• Journal of the Korean earth science society
• /
• v.44 no.2
• /
• pp.148-160
• /
• 2023

The Pliny Letter, the first historical record of volcanic eruptions and disasters on Earth, was studied to better understand the Vesuvius' eruption patterns in 79 AD. The two-day eruption, which began at 1 a.m. on August 24th 79 AD, produced large amounts of volcanic ash and pumice, which were carried by the wind and fell on nearby cities. Furthermore, during the eruption, fast-moving pyroclastic flows flowed down the volcano's sides, and several phenomena such as earthquakes and tsunamis occurred. Cities near Mount Vesuvius were buried and destroyed by volcanic ash and pyroclastic flows. Previous studies were collected, analyzed, and investigated and the scope of damage was chosen from Pompeii, Herculaneum, Stabiae, and Oplontis. The sedimentary stratigraphy and thickness vary according to location and distance from Vesuvius in each region. Within the depositional layers, the remains of residents who died during the eruption were also discovered, and 1,150 remains have been discovered in Pompeii, 306 in Herculaneum, 111 in Stabiae, and 54 in Oplontis, but the exact number of people who killed is unknown. The eruption that exhibited the pattern seen in AD 79 was named the Plinian eruption after Pliny and classified as a new type of eruption as a result of Pliny's detailed description of the eruption.

• Journal of Aerospace System Engineering
• /
• v.17 no.6
• /
• pp.63-71
• /
• 2023

In the present study, the effect of pitch amplitude on the unsteady aerodynamics of a NACA 0012 airfoil is numerically investigated. When the frequency ratio is equal to 1.0, airfoil pitching with 20 and 30 degrees of pitch amplitude shows almost small lift generation, but the lift is significantly increased in case of 10-degree pitch amplitude. When the frequency is 0.5, the lift coefficients have large values, and the lift increases with a decrease in pitch amplitude. When the frequency ratio is 1.0, the airfoil generates large thrust. The thrust decreases as the pitch amplitude decreases. When the frequency ratio is 0.5, drag is generated for the 30-degree pitch amplitude, but the thrust is generated for 10-degree pitch amplitude. In future, the effect of heave amplitude on the unsteady aerodynamics of the airfoil will be studied.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2005.11a
• /
• pp.436-439
• /
• 2005

로봇축구는 과거의 단순한 수비시스템 벗어나 지능적 공격시스템으로 점차 변하기 시작했다. 본 논문에서는 휴리스틱 탐색기법인 최고우선탐색기법을 사용하여 공격로봇의 경험을 통해 로봇 움직임의 최적해를 찾아내고, 각 로봇간의 동기화로 인한 전술변화에 대해 설명하고 있다. 로봇이 공격과정에서 수비하는 로봇을 피해 다른 로봇에게 공을 전달하고 그 로봇이 상황에 따라 공격과 수비의 변화를 주는 방식이다. 이 알고리즘을 적용하여 최적의 로봇축구에이전트 시스템의 행동상황을 추출하고, 시뮬레이션을 통해 그 전략의 유용성을 확인한다.

• Journal of KSNVE
• /
• v.7 no.6
• /
• pp.1039-1048
• /
• 1997

This paper describes the effects of dual dynamic vibration absorbers attached to a primary vibration system with damping. The efficiency of dual dynamic vibration absorbers was investigated with the height of amplitude ratio at the resonance frequency ratio of the damped vibration system according to mass ratio, natural frequency ratio and damping ratio. The variation of amplitude ratio related to frequency ratio of primary vibration system is verified experimentally and theoretically according to dual dynamic vibration systems using computer program designed to find mutual relationship between two absorbers.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
• /
• 2001.06a
• /
• pp.179-180
• /
• 2001

1. 실험목적 : 벼 휴립건답직파재배시 절수재배에 알맞은 질소 수비량을 구명하고자 함. 2. 재료 및 방법 가. 공시품종 : 동진벼 나. 공시토양 : 전북통(미사질양토) 다. 물관리방법 : 3엽기부터 완전낙수기까지 5일 간격 고랑관개 라. 처리내용 -파종량(kg/ha) : 60, 100 -질소 수비량(kg/ha) : 24(50% 감비), 48(표준), 75(50% 증시), 96(100% 증시)(중략)

• Bulletin of the Society of Naval Architects of Korea
• /
• v.10 no.1
• /
• pp.33-44
• /
• 1973

Chine형 선체단면 주상체의 자유표면에서의 상하운동에 수반되는 부가질량과 감쇠력을 Ursell-Tasai 방법에 의하여 계산하였다. Chine형에서 구하여진 결과는 같은 선체단면적 계수와 반폭흘수비를 갖는 등가 Lewis형의 결과와 비교하였고 선체단면의 형상이 부가질량 및 감쇠력에 미치는 영향을 고찰하였다. Chine형과 등가 Lewis형 선체단면 주상체에 파고가 일정한 횡파가 입사할 때의 상하운동을 고찰하였다. 이상과 같은 계산 및 고찰을 통하여 다음 결과를 얻었다. 1) 자유표면이 부가질량에 미치는 영향은 chine형이 등가 Lewis형단면보다 큰 값을 갖는다. 2) 선체단면적계수와 반폭흘수비가 같은 경우에 감쇠력의 크기는 Lewis form, single chine, double chine순서이다. 3) 선체단면계수와 반폭흘수비는 상하운동에 가장 큰 영향을 미치는 것으로 생각되며, 선체단면의 기하학적인 변형이 운동에 미치는 영향은 중요한 요소가 되질 못한다. 4) 감쇠력계수와 선체단면계수와의 관계는 간단한 관계를 유지한다.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.40 no.4
• /
• pp.193-205
• /
• 2003

There has been so many research activities about robot soccer system in the many research fields, for example, intelligent control, communication, computer technology, sensor technology, image processing, mechatronics. Especially researchers research strategy for attacking in the field of strategy, and develop intelligent strategy. Then, soccer robots cannot defense completely and efficiently by using simple defense strategy. Therefore, intention extraction of attacker is needed for efficient defense. In this thesis, intention extractor of soccer robots is designed and developed based on FMMNN(Fuzzy Min-Max Neural networks ). First, intention for soccer robot system is defined, and intention extraction for soccer robot system is explained.. Next, FMMNN based intention extractor for soccer robot system is determined. FMMNN is one of the pattern classification method and have several advantages: on-line adaptation, short training time, soft decision. Therefore, FMMNN is suitable for soccer robot system having dynamic environment. Observer extracts attack intention of opponents by using this intention exactor, and this intention extractor is also used for analyzing strategy of opponent team. The capability of developed intention extractor is verified by simulation of 3 vs. 3 robot succor simulator. It was confirmed that the rates of intention extraction each experiment increase.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2001.09a
• /
• pp.239-243
• /
• 2001

대수층에서 오염물질의 이동은 대류, 확산, 흡착 등의 물리화학적 현상에 영향을 받는다. 지하수 유동과 오염 물질 운송에 관련된 분석은 지하수 자원의 관리와 평가, 복원사업에 필요한 요소이다. 본 연구의 목적은 사질대수층에서의 2차원 plume 모니터링을 통하여 오염운의 관측치와 모사치를 비교하므로써 종분산지수와 종/횡분산지수비를 결정하는 것이다. 실내 자유면 대수층 실험에서 MT3D를 이용한 case study로부터 추정된 종분산지수는 0.4 cm였으며 횡/종분산지수비는 1/5로 나타났다.

• 농업기술회보
• /
• v.47 no.6
• /
• pp.20-21
• /
• 2010

• Journal of Digital Convergence
• /
• v.18 no.6
• /
• pp.495-500
• /
• 2020

This study was intended to quantify the acceleration and deceleration information measured in the competition by using GPS device for the national women's field hockey players and to identify the difference in movement by classifying them by position. For this study, 308 acceleration and deceleration data were collected from 16 women's field hockey players measured at international competitions. According to research results, the frequency of acceleration was in the order of midfield > defender > striker, acceleration distance was midfield > striker > defender. The frequency of deceleration appeared in the order of midfield > defender > striker, deceleration distance was defender > striker > defender. Based on the results of this study, can be used as basic data when setting the strength and amount of training for field hockey players.