• Journal of Positioning, Navigation, and Timing
• /
• v.12 no.2
• /
• pp.185-200
• /
• 2023

The Korea Augmentation Satellite System (KASS) is the first satellite navigation enhancement system in Korea developed in compliance with international standards. Technologies accumulated during the development process should be spread to industries such as academia and serve as the basis for developing the domestic satellite navigation field. This paper introduces the development process from design to implementation, testing, and verification of KASS control systems (KCS). First, development standards, milestones, requirements, and interface standards are presented as KCS development methods, and major functional design, physical design, and hardware/software implementation are described based on the allocated requirements. Subsequently, the verification environment, procedures, and results of the development product are covered and the developed operational and maintenance procedures are described. In addition, based on the experience gained through the development, suggestions were made for beneficial technology development and organization when promoting satellite navigation projects in the future. Since this work has important historical value for the development of domestic satellite navigation, it is expected that the development results will be shared with academia and industry in the future and be used as basic data for similar development.

• Journal of Korean Orthopaedic Sports Medicine
• /
• v.8 no.1
• /
• pp.19-25
• /
• 2009

Purpose: We report mid to long - term results of meniscal transplantation and evaluate the important factors for successful outcomes. Materials and Methods: Between December 1999 and September 2002, 25 meniscal transplantations were performed using fresh frozen allograft. The lateral meniscus was transplanted in 19 cases and medial meniscus in 6 cases. The mean age was 34 years (range, 17~50 years) and the mean follow up was 54.8 months (range, 6~85 months). Preoperative measurements were made using a ruler graded in millimeters. Lateral meniscus was fixed by keyhole technique and medial meniscus was fixed by double bone plug technique with suturing the periphery of the meniscal transplant. All patients were evaluated with Knee Assessment Scoring System (KASS), Lysholm knee score, and Tegner activity scale for daily activity. Results: Symptoms improved in all cases. The average KASS score increased from 61.7 preoperatively to 83.8 postoperatively. The average Lysholm knee score increased from 77.7 preoperatively to 87.7 postoperatively (excellent in 3 cases, good in 17 cases, fair 4 cases, poor 1 case). But painful swellings were 3 cases, numbness in 1 case, and granuloma due to non-absorbable suture material in 1 case. Peroneal nerve palsy in 1 case was recovered after 6 weeks postoperatively. Conclusion: Meniscal allograft transplantation after subtotal or total menisectomy can significantly relieve pain and improve function of the knee joint. The exact preoperative sizing and secure fixation are essential for successful outcomes.

• Journal of Advanced Navigation Technology
• /
• v.22 no.5
• /
• pp.384-390
• /
• 2018

This paper introduces a MATLAB graphical user interface (GUI) based software for analysis of korea augmentation satellite system (KASS) availability performance. This software uses minimum variance (MV) estimator and Kriging algorithm to generate integrity information such as user differential range error (UDRE) and grid ionospheric vertical error (GIVE). The information is offered to ground and aviation users in Korean region. The software also gives accuracy data, protection level data and availability map about each user position by using the integrity information. In particular the software calculates the protection level along a path of aircraft. We verified the result of protection level of aviation user by comparing them with the results of SBASimulator#2, which is a simulation tool of european geostationary navigation overlay service (EGNOS). As a result, the protection level error between the result of our software and the SBASimulator#2 was about 2% which means that the result of our software is accurate.

• Journal of Environmental Science International
• /
• v.15 no.2
• /
• pp.185-191
• /
• 2006

In this paper, removal time of side form from concrete using OPC(ordinary Portland cement) and FAC(fly ash cement) are proposed by appling logistic model, which evaluates the strength development of concrete with maturity. W/B, types of cement and curing temperatures are adapted as test parameters. The estimation of strength development by logistic model has a good agreement between calculated values and measured ones. As for the removal times of form works suggested in this paper, as W/8 increases, curing temperature decreases and fly ash is used, removal time of side form is prolonged. Removal time of form from concrete using OPC suggested in this paper is shorter $2.5\~3.5$ days than those of KASS-5 (Korean Architectural Standard Specifications-5) in the range of over $20^{\circ}C$. And in the range of $10\~20^{\circ}C$ removal time of form is shorter than that of KASS-5 by as much as $4\~4.5$ days. The use of FAC results in an increase in removal time of form compared to that of OPC by about 1 day.

• Journal of Positioning, Navigation, and Timing
• /
• v.9 no.2
• /
• pp.71-77
• /
• 2020

KRS which is subsystem of Korea Augmentation Satellite System (KASS) performs a role of collecting and monitoring GPS signals. In order to generate the accurate correction message, the site which meets the requirements should be selected and verification to meet each requirement should be accompanied. When the sites are selected, the environmental considerations are EMI, clear horizon (CH) and multipath. Of these, EMI and CH can be checked for satisfaction by instrumentation, but multipath error is difficult to predict. Therefore, multipath error analysis for the installation position of actual antenna at each KRS site should be preceded, and multipath scenario should be generated for each location to analyze the effects of the resulting system performance. In this paper, based on satellite signals collected from each KRS sites, the method for analyzing multipath error in each KRS sites is described, and the multipath error is analyzed. Also to perform an analysis of the effects on system performance due to multipath error, multipath error modeling is performed for the generation of simulation scenarios.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2007.04a
• /
• pp.19-23
• /
• 2007

In this paper, the period for the strength correction was determined with each region of south Korea based on the meteorological data of KMA(Korea meteorological administration) by applying KASS-5 regulation. In case of 28 days of strength control age, the period for strength correction with 6MPa was calculated to 50-60 days and, with 3 MPa. to around 80 days. The period for the strength correction was shown to be decreased with the rise of altitude. The period to consider the delay of the strength development due to low temperature including the period of cold weather concrete was nearly 7 months around 1 year. References for determining the strength correction factors with each region of south Korea was provided in this paper.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.30 no.1
• /
• pp.28-37
• /
• 2022

Along with the remarkable advances in GNSS technology, SBAS further enhances the accuracy and integrity of GNSS location information and derives improvement in the safety and efficiency of air traffic management from reducing GNSS location errors, induced by passing through the ionosphere and atmosphere, to less than three meters. In this regard, ICAO specifies the standards of SBAS signals and recommends every party to phase in by 2025; and it is foreseeable that SBAS APV-I and CAT-I will be provided in South Korea by its undertaking the development of KASS, a Korean SBAS. The purpose of the study is to design SBAS APV-I procedure on the basis of the runway 15L of Incheon International Airport and conduct obstacle assessment according to PAN-OPS Doc. 8168, focusing on the usability and usefulness of SBAS APV-I. The results show that SBAS APV-I will provide better decision height compared to other PBN RNP approach procedures such as LNAV and Baro-VNAV at the Incheon International Airport.

• Proceeding of KASS Symposium
• /
• 2005.05a
• /
• pp.52-66
• /
• 2005

Tension and Membrane have the potential to enable the realization of lightweight structures that have the attractive features of structures efficiency and aesthetical expression. Compared with pure (thorough-bred) tension structures such as cable net, air dome and tensegrity, so called hybrid tension structures such as beam string, tensegric system and other mixed structures have Potential still to be realized. After synnaruzubg the simple definition of tensegric structure, some holistic designs for hybrid tension structures completed recently in the author's practice are given.

• Proceeding of KASS Symposium
• /
• 2005.05a
• /
• pp.69-76
• /
• 2005

This paper deals with a problem about synergy effect in design and engineering. So far a design processing is paralleled to both in Korea, A cooperation between concept design and working plan must be kept up all the way. From three Personally designed footbridges 1 will make clear a total problem for throughout design processing. If we must solve a gaps between technology and art for structural design, we can get an unexpected result. It will be synergy effect between art and technology, design and engineering.

• Proceeding of KASS Symposium
• /
• 2005.05a
• /
• pp.83-88
• /
• 2005

This paper deals with design processing for in a east- north Seoul. The pedestrian cross over main street through Seoul and Uijongbu. For resonable beautiful footbridge it need to technical mind and art. The method of process for this footbridge approached in both the field of science and art. Starting with structure planning it need to cooperate both engineering and architect. To design a resonable and economical structural master piece, everyone must solve a gaps between technology and art for structural design.