• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1999년도 유체기계 연구개발 발표회 논문집
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• pp.257-263
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• 1999

The flow characteristics of double suction pump are investigated by numerically Calculations are performed by using SIMPLE algorithm at the design and off-design points. Symmetric nature of flow fields in blade channels is discovered at design point, but asymmetirc effects are discovered at the off-design point. Numerical results show that the formation of secondary flow in volute of double suction pump shows different trends when compared with the case of single suction pump. Also results show that double vortices are formed in the volute cross section.

• 한국과학예술포럼
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• 제20권
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• pp.307-314
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• 2015

Tele-Gesture is a tangible user interface(TUI) device that allows a user to physically point to a 3D object in real life and have their gestures play back by a robotic finger that can point to the same object, either at the same time, or at another point in time. To understand the extent of the gestures as new way of digital collaborative communication, collaboration situation and types were experimented as TUI implementations. The design prototype reveals that there is a rich non-verbal component of communication in the form of gesture-clusters and body movements that happen in an digital communication. This result of analysis can contribute to compile relevant contributions to the fields of communication, human behavior, and interaction with high technology through an interpretive social experience.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.456-459
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• 2013

이안식 일체형 입체카메라는 줌인시 고정된 컨버전스포인트로 인해 촬영된 영상 시청시에 어지러움을 유발하는 시각적 불편이 발생할 수 있다. 본 논문에서는 이안식 일체형 입체카메라에서 줌인시 발생되는 시각적 불편을 방지하기 위해 컨버전스 포인트를 조정하는 기법을 제시한다. 포커스, 피사체 및 컨버전스포인트의 위치에 따른 관계모델을 제시하고 각각에 따라 컨버전스포인트를 조정하여 시각적 불편을 최소화하는 기법을 제안한다. 또한 제안한 기법을 실제로 구현하여 제시한 방법의 우수성을 입증한다.

• 한국축산식품학회지
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• 제39권1호
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• pp.114-120
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• 2019

Response surface methodology (RSM) is a useful set of statistical techniques for modeling and optimizing responses in research studies of food science. As a design for a response surface experiment, a central composite design (CCD) with multiple runs at the center point is frequently used. However, sometimes there exist situations where some among the responses at the center point are outliers and these outliers are overlooked. Since the responses from center runs are those from the same experimental conditions, there should be no outliers at the center point. Outliers at the center point ruin statistical analysis. Thus, the responses at the center point need to be looked at, and if outliers are observed, they have to be examined. If the reasons for the outliers are not errors in measuring or typing, such outliers need to be deleted. If the outliers are due to such errors, they have to be corrected. Through a re-analysis of a dataset published in the Korean Journal for Food Science of Animal Resources, we have shown that outlier elimination resulted in the increase of the maximum possible R-square that the modeling of the data can obtain, which enables us to improve the quality of response surface analysis.

• 디자인학연구
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• 18호
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• pp.189-197
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• 1996

POP광고에서 대한 접근은 여러 학자와 실무자들에 의해 행해져 왔다. 그러나 지금까지의 연구에서는 POP물에 대한 시각적, 디자인 적 측면이 과도하게 강조되어 왔거나 전체적 광고전략의 일부라는 시각보다 POP광고 자체만으로 파악하려는 태도가 주류를 이루었다. 그러나 POP광에 대한 심도 있는 이해를 위하여 POP광고도 커다란 마케팅 전략 중 광고전략의 일부로서 인식될 때 비로소 그 효용성 및 기능을 좀 더 정확히 파악할 수 있을 것이다. 과연 POP광고가 최대한의 효과를 거둘 수 있는 적절한 상황이 무엇이며, 어떤 상품 군에 좀 더 효과적일 수 있을지, 나아가 이러한 POP물은 충동구매와 어떤 관계가 있는지 등을 밝혀보는 것이 하나의 접근 방법으로서 바람직하다고 느껴진다. 본론에 들어가기 전에 기존 POP물의 기능과 역할에 대한 분류를 약술하고 비약적인 현대기술문명과 결합된 사례들도 찾아보았다. 본론은 충동구매에 대한 연구에 대부분이 할애되었다. 마지막으로 결론과 사례는 미국을 중심으로 한 선례 중에 그 일부를 임의로 선택하였다.

• The Journal of the Acoustical Society of Korea
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• 제16권1E호
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• pp.41-48
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• 1997

The very purpose of subband codec is the attainment of data rate compression through the use of quantizer and optimum bit allocation for each decimated signal. Yet the question of floating-point quantization effects in subband codec has received scant attention. There has been no direct focus on the analysis of quantization errors, nor on design with quantization errors embedded explicitly in the criterion. This paper provides a rigorous theory for the modelling, analysis and optimum design of the general M-band subband codec in the presence of the floating-point quantization noise. The floating-point quantizers are embedded into the codec structure by its equivalent multiplicative noise model. We then decompose the analysis and synthesis subband filter banks of the codec into the polyphase form and construct an equivalent time-invariant structure to compute exact expression for the mean square quantization error in the reconstructed an equivalent time-invariant structure to compute exact expression for the mean square quantization error in the reconstructed output. The optimum design criteria of the subband codec is given to the design of the analysis/synthesis filter bank and the floating-point quantizer to minimize the output mean square error. Specific optimum design examples are developed with two types of filter of filter banks-orthonormal and biorthogonal filter bank, along with their perpormance analysis.

• 한국정보통신학회논문지
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• 제4권1호
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• pp.105-113
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• 2000

디지털 통신시스템에 사용되는 파형 성형 필터를 고정소수점으로 설계하는 방법에 대하여 제시한다. 기존에는 설계가 간단한 RCF(Raised Cosine Filter) 또는 Root Squared RCF를 많이 사용했으나 대역제한 특성이 나쁘고 부동소수점 계수로 설계되는 단점이 있다. 본 논문에서는 혼합 선형계획법을 이용하여 고정소수점 파형 성형 필터를 설계하는 방법을 제시하구 정합 필터로 사용하기 위한 Root Squared 형태에 대해서도 소개한다. 몇 개의 설계 예제를 통하여 제안된 설계 방식이 기존의 RCF나 Root Squared RCF와 비교하여 동일한 성능에서 20%이상 간단히 설계가 가능함을 보이고 있다. 특히 급격한 대역제한이 요구되는 IS-95와 같은 무선 통신시스템에서 표준 필터보다 ISI가 75%이상 개선된 결과를 제시하고 있다.

• Journal of Power Electronics
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• 제12권1호
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• pp.164-171
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• 2012

Variable step size maximum power point trackers (MPPTs) are widely used in photovoltaic (PV) systems to extract the peak array power which depends on solar irradiation and array temperature. One essential factor which judges system dynamics and steady state performances is the scaling factor (N), which is used to update the controlling equation in the tracking algorithm to determine a new duty cycle. This paper proposes a novel stability study of variable step size incremental resistance maximum power point tracking (INR MPPT). The main contribution of this analysis appears when developing the overall small signal model of the PV system. Therefore, by using linear control theory, the boundary value of the scaling factor can be determined. The theoretical analysis and the design principle of the proposed stability analysis have been validated using MATLAB simulations, and experimentally using a fixed point digital signal processor (TMS320F2808).

• Journal of Computational Design and Engineering
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• 제3권4호
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• pp.322-329
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• 2016

The advent of high-performance terrestrial laser scanners has made it possible to capture dense point-clouds of engineering facilities. 3D shape acquisition from engineering facilities is useful for supporting maintenance and repair tasks. In this paper, we discuss methods to reconstruct box shapes and polygonal prisms from large-scale point-clouds. Since many faces may be partly occluded by other objects in engineering plants, we estimate possible box shapes and polygonal prisms and verify their compatibility with measured point-clouds. We evaluate our method using actual point-clouds of engineering plants.

• Journal of Computational Design and Engineering
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• 제1권4호
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• pp.223-232
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• 2014

This paper describes a variant of the extended Gaussian image based registration algorithm for point clouds with surface color information. The method correlates the distributions of surface normals for rotational alignment and grid occupancy for translational alignment with hue filters applied during the construction of surface normal histograms and occupancy grids. In this method, the size of the point cloud is reduced with a hue-based down sampling that is independent of the point sample density or local geometry. Experimental results show that use of the hue filters increases the registration speed and improves the registration accuracy. Coarse rigid transformations determined in this step enable fine alignment with dense, unfiltered point clouds or using Iterative Common Point (ICP) alignment techniques.