• Journal of Astronomy and Space Sciences
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• v.20 no.1
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• pp.1-10
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• 2003

A precise kinematic orbit determination (P-KOD) procedure for Low Earth Orbiter(LEO) using the GPS ion-free triple differenced carrier phases is presented. Because the triple differenced observables provide only relative information, the first epoch's positions of the orbit should be held fixed. Then, both forward and backward filtering was executed to mitigate the effect of biases of the first epoch's position. p-KOD utilizes the precise GPS orbits and ground stations data from International GPS Service (IGS) so that the only unknown parameters to be solved are positions of the satellite at each epoch. Currently, the 3-D accuracy off-KOD applied to CHAMP (CHAllenging Min-isatellite Payload) shows better than 35 cm compared to the published rapid scientific orbit (RSO) solution from GFZ (GeoForschungsZentrum Potsdam). The data screening for cycle slips is a particularly challenging procedure for LEO, which moves very fast in the middle of the ionospheric layer. It was found that data screening using SNR (signal to noise ratio) generates best results based on the residual analysis using RSO. It is expected that much better accuracy are achievable with refined prescreening procedure and optimized geometry of the satellites and ground stations.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2019_2020
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• 2009

A recurrent surge oscillograph(RSO) test was performed at the Taean thermal power plant on #5 turbine generator. The test was conducted using a rotor reflectometer and digital oscilloscope. A DC voltage step is applied to each end of the rotor winding in turn. Each reflected wave, at the input end of the winding, is monitored and the two waveforms are superimposed automatically and monitored on a single channel oscilloscope. As the half windings in a rotor are identical, the two waveforms monitored at each end of the rotor will also be identical for a healthy winding. A winding with a fault will cause different voltages to be monitored at the two ends.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.97-99
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• 2002

A radiation incident took place during treatment on MEDNIF Tele cobalt-60 therapy machine in B.P.KOIRALA MEMORIAL CANCER HOSPITAL in Bharatpur, Nepal. This Chinese made machine has activity of 6240 Curies of cobalt -60. This machine has fulfilled safety requirements. ICRP recommendations, safety rules are followed and practiced. The source was struck up during treatment and a technician was exposed to equivalent dose of 13.75 mSv. recorded by Personal film badge. Risks of workers are comparable to other safe industries. All exposures shall be kept as low as reasonably possible. The higher level of safety is achieved only when every one is dedicated to common goal. A lesson is learnt for future. Good practice is essential but not sufficient. A high demand for tele Cobalt therapy convinced management to replace Mednif machine with a new efficient Elite Tele Cobalt theratron Machine.

• Journal of Ocean Engineering and Technology
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• v.7 no.1
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• pp.124-132
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• 1993

In order to examine the effect of anisotropy and stress ratio on fatigue crack propagation rate and opening-closing behavior and also arrest behavior by single tension peak overload, the fatigue tests of constant amplitude atress and single tension peak overload adding to cycle of constant amplitude were carried out in stress ratio of -0.4, -0.2, and 0.4 with materials of T-L and L-T directions in 2024-T3 aluminum alloy plate. Crack opening-closing begavior were measured by the compliance method using COD gage and strain gage. In case of the crack opening-closing behavior was measured by strain gage, the effect of stress ratio is unchangeable. But in the case of COD gage, that is remarkably decreased. Fictitious effective stress intensity factor(U sub(f)) and effective stress intensity factor ratio(U) in L-T direction was higher than those in T-L direction and also threshold arrest overload ratio incrased as stress ratio decreased and that of T-L direction was higher than that in L-T direction.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.1
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• pp.11-14
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• 1988

Field study was conducted to evaluate the relationship between daytime net radiation (Drn) and global solar radiation (Rs) and to develop the empirical equation predicting daytime net radiation above corn canopy from observations of Rs and Ta (mean daily air temperature). The relationship between Drn and Rs under the cloudless day was Drn = 0.6659Rs and that under the cloudy (> 35% of possible sunshine) Drn = 0.729Rs. Thus, Drn/Rs Ratio under cloudless day was found to be lower than that under the cloudy day. Rs and Ta were used in the radiation balance equation to estimate Drn and the empirical model could be expressed as $Drn=[0.9Rs-(352-227{\times}10^{-10}{\times}Ta^4)]$ [1.11Rs/Rso - 0.05].

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.11
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• pp.2535-2540
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• 2010

In traditional Publish/Subscribe system, the first procedure to deliver event from publisher to subscriber is that publisher publishes publisher's event to broker. Next step is that broker checks simple binary notion of matching : an event either matches a subscription or it does not. Lastly, broker delivers the event matched with subscriptions to the corresponding subscribers. In this system, information delivery has been accomplished in one way only. However, current some applications require two way delivery between subscriber and publisher. Therefore, we initiate an extended Publish/Subscribe system that supports two way delivery. Extended Publish/Subscribe system requires additional functions of delivering subscription to publisher and especially deciding top-n subscriptions using priority because broker might has a number of subscriptions. In this paper, we propose two priority retrieval techniques based on SIF using IS-List with deciding priority among subscriptions and defining SIF(Specific Interval First). The performance measurements show that RSO(resulting set sorting) technique results in better performance in index creation time and ITS&IS(insertion time sorting and inverse search using stack) technique results in better performance in search time.