• Title/Summary/Keyword: Parallel Process

Search Result 1,462, Processing Time 0.03 seconds

A Study of the Photoelectrochemical Effects of Squaraine Aggregate in Monolayer (스쿠알렌 집합체의 광전기화학적 효과에 관한 연구)

  • Young Soon Kim;Kock-Yee Law;David G. Whitten
    • Journal of the Korean Chemical Society
    • /
    • v.37 no.7
    • /
    • pp.642-647
    • /
    • 1993
  • Monolayers of pure surfactant squaraine, DSSQ(4-distearyl amino phenyl-4'-dimethylaminophenylsquaraine), were deposited on $SnO_2 $ electrodes by the Langmuir-Blodgett film technique. The DSSQ film exhibits ${\lambda}_{max}$ at ∼530 nm. The absorption is significantly red-shifted from the solution of DSSQ (633 nm in chloroform), suggesting that the squaraine chromophores form aggregates in the LB film. The photogeneration of the squaraine aggregates is studied by measuring the photocurrents in photoelectrochemical cells consisting of the squaraine of the aggregates is found to parallel its absorption spectrum and quantum efficiency as high as 0.3% has been observed. While the photocurrent was attenuated exponentially when stearic acid layers (up to 8 layers) are inserted between the squaraine layer and the electrode, it is nearly extinguished when the squaraine layer is over-coated with 2 layers of stearic acid. A model for the observation is proposed and the roles of the electrolytes and oxygen on the photogeneration process will be discussed.

  • PDF

Numerical Simulation for the Variation of the Fiber Orientation Distribution according to the Flow of High-Flow Steel-Fiber Reinforced Mortar (고유동 강섬유보강 모르타르의 유동에 따른 섬유의 방향성 분포특성 변화의 예측)

  • Kang, Su-Tae;Kim, Jin-Keun
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.22 no.6
    • /
    • pp.639-646
    • /
    • 2009
  • High-flow steel-fiber reinforced mortar may induce a certain fiber orientation distribution in the process of placing and thus have an influence on the tensile properties. In this paper, the variation of the fiber orientation distribution according to the flow of high-flow steel-fiber reinforced mortar was estimated in numerical simulation. The analytical results present that the major variation of fiber orientation distribution is made within 150mm of flow distance, thereafter the tendency of the fiber orientation distribution is not noticeable even though the peak of distribution density in the orientation parallel to the flow direction get bigger along the distance. Considering the close relation between the fiber orientation and the tensile behavior of composite, prediction of fiber orientation distribution make it possible to predict the variation in the tensile behavior of high-flow steel-fiber reinforced mortar according to the flow.

A Simulation Study on Capacity Planning in Hybrid Flowshops for Maximizing Throughput Under a Budget Constraint (혼합흐름공정에서 예산제약하에 생산율을 최대화하는 용량계획에 관한 시뮬레이션 연구)

  • Lee, Geun-Cheol;Choi, Seong-Hoon
    • Journal of the Korea Society for Simulation
    • /
    • v.20 no.3
    • /
    • pp.1-10
    • /
    • 2011
  • In this study, we consider a capacity planning problem where the number of machines at each workstation is determined in manufacturing systems of top-edge electronic products such as semiconductor or display. The considered manufacturing system is the typical hybrid flowshop which has identical parallel machines at each workstation and the setup operation occurs when the types of consecutively processed products are different. The objective of the problem is finding good combinations of the numbers of machines at all workstations, under the given capital amount for purchasing machines. Various heuristic methods for determining the numbers of machines at workstations are proposed and the performances were tested through a series of computational experiments. In the study, a simulation model has been developed in order to simulate the considered manufacturing system with dynamic orders and complex process. The simulation model is also used for conducting the computational comparison test among various proposed methods.

Critical Comments on Akagki's Pediment Morphology in Korea (한국 Pediment 지형의 연구성과에 관한 비판과 문제점)

  • Park, No-Sik
    • Journal of the Speleological Society of Korea
    • /
    • no.68
    • /
    • pp.99-120
    • /
    • 2005
  • It is a wrong decision to use only topographic and geological maps for the study of pediment morphology in Korea. For the study of pediment morphology it is necessary to survey the earth structure by field techniques. In Korea, pediments are mostly found in granite areas with hardrock cover. But, pediments also developed in gneiss areas and what is worse in limestone areas. So, all areas in Korea developed pediment morphology. Only in South Korea pediments show a direction from south to north or from west to east. They developed only in right angles to each other, either parallel or in right angles to the strike, depending on the bedrock structure. Pediments are found in two levels. The upper level pediments are correlated with the lower level erosion surface. Besides this pediments are found in Hoenggye-ri of the Taegwolryong area in a third level 800m above sea level. The pediments developed in basins, at the lower margins of steep slopes dividing three levels of erosion surfaces and around the residual mountains on the erosion surfaces. The first belong to the early stage of pedimentation, the second to the middle stage and the third to the last stage. Also, in Korea monadnock and residual mountain have developed the pediments are correlated the slope of the hinter mountains. Akagki states that the only pedimentation times have been times of arid climate and that they are dissected by gulley erosion with climatic change, but writer's study proves that pedimentation takes place with eustatic movement, reckless defore-station and convectional rain. These facts indicate that the landforms, geological character and process of erosional cycle of the pediments in Korea resemble much those in the Chugoku Mountains of south wertern Japan, but they are larger in scale than those in the Chugoku Mountains. In conclusion, while Akagki emphasizes the geological character and climatic change in pedimentation, the writer studies prove that eustatic movements, especially the sea level rise after the Wurm age are important factors for pedimentation. Besides this the author's studies allow a classification of gentle slopes.

An Analysis of Gender Images of Fashion Style in BTS Music Videos Using Judith Butler's Performativity Theory (버틀러의 수행성 이론으로 본 BTS 뮤직비디오 패션스타일의 젠더 이미지 분석)

  • Jung, Yeonyi;Lee, Youngjae
    • Journal of Fashion Business
    • /
    • v.24 no.1
    • /
    • pp.88-101
    • /
    • 2020
  • The music videos of BTS go beyond the limit of media promoting music and shows their meaning in various ways and complete the visual message of music through fashion style. BTS' fashion style in the music videos shows a change in symbolic representation of the genre of each album and song, of which gender images are changing aligned with the music messages of BTS. The purpose of this study was to derive gender images of fashion style in BTS music videos and to interpret their meaning based on Judith Butler's theory that performativity creates discourse through iterative process. It is conducted as a research method, an analytical study was conducted in parallel with literature studies and empirical case analysis. The scope of the study was limited to 301 costumes that appeared in 21 official music videos from debut single album '2Cool 4 Skool' released in 2013 to the mini album 'Map of the Soul: Persona' released in 2019. As a result of the analysis, the controversial fashion style, challenging fashion style, boyish fashion style, hybrid fashion style, the playful fashion style were revealed. The conclusion of studying the gender image of BTS, interpreted by this analysis using Judith Butler's theory, is as follows. The gender image of BTS is the traditional image that identifies with the dominant gender discourse, the resistive gender image that intentionally distances mainstream culture, the eclectic image parodying the gender of the opposing term, and the deconstructive image that transcends the dominant gender discourse.

Frequency Dependent Properties of Tris(8-Hydroxyquinoline) Aluminum Thin Films

  • Lee, Yong-Soo;Park, Jae-Hoon;Choi, Jong-Sun
    • KIEE International Transactions on Electrophysics and Applications
    • /
    • v.11C no.3
    • /
    • pp.70-74
    • /
    • 2001
  • Admittance or impedance spectroscopy is one of the powerful tools to study dielectric relaxation and loss processes in organic and inorganic materials. In this study, the frequency dependent properties of an indium tin oxide/tris(8-hydroxyquinoline) aluminum($Alq_3$)/aluminum structure have been studied. The conductance of the $Alq_3$ film increases with the DC applied voltage up to 4V and decreases above 4V in the low frequency region. This indicates that the resistance of the device decreases with the applied bias due to the carrier injection enhancement, thereafter the injected carriers form the space charge and the additional injection of carriers is prevented. The Cole-Cole plot of the admittance takes a one-semicircle shape, which means that the device can be modeled as a parallel resistor-capacitor network. The resistance and capacitance were estimated as 8.62k${\Omega}$ and 2.7nF, respectively, at 3V in the low frequency region. The dielectric constant ( ${\epsilon}'$ ) of the $Alq_3$ film is independent of the frequency in the low frequency region below 100kHz, while the frequency dependency was observed at above 100kHz. The dielectric loss factor ( ${\epsilon}"$ ) of the $Alq_3$ film shows the dielectric dispersion below 100kHz and dielectric absorption in higher frequency domain. The dispersion is thought to be related to the hopping process of the carriers. The ${\epsilon}"$ is proportional to the reciprocal of the frequency. The dielectric relaxation time was extracted to about 0.318${\mu}s$ from the dielectric absorption spectrum.

  • PDF

A Design of Turbo Decoder using MAP Algorithm (MAP 알고리즘을 이용한 터보 복호화기 설계)

  • 권순녀;이윤현
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.7 no.8
    • /
    • pp.1854-1863
    • /
    • 2003
  • In the recent digital communication systems, the performance of Turbo Code using the mr correction coding depends on the interleaver influencing the free distance determination and the recursive decoding algorithms that is executed in the huh decoder. However, performance depends on the interleaver depth that needs many delays over the reception process. Moreover, turbo code has been blown as the robust coding methods with the confidence over the fading channel. International Telecommunication Union(ITU) has recently adopted it as the standardization of the channel coding over the third generation mobile communications(IMT­2000). Therefore, in this paper, we preposed the interleaver that has the better performance than existing block interleaver, and modified turbo decoder that has the parallel concatenated structure using MAP algorithm. In the real­time voice and video service over third generation mobile communications, the performance of the proposed two methods was analyzed and compared with the existing methods by computer simulation in terms of reduced decoding delay using the variable decoding method over AWGN and fading channels for CDMA environments.

Projection-based Performance Measurement Methodology of Session Initiation Protocol for the Next Generation Convergence Network (차세대 네트워크를 위한 프로젝션 기법 기반 SIP 성능 측정 방법론)

  • Lee, Kyou-Ho;Sung, Kil-Young
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.13 no.12
    • /
    • pp.2533-2540
    • /
    • 2009
  • Performance of processing protocols is one most important goal in a network or systems constituting the network. Measurement of performance, thus, is an essential element to not only establish the network but also develop systems. A projection in vector mathematics is the transformation of points and lines in one plane onto another plane by connecting corresponding points on the two planes with parallel lines. This is a method, as an application of vector mathematics, which is widely used in engineering as well to consider elements dedicated to the measurement object. This paper proposes a sound methodology for measuring the performance of the SIP protocol, which is based on the projection. The SIP protocol is a typical standard protocol for call-processing in the internet telephony of Next Generation Convergence Network. Owing to use the projected protocol which excludes unnecessary operation paths, the methodology can be effective in implementation and resource utilization. This paper also presents a process based on the proposed methodology to measure the performance of a SIP proxy server.

Study on the Connection with Public Authentication and Bio Authentication (공인인증서와 바이오인증 연계를 위한 연구)

  • Ryu, Gab-Sang
    • Journal of Internet of Things and Convergence
    • /
    • v.1 no.1
    • /
    • pp.39-44
    • /
    • 2015
  • Organization is increasing the authorizing process to use public certificate and bio information. Certificate, has evolved to be able to parallel distributes the bio authentication and portable bio-authentication device. Authentication using an individual's PC and smart devices continue to generalize, while convenience for authentication is increased by comparison Study on cooperation with the security at the network level's a weak situation. If ask authentication method through the cooperation of the public certificate and bio information work with current network access control, there is a possibility to develop a more powerful security policy. by cooperation weaknesses against vulnerable personal authentication techniques on security token in a reliable and secure personal authentication techniques, such as bio-recognition, Bio Information for identification and to prevent exposing a methodology suggest to validate whether or not to carry out in this paper. In addition, organize the scenario that can work with the 802.1x network authentication method, and presented a proposal aimed at realization.

Non-Photorealistic Rendering Using CUDA-Based Image Segmentation (CUDA 기반 영상 분할을 사용한 비사실적 렌더링)

  • Yoon, Hyun-Cheol;Park, Jong-Seung
    • KIPS Transactions on Software and Data Engineering
    • /
    • v.4 no.11
    • /
    • pp.529-536
    • /
    • 2015
  • When rendering both three-dimensional objects and photo images together, the non-photorealistic rendering results are in visual discord since the two contents have their own independent color distributions. This paper proposes a non-photorealistic rendering technique which renders both three-dimensional objects and photo images such as cartoons and sketches. The proposed technique computes the color distribution property of the photo images and reduces the number of colors of both photo images and 3D objects. NPR is performed based on the reduced colormaps and edge features. To enhance the natural scene presentation, the image region segmentation process is preferred when extracting and applying colormaps. However, the image segmentation technique needs a lot of computational operations. It takes a long time for non-photorealistic rendering for large size frames. To speed up the time-consuming segmentation procedure, we use GPGPU for the parallel computing using the GPU. As a result, we significantly improve the execution speed of the algorithm.