• Title/Summary/Keyword: 공간 복잡도

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A study of the space sterilization device using atmospheric-pressure DBDs plasma (대기압 유전체장벽방전을 적용한 플라즈마오존 공간살균장치에 관한 연구)

  • Oh, Hee-Su;Lee, Kang-yeon;Park, Ju-Hoon;Jeong, Byeong-Ho
    • Journal of the Korea Convergence Society
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    • v.13 no.3
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    • pp.281-289
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    • 2022
  • Plasma ozone is utilized in a variety of applications in the field of sterilization due to its high sterilization performance. Dielectric materials used in DBD(dielectric barrier discharges) are mainly polymer, quartz and ceramics. These dielectric layers have the advantage of limiting the amount of supplied electron charge and allowing plasma to occur evenly on the surface of dielectric. Actually, the target or environment for sterilization is often a complex structure, so research and academic study are needed by utilizing the concept of space sterilization. In this study, the device is applied to generate DBD plasma at atmospheric pressure for disinfection due to the effectiveness in producing radicals and ozone. The generator of plasma ozone is a basic structure of dielectric barrier discharge by placing ceramic tube dielectrics and stainless steel electrical conductors at regular intervals. Various applications can be developed based on the proposed design method. Plasma ozone generation for space sterilization device is recognized as an excellent sterilization device. Through the design and verification of the device, we intend to establish an optimal design of the spatial sterilization device and provide the basis data for sterilization applications.

Dynamic Link Recommendation Based on Anonymous Weblog Mining (익명 웹로그 탐사에 기반한 동적 링크 추천)

  • Yoon, Sun-Hee;Oh, Hae-Seok
    • The KIPS Transactions:PartC
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    • v.10C no.5
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    • pp.647-656
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    • 2003
  • In Webspace, mining traversal patterns is to understand user's path traversal patterns. On this mining, it has a unique characteristic which objects (for example, URLs) may be visited due to their positions rather than contents, because users move to other objects according to providing information services. As a consequence, it becomes very complex to extract meaningful information from these data. Recently discovering traversal patterns has been an important problem in data mining because there has been an increasing amount of research activity on various aspects of improving the quality of information services. This paper presents a Dynamic Link Recommendation (DLR) algorithm that recommends link sets on a Web site through mining frequent traversal patterns. It can be employed to any Web site with massive amounts of data. Our experimentation with two real Weblog data clearly validate that our method outperforms traditional method.

Evaluation of Surface Wind Forecast over the Gangwon Province using the Mesoscale WRF Model (중규모 수치모델 WRF를 이용한 강원 지방 하층 풍속 예측 평가)

  • Seo, Beom-Keun;Byon, Jae-Young;Lim, Yoon-Jin;Choi, Byoung-Choel
    • Journal of the Korean earth science society
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    • v.36 no.2
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    • pp.158-170
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    • 2015
  • This study evaluates the wind speed forecast near the surface layer using the Weather Research Forecasting with Large Eddy Simulation (WRF-LES) model in order to compare the planetary boundary layer (PBL) parameterization with the LES model in terms of different spatial resolution. A numerical simulation is conducted with 1-km and 333-m horizontal resolution over the Gangwon Province including complex mountains and coastal region. The numerical experiments with 1-km and 333-m horizontal resolution employ PBL parameterization and LES, respectively. The wind speed forecast in mountainous region shows a better forecast performance in 333-m experiment than in 1-km, while wind speed in coastal region is similar to the observation in 1-km spatial resolution experiment. Therefore, LES experiment, which directly simulates the turbulence process near the surface layer, contributes to more accurate forecast of surface wind speed in mountainous regions.

Estimating Sea Surface Temperature Change after Tide Embankment Construction using Landsat Data (방조제 건설에 의한 해수면 온도 변화 추정)

  • Shin, Dong-Hoon;Lee, Kyoo-Seock
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.4
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    • pp.224-232
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    • 2006
  • This study investigates to detect Sea Surface Temperature (SST) and land cover change after tide embankment construction using Landsat Thematic Mapper (TM) Thermal Infrared (TIR) band data at Shihwa Lake and surrounding area. SST measurement is important for studies of both the structure of the ocean and as the thermal boundary between the ocean and the atmosphere. Since 1970s, the derivation of SST by satellite remote sensing (RS) has been applied to earth surface using Advanced Very High Resolution Radiometer (AVHRR) and Landsat TM. However, AVHRR has restriction in deriving SST in the area whose shoreline is complicated like western coast in South Korea because of coarse spatial resolution. The TIR band of TM images can be used to detect SST change whose shoreline is complicated and narrow like the study site. Thus, multi-temporal TM images were used for SST change detection in this study.

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Efficient Polynomial Multiplication in Extension Field GF($p^n$) (확장체 GF($p^n$)에서 효율적인 다항식 곱셈 방법)

  • Chang Namsu;Kim Chang Han
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.5 s.335
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    • pp.23-30
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    • 2005
  • In the construction of an extension field, there is a connection between the polynomial multiplication method and the degree of polynomial. The existing methods, KO and MSK methods, efficiently reduce the complexity of coefficient-multiplication. However, when we construct the multiplication of an extension field using KO and MSK methods, the polynomials are padded with necessary number of zero coefficients in general. In this paper, we propose basic properties of KO and MSK methods and algorithm that can reduce coefficient-multiplications. The proposed algorithm is more reducible than the original KO and MSK methods. This characteristic makes the employment of this multiplier particularly suitable for applications characterized by specific space constrains, such as those based on smart cards, token hardware, mobile phone or other devices.

Automatic generation of higher level design diagrams (상위 수준 설계 도면의 자동 생성)

  • Lee, Eun-Choul;Kim, Kyo-Sun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.11
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    • pp.23-32
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    • 2005
  • The automatic generation of circuit diagrams has been practically used in the HDL based design for decades. Nevertheless, the diagrams became too complicated for the designers to identify the signal flows in the RTL and system level designs. In this paper, we propose four techniques to enhance the roadability of the complicated diagrams. They include i) the transformation of repetitive instances and terminals into vector forms, ii) an improved loop breaking algorithm, iii) a flat tap which simplifies the two level bus ripping structure that is required for the connection of a bundle net to multiple buses, and iv) the identification of block strings, and alignment of the corresponding blocks. Towards validating the proposed techniques, the diagrams of an industrial strength design m generated. The complexity of the diagrams has been reduced by up to $90\%$ in terms of the number of wires, the aggregate wire length, and the area.

A Study on the ARQ base Relay Selection Scheme of the Cooperation-OFDM Protocol in the Wireless Sensor Network (무선 센서 네트워크에서 협력-OFDM 프로토콜의 ARQ 기반 중계 노드 선택 기법에 관한 연구)

  • Hong, Seong-Wook;Kong, Hyung-Yun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.1
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    • pp.95-101
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    • 2009
  • Wireless Sensor Network (WSN) has limited power and bandwidth. In order to high data rate and high speed communication systems are required. Cooperative communication system can help to decrease power consumption through spatial diversity. In cooperative transmission, one partner node assists one sensor node to transmit their data to destination. Instead of using M partners for M sensor nodes, we propose 1 partner for M sensor nodes. And we proposed relay selection scheme base on ARQ. Proposed protocol offers higher diversity order as conventional one with much less bandwidth and power. The destination will consider the one packets received from the best relay to reduce the complexity of the system. We verified BER performance for the proposed protocol through Monte-Carlo simulation over Rayleigh fading plus AWGN.

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A New Residual Attention Network based on Attention Models for Human Action Recognition in Video

  • Kim, Jee-Hyun;Cho, Young-Im
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.1
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    • pp.55-61
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    • 2020
  • With the development of deep learning technology and advances in computing power, video-based research is now gaining more and more attention. Video data contains a large amount of temporal and spatial information, which is the biggest difference compared with image data. It has a larger amount of data. It has attracted intense attention in computer vision. Among them, motion recognition is one of the research focuses. However, the action recognition of human in the video is extremely complex and challenging subject. Based on many research in human beings, we have found that artificial intelligence-like attention mechanisms are an efficient model for cognition. This efficient model is ideal for processing image information and complex continuous video information. We introduce this attention mechanism into video action recognition, paying attention to human actions in video and effectively improving recognition efficiency. In this paper, we propose a new 3D residual attention network using convolutional neural network based on two attention models to identify human action behavior in the video. An evaluation result of our model showed up to 90.7% accuracy.

Bias-Based Predictor to Improve the Recommendation Performance of the Rating Frequency Weight-based Baseline Predictor (평점 빈도 가중치 기반 기준선 예측기의 추천 성능 향상을 위한 편향 기반 추천기)

  • Hwang, Tae-Gyu;Kim, Sung Kwon
    • Journal of KIISE
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    • v.44 no.5
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    • pp.486-495
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    • 2017
  • Collaborative Filtering is limited because of the cost that is required to perform the recommendation (such as the time complexity and space complexity). The RFWBP (Rating Frequency Weight-based Baseline Predictor) that approximates the precision of the existing methods is one of the efficiency methods to reduce the cost. But, the following issues need to be considered regarding the RFWBP: 1) It does not reduce the error because the RFWBP does not learn for the recommendation, and 2) it recommends all of the items because there is no condition for an appropriate recommendation list when only the RFWBP is used for the achievement of efficiency. In this paper, the BBP (Bias-Based Predictor) is proposed to solve these problems. The BBP reduces the error range, and it determines some of the cases to make an appropriate recommendation list, thereby forging a recommendation list for each case.

Social Distance between Foreign Workers and Koreans : From Foreign Workers' Viewpoint

  • Kim, Seok-Ho;Kim, Sang-Uk;Han, Ji-Eun
    • Korea journal of population studies
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    • v.32 no.2
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    • pp.115-140
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    • 2009
  • 이 연구는 외국인 노동자들의 한국문화에 대한 적응문제를 살펴 보기 위하여 그들이 한국인들에 대하여 가지고 있는 사회적 거리감(social distance)을 분석하고 있다. 사회적 거리감은 인종 간 상호 관계 연구에서 중요한 개념으로 다루어져 왔으며, 특히 사회적응 수준을 드러내는 효과적인 척도로 각광받아왔다. 이 연구는 한국내 외국인 노동자들의 한국인에 대한 사회적 거리감의 결정요인을 규명하려는 목적을 가지고 있다. 서울과 경기 지역에서 수집된 자료에 대한 다중회귀분석(OLS Regression)을 통하여, 이 연구는 서구 사회에서 다수 인종의 사회적 거리감을 효과적으로 설명하는 것으로 판명된 요인들이 한국의 소수 인종인 외국인노동자들에게도적용될수있는가를살펴본다. 구체적으로는 연령, 성, 교육, 종교, 인종과 같은 사회인구학적 변수들과 한국인과의 접촉정도 가사회적 거리감에 유의미한 효과가 있는지 분석된다. 둘째, 이 연구는 외국인 노동자들의 가장 중요한 삶의 공간인 작업장에서의 경험과 관련된 변수들이 사회적 거리감에 대하여 가지는 효과를 탐구한다. 셋째, 구조방정식 모형(Structural Equation Model)의 적용을 통하여, 이 연구는 다중회귀에서 분석된 여러 설명 변수들 간의 복잡한 인과구조를 규명하고, 이들이 사회적 거리감에 미치는 영향을 직접효과, 간접효과, 전체효과로 나누어 살펴본다. 다중회귀분석 결과는 집단 간 사회적 거리감은 사회인구학적 변수들, 한국인들과의 접촉, 작업장 내 경험등 다양한 요인들의 복합적인 결과물이라는 점을 확인해 준다. 특히 분석결과는 작업장에서의 경험과 느낌이 한국 내 외국인 노동자들의 한국인들에 대한사회적거리감형성에결정적이라는사실을보여주는반면, 기존연구에서 효과적인 것으로 판명된 전통적 요인들은 영향력이 미미하다는 점을 말해준다. 한편, 구조방정식 모형을 적용한 분석결과는 한국인 친구들과의 접촉과 이해하기 쉽고 구체적인 노동조건이 사회적 거리감에 직접적으로 영향을 주고 있다는 것을 보여 준다. 한편 추상적인 노동조건은 사회적 거리감에 간접적으로 영향을 미친다. 상사에 대한 평가와 직무만족은 노동조건에 의해 유의미한 영향을 받지만, 한국인 친구와의 접촉과는 관련이 없다. 간단히 말해, 상사에 대한 평가와 직무만족은 노동조건이 사회적거리감에 대하여 가지는 효과를 매개한다. 결론적으로, 구조방정식모형의 분석결과는 작업장 관련 변수들간에 복잡한 인과구조가 존재한다는 점과 작업장 내 경험이 한국인에 대한 사회적 거리감 형성에 가장 중요하다는점을 확인해 준다.