• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.50 no.2
• /
• pp.72-79
• /
• 2001

In the GPS/DR integrated system, the GPS position(or velocity) is used to compensate the DR output and to calibrate errors of the DR sensor. This synergistic relationship ensures that the calibrated DR accuracy can be maintained even when the GPS signal is blocked. Because of the observability problem, however, the DR sensors are not sufficiently calibrated when the vehicle speed is low. This problem can be solved if we use a multi-antenna GPS receiver for attitude determination instead of conventional one. This paper designs a two-antenna GP receiver integrated with DR sensors. The proposed integration system has three remarkable features. First, the DR sensor can be calibrated regardless of the vehicle speed with the aid of two-antenna GPS receiver. Secondly, the search space of integer ambiguities in GPS carrier-phase measurements is reduced to a part of the surface of the sphere using DR heading. Thirdly, the detection resolution of cycle-slips in GPS carrier-phase measurements is improved with the aid of DR heading. From the experimental result, it is shown that the search space is drastically reduced to about 3/20 of the non-aided case and the cycle-slips of 1 or half cycle can be detected.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.05a
• /
• pp.117-120
• /
• 2002

Electrical power system has very complexity problem that it is plan measurement system to achieve Harmonic State Estimation (HSE). This complexity problem depends on discord of necessary accuracy, certainty of noise that exist in data communication damage and converter, adaptability of network modification and minimum of expense size of system, estimated monitering. Also, quantity of available measurement equipment for harmonic measurement has been limited. Therefore, systematic method that choose measurement location for harmonic state estimation. This paper is that see proposed HSE that use Observability Analysis(OA) for harmonic state estimation of electrical power system. OA depends on measurement number, measurement location and measurement form here, it is analysis method that depend on network form and admittance of the system. OA used achieve harmonic state estimation that it is Applied to New Zealand electrical power system to prove validity of HSE algorithm that propose. This study result about harmonic state estimation of electrical power system displayed very economical and effective method by OA.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.11a
• /
• pp.212-215
• /
• 2003

This paper presents constitution of a moderate price thermography system for on-line measurement. All objects with some temperature above absolute zero radiate in the infrared. The intensities and spectra of the infrared radiated from some object depend on the conditions and temperature distributions on the surface of the objects, and the temperature distributions differ from each others with different undersurface structures. Consequently, infrared radiation is useful for diagnosis of the conditions on the surface and undersurface of electric power apparatus. But the present, because engineers directly measure the temperatures of apparatuses in off-line, the measured data do not always have the information of the past. The proposed system is able to analyze not only the information of the past but the trend of deterioration, and the system is able to compensate for the distortion of surface temperature as to weather conditions. The thermal image histogram is equalized to upgrade observability, and a pan-tilter is adopted to control of direction for any target point.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.68 no.1
• /
• pp.108-121
• /
• 2019

This paper presents the study results on the design of the correction filter to improve the azimuth error estimation of the high-speed guided missile launched from the warship after the transfer alignment. We theoretically proved that the transfer alignment performance is determined by the accuracy of the marine inertial navigation system and the observability of the attitude error state variable in the transfer alignment filter, and that most of navigation errors in high-speed guided missile are caused by azimuth error. In order to improve the azimuth estimation performance of the correction filter, the multiple adaptive estimation method and the adaptive filters adapting the measurement noise covariance or the process noise covariance are proposed. The azimuth estimation performance of the proposed adaptive filter and the existing Kalman filter are compared and analyzed each other for 8 different transfer alignment accuracy cases. As a result of comparison and analysis, it was confirmed that the adaptive filter adapting the process noise covariance has the best azimuth estimation performance. These results can be applied to the design of correction filters for high-speed guided missile.

• Journal of Positioning, Navigation, and Timing
• /
• v.10 no.3
• /
• pp.189-196
• /
• 2021

In this paper, we propose techniques to correct the altitude error and heading error of 3D Pedestrian Inertial Navigation (PIN). When a PIN is used to estimate the location of a pedestrian only with an Inetrial Measurement Unit (IMU) without infrastructure, there is a problem in that the location error gradually increases due to the limitation of the observability of the filter. To solve this problem without additional sensors, we propose two techniques in this paper. First, stair walking is recognized in consideration of the altitude difference that may occur during one step. If it is recognized as stair walking, only Zero-velocity UPdaTe (ZUPT) is performed, and if it is recognized as level walking, ZUPT + Altitude Damping (AD) is performed together to correct the altitude error. Second, the straight-line movement direction is calculated through the difference of the estimated position, and the heading error is corrected by matching this information with the link information of the digital map. By applying these techniques, it is verified through real tests that accurate three-dimensional location information of pedestrians can be estimated without infrastructure.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.1
• /
• pp.759-766
• /
• 2021

In this digital age, all organizational environments force businesses to adopt Information and Communication Technologies (ICT) since these technologies have immense impact on such businesses' competitiveness and productivity. Nonetheless, the productivity and the competitiveness enjoyed by such firms vary depending on the size or the organizations, context of the country; developing or developed, and what kinds of technologies are adopted. This investigation focused on small- and medium-sized enterprises (SMEs) of Eastern province of Sri Lanka where such studies are scanty. The adoption of social media (SM) by SMEs is inclined to change how organizations operate, this calls for an investigation of the elements that impact SMEs to adopt SM and such investigation. Technology-Organization-Environment (TOE) framework was based to understand the factors. Research approach was quantitative approach using questionnaire survey. Data were collected using online form to see 285 valid responses. Structural Equation Modelling was deployed to evaluate the proposed model. Results revealed that Relative Advantage, Compatibility, Complexity, Observability, Competitive Intensity, Bandwagon Pressure, and Competitive Pressure were influencing, while Trialability, Top Management Support, CEO's Innovativeness did not show statistically significant influence on SMEs' social media adoption.

• Journal of Korean Academy of Nursing
• /
• v.32 no.2
• /
• pp.155-164
• /
• 2002

With the dynamically changing environment of society, managing change is the vital element of organizations's survival and growth. Health care organizations have expended enormous resources to restructure patient care delivery. Despite the growing literature describing these organizational innovations, there is a paucity of credible data that reflects systematic measurement and evaluation of such changes. This study examined the nurses' psychological response toward the work process redesign, newly introduced by the nursing department in a acute care hospital. The aim of the study was to figure out how nurses's general perception of change and perceived attributes of change affected their acceptance of change during the organizational transition. This was descriptive- correlational. The sample for the study included 50 head nurses and 135 staff nurses. Data was analyzed using SPSS PC+, version 10.0. The major findings of the study were as follows: First, the mean score of the perception of change was 71.2(SD=13.8) with the range of 0-100, which means nurses generally perceived change positively. There were significant differences in perception of change by gender and education level. Head nurses perceived change more positively than staff nurses. The higher education level showed the more positive view of change. Second, among the perceived attributes of change, trialability had the highest mean score, which means nurses perceived the change more positively if it is testable on a limited basis. Relative advantage was perceived the most negatively. Finally, factors influencing the acceptability of the work-process redesign were perceived comparability, complexity, relative advantage, and observability, which accounted for 43.7% of the variance in the acceptability of change. This study evaluated the preliminary effects of the nursing process for reengineering, focusing on nurses' acceptability towards change. The usefulness of this research study was to determine the factors influencing acceptance of organizational members during transitional periods of change and to suggest effective strategies for increasing adoption as well as for decreasing resistance to change.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.45 no.10
• /
• pp.836-843
• /
• 2017

In lunar exploration, the necessity of utilizing rover is verified by the examples of the Soviet Union and China and the similar Mars missions of the United States. In order to achieve the successful management of a lunar rover, a high precision navigation technique is required, and accordingly, high precision initial alignment is essential. Even though it is general to perform initial alignment in a steady state, a multiposition alignment technique is applied when high performance is needed. On the lunar surface, however, the performance of initial alignment decreases from that on Earth, and it cannot be improved by applying multiposition alignment method owing to certain constraints of lunar environment. In this paper, a sun sensor aided multiposition alignment technique is proposed. The measurement model for a sun vector is established, and its observability analysis is performed. The performance of the proposed algorithm is verified through computer simulations, and the results show the estimation performance is improved dramatically.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.13 no.1
• /
• pp.17-24
• /
• 2018

Military camera equipment has a problem that observability is inferior due to various shaking factors. In this paper, we propose an image stabilization algorithm considering performance and execution time to solve this problem and implemented it in Zynq SoC. We stabilized both the simple shaking in the fixed observation position and the sudden shaking in the moving observation position. The feature of the input image is extracted by the Sobel edge algorithm, the subblock with the large edge data is selected, and the motion vector, which is the compensation reference, is calculated through template matching using the 3-step search algorithm of the region of interest. In addition, the proposed algorithm can distinguish the shaking caused by the simple shaking and the movement by using the Kalman filter, and the stabilized image can be obtained by minimizing the loss of image information. To demonstrate the effectiveness of the proposed algorithm, experiments on various images were performed. In comparison, PSNR is improved in the range of 2.6725~3.1629 (dB) and image loss is reduced from 41% to 15%. On the other hand, we implemented the hardware-software integrated design using HLS of Xilinx SDSoC tool and confirmed that it operates at 32 fps on the Zynq board, and realized SoC that operates with real-time processing.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.36 no.10
• /
• pp.1087-1099
• /
• 2012

This study investigated the purchase intention of green fashion products based on Rogers' Diffusion of Innovation theory and compared the differences between Korean and British consumers. In order to identify the impact of personal characteristics, this study also examined the effects of fashion innovativeness and LOHAS tendency on perceived attributes of innovation and intention to purchase. With a convenience sampling method, a survey questionnaire was distributed at popular fashion streets in each country. A total of 426 data were obtained, 203 from the UK and 223 from Korea. About 52% were females, and 69% were in their twenties. A factor analysis generated two LOHAS factors (health concerns and eco concerns) and four attributes of green fashion products (image improvement, symbolic superiority, observability, and compatibility). Two types of green fashion products (organic cotton t-shirts and organic cotton t-shirts with an environmental message) were provided to measure the purchase intention, respectively. The findings were as follows. British consumers were more likely to show LOHAS tendency and to perceive positive advantages of green products compared to Koreans; in addition, British consumers presented higher mean scores on the purchase intentions of organic cotton products. Fashion innovativeness was significant to predict image improvement and symbolic superiority, while eco concerns were significant in compatibility for both nations. Compatibility was important for both countries in order to explain the intention to adopt two types of organic products. In addition, image improvement was another predictor for purchase intention of organic t-shirts with an environmental message. Managerial implications were provided.