• Journal of Astronomy and Space Sciences
• /
• v.24 no.1
• /
• pp.69-78
• /
• 2007

The international EARTHSHINE mission is to measure 1% anomaly of the Earth global albedo and total solar irradiance using Amon-Ra instrument around Lagrange point 1. We developed a new ray truing based integrated end-to-end simulation tool that overcomes the shortcomings of the existing end-to-end performance simulation techniques. We then studied the in-orbit radiometric performance of the breadboard Anon-Ra visible channel optical system. The TSI variation and the Earth albedo anomaly, reported elsewhere, were used as the key input variables in the simulation. The output flux at the instrument focal plane confirms that the integrated ray tracing based end-to-end science simulation delivers the correct level of incident power to the Amon-Ra instrument well within the required measurement error budget of better than ${\pm}0.28%$. Using the global angular distribution model (ADM), the incident flux is then used to estimate the Earth global albedo and the TSI variation, confirming the validity of the primary science cases at the L1 halo orbit. These results imply that the integrated end-to-end ray tracing technique, reported here, can serve as an effective and powerful building block of the on-line science analysis tool in support of the international EARTHSHINE mission currently being developed.

• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.2
• /
• pp.236-244
• /
• 2020

Objective: The objective of this study was to evaluate the effects of different levels of quantitative feed restriction on nutrient intake and digestibility, nitrogen balance, efficiency and feeding behavior, and productive performance in F1 Holstein/Zebu cows during the middle third of their lactation. Methods: Sixty F1 Holstein/Zebu cows with 111.5±11.75 days of lactation and an initial body weight (BW) of 499±30 kg (mean±standard error of the mean) were used. The experimental design was completely randomized with the following diet levels of feed restriction: 3.39%, 2.75%, 2.50%, 2.25%, and 2.00% of BW, with 12 replications for each level. The experiment lasted for 63 days, of which each period lasted 21 days with the first 16 days for diet adaptation followed by 5 days for collection of data and samples. Results: For each 1% of BW diet restriction, there was a decrease in dry matter intake of 5.26 kg/d (p<0.01). There was no difference in daily milk production (p = 0.09) under the restriction levels of 3.39% to 2.0% of BW. When corrected for 3.5% fat, milk production declined (p = 0.05) 3.46 kg/d for each percentage unit of feed restriction. Conclusion: Restricting the feed supply for F1 Holstein/Zebu cows in the middle third of their lactation period altered nutrient intake, nitrogen balance and ingestive behavior but did not affect milk production or feed efficiency. However, considering the observed BW loss and decrease in milk production corrected for 3.5% fat, restriction of no less than 2.5% BW is recommended.

• The Journal of the Acoustical Society of Korea
• /
• v.23 no.2
• /
• pp.180-186
• /
• 2004

The presence of noise in speech signals degrades the performance of recognition systems in which there are mismatches between the training and test environments. To make a speech recognizer robust, it is necessary to compensate these mismatches. In this paper, we studied about an improvement of stochastic feature extraction based on band-SNR for robust speech recognition. At first, we proposed a modified version of the multi-band spectral subtraction (MSS) method which adjusts the subtraction level of noise spectrum according to band-SNR. In the proposed method referred as M-MSS, a noise normalization factor was newly introduced to finely control the over-estimation factor depending on the band-SNR. Also, we modified the architecture of the stochastic feature extraction (SFE) method. We could get a better performance when the spectral subtraction was applied in the power spectrum domain than in the mel-scale domain. This method is denoted as M-SFE. Last, we applied the M-MSS method to the modified stochastic feature extraction structure, which is denoted as the MMSS-MSFE method. The proposed methods were evaluated on isolated word recognition under various noise environments. The average error rates of the M-MSS, M-SFE, and MMSS-MSFE methods over the ordinary spectral subtraction (SS) method were reduced by 18.6%, 15.1%, and 33.9%, respectively. From these results, we can conclude that the proposed methods provide good candidates for robust feature extraction in the noisy speech recognition.

• Journal of the Korean association of regional geographers
• /
• v.19 no.2
• /
• pp.352-361
• /
• 2013

This paper aims to analyze the root mean square errors of MODIS LST data and inland water temperature measurement data in order to use MODIS LST data as an input of numerical weather prediction model. MODIS LST data from July 2011 to June 2012 were compared to water temperature measurement data in the automated water quality measurement network. MODIS data have two composites: day-time and night-time. Monthly errors of day-time and night-time LST range $2{\sim}8^{\circ}C$ and $3{\sim}12^{\circ}C$, respectively. Temporally, monthly errors of day-time LST are less in fall and those of night-time LST are less in summer. Spatially, on the four major rivers including the Han, Nakdong, Geum, and Yeongsan rivers, the errors of Yeongsan river were the smallest, which location is the south-most among them. In this study, the errors of MODIS LST as an input of numerical weather prediction model were analyzed and the results can be used as an error level of MODIS LST data for inaccessible areas such as North Korea.

• Journal of Astronomy and Space Sciences
• /
• v.25 no.4
• /
• pp.425-434
• /
• 2008

The mean temperature equation is a key factor in calculating GPS meteorological information. A local mean temperature equation should be used to improve accuracy of GPS PWV (Precipitable Water Vapor). In this paper, four local mean temperature equations, HP, $HP_M,\;HPt_Y,\;and\;HPt_M$ from Ha & Park (2008) were used to analyze the effects of local models in determining GPS PWV. Four different sets of GPS PWVs were compared with radiosonde PWV to validate the accuracies of local models. GPS PWVs of four local models have similar trends compared against radiosonde PWV. The bias and RMS error were the same level: the bias is ${\sim}3mm$ and the RMS is ${\sim}3.6mm$ after the bias was removed. Especially, with $HPt_Y\;and\;HPt_M$ models one can obtain accurate PWVs even without surface temperature measurements. And we investigated dry bias of radiosonde measurements depending on sensor types and observation time at Sokcho weather station. After the radiosonde sensor equipment was changed from RS80-15L to GRS DFM-06, dry bias of radiosonde PWV decreased about 18.2% during daytime (KST 09:00), and 16.1% during nighttime (KST 21:00).

• Journal of Aerospace System Engineering
• /
• v.12 no.4
• /
• pp.64-74
• /
• 2018

Small high-resolution Earth observation satellites require precise optical alignment at the submicron level. However, misalignments can occur due to the influence of external factors during the launch and operation despite the sufficient alignment processes that take place before the launch. Thus, satellites need to realign their optical elements in orbit in what is known as a refocusing process to compensate for any misalignments. Refocusing algorithms developed for satellites have only considered de-space, which is the most sensitive factor with respect to image quality. However, the existing algorithms can cause correction error when inner and external forces generate tilt amount in an optical system. The present work suggests an improved online refocusing algorithm by considering the tilting effect for application in the case of a de-spaced and tilted optical system. In addition, the algorithm is considered to be efficient in terms of time and cost because it is designed to be used as an online method that does not require ground communication.

• Korean Journal of Veterinary Service
• /
• v.39 no.1
• /
• pp.13-20
• /
• 2016

This study is aimed to find out distribution status of online-market livestock products by purchasing and examining 120 cases of livestock products (seasoned meat: 17, 33 cases of packaged meat, 23 cases of ground meat, 19 cases of ham, 11 cases of sausage, 4 cases of bacon, 1 case of meat processing, 8 cases of Meat extract processed, and 4 cased of Dry storage of meat) at 17 On-line markets from April to August. 2015. We checked the weight of them first, and carried out ingredients test for each of processed meats. And we performed gene screening test on the products which were labelled 'Hanwoo' to investigate that the products were made of Korean native cattle. we also carried out test of identifying domestic animal species on ham, sausage and ground processed products. After weighing all products, we could know that all of them were delivered more than labelled weight or in allowable error. The result values of test which measured level of preservatives, Nitrite, Volatile Basic Nitrite (VBN), and tar Color by the type of processed meat products were in permissible range or not detected. Also, 17 beefs inspected Korean native cattle gene test were confirmed that they were made by real korean native cattle. But 2 cases of Ham, sausage, and ground processed products had difference between label and goods. In this study, we could make a decision that livestock products, distributed in On-line markets, were safe and expect to make higher degrees of hygiene for livestock products seller. Futhermore, we hoped result of this study could be used by basic data for progressive national policy decisions.

• Journal of Cadastre & Land InformatiX
• /
• v.47 no.1
• /
• pp.143-160
• /
• 2017

Since officially assessed land price system was introduced, it has functioned as the criterion for establishing and implementing real estate policies. However, there is a controversial issue about the adequacy of the officially assessed land price system. The problem is that it is difficult to establish a statistical model due to too many land characteristics. Also, local economy, macroeconomic environments and development plans are not reflected in the land price evaluation model. Considering longitudinal and cross-sectional variables, a two-way error component panel model was used in this study. This analysis model includes variables reflecting land characteristics, macroeconomic volatility, and development project. The Paju LCD Industrial Complex was selected as a analysis area and an empirical analysis was performed. According to the analysis, the number of significant land characteristic variables were 14(31%) under 5% significance level. Macroeconomic volatility has had an influence on the land price and year variable reflecting development project has consistently been significant since the industrial complex was designated. Therefore, this study suggests that the land price evaluation model should be improved by simplifying land characteristic variables and including macroeconomic and regional economic variables.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.42 no.3 s.333
• /
• pp.25-34
• /
• 2005

In this paper, we analyzed and measured the electrical crosstalk characteristics of a triplex transceiver module for ethernet Passive optical networks(EPONS). And we improved the electrical crosstalk levels using Dummy ground lines with signal lines. The triplex transceiver module consists of a laser diode as a transmitter, a digital photodetector as a digital data receiver, and a analog photodetector as a community antenna television signal receiver. And there are integrated on silicon substrate. The digital receiver and analog receiver sensitivity have to meet -24 dBm at $BER=10^{-l2}$ and -7.7 dBm at 44 dB SNR. And the electrical crosstalk levels have to maintain less than -86 dB from DC to 3 GHz. From analysis and measurement results, the proposed silicon substrate structure that contains the Dummy ground line with $100\;{\mu}m$ space from signal lines and separates 4 mm among devices respectively, is satisfied the electrical crosstalk level compared to simple structure. This proposed structure can be easily implemented with design convenience and greatly reduced the silicon substrate size about $50\%$.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.43 no.1 s.343
• /
• pp.17-26
• /
• 2006

The analog Viterbi decoder for the PR (1 2 2 1) which is used for BVD read channel is designed with circular analog parallel circuits. Since the inter symbol interference is serious problem in the high density magnetic storage device or DVD, the PRML technology is normally employed for the purpose of minimizing the decoding error. The feature of the PRML technology is with the multi-level coding according to the predetermined combining rule among the neighboring symbols and with the decoding according to the known combining rule. Though the conventional PRML technology is implemented with the digital circuits, the recent trend towards this end is with the utilization of the analog circuits due to the requirements of higher speed and lower power in the DVD read channel. In this study, the Viterbi decoder which is the bottleneck of the PRML implementation is designed with the analog parallel circuit structure. The designed Viterbi decoder for the PR (1 2 2 1) signal shows 3 times faster in the speed and 1/3 times less in the power consumption than thoseoftheconventionaldigitalcounterpart.