• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.1
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• pp.111-119
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• 2011

Recently, urban redevelopment programs and expansion of social infrastructure have caused massive amounts of construction waste in construction fields, and the mounds of it keep increasing every year. The disposal of construction waste is emerging as a national and social issue and the recycled powder generated by the treatment process of waste concrete is all being abolished or buried. Therefore, the purpose of this study is to utilize waste sludge generated by the wet-type treatment process of waste concrete as materials(binder, filler) for cement composite. This study evaluates physical and mechanical properties of mortar using recycled powder according to heating temperature, contents and applications. As a result of the chemical analysis, recycled powder is composed mainly of CaO and $SiO_2$, and that it is even lower in the content of CaO than OPC. The charateristics of mortar using recycled powder, according to drying and heating temperature, shows that as the heating temperature increases, flow decreases. Also, compressive strength and porosity of mortar using recycled powder was superior when heating temperature was $600^{\circ}C$. Thus, it is revealed that an effective development of recycled powder is possible since the binder by cement composite recovers a hydraulic property during heating at $600^{\circ}C$.

• Archives of design research
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• v.15 no.2
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• pp.213-222
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• 2002

A transfer paper, is needed in the third firing, is usually utilized for industrial ceramics in order to produce tablewares or promoting products. Products may have the same form, however; the price might be different by what kinds of design have transferred. We need to fully understand these methods in order to create high value and quality. Remodeling, the so-called second architecture, results from social Needs for renovation of structures and changing functions. Tile satisfying the need for a custom-made design which fits the features of a space. Most importantly, the remodeler must make an individual design ordered for the customer with an emphasis on economy and time efficiency. Tiles currently in the market are mass-produced using an automated system with a high-priced mold. It is difficult to find tiles of distinct design that are made in a small quantity. We need to develop a method for making various kinds of tile designs that would be marketed for the remodeling industry. In this study, after designing a certain wall with the tiffs in the space, 1 will talk about developing a method to make transfer paper to produce individual tiles for the space. 1 hope that the functional and aesthetic effect on remodeling will gain in popularity, and that we will foster a new demand for tiles in harmony with the other materials mentioned in this study.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.205-209
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• 2009

Recently, the increase of the size of GNP and the expansion of the foreign tour opportunities by the common 5 days work system in a week, reaction of the burden for visiting foreign countries, and expansion of airlines caused the rapid increase of overseas tour but slow increase in the number of foreign tourists, due to the price rise which might impact on the competitive power, and lack of tour infrastructure and attractiveness. As the wide area along the east coast of GyeongBuk Province has great amount of cultural, ocean and natural resources, it helps to get focused the tour industries and maximize the synergy effect through the mutual development coupling the resources and regions. On the basis of the potentials for the growth of east coast area to the international level and the development of local resources, a ocean tour and resort complex for four seasons, which has s strong connection to the local areas resulting the wide tour bond, could help to improve the local economy and balance the development of local province, and furthermore, jump to the level of the center in the East Coast area in the international society. Through the investigation and analysis of the ocean space development status and usage at the advanced foreign countries, the new meaning of the ocean space at the tour and resort complex would be proposed to the relevant local government in fit.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.927-939
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• 2015

It appears that the rapid advance in technology has allowed to broaden the variety of rail systems technology, thereby fostering new business opportunity in rail industry. The direction of rail systems operations is mainly two fold. In one direction, long distance operations between mega cities are pursued with help of high speed trains under development. In the other case, relatively short distance operations for covering intra-city or suburban area are becoming popular. A good example of the latter case is light rail transit (LRT) systems. Due to the short distance operation, it is thus expected that both the development and operation cost for LRT systems be reduced to some extent. The cost reduction desired in there can be gained by scaling down the sizes of both the trains and stations as compared to those of normal rail systems. However, it is not well known how the LRT stations can be scaled down. The objective of this paper is to study on how to slim down the stations (particularly, the functions room) of LRT systems. To achieve the objective, an approach is studied based on a modified method of design structure matrix (DSM). Specifically, using the enhanced DSM method, an integrated architecture is developed for the functions room, in which equipments are housed to perform the functions of electricity, signaling, and communication for LRT stations. The use of the result indicates that the desired reduction can be obtained with the approach taken in the paper.

• The KIPS Transactions:PartA
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• v.8A no.4
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• pp.479-488
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• 2001

As the SoC designs complexity constantly increases, the simulation that uses their software models simply takes too much time. To solve this problem, FPGA-based logic emulators have been developed and commonly used in the industry. However, FPGA-based logic emulators are facing with the problems of which not only very low FPGA resource usage rate due to the very limited number of pins in FPGAs, but also the emulation speed getting slow drastically as the complexity of designs increases. In this paper, we proposed a new innovative emulation architecture and its software that has high FPGA resource usage rate and makes the emulation extremely fast. The proposed emulation system has merits to overcome the FPGA pin limitation by pipelined ring which transfers multiple logic signal through a single physical pin, and it also makes possible to use a high speed system clock through the intelligent ring topology. In this topology, not only all signal transfer channels among EPGAs are totally separated from user logic so that a high speed system clock can be used, but also the depth of combinational paths is kept swallow as much as possible. Both of these are contributed to achieve high speed emulation. For pipelined singnals transfer among FPGAs we adopt a few heuristic scheduling having low computation complexity. Experimental result with a 12 bit microcontroller has shown that high speed emulation possible even with these simple heuristic scheduling algorithms.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.673-682
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• 2001

The objective of this study was to monitor vegetation development process after timber harvesting at (Mt.) Baekwoonsan Seoul National University Forests, Korea. Two monitoring plots were established in 1994 and woody plant were monitored from 1994 to 1999. Vegetation development pattern during last six years(1994-1999) after timber harvesting were as follows; Styrax obassia, Styrax japonica and Lindera erythrocarpa as of the existing tree were competitive species in the first year after clearcut, and Styrax japonica and Lindera erythrocarpa as of sprout tree) and Aralia elata as of seedling were dominant species in the sixth years after clearcut. Species diversity indices of harvested forest interior was decreased at the southwestern slope and increased at the northeastern slope. According to DBH distribution pattern, No. of individuals of Lindera erythrocarpa and Aralia elata showed vigorous growth in the sub-canopy layer and then Styrax japonica, Quercus serrata, Maackia amurensis, Lespedeza maximowixzii, Lindera obtusiloba, Staphylea bumalda, Clero-dendrum trichotomum, Weigela subsessilis, in order showed good growth in the sixth year after clearcut. Lindera erythrocarpa with a reversed J-shaped curve pattern by DBH class will be increased while Aralia elata with a J-shaped curve pattern will be decreased.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.3
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• pp.76-88
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• 2016

Machine to Machine (M2M) is a technology that presents communication between two or more devices with or without human intervention. M2M communications can be applied for various use cases such as environmental monitoring, health care, smart metering and etc. In most use cases, M2M utilizes sensor nodes to collect data from the intended environment and the data is transmitted back to M2M application through other devices (gateways, sink nodes). In some use cases, M2M devices are being designed to store and process sensor data for improving the reliability of the service; Gateways and sink nodes are also intended to store and process the gathered data from sensor nodes. This kind of approach is very challenging for both academy and industry. In order to enhance the performance of this approach, in this paper, we propose our Common Service Security Platform (CSSP) for M2M devices and gateways. CSSP platform presents solutions for the devices and gateways by making them operate more accurately and efficiently. Besides, we present a comparative analysis of communication protocols and present their performance in accordance with selected metrics.

• Korean Journal of Construction Engineering and Management
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• v.22 no.3
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• pp.40-51
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• 2021

MLS (Mobile Laser Scanning) which is a scanning method done by moving the LiDAR (Light Detection and Ranging) is widely employed to capture indoor PCD (Point Cloud Data) for floor plan generation in the AEC (Architecture, Engineering, and Construction) industry. The movement and rotation of LiDAR in the scanning phase cause deformation (i.e. skew) of PCD and impose a significant impact on quality of output. Thus, a de-skewing method is required to increase the accuracy of geometric representation. De-skewing methods which use position and pose information of LiDAR collected by IMU (Inertial Measurement Unit) have been mainly developed to refine the PCD. However, the existing methods have limitations on de-skewing PCD without IMU. In this study, a novel algorithm for de-skewing 2D PCD captured from MLS without IMU is presented. The algorithm de-skews PCD using scan matching between points captured from adjacent scan positions. Based on the comparison of the deskewed floor plan with the benchmark derived from TLS (Terrestrial Laser Scanning), the performance of proposed algorithm is verified by reducing the average mismatched area 49.82%. The result of this study shows that the accurate floor plan is generated by the de-skewing algorithm without IMU.

• Journal of the Korea Institute of Construction Safety
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• v.2 no.1
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• pp.28-35
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• 2019

The average number of deaths in the construction industry reaches 500 per year, and in particular, it is confirmed that the type of accidents and deaths caused by disasters such as work platforms has occupied more than 60% of the total. In this study, we presented a structured and combined solution for technology, management, education, and cost that can solve systematically, politically, and external environmental factors as well as direct influence factors. In addition, we examined the safety and safety standards of domestic and international safety, and discussed implications. First, direct impact factors, organizational impact factors, policy influence factors, and external environmental impact factors were examined and classified into technical, education, and institutional dimensions. Second, in relation to the installation of the work scaffold, the standards (OSHA 1926.452), UK (The Work at Height Regulations 2005 No.735, BS5975), Japan (Labor Safety and Sanitation Regulations) and Germany (DIN 4420_4, DIN EN12810). In the case of domestic safety standards, similar to the foreign safety standards, safety measures such as materials and specifications are applied. However, details related to the installation, assembly and structure of the work platform are somewhat different from those in the United States and the United Kingdom excluding Japan. Using the results of this study, it is possible to understand the cause of the accident of foot pedestrian accident more systematically and comprehensively, and safety managers and researchers are expected to help in the accident investigation.

• Journal of Construction Engineering and Project Management
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• v.8 no.4
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• pp.1-24
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• 2018

In the last decade, the use of Building Information Modeling (BIM) as a new technology has been applied with traditional Computer-aided design implementations in an increasing number of architecture, engineering, and construction projects and applications. Its employment alongside construction management, can be a valuable tool in helping move these activities and projects forward in a more efficient and time-effective manner. The traditional stakeholders, i.e., Owner, A/E and the Contractor are involved in this BIM system that is used in almost every activity of construction projects, such as design, cost estimate and scheduling. This article extracts major features of the application of BIM from perspective of participating BIM components, along with the different phrases, and applies to them a logistic analysis using a fuzzy performance tree, quantifying these phrases to judge the effectiveness of the BIM techniques employed. That is to say, these fuzzy performance trees with fuzzy logic concepts can properly translate the linguistic rating into numeric expressions, and are thus employed in evaluating the influence of BIM applications as a mathematical process. The rotational fuzzy models are used to represent the membership functions of the performance values and their corresponding weights. Illustrations of the use of this fuzzy BIM performance tree are presented in the study for the uninitiated users. The results of these processes are an evaluation of BIM project performance as highly positive. The quantification of the performance ratings for the individual factors is a significant contributor to this assessment, capable of parsing vernacular language into numerical data for a more accurate and precise use in performance analysis. It is hoped that fuzzy performance trees and fuzzy set analysis can be used as a tool for the quality and risk analysis for other construction techniques in the future. Baldwin's rotational models are used to represent the membership functions of the fuzzy sets. Three scenarios are presented using fuzzy MEAN, AND and OR gates from the lowest to intermediate levels of the tree, and fuzzy SUM gate to relate the intermediate level to the top component of the tree, i.e., BIM application final performance. The use of fuzzy MEAN for lower levels and fuzzy SUM gates to reach the top level suggests the most realistic and accurate results. The methodology (fuzzy performance tree) described in this paper is appropriate to implement in today's construction industry when limited objective data is presented and it is heavily relied on experts' subjective judgment.