• 한국정보컨버전스학회:학술대회논문집
• /
• 2008.06a
• /
• pp.169-170
• /
• 2008

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.9 s.186
• /
• pp.84-91
• /
• 2006

The synthesis of optimal controllers for multivariable systems usually requires an accurate linear model of the plant dynamics. Real systems, however, contain nonlinearities and high-order dynamics that may be difficult to model using conventional techniques. This paper presents a novel loaming method for the synthesis of LQR controllers that doesn't require explicit modeling of the plant dynamics. This method utilizes the sign of Jacobian and gradient descent techniques to iteratively reduce the LQR objective function. It becomes easier and more convenient because it is relatively very easy to get the sign of Jacobian instead of its Jacobian. Simulations involving an overhead crane and a hydrofoil catamaran show that the proposed LQR-LC algorithm improves controller performance, even when the Jacobian information is estimated from input-output data.

• Proceedings of the KIEE Conference
• /
• 2003.11b
• /
• pp.315-318
• /
• 2003

This paper proposes a switching control method applicable to any affine, 2nd order nonlinear system with single input. The key contribution is to develop a control design method which uses a piecewise continuous Lyapunov function non-increasing at every discontinuous point. The proposed design method requires no restrictions except full state availability. To obtain a non-increasing, piecewise continuous Lyapunov function, we change the sign of off-diagonal term s of the positive definite matrix composing the former Lyapunov function according to the sign of the Inter-connection term. And we use the solution of inequalities which guarantee each Lyapunov function is non-increasing at any discontinuous point.

• Communications for Statistical Applications and Methods
• /
• v.13 no.2
• /
• pp.419-428
• /
• 2006

The method of Reverse Ranked Ordering-Set Sampling(RROSS) as an opposed Ranked Ordering-Set Sampling(ROSS) and Ranked-Set Sampling(RSS) is discussed. We propose the test statistic using sign test on RROSS. This method is effective when observations are expensive and measurement is perhaps destructive or invasive. This method obtains more informations than ROSS and RSS. The asymptotic relative efficiencies of RROSS with respect to ROSS and RSS are always greater than 1 for all sample sizes. We consider a simple model to describe the effect of imperfect judgment errors.

• Journal of Preventive Medicine and Public Health
• /
• v.29 no.3 s.54
• /
• pp.507-519
• /
• 1996

The objectives of this study are to investigate the prevalence of occupation related carpal tunnel syndrome(CTS) among workers in a condom industry : to analyse the sensitivity and specificity of clinical signs or symptoms such as hand diagram, Tinel's sign and Phalen's sign in carpal tunnel syndrome : and to test vibration threshold test using audiometry as a technically easy and noninvasive method in the diagnosis of carpal tunnel syndrome in stead of nerve conduction velocity (NCV). The study group was divided into exposed group(39 cases) and non-exposed group(48 cases) based on whether or not excessive use of wrist movements exsist. 1. There are stastically significant differences in symptoms and signs of carpal tunnel syndrome such as hand diagram, Tinel's sign and Phalen's sign between exposed and non-exposed group(p<0.05). 2. Six cases(9 hands) were comfirmed as carpal tunnel syndrome by NCV. Five cases(7 hands) belonged to exposed group, 1 case(2 hands) to nonexposed group. As there are significant differences in prevalence of carpal tunnel syndrome between two groups(p<0.05), excessive use of wrist in occupation is a risk factor of carpal tunnel syndrome. 3. When we use NCV as a gold standard in the diagnosis of carpal tunnel syndrome, sensitivity and specificity of hand diagram, Tinel's sign and Phalen's sign is as followed; hand diagram , sensitivity 88.9%, specificity 84.2% Tinel's sign ; sensitivity 55.6%, specificity 72.8% Phalen's sign ; sensitivity 14.3%, specificity 88.4%. Among above clinical signs and symptoms, hand diagram is the best clinical screening test. 4. The differences of vibration threshold between median and ulnar nerve at the same time are useful in the diagnosis of carpal tunnel syndrome but the time change of vibration threshold of median nerve over time are not sensitive enough. It is concluded that vibration threshold between median and ulnar nerve at the same time can be used as a supplementary or alternative criterion to indicate that the nerve dysfunction is located in the carpal tunnel.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.15 no.6
• /
• pp.1-9
• /
• 2016

Place names of road sign mean various place names being used on road signs for path guidance of drivers such as administrative district, facility, road, etc. It is very important that not only the choice method of place names for connectivity of road signs but standard establishment of spatial impact zone according to place names. However this standard are not established currently, so it is difficult to fix the spatial range for changing place names around the main facility according to the new construction or relocation of main facility in urban region. Considering the use of big data, one of the Government 3.0, we need to utilize actively the road sign management system database. This paper suggested a methodology for standard establishment of spatial impact zone according to place names of road sign in urban regions based on the road sign management system database. To perform a case study, we selected a major facility ("City Hall") which is the most frequently used the place name of road signs and presented standard of spatial impact zone by urban size in 84 cities.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.13 no.4
• /
• pp.38-47
• /
• 2014

Ministry of Land, Infrastructure and Transport (MOLIT) Affairs of Korean government improved RSMS to be linked with GIS data and now we have research foundation. In case of expressway and rural national highway, there is a referenced place-name for direction road sign, but there is no reference in urban road and is only a guideline. Direction signs in urban could not have consistent place-name and it is vary difficult to select the proper place-name. Based on the change of analysis environment and perception of road sign - related problem, This study is aimed to suggest how to deduce the spatial impact zone of place-name from DB and GIS in RSMS of Changwon City. The results indicated that there is a spatial difference between place-names according to whether is near or far on the road sign. It is expected that this method would be effectively used in case of new road sign and so the process to select the place-name would be simple.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.40 no.6
• /
• pp.48-57
• /
• 2003

In this paper, An 8${\times}$l ID-IDCT processor with adder-based distributed arithmetic(DA) and bit-serial method Is presented. To reduce hardware cost and to improve operating speed, the proposed 8${\times}$1 ID-IDCT used the bit-serial method and DA method. The transform of coefficient equation results in reduction in hardware cost and has a regularity in implementation. The sign extension computation method reduces operation clock. As a result of logic synthesis, The gate count of designed 8${\times}$1 1D-IDCT is 17,504. The sign extension processing block has gate count of 3,620. That is 20% of total 8${\times}$1 ID-IDCT architecture. But the sign extension processing block improves more than twice in throughput. The designed IDCT processes 50Mpixels per second and at a clock frequency of 100MHz.

• Journal of Korea Spatial Information System Society
• /
• v.10 no.2
• /
• pp.13-24
• /
• 2008

A next generation video based car navigation is researched to supplement the drawbacks of existed 2D based navigation and to provide the various services for safety driving. The components of this navigation system could be a load object database, identification module for load lines, and crossroad identification module, etc. In this paper, we proposed the traffic lights and road sign recognition method which can be effectively exploited for crossroad recognition in video-based car navigation systems. The method uses object color information and other spatial features in the video image. The results show average 90% recognition rate from 30m to 60m distance for traffic lights and 97% at 40-90m distance for load sign. The algorithm also achieves 46msec/frame processing time which also indicates the appropriateness of the algorithm in real-time processing.

• Journal of KIISE
• /
• v.42 no.2
• /
• pp.203-212
• /
• 2015

This paper proposes a traffic sign recognition method in real road environments. The video stream in driving environments has two different characteristics compared to a general object video stream. First, the number of traffic sign types is limited and their shapes are mostly simple. Second, the camera cannot take clear pictures in the road scenes since there are many illumination changes and weather conditions are continuously changing. In this paper, we improve a modified census transform(MCT) to extract features effectively from the road scenes that have many illumination changes. The extracted features are collected by histograms and are transformed by the dense descriptors into very high dimensional vectors. Then, the high dimensional descriptors are encoded into a low dimensional feature vector by Fisher-vector coding and Gaussian Mixture Model. The proposed method shows illumination invariant detection and recognition, and the performance is sufficient to detect and recognize traffic signs in real-time with high accuracy.