• 한국수학교육학회지시리즈A:수학교육
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• 제49권3호
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• pp.375-387
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• 2010

The focus of this article is the strategies young children use to solve rectangular covering tasks before they have been taught area measurement. seventy nine children from Grade 1 to 4 were observed while they solved various array-based tasks, and their drawing and explanation were collected and analyzed. Children's solution strategies were classified into incomplete covering, inadequate array, array constructed from moveable unit, measurement of one dimension, measurement of two dimension, and calculation. Implications for the learning of area measurement are addressed.

• 농업과학연구
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• 제38권3호
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• pp.525-532
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• 2011

The aim of this study was to develop a portable electronic nose system for freshness measurement of meats, which could be an alterative of subjective measurements of human nose and time-consuming measurements of conventional gas chromatograph methods. The portable electronic system was o optimized by comparing the measurement sensitivity and hardware efficiency, such as power consumption and dimension reduction throughout two stages of the prototypes. The electronic nose systems were constructed using an array of four different metal oxide semiconductor sensors. Two different configurations of sensor array with dimension were designed and compared the performance respectively. The final prototype of the system showed much improved performance on saving power consumption and dimension reduction without decrease of measurement sensitivity of pork freshness. The results show the potential of constructing a portable electronic system for the measurement of meat quality with high sensitivity and energy efficiency.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.21-24
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• 2002

A sensor array (35mm'! in diaphragm dimension) of 12 sensing elements with different operating temperatures was optimized with respect to thermal operation. This sensor array with single heater on a glass diaphragm over back-etched silicon bulk realizes a novel concept of a sensor array: an way of sensor elements operated at different temperatures can yield more information than single measurement. The proposed micro sensor array could provide well-integrated way structure because it has only single heater at the center of the diaphragm and used the various sensing properties of two kinds of metal oxide layers with various operating temperatures.

• 한국전자파학회논문지
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• 제11권4호
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• pp.514-522
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• 2000

본 논문에서는 위상천이기 없이 전 방향으로 빔의 주사를 가능하도록 하기 위해 기존의 능동 위상배열 안테 나의 슬롯라인 결합구조를 이용하여 패치 안테나와 능동 소자를 Via-hole을 이용하여 접합함으로써 $4\times4$ 능동 위상배열 안테나를 설계하고 제작하여 그 특성을 고찰하였다. 제안된 이차원 능동 위상배열 안테나는 슬롯라인 결합구조를 이용하여 기생방사 결합에 의한 방사패턴의 왜곡울 방지하고, 전체 안테나의 크기도 최소화하며 F FET의 바이어스 전압 조정으로 발진 주파수를 조정할 수 있도록 하였다 .. $4\times4$ 소자를 이용하여 주파수 12.5 GHz에서 발진 주파수가 locking하는 배열된 능동 위상배열 안테나의 일차원 빔 주사 범위는 브로드사이드로부터 $-17^{\circ}~18^{\circ}$로 나타났고, 시율레이션 결과와 대체로 일치했으나 사이드 로브 레벨이 약간 높게 나타났 다. 이차원 빔 주사를 이용하여 $\phi_0=45^{\circ}$일 때의 빔 주사 범위는 $-5^{\circ}~10^{\circ}$로 나타났다. 이를 이용하여 2차원 빔 주사에 응용할 수 있음을 확인하였고, 이것은 위성을 이용한 방송 및 통신 시스탬이나 radar 시스댐에 응용될 수 있을 것이다.

• 한국항해학회지
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• 제20권4호
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• pp.129-137
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• 1996

In this paper, we simulated a radiation pattern directivity of microstrip patch antenna for 9[GHz] using the computer. It is analyzed and compared the directivity of field characteristics at two different aspects. One is that of 1-dimension and 2-dimension array, the other is that of a linear and planar array antenna. We tried the constants for the simulation of teflon substrate, dielectric constant ${\varepsilon}r=2.50$, ground plane conductor thickness t=0.03556, substrate height h=0.72188, dielectric loss degree $tan{\delta}$=0.00085, characteristics impedence of line $Zo=50({\Omega})$. The major advantage of microstrip patch antenna is that the arrangement of antenna is associated with the directivity and effectiveness. We have been studied the difference of the radiation pattern of antenna with wave variety through computer simulation.

• 대한전자공학회논문지SD
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• 제40권12호
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• pp.17-23
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• 2003

서로 다른 동작온도를 가지는 12개의 감지막으로 구성된 고집적형 센서어레이(다이아프램의 크기가 3×5㎟가 설계되고 열동작의 관점에서 최적화되었다. 이 센서어레이는 에칭된 실리콘기판과 접합된 얇은 유리기판 위의 중앙에 하나의 히터가 위치하고 양쪽에 동작온도가 다른 감지박막이 위치하도록 설계됨으로써 개별 마이크로센서 보다 동시에 훨씬 많은 정보를 얻을 수 있는 장점을 가지고 있다. 제안된 마이크로센서 어레이는 다이아프램의 중앙에 하나의 히터만을 가지는 구조를 하고 있기 때문에 고집적 어레이구조를 실현하면서도, 히터를 중심으로 감지박막의 동작온도에 따라 다양한 감지특정을 얻을 수 있다. 또 히터 양쪽의 감지박막의 종류를 다르게 함으로써 다이아프램위의 전 감지막이 모두 다른 감지특성을 가지게 되어 고집적 센서어레이를 구현하기 용이한 구조로 밝혀졌다.

• 한국통신학회논문지
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• 제25권4B호
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• pp.708-714
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• 2000

본 논문에서는 쿼드-트리 방식을 이용한 프랙탈 영상압축 알고리즘의 고속화를 위한 1-차원 VLSI 어레이를 제안한다. 먼저, 순차적 Fisher 알고리즘을 단일할당코드 알고리즘으로 변환하여 데이터의존 그래프를 구현하였다. 구해진 데이터의존 그래프를 최적의 방향으로 투영시켜 2-차원 어레이를 설계하고, 구해진 2-차원 어레이를 변형하여 1-차원 VLSI 어레이를 설계하였다. 설계한 1-차원 VLSI 어레이에서 치역블록 및 정의블록을 입력하는 핀과 처리요소의 내부 연산장치를 고유함으로써 입출력 핀의 수를 줄이고 처리요소의 구조를 간단하게 했다. 또한 각 블록크기에 대한 연산을 위한 처리요소를 재사용하여 처리요소의 이용률을 높였다. 512$\times$512 그레이-스케일 영상의 프랙탈 1-차원 VSLI 어레이의 동작은 컴퓨터 시뮬레이션을 통하여 검증하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1471-1474
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• 2003

The correlation between the object function and the design parameter is shown on this paper by using the characteristic function for tile mixed result of the structure analysis. tile buckling analysis and the table of orthogonal array according to the original crane's dimensional change. About the above two object functions, the effective of design change according to the change of design parameters could be estimated. Also, the crane's weight is reduced up to 20.58 percent maintaining the structural stability according to the thickness of plate.

• Journal of Information Display
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• 제11권4호
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• pp.140-143
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• 2010

A simple and versatile method of fabricating color patterns in two-dimension (2D) and three-dimension (3D) was developed using the selective-wettability approach. Red, green, and blue color elements are sequentially formed on a single substrate in a pattern-by-pattern and/or pattern-on-pattern fashion, through a simple coating process. Either 2D or 3D structures in an array format are produced by controlling the thickness of the hydrophobic layer (HL) coating a substrate within the framework of wetting transition. Moreover, it was demonstrated that the stacked geometry of two successive patterns can be easily tailored for various types of color arrays, with the pattern fidelity of a few tens of nanometers in terms of only a parameter of the HL thickness.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.239.1-239.1
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• 2011

Dye sensitized solar cells (DSC) are promising devices for inexpensive, nontoxic, transparent, and large-scale solar energy conversion. Generally thick $TiO_2$ nanoporous films act as efficient photoanodes with their large surface area for absorbing light. However, electron transport through nanoparticle networks causes the slowdown and the loss of electron transport because of a number of interparticle boundaries inside the conduction path. We have studied DSCs with precisely dimension-controlled $TiO_2$ nanotubes array as photoanode. $TiO_2$ nanotubes array is prepared by template-directed fabrication method with atomic layer deposition. Well-ordered nanotubes array provides not only large surface area for light absorbing but also direct pathway for electrons with minimalized grain boundaries. Large enlongated anatase grains in the nanotubes could enhance the conductivity of electrons, but also suppress the recombination with holes through defect sites during diffusion into the electrode. To study the effect of grain boundaries, we fabricated two kinds of nanotubes which have different grain sizes by controlling deposition conditions. And we studied electron conduction through two kinds of nanotubes with different grain structures. The solar cell performance was studied as a function of thickness and grain structures. And overall solar-to-electric energy conversion efficiencies of up to 7% were obtained.