• Korean Journal of Construction Engineering and Management
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• v.2 no.2 s.6
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• pp.68-80
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• 2001

While opportunities for international construction firms have been growing with globalization, the risk of international construction projects is significantly increasing in severity and complexity. However, the traditional risk management approach in the construction industry has maintained a profit focus. In addition, this approach has not considered the overall risk at the corporate level, but rather has focused only on the risk of individuals at the project level. Corporate risk management should be implemented from the initial stages of new project selection. This paper suggests the Multi-criteria Integrated Systematic Analysis as a strategic decision-making tool for international construction contractors. The model integrates the multi-criteria of risk, return, and efficiency to choose the optimal set of new portfolios at the corporate level. This model also introduces the Value at Risk (VaR) concept to the international construction industry to present the total risk at the corporate level. To validate this model, this paper tested an experimental case study using the historical data of a global general contractor.

• Journal of Broadcast Engineering
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• v.11 no.1 s.30
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• pp.116-129
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• 2006

The progress of data transmission technology through the Internet has spread a variety of realistic contents. One of such contents is multi-view video that is acquired from multiple camera sensors. In general, the multi-view video processing requires encoders and decoders as many as the number of cameras, and thus the processing complexity results in difficulties of practical implementation. To solve for this problem, this paper considers a simple multi-view system utilizing a single encoder and a single decoder. In the encoder side, input multi-view YUV sequences are combined on GOP units by a video mixer. Then, the mixed sequence is compressed by a single H.264/AVC encoder. The decoding is composed of a single decoder and a scheduler controling the decoding process. The goal of the scheduler is to assign approximately identical number of decoded frames to each view sequence by estimating the decoder utilization of a Gap and subsequently applying frame skip algorithms. Furthermore, in the frame skip, efficient frame selection algorithms are studied for H.264/AVC baseline and main profiles based upon a cost function that is related to perceived video quality. Our proposed method has been performed on various multi-view test sequences adopted by MPEG 3DAV. Experimental results show that approximately identical decoder utilization is achieved for each view sequence so that each view sequence is fairly displayed. As well, the performance of the proposed method is examined in terms of bit-rate and PSNR using a rate-distortion curve.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.4
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• pp.375-384
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• 2005

Three dimensional urban models are being increasingly applied for various purposes such as city planning, telecommunication cell planning, traffic analysis, environmental monitoring and disaster management. In recent years, technologies from CAD and GIS are being merged to find optimal solutions in three dimensional modeling of urban buildings. These solutions include modeling of the interior building space as well as its exterior shape visualization. Research and development effort in this area has been performed by scientists and engineers from Computer Graphics, CAD and GIS. Computer Graphics and CAD focussed on precise and efficient visualization, where as GIS emphasized on topology and spatial analysis. Complementary research effort is required for an effective model to serve both visualization and spatial analysis purposes. This study presents an efficient way of using the CAD plans included in the building register documents to reconstruct the internal space of buildings. Topological information was built in the geospatial database and merged with the geometric information of CAD plans. as well as other attributal data from the building register. The GIS network modeling method introduced in this study is expected to enable an effective 3 dimensional spatial analysis of building interior which is developing with increasing complexity and size.

• Asia pacific journal of information systems
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• v.17 no.4
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• pp.133-163
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• 2007

Growth in the outsourcing market signals that firms of all sizes believe outsourcing will ultimately deliver many benefits and conveniences. But there are not many firms satisfied with the results of outsourcing. What is more, previous researches were fragmentary analyses focused on specific variables of outsourcing such as sourcing decisions, partnership rather than comprehensive analysis. Thus, they could not propose general systematic methodologies applicable to the real situation. To solve these problems, we developed an integrated theoretical framework that considered both contract with the hard side and trust with the soft side from a contingency viewpoint and tested this model using 143 data of Korean companies executing outsourcing. In addition, we examined how situational factors(outsourcing task complexity and outsourcing management competence) affects each path in the research model. The results of this study are as follows. First, it was proved the theory that trust is not a substitute for contract but its complement. Previous empirical studies on outsourcing success factors were focused on the establishment of successful partnership on the assumption that trust can replace contract in many situations. According to the results of our empirical analysis, however, contract and trust were in a mutually complementary relation with each other and their emphasis was different. Furthermore, different from previous researches, it was found effective to use trust as a supplementary tool and contract as a main means in outsourcing management strategy. Second, this study provided an integrated view that sees both contract and trust from a contingency viewpoint in theoretically reestablishing the relationship between contract and trust. Previous researches leaned to specific variables or theory-centered fragmentary analysis, but this study proposed a more practical and integrated research model and tested its effectiveness. Based on the results, with the model, decision makers are expected to scrutinize outsourcing situation more closely and to have a practical insight to the situation. Third, it was found that contract mechanism and trust building do not have a direct effect on outsourcing performance but relationship management intensity mediates the effect of contract mechanism and trust building. This is considered significantly meaningful to outsourcing partners who have believed that outsourcing would be successful if a contract is made properly or trust is built. Lastly, the path from trust building to relationship management intensity was moderated by informed buying, as the path coefficients from trust building to relationship management intensity varied by the degree of informed buying competence.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.4
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• pp.933-940
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• 2015

IT environments such as IoT, SNS, BigData, Cloud computing are changing rapidly. These technologies add new technologies to some of existing technologies and increase the complexity of Information System. Accordingly, they require enhancing the security function for new IT services. Information Security Pre-inspection aims to assure stability and reliability for user and supplier of new IT services by proposing development stage which considers security from design phase. Existing 'Information Security Pre-inspection' (22 domains, 74 control items, 129 detail items) consist of 6 stage (Requirements Definition, Design, Training, Implementation, Test, Sustain). Pilot tests were executed for one of IT development companies to verify its effectiveness. Consequently, for some inspection items, some improvement requirements and reconstitution needs appeared. This paper conducts a study on activation of 'Information Security Pre-inspection' which aims to construct prevention system for new information system. As a result, an improved 'Information Security Pre-inspection' is suggested. This has 16 domains, 54 inspection items, 76 detail items which include some improvement requirements and reconstitution needs.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.1
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• pp.37-44
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• 2015

In traditional social network analysis, the betweenness centrality measure has been heavily used to identify the relative importance of nodes. Since the time complexity to calculate the betweenness centrality is very high, however, it is difficult to get it of each node in large-scale social network where there are so many nodes and edges. In our past study, we defined a new type of network, called the expanded ego network, which is built only with each node's local information, i.e., neighbor information of the node's neighbor nodes, and also defined a new measure, called the expanded ego betweenness centrality. In this paper, We propose algorithm that quickly computes expanded ego betweenness centrality by exploiting structural properties of expanded ego network. Through the experiment with virtual network used Barab$\acute{a}$si-Albert network model to represent the generic social network and facebook network to represent actual social network, We show that the node's importance rank based on the expanded ego betweenness centrality has high similarity with that the node's importance rank based on the existing betweenness centrality. We also show that the proposed algorithm computes the expanded ego betweenness centrality quickly than existing algorithm.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.2
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• pp.158-170
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• 2008

In response to the changing demands of ever competitive market, SK Telecom has built a new marketing system that can support dynamic marketing campaigns and, at the same time, scale up to the large volumes of data and transactions for the next decade. The system which employs Unix-based client-server (using Web browser interfaces) architecture will replace the current mainframe-based COIS system. The project, named NGM (Next Generation Marketing ), is unprecedentedly large in scale. However, both managerial and technical problems led the project into a crisis. The application framework that depended on a software solution from a major global vendor could not support the dynamic functionalities required for the new system. In March 2005, SK telecom declared the suspension of the NGM project. The second phase of the project started in May 2005 following a comprehensive replanning. It was decided that no single existing solution could cope with the complexity of the new system and hence the new system would be custom-built. As such. a number of technical challenges emerged. In this paper, we report on the three key dimensions of technical challenges - middleware and application framework, database architecture and tuning, and system performance. The processes and approaches, adopted in building NGM system, may be viewed as "best practices" in the telecom industry. The completed NGM system, now called "U.key System," successfully came into operation on the ninth of October, 2006. This new infrastructure is expected to give birth to a series of innovative, fruitful, and customer-oriented applications in the near future.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.453-467
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• 2018

The excavation performance and the cutting tool wear prediction of shield TBM are very important issues for design and construction in TBM tunneling. For hard-rock TBMs, CSM and NTNU model have been widely used for prediction of disc cutter wear and penetration rate. But in case of soft-ground TBMs, the wear evaluation and the excavation performance have not been studied in details due to the complexity of the ground behavior and therefore few testing methods have been proposed. In this study, a new soil abrasion and penetration tester (SAPT) that simulates EPB TBM excavation process is introduced which overcomes the drawbacks of the previously developed soil abrasivity testers. Parametric tests for penetration rate, foam mixing ratio, foam concentration were conducted to evaluate influential parameters affecting TBM excavation and also ripper wear was measured in laboratory. The results of artificial soil specimen composed of 70% illite and 30% silica sand showed TBM additives such as foam play a key role in terms of excavation and tool wear.

• Journal of Distribution Science
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• v.11 no.6
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• pp.59-65
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• 2013

Purpose - Studies of mechanism as a competitive strategy, a relatively new field in the study of strategic management research, has recently drawn the attention of the business management scholars. The literature has so far proposed the subjective-based view, environment-based view, and the resource-based view in its analyses of firm management. Hence, it is highly likely for the firm management to be reasonably thought of as a combination of and interaction among the three key elements of subject, environment, and resources this is the mechanism-based view (MBV). It is reasonable to consider firm management to be the combination of and interaction among the three key elements of subject, environment, and resources. The overall dynamic process that integrates these three elements and creates functional harmony is identified as the mechanism, the principle of firm management. Much of the extant literatures on MBV has mainly focused on case studies, a qualitative approach prone to subjectivity of the researcher, although the intuition from the study may lead to meaningful insights into a firm-specific mechanism. This study's focus is also on case analysis, but it still attempts a quantitative approach in order to reach a scientific and systematic understanding of the MBV. Research design, data, and methodology - I used both a qualitative and quantitative approach to a single model, given the complexity of the innovation processes. I conducted in-depth interviews with POSCO employees-20 from general management, two from human resources, eight from information technology, five from finance and accounting, and five from production and logistics management. Once the innovative events were selected, the interview results were double-checked by the interviewees themselves to ensure the accuracy of the answers recorded. Based on the interview, I then conducted statistical validation using the survey results as well. Results - This study analyzes the building process of innovation and the effect of the mechanism pattern on innovation by examining the case of POSCO, which has survived over the past 21 years. I apply a new analytical tool to study mechanism innovation types, perform a new classification, and describe the interrelationships among the mechanism factors. This process allows me to see how the "Subject"factor interacts with the other factors. I found that, in the innovation process of the adoption stage, Subject had a mediating effect but that the mediating effect of resource and performance was smaller than the effect of Subject on performance alone. During the implementation stage, the mediating effect of Subject increased. Conclusion - Therefore, I have confirmed that the subject utilizes resources reasonably and efficiently. I have also advanced mechanism studies: whereas the field's research methods have been largely confined to single case studies, I have used both qualitative and quantitative methods to examine the relationships among mechanisms.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.98-104
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• 2018

The assessment of the light trespass in terms of light pollution is difficult due to the complexity of light environments. As a result, the light pollution research has examined the influences of light pollution using simulation program such as RELUX. However, there still exists a differences between the real measurement value and the simulation value for the light trespass. In this paper, we analyzed the light trespass using the RELUX simulation program, and compared results with real measurement values. In this study, the regions (Seoul, Incheon, etc.) were investigated regarding the light trespass for outdoor lighting. The survey of vertical illuminance was analyzed measuring point (more than 2 point) out the window that was expected to light trespass for the higher anticipated to illumination. The illuminational predicted values for the RELUX program were compared with maximum one. As a result of this study, the illuminational errors between the measurement values and predicted values for the simulation were examined from -0.97 lx to 0.65 lx except 2.08 lx and -7.70 lx. The light trespass was analyzed the higher by how much the located close to the height, length, width of the outdoor lighting for the window. For measuring predicted values using RELUX, it was not sufficiently considered in the simulation conditions because of environmental factors and investigator error etc. Limitations of this study include the limited number of measurements, and greater field data is required in future studies.