• Title/Summary/Keyword: rope

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Measuring restraints stress responses using active biotelemetry in cattle (Active biotelemetry를 이용한 젖소의 보정 스트레스 반응 측정)

  • Lee, Dong-Hee;Lee, Byeong-Han;Lim, Joa-Jin;Kim, Jin-Young;Park, Hee-Myung;Chung, Byung-Hyun
    • Korean Journal of Veterinary Research
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    • v.42 no.2
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    • pp.277-282
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    • 2002
  • This study was conducted to investigate the influences of the rope and the tipping chute restraints on body temperature (BT) and heart rate (HR) as acute response for stress caused by restraining for diagnasis and treatment in cattle. Both parameters were recorded by active biotelemetry. In addition cortisol concentration in blood was analyzed as a indicator for stress response. Twelve cattle were divided into two groups based on hydraulic power, the rope restraint group and the tipping chute restraint group. BT and HR were measured at -30 (base), 0, 10, 20, 30, 40, 50, 60, 90, 120, and 180 minutes, including restraint period from 0 to 30 minutes during the experiment. The results obtained in this study was summarized as follows: 1. BT of the rope restraint group was increased ($39.8{\pm}0.3^{\circ}C$) until 20 min after restraint stress for 30 min, and then maintained with high values to the end of experiment. In the tipping chute restraint group, the BT was increased ($39.6{\pm}0.3^{\circ}C$) until the end of the restraint period, but then showed decrese until the end of experiment. 2. HR of both groups was maximized at the beginning of the restraint stress (P<0.05), and then it was decreased gradually but in the tipping chute restraint group showed increase again at the end of the reatraint stress (P<0.05). 3. The cortisol level of the rope restraint group was increased significantly ($9.72{\pm}5.09{\mu}g/d{\ell}$) until 30 min after the end of the restraint stress (P<0.05) and then decreased, but in the tipping chute restraint group showed great increase ($4.68{\pm}1.56{\mu}g/d{\ell}$) at the end of the restraint stress (P<0.05) and then decreased while the tipping chute restraint group was significantly lower than the rope restraint group 30 min after the restraint stress (P<0.05). In conclusion, this study suggests that the tipping chute restraint produces less response to physical stress than the rope restraint but the time for diagnasis and treatment should be shortened when using the tipping chute restraint.

Axial Behavior of Reinforced Concrete Columns Externally Strengthened with Unbonded Wire Rope and T-Shaped Steel Plate (와이어로프와 T 강판으로 비부착 보강된 철근콘크리트 기둥의 중심 축하중 거동)

  • Yang, Keun-Hyeok;Sim, Jae-Il;Byun, Hang-Yong
    • Journal of the Korea Concrete Institute
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    • v.20 no.2
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    • pp.221-229
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    • 2008
  • An improved unbonded-type column strengthening procedure using wire rope and T-shaped steel plate units was proposed. Eight strengthened columns and an unstrengthened control column were tested under concentric axial load. The main variables considered were the volume ratio of wire rope and the flange width and configuration of T-shaped steel plates. Axial load capacity and ductility ratio of columns tested were compared with predictions obtained from the equation specified in ACI 318-05 and those of conventionally tied columns tested by Chung et al., respectively. In addition, a mathematical model was proposed to evaluate the complete stress-strain relationship of concrete confined by the wire rope and T-plate units. Test results showed that the axial load capacity and ductility of columns increased with the increase of the volume ratio of wire rope and the flange width of T-plates. In particular, at the same lateral reinforcement index, a much higher ductility ratio was observed in the strengthened columns having the volume ratio of wire rope above 0.0039 than in the tied columns. A mathematical model for the stress-strain relationship of confined concrete using the proposed strengthening procedure is developed. The predicted stress-strain curves were in good agreement with test results.

Development of an Underwater Rope-cutter Device and Controller for Removal of Propeller and Shaft Foreign Material for Small Vessel (소형선박용 프로펠러 및 샤프트 이물질 제거를 위한 수중절단기 기구 설계 및 제어기 개발)

  • Lee, Hunseok;Oh, Jin-Seok;Choi, Sun-Hong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.7
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    • pp.927-935
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    • 2019
  • Screw-failure accidents in small ships frequently occur in coastal waters. In particular, vessels' propulsion systems are frequently coiled due to objects such as fish-nets and ropes that float on the sea. The failure of the ship's propulsion system can cause primary accidents such as ship operation delays and drifting due to loss of power; furthermore, the possibility of secondary accidents such as those involving operators in the underwater removal of rope stuck in a propeller. Ships that do not have the proper tools to solve these problems must be either lifted onto land to be repaired or divers must dive directly under the ship to solve the problem. Accordingly, some small vessels have been equipped with rope-cutter devices on the propeller shaft to prevent ship propeller system accidents in recent years; however, they are not being applied efficiently due to the cost and time of installation. To solve these problems, this study develops an underwater rope-cutter device and controller for the removal of propeller and shaft foreign material in small vessels. This device has simple structures that use the principle of a saw. Meteor gears and crank pins were used for the straight-line rotation of saw blades of the underwater rope-cutters to allow for long strokes. Furthermore, the underwater rope-cutting machines can be operated by being connected to the ship battery. The user, a non-professional, can ensure convenience and stability by applying reverse current prevention and a speed control circuit so that it can be used more conveniently and safely.

A Study on Safety and Performance of Rope Cutter for Ship's Propeller (선박추진기 로프절단장치의 안전성 및 효용성에 관한 연구)

  • Lee, Won-Ju;Kim, Jong-Ho;Jang, Se-Hyun;Lee, Kyoung-Woo;Kim, Bo-Young;Lee, Woo-Kun;Rho, Beom-Seok;Kim, Jun-Soo;Choi, Jae-Hyuk
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.4
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    • pp.475-481
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    • 2018
  • In this study, the safety and effectiveness of ope cutter, developed to prevent frequent accident propeller windingness at sea. First, we calculated the bolt strength of the three types of rope cutting devices used in the experiment and the torsional stresses on the shafting system theoretical equation and the finite element method. As a result, the bolts used in the rope cutter confirmed from the viewpoint of safety life design and fail safe design. Also, safety satisfactory because of the small effect on the shaft system when locking up. Experiments were carried out to cut ropes and fishing nets from the sea using the ships equipped with three types of rope cutters verified to be safe. As a result, ropes of 20 to 50 mm in thickness were generally cut. It was found that the cutting efficiency of a rope cutter attached to shafting decreased when cutting thick ropes.

A Study on Safety and Performance Evaluation to Shaver Type Rope Cutter for Ships (선박용 Shaver Type 로프절단장치의 안전성 및 성능평가에 관한 연구)

  • Kang, Sung-Hoon;Ko, Jae-Yong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.4
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    • pp.632-638
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    • 2022
  • As Korean coastal activity is high, the incidence of accidents caused by marine waste is extensive. An accident in which marine floating waste ropes and fishing nets are wound around the propeller of a sailing ship is termed "Rope wrapped accident." To prevent such accidents, this study applied the Finite Element Method (F.E.M.) for performance evaluation of the shaver type cutter, commercialized in Korea, through a structural safety review and water tank test. The results demonstrate that all parts constituting the rope cutter were damaged before reaching 0.5s, and the safety factor of each part was found to be at least 2 based on the maximum stress generated compared to the tensile strength. In the basin test, the cutting process of the shaver type rope cutter was reviewed, and the installation angle was set for each case considering that the rope floating in the sea actually enters at various angles. Consequently, as it was successful at cutting in all the cases, it can be concluded that there will be no problem in cutting the rope regardless of the mounted angle of the cutting blade.

Comparative analysis of the effectiveness of the correct knot and the fisherman's knot in a rescue situation using ropes (로프를 활용한 구조상황에서 바른 매듭과 피셔맨 매듭의 효과성 비교 분석)

  • Jeon, Jai-In
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.5
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    • pp.767-773
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    • 2024
  • This study was limited to tying (connecting) knots using rescue ropes, and 5 subjects were selected for the experiment. After performing the correct knot, single-layer knot, figure-8 connecting knot, and fisherman's knot, the speed and convenience of each were analyzed. The results of analyzing the most convenient and fastest rope connecting method in rope tying are as follows. The correct knot and single-layer knot showed similar values of 11.80 seconds and 13.20 seconds, respectively. The figure-8 connecting knot showed significantly higher time of 19.00 seconds, which seems to be because the method of making a loop in the shape of a figure-8 and then inserting the rope along the figure-8 shape took some time to connect the rope. The fisherman's knot showed the lowest time of 9.80 seconds. This method overlaps the rope and forms a sling knot on the left and right, so it seems that the overall result is easy for the subjects to learn because it involves wrapping the rope once and pulling it out in the opposite direction. In an emergency rescue situation, the fisherman's knot is considered to be the most appropriate way to quickly and firmly connect ropes.

Comparison of CME radial velocities from the flux rope model and the ice cream cone model

  • Kim, Tae-Hyeon;Moon, Yong-Jae;Na, Hyeon-Ok
    • Bulletin of the Korean Space Science Society
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    • 2011.04a
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    • pp.28.2-28.2
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    • 2011
  • Coronal Mass Ejections (CMEs) are enormous eruptions of plasma ejected from the Sun into interplanetary space, and mainly responsible for geomagnetic storms and solar energetic particle events. It is very important to infer their direction of propagation, speed and their 3-dimensional configurations in terms of space weather forecast. Two STEREO satellites provide us with 3-dimensional stereoscopic measurements. Using the STEREO observations, we can determine the 3-dimensional structure and radial velocity of the CME. In this study, we applied three different methods to the 2008 April 26 event: (1) Ice cream Cone Model by Xue (2005) using the SOHO/LASCO data, (2) Flux rope model by Thernisien (2009) using the STEREO/SECCHI data, (3) Flux rope model with zero angle using the STEREO/SECCHI data. The last method in which separation angle of flux rope is zero, is similar to the ice cream cone model morphologically. The comparison shows that the radial speeds from three methods are estimated to be about 750km/s and are within ${\pm}120km/s$. We will extend this comparison to other CMEs observed by STEREO and SOHO/LASCO.

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Effects of Group Music Rope-jumping on Body Composition, Fitness and Serum Lipid in Obese Elementary School Boys and Girls (학급 집단 음악줄넘기 프로그램이 비만 아동의 신체구성, 체력, 혈중지질에 미치는 영향)

  • Chang, Hyuk-Ki;Kim, Sung-Ki;Seo, Dong-Il
    • Journal of Korean Public Health Nursing
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    • v.25 no.1
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    • pp.38-47
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    • 2011
  • Purpose: The study investigated the effects of 9 weeks of group music rope-jumping training on health-related physical fitness and blood lipid in obese elementary school boys and girls. Method: Subjects were randomly assigned to either a training group (37 boys and 18 girls) or control group (36 boys and 19 girls). The training group exercised for 1 hour, 2 days per week during the 9-week supervised music rope-jumping training program. The control group was asked to maintain their normal daily physical activities. The effects of the interventions on physical fitness and blood lipids were analyzed by two-way repeated measures ANOVA (group ${\times}$ time). Results: There were significant group ${\times}$ time interaction effects on body weight (p<.023), %body fat (p=.09), body mass index (p=.018), and body fat mass (p=.019) in school girls. However, there was not an interaction effect on serum lipids in both genders. Conclusion: The 9-week music rope-jumping training program used was effective for improving body composition in obese elementary school girls.

Effects on the Escapement of Juvenile Bastard Halibut Paralichthys olivaceus of Actively Stimulating Devices Inside a Model Cod End

  • Kim, Yong-Hae
    • Fisheries and Aquatic Sciences
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    • v.14 no.1
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    • pp.62-69
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    • 2011
  • The effects of actively stimulating devices (ASD) on juvenile flatfish escape were studied to increase escape rates from the cod end by encouraging fish to approach the net wall. Two kinds of ASD were designed: a fluttering net panel, i.e., a free-end flag-like net panel, and a double conical rope array. Escape responses of juvenile bastard halibut were observed in a circulating water channel using two model cod ends, one made with diamond-shaped 43-mm-mesh-size polyethylene (PE) as a high-contrast cod end and the other with polyamid (PA) mono-ply as a low-contrast cod end. Retention rate was significantly lower with the double conical rope-array ASD in the PE cod end than with conventional PE cod ends only or the fluttering net-panel ASD inside the PE cod end. Mean retention rate with the low-contrast PA cod end was also significantly lower than that with the high-contrast PE conventional cod end. Therefore, active fluttering devices using a double conical rope array together with less visible low-contrast netting in the cod end could help to reduce the bycatch of juvenile flatfish by weakening their optomotor response and actively driving fish to the side net panel.

A Study on Dynamic Modeling and Vibration Analysis of Gantry Robot (겐트리 로봇의 동적 모델링 및 진동해석)

  • Cho, Chang-Je;park, Dong-Jun;Yang, Jun-Seok;koo, Young-mok
    • Journal of the Korean Society of Industry Convergence
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    • v.17 no.4
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    • pp.211-216
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    • 2014
  • In general, gantry robot is very useful handling of heavy objects. But rope-driven yard cranes must have a little of sway and skew motion because ropes are passive mechanical device. So many researches have been concentrated on anti-sway algorithm controlling trolley speed. These approaches require sway angle. But it is very difficult to know sway angle and its derivative. Therefore control algorithm of trolley speed is not practical in general. On the contrary, control strategy using auxiliary rope is very useful to sway control of yard crane because rope length is shorter than quay-side container cranes. In this paper, we derive equations of motion of trolley system which have anti-sway controller to use auxiliary rope. And we propose the control strategy and analyse the behavior of the proposed system.