• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.11
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• pp.36-43
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• 2015

A pixel-level readout circuit is studied for 2-dimensional microbolometer focal plane arrays (FPAs). A current mirroring injection (CMI) input circuit with 2-step current-mode bias suppression is proposed for a pixel-level architecture with high responsivity and long integration time. The proposed circuit has been designed using a $0.35-{\mu}m$ 2-poly 4-metal CMOS process for a $320{\times}240$ microbolometer array with a pixel size of $50{\mu}m{\times}50{\mu}m$. The proposed 2-step bias-current suppression has sufficiently low calibration error with wide calibration range, and the calibration range and error can be easily optimized by controlling some design parameters. Due to high responsivity and a long integration time of more than 1 ms, the noise equivalent temperature difference (NETD) of the proposed circuit can be improved to 26 mK, which is much better than that of the conventional circuits, 67 mK.

• Journal of the Korean Society of Propulsion Engineers
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• v.2 no.2
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• pp.47-55
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• 1998

Steady-state and transient performance for the medium scale civil aircraft turbofan engine was analyzed. Steady-state performance was analyzed on maximum take-off condition, maximum climb condition, and cruise condition. At 90％RPM of the low pressure compressor, the partload performance was economized. The transient performance was analyzed with cases of the step increase, the ramp increase, the ramp decrease, and the step increase and ramp decrease for the input fuel flow. For the transient performance analysis, work matching between compressor and turbine was needed. Modified Euler method was used the integration of residual torque in work matching equation. At all flight condition, the overshoot of the high pressure turbine inlet temperature was appeared in the step and ramp increase case, and the surge of high pressure compressor was appeared in the step increase case and the ramp increase case within 5.5 seconds of maximum climb condition.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.2B
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• pp.125-136
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• 2002

It is very important to acquire the synchronization in a intercell asynchronous WCDMA system, and it is carried out through the three-step cell search process. The cell search can operate in a stepwise parallel manner, where each step works in pipelined operation, to reduce the cell search time. In case that the execution time is set to be the same in each step, excessive accumulations will be caused in both step 1 and step 3, because step 2 should take at least one frame for its processing. In general, the effect of post-detection integration becomes saturated as the number of the accumulations increases. Therefore, the stepwise parallel scheme does not give much enhancement. In this paper, the performance of the stepwise parallel processing for cell search in WCDMA system is analyzed over Rayleigh fading channels. Through the analysis, the effect of cell search parameters such as the number of accumulations in each step and the power ratio allocated among channels is investigated. In addition, the performance of the stepwise parallel cell search is improved by adjusting the execution time appropriately for each step and is compared with that of the conventional stepwise serial processing.

• Journal of Internet Computing and Services
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• v.22 no.6
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• pp.141-150
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• 2021

Based on Artificial Intelligence technology, AI-enabled warfare is expected to become the main issue in the future warfare. Natural language processing technology is a core technology of AI technology, and it can significantly contribute to reducing the information burden of underrstanidng reports, information objects and intelligences written in natural language by commanders and staff. In this paper, we propose a Language model-based Multi-source Information Integration (LAMII) framework to reduce the information overload of commanders and support rapid decision-making. The proposed LAMII framework consists of the key steps of representation learning based on language models in self-supervsied way and document integration using autoencoders. In the first step, representation learning that can identify the similar relationship between two heterogeneous sentences is performed using the self-supervised learning technique. In the second step, using the learned model, documents that implies similar contents or topics from multiple sources are found and integrated. At this time, the autoencoder is used to measure the information redundancy of the sentences in order to remove the duplicate sentences. In order to prove the superiority of this paper, we conducted comparison experiments using the language models and the benchmark sets used to evaluate their performance. As a result of the experiment, it was demonstrated that the proposed LAMII framework can effectively predict the similar relationship between heterogeneous sentence compared to other language models.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.6
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• pp.2689-2708
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• 2016

Multi-camera systems which integrate two or more low-cost digital cameras are adopted to reach higher ground coverage and improve the base-height ratio in low altitude remote sensing. To guarantee accurate multi-camera integration, the geometric relationship among cameras must be determined through platform calibration techniques. This paper proposed a combined two-step platform calibration method. In the first step, the static platform calibration was conducted based on the stable relative orientation constraint and convergent conditions among cameras in static environments. In the second step, a dynamic platform self-calibration approach was proposed based on not only tie points but also straight lines in order to correct the small change of the relative relationship among cameras during dynamic flight. Experiments based on the proposed two-step platform calibration method were carried out with terrestrial and aerial images from a multi-camera system combined with four consumer-grade digital cameras onboard an unmanned aerial vehicle. The experimental results have shown that the proposed platform calibration approach is able to compensate the varied relative relationship during flight, acquiring the mosaicing accuracy of virtual images smaller than 0.5pixel. The proposed approach can be extended for calibrating other low-cost multi-camera system without rigorously mechanical structure.

• Journal of Korean Society of Steel Construction
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• v.13 no.5
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• pp.599-608
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• 2001

Many papers which deal with the dynamic instability of shell-like structures under the STEP load has been published but there have been few papers related to the dynamic instability of hybrid cable domes. And also there are a few researches which treat the essential phenomenon of the dynamic buckling using the phase for investigating occurrence of chaos. In this study the indirect buckling of hybrid cable domes considering geometric nonlinearity are investigated numerically and compared it with the static critical load The dynamic critical loads are determined by the numerical integration of the geometric nonlinear equation of motion and the mechanism of the indirect buckling is examined by using the phase curves.

• Journal of Korean Association for Spatial Structures
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• v.4 no.2 s.12
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• pp.81-88
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• 2004

The dynamic instability of snapping phenomena has been studied by many researchers. Few papers deal with dynamic buckling under loads with periodic characteristics, and the behavior under periodic excitations is expected to be different from behavior under STEP excitations. We investigate the fundamental mechanisms of the dynamic instability when the sinusoidally shaped arch structures are subjected to sinusoidally distributed excitations with pin-ends. The mechanisms of dynamic indirect snapping of shallow arches are especially investigated under not only STEP function excitations but also under sinusoidal harmonic excitations, applied i the up-and-down direction. The dynamic nonlinear responses are obtained by the numerical integration of the geometrically nonlinear equation of motion. And using this analyze characteristics of the dynamic instability through the running response spectrum by FFT(Fast Fourier Transform).

• The Journal of Korean Academy of Sensory Integration
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• v.19 no.1
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• pp.24-38
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• 2021

Objective : This study aimed to create a Korea translation of the Evaluation in Ayres Sensory Integration (EASI) and to then test the adapted version for construct validity. Methods : The translation and content validation process were conducted in accordance with a four-step process, namely translation, integration, content validity examination, and backward translation. The construct validity of the translated version was evaluated using the EASI for children aged 3~12 years with and without sensory integration problems, comparing the two groups as well as preschool and school-aged groups. The group comparison was analyzed using the Mann-Whitney U test in SPSS. Results : In terms of content validity, all 20 items averaged more than 3.17 points. Of the four EASI categories, there was a difference in Sensory Perception (p=0.044) between the typical and sensory integration groups, and there was a statistical difference between tactile and vestibular sensations. Between the preschool and school-aged children, statistical difference was observed in two categories, namely Praxis and Ocular-Postural-Bilateral Motor Integration. Conclusion : Based on its construct validity, the Korean version of EASI is suitable for use in research. The construct validity study highlighted items that explain differences between typical and diagnostic children and items that explain those differences by age. Our findings could therefore be considered when interpreting EASI results.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.3
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• pp.116-122
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• 2017

Advances in information technology, communication and network technology are radically facilitating digital convergences as the integration of human, equipment, and space in the current industry 4.0 era. In industry 4.0 environment, the vast amount of information with networked computing technology can be simultaneously accessible even in limited physical space. Two main benefit points out of these information are the convenience and efficiency in their online transactions either buying things online or selling online. Even though there exist so many benefits that information technology can create for the people doing business over the internet there is a critical problem to be answered. In spite of many such advantages, however, online transactions have many dysfunctions such as personal information leakage, account hacking, and cybercrime. Without preparing the appropriate protection methods or schema people reluctantly use the transaction or would find some other partners with enhanced information security environment. In this paper we suggested a novel selection criteria that can be used to evaluate the reliable means of authentication against the expected risks under on-going IoT based environment. Our selection criteria consists of 4 steps. The first step is services and risk identification step. The second step is evaluation of risk occurrence step. The third step includes the evaluation of the extent of damage. And the final step is the assessment of the level of risk. With the help of the above 4 step-approach people can systematically identify potential risks hiding in the online transactions and effectively avoid by taking appropriate counter actions.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.258-261
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• 2003

Demolition is mort dangerous than construction and causes a lot of harmful environmental factors. But temporary fences used on demolition sites cannot play out their roles of blocking harmful environmental factors or securing stability and work space. They only block the view from the outside. This study begins with the possibility that the temporary fence can be installed prior to demolition. As a preceding step. we performed research on the actual conditions of using it. We then realized that it can be installed according to our research plan. First, we focused on actualizing the integration of temporary fences for demolition and construction. Here are the results of this study. First, we need to grasp the limiting factors of integration. Second, we ought to revise the Korean Architecture Standard Specification. Third, we should prepare against damage and transformation of fences. Finally, we can expect to reduce harmful environmental factors, cut down expenses, improve the working environment and raise the image of demolition by the integration of these fences.