• Title/Summary/Keyword: Entry Angle

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Aerodynamics of a wing section along an entry path in Mars atmosphere

  • Zuppardi, Gennaro;Mongelluzzo, Giuseppe
    • Advances in aircraft and spacecraft science
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    • v.8 no.1
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    • pp.53-67
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    • 2021
  • The increasing interest in the exploration of Mars stimulated the authors to study aerodynamic problems linked to space vehicles. The aim of this paper is to evaluate the aerodynamic effects of a flapped wing in collaborating with parachutes and retro-rockets to reduce velocity and with thrusters to control the spacecraft attitude. 3-D computations on a preliminary configuration of a blunt-cylinder, provided with flapped fins, quantified the beneficial influence of the fins. The present paper is focused on Aerodynamics of a wing section (NACA-0010) provided with a trailing edge flap. The influence of the flap deflection was evaluated by the increments of aerodynamic force and leading edge pitching moment coefficients with respect to the coefficients in clean configuration. The study was carried out by means of two Direct Simulation Monte Carlo (DSMC) codes (DS2V/3V solving 2-D/3-D flow fields, respectively). A DSMC code is indispensable to simulate complex flow fields on a wing generated by Shock Wave-Shock Wave Interaction (SWSWI) due to the flap deflection. The flap angle has to be a compromise between the aerodynamic effectiveness and the increases of aerodynamic load and heat flux on the wing section lower surface.

Construction of sports-educational places using resistant and water-repellent raw materials in concrete

  • Wenbo Xu;Zhiqiang Zhu
    • Structural Engineering and Mechanics
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    • v.86 no.1
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    • pp.109-118
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    • 2023
  • Any place where exercise is common, such as a club, sports hall, or school, is considered a place for teaching sports. When doing sports, a very safe environment for sports should be chosen. The athlete should consider the safety of sports facilities and equipment, and if there is a defect, he should refrain from exercising in these places. The safety of sports facilities is very effective in creating people's sports activities, with the benefits of staying away from physical harm, enjoying sports, and having mental peace. Everyone has the right to participate in sports and recreation and to ensure that they enjoy a safe environment. The ability to manage and solve issues that may arise plays the most critical role in creating a safe environment. The quality of construction materials used for the construction of sports facilities is of great importance. In this work, the resistance and water repellency of concrete constituents for the construction of sports buildings have been investigated by nanoscience. Nano-concrete material solves the main problem of concrete surfaces, i.e., the entry of water and humidity into the structure. It also gives it a self-cleaning ability with its water repellency. Nanoparticles are placed between pores and cover the cracks, which causes roughness in the surface structure of concrete. The high roughness of the surface of the coated concrete caused its super-hydrophobicity. In hydrophobic surfaces, the higher the contact angle, the more hydrophobic the surface will be. In order to investigate the hydrophobic properties, silica nanoparticles, silica nanoparticles, and fly ash were prepared on concrete, and their properties were analyzed.

Fluid flow dynamics in deformed carbon nanotubes with unaffected cross section

  • Rezaee, Mohammad;Yeganegi, Arian;Namvarpour, Mohammad;Ghassemi, Hojat
    • Advances in nano research
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    • v.12 no.3
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    • pp.253-261
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    • 2022
  • Numerical modelling of an integrated Carbon NanoTube (CNT) membrane is only achievable if probable deformations and realistic alterations from a perfect CNT membrane are taken into account. Considering the possible forms of CNTs, bending is one of the most probable deformations in these high aspect ratio nanostructures. Hence, investigation of effect associated with bent CNTs are of great interest. In the present study, molecular dynamics simulation is utilized to investigate fluid flow dynamics in deformed CNT membranes, specifically when the tube cross section is not affected. Bending in armchair (5,5) CNT was simulated using Tersoff potential, prior to flow rate investigation. Also, to study effect of inclined entry of the CNT to the membrane wall, argon flow through generated inclined CNT membranes is examined. The results show significant variation in both cases, which can be interpreted as counter-intuitive, since the cross section of the CNT was not deformed in either case. The distribution of fluid-fluid and fluid-wall interaction potential is investigated to explain the anomalous behavior of the flow rate versus bending angle.

Alternative Method of Retrocrural Approach during Celiac Plexus Block Using a Bent Tip Needle

  • An, Ji Won;Choi, Eun Kyeong;Park, Chol Hee;Choi, Jong Bum;Ko, Dong-Kyun;Lee, Youn-Woo
    • The Korean Journal of Pain
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    • v.28 no.2
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    • pp.109-115
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    • 2015
  • Background: This study sought to determine safe ranges of oblique angle, skin entry point and needle length by reviewing computed tomography (CT) scans and to evaluate the usefulness of a bent tip needle during celiac plexus block (CPB). Methods: CT scans of 60 CPB patients were reviewed. Image of the uppermost margin of L2 vertebral body was used to measure the minimal and maximal oblique angles and the distances from the midline to skin puncture point. The imaginary needle trajectory distance was calculated by three-dimensional measurement. When the procedure was performed by using a $10^{\circ}$ bent tip needle under a $20^{\circ}$ oblique X-ray fluoroscopic view, the distance (GF/G'F) from the midline to the actual puncture site was measured. Results: The imaginary safe oblique angle range was $26.4-34.2^{\circ}$ and $27.7-36.0^{\circ}$ on the right and left, respectively. The distance from the midline to skin puncture point was 6.1-7.6 cm on the right and 6.3-7.6 cm on the left. The needle trajectory distance at minimal angle was 9.6-11.6 cm on the right and 9.5-11.5 cm on the left. The distance of GF/G'F was 5.1-6.5 cm and 5.0-6.4 cm on the right and left, respectively. All imaginary parameters were correlated with BMI except for GF/G'F. All complications were mild and transient. Conclusions: We identified safe values of angles and distances using a straight needle. Furthermore, using a bent tip needle under a $20^{\circ}$ oblique fluoroscopic view, we could safely perform CPB with smaller parameter values.

Adaptive Vehicle License Plate Recognition System Using Projected Plane Convolution and Decision Tree Classifier (투영면 컨벌루션과 결정트리를 이용한 상태 적응적 차량번호판 인식 시스템)

  • Lee Eung-Joo;Lee Su Hyun;Kim Sung-Jin
    • Journal of Korea Multimedia Society
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    • v.8 no.11
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    • pp.1496-1509
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    • 2005
  • In this paper, an adaptive license plate recognition system which detects and recognizes license plate at real-time by using projected plane convolution and Decision Tree Classifier is proposed. And it was tested in circumstances which presence of complex background. Generally, in expressway tollgate or gateway of parking lots, it is very difficult to detect and segment license plate because of size, entry angle and noisy problem of vehicles due to CCD camera and road environment. In the proposed algorithm, we suggested to extract license plate candidate region after going through image acquisition process with inputted real-time image, and then to compensate license size as well as gradient of vehicle with change of vehicle entry position. The proposed algorithm can exactly detect license plate using accumulated edge, projected convolution and chain code labeling method. And it also segments letter of license plate using adaptive binary method. And then, it recognizes license plate letter by applying hybrid pattern vector method. Experimental results show that the proposed algorithm can recognize the front and rear direction license plate at real-time in the presence of complex background environments. Accordingly license plate detection rate displayed $98.8\%$ and $96.5\%$ successive rate respectively. And also, from the segmented letters, it shows $97.3\%$ and $96\%$ successive recognition rate respectively.

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The Behaviour of Shrimp , Palaeman Pacificus , to the Model Trap and the Odour of Baits (함정어구와 미끼에 대한 태평줄 새우)

  • Ko, Kwan-Soh;Kim, Yong-Hae
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.19 no.2
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    • pp.85-91
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    • 1983
  • The behaviour of shrimp in response to the trap was much influenced by the type, size and the dimensions of entrance as well as physiological and ecological conditions. The entry and the escape behaviour of shrimp to the model trap were observed in accordance with netting materials, baits, type and slope of entrance, and gathering response were also investigated on the odour of bait extracts in the aquarium from June to August, 1983. Entering shrimp to the circular entrance was significantly more than to the triangular or the square; however, no differences were found in the entry behacior among netting materials i e., P. A, P. E. and cotton. According as the slope of entrance was increased its angle from 0$^{\circ}$ to 90$^{\circ}$, number of entering shrimp was decreased; however, number of escaping shrimp at 30$^{\circ}$or 60$^{\circ}$ with time was fewer than at 0$^{\circ}$ or 90$^{\circ}$. Gathering responses of shrimp on the odours were more sensitive to the flesh of mackerel or the shrimp than to the pickled anchovy, or the pettitioes, while no differences were found between another bait extracts, i e., the shrimp and the flesh of mackerel, the short-necked clam and the horse mackerel, the flesh and the viscera of mackerel.

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A Study on Accounting for Fishery Right (어업권 회계에 관한 연구)

  • 정준수;김태용
    • The Journal of Fisheries Business Administration
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    • v.11 no.1_2
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    • pp.115-155
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    • 1980
  • Nowadays managers of fisheries enterprises and users of accounting information have a considerable interest in the fishery right. The fishery right, which is given by administrative quarters, is referred to exclusive fishing right in a certain coastal fishing ground, and it has been one of the property rights since the turn of the century. The main purpose of this study is to provide an improved accounting method of the fishery right from the side of accounting. To achieve this purpose, legal nature of the fishery right should be understood in the first place, for the fishery right, an intangible asset, is a sort of property right guaranteed by the fisheries laws, According to the basic law in the fisheries "Fisheries Law, " the fishery right is broken down largely into three categories; culture fishing right, set fishing right and common fishing right. The legal characteristics of these fishery rights are as followings: 1. The fishery right is a private right. 2. The fishery right is a property right. 3. The fishery right is a right in rem, and legal provisions pertaining to land are applied to the fishery right with necessary modifications. In addition to the above fishery rights, the Fisheries Law provides some provisions on the so-called entrance right, and those who obtained the right are authorized to access to a certain common fishing right fishing ground where they have been traditionally fishing. In the inland fisheries, the fishery right system similar to that of the coastal fisheries discussed above is adopted in conformity with the Inland Fisheries Developing and Expediting Law. Viewing from an angle of accounting, there are two kinds of additional fishing rights which are dealt as assets. These fishery rights dealt as asset include the license of entry in the so-called permitted fishing which is also called as fishery right in plain language, and tile entrance right obtained abroad. Although these two kinds of rights are not the fishery right from a viewpoint of law, they are regarded as fishing rights in accounting which intends to provide a useful economic information.formation.

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Aerodynamic Characteristic and Reference Trajectory Design of A/L Phase for the Re-Entry Vehicle (재진입 비행체의 A/L 단계 공력특성과 기준궤적 설계)

  • Jang, Jang-Sik;Baek, Jo-Ha;Min, Chan-Oh;Kim, Jong-Hun;Lee, Dae-Woo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.8
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    • pp.753-760
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    • 2008
  • The present study is concerned with aerodynamic characteristics and reference trajectory generation of Hope-X in Approach/Landing phase. To create reference trajectory generation in A/L phase, detailed informations on lift and drag coefficients of Hope-X must be provided. To obtain these informations, aerodynamic characteristics of Hope-X are analyzed using the commercial CFD code, Fluent. The A/L phase is conceptually divided into three sub-phases: the Steepglide Slope phase for stability of vehicle, the Flare Maneuver phase for safety landing, the Circular Flare for smooth connecting with these both phases. The reference trajectory is obtained by determination of flight-path angle through geometrical formulas with consideration of aerodynamic coefficient and dynamic characteristic.

Case study of SAMSUNG TFT-LCD Technology Innovation using TRIZ method (트리즈 기법을 활용한 삼성전자의 TFT-LCD 기술혁신 사례연구)

  • Ban, Byeong-Seob
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.6
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    • pp.3429-3434
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    • 2014
  • In the TFT-LCD(Thin Film Transistor-Liquid Crystal Display) panel manufacturing industry, SAMSUNG, a late entry, can catch up to leading first mover, SHARP. The changes the note, monitor, TV, and mobile markets in the TFT-LCD industry were studied using a system analysis method. In addition, the fast response time technology in SAMSUNG TFT-LCD technology was developed using the TRIZ method. For example, a new liquid crystal mixture of a wide view angle and fast response time were developed by doping a new high birefringence liquid crystal material in a base mixture using the contradiction method and su-field method of TRIZ. The response time of a new liquid crystal mixture was improved to approximately 60%(16.2ms with base LC mixture, 9.8ms with a new LC mixture).

Community Policing Program Operation Case of the U.S.A - Centering Sanmateo County California State - (미국의 지역사회경찰활동 프로그램 운용 사례 - 캘리포니아주 산마테오 카운티를 중심으로 -)

  • Kang, Maeng-Jin
    • The Journal of the Korea Contents Association
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    • v.10 no.2
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    • pp.306-319
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    • 2010
  • Recently, crime prevention is away of important criminal justice policy and police activity also pursuit different change compare to the present times. After modern times, as get to know crime control change, eventually on the basis of experience that crime prevention is best way of crime control, what come out with new sight angle for the role of police is community policing. And emphasis points in police activity are variety of police activity, positive entry of community. In relation to this, we are learning crime prevention of the U.S.A and the program of community policing through crime prevention theory books that published in domestic. Then, there are misunderstanding possibilities that the programs which introduced relation books are doing someways all around the U.S.A In this research two cities san mateo county. california, of the U.S.A made a choice, and is going to search main crime present condition of these cities and really done community policing program or crime prevention program operation case.