• Journal of Christian Education in Korea
• /
• v.76
• /
• pp.213-235
• /
• 2023

Purpose of study: The focus of this study is to explore the potential of using the metaverse platform as a mission field for the MZ generation and to derive utilization strategies. Research content and method: The content and methodology of the research are as follows: examining the metaverse platforms most widely utilized by the MZ generation from a social and cultural perspective, reviewing the characteristics of the MZ generation, and exploring elements in the metaverse that can be utilized as a mission field (Chapters I and II). The study explores the possibilities of approaching the metaverse as a mission site, presenting spatial utilization strategies centered around the active engagement potential of the MZ generation (Chapters III, IV, and V). Conclusions and Suggestions: The conclusion and recommendations are as follows: The metaverse space is considered familiar and highly appealing to the MZ generation, revealing the potential for its effective use and expansion. Therefore, it is urgent not only to utilize the metaverse space as a Christian mission field but also to take responsibility for its use and expansion as a Christian cultural space.

• Journal of Ocean Engineering and Technology
• /
• v.38 no.4
• /
• pp.187-198
• /
• 2024

Autonomous underwater vehicles (AUVs) have a limited bandwidth for real-time communication, limiting rapid responses to unexpected obstacles. This study addressed how AUVs can navigate to a target without a pre-existing obstacle map by generating one in real-time and avoiding obstacles. This paper proposes using forward-looking sonar with an occupancy grid map (OGM) for real-time obstacle mapping and a potential field algorithm for avoiding obstacles. The OGM segments the map into grids, updating the obstacle probability of each cell for precise, quick mapping. The potential field algorithm attracts the AUV towards the target and uses repulsive forces from obstacles for path planning, enhancing computational efficiency in a dynamic environment. Experiments were conducted in coastal waters with obstacles to verify the real-time obstacle mapping and avoidance algorithm. Despite the high noise in sonar data, the experimental results confirmed effective obstacle mapping and avoidance. The OGM-based potential field algorithm was computationally efficient, suitable for single-board computers, and demonstrated proper parameter adjustments through two distinct scenarios. The experiments also identified some of challenges, such as dynamic changes in detection rates, propulsion bubbles, and changes in repulsive forces caused by sudden obstacles. An enhanced algorithm to address these issues is currently under development.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.48 no.4
• /
• pp.275-280
• /
• 1999

The glass-to-glass electrostatic bonding process in vacuum environment was developed and the tubeless-packaged FED was fabricated based on the bonding process. The fabricated tubeless-packaged FED showed stable field emission characteristics and potential applicability to the FED tubeless packaging and vacuum in-line sealing.

• Korean Journal of Environmental Biology
• /
• v.36 no.4
• /
• pp.672-679
• /
• 2018

This study was conducted to predict the potential distribution and risk of invasive alien plant, Amaranthus patulus, in an agricultural area of South Korea. We collected 254 presence localities of A. patulus using field survey and literature search and stimulated the potential distribution area of A. patulus using maximum entropy modeling (MaxEnt) with six climatic variables. Two different kinds of agricultural risk index, raster risk index and regional risk index, were estimated. The 'raster risk index' was calculated by multiplying the potential distribution by the field area in $1{\times}1km$ and 'regional risk index' was calculated by multiplying the potential distribution by field area proportion in the total field of South Korea. The predicted potential distribution of A. patulus was almost matched with actual presence data. The annual mean temperature had the highest contribution for distribution modeling of A. patulus. Area under curve (AUC) value of the model was 0.711. The highest regions were Gwangju for potential distribution, Jeju for 'raster risk index' and Gyeongbuk for 'regional risk index'. This different ranks among the index showed the importance about the development of various risk index for evaluating invasive plant risk.

• Transactions of Materials Processing
• /
• v.11 no.2
• /
• pp.165-170
• /
• 2002

The preform design of forging processes plays a key role in improving product qualities, such as defect prevention, dimensional accuracy and mechanical strengths. In the industry, preforms are generally designed by the iterative trial-and-error approach, but it results in significant tooling cost and time. It is thus necessary to minimize lead-time and human intervention through an effective preform design method. In this paper, the equi-potential lines designed in the electric field are introduced to find the preform shape, and then the optimization process is used to choose the equi-potential lines that will keep the die wear to a minimum Because, in the forging process, the die wear is a function of various important factors, such as forming stress and strain, microstructure and mechanical properties of a Product.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.20 no.1
• /
• pp.41-46
• /
• 2007

Surface potential properties at the interface of pentacene thin films on gold (Au) and aluminum (Al) surfaces were investigated by using a near-field scanning microwave microprobe (NSMM). The surface potential formed across the pentacene film was observed by measuring the microwave reflection coefficient $S_{11}$ and compared with the result of a Kelvin-probe method. The obtained reflection coefficient ${\Delta}S_{11}$ of the pentacene thin films on Al was decreased as the pentacene film thickness increased due to the increased accumulation of negative space charges, while for Au ${\Delta}S_{11}$ was essentially constant.

• 제어로봇시스템학회:학술대회논문집
• /
• 1994.10a
• /
• pp.446-448
• /
• 1994

This paper proposes some dynamic navigation strategy for a mobile robot among multiple moving obstacles. The control force of the robot which consists of repulsive and attractive force is based on the artificial potential field. The artificial potential fields is derived with position or(and) velocities of the objects. The simulation results shows the properties of the proposed strategies.

• The Korean Journal of Ecology
• /
• v.20 no.3
• /
• pp.175-179
• /
• 1997

To explanin allopatric distribution of Carpinus cordata and C. laxiflora in the field the effect of soil flooding on photosynthesis and water relations was tested with field grown saplings. Under the flooding condition stomatal conductance of C. laxiflora decreased markedly from day two after flooding treatment and remanined low throughout the experiment. In contrast, flooding had no effect on stomatal conductance of C. cordata throughout the exper iment. The rate of photosynthesis of C. laxiflora was significantly suppressed under flooding conditions, whereas that of C. cordata was not affected in the flooded condition. On day seven after flooding treatment xylem pressure potential of C. laxiflora significantly decreased. Flooding, however, did not have any effect on the xylem pressure potential of C. cordata throughout the experiment. From these findings it is concluded that there is a difference in resistance to flooding between C. cordata and C. laxiflora and that one of the the factors responsible for allopatric distribution in the two species is flooding.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.4
• /
• pp.785-796
• /
• 2009

In this paper, propose for mobile robot path planning and the reduction in sleep caused by a sleep history suggested a way to compensate for record sensor error. The proposed path plan reduces the robot slip to smooth a potential barrier in the potential field method, and compensates the tachometer error by robot slip using the fuzzy logic system. The efficiency of the proposed method is verified by means of simulations and experiments for path plan and slip revision.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.27 no.7
• /
• pp.829-836
• /
• 2003

Understanding of heat generation in semiconductor devices is important in the thermal management of integrated circuits and in the analysis of the device physics. Scanning thermal microscope was used to measure the temperature and the electric potential distribution on the cross-section of an operating metal-oxide-semiconductor field-effect transistor (MOSFET). The temperature distributions were measured both in DC and AC modes in order to take account of the leakage current. The measurement results showed that as the drain bias was increased the hot spot moved to the drain. The density of the iso-potential lines near the drain increased with the increase in the drain bias.