• 자동차안전학회지
• /
• 제9권2호
• /
• pp.6-12
• /
• 2017

An autonomous driving system based on a precise digital map is developed. The system is implemented to the Hyundai's Tucsan fuel cell car, which has a camera, smart cruise control (SCC) and Blind spot detection (BSD) radars, 4-Layer LiDARs, and a standard GPS module. The precise digital map has various information such as lanes, speed bumps, crosswalks and land marks, etc. They can be distinguished as lane-level. The system fuses sensed data around the vehicle for localization and estimates the vehicle's location in the precise map. Objects around the vehicle are detected by the sensor fusion system. Collision threat assessment is performed by detecting dangerous vehicles on the precise map. When an obstacle is on the driving path, the system estimates time to collision and slow down the speed. The vehicle has driven autonomously in the Hyundai-Kia Namyang Research Center.

• Journal of Information Processing Systems
• /
• 제14권3호
• /
• pp.666-679
• /
• 2018

The discrete wavelet transform (DWT) has good multi-resolution decomposition characteristic and its low frequency component contains the basic information of an image. Based on this, a fragile watermarking using the local binary pattern (LBP) and DWT is proposed for image authentication. In this method, the LBP pattern of low frequency wavelet coefficients is adopted as a feature watermark, and it is inserted into the least significant bit (LSB) of the maximum pixel value in each block of host image. To guarantee the safety of the proposed algorithm, the logistic map is applied to encrypt the watermark. In addition, the locations of the maximum pixel values are stored in advance, which will be used to extract watermark on the receiving side. Due to the use of DWT, the watermarked image generated by the proposed scheme has high visual quality. Compared with other state-of-the-art watermarking methods, experimental results manifest that the proposed algorithm not only has lower watermark payloads, but also achieves good performance in tamper identification and localization for various attacks.

• Archives of Plastic Surgery
• /
• 제32권5호
• /
• pp.635-640
• /
• 2005

Sentinel lymphnode biopsy is widely performed in the management of malignant melanoma and breast cancer. The sentinel lymphnode is the prime site of draining from the malignant lesion and of metastasis. The aim of this study was to evaluate a usefulness of lymphoscintigraphy in conjunction with a removal of sentinel lymphnodes of skin and soft tissue malignancy. We studied 11 patients selected between January, 2003 and November, 2004. Clinically sentinel lymphnodes free of metastasis were examined with lymphoscintigraphy, gamma detection probe and vital dye staining, and we reviewed histopathologic findings and inert status of the nodes and the results fo treatment. Nine cases were malignant melanoma, one was squamous cell carcinoma on the left hand and another one leiomyosarcoma. Sentinel lymphnodes were identified in all cases. Three cases of malignant melanoma had positive sentinel lymphnodes on histological examination. All patients with positive sentinel lymphnodes were treated with therapeutic regional lymphadectomy, chemotherapy and adjuvant regimen. Four patients underwent PET scanning and followed sentinel lymphnode biopsy. Two had no metastasis signs on PET scanning. Therapeutic lymphnode dissection was carried out upon the patients whose sentinel lymphnode was positive on PET scanning. We contend that lymphoscintigraphy and sentinel lymphnode biopsy are reliable to confirm regional lymphnode metastasis of the skin and soft tissue malignancy, and blind extensive lymphnode dissection can be spared.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2012년도 추계학술발표대회
• /
• pp.474-477
• /
• 2012

현대사회는 시각장애인에 대한 복지가 부족하다. 예를 들어 유도블럭의 홰손, 지폐의 점자처리의 모호함 등 시각장애인을 위해 만들어진 복지조차 사용하기 어려운게 현실이다. 그래서 우리는 무선카메라와 Window Phone을 이용하여 상기 불편함을 해소하기 위하여 이 프로젝트를 시작하였다. Guide Line Detection은 앞을 못 보는 시각장애인에게 무선카메라에 보이는 영상에서 유도블럭을 찾아 시각장애인과의 거리를 음성으로 알려준다. Bill Recognition은 지폐를 인식하여 음성으로 알려준다. 길 안내 기능은 길을 찾아가지 못하는 시각장애인에게 특정 지점마다 길 안내정보를 등록하고, 등록된 정보는 시각장애인이 실시간으로 길 안내를 받을 수 있다. 음성인식은 기기를 사용하기 힘든 시각장애인들에 대한 접근성을 높이기 위해 WinPhone Application이 제공하는 모든 기능을 흔들기와 음성만으로 사용할 수 있도록 제공한다. 무선카메라의 화질과 Window Phone의 GPS 불규칙적인 오차 때문에 많은 시행착오가 있었지만 무선카메라는 웹 캠으로, GPS오차는 BingMap API의 GPS 가상 좌표로 대체하여 프로젝트를 마칠 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제13권6호
• /
• pp.2908-2924
• /
• 2019

Multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) is widely applied in wireless communication by virtue of its excellent properties in data transmission rate and transmission accuracy. However, as a major drawback of MIMO-OFDM systems, the high peak-to-average power ratio (PAPR) complicates the design of the power amplifier at the receiver end. Some available PAPR reduction methods such as selective mapping (SLM) suffer from high computational complexity. In this paper, a low-complexity SLM method based on active constellation extension (ACE) and joint space-time selective mapping (AST-SLM) for reducing PAPR in Alamouti STBC MIMO-OFDM systems is proposed. In SLM scheme, two IFFT operations are required for obtaining each transmission sequence pair, and the selected phase vector is transmitted as side information(SI). However, in the proposed AST-SLM method, only a few IFFT operations are required for generating all the transmission sequence pairs. The complexity of AST-SLM is at least 86% less than SLM. In addition, the SI needed in AST-SLM is at least 92.1% less than SLM by using the presented blind detection scheme to estimate SI. We show, analytically and with simulations, that AST-SLM can achieve significant performance of PAPR reduction and close performance of bit error rate (BER) compared to SLM scheme.

• Geosystem Engineering
• /
• 제21권5호
• /
• pp.251-261
• /
• 2018

With the urbanization in recent years, the power line interference noise in electromagnetic signal is increasing day by day, and has gradually become an unavoidable component of noises in magnetotelluric signal detection. Therefore, a kind of power line interference noise elimination method based on independent component analysis in wavelet domain for magnetotelluric signal is put forward in this paper. The method first uses wavelet decomposition to change single-channel signal into multi-channel signal, and then takes advantage of blind source separation principle of independent component analysis to eliminate power line interference noise. There is no need to choose the layer number of wavelet decomposition and the wavelet base of wavelet decomposition according to the observed signal. On the treatment effect, it is better than the previous power line interference removal method based on independent component analysis. Through the de-noising processing to actual magnetotelluric measuring data, it is shown that this method makes both the apparent resistivity curve near 50 Hz and the phase curve near 50 Hz become smoother and steadier than before processing, i.e., it effectively eliminates the power line interference noise.

• Nuclear Engineering and Technology
• /
• 제53권4호
• /
• pp.1199-1209
• /
• 2021

The detection of unexpected loose parts in the primary coolant system in a nuclear power plant remains an extremely important issue. It is essential to develop a methodology for the localization and mass estimation of loose parts owing to the high prediction error of conventional methods. An effective approach is presented for the localization and mass estimation of a loose part using machine-learning and deep-learning algorithms. First, a methodology was developed to estimate both the impact location and the mass of a loose part at the same times in a real structure in which geometric changes exist. Second, an impact database was constructed through a series of impact finite-element analyses (FEAs). Then, impact parameter prediction modes were generated for localization and mass estimation of a simulated metallic loose part using machine-learning algorithms (artificial neural network, Gaussian process, and support vector machine) and a deep-learning algorithm (convolutional neural network). The usefulness of the methodology was validated through blind tests, and the noise effect of the training data was also investigated. The high performance obtained in this study shows that the proposed methodology using an FEA-based database and deep learning is useful for localization and mass estimation of loose parts on site.

• 정보보호학회논문지
• /
• 제14권1호
• /
• pp.15-23
• /
• 2004

초창기 심층 암호의 대부분은 원본 영상의 최하위비트를 비밀 메시지 비트로 치환하는 방식이었기 때문에 인간의 감각으로는 메시지 삽입 여부를 구별해낼 수 없었지만 통계적 분석에 의하여 원본과 은닉물의 구별은 물론, 비밀 메시지의 삽입 량까지도 거의 추정해낼 수 있을 만큼 취약점을 내포하고 있었다. 우리는 Westfeld 와 Fridrich가 판단의 기준으로 정한 통계량을 각각 분석하였고, 이에 근거하여 원본의 통계량을 유지하면서도 대용량의 메시지를 삽입할 수 있는 방법을 제안하고자 한다. 제안하는 방식은 단순히 원본 영상의 최하위 비트를 변화시켜 메시지를 삽입하는 방식이 아닌 원본의 실제 화소 값이 랜덤 하게 증가하거나 감소하는 방식으로 메시지를 삽입하게 된다.

• 반도체디스플레이기술학회지
• /
• 제22권2호
• /
• pp.24-29
• /
• 2023

In this paper, we propose a real-time bus arrival notification system using deep learning to guarantee movement rights for the visually impaired. In modern society, by using location information of public transportation, users can quickly obtain information about public transportation and use public transportation easily. However, since the existing public transportation information system is a visual system, the visually impaired cannot use it. In Korea, various laws have been amended since the 'Act on the Promotion of Transportation for the Vulnerable' was enacted in June 2012 as the Act on the Movement Rights of the Blind, but the visually impaired are experiencing inconvenience in using public transportation. In particular, from the standpoint of the visually impaired, it is impossible to determine whether the bus is coming soon, is coming now, or has already arrived with the current system. In this paper, we use deep learning technology to learn bus numbers and identify upcoming bus numbers. Finally, we propose a method to notify the visually impaired by voice that the bus is coming by using TTS technology.

• 한국컴퓨터정보학회:학술대회논문집
• /
• 한국컴퓨터정보학회 2023년도 제67차 동계학술대회논문집 31권1호
• /
• pp.133-136
• /
• 2023

많은 사람이 "다음 생에 성적 소수자나 이주민, 장애인으로 태어나고 싶니?"라는 질문을 받는다면 대부분 사람은 선뜻 "그렇다"라고 대답하기 어렵다. 그 근본적인 이유는 질문 속 사회적 약자들은 사회에서 다양한 불평등을 마주하고 있다는 의미일 것이다. 본 논문에서는 여러 소수자 중 시각장애인을 위한 보행 보조 기구를 제작하였다. 시각장애인들이 사용하는 지팡이는 지면의 장애물 파악에 도움은 되지만 공중에 떠 있는 장애물을 파악하고 피하기 어렵다. 이러한 단점을 보완하고자 라이다 센서를 이용하여 장애물 감지가 가능한 서비스를 시각장애인에게 제공한다. 라이다 센서는 레이저 광원을 방출하여 목표물에서 튕겨 되돌아오는 특성을 이용하여 사용자에게 전방에 장애물이 감지되면 시각장애인에게 TTS로 경고음을 제공한다.