• 감성과학
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• 제20권1호
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• pp.57-66
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• 2017

다양한 이미지 샘플의 Eye test를 바탕으로 기술적인 화질 지표 조절을 통하여 감성 화질을 최적화 시키는 방법이 소개된다. 여러 가지 이미지 콘텐츠의 다양한 이미지에 대하여, 콘트라스트, 명도, 채도 화질 지표 톤 커브를 사용하여 평가가 수행 되었다. 이미지 화질 향상에 기여하는 우선순위는 명암, 채도 및 밝기 순으로 분석 되었다. 이미지 감성 화질 측정치의 기술적인 화질 지표 변화에 따른 기울기의 공통점을 살펴본 결과, 거의 0, 중간 그리고 최대 기울기의 영역으로 구성된 함수 형태로 모델링을 할 경우, 기존의 역 U 형태의 성질 뿐 아니라 log 또는 포화 형태의 감성 화질 변화까지 분석 가능함을 알 수 있었다. 단일 및 복수의 화질 지표의 경우에 대하여도 화질 개선 방안이 모색되었으며, 기존 및 본 논문에서 분석된 결과를 위한 새로운 함수가 소개 되었다. 복수의 통합적 이미지 화질 지표를 통하여 향상 시킬 경우 오직 몇몇 한정된 지표 제어의 경우에만 실현 가능하다는 것을 알 수 있었다. 또한, 화질 향상 방법은 영상 콘텐츠에 따라 크게 차이가 없음을 알 수 있었다.

• Ocean Systems Engineering
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• 제2권2호
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• pp.137-145
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• 2012

Recent developments in underwater image recognition methods have received large attention by the ocean engineering researchers. In this paper, an improved bi-dimensional empirical mode decomposition (BEMD) approach is employed to decompose the given underwater image into intrinsic mode functions (IMFs) and residual. We developed a joint algorithm based on BEMD and Canny operator to extract multi-pixel edge features at multiple scales in IMFs sub-images. So the multiple pixel edge extraction is an advantage of our approach; the other contribution of this method is the realization of the bi-dimensional sifting process, which is realized utilizing regional-based operators to detect local extreme points and constructing radial basis function for curve surface interpolation. The performance of the multi-pixel edge extraction algorithm for processing underwater image is demonstrated in the contrast experiment with both the proposed method and the phase congruency edge detection.

• 대한기계학회논문집B
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• 제28권5호
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• pp.510-517
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• 2004

A fine hot-wire is used both as a heating element and a temperature sensor in transient hot-wire method. The traditional sensor system is unnecessarily big so that it takes large fluid volume to measure the thermal conductivity. To dramatically reduce this fluid volume, a new sensor fabrication and a data processing method are proposed in this article. Contrast to the conventional and most popular two wire sensor, the new sensor system is made up of divided multiple long and short wires. Through validation experiments, it is found that the measured thermal conductivities of the glycerin are exactly same each other between the conventional and proposed new method. Also some technical considerations in arranging the multiple wires are briefly discussed.

• 한국국방경영분석학회지
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• 제6권1호
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• pp.79-92
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• 1980

In cost-only incentive contract the emphasis is the attainment of efficient and effective cost control. In contrast multiple incentives contract correlates contractor's profit motives with the generalized government objective function, the decision variables of which are performance or quality (technical progress), time or schedule (timely development and delivery) and the cost (efficient and effective cost control) Under multiple incentive structure, it is essential to formulate the trade-off curves between cost and performance, which are called iso-fee curves. Trade-off curves depict the combination of cost and performance achievement for which the contractor will be rewarded with the same fee. The basic function of trade-off curves is to show he the contractor will be motivated by incentive arragement to trade off or sacrifice the achievement in one incentive element for the acnievment in another.

• International Journal of Advanced Culture Technology
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• 제9권3호
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• pp.283-290
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• 2021

Recently, correlated superposition coding (CSC) has been proposed to implement non-orthogonal multiple access (NOMA) without successive interference cancellation (SIC), without loss of spectral efficiency, in contrast to conventional independent superposition coding (ISC). However, correlation between signals has reduced the average total allocated power, which results in degraded performance. Thus, in order to avoid the reduction of the average total allocated power owing to correlation between signals, this paper proposes a cross-correlated quadrature amplitude modulation (QAM) NOMA scheme under Rayleigh fading channel surroundings. First, we design the cross-correlated QAM NOMA scheme. Then, simulations demonstrate that for the weaker channel gain's user, the symbol error rate (SER) performance of the proposed cross-correlated QAM NOMA improves largely, whereas for the stronger channel gain's user, the SER performance of the proposed cross-correlated QAM CSM NOMA degrades little, compared to that of the conventional QAM NOMA.

• 정보보호학회논문지
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• 제10권3호
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• pp.37-48
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• 2000

서울Visual cryptography scheme is a simple method in which can be directly decoded the secret information in human visual system without performing any cryptographic computations. This scheme is a kind of secret sharing scheme in which if a secret of image type is scattered to n random images(slides) and any threshold (or more) of them are stacked together the original image will become visible. In this paper we consider (2, n) visual cryptography scheme and propose a new construction method in which the number of expanded pixels can be reduced by using the sample matrix. The proposed scheme can futhermore distribute the multiple secret image to each group according to the difference of relative contrast.

• Advances in pediatric surgery
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• 제18권2호
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• pp.75-82
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• 2012

In one-stage transanal endorectal pull-through operation (TERPT) for Hirschsprung disease, preoperative evaluation by contrast enema (CE) is important tool in aspect of planning of surgical procedure as well as diagnosis. This study was to evaluate the significance of CE for identifying the extent of aganglionic bowel. A retrospective analysis was performed in 40 patients who underwent TERPT between 2003 and 2011. The authors reviewed the CE studies and their correlation with pathologic extent of aganglionosis. Total 66 contrast enemas were performed in 40 patients. Twenty patients underwent single CE, but 20 patients required multiple CEs. In single CE group, 17 had clear radiographic transition zone, but 3 had less definite transition zone. In multiple CE group, 17 patients who had equivocal finding in first or second CE had definite radiographic transition zone, but 3 patients of this group had less definite radiographic transition zones. Overall, 34 patients (85%)had clear radiographic transition zone by single or repeated CE. One (2.9%) out of 34 patients with clear radiographic transition zone had discordance between radiographic and pathologic transition zone. In contrast 4 (66.7%) out of 6 patients with equivocal radiographic transition zone had discordance between radiographic and pathologic transition zone. Observation of clear radiographic transition zone is important in preparation of TERPT, and repeated CE is helpful to reduce the discordance between radiographic and pathologic transition zone. Awareness of the possibility of discordance is also important if radiographic transitional zone is not clear.

• Asian Pacific Journal of Cancer Prevention
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• 제14권6호
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• pp.3663-3667
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• 2013

Background: Multiple myeloma is a malignant silent incurable plasma cell disorder. The present study aimed to assessed the activation of the oxidative stress pathway in afected patients Materials and Methods: Advanced oxidation protein products (AOPPs), malondialdehyde (MDA), adenosine deaminase (ADA), total antioxidant capacity (TAC) levels, glutathione, ascorbic acid (vitamin C), ${\alpha}$-tocopherol (vitamin E) in addition to related enzymes glutathione peroxidase (GSH-Px), glutathione reductase (GSH-R) and superoxide dismutase (SOD) were analyzed in sixty patients with multiple myeloma before and after one month treatment with induction therapy. Results: The results of the study showed a significant elevation in AOPPs, MDA, ADA levels in patients with multiple myeloma before and after treatment in comparison to healthy control samples In contrast TAC glutathione, vitamin C and E, and the antioxidant enzymes levels were decreased significantly. On comparing samples of MM patients after treatment, there was significant increase of TAC glutathione, vitamin C and E, and the antioxidant enzymes in parallel with decreasing AOPPs, MDA and ADA levels in comparison with samples of patients before treatment. Conclusions: The results indicate oxidative stress and DNA damage activity increase in MM and are alleviated in response to therapy.

• Journal of Mechanical Science and Technology
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• 제18권1호
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• pp.132-144
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• 2004

This paper presents a new method driving multiple robots to their goal position without collision. To consider the movement of the robots in a work area, we adopt the concept of avoidability measure. The avoidability measure figures the degree of how easily a robot can avoid other robots considering the velocity of the robots. To implement the concept to avoid collision among multiple robots, relative distance between the robots is proposed. The relative distance is a virtual distance between robots indicating the threat of collision between the robots. Based on the relative distance, the method calculates repulsive force against a robot from the other robots. Also, attractive force toward the goal position is calculated in terms of the relative distance. These repulsive force and attractive force are added to form the driving force for robot motion. The proposed method is simulated for several cases. The results show that the proposed method steers robots to open space anticipating the approach of other robots. In contrast, since the usual potential field method initiates avoidance motion later than the proposed method, it sometimes fails preventing collision or causes hasty motion to avoid other robots. The proposed method works as a local collision-free motion coordination method in conjunction with higher level of task planning and path planning method for multiple robots to do a collaborative job.

• 전자공학회논문지SC
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• 제48권5호
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• pp.31-36
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• 2011

본 논문에서는 Mel-Frequency Cepstral Coefficient (MFCC), Decorrelated Filter Bank (DFB), Octave-based Spectral Contrast (OSC), Zero-Crossing Rate (ZCR), 그리고 Spectral Contract/Roll-Off를 복합 특징벡터로 결합하여 Support Vector Machine (SVM)을 이용한 음악 장르 분류 시스템을 설계하였다. 기존 방식에서는 전체 학습 데이터에 대한 특징벡터를 정규화를 한 후 SVM 모델을 생성하여 분류를 시행하였다. 본 논문에서는 비교 대상이 되는 한 쌍의 클래스에 대해서 One-Against-One (OAO) SVM으로 모델을 생성할 때 선택된 두 클래스의 특징벡터에 대해서만 정규화를 시행하는 방식을 제안한다. 기존 정규화 방식을 이용하면 단일 특징벡터로 OSC를 사용할 경우에는 60.8%, 복합 특징벡터를 모두 이용하는 경우에는 77.4%의 인식율을 얻을 수 있었다. 또한, 제안된 정규화 방식을 이용하면 OSC와 복합 특징벡터에 대해서 각각 8.2%와 3.3%의 추가적인 성능 향상을 얻을 수 있었다.