• Journal of Advanced Navigation Technology
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• v.15 no.4
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• pp.510-516
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• 2011

For using Global Navigation Satellite System(GNSS) in the civil aviation, it should satisfies the Required Navigation Performances(RNPs) which are defined by International Civil Aviation Organization(ICAO). RNP defines the required accuracy, integrity, availability, continuity of each flight procedure. In order to guarantee user's integrity, user's protection level has to be overestimated. On the other hand, for improving user's availability, user's protection level has to be estimated tightly. Therefore protection level should be estimated as tight as possible while it assuring the user's integrity. This paper describes the current integrity function of Korean WAD GNSS test bed, and predicts the availability performance of Korean WAD GNSS by simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.1034-1041
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• 2013

Liquidated Damages is damages that have to be paid when a debtor could usually work off that which they owe, but didn't due to causes imputable. However, currently the Defense Acquisition Program Administration contracts with domestic businesses in case of delay of implementation occurs; they have to pay damages of deferment unlimitedly as a penalty concept, not in compensation about delay. With this in account, conflicts between the two continuesly happen. DAPA wastes administration and counter business costs increasingly burdening their budget. Defense and military procurement need to revise the compensation of deferment system. This paper analyzes the problems about that system, which is applied to domestic business, and also compares it with that of industrialized countries and suggests measures of set price caps in compensation of the deferment system.

• Journal of Software Engineering Society
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• v.29 no.1
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• pp.7-12
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• 2020

As interest in functional safety has recently increased, application of functional safety standards has been required in various industrial fields. A functional safety standard is a document that defines functional safety-related activities required to prevent system malfunctions. All activities defined in this standard are required differentially according to the classification results calculated through the risk analysis and assessment of the system. In the field of domestic weapon systems, there is a manual for the development and management of weapon system software issued by the Defense Acquisition Program Administration (DAPA ). This manual requires static and dynamic analysis of software for functional safety related activities. However, the manual does not specifically address the classification activity through risk analysis and assessment as required for the preceding activities. Therefore, in this study, we analyze the problems of the manual based on the representative functional safety standards, and propose improvement plans.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.3
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• pp.341-346
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• 2010

The effect of specimen geometry on the bending and tensile strengths of dissimilar joints ($\beta-Si_3N_4/S45C$) with copper interlayers was evaluated. The average bending strength of specimens with circular cross sections was higher than that of specimens with rectangular cross sections. The crack initiation stress ($\sigma_i$) was successfully determined by the acoustic emission (AE) method and was approximately 60~80% of the bending strength. The residual stresses near the interfaces on the ceramic side were measured by X-ray diffraction before conducting the bending test. The bending strength and the crack initiation stress decreased with an increase in the residual stresses. The effect of the bending strain component was evaluated by the tensile testing; the tensile strength decreased with an increase in the bending strain component and was approximately 80% of the bending strength.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.2
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• pp.488-495
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• 2014

The national defense electronic procurement system is an information system supporting DAPA, services (Army, Navy and Air Force), and the procurement companies in the electronic bidding. It has contributed greatly to improving the efficiency of the national defense electronic procurement process by providing various information services based on inter-operation among the related parties. However the national defense electronic procurement system is expected to be upgraded to the next version in accord with rapidly evolving infrastructure based on high technology and increasing various communication channels. This paper investigates the satisfaction level of the system users and proposes directions for the next-generation procurement portal.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4163-4170
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• 2013

The recent studies indicated that the major sources of the failure in carrying out the programs of weapon systems development would be the unsatisfaction of the required key performance and also the use of premature technology. As such, to manage the risk during the weapon systems development, the use of the technical performance measurement (TPM) and the technology maturity assessment (TMA) turned out to be necessary. However, the TPM studied so far seems to cover the assessment of performance at the component level only, and thus is insufficient in considering the system integration effect. On the other hand, the system readiness level (SRL) method has been presented by reflecting the effect on system integration, but the system performance and maturity has not been considered. To overcome this, a measurement method is proposed in the paper by utilizing the combined system readiness level and achieved technical performance at the system level. This system performance measure can be useful in managing the risk in the weapon systems development.

• Journal of the Korea Society for Simulation
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• v.24 no.3
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• pp.1-8
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• 2015

Verification, Validation & Accreditation (VV&A) process is widely applied in various disciplines as a method of acquiring the credibility for M&S tools. The guideline of VV&A states that the detailed process can be established flexibly according to the needs and the availability of resources. For example, DAPA (Defense Acquisition Program Administration) guideline suggests that the accreditation process in the VV&A can be omitted if necessary. On this study, we first introduce and describe V&V process. Accreditation process is omitted due to limited time and resources. However, the proposed V&V is sufficient for our needs. Finally, we apply the proposed process of V&V to the System-Integrated Simulator of "Raybolt", Medium-Range Infantry Missile System, for the acquisition of the M&S credibility.

• Journal of Software Engineering Society
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• v.28 no.1
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• pp.7-12
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• 2019

Recently, as the weight of software in the weapon system increases, the quality of the software becomes a very important factor. In order to improve the quality of the weapon system software, DAPA(Defense Acquisition Program Administration) has institutionalized software reliability in Weapon System Software Development and Management Manual. The manual presents specific methods and procedures to improve the weapon system software quality. In order to meet the required reliability test standards specified in the manual, it is necessary to continuously detect and correct defects throughout the entire development period. However, it is difficult to build proper reliability test environment due to the cost of software reliability tools, setting up secured and separated network environment, and etc. Therefore, in this study, we propose an efficient environment construction method for software reliability test of defense industry field in restricted development environment and limited resources.

• Journal of the Korea Society of Computer and Information
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• v.14 no.10
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• pp.271-281
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• 2009

In this paper, we propose the enhanced Assessment Model of the Embedded Software Process(MND-ESPAM) which is suitable for the development work of weapons in Korea. In 2008. We developed the MND-ESPAM which is the assessment criteria of software process, but this model is inefficient to apply to Korean military area. Therefore, we elicit and analyze the problems of MND-ESPAM through tow methods. One is to research on the actual condition of the domestic defense industry about software process management. And the other is to apply MND-ESPAM to the defense companies acquiring CMMI level. In order to overcome these problems elicited above, we provide solutions to make MND-ESPAM linked with Software Development Process Guide of Defense Acquisition Program Administration(DAPA) and to systematically strengthen testing activities and to reduce the number of process areas. The proposed model was proved by two objective methods such as checking the coverage with CMMI and whether it is satisfied or not by modified requirements ISO/IEC 14598-3. At last, experts in the field of software process confirmed the effect of MND-ESPAM through applying MND-ESPAM to the defense industry company.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.11
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• pp.48-53
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• 2007

In this paper, a high LO-RF isolation W-band MIMIC single-balanced mixer was designed and fabricated using a branch line coupler and a ${\lambda}/4$ transmission line. The W-band MIMIC single-balanced mixer was designed using the $0.1\;{\mu}m$ InGaAs/InAlAs/GaAs Metamorphic HEMT diode. The fabricated MHEMT was obtained the cut-off frequency($f_T$) of 154 GHz and the maximum oscillation frequency($f_{max}$) of 454 GHz. The designed MIMIC single-balanced mixer was fabricated using $0.1\;{\mu}m$ MHEMT MIMIC process. From the measurement, the conversion loss of the single-balanced mixer was 12.8 dB at an LO power of 8.6 dBm. P1 dB(1 dB compression point) of input and output were 5 dBm and -8.9 dBm, respectively. The LO-RF isolations of single-balanced mixer was obtained 37.2 dB at 94 GHz. We obtained in this study a higher LO-RF isolation compared to some other balanced mixers in millimeter-wave frequencies.