• 제목/요약/키워드: Dividing cutting area

검색결과 8건 처리시간 0.023초

룰드 곡면으로 된 임펠러의 5축 황삭 가공에 관한 연구 (A Study on Five-Axis Roughing of Impeller with Ruled Surface)

  • 장동규;임기남;양균의
    • 한국정밀공학회지
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    • 제24권7호
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    • pp.60-68
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    • 2007
  • This paper presents an efficient 5-axis roughing method for centrifugal impeller. The efficient roughing is minimization of cutting time through minimizing tool tilting and rotating motions. To minimized cutting time, machining area is divided into sub-cutting regions using control points on hub curves and shroud curves of blade used to design and analyze centrifugal impeller. For sub-cutting regions, diameters of cutting tools are determined as big as possible. Then, tool paths are generated with the tilting axis and rotating axis of 5-axis machine limited and fixed, which can give more efficient machining speed and machining stability than the conventional methods. Experimental results show that the proposed method is more efficient than the conventional methods to mill with the only one cutting tool without dividing area and the previous methods to mill with simultaneous 5-axis processing with dividing area.

임펠러의 효율적인 5축 NC 황삭가공에 관한 연구 (A Study on Efficient Roughing of Impeller with 5-Axis NC Machine)

  • 조환영;장동규;이희관;양균의
    • 대한기계학회논문집A
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    • 제27권11호
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    • pp.1917-1924
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    • 2003
  • This paper proposes a roughing path generation method fer machining impeller with 5-axis machining center. Traditional researches are focus on finishing for machining impeller. To achieve efficient machining, roughing method must be studied. The proposed method consists two steps : One is to select optimal tool size and tool attitude by dividing cutting area into two regions to reduce cutting time. The regions are automatically divided by character point on the geometry of impeller blade. After dividing, the tool of the optimal size is selected for each divided region. The other is avoidance of tool interference. Tool interference in cutting areas is avoided by checking the distance between tool axis vector and ruling line on blade surface or approximated plan between ruling line. Using this method, the cutting time is reduced efficiently.

룰드 곡면으로 된 임펠러의 효율적인 황삭 가공에 관한 연구 (A Study on Efficient Roughing of Impeller with Ruled Surface)

  • 임기남;장동규;이희관;양균의
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2004년도 추계학술대회 논문집
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    • pp.568-571
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    • 2004
  • This paper presents an efficient 5-axis roughing method for centrifugal impeller. The efficient roughing is minimization of cutting time through minimizing tool tilting & rotating motions. Roughing tool path plan consists of the three steps. First, machining areas are divided into sub cutting regions using ruling lines. The biggest tool diameter is, then, determined for each region. Finally, tool paths are generated after fixing the tilting and rotating axis of 5-axis machine. Experimental results showed that the proposed roughing plan considering the divided machining regions is more efficient than the conventional methods.

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서울 가회동11번지 도시한옥주거지의 필지형성과정 연구 (A Study on The Process of Land-dividing of Urban-Hanok Area in 11 Gahoe-dong, Seoul)

  • 송인호;정기황
    • 건축역사연구
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    • 제23권5호
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    • pp.47-60
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    • 2014
  • Urban-Hanok emerged as a result of urbanization of Hanok in the modern period. In particular, Urban-Hanok has been mass-produced from the early 1920s, when the population is concentrated in cities, until the middle. Large-scale development by the professional developer has been developed in large-scale land rather than individual client because housing shortage was serious problem. 11 Gahoe-dong was made in 1935-36 is representative Urban-hanok area of Bukchon. It was formed through division of large-scale Land in 1930's. In the 1930's, the large-scale development projects of Urban-Hanok was triggered by the two events. One is Land Investigation Project performed by the Japanese government to capitalization of property, another is the pro-japanese bought the large scale-land in Gahoe-dong at bargain price from The Japanese government. Each lot has still a topographical characteristics such as land-dividing quality, the way of development, characteristic quality of urban-tissue. 11 Gahoe-dong, Urban-hanok area was developed two ways. First, development have been adapted to the topography. The lots have reflected topographical conditions such as land cutting area, a retaining wall, land-diving was maintaining the original topography almost. Second, it was street oriented development. The lots have developed sequentially along the street. So, the lots's shape and size is different each. For this reason, this area distribute various type of Hanok.

지리정보시스템(GIS)을 이용한 벌채가능지역의 구분 및 입목가격 산정에 관한 연구 (A Study on Dividing the Feasible Areas to Cut and Calculating the Stumpage Value of Forests using Geographic Information System)

  • 김한수;원현규;최조룡;우종춘
    • 한국지리정보학회지
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    • 제3권3호
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    • pp.54-68
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    • 2000
  • 본 연구는 입목가격의 산정을 위해 지리정보시스템을 적용해 보고자 시도되었다. 우선 지리정보시스템(GIS)에 의해 연구대상지역의 산림에 대한 벌채가능지역을 구분하였고 이 지역산림의 입목가격을 산출하였다. 단위재적당 입목가격은 국유림산물 매각규칙 및 시행내규의 가격산출 공정에 따라 시장가역산법에 의해 산출되었다. 이때 GIS를 이용하여 벌목조재공정과 산지집재공정에 대한 작업량을 산출하여 시장가역산법에 의한 $m^3$당 입목가격을 산출하였다. 그 결과 침엽수의 가격은 $m^3$당 최하 1만원 이하에서부터 최고 5만원 정도까지 입목가격 분포를 나타냈으며 활엽수의 경우는 최하 2만원에서부터 최고 4만원이상으로 나타났다. 본 연구대상지역(250ha)중에서 벌채제한지역을 제외한 벌채가능지역(197.3ha)의 총 판매예상가격은 11억 3,126만원으로서 잣나무가 6억 5,010만원(57%) 낙엽송이 9,695만원(9%)을 차지하였고 활엽수의 가격은 3억 8,299만원으로 전체의 약 34%를 차지하였다. 그리고 소나무는 122만원으로서 그 차지하는 비율이 매우 경미하였다.

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아스팔트포장 유지보수 적정공사비 산정방안 연구 (A Study on the Estimation of Proper Construction Cost for Road Pavement Maintenance Work)

  • 오재훈;송태석;안방율
    • 한국건설관리학회논문집
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    • 제21권6호
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    • pp.16-26
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    • 2020
  • 도로포장 유지보수 공사는 다양한 현장 여건에 의해 작업량이 다양하게 발생되고 있으나, 공사비 예정가격 작성시 세분화된 기준이 없어 적정공사비가 산정되기 어렵다. 도로포장 유지보수는 신설포장과 달리 차량들이 운행하고 있는 상황에서 시공을 할 수 밖에 없어, 도심지, 작업제한시간, 야간, 시공면적 등에 따라 생산성에 많은 차이를 보이고 있다. 이를 보정하기 위해 공사비산정기준 등에서는 차로수, 주택가, 작업가능시간, 야간작업 등의 할증을 제시하고 있으나, 공사관계자들에 따라 상이하게 적용이 되고 있는 실정이다. 본 연구에서는 도로포장 유지보수 주요 작업공종에 대하여 현장의 여건을 제대로 반영 할 수 있는 공사비산정 기준을 마련하고 적용할 수 있는 방안을 조사하였다. 주로 많이 시공되고 있는 '절삭 후 아스팔트 덧씌우기', '표층복구', '포장복구', '도로복구'를 대상으로 현장을 조사·분석 하였으며, 현장조사 결과를 바탕으로 기본적인 번화가, 주택가 등 할증을 포함하여 작업시간과 시공개소 및 면적에 따라 시공량을 구분하여 적용할 수 있는 기준을 제시하였다. 작업시간은 이동과 준비시간을 제외한 순수작업시간을 3개 type(7시간, 5시간, 3시간)으로 구분하여, 각 type에 따라 시공개소의 면적을 5가지로 구분할 수 있는 계수를 마련하였으며, 공사비를 비교·분석 하였다. 이에 따라 시공목적, 현장여건에 따른 공사비산정기준 설계방법을 제시하여 설계자가 현장여건을 고려하여 적정한 공사비를 산정할 수 있는 방안이 마련된 것으로 판단된다.

Meningeal Layers Around Anterior Clinoid Process as a Delicate Area in Extradural Anterior Clinoidectomy : Anatomical and Clinical Study

  • Yoon, Byul Hee;Kim, Han Kyu;Park, Mun Sun;Kim, Seong Min;Chung, Seung Young;Lanzino, Giuseppe
    • Journal of Korean Neurosurgical Society
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    • 제52권4호
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    • pp.391-395
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    • 2012
  • Objective : Removal of the anterior clinoid process (ACP) is an essential process in the surgery of giant or complex aneurysms located near the proximal internal carotid artery or the distal basilar artery. An extradural clinoidectomy must be performed within the limits of the meningeal layers surrounding the ACP to prevent morbid complications. To identify the safest method of extradural exposure of the ACP, anatomical studies were done on cadaver heads. Methods : Anatomical dissections for extradural exposure of the ACP were performed on both sides of seven cadavers. Before dividing the frontotemporal dural fold (FTDF), we measured its length from the superomedial apex attached to the periorbita to the posterolateral apex which connects to the anterosuperior end of the cavernous sinus. Results : The average length of the FTDF on cadaver dissections was 7 mm on the right side and 7.14 mm on the left side. Cranial nerves were usually exposed when cutting FTDF more than 7 mm of the FTDF. Conclusion : The most delicate area in an extradural anterior clinoidectomy is the junction of the FTDF and the anterior triangular apex of the cavernous sinus. The FTDF must be cut from the anterior side of the triangle at the periorbital side rather than from the dural side. The length of the FTDF incision must not exceed 7 mm to avoid cranial nerve injury.

기계화를 전제로 한 산간경사지답경지정리방안에 관한 연구(II) (A Study on the Methodology of Land-Consolidation Sloping Paddies in land Vallry for the Farm-Mechanization (II))

  • 황은
    • 한국농공학회지
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    • 제24권4호
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    • pp.57-68
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    • 1982
  • The paddy fiels slope located in Kangweon province Hwyongsung gun Gonggeun myon Shinchonri was considerably steep and so it was impossible to economically consolidate the field up to date. But for the porpose of farm mechanization, the field (32. 27ha) was consolidated by the auther under the assitance of the Ministry of Agriculture and Fishery and,;the Administration of Kangweon province. This paddy field consolidation was caused by the treatise on "Land-consolidation methods for farm mechanization in the steep-sloped paddy field", of which the auther is the same. The constrution was carried out from September, 1981 to April, 1982. During the 4esign and construction, some Peculiarities were found and discussed. That is, in design, besides the common condititions for a design, some special conditions were considered and written below; (1) The ranges of field slope in this design were 1/100-1/30. (2) Long sides of the land readjustment blocks must be arranged abreast contour line, and so they make the amount of cutting and banking decreased so as to take the maximum advantage of the configuration of the field. (3) In design, the main principles of dividing blocks were written below; i) First of all, long side of a block should be drawn straight abreast a contour line. ii) Long side of a block should arrange abreast contour line and make its length 100-150m, if not, l)reak the side in order to make a bended rectangle. iii) Length of a short side should be determinded within differences of elevation (0.6 -1. 2m) between the two adjacent blocks toward the normal to a contour line. iv) Length of a short side should be above 15m and the ratio of long and short side should be slso kept 1: (4-6). v) A new field surface leveling was determinded from the elevation which produce the least amount of cuttingand banking within the range of 0.6-1. 2m diffe rences of elevation between the two adjacent blocks. vi) In the course of dividing blocks with the same width along the line which was normal to a contour line, all blocks connot keep their shape in a retangle because of steep slope of the field and so on, and so it was also necessory to make some non-retanglar and small blocks such as a trianglar or trapezoidal shape, which was impossible to use some of farm machinery. But because this non-rectanglar and small blocks were divided, larger and many rectanglar blocks can be divided and construction cost can also be lowered. According to the conditions discussed above, the paddy field consolidation project designed and constructed. And the results of this study were obtained as below; (1) Three-forth of total cost of this paddy field consolidation was not construction cost, and these cost consist of land grading (1/4), road and canal construction cost (1/4) and the other cost (1/4) such as surveying or materials and 56 on. (2) The steeper the land slope, the greater cost was assigned for road and canal construction, and than land grading. (3) Curtailment of the road and canal construction cost depended on simplificating their strutures. (4) In the case of the land slopes were low, the land grading cost was high by 1: 1.4 in comparison with the road and canal construction cost, and conversely when the slops were steep, the road and canal construction cost was high by 1 : 5 in compa- rison with the land grading cost. (5) The densities of irrigation canal, drainage canal and trunk and branch road were 150. Sm/ha, 60. im/ha and 17. 4m/ha respectively. The density of irrigation canal of the area was high by 2 times in comparison with the average one of Kangweon Province, and the others were nearly the same. (6) Most farmers (above 85%) knew the effects of paddy field consolidation. The effects are; 1) Improvement of irrigation 2) Improvement of farm management 3) Improvement of transportarion 4) farm mechanization and 5) grouping of the scattered land. And the more farm modernization was accomplished by these projects, the more farmers wanted to live in their land. (7) In spite of the very steep sloped paddy field, the diminution rate of the net farm land caused by consolidation was 7.7% which was nearly the same as the one of Chulweon plain of Kangweon province. Land grading cost was 971, OOOwon/ha which was rather cheap by 13.2% than the one of Ghulweon plain, and unit construction cost was 5, 341, OOOwon/ha (included soil addition) which was also nearly the same as the one of Chulweon plain and FNFIA (The federation of national farmland improvement association).

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