• The Journal of the Convergence on Culture Technology
• /
• v.9 no.5
• /
• pp.159-165
• /
• 2023

This study was limited to the underwater search part among water accidents on the inland water surface, and analyzed five underwater search methods and lifesaving time at 5m underwater. The subjects of the experiment were 10 people. The semi-circle search took the longest with 259 seconds, and the modified round-trip search took 78.60 seconds, showing a significant difference with an average of 180.04 seconds. Subjects B and D showed similar values, with average underwater search times of 199 seconds and 202 seconds, respectively. Subject C showed a significantly higher average underwater search time of 209 seconds. The reason seems to be from increased anxiety and excessive tension due to poor underwater watch. Subject A showed a significantly lower underwater search time of 187 seconds. The reason seems to be the result of E's experience being the most among the test subjects and his rich diving experience in the Han River with poor visibility. As for convenience, semicircle search showed a low score of 6~7, and modified reciprocal search showed a high score of 8~9. The most suitable rescue method as an underwater search method in the Han River where visibility is poor is determined to be a modified round-trip search method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.10a
• /
• pp.708-711
• /
• 2011

The Navy is in the process of developing a sonar-operation strategy to increase the effectiveness of underwater target seeking capability. HMS is the basic strategy to detect underwater targets. The advantages of HMS is that, it has a short preparation time to operate and can be always used regardless of sea conditions and weather. However, it is difficult to effectively detect underwater targets due to the interaction between marine environments and sonar-operations. During the research, the effectiveness of the HMS system's underwater target seeking capability was analyzed by integrating various search patterns and environment conditions into the simulation. In the simulation the ship target an evasive target within a set region. The simulation presented results for an effective searching methods of underwater targets. These research results can be used as foundation for advancing and improving the sonar operational tactics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2009.05a
• /
• pp.539-542
• /
• 2009

해군에서는 소나를 이용하여 수중 표적을 효과적으로 탐색하기 위한 소나운용전술을 개발하기 위해 노력하고 있다. 효율적인 소나운용전술 개발을 위해서는 먼저 다양한 운영전술에 대한 효과도를 분석할 수 있는 시뮬레이션 시스템이 필요하다. 시뮬레이션 시스템은 해양환경 정보, 자함 정보, 소나 정보, 그리고 수중표적의 정보를 매개변수로 입력받아 운용전술에 대한 시뮬레이션을 수행하며, 시뮬레이션의 진행에 따른 다양한 정보를 제공할 수 있어야 한다. 본 연구에서는 다양한 환경에서 수중표적에 대한 함정의 최적 탐색 전략을 평가할 수 있는 탐색효과도 분석용 시뮬레이션 시스템을 설계 개발하였다. 시뮬레이션 시스템은 다양한 형태의 해양상태를 반영할 수 있도록 소나방정식 및 탐지확률곡선을 이용하여 개발되었으며, 표적의 실제적인 행동패턴을 고려하여 여러 가지 형태의 기동 패턴을 시스템에 묘사하였다. 개발된 시스템은 앞으로 수중표적에 대한 효율적인 소나운용전술을 개발하고 발전시키는데 유용하게 사용될 수 있을 것으로 판단된다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.12
• /
• pp.2753-2758
• /
• 2009

The Navy is trying to develop a sonar-operation strategy that efficiently searches for underwater targets. To develop an efficient sonar-operation strategy, a simulation system, which can analyze the efficiency of various operation strategies, is needed. The simulation executes the strategical operation by collecting information of sea environment, destroyer, sonar, and target. Also, it should be able to provide diverse information according to its progression. In this study, the simulation system that can evaluate and analyze the effectiveness of the search strategy for underwater targets in different environments was designed and developed. The simulation system was developed, utilizing the sonar equation and the lateral-range-curve, and it portrays many patterns of realistic movements of a target. This system will contribute to developing and improving efficient sonar-operation strategies to find underwater targets in the future.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2017.11a
• /
• pp.1250-1253
• /
• 2017

본 논문은 드론 산업이 발전함에 따라 하천, 호수, 바다 상공에서 활용하는 드론이 수중에 빠졌을 때, 물에 빠진 드론을 모선(Mothership)과 집게팔이 달린 ROV(Remotely Operated Vehicle)를 이용하여 인양하는 시스템을 제안한다. 제안한 시스템의 구성 요소는 세 가지로 첫 번째는 실시간으로 GCS(Ground Control Station)에 영상을 전송하며 ROV와 전력선 모뎀을 이용하여 통신을 하는 모선, 두 번째는 수중에 들어가 수중 카메라를 이용하여 육안으로 드론을 탐색하고 장착된 집게팔로 드론을 몸체에 고정시키는 ROV, 세 번째는 모선, ROV와 실시간으로 영상 데이터와 명령 신호를 주고 받는 GCS 이다.

• Korean journal of applied entomology
• /
• v.30 no.4
• /
• pp.233-240
• /
• 1991

A female Brachymeria lasus (Walker) was exposed to one or four pupae of host Hyphantria cunea Drury for 20 minutes within a petri dish $(1.5\times9cm)$ to learn factors influencing the host discrimination by the parasitoid. It rejected the parasitized host with its rejection ratio 73.3% for the one pupal exposure vs 100% for the four pupal exposure scheme. The parasitoid could discriminate the parasitized host by its antennal drumming and ovipositor probing due to a pheromone-like external marking which is effective only for a certain peiod of time, and a host quality associated with the parasitoid development, respectively.

• Journal of Advanced Navigation Technology
• /
• v.21 no.4
• /
• pp.332-338
• /
• 2017

Launch and recovery system(LARS) is required to perform an USV-based underwater exploration. Through the analysis of the requirements according to the scenario of underwater exploration, the mechanism of LARS and the conceptual design of the mechanical parts of LARS are carried out. In addition, a USV motion can be induced due to environmental disturbances such as waves, so the detailed design of LARS for recovering the underwater tow-fish stably in consideration of the USV motion is performed. To verify the performance of launch and recovery operations, LARS and test bed were developed. The results show that the proposed LARS can stably launch and recovery an underwater tow-fish.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2000.10b
• /
• pp.1441-1444
• /
• 2000

실시간 정보가 알려지지 않은 해저환경에서 자율수중 운동체(AUV, Autonomous Underwater Vehicle)가 성공적인 임무 수행을 완료하기 위해서는 주어진 목표지점까지의 안전하고 효율적인 경로설정이 선행되어야 한다. 이를 위해 평가함수(evaluation function)에 기반한 휴리스틱 탐색(heuristic search)이 사용되는데 대부분의 평가함수는 목표점까지의 거리, 소모되는 연료로 구성된다[1]. 본 논문에서는 영역전문가가 보유한 장애물회피 관련 경험적 정보(heuristic information)를 반영하여 보다 효율적인 평가함수를 고안하며 후보노드들간의 관계성을 고려한 퍼지관계곱(Fuzzy Relational Products) 기반 휴리스틱 탐색기법을 제안한다. 제안한 탐색기법의 성능을 검증하기 위해 수행시간(cpu time), 경로의 최적화(optimization)정도, 사용 메모리 관점에서 시뮬레이션을 통해 $A^*$ 탐색기법과 비교한다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.18 no.3
• /
• pp.405-412
• /
• 2023

With the development of drone and ICT convergence technology, the use of underwater drones such as leisure underwater drones such as underwater exploration for fishing and industrial drones such as bridge piers is increasing. Existing motor controllers are suitable for aerial drones and these can increase the completeness of underwater drones and their reliability in motor control by developing BLDC motor controllers dedicated to underwater drones. By developing a battery management system (BMS) exclusively for underwater drones, battery stability was ensured by checking the state of charge, checking the state of discharge, adjusting cell balancing, and implementing high/voltage protection functions.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2002.05a
• /
• pp.140-143
• /
• 2002

본 논문에서는 자율수중운동체(AUV, Autonomous Underwater Vehicle)의 실시간 충돌회피에 적용되는 휴리스틱 탐색기법에 적합한 퍼지조건연산자와 알파절단(aleph-cut)의 선택에 관해 논한다. 퍼지조건연산자와 알파절단은 두 퍼지관계에서 새로운 퍼지관계를 생성시키는 퍼지삼각논리곱의 연산에 적용되는데 이것은 휴리스틱탐색기법의 이론적 기반이 된다. 본 논문은 평가함수를 이용한 새로운 휴리스틱탐색기법을 설계하고, 이에 가장 적합한 퍼지조건연산자와 알파절단을 제안한다. 제안된 퍼지조건연산자와 알파절단의 검증을 위해 경로경비와 합리적인 경로를 생성하는 알파절단의 개수 관점에서 모든 경우의 퍼지조건연산자와 알파절단에 대해 시뮬레이션 한다. .