Dong-Su Lee

Learn More
Millimeter wave imaging is finding rapid adoption in security applications such as the detection of objects concealed under clothing. A passive imaging system can be realized as a stand-off type sensor that can operate in open spaces, both indoors and outdoors. In this paper, we address real-time outdoor concealed-object detection and segmentation with a(More)
Due to the benefits of reusability and productivity, component-based approach has become the primary technology in service robot system development. However, because component developer cannot foresee the integration and operating condition of the components, they cannot provide appropriate fault tolerance function, which is crucial for commercial success(More)
We address an image segmentation method to detect concealed objects captured by passive millimeter wave (MMW) imaging. Passive MMW imaging can create interpretable imagery on the objects concealed under clothing, which gives the great advantage to the security system. In this paper, we propose the multi-level expectation maximization (EM) method to separate(More)
Passive millimeter wave imaging has the capability of detecting concealed objects under clothing. However, the image quality is often degraded due to low spatial resolution and low signal level. This paper addresses passive millimeter wave imaging and registration and fusion of a passive millimeter and a visual image in order to visualize human subject's(More)
Growth of large-scale patterned, wrinkle-free graphene and the gentle transfer technique without further damage are most important requirements for the practical use of graphene. Here we report the growth of wrinkle-free, strictly uniform monolayer graphene films by chemical vapor deposition on a platinum (Pt) substrate with texture-controlled giant grains(More)
Passive millimeter wave (MMW) imaging can create interpretable imagery of objects concealed under clothing. Unfortunately, low signal to noise ratio and low temperature resolution make automatic analysis of passive MMW images difficult. In this paper, we analyze passive MMW images generated by 8 mm regime MMW. The imaging system is composed of two channels:(More)
—Passive millimeter (MMW) imaging can penetrate clothing to create interpretable imagery of concealed objects. However, the image quality is often restricted by low signal to noise ratio and temperature contrast as well as low spatial resolution. In this paper, we explore a four-channel passive MMW imaging system operating in the 8 and 3 mm wavelength(More)
The equivalent ray geometry of two horizontally aligned detectors at the focal plane of the main antenna in a millimeter wave imaging system is analyzed to reveal the reason why the images from the detectors are fused as an image with a depth sense. Scanning the main antenna in both horizontal and vertical directions makes each detector perform as a camera,(More)