• Journal of the Korea Society of Computer and Information
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• v.26 no.11
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• pp.101-110
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• 2021

The Weapon Control Software performs the function of supporting weapon operation within the Naval Combat System in connection with the Weapon System. As Weapon Control Software depends on an Weapon System, it has the characteristic that software modification is unavoidable with the change in Interface information. Modification of software causes an increase in development costs since it must take verification step such as software reliability test. In this paper, We design the standard architecture of weapon control software to minimize the modification elements of existing weapon control software. For Interface information management, Feature Model were applied to make a division between common factor and variable factor. In addition, Strategy Pattern were applied to improve the software design. Software evaluation test results show that new architecture provides better modifiability and reuse than existing software as well as the cost of development decrease.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.3
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• pp.136-142
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• 2019

Nuclear power plant concrete structures are in contact with the coast, and durability due to chloride attack is very important because it is used as cooling water by taking seawater. For this purpose, a 3-year long-term saltwater immersion test was carried out to evaluate chloride ion diffusion coefficient and age apponent (m) The m values of the foundation with 4,000 class was 0.35 ~ 0.39, similar to KCI or ACI suggested values. essential service water constructions and tunnels of 5,000 class were 0.44 ~ 0.53 and 6,000 class, and 0.62 of reactor containment buildings were similar to the proposed values of FIB. As a result of the prediction of the service life with the measured age coefficient, all the safety related concrete structures of the nuclear power plants satisfied the service life of more than 60 years.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.9
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• pp.1123-1130
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• 2019

Simulation of the strong clutter occurring from the airborne radar is essential in the efficient development and performance evaluation of the aircraft radar system. If the efficient simulation of the clutter can be successful, algorithms can be proved and analyzed and also the performance evaluation is possible in the laboratory environment. Therefore, development and implementation of the airborne radar system can be achieved very economically in the effective way. However, the clutter simulation procedure is very difficult and tedious since the clutter environment changes in numerous ways as it depends on the flight path, direction of antenna beam, reflectivity of the surface, etc.. Thus, in this paper, the general Doppler spectrum model is suggested for efficient simulation of the various clutter environment. Also, it is shown that the various type of clutter in time domain can be generated easily by changing and adjustment of parameters in the general Doppler spectrum model.

• Journal of the Korean GEO-environmental Society
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• v.12 no.8
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• pp.13-24
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• 2011

In the part of geotechnical engineering, soils are classified as either the coarse grained soil or the fine-grained soil following the fine content($F_c$=50%) according to the granularity, and appropriate design codes are used respectively to represent their mechanical behaviour. However, sand-clay mixtures, which are typically referred to as intermediate soils, cannot be easily categorized as either sand or clay. In this study, several monotonic undrained shear tests were carried out on Silica sand fine mixtures with various proportions, and a wide range of soil structures, ranging from one with sand dominating the soil structure to one with fines controlling the behaviour, were prepared using compaction method or pre-consoldation methods in prescribed energy. The shear strength of mixtures below the threshold fines content is observed that as the fines content increases, maximum deviator stress ratio decrease for dense samples while an increase is noted for loose samples. Then, by using the concept of fines content and granular void ratio, the monotonic shear strength of the mixtures was estimated. It was found that the shear behavior of mixtures is greatly dependent on the skeleton structure of sand particles.

• Journal of the Korean Geosynthetics Society
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• v.21 no.3
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• pp.49-59
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• 2022

This study was conducted to find out the rational and appropriate design of drilled shaft. In other words, in order to find out the variation of ultimate bearing capacity according to the change in the support layer of drilled shaft, back analysis was performed using the bi-directional pile load test performed on drilled shaft. Based on the back-analyzed data, numerical analysis of the pile head load was performed, and the ultimate bearing capacity in the target ground was evaluated using the Davisson method. As a result of numerical analysis of one case where the end of the pile was seated on the top of the weathered rock layer, and three cases where the end of the pile was embedded at different locations in the weathered soil, it was found that sufficient ultimate bearing capacity was secured in all cases. In other words, the case where the end of the pile is seated on the top of the weathered rock layer, not embedded the weathered rock, and the drilled shaft embedded into the weathered soil also have sufficient bearing capacity, so it can be used as a support layer for drilled shaft.

• Journal of the Korean Geotechnical Society
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• v.38 no.11
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• pp.87-95
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• 2022

The geotechnical information constructed in the National Geotechnical Information DB System has been extensively used in design, construction, underground safety management, and disaster assessment. However, it is necessary to refine the geotechnical information because it has nearly 300,000 established cases containing a lot of missing or incorrect information. This research proposes a method for automatic quality control of geotechnical information using a fully connected neural network. Significantly, the anomalies in geotechnical information were detected using a database combining the standard penetration test results and strata information of Seoul. Consequently, the misclassification rate for the verification data is confirmed as 5.4%. Overall, the studied algorithm is expected to detect outliers of geotechnical information effectively.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.6
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• pp.617-627
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• 2022

Military training is an essential item for the fundamental problem of war. However, there has always been a problem that many resources are consumed, causing spatial and environmental pollution. The concepts of defense modeling and simulation and CGF(Computer Generated Force) using computer technology began to appear to improve this problem. The Naval Operations, Resources Analysis Model(NORAM) developed by the Republic of Korea Navy is also a DEVS(Discrete Event Simulation)-based naval virtual force analysis model. The current NORAM is a battle experiment conducted by an operator, and parameter values such as maneuver and armament operation for individual objects for each situation are evaluated. In spite of our research conducted evolutionary, supervised, reinforcement learning, in this paper, we introduce our design of a scenario creation model based on evolutionary learning using genetic algorithms. For verification, the NORAM is loaded with our model to analyze wartime engagements. Human-level tactical scenario creation capability is secured by automatically generating enemy tactical scenarios for human-designed Blue Army tactical scenarios.

• Journal of Aerospace System Engineering
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• v.16 no.4
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• pp.17-27
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• 2022

In this study, a deep learning-based network that can predict the aerodynamic characteristics of airfoils was designed, and the feasibility of the proposed network was confirmed by applying aerodynamic data generated by Xfoil. The prediction of aerodynamic characteristics according to the variation of airfoil thickness was performed. Considering the angle of attack, the coordinate data of an airfoil is converted into image data using signed distance function. Additionally, the distribution of the pressure coefficient on airfoil is expressed as reduced data via proper orthogonal decomposition, and it was used as the output of the proposed network. The test data were constructed to evaluate the interpolation and extrapolation performance of the proposed network. As a result, the coefficients of determination of the lift coefficient and moment coefficient were confirmed, and it was found that the proposed network shows benign performance for the interpolation test data, when compared to that of the extrapolation test data.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.11-11
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• 2023

2020년 기준 우리나라 전체 지하수 시설은 총 1,659천개소, 이용량은 2,916백만m³/년, 년간 지하수 개발가능량은 130억m³대비 22.3%이다(환경부 등, 2021). 단위면적당 지하수 시설수와 이용량은 16.8개소/km², 29,168m³/년/km²(81.1m3/일/km²)이다. 이러한 자료는 가뭄 대응시 신규 관정 개발도 필요하지만, 기존에 개발된 관정들을 최대한 효율적으로 활용하는 방안을 우선적으로 고려해야 한다는 것을 시사한다. 관정들을 상호 연계하게 되면 여러 개의 관정에서 나오는 물을 합하여 총량을 늘릴 수 있기 때문에, 가뭄 등 비상시에 일시적으로 다량의 물을 공급할 수 있다. 또한, 평상시에도 적절한 양수량 조절을 통해 지하수 자원의 손실을 막고 수위 저하에 의한 문제를 최소화할 수 있다. 관정연계시스템(well network system, WNS)은 기존 관정들을 가상의(virtually) 또는 물리적(physical) 연계를 하여, 최적의 지하수를 공급할 수 있는 시스템으로 정의할 수 있다. 가뭄 대응 및 효율적 지하수 자원 활용을 위한 관정연계시스템 개발과 실증을 위해 홍성군 서부면 양곡리 일대에 양수제어, 관로시설, 물탱크 등 물리적인 시설을 시험 설치하여 운영하고 있다. 또한, 관정연계시스템은 ICT 기술과 지하수관리 기법을 연동하여 지하수 관정들을 연계하고 최적으로 운영할 수 있는 하나의 의사결정시스템으로서 관정연계 플랫폼을 개발하였다. 관정연계 플랫폼은 웹기반으로 개발되었으며, 대수층의 수리지질 특성, 수요에 기반한 물공급량 평가, 관정 연계 시나리오 및 최적 운영 알고리즘, 지하수 모델링 등이 가능하도록 각각의 모듈들이 구성 및 통합·운영 되도록 설계되었다. 본 시스템 개발을 통해 가뭄 발생시 현장에서 신속히 지하수로 물을 공급할 수 있으며, 신규 관정 개발에 드는 비용을 절약할 수 있고, 기존 시설을 활용하기 때문에 새로운 수자원 건설 인프라 구축 비용도 절감할 수 있을 것이다. 또한, 개별관정에 대한 이용률 제고와 지하수관리도 보다 체계적, 과학적으로 할 수 있을 것으로 기대한다. 하지만, 이러한 시스템이 제대로 운영 및 보급되기 위해서는 관정연계와 관련한 법제도적 보완과 함께, 지역사회의 공적자원으로서의 지하수에 대한 인식개선과 지하수의 개발 및 보전, 적합한 합리적 배분·이용 등 적극적인 협조가 이루어져야 한다.

• Journal of Advanced Navigation Technology
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• v.27 no.4
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• pp.473-480
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• 2023

This study evaluated a novel method of defining the automatic flight path of unmanned aerial vehicles (UAVs) for search and rescue missions in a VR environment. The developed VR content reserves miniature digital twins of a building in the fire and a steep mountain terrain site. The users drow the UAV's scanning path using hand gestures on the surface of digital twins, and then the UAV make an automatic flight along the defined path. According to human-in-the-loop simulation tests comparing the novel method with a conventional manual flight task with 19 participants, the novel method did not improve the mission performance but participants felt a lower mental workload. The designer may need to consider the automation support on the vulnerable points of the SAR mission environment while maintaining experts' mapping capability.