• Title/Summary/Keyword: wind disturbance

Search Result 129, Processing Time 0.025 seconds

Stability Analysis on Guided Munition at Slow Spin (유도포탄 저속 회전 시 안정성 분석)

  • Kim, Youngjoo;Bang, Hyochoong;Seo, Songwon;Pak, Chang-Ho;Kim, Jin-Won;Seo, Ilwon
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.46 no.9
    • /
    • pp.752-759
    • /
    • 2018
  • This paper presents methods and results of nonlinear simulations for a guided munition for verifying stability at slow spin. The munition is launched by an artillery and it deploys the rear fins to reduce its spin. While the spin speed command is set to 1 rps and 3 rps, wind gusts of 3m/s, 7m/s, 10m/s, and 15m/s in amplitude, and 26 different directions were generated as disturbance for each simulation run. Whereas the munition with the spin speed of 3 rps didn't flip, that with 1-rps spin flipped under some gusts. However, the gusts which increase airspeed in the flight direction didn't introduce harmful effect. Most importantly, all the flips of the munition was observed near the end of the simulation where the munition is going down. No problem was observed near the summit of trajectory.

Study on a Waypoint Tracking Algorithm for Unmanned Surface Vehicle (USV) (무인수상선을 위한 경유점 추적 제어 알고리즘에 관한 연구)

  • Son, Nam-Sun;Yoon, Hyeon-Kyu
    • Journal of Navigation and Port Research
    • /
    • v.33 no.1
    • /
    • pp.35-41
    • /
    • 2009
  • A waypoint tracking algorithm(WTA) is designed for Unmanned Surface Vehicle(USV) in which water-jet system is installed for propulsion To control the heading of USV for waypoint tracking, the steering nozzle of water-jet need, to be controlled. Firstly, target heading is calculated by using the position information of waypoints input from the land control center. Secondly, the command for the steering nozzle of water-jet is calculated in real time by using the heading and the rate-of-turn( ROT) from magnetic compass, In this study, in order to consider the drift angle due to external disturbance such as wind and wave, the course of ground( COG) can be used instead of heading at higher speed than a certain value, To test the performance of newly-designed WTA, the tests were carried out in actual sea area near Gwang-an bridge of Busan. In this paper, the sea trial test results from WTA are analyzed and compared with those from manual control and those from commercial controller.

Treatment of Numbness in Hyungsang Medicine (마목의 형상의학적 치료)

  • Kang Kyung Hwa;Son Jae Ik;Kim Kyung Chul;Lee Yong Tae
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.17 no.4
    • /
    • pp.879-892
    • /
    • 2003
  • This thesis makes a review of symptoms and cause of the numbness in the literature. clinical case are studied and classified according to the Hyungsang of the patients. The followings are the conclusions: In case of Dam type persons, numbness is mainly caused by Fire with blood deficiency and so cured by tonifying the Jung and blood. In case of Bang Kwang type persons. it is generally caused by the deficiency of Ki and damp-phlegm and treated by reinforcing Ki and removing dampness. Persons of Jung and Hyal types are apt to be afflicted with numbness of deficiency symptoms which can be cured by tonifying the Jung and blood. Those of Ki and Shin types are inclined to get numb from the congestion and stagnancy and so treated by promotion the flow of Ki, dispelling stagnancy, resolving phlegm and promoting digestion. Numbness is common to the old people and women. The deficiency of blood and primordial energy is a cause of old people's numbness. Women get numb due to the pent-up feelings and emotional disturbance. The function disharmony of five Jang and six Bu makes the body lose the control of heat and cold or deficiency and excessiveness, which can be a cause of numbness. Especially the deficiency of the spleen results in numbness. When the special parts of the body become numb treatment must be decided after due consideration on which of the Jang and Bu or meridians is related to that affected area. In case of person with six meridian types. unbalance of Ki and blood leads the six atmospheric influences(wind, cold, heat, dampness, dryness and fire) get into the body through the most developed meridian and brings in numbness.

Observational Overview of the May 2024 G5-Level Geomagnetic Storm: From Solar Eruptions to Terrestrial Consequences

  • Young-Sil Kwak;Jeong-Heon Kim;Sujin Kim;Yukinaga Miyashita;Taeyong Yang;Sung-Hong Park;Eun-Kyung Lim;Jongil Jung;Hosik Kam;Jaewook Lee;Hwanhee Lee;Ji-Hyun Yoo;Haein Lee;Ryun-Young Kwon;Jungjoon Seough;Uk-Won Nam;Woo Kyoung Lee;Junseok Hong;Jongdae Sohn;Jaeyoung Kwak;Hannah Kwak;Rok-Soon Kim;Yeon-Han Kim;Kyung-Suk Cho;Jaeheung Park;Jaejin Lee;Hoang Ngoc Huy Nguyen;Madeeha Talha
    • Journal of Astronomy and Space Sciences
    • /
    • v.41 no.3
    • /
    • pp.171-194
    • /
    • 2024
  • This study reports comprehensive observations for the G5-level geomagnetic storm that occurred from May 10 to 12, 2024, the most intense event since the 2003 Halloween storm. The storm was triggered by a series of coronal mass ejections (CMEs) originating from the merging of two active regions 13664/13668, which formed a large and complex photospheric magnetic configuration and produced X-class flares in early May 2024. Among the events, the most significant CME, driven by an X2.2 flare on May 9, caught up with and merged with a preceding slower CME associated with an X-class flare on May 8. These combined CMEs reached 1 AU simultaneously, resulting in an extreme geomagnetic storm. Geostationary satellite observations revealed changes in Earth's magnetosphere due to solar wind impacts, increased fluxes of high-energy particles, and periodic magnetic field fluctuations accompanied by particle injections. Extreme geomagnetic storms resulting from the interaction of the solar wind with the Earth's magnetosphere caused significant energy influx into Earth's upper atmosphere over the polar regions, leading to thermospheric heating and changes in the global atmospheric composition and ionosphere. As part of this global disturbance, significant disruptions were also observed in the East Asian sector, including the Korean Peninsula. Ground-based observations show strong negative storm effects in the ionosphere, which are associated with thermospheric heating and resulting in decreases in the oxygen-to-nitrogen ratio (O/N2) in high-latitude regions. Global responses of storm-time prompt penetration electric fields were also observed from magnetometers over the East-Asian longitudinal sector. We also briefly report storm-time responses of aurora and cosmic rays using all-sky cameras and neutron monitors operated by the Korea Astronomy and Space Science Institute (KASI). The extensive observations of the G5-level storm offer crucial insights into Sun-Earth interactions during extreme space weather events and may help establish better preparation for future space weather challenges.

Environmental factors affecting roost use of shorebirds in the southern Kanghwa Island, Republic of Korea (강화도 남단에 도래하는 도요새들의 해안 내륙 휴식지 이용과 이들의 이용에 영향을 미치는 환경요인들)

  • Kim, Kwan Mok;Moon, Young Min;Yoo, Jeong Chil
    • Journal of Wetlands Research
    • /
    • v.15 no.2
    • /
    • pp.251-264
    • /
    • 2013
  • There are some factors affecting the shorebirds in selecting a coastal inland roost site where they have to stay during the high tide when the entire intertidal zone is covered with water. We investigated eight species (Eastern Curlews Numenius madagascariensis, Green Shanks Tringa nebularia, Bar-tailed Godwits Limosa lapponica, Grey Plovers Pluvialis squatarola, Dunlins Calidris alpine, Whimbrels Numenius phaeopus, Eurasian Curlews Numenius arquata and Terek Sandpipers Xenus cinereus) to identify the spatial and temporal variability in coastal inland roost use in the area and the factors influencing the use. We considered the area and length of the standing water in the roost site, temperature, wind speed, the time of migration and the intensity of disturbance. As a result, number of individuals and type of species using the roost site varied across spatial and temporal scales. And the factors affecting the roost use was species-specific. The roost site of the study area was a closed shrimp farm however, it has been converted to a Salicornia herbacea, a salt marsh plant, farm recently. In a situation where coastal inland roost site is needed, we hereby describe a resolution for the juxtaposition of shorebirds and farming.

An Experimental Study on Air Evacuation from Lunar Soil Mass and Lunar Dust Behavior for Lunar Surface Environment Simulation (달 지상환경 모사를 위한 지반 진공화 및 달먼지 거동에 대한 실험적 연구)

  • Chung, Taeil;Ahn, Hosang;Yoo, Yongho;Shin, Hyu-Soung
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.39 no.2
    • /
    • pp.327-333
    • /
    • 2019
  • For sustainable lunar exploration, the most required resources should be procured on site because it takes tremendous cost to transfer the resources from the Earth to the Moon. The technologies required for use of lunar resources refers to In-Situ Resource Utilization (ISRU). As the ISRU technology cannot be verified in the Earth, a lunar surface environment simulator is necessary to be prepared in advance. The Moon has no atmosphere, and the average temperature of the lunar surface reaches to $107^{\circ}C$ during the daytime and $-153^{\circ}C$ at night. The lunar surface is also covered with very fine soils with sharp particles that are electrostatically charged by solar radiation and solar wind. In this research, generation of vacuum environment with lunar soil mass in a chamber and simulation of electrostatically charged soils are taken into consideration. It was successful to make a vacuum environment of a chamber including lunar soils without soil disturbance by controlling evacuation rate of a vacuum chamber. And an experiment procedure for simulating the charged lunar soil was suggested by theoretical consideration in charging phenomena on lunar dust.

Prediction of Damages and Evacuation Strategies for Gas Leaks from Chlorine Transport Vehicles (염소 운송차량 가스누출시 피해예측 및 대피방안)

  • Yang, Yong-Ho;Kong, Ha-Sung
    • The Journal of the Convergence on Culture Technology
    • /
    • v.10 no.2
    • /
    • pp.407-417
    • /
    • 2024
  • The objective of this study is to predict and reduce potential damage caused by chlorine gas leaks, a hazardous material, when vehicles transporting it overturn due to accidents or other incidents. The goal is to forecast the anticipated damages caused by chlorine toxicity levels (ppm) and to design effective response strategies for mitigating them. To predict potential damages, we conducted quantitative assessments using the ALOHA program to calculate the toxic effects (ppm) and damage distances resulting from chlorine leaks, taking into account potential negligence of drivers during transportation. The extent of damage from toxic gas leaks is influenced by various factors, including the amount of the leaked hazardous material and the meteorological conditions at the time of the leak. Therefore, a comprehensive analysis of damage distances was conducted by examining various scenarios that involved variations in the amount of leakage and weather conditions. Under intermediate conditions (leakage quantity: 5 tons, wind speed: 3 m/s, atmospheric stability: D), the estimated distance for exceeding the AEGL-2 level of 2 ppm was calculated to be 9 km. This concentration poses a high risk of respiratory disturbance and potential human casualties, comparable to the toxicity of hydrogen chloride. In particular, leaks in urban areas can lead to significant loss of life. In the event of a leakage incident, we proposed a plan to minimize damage by implementing appropriate response strategies based on the location and amount of the leak when an accident occurs.

Literatual Study on Etiological Analysis, Pathogenesis and Acupuncture Treatment of Edema (수종(水腫)의 병인병기(病因病機) 및 침구치료(鍼灸治療)에 대한 문헌적(文獻的) 고찰(考察))

  • Oh, Chang-rok;Na, Gun-ho;Choi, Bong-gyun;Yoon, Jung-sun;Lyu, Chung-yeol;Cho, Myung-rae
    • Journal of Acupuncture Research
    • /
    • v.22 no.3
    • /
    • pp.253-270
    • /
    • 2005
  • Objective : The purpose of this study is to establish a category for acupuncture therapy by appropriate etiological analysis and differenciation of edema. Methods : We arrange Huang Di Nei Jing and thirty four kinds of literature about edema. Results : 1. The cause of Edema is functional disorder of lung, spleen, kidney, bladder and tri-energizer by six kinds of natural factors, internal injury and loss of nutritions. 2. Edema compartmentalize into the water of five zang organs, several kinds of edema(e,g. 5, 10, 12, 24) and yang & yin edema. 3. An ultimate cause of edema pathogenesis is the disturbance of Qi function in kidney. 4. In view of the results so far achived,'GV26(水淸)' is a vitally important acupoint in acupuncture treatment of edema.'GV26(水淸)' and 'CV9(水分)' are very useful acupoints in moxibustion. 5. In the acupuncture and moxibustion treatment of yang edema, we can use acupoints as like 'GV26(水溝)', 'S36(足三里)', 'B20(脾兪)' and 'SP9(陰陵泉)' by purgation and reduction for expelling wind, reducing fever and eliminating dampness. In an instance of yin edema, we can use acupoints as like 'CV9(水分)' 'S36(足三里)', 'CV6(氣海)', 'B20(脾兪)', 'B23(腎兪)' and 'K3(太谿)' by reinforcement for tonifying spleen yang-middle energizer-, qi-transmission and water promoting.

  • PDF

Effect of Geijibokryunghwan and each constituent herb on inhibition of platelet aggregation (계지복령환(桂枝茯笭丸) 및 그 구성약물(構成藥物)의 혈소판응집억제(血小板凝集抑制)에 관(關)한 연구(硏究))

  • Kim, Jong-Goo;Park, Sun-Dong;Park, Won-Hwan
    • The Journal of Dong Guk Oriental Medicine
    • /
    • v.8 no.2
    • /
    • pp.115-129
    • /
    • 2000
  • The cause that the increase of animality fat intakes, under exercise, fatness, adding the stress, advanced age etc., the occurrence rate of the circulation system disease has been increased. And the thrombosis importantly came to the front as the risk factor of these circulation system's disease. Nowadays, the ischemic disease has especially discussed, for example the angina or myocardial infarction, originated in thrombosis that came from the platelet aggregation. In the western medicine, as the cure and prevention, using the aspirin or ticlopidine for platelet aggregation suppressant. But in the , the curing method must be used properly according to the pectoralgia or heartache's kind, state, grade. The platelet do not attache to the normal hemangioendothelial cell. But when it stimulated by endothelium peronia and so on, it attache to the injury endothelium or rise aggregation between the platelet. On this time, it secrete the platelet aggregation inducer as like ADP, thromboxane A2 from the inside of platelet. So it has first defensive function through the aggregation augment that prevent the celerity consumption of blood. But the activation of abnormal platelet occur the platelet grume and thrombogenesis. So it bring up the occlusive angiosis, so to speak, cardiovascular disease, cerebrovascular disease, arterial sclerosis. In oriental medicine, the thrombosis in the category of blood stasis and this blood stasis present the generalise or local blood circulation disturbance that generated by all kinds of pathological fact or blood stream retention accompanying with a series of syndrome. As the syndrome, stabbing pain fixed at certain region, squamous and dry skin, fullness and pain of the chest and hypochondrium, firmness and fullness of the lower abdomen, black stool, dark purple tongue or with ecchymoses and petechiae etc.. has been created. And it becomes the pathopoiesis cause that the convulsion and palpitation, severe palpitatiion, tympanites, the symtom complex with a mass or swelling in the abdomen, insanity, stricken by wind etc.. Moreover, it used the drugs for invigorating blood circulation and eliminating blood stasis or drugs for removing blood stasis for all kinds of syndrome through the blood stasis. And the drugs for activating the blood circulation, such as Salviae Radix, Angelicae Sinensis Radix, Persicae Semen, Achyranthis Radix, Cnidii Rhizoma, Carthami Flos are used for that. And it is used to the herbs of insects that has strong effect about the disintergrating blood stasis such as Hirudo, Scolopendrae Corpus, Buthus, Lumbricus etc.. On this study, It used Geijibokryunghwan(GBH) and the consisting herbs to investigate the influence of platelet aggregation about drugs that used to improvement various symptoms created by the thrombosis in oriental medicine. GBH formula has as formula recorded in the , action of 'eleminating the evil and not impairment of healthy energy' and 'promoting the flow of QI and cold and heat, so used for the expel blood stasis herbs from the ancient. Therefore we investigated the restraint effect of GBH and the consisting herbs about the platelet agregation induced to the ADP, AA or collagen. The conclusion is following. 1. When it added the aggregation inducer after that it added GBH and individual consisting herbs in the PRP, GBH showed the (+) inhibition effect on the platelet aggregation and it showed the (+) inhibition effect in the individual consisting herbs as like Paeoniae Radix and Moutan Cortex Radicis. 2. It showed the (+), (+,++) inhibition effect on the platelet aggregation in Paeoniae Radix Hoelen, Paeoniae Radix Moutan Cortex Radicis, Hoelen Moutan Cortex Radicis etc. 3. In the aggregation inhibition activating on the difference of density, GBH showed strong inhibition effect to the aggregation state induced to collagen, and it showed the inhibition effect in the individual consisting herbs as like Paeoniae Radix and Moutan Cortex Radicis about the aggregation induced by the collagen. 4. It showed the strong inhibition effect about the aggregation induced by the collagen in Paeoniae Radix Hoelen, Paeoniae Radix Moutan Cortex Radicis, Hoelen Moutan Cortex Radicis etc Like this, as confirm GBH and the individual consisting herb's inhibition effect of platelet aggregation, We considerated that GBH and the individual consisting herbs have practical applicational value of clinical trial in the thrombosis caused by platelet aggregation.

  • PDF