• Journal of Biosystems Engineering
• /
• v.38 no.3
• /
• pp.180-184
• /
• 2013

Purpose: This study explored the factors influencing heating value in the process of torrefaction of water hyacinth. Methods: Torrefaction was applied with three temperature settings (200, 300, $400^{\circ}C$) and three time settings (1, 2, 3 h) using small electric heaters (11.3L of holding volume). This study investigated the heating values with the washing process and process factors influenced the torrefaction. In addition, this study compared the heating values in washed and unwashed samples and suggested the optimal conditions for increasing heating value. Results: Torrefaction increased the heating value by 8.18 ~ 30.04%. Comparing heating values of each condition, the optimal temperature for torrefaction was $300^{\circ}C$ and holding time was 1 hour. The washing process increased the heating value by 19 ~ 27%. The heating value of the sample treated at $300^{\circ}C$ for three hours was 4310.80 kcal/kg, which was greater than the first class wood pellet of 4300 kcal/kg. Conclusions: This study proved that the torrefaction and washing process increased the heating value of water hyacinth. Therefore, water hyacinth is expected to be an eco-friendly biomass which substitutes for wood pellet.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2006.11a
• /
• pp.21-24
• /
• 2006

This study investigates field application of flowing concrete in order to improve workability, duality and economic evaluation of concrete. Test results showed that slump of fresh concrete satisfied the target value before and after flowing concrete, and setting time indicated 3 hours difference depending on the mixture proportion of ready-mixed-concrete company. As for the hardened concrete, compressive strength of standard curing specimens, both control and flowing concrete, presented designed value at 28 days elapse. However, the specimens curing at atmosphere decreased the value, due to the lower curing temperature, but also performed the designed value at 91 days. For the evaluation of construction fee by value engineering(V.E) concept, a flowing method declined 4.89% of concrete construction fee, which is 4.9% reduction for materials and 25% reduction for labor expenses, compared with previous construction methods.

• Advances in concrete construction
• /
• v.14 no.3
• /
• pp.215-225
• /
• 2022

Thermal comfort and energy conservation are critical issues in the building sector. Energy consumption in the building sector should be reduced whilst enhancing the thermal comfort of occupants. Concrete is the most widely used construction material in buildings. Its thermal conductivity (k-value) has a direct effect on thermal comfort perception. This study aims to find the optimum value of replacing the normal aggregate with lightweight expanded clay aggregate (LECA) under high strengths and low thermal conductivity, density and water absorption. The k-value of the LECA concrete and its physical and mechanical properties have varying correlations. Results indicate that the oven-dry density, compressive strength, splitting tensile strength and k-value of concrete decrease when normal coarse aggregates are replaced with LECA. However, water absorption (initial and final) increases. Thermal conductivity and the physical and mechanical properties have a strong correlation. The statistical optimisation of the experimental data shows that the 39% replacement of normal coarse aggregate by LECA is the optimum value for maximising the compressive and splitting tensile strengths whilst maintaining the k-value, density and water absorption at a minimum.

• Journal of the Korean Institute of Rural Architecture
• /
• v.8 no.1
• /
• pp.17-24
• /
• 2006

The purpose of this study is to provide the systematic report and analysis about Apartment VE application in Design Phase. In this study, the method of VE application is classified into foure groups-changing materials, changing a method of construction, acceptance of new technology, and use of new device. The facts found in this study can be summarized as follows. Application rate of VE is highest in building circumference parts. The main reason would be that there are many applicable factors according to locations, types of work, etc. Parking lots also show similar results with the same reason. It means there are a lot of possibility to adapt value engineering in these steps during the work. So far application of value engineering has been so limited that just small changes of process or method have been tried. One reason is the lack of challenging and the other is some characteristics of construction work which is very difficult to fix after completion. In the future, it would be more efficient to apply new technology and new device in construction work. Though these attempts have been ignored in Korea so far, there are still lots of possibilities to be developed in value engineering.

• Journal of Construction Engineering and Project Management
• /
• v.2 no.4
• /
• pp.42-45
• /
• 2012

In construction industry, the term 'procurement' is considered as a project based job where clients and contractors are always keen to observe performance indicators. These indicators represent financial and non-financial efficiency of project activities. Among these, the monitoring of financial indicators such as cost monitoring is an ongoing process and its importance cannot be undermined during the project life cycle. It can be monitored by using traditional approach of direct reporting of actual cost against budget. However, the comparison of budget versus actual spending does not indicate the worth of the work which is completed at any given time. This approach does not represent the true cost performance of the project. Because of these limitations, this paper discusses the applications of Earned Value Analysis (EVA) for cost monitoring of construction projects in Malaysia. Besides traditional approach, EVA is a three-dimensional approach that compares three cost indicators i.e. the budgeted value of work scheduled with the earned value of physical work completed and the actual cost of work completed. Therefore, cost monitoring by EVA is an objective measure of actual work performed. This paper uses a case study, an example application of EVA as a cost monitoring tool. This case study reaffirms the benefits of using EVA for project cash flow analysis and forecasting.

• International Journal of Quality Innovation
• /
• v.7 no.1
• /
• pp.128-160
• /
• 2006

With the globalization of economy, industries are facing increasingly greater challenges. Business integration, both internally and externally, is undoubtedly an important topic. However, how does an enterprise create its own value will be the key to an enterprise's success in the future. Therefore, this study bases on the evaluation of company value to assess the key factors and competitive strategies of an enterprise. Yet, only with stable enterprise performance can the company value be correctly evaluated. This will be an important issue for enterprise performance and business strategy. Subject of this study are mainly small and medium-sized (enterprises (SMEs). Model construction for SME value assessment is established through the system dynamics approach. Scholars' opinions on literature validation and application of Delphi Method are explored through literature review on local and foreign studies, in order to compile the relevant perspectives and indices for enterprise value creation. Hence model construction of the value creation system is established, and the correlation between the perspectives and related factors is explored to understand the overall dynamics model of SMEs' value creation system. Consequently, a research method based on the system dynamics perspective is provided for the study of enterprise value creation is provided, as policy reference for improvement of decision-making and value creation.

• Advances in concrete construction
• /
• v.15 no.3
• /
• pp.191-202
• /
• 2023

Palm oil fuel ash (POFA) is a newly emerging pozzolanic material having high amount of silica content. Various forms of POFA were used in cement-based materials (CBMs) in replacement of cement in different dosages of low and high volume. Although, there are many researches on POFA to be used in concrete and mortar, however, this material was not practically used in the construction industry. Engineers and designers need to be confident to use any new developed materials by knowing all engineering properties at short and long terms. As durability concern, concrete pH value is one of the most important properties. Portland cement produces are alkaline initially, however, it may be reduced due to aging and its components. It is believed that by incorporation of supplementary cementitious materials in CBMs the pH value reduces due to utilization of Ca(OH)₂ in pozzolanic reaction. This study is the first attempts to understand the pH value of mortars containing up to 30% POFA under different curing conditions and its changes with time. The results were also compared with the pH of ground granulated ballast furnace slag (GGBFS) and fly ash (FA) content mortars. In addition, the compressive strength of different mortars under different curing conditions were also studied. The results showed that the pH value of control mix (without cementitious materials) was more than all the blended cement mortars indifferent curing conditions at the same ages. However, there was a reducing trend in the pH value of all mortar mixes containing POFA.

• International Journal of Quality Innovation
• /
• v.8 no.1
• /
• pp.99-119
• /
• 2007

This research probes into the execution of small and medium-sized enterprises' value creativities by a difference analysis with different classifications, different capital, different turnover, different employees, and different established years. This study develop a questionnaire about value creativity with five dimensions and thirty-five items according to "Valuation" by McKinsey and Company, Inc. and Copeland et al., such as: "Aspiration and target," "Portfolio management," "Organization design," "Process management," and "Business and individual performance management." The results are as follows: (1) Most small and medium-sized enterprises (SMEs) have executed value creativities; (2) There is a difference in the execution of value creativities between the livelihood industry and the chemical industry; the execution of value creativities by livelihood industry is better than the chemical industry; (3) For value creativities of the execution of different capital and turnover for SMEs, bigger entities are better than smaller ones; (4) For the value creativities of the execution of different numbers of staff in SMEs, those with more staff are better than those with fewer staff; (5) For the value creativities of the execution of different established years for SMEs, those established longer are better than those established shorter.

• Journal of Positioning, Navigation, and Timing
• /
• v.2 no.1
• /
• pp.67-74
• /
• 2013

In this study, a remote controller was designed using localization technique. The designed remote controller system consists of infrared transmit/receive module for time synchronization, ultrasonic transmit/receive module for measuring the TOA value, and micro-controller for processing the measured data value. For the position estimation method of remote controller, the Savarese method was used which does not have a problem of diverging solution depending on initial value. The noise included in the measured value was removed by separating the signal and noise with the use of EMD method which is the non-stationary signal analysis technique. The designed system was tested by constructing a simulation environment, and the improvement of accuracy and precision for the application of EMD method was examined.

• Environmental Engineering Research
• /
• v.13 no.1
• /
• pp.41-48
• /
• 2008

The valuation of biodiversity is a fundamental step in conservation. The useful framework for analysing the economic value of biological resources is that of total economic value (TEV) and TEV comprises both use and non-use values, the former related to an actual use made of the resource, the latter to a willingness to pay for the resource independently of any use made of it. There are several valuation approacher in environmental economics literature. However, stated preference approach should be introduced for valuation of biodiversity because it can estimate non-use value as well as use value. Contingent Valuation and Conjoint Analysis are representative methods in stated preference and Conjoint Analysis can be more useful for valuation of biodiversity. Futhermore, the combination of ecology and economics to assess biodiversity leads to an integrated framework. Thus, interdisciplinary work is required, involving both economists and ecologists transferring elements or even theories and models from one discipline to another and transforming them for their specific, mutually consistent purpose.