• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.597-604
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• 2016

The aim of this study was to prevent the decrease in crop output by disease and insect pests and excessive spraying of agricultural pesticides by application uniformity. A 3m height and 15km/h speed is difficult to maintain with an unmanned helicopter for aerial application, which has been affected by the controlling habits and methods or environmental factors, such as changes in the wind. Therefore, in this study, an aerial application system was design to be attached to an unmanned helicopter, which can allow a controlled application width and spray rate automatically and verified experimentally using Rmax of MS-AVIATION. The size of agricultural land was 50 m2 and nine water sensitive cards were arranged at 1.25m intervals in 5 rows with each row having a 10m interval from the position of 5m. The unmanned helicopter was flying at speeds ranging from 7.2km/h to 17.6km/h and heights ranging from 2.32m to 3.47m. The proposed aerial application system allowed application uniformity by making a valid spraying area of 7.5 m2 with 46423 particles distributed on average.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.54.1-54.1
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• 2015

We report results of investigation of amplitude calibration for very long baseline interferometry (VLBI) observations with Korean VLBI Network (KVN). Amplitude correction factors are estimated based on comparison of KVN observations at 22 GHz correlated by Daejeon hardware correlator and DiFX software correlator in Korea Astronomy and Space Science Institue (KASI) with Very Long Baseline Array (VLBA) observations at 22 GHz by DiFX software correlator in National Radio Astronomy Observatory (NRAO). We used the observations for compact radio sources, 3C 454.3 and NRAO 512 which are almost unresolved for baselines in a range of 350-477 km. VLBA visibility data of the sources observed with similar baselines as KVN are selected, fringe-fitted, calibrated, and compared in their amplitudes. We found that visibility amplitudes of KVN observations should be corrected by factors of 1.14 and 1.40 when correlated by DiFX and Daejeon correlators, respectively. These correction factors are attributed to the combination of two steps of 2-bit quantization in KVN observing systems and characteristics of Daejeon correlator.

• Journal of Auto-vehicle Safety Association
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• v.4 no.2
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• pp.5-10
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• 2012

Whiplash is the most frequent injury among occupants in low speed rear-end car collision. The aim of this paper is to analyze thecorrelation between influence parameters of head restraints and whiplash injury criteria.In this paper, DFSS (Design for Six Sigma) method is used for optimum design of head restrains. Four control factors of head restraints have selected by function matrix method. The effects of the control factors have been experimentally evaluated by using a sled pulse from 16km/h relative velocity which is suggested by KNCAP (Korean New Car Assessment Program). In order to reduce the noise factors of dynamic tests, whiplash tests were repeated twice. By using DFSS, the correlation between control factors and injury criteria has been comprehended.

• Korean Management Science Review
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• v.20 no.1
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• pp.1-23
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• 2003

Knowledge Management System is defined as an Information system to support the integrated knowledge management process for maximizing value of the knowledge assets in organizations. From that point of view, the system performance - the usage level of the system and user satisfaction - can be an available measure of the knowledge management system success. Many previous research were focused on the application of a new technological component for knowledge management processes or the construction of the overall system architecture in spite of the importance of the system performance. The purpose of this study is to Identify the factors affecting the knowledge management system performance. To do this, we conducted an exploratory case studies of eight companies. We applied theories of information system success to knowledge management system and investigated some specific strategic components as additional affecting factors. Finally, we proposed research model and ex propositions regarding the factors affecting the knowledge management system performance. The implication of the findings and future research directions were discussed.

• 한국디지털정책학회:학술대회논문집
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• 2004.05a
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• pp.151-165
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• 2004

In this paper we would like to provide a help to implementing KMS(Knowledge Management System) in public sector. For this purpose, we set up five contingency environmental factors and three process factors of knowledge management. And then investigates affecting factors effect on the performance of KMS in public sector by empirical study. A field survey of public officers in Korea local government was conducted. Complete data for 333 KMS users was analyzed to determine relationship of the research constructs. The system of evaluation and compensation is the most important factor effects on the process of KM and the performance of KMS. These results provide empirical evidence that supports the necessity of rational motivation systems does lead to effective implementation of KMS in public sector.

• Journal of Digital Convergence
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• v.2 no.1
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• pp.113-126
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• 2004

In this paper we would like to provide a help to implementing KMS(Knowledge Management System) in public sector. For this purpose, we set up five contingency environmental factors and three process factors of knowledge management. And then investigates affecting factors effect on the performance of KMS in public sector by empirical study, A field survey of public officers in Korea local government was conducted. Complete data for 333 KMS users was analyzed to determine relationship of the research constructs. The system of evaluation and compensation is the most important factor effects on the process of KM and the performance of KMS. These results provide empirical evidence that supports the necessity of rational motivation systems does lead to effective implementation of KMS in public sector.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1989.04a
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• pp.61-65
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• 1989

In this study, measured and calculated responses are compared in order to give how the static and dynamic responses occurred in steel railway bridges Sue to train loads could be calculated appropriately. From this, it is known that the static response ratios (measures / calculated) is high comparing to the highway blisses, and the dynamic response should be obtained by the moving mass problem. And it is known that the factors specifies in the present railway bridge code are very safe under the present service speed below 100 km/h, but are not under the rapid transit system above 100 km/h.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.338-343
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• 2005

The Korean high speed train(KHST), developed since 1996, is presently undergoing commissioning tests on the high-speed track as well as on the conventional track since 2002. The purpose of the commissioning test is twofold: first to verify the performance of the train-set and equipments, and to demonstrate system reliability. Last December, KHST has reached the maximum speed of 350km/h and a number of data proving the performance of the train has been acquired. Among the data noise level and pressure variation in a cabin are important factors effecting passenger's comfort. Discussed in this paper are interior noise and pressure variation when the train passes tunnels during the 350km/h test.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.119-125
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• 2007

The equation of Resistance to motion of the Korean high-speed train has been calculated and evaluated using train speed measurements gathered from coasting tests in the speed range from 30km/h to 300km/h and wind tunnel test of 1/25th scale model. The factors of resistance to motion have been decomposed into various coefficients which compose the coefficients of Davis equation referring the general resistance to motion equation of KTX train. The coefficients of Korean high-speed train has been calculated using the measurements of coasting tests and the results of wind tunnel test has been implemented to consider the minor shape modification after the coasting tests.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.159-163
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• 2004

The KNR(Korean National Railroad) has a speed limit regulation(130km/h) for the train passing the turnout to guarantee a safety. Since that speed is set as below the maximum commercial speed(140km/h), it has been regarded as a major factor to obstacle the total efficiency. The crossing rail part of the turnout system is formed into a antisymmetric, furthermore, there are several discontinuous part. Thus, measuring the strain signals of this part is impossible actually and it must be in the most difficult work related the turnout research. In this research, the program that can anticipate the signals at the various conditions with considering its own shape was developed and the preciousness of its results had been examined by comparing analyzed and measured ones at the other parts. The simulation was performed with varying the factors such as train speed and contact depth. As a results, it was proved that the regulation was not useless and very important guide at least up to now.