• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.885-895
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• 2022

Since the supply and demand of agricultural products are unstable, which causes instability in farm income and consumer prices, the government has sought to mitigate the problems caused by unstable supply and demand by generating and providing agricultural outlook information. However, research should be carried out to increase the quality and utilization of agricultural observation information, because the value of agricultural observation information increases only when more users use this information and apply it to their decisions. In this study, a survey was conducted targeting producers and experts who are users or potential users of agricultural outlook information, and the results were analyzed through quantitative model, specifically importance-performance analysis (IPA) and analytic hierarchy process (AHP). The results show that improvement of promptness was required among the seven items evaluated with regard to agricultural outlook. Also, measures for dissemination of agricultural outlook information and the contents of outlook information should be improved to increase its use. If the quality level and use of agricultural observation information are increased by reflecting the results of the above analysis, decision-making on the supply and demand of agricultural products in Korea will be improved, and it is thought that it will be possible to increase farm household income and stabilize consumer prices through stabilization of supply and demand of agricultural products.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.336-339
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• 2001

In this study an experimental investigation was conducted to find the grinding characteristics of ceramics, as compared to STDll and SUS304 materials. The grinding force and the microscopic observation of the workpieces were obtained in surface grinding. It has been found that the grinding force of ceramics is relatively low as compared to that of steels and that CBN wheel has an excellent performance.

• Journal of the Semiconductor & Display Technology
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• v.21 no.1
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• pp.127-131
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• 2022

The effect of bypass diodes on the output energy of solar cells was investigated under the condition of partial shading. The maximum power point was estimated using the perturbation & observation algorithm, taking into account the correlation effect between the arrangement and number of bypass diodes. The performance of the bypass diode was tested under the consideration of the partial shading effect and simulated using a Matlab/Simulink.

• The Journal of Korean Academic Society of Nursing Education
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• v.19 no.4
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• pp.542-548
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• 2013

Purpose: This study was conducted to explore clinical practice performance according to type of practice in students in pediatric nursing and the relationship with satisfaction of clinical practice. Methods: The subjects consisted of 531 nursing students (307 at a pediatric ward and 224 at a nursery) from 5 colleges of nursing. Data collected from March to June 2012 were analyzed using descriptive statistics, t-test, AVONA and Pearson correlation coefficients. Results: Clinical practice performance on direct nursing activity was significantly different according to the course on pediatric nursing, grade point average, and satisfaction of nursing major. Observation practice was different according to type of college, the course on pediatric nursing, grade point average, duration of practice and clinical educator in the pediatric ward. In the nursery, direct nursing activity was significantly different according to the type of college, the course on pediatric nursing, hospital type, and duration of practice. Observation practice was different according to type of college, satisfaction of a nursing major, and the clinical educator. In addition, significant correlations were found between clinical practice performance and satisfaction of clinical practice. Conclusion: Our research can assist effective pediatric nursing practice planning for nursing students.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.4
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• pp.243-251
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• 2021

Real-Time Kinematic (RTK) is a phase-based differential GNSS technique and uses additional observations from permanent reference stations to mitigate or eliminate effects like atmospheric delays or satellite clocks and orbit errors. In particular, as the position accuracy required in the fields of autonomous vehicles and drones is gradually increasing, the demand for RTK-based precise navigation that can provide cm-level position is increasing. Recently, with the rapid growth of the open-source software market, the use of open-source software for building navigation system of unmanned vehicles, which is difficult to mount an expensive GNSS receivers, is gradually increasing. RTKLIB is an open-source software package that can perform RTK positioning and is widely used for research and education purposes. However, since the performance and stability of RTK algorithm of RTKLIB is inevitably inferior to that of commercial GNSS receivers, users need to verify whether RTKLIB can satisfy the navigation performance requirements of unmanned vehicles. Therefore, in this paper, the performance evaluation of the RTK positioning algorithm of RTKLIB was performed using GNSS observation data acquired in a dynamic environment. Therefore, in this paper, the RTK positioning performance of RTKLIB was evaluated using GNSS observation data acquired in a dynamic environment. Our results show that the current RTK algorithm of RTKLIB is not suitable for precise navigation of unmanned vehicles.

• MALSORI
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• no.64
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• pp.121-135
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• 2007

Speech signal is distorted by channel characteristics or additive noise and then the performances of speaker or speech recognition are severely degraded. To cope with the noise problem, we propose a modified HMM decoder algorithm using SNR-based observation confidence, which was successfully applied for GMM in speaker identification task. The modification is done by weighting observation probabilities with reliability values obtained from SNR. Also, we apply PSO (particle swarm optimization) method to the confidence function for maximizing the speaker identification performance. To evaluate our proposed method, we used the ETRI database for speaker recognition. The experimental results showed that the performance was definitely enhanced with the modified HMM decoder algorithm.

• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.31.1-31.1
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• 2011

In this study, we investigated alignment state estimation performances of the three methods i.e. merit function regression (MFR), differential wavefront sampling (DWS) and Multiple Design Configuration Optimization (MDCO). The three target optical systems are 1) a two-mirror Cassegrain system for deep space Earth observation, 2) intermediate size three-mirror anastigmat for Earth ocean monitoring, and 3) extremely large segmented optical system for astronomical observation. We ran alignment state estimation simulation for several alignment perturbation cases including 1mm to 10mm in decenter and from 0.1 to 1 degree in tilt perturbation error for the two-mirror Cassegrain system. In general, we note that MDCO shows more competitive estimation performance than MFR and DWS. The computational concept, case definition and the simulation results are discussed with implications to future works.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.28.3-28.3
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• 2008

Contamination has the potential for degrading the performance of the optical payload beyond the limits defined by mission requirements, therefore it must be considered a risk to system performance and must be mitigated. To mitigate contamination problem, contamination budget is allocated according to the contamination requirements which is derived from contamination effect analysis. Once the contamination budget is allocated, prediction for on-ground and in-orbit contaminants amounts and cleanliness control is performed. In this article, typical contamination control for observation satellite is described.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.63.1-63.1
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• 2010

CQUEAN (Camera for QUasars in EArly uNiverse) is a newly developed camera system by CEOU optimized at 0.8 - $1.1{\mu}m$ wavelength region. From Aug. 10 to Aug. 17, 2010, the camera was installed at 2.1m Otto Struve telescope at McDonald Observatory, USA, and engineering test observation was performed. We obtained the data for the characteristics of camera and scientific purpose using 7 filters (g, r, i, z, Is, Iz, Y). For the purpose of discovery of z - 5~6 quasar, we specially used new filters (Is,Iz). During the test observation, we obtained the data of Gamma-Ray Burst, high redshift quasars, high redshift quasar candidates and other calibration data. We present general characteristics of the reduced data taken with CQUEAN and show the performance of the camera.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.9
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• pp.1019-1026
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• 1988

A parametric detection scheme for determenistic signals is obtained in a generalized observation model which contains non-additive noise. The model employed in this paper includes several special cases such as those describing purely-additive noise, multiplicative noise, and signal dependent noise and allows the consideration of deterministic and random signals. Locally optimum detectors for known deterministic signals in the model are derived and analyzed for performance. It is shown that the locally optimum detectors are interesting generalizations of those for the purely-additive noise model. Performance of the locally optimum detectors designed for the generalized observation model is compared to that of other common detectors.