• 한국세라믹학회지
• /
• 제14권4호
• /
• pp.242-247
• /
• 1977

By means of coloring of plane nets a number of different tetrahedral frameworks can be derived. With the aid of this method all tetrahedral framework structures which built up of layer structures with 2, 4, 8 tetrahedra per unit cell and 6-membered ring or 4-8-membered ring are given. For the systematic derivation of all possible structures, graph theory may be introduced.

• 한국공간구조학회지
• /
• 제21권2호
• /
• pp.12-17
• /
• 2021

• 유통과학연구
• /
• 제7권1호
• /
• pp.35-53
• /
• 2009

본고는 홈네트워크 시장에 대한 관심이 증대되고 있는 가운데 이미 건축된 주택(기축시장)을 대상으로 영상전화기(비디오폰)의 판매활성화 방안을 찾는데 목적을 두고 있다. 최근 가전, 네트워크장비, 통신서비스업체들은 새로운 시장을 보며 홈 네트워크에 관심을 가지고 있는데 대부분의 홈네트워크 시장은 신축 고급아파트를 중심으로 활성화되고 있다. 신축시장의 경우 최종고객의 선택권이 없기 때문에 건설 회사를 통해 영업.마케팅을 해야 한다. 그래서 신축시장은 개별적인 수요파악이 어려워 판매활성화를 통해 수익을 창출하는데 에는 한계가 있다고 판단하여 기축시장을 대상으로 향후 수요가 서민주택으로까지 확대될 것에 대비해 기능이 단순하고 가격이 저렴한 보급형 비디오폰 시장개척에 더 많은 노력이 요구된다고 할 수 있다. 이러한 이유로 본고에서는 비디오폰의 개념과 시장동향을 분석하고, 유통경로형태와 A/S 처리시스템을 파악하며 기축시장에 적합한 비디오폰 판매활성화 방안을 모색하는데 그 목적이 있다.

• 건축역사연구
• /
• 제15권3호
• /
• pp.99-118
• /
• 2006

We have focused on the building appearance according to the change of conservation policy and urban fabric in Bukchon, Seoul. The Urban Hanok, urban traditional housing type, had been evolved in modern contort from 1920's to 1960's, that is to say, many buildings(Urban Hanok) in Bukchon area has built up with a lot and road at the same time. But the change of conservation policy has an effect on the urban fabric and building(wooden structure, RC and brick building). Thus many types of building in Bukchon has undergone a various change. The purpose of this paper is to define a change factor of Bukchon buildings. Thus we need to pay attention to policy and urban fabric. We reached the result as follows. First, the change of architecture regulations according to the several policies(an aesthetic area, an altitude area for sky line restriction and so on) brought into building deformation and eventually the historic scenery of Bukchon has been spoiled. Second, the change of policy had an effect on the change of roads and lots. Buildings on a widen road and a united lot was built newly. But new buildings built up with a concrete or brick structure was not in harmony with the historic scenery of Bukchon area. Third, a development method of a large lot with lack prudence(disregarded a scale and size of lot) did damage to Urban hanok and urban fabric. With the understanding on the relationship of buildings, a urban fabric and a policy in Bukchon, we can define the identity and correspond with the urgent request for a the conservation of historic urban scenery In addition we can suggest the policy and the design guidelines for the reservation and rehabilitation for Bukchon, Seoul.

• Earthquakes and Structures
• /
• 제9권1호
• /
• pp.195-219
• /
• 2015

A partial (hybrid) seismic isolation scheme for precast girder bridges in the form of a "buffer-gap-elastomeric bearings" system has been endorsed in the literature as an efficient seismic design system. However, no guides exist to detail an optimal gap size for different configurations. A numerical study is established herein for different scenarios according to Euro code seismic requirements in order to develop guidelines for the selection of optimal buffer-gap arrangements for various design cases. Various schemes are hence designed for ductile and limited ductility behavior of the bridge piers for different seismic demand levels. Seven real ground records are selected to perform incremental dynamic analysis of the bridges up to failure. Bridges with typical short and high piers are studied; and different values of initial gaps at piers are also investigated varying from a zero gap (i.e., fully locked) condition up to an initial gap at piers that is three quarters the gap left at abutments. Among the main conclusions is that the as-built initial gaps at piers (and especially large gap sizes that are ${\geq}1/2$ as-built gaps at abutments) do not practically reduce the seismic design demand and do not affect the reserve capacity of the bridge against failure for bridges featuring long piers, especially when these bridges are designed a priori for ductile behavior. To the contrary, the "buffer-gap-elastomeric bearings" system is more effective for the bridge schemes with short piers having a large difference between the stiffness of the bearings and that of their supporting (much stiffer) squat piers, particularly for designs with limited ductility. Such effectiveness is even amplified for the case of larger initial as-built gap sizes at piers.

• 한국지진공학회논문집
• /
• 제10권1호
• /
• pp.25-32
• /
• 2006

본 연구에서는 1994년 미국 노스리지 지진 이전에 건설된 기존 철골 건물의 용접형 철골 박스기둥과 보 접합부의 내진성능을 반복재하 실험에 의해 평가하였다. 실험결과에 의하면 노스리지 지진 이전 접합상세를 갖는 박스기둥과 보 접합부에서도 H-형강 기둥과 보 접합부 실험결과와 유사하게 취성파단이 발생하였다. 하지만, 박스기둥과 보 접합부에서의 플랜지 응력전달 경로가 H-형강 기둥과 보 접합부에서의 것과 상당한 차이가 있고 또한 박스기둥의 형상에 따라 균열 전파의 형태가 다를 수 있다는 것이 밝혀졌다. 따라서 용접형 철골 박스기둥과 보 접합부의 내진성능을 향상시키기 위해서는 H-형강 기둥과 보 접합부에 대한 기존 연구결과를 그대로 적용하기보다는 박스기둥에 적합한 접합부의 보강상세 개발이 요구된다.

• 농업과학연구
• /
• 제38권1호
• /
• pp.153-162
• /
• 2011

This study analyzed the spatio-temporal change detection of land-use and urbanization in Yongin and Anseong regions, Kyunggi Province, using three Landsat-5 TM images for 1990, 1996, and 2000. Remote sensing (RS) and geographic information system (GIS) techniques were used for image classification and result analysis. Six land-use types were classified using supervised maximum likelihood classification. In the two study areas, the land-use changed significantly, especially the decrease of arable land and forest and increase of built-up area. Spatially, the urban expansion of Yongin region showed a spreading trend mainly along the national road and expressways. But in Anseong region the expansion showed 'urban sprawl phenomenon' with irregular shape like starfish. Temporally, the urban expansion showed disparity - the growth rates of urbanized area rose from the period 1990-1996 to 1996-2000 in both study areas. The increased built-up areas were converted mainly from paddy, dry vegetation, and forest.

• 한국생산제조학회지
• /
• 제8권5호
• /
• pp.102-107
• /
• 1999

In this paper hardened SCM440 material and annealed SCM440 material are for cutting experiments by the cutting con-dition which is chosen respectively by tool three components of cutting force are recorded using multicorder, Then the surface roughness for various force are measured by Roughness Tester. The results of the experiment are summarized as follow. The hardened material cut by ceramic tool(BX20) gives the highest radial component values among the cutting resistance radial components is increased higher for the higher cutting speed even though vertical component and axial component tend to decrease. But when the annealed material was cut increase in cutting speed results in the increase of three component forces. Since ceramic insert tip used the experiment hardly affect Built-up Edge and heat the cutting resistance decrease slightly regardless of the increased of cutting speed. The hardened material has higher three compo-nent force value than the annealed material because the material of high hardness is increased cutting resistance. The low-est cutting forces for hardened material and annealed material are shown in the cutting speed of 60m/min and 180m/min. respectively.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2007년도 추계학술대회논문집
• /
• pp.221-225
• /
• 2007

Recently, on account of stress relief and settlement of a healthy drinking culture, many people are visiting a song practice room. In case of such song practice room, since the mechanical voice through a loud accompaniment-music and microphone is on using, there has made a very loud noise, and it influences a lot to the adjacent other space and song practice room booth. Consequently, from the designing stage an efficient measures for soundproof and sound-insulation should be arranged. However, as most of the song practice room wall-bodies that already built up or under construction step were constructed merely with consideration on an interior-wise factor only, it is suffering at the soundproof and sound-insulation. Reflecting such viewpoint, this Study has measured Sound Transmission Loss on the subject for the song practice room wall-body recently built up, and based on the actually measured data, by practice of comparison?analysis on it using various evaluation methods, would intends to present a fundamental material for establishment an efficient sound-insulation measure.

• 한국안전학회지
• /
• 제27권5호
• /
• pp.1-8
• /
• 2012

The purpose of this study were to evaluate the dynamic characteristics of the portable slipmeters with respect to actual slipping and to compare their output with those of force platform. The selected slipmeters were commonly used devices for slipperiness measurement in situ floors. Their output quantity represented force (BOT-3000), loss of energy(British pendulum striker) and angle of inclination(English XL). The validity of these devices was studied with respect to actual slipping using a force platform. The precision of these devices was also evaluated with force platform. Based on dynamics of human subject behavior when slipping during normal walking, the all devices tested in this study showed poor performances: low built up ratio, low normal pressure, and long contact time prior to slip. Nevertheless, their results reasonably correlated with those calculated from the ground reaction forces generated by the operation of the selected slipmeters on the force platform although the absolute values of COF from these three devices could be quite different. Also the results showed good repeatability under the some test conditions.