• Journal of Korean Neurosurgical Society
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• v.29 no.11
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• pp.1451-1455
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• 2000

Objective : The goal of this study is to present whether endoscopic release(ER) is superior to open release(OR) for the treatment of carpal tunnel syndrome(CTS). Method and Material : Fifty-nine wrists in 43 patients who had clnical signs and symptoms consistent with CTS, not responded to non-operative management, were entered into the study. Authors retrospectively compared 27 wrists treated with ER(February 1999-June 1999) with 32 wrists treated with OR(October 1997-March 1999). We performed conventional open surgery in 25 patients(mean age ; 46 years) and Brown's two-portal technique in 18 patients(mean age ; 53 years) under intravenous regional block or general anesthesia. Results : Sixteen patients had CTS on both hands and left hands were affected more frequently than right hand, 34 and 25 respectively. Successful and poor results of ER were similar to those of OR. For patients in OR group, mean duration of symptoms was 5 years(range 1 month-30 years), and postoperative outcome was good in 27(84.4%) of wrists and poor in 5(15.6%). For patients in ER group, mean duration of symptoms was 7 months (range 2 months-25 years), outcome was good in 23(85.2%) of wrists and poor in 4(14.8%). The average time for complete relief of pain was 1.3 weeks and 7.6 weeks, respectively for OR and ER groups. No complication was noted in either group. Conclusion : This preliminary analysis suggests that faster relief of pain was achieved when the endoscopic method was used, although there were no significant differences in their efficacies regarding the improvement of symptoms.

• Tunnel and Underground Space
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• v.32 no.6
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• pp.345-352
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• 2022

The existing NATM (New Austrian Tunneling Method) has induced civil compliants due to blasting vibration and noise. Machanized excavation methods such as TBM (Tunnel Boring Machine) are being adopted in the planning and construction of tunneling projects. Shield TBM method is composed of repetition processes of TBM excavation and segment installation, the machine has to be stopped during the later process. Consecutive excavation technology using helical segment is under developing to minimize the stoppage time. The modification of thrust jacks and module are planned to ensure the advance force acting on the inclined surface of helical segment. Also, the integrated system design of hydraulic circuit will be remodeled. This means that the system deactivate the jacks on the installing segment while the others automatically act the thrusting forces on the existing segments. This report briefly introduces the mechanical research part of the current consecutive excavation technological development project of TBM.

• Fire Science and Engineering
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• v.30 no.2
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• pp.19-26
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• 2016

In this study, we conducted a low temperature operating test and miniature tunnel model test to study the fire detection capability and properties of an early fire detection system using an optical sensor linear detector that can be installed in harsh environments such as tunnel or utility-pipe conduits which are becoming the major and national infrastructure facilities. The test showed that the optical sensor linear detector was the only one functioned properly among five thermal detectors installed at a low temperature of $-20^{\circ}C$ for 5 days. To study were analyzed adaptability of optical sensor linear detector in the windy tunnel, the operating properties of the optical sensor linear detector when the wind velocity was varied between 0 m/s and 1 m/s in a miniature tunnel model. The temperature change was high when the wind velocity was 0 m/s.

• Journal of Korean Tunnelling and Underground Space Association
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• v.4 no.4
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• pp.343-353
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• 2002

In the past many tunnels have been built to lowest capital investment cost without adequate regard for the cost of operation. But according to increasing the capacity of a ventilation system and to becoming diverse, it is to become more important to come up with the optimal operation stage of ventilation system. In this study, the tunnel ventilation dynamic simulation program had been developed. it is used to calculate the unsteady-state tunnel air velocity and concentration of pollutants according to the assumed average day traffic profile and summarize the energy consumption for the operation of ventilation system. And the operation energy consumption for the electric precipitation system and vertical vent shaft system are evaluated and compared in various operation mode. As the results of this study, the optimal operation stage for these ventilation system are provided.

• Annals of Clinical Neurophysiology
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• v.23 no.2
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• pp.99-107
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• 2021

Background: Pain and autonomic dysfunction are prominent symptoms in some patients with carpal tunnel syndrome (CTS). Infrared thermography (IRT) has been used to evaluate CTS by measuring the cutaneous temperature and sympathetic vasomotor function. Methods: This study enrolled the 66 hands of 33 subjects, some of which had clinical CTS and the others were healthy. The enrolled patients completed the Boston Carpal Tunnel Questionnaire (BCTQ) and Historical-Objective scale, and underwent nerve conduction studies (NCSs) and IRT. Skin temperature was measured at the fingertips and the thenar and hypothenar regions in each hand. We analyzed (1) the correlations between self-reported severity, physician-assessed severity, and test results, and (2) the sensitivity and specificity of IRT in diagnosing CTS. Results: No significant correlation was observed between the results of the BCTQ, NCS, and IRT. IRT had a low sensitivity and high specificity in diagnosing CTS. Conclusions: IRT cannot replace NCS in diagnosing CTS, nor did it provide an advantage in combination with NCS. However, lower temperatures at the median nerve in some hands with moderate-to-severe CTS suggested the involvement of sympathetic nerve fiber function. Follow-up studies with a larger-scale and complementary design are required to elucidate the relationships.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.3
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• pp.223-228
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• 2009

The aim of this research is to analyse the dynamic characteristics of the hot upper smoke layer in case of fire in a tunnel. In order to get the result, computer simulation technique has been used. The fire scenarios were set on the basis of standard cross section of national and express highways through NIST's FDS. As the area of a tunnel increased, the influence of the wind velocity decreased. Furthermore, the influence of the slope of a road was reduced as the wind velocity increased. On the other hand, as the wind velocity increased, the influence of the slope of a road decreased. This phenomena is believed to be caused by the cooling effect of wind which is over 1 m/s in speed, hence, reducing the influence of the effect of slope.

• Annals of Clinical Neurophysiology
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• v.13 no.1
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• pp.31-37
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• 2011

Background: Carpal tunnel syndrome (CTS) and tarsal tunnel syndrome (TTS) are thought to share a similar pathophysiology, compression of the median and plantar nerve by the carpal tunnel and flexor retinaculum. A few reports introduced the relationship between idiopathic CTS and TTS without definite evidence of coexistence. The current study was designed to analyze the electrophysiologic characteristics of combined idiopathic CTS and TTS by comparing with each idiopathic CTS or TTS. Methods: We retrospectively collected patients with combined idiopathic CTS and TTS (CTS-TTS group) from June 2001 to February 2009. Patients with each idiopathic CTS or TTS were collected as controls. Electrophysiologic data of median and plantar nerves were compared between CTS-TTS group and controls. Results: CTS-TTS group was composed of 31 patients. Control group of each CTS or TTS were 50 CTS and 49 TTS patients. In comparison of median nerve conduction study between CTS-TTS group and CTS control group, decreased compound muscle action potential amplitude (p<0.001), decreased median sensory nerve action potential amplitude (p<0.001) and sensory nerve conduction velocity at finger stimulation (p=0.013) were prominent in CTS-TTS group. Decreased medial plantar sensory nerve action potential amplitude (p=0.034) was indicated when CTS-TTS groups and TTS control group were compared. Conclusions: If the electrophysiology study of patients with CTS or TTS was suggestive of severe degree of nerve injury, concerns about the possibility of combined CTS and TTS would be helpful.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.331-346
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• 2018

In the tunnel of domestic high - speed railway, the main fire - fighting facility, fire - extinguishing passageway, is installed. However, due to the high pressure of the high - speed train, frequent breakage and maintenance are caused by strong shock and long - term vibration. In order to solve these problems, it is necessary to improve the fire door, but in Korea, it is installed by submitting a certificate by simple KS F 2296 performance test. At present, it is developed as a simple test certification by producing a real scale fireproof door without the theoretical examination in advance, so that a high cost for improvement is occurring in Korea. Therefore, through this study, structural analysis study which can preliminary structure review was carried out in order to design the refuge connection passage fire door and to improve the performance improvement. In order to secure the reliability of the result value, the official authentication test (KS F 2296) were compared.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.4
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• pp.429-440
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• 2015

In this study, model test equipment was developed to evaluate the hydraulic pressure reduction in appling the drainage shield tunnel and the model test for hydraulic pressure difference was performed in case of drainage and undrained conditions. In the result of model test, increase ratio of pore water pressure was decreased in drainage condition and total stress in drainage condition was smaller than that in undrained condition, so the hydraulic pressure was reduced by the groundwater inflow into the model tunnel. In the result of field instrumentation, the hydraulic pressure in the back ground of shield tunnel was small by 11~22% in comparison with the calculated hydraulic pressure ($r_w{\cdot}H$) in same groundwater level. In the result of model test and field instrumentation, it was appeared in drainage and undrained conditions that the difference between the theoretical hydraulic pressure and the real hydraulic pressure. It shows that it is possible to apply the reduced hydraulic pressure in applying the drainage shield tunnel and to reduce the segment section due to hydraulic pressure reduction.

• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.3
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• pp.215-222
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• 2010

An experimental study was carried out on a reduced scale model tunnel to investigate the efficiency of disaster prevention at underground and ground ventilation equipments for the fire in road tunnels. Based on Froude modeling, the 1/50 scaled model tunnel (20 m long) was manufactured. The vertical shafts that are used in the analysis of efficiency of disaster prevention are the two models that had considered when the real tunnels are designed and the amounts of smoke exhaust are applied the miniature of the real tunnels' smoke exhaust, 560 and $280\;m^3/s$. As the result of analysis, it is the possible the emissions of the entire quantity of CO gas through the vertical shafts. In the ground ventilation equipments, the concentration of CO is discharged 2.23~2,73 ppm smaller than the underground ventilation equipments. And the temperature rise in the ground ventilation equipments is $0.53{\sim}0.94^{\circ}C$ lower than in the underground ventilation equipments because of a cooling effect of the surface of the tunnel wall. As a result of analysis of CO concentration and the temperature rise in the modeling ventilation equipment, the position of ground ventilation equipment is more effective than the underground ventilation equipment in disaster prevention measures.