• Title/Summary/Keyword: Cranes

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Free Surface Procedure for Lifting Operation by Parallel Connected Floating Cranes using Synchronized Operation System and Its Applications to Lifting Operations of a Heavy Cargo (동조 시스템을 적용한 다수대의 해상크레인 병렬 운용 절차 및 대형 중량물의 리프팅 작업 적용)

  • Hwang, Jin-Ho;Ahn, Jeong-Ik;Lee, Soo-Bae;Kim, Yun-Ho;Choung, Jin-Sik;Ham, Seung-Ho;Lee, Won-Joon
    • Special Issue of the Society of Naval Architects of Korea
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    • 2009.09a
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    • pp.97-106
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    • 2009
  • Many production methods are tried to enhance the productivity efficiency. Parallel connected floating cranes are one of the examples to lift mega-blocks quickly and efficiently. However, a general operation manual to operate parallel connected floating cranes and a method to consider risks during lifting operation are not confirmed. And if each floating crane is operated by itself, it is very hard to cooperate. Therefore, Synchronized operation system is installed to control parallel connected floating cranes simultaneously and to be informed of each floating cranes data. And weighting factor is calculated by considering all hazards during the operation and the general operation manual is confirmed based on the factor. This paper introduces the procedure for lifting operations by parallel Connected Floating Cranes using synchronized operation system, and its applications to lifting operation of a heavy cargo such as barge lifting test, floating dock installation and 900 ton goliath crane replacement operation, etc.

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A Heuristic Approach to Scheduling Multiple Cranes for Intra-Block Remarshalling (복수 크레인을 활용한 블록 내 컨테이너 이적 계획)

  • Oh, Myung-Seob;Kang, Jae-Ho;Ryu, Kwang-Ryel;Kim, Kap-Hwan
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.29 no.1
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    • pp.413-421
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    • 2005
  • Intra-block remarshalling is the task of rearranging into some target bays those containers which are scattered within around the block. If multiple transfer cranes installed in the block are all used together we may be able to complete the remarshalling task as early as possible. However, when multiple cranes are used simultaneously, there may occur significant delays if we do not carefully consider interferences between the cranes at the time of scheduling. Especially, delays caused by interferences occur more frequently in case of using non-crossing cranes. This paper presents an efficient heuristics method for assigning moves of containers to each crane and for determining an appropriate container moving order in a manner sensitive to the interferences. Simulation experiments have shown that the proposed method can effectively reduce delays in various environments.

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Alternative Prevention on Human Error of Fatal Injuries by the Mobile Cranes (이동식 크레인 사망재해의 인지공학적 대안)

  • Kang, Hyunsu;Park, Peom
    • Journal of the Korea Safety Management & Science
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    • v.17 no.4
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    • pp.135-141
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    • 2015
  • According to the statistics, occupational fatal injuries by mobile cranes were about 12 per year in whole industrial. Mobile cranes are widely used in various parts of industries to improve the efficiency of the work. However considerable number of fatal injuries happen each year during the operation of the machines. In this study, the current regulations to be adequate in industrial site have to be renew in order to prevent the fatal injuries by mobile cranes. Fatal injury analyses were conducted with several accident cases by the mobile cranes. For each accident, the causes of the injuries were examined and proper safety measures were proposed. In this study, the mobile crane showed a high fatality rate in industrial accidents and no detailed cause analysis of fatal accidents was conducted in terms of unsafe acts or conditions. This study proposed a revision of the standard guideline as an accident prevention measures through in-depth analysis of fatal accidents. First, among the mainly five machines caused the accidents, mobile crane was higher for the second showed 0.6% for number of fatalities compared to number of mobil cranes and for the third showed 11% for number of fatalities compared to number of injuries. Second, main cause of cognitive engineering agenda was visibility, responsibility, affordance. As the measures to prevent accidents before starting operation, alternative revision for the fool proof including visibility, responsibility, affordance etc. for the fool proof measures was proposed. Third, alternative revision as cognitive accident prevention for the fail safe measures was proposed.

The Optimization Algorithm for Wall Bracing Supports of Tower Cranes (타워크레인의 횡지지 최적설계 알고리즘 개발)

  • Lee, Hyun-Min;Ho, Jong-Kwan;Kim, Sun-Kuk
    • Korean Journal of Construction Engineering and Management
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    • v.11 no.1
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    • pp.130-141
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    • 2010
  • Poor expertise in equipment operation and installation, coupled with unpredictable natural disaster, usually directly leads to disastrous accidents of large lifting equipment such as tower cranes. For example, 52 tower cranes fell down due to the unstable support in Korea at the attack of Typhoon "Maemi" in 2003, which damaged property and caused loss of life. In high-rise construction projects, top-slewing or luffing-jib tower cranes needs checking the stability of lateral-support in addition to the bottom support such as the foundation. In this study, the optimization algorithm for lateral-support of tower cranes is conducted, which is expected to enhance the structural stability of tower cranes and save the cost in conflict with the safety.

A Heuristic Approach to Scheduling Multiple Cranes for Intra-Block Remarshalling (복수 크레인을 활용한 블록 내 컨테이너 이적 계획)

  • Oh Myung-Seob;Kang Jaeho;Ryu Kwang Ryel;Kim Kap Hwan
    • Journal of Navigation and Port Research
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    • v.29 no.5 s.101
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    • pp.447-455
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    • 2005
  • Intra-block remarshalling is the task of rearranging into some target bays those containers which are scattered within around the block. If multiple transfer cranes installed in the block are all used together we may be able to complete the remarshalling task as early as possible. However, when multiple cranes are used simultaneously, there may occur significant delays if we do not carefully consider interferences between the cranes at the time of scheduling. Especially, delays caused by interferences occur more frequently in case of using non-crossing cranes. This paper presents an efficient heuristic method for assigning moves of containers to each crane and for determining an appropriate container moving order in a manner sensitive to the interferences. Simulation experiments have shown that the proposed method can effectively reduce delays in various environments.

The change of core habitats of the cranes due to release of the civilian control zone; CCZ and construction disturbance (서식지 교란 및 민간인통제지역 해제에 의한 두루미와 재두루미의 핵심서식지 변화)

  • Yoo, Seunghwa;Jung, Hwayoung;Kim, Kyoungsoon;Yu, Dong Su;Kim, Namshin;Kim, Hwajung;Hur, Weehaeng;Kim, Jinhan;Lee, Kisup
    • Journal of Environmental Impact Assessment
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    • v.24 no.4
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    • pp.301-316
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    • 2015
  • The endangered species, The Red-crowned Crane and the White-naped Crane are vulnerable species to the disturbance for human beings. We examined the importance of CCZ for the cranes by comparing the crane's density in some CCZ-released areas, which are cranes' wintering site in Cheorwon. We also assessed influence of disturbance such as construction and greenhouses on core habitats of cranes. Our study results suggested that the construction and reclamation in the CCZ shrunk core habitat area while increasing core area of far from the construction and reclamation area. The CCZ has been set since March, 2011 and the number of greenhouse has rapidly increased after 2012. As the number and size of greenhouse in the area where designation of CCZ was cancelled increased, foraging area of cranes diminished. Although the area where designation of CCZ was cancelled seemed to have more human disturbance than CCZ, the foraging density of cranes did not decline and even that of white-naped cranes increased. This could be the influence of artificial food supply at their roosting site. In conclusion, if the area of CCZ decline continuously in the future, density of cranes would decrease.

Wintering Habitat Use of white-naped Cranes Grus vipio in Han River Estuary, Korea (한강하구에 도래하는 재두루미의 서식지 이용 현황)

  • Kang, Tae-Han;Yoo, Seung-Hwa;Kim, Hwa-Jung;Lee, Ki-Sup
    • Korean Journal of Environment and Ecology
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    • v.23 no.3
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    • pp.250-257
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    • 2009
  • This study was conducted to investigate the habitat use of White-naped Cranes Grus vipio in Han river estuary during the wintering period from 2006 to 2008 (October$\sim$March). The average numbers of wintering White-naped Cranes were 106.6$\pm$21.7 (Mean$\pm$SD) individuals, and the highest number of 140 individuals were recorded in the early January, 2008. The wintering habitat use of White-naped Cranes between rice field and mudflat was not significantly different (Mann-Whitney test. p=0.40) during the wintering period. However, White-naped Cranes spent more time on the rice field in the early winter (p<0.01), and on the mudflat in the late winter(p<0.01). There was not a difference of the habitat use rate on middle winter. White-naped cranes used four different sites of rice field: Hongdopyoung, Pyoungdong, Ihwadong and Janghang rice fields. Among them, Hongdopyoung was the main foraging site. There was significant differences of habitat use ratio in the early and mid winter ((Kruskal-wallis test. p<0.01). White-naped Cranes used mudflat area from Gimpo Daegyo to Nusanri of Han river estuary. Especially, they preferred four sites from Gimpo Daegyo to Ilsan Daegyo more than the other sites. Habitat use rate of mud flats were significantly different among each site during the wintering period (Kruskal-wallis test. p<0.01)

Spatial Distribution of Feeding Site and the Relationship between Density and Environmental Factors(Roosting Site, Road and Residence) of Cranes in Cheorwon Basin, Korea (두루미류 취식지역의 공간적 분포 및 서식밀도와 잠자리, 도로, 인가지역과의 관계)

  • Yoo, Seung-Hwa;Kwon, Hyuk-Soo;Park, Jong-Jun;Park, Chong-Hwa
    • Korean Journal of Environment and Ecology
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    • v.25 no.4
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    • pp.516-525
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    • 2011
  • We studied the influence certain environmental factors (proximity of roosting site, roads, and residential areas) have on the spatial distribution of cranes in the Cheorwon, Korea. Using a range finder and GPS, data were collected from January to February 2007 and were subsequently evaluated with ArcGIS. The size of the cranes' wintering habitat was estimated to be 7$76.9km^2$. Five hundred and fifty-five flocks of cranes were observed and detailed distributions were collected. Feeding distribution of the cranes showed clustered distribution, however, no tendencies of spatial autocorrelation were apparent. Adjacent regions with paved roads and residences showed lower densities than other areas. Distances at which paved roads and residential areas induced changes in feeding flock densities were 1500m and 1750m, respectively. Feeding flock density decreased with increased distance from roosting site. Feeding flock density of the two crane species did not increase as distance from roads increased, however, the density of individuals showed a significant increasing tendency with increased distance from roads. In both species, density of feeding flocks and individuals significantly increased with increasing distance from residential areas. In Red-crowned Cranes, the density of feeding flocks and individuals significantly decreased with increasing distance from roosting site, however, in the case of White-naped Cranes, there was an even distribution in density of feeding flocks and individuals.

Mime Elements in Court Hagmu ; focusing on literature and expression of current practice (궁중 학무에 나타난 마임적 요소 - 문헌과 현행의 표출 현상을 중심으로 -)

  • Son, Sun Sook
    • (The) Research of the performance art and culture
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    • no.18
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    • pp.47-72
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    • 2009
  • This study explores mime elements of court Hagmu(鶴舞) in literature and what is expressed in the practice of current Hagmu and examines what has been changed while others are kept intact. The content of Hagmu is that "attracted by lotus flowers in a pond, cranes dance around and peck at them, when the blossoms open wide with a girl [dancer] inside, upon which the surprised cranes fly away." The dance consists of 4 steps: the first step is for the entrance of cranes; in the second step the cranes dance moving across jidang(池塘) and the north; in the third step the cranes are curious about the lotus calyces, yeontong(蓮筒); and the cranes withdraw in the fourth step. The literature suggests that the dancing courses on the stage are limited to the east, the west, the south, and the north. The movement is limited to naeson (內旋) only in mujin(舞進) and mutoe(舞退). Furthermore, the gaze is only allowed toward the north and jidang. Motions are limited to naejog(內足), oego (外顧), and naego(內顧). However, the mime elements of current Hagmu are attributed to the effort of translating crane's life into a realistic story. It relates the life of cranes to that of human beings and implies love in it. Finally, the court Hagmu has entered the real world out of the literature, enriched with new elements. Under the transition from literature to practice the diversity of expression is added while the elements related with court codes such as courses, movements, directions, and motions are kept intact. These limitations, however, are coupled with the sensitive 'love' and the exposure of dancing instruments intrigues audience and creates dramatic effect. In conclusion the significance of mime elements in court Hagmu is in enhancing communication with audience.

An Experimental Study on the Accurate Tracking Control of a Transfer Crane Based on the 2DOF Servosystem Design Approach (트랜스퍼 크레인의 고정도 주행제어에 관한 연구 : 2자유도 서보계 설계법을 이용한 제어계 설계 및 실험적 연구)

  • Kim, Young-Bok;Lee, Kwon-Soon;Han, Seong-Hoon
    • Journal of Ocean Engineering and Technology
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    • v.20 no.5 s.72
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    • pp.57-62
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    • 2006
  • The most important thing in acontainer terminal is to handle the cargo effectively in the limited time available. To achieve this objective, many strategies have been introduced and applied. To create an automated container terminal, it is necessary for the cargo handling equipment to be equipped with more intelligent control systems. From the middle of the 1990's, automated rail-mounted gantry cranes (RMGC) and rubber-tired gantry cranes (RTG) have been widely used to handle containers in yards. Recently, many pieces of equipment, like CCD cameras and sensors, have beenmounted in these cranes to cope with the automated terminal environment. In this paper, we try to support the development of more intelligent automated cranes, which allow for more effective cargo handling in yards. For this purpose, the modeling, tracking control, anti-sway system design, skew motion suppressing, and complicated motion control and suppressing problems must be considered. Especially, in this paper, the system modeling and a new tracking control approach are discussed, and an experimental study is performed based on a two-degree-of-freedom (2DOF) servosystem design.