• Transactions of the Korean hydrogen and new energy society
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• v.29 no.2
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• pp.219-225
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• 2018

This study was carried out to investigate the injection characteristics of 800 kPa compressed natural gas compressed natural gas (CNG) injector developed in Korea. The CNG injector with multi-holes, employed in this experiment, was designed to inject CNG in the manifold at high pressure of 800 kPa. The spray macroscopic visualization test was carried out via Schlieren photography to study fuel-air mixing process. The fundamental spray characteristics, such as spray penetration, spray cone angle and spray velocity, were evaluated in the constant volume combustion chamber (CVCC) with varying the constant back pressure in CVCC from 0 to 1.8 bar. For the safety reason, nitrogen ($N_2$) and an acetone tracer were utilized as a surrogate gas fuel instead of CNG. The surrogate gas fuel pressures were controlled at 3, 5.5, and 8 bar, respectively. Injection durations were set at 5 ms throughout the experiment. The simulating events of the low engine speed were arranged at 1,000 rpm. The spray images were recorded by using a high-speed camera with a frame rate of 10,000 f/s at $512{\times}256pixels$. The spray characteristics were analyzed by using the image processing (Matlab). The results showed the significant difference that higher injection pressure had more effect on the spray shape than the lower injection pressure. When the injection pressure was increased, the longer spray penetration occurred. Moreover, the linear relation between speed and time are dependent on the injection pressure as well.

• Convergence Security Journal
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• v.12 no.6
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• pp.31-37
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• 2012

Today, the core technology of an automobile is becoming to IT-based convergence system technology. To cope with many kinds of situations and provide the convenience for drivers, various IT technologies are being integrated into automobile system. In this paper, we propose an convergence system, which is called Augmented Driving System (ADS), to provide high safety and convenience of drivers based on image information processing. From imaging sensor, the image data is acquisited and processed to give distance from the front car, lane, and traffic sign panel by the proposed methods. Also, a converged interface technology with camera for gesture recognition and microphone for speech recognition is provided. Based on this kind of system technology, car accident will be decreased although drivers could not recognize the dangerous situations, since the system can recognize situation or user context to give attention to the front view. Through the experiments, the proposed methods achieved over 90% of recognition in terms of traffic sign detection, lane detection, and distance measure from the front car.

• The Research Journal of the Costume Culture
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• v.23 no.6
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• pp.1097-1115
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• 2015

ICT in the IOT era is the core basis of modern society. This study investigated and analyzed the recent commercialization trends of smart fashion products internationally and domestically, to utilize them as the basis of data for developing user-friendly smart fashion products that can meet the needs of consumers. Keyword research using the most representative search engines, Google and Naver was conducted for searching for various wearable items commercialized actively since 2010. The final 78 products were classified by the physical area, and the key features and benefits were analyzed. Smart fashion products were classified as four physical types for the head and face, torso, arms and hands, and ankles and feet. Smart fashion products for each body part were developed in various ways, such as hats, glasses, lenses, virtual screens, earphones, headsets, clothing, watches, wrist bands, gloves, rings, wallets, bags, anklets, shoes, socks, and insoles. The main features were music playback, bluetooth, a camera based on NFC, virtual effects, health and safety protection through measuring heartbeat and momentum, and social network sharing of all kinds of information, based on inter-working with a smartphone. These functions represent the physical, social, and emotional interactions among users and their surroundings, as well as the users, themselves. The research results are expected to be used in future studies on planning user-friendly and marketable products through in-depth analysis of the design characteristics of smart fashion products as well as consumer responses.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.10
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• pp.162-170
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• 2013

In recent years, the interests and needs of the Pedestrian Protection System (PPS), which is mounted on the vehicle for the purpose of traffic safety improvement is increasing. In this paper, we propose a pedestrian candidate window extraction and unit cell histogram based HOG descriptor calculation methods. At pedestrian detection candidate windows extraction stage, the bright ratio of pedestrian and its circumference region, vertical edge projection, edge factor, and PCA reconstruction image are used. Dalal's HOG requires pixel based histogram calculation by Gaussian weights and trilinear interpolation on overlapping blocks, But our method performs Gaussian down-weight and computes histogram on a per-cell basis, and then the histogram is combined with the adjacent cell, so our method can be calculated faster than Dalal's method. Our PCA reconstruction error based pedestrian detection candidate window extraction method efficiently classifies background based on the difference between pedestrian's head and shoulder area. The proposed method improves detection speed compared to the conventional HOG just using image without any prior information from camera calibration or depth map obtained from stereo cameras.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.8
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• pp.837-848
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• 2014

This paper describes the development of a walking assistive robot for effective self-rehabilitation for elderly people facing an inconvenience in walking. The main features of the developed robot are enhanced safety and mobility using the baby walker and electric wheelchair mechanisms and an accurate walking tracking control algorithm using potentiometers and stereo cameras. Specifically, a pelvis supporter is designed to prevent the user from falling down and reduce the burden on their legs, and electric motors are used for easy locomotion with low effort. Next, the walking intention and direction of the user are automatically recognized by using potentiometers attached at the pelvis supporter so that the robot can track the user, and the rapidity and accuracy of the tracking were increased by applying a lower-body motion analysis algorithm with stereo cameras. Finally, the user-tracking performance of the developed robot was experimentally verified through stepwise walking assistance experiments.

• International Journal of Highway Engineering
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• v.10 no.3
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• pp.19-31
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• 2008

Video image processing systems(VIPS) offer numerous benefits to transportation models and applications, due to their ability to monitor traffic in real time. VIPS based on wide-area detection, i.e., multi-lane surveillance algorithm provide traffic parameters with single camera such as flow and velocity, as well as occupancy and density. However, most current commercial VIPS utilize a tripwire detection algorithm that examines image intensity changes in the detection regions to indicate vehicle presence and passage, i.e., they do not identify individual vehicles as unique targets. If VIPS are developed to track individual vehicles and thus trace vehicle trajectories, many existing transportation models will benefit from more detailed information of individual vehicles. Furthermore, additional information obtained from the vehicle trajectories will improve incident detection by identifying lane change maneuvers and acceleration/deceleration patterns. The objective of this research was to relate traffic safety to VIPS tracking and this paper has developed a computer vision system of monitoring individual vehicle trajectories based on image processing, and offer the detailed information, for example, volumes, speed, and occupancy rate as well as traffic information via tripwire image detectors. Also the developed system has been verified by comparing with commercial VIP detectors.

• Journal of Sensor Science and Technology
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• v.9 no.1
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• pp.44-50
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• 2000

Every object emits some energy from its surface. The emission energy forms surface heat distribution which we can capture by using an infrared thermal imager. The infrared thermal image may include valuable information regarding to the subsurface anomaly of the object. Since a thermal image reflects surface clutter and subsurface anomaly, we have difficulty in extracting the information on the subsurface anomaly only with thermal images taken under a wavelength. Thus, we use visible wavelength images of the object surface to remove exterior clutter. We, therefore in this paper, visualize the infrared image for overlaying it with a visible wavelength image. First, we make an interpolated image from two ordinary images taken from both sides of an infrared sensor. Next, we overlay the intermediate image with an infrared image taken from the infrared camera. The technique suggested in this paper can be utilized for analyzing the infrared images on non-destructive inspection against disaster and for safety.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.4
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• pp.95-103
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• 2009

Global interests for construction of 3 dimensional spatial information has risen due to development of measurement sensors and data processing technologies. In spite of criticism for the violation of personal privacy, CCTV cameras equipped in outdoor public space of urban area are used as a fundamental sensor for traffic management, crime prevention or hazard monitoring. For safety guarantee in urban environment and disaster prevention, a surveillance system integrating pre-constructed 3 dimensional spatial information with CCTV data or video sequence is needed for monitoring and observing emergent situation interactively in real time. In this study, we proposed applicability of the prototype system for web visualization based on X3D, an international standard of real time web visualization, by integrating 3 dimensional spatial information with video sequence.

• Journal of Aerospace System Engineering
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• v.11 no.2
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• pp.30-34
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• 2017

This paper is concerned with product assurance for the secondary payload, which is used for technology and science research, in the satellite system, which consists primarily of the spacecraft and the primary payload (a high-resolution optical camera). The Korean satellite development program has successfully insured the safety of the spacecraft and primary payload. However, given the limits of budget and schedule, it is very important to establish adequate product assurance for the secondary payload, which has a lower priority than the spacecraft or primary payload. This paper studies the concept of product assurance for the secondary payload of technological and scientific equipment.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.12
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• pp.123-129
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• 2014

In accordance with the development of various convergence devices, cameras are being used in many types of the systems such as security system, driver assistance device and so on, and a lot of people are exposed to these system. Therefore the system should be able to recognize the human behavior and support some useful functions with the information that is obtained from detected human behavior. In this paper we use a machine learning approach based on 2D image and propose the human behavior pattern recognition methods. The proposed methods can provide valuable information to support some useful function to user based on the recognized human behavior. First proposed one is "phone call behavior" recognition. If a camera of the black box, which is focused on driver in a car, recognize phone call pose, it can give a warning to driver for safe driving. The second one is "looking ahead" recognition for driving safety where we propose the decision rule and method to decide whether the driver is looking ahead or not. This paper also shows usefulness of proposed recognition methods with some experiment results in real time.