• The Journal of the Korea Contents Association
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• v.19 no.2
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• pp.469-476
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• 2019

Robotic motion is designed by the rotation and the translation of multiple joint coordinates in a three-dimensional space. Joint coordinates are generally modeled by homogeneous transform matrix. However, the complexity of three dimensional motions prefers the visualization methods based on simulation environments in which models and generated motions work properly. Many simulation environments have the limitations of usability and functional extension from platform dependency and interpretation of predefined commands. This paper proposes the web-based three dimensional simulation environment toward high user accessibility. Also, it covers the small size web server that is linked with Python script. The non linearities of robot control apply to verify the computing efficiency, the process management, and the extendability of user scripts.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.2
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• pp.69-76
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• 2014

Multiple-input and multiple-output (MIMO) technique is used in many communication fields in order to increase the channel capacity. However, this MIMO system has difficulty of miniaturization of antenna size due to the multiple RF chains Also, multiple RF chain raises some problems which increase power consumption at RF circuit and degrade the system performance due to the interference between RF chains. Because of these reasons, beamspace MIMO (BS-MIMO) technique with only single RF chain was proposed for MIMO transmission. This BS-MIMO system basically uses electronically steerable parasitic array radiator (ESPAR) antenna. Existing ESPAR antenna has a 5-element structure. So, it is possible to do only $3{\times}3$ MIMO transmission. Therefore, in order to extend BS-MIMO dimension, extension of ESPAR antenna structure is essential. In this paper, we show that BS-MIMO dimension can be increased according to the extension of structure of the ESPAR antenna, as in the conventional MIMO techniques. For example, we show that it is possible to design the $7{\times}7$ BS-MIMO transmissions with the 13-element ESPAR antenna. Also, when the number of parasitic elements of ESPAR antenna increases by two elements, MIMO dimension is expanded by 1.

• Bulletin of the Korean Mathematical Society
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• v.7 no.1
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• pp.21-25
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• 1970

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.171-171
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• 2003

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.07a
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• pp.497-498
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• 2015

영상을 취득한 후 다양한 응용프로그램으로 확장이 가능한 4 차원 light field 영상은 일반적인 2 차원 공간 (spatial) 영역과 추가적인 2 차원 각 (angular) 영역으로 구성된다. 그러나 이러한 4 차원 light field 영상을 2 차원 CMOS 센서로 취득하므로 이에 따른 해상도 제약이 존재한다. 본 논문에서는 이러한 4 차원 light field 영상이 가지는 해상도 제약 조건을 해결하기 위하여, 4 차원 light field 영상에 적합한 학습 기반 (learning-based) 초해상도 (superresolution) 알고리즘을 제안한다. 제안하는 알고리즘은 공간영역 해상도 그리고 각영역의 해상도를 각각 2 배 향상시킨다. 실험에 사용되는 영상은 상용 light field 카메라인 Lytro 에서 취득하며, 기존의 선형 보간 기법인 bicubic 기법과의 비교를 통해 제안하는 기법의 우수성을 검증한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.7-10
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• 2001

웹의 특징인 조작의 간편함, 뛰어난 접근성 등으로 인해 웹을 통한 지리정보의 검색, 접근을 위한 웹 맵 서비스의 요구가 증대되고 있다. 지리정보 분야의 대표적인 컨소시움인 OGC 를 통해서 웹 맵 서비스를 위한 표준 인터페이스가 정의됨에 따라 향후 웹을 통한 지리정보의 공유가 활발히 진행될 것으로 예상된다. 그런데, 현재 정의된 웹 맵 서비스에는 3 차원 맵 서비스를 고려하고 있지 않다. 왜냐하면, 3 차원 데이터 모델에 따라 구축된 공간 데이터가 거의 없으며, 맵 출력을 위한 출력 요소 정의 언어인 SVG 또는 WebCGM 등이 3 차원 기하를 표현할 수 없기 때문이다. 이 논문에서는 OCG 의 웹 맵 서비스를 위한 표준 인터페이스를 준수하면서, 최소한의 확장을 통해 3 차원 맵 서비스를 지원하기 위한 웹 맵 서비스 컴포넌트를 제안한다. 3 차원 맵은 2 차원 공간 데이터와 속성 정보를 이용하여 생성하므로, 3 차원 공간 데이터베이스 구축을 위한 추가의 비용이 발생하지 않는다.

• Management & Information Systems Review
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• v.34 no.5
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• pp.93-110
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• 2015

This research is based on studies about functional service quality in service marketing field and tries to expand application of lovemark effect for service employee. To test the effect of service employee job attributes on lovemark as the antecedents, the analysis was held with customers who experienced specific service retail store recently. According to the research result, service employee job attributes factors including expertise and communication have positive effect on the lovemark. Furthermore, lovemark affected store loyalty significantly. The research has several marketing implication on service marketing and lovemark theory. For service providers, customers'perception of service employee's job attributes can present 'positive lovemark effect' and develop store loyalty in the service marketing perspectives.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.931-934
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• 2003

DWT(Discrete Wavelet Transform)를 2차원 하드웨어로 구현하기 위해서 많은 하드웨어와 실행시간이 들기 때문에 효율적인 구조가 중요하다. 그래서, 이 논문에서는 2차원 DWT에 대한 효율적인 하드웨어 이용률과 크기의 감소, 완벽한 레지스터 이용률, 규칙적인 데이터 흐름으로 필터 길이의 확장을 쉽게 할 수 있도록 구조를 개선하고, 개선된 구조를 VHDL로 검증하였다.

• Science of Emotion and Sensibility
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• v.20 no.1
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• pp.75-82
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• 2017

We propose a novel method for modeling emotional dimensions using expansion of Russell's (1980) emotional dimensions (Circumplex Model). The Circumplex Model represents emotional words in two axes (Arousal, Valence). However, other researchers have insisted that location of word in Russell's model which is expressed by single point could not represent exact position. Consequently, it is difficult to apply this model in engineering fields (such as Science of Emotion & Sensibility, Human-Computer-Interaction, Ergonomics, etc.). Therefore, we propose a new modeling method which expresses emotional word not as a single point but as a region. We conducted survey to obtain actual data and derived equations using ellipse formula to represent emotional region. Furthermore, we applied ANEW and IAPS which are commonly used in many studies to our emotional model using pattern recognition algorithm. Using our method, we could solve problems with Russell's model and our model is easily applicable to the field of engineering.

• The Korean Journal of Applied Statistics
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• v.36 no.4
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• pp.323-335
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• 2023

In causal analysis of high dimensional data, it is important to reduce the dimension of covariates and transform them appropriately to control confounders that affect treatment and potential outcomes. The augmented inverse probability weighting (AIPW) method is mainly used for estimation of average treatment effect (ATE). AIPW estimator can be obtained by using estimated propensity score and outcome model. ATE estimator can be inconsistent or have large asymptotic variance when using estimated propensity score and outcome model obtained by parametric methods that includes all covariates, especially for high dimensional data. For this reason, an ATE estimation using an appropriate dimension reduction method and semiparametric model for high dimensional data is attracting attention. Semiparametric method or sparse sufficient dimensionality reduction method can be uesd for dimension reduction for the estimation of propensity score and outcome model. Recently, another method has been proposed that does not use propensity score and outcome regression. After reducing dimension of covariates, ATE estimation can be performed using matching. Among the studies on ATE estimation methods for high dimensional data, four recently proposed studies will be introduced, and how to interpret the estimated ATE will be discussed.