• Current Optics and Photonics
• /
• v.8 no.1
• /
• pp.30-37
• /
• 2024

Implemented at the Geochang Observatory in South Korea, our slope detection and ranging (SLO-DAR) system features a 508 mm Cassegrain telescope (f /7.8), incorporating two Shack-Hartmann wave-front sensors (WFS) for precise measurements of atmospheric phase distortions, particularly from nearby binary or double stars, utilizing an 8 × 8 grid of sampling points. With an ability to reconstruct eight-layer vertical atmospheric profiles, the system quantifies the refractive index structure function (C_n²) through the crossed-beam method. Adaptable in vertical profiling altitude, ranging from a few hundred meters to several kilometers, contingent on the separation angle of binary stars, the system operates in both wide (2.5 to 12.5 arcminute separation angle) and narrow modes (11 to 15 arcsecond separation angle), covering altitudes from 122.3 to 611.5 meters and 6.1 to 8.3 kilometers, respectively. Initial measurements at the Geochang Observatory indicated C_n² values up to 181.7 meters with a Fried parameter (r₀) of 8.4 centimeters in wide mode and up to 7.8 kilometers with an r₀ of 8.0 centimeters in narrow mode, suggesting similar seeing conditions to the Bohyun Observatory and aligning with a comparable 2014-2015 seeing profiling campaign in South Korea.

• Journal of Agricultural Extension & Community Development
• /
• v.31 no.3
• /
• pp.115-126
• /
• 2024

This study aims to examine the importance-performance for management capabilities of the rural tourism business operators using the Revised Importance-Performance Analysis(R-IPA). To make up for the limitations of the traditional Importance-Performance analysis method, the R-IPA analysis method based on the Kano's three-factor model was applied to establish a management capabilities for better credibility and validity. Online survey measuring 15 items for management capabilities of rural tourism business were conducted for domestic rural tourism business operators based on power allocation sampling method. The results identified three attributes(e.g., business concept, negotiation, organizational competency) that belong to "concentrate here" quadrant and five attributes(e.g., self-awareness, environmental awareness, goal setting, network, supervisory competency) that belong to "keep up the good work" quadrant. The result of this study provides rural tourism operators with valuable information on management capabilities that potentially increase the business performance. The results suggest a way to effectively allocate resources into management strategies.

• Journal of the Korea Convergence Society
• /
• v.9 no.3
• /
• pp.165-171
• /
• 2018

In this study, to analyze the detection of limit for sensitivity of the influenza rapid antigen test kit, the positive detection of limits were analyzed by serial dilution of influenza virus A and B type for five influenza rapid antigen test kits in Korea. As a result of analysis, visual measurement of type A were up to 1:8192 for the Wellsbio product and up to 1:4096 for the II product, up to 1:512 for the I and III products, and only 1:128 for the IV product, and type B were positive for up to 1:8192 for the Wellsbio product, up to 1: 4096 for the II product and up to 1:1024 for the I, III and IV products. For instrument readings with the same specimen, both A and B types were found to be positive for up to 1:8192 for the Wellsbio product, up to 1: 4096 for the II product, and up to 1:2048 for the I product. The sensitivity of the rapid antigen test for influenza differs greatly depending on the sampling area of the patient, infection period, specimen volume, etc. Therefore, it is necessary to observe exactly the collection timing and method of the specimen. And it is necessary further study to improve the sensitivity for influenza rapid antigen test.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.4 no.4
• /
• pp.280-285
• /
• 2004

In this paper, a 9-bit analog-to-digital converter (ADC) is designed for optical disk drive (ODD) servo applications. In the ADC, the circuit technique to increase the operating range of the sample-and-hold amplifier is proposed, which can process the wide-varying input common-mode range. The algorithmic ADC structure is chosen so that the area can be significantly reduced, which is suitable for SoC integration. The ADC is fabricated in a 0.18-$\mu\textrm{m} $ CMOS 1P5M technology. Measurement results of the ADC show that SNDR is 51.5dB for the sampling rate of 6.5MS/s. The power dissipation is 36.3mW for a single supply voltage of 3.3V.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.2
• /
• pp.462-482
• /
• 2014

This paper proposes a new resampling detection method for images that detects whether an image has been resampled and recovers the corresponding resampling rate. The proposed method uses a given set of zeroing masks for various resampling factors to evaluate the convolution values of the input image with the zeroing masks. Improving upon our previous work, the proposed method detects more resampling factors by checking for some periodicity with an approximate detection mechanism. The experimental results demonstrate that the proposed method is effective and efficient.

• Journal of Korea Multimedia Society
• /
• v.23 no.7
• /
• pp.883-890
• /
• 2020

In this paper, we propose a variational expectation-maximization algorithm that computes posterior probabilities from Latent Dirichlet Allocation (LDA) model. The algorithm approximates the intractable posterior distribution of a document term matrix generated from a corpus made up by 50 papers. It approximates the posterior by searching the local optima using lower bound of the true posterior distribution. Moreover, it maximizes the lower bound of the log-likelihood of the true posterior by minimizing the relative entropy of the prior and the posterior distribution known as KL-Divergence. The experimental results indicate that documents clustered to image classification and segmentation are correlated at 0.79 while those clustered to object detection and image segmentation are highly correlated at 0.96. The proposed variational inference algorithm performs efficiently and faster than Gibbs sampling at a computational time of 0.029s.

• Journal of Korean Academy of Nursing
• /
• v.34 no.6
• /
• pp.954-963
• /
• 2004

Purpose: This study was designed to identify the variables affecting male adolescents' sexual intercourse through a comprehensive analysis of individual and environmental factors. Method: The subjects of this descriptive survey on causal relations were 462 subjects enrolled in liberal and vocational high schools selected on a convenience sampling basis. The data collected from May-July 2002 was put to logistic regression analysis to build a forecast model. Findings: 1) Individual factors such as school record, experience seeking, non-inhibition and sexual permissiveness, 2) family factors such as parental living arrangement, 3) school factors such as career tract and 4) peer factors such as having a boy/girl friend were identified as significant variables forecasting sexual intercourse. Conclusion and Recommendation: The theoretical model built on the basis of the major findings of this study will hopefully help promote a wholesome youth culture related to sexual intercourse. It is recommended that a program be developed that can help control the variables identified in this study along with a follow-up study to verify the model.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.8
• /
• pp.911-913
• /
• 2016

Recently barcode detection using a camera is popular, but the recognition performance is low at the effectively low-resolution. The paper propose sub-pixel synchronization technique for better recognition performance. The experiments with ITF-18 demonstrates its performance gain (66% for CIF, 100% for VGA) against the existing recognition algorithms.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.19 no.2
• /
• pp.52-64
• /
• 1991

The actual vegetation and environmental impact grade of Daekwanrim in Hamyang were investigated and the structure of the plant community was analyzed by the classification of TWINSPAN and three kinds of multivariate ordination (PCA, RA, DCA) techniques.Twenty-eight plots were set up by the clumped sampling method in June of 1990. Carpinus laxiflora and C. tschonoskii communities covered 38% and Quercus species communities covered 39% of the total rea. Environmental impact class 3 and 4 area. Twenty-eight plots were divided into three groups according to the degree of damage by TWINSPAN and ordination techniques. The dominant species in the shrub layer of the heavily damaged site and the light damaged site were Styrax japonica and Sasamorpha purporanscens, so the sucessional trends should be disturbed. As a result of the analysis for the relationship between the stand scores of DCA and the environmental impact class, they had a tendancy to increase from the light damaged to heavily damaged site.

• Journal of Environmental Science International
• /
• v.15 no.2
• /
• pp.141-155
• /
• 2006

This study is aimed at the development of a runoff forecasting model to solve the uncertainties occurring in the process of rainfall-runoff modeling and improve the modeling accuracy of the stream runoff forecasting, The study area is the downstream of Naeseung-chun. Therefore, time-dependent data was obtained from the Wolpo water level gauging station. 11 and 2 out of total 13 flood events were selected for the training and testing set of model. The model performance was improved as the measuring time interval$(T_m)$ was smaller than the sampling time interval$(T_s)$. The Neuro-Fuzzy(NF) and TANK models can give more accurate runoff forecasts up to 4 hours ahead than the Feed Forward Multilayer Neural Network(FFNN) model in standard above the Determination coefficient$(R^2)$ 0.7.