• Journal of the Korean Society for Precision Engineering
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• v.11 no.2
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• pp.65-74
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• 1994

Backcap is an electric remote control system for the operation of directional flow control valves. This paper presents a new type of basckcap system which is characterized by its simple construction. The backcap is essentially a hydraulic cylinder of which the piston is connected to a spool of hydraulic valve and controlled by input current. An inherent feedback is imposed on its mechanism so that no artificial noe is needed. Characteristics of the backcap is verified by stability analysis, transient motion and steady state positioning for step inputs. Design parameter analyses have been executer by some analytical approaches and computer simulations, which lead to their optimal valves. These results contributed to an effective new backcap system and its design strategy.

• Korean Journal of Remote Sensing
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• v.15 no.4
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• pp.357-365
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• 1999

The optical sensors of Electro-Optical Camera (EOC) and Ocean Scanning Multi-spectral Imager (OSMI) aboard the KOrea Multi-Purpose SATellite (KOMPSAT) will be placed in a sun synchronous orbit in late 1999. The EOC and OSMI sensors are expected to produce the land mapping imagery of Korean territory and the ocean color imagery of world oceans, respectively. Utilization of the EOC and OSMI data would encompass the various fields of science and technology such as land mapping, land use and development, flood monitoring, biological oceanography, fishery, and environmental monitoring. Readiness of data support for user community is thus essential to the success of the KOMPSAT program. As a part of testing such readiness prior to the KOMPSAT launch, we have performed the preliminary acceptance test for the KOMPSAT data processing system using the simulated EOC and OSMI data sets. The purpose of this paper is to demonstrate the readiness of the KOMPSAT data processing system, and to help data users understand how the KOMPSAT EOC and OSMI data are processed, archived, and provided. Test results demonstrate that all requirements described in the data processing specification have been met, and that the image integrity is maintained for all products. It is however noted that since the product accuracy is limited by the simulated sensor data, any quantitative assessment of image products can not be made until actual KOMPSAT images will be acquired.

• The Journal of the Korea Contents Association
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• v.21 no.7
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• pp.440-447
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• 2021

The purpose of this study is to verify the effectiveness of non-face-to-face lectures conducted at universities in Korea under the influence of COVID-19. So this study analyzed the satisfaction level of the students according to the type of class operation, such as face-to-face classes and remote video classes. To this end, this study compared the differences in class satisfaction by class type and class size for a total of 8,707 courses operated by a university between 2019 and 2020. The study found that the satisfaction level of the remote video class was significantly high. In addition, the combination of remote video classes and face-to-face was more satisfactory than other cases. On the other hand, the satisfaction level of small classes in both face-to-face and remote video classes was higher than that of medium or large classes. This means that even remote video classes are highly satisfactory in small-scale classes. Based on the findings, the study proposes a paradigm for new college classes.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.31-33
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• 2003

Recently, KARI developed in-house meteorological sensor processing system named MESIS for GOES GVAR 5-CH Imager for better KOMPSAT EOC mission operation. MESIS consists of antenna system, receiver, serial telemetry card, processing and mapping software, and 2 NT PC systems. This paper shows system requirement, system design, characteristic and test results of processing system. System operation concept and sample image are also provided. Implemented system was proven to be fully operational through lots of operations covering from RF signal reception to web publishing.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.305-308
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• 2005

The COMS, Korea's first geostationary multipurpose satellite program will accommodate 3 kind of payloads; Ka-Band communication transponder, GOCI (Geostationary Ocean Color Imager), and MI (Meteorological Imager). MI raw data will be transferred to ground station via L-band link. The ground station will perform image data processing for raw data, generate them into the LRIT/HRIT format, the user dissemination data recommended by the CGMS. The LRIT/HRIT are disseminated via satellite to user stations. This paper shows the COMS LRIT data generation procedure based on COMS LRIT specification and its verification results using the LRIT user station.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.501-504
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• 2005

In general, most incomplete communication link setup between satellite and ground station right after separation from launcher come from less accurate orbital vector ground station uses to track the satellite because only predicted orbital state vector is available during first few orbits. This paper describes the developed procedure for successful initial acquisition for KOMPSAT-2 using scanning functions ofK13 antenna system with predicted orbital information. Azimuth scan, raster scan, spiral scan functions were tested with KOMPSA Tl under intentionally degraded orbital information for antenna operation. Through tests, spiral scan function was decided to be best search scan among 3 scans. Developed procedure can assure the successful acquisition only if azimuth offset and time offset value are within +/-2deg and +/-30sec, respectively.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.582-585
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• 2005

The Geostationary Operational Environmental Satellite (GOES) 9, which is currently located at 155°E geostationary orbits, has transmitted earth observation data acquired by imager to CDA at NOAA. After the acquisition on ground, observation data are corrected on ground and re-transmitted to GOES-9 for the dissemination to users. In this paper, the procedure and result from raw data acquisition and pre-processing for earth observation imagery retrieval from GOES-9 Raw data acquired in Korea at May 2005 are introduced.

• Proceedings of the KSRS Conference
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• v.1
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• pp.216-219
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• 2006

This paper analyzes on LHGS (LRIT/HRIT Generation Subsystem) processing timeline for COMS LHGS design. The LHGS shall transmit LRIT/HRIT (Low Rate Information Transmission/ High Rate Information Transmission) data to the users within 15 minutes after the end of the image acquisition. So, this paper performs experiment using MTSAT-1R LRIT/HRIT (11 days) and calculates minimum LHGS processing time. Only HRIT FD (Full Disk) image is considered in this paper because data size of HRIT FD image is the largest. As a result of experiment, COMS LHGS should be able to receive MI Level 1B product within 157 seconds at least.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.821-826
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• 2002

The KOMPSAT-2 DCSU(the data compression & storage unit) performs the acquisition of image data from cameras, the compression with requested compression rate, the storage with specified file ID on the mission command and the distribution to the assigned DLS(Data Link System) channels per the mission and operation requirements. The worldwide observation using the MSC is able to be achieved by this DCSU's behavior. This paper presents the features of KOMPSAT-2 DCSU and provides proper ground operation concept after launch.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.464-466
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• 2004

Ranging and 2-way Doppler measurements are very essential source for orbit determination in LEOP (Launch and Early Operation). This paper shows ranging system features of 13M TT &C antenna and test results recently acquired with KOMPSAT-l. Ranging and 2-way Doppler measurements were compared with KOMPSAT-I GPS telemetry data. Through comparison, it was found that constant and accurate ranging measurements are available with 13M antenna system. Ranging and Doppler measurement function is expected to be used for KOMPSAT-1 and KOMPSAT-2.