• Journal of The Korean Association of Information Education
• /
• v.8 no.4
• /
• pp.489-500
• /
• 2004

In this paper, an investigation on internet safety of 244 national or public elementary schools' web sites was performed with two points of view : inappropriate material posting and personal information exposure. The investigation results showed that obscene materials and commercial advertisements were uploaded into the bulletin board(67.2%) and students' personal information such as photograph, address, telephone number were exposed(87.3%). Most of the inappropriate materials were posted by auto-register programs. This problem was occurred due to reckless bulletin board opening and inappropriate management. On the contrary, personal information was exposed by teachers and students. They didn't not care about their personal information. It shows the fact that they have not recognized the danger of personal information exposure. Therefore managing real-name membership and enforcing permission to bulletin board were required to construct and use a safe school web site. Teachers have to understand not only negative effects appeared in a school web site but also latent dangerous factors.

• Radiation Oncology Journal
• /
• v.11 no.2
• /
• pp.449-454
• /
• 1993

The skin sparing effect associated with high energy x-ray or gamma ray beams may be reduce or lost under certain conditions of treatment. Current trends in using large fields. Shield carrying trays, compensating filters, and isocentric methods of treatment have posed problems of increased skin dose which sometimes become a limiting factor in giving adquate tumor doses. We used the shallow ion chamber to measure the phantom surface dose and the physical treatment variables for Co-60 gamma ray, 4MV and 10 MV x-ray beam. The dependence of percent surface dose on field sizes, atomic number of the shielding tray materials and its distance from the surface for 4, 10MV x-rays and Co-60 gamma ray is qualitatively similar. The use of 2 mm thick tin filter is recommended for situations where a low atomic number tray is introduced into the beam at distances less than 15 cm from the surface and with the large field sized for 4 MV x-ray beam. In case of Co-60 gamma ray, the lead glass tray is suitable for enhancement of skin sparing. Also, the filter distance should be as large as possible to achieve substantial skin sparing.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.18 no.3
• /
• pp.223-240
• /
• 1998

본 고는 1997년 12월 31일 개정된 "강 용접부의 방사선투과시험 방법 및 투과 사진의 등급분류 방법" (한국산업규격 KS B 0845)을 이해하는데 참고가 될 수 있도록 일본공업규격 JIS Z 3104의 해설부분을 번역한 것으로 KS B 0845의 모체가 되는 JIS Z 3104의 본래취지를 정확히 전달하기 위하여 편집하거나 가감하지 않고 원문 그대로 기술하였으며 KS B 0845와는 일부 용어나 항목구성에 차이가 있으나 번호에 관계없이 각항목의 제목을 보고 이해하게 하였다. 특히 일부 부속 규격의 미 제정상태에서 개정판이 발표되어 적용에 혼란을 초래할 수도 있겠으나 부분적인 적용은 가능할 것으로 판단된다.

• The Magazine of the IEIE
• /
• v.15 no.1
• /
• pp.106-113
• /
• 1988

현재 필자가 소속하고 있는 연구실에서는, 컴퓨터 아니메이숀, 컴퓨터 그래픽, 화상처리, 인공지능에 관한 연구등을 하고 있다. 본고에서는 화상처리에 관한 연구중에서, 본 연구실에서 최근에 발표한 컴퓨터 비죤에 관계있는 각종의 도로 정보처리에 관한 연구에 대해서 소개한다. 우선, 화상처리의 수법을 이용한 자동조종의 연구로서, 고속도로에서의 선행차의 자동동정에 관한 연구와 하프변환을 이용한 차량번호판 추출에 관한 연구에 대해서 소개한다. 다음에 도로망 지도처리에 관한 연구로서, 차재형 자동항법 시스템의 개요에 관한 소개와 최단시간 경로에 관한 연구, 도로지도의 자동판독에 관한 연구에 대해서 소개한다. 가까운 미래에, 점점 자동차의 자동화가 추진되고, 인공위성을 이용해서 자동차의 현재 위치를 정확하게 파악할 수 있게 되면, 본고에서 소개하는 연구들이 보다 중요한 의미를 가지게 되리라 생각한다.

• Korean Management Science Review
• /
• v.13 no.2
• /
• pp.1-11
• /
• 1996

Two different methods to extract the license plate area of a vehicle have been used for automatic recognition purposes. One method is with a color vision system and the other is with an edge detecting operator. The system with color vision has some problems if the colors of license plate and vehicle's body are similar. The various plate colors in Korea also drops the system performance. The edge detecting operator also has a problem for a real time processing since it performs on all pixels of the scene. In this paper a possible method using gray level vision system and available pre-known information of license plates is suggested. The suggested procedure searches the lower boundary of the plate by counting high contrast points between one and near pixel from the bottom line of the scene. It finds the upper boundary from the bottom line by adding number plate height after finding the lower boundary. The left and right boundaries are found by similar processes.

• Journal of Korea Multimedia Society
• /
• v.18 no.10
• /
• pp.1172-1179
• /
• 2015

A wireless license plate region extracting module is proposed for LPR system controlling multiple gates. This module is cheaply implemented using Raspberry Pi which is open source and high performance. First, as the upper 1/3 of the captured image is discarded as it has no useful information on license plate. Using the OpenCV libraries the edge image is got by Canny algorithm after applying Gaussian filtering to gray image, and the labeling is conducted for 4 consecutive numbers in license plate. These numbers are located using various decision equations, and expanding the numbers region the final license plate region can be extracted. The result image is transferred to Server using wifi direct. Using the proposed module it becomes easy to set up and maintain the LPR system. The experimental results showed that the successful extracting rate was 98.4% using 500 car images with 640 × 480 resolution.

• Proceedings of the IEEK Conference
• /
• 2008.06a
• /
• pp.1037-1038
• /
• 2008

Since the characters are not clear always due to lighting conditions, sometimes only a part of the characters are detected and the boundary of the number plate is not completely shown. To solve this problem, this paper presents a new efficient algorithm for segmenting the number plate using the topological relationship among the characters in the number plate and its outer contour. The boundary of the number plate is estimated using the detected characters and detected by testing the connectivity of the vertical and horizontal edges. The superior performance of the proposed algorithm has been proved by the experiments.

• Proceedings of the KIEE Conference
• /
• 1997.07b
• /
• pp.507-509
• /
• 1997

One of the most difficult tasks in the process of car license plate is the extraction of each character from within license plate region. This paper presents a real-time recognition of car licence number using neural network in parking lot. The feature parameters of letters and numbers of license plate are extracted by thinning algorithm. Both feature parameters are used to train neural networks for the image recognition.

• Proceedings of the Korean Information Science Society Conference
• /
• 1998.10b
• /
• pp.496-498
• /
• 1998

현재 우편 처리용 바코드는 광학문자판독기에 의해 판독된 우편번호를 3 of 5 형광 바코드로 인쇄하고, 판독하여 우편물을 자동구분 처리하는 LSM(Letter Sorting Machine)을 사용하고 있다. 광학문자판독에 의한 인쇄체 문자 인식율은 94~96%정도로 처리되므로 오류 우편물의 최소화를 위하여 LSM에 형광 바코드와 동일한 체계로 구성된 흑색 바코드를 적용하고, 광학문자판독을 하지 않고도 우편물을 자동처리할 수 있는 체계를 구축하고 있다. 우편고객이 흑색 바코드를 우편물에 사전에 인쇄하여 접수하도록 하여 공학문자판독에 의한 처리 과정 축소함으로써, 보다 효과적인 우편 배달 서비스를 제공하기 위한 노력을 시도하고 있다. 본 논문에서는 우편 고객이 인쇄한 3 of 5 고객 바코드를 사전에 검사하여 우편물 자동처리를 보다 효과적으로 수행될 수 있도록 하기 위한 방법을 제고하는 고객 바코드 검증 시스템의 설계 및 구현에 대한 것이다.

• Proceedings of the KIEE Conference
• /
• 1995.07b
• /
• pp.965-967
• /
• 1995

One of the most difficult tasks in the process of automatic vehicle license plate recognition is the extraction of each character from within license plate region. In many cases, characters, especially serial numbers of plates are connected together due to noise and plate accessories. The recognition process may not be successful without extracting these characters effectively. This paper presents an algorithm to extract these connected characters very effectively. The algorithm utilizes mathematical morphology, connected component analysis, and gradient filters for character extraction. The paper also presents thorough experimental results as well as details of the algorithm.