• Progress in Medical Physics
• /
• v.14 no.3
• /
• pp.151-160
• /
• 2003

The application of more complex radiotherapy techniques using multileaf collimation (MLC), such as 3D conformal radiation therapy and intensity-modulated radiation therapy (IMRT), has increased the significance of verifying leaf position and motion. Due to thier reliability and empirical robustness, quality assurance (QA) of MLC. However easy use and the ability to provide digital data of electronic portal imaging devices (EPIDs) have attracted attention to portal films as an alternatives to films for routine qualify assurance, despite concerns about their clinical feasibility, efficacy, and the cost to benefit ratio. In this study, we developed method for daily QA of MLC using electronic portal images (EPIs). EPID availability for routine QA was verified by comparing of the portal films, which were simultaneously obtained when radiation was delivered and known prescription input to MLC controller. Specially designed two-test patterns of dynamic MLC were applied for image acquisition. Quantitative off-line analysis using an edge detection algorithm enhanced the verification procedure as well as on-line qualitative visual assessment. In conclusion, the availability of EPI was enough for daily QA of MLC leaf position with the accuracy of portal films.

• Journal of Technology Innovation
• /
• v.23 no.3
• /
• pp.201-223
• /
• 2015

Existing research on international standardization has largely taken a qualitative approach focusing on comparative studies of national institutions and policies on standards or international rivalries from the perspectives of international relations or innovation studies. While there exists a handful of quantitative studies, they are mostly confined to simple numeric counts of essential patents, new work item proposals, or secretaries staffing international standards development organizations (SDOs). This study aims to contribute to our understanding of the dynamics of international standardization by the analysis of the data coding systematically national activities in the standardization process of the International Organization for Standardization (ISO), by far the largest international SDO. Our analysis of the four critical types of standardization documents generated in the Working Group 7 of the ISO/IEC Joint Technical Committee 1 reveals interesting dynamics among key players of global ICT standards regime. First, while the US takes a dominant share of the personnel as well as new work item proposals for standardization, its quality of activities rather falls behind as it mostly focuses on keeping in check other countries' standardization activities. Second, European countries tend to spread their effort evenly across different types of standardization activities. Finally, despite such differences between the US and European countries, both rely heavily on multinational companies to gain an advantage in the voting stage of standardization process.

• Analytical Science and Technology
• /
• v.18 no.1
• /
• pp.43-50
• /
• 2005

A number of carbonyl compounds including formaldehyde and acetaldehyde are well known for their toxicity and irritancy. Hence, acquisition of both qualitative and quantitative tool for their analysis is essential to resolve issues associated with malodor or indoor pollution. Using HPLC/UV method, we examined various aspects involved in the measurements of formaldehyde in environmental samples. The results of our analysis indicated that its detection was made as low as 0.5 ppb (assuming 5 L of sample volume), while its precision was maintained near 2% in terms of relative standard error (RSE). When the stability of calibration was checked by variability of slope values obtained over long-term period (e.g., one month), its values were found to remain constantly with RSE values of 3%. It was also found that liquid-phase reaction between formaldehyde and DNPH proceed very slowly to attain equilibrium (one and half hour), while requiring adequate amount of DNPH to form their derivatives. The overall results of our study thus suggest that there are a number of factors to consider for the accurate analysis of formaldehyde in ambient air.

• Journal of the Korean Society of Earth Science Education
• /
• v.10 no.2
• /
• pp.185-198
• /
• 2017

In this study, the researches published in Korea during the six years since 2011, when the STEAM started in earnest, were classified by year, content, type, subject, and center area. in 2011, when STEAM was launched, it was hard to find relevant articles, but it has been increasing rapidly since 2013. The number of articles published by the contents was development application 650(48.9%), effect analysis 394(29.6%), theory contents 179(13.5%), and actual condition recognition 107(8.0%). The number of articles published by research type were quantitative research 347(34.7%), qualitative research 274 (27.4%), mixed research 379(37.9%). The number of articles published by research subjects was 435(40.2%) for elementary school, 209(19.4%) for middle school, 151(14.0%) for high school, 150(13.9%) for literature, 88(8.1%) for teacher, 19(1.8%) for child, 11(1.0%) for preliminary teacher, 9(0.8%) for university and 9(0.8%) for Public. The percentage of research centered on science is the highest of 383(33.2%), while the research on art, technology, and mathematics is also 266(23.0%), 161(13.9%), 152(13.2%). In elementary science, the articles related to STEAM education showed a tendency to decrease in 2014, unlike overall trends, and it mainly conducted research on development and application, effect analysis, and preferred mixed research.

• Analytical Science and Technology
• /
• v.27 no.2
• /
• pp.108-113
• /
• 2014

The harmful materials as volatile organic compounds (VOCS) that is easy for gas to be changed from liquid on ambient temperature, those should be controlled by Korea Chemicals Management Association. The VOCs samples should be collected directly in place so that those could be analyzed. Generally but it couldn't avoid to have the risk of analyst. Moreover, if there is the place limited to entrance, it is impossible to collect directly and measure. Owing to such problem, it tried to be solved by open path FT-IR spectrometer that could be studied on the combustion gases within long path and VOCs samples were tried to measure to large volume by remote and real time. Firstly, it was to investigate optimized measured length between the system and benzene sample of VOCs. As result, The optimized measured length was confirmed with 15 meter length and the qualitative analysis could be measured on seven VOC samples. The calibration curve as quantitative analysis of benzene samples could be worked. On the basis of the result, the system as remote monitor could show to have potentiality.

• The Journal of the Korea Contents Association
• /
• v.15 no.8
• /
• pp.448-459
• /
• 2015

This study discusses on the social communication phenomenon on online social media by comparative analysis among bridging and bonding social capital. It examined the social media usage, social communication recognition, social communication satisfaction and intent social participation by exploring social capital which are the main influential factors of online social media. The online survey was conducted on 500 adults over the age of 20. As a result, in a quantitative respect a high rate of online media usage was observed all social capital. On the other hand, in a qualitative aspects 'understand' and 'trust' was came out in the bonding capital, but 'agreement' was not observed in all social capital. Also the influential factors of intent social participation were different in the social capital. The bonding was affected by 'understanding' but the bridging was affected by 'trust' and 'agreement'. Therefore, it was able to discuss that the understanding of online social media user and social communication characteristic must be preceded and the activator policy of social communication must consider the different features of online social capital.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.9
• /
• pp.5861-5869
• /
• 2014

Existing studies of building exterior materials have focused on the colors or textures of cladding, and in terms of a design planning approach, have focused on the use of the environment and equipment and fire safety topics from an engineering perspective. As a result, little research has been done on performance guidelines for exterior materials, specifically according to the building type. Research into eco-friendly cladding materials is also in the rudimentary stage in a practical sense. In this study, the use of exterior materials over the last ten years in domestic construction was analyzed. The usage status of building exterior materials was evaluated quantitatively by frequency analysis, and its environmental performance is proposed through complex (qualitative + quantitative) analysis. The average value of the exterior material type number used for all analyzed buildings was 2.59. Glass, metal, stone, resin, cement, wood, and clay were used in that order with regard to the usage status. The analysis found that five of the materials satisfied the high efficiency and eco-friendly grading in terms of the four characteristics of an eco-friendly exterior. A list of eight eco-friendly elements was also proposed. The eco-friendly elements and characteristics of the exterior materials were derived to provide basic guidelines for domestic construction companies and design offices.

• Journal of Astronomy and Space Sciences
• /
• v.22 no.1
• /
• pp.13-20
• /
• 2005

Bound abrasive grinding is used for the initial fabrication phase of the precision aspheric mirrors for both space and ground based astronomical telescopes. We developed a new grinding optimization process that determines the input grinding variables for the target surface roughness, checks the grinding error magnitude in resulting surface roughnesses, and minimizes the required machining time. Using the machining data collected from the previous grinding runs and subsequently fed into the multivariable regression engine, the process has the evolving controllability that suggests the optimum set of grinding variables for each target surface roughness. The process model was then used for ten grinding experiments that resulted in the grinding accuracy of $=-0.906{\pm}3.38(\sigma)\;nm(Ra)$ for the target surface roughnesses of Zerodur substrate ranging from 96.1 nm (Ra) to 65.0 nm (Ra) The results imply that the quantitative process optimization technique developed in this study minimizes the machining time and offers the nanometric surface roughness controllability superior to the traditional, qualitative, craftsman based grinding process for the astronomical optical surfaces.

• Korean Journal of Cognitive Science
• /
• v.20 no.1
• /
• pp.79-107
• /
• 2009

Episodic memory, i.e. memorization of information within a spatiotemporal environment, is affected Alzheimer's disease(AD), but its impairment may also be occurred in the normal aging process. The purpose of this study is to analyze and evaluate memory in with Dementia of Alzheimer Type by examining their cognitive skills in episodic memory using the technique. This new method involves assessing the mental images the subject's own past in the mind like projected and movies. Three patients in the early stage of Dementia of Alzheimer Type, one with mild depression, and 2 healthy controls for comparison were asked to retrieve their episodic memory of the previous day, week, month, and a day testing day. The answers were then analyzed with regards to their specific features as emotional state, color, and time order. In the following day, the subjects were tasked to recall again the images they reproduced in the day's test order to observe of memory. Results showed that all 3 patients failed to arrange the retrieved images in time order and their images of the previous day were unclear in color and were stationary like photographs, even when they reproduced the mental images at much quantity as controls. patients could not remember particular events of yesterday, and only recalled the general occurrences of every day life. These results suggest that in the early stage of Dementia of Alzheimer Type, difficulties in the retrieval of recent episodic memory begin to primarily occur, and qualitative impairment happens earlier than quantitative.

• The KIPS Transactions:PartB
• /
• v.9B no.1
• /
• pp.1-6
• /
• 2002

Many customers consult the Internet before making purchase goods and using contents. The systems in the Internet could store a lot of data and classify the data into information to get relationship between a company and customers. To do that, let's consider a knowledge-assisted hybrid system that utilizes individually a customer's preference to make an optimal solution in the his/her decision making. The knowledge made by using the preference is employed to select an domain set appropriate to him/her business, and the process of selecting definitely provides the customer some benefits: elimination of discomfort from unknown information and reduction of costs and search time for forming an suitable domain set. To effectively adopt individual customer's preference and actively adapt change of business situation, this study propose an architecture of the system which includes rule presentations and an inference engine, and integrates a knowledge-based component into a quadratic programming component. In the experimental results, it is found that a knowledge-assisted hybrid system implemented by this idea is more flexible than existing systems in extension of knowledge about an customer's preference and goes beyond the traditional models.