• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.244-247
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• 2010

최근 Application 의 취약성을 악용한 해커들의 시스템 공격 사례가 증가하고 있다. 본 논문에서 다루는 코드 분석기는 이러한 해커의 공격을 사전에 차단하기 위해 사용자로부터 입력받은 Application 의 소스 코드가 사전에 탑재해 놓은 일련의 보안 규칙(Security Rule)을 제대로 준수하는지의 여부를 어휘 분석(Lexical Analysis)과 구문 분석(Semantic Analysis)을 통해 판별해 낸다. 본 코드 분석기는 미국 카네기멜론대학(CMU) 산하의 인터넷 해킹 보안 기구인 CERT 에서 제시하는 규칙을 그대로 적용하여 분석 결과의 정확도와 객관성을 높였으며, 이 분석기를 통해 프로그래머가 신뢰도와 보안성이 높은 소프트웨어를 개발할 수 있도록 하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.874-875
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• 2005

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.104-107
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• 2021

전 세계적으로 건조한 지역이 늘어남에 따라 산불 발생 빈도가 증가하고 있다. 이에 대한 대안으로 센서를 이용한 산불 감지 시스템의 연구가 이루어지고 있다. 기존의 서버가 센서의 작동시간 설정값을 보내는 방식은 산불 발생 빈도가 높은 환경에서는 산불 감지가 늦어지고 산불 발생 빈도가 낮은 환경에서는 불필요한 산불 감지로 센서의 생명주기 낮아지는 비효율적인 면이 있다. 이에 본 논문에서는 센서 기반 산불 감지 시스템을 위한 향상된 센싱 주기 기법을 제안한다. 제안하는 센싱 주기 기법은 환경 요인, 센서의 작동시간 알고리즘을 이용하여 환경에 맞는 센서의 작동시간 설정값을 결정한다. 그 후 센서의 화재 감지 알고리즘을 통해 센서는 서버로부터 설정값을 받아 운용모드로 전환하여 화재상황이 났을 시에 서버로 메세지를 보낸 후 생명주기를 위해 저전력모드로 전환한다. 성능평가를 통해 기존의 방식보다 평균 18.1분 빠르게 화재상황을 감지할 수 있고 소모전력도 2.2mA만큼 낮았다. 향우 실제 화재환경에서의 성능평가가 필요하다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.808-810
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• 2021

얼굴 인식 기술들은 다양한 인공지능 플랫폼들의 발달 및 알고리즘들의 연구 개발로 인해 발전하고 있다. 대부분의 얼굴 인식 알고리즘들은 정확도를 높이기 위해 많은 양의 데이터 학습을 요구하고 잇다. 그러나 커피숍이나 음식점과 같이 사람들이 짧은 시간 머물고 있는 환경에서는 사람들의 출입 여부를 체크하기 기존의 얼굴인식 기술들을 적용함에 있어 학습량의 부족으로 부적합하다. 이에 본 논문에서 카페와 음식점의 사용자 출입 관리를 위한 단시간 얼굴 학습을 통한 얼굴 인식 시스템 구현한다. 이로 인해 카페 및 음식점의 운영자는 사용자들의 입·출입 데이터를 활용하여 테이블 회전율 분석 및 코로나19 방역수칙인 카페 2인 이상 1시간 이내 사용을 체크가 가능하다.

• Polymer(Korea)
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• v.37 no.3
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• pp.288-293
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• 2013

A group of molecularly imprinted polymers (MIPs) with specific recognition for chiral (S)-ibuprofen were successfully prepared based on hydrogen bonds, utilizing ${\alpha}$-methacrylic acid as a functional monomer. The IR analysis of MIPs showed that the blue- and red-shifted hydrogen bonds were formed between templates and functional monomers in the process of self-assembly imprinting and re-recognition, respectively. According to UV-Vis analysis, we found that the ratio of host-guest complexes between template molecule and functional monomer was 1:1. The effect of cross-linker's quantity on the polymerization was studied by transmission electron microscope (TEM). The adsorption selectivity experiments indicated that MIPs exhibited higher selectivity to (S)-ibuprofen than those to ketoprofen and (R)-ibuprofen, (S)-ibuprofen's structural analogs.

• Journal of Power Electronics
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• v.11 no.4
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• pp.499-506
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• 2011

This paper presents an interleaved active-clamping zero-voltage-switching (ZVS) forward-flyback converter without an output choke. The presented topology has two active-clamping circuits with two separated transformers. Because of the interleaved operation of the converter, the output current ripple will be reduced. The proposed converter can approximately share the total load current between the two secondaries. Therefore, the transformer copper loss and the rectifier diodes conduction loss can be decreased. The output capacitor is made of two series capacitors which reduces the peak reverse voltage of the rectifier diodes. The circuit has no output inductor and few semiconductor elements, such that the adopted circuit has a simpler structure, a lower cost and is suitable for high power density applications. A detailed analysis and the design of this new converter are described. A prototype converter has been implemented and experimental results have been recorded with an ac input voltage of 85-135Vrms, an output voltage of 12V and an output current of 16A.

• Smart Structures and Systems
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• v.29 no.1
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• pp.41-51
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• 2022

Cables are critical components of cable-stayed bridges. A structural health monitoring system provides real-time cable tension recording for cable health monitoring. However, the measurement data involve multiple sources of variability, i.e., varying environmental and operational factors, which increase the complexity of cable condition monitoring. In this study, a one-class classification method is developed for cable condition assessment using Bayesian factor analysis (FA). The single-peaked vehicle-induced cable tension is assumed to be relevant to vehicle positions and weights. The Bayesian FA is adopted to establish the correlation model between cable tensions and vehicles. Vehicle weights are assumed to be latent variables and the influences of different transverse positions are quantified by coefficient parameters. The Bayesian theorem is employed to estimate the parameters and variables automatically, and the damage index is defined on the basis of the well-trained model. The proposed method is applied to one cable-stayed bridge for cable damage detection. Significant deviations of the damage indices of Cable SJS11 were observed, indicating a damaged condition in 2011. This study develops a novel method to evaluate the health condition of individual cable using the FA in the Bayesian framework. Only vehicle-induced cable tensions are used and there is no need to monitor the vehicles. The entire process, including the data pre-processing, model training and damage index calculation of one cable, takes only 35 s, which is highly efficient.

• Imaging Science in Dentistry
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• v.52 no.3
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• pp.303-308
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• 2022

Purpose: This technical report aims to describe and detail the use of micro-computed tomography for a reliable evaluation of the bulk-fill composite/tooth interface. Materials and Methods: Bulk-fill composite restorations in tooth cavities were scanned using micro-computed tomography to obtain qualitatively and quantitatively valuable information. Two-dimensional information was processed using specific algorithms, and ultimately a 3-dimensional (3D) specimen reconstruction was generated. The 3D rendering allowed the visualization of voids inside bulk-fill composite materials and provided quantitative measurements. The 3D analysis software VG Studio MAX was used to perform image analysis and assess gap formation within the tooth-restoration interface. In particular, to evaluate internal adaptation, the Defect Analysis addon module of VG Studio Max was used. Results: The data, obtained with the processing software, highlighted the presence and the shape of gaps in different colours, representing the volume of porosity within a chromatic scale in which each colour quantitatively represents a well-defined volume. Conclusion: Micro-computed tomography makes it possible to obtain several quantitative parameters, providing fundamental information on defect shape and complexity. However, this technique has the limit of not discriminating materials without radiopacity and with low or no filler content, such as dental adhesives, and hence, they are difficult to visualise through software reconstruction.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06b
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• pp.455-459
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• 2010

본 논문에서는 운전자의 운전 패턴에 따른 연료 소비량을 감소하는 ECO_Driving에서 효율적으로 방법을 제안하였다. 이 ECO-Driving 시스템은 차량의 정확한 상태 정보를 바탕으로 운전 상태를 운전자에게 제공하여 경제운전 행동으로 배기가스 감축, 에너지절약을 유도하였다. 차량의 상태정보를 추출하기 위해서 차량 네트워크인 CAN 버스를 사용하였으며, 이를 하드웨어로 구현하였다. 효율적인 ECO_Driving을 위한 차량 데이터들을 추출하여 분석하였으며, 이들 데이터를 바탕으로 운전자에게 에코여부를 제공하는 프로그램을 구현하였다. 제한적인 실험이었지만 연비를 감소하는 것을 확인할 수 있었다.

• Journal of Practical Engineering Education
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• v.9 no.1
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• pp.69-75
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• 2017

In this paper, we analyzed the factors influencing the size of Korea Polytechnic as a public vocational education and training institution through analysis of demand, region, industry, and demand with established existing campus and new campus in Korea Polytechnic. By analyzing data on admission, training, and employment for 3 years out of 37 campuses, we have sampled 5 campuses by type of Korea Polytechnic, fused with the results derived from the literature analysis and in-depth analysis results, so that the regional campus will play a leading role and the direction of development. The selection of five campuses by type is a precedent study to analyze 37 campuses in the future. As a result of the study, the demand analysis through objective indicators such as the number of high school graduates, the number of employed persons, the presence of nearby industrial complexes, and policy variables is very important and reflects the reality well. Therefore, it is necessary to analyze the demand through the objective indicators in decision making related to the new campus at the pre-analysis stage. In addition to the general data proposed in this paper, that is, common variables in all regions, it is important to consider the factors that can reflect local demand characteristics when considering specific locations.