• Toxicological Research
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• v.26 no.1
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• pp.53-59
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• 2010

This study was conducted to obtain acute information of the oral dose toxicity of DHU001, a polyherbal formula in male and female mice. In order to calculated 50% lethal dose ($LD_{50}$) and approximate lethal dose (LD), test material was once orally administered to male and female ICR mice at dose levels of 2000, 1000, 500, 250 and 0 (vehicle control) ml/kg (body weight). The mortality and changes on body weight, clinical signs, gross observation, organ weight and histopathology of principle organs were monitored 14 days after treatment with DHU001. We could not find any mortalities, DHU001 treatment-related clinical signs, changes on the body and organ weights, gross and histopathological findings. The results obtained in this study suggest that $LD_{50}$ and approximate LD in mice after single oral dose of DHU001 were considered over 2000 mg/kg in both female and male mice.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.3
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• pp.87-93
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• 2017

A maximum likelihood (ML) approach is presented for estimating the mean of radar cross section (RCS) of a Swerling III target and its numerical solution methods are discussed. The solution methods are based on an approximate expression for implementing the expectation maximization (EM) algorithm. The methods are evaluated and compared through Monte Carlo simulations in terms of estimation accuracy and computational efficiency to obtain a most efficient method for both Swerling I and Swerling III targets. The methods are also compared with a previously reported method based on heuristics.

• The Korean Journal of Pain
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• v.31 no.2
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• pp.125-131
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• 2018

Background: The thoracic transforaminal epidural block (TTFEB) is usually performed to treat herpes zoster or postherpetic neuralgia (PHN). Especially, multiple segmental involvements and approximate contrast medium spread range, according to volume, help to choose the proper drug volume in the transforaminal epidural block. This study investigated the contrast medium spread patterns of 1-ml to 3-ml TTFEBs. Methods: A total of 26 patients with herpes zoster or PHN were enrolled in this study. All participants received 1 ml, 2 ml, or 3 ml of contrast medium. Results were divided into Groups A, B and C based on the volume (1, 2, or 3 ml), with n = 26 for each group. After the injection of contrast medium, the spread levels were estimated in both the lateral and anteroposterior (AP) images using fluoroscopy. Results: The cephalad spread of contrast medium in the lateral image as expressed by the median (interquartile range) was 2.00 levels (1.00-2.00) for Group A, 2.50 (2.00-3.00) for Group B, and 3.00 (2.00-4.00) for Group C. The caudal spread level of contrast medium was 1.00 (1.00-2.00) for Group A, 2.00 (2.00-3.00) for Group B, and 2.00 (2.00-3.00) for Group C. There was ventral and dorsal spread of the 3-ml contrast medium injection in 88% (23/26) of cases in the lateral image. Conclusions: Injection of 3 ml of contrast medium through the foramina spread 6 levels in a cephalocaudal direction. Spread patterns revealed a cephalad preference. TTFEB resulted in dorsal and ventral spread in a high percentage of cases. This procedure may be useful for transferring drugs to the dorsal and ventral roots.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.11
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• pp.886-893
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• 2017

Recently, for detection of low-RCS targets, bistatic radar and multistatic radar have been widely employed. In this paper, we present the process of deriving the received signal modeling of the bistatic MIMO radar system and deals with the performance analysis of applying the bistatic signal to the ML arrival angle estimation algorithm. In case of the ML algorithm, as the number of the targets increases, azimuth search dimension for DOA estimation also increases, which implies that the ML algorithm for multiple targets is computationally very intensive. To solve this problem a closed-form expression of estimation error is presented for performance analysis of the algorithm.

• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.312-317
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• 1995

The polygalacturonase (PG) production in rotten apples by Botryosphaeria dothidea was purified by using gel filtration and ion exchange column chromatography, and the biochemical characters of PG were investigated. The purified PG appeared as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with approximate molecular weight of 49 kilodalton (kDa). The molecular weight was equal to the native molecular weight estimated by gel filtration. The Km and Vmax values of PG were 0.51 mg/ml and 90.9 $\mu$M/min/ml, respectively. Optimum pH was 4.0~5.0, and the PG activity was stable from pH 5.0~10.0. Optimum temperature of the enzyme activity was 4$0^{\circ}C$. The PG activity was relatively stable at 2$0^{\circ}C$, but it was reduced 45% at 4$0^{\circ}C$ and completely inactivated at 8$0^{\circ}C$. The PG activity was considerably inhibited by Cu2+, Zn2+, SDS and EDTA, whereas it was not effected by Ca2+, K+, Mg2+ or Na+ ions.

• Communications for Statistical Applications and Methods
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• v.26 no.3
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• pp.315-323
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• 2019

Panel data sets have recently been developed in various areas, and many recent studies have analyzed panel, or longitudinal data sets. Often a dichotomous dependent variable occur in survival analysis, biomedical and epidemiological studies that is analyzed by a generalized linear mixed effects model (GLMM). The most common estimation method for the binary panel data may be the maximum likelihood (ML). Many statistical packages provide ML estimates; however, the estimates are computed from numerically approximated likelihood function. For instance, R packages, pglm (Croissant, 2017) approximate the likelihood function by the Gauss-Hermite quadratures, while Rchoice (Sarrias, Journal of Statistical Software, 74, 1-31, 2016) use a Monte Carlo integration method for the approximation. As a result, it can be observed that different packages give different results because of different numerical computation methods. In this note, we discuss the pros and cons of numerical methods compared with the exact computation method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.12
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• pp.4099-4113
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• 2022

In this paper, we propose improved maximum access delay time, noise variance, and power delay profile (PDP) estimation schemes for orthogonal frequency division multiplexing (OFDM) system in multipath fading channels. To this end, we adopt the approximate maximum likelihood (ML) estimation strategy. For the first step, the log-likelihood function (LLF) of the received OFDM symbols is derived by utilizing only the cyclic redundancy induced by cyclic prefix (CP) without additional information. Then, the set of the initial path powers is sub-optimally obtained to maximize the derived LLF. In the second step, we can select a subset of the initial path power set, i.e. the maximum access delay time, so as to maximize the modified LLF. Through numerical simulations, the benefit of the proposed method is verified by comparison with the existing methods in terms of normalized mean square error, erroneous detection, and good detection probabilities.

• Korean journal of food and cookery science
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• v.31 no.1
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• pp.26-32
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• 2015

The purpose of this research is to evaluate the quality characteristics and antioxidant activities of Makjang, Korean traditional fermented soybean paste, which has recently been disappearing, for its preservation. Six kinds of commercial Makjang from three different regions (Kang-won-do, Choong-chung-do, and Kyung-sang-do) were analysed for approximate composition, salinity, pH, total phenol contents, and DPPH and hydroxyl radical scavenging activities. Moisture content of samples was 48.30-58.93% while, crude protein was 9.42-13.67%. Crude fat was 2.45-6.50%, crude fiber was 2.08-6.45%, and ash was 6.59-14.64%. Salinity content ranged from 5.63-12.68%, and pH ranged from 4.36-5.67. Soluble solid content and reducing sugar content of samples ranged from 38.3-54.5 Brix and 22.38-31.61% respectively. The lightness, redness, and yellowness of the Hunter color system of samples were 16.58-28.19, 7.8-16.51, and 8.35-14.21, respectively. Total polyphenol contents were 0.20-0.45 mg/ml. Antioxidant activities determined by DPPH radical scavenging activity and hydroxyl radical scavenging activity ($IC_{50}$ value) ranged from 45.07 mg/ml to 95.93 mg/ml and 69.81 mg/ml to 309.40 mg/ml, respectively. From these results, it was suggested that the manufacturing process of Makjang is needed to standardize for quality control, and for mass production.

• Toxicological Research
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• v.25 no.3
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• pp.147-157
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• 2009

This study was conducted to obtain acute information of the oral dose toxicity of lyophilized water extract of Pinelliae Rhizoma, a dried tuber of Pinellia ternata (PR) in male and female mice. In order to calculated 50% lethal dose (LD$_{50}$) and approximate lethal dose (ALD), test material was once orally administered to male and female ICR mice at dose levels of 2000, 1000, 500, 250, 125 and 0 (vehicle control) ml/kg (body weight). The mortality and changes in body weight, clinical signs, gross observation, organ weight and histopathology of principle organs were monitored 14 days after treatment with PR extract. We could not find any mortalities, clinical signs, changes in the body and organ weights, gross and histopathological findings except for dose-dependent increases in the hepatic fatty change frequencies detected in PR extract 2000 and 1000mg/kg treated in both male and female mice. The results obtained in this study suggest that LD$_{50}$ and approximate LD in mice after single oral dose of PR extracts were considered over 2000 mg/kg in both and female male mice, but more than 1000mg/kg of PR extracts treatment could induce slight hepatotoxicity the fatty changes in mice.

• Journal of the Korean Data and Information Science Society
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• v.21 no.3
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• pp.419-425
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• 2010

Kernel machine learning is gaining a lot of popularities in analyzing large or high dimensional nonlinear data. We use this technique to estimate a GARCH model for predicting the conditional volatility of stock market returns. GARCH models are usually estimated using maximum likelihood (ML) procedures, assuming that the data are normally distributed. In this paper, we show that GARCH models can be estimated using kernel machine learning and that kernel machine has a higher predicting ability than ML methods and support vector machine, when estimating volatility of financial time series data with fat tail.