• 한국도로학회논문집
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• 제14권6호
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• pp.183-190
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• 2012

PURPOSES : The fundamental diagram provides basic information necessary in the analysis of traffic flow and highway operation. When traffic flow is congested, the density-flow points in the fundamental diagram are widely scattered and move in a stochastic manner. This paper investigates the pattern of density-flow point transitions and identifies car-following behaviors underlying the density-flow transitions. METHODS : From a microscopic analysis of 722 fundamental diagrams of NGSIM data, a total of 20 transition patterns of fundamental diagrams are identified. Prominent features of the transition patterns are explained by the behavior of the leader and follower. RESULTS : It is found out that the average speed and the speed difference between the leader and the follower critically determine the density-flow transition pattern. The density-flow path is very sensitive to the values of vehicle speed and spacing especially at low speed and high density such that most fluctuations in the fundamental diagram in the congested regime is due to the noise of speed and spacing variations. CONCLUSIONS : The result of this study suggests that the average speed, the speed difference between the leader and the follower, and the random variations of speed and spacing are dominant factors that explain the transition patterns of a fundamental diagram.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1993년도 추계학술대회
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• pp.128-131
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• 1993

In order to get the basic data for the study of the heat stimulation of burning moxa, the pattern of combustion temperature, which is one of the important factors of thermal characteristics, was measured by density of cone moxa along the time procedure. The following results have been obtained 1) The pattern of combustion temperature by moxa burning was classified into input period which means the infiltration of heat into the area and output period which means the radiation of heat from the area. The input period consists of preheating and heating periods, while the output period consists of heat retaining and cooling periods. 2) The pattern of combustion temperature showed the same type or curve, which was not influenced by the moxa weight. However, Its pattern gradient are varied by density. It is considered that the pattern of combution temperature is primarily influenced by the rate of combustion temperature, gradient temperature and duration of combustion.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.590-595
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• 2004

The shape and size variations of the nanopatterns produced on a positive photoresist using a near-field scanning optical microscope(NSOM) are investigated with respect to the process variables. A cantilever type nanoprobe having a 100nm aperture at the apex of the pyramidal tip is used with the NSOM and a He-Cd laser at a wavelength of 442nm as the illumination source. Patterning characteristics are examined for different laser beam power at the entrance side of the aperture( $P_{in}$ ), scan speed of the piezo stage(V), repeated scanning over the same pattern, and operation modes of the NSOM(DC and AC modes). The pattern size remained almost the same for equal linear energy density. Pattern size decreased for lower laser beam power and greater scan speed, leading to a minimum pattern width of around 50nm at $P_{in}$ =1.2$\mu$W and V=12$\mu$m/. Direct writing of an arbitrary pattern with a line width of about 150nm was demonstrated to verify the feasibility of this technique for nanomask fabrication. Application on high-density data storage using azopolymer is discussed at the end.

• 한국주조공학회지
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• 제12권4호
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• pp.305-316
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• 1992

Steel and iron castings made with expandable polystylene (referred to hereafter as EPS) patterns are often affected by distinctive defects associated with incomplete decomposition of the EPS as the molds are filled with metal. The effects of practical factors on carbon pick-up were investigated on the specimens, by taking successive layers of swarf and analysis, whereas the lustrous carbon is determined by using combustion analysis. The quality of the castings, with particular reference to carbon pick-up in low carbon steel and lustrous carbon on gray iron, is further influenced to a significant extent by such practical factors as reduced pressure, the pouring temperature, the density of EPS pattern, the additive in coating and in pattern and the casting thickness. The rate at which carbon pick-up and lustrous carbon deposites are formed can be reduced by reducing the density of the pattern and also reducing pressure, especially by adding $Na_2CO_3$ in coating and in pattern to promote $CO_2$ evolution. The upper parts of castings obtained using EPS patterns are slightly higher in carbon pick-up and in lustrous carbon than other parts.

• ETRI Journal
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• 제26권6호
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• pp.520-534
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• 2004

As the density of memories increases, unwanted interference between cells and the coupling noise between bit-lines become significant, requiring parallel testing. Testing high-density memories for a high degree of fault coverage requires either a relatively large number of test vectors or a significant amount of additional test circuitry. This paper proposes a new tiling method and an efficient built-in self-test (BIST) algorithm for neighborhood pattern-sensitive faults (NPSFs) and new neighborhood bit-line sensitive faults (NBLSFs). Instead of the conventional five-cell and nine-cell physical neighborhood layouts to test memory cells, a four-cell layout is utilized. This four-cell layout needs smaller test vectors, provides easier hardware implementation, and is more appropriate for both NPSFs and NBLSFs detection. A CMOS column decoder and the parallel comparator proposed by P. Mazumder are modified to implement the test procedure. Consequently, these reduce the number of transistors used for a BIST circuit. Also, we present algorithm properties such as the capability to detect stuck-at faults, transition faults, conventional pattern-sensitive faults, and neighborhood bit-line sensitive faults.

• 대한기계학회논문집
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• 제14권5호
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• pp.1290-1299
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• 1990

본 연구에서는 이러한 개념을 확장하여 직경이 26nm와 38nm인 두 개의 수평관 내 기액 2상유동에서 오리피스의 차압교란치의 확률밀도함수, 자기상관함수와 파워 스 펙트럼 밀도함수를 구하여 유동양식에 따른 이 들 통계치의 특성을 구명하였다. 본 연구에서 다룬 유동양식은 기포, 플러그, 슬러그, 성층, 파상, 환상, pseudo-slug 유 동이다. 이 결과 차압교란치의 통계적 해석을 통한 유동양식 판별법이 매우 유용하 다는 사실을 밝혔으며, 또 본 판별법을 관내 압력강하치의 통계적 해석을 통하여 유동 양식을 구분한 타 연구자들의 방법과 비교 분석하였다.

• 한국의상디자인학회지
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• 제16권1호
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• pp.53-64
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• 2014

The main objective of this research was to understand the characteristics of printed geometric patterns through the statistical & qualitative analysis of fashion appeared in contemporary female collections 2011 S/S to 2013 A/W. Data collection of 294 was done through review of 'pr$\hat{e}$t-$\grave{a}$-porter Collections' of three major fashion cities; Paris, Milan and NY. Statistical analysis of frequency was conducted. Also qualitative interpretation of natural print design' characteristics were completed. The main findings were as followed; 1,636 of the total 15,852 designs were printed patterns in 12 Collections and the occurrence rate of printed geometric patterns in three collections were 8.6% in Milan, 9.2% in Paris and 12.9% in N.Y. Most geometric patterns were the types of compact or medium density in a front patterns with a variety of sizes and mainly applied to the one piece dress or two piece clothing item combination styles. Formative Characteristics of printed geometric patterns were classified into four types. First, a variety of thicknesses and shapes, such as a line or a rectangle shape to take advantage of the types of the typical geometric pattern. Second types were using the motifs which inspired by geometric shapes such as point, circle star and other special geometric shapes and arranging them regularly with various sizes and density. The third was repeated particular motifs which based on complex and sophisticated mathematical formulas. Fourth were the specific diagram types of bold and free shapes or dividing the flat and arranging them without rules, or the combination type of various geometric motifs.

• 한국수산과학회지
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• 제37권6호
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• pp.469-477
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• 2004

This study examined distributional patterns of Asterias amurensis in Tongyeong, the central South Sea of Korea. The density of the sea star was estimated at 10 chosen sites in the inner and the outer parts of the Tongyeong coast from December 2000. The mean density of the species in this area was $2.4ind./m^{2}$. The seasonal surveys conducted at 3 arbitrary chosen sites (i.e., sea cage, reef and soft sediment) also showed that the abundance of the species at the sea cage site $(density:\;3.6\;ind./m^{2};\;biomass:\;250.7\;gwwt/m^{2})$ was significantly higher than at the reef site $(density:\;1.7\;ind./m^{2};\;biomass:\;63.5\;gwwt/m^{2})$ and the soft sediment site $(density:\;0.4\;ind./m^{2};\;biomass:\;18.9\;gwwt/m^{2})$. Densities were higher at sea cages areas than at reefs and soft bottom sites. At sea cage site, A. amurensis population exhibited a strong aggregated distributional pattern. In contrast, at reef and soft bottom sites, A. amurensis population showed a random distributional pattern. The spatial difference in prey species and its abundance was the primary factor determining the spatial heterogeneity of the sea star in its behavior characteristics. Experiments on the feeding preference indicated that A. amurensis had a strong selectivity on its prey, but this selectivity varied between populations living in different sites. In particular, A. amurensis populations at the reef site showed a strong selectivity on various sessile and mobile animals living in reef areas, suggesting that these animal groups may play a role as "windows for the survival of A. amurensis". These results suggest that the distribution of A. amurensis in Tongyeong is closely associated with abundance of prey species and the bottom composition.

• 전기전자학회논문지
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• 제5권1호
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• pp.43-51
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• 2001

메모리의 집적도가 올라갈수록 원치 않는 셀간의 간섭과 동시에 bit-line간의 상호 노이즈도 증가하게 된다. 그리고 높은 고장 검출율을 요구하는 고집적 메모리의 테스트는 많은 테스트 백터를 요구하게 되거나 비교적 큰 추가 테스트 회로를 요구하게 된다. 지금까지 기존의 테스트 알고리즘은 이웃 bit-line의 간섭이 아니라 이웃 셀에 중점을 두었다. 본 논문에서는 NPSFs(Neighborhood Pattern Sensitive Faults)를 기본으로 한 NBLSFs(Neighborhood Bit-Line Sensitive Faults)를 위한 새로운 테스터 알고리즘을 제안한다. 그리고 제안된 알고리즘은 부가 회로를 요구하지 않는다. 메모리 테스트를 위해 기존의 5개의 셀 레이아웃이나 9개의 셀 레이아웃을 사용하지 않고 NBLSF 검출에 최소한 크기인 3개의 셀 레이아웃을 이용하였다. 더구나 이웃 bit-line에 의한 최대의 상호잡음을 고려하기 위해 테스트 동작에 refresh 동작을 추가하였다(예 $write{\rightarrow}\;refresh{\rightarrow}\;read$). 또한 고착고장, 천이고장, 결합고장, 기존의 pattern sensitive 고장, 그리고 이웃 bit-line sensitive 고장 등도 검출될 수 있음을 보여준다.

• Environmental Engineering Research
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• 제10권1호
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• pp.15-21
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• 2005

A computer program is developed for the prediction of the flow pattern and the removal efficiency of suspended solid (SS) in a circular secondary clarifier. In this study the increased density effect by SS on hydrodynamics has been systematically investigated in terms of Froude Number (Fr), baffle existence, and a couple of important empirical models associated with the particle settling and Reynolds stresses. A control-volume based-finite difference method by Patankar is employed together with the SIMPLEC algorithm for the resolution of pressure-velocity coupling. The k-ε turbulence and its modified version are incorporated for the evaluation of Reynolds stresses. The calculation results predicts well the overall flow pattern such as the waterfall phenomenon at the front end of the clarifier and the bottom density current with the formation of strong recirculation especially for the case of decrease of Fr. Even if there are some noticeable differences in the prediction of two turbulence models, the calculated results of the radial velocity profiles are generally in good agreement against experimental data appeared in open literature. Parametric investigation has been systematically made with the Fr and baffle condition with detailed analysis.