• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.4 no.4
• /
• pp.264-271
• /
• 2011

ILS(Instrument Landing System) is the international standard system for approach and landing guidance. ILS was adopted by ICAO(International Civil Aviation Organization) in 1947 and is currently being used in commercial systems. To design the digital transmitter and receiver modules that can be mounted in the integrated ILS, we propose the digital design methods of digital double AM modulator and demodulator using FPGA chip, DDS(Direct Digital Synthesizer) for generation of sampling clock, demodulator of DDC(Digital Down Converter) structure, and spectrum analyzer using DSP chip. We demonstrate the efficiency of the proposed design method through experiments using developed transmitter and receiver modules. This system can be used as a high-performance commercial system.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.13 no.5
• /
• pp.801-807
• /
• 2010

Requirements management is one of the most essential activities of systems engineering in developing successful weapon systems. Particularly it is very important to consistently manage the traceability among the user requirements, the system requirements, the development specifications and the testing plans throughout the entire life cycle of the weapon system. However, the most part of requirements-related activities has centered around the functional and performance requirements but the integrated logistics support(ILS) requirement has not properly been managed. In this regard, a special attention is needed to develop and manage the ILS requirements. To do so, the ANSI/EIA-632 standard can be referred as a starting point since the ILS requirements of the weapon system under development are specified by the enabling products whereas the functional and performance requirements are covered by the end product requirements. Specifically, we first review and model several cases of previous weapon systems development, which reveals the problem of interest. Then, under the framework of ANSI/EIA-632, we study a hierarchical model for effectively managing ILS requirements by analyzing the features of ILS requirements. Finally, the value of the proposed model is discussed through the case study of electronic warfare equipment.

• Journal of the Korea Society for Simulation
• /
• v.24 no.2
• /
• pp.19-29
• /
• 2015

M&S techniques are utilized for various purposes on the national defense, and its importance is increasing than ever. For analyzing RAM (Reliability, Availability and Maintainability) of weapon system, using M&S techniques can be more effective and practical way than deterministic approach, because M&S approach can consider uncertain variables and various constraints in the ILS (Integrated Logistics support) field. For design of ILS M&S, we first set up a purpose of M&S, attributes of real system and other similar ILS M&S tool. Then, we convert real system into model which consists of mathematical formula and logical expression. In this thesis, we introduce modeling procedures of M&S that describes total life cycle of 'OO guided weapon system' and the contents proposed in this paper can provide references for developing other M&S tool.

• Journal of Applied Reliability
• /
• v.14 no.3
• /
• pp.162-168
• /
• 2014

This paper discusses the application of Bayesian techniques with test data on similar products for performing the Economical Reliability Test of new one-shot device. Using the test data on similar products, reliability test required lower sample size currently being spent in order to demonstrate a target reliability with a specified confidence level. Furthermore, lower sample size reduces cost, time and various resources on reliability test. In this paper, we use similarity as calculating weight of similar products and analyze similarity between new and similar product for comparison of the essential function.

• Proceedings of the CALSEC Conference
• /
• 1998.10a
• /
• pp.197-213
• /
• 1998

이 연구에서는 ILS에 관한 개발 추세를 살펴보고, ILS의 정의, ILS와 관련된 표준들, ILS의 구성요소들, ILS관련 분석기법들에 대하여 정리한다. 군의 ILS 적용 현황과 문제점들을 살펴보고 ILS의 개념 개발과 민간기업들의 활용을 확대하기 위한 방안들을 요약한다. 이어서, ILS 구축을 위하여 광의의 제품수명주기를 바탕으로 물류의 흐름 및 지원 활동들을 분석 및 설계할 수 있는 객체지향 물류 프로세스 모델링을 제안하고 객체구조물들을 개발하였다. 제안된 모델링 기법의 구조물들을 활용하여 기업의 물류흐름과정과 물류지원과정을 모델링하는 예제를 보여준다. 끝으로 CALS 환경하에서의 기업간 ILS구축 과정을 제안하고, 기업간 통합물류과정 및 통합물류지원과정에 대한 간단한 모델을 제공한다.

• Journal of the military operations research society of Korea
• /
• v.30 no.1
• /
• pp.168-188
• /
• 2004

Integrated Logistic Support (ILS) is a management and technical process whereby all the diverse elements needed to fully operate, maintain, and totally support a materiel system in the field are identified, developed, and deployed simultaneously and on an equal priority with the item of materiel being supported. The test and evaluation (T＆E)of ILS act the important role of reduction of life-cycle cost and keeping of good performance for weapon system. In this article, we suggest the alternatives for improvement in the test and evaluation of ILS during weapon system acquisition. It is hoped that this research is valuable and beneficial to persons related weapon system acquisition, in order to maximize the efficiency of defense acquisition management by reducing the life-cycle cost and enhancing the quality of weapon system.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1995.05a
• /
• pp.602-607
• /
• 1995

This article presents safety review experience of microprocessor-based Interposing Logic System(ILS) of Engineering Safety Feature Actuation System(ESFAS). The ILS is the first application of computerized logic design to safety system in Korean nuclear power plants without verification of the system reliability by proven technology concept. As a result of evaluation for the ILS, Korea Institute of Nuclear Safety(KINS) concluded that the microprocessor-based ILS is not acceptable in some features detailed enough to defend against software common mode failures(CMF). Therefore, we required licensee to install hardwired interlock signal configuration and a Hardwired Backup Panel to control safety-related equipment. We believe that the microprocessor-based ILS with the hardwired backup panel and inter-connection of interlock signal by hardwired configuration will improve the plant safety.

• Journal of Electrochemical Science and Technology
• /
• v.5 no.4
• /
• pp.95-104
• /
• 2014

Electrochemical performance of Li-ion cells with $LiMn_2O_4$ cathodes and graphite anodes with carbonates electrolytes containing quaternary ammonium-based room temperature ionic liquids (ILs) is investigated. Eight different ILs based on tetraalkylammonium, pyrrolidinium or piperidinium cations paired with bis(trifluoromethylsulfonyl)imide or tris(pentafluoroethyl)trifluorophosphate anions are examined in combination with dimethyl carbonate as a main solvent and fluoroethylene carbonate as a solid electrolyte interface forming agent. It is shown that cycling properties of the cells are strongly affected by the content of ILs in the electrolyte mixtures and its increase corresponds to lower discharge capacity retention. Since viscosity and conductivity of ILs are of a great importance for the electrolytes formulation, some kind of combined parameter should be used for the assessment of IL applicability and calculated values of Walden products for neat ILs represent one of the possible options. Besides, positive effect of ILs on reduction of flammability and enhancement of thermal stability of electrolytes in contact with charged electrodes have been demonstrated by means of self-extinguishing time test and differential scanning calorimetry respectively.

• Wind and Structures
• /
• v.24 no.4
• /
• pp.351-365
• /
• 2017

The minimization method is widely used to predict the dynamic characteristics of a system. Generally, data recorded by experiment (for example displacement) tends to contain noise, and the error in the properties of the system is proportional to the noise level (NL). In addition, the accuracy of the results depends on various factors such as the signal character, filtering method or cut off frequency. In particular, coupled terms in multimode systems show larger differences compared to the true value when measured in an environment with a high NL. The iterative least square (ILS) method was proposed to reduce these errors that occur under a high NL, and has been verified in previous research. However, the ILS method might be sensitive to the signal processing, including the determination of cutoff frequency. This paper focused on improving the accuracy of the ILS method, and proposed the modified ILS (MILS) method, which differs from the ILS method by the addition of a new calculation process based on correlation coefficients for each degree of freedom. Comparing the results of these systems with those of a numerical simulation revealed that both ILS and the proposed MILS method provided good prediction of the dynamic properties of the system under investigation (in this case, the damping ratio and damped frequency). Moreover, the proposed MILS method provided even better prediction results for the coupling terms of stiffness and damping coefficient matrix.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.4
• /
• pp.601-606
• /
• 2007

The chromatographic behaviors of nucleotides (inosine 5'-monophosphate, uridine 5'-monophosphate, guanosine 5'-monophosphate, and thymine monophosphate disodium salts) on a C18 column were studied with different types of ionic liquids (ILs) as additives for the mobile phase in reversed-phase liquid chromatography (RPLC). Three ILs, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIm][BF4]), and 1-ethyl-3-methylimidazolium methylsulfate ([EMIm][MS]), were used. Eluents were composed of water and methanol (90/10%, vol) with the addition of 0.5-13.0 mM of ILs. The effects of the concentration of ILs on retention and separation were investigated and discussed. The results showed that the addition of ILs affects the retention and resolution of the tested compounds. Use of 13.0 mM of [BMIm][BF4] as the eluent modifier resulted in a baseline separation of nucleotides without requiring gradient elution. This study demonstrates that ILs can be potentially applied as a mobile phase modifier in RPLC.