• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.780-791
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• 1996

A hybrid image processing system which automatically distinguished lean tissues in the image of a complex beef cut surface and generated the lean tissue contour has been developed. Because of the in homegeneous distribution and fuzzy pattern of fat and lean tissue on the beef cut, conventional image segmentation and contour generation algorithm suffer from a heavy computing requirement, algorithm complexity and poor robustness. The proposed system utilizes an artificial neural network enhance the robustness of processing. The system is composed of pre-network , network and post-network processing stages. At the pre-network stage, gray level images of beef cuts were segmented and resized to be adequate to the network input. Features such as fat and bone were enhanced and the enhanced input image was converted tot he grid pattern image, whose grid was formed as 4 X4 pixel size. at the network stage, the normalized gray value of each grid image was taken as the network input. Th pre-trained network generated the grid image output of the isolated lean tissue. A training scheme of the network and the separating performance were presented and analyzed. The developed hybrid system showed the feasibility of the human like robust object segmentation and contour generation for the complex , fuzzy and irregular image.

• 한국측량학회지
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• 제8권2호
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• pp.1-8
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• 1990

수치지형모텔의 데이타 구조로는 정규격자망 및 비정규삼각망 데이타구조가 널리 이용되고 있다. 정규격자망은 그 구조가 단순하고 간단한 반면에 지형 특성을 잘 반영하지 못하며 많은 데이타 용량을 요한다. 이와는 반대로 비정규삼각망 데이타 구조는 그 구축 방법이 어렵지만 지형 특성을 잘 살릴 수 있으며 적은 양의 데이타로 그의 응용분야에 적합한 정확도를 얻을 수 있다. 본 연구는 Delaunay triangulation에 바탕을 두고, 비정규삼각망 데이터 구조를 연구 개선시킴으로써 좀더 효율적인 수치지형모텔을 구성하는데 목적을 두었다. 이를 위하여 기존의 지도로부터 정규 및 비정규 데이타가 추출되었으며 두 데이터 구조에 대한 상호 비교가 이루어졌다.

• 정보처리학회논문지B
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• 제17B권5호
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• pp.375-380
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• 2010

객체 윤곽을 추출하는 대부분의 기존 방법들은 단일객체의 윤곽검출에 대해 연구하였다. 그러나, 실 세계에서는 복수객체가 일반적이다. 본 논문에서 제안한 복수객체 윤곽추출 알고리즘은 2 단계로 구성된다. 첫 번째 단계는 외적 및 내적을 사용하여 초기에 복수객체를 포함한 윤곽을 고속으로 분리하고 연결하여 각각이 윤곽이 단일 개체만을 포함하는 방법을 제안한다. 두 번째 단계는 각각의 윤곽에 포함된 단일 객체의 윤곽을 추출하는 개선된 능동윤곽모델 알고리즘을 설명한다. 여러 실험영상에 대한 실험결과는 다른 방법과 비교하여 속도가 빠르며 정확하게 윤곽을 추출한다.

• 지능정보연구
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• 제9권2호
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• pp.1-18
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• 2003

The automatic recognition of transport containers using image processing is very hard because of the irregular size and position of identifiers, diverse colors of background and identifiers, and the impaired shapes of identifiers caused by container damages and the bent surface of container, etc. We proposed and evaluated the novel recognition algorithm of container identifiers that overcomes effectively the hardness and recognizes identifiers from container images captured in the various environments. The proposed algorithm, first, extracts the area including only all identifiers from container images by using CANNY masking and bi-directional histogram method. The extracted identifier area is binarized by the fuzzy binarization method newly proposed in this paper and by applying contour tracking method to the binarized area, container identifiers which are targets of recognition are extracted. We proposed and applied the ART2-based RBF network for recognition of container identifiers. The results of experiment for performance evaluation on the real container images showed that the proposed algorithm has more improved performance in the extraction and recognition of container identifiers than the previous algorithms.

• 한국기계가공학회지
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• 제9권1호
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• pp.55-60
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• 2010

The air resistance about automotive body is studied by the flow analysis in this study. Maximum air flow velocity is shown with 28 to 30 m/s on the upper roof of automotive body. The air flow becomes most regular at automotive body model 3 but the model of 2 or 3 becomes irregular in comparison with the model 1. The maximum air resistance pressure is shown with 413 to 420 Pa at the front bumper of automotive body. The flow velocity at inlet or middle plane of automotive body is shown as the contour same with the model of 1, 2, or 3. But the velocity at outlet plane at model 1 is shown as the contour different with the model of 2 or 3.

• 한국측량학회지
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• 제10권2호
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• pp.49-55
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• 1992

수피표고모형에 있어서 표고자료의 추출은 매우 중요하다. 표고의 추출은 스캐닝방법과 디지타이징 방법이 있으나 본 연구에서는 디지타이징에 대한 것이다. 연속적 추출법은 하나의 등고선을 동일한 개체로 묶는 것이며, 정규적자법은 각 격자를 대표할 수 있는 표고데이타를 직접 읽는 방법이다. 그리고 지성선을 구성하는 등고선내의 추출점을 동일의 개체로 묶는 방법이 불규칙 삼각망법이다. 연구결과에서 연속적 추출법은 입력시간이 적게 걸렸으며, 불규칙 삼각망법은 추출점의 수가 가장 적게 나타났다.

• 대한세포병리학회지
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• 제8권1호
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• pp.1-10
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• 1997

The fine needle aspiration biopsy(FNAB) has become a popular method to diagnose mass lesions of the liver. Although many reports have listed FNAB criteria to be used to diagnose hepatocellular carcinoma(HCC), a diagnostic dilemma still exists at the extreme ends of the spectrum, particularly for well differentiated HCC. The authors reviewed a series of FNAB specimens of the liver to distinguish well differentiated HCC from nonneoplastic liver. Fifteen cytologic features were examined in this study: high cellularity, large sheet formation, trabecular pattern, acinar pattern, dispersed pattern, irregular arrangement, increased nuclear/cytoplasmic ratio, naked nuclei, irregular chromatin, irregular nuclear contour, multinucleation, uniform macronucleoli, multiple nuclei, uniform small cytoplasm and monotony of atypia. These features were examined in a series of 76 FNAB specimens. Fifty two specimens were from patients with HCC and 24 specimens were from patients with nonneoplastic lesion or tumors other than HCC containg adequate amount of nonneoplastic hepatocytes in smear. All specimens were coded as to the presence or absence of the above cytologic features. With the use of step-wise logistic regression analysis, three features were identified as the key cytologic features predictive of HCC: irregular chromatin, monotony of atypia and absence of large sheet formation. When these criteria were used, the sensitivity diagnosing HCC by FNAB was 94.2%, specificity 100%, positive predictive value 100% and negative predictive value was 88.9%.

• Spatial Information Research
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• 제11권1호
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• pp.23-32
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• 2003

GIS분야에서 불규칙삼각망은 저수량계산, 지형분석 등에 활용되며 표고, 경사, 방향 정보를 가지고 있기 때문에 처리시간과 용량이 많이 소요된다. 등고선을 활용하여 TIN을 구축하는 과정에서, 선의 단순화를 위해 사용하는 weed tolerance는 등고선상의 샘플 간격에 영향을 미치게 된다. 본 연구에서는 다양한 크기의 weed tolerance에 따른 TIN의 처리시간과 용량을 계산하였으며, 적절한 weed tolerance를 제시하기 위해 TIN으로부터 생성된 수치표고모형의 표준오차를 평가하여 허용오차 범위를 만족하는 weed tolerance를 결정하였다. 평가결과, DEM 표준오차 5m를 만족하는 TIN의 weed tolerance 는 70m였으며, DEM의 해상도는 20m로 나타났다.

• Journal of Computational Design and Engineering
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• 제3권3호
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• pp.286-294
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• 2016

In this paper we present an efficient technique for sketch-based 3D modeling using automatically extracted image features. Creating a 3D model often requires a drawing of irregular shapes composed of curved lines as a starting point but it is difficult to hand-draw such lines without introducing awkward bumps and edges along the lines. We propose an automatic alignment of a user's hand-drawn sketch lines to the contour lines of an image, facilitating a considerable level of ease with which the user can carelessly continue sketching while the system intelligently snaps the sketch lines to a background image contour, no longer requiring the strenuous effort and stress of trying to make a perfect line during the modeling task. This interactive technique seamlessly combines the efficiency and perception of the human user with the accuracy of computational power, applied to the domain of 3D modeling where the utmost precision of on-screen drawing has been one of the hurdles of the task hitherto considered a job requiring a highly skilled and careful manipulation by the user. We provide several examples to demonstrate the accuracy and efficiency of the method with which complex shapes were achieved easily and quickly in the interactive outline drawing task.

• Journal of Korean Neurosurgical Society
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• 제40권3호
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• pp.206-209
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• 2006

Objective : Traditionally, standard access to the posterior fossa was a suboccipital craniectomy. After introducing the technique and benefit of posterior fossa craniotomy, several surgeons have used this procedure to manage various pathologies in posterior fossa in children. Though this approach offers several advantages over conventional suboccipital craniectomy, the elevation of bone flap is not easy in adult because of the irregular contour of inner bone surface and tight adhesion of dura to the skull. The aim of this article is to describe the technical aspects of this approach and to delineate the important landmarks for a safe and quick performance in adult. Methods : We report on our series of twenty-five adult patients who underwent craniotomy for posterior fossa pathologies between 2002 and 2005. The maximal follow-up period was 4 years. Results : None of the patients complained of persistent headache and no CSF leaks have occurred postoperatively. We have encountered only two cases of transient subcutaneous CSF retention after craniotomy. Three-dimensional reconstruction of the CT scan confirmed the well-fitted suboccipital bone contour after craniotomy. And patients were satisfied with the cosmetic results. Conclusion : This method is safer and simpler. It restores normal anatomical planes and improves protection of the contents of the posterior fossa. The authors recommend craniotomy as an alternative method of access to the posterior fossa in all age groups.