• 대한기계학회논문집A
• /
• 제29권1호
• /
• pp.67-73
• /
• 2005

The paper presents a single-heater microfluid injector, whose ejected droplet volume is adjusted by digital current path control for a single microheater. The previous droplet volume adjustable methods have used the digital current control for multiple heaters or the analog current control for a single heater, while the present method uses the digital current control for a single microheater. Two different microinjectors, having a rectangular heater and a circular hearter, are designed and fabricated in the chip area of $7.64\;mm{\times}5.26\;mm$. The fabricated microinjectors have been tested and characterized for the number, size, shape and lifetime of the generated bubbles as well as for the volume and velocity of the ejected droplets. The input power for the rectangular heater and the circular heater has been varied in the ranges of $8.7{\sim}24.9{\mu}W\;and\;8.1{\sim}43.8{\mu}W$, respectively. The projected area of the generated bubble has been changed in the ranges of $440{\sim}l,3600{\mu}m^2\;and\;800{\sim}3,300{\mu}m^2$ for the rectangular heater and the circular heater, respectively. The microinjector with the rectangular heater ejects three discrete levels of the droplet in the volume range of $9.4{\sim}20.7pl$ with the velocity range of $0.8{\sim}1.7m/s$, while the microinjector with the circular heater achieves five discrete levels of the droplet in the volume range of $7.4{\sim}27.4pl$ with the velocity range of $0.5{\sim}2.8m/s$.

• 한국항행학회논문지
• /
• 제20권5호
• /
• pp.433-439
• /
• 2016

저가형 GNSS (global navigation satellite system) 수신 모듈에 DGNSS (differential GNSS) 서비스를 적용하기 위한 방안으로 거리 영역의 보정정보를 위치 영역으로 투영한 후, stand-alone으로 산출한 위치에 적용하는 DGNSS-CP 방식이 제안된 바 있다. DGNSS-CP 를 상용 수신기 또는 휴대폰에 적용하기 위해서는 항법 방정식의 관측행렬을 이용하여 위치영역 투영 방정식을 구성하므로, 각 위성의 시선벡터를 산출하여야 한다. GNSS 항법 메시지, 배치 정보 등이 시선벡터 산출을 위하여 사용되는데, 각 방법에 따라 정확도와 연산량 등의 성능에 차이가 발생한다. 본 연구에서는 제시된 두 가지 시선벡터 산출 방식에 따라 DGNSS-CP의 성능에 어떠한 영향을 끼치는지 확인하기 위하여, Septentrio PolaRx4 Pro 수신기에서 stand-alone mode 로 저장된 데이터에 해당 알고리즘을 적용하였고, 배치 정보를 사용하는 방법이 궤도정보를 사용하는 방법에 비해 정확도 면에서는 그 성능이 RMS (root mean square) 0.1 m 가량 저하되는 반면, 연산량은 약 1/15수준으로 줄일 수 있음을 확인하였다.

• 정보처리학회논문지:소프트웨어 및 데이터공학
• /
• 제4권4호
• /
• pp.177-186
• /
• 2015

레이저 거리센서와 비전 카메라의 정보를 융합하기 위해서는 두 센서 사이의 상대적인 위치관계를 설명하는 외부 파라미터를 정확하게 보정하는 것이 필수적이다. 본 논문에서는 레이저 거리센서와 카메라 좌표계 간의 외부 파라미터를 기존에 알려진 방법보다 쉬우면서도 정확하게 획득할 수 있는 새로운 보정 방법을 제안하고자 한다. 본 논문에서 제안한 방법의 접근법은 레이저 거리센서로 획득한 3차원 구조물의 모서리 정보를 영상으로 투영하였을 때 반드시 하나의 직선상에 존재해야 한다는 것을 제약조건으로 한다. 이러한 제약조건을 만족하는 3차원 기하모델을 제시하고 이 모델의 에너지 함수를 최소화하기 위한 수치적 해법을 소개한다. 또한 높은 정밀도의 보정을 위하여 레이저 거리정보 및 카메라 영상의 획득 과정에 대해서도 상세히 설명한다. 실험을 통해 제안된 방법의 성능이 기존의 방법에 비하여 보다 높은 정밀도를 보임을 확인할 수 있었다.

• 한국항행학회논문지
• /
• 제19권4호
• /
• pp.278-287
• /
• 2015

항공기 배기가스가 지구의 현재와 미래의 기후에 미치는 잠재적 영향력은 항공산업계가 당면하고 있는 매우 중요한 환경 이슈 중 하나이다. 온실가스 배출의 잠재적 악영향에 대한 우려가 증가함에 따라 항공기의 배기가스 배출을 줄이고 기후에 관한 항공기의 영향을 완화하는 수단 중 하나로 항공기 배기가스를 산정하고 예측하는 시스템 개발의 필요성이 제기되고 있다. 따라서 본 연구에서는 영국 Lissys사에서 개발한 Piano-X 소프트웨어를 사용하여 3가지 항공기 급에 대한 다양한 비행거리와 경로에 대해 유상하중의 변화에 따른 항공기 온실가스 배출량을 산정하였다. 다양한 항속거리와 고도에 따른 경제속도, 장거리 순항속도, 최대 운항거리 속도에 대해 연료소모량도 분석하였다.

• 복식문화연구
• /
• 제20권6호
• /
• pp.923-936
• /
• 2012

Apparel companies define their target customers to integrate consumers' needs into their product development processes. The sizing standards play a significant role in ready-to-wear garment business. Consumers' body build and sizes are different according to gender, age, and body type. The consumers' morphological feature of the one geographical area has changed with immigration, aging, and lifestyle change. In this study the way of defining body types in the standard garment sizing systems published in USA., UK, Germany, Japan, and Korea were compared. The results of this study show that most of the systems classified the body types by the index value. The chest-waist drop value was used for men's body type classification. Women's body types were defined by hip proportion. The hip-bust drop value was used for it. German and European garment sizing systems provide a wide range of men's body types. US men's garment sizes are developed for very conservative body type. US women's garment sizing system has had clearly defined women's body types. The Misses body types projected in the US garment sizing system had changed as women's waist girth got bigger compared to the past. In 2011 the US Misses sizes were divided into Curvy Misses size and Straight Misses size by the hip-waist drop value. The Curvy Misses sizes have smaller waist girth and larger hip girth than the Straight Misses sizes.

• 천문학회보
• /
• 제38권2호
• /
• pp.72.1-72.1
• /
• 2013

Even though current microlensing follow-up observations focus on high-magnification events due to the high efficiency of planet detection, it is very difficult to do a confident detection of planets in high-magnification events with extremely weak central perturbations (i.e., the fractional deviation is ${\delta}{\leq}0.02$). For the confident detection of planets in the extremely weak central perturbation events, it is needed both the high cadence monitoring and the high photometric accuracy. A next-generation ground-based observation project, KMTNet (Korea Microlensing Telescope Network), satisfies both the conditions. Here we investigate how well planets in high-magnification events with extremely weak central perturbations are detected by KMTNet. First, we determine the probability of occurrence of events with ${\delta}{\leq}0.02$. From this, we find that for ${\leq}100M_E$ planets in the separation of $0.2AU{\leq}d{\leq}20AU$, events with ${\delta}{\leq}0.02$ occur with a frequency of more than 70%, in which d is the projected planet-star separation. Second, we estimate the efficiency of detecting planetary signals in the events with ${\delta}{\leq}0.02$ via KMTNet. We find that for main-sequence and subgiant source stars, ${\geq}1M_E$ planets can be detected more than 50% in a certain range that has the efficiency of ${\geq}10%$ and changes with the planet mass.

• International Journal of Control, Automation, and Systems
• /
• 제4권4호
• /
• pp.438-447
• /
• 2006

Fuzzy controller's design depends mainly on the rule base and membership functions over the controller's input and output ranges. This paper presents two different approaches to deal with these design issues. A simple and efficient approach; namely, Fuzzy Subtractive Clustering is used to identify the rule base needed to realize Fuzzy PI and PD type controllers. This technique provides a mechanism to obtain the reduced rule set covering the whole input/output space as well as membership functions for each input variable. But it is found that some membership functions projected from different clusters have high degree of similarity. The number of membership functions of each input variable is then reduced using a similarity measure. In this paper, the fuzzy subtractive clustering approach is shown to reduce 49 rules to 8 rules and number of membership functions to 4 and 6 for input variables (error and change in error) maintaining almost the same level of performance. Simulation on a wide range of linear and nonlinear processes is carried out and results are compared with fuzzy PI and PD type controllers without clustering in terms of several performance measures such as peak overshoot, settling time, rise time, integral absolute error (IAE) and integral-of-time multiplied absolute error (ITAE) and in each case the proposed schemes shows an identical performance.

• 한국지구과학회지
• /
• 제23권2호
• /
• pp.119-131
• /
• 2002

Constructivism is defined in a variety of ways (e.g., constructivist research paradigm, sociological constructivism, and philosophical constructivism) and applied in vastly different contexts. Among the various usages and interpretations of constructivism, one is educational constructivism that embodies an epistemological view of knowledge and learning that is an alternative to naive empiricism or classical behaviorism. To represent the full range of stances taken by educational constructivists, three versions of educational constructivism were considered in this study: individual constructivism originating in the work of Piaget, the radical version of constructivism associated with von Glasersfeld, and the social constructivism of Vygotsky. I investigated preservice teachers' meaning construction about constructivist epistemology as they went through their preservice teacher education program using in-depth interviews. This preservice teacher education program employs constructivist aspects of teacher education and generates applications of constructivism to the practice of teaching. Features of preservice teachers' internalized meanings of educational constructivism include: (1)traditional pedagogy as the default, (2) Literal interpretation of constructivism, (3) Individual constructivism as conceptual change learning, (4) Radical constructivism as a strong individualistic philosophy, (5) Social constructivism as being too ideal to be practical. A compilation of the teachers' own statements about how to implement conceptual change learning and their projected role as constructivist teacher is also provided.

• 복식
• /
• 제22권
• /
• pp.333-344
• /
• 1994

In this study an experiment was made using the function of computer simulation os to whether the phenomenon of optical illusion takes place also in clothing on the human body three-dimensional space through the case study of the Gestalt illusion of planar con-traction and expension by amodal completion in perceptual organization. One woman of latter 30s was selected as the experimental subject. She was made to wear the experimental clothing and then the frontal picture was projected of in the experimental clothing which was scanned into the com-puter. For the sake of the contractive experiment 5 stages were divided by 5-15cm the thick-nes of the black vertical line in the center of the upper garmet as the variable and for the sake of the expansive experiment the skirt length was set as the variable. It length measured 50-90cm which was divided by 10cm into 5 stages and simulated using the CAD. The basic design and the experimental de-sign were made one pair and the pictures totalled 20 pictures such as ten pictures save the human body for the estimation of the up-per garmet alone and ten pictures for the ob-servation of the effect on the human body. The extimating panel consisting of 20 panellers estimated contraction/expansion in the estimation of the upper garmet and the tall effect/the slim effect in the estimation of optical illusion as the estimating factors on the 9-point scale. All the date from experiment were analyzed by ANOVA(analysis of variance) and DUNCAN'S multiple range. As a result the experimental designs all showed a significant optical illusion in comparision with the basic design.

• International Journal of Costume and Fashion
• /
• 제7권2호
• /
• pp.49-63
• /
• 2007

In this study, we inquire into the general concepts of eroticism as it appears in literature and the arts, and use this as a foundation to meditate on the eroticism of attire throughout history. We also ascertained external forms based on the range of "The way we look" by Delong. In this way we inclusively studied both the content and form of modes of eroticism in the perspective of Brodsky's "linked solution." The original concept of eroticism is a technique by which one attains physical passion, referring to a nature which is deeply rooted in the cultural traditions, myths, habits. religion and arts of mankind, inducing expressions of sensual love. We integrated this eroticism in 4 categories: sensuality, which induces beauty; naturality, denoting idealization or rational beauty; primitivity, characterized by grotesque expressions or direct and natural sexual depictions; and symbolism by which sex is symbolically or mechanically projected. The concept of eroticism contains both positive and negative aspects, but rather than dealing with sex in a mechanical or perverted manner to express eroticism, it is more appropriate to guide the direction of modes of eroticism by stimulating the "desire to show" and the "desire to see" with the dialectic of obstruction and exposure as a figurative expression of true passion, and narcistic phenomena in which beauty is expressed through exaggeration or magnification and adhesion.