• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.10
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• pp.49-54
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• 2007

As digital contents based on 3D graphics are increased, the requirement for low power 3D graphic hardware for mobile devices is increased. We design a transformation engine for mobile 3D graphic processor. We propose a simplified transformation engine for mobile 3D graphic processor. The area of the transformation engine is reduced by merging a mapping transformation unit into a projective transformation unit and by replacing a clipping unit with a selection unit. It consists of a viewing transformation unit a projective transformation unit a divide by w nit, and a selection unit. It can process 32 bit floating point format of the IEEE-754 standard or a reduced 24 bit floating point format. It has a pipelined architecture so that a vertex is processed every 4 cycles except for the initial latency. The RTL code is verified using an FPGA.

• Biomedical Science Letters
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• v.6 no.1
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• pp.1-9
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• 2000

To identity the genes responsible for the biosynthesis of exopolysaccharide, recombinant plasmids pUEX10 and pLEX10 were constructed from plasmid pLEX3 which was isolated from the recombinant cosmid library of Zoogloea ramigera 115. The complete nucleotide sequence of the 1.7 kb genomic DNA insert in plasmid pUEX10 was determined. Its analysis identified two open reading frames (ORF3 & ORF4) which could encode two proteins. The amino acid sequence derived from ORF3 showed the homology with gumC protein in Xanthomonas campestris as well as exoP protein in Rhizobium melizoti. The partial amino acid sequence of ORF4 showed the homology with polysaccharide export protein in Thermotoga maritima. Z. ramigera 115SLR and Z. ramigera 115SLR/pLEX10 showed the similar pattern for EPS production. Yield of exopolysaccharides produced by Z. ramigera 115SLR and Z. ramigera 115SLR/pLEX10 was 0.26% (w/v) and 0.16% (w/v), respectively.

• Journal of the Korea Society of Computer and Information
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• v.11 no.2 s.40
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• pp.169-175
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• 2006

In this paper we propose a method of reconstruction of cylindrical panorama using simplified projective transform from the panning image on the fixed camera. For the practical construction of cylindrical panorama we consider the rotation of the camera on the Y-axis only, even though considering the rotation components on all of the X,Y,Z axis on three-dimensional space for projective transform between general panoramas. The restriction mentioned above simplifies projective transform with existing 8 degrees of freedom into the one with 4 degrees of freedom. In the results, overall computation for projective transform can be decreased to the great extents in quantify, because the number of corresponding points required for inducing the transforming formula is gone down by half. Proposed algorithm from the simulation carried out in this paper shows similar performance and decreased computational quantity compared with existing algorithm. Also, it shows the construction of cylindrical panorama using simplified projective transform.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.3
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• pp.223-232
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• 1995

Abstract Urea($(NH_2)_2CO$) and THAMP (Tris(hydroxymethyl) aminomethane phosphate) are new organic nonlinear optical materials (NLO) for the device application such as the frequency conversion of laser radiation. The single crystals of urea and THAMP have been grown by the falling temperature method and the temperature difference method. The crystal growth parameters were presented associated with the molphology of the grown crystals. Based on the solubility measurements, methanol was a suitable solvent for the growth of urea. The solubilities of urea have a positive temperature coefficient and the heat of solution of urea was estimated to be -2.58 kcal/mol. The grown crystals of urea have the preferential growth habit in the z-axis. Additives such as $NH_4_H_2PO_4$, KCL, $H_3PO_4$, $CaCl_2{\cdot}2H_2O$, $C_2H_5OH$ were used for the favourable growth in the x - and y-axis and the preventive growth in the z-axis. The moleratio of THAM and H3P04 for the solution of THAMP was 1 : 1. The solubilities of THAMP have a positive temperature coefficient. The heat of solution was estimated to be - 1.70 kcal/ mol.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.321-321
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• 2013

열전재료는 열과 전기의 변환이 상호 가역적으로 일어나는 현상을 갖는 재료로서, 사용온도별로 여러 가지 재료가 개발되고 있다. 중온 영역에서 우수한 열전특성을 보이는 skutterudite는 격자 내에 2개의 공극을 갖고 있고 이에 적절한 원자를 충진하여 포논산란을 유도하고, PGEC(phonon-glass and electron-crystal) 개념을 적용하여 재료의 열적인 성질과 전기적인 성질을 동시에 제어함으로써 열전성능의 향상을 도모할 수 있는 재료이다. 본 연구에서는 챔버 내부 기체를 연속적으로 뽑아내어 진공도를 유지하는 방식이 아닌, 석영관을 앰플화한 진공밀폐 용해법을 사용하였다. 진공밀폐 용해법은 성분원소의 산화와 휘발을 억제하는데 있어 매우 유용한 공정이다. 용해를 통해 얻어진 잉곳을 용해와 동일한 방법으로 석영관에 밀봉하여 873 K에서 100시간 동안 진공열처리를 실시하였다. 또한, 합성된 잉곳의 기계적 특성 향상을 위해 $75{\mu}m$ 이하로 파쇄하여 진공 열간 압축 소결하였다. La가 충진된 $La_zCo_4Sb_{12}$ Skutterudites 단일상을 합성하여 La의 충진량(z)에 따른 열전특성과 전자이동특성을 조사하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.05a
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• pp.1-4
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• 1995

The most of conventional ultrasonic transducers are constructed to generate either longitudinal or shear waves, but not both of them. We investigated the mechanism of dual mode transducers that generates both of the longitudinal and shear waves simultaneously with a single PZT element. The study has been aimed to find the desired cut by the examining the piezoelectric properties. Theory predicts that a mixed P/S mode transducer can be constructed using a related Z-cut of a PZT ceramics. We studied the performance of a PZT element as a function of its rotation angle so that its efficiency is optimized to excite the two waves equally strongly. The results are verified by checking the impedance variation of the element with Finite Element Methods, and chocking the wave form by pulse-echo test simulation. Based upon the theory a rotated Z-cut was prepared and a transducer were fabricated. Validity of the theory calculation is verified through the

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.6
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• pp.554-562
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• 1987

In this paper, we have proposed the RC Wien-Bridge oscillator consisting of three oprational amplifiers in order to improve the frequency range, and the proposed oscillator has been realized a new SC Wien-Bridge oscillator for LSI realization by the forward Z transform method. The realized SC oscilltor has been affirmed that the frequency range has been improved more than Reddy's. Budak and Nay's by the analysis of pole loci as a frequency function f. Also, it has been confirmed that the designed SC oscillator has been satisfied substantially the oscillated condition by the open-loop measurements.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.2
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• pp.193-199
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• 2017

In this paper, we proposed an architecture of error detection in $Z_N$ operations using $Z_{(2^r-1)N}$. The error detection can be simply constructed in hardware. The hardware overheads are only 50% and 1% with respectively space and time complexity. The architecture is very efficient because it is detection 99% for 1 bit fault. For 2 bit fault, it is detection 99% and 50% with respective r=2 and r=3.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1713-1716
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• 2005

최근 3 차원 그래픽 영상의 복잡도가 점점 증가함에 따라, 가시성 선별에 관련된 연구는 3 차원 렌더링 프로세서 설계에 있어서 중요한 핵심 연구 중 하나가 되었다. 본 논문에서는 기존의 픽셀 캐쉬의 정보를 이용하여 가시성 선별을 수행하는 새로운 래스터라이제이션 파이프라인을 제안하고 있다. 제안 구조에서는 가시성 정보를 관리하기 위해서 계층적 z-버퍼 (HZB)와 같이 규모가 큰 별도의 하드웨어를 추가하지 않고, 픽셀 캐쉬에 저장되어 있는 데이터를 참조하여 주사 변환 과정에서 가시성 선별을 수행하고 있다. 캐쉬에서 접근 참조 실패된 프리미티브에 대해서는 픽셀 래스터라이제이션 파이프라인의 z-테스트 과정에서 은면 제거를 수행하도록 하였고, 선 인출 기법을 적용하여 픽셀 캐쉬의 접근 실패에 따른 손실을 줄여주었다. 실험 결과, 제안 구조는 일반 픽셀 파이프라인 구조에 비해 약 32%, HZB 구조에 비해 약 7%의 성능 향상을 보이고 있다.

• Proceedings of the KOSOMBE Conference
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• v.1989 no.05
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• pp.55-59
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• 1989

A true three-dimensional cone-beam reconstruction (TTCR) algorithm for the complete sphere geometry is derived, which is applicable to the direct volume image reconstruction from 2-D cone-beam projections. The algorithm is based on the modified filtered backprojection technique which uses a set of 2-D space-invariant filters and is derived from the previously developed parallel-beam true three-dimensional reconstruction(TTR) algorithm. The proposed algorithm proved to be superior in spatial resolution compared with the parallel-beam TTR algorithm.