• Journal of Mechanical Science and Technology
• /
• 제17권11호
• /
• pp.1746-1755
• /
• 2003

Operating characteristics of a triple pressure reheat HRSG are analyzed using a commercial software package (Gate Cycle by GE Enter Software). The calculation routine determines all the design parameters including configuration and area of each heat exchanger. The off-design calculation part has the capability of simulating the effect of any operating parameters such as power load, process requirements, and operating mode, etc., on the transient performance of the plant. The arrangement of high-temperature and intermediate-temperature components of the HRSG is changed, and its effect on the steam turbine performance and HRSG characteristics is examined. It is shown that there could be a significant difference in HRSG sizes even though thermal performance is not in great deviation. From the viewpoint of both economics and steam turbine performance, it should be carefully reviewed whether the optimum design point could exist. Off-design performance could be one of the main factors in arranging components of the HRSG because power plants operate at various off-design conditions such as ambient temperature and gas turbine load, etc. It is shown that different heat exchanger configurations lead to different performances with ambient temperature, even though they have almost the same performances at design points.

• Structural Engineering and Mechanics
• /
• 제65권6호
• /
• pp.771-784
• /
• 2018

This study aims to investigate the stochastic response of isolated and non-isolated highway bridges subjected to spatially varying earthquake ground motion model. This model includes wave passage, incoherence and site response effects. The wave passage effect is examined by using various wave velocities. The incoherency effect is investigated by considering the Harichandran and Vanmarcke coherency model. The site response effect is considered by selecting homogeneous firm, medium and soft soil types where the bridge supports are constructed. The ground motion is described by power spectral density function and applied to each support point. Triple concave friction pendulum (TCFP) bearing which is more effective than other seismic isolation systems is used for seismic isolation. To implement seismic isolation procedure, TCFP bearing devices are placed at each of the support points of the deck. In the analysis, the bridge selected is a five-span featuring cast-in-place concrete box girder superstructure supported on reinforced concrete columns. Foundation supported highway bridge is regarded as three regions and compared its different situation in the stochastic analysis. The stochastic analyses results show that spatially varying ground motion has important effects on the stochastic response of the isolated and non-isolated bridges as long span structures.

• 디지털산업정보학회논문지
• /
• 제8권3호
• /
• pp.133-145
• /
• 2012

This paper describes the high density discrete wavelet transformation which is one that expands an N point signal to M transform coefficients with M > N. The double-density discrete wavelet transform is one of the high density discrete wavelet transformation. This transformation employs one scaling function and two distinct wavelets, which are designed to be offset from one another by one half. And it is nearly shift-invariant. Similarly, triple-density discrete wavelet transformation is a new set of dyadic wavelet transformation with two generators. The construction provides a higher sampling in both time and frequency. Specifically, the spectrum of the first wavelet is concentrated halfway between the spectrum of the second wavelet and the spectrum of its dilated version. In addition, the second wavelet is translated by half-integers rather than whole-integers in the frame construction. This arrangement leads to high density wavelet transformation. But this new transform is approximately shift-invariant and has intermediate scales. In two dimensions, this transform outperforms the standard and double-density discrete wavelet transformation in terms of multiple directions. Resultingly, the proposed wavelet transformation services good performance in image and video processing fields.

• Bulletin of the Korean Chemical Society
• /
• 제22권8호
• /
• pp.903-908
• /
• 2001

The gene aeg-46.5, which is expressed under anaerobic condition, has putative triple -10 regions and four transcription start sites. The mRNA transcription level and its start point change depending on the aerobic/anaerobic growth condition. RNA polymerase and its regulatory proteins must choose which of three -10 region to use. The putative triple 10 region was mutated to make only one of them function with consensus -10 region sequence (TATAAT) and the other two as non-functional region. The results show that the second and third -10 regions are used for the aerobic/anaerobic expression. The third -10 region is responsible for the high aerobic to anaerobic switch ratio. This suggests that only the last two of the putative triple -10 region have functions on aeg-46.5 gene expression switch control. The phenotype of the mutated promoter was tested in the wild type cell and narL - cell. The results indicate that the control by NarL is independent from the selection of -10 region. The expression patterns on multi-copy plasmids and on single-copy chromosome were compared. These results show that the aerobic/anaerobic switch control of aeg-46.5 is through the choice of -10 region. The mechanism of choosing different -10 region remains to be seen.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2013년도 추계학술대회
• /
• pp.346-349
• /
• 2013

본 논문에서는 MPPT(Maximum Power Point Tracking) 제어기능을 갖는 빛, 진동 그리고 열 에너지를 이용한 삼중입력 에너지 하베스팅 회로를 설계하였다. 설계된 회로는 MPPT 제어를 통해 솔라셀과 압전소자 그리고 열전소자로부터 최대 가용 전력을 수확하고, 수확된 에너지를 저장 커패시터에 병합하여 저장한다. 병합된 에너지는 PMU(Power Management Unit)를 통해 센서노드로 공급된다. MPPT 제어는 변환소자의 개방회로전압과 MPP(Maximum Power Point) 전압간의 비례관계를 이용하여 구현하였다. 제안된 회로는 $0.18{\mu}m$ CMOS 공정으로 설계하였으며, 모의실험을 통해 동작을 검증하였다. 설계된 에너지 하베스팅 회로의 칩 면적은 $945{\mu}m{\times}995{\mu}m$이다.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2007년도 추계 학술대회논문집
• /
• pp.232-235
• /
• 2007

A comprehensive numerical study was carried out to identify the on-set condition of the cell structures of oblique detonation waves (ODWs). Mach 7 incoming flow was considered with all other flow variables were fixed except the flow turning angles varying from 35 to 38. For a given flow conditions theoretical maximum turning angle is $38.2^{\circ}$ where the oblique detonation wave may be stabilized. The effects of grid resolution were tested using grids from $255{\times}100$ to $4,005{\times}1,600$. The numerical smoked foil records exhibits the detonation cell structures with dual triple points running opposite directions for the 36 to 38 turning angles. As the turning angle get closer to the maximum angle the cell structures gets finer and the oscillatory behavior of the primary triple point was observed. The thermal occlusion behind the oblique detonation wave was observed for the $38^{\circ}$ turning angle.

• Journal of Mechanical Science and Technology
• /
• 제19권8호
• /
• pp.1554-1567
• /
• 2005

When multiple robotics systems with several sub-chains grasp a common object, the inherent force redundancy provides a chance of utilizing internal loading. Analysis of grasping space based internal loading is proposed in this work since this method facilitates understanding the physical meaning of internal loadings in some applications, as compared to usual operational space based approach. Investigation of the internal loading for a triple manipulator has been few as ,compared to a dual manipulator. In this paper, types of the internal loading for dual and triple manipulator systems are investigated by using the reduced row echelon method to analyze the null space of those systems. No internal loading condition is derived and several load distribution schemes are compared through simulation. Furthermore, it is shown that the proposed scheme based on grasping space is applicable to analysis of special cases such as three-fingered and three-legged robots having a point contact with the grasped object or ground.

• 정보교육학회논문지
• /
• 제15권3호
• /
• pp.345-353
• /
• 2011

정보통신은 편리하기도 하지만 일면 심각한 부작용이 존재한다. 특히, 가치관이 정립되지 못한 초등학생들의 정보통신윤리 확립은 매우 중요한 과제라고 할 수 있다. 본 논문에서는 학생들이 가장 일반적으로 접하고 있는 대표적 방법인 수업을 통해 초등 정보통신윤리 교육수준을 제고하고자 3중 연계교수학습모형을 제안한다. 3중 연계교수학습모형은 임의의 수업모형 3가지를 선택하여 차시별로 내용을 연계하여 각각의 수업시간에 독립적으로 적용하는 형태이다. 수업모형 3가지는 수업자가 전달하고자 하는 내용에 맞게 선택 가능한 형태이다. 본 실험에서는 배려모형, 가정연계모형, 가상체험모형을 연계하였다. 실험은 동일한 조건 속에서 적용되는 모형을 달리하여 실행한다. 정보통신윤리 수준 제고에 미치는 교육적 효과를 비교 분석하여 3중 연계교수학습모형이 단일 교수학습 모형에 비하여 학생들의 정보통신윤리 함양 및 실천능력을 신장시키는데 유의미한 효과가 있음을 보이고 있다.

• Journal of Acupuncture Research
• /
• 제15권2호
• /
• pp.455-478
• /
• 1998

The result as following one was founded that investigate cause and acupuncture point for symptoms of headache; 1. Headache in distinction from doo-pung(頭風.) was defined that it' period is short and treatment is easy. 2. The cause of headache was classified according to the interior and exterior cause of the body. 3. Total number of used acupuncture point was one hundred and six, and in order of using time acupuncture point was appeared as LI4(15), LU7(12), GB20(12), BL2(11), GV20(9), TE23(9), SI3(7), GV24(7), GV23(7) 4. The meridian distribution of acupuncture point is appeared as Bladder Meridian(21points), Gallbladder Meridian(18points), Governer vesseI(14points), Triple Energizer meridian(12points), Large Intestine Meridian(9points), Small Intestine Meridian(7points), Stomach Meridian(7points) 5. According to headache position, the distribution of acupuncture point $Yangmy\check{o}ng\;Ky\check{o}ng$ and Governer vessel was used to frontal headache, Soyang $Ky\check{o}ng$ to migraine, Taeyang $Ky\check{o}ng$ and Governer vessel to occipital headache. 6. LI4(合谷) and LU7(列缺) was used to general headache as basic acupuncture point.

• 혜화의학회지
• /
• 제11권1호
• /
• pp.111-135
• /
• 2002

The result as following one was founded that investigate cause and acupuncture point for symptoms of headache, 1. Headache in distinction from doo-pung(頭風) was defined that it' period is short and treatment is easy. 2. The cause of headache was classified according to the interior and exterior cause of the body. 3. Total number of used acupuncture point was one hundred and six, and in order of using time acupuncture point was appeared as LI4(15), LU7(12), GB20(12), BL2(11), GV20(9), TE23(9), SI3(7), GV24(7), GV23(7) 4. The meridian distribution of acupuncture point is appeared as Bladder Meridian(21points), Gallbladder Meridian(18points), Governer vessel(14points), Triple Energizer meridian(12points), Large Intestine Meridian(9points), Small Intestine Meridian(7points), Stomach Meridian(7points) 5. According to headache position, the distribution of acupuncture point was appeared that $Yangmy\breve{o}ng$ $Ky\breve{o}ng$ and Governer vessel was used to frontal headache, Soyang $Ky\breve{o}ng$ to migraine, Taeyang $Ky\breve{o}ng$ and Governer vessel to occipital headache. 6. LI4(合谷) and LU7(列缺) was used to general headache as basic acupuncture point.