• Journal of Space Technology and Applications
• /
• v.1 no.1
• /
• pp.104-120
• /
• 2021

Some optical schemes of lenses for spacecraft developed by the author are considered. The main optical characteristics of telescope lenses of various architectures are compared. We propose compact solutions of mirror, lens-mirror, and lens systems with maximum available angular resolutions and other parameters. Examples of calculating the optical systems of lenses used for various tasks both in the field of astronomy and in the field of remote sensing of the Earth and other planets are given. The example of onboard computer system is discussed. Practical recommendations on the development and use of telescope lenses are given.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11a
• /
• pp.320.1-320
• /
• 2002

In a hard disk drive (HDD) control system, a state-space controller/observer design is popularly adopted fur its advantages such as effective filtering of position and velocity, use of estimation error to handle servo defects, etc. In this report, a systematic method is proposed to accommodate the transport delay in the plant dynamics into the state estimator. (omitted)

• Kyungpook Mathematical Journal
• /
• v.62 no.1
• /
• pp.69-88
• /
• 2022

In this work, the three-step intermixed iteration for two finite families of nonlinear mappings is introduced. We prove a strong convergence theorem for approximating a common fixed point of a strict pseudo-contraction and strictly pseudononspreading mapping in a Hilbert space. Some additional results are obtained. Finally, a numerical example in a space of real numbers is also given and illustrated.

• Science of Emotion and Sensibility
• /
• v.21 no.1
• /
• pp.3-16
• /
• 2018

The emergence of the fourth industrial revolution is rapidly changing the conventional society and the industry, eroding the boundaries among the technology, culture, and finance. In the mobility industry, as the engineering-based industry converges with the information technology, the mobile space is changing from mobility or safety-centric space into space where the passengers can consume infotainment or contents services. The contents evaluation of the future mobility is conducted in terms of usability or technology acceptance aspect, but according to the trend analysis, the mobility industries, such as vehicle OEMs, it is necessary to evaluate the emotional or sensibility factors for the development of their future mobile space design. Herein, this research study evaluates which sensibility factor should be evaluated in priority to develop the contents interaction in the future mobile space. Thus, using Patrick Jordan's Four Pleasure Model, the priority evaluation has been conducted among 116 Korean drivers. As a result of the statistical analysis and AHP (Analytic Hierarchy Process), it has been found that first, it is necessary to evaluate psychological, ideological, social and physical sensibility in the respective order, and second, it is necessary to evaluate based on the contents user type.

• Economic and Environmental Geology
• /
• v.55 no.4
• /
• pp.421-428
• /
• 2022

This study analyzes emerging earthquake and space use technologies from the latest Korean and Japanese scientific and technological foresights in 2022 and 2019, respectively. Unlike the earthquake prediction and early warning technologies presented in the 2017 study, the emerging earthquake technologies in 2022 in Korea was described as an earthquake/complex disaster information technology and public data platform. Many detailed future technologies were presented in Japan's 2019 survey, which includes largescale earthquake prediction, induced earthquake, national liquefaction risk, wide-scale stress measurement; and monitoring by Internet of Things (IoT) or artificial intelligence (AI) observation & analysis. The latest emerging space use technology in Korea and Japan were presented in more detail as robotic mining technology for water/ice, Helium-3, and rare earth metals, and manned station technology that utilizes local resources on the moon and Mars. The technological realization year forecasting in 2019 was delayed by 4-10 years from the prediction in 2015, which could be greater due to the Corona 19 epidemic, the declaration of carbon neutrality in Korea and Japan in 2020 and the Russo-Ukrainian War in 2022. However, it is required to more active research on earthquake and space technologies linked to information technology.

• International Journal of Aeronautical and Space Sciences
• /
• v.16 no.4
• /
• pp.590-601
• /
• 2015

This paper gives an overview of research on the field of structure vibration-attitude coordinated control of spacecraft. First of all, the importance of the technology has been given an introduction, and then later the research progress of space structure dynamics modeling, research progress of structure vibration-attitude coordinated control of flexible spacecraft have been discussed respectively. Finally, future research on application of structure vibration-attitude coordinated control of spacecraft has been recommended.

• Journal of The Korean Astronomical Society
• /
• v.51 no.6
• /
• pp.197-206
• /
• 2018

We present the analysis of KMT-2016-BLG-0212, a low flux-variation ($I_{flux-var}{\sim}20mag$) microlensing event, which is in a high-cadence (${\Gamma}=4hr^{-1}$) field of the three-telescope Korea Microlensing Telescope Network (KMTNet) survey. The event shows a short anomaly that is incompletely covered due to the brief visibility intervals that characterize the early microlensing season when the anomaly occurred. We show that the data are consistent with two classes of solutions, characterized respectively by low-mass brown-dwarf (q = 0.037) and sub-Neptune (q < $10^{-4}$) companions. Future high-resolution imaging should easily distinguish between these solutions.

• Journal of the Korea Computer Graphics Society
• /
• v.25 no.3
• /
• pp.115-122
• /
• 2019

We In this study, We tested for artificial intelligence-based virtual space story books were planned. The proposed virtual space concept, a story book with the characteristics of Augmented Virtuality, was implemented Several steps are needed to proceed with the virtual space storybook's story. First, a user brings a real object in to virtual space and recognizes the real object with an artificial intelligence-based object-recognition software. Second, when object recognition progresses, the virtual 3D model is augmented in the virtual space, which is then inserted into the virtual space and rendered. Finally, software projected a virtual space storybook on the desk in which users can touch and select real-objects. This virtual space storybook was implemented using the new story-making technology by applying the virtual space concept. the Augmented Virtuality concept is to augment real objects based on virtual space. To confirm this we tested a user test using the virtual space storybook. the user seemed as if can the distinction between real objects and virtual images. Also very well and that understood the process of putting the real objects in virtual space.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2007.05a
• /
• pp.272-275
• /
• 2007

This paper is concerned with modified integration algorithm on the strain-space for rate and temperature dependent elasto-plastic constitutive relations in order to obtain more accurate results in numerical implementation. The proposed algorithm is integrated analytically using integration by part and chain rule and then is applied to the 2-stage Lobatto IIIA with second-order accuracy. It has advantage that is able to consider the convective stress rates on the yield surface of the strain-space. Also this paper is carried out the iteration procedure using the Newton-Raphson method to enforce consistency at the end of the step. And the performance of the proposed algorithm for rate and temperature dependent constitutive relation is illustrated by means of analysis of adiabatic shear bands.

• Journal of the Korean Institute of Educational Facilities
• /
• v.14 no.4
• /
• pp.4-13
• /
• 2007

In 21st century, mankind greets an era of ubiquitous computing where physical and virtual space are merged through the innovation of digital and IT(Information Technology), meanwhile ubiquitous computing and network paradigm suggest a new direction which our future educational system should head for. A society where people, computers, and objects can be connected with each other anytime and anywhere, that is, a society of ubiquitous computing where everything in our living space are interconnected by a immense network system may bring a variety of changes into our educational environment in schools. In this study I analysed the forecast of school educational orientation and ubiquitous educational environment and facilities in developed countries, and on the basis of the result, I performed a fundamental work for formation of a ubiquitous classroom environment which is feasible in Korea. In the section of conclusion, I present a model of ubiquitous classroom as a scenario based on ubiquitous computing technology applicable to future classroom environment.