• International Journal of Air-Conditioning and Refrigeration
• /
• 제17권2호
• /
• pp.37-44
• /
• 2009

It is well known that a refrigerant-induced noise is caused by two-phase flow in the indoor unit of a heat pump air-conditioner. Especially when the flow pattern in a pipe is intermittent flow, the irregular noise occurs frequently. But it is very difficult to avoid this kind of the noise for the application of air-conditioner. Therefore, in this research, the flow patterns at two-phase flow state in a pipe of the indoor unit for the air-conditioner are researched using cycle simulator at typical cycle conditions. In order to find the relationship between refrigerant-induced noise and flow pattern, the noise patterns are investigated with respect to the estimated flow pattern from the various flow pattern maps. Base on the estimations of the flow patterns by those maps, the refrigerant-induced noise is evaluated as decreasing tube diameter, which can transit the flow pattern from slug to annular flow.

• 한국산학기술학회논문지
• /
• 제15권7호
• /
• pp.4100-4104
• /
• 2014

대중음악산업에서 이용매체의 변화는 음악 소비자들의 이용패턴의 변화와 함께 나타나며, 여러 매체의 복합적인 영향이 음악 소비자들의 선호도에 추가적인 영향을 미친다. 본 논문에서는 소유에서 소비로 빠르게 진화하고 있는 국내 음악 소비자들의 이용패턴을 AIDMA 모델과 AISAS 모델의 관점과 통계의 추이를 살펴보고 분석해 보았다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2004년도 하계종합학술대회 논문집(1)
• /
• pp.59-62
• /
• 2004

The performance of turbo code is improved by updating extrinsic information. The bit patterns are categorized by the transition characteristics of extrinsic information in this paper. And the distribution of these patterns is surveyed according to signal-to-noise ratio. Based on the results, the dominant error pattern is determined at high signal-to-noise ratio range. Thus, it is expected to improve the error performance in the error floor region by correcting the dominant error pattern which is found in this paper.

• 대한기계학회논문집B
• /
• 제26권5호
• /
• pp.695-702
• /
• 2002

Nonlinear dynamics of striped diffusion flames, by the diffusional-thermal instability with Lewis numbers sufficiently less than unity, is numerically investigated by examining various two-dimensional flame-structure solutions. The Lewis numbers for fuel and oxidizer are assumed to be identical and an overall single-step Arrhenius-type chemical reaction rate is employed in the model. Particular attention is focused on identifying the flame-stripe solution branches corresponding to each distinct stripe pattern and hysteresis encountered during the transition. At a Damkohler number slightly greater than the extinction Damkohler number, eight-stripe solution first emerges from one dimensional solution. The eight-stripe solution survives Damkohler numbers much smaller than the extinction Damkohler number until the transition to four-stripe solution occurs at the first forward transition Damkohler number. At the second forward transition Damkohler number, somewhat smaller than the first transition Damkohler number, the transition to two-stripe solution occurs. However, anu further transition from two-stripe solution to one-stripe solution is not always possible even if one-stripe solution can be independently accessed for particular initial conditions. The Damkohler number ranges for two-stripe and one-stripe solutions are found to be virtually identical because each stripe is an independent structure if distance between stripes is sufficiently large. By increasing the Damkohler number, the backward transition can be observed. In comparison with the forward transition Damkohler numbers, the corresponding backward transition Damkohler numbers are always much greater, thereby indicating significant hysteresis between the stripe patterns of strained diffusion flames.

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

• 동의생리병리학회지
• /
• 제26권6호
• /
• pp.818-822
• /
• 2012

We in this paper propose a prognosis graph, analyzing prognoses of each pattern described in the Korean medicine literatures. This graph is represented as the integrated graphs about knowledge of patterns and their transitions in the prognoses, where a node becomes a pattern name and a edge becomes a transition between patterns, along with a condition with respect to cause or mechanism of the pattern. The knowledge of prognoses which a pattern is transit into another pattern can be identified at a glance by using this model. We also construct a upper-level prognosis graph, excluding five viscera and six entrails from the model. This upper-level prognosis graph contains the conceptual knowledge than clinical one so that it may be helpful to students and researchers in the Korean medicine fields.

• Korean Chemical Engineering Research
• /
• 제59권1호
• /
• pp.94-99
• /
• 2021

2단 Rushton turbine 날개를 장착한 접시바닥형 교반조 내의 유동 상태가 어떤 회전수에서 변화하는 현상을 찾아냈다. 층류 영역에서는 회전수를 변화시켜도 안정적인 도넛 링이 형성되어 혼합 패턴에 특이한 변동은 관찰되지 않았다. 전이영역에서의 평바닥형 교반조에서는 회전수에 변화를 주어도 두꺼운 2개의 미혼합 도넛 링에 변화가 없는 반면, 접시바닥형 교반조에서는 회전수가 450 rpm이 되면 두꺼운 2개의 미혼합 도넛 링이 아주 얇은 3개의 도넛 링으로 바뀌어 혼합이 개선되었다. 접시바닷형 교반조에서는 Re=138~178의 영역에서 링 모양의 미혼합 영역이 3곳에서 나타났고 그 크기도 컸지만, 평바닥형 교반조에서는 Re=116~176에서 링모양의 미혼합 영역은 2곳에서 나타났으며 그 크기도 작았다. 이러한 현상이 관찰되는 조건은 전이영역으로, 방해판을 부착하였을 때가 방해판이 없을 때와 비교하여 동력수가 커지기 시작하는 영역임을 알 수 있었다. 또한 교반 레이놀즈수가 300을 넘어 유동 상태에 약간의 난류가 섞이게 되면, 이 같은 흐름 양상의 단절이 해소되어 완전히 혼합되었다.

• 동남아시아연구
• /
• 제20권3호
• /
• pp.147-182
• /
• 2010

The purpose of this study is to examine the population changes in the nine Southeast Asian countries, including Cambodia, Lao People's Democratic Republic, Philippine, Indonesia, Malaysia, Myanmar, Singapore, Vietnam, and Thailand. According to the demographic transition theory which described the transition from high birth and death rates to low birth and death rates, the demographic changes in less developed countries, including the Southeast Asian countries, follow the general pattern of the population changes that the Western countries had experienced. However, this theory does not consider the fact that the demographic behaviors such as fertility and mortality tend to be ethnocentric (or particular). Therefore, I examine in this paper both the generality and particularity of the population changes in the Southeast Asia . The analytic results are consistent with my assumptions. Every country in the Southeast Asia will soon reach the third phrase of the demographic transition and meet population ageing process. However, the timings arriving at the third phrase can differ. Singapore which is the most developed country had firstly passed through the demographic transition and the highest level of population ageing. Cambodia and Lao People's Democratic Republic, the least developed countries, will lastly arrive at the third phrase and the ageing society. In addition, among the three countries which had experienced war or civil war, only Cambodia had experienced babyboom.

• 한국전자파학회논문지
• /
• 제19권7호
• /
• pp.785-790
• /
• 2008

본 논문에서는 새로운 발룬 구조를 제안한다. 신호선의 기준점인 접지 면에는 인위적인 결함 기저면이 존재한다. 전송 선로는 마이크로스트립 라인과 슬롯 라인의 변환을 갖는다. 접지면에 존재하는 결함 기저면과 신호선의 전송 모드 변환은 발룬의 특성을 만드는데 유용하게 쓰인다. 결함 기저면의 공진 주파수는 발룬의 동작 주파수를 결정한다. 또한, 전송선의 모드 변환은 투 출력 단자 사이의 위상 반전을 추가 선로 없이 만들 수 있다. 본 논문에서는 발룬의 동작 주파수를 효과적으로 낮출 수 있는 수직 결함 기저면을 적용하여 동작 주파수 2 GHz의 발룬을 설계, 제작 및 측정하여 제시한 설계법의 타당성이 검증되었다.

• 한국생활과학회지
• /
• 제10권3호
• /
• pp.275-290
• /
• 2001

The purpose of this study was to investigate the transition of clothing behavior and clothing consumption pattern of college students in Choong Nam province. 75 subjects were surveyed in 1995 and 2000. For statistical analysis, $X^2$-test were used by SPSSWIN program. The results of this study were as follows. 1. Number of clothing showed significant difference according to year and the number of coat and formal wear increased in 2000 compared with 1995. 2. Clothing consumption pattern showed significant difference according to year. College students purchased on sale more frequently and preferred more expensive clothes in the year 2000 compared with 1995. 3. Contentment for clothing behavior showed significant difference according to year and the extent of contentment decreased as years go by. 4. Number of clothing showed significant difference according to sex and female students had more clothes than male students, but the difference between male and female decreased as years go by from 1995 to 2000. 5. Clothing consumption pattern showed significant difference according to sex and female students purchased ell sale more frequently than male students, but the difference between male and female decreased as years go by. 6. Contentment for clothing behavior showed significant difference according to sex, but female students described to not adequate the quantity of feminine style wear and the interest in fashion of male students was increased as years go by.