• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2008년도 추계 학술발표회
• /
• pp.691-699
• /
• 2008

In the design of a foundation, settlement of the foundation may exceed allowable design criteria even with a competent bearing stratum. In such a case, a piled-raft foundation system may be adopted using piles as settlement reducing component. In this paper, Disconnected Piled Raft Foundation (DPRF) system, which installs disconnected piles underneath the raft and uses the piles as ground reinforcements, is studied as a cost effective design method against the classical piled-raft foundation system. To this end, large size loading tests were carried out on weathered ground changing area replacement ratio and length of piles. The results indicated that the settlement of the reinforced ground was reduced by 34~87% and the allowable bearing pressure increased by 70% on average from those of the unreinforced original ground, respectively. The correlating formula between the area replacement ratio and the load bearing ratio of piles were derived from the test results and numerical analysis. From the correlation, a design method determining the size and the quantity of the disconnected piles to enhance the bearing capacity of original ground to the desired value was proposed based on one inch settlement criteria.

• 한국유기농업학회지
• /
• 제31권4호
• /
• pp.259-289
• /
• 2023

This study analyzed farmers' and experts' perceptions of the Agricultural Income Survey (AIS) conducted by the Rural Development Administration and estimated its socioeconomic value. The research surveyed 104 farmers in Gyeongsangbuk-do and Jeollanam-do. To estimate the AIS's socioeconomic value, this study examined public information projects in the field of agriculture and public information, proposing an estimation methodology based on prior research. The socioeconomic value of the AIS was calculated in three stages (information generation, collection and analysis, and utilization) using the replacement cost and contingent valuation methods. In 2020, the estimated socioeconomic value of the AIS ranged from a minimum of KRW 631.2 billion to a maximum of KRW 799.1 billion per year. To improve the socioeconomic value of the AIS, it is important to booster awareness, expand sample sizes for more reliable data, increase manpower and budget, refine survey questions, and enhance analyzing capabilities. And it's crucial to foster cooperation with surveyed farms, promote collaboration among investigative agencies, improve investigator skills, and strengthen management capabilities to facilitate information dissemination.

• Advances in concrete construction
• /
• 제11권4호
• /
• pp.285-298
• /
• 2021

This study focused on experimental evaluation of mechanical properties of pervious concrete mixtures with the aim of achieving higher values of strength while considering the associated costs. The effectiveness of key parameters, including cement content, water to cement ratio (W/C), aggregate to cement ratio (A/C), and sand replacement was statistically analyzed using paired-samples t-test, Taguchi method and one-way ANOVA. Taguchi analysis determined that in general, the role of W/C was more significant in increasing strength, both compressive and flexural, than cement content and A/C. It was found that increase in replacing percent of coarse aggregate with sand could undermine specimens to percolate water, though one-way ANOVA analysis determined statistically significant increases in values of strength of mixtures. Cost analysis revealed that higher strengths did not necessarily correspond to higher costs; in addition, increasing the cement content was not an appropriate scenario to optimize both strength and cost. In order to obtain the optimal values, response surface method (RSM) was carried out. RSM optimization helped to find out that W/C of 0.40, A/C of 4.0, cement content of about 330 kg/m3 and replacing about 12% of coarse aggregate with sand could result in the best values for strength and cost while maintaining adequate permeability.

• 대한가정학회지
• /
• 제28권2호
• /
• pp.73-89
• /
• 1990

The aim of the present study is to estimates the economic value of household work done by fulltime home makers, using alternative methods of valuation household work in Pusan Korea. Eight findings, five different methods -Self Estimation by Home Makers, Reservation Wage, Opportunity Cost, Individual function Cost, Replacement Cost(Visiting Housekeeper, Housekeeper, General Managemet, Housekeeper & General Management)- are tried for the estimation of economic value of household work. The results of this study can be outlined as follows : 1) The economic value of household work varies substantially by the methods of estimating. The averages are : 2) The economic value of household work varies with the level of education, ages, the number of children, the stage of FLC in all method of estimation, and the level of income in self estimation by home makers, Reservation wage. Specially, FLC revealed good explanation variable in method of estimation as input household work time. 3) The gap between two-day survey and three-day survey in household work time questionaire didn't so much.

• 대한기계학회논문집B
• /
• 제39권1호
• /
• pp.71-78
• /
• 2015

본 논문에서는 복합발전시스템을 구성하는 각 단위 구성품의 교체비용이 변화할 때 각 단위 구성품의 용량 및 전체시스템의 경제성이 얼마나 변화하는지를 나타내는 민감도 분석을 수행하는 방법을 제시한다. 민감도 분석에는 복합발전시스템 경제 분석용 툴인 HOMER를 이용한다. 민감도 분석을 통해 교체비용 변화에 대해 민감도가 높은 구성품의 비중이 최소화 되게 설계하거나 예상되는 가격변동을 사전에 고려함으로써 복합발전시스템의 경제성을 최적화할 수 있으며, 민감도가 높은 구성품의 비중을 낮추기 위한 다른 조합의 복합 발전시스템 구성에 대한 정보도 제공할 수 있다. 민감도 분석의 예로서 주택용 부하 모델에 대해 HOMER에서 제공되는 일반적인 데이터를 사용하여 각 구성품 교체비용에 대한 용량 및 경제성 민감도를 정량적으로 분석하였다.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2004년도 춘계학술발표회
• /
• pp.525-532
• /
• 2004

Among soft ground treatment methods with granular soil used in domestic, the sand compaction pile method has been utilized greatly, but, as a result of exhaustion of sand and increase of unit cost, a necessity of an alternative method is suggested. In this study, the static load tests for crushed-stone compaction piles which were constructed on test field were performed. Based on test results, stress concentration ratios between the crushed-stone compaction pile and the soft ground were investigated and estimated. The stress concentration ratio was the range of 1.7 to 3.0 and the higher it was the more replacement rate was increased.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2015년도 춘계학술발표대회
• /
• pp.143-146
• /
• 2015

Software Defined Network (SDN) separates control plane and data plane to achieve benefits such as centralized management, centralized provisioning, lower device cost and more flexibility. In SDN, scalability is an important issue. Centralized controller can be a bottle neck and many research tried to solve this issue on the control plan. However, scalability issue does not only happen in the control plane, but also happen in the data plane. In the data plane, flow table is an important component and its size is limited. In a large network operated by SDN technology, the performance of the network can be highly degraded because of the size limitation of a flow table. In this paper, we propose a ranking-based flow replacement method, Flow Table Management (FTM), to overcome this problem.

• 한국건설관리학회논문집
• /
• 제11권6호
• /
• pp.35-44
• /
• 2010

효율적인 교량의 유지관리를 위해서는 우선순위를 고려한 유지보수비용 예측과 전략적인 예산배분이 가능한 자산관리시스템의 구축이 필요하다. 본 연구는 이를 돕기 위한 교량의 자산가치 평가방법 연구를 통해 국내 실정에 적합한 실효성 있는 자산가치 평가방법의 제안을 주목적으로 하였다. 우선 국내외 교량시설물의 자산가치 평가 적용사례를 조사하여 그 장단점을 파악하고 국내 실정에 적합한 교량자산가치 평가 방법을 고찰하였다. 이를 바탕으로 취득원가에 의한 자산가치 평가방법과 대체원가를 활용한 가치평가 방법을 제안하고 교량의 가치평가를 위한 모델을 정립하였다. 또한 제안된 두 가지 자산가치 평가방법을 활용하여 국내에서 공용중인 교량의 가치평가를 수행하였다. 회계적 목적의 자산가치 평가 지원을 위해서는 초기건설비용에 근거한 취득원가를 고려한 자산가치 평가방법이 바람직한 것으로 분석되었으며, 유지관리 의사결정의 목적을 위해서는 보다 다양한 의사결정 인자의 고려가 가능한 감가상각 후 대체원가방법을 활용하는 것이 적합한 것으로 분석되었다.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
• /
• pp.472-485
• /
• 2008

In this study, sand compaction pile method was adopted to improve the soft ground under the permanent dyke, namely west sea dyke of Incheon New Port. The row replacement ratio 30% was applied to consider the ground condition, environmental side and the construction cost of the site. The stability and displacement analysis was carried out by respectively SLOPE/W and PLAXIS 2D program. Based on this analysis, it is found that the safety factor and displacement is within an allowable criteria. The model experiment was carried out using the acryl soil box with $400(H){\times}1200(L){\times}250(W)mm$ to show the displacement of the dyke and behavior of soft ground. Based on this experiment results, it is found that the settlement does not occur from 1 and 2 loading phases and horizontal displacement of 0.0075% occurs from 2 phases. It is also found that the differential settlement occurs 0.05mm corresponding respectively 0.02% and 0.03% of the dyke height(15cm).

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2005년도 춘계 학술발표회 논문집
• /
• pp.705-712
• /
• 2005

Among soft ground treatment methods with granular soil used in domestic, the sand compaction pile method has been utilized greatly, but, as a result of exhaustion of sand and increase of unit cost, a necessity of an alternative method is suggested. In this study, the static load tests for group crushed-stone compaction piles which were constructed at in-situ site were performed. Pile diameter was 700mm and area of loading plates were changed. The static load tests of single and group piles were performed for area replacement ratio of 20, 30 and 40%. Based on test results, bearing capacity of group crushed-stone compaction pile were estimated. The more both single pile and group pile increase, the more yield bearing capacity tended to increase. Also, the yield bearing capacity of a group pile is about 50% less than the yield bearing capacity of a single pile. If the ground reinforced with the crushed-stone compaction pile is replacement ratio of $20{\sim}40%$, RIYB of both single pile and group pile increases qualitative tendency of linear more than original ground