• Educational Technology International
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• 제20권2호
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• pp.137-168
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• 2019

This study examined the effects of information volume and distribution on learners' cognitive load and recall in a mobile augmented reality (AR) environment. Information volume refers to the degree of information users are provided in a learning task, while information distribution indicates the way in which information is distributed, either in a virtual or real format. Sixteen undergraduate students participated in the study, which employed a 2 × 3 randomized block factorial design with repeated measures. Information volume and distribution were independent variables, and factors in learners' cognitive load (mental effort, perceived ease of use, and perceived task difficulty) and recall test scores were the dependent variables. Information volume had significant main effects on perceived ease of use and task difficulty, and recall test scores, while information distribution had significant main effects on perceived task difficulty and test scores. A detailed discussion and implications are provided.

• 한국의류학회지
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• 제34권1호
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• pp.67-78
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• 2010

This paper analyzes how to measure breast volume and the change in breast volume after wearing a brassiere. Measurement using a breast replica is used to measure the breast volume of 41 women in their twenties. The rate of persons having flat and hemispherical breast are high. The majority of subjects are size 75A, 80A, and 75B, and their under-bust size is 70. The current size specification should be refined for fitting according as the girth under bust decreases. The correlation between breast volume and the circumference of the breasts was high. It was more reliable to set up the cup size of a brassiere using the breast circumference. The mean breast volume is 263.68cc (nude) and the total volume wearing brassiere is 342.05cc. The volume difference according to wearing a brassiere is 78.37cc, which is less than the brassiere volume itself. The results show, the less breast volume of a subject, then the greater volume in wearing a brassiere.

• The Journal of Asian Finance, Economics and Business
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• 제6권4호
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• pp.297-307
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• 2019

Despite the fact that the implementation of 5% rule is widely recognized to enhance the transparency of capital market and fairness of corporate governance market, a few evidences present information effect of 5% rule. Using 7,088 non-financial firm-year observations listed on the Korea Stock Exchange from 2006 to 2012, we analyze the relation between trading volume and 5% rule disclosure. The results show that the daily and abnormal trading volume is increased when 5% rule disclosure is released. Moreover, the trading volume is significantly increased during cooling period. Specifically, trading volume is significantly greater when one day before cooling period or the expiration day of cooling period. We also find the information effect of firms with stable ownership structure before 5% rule disclosure is relatively smaller than the firms with unstable ownership structure with unstable ownership structure. These results imply that capital market participants use the information from 5% rule disclosure and reflect in their real economic decision.

• Journal of Multimedia Information System
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• 제5권1호
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• pp.35-42
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• 2018

Direct volume rendering (DVR) is an important 3D visualization method for medical images as it depicts the full volumetric data. However, because DVR renders the whole volume, regions of interests (ROIs) such as a tumor that are embedded within the volume maybe occluded from view. Thus, conventional 2D cross-sectional views are still widely used, while the advantages of the DVR are often neglected. In this study, we propose a new visualization algorithm where we augment the 2D slice of interest (SOI) from an image volume with volumetric information derived from the DVR of the same volume. Our occlusion-based DVR augmentation for SOI (ODAS) uses the occlusion information derived from the voxels in front of the SOI to calculate a depth parameter that controls the amount of DVR visibility which is used to provide 3D spatial cues while not impairing the visibility of the SOI. We outline the capabilities of our ODAS and through a variety of computer tomography (CT) medical image examples, compare it to a conventional fusion of the SOI and the clipped DVR.

• 한국컴퓨터그래픽스학회논문지
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• 제11권1호
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• pp.40-49
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• 2005

Several optimization techniques have been proposed for volume ray casting, but these cannot achieve real-time frame rates. In addition, it is difficult to apply them to some applications that require perspective projection. Recently, hardware-based methods using 3D texture mapping are being used for real-time volume rendering. Although rendering speed approaches real time, the larger volumes require more swapping of volume bricks for the limited texture memory. Also, image quality deteriorates compared with that of conventional volume ray casting. In this paper, we propose a data structure for real-time volume ray casting named PERM (Precomputed dEnsity and gRadient Map). The PERM stores interpolated density and gradient vector for quantized cells. Since the information requiring time-consuming computations is stored in the PERM, our method can ensure interactive frame rates on a consumer PC platform. Our method normally produces high-quality images because it is based on conventional volume ray casting.

• 한국정보처리학회논문지
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• 제7권10호
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• pp.3280-3289
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• 2000

본 논문에서는 볼륨데이터와 전역적 형태정보를 이용하여 볼륨렌더링의 질적측면과 속도측면에서 개선할 수 있는 선택적 볼륨렌더링방법을 제안한다. 선택적 볼륨렌더링방법은 관심부위를 구성하는 외곽선으로부터 최소거리를 결정하는 거리변환을 통하여 거리변환볼륨을 생성하고 이를 렌더링하는 방법으로 형태정보를 이용함으로써 서로 다른 객체들간에 비슷한 명암도로 인해 동일 객체로 인식되는 것을 방지하고, 복잡한 형태를 효과적으로 나타낼 수 있다. 실험결과로는 EBCT 심장데이터에 선택적 볼륨렌더링방법을 적용하여 좌심실, 우심실 렌더링 결과영상과 함께 보간법에 따른 선택적 샘플링 방법 적용결과를 제시한다. 본 제안방법은 볼륨데이터로부터 얻은 형태정보로부터 관심객체 표면을 정확하고 빠르게 가시화할 수 있다.

• Journal of Information Processing Systems
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• 제15권4호
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• pp.820-832
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• 2019

Estimation of accurate blood volume flow in ultrasound Doppler blood flow spectrograms is extremely important for clinical diagnostic purposes. Blood volume flow measurements require the assessment of both the velocity distribution and the cross-sectional area of the vessel. Unfortunately, the existing volume flow estimation algorithms by ultrasound lack the velocity space distribution information in cross-sections of a vessel and have the problems of low accuracy and poor stability. In this paper, a new robust ultrasound volume flow estimation method based on multigate (RMG) is proposed and the multigate technology provides detail information on the local velocity distribution. In this method, an accurate double iterative flow velocity estimation algorithm (DIV) is used to estimate the mean velocity and it has been tested on in vivo data from carotid. The results from experiments indicate a mean standard deviation of less than 6% in flow velocities when estimated for a range of SNR levels. The RMG method is validated in a custom-designed experimental setup, Doppler phantom and imitation blood flow control system. In vitro experimental results show that the mean error of the RMG algorithm is 4.81%. Low errors in blood volume flow estimation make the prospect of using the RMG algorithm for real-time blood volume flow estimation possible.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1999년도 추계 학술대회논문집
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• pp.158-162
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• 1999

This thesis presents applications of three dimensional visualization technique based on shear-warp volume rendering to medical information. Volume rendering is compared to surface rendering and acceleration technique is also presented. The presented rendering techniques by using three-dimensional arrays of data are a widely used representation for computational fluid dynamics and geological structures as well as medical information.

• 한국생활과학회지
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• 제18권6호
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• pp.1267-1276
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• 2009

The purpose of this study is to classify breast types and to inquire about characteristics depending on breast types of women subjects in their twenties. We researched size items affecting breast volume and regression equations for the prediction of breast volume, and thereby, we will be able to provide some basic data, useful to the development of the brassiere depending on breast types. As a result of categorizing the types of three breast types, "type 1" was characterized by big and greatest protrusion of the breast with large breast volume and a large bust, while "type 2" was characterized by flat breasts with the least breast volume and least bust, and "type 3" was characterized by breast location apart from the center front line. Breast volume is significant in establishment of the brassiere cup depending on breast type. Five items such as, the circumference of the breast, the length of the upper breast, the depth of the breast point, the length of the shoulder point-breast point, and the length of the inferior breast were extracted through regression equations for breast volume.

• 한국게임학회 논문지
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• 제9권6호
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• pp.191-196
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• 2009

볼륨 렌더링은 볼륨 데이터로부터 유용한 정보를 추출하여 시각화 하는 방법이다. 일반적으로 볼륨 렌더링에서 사용하는 데이터가 크기 때문에 실시간 처리가 가능한 수준의 빠른 렌더링을 위한 가속기법들이 중요하다. 최대-최소 8진트리는 고속 볼륨 렌더링을 위한 자료구조이지만, 볼륨데이터가 클수록 생성시간이 오래 걸리는 문제가 있다. 본 논문에서는 CUDA를 이용하여 GPU에서 최대-최소 8진트리의 생성을 가속화 하는 방법을 제안한다. 먼저 볼륨데이터에 Space Filling Curve를 적용하여 3차원의 데이터를 연속적인 1차원 배열형태로 변환한다. 이렇게 변환된 데이터로부터 최대-최소 8진트리 자료구조를 만들어 빈공간 도약기법에 적용함으로써 렌더링 속도를 향상시킬 수 있다.