• Title/Summary/Keyword: stepped building

검색결과 18건 처리시간 0.027초

EVA를 이용한 가변 용착 쾌속 조형 공정 개발 (Development of Variable Deposition Manufacturing for Ethylene Vinyl Acetatecopolymer)

  • 이상호;신보성;정준호;안동규;양동열
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2000년도 춘계학술대회 논문집
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    • pp.771-774
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    • 2000
  • RP techniques have inherent disadvantages caused by their working principles: stair-stepped surface of parts due to layer-by-layer stacking of layers, low build speed caused by line-by-line solidification to finish one layer, and post processing to improve surface finish, etc. The objective of this study is to propose a new RP technique, variable deposition manufacturing (VDM), which can make up for the disadvantages of the existing RP techniques, and to develop an apparatus to implement the technique. The proposed process can greatly reduce the building time and improve the surface finish of parts generated. The experiments are carried out to obtain the range of temperature of molten material to maintain its fluidity and to investigate the effect of gas cooling on the preservation of the slopes. Based on the results, some simple shapes such as a line-shape. an S-shape, and a circle-shape were fabricated from Ethylene Vinyl Acetatecopolymer (EVA). In order to examine the applicability of VDM to more general shapes, a tensile specimen and a yo-yo shape were manufactured by the proposed RP method using EVA material as the first trial approach. The present basic study has shown the possibility of a practicable utilization of the proposed VDM process to prototyping of a general three-dimensional shape.

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희양산봉암사 극락전의 연구 -조성시기와 용도를 중심으로- (A Study on Geungnakjeon(Paradise Shrine) of Bong-amsa Temple at Mountain Hiyangsan - Based on its applications and historical period of establishment -)

  • 홍병화;김성우
    • 건축역사연구
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    • 제16권5호
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    • pp.7-20
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    • 2007
  • Bong-amsa Temple is a special temple in the custody of Jogye sect, a branch of Buddhism in Korea. Due to limited public access to this temple, its Geungnakjeon(paradise shrine) has been little known to outside. But it is known that the Geungnakjeon has been not yet explored from academic standpoints in terms of its historical establishment as well as applications, and it would be two-storied wooden pagoda or the like. In order to examine its historical establishment, this study investigated historical records related to Bong-amsa Temple and its intrinsic architectural style. As a result, it was estimated that the building was established around the transitional period ranging from the late Koryo dynasty to the early Joseon dynasty. And it was found that the Geungnakjeon is not the two-storied wooden pagoda, but the unique building including an incidental component called Chayanggan(遮陽間; a sort of stepped penthouse) in Korea. In order to examine its possible applications, this study compared this building with other Buddhist funeral articles in forms similar thereto, such as Buddhist pagoda(僧塔), sarira container(舍利器) and Gamnodo(甘露圖) which depicts Byeoknyeon Daeban(碧蓮臺畔; a palanquin carrying malignant spirit). Then, this study estimated its possible applications on the basis of relevant historical literatures. As a result, it was found that this building was used as Wondang(願堂; a sort of Buddhist prayer house) to wish royal family's going to Nirvana after death, and it was not Confucian-style architecture popularized in the era of Joseon dynasty, but Buddhist-style architecture built widely from the era of Koryo dynasty to the early Joseon dynasty.

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발포 폴리스티렌 폼을 이용한 가변적층 쾌속조형공정의 형상 정밀도 개선을 위한 열전달 특성 및 잔여 재료폭 영향에 관한 연구 (Investigation of Thermal Characteristics and Skeleton Size Effects to improve Dimensional Accuracy of Variable Lamination Manufacturing by using EPS Foam)

  • 안동규;이상호;양동열
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.910-913
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    • 2001
  • Rapid Prototyping(RP) techniques have unique characteristics according to their working principle: the stair-stepped surface of a part due to layer-by-layer stacking, low building speed, and additional post-processing to improve surface roughness. A new RP process, Variable Lamination Manufacturing by using expandable polystyrene foam(VLM-S), has been developed to overcome the unfavorable characteristics. The objective of this study is to investigate the thermal characteristics and skeleton size effects as the hotwire cuts EPS foam sheet in order to improve dimensional accuracy of the parts, which is produced by VLM-S. Empirical and analytical approaches are performed to find the relationship between cutting speed and heat input, and the relationship between maximum available cutting speed and heat input. In addition, empirical approaches are carried out to find the relationship between cutting error and skeleton size, and cutting deviation and skeleton size. Based on these results, the optimal hotwire cutting condition and available minimum skeleton size are derived. The outcomes of this study are reflecting in the enhancement of VLM-S input data generation S/W.

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단속형 재료공급식 가변적층 쾌속조형공정 및 장치 개발에 관한 연구 (Investigation into Development of Transfer Type for Variable Lamination Manufacturing Process and Apparatus)

  • 안동규;이상호;최홍석;양동열;박승교
    • 한국정밀공학회지
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    • 제19권2호
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    • pp.95-105
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    • 2002
  • In order to reduce the lead-time and cost, the technology of rapid prototyping (RP) has been widely used. However, RP technologies have disadvantageous characteristics according to their working principle: low building speed, high cost for introduction and maintenance of RP apparatus, stair-stepped surface and additional post processing. A new rapid prototyping process, as a transfer type of Variable Lamination Manufacturing by using expandable polystyrene room (VLM-ST), has been developed to reduce building lime. apparatus cost including the introduction and the maintenance and additional post-processing. The objective of this study is to propose a VLM-ST process and to develop an apparatus for implementation of the process. Design criteria of the apparatus are defined and the techniques arc proposed to satisfy the design criterion. In order to examine the efficiency and applicability of the developed process, various three-dimensional shapes, such as a world-cup logo. a knob shape, an extruded cross, a twisted shape, a character, Son-o-kong. a helical gear shaped and a scissor shape are fabricated on the apparatus in which unit shape layer (USL) was generated to build up each layer.

발포 폴리스티렌 폼을 이용한 가변 적층 쾌속 조형 공정 밀 장치 개발 (Development of Variable Lamination Manufacturing(VLM) Process and Apparatus by Using Expandable Polystyrene Foam)

  • 안동규;이상호;양동열;신보성;박승교;이용일
    • 한국정밀공학회지
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    • 제18권8호
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    • pp.54-63
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    • 2001
  • Rapid Prototyping(RP) techniques have their unique characteristics according to the working principles: stair-stepped surface of a part due to layer-by-layer stacking, low build speed caused by point-by-point or line-by-line solidification to build one layer, and additional posts processing to improve surface roughness, so high cost is required to introduce and to maintain the RP apparatus. The objective of this study is to develop a new RP process, Variable Lamination Manufacturing by using expandable polystyrene foam sheet as part material(VLM-S), and to design an apparatus for implementation of the process. So, the process parameters and design criterions of the apparatus were defined and the techniques were proposed to satisfy the design criterion. Based on the results, a knob-shape, pyramid shape. and a solid block were fabricated on the apparatus in which unit shape part(USP) was generated for building each layer.

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중국군의 해양작전능력과 한국군의 과제 (PRC Maritime Operational Capability and the Task for the ROK Military)

  • 김민석
    • Strategy21
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    • 통권33호
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    • pp.65-112
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    • 2014
  • Recent trends show that the PRC has stepped aside its "army-centered approach" and placed greater emphasis on its Navy and Air Force for a wider range of operations, thereby reducing its ground force and harnessing its economic power and military technology into naval development. A quantitative growth of the PLA Navy itself is no surprise as this is not a recent phenomenon. Now is the time to pay closer attention to the level of PRC naval force's performance and the extent of its warfighting capacity in the maritime domain. It is also worth asking what China can do with its widening naval power foundation. In short, it is time to delve into several possible scenarios I which the PRC poses a real threat. With this in mind, in Section Two the paper seeks to observe the construction progress of PRC's naval power and its future prospects up to the year 2020, and categorize time frame according to its major force improvement trends. By analyzing qualitative improvements made over time, such as the scale of investment and the number of ships compared to increase in displacement (tonnage), this paper attempts to identify salient features in the construction of naval power. Chapter Three sets out performance evaluation on each type of PRC naval ships as well as capabilities of the Navy, Air Force, the Second Artillery (i.e., strategic missile forces) and satellites that could support maritime warfare. Finall, the concluding chapter estimates the PRC's maritime warfighting capability as anticipated in respective conflict scenarios, and considers its impact on the Korean Peninsula and proposes the directions ROK should steer in response. First of all, since the 1980s the PRC navy has undergone transitions as the focus of its military strategic outlook shifted from ground warfare to maritime warfare, and within 30 years of its effort to construct naval power while greatly reducing the size of its ground forces, the PRC has succeeded in building its naval power next to the U.S.'s in the world in terms of number, with acquisition of an aircraft carrier, Chinese-version of the Aegis, submarines and so on. The PRC also enjoys great potentials to qualitatively develop its forces such as indigenous aircraft carriers, next-generation strategic submarines, next-generation destroyers and so forth, which is possible because the PRC has accumulated its independent production capabilities in the process of its 30-year-long efforts. Secondly, one could argue that ROK still has its chances of coping with the PRC in naval power since, despite its continuous efforts, many estimate that the PRC naval force is roughly ten or more years behind that of superpowers such as the U.S., on areas including radar detection capability, EW capability, C4I and data-link systems, doctrines on force employment as well as tactics, and such gap cannot be easily overcome. The most probable scenarios involving the PRC in sea areas surrounding the Korean Peninsula are: first, upon the outbreak of war in the peninsula, the PRC may pursue military intervention through sea, thereby undermining efforts of the ROK-U.S. combined operations; second, ROK-PRC or PRC-Japan conflicts over maritime jurisdiction or ownership over the Senkaku/Diaoyu islands could inflict damage to ROK territorial sovereignty or economic gains. The PRC would likely attempt to resolve the conflict employing blitzkrieg tactics before U.S. forces arrive on the scene, while at the same time delaying and denying access of the incoming U.S. forces. If this proves unattainable, the PRC could take a course of action adopting "long-term attrition warfare," thus weakening its enemy's sustainability. All in all, thiss paper makes three proposals on how the ROK should respond. First, modern warfare as well as the emergent future warfare demonstrates that the center stage of battle is no longer the domestic territory, but rather further away into the sea and space. In this respect, the ROKN should take advantage of the distinct feature of battle space on the peninsula, which is surrounded by the seas, and obtain capabilities to intercept more than 50 percent of the enemy's ballistic missiles, including those of North Korea. In tandem with this capacity, employment of a large scale of UAV/F Carrier for Kill Chain operations should enhance effectiveness. This is because conditions are more favorable to defend from sea, on matters concerning accuracy rates against enemy targets, minimized threat of friendly damage, and cost effectiveness. Second, to maintain readiness for a North Korean crisis where timely deployment of US forces is not possible, the ROKN ought to obtain capabilities to hold the enemy attack at bay while deterring PRC naval intervention. It is also argued that ROKN should strengthen its power so as to protect national interests in the seas surrounding the peninsula without support from the USN, should ROK-PRC or ROK-Japan conflict arise concerning maritime jurisprudence. Third, the ROK should fortify infrastructures for independent construction of naval power and expand its R&D efforts, and for this purpose, the ROK should make the most of the advantages stemming from the ROK-U.S. alliance inducing active support from the United States. The rationale behind this argument is that while it is strategically effective to rely on alliance or jump on the bandwagon, the ultimate goal is always to acquire an independent response capability as much as possible.

디지털 문화에서 TV 방송의 브랜드 아이덴티티 연구 -시사 교양 프로그램의 사례비교 및 개발을 중심으로- (A Study on Brand Identity of TV Programs in the Digital Culture - Focusing on the comparative research of current issue programs, and development -)

  • 정봉금;장동련
    • 디자인학연구
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    • 제18권4호
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    • pp.53-64
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    • 2005
  • 디지털이라는 새로운 커뮤니케이션 미디어의 등장은 경이로운 한편 문화적 긴장이기도 하다. 인간의 능력을 극적으로 확장시켜주는 산업기술들은 우리가 그것에 적응해 가는 속도보다 훨씬 빠르게 세력을 확대하고 곤다. 이것은 예외 없이 인간에 대한 개념 자체를 뒤흔듦으로써 새로운 문화의 내용과 형식을 만들어낸다. 디지털의 영향으로 우리나라 방송환경은 지상파, 케이블, 위성, 인터넷 등으로 다원화됨으로써 다매체, 다채널 시대로 진입되었다. 디지털 문화피서 방송은 정보전달과 커뮤니케이션 매체로서 과거보다 더 큰 영향력을 발휘하게 되었다. 이 같은 방송환경의 변화는 TV 시청자들을 능동적인 커뮤니케이션의 주체자, 참여자, 이용자로서 미디어를 선택하고 이용하는 존재라는 새로운 개념의 수용자로 출현시켰다. 본 연구는 채널선택의 주체로 능동적 수용자가 방송의 중심에 서게 되면서, 방송의 코어 아이덴티티(Core Identity)에 대한 문제제기를 브랜드를 통해 구조화시키고자 한다. 능동적 수용자에 대한 인지심리학적 접근방법으로 이야기 스키마(Schema) 이론을 적용하여 '정보처리과정(information processing)'과 연관되어 있는 '인지적 과정(cognitve processes)'을 설명할 수 있다. 이것은 이야기가 있는 디자인으로서 브랜드의 스토리텔링 사례로 나타난다. 연구범위는 지상파 TV 방송에서 시사 교양 단위 프로그램들을 대상으로 했으며, 기간은 2004년 5월에서 8월에 걸쳐 방송중인 브랜드를 국내외 각 방송사별로 사례 비교하였다. 본 연구를 통해 방송의 채널 아이덴티티가 단위 프로그램의 브랜드 전략에서도 함께 고려되어야 한다 것은 중요하였다. 특히 방송사를 대표하는 프로그램은 별개의 단위 프로그램으로 취급되어서는 안 되며, 채널 아이덴티티를 형성하는 내용과 형식에서 함께 다루어져야 할 것이다. 또한 앵커의 브랜드화 역시 방송의 브랜드 정체성에 중요한 변인이 될 수 있음을 재차 확인할 수 있었다.

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능원(陵園) 정자각(丁字閣)의 첨차초각(檐遮草刻) 변화에 대하여 (A Study on the Change of the Cheomcha-chogak of the Neungwon-Jeongjagak)

  • 전종우
    • 헤리티지:역사와 과학
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    • 제54권1호
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    • pp.280-301
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    • 2021
  • 첨차초각은 부재의 장식을 위한 그림에서부터 비롯된 것으로 여겨진다. 고구려 고분벽화에서 사용된 여러 가지 문양의 그림은 봉정사 극락전에서 보이는 덩굴문양 단청으로 이어진 것으로 보이며 봉정사 극락전의 첨차에서는 단청뿐만 아니라 하단에 연화두식을 새기면서 비로소 첨차초각이 시작되었다. 또한 봉정사 대웅전에서는 초기적인 덩굴초각을 가진 첨차가 만들어졌는데 이것은 부재 표면에 직접 초각을 새기는 것이었다. 이후 덩굴초각은 오랫동안 전통 목조건축에서 중요한 첨차의 장식 기법이 되었다. 정자각은 임란 이후부터 조선 말까지 지속해서 조영된 건축물로서 대부분 덩굴초각을 새긴 첨차를 사용하였기 때문에 여러 세대를 거치면서 변화된 모습을 볼 수 있다. 첨차초각은 처음에는 초각줄기가 주두를 기점으로 올라가는 모양(상향형)으로 시작되다가 종래에는 재주두를 기점으로 그 줄기가 아래로 내려가는 모양(하향형)으로 변하였다. 필자는 이러한 변화에 관심을 가지고 변화과정과 그 원인을 살펴보았는데, 상향형이 하향형으로 변화는 과정 중에는 방향성과 연관이 없는 새로운 초각의 연결 방식이 사용되었음을 알게 되었고 이 기간은 경종의릉과 인조장릉의 정자각이 지어지던 시기로 화반초각에서도 연꽃이 사라지기 직전의 과도기와 일치하는 것이었다. 또한 첨차초각의 방향성이 변한 원인으로는 이익공의 내부에 두 단에 걸쳐 새겨지는 덩굴초각이 주두를 기점으로 상하 양방향으로의 분리가 일어났는데 이는 초익공 내부에 하향형 초각을 새기는 계기가 되었고 변화된 초익공의 덩굴초각은 나아가 첨차초각의 방향에까지 영향을 주었을 것이라고 추론하게 되었다. 이 글은 2018년 투고한 「능원 정자각의 화반초각에 대하여」의 후속된 글로서 정자각에 있는 여러 부재 중 하나인 첨차라는 부재를 중심으로 한 것이기에 나머지 초각들을 완전히 이해하지 못하였다는 한계를 안고 있다는 점을 밝혀 두고자 한다.