• Korean Journal of Construction Engineering and Management
• /
• v.15 no.1
• /
• pp.3-10
• /
• 2014

High-rise buildings need thorough cost management because of large size and high risk. Cost management makes a budget by establishing and analyzing detail element at planning phase, needs cost control as each design phase, then reflected to next design. This research develops a schematic estimation model based on vertical and horizontal elements at design phase for structure cost of high-rise buildings to reduce error range and use data as design management. Usability of the model is confirmed by case study. The estimation model is expected to contribute to making the cost model more effective and satisfactory to concerned in construction or budget department and manage keeping track of the cost.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.31 no.6_1
• /
• pp.447-454
• /
• 2013

The geolocation accuracy of SAR satellite imagery is affected by orbit and sensor information and external variables such as DEM accuracy and atmospheric delay. To predict geolocation accuracy of KOMPSAT-5 and KOMPSAT-6, this paper uses TerraSAR-X imagery which has similar spec. Simulation data for sensitivity analysis are generated using range equation and doppler equation with several key error sources. As a result of simulation analysis, the effect of sensor information error is larger than orbit information error. Especially, onboard electronic delay needs to be monitored periodically because this error affects geolocation accuracy of slant range direction by 30m. Additionally, DEM accuracy causes geolocation error by 20~30m in mountainous area and atmospheric delay can occur by 5m in response to atmospheric condition and incidence angle.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37A no.9
• /
• pp.728-737
• /
• 2012

An analytical method for identifying terrestrial broadcasting coverages is proposed for a terrestrial broadcasting transmission system adopting a hierarchical modulation technique. Bit Error Rates(BERs) are derived for hierarchically modulated non-uniform QAM constellations based on the Q-function analysis in AWGN environments. The derived BERs depend on the hierarchical modulation factor ${\alpha}$(HMF) and could be mapped to the broadcasting coverages according to the link budget analysis based on the log-distance path loss model. Finally the broadcasting coverage ratios for high priority(HP) streams and low priority(LP) streams are calculated and presented for the determination of the HMF.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.11 no.6
• /
• pp.130-138
• /
• 2012

There are increasing demands from the industry for intelligent robot-calibration solutions, which can be tightly integrated to the manufacturing process. A proposed solution can simplify conventional robot-calibration and teaching methods without tedious procedures and lengthy training time. iGPS(Indoor GPS) system is a laser based real-time dynamic tracking/measurement system. The key element is acquiring and reporting three-dimensional(3D) information, which can be accomplished as an integrated system or as manual contact based measurements by a user. A 3D probe is introduced as the user holds the probe in his hand and moves the probe tip over the object. The X, Y, and Z coordinates of the probe tip are measured in real-time with high accuracy. In this paper, a new approach of robot-calibration and teaching system is introduced by implementing a 3D measurement system for measuring and tracking an object with motions in up to six degrees of freedom. The general concept and kinematics of the metrology system as well as the derivations of an error budget for the general device are described. Several experimental results of geometry and its related error identification for an easy compensation / teaching method on an industrial robot will also be included.

• Journal of Cadastre & Land InformatiX
• /
• v.50 no.1
• /
• pp.63-73
• /
• 2020

The Ministry of Land, Infrastructure and Transport carried out a pilot project for data maintenance in 2011 to ensure the accuracy of cadastral records nationwide, and now trying to reduce the errors such as omission of the cadastral book, inconsistency of land category between cadastral account book and cadastral map, etc. and the boundary between the map boundary, scale, and administrative areas. In this study, we looked at the currents status and problems of the cadastral research, improving the cadastral map, which has been promoted by the government and the cadastral office. In order to revitalize the cadastral map data maintenance project, it is necessary to re-establish the plan for each step for challenging the limitation of current data maintenance, and the master plan for promotion system, and develop manuals to maintain consistency and secure accuracy of cadastral map maintenance, such as "Coverage and Maintenance Guidelines for Cadastral Maps", and secure the national budget for error correction in cadastral map led by government.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.8A
• /
• pp.787-793
• /
• 2008

3GPP evolved packet system (EPS) is an all-IP based system that supports various access networks such LTE, HSPA/HSPA+, and non-3GPP networks. Recently, the support of IP flows with packet level QoS profiles was added to the requirements of the EPS. This paper proposes an adaptive modulation and coding (AMC) scheme that supports the QoS of such IP flows in the 3G LTE access network of the EPS. Defining the retransmission as a critical factor for QoS, the proposed scheme applies different maximum packet error probability $P_{max}$ to each packet when selecting the AMC transmission mode. In determining $P_{max}$, the QoS constraints and NACK-to-ACK error as well as channel condition are considered, balancing two objectives: the satisfaction of the QoS and the maximization of spectral efficiency. The simulation results show that it is able to reduce both delay violation and status report by 10%, while improving the throughput 10% in comparison with an existing scheme.

• International Area Studies Review
• /
• v.18 no.3
• /
• pp.175-201
• /
• 2014

This paper analyses the effect of R&D investment on local economies. R&D investment contributes to the regional local economy by increasing employment and production activity of the investees. The investees may end up with increased productivity, sales and employment. At the regional R&D level, the central government R&D fund and firm self R&D budget will be the source of R&D investment. Further positive effects are inter-related with local industries. This study carried out an empirical analysis on the effect of R&D investment on local economies using Korean panel data after comparing international literatures. The dynamic panel estimator is used to estimate an autoregressive model with lagged dependent variable. Using the Da Silva method, mixed variance-component moving-average error process is estimated and selected. R&D investment is very important factor to improve the productivity of a region and the size of the effect is dependent on the time periods within the Korean economic history.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.35 no.3
• /
• pp.175-186
• /
• 2017

In this study was to survey method of national/public land actual condition survey to utilization of UAV, in order to evaluate the economic and accuracy. we carried out the comparative evaluation of the cadastral status surveying in terms of accuracy of parcel checkpoint, economical costs. The results are summarized as follows. First, average position error of the orthoimage was 0.033m in X error, 0.023m in Y error when the RMSE average calculated 0.046m from the intersection of plane distance connections. Secondly, it was appeared the accuracy of the orthophotograph is 0.076m at the maximum RMSE of the UAV orthoimage check point and 0.042m at the minimum RMSE compared with the VRS-GNSS survey results. Thirdly, when the allowable error specified in the implementing regulation of the current cadastral survey is applied, all of the checkpoint of 0.360m tolerance corresponding to the scale of 1/1,200 is satisfied. Finally, UAV utilization method in national/public land actual condition survey is 26,497,436(KRW) cheaper than cadastral survey method for In the economic evaluation of national/public land actual condition survey. Therefore, as a result of this study shows that the method of utilizing UAV in the national/public land actual condition survey satisfies legal standards in terms of accuracy and economical aspect is a way to further reduce the local government budget.

• Journal of Information Technology Applications and Management
• /
• v.11 no.4
• /
• pp.87-94
• /
• 2004

The software reliability growth model(SRGM) has been developed in order to estimate such reliability measures as remaining fault number, failure rate and reliability for the developing stage software. Almost of them assumed that the faults detected during testing were evetually removed. Namely, they have studied SRGM based on the assumption that the faults detected during testing were perfectly removed. The fault removing efficiency. however. IS imperfect and it is widely known as so in general. It is very difficult to remove detected fault perfectly because the fault detecting is not easy and new error may be introduced during debugging and correcting. Therefore, the fault detecting efficiency may influence the SRGM or cost of developing software. It is a very useful measure for the developing software. much helpful for the developer to evaluate the debugging efficiency, and, moreover, help to additional workloads necessary. Therefore. it is very important to evaluate the effect of imperfect dubugging in point of SRGM and cost. and may influence the optimal release time and operational budget. I extent and study the generally used reliability and cost models to the imperfect debugging range in this paper.

• International Journal of Railway
• /
• v.9 no.2
• /
• pp.36-40
• /
• 2016

TETRA communication system is very versatile system which can transmit voice + data and packet data optimized. Direct mode operation permits to connect between mobiles when mobile stain is out of coverage of networks. It can be more secure communication channel for railway signaling systems. Railway signaling systems use many of wayside signal equipment, which require many maintenance efforts and budget. Many railway authorities want to reduce and replace the wayside equipment. Radio based signaling systems are one of candidate for replacing the conventional signaling systems. The radio based signaling systems can replace track circuit and wayside signal. The radio systems permit to connect between control centers and trains. The radio systems have to ensure high quality of the connectivity more or equal to the existed track circuits. We studied the application of TETRA systems for railway radio systems for bridging between train control centers and trains. We provide an operation scenario for radio based train control system to ensure the safety require to the existed trains control system and satisfied the existed operational availability. We showed the data transmission speed, maximum bit error rate, and data coding for the radio-based signal system using TETRA systems.