• IEIE Transactions on Smart Processing and Computing
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• 제5권4호
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• pp.289-293
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• 2016

As more mobile devices are equipped with multi-core CPUs and are required to execute many compute-intensive multimedia applications, it is important to optimize the systems, considering the underlying parallel hardware architecture. In this paper, we implement and optimize ray-tracing application tailored to a given mobile computing platform with multiple heterogeneous processing elements. In this paper, a lightweight ray-tracing application is specified and implemented in Kahn process network (KPN) model-of-computation, which is known to be suitable for the description of real-time applications. We take an open-source C/C++ implementation of ray-tracing and adapt it to KPN description in the Distributed Application Layer framework. Then, several possible configurations are evaluated in the target mobile computing platform (Exynos 5422), where eight heterogeneous ARM cores are integrated. We derive the optimal degree of parallelism and a suitable distribution of the replicated tasks tailored to the target architecture.

• 한국세라믹학회지
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• 제53권2호
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• pp.150-161
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• 2016

The conventional brick-layer model is not satisfactory either in theory or in practice for the description of dispersive responses of polycrystalline solid electrolytes with current-constriction effects at the grain boundaries. Parallel networks of complex dielectric functions have been shown to successfully describe the AC responses of polycrystalline sodium conductors over a wide temperature and frequency range using only around ten model parameters of well-defined physical significance. The approach can be generally applied to many solid electrolyte systems. The present work illustrates the approach by simulation. Problems of bricklayer model analysis are demonstrated by fitting analysis of the simulated data under experimental conditions.

• 환경생물
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• 제39권2호
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• pp.156-159
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• 2021

Arcuphantes catillus n. sp., a new species of the genus Arcuphantes Chamberlin and Ivie, 1943 is described from Korea. The present species is distinguishable from its known similar congeners by a conspicuous proximal process and a blunt lateral process of the paracymbium, feathery tipped lamellar extension of the pseudolamella, and bowl-like posterior part of radix. The present new species was collected from the leaf litter layer of mixed forest on a hillock around rice fields with a pitfall trap.

• Journal of the Optical Society of Korea
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• 제15권3호
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• pp.209-215
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• 2011

A new iterative algorithm is developed to estimate LIDAR ratio for a thin cirrus cloud over an aerosol layer. First, the thin cirrus cloud is screened out and replaced by a modeled LIDAR signal and the extinction coefficients of the aerosol layer are derived using the Fernald backward method. These aerosol coefficients are referred as the "actual values". Second, the original LIDAR signal which includes the thin cirrus cloud is also inverted by the Fernald backward method down to the aerosol layer but using different LIDAR ratio for the thin cirrus cloud. Depending on the different assumptions about the LIDAR ratio of the thin cirrus cloud, different sets of aerosol extinction can be derived. The "actual values" which are found in the first step can be used to constrain this iterative progress and the correct LIDAR ratio of the thin cirrus cloud can be found. The detailed description of this method and retrieval examples are given in the paper. The cases compared with other methods are presented and the statistical result is also shown and agrees well with other studies.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.11-14
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• 2001

In all Rapid Prototyping(RP) processes, computer-aided design(CAD) solid model is sliced into thin layers of uniform, but not necessarily constant, thickness in the building direction. Each cross-sectional layer is successively deposited and, at the same time, bonded onto the previous layer, the stacked layers form a physical part of the model. The objective of this study is to develop a method for obtaining necessary coordinates$(x,\;y,\;\theta_x,\;\theta_y)$ to position linear hotwire of the cutting system in three-dimensional space for the Variable Lamination Manufacturing process (VLM-S), which utilizes expandable polystyrene foam sheet as part material. In order to examine the applicability of the developed method to VLM-S, various three-dimensional shapes, such as a spanner, a patterned columm, and a pyramid were made using data obtained from the method.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제7권2호
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• pp.109-120
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• 2001

본 논문에서는 최적의 성능을 갖는 병렬프로그램 개발을 위한 도구로 이식성, 확장성, 효율성을 고려한 성능가시화 프레임워크의 설계 및 구현을 제시한다. 본 프레임워크는 독립적으로 개발 가능한 인스트루멘테이션 층, 인터페이스 층 그리고 가시화 층으로 이루어진 계층구조를 갖도록 설계되었다. 인스트루멘테이션 층은 사건(event) 포획을 위한 라이브러리인 ECL(Event Capture Library)로 구성되며, 인터페이스 층은 인스트루멘테이션 층과 가시화 층 간에 문제중심의 인터페이스를 제공하기 위해 개발된 EDL/JPAL(Event Description Language/Jave Problem-oriented trace Access Library)로 구성되었다. 또한 가시화 층은 뷰와 필터의 추가, 수정 및 custom 뷰 그룹의 구성이 용이하도록 plug and play 스타일로 설계되었다. 이렇게 구현된 성능 가시화 프레임워크는 독립된 도구로서 뿐만 아니라 프로그래밍, 디버깅 그리고 성능분석이 통합된 병렬프로그램 개발환경의 핵심도구로 사용될 수 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권1호
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• pp.52-68
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• 2019

Aiming at the optimal placement of communication relay nodes (OPCRN) problem in manned/unmanned aerial vehicle cooperative engagement system, this paper designed a kind of fully connected broadband backbone communication topology. Firstly, problem description of OPCRN was given. Secondly, based on problem analysis, the element attributes and decision variables were defined, and a bi-level programming model including physical layer and logical layer was established. Thirdly, a hierarchical artificial bee colony (HABC) algorithm was adopted to solve the model. Finally, multiple sets of simulation experiments were carried out to prove the effectiveness and superiority of the algorithm.

• 방송공학회논문지
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• 제24권3호
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• pp.401-410
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• 2019

본 논문에서는 SHVC 부호화 성능 개선을 위하여 딥러닝 기반 계층간 예측을 위한 참조 픽처 생성 방법을 제안한다. 새로운 참조 픽처를 생성하기 위하여 DCT-IF기반 업샘플링 된 픽처를 VDSR 네트워크를 이용한 필터링을 진행하는 구조와 SHVC 계층간 참조 픽처를 생성하기 위한 트레이닝 방법에 대해 설명한다. 제안하는 방법은 SHM 12.0 기반으로 구현되어 있다. 성능 평가를 위하여 사전 학습을 이용하여 계층간 예측 픽처를 생성하는 방법과 비교를 진행하였다. 그 결과 상위 계층의 부호화 성능은 사전 학습을 이용한 방법 대비 최대 13.14%의 비트 감소, SHM 대비 최대 15.39%의 비트 감소율을 보였고, 평균 6.46%의 비트 감소율을 보였다.

• 천문학회보
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• 제40권1호
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• pp.70.3-70.3
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• 2015

After a short description of the telescope, we will report on the recent developments in three main areas: - Commissioning of the last of LBT's first generation instruments, now well underway, - Adaptive Optics (AO) and ground-layer AO progress and planned upgrades, - Interferometry first science results. We will also explore the future of the facility as it moves to full operation and strive to be the first of the ELTs in the decade-long window in which GMT, TMT, and E-ELT break ground and start taking shape.

• 한국통신학회논문지
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• 제18권5호
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• pp.650-662
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• 1993

본 논문은 ISO 8073과 ADDENDUM 2 프로토콜에 의해 규정되는 CLNS위에 작용하는 트랜스포트 레이어의 테스트와 구현을 설명하였다. 트렌스포트 레이어의 구현을 위해, 다섯개의 모듈과 인터페이스 프리미티브가 정의되었다. 이 프로토콜은 정식으로 SDL이라 칭하고 C언어로 프로그램 되었다. 소프트웨어 검증을 위해, 프로토콜 테스트가 정의되고 테스트 시나리오가 정의되었다. 검증은 테스트 시나리오를 기초로 구현되었다. 본 논문에 나타난 트랜스포트 레이어 소프트웨어는 약간의 변조로 실상황에서 사용되어 진다. 이 논문에 나타난 프로토콜 테스터는 또한 다른 프로토콜 테스터의 검증을 위해 사용된다.