• 한국시뮬레이션학회논문지
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• 제7권1호
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• pp.15-26
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• 1998

In building a shell-based FMS, which is known as one of the top-down approaches in the field of factory automation, we may take a hybrid simulation into consideration. The modeling of a hybrid simulation consists of real physical entities, virtual simulation, and central clock algorithm, etc. to carry out the whole system operation. In this paper, we sow a way to construct a hybrid simulation software system in manufacturing environments. We bring in the object-oriented methodology in system design and it can contribute in dealing with a wide variety of production types and configurations. Some classes such as project, product, process, order, schedule, stage are defined. These are used and tested by implementing a specific LSI circuit assembly line process.

• Journal of Positioning, Navigation, and Timing
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• 제11권2호
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• pp.99-107
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• 2022

Urban Air Mobility (UAM) such as a drone taxi is one of the future transportations that have recently been attracting attention. Along with the construction of an urban terminal, an accurate landing system for UAM is also essential. However, in urban environments, reliable Global Navigation Satellite Systems (GNSS) signals cannot be received due to obstacles such as high-rise buildings which causes multipath and non-line of sight signal. Thus, the positioning result in urban environments from the GNSS signal is unreliable. Consequently, we propose the Ultra-Wideband (UWB) network to assist the soft landing of UAM on a vertiport. Since the positioning performance of UWB network depends on the layout of UWB anchors, it is necessary to optimize the layout of UWB anchors. In this paper, we propose a two-steps genetic algorithm that consists of binary genetic algorithm involved multi objectives fitness function and integer genetic algorithm involved robust solution searching fitness function in order to optimize taking into account Fresnel hole effects.

• 한국전자통신학회논문지
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• 제17권6호
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• pp.1243-1248
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• 2022

비정형 환경인 건설 현장에서 안정적으로 운영할 수 있는 이동 플랫폼은 스마트 건설기술 개발에 있어 중요한 문제이다. 본 논문에서는 건설 현장 지형정보 수집 지원을 위해 비정형 환경에서도 강인하게 주행할 수 있는 이동 로봇 플랫폼을 소개한다. 제안한 이동 플랫폼은 종경사 뿐만이 아닌 횡경사에도 대처할 수 있도록 설계하였으며 시뮬레이션 실험을 통해 제안한 플랫폼의 단차 극복성능을 분석하였다.

• International Journal of Advanced Culture Technology
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• 제10권2호
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• pp.43-52
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• 2022

This study used a descriptive survey design to examine the impact of the clinical learning environments and learning transition nursing students experienced the gerontological nursing clinical on the satisfaction with clinical practice. A convenient sample of 211 4^th year nursing students who had the gerontological nursing clinical practicum from one College of Nursing at Private University in South Korea was recruited and completed the surveys from October to December 2019. This study showed that the satisfaction with a gerontological nursing clinical practicum was significantly correlated with clinical learning environments and learning transition. The results of this study highlights the need to create a safe and positive clinical learning environment for quality gerontological nursing clinical practicum, so hospitals and nursing schools need to make efforts to promote clinical sites as an educational learning environment in collaborative relationships.

• 로봇학회논문지
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• 제18권3호
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• pp.271-280
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• 2023

FMCW (Frequency Modulated Continuous Wave) radar system is widely used in autonomous driving and navigation applications due to its high detection capabilities independent of weather conditions and environments. However, radar signals can be easily contaminated by various noises such as speckle noise, receiver saturation, and multipath reflection, which can worsen sensing performance. To handle this problem, we propose a learning-free noise removal technique for radar to enhance detection performance. The proposed method leverages adaptive thresholding to remove speckle noise and receiver saturation, and wavelet transform to detect multipath reflection. After noise removal, the radar image is reconstructed with the geometric structure of the surrounding environments. We verify that our method effectively eliminated noise and can be applied to autonomous driving by improving the accuracy of odometry and place recognition.

• ETRI Journal
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• 제45권3호
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• pp.479-491
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• 2023

The automation of agricultural machines is an irreversible trend considering the demand for improved productivity and lack of labor in handling agricultural tasks. Unstructured working environments and weather often inhibit a seemingly simple task from being fully autonomously performed. In this context, we propose a remote driving system (RDS) to aid agricultural machines designed to operate autonomously. Particularly, we modify a commercial speed sprayer for orchard environments into a robotic speed sprayer to evaluate the proposed RDS's usability and test three sensor configurations in terms of human performance. Furthermore, we propose a confidence error ellipsebased task performance measure to evaluate human performance. In addition, we present field experimental results describing how the sensor configurations affect human performance. We find that a combination of a semiautonomous line tracking device and a wide-angle camera is the most effective for spraying. Finally, we discuss how to improve the proposed RDS in terms of usability and obtain a more accurate measure of human performance.

• 한국실내디자인학회논문집
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• 제17권6호
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• pp.63-70
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• 2008

The service sector is growing and service is complicated with various customer needs in the competitive markets. Bill Hollins urges that services must be designed. I believe that service experiences must be designed with servicescape as an environment surrounding services. Servicescape is the physical and social environments of service. Service experiences do not depend only on the aesthetic impression of physical servicescape. One of the main characteristics of services is that the most value of services are accomplished from interaction between customer and service encounters. The design of physical servicescape affects the interaction between customer and service encounters and the behavior of both customer and service suppliers' including social factors such as display emotions and the interpersonal distance between customers. Servicescape design should control tangible and intangible area of service events. In addition servicescape design creates customer's good experiences in the servicescape. This research proposes the possibilities and proper design process of servicescape design. Servicescape Design should control the activities including interrelations of participants, efficient service delivery process, and the united images of services for creating the satisfied service experience values.

• 한국통신학회논문지
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• 제30권3C호
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• pp.83-91
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• 2005

본 논문에서는 DS-CDMA 시스템을 위한 적응 혼합 검색형 동기획득 알고리즘의 성능을 저속 페이딩 환경에서 해석한다. 먼저, CDMA 순방향 링크에서의 간섭의 불안정성 (nonstationarity)에 효율적으로 대처하기 위해 CFAR (constant false alarm rate) 특성을 갖도록 동기획득 알고리즘을 설계한다. 설계된 알고리즘의 평균 동기획득 시간 (mean acquisition time)을 이론적으로 해석하고 주파수 선택성 레일라이 페이딩 환경에서 신호탐지 확률, 탐지실패 확률, 및 오경보 율을 유도한다. 성능 해석 시 저속 페이딩 환경을 고려해, 수신 신호의 포락선이 PDI(post-detection integration) 구간 동안 일정하다고 가정한다. 끝으로 설계된 동기획득 알고리즘 대하여 부 윈도우 (sub-window)의 크기, PDI 크기, 판정 임계치 등에 따른 동기획득 성능의 변화를 cdma2000 환경을 고려하여 분석한다.

• 한국조경학회지
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• 제30권5호
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• pp.16-30
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• 2002

This study tried to understand an ambiguous urban landscape through a relational context. Gongpyeong district, an urban renewal area in Seoul, was selected as the site of the case study because traditional and modern styles coexist in this district. The research method and processes are summarized as follows. First, the district, which has both a redeveloped environment and an inherent environment, was divided into Yin & Yang structures. Next, an effort was made to grasp the fundamental relational characteristics(external relationships) of each type through three aspects: physical environment, activities, and meaning. As a result, Yin characteristics were found in the redeveloped environment which has predominantly Yang characteristics. In many cases, advertising, which is a Yang element, was missing in the redeveloped area. On the other hand, in the inherent environment which has Yin characteristics in general, shabby appearances were evident in aspects beyond advertising, and Yang elements, were found from the viewpoint of the theory of place. On the basis of these results, new dualistic frameworks with respect to the functions were re-structured, and complementary characteristics (internal relationship) based on topological aspects were analyzed. Unlike the monotonous appearances found in large scale environments, a variety of spatial characteristics were found in the various small scale environments. This explains that the dualistic coexistence has made a contribution to the complementary attributes of urban landscape. This study has the following ramifications. Much research of urban landscapes that has used western methodology which employs analytic aspects. As a methodology of urban landscape research this study introduced Iching, which tries to understand phenomena in a relational context. In addition, this study expects that the profound understanding of urban environments and the detailed relationship through this framework will suggest a new approach to urban planning, design and management related to future urban environments.

• 한국산업정보학회논문지
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• 제6권4호
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• pp.12-21
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• 2001

최근 들어 작업강도가 심화, 노동환경의 변화 등으로 단순반복작업자의 누적외상장애가 많이 발생하고 있다. 따라서, 본 연구는 단순반복작업자의 근피로도를 분석하기 위하여 수작업과 Air Balance 시스템 설계장치를 이용할 때 각 근육의 피로도의 차이를 밝히고 단순반복작업의 기계에 의한 시스템설계제안을 목적하였다. 연구 결과, 내화벽돌 적재작업시에 수작업과 Air Balance 시스템을 이용한 근피로도 비교에서 Air Balance를 이용한 적재작업에서는 수작업 대비 근육별 AEMG 64.1%, MF 65.3%, MPF 64.3%, ZCR 63.6%로 근피로도가 낮게 나타났다. 근육의 동원정도는 전체적으로 비슷한 천이를 보였다. 즉, Aire Balance시스템을 사용하는 것이 수작업보다 근피로도 값은 낮게 나타났으며, 누적외상성 질환에 대한 노출도 작은 것으로 나타났다.