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  • Title/Summary/Keyword: National Control Points

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The Effective Means to Promote GPS-Based Survey for Cadastral Surveying of GPS Performance Standards and Measures (GPS기반의 효율적인 지적측량성과를 위한 측량기준 및 방안에 대한 연구)

  • Ahn, Jong Soon;Kang, Joon Mook;Yun, Hee Cheon
    • Journal of Korean Society for Geospatial Information Science
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    • v.21 no.1
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    • pp.65-75
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    • 2013
  • In this study, one of the main aims is to build up a technical foundation for promoting the cadastral resurvey effectively and to improve the accuracy of cadastral surveying is to make use of precise surveying techniques in allowance of position errors as reference accuracy in cadastral resurvey, which is proper to obtain the sufficient accuracy of the cadastral control points, and parcel boundary points by introducing the GNSS-based surveying techniques on cadastral survey. In detail, the existing procedures and outcomes of cadastral survey were compared and analyzed for suggesting a better survey technique than that of the other techniques in a variety of aspects of capability of cadastral survey. The new skills and supports could be upmost importance when doing cadastral survey. What's more, essentially, 'The Measurement Department' makes all the efforts to establish 'The Surveying Regulations'. This could possibly apply GNSS-based surveying technique to the cadastral resurvey for the foreseeable future and this research paper suggested that how to improve absolute accuracy of cadastral reference points by means of putting to use the appropriate models of measurement further.

QUANTITATIVE DATA TO SHOW EFFECTS OF GEOMETRIC ERRORS AND DOSE GRADIENTS ON DOSE DIFFERENCE FOR IMRT DOSE QUALITY ASSURANCE MEASUREMENTS

  • Park, So-Yeon;Park, Jong-Min;Ye, Sung-Joon
    • Journal of Radiation Protection and Research
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    • v.36 no.4
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    • pp.183-189
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    • 2011
  • To quantitatively evaluate how setup errors in conjunction with dose gradients contribute to the error in IMRT dose quality assurance (DQA) measurements. The control group consisted of 5 DQA plans of which all individual field dose differences were less than ±5. On the contrary, the examination group was composed of 16 DQA plans where any individual field dose difference was larger than ±10 even though their total dose differences were less than ±5. The difference in 3D dose gradients between the two groups was estimated in a cube of 6×6×6mm3 centered at the verification point. Under the assumption that setup errors existed during the DQA measurements of the examination group, a three dimensional offset point inside the cube was sought out, where the individual field dose difference was minimized. The average dose gradients of the control group along the x, y, and z axes were 0.21, 0.20, and 0.15 cGymm1, respectively, while those of the examination group were 0.64, 0.48, and 0.28 cGymm1, respectively. All 16 plans of the examination group had their own 3D offset points in the cube. The individual field dose differences recalculated at the offset points were mostly diminished and thus the average values of total and individual field dose differences were reduced from 3.1% to 2.2% and 15.4% to 2.2%, respectively. The offset distribution turned out to be random in the 3D coordinate. This study provided the quantitative data that support the large individual field dose difference mainly stems from possible geometric errors (e.g., random setup errors) under the influence of steep dose gradients of IMRT field.

Quality Evaluation of Orthoimage and DSM Based on Fixed-Wing UAV Corresponding to Overlap and GCPs (중복도와 지상기준점에 따른 고정익 UAV 기반 정사영상 및 DSM의 품질 평가)

  • Yoo, Yong Ho;Choi, Jae Wan;Choi, Seok Keun;Jung, Sung Heuk
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.3
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    • pp.3-9
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    • 2016
  • UAV(unmanned aerial vehicle) can quickly produce orthoimage with high-spatial resolution and DSM(digital surface model) at low cost. However, vertical and horizontal positioning accuracy of orthoimage and DSM, which are obtained by UAV, are influenced by image processing techniques, quality of aerial photo, the number and position of GCPs(ground control points) and overlap in flight plan. In this study, effects of overlap and the number of GCPs are analyzed in orthoimage and DSM. Positioning accuracy are estimated based on RMSE(root mean square error) by using dataset of nine pairs. In the experiments, Overlaps and the number of GCPs have influence on horizontal and vertical accuracy of orthoimage and DSM.

A Horticultural Therapy Program Focusing on Gardening Activities to Promote Psychological, Emotional and Social Health of the Elderly Living in a Homeless Living Facility for a Long Time: A Pilot Study

  • Kim, Yong Hyun;Lee, So-Hyeon;Park, Chul-Soo;Bae, Hwa-ok;Kim, Yun Jeong;Huh, Moo Ryong
    • Journal of People, Plants, and Environment
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    • v.23 no.5
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    • pp.565-576
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    • 2020
  • Background and objective: The elderly living in homeless living facilities for a long time suffer from various mental health problems. This study aims to determine the psychological, emotional, and social effects of a horticultural therapy program composed of gardening activities, which was designed based on the semantic structures of life for the homeless elderly living in the facilities for a long time. Methods: A total of 12 subjects (6 in the control group and 6 in the experimental group) participated in the study. The horticultural therapy program consisted mainly of gardening activities, and a total of 16 sessions were conducted once a week for 16 weeks, 60-90 minutes per session. The subjects were tested to evaluate their self-esteem, depression, and horticultural activities. The data were analyzed using the Mann-Whitney U test, Wilcoxon rank test, and Friedman test, which were nonparametric tests, conducted at a 95% significance level. Results: First, in the case of self-esteem, a significant difference was found between the groups, 20.00 points (SD = 5.69) in the control group, and 25.50 points (SD = 3.73) in the experimental group (p = .034). Second, in the case of depression, no statistically significant difference was found in the posttest. Finally, in the case of the horticultural activity evaluation, the scores of most variables gradually and significantly increased during the program [Verbal interaction during activity (p = .006), Self-concept and identity (p = .006), Need-drive adaptation (p < .001), Interpersonal and social relations (p < .001)]. Conclusion: These results support that the horticultural therapy program could help the elderly improve psychological relaxation, emotional stability, and social relationships. In order to generalize the results, it is suggested to increase the number of subjects or conduct additional repetitive experiments in further research.

HACCP in Changran Jeotgal

  • Park Mi-Yeon;Choi Seung-Tae;Chang Dong-Suck
    • Fisheries and Aquatic Sciences
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    • v.5 no.1
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    • pp.48-53
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    • 2002
  • The HACCP (hazard analysis critical control point) concept becomes an important aspect of Good Manufacturing Practices (GMP) in safe food production. The HACCP plan was developed with food safety objective. The authors already carried out hazards analysis on Changran Jeotgal manufacturing process in a previous report. In this study we developed a HACCP plan on the manufacturing process of Changran Jeotgal. We could decide two CCPs those were salt concentration and eliminations of foreign materials before packaging. Foreign materials should be certainly checked out with laser detector just before packaging. Salt should be maintained more than 8% to inhibit pathogenic bacteria in end product. On the Jeotgal process free water is removed after salting and Jeotgal is seasoned with several subsidiary materials such as com syrup. In result end products have 8% salt with water activity 0.82. Most bacteria are inhibited but some can live in this condition. Materials on the working may be contaminate by pathogens, chemicals or physical hazards. It will be decreased by SSOP (standard sanitary operating program). The SSOP needed in Jeotgal plants is nearly same as other general food manufacturing plants but essential to fulfill HACCP program.

A Design of Linear State Observers for Motorized Seat Belt System (전동식 안전벨트 시스템의 선형 상태 관측기 설계)

  • Lee, Kang-Seok;Choi, Chin-chul;Lee, Woo-Taik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.20 no.3
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    • pp.58-66
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    • 2012
  • This paper describes a design and a verification of linear state observers for a motorized seat belt system to estimate state information such as angular velocity and load torque. The motorized seat belt system provides functions to protect passengers and improve passenger's convenience. To realize these functions, sensors which can measure an angular velocity and load torque are needed. By use of the linear state observer, state information can be estimated without sensors. The motorized seat belt system is analysed and represented as a state space model which contains load torque as an augmented state. By the developed state space model, a full and reduced order observer are designed and verified by experiments. The full and reduced order observer are also compared from points of view of execution time and noise robustness.

An Efficient Association Control Method for Vehicular Networks with Mobile Hotspots

  • Hwang, Jae-Ryong;Choi, Jae-Hyuk;Yoo, Joon;Lee, Hwa-Ryong;Kim, Chong-Kwon
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.5
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    • pp.888-908
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    • 2011
  • The increasing demand from passengers in vehicles to improve safety, traffic efficiency, and comfort has lead to the growing interest of Wi-Fi based vehicle-to-infrastructure (V2I) communications. Although the V2I system provides fast and cost-effective Internet connectivity to vehicles via roadside Wi-Fi access points (APs), it suffers from frequent handoffs due to the high mobility of vehicles and the limited coverage of Wi-Fi APs. Recently, the Mobile AP (MAP) platform has emerged as a promising solution that overcomes the problem in the V2I systems. The main advantage is that MAPs may yield longer service duration to the nearby vehicles that have similar mobility patterns, yet they provide smaller link capacities than the roadside APs. In this paper, we present a new association control technique that harnesses available connection duration as well as achievable link bandwidth in high-speed vehicular network environments. We also analyze the tradeoff between two association metrics, namely, available connection duration and achievable link bandwidth. Extensive simulation studies based on real traces demonstrate that our scheme significantly outperforms the previous methods.

The Effect of Electro-Acupuncture Treatment for Chronic Back Pain in Horses (말의 만성요통에 대한 전침치료 효과)

  • Kim Min-su;Xie Huisheng;Seo Kang-moon;Nam Tchi-chou
    • Journal of Veterinary Clinics
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    • v.22 no.2
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    • pp.144-147
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    • 2005
  • This study was performed to investigate that electro-acupuncture might relieve chronic back pain in horses. Twenty horses with chronic back pain were chosen from referring to College of Veterinary Medicine, University of Florida. They were assigned the patients referred to 2 treatment groups and 1 control group. The treatment group I was electrostimulated to 4 acupoints. The acupuncture points of Lumbosacral point, GV-6, BL26, and BL54 were used.; The treatment group II was taken the phenylbutazone orally. Control group was administered the normal saline per oral. Back pain score system was used to evaluate the degree of back pain. The treatment group r had significant lower back pain score from two times of electroacupuncture treatment. However, the treatment group II and control group did not change back, pain scores during experimental periods. Thus, Electroacupuncture treatment might be effective therapy for chronic back pain in horses.

Gearless Doubly-fed Induction Generator for Wind Power Generation (풍력발전용 기어리스 이중여자 유도 발전기)

  • Park, Taesik;Moon, Chaejoo;Kim, Seonghwan
    • Journal of IKEEE
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    • v.21 no.1
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    • pp.81-84
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    • 2017
  • As the demands for offshore wind power generation systems on a large scale have grown dramatically, and extensive developments in PMSG (Permanent Magnet Synchronous Generator) and DFIG (Doubly-fed Induction Generator) wind turbine system have been going on. However, the wind power systems have been more sophisticated, and their reliability becomes critical issues. Averagely, wind turbines have shut down for about a week per year for repairs and maintenance. Especially the high speed gearbox of DFIG is inevitable components for high power generation, but becomes one of the critical failures. In this paper, a new reliable gearless wind turbine structure is proposed. The gearless wind turbine can operate on a maximum power points by controlling the speed of a rotational stator. The proposed approach is verified by PSIM simulations, resulting in increased energy reliability.

Precision Evaluation of Recent Global Geopotential Models based on GNSS/Leveling Data on Unified Control Points

  • Lee, Jisun;Kwon, Jay Hyoun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.38 no.2
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    • pp.153-163
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    • 2020
  • After launching the GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) which obtains high-frequency gravity signal using a gravity gradiometer, many research institutes are concentrating on the development of GGM (Global Geopotential Model) based on GOCE data and evaluating its precision. The precision of some GGMs was also evaluated in Korea. However, some studies dealt with GGMs constructed based on initial GOCE data or others applied a part of GNSS (Global Navigation Satellite System) / Leveling data on UCPs (Unified Control Points) for the precision evaluation. Now, GGMs which have a higher degree than EGM2008 (Earth Gravitational Model 2008) are available and UCPs were fully established at the end of 2019. Thus, EIGEN-6C4 (European Improved Gravity Field of the Earth by New techniques - 6C4), GECO (GOCE and EGM2008 Combined model), XGM2016 (Experimental Gravity Field Model 2016), SGG-UGM-1, XGM2019e_2159 were collected with EGM2008, and their precisions were assessed based on the GNSS/Leveling data on UCPs. Among GGMs, it was found that XGM2019e_2159 showed the minimum difference compared to a total of 5,313 points of GNSS/Leveling data. It is about a 1.5cm and 0.6cm level of improvement compare to EGM2008 and EIGEN-6C4. Especially, the local biases in the northern part of Gyeonggi-do, Jeju island shown in the EGM2008 was removed, so that both mean and standard deviation of the difference of XGM2019e_2159 to the GNSS/Leveling are homogeneous regardless of region (mountainous or plain area). NGA (National Geospatial-Intelligence Agency) is currently in progress in developing EGM2020 and XGM2019e_2159 is the experimentally published model of EGM2020. Therefore, it is expected that the improved GGM will be available shortly so that it is necessary to verify the precision of new GGMs consistently.