• Journal of the Korea Society of Computer and Information
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• v.29 no.1
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• pp.21-30
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• 2024

In this paper, we propose a method to build a sample dataset of the features of eight sensor-only facilities built as infrastructure for autonomous cooperative driving. The feature extracted from point cloud data acquired by LiDAR and build them into the sample dataset for recognizing the facilities. In order to build the dataset, eight sensor-only facilities with high-brightness reflector sheets and a sensor acquisition system were developed. To extract the features of facilities located within a certain measurement distance from the acquired point cloud data, a cylindrical projection method was applied to the extracted points after applying DBSCAN method for points and then a modified OTSU method for reflected intensity. Coordinates of 3D points, projected coordinates of 2D, and reflection intensity were set as the features of the facility, and the dataset was built along with labels. In order to check the effectiveness of the facility dataset built based on LiDAR data, a common CNN model was selected and tested after training, showing an accuracy of about 90% or more, confirming the possibility of facility recognition. Through continuous experiments, we will improve the feature extraction algorithm for building the proposed dataset and improve its performance, and develop a dedicated model for recognizing sensor-only facilities for autonomous cooperative driving.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.854-861
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• 2015

This study investigated the association between breakfast frequency (0~2 times, 3~6 times, and 7 times per week) and awareness of general school life (physical activity, relationships with teachers and friends, rule compliance, study attitudes, study records, and overall school life) in high school students (boys 146 and girls 155) in the Yongin region. Awareness of physical activity was higher in girls (77.4%) than in boys (65.1%). Rule compliance showed a significant difference in girls (P<0.01), whereas boys did not show any difference. Percentage of 'effective' awareness of study attitudes was 24.0% and 44.5% in boys and girls, respectively. Awareness of study records in girls showed significant difference (0~2 times 37.5%, 3~6 times 30.4%, and 7 times 52.2%) (P<0.05), whereas boys did not show any difference. Awareness of overall school life showed a significant difference in both boys (P<0.05) and girls (P<0.01). Association between breakfast frequency and general school life in boys was as follows: awareness of overall school life had the highest positive value (+0.185) (P<0.05) and relationships with teachers had the second (+0.168) (P<0.05). Girls also showed the highest positive value (+0.323) (P<0.01) for awareness of overall school life, which occurred in the following order: rule compliance (+0.316) (P<0.01)> awareness of study attitudes (+0.267) (P<0.01)> relationships with friends (+0.215) (P<0.01). In conclusion, high school students showed a high positive association between breakfast frequency and general school life, particularly in girls. Therefore, effective nutrition education programs in connection with national policy and school support are highly required to provide healthy breakfast and school life to high school students.

• Tunnel and Underground Space
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• v.33 no.4
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• pp.281-298
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• 2023

Continuous research efforts are being devoted to unmanned mobile platforms for lunar exploration. There is an ongoing demand for real-time information processing to accurately determine the positioning and mapping of areas of interest on the lunar surface. To apply deep learning processing and analysis techniques to practical rovers, research on software integration and optimization is imperative. In this study, a foundational investigation has been conducted on real-time analysis of virtual lunar base construction site images, aimed at automatically quantifying spatial information of key objects. This study involved transitioning from an existing region-based object recognition algorithm to a boundary box-based algorithm, thus enhancing object recognition accuracy and inference speed. To facilitate extensive data-based object matching training, the Batch Hard Triplet Mining technique was introduced, and research was conducted to optimize both training and inference processes. Furthermore, an improved software system for object recognition and identical object matching was integrated, accompanied by the development of visualization software for the automatic matching of identical objects within input images. Leveraging satellite simulative captured video data for training objects and moving object-captured video data for inference, training and inference for identical object matching were successfully executed. The outcomes of this research suggest the feasibility of implementing 3D spatial information based on continuous-capture video data of mobile platforms and utilizing it for positioning objects within regions of interest. As a result, these findings are expected to contribute to the integration of an automated on-site system for video-based construction monitoring and control of significant target objects within future lunar base construction sites.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.3
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• pp.87-94
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• 2006

For realizing an ubiquitous home network(uHome-net), various sensors should be able to be connected to an integrated wire/wireless sensor network. This paper describes an application case of applying LonWorks technology being widely used in control network to wire/wireless sensor network in uHome-net and the design and application of LonRF device that consists of a neuron chip including LonTalk protocol, a 433.92MHz RF transceiver, a sensor, and application programs. As an application example of the LonRF device, the LonRF smart badge that can measure the 3D location of objects in indoor environment and interwork with the uHome-net was developed. LonRF device based home network services were realized on the uHome-net testbed such as indoor positioning service, remote surveillance service and remote metering service were realized. This research shows that LonWorks technology based sensor network could be applicable to the control network in an ubiquitous home network and the LonRF device can be used as a wireless node in various sensor networks.

• Journal of the Korea Computer Graphics Society
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• v.29 no.3
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• pp.149-158
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• 2023

HMD, which is applied with the latest technology, minimizes motion sickness with high-resolution displays and fast motion recognition, and can accurately track location and motion. This can provide an environment where you can immerse yourself in a virtual three-dimensional space, and virtual reality contents such as disaster simulators and high-risk equipment learning spaces are developing using these characteristics. These advantages are also applicable in the field of basic science education. In particular, expanding the concepts of electric and magnetic fields in physics described by existing two-dimensional data into three-dimensional spaces and visualizing them in real time can greatly help improve learning understanding. In this paper, realistic physical education environments and contents based on three-dimensional virtual reality are developed and the developed learning contents are experienced by actual learning subjects to prove their effectiveness. A total of 46 middle school and college students were taught and experienced in real time the electric and magnetic fields expressed in three dimensions in a virtual reality environment. As a result of the survey, more than 85% of positive responses were obtained, and positive results were obtained that three-dimensional virtual space-based physical learning could be effectively applied.

• Journal of the Korea Convergence Society
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• v.8 no.4
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• pp.131-137
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• 2017

In the present study, we developed the 4D CT data generation program from CAD-based models. To evaluate the developed program, a CAD-based respiratory motion phantom was designed using CAD software, and converted into 4D CT dataset, which include 10 phases of 3D CTs. The generated 4D CT dataset was evaluated its effectiveness and accuracy through the implementation in radiation therapy planning system (RTPS). Consequently, the results show that the generated 4D CT dataset can be successfully implemented in RTPS, and targets in all phases of 4D CT dataset were moved well according to the user parameters (10 mm) with its stationarily volume (8.8 cc). The developed program, unlike real 4D CT scanner, due to the its ability to make a gold-standard dataset without any artifacts constructed by modality's movements, we believe that this program will be used when the motion effect is important, such as 4D radiation treatment planning and 4D radiation imaging.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1397-1407
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• 2017

The aim of a school attendance policy (SAP) is to ensure breakfast time for school-aged adolescents. Therefore, this study investigated the effects of SAP on dietary behavior, particularly breakfast consumption, among adolescent middle school students (n=426) in the Ansan area of Gyeonggi-do. After implementation of the SAP, the response rates for eating breakfast every-day among boys (P>0.05) and girls (P<0.05) slightly increased by 44.6% and 35.8%, respectively, compared to before the SAP. Further, the degree of satisfaction with breakfast increased among both boys ('satisfied' and 'strongly satisfied'; 32.4% and 21.6%, respectively) (P<0.01) and girls ('satisfied' and 'strongly satisfied'; 32.8% and 14.2%, respectively) (P<0.001) compared to before the SAP. Moreover, boys (56.8%) and girls (53.9%) were aware that the SAP increased breakfast-eating frequency. Increases in deep sleep as a result of the SAP were high in both boys (39.2%) and girls (47.1%), and sleeping hours among boys (P<0.05) and girls (P<0.01) increased compared to before the SAP. The respondents were aware of the positive effects on physical function such as reduction of physical fatigue (boys 40.1%, girls 38.2%) and improvement of physical health (boys 36.5%, girls 32.8%). Thus, systematic and sustained political support at the national level is required to encourage healthy breakfast eating and physical activity in middle school students.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.3
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• pp.90-97
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• 2007

For a highly reliable fingerprint recognition system, the precise and accurate feature extraction is indispensable. In this paper, We propose a highly efficient crease extraction method, which can improve the accuracy of feature extraction within the fingerprint image. The proposed method applies the 1-dimensional directional slit for each pixel in fingerprint image. And then it calculates the average grey level and variance to determine whether the current pixel composes the crease, and estimates the direction of crease. Once the direction of every pixel in crease candidate area is estimated, it is decomposed into 8 different images depending on their direction. From the 8 directional images, the crease clusters are estimated by utilizing the property of crease area. The proposed method finally extracts the crease from the crease clusters estimated from directional images. In conclusion, the proposed method highly improved the accuracy of overall feature extraction by accurate and precise extraction of the crease from fingerprint image.

• Journal of the Korean Society of Radiology
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• v.81 no.6
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• pp.1397-1411
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• 2020

Purpose To survey the perception, knowledge, wishes, and expectations of Korean radiology residents regarding artificial intelligence (AI) in radiology. Materials and Methods From June 4th to 7th, 2019, questionnaires comprising 19 questions related to AI were distributed to 113 radiology residents. Results were analyzed based on factors such as the year of residency and location and number of beds of the hospital. Results A total of 101 (89.4%) residents filled out the questionnaire. Fifty (49.5%) respondents had studied AI harder than the average while 68 (67.3%) had a similar or higher understanding of AI than the average. In addition, the self-evaluation and knowledge level of AI were significantly higher for radiology residents at hospitals located in Seoul and Gyeonggi-do compared to radiology residents at hospitals located in other regions. Furthermore, the self-evaluation and knowledge level of AI were significantly lower in junior residents than in residents in the 4th year of training. Of the 101 respondents, only 16 (15.8%) had experiences in AI-related study while 91 (90%) were willing to participate in AI-related study in the future. Conclusion Organizational efforts through a radiology society would be needed to meet the need of radiology trainees for AI education and to promote the role of radiologists more adequately in the era of medical AI.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.548-552
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• 2005

새만금호의 완공이후 내부 개발이 완료된 시점에서 만경강 및 동진강 홍수량 유입이 담수호의 수위 및 유속등 수리특성에 어떠한 변화를 가져올 것인가를 평가하기 위한 수치실험이 내부 관리수위(DL=-0.5m, DL=-1.0m, DL=-1.5m)별로 실시되었다. 홍수파의 전파에 따른 동적거동을 이상적으로 모의하기 위해서 본 연구에서는 2차원 수심적분의 모형인 ADCIRC 모형을 새만금 하구호에 적용하였다. 상류의 유입 경계조건으로는 50년 빈도의 홍수수문곡선도를 사용하여 만경강과 동진강의 유입량이 30분 간격으로 변화되는 홍수량을 이용하였다. 하류의 경계조건으로는 신시 수문이 외해의 조위와 내부 관리수위와 연동되어 외조위가 낮아질 때만 수문이 열리는 조건을 설정하는 동적인 경계조건이 설정되었다. 홍수 계산은 4일에 걸쳐 실시되어 새만금호 내부에서 수위와 유속의 변화를 관찰하였다. 만경수계내 홍수파의 동적 거동은 시간이 경과함에 따라 홍수파가 하류로 전파되어 수위와 유속 변화가 크게 나타난다. 만경강 유입부에서는 홍수수문곡선의 시간적 변화가 민감하게 작용하는 반면, 홍수파 전파가 하류로 진행하면서 유입부에서 높아졌던 수위가 새만금호 내부에서는 점차 낮아지면서 안정화 되는 것을 보여주고 있다. 그러나 수문이 위치한 지점에서는 유입 홍수에 의한 영향은 거의 나타나지 않고, 신시수문의 개방에 따라 동적으로 변동되는 것이 지배적이다. 유속 모의 결과 상류 수로부에서는 $1.8m/s\~0.5m/s$로 나타나지만 새만금호에 진입하면서 $0.5m/s\~0.2m/s$의 낮은 유속으로 변한다. 신시 갑문 인근에서는 수문을 닫을 때 일시적인 충격파가 내부로 전파되면서 와동현상을 보이는 등 유속과 수위 변화에 있어 동적으로 복잡한 거동을 보이는 것으로 해석 된다.한 영향을 미치는 인자에 대한 이론적인 분석을 수행하고, 배수갑문 개방에 의한 수질개선효과를 최대화하기 위한 환경관리 방안 제시에 중점을 두어 수행하였다.ncy), 환경성(environmental feasibility) 등을 정성적으로(qualitatively) 파악하여 실현가능한 대안을 선정하였다. 이렇게 선정된 대안들은 중유역별로 검토하여 효과가 있을 것으로 판단되는 대안들을 제시하는 예비타당성(Prefeasibility) 계획을 수립하였다. 이렇게 제시된 계획은 향후 과학적인 분석(세부평가방법)을 통해 대안을 평가하고 구체적인 타당성(feasibility) 계획을 수립하는데 토대가 될 것이다.{0.11R(mm)}(r^2=0.69)$로 나타났다. 이는 토양의 투수특성에 따라 강우량 증가에 비례하여 점증하는 침투수와 구분되는 현상이었다. 경사와 토양이 같은 조건에서 나지의 경우 역시 $Ro_{B10}(mm)=20.3e^{0.08R(mm)(r^2=0.84)$로 지수적으로 증가하는 경향을 나타내었다. 유거수량은 토성별로 양토를 1.0으로 기준할 때 사양토가 0.86으로 가장 작았고, 식양토 1.09, 식토 1.15로 평가되어 침투수에 비해 토성별 차이가 크게 나타났다. 이는 토성이 세립질일 수록 유거수의 저항이 작기 때문으로 생각된다. 경사에 따라서는 경사도가 증가할수록 증가하였으며 $10\% 경사일 때를 기준으로 $Ro(mm)=Ro_{10}{\times}0.797{\times}e^{-0.021s(\%)}$로 나타났다.천성 승모판 폐쇄 부전등을 초래하는 심각한 선천성 심질환이다. 그러나 진단 즉시 직접 좌관상동맥-대동맥 이식술로 수술적 교정을 해줌으로써 좋은 성적을 기대할 수 있음을 보여주었다.특히 교사들이 중요하게 인식