• 한국지능시스템학회논문지
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• 제18권5호
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• pp.706-711
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• 2008

본 논문에서는 Inertial Navigation System (INS)와 Ultrasonic-SATellite (U-SAT)의 센서융합을 기반으로 100mm 이하의 정밀위치측정 시스템을 보여준다. INS는 자이로와 두 개의 엔코더로 구성되고, U-SAT는 네 개의 송신기와 한 개의 수신기로 구성하였다. 구성된 센서들은 정밀한 정밀위치측정을 위하여 Extended Kalman Filler (EKF)를 통해 센서들을 융합하였다. 위치측정의 성능을 증명하기 위해 본 논문에서는 로봇이 0.5 m/s의 속도로 주행한 실제 데이터(직진, 곡선)와 시뮬레이션을 통한 실험을 하였으며, 실험에 사용된 위치측정방법은 일반적인 센서융합과 INS 데이터만을 칼만 필터에 이용한 센서융합을 비교하였다. 시뮬레이션과 실제 데이터를 통해 실험한 결과, INS 데이터만을 칼만 필터에 이용한 센서융합이 더 정밀함을 확인할 수 있었다.

• Smart Structures and Systems
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• 제16권2호
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• pp.295-328
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• 2015

In recent years the monitoring of structural behavior through acquisition of vibrational data has become common practice. In addition, recent advances in sensor development have made the collection of diverse dynamic information feasible. Other than the commonly collected acceleration information, Global Position System (GPS) receivers and non-contact, optical techniques have also allowed for the synchronous collection of highly accurate displacement data. The fusion of this heterogeneous information is crucial for the successful monitoring and control of structural systems especially when aiming at real-time estimation. This task is not a straightforward one as measurements are inevitably corrupted with some percentage of noise, often leading to imprecise estimation. Quite commonly, the presence of noise in acceleration signals results in drifting estimates of displacement states, as a result of numerical integration. In this study, a new approach based on a time domain identification method, namely the Unscented Kalman Filter (UKF), is proposed for correcting the "drift effect" in displacement or rotation estimates in an online manner, i.e., on the fly as data is attained. The method relies on the introduction of artificial white noise (WN) observations into the filter equations, which is shown to achieve an online correction of the drift issue, thus yielding highly accurate motion data. The proposed approach is demonstrated for two cases; firstly, the illustrative example of a single degree of freedom linear oscillator is examined, where availability of acceleration measurements is exclusively assumed. Secondly, a field inspired implementation is presented for the torsional identification of a tall tower structure, where acceleration measurements are obtained at a high sampling rate and non-collocated GPS displacement measurements are assumed available at a lower sampling rate. A multi-rate Kalman Filter is incorporated into the analysis in order to successfully fuse data sampled at different rates.

• 한국환경복원기술학회지
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• 제16권1호
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• pp.109-130
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• 2013

This study is to offer the raw data for conservation and restoration of national park by surveying and analysing the vascular plants in the Gayasan national park. The flora were summarized as 102 families, 328 genera, 469 species, 4 subspecies, 59 varieties and 9 forms. The endangered plants designated by Ministry of Environment were 2 taxa; Pedicularis hallaisanensis Hurus. and Gymnadenia conopsea for. albiflora Y.N.Lee. The rare plants designated by Korea Forest Service were 13 taxa; Crypsinus hastatus (Thunb.) Copel., Ligusticum tachiroei (Franch. & Sav.) M. Hiroe & Constance, Primula modesta var. fauriae (Franch.) Takeda, Lilium distichum Nakai ex Kamibay and so forth. The korean endemic plants were 15 taxa; Betula ermanii Cham., Carpinus laxiflora (Siebold & Zucc.) Blume, Stewartia pseudocamellia Maxim., Galium koreanum (Nakai) Nakai, Heloniopsis koreana Fuse, N.S. Lee & M.N. Tamura and so forth. The specific plants by floristic region were 66 taxa; Betula chinensis Maxim., Spiraea fritschiana Schneid., Vaccinium hirtum var. koreanum (Nakai) Kitam., Cimicifuga heracleifolia Kom., Adoxa moschatellina L. and so forth. The plants with approval for delivering oversea were 22 taxa; Salix hallaisanensis H.L$\acute{e}$v., Sanguisorba argutidens Nakai, Viola albida Palib., Weigela subsessilis (Nakai) L.H.Bailey and so forth. The naturalized plants were 30 taxa; Chenopodium album L., Lepidium apetalum Willd., Trifolium pratense L., Bidens frondosa L., Helianthus tuberosus L. and so forth.

• 한국지능시스템학회논문지
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• 제18권1호
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• pp.72-77
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• 2008

개인 식별 연구는 보안, 감시 시스템에서 중요한 부분이다. 최선의 성능을 가진 시스템을 설계하기 위하여 감지기들로부터 최대 정보를 이용할 수 있도록 설계한다. 다양한 생체 인식 시스템은 등록, 확인, 또는 개인 식별을 위하여 생리 특성이나 행동 특성을 하나이상 활용한다. 발걸음 인식만을 가지고는 아직 개인별 변별적 특징을 안정적으로 나타내지 못하므로, 본 논문에서는 얼굴과 발걸음을 결합한 개인 식별 시스템을 제안한다. 본 논문에서 우리는 한 개의 카메라를 이용한다. 즉, 얼굴과 발걸음 인식 모두 하나의 카메라를 이용하여 획득된 같은 이미지 셋을 사용한다. 본 논문의 중점은 이미지들에서 이용할 수 있는 최대 정보량을 활용하는 것으로 시스템의 성능을 향상시키는 것이다. 결합은 결정 단계에서 고려된다. 제안된 알고리듬은 NLPR 데이터베이스를 사용한다.

• Journal of Information Processing Systems
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• 제10권1호
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• pp.1-22
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• 2014

Recent technological advances provide the opportunity to use large amounts of multimedia data from a multitude of sensors with different modalities (e.g., video, text) for the detection and characterization of criminal activity. Their integration can compensate for sensor and modality deficiencies by using data from other available sensors and modalities. However, building such an integrated system at the scale of neighborhood and cities is challenging due to the large amount of data to be considered and the need to ensure a short response time to potential criminal activity. In this paper, we present a system that enables multi-modal data collection at scale and automates the detection of events of interest for the surveillance and reconnaissance of criminal activity. The proposed system showcases novel analytical tools that fuse multimedia data streams to automatically detect and identify specific criminal events and activities. More specifically, the system detects and analyzes series of incidents (an incident is an occurrence or artifact relevant to a criminal activity extracted from a single media stream) in the spatiotemporal domain to extract events (actual instances of criminal events) while cross-referencing multimodal media streams and incidents in time and space to provide a comprehensive view to a human operator while avoiding information overload. We present several case studies that demonstrate how the proposed system can provide law enforcement personnel with forensic and real time tools to identify and track potential criminal activity.

• KEPCO Journal on Electric Power and Energy
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• 제8권1호
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• pp.5-7
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• 2022

KEPCO's plan is undergoing a trial operation to replace the open-loop section with ring main units configuration where underground distribution lines are installed, by linking the multi-way circuit breakers auto (MCA) on the power side of each pad-mounted transformer. However, ring main units application mentioned above may cause the ripple effects, when implementing the configuration without a study of protection coordination. Because ring main units with classical pre-set protection devices contribution in fault condition didn't consider yet. For the reliable ring main units operation, it is necessary to resolve several protection issues such as the protection coordination with substation side, prevention of the transformer inrush current. These issues can radically deteriorate the distribution system reliability Hence, it is essential to design proper protection coordination to reduce these types of problems. This paper presents a scheme of ring main units' configuration and MCA's settings of time-current curves to preserve the performance of protection coordination among the switchgears considering constraints, e.g. prevention of the ripple effects (on the branch section when a transformer failure occurs and the mainline when a branch line failure occurs). It was confirmed that the propagation of the failure for each interrupter segment could be minimized by applying the proposed TCC and the interrupter settings for the MCAs (branch, transformer). Further, it was verified that the undetected area of the distribution automation system (DAS) could be supplemented by having the MCA configurated ring main units operate first, instead of the internal protection equipment in the transformer such as the fuse, STP when a transformer failure occurs.

• 한국산학기술학회논문지
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• 제21권5호
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• pp.93-102
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• 2020

자동차, 항공기, 선박과 같은 대형 복합 기계시스템 설계는 다분야 설계최적화의 영역이다. 다양한 영역의 전문지식과 경험을 동시에 요구하기 때문이다. 최근 급격한 기술발전과 더불어 인간의 편의 증진을 위한 요구로 이들 시스템의 복합도와 복잡도가 점증되고 있다. 이런 복합 시스템의 설계를 위해서는 도메인별 지식뿐만 아니라 다양한 분야의 지식, 경험 그리고 관점을 융합할 수 있는 통합 시스템 설계, 즉 다분야 설계최적화가 필요하다. 과거 다분야 설계최적화는 주로 설계자의 직관과 경험에 의존함으로써 해의 정확도나 시간 효율면에서 효용성이 크게 높지 않았다. 최근 다분야 설계최적화는 정보통신기술(IT)의 발전에 힘입어 프로세스통합 및 설계최적화(PIDO) 프레임워크에 의해 주로 구현된다. 본 논문은 오픈소스 PIDO 프레임워크인 RCE를 이용하여 합리적 수준의 노력과 시간 투입으로 효율적인 다분야 설계최적화를 구현하는 프로세스와 방법론을 찾고자 한다. 벤치마킹 예제로 벌크선 개념설계 모델에 본 논문이 제안한 다분야설계최적화 프로세스와 방법론을 적용해 보았다. 최적설계 결과에 대한 시각적 분석을 통해 제안된 방법론의 타당성을 확인하였다.