• Journal of the Korean Wood Science and Technology
• /
• v.36 no.1
• /
• pp.79-87
• /
• 2008

Many researchers have studied on rooftop greening that can be installed in abandoned spaces on a building roof. The most important issue in rooftop greening is the soil weight problem. The light greening materials are needed to solve this problem. Therefore, many alternative materials against the soil were investigated for rooftop greening. In this study, the waste wood chips and the waste paper slurry were evaluated as the lightweight vegetation foundation for rooftop greening. It also has a meaning for recycling of waste materials. The mixture ratio of waste wood chips to waste paper slurry for the board (the foundation of greening) was 60 to 40. The wet strength resin and the sizing agent were additionally added with different amount. After the forming of the board, physical and chemical properties were tested with the variation of wet strength resin and sizing agent. As the result of the test, the board with 15% of wet strength resin in the wet condition showed the highest strength. Futhermore, the moisture evaporation loss from the board surface with sizing agent was much lower than that from the board without sizing agent. Therefore, it was clear that the sizing agent was effective for water retention. The change of thickness in the wet condition was less than 1 mm, and it showed that the board is the predominant material on the dimensional stability. The average pH value of the board was ranged from 7.6 to 8.25.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.1 no.2
• /
• pp.1-15
• /
• 1997

This paper presents substructural identification methods for the assessment of local damages in complex and large structural systems. For this purpose, an auto-regressive and moving average with stochastic input (ARMAX) model is derived for a substructure to process the measurement data impaired by noises. Using the substructural methods, the number of unknown parameters for each identification can be significantly reduced, hence the convergence and accuracy of estimation can be improved. Secondly, the damage index is defined as the ratio of the current stiffness to the baseline value at each element for the damage assessment. The indirect estimation method was performed using the estimated results from the identification of the system matrices from the substructural identification. To demonstrate the proposed techniques, several simulation and experimental example analyses are carried out for structural models of a 2-span truss structure, a 3-span continuous beam model and 3-story building model. The results indicate that the present substructural identification method and damage estimation methods are effective and efficient for local damage estimation of complex structures.

• Journal of the Korean Society for information Management
• /
• v.19 no.1
• /
• pp.23-46
• /
• 2002

With explosively increasing digital contents, library and Information center should have a new role between knowledge providers and knowledge users as information brokering organization. Electronic transaction system should be required for performing this brokering service since economic value is added to information and knowledge in information society. The developments and changes around library are keeping up with increasing building digital library and digitalizing printed sources. With the rapidly changing circumstances, the Internet is currently witnessing an explosive growth. By serving as a virtual information resource. the Internet can dramatically change the way business is conducted and Information is provided. However because of features o( the Internet like openness and information sharing, it has fundamental vulnerabilities in security issues. For Instance, disclosure of private information and line eavesdropping such as password, banking account, transaction data on network and so on are primary obstruction factors to activation of digital contents delivery on network. For high network security and authentication, this paper looks at smart card technologies and proposes multi-authentication protocol based on smart card on open network, implements and analyzes it.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.9 no.1
• /
• pp.66-77
• /
• 2006

Considering constantly increasing number of internet users and information-oriented society with high speed internet network, the application of computer technology is considered to be valuable in urban planning. Particularly, since using Geographic Information System (GIS) is expected to be the best method to convey the information related to the urban planning. Therefore, this study aims at the development of participation system by using GIS and Internet. The system consists of Basic Module, Disposal Module and Decision Support Module. Each module is designed for expressing planning information and processing database, opinion statement and convenience of citizens, and the effectiveness of administration process and decision making. These are connected each other in a basic and simple form, i.e. Java Script and HTML, and the system was realized through data process, Map date and PostGIS for Mapping, and PHP. Last but not least, this system has been tested on the internet and the result indicated its convenience and availability in actual use concluding that participation system has enough application value on urban planning process.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.1
• /
• pp.347-354
• /
• 2013

In the recent global construction environment, EPC contracts that integrate planning, design, procurement, and construction have been widely used for industrial facilities. Similarly, as the importance of the engineering capability such as project management consulting(PMC) and front end engineering design(FEED) has been increased, design-build contracts also have been gradually adopted for infrastructure projects. Whereas, the Korean infrastructure industry has fragmentary features which mainly emphasize on the construction sector. Therefore, this study aims at developing strategies for enhancing the engineering capability and for balancing the competitiveness between engineering and construction sectors in the Korean infrastructure industry. To this end, the authors first carried out market analysis for both global and domestic market. Then, a structured survey and expert in-depth interviews were sequentially performed in order to reflect practitioners' perspectives and needs for institutional strategies. As a result, five strategies drawn from this study are as follows: 1) rearranging the government's roles for supporting the engineering sector; 2) establishing institutional bases being compatible with global standards; 3) fostering value-added workforce for undertaking complex tasks; 4) constructing an consortium between an engineering association and general contractors; and 5) building a nationwide collaborative networks for overseas market expansion.

• Journal of Distribution Science
• /
• v.12 no.4
• /
• pp.47-54
• /
• 2014

Purpose - The postponement strategy, which delays the form, place, and production of products as late as possible, has been widely considered as a competitive supply chain management scheme in an era of mass customization and modular manufacturing. An interesting business phenomenon is that not all manufacturing/logistics firms choose the postponement strategy. Given that postponement is a counter-measure to speculation, which has some advantages under certain environments, the current imprudent inclination toward the postponement strategy may cause firms to lose the potential of the speculation strategy, an alternative strategy in supply chain management. Building on the logistics and manufacturing literature, this study examines characteristics of two contrasting strategies, postponement and speculation, and major factors favoring each strategy. Research design, data, and methodology - We apply the profiling approach to two business cases, HP printer and LG mobile phone. The profiling approach is a method of choosing a particular strategy aligned with environmental factors. While various approaches have been used to check the fit between a business strategy and environmental factors, the literature on manufacturing strategy and logistics has commonly adopted the profiling approach. Major factors used in profiling variables are derived from the literature. Two samples, HP printer and LG mobile phone, are selected, because they represent major characteristics appropriate for each strategy. The profiling is based on data from semi-organized interviews with managers. Results - The profiling approach shows that the postponement strategy is a suitable one for HP printers. Most factors, such as product life cycle, large production volume, low-price, product value, and monetary density, support delaying end products until as late as possible. Despite some exceptions, such as delivery time and economy of scale, our analysis states that the overall profile of HP printer is favorable for the postponement strategy. On the other hand, LG mobile phone may adapt the speculation strategy. Although it has large production volume and low delivery frequency, most characteristics support the speculation strategy for this product. An interesting finding is that, despite common perception that advanced technology products such as mobile telephones favor the postponement strategy, profiling proposes the speculation strategy for this product. Conclusions - Our analysis shows that speculation is not the universal option for supply chain management, and that, when choosing a specific strategy, one should consider many factors simultaneously. A major implication of our work is to emphasize the role of environmental factors such as supply chain variables in choosing an inventory strategy, and the importance of fit rather than solely strategic orientation. A theoretical contribution is to demonstrate the benefit of the simultaneous consideration of business variables in choosing specific strategies. For practitioners, our work leads us to consider the existence and the potential of speculation as a counter-measure to postponement. In addition, the comprehensive framework in this research may be instantly used in examining a practical strategy.

• Journal of the Korean Geosynthetics Society
• /
• v.18 no.4
• /
• pp.1-13
• /
• 2019

The purpose of this study is to examine the effect of soft ground improvement by dynamic replacement with utilizing crushed rock. In order to understand the ground improvement effect when applying dynamic replacement method with crushed rock, the laboratory test and field test were performed. The internal friction angle and apparent cohesion were derived through direct shear test. The dynamic replacement characteristics were identified by analyzing the weight, drop, and number of blows needed for dynamic replacement. Through the field plate bearing test and density test, the bearing capacity and settlement of the improved ground were measured, and the numerical analysis were conducted to analyze the behavior of the improved ground. In this study, it proposes modified soil experimental coefficient(C_DR) to 0.3~0.5 in the dynamic replacement method with crushed rock. Also when applying the dynamic replacement method using crushed rock, the particle size range is less than 100 mm, D₉₀ is less than 80 mm and D₁₅ is more than 30 mm.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.39 no.6
• /
• pp.877-886
• /
• 2019

The size of the subway entrance should be calculated according to the user's demand, but Korea has the same size for each entrance by applying a uniform value. Recently, the installation of mobile convenience facilities such as escalators, elevators, etc. is mandated by the traffic weakness promotion law, but it is inconvenient to use the existing stations because it is mainly arranged in the place where it can be installed regardless of user demand. This study aims to establish a model for estimating the size of mobile convenience facilities by predicting the use demand of each station entrance so that the location and size of mobile facilities can be reflected in the design or construction of the station. To this end, a multiple regression model was established to forecast daily demand by utilizing the demand for getting on and off by station and the building association area for each purpose around the railway station. The actual data of Dongdaemun and Jonggak Stations were used to verify the estimated model. In addition, the escalator installation scale was compared / analyzed by doorway using domestic and overseas escalator equations. As a result, it was more accurate to estimate the usage demand for a single station. Also, Jonggak Station has an up and down escalator installed at exit 1, but it was analyzed that it is appropriate to install at exit 4. This study is an advanced form of the essay model for estimating the users of the entrance and exit users of urban railway stations published in 2018. In addition, it seems to be the basis of the current escalator installation criteria.

• The Journal of the Korea Contents Association
• /
• v.20 no.6
• /
• pp.653-667
• /
• 2020

The Purpose of this study is to propose an effective service delivery system for children and youth considering service users and developmental stage. To accomplish this purpose, this study examined public service utilization for children and youth focusing on age difference, using statistical method and network analysis. The key results were as follows. The significant difference of service utilization among different age groups appeared in community center, youth training center, healthy family support center, public health center, public office and office of education. In terms of service utilization for special needs, the differences in Wee Center, Wee School and community child center were significant. Top value of degree centrality in network analysis showed on public heath center for elementary school, youth training center for middle school, and community center for high school. Finally, modeling results by Concor presented several distinctive relationship patterns in public service utilization for children and youth according to different age groups. On the base of these results, building a gateway applying age difference and developing a individualized service utilization database were suggested to improve the quality of service delivery system for children and youth.

• Korean Journal of Construction Engineering and Management
• /
• v.17 no.6
• /
• pp.40-52
• /
• 2016

In the 1960s and 1970s when Korea experienced rapid economic growth, a considerable number of buildings were constructed in the country. And since 2000, a large number of sizable and complex buildings have been being built. Specifically, as the operation and maintenance cost alone accounts for 85% of the life cycle cost of a building, efficient Facility Management (FM) is required. However, data needed in the operation and maintenance phase are not sufficiently exchangeable with data created in other phases like the planning, design and construction phases. The upper phase has higher value of data but data exchange rate is low, resulting in inefficiency. To this end, this research derived major business functions for facility management: three categories and 19 detailed functions in classification from owner's perspective. Based on the derived items, this research proposes a methodology to evaluate the 'FM Workload', 'Facility Management (FM) Data', and 'FM Data Created in Engineering and Construction Phases' thereby analyzing plans for efficient operation and maintenance. The applicability of proposed methodology was tested by examining real-world cases of public and private companies.