• Title/Summary/Keyword: lifting method

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A Study on Loading Method of Large Scaffolding Module for LNG Carriers Using TRIZ (TRIZ를 이용한 LNG 운반선 대형 비계 모듈의 탑재 방안 연구)

  • Park, Myeong-Chul;Shin, Sang-Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.3
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    • pp.94-100
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    • 2021
  • To improve the productivity of cargo containment construction for a membrane LNG carrier, it is important to shorten the installation period and process of the scaffolding system, which is a construction workbench of a cargo containment for a membrane LNG carrier. As an effective method, opinions are being gathered to enlarge the lifting unit from the existing two stages to eight stages. On the other hand, the stresses around the pin and hole will increase significantly because of the increase in lifting load according to the large size of the module. The purpose of this study was to establish a new large module-lifting plan by introducing TRIZ to solve these problems. This study adopted a method to utilize 40 inventive principles, which is one of the various problem-solving tools of TRIZ. First, technical contradictions were derived, the engineering parameters were selected. Second, efficient inventive principles were selected to overcome the technical contradictions using a contradiction matrix. Finally, the general and specific solutions were derived through the selected inventive principle, and structural analysis confirmed that the stress generated in the structure was low. The utility of TRIZ was confirmed by the successful lifting of large modules using the established lifting method.

Hybrid RANS and Potential Based Numerical Simulation for Self-Propulsion Performances of the Practical Container Ship

  • Kim, Jin;Kim, Kwang-Soo;Kim, Gun-Do;Park, Il-Ryong;Van, Suak-Ho
    • Journal of Ship and Ocean Technology
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    • v.10 no.4
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    • pp.1-11
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    • 2006
  • The finite volume based multi-block RANS code, WAVIS developed at MOERI is applied to the numerical self-propulsion test. WAVIS uses the cell-centered finite volume method for discretization of the governing equations. The realizable $k-{\epsilon}$ turbulence model with a wall function is employed for the turbulence closure. The free surface is captured with the two-phase level set method and body forces are used to model the effects of a propeller without resolving the detail blade flow. The propeller forces are obtained using an unsteady lifting surface method based on potential flow theory. The numerical procedure followed the self-propulsion model experiment based on the 1978 ITTC performance prediction method. The self-propulsion point is obtained iteratively through balancing the propeller thrust, the ship hull resistance and towing force that is correction for Reynolds number difference between the model and full scale. The unsteady lifting surface code is also iterated until the propeller induced velocity is converged in order to obtain the propeller force. The self-propulsion characteristics such as thrust deduction, wake fraction, propeller efficiency, and hull efficiency are compared with the experimental data of the practical container ship. The present paper shows that hybrid RANS and potential flow based numerical method is promising to predict the self-propulsion parameters of practical ships as a useful tool for the hull form and propeller design.

Basic Study for Development of Qigong Exercise Appropriate for Musculoskeletal Characteristics of Seniors (노인의 근골격계 특성에 적합한 기공운동 개발을 위한 기초연구)

  • Kim, Yi Soon;Lee, Jeong Won;Kim, Gyeong Cheol;Park, Tae Soeb;Kwak, Yi Sub;Lee, Hai-Woong
    • Journal of Society of Preventive Korean Medicine
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    • v.18 no.2
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    • pp.115-123
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    • 2014
  • Objective : The objective of this study is to develop a Qigong exercise program to reinforce musculoskeletal system of seniors appropriate for physical strength and conditions of seniors aged 65 years or above based on health Qigong exercise of oriental medicine. Method : Qigong exercise motions that can improve strength, muscular endurance, flexibility, and cardiovascular endurance of seniors were developed by primarily performing literature review of Qigong experts on the fields like oriental medicine, Qigong exercise, physical education and health science and secondarily using motion training for increased validity of motions. Results : The Qigong exercise program for musculoskeletal system of seniors was designed with 12 motions repeated 8 times and 20 minutes per session, including shoulder exercises (alternate turning of left and right shoulders, turning both arms back and forth, holding and lifting elbow to put it aside), waist exercises (wrapping the head with hands to bow, twisting waist while looking at the tip of hand, large spinning of ball, putting hands together to pull back), and knee exercises (going up a down while lifting a rock, balancing the body while lifting a knee, lifting and spreading knees while drawing circle with arms, raising both arms to the side while lifting heels, breathing). Conclusion : Once the effects of Qigong exercise for musculoskeletal system of seniors developed in this study are tested, the program is expected to contribute to development of Qigong exercise, a core part of oriental medicine health improvement project.

Hydraulic Cylinder Design of Lifting Pump Mounting and Structural Safety Estimation of Mounting using Multi-body Dynamics (다물체 동역학을 이용한 양광펌프 거치대의 유압 실린더 설계 및 구조 안전성 평가)

  • Oh, Jae-Won;Min, Cheon-Hong;Lee, Chang-Ho;Hong, Sup;Kim, Hyung-Woo;Yeu, Tae-Kyung;Bae, Dae-Sung
    • Journal of Ocean Engineering and Technology
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    • v.29 no.2
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    • pp.120-127
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    • 2015
  • When a deep-seabed lifting pump is kept this device has bending and deformation in the axis due to its long length(8m). These influences can be caused a breakdown. Therefore, a mounting must be developed to keep the lifting pump safe. This paper discusses the hydraulic cylinder design of the lifting pump and structural safety estimation of the mounting using SBD(simulation-based design). The multi-body dynamic simulation method is used, which has been used in the automotive, structural, ship building, and robotics industries. In this study, the position and diameter of the hydraulic cylinder were determined based on the results of the strokes and buckling loads for the design positions of the hydraulic cylinder. A structural dynamic model of the mounting system was constructed using the determined design values, and the structural safety was evaluated using this dynamic model. According to these results, this system has a sufficient safety factor to manufacture.

High-Performance Line-Based Filtering Architecture Using Multi-Filter Lifting Method (다중필터 리프팅 방식을 이용한 고성능 라인기반 필터링 구조)

  • 서영호;김동욱
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.8
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    • pp.75-84
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    • 2004
  • In this paper, we proposed an efficient hardware architecture of line-based lifting algorithm for Motion JPEG2000. We proposed a new architecture of a lifting-based filtering cell which has an optimized and simplified structure. It was implemented in a hardware accommodating both (9,7) and (5,4) filter. Since the output rate is linearly proportional to the input rate, one can obtain the high throughput through parallel operation simply by adding the hardware units. It was implemented into both of ASIC and FPGA The 0.35${\mu}{\textrm}{m}$ CMOS library from Samsung was used for ASIC and Altera was the target for FRGA. In ASIC, the proposed architecture used 41,592 gates for the lifting arithmetic and 128 Kbit memory. For FPGA it used 6,520 LEs(Logic Elements) and 128 ESBs(Embedded System Blocks). The implementations were stably operated in the clock frequency of 128MHz and 52MHz, respectively.

Effects of Exercise using PNF Chopping and Lifting Pattern on the Respiratory Function of Chronic Stroke Patients (만성 뇌졸중 환자에게 PNF 내려치기와 들어올리기 패턴을 이용한 운동이 호흡기능에 미치는 영향)

  • Kwon, Gyo-Im;Cho, Yong-Ho
    • Journal of the Korean Society of Physical Medicine
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    • v.16 no.4
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    • pp.77-83
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    • 2021
  • PURPOSE: This study examined the changes in the respiratory function when PNF chopping and lifting patterns were used in chronic stroke patients METHOD: The subjects were 30 patients diagnosed with chronic stroke. The respiratory function (FVC, FEV1, and FEV1/FVC) were measured by spirometry. Thirty subjects were divided randomly into an experimental group to which 15 PNF chopping and lifting were applied and a control group to which chest breathing exercise was performed. The intervention was conducted three times a week for six 6 weeks. To examine the effects of intervention, the pre- and post-intervention values for each group were compared using a paired t-test. An independent t-test was used to compare the differences in the values of changes pre- and post-intervention in the two groups. Statistical significance was set to .05. RESULTS: Satistically significant differences in FVC and FEV1 were observed in both the experimental group and control group according to the intervention (p < .05). A statistically significant difference was found in FVC and FEV1 compared to values of changes pre- and post-intervnetion between the experimental and control groups. There was no difference in FEV1/FVC. CONCLUSION: The results suggest that PNF chopping and lifting can be applied as an excellent respiratory intervention program compared to general chest breathing exercises to improve respiratory function in stroke patients.

The Analysis of Frame Structure in Farm Vehicle (농장차의 프레임 구조 해석)

  • Pratama, Pandu Sandi;Supeno, Destiani;Woo, Ji-Hee;Lee, Eun-Sook;Park, Cun-Sook;Yoon, Woo-Jin;Chung, Sung-Won;Choi, Won-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.20 no.1
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    • pp.27-33
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    • 2017
  • An agriculture machines are subjected to different loads conditions. Due to this loads variations there will be certain deformations and stress which affect the performance of the electric vehicle in adverse manner. The purpose of this paper is to analyze the total deformation and stress of the electric farm vehicle middle frame based on the finite element method. The proposed electric farm vehicle has lifting and dumping capability. Therefore, in this research four operational condition such as normal condition, dumping condition, lifting condition, and lifting-dumping condition was analyzed. In this research, the design for whole frame structure is elaborated. According to the mechanical characteristics of the frame, materials are selected and manufacturability requirements are limited. Based on ANSYS 15 software, the finite element model of electric farm vehicle is established to carry out static analysis on full-loaded conditions. The simulation results shows that the proposed design meet the strength requirements and displacement requirements. The maximum deformation 0.53611 mm and maximum stress 30.163 MPa occurred at lifting-dumping condition.

Development of a Real-time Lifting-path Tracking System of a Tower-crane for Steel Members based on an Integrated Wireless RF Modem and GPS System (무선 RF모뎀과 GPS를 통합한 타워크레인의 철골부재의 실시간 양중위치 추적시스템 개발)

  • Yun, Seok-Heon;Lee, Ghang
    • Journal of the Korea Institute of Building Construction
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    • v.10 no.3
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    • pp.65-70
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    • 2010
  • Steel frame construction in high places entails many risk factors. In order to improve the safety and productivity of steel frame construction, a project to develop a robotic tower-crane has been undertaken. As the first step, a real-time lifting-path tracking system is being developed. In a previous study, a laser-based tracking system was proposed. While a laser-based tracking system requires at least three laser sensors to detect the x, y, z coordinates of a lifted steel member, a GPS-based system has an advantage over the laser-based system, in that the x, y, z coordinates of a lifted steel member can be detected by a single GPS sensor. To improve the accuracy, arelative positioning method using two GPS sensors was proposed in a previous study. This paper reports an improved GPS-based lifting-path tracking system of a tower crane based on an integrated RF modem and GPS system. The results showedthat the RF modem could successfully send the identifier information to a server a maximum distance of 1 km away from the lifted steel beam, and the lifting path information of each beam captured by the GPS-based tracking system was successfully saved together. Also, byusing an improved algorithm for the GPS relative positioning method, the deviation was reduced to 0.61 m on average.

A High Speed 2D-DWT Parallel Hardware Architecture Using the Lifting Scheme (Lifting scheme을 이용한 고속 병렬 2D-DWT 하드웨어 구조)

  • 김종욱;정정화
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.40 no.7
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    • pp.518-525
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    • 2003
  • In this paper, we present a fast hardware architecture to implement a parallel 2-dimensional discrete wavelet transform(DWT)based on the lifting scheme DWT framework. The conventional 2-D DWT had a long initial and total latencies to get the final 2D transformed coefficients because the DWT used an entire input data set for the transformation and transformed sequentially The proposed architecture increased the parallel performance at computing the row directional transform using new data splitting method. And, we used the hardware resource sharing architecture for improving the total throughput of 2D DWT. Finally, we proposed a scheduling of hardware resource which is optimized to the proposed hardware architecture and splitting method. Due to the use of the proposed architecture, the parallel computing efficiency is increased. This architecture shows the initial and total latencies are improved by 50% and 66%.

Propeller Skew Optimization Considering Varying Wake Field (선체반류를 고려한 프로펠러 최적 스큐화)

  • 문일성;김건도;유용완;류민철;이창섭
    • Journal of the Society of Naval Architects of Korea
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    • v.40 no.5
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    • pp.26-35
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    • 2003
  • Propellers operating in a given nonuniform ship wake generate unsteady loads leading to undesirable stern vibration problems. The skew is known to be the most proper and effective geometric parameter to control or reduce the fluctuating forces on the shaft. This paper assumes the skew profile as either a quadratic or a cubic function of the radius and determines the coefficients of the polynomial function by applying the simplex method. The method uses the converted unconstrained algorithm to solve the constrained minimization problem of 6-component shaft excitation forces. The propeller excitation was computed either by applying the two-dimensional gust theory for quick estimation or by the fully three-dimensional unsteady lifting surface theory in time domain for an accurate solution. A sample result demonstrates that the shaft forces can be further reduced through optimization from the original design.