, non-vibration methods not only cause increase of excavating cost, but need much time than explosives. Generally, the lower velocity explosives with 2,000 m/s VOD have been applied to ambient vibration blasting in open cut area, but difficult in tunneling in its use. However, by charging the hole together with lower velocity explosives and normal explosives, we have got the result which shows 20~30% vibration decrease compared with using only normal explosives. Therefore, I’ like to suggest the blasting method which is able to do as ambient vibration using lower velocity explosives mixed with normal explosives in urban tunnel and the area which is adjacent to security facilities within the vibration regulation.

Sequential prediction of TBM penetration rate using a gradient boosted regression tree during tunneling

  • Lee, Hang-Lo;Song, Ki-Il;Qi, Chongchong;Kim, Kyoung-Yul
    • Geomechanics and Engineering
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    • v.29 no.5
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    • pp.523-533
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    • 2022
  • Several prediction model of penetration rate (PR) of tunnel boring machines (TBMs) have been focused on applying to design stage. In construction stage, however, the expected PR and its trends are changed during tunneling owing to TBM excavation skills and the gap between the investigated and actual geological conditions. Monitoring the PR during tunneling is crucial to rescheduling the excavation plan in real-time. This study proposes a sequential prediction method applicable in the construction stage. Geological and TBM operating data are collected from Gunpo cable tunnel in Korea, and preprocessed through normalization and augmentation. The results show that the sequential prediction for 1 ring unit prediction distance (UPD) is R2≥0.79; whereas, a one-step prediction is R2≤0.30. In modeling algorithm, a gradient boosted regression tree (GBRT) outperformed a least square-based linear regression in sequential prediction method. For practical use, a simple equation between the R2 and UPD is proposed. When UPD increases R2 decreases exponentially; In particular, UPD at R2=0.60 is calculated as 28 rings using the equation. Such a time interval will provide enough time for decision-making. Evidently, the UPD can be adjusted depending on other project and the R2 value targeted by an operator. Therefore, a calculation process for the equation between the R2 and UPD is addressed.

Development of Artificial Neural Networks for Stability Assessment of Tunnel Excavation in Discontinuous Rock Masses and Rock Mass Classification (불연속 암반내 터널굴착의 안정성 평가 및 암반분류를 위한 인공 신경회로망 개발)

  • 문현구;이철욱
    • Tunnel and Underground Space
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    • v.3 no.1
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    • pp.63-79
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    • 1993
  • The design of tunnels in rock masses often demands more informations on geologic features and rock mass properties than acquired by usual field survey and laboratory testings. In practice, the situation that a perfect set of geological and mechanical input data is given to geomechanics design engineer is rare, while the engineers are asked to achieve a high level of reliability in their design products. This study presents an artificial neural network which is developed to resolve the difficulties encountered in conventional design techniques, particulary the problem of deteriorating the confidence of existing numerical techniques such as the finite element, boundary element and distinct element methods due to the incomplete adn vague input data. The neural network has inferring capabilities to identify the possible failure modes, support requirements and its timing for underground openings, from previous case histories. Use of the neural network has resulted in a better estimate of the correlation between systems of rock mass classifications such as the RMR and Q systems. A back propagation learning algorithm together with a multi-layer network structure is adopted to enhance the inferential accuracy and efficiency of the neural network. A series of experiments comparing the results of the neural network with the actual field observations are performed to demonstrate the abilities of the artificial neural network as a new tunnel design assistance system.

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Advanced Circuit-Level Model of Magnetic Tunnel Junction-based Spin-Torque Oscillator with Perpendicular Anisotropy Field

  • Kim, Miryeon;Lim, Hyein;Ahn, Sora;Lee, Seungjun;Shin, Hyungsoon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.13 no.6
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    • pp.556-561
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    • 2013
  • Interest in spin-torque oscillators (STOs) has been increasing due to their potential use in communication devices. In particular the magnetic tunnel junction-based STO (MTJ-STO) with high perpendicular anisotropy is gaining attention since it can generate high output power. In this paper, a circuit-level model for an in-plane magnetized MTJ-STO with partial perpendicular anisotropy is proposed. The model includes the perpendicular torque and the shift field for more accurate modeling. The bias voltage dependence of perpendicular torque is represented as quadratic. The model is written in Verilog-A, and simulated using HSPICE simulator with a current-mirror circuit and a multi-stage wideband amplifier. The simulation results show the proposed model can accurately replicate the experimental data such that the power increases and the frequency decreases as the value of the perpendicular anisotropy gets close to the value of the demagnetizing field.

Parallel tunnel settlement characteristics: a theoretical calculation approach and adaptation analysis

  • Liu, Xinrong;Suliman, Lojain;Zhou, Xiaohan;Abd Elmageed, Ahmed
    • Geomechanics and Engineering
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    • v.28 no.3
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    • pp.225-237
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    • 2022
  • Settlement evaluation is important for shallow tunnels in big cities to estimate the settlement that occurs due to the excavation of twin tunnels. The majority of earlier research on analytical solutions, on the other hand, concentrated on calculating the settlement for a single tunnel. This research introduces a procedure to evaluate the settlement induced by the excavation of twin tunnels (two parallel tunnels). In this study, a series of numerical analysis were performed to validate the analytical solution results. Two geological conditions were considered to derive the settlement depending on each case. The analytical and numerical methods were compared, which involved considering many sections and conducting a parametric study; the results have good agreement. Moreover, a comparison of the 3D flat model and 2D (FEM) with the analytical solution shows that in the fill soil, the maximum settlement values were obtained by the analytical solution. In contrast, the values obtained by the analytical solution in the rock is more conservative than those in the fill. Finally, this method was shown to be appropriate for twin tunnels dug side by side by utilizing finite element analysis 3D and 2D (PLAXIS 3D and PLAXIS 2D) to verify the analytical equations. Eventually, it will be possible to use this approach to predict settlement troughs over twin tunnels.

Simplified Failure Mechanism for the Prediction of Tunnel Crown and Excavation Front Displacements

  • Moghaddam, Rozbeh B.;Kim, Mintae
    • Magazine of korean Tunnelling and Underground Space Association
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    • v.21 no.1
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    • pp.101-112
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    • 2019
  • This case study presented a simplified failure mechanism approach used as a preliminary deformation prediction for the Mexico City's metro system expansion. Because of the Mexico City's difficult subsoils, Line 12 project was considered one of the most challenging projects in Mexico. Mexico City's subsurface conditions can be described as a multilayered stratigraphy changing from soft high plastic clays to dense to very dense cemented sands. The Line 12 trajectory crossed all three main geotechnical Zones in Mexico City. Starting from to west of the City, Line 12 was projected to pass through very dense cemented sands corresponding to the Foothills zone changing to the Transition zone and finalizing in the Lake zone. Due to the change in the subsurface conditions, different constructions methods were implemented including the use of TBM (Tunnel Boring Machine), the NATM (New Austrian Tunneling Method), and cut-and-cover using braced Diaphragm walls for the underground section of the project. Preliminary crown and excavation front deformations were determined using a simplified failure mechanism prior to performing finite element modeling and analysis. Results showed corresponding deformations for the crown and the excavation front to be 3.5cm (1.4in) and 6cm (2.4in), respectively. Considering the complexity of Mexico City's difficult subsoil formation, construction method selection becomes a challenge to overcome. The use of a preliminary results in order to have a notion of possible deformations prior to advanced modeling and analysis could be beneficial and helpful to select possible construction procedures.

Evaluation of Cave-in Possibility of a Shallow Depth Rock Tunnel by Rock Engineering Systems and Uumerical Analyses (암반공학시스템과 수치해석을 이용한 저심도 암반터널에서의 붕락 발생 가능성 평가)

  • Kim, Man-Kwang;Yoo, Young-Il;Song, Jae-Joon
    • Tunnel and Underground Space
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    • v.19 no.3
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    • pp.236-247
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    • 2009
  • Overpopulation has significantly increased the use of underground spaces in urban areas, and led to the developments of shallow-depth underground space. Due to unexpected rock fall, however, it is very necessary to understand and categorize the rock mass behaviors prior to the tunnel excavation, by which unnecessary casualties and economic loss could be prevented. In case of cave-in, special attention should be drawn since it occurs faster and greater in magnitude compared to rock fall and plastic deformation. Types of cave-in behavior are explained and categorized using seven parameters - Uniaxial Compressive Strength (UCS), Rock Quality Designation (RQD), joint surface condition, in-situ stress condition, ground water condition, earthquake & ground vibration, tunnel span. This study eventually introduces a new index called Cave-in Behavior Index (CBI) which explains the behavior of cave-in under given in-situ conditions expressed by the seven parameters. In order to assess the mutual interactions of the seven parameters and to evaluate the weighting factors for all the interactions, survey data of the experts' opinions and Rock Engineering Systems (RES) were used due to lack of field observations. CBI was applied to the tunnel site of Seoul Metro Line No. 9. UDEC analyses on 288 cases were done and occurrences of cave-in in every simulation were examined. Analyses on the results of 288 cases of simulations revealed that the average CBI for the cases when cave-in for different patterns of tunnel support was estimated by a logistic regression analysis.

An Estimation Technique of Rock Mass Classes for a Tunnel Design (터널 설계를 위한 암반등급 산정 기법에 관한 연구)

  • 유광호
    • Journal of the Korean Geotechnical Society
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    • v.19 no.5
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    • pp.319-326
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    • 2003
  • In site investigation for tunnel designs, nowadays, geophysical exploration such as seismic exploration and electric resistivity exploration as well as drilling logging is frequently carried out. A method which can systematically make the utmost use of all available data obtained from investigation, therefore, is strongly required for the optimal evaluation of ground conditions in terms of rock mass class, etc. Many researchers have proposed using qualitative data to cope with the lack of quantitative data. In this study, an evaluation technique of rock mass classes in undrilled region was proposed based upon multiple indicator kriging method which is a geostatistical technique. It was shown that two types of data with different degree of uncertainty, for example, drilling logging data and geophysical exploration data, could be simultaneously utilized in evaluating rock mass classes for a real tunnel design.