• Journal of Sensor Science and Technology
• /
• v.11 no.2
• /
• pp.93-101
• /
• 2002

The quality of agricultural products is classified with various factors which are measured and determined by destructive and/or nondestructive method. NIR spectrum analysis method is used to determine internal qualities such as a brix and an acidity. CCD color camera is used to measure external quality like color and a size of fruit. Today, nondestructive methods are widely researched. The quality and the grade of fruit loaded into a cup automatically and measured in real time by camera and NIR system is determined by infernal and external factors. This paper proposes modified boundary tracking algorithm which detects the contour of fruit's color image and make chain code faster than conventional method. The chain code helps compute a size of fruit image and find multiple loading of a fruit in single cup or fruit between two cups. The designed classification system sorts a citrus at speed of 8 fruit/s, with evaluating a brix, an acidity and a size grade.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• v.9 no.2
• /
• pp.393-398
• /
• 2005

본 논문에서는 ART2 기반 자가 생성 지도 학습 알고리즘을 이용한 운송 컨테이너 식별자 인식 시스템을 제안한다. 일반적으로 운송 컨테이너의 식별자들은 글자의 색이 검정색 또는 흰색으로 이루어져 있는 특징이 있다. 이러한 특성을 고려하여 원 컨테이너 영상에 대해 검은색과 흰색을 제외한 모든 부분을 잡음으로 처리하기 위해 퍼지를 이용한 잡은 판단 방법을 적용하여 식별자 영역과 잡음을 구별한다. 식별자 영역을 제외한 잡음 영역을 전체 영상의 평균 픽셀값으로 대체시킨다. 그리고 Sobel 마스크를 이용하여 에지를 검출하고, 추출된 에지를 이용하여 수직 블록과 수평 블록을 검출하여 컨테이너의 식별자 영역을 추출하고 이진화한다. 이진화된 식별자 영역에 대해 검정색의 빈도수를 이용하여 흰바탕과 민바탕을 구분하고 8방향 윤곽선 추적 알고리즘을 적용하여 개별 식별자를 추출한다. 개별 식별자 인식을 위해 ART2 기반 자가 생성 지도 학습 알고리즘은 입력층과 은닉층 사이에 ART2를 적용하여 은닉층의 노드를 생성하고, 은닉층과 출력층 사이에 일반화된 델타 학습 방법과 Delta-bar-Delta 알고리즘을 적용하여 학습 성능을 개선한다. 실제 컨테이너 영상을 대상으로 실험한 결과, 기존의 식별자 추출 방법보다 제안된 식별자 추출 방법이 개선되었다. 그리고 기존의 식별자 인식 알고리즘보다 제안된 ART2 기반 자가 생성 지도 학습 알고리즘이 식별자의 학습 및 인식에 있어서 우수한 성능이 있음을 확인하였다.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.42 no.3 s.303
• /
• pp.39-52
• /
• 2005

In this paper, a registration method is presented to register partial 3D point clouds, acquired from a multi-view camera, for 3D reconstruction of an indoor environment. In general, conventional registration methods require a high computational complexity and much time for registration. Moreover, these methods are not robust for 3D point cloud which has comparatively low precision. To overcome these drawbacks, a projection-based registration method is proposed. First, depth images are refined based on temporal property by excluding 3D points with a large variation, and spatial property by filling up holes referring neighboring 3D points. Second, 3D point clouds acquired from two views are projected onto the same image plane, and two-step integer mapping is applied to enable modified KLT (Kanade-Lucas-Tomasi) to find correspondences. Then, fine registration is carried out through minimizing distance errors based on adaptive search range. Finally, we calculate a final color referring colors of corresponding points and reconstruct an indoor environment by applying the above procedure to consecutive scenes. The proposed method not only reduces computational complexity by searching for correspondences on a 2D image plane, but also enables effective registration even for 3D points which have low precision. Furthermore, only a few color and depth images are needed to reconstruct an indoor environment.

• Journal of the Korean Society of Radiology
• /
• v.84 no.6
• /
• pp.1339-1349
• /
• 2023

Purpose To determine the efficacy and safety of iliac branch device (IBD) implantation and to evaluate its limitations based on 7 years of experience in a single center. Materials and Methods This single-center study included patients with bilateral common iliac artery aneurysms (CIAAs). We investigated follow-up CT and reviewed the internal iliac artery (IIA) patency and complications related to IBD. A retrospective analysis was performed and the overall survival rate and freedom from reintervention rate were reported according to the Kaplan-Meier method. Results Of the 38 patients with CIAAs, only 10 (12 CIAAs) were suitable for IBD treatment. Five patients underwent unilateral IBD insertion with contralateral IIA embolization, and three (60%) showed claudication; however, symptoms resolved within 6 months. The 7-year freedom from IBD-related reintervention rate was 77.8%. No procedure-related deaths occurred. Conclusion IBD has good technical success and long-term patency rates; however, anatomical factors frequently limit its application, particularly in Asians. Additionally, unilateral IIA embolization showed relatively mild complications and a good prognosis; therefore, it can be performed safely for anatomically complex aortoiliac aneurysms.

• The Korean Journal of Nuclear Medicine
• /
• v.28 no.1
• /
• pp.62-68
• /
• 1994

This study was aimed to compare the density of the functional microcirculation of hepatocellular carcinoma (HCC) with normal liver and to investigate the effect of hepatic-arterial oily chemoembolization (HAE) by radionuclide examination. Methods : Eight patients with HCC proven by biopsy in five, and clinically and radiologically in three were included. The mixture of 2 cc normal saline with three to four mCi of $^{99m}Tc$-MAA was infused through a hepatic-arterial catheter for a minute. Dynamic images were obtained at a rate of 4 sec per frame for a minute, and static images and SPECT were followed. Results : In three patients who underwent hepatic arterial angiography (HAA) alone, radioactivity was markedly increased in tumors compared to the adjacent liver immediately after infusion of $^{99m}Tc$-MAA. The ratios of tumoral and extratumoral up-take (T/E ratio) were above 6.5 (range; $6.5{\sim}l9$, mean; 12.5). In four of the five patients who under-went superselective HAE, T/E ratio were remark-ably decreased ($0.5{\sim}1.3$). The areas of embolization were better delineated in radionuclide study than in postembolization HAA. In the other one who was considered to be embolized completely on HAA, strong radiouptake in the tumor was disclosed (T/E ratio; 7.0). Conclusions : Therefore hepatic-arterial flow study with radionuclide imaging using $^{99m}Tc$-MAA can be a valuable method to assess the accurate embolization effect in HCC.

• Tuberculosis and Respiratory Diseases
• /
• v.46 no.1
• /
• pp.53-64
• /
• 1999

Background : Massive and untreated hemoptysis is associated with a mortality of greater than 50 percent. Since the bleeding is from a bronchial arterial source in the vast majority of patients, embolization of the bronchial arteries(BAE) has become an accepted treatment in the management of massive hemoptysis because it achieves immediate control of bleeding in 75 to 90 percent of the patients. Methods: Between 1990 and 1996, we treated 146 patients with hemoptysis by bronchial artery embolization. Catheters(4, 5, or 7F) and gelfoam, ivalon, and/or microcoil were used for embolization. Results: Pulmonary tuberculosis and related disorders were the most common underlying disease of hemoptysis(72.6%). Immediate success rate to control bleeding within 24hours was 95%, and recurrence rate was 24.7%. The recurrence rate occured within 6 months after embolization was 63.9%. Initial angiographic findings such as bilaterality, systemic-pulmonary artery shunt, neovascularity, aneurysm were not statistically correlated with rebleeding tendency(P>0.05). Among Initial radiographic findings, only pleural lesions were significantly correlated with rebleeding tendency(P<0.05). At additional bronchial artery angiograpy done due to rebleeding, recanalization of previous embolized arteries were 63.9%, and the presence of new feeding arteries were 16.7%, and 19.4% of patients with rebleeding showed both The complications such as fever, chest pain, headache, nausea and vomiting, arrhythmia, paralylytic ileus, transient sensory loss (lower extremities), hypotension, urination difficulty were noticed at 40 patients(27.4%). Conclusion: We conclude that bronchial artery embolization is relatively safe method achieving immediate control of massive hemoptysis. At initial angiographic findings, we could not find any predictive factors for subsequent rebleeding. It may warrant further study whether patients with pleural disease have definetely increased rebleeding tendency.

• Korean Journal of Optics and Photonics
• /
• v.26 no.3
• /
• pp.139-146
• /
• 2015

The effects of a dielectric multilayer mirror on the efficiency of organic light-emitting diodes (OLEDs) were investigated by using optical simulation. Adoption of a dielectric mirror consisting of alternating SiN and $SiO_2$ layers narrowed the emission spectrum due to the microcavity effect, and increased the outcoupling efficiency by a few percent. The layer thicknesses of the dielectric mirror were adjusted to change the wavelength of the resonance mode, which may be used to increase the color purity.

• Korean Journal of Digital Imaging in Medicine
• /
• v.17 no.1
• /
• pp.9-12
• /
• 2015

임상용 모니터의 출력값 중 가장 큰 영향을 주는 것이 휘도이다. 최근 컬러 모니터의 임상용 사용으로 인해 출력값의 보정은 매우 중요하게 관리되고 있다. 색보정 변위의 특성화가 휘도와 동일한 인자로 영향을 주는지 분석하기 위해 사용된 특성화 보정 모델은 GOG모델과 S-curve모델 이다. 두 개의 모델을 통해 모니터의 휘도는 장치의 출력과 직접적인 관계가 있다는 것을 증명하고 동일한 출력에 입력값을 가질 수 있도록 구성하고자 한다. 동일한 출력을 디스플레이 할 경우 동일한 출력값을 얻어야 한다. 그러나 모니터에 따라 서로 다른 출력값을 산출한다. 컬러모니터의 경우는 출력의 안정성에 휘도뿐만 아니라, 색감(R,G,B) 변화가 큰 역할을 수행한다. 본 연구에서는 분석인자 중 대조도에 영향을 주는 인자를 역추적하여 특성화 보정 S-curve모델을 LCD에 적용하였다. 이는 GOG모델을 적용한 CRT와 동일한 결과를 얻었다. 따라서 인자는 CIEXYZ의 결과값과 동일한 인자를 구할 수 있다.

• Journal of the Korea Society of Computer and Information
• /
• v.19 no.5
• /
• pp.71-78
• /
• 2014

The RFID-tag objects can be recognized by a distinct reader where it is installed. The RFID-tag objects are likely described as storages rather than the mobiles in the use of GPS. As RFID tags are large in number compared to moving objects, so the storing and retrieval costs are highly expensive. Here, two solutions for spatio-temporal model taking account of the feature in the tagged objects are proposed. First, the moving-tag objects are expressed by the terms "now" as well as "path location". Second, the size of storing index was noticeably reduced by not saving the tag information of palletizing products but mapping the tagged objects.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.1
• /
• pp.142-151
• /
• 2015

This paper proposes a method for detection of objects temporally stop moving in video sequences taken by a moving camera. Even though the consequence of missed detection of those objects could be catastrophic in terms of application level requirements, not much attention has been paid in conventional approaches. In the proposed method, we introduce cues for consistent detection and tracking of objects: motion potential, position potential, and color distribution similarity. Integration of the three cues in the graph-cut algorithm makes possible to detect objects that temporally stop moving and are newly appearing. Experiment results prove that the proposed method can not only detect moving objects but also track objects stop moving.