• The Korean Journal of Ceramics
• /
• v.1 no.3
• /
• pp.143-146
• /
• 1995

Twins along(202) and (211) planes are observed in monoclinic $ZrO_2$ thin film, which is deposited on Si substrate by MOCVD at $350^{\circ}C$ and annealed at $1150^{\circ}C$ for 10 hours in air. These types of twin have not been reported in monoclinic $ZrO_2$. The twins seem to be originated from the two dimensional tensile stresses applied to the $ZrO_2$ thin film due to the different thermal expansions of $ZrO_2$ thin film and Si substrate.

• Journal of computational fluids engineering
• /
• v.1 no.1
• /
• pp.1-8
• /
• 1996

본 논문은 전산 유체 역학에서 필요한 3차원 다구획 격자구성 프로그램을 개발한 것이다. 유동장에 격자를 구성하는 것은 유동해석 방정식을 푸는 것 보다 일반적으로 시간이 더 소요되므로 격자구성 시간을 단축하기 위해서 사용자 편의를 도모하는 컴퓨터 화면과의 대화형 코드를 개발하였다. PIGG라고 부르는 본 격자구성 프로그램은 형상 모델링, 표면격자 구성, 유동장격자 생성, 그리고 격자의 재구성에 이르는 일련의 과정이 대화형/화면게시 형태로 수행된다. 본 PIGG를 이용하여 전통적인 전투기 형상 격자를 구성한 결과 많은 시간을 단축할 수 있었다.

• Journal of computational fluids engineering
• /
• v.17 no.3
• /
• pp.45-52
• /
• 2012

This paper is a study on the design of the solar lamp bank which is a very important part of the solar simulator with the commercial metal halide lamps and infrared lamps. Lamp Bank is designed by the lamp bank design program based on point light source theory. The reliability of the program for lamp bank design is verified through irradiance variation experiments of a kind of lamp according to horizontal distance. Solar lamp bank facilitates heat distribution and satisfies the irradiance in the three wave length which test guidelines require. The shape of the ceiling board next to the lamp bank to promote the lamp cooling efficiency and to reduce temperature deviation and air velocity deviation in the chamber is so creative. The ceiling board of partial closed type is the best among several types.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.03a
• /
• pp.722-725
• /
• 2004

An experimental investigation was conducted to investigate the effects of the equivalence ratio and air mass flux on the combustion efficiency in a solid fuel ramjet used fuel grains which were highly loaded with boron carbide. Combustion efficiency increased with increasing equivalence ratio (grain length), and decreasing air mass flux. Higher inlet air temperature produced higher combustion efficiencies, apparently the result of enhanced combustion of the larger boron particles those bum in a diffusion controlled regime. Short grains which considered primarily of the recirculation region produced larger particles and lower combustion efficiencies. The result of the normalized combustion efficiency increased with inlet air temperature, is coincident with the result of the Brayton cycle thermal and the total efficiency relating to the heat input.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.42 no.10
• /
• pp.884-892
• /
• 2014

In this paper, a meta model using neural network substituting for the simulator aerodynamic database is proposed to improve simulation fidelity near the critical flight area and real-time performance. It is shown that the accuracy of the meta model is relatively higher than the existing table lookup methods for arbitrary nonlinear database and the calculation speed is also improved for a specific F-16 maneuver simulation. The increase in the number of hidden nodes in the meta model for better accuracy of database representations causes a delay in function generation due to increased time required for computing exponential functions. In order to make up this drawback, we additionally study the fast exponential function method.

• Journal of the Korea Society for Simulation
• /
• v.21 no.1
• /
• pp.81-88
• /
• 2012

In the M&S filed, The Battle Lab is available for acquisition, design, development tool, validation test, and training in the weapon system of development process. Recently, the Battle Lab in the military of Korea is still in an early stage, in spite of importance of battle lab construction. In the environment of network centric warfare, a practical use of the M&S which is connecting live, virtual and constructive model can be applied to all field of System Engineering process. It is necessary thar the Battle Lab is not restricted by time and space, and is possible for the technical implementation. In this paper, to guarantee the interoperability of live and virtual simulation, virtual simulators connect live simulators by using the tactical data link. To guarantee the interoperability of virtual and constructive simulation, both virtual simulators and constructive simulators use the RTI which is the standard tool of M&S. We propose the System that constructed the Air Defence Battle Lab. In case of the approach of target tracks, The Air Defence Battle Lab is the system for the engagement based on a command of an upper system in the engagement weapon system. Constructive simulators which are target track, missile, radar, and launcher simulator connect virtual simulators which are MCRC, battalion, and fire control center simulators using the RPR-FOM 1.0 that is a kind of RTI FOM. The interoperability of virtual simulators and live simulators can be guaranteed by the connection of the tactical data links which are Link-11B and ATDL-1.

• Journal of Aerospace System Engineering
• /
• v.8 no.4
• /
• pp.44-51
• /
• 2014

This thesis analyzes the latest operating concept and status for Air Defense Identification Zone (ADIZ) researching overseas ADIZ CONOPS, international legal basis for ADIZ, the intention & background of proclamation for China Air Defense Identification Zone(CADIZ). Firstly, ADIZ is lawful concerning international connivance for ADIZ where around 20 countries have operated, Article 56 "Rights, jurisdiction & duties of the coastal State" and Article 301 "Peaceful uses of the seas" on the United Nations Convention on the Law of the Sea(UNCLS). Secondly, ADIZ has been regarded as a support means for national interest & policy as well as military air defense one. Thirdly, Based on legal re-interpretation for UNCLS relating to ADIZ, China proclaimed CADIZ where can ensure national maritime policy and strategy including A2/AD(Anti-Access & Area Defence), inroad into the ocean, claim for Senkaku Islands possession, etc..

• International Journal of Aeronautical and Space Sciences
• /
• v.15 no.1
• /
• pp.54-62
• /
• 2014

The Air and Space Interoperability Council (ASIC) has adopted the European Defence Agency (EDA) process for inter-regulatory military airworthiness authority recognition. However, there are gaps in the application of this process to nations outside of the European Union. This paper proposes a model that can effectively map diverse technical airworthiness regulatory frameworks. This model, referred to as the Product-Behaviour-Process (PBP) Bow-Tie model, provides the systematic structure needed to represent and compare regulatory frameworks. The PBP Bow-Tie model identifies key points of difference that need to be addressed, during inter-agency recognition between the two regulatory authorities. With the intention to adopt global use of the EDA process, the proposed PBP Bow-Tie model can be used as a basis for the successful recognition of regulatory frameworks outside of the European Union. Iris plots produced from the implementation of this model are presented, and proposed as a suitable means of illustrating the outcome of an assessment, and of supporting the comparisons of results. A comparative analysis of the Australian Defence Force and New Zealand Defence Force airworthiness regulatory frameworks is used as a case study. The case study clearly illustrates the effectiveness of the model in discerning regulatory framework differences; moreover, it has offered an opportunity to explore the limitations of the Iris plot.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.8
• /
• pp.336-342
• /
• 2018

Noise reduction is an important issue in auxiliary power unit(APU) of tracking equipments for using military. In this study, we designed and tested reduction methods of structure borne noise and airborne source noise at the auxiliary power unit. From the bench test results, it is found that the effect of noise reduction is about 22 dB(A) if the silencer is redesigned, which is the rescue structure. However, the influence of noise reduction by air is insufficient. In addition, it is confirmed that the effect of noise reduction is excellent when structure borne noise reduction is applied to the vehicle. We expected that the test results of this study are used as basic data to reduce the noise of other tracking equipment developed later.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.2
• /
• pp.26-35
• /
• 2019

By operating servers, storage, and networking devices, Data centers consume a lot of power such as cooling facilities, air conditioning facilities, and emergency power facilities. In the United States, The power consumed by data centers accounted for 1.8% of total power consumption in 2004. The data center industry has evolved to a large scale, and the number of large hyper scale data centers is expected to grow in the future. However, as a result of examining the server share of the data center, There is a problem where the server is not used effectively such that the average occupancy rate is only about 15% to 20%. To solve this problem, we propose a Virtual Machine Reallocation research using virtual machine migration function. In this paper, we use meta-heuristic for effective virtual machine reallocation. The virtual machine reallocation problem with the goal of maximizing the idle server was designed and solved through experiments. This study aims to reducing the idle rate of data center servers and reducing power consumption simultaneously by solving problems.