• 한국음향학회지
• /
• 제31권7호
• /
• pp.472-479
• /
• 2012

본 논문은 음성과 오디오의 혼합 콘텐츠를 대상으로 하는 9.2 kbps 저 전송률 변환여기 부호화기 설계를 목표로 한다. 저 전송률 환경을 위하여 주파수 영역 신호의 중요도에 따른 Band-Selection 방법과 Gain-Shape 양자화를 이용한 Analysis by Synthesis(AbS) 구조를 이용한다. AbS 구조를 이용하는 과정에서 발생하게 되는 연산량을 감소시키기 위하여 밴드별 IDFT를 취하고 합성하는 방법을 이용한다. 전송 되지 않는 구간에 대하여 Comfort Noise를 삽입함으로써 음질 저하 없이 설계한다. 기존의 TCX모드와 비교하여 저 전송률에서 성능의 저하 없는 부호화기를 제안한다.

• 한국CDE학회논문집
• /
• 제10권4호
• /
• pp.254-261
• /
• 2005

The purpose of this research is to develop a method for cutting non-circular holes on a bent thick plate. Generally in order to cut the holes on the large plates, a special-purpose 5-axis machine is needed. However, such a machine is unavailable in most of the machine shops. This paper provides a description of such a method that utilizes a general-purpose 5-axis water-jet machine in place of the special-purpose machine: First, the bent piece is transformed into a flat plate, where the shape of the holes is reconstructed by considering deformation during bending. Then, after a 5-axis NC data is generated, the holes on the flat plate are cut using the 5-axis water-jet machine. The final step is to return to its, original shape by bending the plate with its newly-cut holes. The proposed methodology is implemented as a dedicated system by customizing a commercial CAD/CAM system. Some illustrations are provided throughout the paper in order to show the validity of the proposed methods and the developed system.

• 한국멀티미디어학회논문지
• /
• 제23권8호
• /
• pp.965-976
• /
• 2020

We present in this work a segmentation method of E. coli bacterial images generated via phase contrast microscopy using a deep learning based hybrid feature generation. Unlike conventional machine learning methods that use the hand-crafted features, we adopt the denoising autoencoder in order to generate a precise and accurate representation of the pixels. We first construct a hybrid vector that combines original image, difference of Gaussians and image gradients. The created hybrid features are then given to a deep autoencoder that learns the pixels' internal dependencies and the cells' shape and boundary information. The latent representations learned by the autoencoder are used as the inputs of a softmax classification layer and the direct outputs from the classifier represent the coarse segmentation mask. Finally, the classifier's outputs are used as prior information for a graph partitioning based fine segmentation. We demonstrate that the proposed hybrid vector representation manages to preserve the global shape and boundary information of the cells, allowing to retrieve the majority of the cellular patterns without the need of any post-processing.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2010년도 춘계학술대회
• /
• pp.407-409
• /
• 2010

기계장치에 있어서 브레이크 시스템은 기계의 동작시스템 부분들 중에 매우 중요한 역할을 담당하는 부분이다. 만약 기계가 작동 중 멈추지 않으면 사고 시설물 피해 인명 피해 등을 유발할 수 있기 때문이다. 이것은 선박에서 또한 마찬가지이다. 선박에서 항해 중 배를 정지시키기 위해서는 윈드라스 윈치 브레이크 시스템을 사용하고 있으며, 배를 항구에 계류시키기 위해서는 무어링 윈치 브레이크 시스템을 사용한다. 본 연구에서는 배를 항구에 계류시키는 무어링 윈치 브레이크 시스템의 제동력을 향상시키기 위해 기존의 무어링 윈치 브레이크 시스템의 형상 변경한 후 무어링 윈치 브레이크 시스템의 제동력과 강도해석을 실시해 보았다.

• 한국수학교육학회지시리즈D:수학교육연구
• /
• 제14권3호
• /
• pp.195-209
• /
• 2010

Utilizing a structure of operations known as Dissection-Motion-Operations (DMO), a set of mathematics propositions or area-formulas in school mathematics will be introduced through shape-to-shape transforms. The underlying theme for DMO is problem-solving through visual reasoning and proving manipulatively or electronically vs. rote learning and memorization. Visual reasoning is the focus here where two operations that constitute DMO are utilized. One operation is known as Dissection (or Decomposition) operation that operates on a given region in 2D or 3D and dissects it into a number of subregions. The second operation is known as Motion (or Composition) operation applied on the resultant sub-regions to form a distinct area (or volume)-equivalent region. In 2D for example, DMO can transform a given polygon into a variety of new and distinct polygons each of which is area-equivalent to the original polygon (cf [Rahim, M. H. & Sawada, D. (1986). Revitalizing school geometry through Dissection-Motion Operations. Sch. Sci. Math. 86(3), 235-246] and [Rahim, M. H. & Sawada, D. (1990). The duality of qualitative and quantitative knowing in school geometry, International Journal of Mathematical Education in Science and Technology 21(2), 303-308]).

• 박물관보존과학
• /
• 제5권
• /
• pp.17-22
• /
• 2004

일제시대에 발굴되어 여러 편으로 분리되어 있던 철제용기를 보존처리하였다. 보존처리를 통하여 유물을 안정화시키고, 본래의 형상을 복원하였다. 보존처리 결과 철제용기는 굽이 있으며 구연부에 턱이 있고 안으로 오므라드는 유선형이었다. X-선 투과검사 결과 주조과정에서 기공이 많이 발생한 것이 관찰되었으며, 금속조직을 통해 재질이 초정흑연을 가진 과공정 백주철임을 알 수 있었다.

• 한국컴퓨터그래픽스학회논문지
• /
• 제23권1호
• /
• pp.57-65
• /
• 2017

본 논문에서는 포인트 클라우드로 구성된 모델 내의 오류를 줄이고, 기하학적 형태를 복원하기 위한 사전 학습 방법을 제시한다. 이를 위해, 대상 모델과 유사한 형태 특징을 갖는 모델로부터 3차원 특징 정보를 추출하여 사전을 구성하고, 이를 통해 기하 복원을 수행한다. 본 연구에서 제시한 방법은 다음과 같이 세 단계로 구성된다. 첫째, 유사 모델로부터 기하 패치를 구성하는 단계, 둘째, 획득한 패치의 3차원 형태 특징을 학습하는 단계, 셋째, 학습된 사전을 이용하여 기하를 복원하는 단계이며, 최종적으로 원본 모델과 복원 결과의 오차를 계산하며, 복원 결과의 정확도를 확인한다.

• 한국정밀공학회지
• /
• 제20권5호
• /
• pp.66-72
• /
• 2003

In case of hollow cylinder extrusion using porthole die, the effects of extrusion parameters-temperature, the speed of extrusion, the shape of the die and mandrel-on metal flow in porthole die extrusion of aluminum have been investigated. However, there have been few studies about condenser tube extruded by porthole die. Original metal flow of condenser tube by porthole die extrusion is similar to hollow cylinder extrusion but the estimation of metal flow for extrusion parameters is different. For example, variation of chamber length in hollow extrusion only affects the welding pressure, however, the welding chamber length in condenser tube extrusion influences to the welding pressure as well as the deflection of mandrel. This study was designed to evaluate metal flow, welding pressure, extrusion load, tendency of mandrel deflection according to angular variation in the bottom of chamber in porthole die. Estimation was carried out using finite element method in as non-steady state. Analytical results can provide useful information the optimal design of porthole die.

• 한국생활과학회지
• /
• 제15권4호
• /
• pp.573-583
• /
• 2006

Hair styles for human being develope according to the natural environment. Chinese hair styles have been changed from tousled hair to pigtailed hair, later additional style of shaved hair, became pigtailed. Each hair style for people, however, is based on each people's culture and history. Thus, the same changed had not been applied to each culture simultaneously. Hairstyle for Yao(遼) Jin(金) Yuan(元) that is a representation of ancient northern tribe, is summarized as follow; Tung Hu'(東胡)s inferior, Khitai(契丹)'s hair style is tousled hair and Sushen(肅愼),'s inferior, Jurchen(女眞) has partial shave and left 2 strand of pigtail. Hun'(匈奴)s inferior, Mongol(蒙古) has hair in top and shaved head except both sides and rear. One style is circular shape of braided hair at both sides. The other is one strand pigtail at the rear head, which is the original shape for Man'(滿) pigtail later.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2008년도 학술발표회 논문집
• /
• pp.1732-1736
• /
• 2008

The characteristics of a river flow analysis are significant for river maintenance plan. At the present time, HEC-RAS, 1-Dimensional Numerical Analysis Model, is mainly applied to analyze the character of a river flow. The shape of a river is somewhat in longitudinal linear form. It was suspected that the usage of 1-dimensional numerical analysis model is more economical. Development of numerical analysis models and computers are possible to calculate large volume. Hence, it is possible to adapt the analysis of the key stations by 2-dimensional numerical analysis model. The limitation of 1-Dimensional Numerical Analysis Model is that it is hard to evaluate structure affection of numerical simulation by energy loss coefficient at river structure analyzing. When adaptation of the 2-dimensional numerical analysis model in river structure ensues, it takes more objective analyzing than 1-dimensional numerical analysis model for flow affection by river structure. 2-dimensional numerical analysis model consults with the different structure position of hydraulic characteristics and different water depth of shape and scope in vertical flow. 1-dimensional numerical analysis model is possible to simulate with only energy loss coefficient for sudden river section changing, sudden waterway changing by curved. 2-dimensional numerical analysis model use original geographical features. So the model removes technical subjectivity of faulty judgment. It is an objective analysis.