• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6D
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• pp.867-874
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• 2011

The ballast abrasion occurs on the ballasted track upon bridges more than soil roadbed because the track vibration occurs a lot in the ballasted track upon bridges due to girder vibration when a train's weight is loaded onto track even though the identical ballast is used. The phenomena of mud pumping especially, which occurs when drainage is not properly secured for heavy rain, leads to the increase of maintenance work load and the decline of ride comfort. The ballast thickness range in domestic railroad construction rule is uniformly set up according to the design speed of railroad and passing tonnage of train without considering field conditions which is considered in foreign railroad companies. The purpose of this study is to verify the effect of vibration decrease by measuring the acceleration, displacement and ride comfort of ballasted track with the change of ballast thickness on the ballast tracked bridges and to suggest the optimal height of ballast on the Yocheon Bridge built for the test in Honam Line.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.28 no.3
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• pp.7-25
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• 2017

The problem of library space has long been discussed in various aspects such as library relations, architecture, and space design. The purpose of this study is to examine the change of the concept of the complex space of the library according to the development of advanced technology and the social paradigm, and to present the direction of constructing the complex space of the future library by analyzing each case. All concepts such as mediatheque, information commons, larchiveum, and the maker space that is recently introduced into the library are important elements of the complex space presented as a problem of library construction and space. The future library reflects these concepts and serves as a mediator between information and users, users and users, users and media to support reading, information, learning, rest, community-oriented culture and creation, start-up and collaboration. It should be constructed as a multi-space platform to create new value through.

• International Journal of Concrete Structures and Materials
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• v.10 no.sup3
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• pp.1-17
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• 2016

Recently, advanced transit systems are being constructed to reduce traffic congestions in metropolitan areas. For these projects, curved bridges with various curvatures are required. Many curved bridges in the past were constructed using aesthetically unpleasant straight beams with curved slabs or expensive curved steel box girders with curved slabs. Therefore, many recent studies have been performed to develop less expensive and very safe precast prestressed concrete (PSC) curved girder. One method of reducing the construction cost of a PSC curved girder is to use a reusable formwork that can easily be adjusted to change the curvature and length of a girder. A reusable and curvature/dimension adjustable formwork called Multi-tasking formwork is developed for constructing efficient precast PSC curved girders. With the Multi-tasking formwork, two 40 m precast PSC box girders with different curvatures were constructed to build a two-girder curved bridge for a static flexural test to evaluate its safety and serviceability performance. The static flexural test results showed that the initial cracking load was 1400 kN, exceeding the design cracking load of 450 kN. Also, the code allowed deflection of 50 mm occurred at a load of 1800 kN, verifying the safety and serviceability of the precast PSC curved bridge constructed using the multi-tasking formwork.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.6 s.119
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• pp.39-53
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• 2007

Unlike conventional roof landscaping, where various kinds of plants and structures are employed, a grass roof is a roof on which herbaceous plants are grown in planting medium and which is not accessed or maintained, mainly because it doesn't have sufficient load capacity to support a regular roof garden. They are mostly built on existing roofs, whether flat slab or gabled. Planting on roofs has numerous advantages, such as creating a biotope, purifying urban air, adding moisture to the atmosphere, storing rain water, preventing flash floods, reducing energy use for heating and air conditioning, enhancing the urban landscape and providing relaxation to the city dwellers, not to mention the alleviation of global warming by absorbing $CO_2$. In addition to the general merits of roof planting, the grass roof has its own unique qualities. Only herbaceous species are planted on the roof, resulting in light weight which allows roofs of existing buildings to be planted without structural reinforcement. The species chosen are mostly short, tough perennials that don't need to be maintained. These conditions provide an ideal situation where massive planting can be done in urban areas where roofs are often the only and definitely the largest space available to be planted. If roofs are planted on a massive scale they can play a significant role in alleviating global warming, heat island effects and energy shortages. Despite the advantages of grass roofs, there are some problems. The most significant problem is the invasion of neighboring plants. They may be brought in with the planting medium, by birds or by wind. These plants have little aesthetic value comparing to the chosen species and are usually taller. Eventually they dominate and prevail over the original species. The intended planting design disappears and the roof comes to look wild. Since the primary value of a grass roof is ecological, a change in attitude towards what constitutes beauty on the roofscape is necessary. Instead of keeping the roof neat through constant maintenance, people must learn that the wild grass with bird's nests on their roof is more beautiful as it is.

• Journal of The Korea Institute of Healthcare Architecture
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• v.9 no.1
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• pp.7-15
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• 2003

Contemporary hospital has more and more extension because the growth and change of hospital has to respond the various needs. For expanding, the sky bridge(sky walk) becomes one of the method to interconnect two or more buildings on the air. Sometimes the designers don't know exactly how the sky bridge works after construction. Beyond the role of interconnecting two buildings, the role of sky bridge is transformed the main axis of pedestrian in the whole hospital organization. This scope of analysis is about the sky bridge of Hanyang University hospital. The first method is the investigation of the utilization in this time. The second is the analysis of design drawings got form the designing of the past(1994-1998). From this analysis, the conclusions are followings.；The designer who wants to apply the sky bridge should more consider about, 1) how the sky bridge impacts the whole spatial system such as the pedestrian, patients, physicians, service's facilities etc. 2) what the inside of sky bridge has something such as natural light, ventilation, and the height, depth, width of aisle, the sign for seeking orientation. etc. In future the research relating sky bridge should be studied some hospital as well as one hospital for comparing the characteristics of the concepts and organizations

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.6
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• pp.581-591
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• 2016

Several attempts to construct multi-purpose tunnel for both road and waterway have been made. The multi-purpose tunnel is mainly used as a road tunnel, however it is transferred to waterway to control flood during rainy season. The planning of the multi-purpose tunnel is recognized as cost-effective way of infrastructure construction. In case of the multi-purpose tunnel constructed beneath groundwater table, seasonal fluctuation of groundwater table and repeated flow in the tunnel may cause long-term deterioration of the tunnel system. In this study, the behavior of multi-purpose tunnel in view of groundwater table or flow in the tunnel is investigated using model test and numerical modeling method. The results have shown that rising of groundwater table caused buoyant force to the tunnel and the fluctuation of rainwater in the tunnel generated loosening of surrounding ground. It is recommended to evaluate the effect of the long-term water pressure variation in the design of a multi-purpose tunnel.

• Tunnel and Underground Space
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• v.28 no.4
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• pp.293-303
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• 2018

Monitoring is the act of collecting and analyzing accurate engineering information using various methods and instruments. The purposes of the monitoring are design verification, construction management, quality control, safety management, and diagnose of structure etc.. The diagnose evaluation of the geotechnical structures corresponds to the confirmation of the structural performance. It is aimed to judge the soundness of geotechnical structures considering the degree of damage due to the environmental change and elapsed time. Recently, microseismicity, which is widely known in Korea, can be used for safety management and diagnoses of structure as it detects the micro-damage without disturbance of the structure. This report provides guideline on the procedure for assessing an underground oil storage cavern using microseismic monitoring techniques. Guidelines cover the selection of monitoring systems, sensor array, sensor installation and operation of systems, and interpretation.

• Journal of the Korean housing association
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• v.26 no.1
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• pp.1-10
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• 2015

In line with the recent public concern on the environmental issues in building industry, there has been a rise in demand for a healthy, sustainable housing environment in South Korea. In order to achieve a healthy environment in residential buildings, considerable efforts have been made in a wide range of sectors. Among others, the development of the certification schemes to promote environment-friendly planning and building construction is remarkable. In urban South Korea, recently built houses tend to be significantly high-rise, high-density buildings. Global warming has brought about drastic climate change and continued to increase the average annual temperature year by year. These changes should be well reflected on the government's implementation of the building environmental assessment system. For guidance, therefore, this study looks to the case of Hong Kong which is well known for high-density housing development and subtropical climate conditions. It compares the features of the green building certification schemes for newly developed multifamily housing in two regions, namely HK-BEAM in Hong Kong and G-SEED in South Korea. Based on the findings, it argues that the G-SEED implementor should have expanded roles in providing training programs and follow-up services in collaboration with the certification authorities. It is also argued that G-SEED professionals should be involved in the early stages of design processes, and training programs and licence systems to produce green building professionals should be developed. Finally, it points out that the assessment indicators should be more detailed and diversified.

• Journal of the Korean housing association
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• v.25 no.2
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• pp.27-36
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• 2014

The revision of regulations for apartment unit design, which are concerning the area calculating criteria (revised in 1998) and use of balcony (revised in 2005), considerably have increased livable space of apartment unit. This paper aims to verify its effect to apartment unit plan in the aspect of number of rooms and size of each room. For this purpose, 60 and 85 $m^2$ sized apartment unit plans in Seoul Gangnam district have been analysed by construction period, and a conclusion is drawn out as following; (1) The revison of regulations in 1998 and 2005 increased livable space of 60 and 85 $m^2$ sized apartment about 16.4~20.6 $m^2$ area. (2) Bedrooms, living room, dining room and kitchen have no change in size in nominal sense, actually, they increase their size after the fact by converting balcony to livable space. (3) Bathroom, dress room and entrance space have been considerably increased in size, which is possible for available area added in place of wall footprint according to 1998 revision.

• The Journal of Information Systems
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• v.26 no.4
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• pp.379-400
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• 2017

Purpose The purpose of this study is to investigate the effects of ICT on multilevel marketing organizations (MLMs) whose members are both salespeople and consumers. This study explores the effects of the latest ICT convergence on the direct selling, which is the oldest sales method, and suggests the direction for the development of network marketing. Therefore, we will propose the changes in direct sales brought by ICT and predict the future direction of network marketing in preparation for the 4th Industrial Revolution era. Design/methodology/approach Exploratory case study was the methodology selected for this paper. The case study enables the use of multiple methods for data collection and analysis. This study applies qualitative case-study methodology on Amway Korea, which is the top seller of MLM organizations, to better understand the impact of ICT. This study conducted an in-depth interview with four different levels of MLM members (e.g. membership, ruby, emerald, diamond) which are based on the qualification system of MLM organizations and observed their behaviors. Findings This study revealed that the ICT impact on network marketing organizations(MLMs) could be summarized as follows : new membership growth, easier communication with customers, increase in work efficiency, increase in organizational trust, change in educational environment, and increase in the use of social media. Based on the interview, we propose the changes of network marketing organizations in the fourth industrial revolution era and the future strategy of Amway Korea as follows: (1) retention of royal ABOs, (2) harmony with SMEs, (3) utilization of Big Data, (4) creation of IoT business model, and (5) construction of successful O2O business platform.