• Title/Summary/Keyword: Interceptors

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An experimental investigation of interceptors for a high speed hull

  • Avci, Ahmet Gultekin;Barlas, Baris
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.11 no.1
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    • pp.256-273
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    • 2019
  • Nowadays interceptors have been widely used in a vast range of high-speed crafts. In this study, the results of interceptor adeptness experiments made in Istanbul Technical University's Towing Tank are unveiled. The model was tested through three transverse locations of interceptors with six different deployment depths. For three locations, the interceptor was positioned transverse on the aft; close to chine, in the middle and close to the keel. The fourth interceptor was a full length of 13.00% LWL. The results show a significant drag reduction in benefits of 1.50%-11.30% for Fn 0.58-1.19 and the trim reduction was observed in between 1.60 and $4.70^{\circ}$. Besides, one of the most significant conclusions indicates that the effect of the interceptor decreases from keel to chine for the same blade deployment heights so the blades should be controlled separately at least in three parts from keel to chine area, if operable.

Types and Development status of Standard Missile Interceptors (스탠더드 대공미사일의 종류와 발전현황)

  • Jo, Sung-bin;Park, Tae-yong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.427-429
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    • 2015
  • Standard missile, which is operated by our navy force by loading on DDH-II and DDG, is representative interceptors of U.S. Navy. To defend from rapidly increased air threats after World War II, U.S. Navy had accelerated the development of interceptors, and consequently 3Ts series(Tartar, Talos, Terrier) were developed. Since Standard Missile(SM) series were developed on the back of 3Ts, SM series has been positioned as main surface-to-air interceptors. In this paper, types and technical characteristics of Standard Missile Series from SM-1 to SM-6 are investigated and described.

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Skin safety of the UV Absorbers by Measurement Cytotoxicity High Functional Product with Water-in-Silicone System

  • In-Young Kim;Min
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.23 no.3
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    • pp.134-146
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    • 1997
  • Consumers have recently preferred to purchase extensive UV intercepting products, which are waterproof and free from side effects on skin. Testing Cytoroxicity in SR method, cell survivial ratio of UV-B interceptors decreased above 0.08W/V%, and so did that of UV-A interceptors above 0.06W/V%. Also, Patch-test of inorganic UV interceptors resulted in no skin irritation even below 10.0 and 11.25. UV interceptors in the sunlight showed yellowish discoloration in 5 to 14 days. In absorption curves, UV-B was most suitable for Octyl methoxycinnamate and UV-A for Butyl methoxy dibenzoylmethane. Fro this reason, Nylonpoly UVA/UVB the material of OMC and BMDM coated with Nylon & polyethylene, was used as the organic UV interceptor. And zinc oxide and titanium dioxide was used as inorganic UV ibterceptors. The appropriate mixture ratio of ZnO and TiO2 was 6 to 4.6% of ZnO, 4% of TiO2 and 5% of Nylonpoly UVA/UVB were all combined with our sunscreen cream. The SPF value of in-vivo applied to a guinea pig was 34.9 and that of in-vivo was 38.5. Cyclomerhicone and dimerthicone were used in water-in-Silicone system. Ceryl diverhicone and sorbitan sesquioleate were used as emulsifiers and MgSO4, 7H2O, Mg-stearate/Mg-Al-stearate copolymer as emulsification stabilizers. In practical application, each SPF duration of O/W type and W/S type containing sunscreen cream of the same content showed that W/S type of sunscreen cream was 5 times as durable as the other. This product is fit for using in swimming, climbing or skiing. This research is to minimize skin trouble used by UV interceptors and to make one with proper softness, skin safety and UV intercepting efficiency.

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SPF Measurement and Cytotoxicity of Sunscreen Agents in Cosmetic (화장품에서 UV 차단제의 피부 자극성과 SPF 측정)

  • Kim, In-Young;Kang, Sam-Woo
    • Analytical Science and Technology
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    • v.11 no.2
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    • pp.79-87
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    • 1998
  • Consumers have recently preferred to purchase extensive UV intercepting products, which are waterproof and free from side effects on skin. During the testing of cytotoxicity (in-vitro) in neutral red (NR) method, cell survival ratio of UV-B interceptors decreased to just above 0.08 w/v%, and it was observed that the UV-A interceptors the ratio also decreased to just above 0.06 w/v%. In addition patch-tests of inorganic UV interceptors resulted in no skin irritation even below 10.0 and 11.25. In absorption curves, UV-B was most suitable for octyl methoxycinnamate (OMC) and UV-A for butyl methoxy dibenzoylmethane (BMDM). For this reason, $Nylonpoly^{TM}$ UVA/UVB the material of OMC and BMDM coated with Nylon & polyethylene, was used as the organic UV interceptor. Zinc oxide (ZnO) and titanium dioxide ($TiO_2$) was used as inorganic UV interceptors. The appropriate mixture ratio of ZnO and $TiO_2$ was 6 to 4:6% of ZnO, 4% of $TiO_2$ and 5% of $Nylonpoly^{TM}$ UVA/UVB were all combined and added to our sunscreen cream. The SPF value of in-vitro was 38.9. In practical application, each sun protection factor (SPF) duration of oil-in-water (O/W) emulsion and water-in-silicone (W/S) emulsion containing sunscreen cream of the same content showed that W/S type of sunscreen cream was 5 times as durable as the other. Therefore, this product is fit for use in swimming, climbing or skiing. This research is to minimize skin trouble caused by UV interceptors and to make one with proper softness, skin safety and UV intercepting efficiency.

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Cooperative Guidance Law for Multiple Near Space Interceptors with Impact Time Control

  • Guo, Chao;Liang, Xiao-Geng
    • International Journal of Aeronautical and Space Sciences
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    • v.15 no.3
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    • pp.281-292
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    • 2014
  • We propose a novel cooperative guidance law design method based on the finite time disturbance observer (FTDO) for multiple near space interceptors (NSIs) with impact time control. Initially, we construct a cooperative guidance model with head pursuit, and employ the FTDO to estimate the system disturbance caused by target maneuvering. We subsequently separate the cooperative guidance process into two stages, and develop the normal acceleration command based on the super-twisting algorithm (STA) and disturbance estimated value, to ensure the convergence of the relative distance. Then, we also design the acceleration command along the line-of-sight (LOS), based on the nonsingular fast terminal sliding mode (NFTSM) control, to ensure that all the NSIs simultaneously hit the target. Furthermore, we prove the stability of the closed-loop guidance system, based on the Lyapunov theory. Finally, our simulation results of a three-to-one interception scenario show that the proposed cooperative guidance scheme makes all the NSIs hit the target at the same time.

A Study on Intercept Probability and Cost based Multi-layer Defense Interceptor Operating Method using Mathematical Model (수리모형을 이용한 요격확률 및 비용 기반의 다층 방어 요격미사일 운용방법 연구)

  • Seo, Minsu;Ma, Jungmok
    • Journal of the Korea Society for Simulation
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    • v.29 no.2
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    • pp.49-61
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    • 2020
  • It is important to operate a limited number of interceptors effectively to counter ballistic missile threats. The existing interceptor operating method determines the number of interceptors according to the level of TBM (Theater Ballistic Missile) engagement effectiveness applied to a defended asset. It can cause either excessive interceptor waste compared to the intercept probability or the intercept probability decrease. Thus, interceptor operating method must be decided considering the number of ballistic missiles, intercept probability and cost. This study proposes a mathematical model to improve the existing interceptor operating method. In addition, the efficiency indicator is proposed for trade-off between intercept probability and cost. As a result of the simulations, the mathematical model-based interceptor operating method can achieve better results than the existing interceptor operating method.

An experimental study on the stern bottom pressure distribution of a high-speed planing vessel with and without interceptors

  • Seok, Woochan;Park, Sae Yong;Rhee, Shin Hyung
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.12 no.1
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    • pp.691-698
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    • 2020
  • In this study, the effects of hydrodynamic interceptors on a high-speed vessel were investigated to identify the operating principle based on experiments. Model tests were performed using a high-speed towing carriage. The resistance, trim and rise of Center of Gravity (CG) of the high-speed vessel were measured for various ship speeds and interceptor heights. As the interceptor height increased, the trim and rise of CG were reduced. In order to quantitatively analyze these phenomena, the pressure at the stern bottom was measured using tactile sensors. The reliability of the measured results from the tactile sensors was verified through repeat tests. The pressure on the stern bottom increased in proportion to the interceptor height, as the interceptor partially blocked the flow there. Then, the trim was reduced. However, as the ship speed increases, the pressure at the location close to the interceptor decreases when the interceptor height is small, leading to increased trim. Therefore, the interceptor height for running attitude control should be carefully determined considering multiple factors in the operating condition of the high-speed planing hull.

Characteristics of Water Quality Change of Urban River according to Installation of Interceptors and Wastewater Treatment Plant (차집관로와 하수처리시설의 설치에 따른 도시하천의 수질변화 특성)

  • Zhou, Juan Juan;Lim, Bong Su
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.12
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    • pp.813-820
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    • 2014
  • In this study, the characteristics of water quality change of the three streams in Daejeon were analyzed according to the expanded installation of interceptors and wastewater treatment plant (WTP). Gabcheon 5 (Singu Bridge) location showed the maximum difference of the highest and lowest concentrations in the last decade. However, the recent water quality of this location was worse than other locations, because of the impact of the effluent from the WTP. In the upstream of the WTP, the Daejeon stream was relatively better than the other locations in organic pollution reduction, and this was caused by the investment for the management of the interceptors in three streams of Daejeon. According to the water quality standard of the stream water quality, the recent water quality of the three streams in Daejeon was acceptable within them in the most of the water quality items, but because the total phosphorus concentration of the upstream such as Daejeon stream, Yudeng stream, Gabchen 3 location did not reach the standard values, a better management of the interceptor was required in the upstream of WTP than its downstream. The upstream of WTP also required a better management of the interceptor than the downstream. The operation and management of WTP was required a high efficiency because the water quality of the effluent from the WTP incurred an adverse effect to the target water quality in the location of the total water pollution load management system.

Experimental investigation of dynamic trim control devices in fast speed vessel (고속선의 트림제어 장치가 항주 자세 및 저항 성능에 미치는 영향)

  • Seo, Kwang-Cheol;Gopakumar, Nithin;Atlar, Mehmet
    • Journal of Navigation and Port Research
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    • v.37 no.2
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    • pp.137-142
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    • 2013
  • The displacement Deep-V catamaran concept was developed in Newcastle University(UNEW) through development of the systematic Deep-V catamaran series. One of the most important Deep-V catamaran launched to date is Newcastle University's own multi-purpose research vessel, The Princess Royal. The vessel was launched in 2011 and enhanced the Deep-V catamaran concept further with the successful adoption of a novel anti-slamming bulbous bow and tunnel stern for improved efficiency. It was however identified that the vessel has substantial amount of dynamic trim that limited the visibility of the captain. The dynamic trim also increased the wave-making resistance thereby preventing the vessel from attaining its maximum speed in certain sea states. This paper therefore presents the application of devices such as Trim Tabs, Interceptors, Transom Wedges and Integrated Transom Wedges-Tabs to control the dynamic trim and improvement of fuel efficiency of the vessel. All of these energy saving devices were fitted into a model for tests in Newcastle University's Towing Tank. Model test verification confirmed that the optimum appendage was the interceptors, they produced a 5% power saving and 1.2 degree trim reduction at 15 knots, and investigations of full scale trials will be scheduled with and without application of device to compare the improvement of performance.