• Journal of Korean Ophthalmic Optics Society
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• v.16 no.4
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• pp.433-438
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• 2011

Purpose: To investigate the proper distance from patient to target when measuring refractive error using open view target type auto-refractor(OVTAR), it was compared refractive errors between by OVTAR using N-vision-K5001 auto-refractor and internal fixation target type auto-refractor(IFTAR) using Canon auto-refractor. Methods: 21 subjects(42 eyes) aged 22.2(${\pm}$3.4) years old who had over 1.0 of corrected visual acuity and no ocular disease were participated for this study. Noncycloplegic measurements of refractive error were performed using a IFTAR(RK-F1, Canon, Japan) and an OVTAR(N-vision-K5001, Shin-nippon, Japan). The distances from subjects to targets in using the open the view target type auto-refractor were 1 m, 3 m, 4 m and 6 m. The refractive errors were compared between by IFTAR and by 1 m, 3 m, 4 m and 6 m target distances respectively using OVTAR. Results: At 1 m fixation distance the mean of refractive errors for total subjects was not significantly different between by OVTAR(-2.75${\pm}$1.84 D) and by IFTAR(-2.95${\pm}$2.04 D)(p=0.06). However at 3, 4 and 6 m fixation distance refractive errors by OVTAR were significantly lower myopic refractive errors than by IFTAR(p<0.05). Conclusions: The distance from subject to fixation target is needed over 3 m for the measurement of refractive error using OVTAR even not to 5~6 m distance.

• Education of Primary School Mathematics
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• v.4 no.2
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• pp.139-150
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• 2000

The objectives of the current study are first, to compare and analyze the two different teaching methods of elementary mathematics in the traditional method and in the constructivists view, and, second, thereby to reveal possible problems of the present teaching practice and to suggest some guidelines to solve those problems.The results of this research are as follows: First, longer time was spent to reach the target pont of class because the class was a little bit disturbed and noisy due to a large amount of student activities in the beginning of the class in the constructive view. Second, in the class in the constructive view, the teacher should be able to respond appropriately to the situation where the students were cognitively. And the teachers sufficient preparation for the class was found essential to have the students reach the target point by themselves through identifying children`s minds. Third, the class in the constructivists view provide the teaching environment were the teacher could evaluate each students ability accurately and study progress of the class. And fourth, finally, it was not easy for the teacher to pay attention individually to each student in the current situation of large class, The effort to have more concern for students seems to contribute to opening student`s closed minds and to forming positive attitudes toward mathematics.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.3
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• pp.313-322
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• 2014

This paper is to survey and put in perspective the working methods of multi-target tracking in clutter. This paper includes theories and practices for data association and related filter structures and is motivated by increasing interest in the area of target tracking, security, surveillance, and multi-sensor data fusion. It is hoped that it will be useful in view of taking into consideration a full understanding of existing techniques before using them in practice.

• Journal of the Korean Vacuum Society
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• v.14 no.4
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• pp.245-251
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• 2005

A high performance dual rocking magnet sputtering gun has been developed. The rocking magnet sputtering gun introduces full-face erosion by rapidly rocking the magnet in the region where the high plasma density is maintained. The newly developed dual rocking magnet sputtering gun whose target utilization was 77 percent achieved high performance in quality in the view of target utilization and target life-time comparing to the existing magnetron sputtering gun. The PIC-MCC target erosion simulation has been performed simultaneously. Comparing experimental target erosion profiles with simulated target erosion profiles, the simulation could estimate the tendency of the target erosion profiles but could not estimate an exact target erosion profile. If the simulation were improved more precisely, the cost reduction for the development of the multiple rocking magnet sputtering gun would be expected.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.292-296
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• 2002

This study has been accomplished as a experimental study for field application of 3D Perspective Image Map creation using Digital Topographical Map and based on the Ortho-Projection Image which is generated from Satellite Overlay Images and the precise Relative Coordinates of longitude, latitude and altitude which is corrected by GCP(Ground Control Point). AS to Contour Lines Map which is created by Coordinate conversion of 1:5,000 Topographical Map, we firstly made Satellite Image Map to substitute for Digital Topographical Map through overlapping the original images on top of each Ortho-Projection Image created and checking the accuracy. In addition to 3D Image Map creation for 3D Terrain analysis of a target district, Slope Gradient Analysis, Aspect Analysis and Terrain Elevation Model generation, multidirectional 3D Image generation by DEM can be carried out through this study. This study is to develop a mapping technology with which we can generate 3D Satellite Images of a target district through the composition of Digital Maps and Facility Blueprint and arbitrarily create 3D Perspective Images of the target district from any view point.

• International Journal of Aeronautical and Space Sciences
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• v.9 no.2
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• pp.87-97
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• 2008

Modem anti-ship missiles employ complex and sophisticated guidance laws to hit the target and enhance their survivability by executing additional maneuvers. However, such maneuvers may cause the target to move out of the missile seeker's Field-Of-View (FOV). Maintaining seeker lock-on during an engagement is a critical factor for missile guidance. In this paper, a guidance law switching logic that maintains seeker lock-on and a simple guidance law that keeps the target look angle of the seeker constant is proposed. The proposed method can be used for the terminal homing phase, and can be switched from any kind of guidance laws if a proper switching condition is satisfied. The minimum and maximum flight time calculation method in consideration of the missile maneuver limit and the FOV of the seeker is also provided.

• Science of Emotion and Sensibility
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• v.24 no.4
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• pp.17-28
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• 2021

The purpose of the research was to examine the effect of field of view on egocentric distance perception in the real and virtual environment. The replica that mimicked the real environment condition was used to create the virtual environment condition. We manipulated field of view levels equally in both viewing conditions using glasses that limit the field of view in real-world conditions and limiting the field of view in virtual-world conditions in a manner equivalent to real-world conditions via HMD. Eighteen participants observed the target with a limited field of view in a real and virtual environment without head movement. Then, we measured perceived distance using the timed imagined walking method, which measures the time taken by each participant to mentally walk to the target. The target was shown three times at three different distances from the participants: 3, 4, and 5 m. For the analysis, we converted time estimates into distance estimates. Consequently, the estimated distance in the virtual environment condition was less than the estimated distance in the real environment condition. And as the field of view shrank, the estimated distance also decreased. The estimated distance did not vary with field of view levels in real-world conditions. In the virtual environment, the estimated distance decreased as the field of view decreased, whereas in the real environment, the estimated distance increased. The implications of the results and some future research directions are discussed below.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.3
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• pp.343-349
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• 2012

To detect targets for autonomous navigation of unmanned ground vehicle, mounted sensors are required to work all-weather condition. In this point of view, the FMCW radar is quietly appropriate. In this paper, we present development results of target signal simulator for multi-beam type FMCW radar. A target signal simulator make pseudo target signals which simulates multiple moving targets. And we describe how to make hit information for each target in multi-beam type radar. The developed methods are utilized for target tracking device. Moreover it can be applied to similar target signal simulator.

• Journal of radiological science and technology
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• v.39 no.4
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• pp.631-636
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• 2016

Hitherto, spatial resolution has commonly been evaluated by test patterns or phantoms built on some specific distances (from close to far) between two objects (or double targets). This evaluation method's shortcoming is that resolution is restricted to target distances of phantoms made for test. Therefore, in order to solve the problem, this study proposes and verifies a new method to efficiently test spatial resolution with a single target. For the research I used PSF and JND to propose an idea to measure spatial resolution. After that, I made experiments by commonly used phantoms to verify my new evaluation hypothesis inferred from the above method. To analyse the hypothesis, I used LabVIEW program and got a line pixel from digital image. The result was identical to my spatial-resolution hypothesis inferred from a single target. The findings of the experiment proves only a single target can be enough to relatively evaluate spatial resolution on a digital image. In other words, the limit of the traditional spatial-resolution evaluation method, based on double targets, can be overcome by my new evaluation one using a single target.

• KIEAE Journal
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• v.6 no.4
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• pp.3-10
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• 2006

To preserve scenic-view of Gwanak Mountain from the urban development, the viewshed component ratio and the scenic-view preference are investigated and analyzed by selecting view points at Nangokro. After 16 candidate view points are selected from the site, sight component ratio is measured through visual structure analysis and preference are measured by using the Likert scale. In addition, factor analysis, and regression analysis were conducted to examine the relationship between influencing factors and preference. As a result of the regression analysis of the 9 factors to influence the scenic-view preference, two factors such as degree of natural landscape and degree of arrangement around the site are chosen to influence the scenic-view preference. Through the preference factor analysis, two preference factors are selected as follows; 1) The factor of the landscape formation - Existence and nonexistence of the scenic-view conservation, degree of the landscape opening, and degree of natural landscape, degree of the landscape originality, and degree of the landscape sequence, degree of the landscape intimacy 2) The factor surrounding the landscape - Degree of arrangement around the site, degree of the landscape complexity, and atmosphere around the site.