• 융합보안논문지
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• 제18권1호
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• pp.85-91
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• 2018

이 연구에서는 해양환경 변화로 인한 양식장 피해절감을 위한 위성영상기반 관심위치의 해양환경정보 서비스 시스템을 설계한다. 수온, 클로로필, 부유물 등의 위성해양정보를 계층형 문자로 제공할 수 있도록 하는 OpenAPI 환경에서 확장이 자유로운 단위모듈 Web 서비스를 구현하고, 모듈 플러그인 이식 시 시스템의 안정성 및 서비스 시간, 데이터 추출 정밀도 및 신속성 등을 기준으로 서비스의 안정성을 확보한다. 본 연구에서 구현한 서비스시스템의 기능과 성능을 확보함으로써 위치기반으로 운영되는 기존 시스템들의 일반서비스 뿐만 아니라 특정관심지역의 정보를 추가함으로써 사용자를 그룹 단위로 특화시킬 수 있는 복합기술로 확장될 수 있다. 특히 해양환경정보를 포함한 기타 다양한 관심항목을 모듈단위로 개발함으로써 시스템에 플러그인 하여 시스템을 확장하고 서비스할 수 있기 때문에 유관기관 정보시스템과 기술적 연계하여 확산될 수 있을 것으로 기대한다.

• 생약학회지
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• 제52권3호
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• pp.186-191
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• 2021

We developed a method to identify and quantify 6-hydroxyluteolin 7-O-glucoside in the powder of Salvia plebeia (PS) using high-performance liquid chromatography coupled with diode array detector (HPLC/DAD) and equipped with reverse-phase INNO C18 column. The analytical method was optimized and validated using novel parameters. The obtained values for the limits of detection and quantification were 3.60 and 10.90 ㎍/mL, respectively. Calibration curve showed good linearity in the concentration range tested (0.00625-0.1 mg/mL, r² = 1.0000), high accuracy (96.2-101.4%), and precision values (RSD ≤ 0.27%). Our analysis support the use of our method for accurately identifying and quantifying 6-hydroxyluteolin 7-O-glucoside from PS in routine analyses and large-scale extraction processes for content determination.

• 디지털융복합연구
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• 제19권4호
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• pp.25-31
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• 2021

고령화 시대에 따라 고령운전자 역시 증가하고 있으며, 이들에 의한 교통사고 심각성에 대한 관심이 높아지고 있다. 이에 고령운전자에 의한 사고심각도 예측 모형의 필요성이 점차 요구됨에 따라, 본 연구에서는 기계학습 기법을 활용하여 고령운전자에 의한 차대사람 사고심각도 예측을 위한 모형 정립 및 분석을 수행하고자 한다. 이를 위해 4개의 기계학습 알고리즘 (Logistic Model, KNN, RF, SVM)을 활용, 예측 모형을 개발하고 각 결과를 비교하였다. 연구 결과에 따르면 Logistic과 SVM 모형이 상대적으로 높은 예측력을 보였으며, 정확도 측면에서는 RF가 높은 것으로 나타났다. 추가적으로 각 중요 변수들을 이용하여 교차분석을 수행한 후 그 결과를 제시하였다. 본 연구의 결과들은 고령화시대에 고령운전자에 의한 사고심각성을 예방하기 위한 안전정책 및 인프라 개발에 활용될 것으로 판단된다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권spc호
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• pp.1-18
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• 2022

A conceptual site model is used to support decision-making of response strategy development, determination, and implementation within a risk-based contaminated site management system. It aims to provide base information of the relevant site characteristics and surface/subsurface conditions in order to understand the contaminants of concern and the associated risk they pose to the receptors. This study delineated the technical details of conceptual site model development, and discussed the possibility of applying it in domestic subsurface contamination management. Conceptual site models can be developed in various formats such as tables, diagrams, flowcharts, and figures. Contaminated sites are managed for a long period of time following the steps of investigation, remediation design, remediation, verification, and post-remedation management. The conceptual site model can be enhanced in each stage of the contaminated site management based on the continuously updated information on the site's subsurface environment. In the process of enhancement for conceptual site model, precision is gradually improved, and it can evolve from a conceptual and qualitative form to a more quantitatvive and three-dimensional model. In soil pollution management, it is desirable to incorporate the conceptual site model into the soil scrutiny system to better assess the current status of the contaminated site and support follow-up investigation and management.

• 창의정보문화연구
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• 제7권2호
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• pp.91-98
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• 2021

코로나19로 인해 초등학생이 온라인 환경에 머무는 시간이 증가함에 따라 작성하는 게시글, 댓글, 채팅의 양이 증가하였고, 타인의 감정을 상하게 하거나 욕설을 하는 등의 문제가 발생하고 있다. 네티켓을 초등학교에서 교육하고 있지만, 교육시간이 부족할 뿐 아니라 행동의 변화까지 기대하기는 어려움이 있어 자연어처리를 통한 기술적인 지원이 필요한 상황이다. 본 연구는 초등학생이 작성하는 문장에 사전언어학습 모델에 적용하여 자동으로 욕설문장을 필터링하는 실험을 진행하였다. 실험은 온라인 학습 플랫폼에서 초등학교 4-6학년의 채팅내역을 수집하였고, 채팅 내역중에 욕설로 신고되어 판정된 욕설문장을 함께 수집하여 사전학습된 언어모델을 통해 훈련하였다. 실험결과, 욕설문장을 분류한 결과 75%의 정확률을 보이는 것으로 분석되어 학습 데이터가 충분히 보완된다면, 초등학생이 사용하는 온라인 플랫폼에서 적용할 수 있음을 보여주었다.

• 방송공학회논문지
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• 제27권5호
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• pp.751-761
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• 2022

디지털 기술의 발전에 따라 메타버스가 콘텐츠 시장의 주요 트렌드로 자리하면서 고품질의 3D(dimension) 모델을 생성하는 기술에 대한 수요가 급증하고 있다. 이에 따라 디지털 휴먼으로 대표되는 고품질 3D 가상 인간의 제작과 관련된 다양한 기술적 시도가 이루어지고 있다. 3D 볼류메트릭 캡처는 기존의 3D 모델 생성 방식보다 빠르고 정밀한 3D 인체모형을 생성할 수 있는 기술로 각광 받고 있다. 본 연구에서는 볼류메트릭 3D 및 4D 모델 생성 분야에서 적용되는 기술들과 콘텐츠 제작의 애로사항에 대해 실제 사례를 바탕으로 3D 고정밀 페이셜 제작 기술의 분석을 시도한다. 그리고 실제 볼류메트릭 캡처를 통한 모델의 구현 사례를 바탕으로 3D 가상인간의 얼굴 제작에 대한 기술들을 고찰하고 효율적인 휴먼 페이셜 생성을 위한 그래픽스 파이프라인을 활용하여 새로운 메타휴먼을 제작하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권11호
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• pp.4084-4104
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• 2021

Visual place recognition (VPR) is a fundamental yet challenging task of mobile robot navigation and localization. The existing VPR methods are usually based on some pairwise similarity of image descriptors, so they are sensitive to visual appearance change and also computationally expensive. This paper proposes a simple yet effective four-step method that achieves adaptive convolutional neural network (CNN) landmark matching for VPR. First, based on the features extracted from existing CNN models, the regions with higher significance scores are selected as landmarks. Then, according to the coordinate positions of potential landmarks, landmark matching is improved by removing mismatched landmark pairs. Finally, considering the significance scores obtained in the first step, robust image retrieval is performed based on adaptive landmark matching, and it gives more weight to the landmark matching pairs with higher significance scores. To verify the efficiency and robustness of the proposed method, evaluations are conducted on standard benchmark datasets. The experimental results indicate that the proposed method reduces the feature representation space of place images by more than 75% with negligible loss in recognition precision. Also, it achieves a fast matching speed in similarity calculation, satisfying the real-time requirement.

• Smart Structures and Systems
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• 제32권2호
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• pp.101-109
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• 2023

In order to improve the measurement accuracy of the 6-dimensional accelerometer, the cross coupling compensation method of the accelerometer needs to be studied. In this paper, the non-linear error caused by cross coupling of piezoelectric six-dimensional accelerometer is compensated online. The cross coupling filter is obtained by analyzing the cross coupling principle of a piezoelectric six-dimensional accelerometer. Linear and non-linear fitting methods are designed. A two-level calibration hybrid compensation algorithm is proposed. An experimental prototype of a piezoelectric six-dimensional accelerometer is fabricated. Calibration and test experiments of accelerometer were carried out. The measured results show that the average non-linearity of the proposed algorithm is 2.2628% lower than that of the least square method, the solution time is 0.019382 seconds, and the proposed algorithm can realize the real-time measurement in six dimensions while improving the measurement accuracy. The proposed algorithm combines real-time and high precision. The research results provide theoretical and technical support for the calibration method and online compensation technology of the 6-dimensional accelerometer.

• The Journal of Advanced Prosthodontics
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• 제15권4호
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• pp.179-188
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• 2023

PURPOSE. This in vitro study aimed to evaluate the performance of digital intraoral scanners in a completely edentulous patient with angled and parallel implants. MATERIALS AND METHODS. A total of 6 implants were placed at angulations of 0°, 5°, 0°, 0°, 15°, and 0° in regions #36, #34, #32, #42, #44, and #46, respectively, in a completely edentulous mandibular polyurethane model. Then, the study model created by connecting a scan body on the implants was scanned using a model scanner, and a 3D reference model was obtained. Three different intraoral scanners were used for digital impressions (PS group, TR group, and CS group, n = 10 in each group). The distances and angles between the scan bodies in these measurement groups were measured. RESULTS. While the Primescan (PS) impression group had the highest accuracy with 38 ㎛, the values of 104 ㎛ and 171 ㎛ were obtained with Trios 4 IOSs (TR) and Carestream 3600 (CS), respectively (P = .001). The CS scanner constituted the impression group with the highest deviation in terms of accuracy. In terms of dimensional differences in the angle parameter, a statistically significant difference was revealed among the mean deviation angle values according to the scanners (P < .001). While the lowest angular deviation was obtained with the PS impression group with 0.185°, the values of 0.499° and 1.250° were obtained with TR and CS, respectively. No statistically significant difference was detected among the impression groups in terms of precision values (P > .05). CONCLUSION. A statistically significant difference was found among the three digital impression groups upon comparing the impression accuracy. Implant angulation affected the impression accuracy of the digital impression groups. The most accurate impressions in terms of both distance and angle deviation were obtained with the PS impression group.

• 센서학회지
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• 제33권1호
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• pp.24-29
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• 2024

Inkjet printing technology is used to mass-produce displays and electrochemical sensors by dropping tens of pico-liters or less of specific-purpose ink through nozzles, just as ink is sprayed and printed on paper. Unlike the deposition method for vaporizing material in a vacuum, inkjet printing technology can be used for processing even under general atmospheric pressure and has a cost advantage because the material is dissolved in a solvent and used in the form of ink. In addition, because it can only be printed on the desired part, masks are not required. However, a technical shortcoming is the difficulty for commercialization, such as uniformity for forming the thickness and coffee ring effect. As sizes of devices decrease, the need to print electrodes with precision, thinness, and uniformity increases. In this study, we improved the printing and processing conditions to form a homogeneous electrode using Ag ink (DGP-45LT-15C) and applied this for patterning to fabricate a heat sensor. Upon the application of voltage to the heat sensor, the model with an extended width exhibited superior heat performance. However, in terms of sheet resistance, the model yielded an equivalent value of 21.6 Ω/□ compared to the ITO.