• Smart Structures and Systems
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• v.12 no.3_4
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• pp.399-414
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• 2013

The smart sensor technology has opened new horizons for assessing and monitoring structural health of civil infrastructure. Smart sensor's unique features such as onboard computation, wireless communication, and cost effectiveness can enable a dense network of sensors that is essential for accurate assessment of structural health in large-scale civil structures. While most research efforts to date have been focused on realizing wireless smart sensor networks (WSSN) on bridge structures, relatively less attention is paid to applying this technology to buildings. This paper presents a decentralized damage detection using the WSSN for building structures. An existing flexibility-based damage detection method is extended to be used in the decentralized computing environment offered by the WSSN and implemented on MEMSIC's Imote2 smart sensor platform. Numerical simulation and laboratory experiment are conducted to validate the WSSN for decentralized damage detection of building structures.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2211-2213
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• 2005

Recently, the membrane technology has actively been applied to make generating water because the convention; chemical treatment technology for purifying water has caused second environmental pollution. In spite of its ecological advantages, this membrane technology has some drawbacks such as ease of membrane contamination, efficiency and running cost. The purpose of this research is reduction of membrane contamination by applying high voltage pulsed electric field to the water prior to its penetrating membrane.

• Advances in environmental research
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• v.5 no.1
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• pp.37-50
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• 2016

The main objective of this study is to evaluate adsorptive removal of Methylene Blue (MB) dye from aqueous solution using pumice powder. The effects of pH, adsorption time, agitation speed, adsorbent dose, and dye concentrations on dye adsorption were investigated. Process kinetics and isotherm model constants were determined accordingly. The results showed that adsorbent dose, dye concentration and agitation speed are the important parameters on dye adsorption and the removal of MB did not significantly change by varying pH. A total adsorption process time of 60 min was observed to be sufficient to effectively remove 50 mg/L MB concentration. The MB adsorption data obeyed both pseudo first order and second order kinetic models. Adsorption of MB by pumice fitted well both Langmiur and Freundlich isotherms ($R^2{\geq}0.9700$), except for 150 rpm agitation speed that system fitted only Langmiur isotherm. The results of this study emphasize that pumice powder can be used as a low cost and effective adsorbent for dye removal.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.427-427
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• 2021

During the rainy season, heavy downpours are always a source of concern for the world. Flooding and heavy rains can devastate communities, disrupt agriculture, and contribute to traffic accidents.. Weir and flow hall effect sensors are the conventional analytical methods for measuring flow rate; in this paper, we analyzed manhole flowrate statistics. The measurement of the flow rate of a notch/weir is a time-consuming task that necessitates continuous mathematical analysis. . We created three types of IoT sensors in this study: (HC-SR04 ultrasonic, YF-S201 magnetic, and HB100 radar), which take the sensor's real-time input signal and estimate the flow using a notch equation and a previously calibrated optimized coefficient of discharge. The proposed systems are cost-effective, but in terms of accuracy, we found that the HC-SR04 ultrasonic sensor is the best of the three systems

• International conference on construction engineering and project management
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• 2015.10a
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• pp.604-605
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• 2015

To secure quality of dam construction needs appropriate construction duration. Tight construction schedule may have negative influence on infrastructure quality, work safety and maintenance cost. It is necessary to reflect proper construction duration in the planning phase. There have been standards for estimating construction duration of building and industrial complex development but dam construction have not. In order to estimate construction duration of CFRD, feasible study reports and design reports were analyzed to acquire available information. After that, considering on construction duration methods such as comparison with similar cases, approximate estimating formula, approximate quantity assumption were adapted to Critical Path items. Hence, this study present framework for construction duration estimating of CFRD in the planning phase. This framework can be applied other types of dam along the same line.

• Journal of Forest and Environmental Science
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• v.40 no.2
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• pp.118-122
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• 2024

This study reported the novel use of fallen leaf extract as a microbial culture media for the first time. Extract from hardwood fallen leaves (HLE) was prepared under high temperature and pressure conditions and then supplemented with specific nutrients. The growth of four industrially significant prokaryotes on the HLE-based media was measured and compared with that on enriched media (Luria-Bertani, LB). Notably, supplementing HLE with only 0.5 g of yeast extract and 1 g tryptone per liter showed a similar growth rate of Pseudomonas chlororaphis compared to standard LB media. Overall, the HLE media developed in this study offers a sustainable and cost-effective approach to microbial media production, capitalizing on the valorization of forest waste.

• International Journal of High-Rise Buildings
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• v.13 no.2
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• pp.113-145
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• 2024

Bamboo is seen as a low cost, lightweight, widely available and environmental-friendly material. In Vietnam, it also connects deeply to our culture. However, it wasn't seen as a viable material for large structures before VTN Architects. Furthermore, Vietnamese cities are facing the same environmental problems as many developing metropolises in the world. Globally, climate change is a serious issue. The need for sustainable construction material is clear. The increasing development of eco-tourism in Vietnam and Asia is also a background. These become the background to the foundation and the development of bamboo architecture by VTN Architects. The journal analyses our development of bamboo construction, joints, structures, and how to use them to realise space and to create eco-friendly architecture. We will talk about our process of bamboo procurement, our construction methods, our unique joint system, how we make a frame unit and how we construct VTN bamboo structures from units.

• Journal of Distribution Science
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• v.11 no.8
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• pp.15-23
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• 2013

Purpose - This is a case study aimed at finding a solution for improving the pallet loading efficiency in the process of delivering products through a transshipment using the T-11 and T-12 pallet systems. The study proposes a solution by demonstrating the case of a certain manufacturer A, who aims to reduce the logistics cost by using packaging sizes that are commonly applicable and can improve the compatibility between the T-11 pallet system, designated as the standard pallet in Korea, and the T-12 pallet system, which is commonly used in other foreign countries. The use of common sizes increases compatibility among the two systems and reduces both logistics and environmental costs. Thus, this case study calculates the quantitative benefits of applying common packaging sizes to improve the compatibility between the T-11 and T-12 pallet systems. These systems are considered to be the most important and widely used transportation systems in the global logistics industry. Research design, data, and methodology - This study examined manufacturer A's representative product and delivery system and assessed how manufacturer A was affected by the use of incompatible packaging sizes in the T-11 (1100 mm×1100 mm) and T-12 (1200mm×1000 mm) pallet systems, which were specified in the KS T 1002 standard. In addition, this study analyzed the impact of these packaging sizes on A's logistics cost. The TOPS program (Total Packaging System) was used to simulate pallet loading efficiency,and the main parameter studied was volume, as calculated from length, width, and height. Results - When the sizes of secondary packaging were not compatible across the T-11 and T-12 pallet systems, a reduction in loading efficiency was observed, leading to an increase in logistics cost during transshipment. Such low loading efficiencies led to a further loss of efficiency in transportation, storage and unloading. This may have a possible environmental impact with high social expenses, such as increased CO₂ emissions. Hence, this study proposed that the KS T 1002 standard be amended to include 21 packaging sizes, including 7 sizes of the 600 mm×500 mm category, which are compatible with both the T-11 and T-12 pallet systems. Conclusions - This study found that the 69 standard sizes under the T-11 pallet system and the 40 standard sizes under the T-12 system in the KS T 1002 standard can be simplified and reduced to 21 mutually compatible packaging sizes, enabling logistics standardization and reducing national-level logistics costs. If the government pays attention to this study and considers the standardization of common sizes for the T-11 and T-12 pallet systems and amends the KS T 1002 standard, this study will deliver practical value to the global logistics industry, apart from being of academic significance.

• Journal of Korean Society of Forest Science
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• v.105 no.3
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• pp.377-390
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• 2016

The aim of this study is 1) to design an auction-type and area-based payments for ecosystem services (PES) in application to private forest in Korea, 2) to develop the framework of index to implement the PES program proposed, and 3) to examine the feasibility and validity of the index framework by conducting a case study. The index framework measures quantities of ecosystem services currently supplied, improvement of ecosystem services anticipated from the proposed management activities, and real implementing costs of the program. The total scores from the case study vary from 301 to 501 for site 1, Goesan-gun and 273 to 460 for site 2, Pyeongchang-gun, respectively, indicating that total index score - measurement of cost-effectiveness - can be varied by the levels of management and real cost even if the scores from ecosystem service indicator group are the same. The index framework which can locate a cost-effective program has significant policy implication given the budget constraints in biodiversity/ecosystem services policy arena.

• Journal of Distribution Research
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• v.8 no.1
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• pp.91-116
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• 2003

This study empirically analyzes the relationships among small and medium-sized stores' competitive strategies, marketing capabilities, and retail performance to cope with hostile environments like mass merchandisers' threats. To accomplish the proposed research objectives, data were collected from 325 small and medium-sized stores scattered nationwide. Three types of competitive strategies were significantly classified as follows cost leadership, merchandise differentiation, and service differentiation. Also, several strategic groups such as doing-nothing type, service differentiation type, cost leadership type, and merchandiser differentiation type were recognized through the cluster analysis. The test results show that the small and medium-sized stores perceiving hostile environments less importantly marked the high retail performance among clusters like cost leadership type, merchandise differentiation type, and even doing-nothing type. On the other hand, the moderating effects resulted from the interaction between strategic groups and environmental hostility did not have significant influence on retail performance. Additionally, merchandise differentiation cluster obtains and accumulates marketing capability most efficiently and the cluster like cost leadership, service differentiation, and doing-nothing follows next in order. Finally, merchandise differentiation cluster shows the most highest retail performance among the clusters while there was no difference between cost leadership and service differentiation cluster in terms of retail performance.