• Journal of the Korea Institute of Military Science and Technology
• /
• v.12 no.5
• /
• pp.644-651
• /
• 2009

In this paper, the design results of a $22.5^{\circ}$ diode phase shifter for the RADANT lens and two $11.25^{\circ}$, $22.5^{\circ}$ dielectric phase shift layers for the diode phase shifter are presented. The amount of phase shift introduced by each dielectric layer depends on the thickness and the shape of the metal strip and the electrical property of the diode. The equivalent circuit model is employed to represent the dielectric phase shift layer, and the simulated result of the equival circuit model is compared with the result of the field simulation. The measured data of the fabricated $11.25^{\circ}$, $22.5^{\circ}$ dielectric phase shift layer shows about $2^{\circ}$ phase shift error.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.05a
• /
• pp.207-212
• /
• 2006

A dynamic analysis of a tilting actuator for projection TV is presented in this study. Generally, an excessive vibration of a tilting actuator is occurred a lowering of video quality of projection TV because of a dynamic unstability of it. Therefore, a dynamic analysis of a tilting actuator system is positively necessary. In this study, a mathematical model about a mirror-reactive type tilting actuator is presented and evidenced by experiment. A FEM model of a lens-transmissive type tilting actuator is presented and we made prototype of it. Then, it is evidenced by experiment. Besides, a design for hinge configuration of it is presented.

• Journal of Intelligence and Information Systems
• /
• v.1 no.2
• /
• pp.1-16
• /
• 1995

The field of human judgment and decision making provides useful methodologies for examining the human decision making process and substantive results. One of the methodologies is a lens model analysis which can examine valid nonlinearity in the human decision making process. Using the method, valid nonlinearity in human decision behavior can be successfully detected. Two linear(statistical) models of human experts and two nonlinear models of human experts are compared in terms of predictive accuracy (predictive validity). The results indicate that nonlinear models can capture factors(valid nonlinearity) that contribute to the expert's predictive accuracy, but not factors (inconsistency) that detract from their predictive accuracy. Then, it is argued that nonlinear models cab be more accurate than linear models, or as accurate as human experts, especially when human experts employ valid nonlinear strategies in decision making.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.5 no.3
• /
• pp.262-268
• /
• 2010

In this paper, this study restores the distorted image to its original image by compensating for the distortion of image from a fixed-focus camera lens. The various developments and applications of the imaging devices and the image sensors used in a wide range of industries and expanded use, but due to the needs of the small size and light weight of the camera, the distortion from acquiring images of the distorted curvature of the lens tends to affect many. In particular, the three-dimensional imaging camera, each different distortion of left and right lens cause the degradation of three-dimensional sensitivity and left-right image distortion ratio. we approached the way of generalizing the approximate equations to restore each part of left-right camera images to the coordinators of the original images. The adaptive Neuro-Fuzzy Inference System is configured for it. This system is divided from each membership function and is inferred by 1st order Sugeno Fuzzy model. The result is that the compensated images close to the left, right original images. Using low-cost and compact imaging lens by which also determine the exact three-dimensional image-sensing capabilities and will be able to expect from this study.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2020.06a
• /
• pp.317-317
• /
• 2020

수재해는 수자원 인프라의 부족 및 관리 미흡 등 많은 요인들이 있지만 강우의 유무와 크기가 가장 원초적인 요인들 중 하나이다. 정확한 강우량 추정 및 강우발생시간 예측은 수재해로 인한 피해를 예방하고 빠르게 대처할 수 있다. 그러나 강우예측에는 많은 불확실성을 내포하고 있기 때문에 이러한 불확실성을 이해하고 줄여 나가는 것이 필요하다. 최근 컴퓨터의 성능의 발전에 비례해 강우 예측 자료들도 점진적으로 발전을 거듭하고 있다. 이를 강우-유출 모형에 적용시 유출량 예측의 정확성 또한 비례하여 한층 더 발전할 수 있을 것이다. 하지만 신뢰성이 낮은 입력자료를 대상으로 하는 유출해석 모형은 많은 불확실성을 내포할 것이다. 따라서 본 연구에서는 위천 유역에 대해 LENS(Limited area ENsemble prediction System) 강우앙상블 예측자료의 적용성을 검토하고 그리드 기반 강우 유출 모델 GRM(Grid based Rainfall-runoff Model) 에 적용하여 유출예측의 불확실성을 평가하고자 하였다. 또한 강우예측 및 유출예측은 수 많은 매개변수를 포함하며 최종적인 예측은 더 큰 불확실한 범위로 산출될 수 있다. 이에 따라 본 연구에서는 Python3 기반 코딩으로 LENS 자료 구축 및 GRM 모형의 매개변수 보정을 각 2000회 씩에 걸쳐 총 2회 실시하여 수문학적, 지형학적 인자에 따른 불확실성 범위를 보정하고자 하였다. 매개변수의 보정은 비정형우도(Informal likelihood) NSE, 정형우도(Formal likelihood) Lognormal(Log-likelihood function)의 우도에 따른 행위모델을 산정하여 보정하였다. 따라서 본 연구에서는 선행연구들을 참고한 정형, 비정형 우도의 임계치를 이용한 불확실성해석에 적용하였으며 이는 사용자의 행위모델선정 임계치 범위 선정으로 인한 불확실성을 줄여나감에 기여할 수 있을것으로 사료된다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.21 no.3
• /
• pp.229-236
• /
• 2003

This study recorded an object using a digital video recorder, and then tried to estimate 3-D positional information and to reconstruct an image. Firstly, the accuracy of measurement results from a video recorder was evaluated and tested for an applicability, then it applied to a real object to construct 3-D digital model. This study assumed that there is no lens distortion in a video recorder, and all bundles should precisely pass through the projection center of a lens. The image size for orientations is determined by the size of CCD chip and the number of pixels. The average squared error from the result by a digital video recorder and that by triangular survey from 1-second theodolite shows 0.0173m error in x,y coordinates. Without knowing the accurate information on the lens distortion and the coordinates of the projection center, this study reasonably produces acceptable results in the reconstruction of 3-D model. In consequence, this study found that the image from a digital video camera can be reconstructed 3-D model only from the information on a camera type.

• Journal of the Ergonomics Society of Korea
• /
• v.25 no.4
• /
• pp.81-90
• /
• 2006

Despite the government promoting women's participation in the engineering field, some statistics show that it has yet to be achieved. Potential reasons for this phenomenon include lower level of applications by women, or inherent gender gap in the professional field. Therefore, this study attempted to find impact of gender on college admission from the Lens Model perspective and Signal Detection Theory. This study consisted of three phases: identifying the necessary cues used in the admission process, analyzing existing data, and conducting two experiments to identify the effect of gender on admission decisions. Although the college application consisted of many cues, only five cues, school ranking, GPA, SAT score, resident status, and gender, were used to capture the officers' judgment policies for engineering admissions. Two experiments were conducted to investigate the impact of the gender factor in college admission. The enrollment officers first were presented with the existing data without the gender and asked to make dichotomous judgments. Secondly, the officers were asked to perform the judgment task with the gender cue present. Results showed that the gender did not play an important role in the judgments as expected. However, ideographical analyses on judgment strategies revealed that there were significant differences between the admission officers. Possible training implications are discussed.

• Journal of Surface Science and Engineering
• /
• v.40 no.4
• /
• pp.185-189
• /
• 2007

A scanning electron microscope (SEM) is a complex system, consisting of many sophisticated components. For a systematic characterization, a $2^4$ full factorial experiment was conducted. The SEM components examined include condenser lens 1 and 2 (denoted as A and B, respectively), and Objective lens (coarse and fine-denoted as C and D respectively). A statistical analysis was conduced to investigate factor effects and variations In response surfaces. Among four factors, main effect analysis revealed that A and D were Identified as the dominant factor. Moreover, B showed conflicting effect against C. The $R^2$ of statistical regression model constructed was about 69.6%. The model generated 3D response surface plots facilitated understanding of complex tactor effects.

• Journal of the Korean Society of Radiology
• /
• v.18 no.3
• /
• pp.283-292
• /
• 2024

Radiation side effects and complications on the ocular adnexa during electron beam therapy for orbital lymphoma can increase the incidence of posterior subcapsular cataracts. This study simulated a medical linear accelerator and a mathematical model of the eye using monte carlo simulations to evaluate the dose to the ocular adnexa and compare the shielding effectiveness on different parts of the ocular adnexa based on lens shield thickness. The dose assessment results of the ocular adnexa showed that the lens's sensitive area had the highest absorbed dose distribution when no shield was used, followed by the lens's non-sensitive area, the anterior chamber, vitreous humor, cornea, and eyelid in descending order. With the use of a shield, a 2 mm thick shield demonstrated a dose reduction effect of over 90% in the lens's sensitive area, over 83% in the non-sensitive area and anterior chamber, and a dose reduction effect of 30 to 62% in the vitreous body, cornea, and eyelid. For dose reduction in the lens's sensitive area during electron beam therapy for orbital lymphoma, it is necessary to use a shield of at least 2 mm thickness. Additionally, shielding strategies considering the thickness and area of the shield for other ocular adnexa besides the lens are required.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.5
• /
• pp.1413-1432
• /
• 2023

Recommender systems aim to recommend items to users by taking into account their probable interests. This study focuses on creating a model that utilizes multiple sources of information about users and items by employing a multimodality approach. The study addresses the task of how to gather information from different sources (modalities) and transform them into a uniform format, resulting in a multi-modal feature description for users and items. This work also aims to transform and represent the features extracted from different modalities so that the information is in a compatible format for integration and contains important, useful information for the prediction model. To achieve this goal, we propose a novel multi-modal recommendation model, which involves extracting latent features of users and items from a utility matrix using matrix factorization techniques. Various transformation techniques are utilized to extract features from other sources of information such as user reviews, item descriptions, and item categories. We also proposed the use of Principal Component Analysis (PCA) and Feature Selection techniques to reduce the data dimension and extract important features as well as remove noisy features to increase the accuracy of the model. We conducted several different experimental models based on different subsets of modalities on the MovieLens and Amazon sub-category datasets. According to the experimental results, the proposed model significantly enhances the accuracy of recommendations when compared to SVD, which is acknowledged as one of the most effective models for recommender systems. Specifically, the proposed model reduces the RMSE by a range of 4.8% to 21.43% and increases the Precision by a range of 2.07% to 26.49% for the Amazon datasets. Similarly, for the MovieLens dataset, the proposed model reduces the RMSE by 45.61% and increases the Precision by 14.06%. Additionally, the experimental results on both datasets demonstrate that combining information from multiple modalities in the proposed model leads to superior outcomes compared to relying on a single type of information.