• Title/Summary/Keyword: Air Operation

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Aerodynamic Force Measurements and PIV Study for the Twisting Angle of a Swift Wing Model (칼새 날개의 비틀림 각에 대한 공력측정 및 PIV 연구)

  • Bok, Jung Jin;Chang, Jo Won
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.9
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    • pp.765-772
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    • 2015
  • Aerodynamic force measurements and phase-locked PIV study were carried out to check the bio-mimetic MAV applicability of a swift flight. Two-rotational DOF robotic wing model and blowing-type wind tunnel were employed. The amplitude of twist angle were ${\pm}0$, ${\pm}5$, ${\pm}10$, and ${\pm}20$ deg. and stroke angles were manipulated by simple harmonic function with out-of-phase in regards to the stroke motion. It is acknowledged that the time-varying lift coefficients in accordance with the change of the twist angle did not result in any noticeable differences, just the small decrease and delay. However, the drag exhibited that the small change of the twist angle can produce large thrust. These findings imply why a swift uses small twist angle during flight. The PIV results displayed that the delay of aerodynamic forces is highly associated with the vortical structures around the wing. It is therefore indicated that a process of designing a swift-based Micro Air Vehicle should take the twist angle into consideration, as the essential parameter.

Tactical Fire Direction Automation for Command and Control of Artilliary Battalion Unit (대대급 화력(포병 부대)의 지휘통제(C2)를 위한 전술적 사격지휘 자동화 절차)

  • Ahn, Myong-Hwan;Ji, Jae-Kyung;Cho, Hyun-Ho;Sin, Chul-Soo;Park, Young-Woo;Lee, Teuc-Soo;Kim, Tae-Yeong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.11B
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    • pp.1738-1747
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    • 2010
  • This report shows the analysis and design of tactical decision automation procedure and the result of core algorithm. Expecially scheme of analysis and design includes result of tactical decision supporting procedure analysis for target engagement to fire in refer to AFATDS. Tactical decision automation procedure has three phases like target analysis, target priority, fire unit decision, fire method and attack method. Target analysis creates base information to decide priorities and attack methods through target activity, size and protection status. Target priority and fire unit decision judge target priority and fire unit with unit status and operation mission basis of target priority. Fire unit and Attack method decide fire style according to the kind of fire and ammunition for effective firing achievement. Finally, we show the effective tactical decision automation procedure through making the algorithm of priority and air control.

Reuse Technology of LiCl Salt Waste Generated from Electrolytic Reduction Process of Spent Oxide Fuel (전해환원공정발생 LiCl 염폐기물 재생기술)

  • Cho, Yung-Zun;Jung, Jin-Seok;Lee, Han-Soo;Kim, In-Tae
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.8 no.1
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    • pp.57-63
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    • 2010
  • Layer crystallization process was tested for the separation(or concentration) of cesium and strontium fission products in a LiCl waste salt generated from an electrolytic reduction process of a spent oxide fuel. In a crystallization process, impurities (CsCl and $SrCl_2$) are concentrated in a small fraction of the LiCl salt by the solubility difference between the melt phase and the crystal phase. Based on the phase diagram of LiCl-CsCl-$SrCl_2$ system, the separation possibility by using crystallization was determined and the molten salt temperature profile during layer crystallization operation was predicted by using mathematical calculation. In the layer crystallization process, the crystal growth rate strongly affects the crystal structure and therefore the separation efficiency. In the conditions of about 20-25 l/min cooling air flow rate and less than 0.2g/min/$cm^2$ crystal flux, the separation efficiency of both CsCl and $SrCl_2$ showed about 90% by the layer crystallization process, assuming a LiCl salt reuse rate of 90wt%.

Effect of Oxygen Supply on the Production of Interferon ${\alpha}$-1 by Recombinant Escherichia coli in Fed-batch Fermentation (유가식 배양에서 재조합 대장균으로부터 Interferon ${\alpha}$-1 생산에 산소 공급이 미치는 영향)

  • Yi, Jong-Ghil;Moon, Seok-Young;Kim, Young-Jun;Shin, Chul-Soo;Koo, Yoon-Mo
    • Microbiology and Biotechnology Letters
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    • v.35 no.3
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    • pp.226-230
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    • 2007
  • In order to achieve high-level expression of interferon-${\alpha}1$ (IFN-${\alpha}1$) during fed-batch fermentation of recombinant E. coli, effects of oxygen supply and induction temperature on the expression of recombinant proteins were evaluated. Supplementation of oxygen and its transfer into cells is one of the most important parameters involved in the design and operation of mixing-sparging equipment for bioreactors. Generally, higher oxygen supply stimulates cell growth of aerobic microorganism and consequently the amount of products is increased. In this study, the optimum aeration strategy for the higher production of IFN-${\alpha}1$ during fed-batch fermentation of recombinant E. coli was surveyed. The growth of the cells was also monitored with four different concentrations of dissolved oxygen (DO; limiting, 20%, 35%, 50%) conditions. The DO was controlled by varying aeration rates of air and pure oxygen. Oxygen uptake rate (OUR) and specific oxygen uptake rate (SOUR) were evaluated and compared for the enhanced growth and induction of the cells and IFN-${\alpha}1$, respectively. We confirmed that increased DO by additional oxygen supply, up to 35%, can improve the production of IFN-${\alpha}1$ during the fermentation.

A Study on Reduction of Nitrogen Oxide (NOx) and Stability of Incineration Facility by the Food Wastewater Incineration (음식물류 폐수 소각처리에 따른 질소산화물 저감 및 소각설비의 안정성 평가에 관한 연구)

  • Hwang, Seung-Min;Chung, Jin-Do;Song, Jang-Heon
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.10
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    • pp.901-908
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    • 2009
  • We examine the processing method of the food wastewater to direct spray at living waste incinerator. The demoscale stoker system is used as a incineration facility. The results show that it brings effect on the reduction of nitrogen oxide ($NO_x$) concentration as well as the ammonia ($NH_3$) amount in SNCR (selective non-catalytic reduction) by the incineration of food wastewater which is containing a plentiful ammoniac nitrogen ($NH_3$-N). Furthermore, the stability of incineration facility and the extension of operation period is actualized as a improvement of clogging phenomenon on outer wall of water pipe as the 870~$950^{\circ}C$ maintain of exit temperature in a second combustor by spray of the food wastewater. The 26 items of air pollution matter of nitrogen oxide ($NO_x$), sulfur oxide ($SO_x$) and dioxin etc. are measured. The results show that it is under the value of allowable exhaust standard.

Development of Spherical Granule of Fermented Red Ginseng Extracts (발효홍삼농축액 구형과립 제조 기술 개발)

  • Shin, Myung-Gon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.7
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    • pp.1064-1071
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    • 2015
  • Viscous fermented red ginseng extracts were dried and coated using a fluidized bed coater to increase convenience and consumer acceptance. The methods for making spherical granules of fermented red ginseng extracts with increasing convenience were established by using indigestible dextrin. Spherical granules of fermented red ginseng extracts with increasing convenience were made by mixing indigestible dextrin at 40% (40% IDD), 50% (50% IDD), and 60% (60% IDD) versus the soluble solid content of fermented red ginseng extracts. Spherical granules of fermented red ginseng extracts showed less angle of repose than powder of fermented red ginseng extracts. This means that spherical granules of fermented red ginseng extracts had good fluency with increased convenience. The more indigestible dextrin showed higher yields. Although 50% IDD showed less yield than 60% IDD, 50% IDD was the best mixing ratio for making spherical granules of fermented red ginseng extracts, as fermented red ginseng extracts is known as a healthy food. The optimized operation conditions of the fluidized bed coater for making 50% IDD were feeding rate 0.54 mL/min, atomization air pressure 2.15 bar, and product temperature $83.03^{\circ}C$.

A Study on the Concept of Convergence and Combined Combat Based on South Korean-style AICBM for the Victory of Future War (미래전 승리를 위한 한국형 AICBM 기반 융·복합 전투개념 연구)

  • Jung, Min-Sub;Lee, Woong;Park, Sang-Hyuk
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.2
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    • pp.321-325
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    • 2020
  • The purpose of this study is to re-concept the future battle of the Army, which combines the effects of advanced technology on the concept of combat and the AICBM technology. The "war concept" changes with the times, and can be seen through the following two examples. First, it is a concept that achieves relative superiority by analyzing enemies. A case in point is the U.S. military's development of a "public joint battle" into a "multi-domain operation." Second, it is 'science and technology' that leads to a change in the concept of combat. A case in point is that the firepower warfare on land and sea in World War I developed from World War II to "air warfare" due to the emergence of aircraft. In this regard, the U.S. military is focusing on the concept of fighting in line with the future operational environment based on high-tech science and technology and the construction of the future military through the creation of the "Future Command." Therefore, our military needs to utilize the major technologies of the fourth industrial revolution as an opportunity to develop the concept of future combat, and the future war will greatly affect the development of the concept of advanced science and technology carrying out war, as AIC technology based on the fourth industrial revolution will promote innovation in defense operations in the form of super-connected, super-intelligence and super-integration. Therefore, this study will present the impact of advanced technology on the concept of combat and the concept of battle of the future Army incorporating the technology of AICBM.

A Study on Network Based Traffic Signal Optimization Using Traffic Prediction Data (교통예측자료 기반 Network 차원의 신호제어 최적화 방안)

  • Han, Jeong-hye;Lee, Seon-Ha;Cheon, Choon-Keun;Oh, Tae-ho;Kim, Eun-Ji
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.14 no.6
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    • pp.77-90
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    • 2015
  • An increasing number of vehicles is causing various traffic problems such as chronic congestion of highways and air pollution. Local governments have been managing traffic by constructing systems such as Intelligent Transport Systems (ITS) and Advanced Traffic Management Systems (ATMS) to relieve such problems, but construction of an infrastructure-based traffic system is insufficient in resolving chronic traffic problems. A more sophisticated system with enhanced operational management capabilities added to the existing facilities is necessary at this point. As traffic patterns of the urban traffic flow is time-specific due to the different vehicle populations throughout the time of the day, a local network-wide signal operation plan that can manage such situation-specific traffic patterns is deemed to be necessary. Therefore, this study is conducted for the purpose of establishment of a plan for contextual signal control management through signal optimization at the network level after setting the Frame Signal in accordance to the traffic patterns gathered from the short-term traffic forecast data as a means to mitigate the problems with existing standardized signal operations.

Perforated Duodenal Diverticulum after Distal Subtotal Gastrectomy and Billorth II Gastrojejunostomy (위아전절제술 및 위공장 문합술 후 생긴 십이지장 게실 천공 환자 1예)

  • Jee, Sung-Bae;Kim, Sin-Sun;Jun, Kyong-Hwa;Kim, Wook;Park, Kyong-Sin;Jeon, Hae-Myung
    • Journal of Gastric Cancer
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    • v.6 no.1
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    • pp.52-56
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    • 2006
  • A 69-year old man presented with severe epigastric pain for 1 day. He had early gastric cancer at the antrum and underwent a distal subtotal gastrectomy and Billorth II gastrojejunostomy one month later without any post-operative complications. Radiologic examination revealed a large amount of retroperitoneal free air formation. Because of unremitting pain and unstable vital sign, exploratory laparotomy was followed. During the operation, a perforated duodenal diverticulum at the posterior wall of the 2nd portion of the duodenum was identified. He underwent diverticulectomy and primary closure. He was discharged on the 18th post operative day and has been followed up without any evidence of comlpication for several months.

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A Numerical Study on the Effect of Pressure Relief Ducts on the Normal Pressure in a Preliminary Design of Honam-Jeju Subsea Tunnel (호남-제주 해저터널 가상설계의 공기압력 제어 덕트가 열차 주행에 미치는 영향에 대한 수치해석 연구)

  • Seo, Sangyeon;Ha, Heesang
    • Journal of the Korean GEO-environmental Society
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    • v.17 no.8
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    • pp.17-27
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    • 2016
  • High-speed trains have been developed widely in European countries and Japan in order to transport large quantity of people and commodities in short time. Additionally, a high speed train is one of the most desirable and environmentally friendly transportation methods. When a high speed train enters a tunnel, aerodynamic resistance is generated suddenly. This resistance causes micro pressure wave and discomfort to passengers. Due to this aerodynamic pressure against the train, a large amount of traction is required for the operation of a train in a tunnel. Therefore, it is essential to incorporate a pressure relief system in a tunnel in order to reduce aerodynamic resistance caused by a high-speed train. A pressure relief duct and a vertical shaft are representative measures in a tunnel. This study represents the effect of pressure relief ducts in order to alleviate positive and negative normal pressures acting on a train. One-dimensional numerical simulations were carried out in order to estimate the effect of pressure relief systems.