• Radiation Oncology Journal
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• v.28 no.4
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• pp.238-248
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• 2010

Purpose: To compare the dose distributions between three-dimensional (3D) and four-dimensional (4D) radiation treatment plans calculated by Ray-tracing or the Monte Carlo algorithm, and to highlight the difference of dose calculation between two algorithms for lung heterogeneity correction in lung cancers. Materials and Methods: Prospectively gated 4D CTs in seven patients were obtained with a Brilliance CT64-Channel scanner along with a respiratory bellows gating device. After 4D treatment planning with the Ray Tracing algorithm in Multiplan 3.5.1, a CyberKnife stereotactic radiotherapy planning system, 3D Ray Tracing, 3D and 4D Monte Carlo dose calculations were performed under the same beam conditions (same number, directions, monitor units of beams). The 3D plan was performed in a primary CT image setting corresponding to middle phase expiration (50%). Relative dose coverage, D95 of gross tumor volume and planning target volume, maximum doses of tumor, and the spinal cord were compared for each plan, taking into consideration the tumor location. Results: According to the Monte Carlo calculations, mean tumor volume coverage of the 4D plans was 4.4% higher than the 3D plans when tumors were located in the lower lobes of the lung, but were 4.6% lower when tumors were located in the upper lobes of the lung. Similarly, the D95 of 4D plans was 4.8% higher than 3D plans when tumors were located in the lower lobes of lung, but was 1.7% lower when tumors were located in the upper lobes of lung. This tendency was also observed at the maximum dose of the spinal cord. Lastly, a 30% reduction in the PTV volume coverage was observed for the Monte Carlo calculation compared with the Ray-tracing calculation. Conclusion: 3D and 4D robotic radiotherapy treatment plans for lung cancers were compared according to a dosimetric viewpoint for a tumor and the spinal cord. The difference of tumor dose distributions between 3D and 4D treatment plans was only significant when large tumor movement and deformation was suspected. Therefore, 4D treatment planning is only necessary for large tumor motion and deformation. However, a Monte Carlo calculation is always necessary, independent of tumor motion in the lung.

• Korean Journal of Construction Engineering and Management
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• v.14 no.5
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• pp.175-187
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• 2013

Each participant in building construction project requires their own workspace to execute their activities. In this environment, inappropriate workspace planning in construction site causes workspace conflicts which result in a loss of productivity, safety hazard and poor-quality issues. Therefore, workspace should be regarded as one of the most important resources and constraints have to be managed at construction site. However, current construction planning techniques such as Gantt chart, network diagram and critical path method have proven to be insufficient to workspace planning. This paper contains formalized process for workspace planning in 4D BIM environment to prevent workspace related problems in construction project. The proposed process in this paper represents workspace occupation status for each activity and suitable solutions for identified workspace conflicts by integrating workspace attributes and activity execution plan. Based on the result of this study, project manager will be able to prevent probable workspace conflicts and negative effect on project performance by devising appropriate workspace plan during preconstruction phase.

• Progress in Medical Physics
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• v.28 no.1
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• pp.27-32
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• 2017

We investigated the effect of a commercial iterative reconstruction technique (iDose, Philips) on the image quality and the dose calculation for the treatment plan. Using the electron density phantom, the 3D CT images with five different protocols (50, 100, 200, 350 and 400 mAs) were obtained. Additionally, the acquired data was reconstructed using the iDose with level 5. A lung phantom was used to acquire the 4D CT with the default protocol as a reference and the low dose (one third of the default protocol) 4D CT using the iDose for the spine and lung plans. When applying the iDose at the same mAs, the mean HU value was changed up to 85 HU. Although the 1 SD was increased with reducing the CT dose, it was decreased up to 4 HU due to the use of iDose. When using the low dose 4D CT with iDose, the dose change relative to the reference was less than 0.5% for the target and OARs in the spine plan. It was also less than 1.1% in the lung plan. Therefore, our results suggests that this dose reduction technique is applicable to the 4D CT image acquisition for the radiation treatment planning.

• Journal of Science and Technology Studies
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• v.4 no.2 s.8
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• pp.103-127
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• 2004

This paper analyzes the strategic planning process of NASA (National Aeronautics and Space Administration) including its center, GSFC (Goddard Space Flight Center) in the framework of strategic planning in publicly funded R&D organizations. To construct this framework, theories have been considered mainly focused on strategic management and planning, its application on public sector, and characteristics of R&D activities. As a result, the framework could be set up in accordance with the process of strategic planning. Also, as a case study, we explored the practice of strategic planning process and organizational implementation of NASA and GSFC. During the analysis on the strategic process of NASA and GSFC, we could draw some lessons out as follows: First, we should consider the differences between private and public sectors when we establish strategic planning in public sector. Second, the stakeholder analysis should be involved in setting the mission, goals, and strategies of an organization. Third, it is necessary to identify and assess the socio-economic effects or public benefits by R&D programs of the organization and use the feedback on its goal. Fourth, to implement strategic planning effectively, planning process should be closely integrated with the management process such as setting goals, securing budgets, and evaluating the organization. Conclusively, the analysis on NASA and GSFC contribute to implementing strategic planning in publicly funded R&D organizations by providing the appropriately modified framework. As an extension of this study, more deliberate analysis on various practices of strategic planning and performance indicators should be followed.

• Journal of the Korea Convergence Society
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• v.8 no.4
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• pp.131-137
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• 2017

In the present study, we developed the 4D CT data generation program from CAD-based models. To evaluate the developed program, a CAD-based respiratory motion phantom was designed using CAD software, and converted into 4D CT dataset, which include 10 phases of 3D CTs. The generated 4D CT dataset was evaluated its effectiveness and accuracy through the implementation in radiation therapy planning system (RTPS). Consequently, the results show that the generated 4D CT dataset can be successfully implemented in RTPS, and targets in all phases of 4D CT dataset were moved well according to the user parameters (10 mm) with its stationarily volume (8.8 cc). The developed program, unlike real 4D CT scanner, due to the its ability to make a gold-standard dataset without any artifacts constructed by modality's movements, we believe that this program will be used when the motion effect is important, such as 4D radiation treatment planning and 4D radiation imaging.

• Radiation Oncology Journal
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• v.28 no.3
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• pp.177-183
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• 2010

Purpose: Simulation using computed tomography (CT) is now widely available for radiation treatment planning for breast cancer. It is an important tool to help define the tumor target and normal tissue based on anatomical features of an individual patient. In Korea, most patients have small sized breasts and the purpose of this study was to review the margin of treatment field between conventional two-dimensional (2D) planning and CT based three-dimensional (3D) planning in patients with small breasts. Materials and Methods: Twenty-five consecutive patients with early breast cancer undergoing breast conservation therapy were selected. All patients underwent 3D CT based planning with a conventional breast tangential field design. In 2D planning, the treatment field margins were determined by palpation of the breast parenchyma (In general, the superior: base of the clavicle, medial: midline, lateral: mid - axillary line, and inferior margin: 2 m below the inframammary fold). In 3D planning, the clinical target volume (CTV) ought to comprise all glandular breast tissue, and the PTV was obtained by adding a 3D margin of 1 cm around the CTV except in the skin direction. The difference in the treatment field margin and equivalent field size between 2D and 3D planning were evaluated. The association between radiation field margins and factors such as body mass index, menopause status, and bra size was determined. Lung volume and heart volume were examined on the basis of the prescribed breast radiation dose and 3D dose distribution. Results: The margins of the treatment field were smaller in the 3D planning except for two patients. The superior margin was especially variable (average, 2.5 cm; range, -2.5 to 4.5 cm; SD, 1.85). The margin of these targets did not vary equally across BMI class, menopause status, or bra size. The average irradiated lung volume was significantly lower for 3D planning. The average irradiated heart volume did not decrease significantly. Conclusion: The use of 3D CT based planning reduced the radiation field in early breast cancer patients with small breasts in relation to conventional planning. Though a coherent definition of the breast is needed, CT-based planning generated the better plan in terms of reducing the irradiation volume of normal tissue. Moreover it was possible that 3D CT based planning showed better CTV coverage including postoperative change.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.4
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• pp.48-54
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• 2012

In this paper, quantitative and systematic procedures for establishing Key Performance Indicators (KPI's) of R&D departments are presented. The proposed methodology is composed of 4 steps : 1) identification of critical success factors, 2) identification of potential KPI's, 3) determination of KPI's and 4) monitoring and execution. A Strategy Map has been presented to better align KPI's with a company's competitive strategies. Also, Analytical Hierarchy Planning (AHP) is used to determine weights of KPI's and Data Envelopment Analysis (DEA) is used to analyze the effectiveness of R&D departments. To demonstrate its validity of the proposed method, it has been applied to the R&D divisions of a semiconductor company.

• Journal of Korea Technology Innovation Society
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• v.18 no.1
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• pp.1-27
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• 2015

Korea has increased R&D investment continuously for the improvement of global technological competencies. Korea ranked first in the world with 4.15 percent in the ratio of R&D investment to GDP. In particular, the private sector occupies a crucial position of technological innovations in Korea, constituting 78.5% of total R&D investment. However, quantitative growth strategy is no longer effective, so efforts to enhance efficiency by upgrading qualitative level are badly needed. This paper studied methods for improving firms' business performance. For this, it tried to empirically verify technology strategy and technology planning capability's influence factors on the improvement of business performance. The study showed that technology strategy and technology planning activities have positive effects on the improvement of business performance. And it was revealed that coordination flexibility contributes to the enhancement of business performance by positively controlling technology planning activities. The study performed sample survey on the companies with R&D centers and multiple regression analysis and quantile regression were used for the analysis.

• International Journal of High-Rise Buildings
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• v.3 no.4
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• pp.311-323
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• 2014

This paper introduces recent applications of three-dimensional building/construction data modeling (3D) and building information modeling (BIM) to large-scale complex building construction projects in Japan. Recently, BIM has been utilized as a tool in construction process innovation through planning, design, engineering, procurement and construction to establish a front-loading-type design building system. Firstly, the background and introduction processes of 3D and BIM are described to clarify their purposes and scopes of applications. Secondly, 3D and BIM applications for typical large-scale complex building construction projects to improve planning and management efficiency in building construction are presented. Finally, future directions and further research issues with 3D and BIM applications are proposed.

• Industry Promotion Research
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• v.8 no.2
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• pp.1-9
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• 2023

To bridge the research gap in the area of the Fourth Industrial Revolution, we explore the correlation between the core technologies of the Fourth Industrial Revolution and the economic performance of companies. The results show that the technologies have a statistically significant positive (+) correlation with company sales. The size of the correlation is highest for 3D printing (139%), followed by big data (129%), cloud computing (127%), artificial intelligence (78%), and the internet of things (70%). We also found a statistically significant negative (-) interaction effect between the internet of things and 3D printing, cloud computing and big data, and cloud computing and 3D printing when examining the interaction effect of introducing core technologies of the Fourth Industrial Revolution on company sales. This paper represents an early attempt to examine the correlation between the core technologies of the Fourth Industrial Revolution and the economic performance of companies and may serve as a basis for further empirical research.