• 대한의용생체공학회:의공학회지
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• 제43권1호
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• pp.52-60
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• 2022

Purpose: For now, cognitive load is assessed based on survey-based methods, which can be difficult to track the amount of cognitive load in real-time. In this study, we investigated the difference in electrophysiological activation due to different levels of cognitive load not only at sensor-level but also at source-level using electroencephalogram that might be potentially used for quantitative cognitive load evaluation. Materials and Methods: In this study, ten healthy subjects (mean age 24.3 ± 2.1, three female) participated the experiment. All participants performed 4 sessions of n-back task in different difficulties: 0-, 1-, 2-, and 3-back during electroencephalogram recording. For sensor-level analysis, we calculated the event-related potential and event-related spectral perturbation while low resolution brain electromagnetic tomography (LORETA) to estimate the source activation. Each result was compared between different workload conditions using statistical analysis. Results: Statistical results revealed that the accuracy of the task performance was significantly different between different cognitive loads (p = 0.018). The post-hoc analysis confirmed that the accuracy of the 3-back task was significantly decreased compared to 1-back condition (p = 0.018), but not with 2-back condition (p = 0.180). ERP results showed that P300 target amplitude between 1-back and 3-back had a marginal difference in Cz (p = 0.059) and Pz(p = 0.093). A significant inhibition in Cz high-beta activation (p = 0.017) and decrease in source activation of right parahippocampal gyrus was found in 3-back condition compared to 1-back condition (p < 0.05). Conclusion: In this study, we compared the sensor- and source-level differences in electroencephalogram between different levels of cognitive load, that were found to be in line with the previous reports related to cognitive load evaluation. We expect that the outcome of the current study can be used as a feature to establish a quantitative cognitive load assessment system.

• Safety and Health at Work
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• 제8권3호
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• pp.306-314
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• 2017

Background: In order to obtain a deeper understanding of an incident, it needs to be investigated to "peel back the layers" and examine both immediate and underlying failures that contributed to the event itself. One of the key elements of an effective accident investigation is recording the scene for future reference. In recent years, however, there have been major advances in survey technology, which have provided the ability to capture scenes in three dimension to an unprecedented level of detail, using laser scanners. Methods: A case study involving a fatal incident was surveyed using three-dimensional laser scanning, and subsequently recreated through virtual and physical models. The created models were then utilized in both accident investigation and legal process, to explore the technologies used in this setting. Results: Benefits include explanation of the event and environment, incident reconstruction, preservation of evidence, reducing the need for site visits, and testing of theories. Drawbacks include limited technology within courtrooms, confusion caused by models, cost, and personal interpretation and acceptance in the data. Conclusion: Laser scanning surveys can be of considerable use in jury trials, for example, in case the location supports the use of a high-definition survey, or an object has to be altered after the accident and it has a specific influence on the case and needs to be recorded. However, consideration has to be made in its application and to ensure a fair trial, with emphasis being placed on the facts of the case and personal interpretation controlled.

• 한국콘텐츠학회논문지
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• 제14권2호
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• pp.39-47
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• 2014

개인용 스마트 디바이스의 빠른 발전과 역동적 보급은 개인 사용자들을 영상시청 중심의 소비자에서 영상의 촬영에서 공유로 확장된 프로슈머로 변화 시키고 있다. 이러한 변화 속에서 방송영상에 비견되는 소비가 발생되고 지속적으로 생산 및 공유되는 사용자 제작 영상(User Created Video,UCV)이 다양한 콘텐츠 서비스가 가능한 플랫폼으로 주목을 받고 있다. 특히 경험의 공유 목적으로 제작되는 UCV는 복수의 사용자들이 한정된 시간, 공간의 동일한 이벤트로부터 촬영된 것으로, 방송영상과 유사하게 동일한 이벤트를 다양한 앵글의 카메라로 촬영된다. 본 논문에서는 UCV의 다시점적 특성을 제시하고, 이러한 특징을 기반하여 동일한 이벤트에서 촬영된 UCV를 앵글 전환하며 시청할 수 있는 다시점 UCV 서비스를 제안하였다. 또한 사용자 만족도 설문을 통해 중복영역이 포함된 UCV의 시청방식으로 다시점 UCV 서비스를 기존의 선형적 시청방식보다 더 선호함을 알 수 있었다.

• 융합신호처리학회논문지
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• 제12권4호
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• pp.303-308
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• 2011

차량 사고로 인한 인명, 재산 손실 때문에 비행기에서 사용하고 있는 블랙박스와 비슷한 기능을 하는 차량용 블랙박스를 차량에 장착하여 사용되고 있다. 현재 자동차 시장에서 쓰이고 있는 제품으로는 EDR(Event Data Recorders) 시스템과 블랙박스 제품이 출시되어 지고 있다. 하지만 기존 차량의 블랙박스들은 대부분 차량의 외부 영상이나 이미지만 저장되어 사고가 났을 때 차량의 주행 상태를 알지 못하고, EDR제품들은 차량의 주행 상태만 저장 하고 차량의 외부 영상들을 알지 못한다. 본 논문에서는 영상과 이미지 정보만 저장되는 블랙박스의 문제점과 자동차와 주행 정보만 저장되는 EDR의 문제점을 보완하기 위해 차량 네트워크인 MOST(Media Oriented System Transport) OBD-II(On-Board Diagnostics-II)와 CAM(CAMera), GPS(Global positioning system)를 이용하여 영상 수집 및 시간 및 위치 정보 Data를 취합하여 통합형 자동차 상태 및 영상 저장 시스템을 구현한다.

• 한국운동역학회지
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• 제16권1호
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• pp.139-149
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• 2006

This study is to analyze the kinematic variables of inward $1{\frac{1}{2}}$ somersault in platform diver. For the manner, 3 people form the national diving team in the year 2000were chosen as the subjects and two S-VHS video cameras set in 60frames/sec were used for recording their motions. Coordinated raw positions data through digitizing are smoothing by butter-worth's low-pass filterin method at a cut off frequency 6.0Hz. and the direct linear transformation(DLT) method was employed to obtain 3-D position coordinates. The conclusions were as follows. However, horizontal distance which is the change of the COG, form the point of the jump to the point of Event 3 where the player is out of the board range completely, Subject B showed 105.1cm and 71.1cm of the vertical distance which are shorter horizontal distance and higher vertical distance, thus, took a great advantage of the position to prepare for the entry. Therefore, if a player takes higher position by speeding up the vertical velocity at the moment of the jumping off the board, and stays in the air longer, the player can have more time to show his skill. Because of the use of the characteristics of the inward somersault, keeping the safe distance form the board is important but in order to higher the completeness, it is ideal to keep the horizontal distance little over 100cm. Also, the angles of shoulder and elbow from Event 1 to 4, depending on swing of the arms, motions in the air, getting ready for the entry, showed some difference individual by individual, according to the velocity of the thigh and shank showed much difference while getting ready and take-off, and it's because of the individual's different bending and straightening for horizontal and vertical distance.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.421-425
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• 2006

헬스케어와 무선 기술의 접목은 새로운 생체신호 모니터링 방법과 환자의 이동성 및 편의성을 제공하며 더 나은 방법으로 환자를 돌볼 수 있으며 이러한 장점으로 인해 최근 무선기술을 이용한 ECG 모니터링 및 계측 시스템이 개발되고 있다. 본 논문에서는 중요한 생체신호 중 가장 중요한 신호의 하나인 ECG 신호를 무선센서네트워크를 이용하여 무선으로 받은 후, 이를 서버컴퓨터에서 의사, 간호사 또는 환자의 보호자에게 진단의 기초자료로 제공할 수 있게 빈맥, 서맥, 동정지와 같은 비정상적인 ECG신호를 판단하는 ECG 모니터링 시스템을 구현하였다. 신체에서 계측된 ECG신호는 무선으로 서버와 RS-232로 연결된 베이스스테이션으로 전송되고 서버는 비정상적인 ECG 신호를 검사하여 저장 및 모니터링을 위해 PC/PDA로 데이터를 전송하며, 이러한 시스템을 활용하여 의료비 절감 및 더 편리한 의료서비스를 받을 수 있을 것으로 예상된다.

• 동양고전연구
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• 제63호
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• pp.83-113
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• 2016

본 논문은 "좌계부담"의 체재와 구성, 서술방식과 내용의 검토를 통해 그 편찬 목적과 의미를 살펴본 것이다. "좌계부담"은 우선 구성면에서 약 16세기 말부터 18세기 중반까지의 인물을 시대 순으로 기록하였고, 그 안에서 인물 유형에 따라 근거리 배치하는 모습을 보여준다. 서술방식 면에서는 "사기열전"에 보이는 '호견법(互見法)'과 같은 방식을 활용하여, 개인 및 동일 사건의 내용을 관련된 다른 사람들과 나누어 기록하여 주제를 입체화 집중화하는 한편, 인물의 평가를 객관화하는 효과를 획득하고 있다. 인물 형상화 방식에 있어서는 해당 인물의 일생의 특징적 면모에 초점을 맞춰서 그와 관련된 시 또는 일화 등을 기록하여 인물을 구체적으로 그려내고 있다. 또한 목차의 각 인물 이름 옆에 수록 내용의 핵심사항을 요약한 '부제'형식의 짧은 글을 부기하여 내용 파악 및 이해를 돕는다. "좌계부담"은 견문을 자유롭게 엮어가는 방식의 필기 가운데, 인물중심으로 특화된 필기, 즉 '인물지(人物志)' 혹은 '전기집(傳記集)'이며, 더 넓게는 '사서(史書)' 및 '시화(詩話)'의 기능을 아우르는 필기이다. 이에 저자는 사가(史家)의 사명감으로 본서를 집필하였던 것으로 보인다. 18세기 말부터 19세기에 인물을 중심 내용으로 하는 인물지(人物誌) 형태의 특화된 필기류가 등장하게 되는데, "좌계부담"은 그보다 앞선 시기, 즉 18세기 중 후반에 편찬된 인물소전형(人物小傳型)의 필기라는 점에 의미가 있다. 필기류의 역사적 전통 속에서 그 수록 방식 및 서술방식의 변화 시작점에 있는 것으로, 조선 후기 필기류가 점차 전문화된 형태로 이행하는 모습을 보여주는 것이라 할 수 있다.

• Earthquakes and Structures
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• 제3권2호
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• pp.117-140
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• 2012

The proposed research includes a comprehensive study on the seismic vulnerability assessment of typical building types, representative of the structural materials, the seismic codes and the construction techniques of Southern Europe. A damage database is created after the elaboration of the results of the observational data obtained from post-earthquake surveys carried out in the area struck by the September 7, 1999 Athens earthquake, a near field seismic event in an extended urban region. The observational database comprises 180.945 buildings which developed damage of varying degree, type and extent. The dataset is elaborated in order to gather useful information about the structural parameters influence on the seismic vulnerability and their correlation to the type and degree of building damages in near field earthquakes. The damage calibration of the observational data was based on label - damage provided by Earthquake Planning and Protection Organization (EPPO) in Greece and referred to the qualitative characterization for the recording of damage in post-earthquake surveys. Important conclusions are drawn on the parameters that influence the seismic response based on the wide homogeneous database which adds to the reliability of the collected information and reduces the scatter on the produced results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.1.1-5
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• 1994

In the single sweep record of event-related potential (ERP), the peak latency of P300, which is one of the most prominent positive peaks in the ERP record, might fluctuate according to the recording conditions. The fluctuation of the peak latency (measurement fluctuation) is the summation of the fluctuation caused by physiological factor (physiological fluctuation) and one by noise of background EEG (noise fluctuation). We propsed a method for estimating the interval of the physiological fluctuation based on a limited number of single sweep records. The noise fluctuation was estimated by using the relationship between the signal-to-noise (SN) ratio and the noise fluctuation based on the P300 model and the background EEG model. The interval estimate of the physiological fluctuation were obtained by subtracting the interval estimate of the noise fluctuation from that of the measurement fluctuation. The proposed method was tested by using simulation data of ERP and applied to actual ERP and data of normal subjects, and gave satisfactory results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.493-493
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• 2000

Multi-valued decision making for transitional stochastic events was newly derived based on conditional probability of database. The two values (on-off) decision making method without transition had been proposed by one of the author in a previous work for a purpose of realizing human on-off decision making. The current method is an extension of the previous on-off decision making. By combining the conditional probability and the transitional probability, the closed form of the algorithm for the multi-valued transitional decision making was derived. The proposed multi-valued decision making was successfully applied to the determination of the five levels of the vigilance of a subject during the EEG recording; awake stage, drowsy stage and sleeping stages (stage 1, stage 2/3, REM (rapid eye movement)). The method for determining the vigilance level can be directly usable for the two purposes; selection of awake EEG segments for automatic EEG interpretation, and determination of sleep stages through sleep EEG. The proposed multi-valued decision making with a mathematical background of the probability can be applicable widely, in industries and in medical fields for purposes of the multi-valued decision making.