• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1330-1338
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• 2024

Information on isotopic composition and geometric structure is necessary for identifying a true warhead. Nevertheless, such classified information should be protected physically or electronically. With a novel Hash encryption algorithm, this paper presents a Monte Carlo-based design of a neutron activation analysis verification module. The verification module employs a thermal neutron source, a non-uniform mask (physically encrypting information about isotopic composition and geometric structure), a gamma detector array, and a Hash encryption algorithm (for electronic encryption). In the physical field, a non-uniform mask is designed to distort the characteristic gamma rays emitted by the inspected item. Furthermore, as part of the Hash algorithm, a key is introduced to encrypt the data and improve the system resolution through electronic design. In order to quantify the difference between items, Hamming distance is used, which allows data encryption and analysis simultaneously. Simulated inspections of simple objects are used to quantify system performance. It is demonstrated that the method retains superior resolution even with 1% noise level. And the performances of anti-statistical attack and anti-brute force cracking are evaluated and found to be very excellent. The verification method lays a solid foundation for nuclear disarmament verification in the upcoming era.

• Journal of the Optical Society of Korea
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• 제15권3호
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• pp.209-215
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• 2011

A new iterative algorithm is developed to estimate LIDAR ratio for a thin cirrus cloud over an aerosol layer. First, the thin cirrus cloud is screened out and replaced by a modeled LIDAR signal and the extinction coefficients of the aerosol layer are derived using the Fernald backward method. These aerosol coefficients are referred as the "actual values". Second, the original LIDAR signal which includes the thin cirrus cloud is also inverted by the Fernald backward method down to the aerosol layer but using different LIDAR ratio for the thin cirrus cloud. Depending on the different assumptions about the LIDAR ratio of the thin cirrus cloud, different sets of aerosol extinction can be derived. The "actual values" which are found in the first step can be used to constrain this iterative progress and the correct LIDAR ratio of the thin cirrus cloud can be found. The detailed description of this method and retrieval examples are given in the paper. The cases compared with other methods are presented and the statistical result is also shown and agrees well with other studies.

• Journal of the Optical Society of Korea
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• 제14권4호
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• pp.444-450
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• 2010

The traditional approach to inverting aerosol extinction makes use of the assumption of a constant LIDAR ratio in the entire Mie-LIDAR signal profile using the Fernald method. For the large uncertainty in the cloud optical depth caused by the assumed constant LIDAR ratio, an not negligible error of the retrieved aerosol extinction below the cloud will be caused in the backward integration of the Fernald method. A new algorithm to determine aerosol extinction below a cirrus cloud from Mie-LIDAR signals, based on a new cloud boundary detection method and a Mie-LIDAR signal modification method, combined with the backward integration of the Fernald method is developed. The result shows that the cloud boundary detection method is reliable, and the aerosol extinction below the cirrus cloud found by inverting from the modified signal is more efficacious than the one from the measured signal including the cloud-layer. The error due to modification is less than 10% taken in our present example.

• 대한산업공학회지
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• 제22권4호
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• pp.705-718
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• 1996

A similarity coefficient based algorithm is proposed to solve the machine cells and part families formation problem in group technology. Similarity coefficients are newly designed from the machine-part incidence matrix. Machine cells are formed using a recurrent neural network in which the similarity coefficients are used as connection weights between processing units. Then parts are assigned to complete the cell composition. The proposed algorithm is applied to 30 different kinds of problems appeared in the literature. The results are compared to those by the GRAFICS algorithm in terms of the grouping efficiency and efficacy.

• 한국콘텐츠학회논문지
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• 제8권3호
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• pp.8-17
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• 2008

본 논문에서는 새로운 주요객체 자동추출 알고리즘을 제안한다. 제안된 알고리즘은 크게 2단계 과정으로 요약될 수 있다. 1단계로 객체와 배경을 분리하는 영상분할 작업을 수행한다. 우선적으로 '인간은 3또는 4개의 주요 색상으로 축약하여 사물을 인식한다'는 연구 결과에 따라 K-means 알고리즘을 이용하여 3구역으로 분할하고, 분할된 영상 간 히스토그램 유사도를 계산하여 임계값 이상으로 유사하면 병합하는 과정을 수행한다. 2단계로 영상구도에 근거해 분할된 영상 중에 객체라고 지정하는 작업을 수행한다. 사람이 사진을 잘 찍기 위해서는 '주요객체의 위치를 영상구도에 맞추어 촬영하는 것이 바람직하다는 사실'에 근거하여 삼각구도를 바탕으로 가중치 마스크를 설계하여 객체위치를 역 추정하였다. 제안된 방법의 우수성을 보이기 위해 약 400개의 영상에 대해 실험하였으며, 최근에 발표된 KMCC, GBIS방법과도 비교하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권12호
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• pp.5231-5248
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• 2016

As a service-oriented paradigm, web service composition has obtained great attention from both academia and industry, especially in the area of cloud service. Nowadays more and more web services providing the same function but different in QoS are available in cloud, so an important mission of service composition strategy is to select the optimal composition solution according to QoS. Furthermore, the selected composition solution should satisfy the service level agreement (SLA) which defines users' request for the performance of composite service, such as price and response time. A composite service is feasible only if its QoS satisfies user's request. In order to obtain composite service with the optimal QoS and avoid SLA violations simultaneously, in this paper we first propose a QoS evaluation method which takes the SLA satisfaction into account. Then we design a service selection algorithm based on our QoS evaluation method. At last, we put forward a parallel running strategy for the proposed selection algorithm. The simulation results show that our approach outperforms existing approaches in terms of solutions' optimality and feasibility. Through our running strategy, the computation time can be reduced to a large extent.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1995년도 학술대회
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• pp.77-81
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• 1995

Video composition is to integrate multiple image materials into one scene. It considerably enhances the degree of freedom in producing various scenes. However, we need to adjust the viewing point sand the image planes of image planes of image materials for high quality video composition. In this paper, were propose an intelligent video composition technique concentrating on the composition of CG and real scene. We first model the camera system. The projection is assumed to be perspective and the camera motion is assumed to be 3D rotational and 3D translational. Then, we automatically extract camera parameters comprising the camera model from real scene by a dedicated algorithm. After that, CG scene is generated according to the camera parameters of the real scene. Finally the two are composed into one scene. Experimental results justify the validity of the proposed method.

• 한국세라믹학회지
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• 제48권6호
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• pp.493-498
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• 2011

Optimal atomic configurations in a nanoparticle were predicted by genetic algorithm. A truncated octahedron with a fixed composition of 1 : 1 was investigated as a model system. A Python code for genetic algorithm linked with a molecular dynamics method was developed. Various operators were implemented to accelerate the optimization of atomic configuration for a given composition and a given morphology of a nanoparticle. The combination of random mix as a crossover operator and total_inversion as a mutation operator showed the most stable structure within the shortest calculation time. Pt-Ag core-shell structure was predicted as the most stable structure for a nanoparticle of approximately 4 nm in diameter. The calculation results in this study led to successful prediction of the atomic configuration of nanoparticle, the size of which is comparable to that of practical nanoparticls for the application to the nanocatalyst.

• 정보과학회 논문지
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• 제42권11호
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• pp.1332-1338
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• 2015

최근 고품질, 초고해상도 실시간 렌더링 지원을 위하여 다중 GPU 렌더링에 대한 관심이 커지고 있다. 실시간 렌더링에서 여러 개의 GPU로 고성능을 달성하기 위해서는 GPU 간의 데이터 전송 지연과 프레임 합성 부하를 고려해야 한다. 이 논문은 이러한 부하를 최소화하고 다중 GPU의 효율을 향상하기 위해 split frame 렌더링의 동기화를 묵시적 질의 기반으로 향상하는 기법을 제안한다. 또한, 이러한 묵시적 동기화 기반 프레임 합성을 지원하기 위한 메시지 큐 기반의 렌더링 스케줄링 알고리즘도 제안한다. 본 알고리즘을 적용한 실험은 본 알고리즘이 기존 알고리즘 대비 200% 이상 효율을 향상함을 확인하였다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.404-409
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• 1998

In this paper, we propose a learning algorithm of fuzzy neural networks with trapezoidal fuzzy weights. This fuzzy neural networks can use fuzzy numbers as well as real numbers, and represent linguistic information better than standard neural networks. We construct trapezodal fuzzy weights by the composition of two triangles, and devise a learning algorithm using the two triangular membership functions, The results of computer simulations on numerical data show that the fuzzy neural networks have high fitting ability for target output.