• Title/Summary/Keyword: Nesting time

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Development of Creating Continuous and Common Cutting NC Data Program (소부재 연속/공용 절단 데이터 생성 프로그램 개발)

  • Hyun, Sung-Yeol;Oh, Sung-Kwon;Huh, Ok-Jae;Shim, Hyun-Sang
    • Special Issue of the Society of Naval Architects of Korea
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    • 2011.09a
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    • pp.101-105
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    • 2011
  • In most shipbuilding company, cutting procedure is proceed by cutting machine which run by CNC(Computer Numerical Code) data. In our cutting process, all CNC data is created by our nesting post processor system automatically. Among them, in case that cutting piece in the remnant plate, our system creates only one piece CNC data. Because remnant plate is not typical shape, and ship designers don't know remnant plate shape and quantity. In can happen some merit and good point if we modify 1:1 piece NC data by shorten cutting path, reducing cutting time or re-arrangement piece. For modifying cutting data, outside workers have to call to ship designer or have to go to NC control room where control the CNC system and cutting machine. It makes stop work process, and it waste time. In this paper, we introduce a program that can modify and replace 1:1 NC data with continuous or common NC data automatically.

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A Study on Torch Path Generation for Laser Cutting Process (레이저 절단공정에서의 토지경로 생성에 관한 연구)

  • Han, Guk-Chan;Na, Seok-Ju
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.6
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    • pp.1827-1835
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    • 1996
  • This paper addresses the problem of a torch path generation for the 2D laser cutting of a stock plate nested with resular or irregular parts. Under the constaint of the relative positions of parts enforced by nesting, the developed torch path algorithm generate feasible cutting path. In this paper, the basic object is a polygon( a many-slide figure) with holes. A part may be represented as a number of line segments connected end-to-end in counterclockwise order, and formed a closed contour as requied for cutting paths. The objective is to tranverse this cutting contours with a minimum path length. This paper proposes a simulated annealing based dtorch path algorithm, that is an improved version of previously suggested TSP models. Since everypiercing point of parts is not fixed in advance, the algorithm solves as relazed optimization problem for the constraint, thich is one of the main features of the proposed algorithm. For aolving the torch path optimization problem, an efficient generation mechanism of neighborhood structure and as annealing shedule were introduced. In this way, a global solution can be obtained in a reasonable time. Seveeral examples are represented to ilustrate the method.

The Effects of Technical Development, Market Expansion, Ecological Features, and Infirm Protective Policy on the Extinction of a Wild Life: A Case Study of Passenger Pigeons (기술발전, 시장팽창, 생태적 특성, 그리고 소극적 보호정책이 야생 동물의 멸종에 미친 영향: 미국 서부개척기의 여행비둘기를 사례로)

  • Song, Myung-Gyu
    • Journal of Environmental Impact Assessment
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    • v.19 no.5
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    • pp.483-495
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    • 2010
  • The passenger pigeon (Ectopistes migratorius) was a species of pigeon that was once the most common bird in North America. According to some ornithologists, the number of passenger pigeons is estimated as many as five to six billions at the time when the first Europeans arrived there. But this species became extinct in 1914. There were a multiplicity of causes in the extinction; first, the extension of telegraph lines and railroads into the Middle West of the USA beginning in 1850s, second, the loss of vast feeding, nesting, and roosting sites of the passenger pigeon due to the massive deforestation, third, the rapid population growth of the USA during nineteen century, fourth, the commercial exploitation of the species, and finally, the infirm and weak protective efforts. Some important lessons can be learned from the extinction of the passenger pigeon. First, it shows how much critical the public interest is for a successful conservational movement. Second, it illustrates the need for strong laws and practices in the protection of an endangered species from going extinct. Third, the fate of the passenger pigeon proves a very important principle in conservational biology. That is, for each species (bird or other animal) there is a minimum population to sustain the species. Ecologists generally believe that the extinction of the passenger pigeon was due to the loss of their numbers below the minimum owing to overexploitation.

Jewel of Thar Desert: Case study of a hidden wetland

  • Monali Sen
    • Journal of Wetlands Research
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    • v.25 no.1
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    • pp.26-34
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    • 2023
  • Wetlands are very critical for the conservation of aquatic ecosystems, while also serving as the breeding/ nesting/ resting grounds for water birds. Generally, wetlands support both resident and migratory birds, thus serving as connecting dots in the global flyways. The Rajasthan state of India has two Ramsar sites (Keoladeo National Park and Sambhar Lake) and many other water bodies/wetlands. However, most of these areas are segregated in the eastern, southeastern, southern, and northern parts. In the western part of Rajasthan, where lies the Great Indian or Thar desert, there are no such reported prominent wetlands drawing attention towards a substantial number of resident and migratory water birds. The author is an Indian Forest Service officer, who was posted in the Thar Desert region and during that time had identified a hidden wetland in the desert landscape. This study deliberates on the wetland location and its faunal diversity with prospects of developing the area as a proper wetland conservation zone. India is a signatory to the Central Asian Flyway of migratory species and serves as an important member in terms of having significant wetlands and reported migratory birds count. The need of preserving and bring the arid zone's hidden wetlands to the forefront can serve as an important tool to conserve water birds and comply with worldwide bird migration conservation efforts.

Breeding Biology of the Common Kingfisher Alcedo atthis bengalensis Gmelin (물총새 Alcedo atthis bengalensis Gmelin 의 繁殖生活史)

  • Lee, Bong Choon;Ki Chung Kwon
    • The Korean Journal of Ecology
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    • v.8 no.2
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    • pp.119-126
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    • 1985
  • One nest of the Common Kingfisher Alcedo atthis bengalensis Gmelin breeding in the area of Mt. Bangu, Mugye-ri, Jangye-ri, Jangyu-myon, Gimhae-gun, Gyongnam province, was observed for 43 days from July 18 to August 29, 1984. The nest was found at a height of 71cm in a steep mountain side. It was tunnel-shaped, with a size of 53cm(length), 5.5*6.4cm (the diameter of entrance) and 16.1*10.5cm (the diameter of incubation seat). The cluth size was 5 eggs. The eggs were white in color, the average size of 5 eggs being 20mm (length)*17.9mm(width). The incubation period was 18 days, the parent birds stayed in the nest at on average of 494 minutes and the rate of incubation was 82.20%. The incubation time increased gradually. The nesting period of 3 chicks was 25 days, and the average feeding frequency was 5, 50 times per day with the highest frequency of 10 times on the 14th days after hatching. The time and frequency of attendance gradually decreased as their chicks grew up. Total increase length in body was; body length 45.35longrightarrow147.80mm, wing 6.95longrightarrow63.40mm, bill 1.73longrightarrow29.36mm and body weight 2.93longrightarrow41.00gr. The prey for the 3 chicks of the nest was entirely fish. The main food item was the fry of Gobiobotidae. The home range of the nest was 0.43ha. and the territory size was 0.05ha. Their feeding ground were outside of their territory.

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Multitarget effects of Korean Red Ginseng in animal model of Parkinson's disease: antiapoptosis, antioxidant, antiinflammation, and maintenance of blood-brain barrier integrity

  • Choi, Jong Hee;Jang, Minhee;Nah, Seung-Yeol;Oh, Seikwan;Cho, Ik-Hyun
    • Journal of Ginseng Research
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    • v.42 no.3
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    • pp.379-388
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    • 2018
  • Background: Ginsenosides are the main ingredients of Korean Red Ginseng. They have extensively been studied for their beneficial value in neurodegenerative diseases such as Parkinson's disease (PD). However, the multitarget effects of Korean Red Ginseng extract (KRGE) with various components are unclear. Methods: We investigated the multitarget activities of KRGE on neurological dysfunction and neurotoxicity in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD. KRGE (37.5 mg/ kg/day, 75 mg/kg/day, or 150 mg/kg/day, per os (p.o.)) was given daily before or after MPTP intoxication. Results: Pretreatment with 150 mg/kg/day KRGE produced the greatest positive effect on motor dysfunction as assessed using rotarod, pole, and nesting tests, and on the survival rate. KRGE displayed a wide therapeutic time window. These effects were related to reductions in the loss of tyrosine hydroxylase-immunoreactive dopaminergic neurons, apoptosis, microglial activation, and activation of inflammatory factors in the substantia nigra pars compacta and/or striatum after MPTP intoxication. In addition, pretreatment with KRGE activated the nuclear factor erythroid 2-related factor 2 pathways and inhibited phosphorylation of the mitogen-activated protein kinases and nuclear factor-kappa B signaling pathways, as well as blocked the alteration of blood-brain barrier integrity. Conclusion: These results suggest that KRGE may effectively reduce MPTP-induced neurotoxicity with a wide therapeutic time window through multitarget effects including antiapoptosis, antiinflammation, antioxidant, and maintenance of blood-brain barrier integrity. KRGE has potential as a multitarget drug or functional food for safe preventive and therapeutic strategies for PD.

Intelligent 3D packing using a grouping algorithm for automotive container engineering

  • Joung, Youn-Kyoung;Noh, Sang Do
    • Journal of Computational Design and Engineering
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    • v.1 no.2
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    • pp.140-151
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    • 2014
  • Storing, and the loading and unloading of materials at production sites in the manufacturing sector for mass production is a critical problem that affects various aspects: the layout of the factory, line-side space, logistics, workers' work paths and ease of work, automatic procurement of components, and transfer and supply. Traditionally, the nesting problem has been an issue to improve the efficiency of raw materials; further, research into mainly 2D optimization has progressed. Also, recently, research into the expanded usage of 3D models to implement packing optimization has been actively carried out. Nevertheless, packing algorithms using 3D models are not widely used in practice, due to the large decrease in efficiency, owing to the complexity and excessive computational time. In this paper, the problem of efficiently loading and unloading freeform 3D objects into a given container has been solved, by considering the 3D form, ease of loading and unloading, and packing density. For this reason, a Group Packing Approach for workers has been developed, by using analyzed truck packing work patterns and Group Technology, which is to enhance the efficiency of storage in the manufacturing sector. Also, an algorithm for 3D packing has been developed, and implemented in a commercial 3D CAD modeling system. The 3D packing method consists of a grouping algorithm, a sequencing algorithm, an orientating algorithm, and a loading algorithm. These algorithms concern the respective aspects: the packing order, orientation decisions of parts, collision checking among parts and processing, position decisions of parts, efficiency verification, and loading and unloading simulation. Storage optimization and examination of the ease of loading and unloading are possible, and various kinds of engineering analysis, such as work performance analysis, are facilitated through the intelligent 3D packing method developed in this paper, by using the results of the 3D model.

An Interpretation of Deleuze's Other Geometry in Terms of Liquid Space - Focused on Works Published since 2000 - (리퀴드 스페이스에 대한 들뢰즈의 타자의 기하학적 해석 - 2000년도 이후 발표된 작품을 중심으로 -)

  • Kim Sun-Hee;Lee Hanna
    • Korean Institute of Interior Design Journal
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    • v.14 no.5 s.52
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    • pp.98-105
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    • 2005
  • Through advanced computer technology, our physical environment became a flexible and liquid space that is a multi-functional space structure, hetero-alliance, formless, interactivity. We attempt to interpretate Deleuze's Other geometry as a space designer. Hence first, the aim of this study is to define the meaning of the Other and Other geometry. Second, to extract keywords out of the Other geometry to analyze the work. Third, to analyze the work using the space formative languages(blob, blurring, distortion, folding, layering, lightness, nesting, repetition, shear, transparency, twisting, unfolding, warping, waving, and weaving). The 13 works were selected which have been issued after year 2000 with the focus on liquid space studies. The methods of this study are literature research and contents analysis. The results of the analysis were as follows. First, the source is the Other who is a hidden potentials in the surrounding environment, and this source has the capability of making it part of reality anytime. Other geometry means it is a theory that is comprised of various lines that with the kind of experiences that one has in life. Second, the key words that were extracted from the theory of Deleuze's Other geometry were of (1)hetero-alliance(reflected in a sculptured shape or a fluid abstract form), (2)dis-form(by speculating the user's movements, and combining space elements with external forces), (3)interactivity (information was exchanged real time between the user and his environment where the space took on a sensory institution). Finally, after studying the works using the space formative languages, we found that blob, warping, waving were used externally, and repetition, warping and waving for mostly used internally.

Distribution and Strandings of Endangered Sea Turtles in Korean Waters (한국 연안의 멸종위기 바다거북의 분포 및 좌초 현황)

  • Moon, Dae-Yeon;Jung, Min-Min;An, Yong-Rock;Choi, Seok-Gwan;Oh, Bong-Se;Kim, Zang-Geun;Lee, Chu;Kim, Moon-Jin;Kim, Sam-Yeon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.42 no.6
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    • pp.657-663
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    • 2009
  • This paper reports the strandings of sea turtles on Korean shores monitored for the first time in 2008. A total of 19 sea turtles, consisting of 12 greens and 7 loggerheads, were recorded as stranded from the east coast to the south including Jeju Island. Reported strandings reached a peak in July and dominant area was Jeju Island. The curved carapace length of loggerhead sea turtles ranged 65-84.2cm and that of green sea turtles ranged 39.2-90cm, indicating most of them were immature to sub-adult. Out of 19 turtles, 11 were found dead with unknown reasons. Possible causes of death may include drawning by fishing gear, swallowing of marine debris, boat collision, and diseases. An immature green sea turtle tagged with a satellite transmitter spent winter near Jeju Island where it was released, suggesting that the Island provide immature greens a feeding ground. Considering thousands of sea turtles crawl on Japanese shores for nesting every year, the number of sea turtles reported in Korean waters was relatively small. Therefore, it is suggested that an appropriate monitoring system be necessary to protect and conserve endangered sea turtle species in Korean waters.

A Case Study of WRF Simulation for Surface Maximum Wind Speed Estimation When the Typhoon Attack : Typhoons RUSA and MAEMI (태풍 내습 시 지상 최대풍 추정을 위한 WRF 수치모의 사례 연구 : 태풍 RUSA와 MAEMI를 대상으로)

  • Jung, Woo-Sik;Park, Jong-Kil;Kim, Eun-Byul;Lee, Bo-Ram
    • Journal of Environmental Science International
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    • v.21 no.4
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    • pp.517-533
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    • 2012
  • This study calculated wind speed at the height of 10 m using a disaster prediction model(Florida Public Hurricane Loss Model, FPHLM) that was developed and used in the United States. Using its distributions, a usable information of surface wind was produced for the purpose of disaster prevention when the typhoon attack. The advanced research version of the WRF (Weather Research and Forecasting) was used in this study, and two domains focusing on South Korea were determined through two-way nesting. A horizontal time series and vertical profile analysis were carried out to examine whether the model provided a resonable simulation, and the meteorological factors, including potential temperature, generally showed the similar distribution with observational data. We determined through comparison of observations that data taken at 700 hPa and used as input data to calculate wind speed at the height of 10 m for the actual terrain was suitable for the simulation. Using these results, the wind speed at the height of 10 m for the actual terrain was calculated and its distributions were shown. Thus, a stronger wind occurred in coastal areas compared to inland areas showing that coastal areas are more vulnerable to strong winds.