• Journal of the Society of Naval Architects of Korea
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• v.39 no.4
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• pp.17-23
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• 2002

The present paper describes the optimum inverse design of 2-D linear cascade airfoil. The pressure coefficient of an airfoil surface is taken as the objective function, and non-orthogonal incompressible Navier-Stokes equation is applied to calculate the pressure coefficient. Both of steepest descent and conjugate gradient method have been used to make the objective function go to zero. The 1st order finite differential method is applied to the searching direction and the golden section method is used to compute the searching distance. As a result of the present work, a good convergence to the target airfoil has been obtained.

• Archives of Plastic Surgery
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• v.32 no.5
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• pp.589-592
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• 2005

Since G.N. Hounsfield's clinical use of computed tomography in 1971, digital imaging technique using computers has shown an eye opening progress. Progress has made 3-dimensional understanding of not only facial bones but muscles and other connective tissues possible through 3-dimensional reconstruction of preexisting tomographical images. Also, quantitative analysis of density, distance, volume has become possible, allowing objective analysis of preoperative and postoperative states through imaging. The authors measured the masseter muscle volume of 20 normal individuals and 8 female patients through 3-D reconstructive CT imaging and made a statistical analysis of the measurements. The method used in our study may be applied to the diagnosis of disease causing the change of the facial volume and presurgical design as a useful tool to provide objective information on the evaluation of surgery outcome.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.1
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• pp.161-167
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• 2021

This paper proposes a new personalized HRTF estimation method which is based on a deep neural network (DNN) model and improved elevation reproduction using a notch filter. In the previous study, a DNN model was proposed that estimates the magnitude of HRTF by using anthropometric measurements [1]. However, since this method uses zero-phase without estimating the phase, it causes the internalization (i.e., the inside-the-head localization) of sound when listening the spatial sound. We devise a method to estimate both the magnitude and phase of HRTF based on the DNN model. Personalized HRIR was estimated using the anthropometric measurements including detailed data of the head, torso, shoulders and ears as inputs for the DNN model. After that, the estimated HRIR was filtered with an appropriate notch filter to improve elevation reproduction. In order to evaluate the performance, both of the objective and subjective evaluations are conducted. For the objective evaluation, the root mean square error (RMSE) and the log spectral distance (LSD) between the reference HRTF and the estimated HRTF are measured. For subjective evaluation, the MUSHRA test and preference test are conducted. As a result, the proposed method can make listeners experience more immersive audio than the previous methods.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.92-99
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• 2024

To minimize the cumulative radiation dose, various path-finding approaches for single agent have been proposed. However, for emergence situations such as nuclear power plant accident, these methods cannot be effectively utilized for evacuating a large number of workers because no multi-agent method is valid to conduct the mission. In this study, a novel algorithm for solving the multi-agent path-finding problem is proposed using the conflict-based search approach and the objective function redefined in terms of the cumulative radiation dose. The proposed method can find multi paths that all agents arrive at the destinations with reducing the overall radiation dose. To verify the proposed method, three problems were defined. In the single-agent problem, the objective function proposed in this study reduces the cumulative dose by 82% compared with that of the shortest distance algorithm in experiment environment of this study. It was also verified in the two multi-agent problems that multi paths with minimized the overall radiation dose, in which all agents can reach the destination without collision, can be found. The method proposed in this study will contribute to establishing evacuation plans for improving the safety of workers in radiation-related facilities.

• Journal of the Korean Institute of Landscape Architecture
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• v.25 no.3
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• pp.12-24
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• 1997

One argument of this study is that the policy to handle and landscape of cultural and historical property had to do with people's visual preferences. This study seeks to investigate people's visual preferences toward the landscape of cultural /historical property, specifically dealing with 'Namdaemun', which is the first class cultural property of Korea. People's visual preference was specifically examined into the four specific concepts : 'visual identity','harmony','beauty of the target property', and 'overall beauty'. Two objective variables, such as, 'distance' between the viewer and the cultural property, and 'height' of background buildings were considered possible predictors of the four visual preference variables. Photos of 'Namdaemun' were taken at three different directions and at three different distances. The photographed images of 'Namdaemun' were transferred ito the digitalized graphic images, where the height of background buildings was artificially changed and simulated. The simulated visual images were taken into the slides again. A total of 59 students of the Department of Landscape architecture at Seoul City University were sampled as subjects. A series of 17 slides were shown to the subjects four times. The subjects were asked to check their preference ratings concerning the four concepts on a 7-point Likert scale. The results found in this study were as follows : 1) In the results of ANOVA, it was clear that people visually preferred the view where the height of background buildings were lower than 15 floors to the view of more than 15 floors . 2) From the results of the path analysis, it was found that 'harmony','visual identity' and 'beauty of the target property' were direct predictors of 'the overall beauty'. The 'height ' of background buildings and the viewer's 'distance' were not found to be direct predictors, however, they demonstrated their effects on 'the overall beauty' through the other variable, which were direct predictors of 'the overall beauty'. In sum, the longer the distance and the higher the background buildings, the lower people's preference with the 'overall beauty'. These indirect paths, in turn, also explain why and how the 'height' of background buildings and the viewer's 'distance' negatively influence the 'overall beauty'. An implication from the these results is that when the height of background buildings were not controllable, there would be some other strategies for improving people's visual preference toward the historical /cultural view. To increase 'visual identity' of the cultural property, for example, changing colors of the cultural property or increasing the lighting level, etc., would be one strategy, since the increased 'visual identity' will, in turn, increase 'the overall beauty'.

• Korean Journal of Cognitive Science
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• v.29 no.4
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• pp.265-281
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• 2018

This study examines the effect of present and future situation on the temporal distance estimation to the future. The effect of present and future situation on time expression was verified. In Experiment 1, an experiment was conducted to investigated the effects of positivity/negativity situation of the present and the future on the judgment of subjective the distance to a certain future time. The results are as follows. When the present is positive and the future is negative, the future looks closer than the objective temporal distance and comes faster, When the present is negative and the future is positive, the future looks farther and comes slower. On the other hand, when the present and the future are both negative, the future looks coming slower. And when the present and the future are both positive, the future is expected to come faster. In Experiment 2, the cognitive and emotional aspects of subjective time through time expressions. It can be said to be 'the time of perseverance' in the sense of time for effort. On the other hand, when the present is positive compared to the future, the time seems go fast and we generally prefer to use cognitive expressions such as 'fast' and emotional expressions such as 'near' and 'pleasant' and 'flutter'. It is 'the time of availability', which means the time to enjoy and utilize.

• Animal Bioscience
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• v.34 no.7
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• pp.1105-1115
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• 2021

Objective: To conserve and utilize the genetic resources of a traditional Chinese indigenous pig breed, Liangshan pig, we assessed the genetic diversity, genetic structure, and genetic distance in this study. Methods: We used 50K single nucleotide polymorphism (SNP) chip for SNP detection of 139 individuals in the Liangshan Pig Conservation Farm. Results: The genetically closed conserved population consisted of five overlapping generations, and the total effective content of the population (Ne) was 15. The whole population was divided into five boar families and one non-boar family. Among them, the effective size of each generation subpopulation continuously decreased. However, the proportion of polymorphic markers (P_N) first decreased and then increased. The average genetic distance of these 139 Liangshan pigs was 0.2823±0.0259, and the average genetic distance of the 14 boars was 0.2723±0.0384. Thus, it can be deduced that the genetic distance changed from generation to generation. In the conserved population, 983 runs of homozygosity (ROH) were detected, and the majority of ROH (80%) were within 100 Mb. The inbreeding coefficient calculated based on ROH showed an average value of 0.026 for the whole population. In addition, the inbreeding coefficient of each generation subpopulation initially increased and then decreased. In the pedigree of the whole conserved population, the error rate of paternal information was more than 11.35% while the maternal information was more than 2.13%. Conclusion: This molecular study of the population genetic structure of Liangshan pig showed loss of genetic diversity during the closed cross-generation reproduction process. It is necessary to improve the mating plan or introduce new outside blood to ensure long-term preservation of Liangshan pig.

• Journal of IKEEE
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• v.26 no.2
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• pp.160-168
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• 2022

In this paper, we propose a 3D mesh reconstruction method from a single image using deep learning and a sphere shape transformation method. The proposed method has the following originality that is different from the existing method. First, the position of the vertex of the sphere is modified to be very similar to the 3D point cloud of an object through a deep learning network, unlike the existing method of building edges or faces by connecting nearby points. Because 3D point cloud is used, less memory is required and faster operation is possible because only addition operation is performed between offset value at the vertices of the sphere. Second, the 3D mesh is reconstructed by covering the surface information of the sphere on the modified vertices. Even when the distance between the points of the 3D point cloud created by correcting the position of the vertices of the sphere is not constant, it already has the face information of the sphere called face information of the sphere, which indicates whether the points are connected or not, thereby preventing simplification or loss of expression. can do. In order to evaluate the objective reliability of the proposed method, the experiment was conducted in the same way as in the comparative papers using the ShapeNet dataset, which is an open standard dataset. As a result, the IoU value of the method proposed in this paper was 0.581, and the chamfer distance value was It was calculated as 0.212. The higher the IoU value and the lower the chamfer distance value, the better the results. Therefore, the efficiency of the 3D mesh reconstruction was demonstrated compared to the methods published in other papers.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.487-492
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• 2014

Purpose: This study relates to the development of the 3X scope, whose objective part is configured with a doublet + a meniscus lens. Methods: By the initial condition of the objective part having a configuration of a doublet + a singlet, we could optimize the optical system of scope in order to minimize the finite ray aberrations of the objective part and the whole optical system of scope, and so we could develope a new type 3X scope. Results: On the condition of the objective part having a configuration of a doublet + a singlet, when the optical system of scope was optimized in order to minimize the finite ray aberrations, we could find that the singlet became the meniscus type lens having the concave shape to the direction of the doublet, and the longer the distance between the doublet and the meniscus lens is, the more the finite ray aberrations are minimized. Conclusions: In this study, we could develope a new type 3X scope of which finite ray aberrations can be reduced to 1/14 than the existing scope by adopting the objective part of the 3X scope having a configuration of three lenses composed of a doublet + a singlet. We could confirm that this reduction of aberrations can be a means to increase the effective aperture than the existing scope and to shorten the length of the optical system.

• Journal of Korean Academy of Nursing
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• v.40 no.2
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• pp.182-190
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• 2010

Purpose: This study was done to identify self-directed learning readiness, achievement goal orientations, learning satisfaction and learning achievement, and to evaluate the factors affecting learning achievement for nursing students using a web-based Health Assessment e-Book. Methods: The research design was a cross-sectional study with a structured questionnaire and data were collected before using the web-based Health Assessment e-Book and 1 week after finishing. The participants were 80 nursing students who were taking the Health Assessment class from March to June 2009. Results: Mean score for subjective learning achievement was 31.26 and for objective learning achievement, 69.25. Subjective and objective learning achievement were positively correlated with self-directed learning readiness, mastery goal, attitude toward distance education, and learning satisfaction. In subjective learning achievement, learning satisfaction and mastery goal were significant predictive factors and explained 64% of the variance. Objective learning achievement was significantly predicted by learning satisfaction and self-directed learning readiness, which explained 24% of the variance. Conclusion: Learning satisfaction, mastery goal and self-directed learning readiness were found to be very important factors associated with learning achievement for nursing students using a web-based Health Assessment e-Book. To provide high quality and effective web-based courses and to improve nursing students' learning achievement and learning satisfaction, educators should consider the learner's characteristics from the initial stages of lecture planning.