• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.506-508
• /
• 2002

As an advancement of medical imaging modalities and analyzing software with multi-function, active researches to acquire high contrast and high resolution image being done. In recently, development of medical imaging modalities like as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) is aiming to display anatomical structure more accuracy and faster. Thus, one of the important areas in CT today is the use of CT scanner for the quantitative evaluation of 3-D reconstruction images from 2-D tomographic images. In CT system, the effective slice thickness and the quality of 3-D reconstructed image will be influenced by imaging acquisition parameters (e.g. pitch and scan mode). In diagnosis and surgical planning, the accurate distance measurements of 3-D anatomical structures play an important role and the accuracy of distance measurements will depend on the acquisition parameters such as slice thickness, pitch, and scan mode. The skull phantom was scanned with SDCT for various acquisition parameters and acquisition slice thicknesses were 3 and 5 mm, and reconstruction intervals were 1, 2, and 3 mm to each pitch. 3-D visualizations and distance measurements were performed with PC based 3-D rendering and analyzing software. Results showed that the image quality and the measurement accuracy of 3-D SDCT images are independent to the reconstruction intervals and pitches.

• Korean Journal of Construction Engineering and Management
• /
• v.8 no.5
• /
• pp.152-160
• /
• 2007

Recently, the government is very active to secure the financial resources by inducement of the private investment in fulfilling an extension of the SOC facilities. One of the reasons that the private investors hesitate to put money into the private finance projects, however, is the lack of knowledges about various risks to be possibly incurred during the project execution. This research was performed as one of the preparation works in order for a A engineering company to act as a prime contractor of the project management service in the private finance project, and finally developed the risk factor dictionary as a new concept to satisfy the requirement of a A company and overcome a limit of the existing risk checklists. Although the risk factor dictionary looks like the only simplified table to be the risk factors identified in three dimensions, the impacts and response strategies expressed in narrative and multi-items, and the responsible parties indicated, it has great meanings to get a lot of direct and indirect accomplishments over the simplified table during the development process.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.4
• /
• pp.1502-1520
• /
• 2021

This paper attempts to investigate Korean youth Not in Education, Employment and Training (NEET) and how daily activities and community participation may influence their positive emotions and job search desire. First, we conducted a focus group interview with 16 NEETs who participated in the Kakao NEET Company project. The project allowed participants to experience employment by founding a virtual company in which each participant selected a daily activity to perform as part of the company's operations. Second, the interview responses were categorized and assigned emotional values using the card sorting technique and multi-dimensional analysis (MDS). A total of 11 emotional values were derived through this process. Finally, a social network analysis was conducted in order to measure the density of relations among the emotional values. Results suggest that immersion, confidence, belongingness were the three highest values evaluated by participants. Furthermore, network diagrams imply that the stronger participants perceived social support and belongingness with others, the stronger their responsibility grew, further leading them to establish steady goals. In particular, the high eigenvector score for "desire for job" suggests that emotional values are sequentially connected to the immersion-social support-responsibility-goal-job desire. This sequence suggests that digital services that are developed with the aim to enhance social values such as the Kakao NEET Project may engender motivation and confidence in youth NEETs. The overall results suggest that a systematic approach to policymaking should be considered in order to provide fundamental solutions and expand opportunities for social participation and emotional comfort, as social isolation due to low self-esteem has been reported as one of the reasons for NEETs' failure in the labor market.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.49 no.5
• /
• pp.91-98
• /
• 2012

Since the major cellular data service providers in U.S, Japan as well as in Korea started the LTE (Long Term Evolution) service, there has been more strong need for the methods that can accurately measure the MIMO (Multi Input-Multi Output) OTA (Over The Air) performance of LTE handsets because the performance of the MIMO antenna determines the data throughput in the downlink. In this paper, the hand effect on the MIMO antenna performance is analyzed by numerically and experimentally. The hand effect on the LTE mobile handset is analyzed by measuring the link level performance in the MIMO OTA system.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.108-113
• /
• 2009

Buildings with multi-complex spaces designed for architectural values and functional requirements give rise to technical challenges in terms of energy efficiency and thermal comfort. Since spaces in such buildings are connected with openings with geometrical complexity, it is hard to define zoning plan and to control heating/cooling loads effectively. This paper presents a case study on the evaluation of operation strategy for a building with multi-complex spaces using computer simulation. The modelling methodology and the results of the simulations are also described.

• Journal of the Korean housing association
• /
• v.19 no.2
• /
• pp.43-54
• /
• 2008

The aim of the research is to find out the direction of unit-plans in multi-dwellings for the future society. Shinonome Canal Court where residents actually live now are the objects in this study, and the residential floor plan of unit-plans were analyzed to find out the typical types. The analysis was focused on the unit-plans of 5 blocks of Shinonome Canal Court. Space Syntax Theory was used as the analysis method. As the first stage of the analysis, justified graphs were made to find out the characters of unit-plans through the classification of the graphs. Contents of the analysis are as follows: Relationship between classified justified graphs and dimension according to node number. Relationship between classified justified graph patterns and unit-plans. Characters of unit-plans in each blocks. Shinonome Canal Court consists of mainly small scale unit-plans and 30unit-plans are classified. 1LDK, 2LDK, 1LDK+S, 1LDK+f are typical unit-plans which are mainly supplied in the complex. It is noted that the results of the analysis by node, justified graph pattern and dimension are the same. It also presents diverse unit-plans which shows a change in nLDK pattern or add f (foyer), AN (annex), S (service room), Fs (free space) to basic nLDK type. In summary, it demonstrates the possibility of creating new residental floor plans in multi-dwellings.

• Steel and Composite Structures
• /
• v.31 no.5
• /
• pp.517-527
• /
• 2019

To move forward in large steps rather than in small increments, the community would benefit from a systematic and comprehensive database of multi-scale composites and measured properties, driven by comprehensive studies with a full range of types of fiber-reinforced polymers. The multi-scale hierarchy is a promising chemical approach that provides superior performance in synergistically integrated microstructured fibers and nanostructured materials in composite applications. Achieving high-efficiency thermal conductivity and mechanical properties with a simple surface treatment on single-walled carbon nanotubes (SWCNTs) is important for multi-scale composites. The main purpose of the project is to introduce ozone-treated SWCNTs between an epoxy matrix and basalt fibers to improve mechanical properties and thermal conductivity by enhancing dispersion and interfacial adhesion. The obvious advantage of this approach is that it is much more effective than the conventional approach at improving the thermal conductivity and mechanical properties of materials under an equivalent load, and shows particularly significant improvement for high loads. Such an effort could accelerate the conversion of multi-scale composites into high performance materials and provide more rational guidance and fundamental understanding towards realizing the theoretical limits of thermal and mechanical properties.

• Journal of the Korean Society of Systems Engineering
• /
• v.16 no.2
• /
• pp.1-15
• /
• 2020

Nuclear power plants in South Korea are operated to cover the baseload demand. Hence they are operated at 100% rated power and do not deploy power tracking control except for startup, shutdown, or during transients. However, as the contribution of renewable energy in the energy mix increases, load follow operation may be needed to cover the imbalance between consumption and production due to the intermittent nature of electricity produced from the conversion of wind or solar energy. Load follow operation may be quite challenging since the operators need to control the axial power distribution and core reactivity while simultaneously conducting the power maneuvering. In this paper, a systems engineering approach for multi-physics load follow simulation of APR1400 is performed. RELAP5/SCDAPSIM/MOD3.4/3DKIN multi-physics package is selected to simulate the Korean Advanced Power Reactor, APR1400, under load follow operation to reflect the impact of feedback signals on the system safety parameters. Furthermore, the systems engineering approach is adopted to identify the requirements, functions, and physical architecture to provide a set of verification and validation activities that guide this project development by linking each requirement to a validation or verification test with predefined success criteria.

• Journal of The Korean Astronomical Society
• /
• v.38 no.2
• /
• pp.187-190
• /
• 2005

The Cosmic Evolution Survey (COSMOS) is a Hubble Space Telescope (HST) treasury project. The COSMOS aims to perform a 2 square degree imaging survey of an equatorial field in I(F814W) band, using the Advanced Camera for Surveys (ACS). Such a wide field survey, combined with ground-based photometric and spectroscopic data, is essential to understand the interplay between large scale structure, evolution and formation of galaxies and dark matter. In 2004, we have obtained high-quality, broad band images of the COSMOS field (B, V, r', i', and z') using Suprime-Cam on the Subaru Telescope, and we have started our new optical multi-band program, COSMOS-21 in 2005. Here, we present a brief summary of the current status of the COSMOS project together with contributions from the Subaru Telescope. Our future Subaru program, COSMOS-21, is also discussed briefly.

• Journal of the Korea Institute of Building Construction
• /
• v.8 no.1
• /
• pp.49-56
• /
• 2008

According to the recent trends which are the diversity of customer requests and the multi-function of buildings, A construction company's business has converted from the producer-oriented approach to the consumer-oriented approach. Therefore, each construction company is continuously trying to improve the quality level as a way of corresponding to customer needs in these changing situations. The quality is one of the main management targets which judge the success of a project along with the schedule, the cost and the safety. As construction companies execute the quality management which they aimed at, it should be completed within the optimum schedule and the limit of the budget. Accordingly, the importance of the construction site management to complete a project is continuously increasing. The construction site management is the systematic method to perform the project goals such as the quality improvement, the cost saving and the safety management, which organically operate one another, by procuring the manpower, the material and the machine in the right time. Specially, as the construction industry has based on the construction site, the establish of systematic construction site management, which can effectively correspond sudden changes of the construction business environment, is essential to maximize the construction productivity. On top of that, the necessity of the quality management method is increasing to accommodate customer needs more spontaneously in the construction site. These endeavors could guarantee their competitive power.