• Journal of Biosystems Engineering
• /
• 제30권3호
• /
• pp.141-146
• /
• 2005

Worldwide consumption of vegetable soybean has been increasing recently, but, in the process of vegetable soybean production threshing and seperation work accounts for about $80\%$ of overall labor. Therefore, developing of the vegetable soybean thresher is necessary to reduce the cost of labor. The main objective of this study is to develop the vegetable soybean thresher which is suitable for domestic circumstances. The threshing and separating performance, operating cost, and field capacity of developed vegetable soybean thresher are investigated and analysed. The results are as follows. The effective field capacity of the developed vegetable soybean thresher was shown as 4.8hr/10a, and reduced as much as 11.7 times compared with human labor. The ratio of unthreshed soybean-pod to stem after threshing work was shown as $1.5\%$ and the damaged pod ratio of detached soybean was shown as $1.8\%$. The cost of human labor was shown as 2,560,000 won/ha, but the operating of the developed vegetable soybean thresher was shown as 503,000won/ha. If the vegetable soybean thresher would be used in our farm, the minimum cultivation area appeard to be 22.7a for the cost effective management.

• 태양에너지
• /
• 제18권3호
• /
• pp.147-151
• /
• 1998

Several PV-diesel hybrid systems were built in isolated islands in Korea, where they are far from the inland to be supplied the electric power to a utility level from it. A lot of efforts has been concentrated to find a cost-effective electric supply system with higher reliability and minimum maintenance when compared with a diesel generator. For this purpose, an autonomous PV-diesel hybrid system with multi-channel remote monitoring system was investigated to supply electric power under minimum operating cost and maintenance in a small isolated island. In this report, the economic analysis was performed for comparison with photovoltaic system and diesel generator by computer simulation. And it was proven that a PV system is more cost-effective than an internal combustion engine for the remote island with less than 150 households. Especially, in the case of islands with less than 50 households, the initial construction cost of the PV system is comparable to and its operating cost is about 70% less than the diesel generator.

• Journal of Information Processing Systems
• /
• 제10권4호
• /
• pp.628-645
• /
• 2014

In past few years, distributed hash table (DHT)-based P2P systems have been proven to be a promising way to manage decentralized index information and provide efficient lookup services. However, the skewness of users' preferences regarding keywords contained in a multi-keyword query causes a query load imbalance that combines both routing and response load. This imbalance means long file retrieval latency that negatively influences the overall system performance. Although index replication has a great potential for alleviating this problem, existing schemes did not explicitly address it or incurred high cost. To overcome this issue, we propose, in this paper, an integrated solution that consists of three replication schemes to alleviate query load imbalance while minimizing the cost. The first scheme is an active index replication that is used in order to decrease routing load in the system and to distribute response load of an index among peers that store replicas of the index. The second scheme is a proactive pointer replication that places location information of each index to a predetermined number of peers for reducing maintenance cost between the index and its replicas. The third scheme is a passive index replication that guarantees the maximum query load of peers. The result of simulations indicates that the proposed schemes can help alleviate the query load imbalance of peers. Moreover, it was found by comparison that our schemes are more cost-effective on placing replicas than PCache and EAD.

• Structural Monitoring and Maintenance
• /
• 제9권4호
• /
• pp.359-371
• /
• 2022

Bridges are critical to the civil engineering infrastructure network as they facilitate movement of people, the transportation of goods and services. Given the aging of bridge infrastructure, federal officials mandate visual inspections biennially to identify necessary repair actions which are time, cost, and labor-intensive. Additionally, the expansion joints of bridges are rarely monitored due to cost. However, expansion joints are critical as they absorb movement from thermal effects, loadings strains, impact, abutment settlement, and vehicle motion movement. Thus, the need to monitor bridge expansion joints efficiently, at a low cost, and wirelessly is desired. This paper addresses bridge joint monitoring needs to develop a cost-effective, real-time wireless system that can be validated in a full-scale bridge structure. To this end, a wireless expansion joint monitoring was developed using commercial-off-the-shelf (COTS) sensors. An in-service bridge was selected as a testbed to validate the performance of the developed system compared with traditional displacement sensor, LVDT, temperature and humidity sensors. The short-term monitoring campaign with the wireless sensor system with the internet protocol version 6 over the time slotted channel hopping mode of IEEE 802.15.4e (6TiSCH) network showed reliable results, providing high potential of the developed system for effective joint monitoring at a low cost.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2021년도 학술발표회
• /
• pp.145-145
• /
• 2021

Water distribution networks (WDNs) are designed to satisfy water requirement of an urban community. One of the central issues in human history is providing sufficient quality and quantity of water through WDNs. A WDN consists of a great number of pipelines with different ages, lengths, materials, and sizes in varying degrees of deterioration. The available annual budget for rehabilitation of these infrastructures only covers part of the network; thus it is important to manage the limited budget in the most cost-effective manner. In this study, a novel pipe replacement scheduling approach is proposed in order to smooth the annual investment time series based on a life cycle cost assessment. The proposed approach is applied to a real WDN currently operating in South Korea. The proposed scheduling plan considers both the annual budget limitation and the optimum investment on pipes' useful life. A non-dominated sorting genetic algorithm is used to solve a multi-objective optimization problem. Three decision-making objectives, including the minimum imposed LCC of the network, the minimum standard deviation of annual cost, and the minimum average age of the network, are considered to find optimal pipe replacement planning over long-term time period. The results indicate that the proposed scheduling structure provides efficient and cost-effective rehabilitation management of water network with consistent annual budget.

• Nuclear Engineering and Technology
• /
• 제56권2호
• /
• pp.644-654
• /
• 2024

After the Tohoku earthquake and tsunami (Japan, 2011), regulatory efforts to mitigate external hazards have increased both the safety requirements and the total capital cost of nuclear power plants (NPPs). In these circumstances, identifying not only disaster robustness but also cost-effective capacity setting of NPPs has become one of the most important tasks for the nuclear power industry. A few studies have been performed to relocate the seismic capacity of NPPs, yet the effects of multiple hazards have not been accounted for in NPP capacity optimization. The major challenges in extending this problem to the multihazard dimension are (1) the high computational costs for both multihazard risk quantification and system-level optimization and (2) the lack of capital cost databases of NPPs. To resolve these issues, this paper proposes an effective method that identifies the optimal multihazard capacity of NPPs using a multi-objective genetic algorithm and the two-stage direct quantification of fault trees using Monte Carlo simulation method, called the two-stage DQFM. Also, a capacity-based indirect capital cost measure is proposed. Such a proposed method enables NPP to achieve safety and cost-effectiveness against multi-hazard simultaneously within the computationally efficient platform. The proposed multihazard capacity optimization framework is demonstrated and tested with an earthquake-tsunami example.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2012년도 추계 학술논문 발표대회
• /
• pp.111-112
• /
• 2012

Korean government is planning to supply a half million public and permanent rental houses from 2013 to 2018 for settlement of non-homeowners. It is requested an objective criterion to appropriate the budget for the rental houses construction project cost. In this study, construction cost indices, which reflect the inflation trend of construction resources, were explorated to suggest a effective methodology for the construction cost estimation of therental houses. We figured out the future construction cost indices using several scientific methods, and seven estimated indices values were shown. It is required an additional research to select the proper value among the analyzed indices.

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 2001년도 춘계학술대회
• /
• pp.39-43
• /
• 2001

The existent system of management for Measurement of Safety Cost are not effective because of the data loss and time loss and occurrence of errors through manual calculation. Therefore, tile development of the software for measurement of safety cost can solve the problem through the systematic calculation for safety cost and converting the related data to database, and also can build the strategy of the investment of Safety cost through analysing and comparing with the past data in the database. As a part of development of the software of Measurement of Safety Cost which is appropriate for the domestic environment, this study is developing a software based on Noguji method, which is one of the methods of Measurement of Safety Cost, and to appraise the efficiency of the management of Measurement of Safety Cost we will implement and improve the software in the case of the domestic enterprises.

• 대한안전경영과학회지
• /
• 제3권1호
• /
• pp.1-10
• /
• 2001

The existent system of management for Measurement of Safety Cost are not effective because of the data loss and time loss and occurrence of errors through manual calculation. Therefore, the development of the software for measurement of safety cost can solve the problem through the systematic calculation for safety cost and converting the related data to database, and also can build the strategy of the investment of Safety cost through analysing and comparing with the past data in the database. As a part of development of the software of Measurement of Safety Cost which is appropriate for the domestic environment, this study is developing a software based on Noguji method, which is one of the methods of Measurement of Safety Cost, and to appraise the efficiency of the management of Measurement of Safety Cost we will implement and improve the software in the case of the domestic enterprises.

• 교육녹색환경연구
• /
• 제11권3호
• /
• pp.46-54
• /
• 2012

The accuracy of cost estimation at an early stage in school building project is one of the critical factors for successful completion. So various of techniques are developed to predict the construction cost accurately and expeditely. Among the techniques, Support Vector Machine(SVM) has an excellent ability for generalization performance. Therefore, the purpose of this study is to construct the prediction model for construction cost of educational building project using support vector machine technique. And to verify the accuracy of prediction model for construction cost. The performance data used in this study are 217 school building project cost which have been completed from 2004 to 2007 in Gyeonggi-Do, Korea. The result shows that average error rate was 7.48% for SVM prediction model. So using SVM model on predicting construction cost of educational building project will be a considerably effective way at the early project stage.