• Title/Summary/Keyword: air support

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A Study on the Introduction of SCM for Air Force Logistics Support System (공군 군수지원체계에 SCM 도입방안 연구)

  • Hyun, Sung-Mun;Choi, Seok-Cheol
    • Journal of the military operations research society of Korea
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    • v.32 no.2
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    • pp.40-55
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    • 2006
  • The objective of this paper is to provide an introductory scheme of Supply Chain Management(SCM) for the Air Force logistics support system. To accomplish our goal, we analyzed the successful example of the military logistics reform based on SCM in the United States, after we observed the concept and concerning methods of SCM. The introductory scheme of SCM was specifically provided on the transportation system and material information system of the aircraft repair parts, which are considered important in the Air Force logistics support system. The Air Force will be able to raise the complete mission supportability through the construction of an innovative logistics support system, which is low in cost and efficient, based on state of the art information and communication technology.

Adaptive Control Scheme of Air Tanker Ground Waiting Time Based on a Multi-Server Queuing Model (다중서버 큐잉 모델을 이용한 공중급유기 지상 대기시간 적응적 제어 기법)

  • Sohn, Yong-Sik;Chung, Jong-Moon
    • Journal of Internet Computing and Services
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    • v.23 no.5
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    • pp.33-46
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    • 2022
  • This paper, in order to minimize the ground waiting time of an Air tanker, the queuing theory, that is, a queue that calculates the waiting time under single-server and multi-server situations, was used in the study. Since the national budget and resources are limited, the unlimited increase of the logistics support service team is limited. Therefore, the number of logistic support service teams that can adaptively control the ground waiting time according to the wartime preparation stage or war environment was calculated. The results of this study provide a stipulated standard for calculating the optimal number of air tanker logistic support service teams of the Air Force, providing a basis for the logistical commander to assign logistic support service teams to each stage from peacetime to wartime.

The Data Compression Method for increase of Efficiency in Tactical Data Communication over Legacy Radios (Legacy Radio 기반의 전술데이터 통신 효율성 향상 위한 데이터 압축 기법)

  • Sim, Dong-Sub;Shin, Ung-Hee;Kim, Ki-Hyung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.4
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    • pp.577-585
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    • 2010
  • The Military Tactical Communication technology for effective network-centric warfare is developing. Targeting broadband wireless transmission, core technology for connection, and Transmission technology that secure survivability under High-speed Movement environment. On the one hand, Tactical data communication system that reflects military characteristic is developing on the base of Legacy communication equipment which is used in the field. Because almost every military units in the field have used voice to communicate which lower efficiency of operation, they have made effort to Substitute voice communication which delays military Operation Tempo to digital communication. The Communications environment of troops in Forward edge of battle field area is very poor. Especially in terms of limited frequency allocation and bandwidth. Therefore, improving the efficiency of frequency is essential for Military Tactical Communication. This paper is about The Data Compression Method for increase of Efficiency in Tactical Data Communication over Legacy Radios which are UHF, VHF, HF Radio. I proposed and proved the most efficient Data Compression Method that reflects military characteristic, after analyzing the experimentation, which simulate CAS(Close Air Support mission) data transmission between Pilot and TACP.

Vibration Reduction of an Air Cooled Heat Exchanger with Axial Flow Fan (축류송풍기 부착형 공냉식 열교환기의 진동 저감)

  • Jung, Goo-Choong;Choi, Yeon-Sun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.11a
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    • pp.75-81
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    • 2000
  • Vibration problems induced by an air cooled heat exchanger with axial flow fan were investigated during the operation of a petrochemical plant. Two different studies were done; one was experimental field test and the other was theoretical verification. To find main cause of the blade passing frequency of the fan after installing additional blockage board at the air inlet of the axial fan, the frequency spectrum was measured. The vibrations of the blade passing frequency became higher. The natural frequency of driving support of the heat exchanger was theoretically calculated. It was approximately equal to the blade passing frequency. During the normal operation of the plant, it was impossible to modify the structure of the driving support. Instead, the blade number was increased to reduce vibration level. It increased the ratio of the forcing frequency to the natural frequency of the driving support over the resonance region.

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The Influence of Auditory-Feedback Device Using Wearable Air-Pressure Insole on Spatiotemporal Gait Symmetry in Chronic Hemplegia

  • Heo, Ji-Hun;Song, Changho;Jung, Sangwoo
    • Physical Therapy Rehabilitation Science
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    • v.10 no.3
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    • pp.311-319
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    • 2021
  • Objective: To investigate the effect of emphasized initial contact by using a wearable air-pressure insole to provide auditory-feedback with variations of maximum peak pressure (MPP) of the affected side on spatiotemporal gait parameters and gait symmetry of stroke patients Design: A cross-sectional study Methods: Eighteen stroke patients participated in this study. All subjects walked five trials using an air-pressure insole that provides auditory feedback with different thresholds set on the insole. First, subjects walked without any auditory feedback. Then, the MPP threshold on the affected side was set from 70% and increase threshold by 10% after each trial until 100%. They walked three times or more on the gait analyzer for each trial, and the average values were measured. Before starting the experiment, subjects measured body weight, initial gait abilities and affected side MPP without auditory feedback. Results: Temporal and spatial variables were significantly increased in trials with auditory feedback from air-pressure insole except for non-paralyzed single support time and spatial gait symmetry compared to trials without auditory feedback(p<0.05). Among the four different thresholds, the walking speed, unaffected side single support time, affected and unaffected side stride, and affected side step length were greatest at 80% threshold of maximum peak, while affected single support time, temporal gait symmetry, and unaffected step length were greatest at the maximum peak of 100% threshold. Conclusions: These results indicate that auditory feedback gait using air-pressure insoles can be an effective way to improve walking speed, single support time, step length, stride, and temporal gait symmetry in stroke patients.

Enhancement of Heat Transfer from an Air-Cooled 3-Dimensional Module by means of Heat Spreading in the Board (기판의 열확산에 의한 3차원 공랭모듈로부터의 열전달촉진에 관한 연구)

  • Park, Sang-Hee;Hong, Taek
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.7
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    • pp.1022-1030
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    • 2002
  • The experiments were performed with a $31{\times}31{\times}7mm^3$ simulated 3-dimensional module on the thermal conductive board of a parallel plate channel. The convective thermal conductance for the path from the module surface directly to airflow and conjugate thermal conductance for the path leading from the module to the floor by way of a module support, then, to the airflow were determined with several combinations of module-support-construction(210, 0.32, 0.021 K/W)/floor-material(398, 0.236W/mK) and channel height(15-30mm). As the result, it was found that the conjugate thermal conductance and the temperature distribution around the module depend on the thermal resistance of the module support, and the channel height. These configurations were designed to investigate on the feasibility of using the substrate as an effective heat spreader in the forced convective air-cooling of surface mounted heat source. The experimental results were discussed in the light of interactive nature of heat transfer through two paths, one directed from the module to the airflow and the other via the module support and the floor to the air.

Influence of the environments on the movement precision of the guide table using externally pressurized porous air bearing (다공질 정압공기 베어링을 이용한 직진 테이블에 있어 주위환경이 움직임 정밀.정확도에 미치는 영향)

  • 한응교;허석환;노병옥
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.4
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    • pp.721-729
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    • 1988
  • Recently, the precision required by precision manufacturing and machinery related to electronics is within the domain of submicron that it is difficult to evaluate them by traditional measuring equipments and methods. Accordingly, precision of sub 0.1.mu.m super precise position-decision-apparatus and straight-guide air bearing have been researched and they are almost ready to be used. In utilizing straight-guide-table for super-precision-measurement which used externally pressurized porous air bearing as a way of externally pressurized air bearing, the high-precision-straight movement is the most crucial. In this study, the researcher conducted the experimental study with trial manufacture to see how the surrounding temperature and support condition influenced the selection and allocation of the machine composing element which is important to the high-precision-straight movement. The researcher finding showed that when the property of the rail part and support part of the semi-closed slider form is different, the heat generation of the working motor and surrounding temperature influence the high-precision-straight movement significantly and the researcher showed the influence of the condition of central load and eccentric load to the straight movement precision when the support stand of the straight-table was supported by numerical values.

Assessment of Air Pollution and Estimation of Emission from Incheon International Airport by EDMS (EDMS를 이용한 인천국제공항의 대기오염 배출량 산정과 주변지역에 미치는 영향 평가)

  • Lee, Seong-Yong;Jang, Young-Kee
    • Journal of Environmental Impact Assessment
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    • v.11 no.2
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    • pp.67-77
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    • 2002
  • Air traffic increased 12% annually in Korea since 1988 after the Olympics, this rate is two times than the rate of the world average. In order to accommodate fast growing aviation demand, Incheon International Airport is operated at Yongjong Island since March, 2001. The Incheon airport project will continue till 2020. After the final phase in 2020, Incheon International Airport will handle 100 million passengers, 530,000 flights and 7 million tons of cargo annually. In this study, air pollution from aircraft and other sources are calculated and assessed in Incheon International Airport area by EDMS(Emission and Dispersion Modeling System), which is a combined emission and dispersion model for airport. EDMS could also be considered power plant, incinerator and aircraft support equipment such as ground support equipment, aerospace ground equipment, auxiliary power units. And EDMS is recommended as preferred model for air quality assessment of the airport area by U.S. EP A. The result of this study shows that NOx emission from aircraft and support utility is estimated as 27,000 - 35,000 ton/yr and Namdong-Gu area in Incheon city is affected as 30-60 ppb by the NOx emission from these sources in 2020, the final phase of Incheon international airport construction.

Vibration Reduction of an Air Cooled Heat Exchanger with Axial Flow Fan (축류송풍기 부착형 공냉식 열교환기의 진동저감)

  • 정구충;최연선
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.11 no.6
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    • pp.163-168
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    • 2001
  • Vibration problems occurred in an air cooled heat exchanger with axial flow fan for a petrochemical plant were investigated. Experimental field test and theoretical verification were performed. To find the main cause of the high vibration of the fan at the air inlet of the axial fan, the frequency spectrum was measured. The natural frequency of the driving support of the heat exchanger was numerically calculated. Both of the measured and the natural frequency were approximately equal to the blade passing frequency. Because it was difficult to modify the structure of the driving support during the normal operation of the plant, the blade number of the fan was increased, which greatly reduced the vibration level of the heat exchanger.

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