• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.12
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• pp.1648-1656
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• 2018

The configuration of redundant inertial sensors are very important when considering navigation performance and fault detection and isolation (FDI) performance. By constructing a redundant sensor system using multiple inertial sensors, it is possible to improve the navigation performance and fault detection and isolation performance, which are highly related to the sensor configuration and allocation. In order to deploy multiple MEMS inertial measurement units effectively, a configuration and allocation methods considering navigation performance, fault detection and isolation performance, and lever arm effect in one plane are presented, and the performance is analyzed through simulation in this research. From the results, it is confirmed that the proposed configuration and allocation method can improve navigation, FDI, and lever arm effect rejection performances more effectively by more than 70%.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.8
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• pp.10-19
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• 1997

In this paper, perfodrmance of matched-filter (MF) acquisition scheme is analyzed for a direct-sequence/code-division-multiple-access (DS/CDMA) system in a microcellular environment. Mean acquistion time is used as a performance measure. It is demonstrated that acquisition performance is enhanced using interference suppression filter in a Rician fading channel. To apply for multiuser environments, multiple access interference is considered in the performance analysis. From the numerical results, it is shown that mean acquistion time decreases with the increasing SNR/chip, and acquisition performance is improved as the number of taps of interference suppression filter. It is also shown that mean acquisition time increases with the number of users in the system, and acquistion performance is degraded as the icrease of narrowband interference bandwidth. The analysis in this paper can be applied to a DS/CDMA overlay environment.

• 한국디지털정책학회:학술대회논문집
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• 2006.06a
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• pp.87-109
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• 2006

The purpose of this paper is to examine the present performance evaluation methods and to make Monte Carlo Simulation Model for the IT-based Government innovation project. It is suggested the proper ways in applying of Monte Carlo Simulation Model by integration of present evaluation methods. It develops the theoretical framework for this paper, examining the existing literature on proposing an approach to the key concepts of the economic impact analysis methods. It examines the actual conditions of performance evaluation focusing on the It-based Government Innovation project. It considers how the simulation model is applied to the performance management in the public innovation project focusing on the framework, process and procedure of performance management.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.12
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• pp.1187-1192
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• 2016

Performance analysis results are limited to of network level, because network level transmission parameters are used for performance measure and analysis of network design, construction and operation on underwater MANET, With this way of performance analysis based on network level, it is not easy to analyze transmission performance related with user level transmission quality. In this paper, transmission performance focused on application traffic be required by user is investigated to supplement weakness of performance analysis based on network level. Voice traffic, which is expected to be increasingly used on underwater MANET, is considered as application service, Some conditions for underwater MANET will be proposed to support transmission quality, MOS, CCR and EED, etc.. A computer simulation based on NS-2 is used for performance measure, voice traffic is generated as VoIP specification.

• Journal of the Korean Institute of Educational Facilities
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• v.21 no.2
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• pp.33-39
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• 2014

In the case of low-rise buildings in seismic performance evaluation, lateral force resistance of the pillars affects the seismic performance of the building. Evaluation of the seismic performance of the column is determined by the holding performance is evaluated by comparing the shear strength and bending strength it was destroyed bylow intensity. In case of the school building, in order to install the large windows for ventilation and lighting of the partition walls are located between the pillars. The case of the pillars of these, shear failure occurs in the event of an earthquake is often, in the seismic performance evaluation, partition wall and the wall of the shim is evaluated ignoring, pillar of the general pillars If you have to calculate the results of the seismic performance distorted that are destroyed by bending behavior can be evaluated as often. Results of the study, when assessed by distinguishing the effective length of the column, it was found that when a seismic load is applied, it is possible to accurately predict the failure mode, reliable results of seismic performance evaluation of the school building.

• Journal of Ocean Engineering and Technology
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• v.37 no.4
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• pp.129-136
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• 2023

To evaluate manoeuvring performance of merchant ships, the mathematical modeling group (MMG) or computational fluid dynamics (CFD) simulations are used. However, it is difficult to use the MMG to evaluate the manoeuvring performance of fishing vessels, thus research using CFD simulations is necessary. Also, since the course-changing and turning ability is crucial in fishing operations, a rudder design suitable for fishing vessels is necessary. This study designs a rudder using National Advisory Committee for Aeronautics (NACA) airfoil sections and evaluates its manoeuvring performance. A CFD model is used to evaluate the manoeuvring performance of the fishing vessel, and turning and zig-zag tests are conducted. The effectiveness of using CFD simulations based on Reynolds averaged Navier-Stokes equations to assess the manoeuvring performance of fishing vessels was validated. No significant difference was found in the manoeuvring performance for hull forms and rudder designs for course-changing ability. However, the original hull form showed superior turning performance. Among five rudders with varying aspect ratios and shapes, the rudder with 5.5% aspect ratio had the best turning performance. Regarding the rudder design for fishing vessels, NACA airfoil was employed, and a rudder aspect ratio of 5.5% based on the immersed hull side area is recommended.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.4
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• pp.379-389
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• 2023

According to the Korea Urban Air Mobility (K-UAM) Concept of Operation (ConOps), the Global Navigation Satellite System (GNSS) is recommended as the primary navigation system and the performance specification will be implemented considering the standard of Performance Based Navigation (PBN). However, by taking into account the characteristics of an urban environment and the concurrent operations of multiple UAM aircraft, the current PBN standards for civil aviation seem difficult to be directly applied to an UAM aircraft. Therefore, by referring to technical documents published in the literature, this paper examines the feasibility of applying the proposed performance requirements to K-UAM, which follows the recommendation of navigation performance requirements for K-UAM. In accordance with the UAM ConOps, the UAM aircraft is anticipated to maintain low altitude during approach and landing phases. Subsequently, the navigation performance degradation could occur in the urban environment, and the primary degradation factor is identified as multipath error. For this reason, to ensure the safety and reliability of the K-UAM aircraft, it is necessary to analyze the degree of performance degradation related to the urban environment and then propose an alternative aid to enhance the navigation performance. To this end, the aim of this paper is to model the multipath effects of the GNSS in an urban environment and to carry out the simulation studies using the real GNSS datasets. Finally, the initial navigation performance requirement is proposed based on the results of the numerical simulation for the K-UAM.

• Journal of the Earthquake Engineering Society of Korea
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• v.28 no.3
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• pp.141-147
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• 2024

Earthquakes of magnitude 3.0 or greater occur in Korea about 10 times on average yearly, and the number of earthquakes occurring in Korea is increasing. As many earthquakes have recently occurred, interest in the safety of nuclear power plants has increased. Nuclear power plants are equipped with many cabinet-type control facilities to regulate safety facilities, and function maintenance is required during an earthquake. The seismic performance of the cabinet is divided into structural and functional performances. Structural performance can be secured during the design procedure. Functional performance depends on the vibration performance of the component. Therefore, it is necessary to confirm the seismic performance of the components. Generally, seismic performance is confirmed through seismic simulation tests. When checking seismic performance through seismic simulation tests, it is difficult to determine the effect of frequency and maximum acceleration on an element. In this paper, shaking table tests were performed using various frequencies and various maximum accelerations. The seismic performance characteristics of the functions of electrical equipment components were confirmed through tests.

• Journal of the Korea Safety Management & Science
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• v.10 no.1
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• pp.107-116
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• 2008

Nowadays, BSC presented by alpan is observed by many enterprises and is being operated gradually. BSC includes non-financial factor as well as financial factor in performance assessment and it is a tool that will be able to evaluate even strategy of long-term view. In point of performance management, BSC brings in relief importance on non-financial performance as well as financial performance and it shares with viewpoint of 4 things of financial viewpoint, customer viewpoint, internal process view point, learning and growth viewpoint. then these make an array with vision and strategy of organization by causal relationship, it presented necessity of performance control on organization as center on KPI of inner of each viewpoint. Thus, study on measures and control of management performance is progressed actively and is accomplishing much development. This study is aimed at calculation of weight that is able to reflect its importance about AHP on KPI of each viewpoint. The purpose of this study is to present desirable performance measurement model and to give a weight in consideration of working-level character.

• Journal of Korea Trade
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• v.24 no.8
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• pp.101-120
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• 2020

Purpose - The buyer's right to withhold performance is a useful and important self-help remedy to protect himself from the seller's breach of contract, and it is also the coercive means to induce the seller to perform his part of contract. However, the buyer's exercise of such a right often exposes himself to the risk of breaching the contract. This is generally due to his ignorance when he is entitled to the right and also uncertainties inherent in the law. Therefore, the purpose of this paper is to examine what the requirements should be fulfilled before the buyer exercises the right for the seller's actual breach of contract. Design/methodology - In order to achieve the purposes of the study, it executes a comparative study of the rules as to the requirements for the buyer's right to withhold performance for the seller's actual non-performance under the CISG and the CESL. It mainly focuses on performance due, the seller's non-performance, the buyer's readiness to perform and the requirement of notice. Findings - The main findings of this comparative study can be summarized as follows: Although the CISG has no expressive provision for the buyer's general right to withhold performance for the seller's actual non-performance, it may be inferred from the general principles the CISG underlies, synallagmatic nature of the contract. In addition, it can be drawn by analogy from relevant provisions of the CISG. On the other hand, the CESL expressively provides that the buyer has a general right to withhold performance where the seller fails to tender performance or perform the contract. Therefore, it seems that the position of CESL is rather easier and more apparent to allow the buyer to withhold performance for the seller's non-performance. Originality/value - Most of the existing studies on the right to withhold performance under the CISG have centered on the right to withhold performance for an anticipatory breach of contract. On the other hand, there have been few prior studies on the right to withhold performance for the actual nonperformance during a contractual period of performance. Therefore, this paper examined the requirements for the buyer's right to withhold performance under the CISG and the CESL in a comparative way for the seller's actual breach of obligation. In this conclusion, it may provide practical and legal considerations and implications for business people who are not certain about the right to withhold performance.