• Title/Summary/Keyword: tension control

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Novel Roaming and Stationary Tethered Aerial Robots for Continuous Mobile Missions in Nuclear Power Plants

  • Gu, Beom W.;Choi, Su Y.;Choi, Young Soo;Cai, Guowei;Seneviratne, Lakmal;Rim, Chun T.
    • Nuclear Engineering and Technology
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    • v.48 no.4
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    • pp.982-996
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    • 2016
  • In this paper, new tethered aerial robots including roaming tethered aerial robots (RTARs) for radioactive material sampling and stationary tethered aerial robots (STARs) for environment monitoring are proposed to meet extremely-long-endurance missions of nuclear power plants. The flight of the proposed tethered aerial robots may last for a few days or even a few months as long as the tethered cable provides continuous power. A high voltage AC or DC power system was newly adopted to reduce the mass of the tethered cable. The RTAR uses a tethered cable spooled from the aerial robot and an aerial tension control system. The aerial tension control system provides the appropriate tension to the tethered cable, which is accordingly laid down on the ground as the RTAR roams. The STAR includes a tethered cable spooled from the ground and a ground tension control system, which enables the STAR to reach high altitudes. Prototypes of the RTAR and STAR were designed and successfully demonstrated in outdoor environments, where the load power, power type, operating frequency, and flight attitude of the RTAR and STAR were: 180 W, AC 100 kHz, and 20 m; and 300 W, AC or DC 100 kHz, and 80 m, respectively.

An unstable patient with a large sucking chest wound managed with gauze packing for preventing tension and bleeding control before surgery in Korea: a case report

  • Chang-Sin Lee;Min-Jeong Cho;Tae-Wook Noh;Nak-Jun Choi;Jun-Min Cho
    • Journal of Trauma and Injury
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    • v.37 no.2
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    • pp.147-150
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    • 2024
  • This case report describes the management of a 51-year-old female patient who arrived at the emergency room with a stab wound to the upper right chest. Immediate medical interventions were undertaken, including blood transfusions and endotracheal intubation. To prevent tension and control bleeding, gauze packing was applied directly through the large open wound. Further surgical exploration identified a laceration in the lung, necessitating a right upper lobe resection. Postoperatively, the patient's vital signs stabilized, and she was subsequently discharged without complications. This case highlights the decision-making process in selecting between an emergency department thoracotomy and an operating room thoracotomy for patients with penetrating chest trauma. It also illustrates the role of gauze packing in managing tension and hemorrhage. In summary, gauze packing can be an effective interim measure for stabilizing patients with traumatic injuries, unstable vital signs, and large open chest wounds, particularly when a chest tube is already in place, to prevent tension and facilitate bleeding control prior to surgical intervention.

The Study of Faulty Vocal Habits in Patients with Hoarsenes (애성환자에 있어서 잘못된 발성습관에 관한 연구)

  • 안철민;박정은
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.10 no.1
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    • pp.12-16
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    • 1999
  • Background and Objectives : The common cause of voice disorders may be bad habits of phonation. faulty vocal habits might aggravate the voice disorder or make the dysphonia. Authors thought the analysis of faulty vocal habits might help to evaluate the causes and to choose the treatment methods in patients with dysphonia. Authors studied to evaluate which vocal habits were used in patients with dysphonia. Materials and Methods : Patients with dysphonia(N= 32) and person without dysphonia(N=20) were evaluated through pre-evaluation test by otolaryngologist and SLP. All subjects were evaluated accordingly Posture of body, expansion of cervical vein, excessive movements of thyroide prominence, position of tongue, tension of lower lip, tension of jaw, breathing pattern related with phonation. Results : In dysphonia group, we found 23 cases with tension of jaw, 15 cases with expansion of cervical vein, 7 cases with bad position of tongue, 3 cases with excessive movement of thyroid prominence and a lot of cases with bad breathing Pattern on Phonation. In control group, only 3 cases with bad position of tongue, 2 cases with tension of lower lip, 1 case with tension of jaw were found. Conclusions : More faulty vocal habits were found in dysphonia group. Authors thought faulty vocal habits could be the cause of dysphonia and aggravate the dysphonia and the control of vocal habits would be very important in patients with dysphonia.

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A Clinical Study of Tension Headache Patients using Depression & Anxiety Scales (우울(憂鬱), 불안(不安) 척도(尺度)를 이용(利用)한 긴장성(緊張性) 두통(頭痛) 환자(患者)의 임상고찰(臨床考察))

  • Jung, In-Chul;Lee, Sang-Ryong;Park, Ji-Un
    • Journal of Oriental Neuropsychiatry
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    • v.14 no.2
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    • pp.145-154
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    • 2003
  • Objective : The aims of this study were to show the clinical state and to investigate depression and anxiety by BDI and STAI scale in tension headache patients. Method : The patient group was consisted of the 20 patients with Tension Headache who were treated in Department of Neuropsychiatry, Daejeon University Oriental Hospital from 3 March 2003 to 30 September 2003. The control group was consisted of the 20 patients on physical therapy with cerebaral vascular disorder in the Daejeon University Cheonan Oriental Hospital. The patient group was investigated by various characteristics, and compared with the control group by BDI and STAI scores. Result : 1. The ratio of female was higher, the 40 aged were higher frequence, in distribution of the period of the clinical history, short term within 1 week was the most.. 2. Tension headache was most frequent at whole portion, neck stiffness, shoulder pain, general body weakness were mainly coexited, and the prescription invigorating spleen supplementing qi and tonifying qi and blood. 3. The BDI score was higher in patient group, but there was no significant difference 4. The STAI score was higher in patient group, but there was no significant difference.

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Experiments on Tension Characteristics of Perforated-type Floating Breakwaters (유공형 부방파제의 장력특성에 관한 실험)

  • Yoon, Jae Seon;Ha, Taemin
    • Proceedings of the Korea Water Resources Association Conference
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    • 2017.05a
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    • pp.514-514
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    • 2017
  • Floating breakwaters were treated as solid bodies without any perforation in previous studies. In this study, however, a floating breakwater is perforated to allow the partial absorption of the energy produced by incident waves and an air chamber is placed in the upper part to control the breakwater draft. A series of laboratory experiments for a floating breakwater installed with a mooring system are carried out. In general, a mooring system can be classified by the number of mooring points, the shape of the mooring lines, and the degree of line tension. In this study, a four-point mooring is employed since it is relatively easier to analyze the measured results. Furthermore, both the tension-leg and the catenary mooring systems have been adopted to compare the performance of the system. In laboratory experiments, the hydraulic characteristics of a floating breakwater were obtained and analyzed in detail. Also, a hydraulic model test was carried out on variable changes by changing the mooring angle and thickness of perforated wall. A hydraulic model was designed to produce wave energy by generating a vortex with the existing reflection method. Analysis on wave changes was conducted and the flow field around the floating breakwater and draft area, which have elastic behavior, was collected using the PIV system. From the test results the strong vortex was identified in the draft area of the perforated both-sides-type floating breakwater. Also, the wave control performance of the floating breakwater was improved due to the vortex produced as the tension in the mooring line decreased.

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Immediate Effects of Combined Stretching Exercise and Therapeutic Ultrasound on the Muscles Around the Neck in Tension-type Headache Patients (치료적 초음파를 결합한 뻗침운동이 긴장성 두통 환자의 목주변 근육에 미치는 즉각적인 효과)

  • Heo, Jae-Won;Park, Sam-Heon
    • Journal of muscle and joint health
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    • v.29 no.1
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    • pp.11-17
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    • 2022
  • Purpose: This study aimed to provide objective and basic data for an effective treatment method by examining changes in the mechanical properties of muscles and the degree of tenderness when a combination of stretching exercise and ultrasound therapy is applied to patients with tension headaches. Methods: The participants were classified into two groups based on the intervention received: the therapeutic ultrasound combined with suboccipital stretching (n=15, experimental group) and infrared combined with suboccipital stretching (n=15, control group) groups. The intragroup differences in mechanical muscle properties and modified total tenderness score were compared and analyzed. Results: The comparison and analyses of the changes in muscle tone and stiffness revealed statistically significant intragroup decreases in the upper trapezius and suboccipitalis in the experimental group. Similarly, the comparison and analyses of the changes in muscle stiffness revealed statistically significant intragroup decreases in the upper trapezius in the control group. Conclusion: Therapeutic ultrasound combined with suboccipitalis stretching effectively increased the flexibility of the muscles around the cervical vertebrae and reduced muscle tension and stiffness in tension-type headache patients

Design of Two-DOF Optimal Controller for Strip Gage and Tension Control of Cold Tandem Mills Using Reference Shaping Filter and Disturbance Observer (목표치 정형화 및 외란 관측기를 활용한 연속 냉간압연 시스템의 2-자유도 스트립 두께 및 장력 최적 제어기 설계)

  • Hong, Wan-Kee;Kang, Hyun-Seok;Hwang, I-Cheol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.2
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    • pp.237-244
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    • 2012
  • This paper studies the design of a two-DOF optimal controller for the strip gauge-tension of cold tandem mill processes, that uses a reference shaping filter and a disturbance observer. First, a mathematical model of the strip gauge and tension system is constructed using the gauge meter equation and Hooke's law, respectively. Next, a two-DOF controller considering of a feedforward controller and a feedback controller is designed. The former is based on the reference shaping filter and the disturbance observer, and the latter is based on the ILQ optimal control algorithm. Finally, it is shown through a computer simulation that the proposed optimal controller is able to improve the strip gauge accuracy and the tension variation more than the conventional MV-AGC controller.

The Effect of Tension and Drop Height on Contact Angle of Droplet on Flexible Substrate in Roll-to-Roll Systems (롤투롤 시스템에서 플렉시블 소재에 인가된 장력과 분사 높이가 액적 접촉각에 미치는 영향)

  • Kim, Dongguk;Lee, Changwoo
    • Journal of the Korean Society for Precision Engineering
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    • v.34 no.3
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    • pp.167-172
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    • 2017
  • This study proposes a method for identifying correlations between tension and drop height for sessile droplets in a roll-to-roll processing system. The effect of tension and drop height on the contact angle of a sessile droplet is presented. Design of experiment (DOE) methodology and statistical analysis are used to define a correlation between the process parameters. The contact angle is decreased while increasing tension and drop height. The influence of the tension is less significant on the contact angle compared with the effect of the drop height. However, tension should be considered as a major parameter because it is not easy to fix with roll eccentricity and compensating speed of the driven roll. The results of this study show that the effect of tension on the contact angle of a sessile droplet is more important than drop height because the drop height is fixed when the process systems are determined.

A dynamic finite element method for the estimation of cable tension

  • Huang, Yonghui;Gan, Quan;Huang, Shiping;Wang, Ronghui
    • Structural Engineering and Mechanics
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    • v.68 no.4
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    • pp.399-408
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    • 2018
  • Cable supported structures have been widely used in civil engineering. Cable tension estimation has great importance in cable supported structures' analysis, ranging from design to construction and from inspection to maintenance. Even though the Bernoulli-Euler beam element is commonly used in the traditional finite element method for calculation of frequency and cable tension estimation, many elements must be meshed to achieve accurate results, leading to expensive computation. To improve the accuracy and efficiency, a dynamic finite element method for estimation of cable tension is proposed. In this method, following the dynamic stiffness matrix method, frequency-dependent shape functions are adopted to derive the stiffness and mass matrices of an exact beam element that can be used for natural frequency calculation and cable tension estimation. An iterative algorithm is used for the exact beam element to determine both the exact natural frequencies and the cable tension. Illustrative examples show that, compared with the cable tension estimation method using the conventional beam element, the proposed method has a distinct advantage regarding the accuracy and the computational time.

Automatic Tension Control of a Timber Carriage Used for Biomass Collection

  • Choi, Yun-Sung;Oh, Jae-Huen;Euh, Seung-Hee;Oh, Kwang-Cheor;Choi, Hee-Jin;Kim, Dae-Hyun
    • Journal of Biosystems Engineering
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    • v.37 no.2
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    • pp.106-112
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    • 2012
  • Purpose: A lab-scale timber carriage using a servo motor system was built. When two motors move a carriage, wire tension is changed according to the different line speeds caused by a wire drum's changing diameter, leading to inappropriate traveling characteristics of the carriage. In order to overcome this problem, PID Control was used to control the motor speed. Methods: Ziegler-Nichols method was used to determine PID gains. Results: The initial PID gains were 1.8, 0.025, and 0.006, respectively, and optimal gains of 1.4 and 0.010 for P and I gain were obtained experimentally. Conclusions: The results showed that constant wire tension could be maintained by controlling the speed of the motor using PI control. Overshoot occurred at initial motor operation due to vibration and elasticity of the wire itself.