• Journal of the Korean Institute of Navigation
• /
• v.11 no.1
• /
• pp.93-106
• /
• 1987

Nowadays natural resources on shore have been almost exhausted all over the world and mankind is beginning searching for unexploited resources on the bed of deep-sea floor. In exploring mineral resources and etc. in the ground of sea-bed, a sumbersible craft is one of the most important tools. These days, the stage of the technique of building and operating an exploring submersible craft is almost alike that of building and operating an airplane in the first years of the nineteen-twenties. At the present time, the problems arising in building and operating a submersible craft can be divided into four parts as follows; 1. How to build a hull that can bear high pressure under deep sea level. 2. How to decide the necessary facilities to be put on it. 3. How to decide the scope of stabilities and maneuvering characteristics of it. 4. On what sea conditions, the devices of launching and recovering it should be designed on the mother-ship. In this paper treating one of the third problems the author made a mathematic formula that can be useful in deciding the scope of dynamic course stability on the vertical plane and actually calculated the onset speed of pitch instability of an exploring craft. With the above mentioned calculations the author demonstrated that the value of $Z_g$ and the speed of a submerged craft are the most important factors in decideing the scope of dynamic stability on the vertical plane.

• Journal of Distribution Science
• /
• v.13 no.6
• /
• pp.11-15
• /
• 2015

Purpose - Robot path planning, a constrained optimization problem, has been an active research area with many methods developed to tackle it. This study proposes the use of a Rapidly-exploring Random Tree and Particle Swarm Optimizer algorithm for path planning. Research design, data, and methodology - The grid method is built to describe the working space of the mobile robot, then the Rapidly-exploring Random Tree algorithm is applied to obtain the global navigation path and the Particle Swarm Optimizer algorithm is adopted to obtain the best path. Results - Computer experiment results demonstrate that this novel algorithm can rapidly plan an optimal path in a cluttered environment. Successful obstacle avoidance is achieved, the model is robust, and performs reliably. The effectiveness and efficiency of the proposed algorithm is demonstrated through simulation studies. Conclusions - The findings could provide insights to the validity and practicability of the method. This method makes it is easy to build a model and meet real-time demand for mobile robot navigation with a simple algorithm, which results in a certain practical value for distribution environments.

• Journal of Integrative Natural Science
• /
• v.1 no.2
• /
• pp.160-179
• /
• 2008

Field classes are necessary to grow the ability of and an attitude toward exploring nature and to shape the basic concept of natural science. I tried to develop a site for field classes and the old road Naori's hill is an ideal place with convenient traffic and established youth camps. As a result the vegetation was divided into five associations and communities. The vegetation units obtained in the present study were as follow: Quercus acutissima community, Pinus densiflora community, Pinus densiflora-Quercus acutissima community, Quercus acutissima-Pinus densiflora community, and Quercus mongolica community. In all survey areas 100 family 336 genus 587 species of palants was found. Furthermore, it provides lots of plants throughout the seasons. Not only the flora but also flowering phenology, variety of floral color and growth habits can be used as teaching items. Incorporation of diverse knowledge of plants at the old road Naori's hill into biology teaching will give students academic stimuli and teachers an opportunity of retraining. With a combination of use of visual instruments, the purpose of conceptual and exploring biology is more easily achieved.

• Journal of Korea Multimedia Society
• /
• v.22 no.8
• /
• pp.874-886
• /
• 2019

To delve into the semantic gap problem of the automatic video summarization, we focused on an endogenous ERP responses at around 400ms and 600ms after the on-set of audio-visual stimulus. Our experiment included two factors: the topic exploration of experimental conditions (Topic Given vs. Topic Exploring) as a between-subject factor and the topic relevance of the shots (Topic-Relevant vs. Topic-Irrelevant) as a within-subject factor. For the Topic Given condition of 22 subjects, 6 short historical documentaries were shown with their video titles and written summaries, while in the Topic Exploring condition of 25 subjects, they were asked instead to explore topics of the same videos with no given information. EEG data were gathered while they were watching videos in real time. It was hypothesized that the cognitive activities to explore topics of videos while watching individual shots increase the amplitude of endogenous ERP at around 600 ms after the onset of topic relevant shots. The amplitude of endogenous ERP at around 400ms after the onset of topic-irrelevant shots was hypothesized to be lower in the Topic Given condition than that in the Topic Exploring condition. The repeated measure MANOVA test revealed that two hypotheses were acceptable.

• Journal of Information Processing Systems
• /
• v.16 no.6
• /
• pp.1324-1342
• /
• 2020

Various modified algorithms of rapidly-exploring random tree (RRT) have been previously proposed. However, compared to the RRT algorithm for collision avoidance with global and static obstacles, it is not easy to find a collision avoidance and local path re-planning algorithm for dynamic obstacles based on the RRT algorithm. In this study, we propose boundary-RRT*, a novel-algorithm that can be applied to aerial vehicles for collision avoidance and path re-planning in a three-dimensional environment. The algorithm not only bounds the configuration space, but it also includes an implicit bias for the bounded configuration space. Therefore, it can create a path with a natural curvature without defining a bias function. Furthermore, the exploring space is reduced to a half-torus by combining it with simple right-of-way rules. When defining the distance as a cost, the proposed algorithm through numerical analysis shows that the standard deviation (σ) approaches 0 as the number of samples per unit time increases and the length of epsilon ε (maximum length of an edge in the tree) decreases. This means that a stable waypoint list can be generated using the proposed algorithm. Therefore, by increasing real-time performance through simple calculation and the boundary of the configuration space, the algorithm proved to be suitable for collision avoidance of aerial vehicles and replanning of local paths.

• The Journal of the Convergence on Culture Technology
• /
• v.4 no.3
• /
• pp.15-26
• /
• 2018

This is a qualitative study conducted to understand and explain the experience of nursing students' exploring historic sites of independence movement overseas. The study's participants were 24 nursing students in the first and second graders who participated in a program to explore the historic sites of independence movement overseas at a college in C County, Gyeongsangbuk-do. The data collection period was from December 23, 2017 to December 25, 2017. The data collection was carried out in an open self-reporting process, and the collected data were analyzed using the qualitative content analysis method of Krippendorff[13]. Based on the analysis of the experience of nursing students' exploring historic sites of independence movement overseas 19 sub-theme, 10 themes, and 4 categories were derived. The four categories are "Our History Represented in the wake of the independence movement", "Footprint projected of an independent activist ", " Rage Boiling But Hope Remaining", "blooming patriotism through reflection". The results of this study provided an understanding of nursing students' experience in exploring the historical sites of independence movement and have shown that nursing students had the opportunity to recognize the history of independence movements, inspire patriotism and reflect on their attitude as nurses. In addition, institutional efforts and resources should be supported to address the lack of policies on the preservation of the historic sites for independence movements overseas, which are dependent on the private sector.

• Journal of Environmental Health Sciences
• /
• v.49 no.1
• /
• pp.11-21
• /
• 2023

Background: The need to develop alternative chemicals is increasing worldwide due to the strengthening of global chemical regulations and consumer safety awareness in the marketplace. Objectives: We aimed to review domestic and foreign technology trends for exploring alternative candidate algorithms that can be used to develop safer alternatives to strengthen global market competitiveness and protect public health in the future. Methods: We searched the current status of research trends, companies related to the development of alternative chemicals in domestic and foreign countries. For this, we referred to research papers and websites by companies and institutes related to such alternatives. Results: Among the domestic and foreign research trends, more studies in South Korea were focused on predicting molecular-based physicochemical properties and toxicity than were reporting on research exploring alternative candidates. Three web-based databases and six tools were being developed. More studies in other countries predicted information to consider in alternative development than reported on research exploring alternative candidates, and four web-based databases and three tools were being developed. Among the companies related to the development of alternative chemicals, 286 alternatives classified as 'EVALUATED ALTERNATIVE' in MARKETPLACE accounted for the most significant proportion in Europe on a continent basis, and the largest number in the United States (US) on a national basis. In South Korea, only significant companies were registered. Conclusions: In this study, it was found to be necessary to provide public technology support platforms to explore alternative candidates considering various aspects in order to support alternative development. In conclusion, exploring alternative candidate algorithms could contribute to the response to the global trends in the chemical industry and to supporting companies and researchers developing safer alternatives in the future.

• The Korea Genome Conference
• /
• 2006.09a
• /
• pp.17-17
• /
• 2006

• Proceedings of the Korea Association of Information Systems Conference
• /
• 2003.11a
• /
• pp.215-226
• /
• 2003

• Proceedings of the Korean Society of Potoscience Conference
• /
• spring
• /
• pp.39-39
• /
• 2004