• 융합신호처리학회논문지
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• 제3권3호
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• pp.47-53
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• 2002

본 논문은 동영상의 대표프레임에서 eigen value와 휘도 성분을 이용한 내용기반 검색 기법에 관한 연구이다. video를 shot단위로 분할하여 shot을 대표하는 대표프레임을 얻어내고, 그 대표프레임을 Eigen Component Analysis(ECA)를 이용하여 데이터베이스를 생성하여 shot들의 휘도값 분포를 구한다. 생성된 코드북과 각 대표 프레임에 대한 코드북 인덱스 값, 휘도값을 database화하여 질의 영상과 video database간의 저장된 비디오들의 코드북과 코드워드간의 유클리디안 거리를 이용하여 유사도 높은 비디오를 찾고, 검색되어진 video에 포함된 대표프레임들의 코드북 인덱스 값과 입력 영상의 코드북 인덱스 값을 비교하여 입력 영상의 특징과 가장 유사한 대표프레임을 얻어낸다. 실험결과 제안된 방법이 검색에 있어서 영상의 형태에 대한 전체적인 특징을 제공하는 대표프레임의 eigen value와 휘도 성분을 이용함으로서 보다 검색 결과가 우수하며, 영상의 통계적인 특성을 이용함으로서 시간과 메모리 공간을 줄일 수 있음을 확인하였다.

• Smart Structures and Systems
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• 제14권3호
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• pp.469-477
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• 2014

As a kind of intelligent materials, conductive asphalt concrete has a broad application prospect including melting ice and snow on the pavement, closing cracks in asphalt concrete, sensing pavement damage, and so on. Conductive pavement will be suffered from fatigue failure as conventional pavement in the process of service, and this fatigue damage of internal structure can be induced by electrical signal output. The characteristics of electrical signal variation of conductive asphalt concrete in the process of fatigue cracking were researched in this paper. The whole process was clearly divided into three stages according to resistance changes, and the development of fatigue damage wasn't obvious in stage I and stage II, while in stage III, the synchronicity between the resistance and damage began to appear. Thus, fatigue damage variable D and initial damage value $D_0$ represented by the functions of resistance were introduced in stage III. After calculating the initial damage value $D_0$ under different stress levels, it was concluded that the initial damage value $D_0$ had no noticeable change, just ranged between 0.24 and 0.25. This value represented a critical point which could be used to inform the repair time of early fatigue damage in the conductive asphalt pavement.

• 무역학회지
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• 제43권6호
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• pp.193-214
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• 2018

최근 공공기관은 경제적 가치창출을 넘어 사회적 가치(Social Value) 창출 역할을 강조받고 있다. 본 연구에서는 항만을 관리·운영하는 주체인 항만공사에 대한 사회적 가치 실현을 위한 평가지표 및 항만공사형 사회적 가치 실현모델을 제시하고자 하였다. 경영평가제도의 5가지 사회적 가치 평가지표를 중심으로 정량적으로 측정가능한 KPI(Key Performance Index)를 제시하고 항만공사별 비전, 미션과 사회적 가치 추진전략 및 이해관계당사자 분석을 통해 항만공사 고유업무영역에 기반한 항만서비스 전달 및 구매 고객형 사회적 가치 모델 개념을 제시하였다.

• 정보학연구
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• 제9권4호
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• pp.49-55
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• 2006

In this paper, a new fragile watermarking algorithm for digital image is presented, which makes resolving the security and forgery problem of the digital image to be possible. The most suitable watermarking method that verifies the authentication and integrity of the digital image is the Wong's method, which invokes the hash function (MD5). The algorithm is safe because this method uses the hash function of the cryptology. The operations such as modulus, complement, shift, bitwise exclusive-or, bitwise inclusive-or are necessary for calculating the value of hash function. But, in this paper, an Arithmetic encoding method that only includes the multiplication operation is adopted. This technique prints out accumulative probability interval, which is obtained by multiplying the input symbol probability interval. In this paper, the initial probability interval is determined according to the value of the key, and the input sequence of the symbols is adjusted according to the key value so that the accumulative probability interval will depend on the key value. The integrity of the algorithm has been verified by experiment. The PSNR is above the 51.13db and the verifying time is $1/3{\sim}1/4$ of the verifying time of using the hash function (MD5), so, it can be used in the real-time system.

• Journal of Power Electronics
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• 제18권1호
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• pp.300-308
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• 2018

An online estimation method for wireless power transfer (WPT) systems is presented without using any measurement of the secondary side or the load. This parameter estimation method can be applied with a controlling strategy that removes both the receiving terminal controller and the wireless communication. This improves the reliability of the system while reducing its costs and size. In a wireless power transfer system with an LCCL impedance matching circuit under a rectifier load, the actual load value, voltage/current and mutual inductance can be reflected through reflected impedance measuring at the primary side. The proposed method can calculate the phase angle tangent value of the secondary loop circuit impedance via the reflected impedance, which is unrelated to the mutual inductance. Then the load value can be determined based on the relationships between the load value and the secondary loop impedance. After that, the mutual inductance and transfer efficiency can be computed. According to the primary side voltage and current, the load voltage and current can also be detected in real-time. Experiments have verified that high estimation accuracy can be achieved with the proposed method. A single-controller based on the proposed parameter estimation method is established to achieve constant current control over a WPT system.

• Asian-Australasian Journal of Animal Sciences
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• 제23권12호
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• pp.1639-1644
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• 2010

An experiment was conducted to evaluate the effects of dietary acetyl-L-carnitine (ALC) on growth performance, carcass characteristics, meat quality and lipid metabolism in broilers. A total of 240 one-day-old male Arbor Acres broilers were randomly allocated to 4 dietary treatments (0, 300, 600, and 900 mg/kg dietary ALC supplementation, respectively). Compared with the control treatment, addition of ALC resulted in lower (linear effect, p<0.05) ADG and AFI. Abdominal fat percentage decreased (linear effect, p<0.05) as dietary ALC was increased, but there was no effect on dressing percentage, breast muscle percentage or thigh muscle percentage. Breast muscle pH value 24 h post-mortem increased (linear effect, p<0.05), but there were no significant differences among treatments. However, thigh muscle pH value increased (linear effect, p<0.05) as dietary ALC was increased. Breast and thigh muscle $a^*$ values increased (linear effect, p<0.05), and breast and thigh muscle $b^*$ values decreased (linear effect, p<0.05) with increased ALC in the diet. In addition, breast and thigh muscle shear force value decreased (linear effect, p<0.05) as dietary ALC was increased. Total cholesterol, triglyceride, low-density lipoprotein cholesterol and lipoprotein lipase decreased (linear effect, p<0.05) and free fatty acid and lipase in serum increased (linear effect, p<0.05) with increased ALC in diets.

• Korean Journal of Radiology
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• 제21권5호
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• pp.550-560
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• 2020

Objective: To evaluate the interobserver agreement, diagnostic value, and associated clinical factors of automated breast ultrasound (ABUS) coronal features in differentiating breast lesions. Materials and Methods: This study enrolled 457 pathologically confirmed lesions in 387 female (age, 46.4 ± 10.3 years), including 377 masses and 80 non-mass lesions (NMLs). The unique coronal features, including retraction phenomenon, hyper- or hypoechoic rim (continuous or discontinuous), skipping sign, and white wall sign, were defined and recorded. The interobserver agreement on image type and coronal features was evaluated. Furthermore, clinical factors, including the lesion size, distance to the nipple or skin, palpability, and the histological grade were analyzed. Results: Among the 457 lesions, 296 were malignant and 161 were benign. The overall interobserver agreement for image type and all coronal features was moderate to good. For masses, the retraction phenomenon was significantly associated with malignancies (p < 0.001) and more frequently presented in small and superficial invasive carcinomas with a low histological grade (p = 0.027, 0.002, and < 0.001, respectively). Furthermore, continuous hyper- or hypoechoic rims were predictive of benign masses (p < 0.001), whereas discontinuous rims were predictive of malignancies (p < 0.001). A hyperechoic rim was more commonly detected in masses more distant from the nipple (p = 0.027), and a hypoechoic rim was more frequently found in large superficial masses (p < 0.001 for both). For NMLs, the skipping sign was a predictor of malignancies (p = 0.040). Conclusion: The coronal plane of ABUS may provide useful diagnostic value for breast lesions.

• 한국컴퓨터정보학회논문지
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• 제10권3호
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• pp.151-159
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• 2005

기존의 디지털 워터마킹 기술은 대부분 삽입과 검출에서 동일한 키를 사용하는 대칭키 방식이다. 이러한 대칭키 워터마킹 방식은 검출을 쉽게 할 수 있는 반면에 공격자에 의하여 검출기의 비밀 키 정보가 유출될 경우 삽입 정보가 제거되거나 변조되는 치명적인 공격을 받을 수 있다. 따라서 최근에는 삽입기에서 삽입한 비밀 정보를 검출기에서 공개 키를 이용하여 검출하는 비대칭 워터마킹(Asymmetric watermarking)방식이 차세대 워터마킹 기술로 주목을 받고 있다. 본 논문에서는 선형 연립방정식의 해집합을 이용하여 개인 키의 탐색 공간을 효과적으로 확장하였다. 또한 공개 키로부터 개인 키를 유출할 수 없도록 하기 위하여 공개 키의 생성은 안전한 선형변환 방식에 기초하였으며 높은 상관도 검출이 가능하도록 구성되었다. 실험결과 워터마크가 삽입된 영상에서 1비트의 정보 뿐만 아니라, 멀티 비트의 정보에 대한 공개 키 상관도 검출이 정확히 이루어짐을 확인할 수 있었으며 JPEG압축 후에도 높은 상관도 검출이 가능한 것으로 나타났다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권12호
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• pp.5596-5615
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• 2016

Security is one of the major challenges in the Wireless Sensor Networks (WSNs). WSNs are more vulnerable to adversarial activities. All cryptographic security services indirectly depend on key management. Symmetric key management is the best key establishment process for WSNs due to the resource constraints of the sensors. In this paper, we proposed dynamic session key establishment scheme based on randomly generated nonce value and sensor node identity, in which each sensor node is equipped with session key on expire basis. The proposed scheme is compare with five popular existing key management systems. Our scheme is simulated in OMNET++ with MixiM and presented experimental results. The analytical study and experimental results show the superiority of the proposed scheme over the existing schemes in terms of energy, storage, resilience and communication overhead.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2010년도 한국컴퓨터종합학술대회논문집 Vol.37 No.1(A)
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• pp.46-47
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• 2010