• 한국지반공학회논문집
• /
• 제37권11호
• /
• pp.37-49
• /
• 2021

마이크로파일은 기초의 지지력 증대와 침하량 저감을 위해 건설분야에서 널리 활용되는 기초이다. 본 기초는 낮은 건설비용, 단순한 시공 프로세스와 비교적 작은 장비로 시공이 가능하다는 장점이 있다. 최근 지지력을 효과적으로 증대시킬 수 있는 선단확장형 마이크로파일이 개발되었다. 본 기초는 수직하중이 재하될 때 마이크로파일 선단부에 설치된 지압구가 팽창하여 주변지반에 작용하는 수평토압을 증가시키며, 이로 인해 기초의 지지력이 향상된다. 하지만, 현재까지 지압구 확장 메커니즘과 지지력 증대효과가 실험적으로 명확히 검증되지 않았다. 따라서, 본 연구에서는 지압구의 설치효과를 검증하기 위해 원심모형실험이 수행되었다. 이를 위해, 모래지반과 풍화암으로 구성된 지반을 각각 조성하고, 실제 선단확장형 마이크로파일에 대한 하중재하실험을 수행하였으며, 기초에 수직하중이 작용할 때 지압구 주변에 설치된 토압계를 통해 지압구의 팽창거동을 관찰하였다. 실험 결과, 30kN의 하중이 기초에 작용할 때 모래지반에서는 수직토압대비 수평토압의 증가량(∆σ_h/∆σ_𝜈)이 0.4 - 0.58의 범위를 보였으며, 풍화암지반에서는 ∆σ_h/∆σ_𝜈 = 0.19로 확인되었다. 본 결과를 통해 지압구 확장에 따른 수평토압 증가가 실험적으로 확인되었으며, 이로 인해 마이크로파일의 지지력이 증가될 것으로 판단된다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
• /
• pp.88-90
• /
• 2003

We reported an AC PDP structure with grooved front panel dielectric layer. The structure exhibits low breakdown voltage, better luminance, and better endurance to crosstalk in high Xe contents. It also shows less luminous efficacy then conventional structure because of the thinner dielectric layer, but we can apply the higher Xe contents to the grooved dielectric structure, which results in the higher luminous efficacy. We made experiments with the Xe contents from 4 to16% and total gas pressure from 400 to 600Torr. The grooved dielectric structure shows the improvement of 20% luminous efficacy and 17% luminance. The firing voltages lower about 40V at 600Torr and Xe 12, 16%. The discharge characteristics of grooved dielectric structure are verified also with 2D simulation.

• 동굴
• /
• 제79호
• /
• pp.53-63
• /
• 2007

While cave being active it will can occur and to be big the preparation against a small accident steadily and only objection the bay it knows to draw up the scenario of virtuality against the actual structure which leads a rescue work practice must practice. It systematizes a cave structure commission wheat cave structure association from the world-wide each nation and it does a cave relief activity. To found the cave structure center even in Korea and executing the improvement of structure setup and equipment and simultaneously, it is prevention of accident and accident occurrence right time and appropriate and to dispose and it is important to go out. The cave structure center must establish and inside Korean cave academic society it must maintain it must be strengthened feed with the fact that it becomes the relationship with academic society and the other cave structure specific authorization and a public relation.

• 한국조경학회지
• /
• 제40권5호
• /
• pp.148-159
• /
• 2012

본 연구의 목적은 서울시 솔밭근린공원 소나무림을 대상으로 울타리 설치, 관목 및 초본식물 식재 등의 답압 피해 개선사업의 효과를 검증하는 것이다. 2005년과 2010년 현장조사를 통해 소나무 식재유형, 식재구조, 토양경도, 토양단면구조, 토양 이화학적 특성 등의 변화 상태를 분석하였다. 또한 소나무의 가지생장량과 직경생장량을 측정하여 개선사업전과 후 상태를 비교 분석하여 답압 피해지역 개선사업에 따른 효과를 고찰하였다. 식재유형 변화에서는 하층 식생이 없는 소나무림이 2005년 48.5%에서 2010년에는 6.8%로 감소하였으며, 관목 및 초본이 식재된 소나무림이 7.4%에서 46.8%로 크게 증가하였다. 식재구조 변화에서는 대부분 조사구가 하층식생이 거의 없는 소나무림에서 진달래, 철쭉꽃, 원추리, 돌단풍, 옥잠화 등 관목 및 초본식생이 넓게 피복된 소나무림으로 변화되었다. 2005년 솔밭근린공원의 토양경도는 평균 $54.8kg/cm^2$로 딱딱한 토양층이었다. 2010년 솔밭근린공원 개선사업 후 토양경도는 대부분 $4kg/cm^2$ 미만으로 식물생육에 영향이 없는 양호한 상태였다. 2005년에 토양단면구조는 답압 영향으로 인해 낙엽층이 소실되어 있었으며, 유기물층이 1.0cm로 식물이 생육하는데 적합하지 않았다. 개선사업 후 2010년에는 답압에 대한 피해가 줄어서 낙엽층이 3.0cm까지 새롭게 형성되었고, 지속적인 시비에 따라 유기물층의 깊이도 1.5~8.0cm로 증가하였다. 2005년 토양 이화학적 특성에서는 pH 5.76~6.70, 유기물 함량 7.15~10.55%, 유효인산 9.38~26.47mg/kg으로 소나무 생육 토양환경조건으로 큰 문제가 없었다. 또한 소나무 15주를 선정하여 가지생장량을 분석한 결과, 개선사업 이후 가지생장량이 점차 증가하는 경향이었다. 토양경도 등급에 따라 소나무 70주를 선정하여 직경생장량을 측정한 결과, 대부분 조사구에서 소나무가 개선사업 이후 생육이 양호해지는 것을 확인할 수 있었다. 본 연구결과를 통해 울타리 설치, 관목 및 초본식물 식재 등의 답압 피해 개선사업이 소나무 생장을 향상시키는 효과를 검증할 수 있었다.

• 한국안전학회지
• /
• 제35권1호
• /
• pp.53-61
• /
• 2020

This study proposes a new damper configuration for seismic performance improvement of heavy sliding facilities inside a building. For this purpose, we deal with two connection types of control system, and the parametric study has been performed to investigate their comparative seismic performances according to the variations of the control capacity. In order to simulate the seismic responses of the proposed system, we employed a recently-developed seismic response analysis method that can deal with the two-mass system with nonlinear frictional sliding behavior. The numerical results demonstrate that the typical method of diagonal bracing damper connection can exhibit effective control performance both on structure and the heavy sliding facilities, whereas the structure-facilities connection method does not show any control effect on both responses. On the other hand, the typical method has some limitations that it can adversely cause excessive sliding of the facilities, depending upon the frequency characteristics of structure and earthquake. On the contrary, the structure-facilities connection method is very effective in reducing the sliding displacement of the heavy facilities, even with small amount of control capacity. Thus, the following potential expectations can be inferred from these results: The typical diagonal bracing damper connection method will have some promising benefits in controlling the sliding facilities inside the building as well as the building itself, and the structure-facilities connection method can be a cost-effective way of protecting the internal heavy important facilities inside the structure already designed with sufficient seismic performance.

• 한국건축시공학회지
• /
• 제14권1호
• /
• pp.76-86
• /
• 2014

The cause of crack on reinforced concrete structures is varied, while the studies, which have intended to analyze this in the material side, have been the mainstream so far. Therefore, in this study, we intended to suggest the proposals for enhancement of the system to reduce crack and to improve the quality of the reinforced concrete structures, by reviewing the cause of crack mainly in the structural aspect and analyzing the practices and the system. The result has been shown as following. (1) As one of the measures for improving the constructional system related to the structure, it is to enhance the relevant system so that design on construction, structure, and equipment, can be separately ordered or jointly ventured, and the owner or the agent of the owner can discuss and mediate the business in each specialized field. (2) Importance on construction supervision and new establishment of regulations related to structure supervision.

• 산업경영시스템학회지
• /
• 제29권3호
• /
• pp.33-42
• /
• 2006

From middle of 90's, SCM had emphasized the importance of connection of all companies which participate to a market, and outsourcing has emphasizes the slim structure of companies for pursing cost reduction and service improvement. But outsourcing as '2-1=1' and integration as '1+1=2' not adapt to the advanced market but return to the former state. Besides, it is impossible of subcontractors and logistics companies to execute these strategies which are win-win strategy and outsourcing. So many logistics companies have sharp competition in price recently. Therefore logistics companies have increased the need for a profitable business model and strategy. This paper researches the limitations of logistics market and redefines the role of logistics through the evolution of logistics. Also this paper proposes new role(Logister) and structure(Velcro structure) for not maker-oriented logistics but market-oriented logistics. The introductory case study will help to understand 2 terms(logister and velcro structure).

• Structural Monitoring and Maintenance
• /
• 제4권4호
• /
• pp.351-364
• /
• 2017

In this study effects of various parameters like a number of bays, the stiffness of the structure along with the height of the structure was examined. The fundamental period of vibration T of the building is an important parameter for evaluation of seismic base shear. Empirical equations which are given in the Indian seismic code for the calculation of the fundamental period of a framed structure, primarily as a function of height, and do not consider the effect of number of bays and stiffness of the structure. Building periods predicted by these expressions are widely used in practice, although it has been observed that there is scope for further improvement in these equations since the height alone is inadequate to explain the period variability. The aim of this study is to find the effects of a number of bays in both the directions, the stiffness of the structure and propose a new period equation which incorporates a number of bays, plan area, stiffness along with the height of the structure.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1996년도 춘계학술대회 논문집
• /
• pp.239-243
• /
• 1996

In this paper, we have tried to focus on the optimum conditions of crystal structure parameters on YBCO high Tc oxide-superconductor as an excel lent electronic parts. When we verify the characteristic improvement of superconductance and accurate reproduction and so forth, we have made use of RIETAN. We have varied the lattice constant with oxygen content from 6.0 to 7.0 as for transition of orthogonal structure and tetragonal structure for the superconductor. As the result of above, we have preyed that transition from orthogonal structure to tetragonal structure is made at the point of 6.6(oxygen content) by using the simulation.

• 한국가시화정보학회지
• /
• 제17권2호
• /
• pp.17-24
• /
• 2019

The purpose of this study is to study the fluid-dynamic and structural characteristics of the conventional greenhouse and to find possible improvement on the current greenhouse. The greenhouse is required to have enough rigidity of the structure while the installation and reinforcement should be as easy as possible. In this study, the structural stability to the snow load was tested through the computational structure analysis based on the building structure standard, and the wind load was computed by computational fluid-structure interaction analysis. The current analysis can be used as a reference data for a new greenhouse and it will be economically viable by reducing installation and maintenance costs.