• Journal of radiological science and technology
• /
• v.46 no.3
• /
• pp.231-238
• /
• 2023

This study aimed to compare the results of delivery quality assurance (DQA) using MapCHECK and OCTAVIUS for radiation therapy. Thirty patients who passed the DQA results were retrospectively included in this study. The point dose difference (DD) and gamma passing rate (GPR) were analyzed to evaluate the agreement between the measured and planned data for all cases, Plan complexity was evaluated to analyze dosimetric accuracy by quantifying the degree of modulation according to each plan. We analyzed the monitor units (MUs) and total MUs for each plan to evaluate the correlation between the MUs and plan complexity. We used a paired t-test to compare the DD and GPRs that were obtained using the two devices. The DDs and GPRs were within the tolerance range for all cases. The average GPRs difference between the two devices was statistically significant for the brain, and head and neck for gamma criteria of 3%/3 mm and 2%/2 mm. There was no significant correlation between the modulation index and total MUs for any of the cases. These DQA devices can be used interchangeably for routine patient-specific QA in radiation therapy.

• The Journal of Engineering Geology
• /
• v.17 no.3
• /
• pp.411-418
• /
• 2007

It is a very difficult thing to estimate an occurrence possibility location and hazard expectation area by landslide. The prediction difficulty of landslide occurrence has relativity in factor of various geological physical factors and contributions. However, estimation of landslide occurrence possibility and classification of hazard area became available correlation mechanism through analysis of landslide occurrence through landslide data analysis and statistical analysis. This study analyzed a damage possibility of a cultual heritage area due to landslide occurrence by a heavy rainfall. We make a landslide prediction map and tried to analysis of landslide occurrence possibility for the cultural heritage site. The study area chooses a temple of Silsang-Sa Baekjang-Am site and made a landslide prediction map. In landslide prediction map, landslide hazard possibility area expressed by occurrence probability and divided by each of probability degrees. This degree used to evaluate occurrence possibility for existence and nonexistence of landslide in the study site. For the prediction and evaluation of landslide hazard for the cultural heritage site, investigation and analysis technique which is introduced in this study may contribute an efficient management and investigation in the cultural heritage site, Korea.

• Journal of the Korean Geographical Society
• /
• v.38 no.6
• /
• pp.949-960
• /
• 2003

The marginal implicit price of air quality can be measured by taking a partial derivative of hedonic price function (HPF) with respect to the level of air quality. It has been pointed out that the size of the marginal implicit price varies with the use of different function forms, different estimation methods, and the different ways of measuring air quality level in estimating HPF. In addition to these factors, this study shows theoretically and empirically the way housing properties are represented on a digital map could differentiate the size of marginal implicit price of air quality when GIS is used to measure location attributes of the housing properties in the Korean apartment market. Furthermore, this study shows that the degree of difference in the marginal implicit price due to the manner in which housing properties are represented on a digital map can be larger than the degree of difference in the marginal implicit price due to using different function forms and estimation methods. The major implication from the results of this study is that one should carefully try diverse ways of representing housing properties in the Korean apartment market on a digital map in the process of estimating HPF, as he or she usually tries diverse function forms and estimation methods, to see if the value of the marginal implicit price of air quality varies substantially.

• Computational Structural Engineering
• /
• v.10 no.4
• /
• pp.239-249
• /
• 1997

The method to distinguish chaotic attractors in the perturbed response behaviors of a piecewise-linear system under combined regular and external randomness is provided and examined. In the noisy fields such as the ocean environment, excitation forces induced by wind, waves and currents contain a finite degree of randomness. Under external random perturbations, the system responses are disturbed, and consequently chaotic signatures in the response attractors are not distinguishable, but rather look just random-like. Mean Poincare map can be utilized to identify such chaotic responses veiled due to the random noise by averaging the noise effect out of the perturbed responses. In this study, the procedure to create mean Poincare map combined with the direct numerical simulations is provided and examined. It is found that mean Poincare maps can successfully distinguish chaotic attractors under stochastic excitations, and also can give the information of limit value of noise intensity with which the chaos signature in system responses vanishes.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.7
• /
• pp.12-19
• /
• 2020

The clustered heterogeneous wireless sensor network is comprised of sensor nodes and cluster heads, which are hierarchically organized for different objectives. In the network, we should especially take care of managing node resources to enhance network performance based on memory and battery capacity constraints. For instances, if some interesting events occur frequently in the vicinity of particular sensor nodes, those nodes might receive massive amounts of data. Data congestion can happen due to a memory bottleneck or link disconnection at cluster heads because the remaining memory space is filled with those data. In this paper, we utilize drones as mobile sinks to resolve data congestion and model the network, sensor nodes, and cluster heads. We also design a cost function and a congestion indicator to calculate the degree of congestion. Then we propose a data congestion map index and a data congestion mapping scheme to deploy drones at optimal points. Using control variable, we explore the relationship between the degree of congestion and the number of drones to be deployed, as well as the number of drones that must be below a certain degree of congestion and within communication range. Furthermore, we show that our algorithm outperforms previous work by a minimum of 20% in terms of memory overflow.

• Journal of Korean Society of Water and Wastewater
• /
• v.26 no.5
• /
• pp.669-683
• /
• 2012

The water supply pipes are buried across wide range of areas, so it is hard to spot them using excavation and takes a large amount of expense. Thus, there is a high risk for direct research and application, accompanying many difficulties in implementation of them. Therefore, it is more economical and convenient to use indirect evaluation variables than direct evaluation of the buried pipes in assessing the degree of pipe deterioration. To assess the degree of pipe deterioration using the indirect evaluation variables, it should be done first to identify how and to what extent they affect the degree of deterioration. This study measured the evaluation variables for pipe deterioration using the pipe endoscope and analyzed the measurement results and the degree of impact on the pipes. In addition, this study attempted to evaluate the adequateness of the pipe deterioration evaluation using the indirect variables based on the analysis results. The evaluation variables measured through the pipe endoscope were the thickness of sediments, size of scale, degree of desquamation and condition of connections. For the indirect evaluation variables, the data such as the property data from GIS pipe network map as well as the material, diameter, age and pipe lining material of the pipe, road type, leakage frequency, average water velocity and water pressure using the leakage repair records was collected. Using the collected data, this study comparatively analyzed the indirect evaluation variables for the degree of pipe deterioration and the results from the pipe endoscope to choose appropriate variables for pipe deterioration evaluation and calculated the weights of the indirect variables on the degree of deterioration. The results showed that the order of the impact of indirect variables on deterioration was pipe age > pipe lining material > road type > leakage frequency > average water velocity with their weights of 0.45, 0.20, 0.15, 0.10, and 0.10, respectively. Conclusively, the results suggest that the measures of sediment thickness, scale size, degree of desquamation and condition of connections are appropriate for the evaluation of pipe deterioration and sufficient for the analysis of the impact of the indirect variables on deterioration.

• Journal of Broadcast Engineering
• /
• v.24 no.6
• /
• pp.1053-1063
• /
• 2019

Recently, tile-based streaming that transmits one 360 video in several tiles, is actively being studied in order to transmit these 360 video more efficiently. In this paper, for the transmission of high-definition 360 video corresponding to user's viewport in tile-based streaming scenarios, a system of assigning the quality of tiles at each tile by applying the saliency map generated by existing network models is proposed. As a result of usage of Motion-Constrained Tile Set (MCTS) technique to encode each tile independently, the user's viewport was rendered and tested based on Salient360! dataset, streaming 360 video based on the proposed system results in gain to 23% of the user's viewport compared to using the existing high-efficiency video coding (HEVC).

• Journal of the Korean Society of Clothing and Textiles
• /
• v.39 no.4
• /
• pp.505-516
• /
• 2015

This study investigated difference of product interest and its relation to consumers' innate innovativeness according to gender as well as compared the perceptive construct of products between male and female consumers. A survey involving male and female college students was conducted in the Daegu and Gyeongbuk areas in December 2013. Subsequently, 400 responses were analyzed using descriptive statistics, correlations, independent sample t-test, reliability analysis, ANCOVA, and multidimensional scaling. Among 45 products, male respondents showed a significantly high degree of interest over 12 categories such as watches, desktop computers, cars, sports products, and video games compared to females. The female sample showed a significantly high degree of interest for 29 product categories such as clothing, movies, skin care shops, cosmetics, eating-out, teeth whitening, coffee, cameras, and performances compared to males. Innovative male consumers were interested in traveling, movies, clothing, eating-out, running shoes, and wallets; however, female consumers' innovativeness was significantly related to previously determined items of interest. Two dimensions explaining the male consumers' products perception construct were 'hard versus soft' and 'usual versus special'. Instead, female consumers' were 'special versus usual' and 'expressive versus functional'.

• Journal of Korean Academy of Nursing Administration
• /
• v.15 no.4
• /
• pp.571-580
• /
• 2009

Purpose: The purpose of this study was to explore roles of cancer care coordinator's by developing job description, job specification and job process map using dynamic job analysis. Method: The development process consisted of three stages of vertical job analysis and three stages of horizontal job analysis by modifying Song(1997)'s dynamic job analysis. Focus group interview was used to validate the content of the job analysis. Results: Cancer care coordinator's job description was categorized into six major categories, fourteen intermediate categories and one hundred forty specific jobs. Major categories are professional nursing practice, consultation and counsel, coordination and collaboration, education, research and leadership. Cancer care coordinator's job specification included master's degree with over five years of clinical experience preferably relevant clinical area, professional knowledge on pathophysiology of cancer, case management and cost control, competency for communication and counselling skills and clinical decision making. Cancer care coordinator's job process map was framed with time(horizontal) and activities(vertical). Conclusion: The Outcomes of this study will guide to develop possible areas of oncology advanced practice nurses in hospital setting and facilitate the use of oncology nurse practitioners by developing care coordinator roles in cancer care.

• Journal of the Korean Geographical Society
• /
• v.43 no.4
• /
• pp.638-654
• /
• 2008

A questionnaire survey is conducted to identify the middle school students' abilities to recognize the proportional symbolic maps. After analyzing the data from the respondents, three facts could be concluded. First, the trends of under-estimation are represented as the power function and the degree of under-estimation is increased as the sequence of line, square, circle, sphere symbols. Second, the estimations of symbol size are effected by the number of symbols in the legend(3, 5, 7), the presentation methods of legends(linear, nested), and the system to scale the symbol size(mathematical, perceptual). Lastly, the size of symbols on the map tends to be over-estimated comparing to the symbols in the legend, and the differences between the first year and third year students to recognize the proportional symbol maps are not identified.