• Title/Summary/Keyword: Knot

Search Result 586, Processing Time 0.032 seconds

A Study on the Characteristics of the Circulation and Diffusion in Suyeong Bay (수관만의 해수유동과 확산지성에 관한 연구)

  • Kim, Young-seup;Han, Young-ho
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.18 no.2
    • /
    • pp.55-61
    • /
    • 1982
  • Simultaneous investigations for drift bottle and dye diffusion experiment were carried out in Suyeong bay. Seawater in Suyeong bay flowed differently in the vicinity of Suyeong river estuary and Nam-cheon Dong respectively. The speed of current did not exceed one knot in this bay. The dye patch moved to Kwangan beach in the dye diffusion experiment. The relationship between apparent diffusivity and diffusion time was appeared as Ka=0.0025t super(1.9). The variance was calculated to be 2.9 power of the diffusion time. And the exponent diffusivity versus the scale of diffusion time was appeared to be 1.3.

  • PDF

From Law/Superego to Love: Law, Violence, and the Possibility of Love in Herman Melville's Billy Budd, Sailor (법/초자아에서 사랑으로 -허먼 멜빌의 『빌리 버드』에 나타나는 법, 폭력, 그리고 사랑의 가능성)

  • Jeong, Jin Man
    • Journal of English Language & Literature
    • /
    • v.57 no.5
    • /
    • pp.787-812
    • /
    • 2011
  • This essay aims to explore Herman Melville's recognition and resolution of the vicious link between law and violence in his posthumous Billy Budd, Sailor (1924). In order to investigate the issues, this essay refers to Freud, Benjamin, Derrida, Lacan, and Žižek, all perceptive to the uncanny affinity of law and violence. Especially, Žižek's arguments of "superego" as an embodiment of cruel and destructive violence supplementing the official law and of "love" as an ethical possibility beyond the limit of the problematic law are introduced in this study to make Melville's reflection of the inseparableness between law and violence much clearer. John Claggart and Captain Vere embody the legal (superegoic) violence. Claggart even procurs secret enjoyment, in the name of maintaining positive law. Billy Budd discloses another violence defending his justness according to natural law. However, Melville suggests the possibility of suspending the problematic tie of law/violence through "love," as portrayed at the last part of the story. The two final words from Billy and Vere, as a sort of delayed dialogue between them after the event of their secret interview before Billy's hanging, suggest that they finally distance from the obscene nightly law of superego-respectively from outward punitiveness toward Vere and from inward punishment for Vere's excessive enforcement of Billy's hanging-and identify each other's lack as their own. Their love implicated in the last words is for the real other-in Lacan's sense-who discloses the constitutive lack or incompleteness of beings and aporia of the law. This essay's examination of Melville's representations about the superegoic violence as the (im-)possible condition of law and the possibility of withdrawing from it would help us recognize Billy Budd, Sailor as the author's own last word for the possible vision of love cutting the vicious knot of law/violence.

A study on the path following of an unmanned surface vessel (무인선의 경로추종에 관한 연구)

  • Hansol Park;Namsun Son;Chunseon Pyo;Jae yong Lee
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2022.11a
    • /
    • pp.187-187
    • /
    • 2022
  • 최근 선박의 자율운항기술이 활발하게 연구되어 오면서, 경로추종 제어 및 충돌회피 등의 자율운항 기술 연구가 많이 진행되고 있으며 그에 따른 시뮬레이션과 실해역 시험 등도 활발하게 수행되고 있다. 이러한 자율운항기술 중 본 연구에서는 AUV(Autonomous Underwater Vehicle) 진회수 시 모함에 활용되며 쌍동선형을 갖는 쌍동형 무인수상선을 대상으로 경로추종 제어에 대한 실해역 시험을 수행한 내용을 소개한다. 대상선인 쌍동형 무인수상선은 배수량이 약 10ton, 최대속도 10knots를 기준으로 설계된 선형이며 Sail drive 타입의 쌍축 추진기를 탑재하고 있으며 Fig. 1에 나타내었다. 실해역 시험은 경기도 화성시에 위치한 제부마리나 전면 해역에서 여러 속도에 대해 Fig. 2의 경로(빨간색)를 활용하여 수행되었다. 해당 경로는 변침각이 45도까지 이루어져 있다. 경로추종 제어 알고리즘은 목표경유점을 향하기 위해 선수각을 제어하는 부분과 목표속도로 추진하기 위해 속도를 제어하는 부분으로 나뉘어져 있다. 선수각 제어 시 경로와 무인선과의 위치 오차를 줄이는 방향으로 선수각이 향할 수 있도록 알고리즘이 설계되었다. 속도 제어의 경우 RPM 별로 실제 속도를 계측하여 데이터화 한 후, 실제 속도가 명령 속도와 다를 경우 RPM을 가감하여 명령 속도로 추진하기 위해 제어할 수 있도록 하였다. Fig. 2에서 파란색 선은 설계한 알고리즘을 활용하여 경로추종 제어를 한 결과의 궤적을 보여준다.

  • PDF

Verification of Low-Level Wind Shear Prediction System Using Aircraft Meteorological Data Relay (AMDAR) (항공기 기상관측자료(AMDAR)를 이용한 인천국제공항 저고도 급변풍 예측시스템 검증)

  • Jae-Hyeok Seok;Hee-Wook Choi;Geun-Hoi Kim;Sang-Sam Lee;Yong Hee Lee
    • Journal of the Korean Society for Aviation and Aeronautics
    • /
    • v.31 no.3
    • /
    • pp.59-70
    • /
    • 2023
  • In order to predict low-level wind shear at Incheon International Airport (RKSI), a Low-Level Wind Shear prediction system (KMAP-LLWS) along the runway take-off and landing route at RKSI was established using Korea Meteorological Administration Post-Processing (KMAP). For the performance evaluation, the case of low-level wind shear cases calculated from Aircraft Meteorological Data Relay (AMDAR) from July 2021 to June 2022 was used. As a result of verification using the performance evaluation index, POD, FAR, CSI, and TSS were 0.5, 0.85, 0.13, and 0.34, respectively, and the prediction performance was improved by POD, CSI, and TSS compared to the Low-Level Wind Shear prediction system (LDPS-LLWS) calculated using the Korea Meteorological Administration's Local Data Assimilation and Prediction System (LDAPS). This means that the use of high-resolution numerical models improves the predictability of wind changes. In addition, to improve the high FAR of KMAP-LLWS, the threshold for low-level wind shear strength was adjusted. As a result, the most effective low-level wind shear threshold at 8.5 knot/100 ft was derived. This study suggests that it is possible to predict and respond to low-level wind shear at RKSI. In addition, it will be possible to predict low-level wind shear at other airports without wind shear observation equipment by applying the KMAP-LLWS.

Synthesis of Nano Sulfur/Chitosan-Copper Complex and Its Nematicidal Effect against Meloidogyne incognita In Vitro and on Coffee Pots

  • Hong Nhung Nguyen;Phuoc Tho Tran;Nghiem Anh Tuan Le;Quoc Hien Nguyen;Duy Du Bui
    • The Plant Pathology Journal
    • /
    • v.40 no.3
    • /
    • pp.261-271
    • /
    • 2024
  • Sulfur is one of the inorganic elements used by plants to develop and produce phytoalexin to resist certain diseases. This study reported a method for preparing a material for plant disease resistance. Sulfur nanoparticles (SNPs) stabilized in the chitosan-Cu2+ (CS-Cu2+) complex were synthesized by hydrolysis of Na2S2O3 in an acidic medium. The obtained SNPs/CS-Cu2+ complex consisting of 0.32% S, 4% CS, and 0.7% Cu (w/v), contained SNPs with an average size of ~28 nm as measured by transmission electron microscopy images. The X-ray diffraction pattern of the SNPs/CS-Cu2+ complex showed that SNPs had orthorhombic crystal structures. Interaction between SNPs and the CS-Cu2+ complex was also investigated by ultraviolet-visible. Results in vitro nematicidal effect of materials against Meloidogyne incognita showed that SNPs/CS-Cu2+ complex was more effective in killing second-stage juveniles (J2) nematodes and inhibiting egg hatching than that of CS and CS-Cu2+ complex. The values of LC50 in killing J2 nematodes and EC50 in inhibiting egg hatching of SNPs/CS-Cu2+ complex were 75 and 51 mg/l, respectively. These values were lower than those of CS and the CS-Cu2+ complex. The test results on the nematicidal effect against M. incognita on coffee pots showed that the SNPs/CS-Cu2+ complex was 100% effective at a concentration of 150 mg/l. Therefore, the SNPs/CS-Cu2+ complex could be considered as a biochemical material with potential for agricultural applications to control root-knot nematodes.

Percutaneous femoral access: Stuck guide wire, decannulation difficulty due to unravelling and knotting

  • Bhanu Pratap Singh Chauhan;Binita Dholakia;Ashfaque Khan;Chirag Hirani;Satheesh Kumar;Dibya Jyoti Mahakul;Abhishek Katyal;Wajid Nazir;Daljit Singh
    • Journal of Cerebrovascular and Endovascular Neurosurgery
    • /
    • v.26 no.2
    • /
    • pp.223-226
    • /
    • 2024
  • Percutaneous techniques for femoral arterial access are increasingly being performed due to advances in endovascular cerebral procedures, as they provide a less morbid and minimally invasive approach than open procedures. Common complications associated with this peripheral puncture include hematoma, bleeding, pseudoaneurysm, arteriovenous fistula, retroperitoneal bleeding, inadvertent venous puncture, dissection, etc. The retrograde femoral access is currently the most frequently used arterial access as it is technically straightforward, allows for the use of larger size sheaths and catheters, allows repeated attempts, etc. Although being technically less challenging, grave complications can occur due to hardware failure. Here, we present a case of unruptured posterior inferior cerebellar artery (PICA) aneurysm, who underwent uneventful diagnostic cerebral digital substraction angiography (DSA) via right femoral artery route on first attempt, but on second attempt for therapeutic intervention, landed up with stuck guide wire and faced decannulation difficulty due to unravelling of guide wire and multiple knot formation, which was finally removed after multiple attempts at pulling and improvised manoeuvres. Such cannulation and decannulation difficulties have been reported multiple times for central venous access, but extremely rarely for femoral routes, making this case a rarity and worth reporting.

Attachment of Pasteuria penetrans Endospores to Meloidogyne spp. Juveniles Affected by Temperatures and the Nematode species (선충기생세균(Pasteuria penetrans) 내생포자의 뿌리혹선충(Meloidogyne spp.) 유충 부착에 대한 온도와 선충종의 영향)

  • Cho, Myoung Rae;Kim, Hyung Hwan;Kang, Taek Joon;Ahn, Seung Joon;Yang, Chang Yul;Jeon, Sung Wook
    • Korean journal of applied entomology
    • /
    • v.52 no.2
    • /
    • pp.109-113
    • /
    • 2013
  • A greenhouse soil infested with an obligate nematode parasitic bacterium, Pasteuria penetrans, was used to test the effect of temperatures on the endospore attachment to root-knot nematode, Meloidogyne arenaria, juveniles (J2). Freshly hatched J2s were inoculated to the soil in petri dish and incubated under different temperatures of $20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$, and $35^{\circ}C$ for 7 days. The endospore attachment rates were 100% in all the temperatures, while the number of endospores attached per J2 was highest in $25^{\circ}C$ with 28.3 endospores/J2 followed by 20.2, 18.6, and 13.6 in $30^{\circ}C$, $20^{\circ}C$, and $35^{\circ}C$, respectively. When the soil was pre-treated under different temperatures before the J2 inoculation, the endospore attachment rates significantly decreased from 60% in room temperature to $25^{\circ}C$, 31.7, 8.3, 5.0, and 0% after the soil incubation in $-30^{\circ}C$, $4^{\circ}C$, $40^{\circ}C$, $50^{\circ}C$, and $100^{\circ}C$ for 10 days, respectively. The endospore numbers attached per J2 were 3.5, 4.3, 1, 1, and 0 when the soil was pre-treated in $-30^{\circ}C$, $4^{\circ}C$, $40^{\circ}C$, $50^{\circ}C$, and $100^{\circ}C$, respectively, which were lower than 5.3/J2 of room temperature treated soil. The P. penetrans isolate in the soil showed nematode species-specific endospore attachment characteristics with 100% attachment rate only on M. arenaria J2s while the rates were 0% on M. hapla and M. incognita J2s.

Pollutant Loading and Changes of the Self - Purification Capacity with Season in Gokneung Stream Ecosystem (곡릉천 생태계의 오염부하량과 계절에 따른 자정능의 변화)

  • 이선경;심규철;김재영;김준민;장남기
    • The Korean Journal of Ecology
    • /
    • v.17 no.3
    • /
    • pp.355-366
    • /
    • 1994
  • The purpose of this study was to investigate the changes of water quality and the patterns of self-purification with season in Gokneung stream. The vegetation in the ecosystem around Gokneung stream was dominated by Quercus species. In the physicochemical analysis based on the contents of DO, BOD, conductivity and total phosphorus, the upstream seemed to have been polluted, but the downstream was self-purified. In biological investigation by bentic macroinvertebrates, the result was similar to that in the physicochemical analysis. The self-purification constant based on BOD of the upstream, 1.013, was the highest. In the self-purification constants with month, that of September was 0.995 and that of January was 0.272. These results indicated that the self purification capacities of spring and autumn were larger than those of winter and summer in Gokneung stream.

  • PDF

Properties in Strength of Raschel Netting (랏쉘그물감의 강도)

  • KIM Dai An
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.11 no.1
    • /
    • pp.39-48
    • /
    • 1978
  • 1) The decrease in strength of Raschel twines at Raschel joints is regarded to be due mainly to the frictional force between yarns and the unbalanced tensile distribution by the deformation of the joints. The rate of the decrease is about $13\%$ in lengthwise pull and 22 to $26\%$ in breadthwise pull. 2) The 3-course joint is less in deformation and stronger than the 2-course joint in all cases of pulls. 3) The variation of Raschel joint strength $T_R$ with the angle $\varphi$ between the adjacent bars is expressed as $T_R=T_{R0}-k\varphi$ where $T_{R0}$ is the strength at $\varphi=0^{\circ}$ and K is a constant. 4) The tensile strength ${\sigma}R$ and tile breaking energy $E_R$ of Raschel netting are given by $${\sigma}R=KN\;or\;${\sigma}R=T_RN$$ and $$E_R=AN$$ respectively, where N is the number of meshes at the pulling side, and K and A are constants. But the breaking energy of the netting is almost constant independent of tile variation of N. 5) The Raschel netting with some bars cut already breaks from tile joints of the bars next to the cut bars and its tensile strength, breaking energy, and breaking elongation decrease largily even if only one bar is in already cut state. 6) The tearing strength of Raschel netting is almost equal to the tensile strength of its single joint pulled by two bars. 7) The twisted joint is much more excellent in strength than the knot or the Raschel joint. The knot strength is 69 to $76\%$, and the Raschel joint strength is 71 to $74\%$ in lengthwise pull and 62 to $67\%$ in breadthwise pull, respectively, of the twisted joint strength.

  • PDF

Arthroscopic Transosseous Suture Repair for Bankart Lesion with a Flexible Drill Device - An Experimental and Preliminary Clinical Report - (유연성 천공기를 이용한 Bankart 병변의 골관통식 봉합 - 동물 실험 및 예비 임상 결과 보고 -)

  • Park, Jin-Su;Won, Ye-Yeon;Yoo, Jung-Han;Park, Yong-Wook;Noh, Kyu-Chul;Chung, Kuk-Jin;Kim, Hong-Kyun;Hwang, Ji-Hyo;Lee, Young-Bum;Suh, Il-Woo
    • Clinics in Shoulder and Elbow
    • /
    • v.13 no.1
    • /
    • pp.72-78
    • /
    • 2010
  • Purpose: Too develop a flexible drill device that can be inserted into the shoulder joint so that arthroscopic transosseous suture repair for Bankart lesion is possible. Materials and Methods: We created a device composed of a flexible drill unit and a guide pipe unit. The flexible drill unit was made of flexible multifilament wires (1.2 mm in diameter) that was twisted into one cord so that it can flex in any direction and a drill bit (1.2 mm in diameter) that is attached onto one end of the flexible wire. The guide pipe unit was a 150 mm long metal pipe (2.0 mm in inner diameter and 3.0 mm in outer diameter), with one end bent to 30 degrees. The flexible drill set was inserted into the shoulder joint through the posterior portal of the joint. The guide pipe component was placed onto the medial wall of the glenoid so that the pipe was placed 5 mm posterior to the margin of the anterior glenoid rim. The flexible drill was driven through the glenoid by the power drill so that holes were made in the glenoid. A non- absorbable suture was passed through the hole. Tying of a sliding knot tying was accomplished over the capsule and labrum after making a stitch through the capsule and labrum with a suture hook loaded with suture passer. The same procedures were done at the 2 and 4 O'Clock positions of the glenoid. Results: Five cases with Bankart lesion received arthroscopic transosseous repair with our flexible drill device. There were no intraoperative problems. Neither redislocation nor subluxation was reported at final follow-up. Conclusion: Arthroscopic transosseous suture repair without suture anchors and easy tying of a sliding knot are possible with a flexible drill set.