• Journal of Food Hygiene and Safety
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• v.16 no.1
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• pp.21-26
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• 2001

Risk assessment traditionally are conducted on individual chemicals; however, humans are exposed to multiple chemicals in daily life. The organophosphorus (OP) pesticides are considered in a single risk assessment because they act by a common mechanism of toxicity, and there is likely to be expose to multiple OP pesticides simultaneously or sequentially. The OP pesticides act by inhibiting the enzyme acetylcholinesterasc (AChE) and have available extensive database. AChE is widely distributed throughout the body, most importantly in the nervous system. Inhibition of AChE results in accumulation of acetylcholine in the nervous system that results in clinical signs of cholinergic toxicity, including increased salivation and lacrimation, nausea and vomiting, muscle fasciculation, lethargy and fatigue, among others. To conduct an exposure assessment for pesticides in the diet, we need to know the food consumption patterns of the populations, and the pesticide residue levels in the foods that are consumed. This study was conducted to identify cumulative dietary risk due to multiple OP pesticides that can be exposed through various foods. Total 22 food samples including cereals, vegetables and fruits were collected randomly two times from food markets in several sites (4 cities). The subjected foods were selected by regarding of highly consumed foods to general Korean people. The 12 OP pesticides including Acephate, Azinphos-methyl, Chlorpyrifos, and Diazinon were monitored. For the exposure assessment, general adult group of 60 kg body weight was regarded as target population and food consumption data suggested by Lee et al. (2000) were used as consumed value of individual food. Analyses of samples for OP pesticides have been carried out according to the multiclass multiresidue analysis method and acephate and methamidophos analysis method of Korea Food Code. In general the levels of OP pesticides found in the food samples were very low or not detected.

• The Korean Journal of Food And Nutrition
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• v.15 no.2
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• pp.112-118
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• 2002

Sporulation in the fission yeast Schizosaccharomyces pombe has been regarded as an important model of cellular development and differentiation. S. pombe cells proliferate by mitosis and binary fission on growth medium. Deprivation of nutrients especially nitrogen sources, causes the cessation of mitosis and initiates sexual reproduction by matting between two sexually compatible cell types. Meiosis is then followed in a diploid cell in the absence of nitrogen source. DNA fragment complemented with the mutations of sporulation gene was isolated from the S. pombe gene library constructed in the vector, pDB 248' and designated as pDB(spo5)1. We futher analyzed six recombinant plasmids, pDB(spo5)2, pDB(spo5)3, pDB(spo5)4, pDB(spo5)5, pDB (spo5)6, pDB(spo5)7 and found each of these plasmids is able to rescue the spo5-2, spo5-3, spo5-4, spo5-5, spo5-6, spo5-7 mutations, respectively. Mapping of the integrated plasmid into the homologous site of the S. pombe chromosomes demonstrated that pDB(spo5)1, and pDB(spu5)Rl contained the spo5 gene. Transcripts of spo5 gene were analyzed by Northern hybridization. Two transcripts of 3.2 kb and 2.5kb were detected with 5kb Hind Ⅲ fragment containing a part of the spo5 gene as a probe. The small mRNA(2.5kb) appeared only when a wild-type strain was cultured in the absence of nitrogen source in which condition the large mRNA (3.2kb) was produced constitutively. Appearance of a 2.5kb spo5-mRNA depends upon the function of the meil, mei2 and mei3 genes.

• Journal of Life Science
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• v.26 no.12
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• pp.1376-1382
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• 2016

Xylitol is widely used in the food and medical industry. It is produced by the reduction of xylose (lignocellulosic biomass) in the Saccharomyces cerevisiae strain, which is considered genetically safe. In this study, the expression system of the GRE3 (YHR104W) gene that encodes xylose reductase was constructed to efficiently produce xylitol in the S. cerevisiae strain, and the secretory production of xylose reductase was investigated. To select a suitable promoter for the expression of the GRE3 gene, pGMF-GRE3 and pAMF-GRE3 plasmid with GAL10 promoter and ADH1 promoter, respectively, were constructed. The mating factor ${\alpha}$ ($MF{\alpha}$) signal sequence was also connected to each promoter for secretory production. Each plasmid was transformed into S. cerevisiae $SEY2102{\Delta}trp1$, and $SEY2102{\Delta}trp1$/pGMF- GRE3 and $SEY2102{\Delta}trp1$/pAMF-GRE3 transformants were selected. In the $SEY2102{\Delta}trp1$/pGMF-GRE3 strain, the total activity of xylose reductase reached 0.34 unit/mg-protein when NADPH was used as a cofactor; this activity was 1.5 fold higher than that in $SEY2102{\Delta}trp1$/pAMF-GRE3 with ADH1 as the promoter. The secretion efficiency was 91% in both strains, indicating that most of the recombinant xylose reductase was efficiently secreted in the extracellular fraction. In a baffled flask culture of the $SEY2102{\Delta}trp1$/pGMF-GRE3 strain, 12.1 g/l of xylitol was produced from 20 g/l of xylose, and ~83% of the consumed xylose was reduced to xylitol.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.605-612
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• 2005

In previous studies, we evaluated the effect of the 6 energy-tonic or blood-building prescriptions of traditional oriental medicine, and observed that Si-Wu-Tang and Bu-Zhong-Yi-Qi-Tang showed high activity in the protection of the gastrointestinal and hematopoietic organs in irradiated mice. But any of these prescriptions did not show a high activity in the activation of the immune cells. We performed this study to design an herb mixture which protects the self-renewal tissues and also promotes recovery of the immune system against radiation damage. In order to meet all the requirements, we designed a new mixture of 3 edible herbs listed in Korean Food Code. The mixture of Angelim gigas radix, Cnidium officinale rhizoma and Paeonia japonica radix was decocted with hot water, and the activities of the water extract (HIM-I) were evaluated. HIM-1 stimulated the immune cells in a much higher extent than the traditional prescriptions, and promoted dramatically the growth of bone marrow stem cells in vitro. Also, HIM-1 protected digestive and hematopoietic organs against radiation as effectively as the 2 prescriptions, Si-Wu-Tang and Bu-Zhong-Yi-Qi-Tang. On the other hand, it showed high in vitro antioxidative activity that might be considered as a mechanism of the protective effects against radiation. Although the detailed mechanisms of those effects remain to be elucidated, these results indicated that HIM-I might be a useful agent for protection and recovery of body from various risk factor as well as radiation, especially since it is a relatively nontoxic natural product.

• Restorative Dentistry and Endodontics
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• v.33 no.4
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• pp.352-368
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• 2008

This study was done to evaluate the reliability of the digital color analysis system (ShadeScan, CYNOVAD, Montreal. Canada) for dentistry. Sixteen tooth models were made by injecting the A2 shade chemical cured resin for temporary crown into the impression acquired from 16 adults. Surfaces of the model teeth were polished with resin polishing cloth. The window of the ShadeScan handpiece was placed on the labial surface of tooth and tooth images were captured, and each tooth shade was analyzed with the ShadeScan software. Captured images were selected in groups, and compared one another. Two models were selected to evaluate repeatability of ShadeScan, and shade analysis was performed 10 times for each tooth. And, to ascertain the color difference of same shade code analyzed by ShadeScan, CIE $L^*a^*b^*$values of shade guide of Gradia Direct (GC, Tokyo, Japan) were measured on the white and black background using the Spectrolino (GretagMacbeth, USA), and Shade map of each shade guide was captured using the ShadeScan. There were no teeth that were analyzed as A2 shade and unique shade. And shade mapping analyses of the same tooth revealed similar shade and distribution except incisal third. Color difference (${\Delta}E^*$) among the Shade map which analyzed as same shade by ShadeScan were above 3. Within the limits of this study, digital color analysis instrument for dentistry has relatively high repeatability, but has controversial in accuracy.

• Journal of Food Hygiene and Safety
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• v.37 no.2
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• pp.69-79
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• 2022

The purpose of this study is to monitor the pesticide residues in frozen fruits and vegetables distributed and sold in online and offline markets in Korea. For the study, 107 samples of 34 types of frozen fruits and vegetables were examined, and a total of 341 pesticide residues were analyzed by using multiclass pesticide multi-residue methods of the Korean Food Code. As a result, pesticide residues were detected from 16 of 64 frozen fruits samples and 15 of 43 frozen vegetables samples. Conclusively, residues were detected from 31 samples in total, showing a detection rate of 29.0%. Specifically, pyridaben exceeded the Maximum Residue Limits (MRLs) based on the Positive list system (PLS) in one of the frozen radish leaves, and the violation rate was 0.9%. Detection on frozen fruits and vegetables was made 23 times for 11 types and 36 times for 21 types. In total, 28 types of pesticide residues were detected 59 times. Fungicides were detected the most in frozen fruits, while insecticides were detected the most in frozen vegetables. The most detected pesticides were the insecticide, acaricide chlorfenapyr (5) and the fungicide boscalid (5). Chlorfenapyr was detected only in frozen vegetables, and boscalid was detected in frozen fruits except one.

• The Transactions of the Korea Information Processing Society
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• v.13 no.4
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• pp.189-198
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• 2024

Lipreading is one of the important parts of speech recognition, and several studies have been conducted to improve the performance of lipreading in lipreading systems for speech recognition. Recent studies have used method to modify the model architecture of lipreading system to improve recognition performance. Unlike previous research that improve recognition performance by modifying model architecture, we aim to improve recognition performance without any change in model architecture. In order to improve the recognition performance without modifying the model architecture, we refer to the cues used in human lipreading and set other regions such as chin and cheeks as regions of interest along with the lip region, which is the existing region of interest of lipreading systems, and compare the recognition rate of each region of interest to propose the highest performing region of interest In addition, assuming that the difference in normalization results caused by the difference in interpolation method during the process of normalizing the size of the region of interest affects the recognition performance, we interpolate the same region of interest using nearest neighbor interpolation, bilinear interpolation, and bicubic interpolation, and compare the recognition rate of each interpolation method to propose the best performing interpolation method. Each region of interest was detected by training an object detection neural network, and dynamic time warping templates were generated by normalizing each region of interest, extracting and combining features, and mapping the dimensionality reduction of the combined features into a low-dimensional space. The recognition rate was evaluated by comparing the distance between the generated dynamic time warping templates and the data mapped to the low-dimensional space. In the comparison of regions of interest, the result of the region of interest containing only the lip region showed an average recognition rate of 97.36%, which is 3.44% higher than the average recognition rate of 93.92% in the previous study, and in the comparison of interpolation methods, the bilinear interpolation method performed 97.36%, which is 14.65% higher than the nearest neighbor interpolation method and 5.55% higher than the bicubic interpolation method. The code used in this study can be found a https://github.com/haraisi2/Lipreading-Systems.

• Journal of Intelligence and Information Systems
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• v.23 no.2
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• pp.1-17
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• 2017

The deep learning framework is software designed to help develop deep learning models. Some of its important functions include "automatic differentiation" and "utilization of GPU". The list of popular deep learning framework includes Caffe (BVLC) and Theano (University of Montreal). And recently, Microsoft's deep learning framework, Microsoft Cognitive Toolkit, was released as open-source license, following Google's Tensorflow a year earlier. The early deep learning frameworks have been developed mainly for research at universities. Beginning with the inception of Tensorflow, however, it seems that companies such as Microsoft and Facebook have started to join the competition of framework development. Given the trend, Google and other companies are expected to continue investing in the deep learning framework to bring forward the initiative in the artificial intelligence business. From this point of view, we think it is a good time to compare some of deep learning frameworks. So we compare three deep learning frameworks which can be used as a Python library. Those are Google's Tensorflow, Microsoft's CNTK, and Theano which is sort of a predecessor of the preceding two. The most common and important function of deep learning frameworks is the ability to perform automatic differentiation. Basically all the mathematical expressions of deep learning models can be represented as computational graphs, which consist of nodes and edges. Partial derivatives on each edge of a computational graph can then be obtained. With the partial derivatives, we can let software compute differentiation of any node with respect to any variable by utilizing chain rule of Calculus. First of all, the convenience of coding is in the order of CNTK, Tensorflow, and Theano. The criterion is simply based on the lengths of the codes and the learning curve and the ease of coding are not the main concern. According to the criteria, Theano was the most difficult to implement with, and CNTK and Tensorflow were somewhat easier. With Tensorflow, we need to define weight variables and biases explicitly. The reason that CNTK and Tensorflow are easier to implement with is that those frameworks provide us with more abstraction than Theano. We, however, need to mention that low-level coding is not always bad. It gives us flexibility of coding. With the low-level coding such as in Theano, we can implement and test any new deep learning models or any new search methods that we can think of. The assessment of the execution speed of each framework is that there is not meaningful difference. According to the experiment, execution speeds of Theano and Tensorflow are very similar, although the experiment was limited to a CNN model. In the case of CNTK, the experimental environment was not maintained as the same. The code written in CNTK has to be run in PC environment without GPU where codes execute as much as 50 times slower than with GPU. But we concluded that the difference of execution speed was within the range of variation caused by the different hardware setup. In this study, we compared three types of deep learning framework: Theano, Tensorflow, and CNTK. According to Wikipedia, there are 12 available deep learning frameworks. And 15 different attributes differentiate each framework. Some of the important attributes would include interface language (Python, C ++, Java, etc.) and the availability of libraries on various deep learning models such as CNN, RNN, DBN, and etc. And if a user implements a large scale deep learning model, it will also be important to support multiple GPU or multiple servers. Also, if you are learning the deep learning model, it would also be important if there are enough examples and references.

• The Korean Journal of Nuclear Medicine
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• v.34 no.1
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• pp.62-73
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• 2000

Purpose: Esophageal cancer patients have a difficulty in the intake of meals through the blocked esophageal lumen, which is caused by an ingrowth of cancer cells and largely influences on the prognosis. It is reported that esophageal cancer has a very low survival rate due to the lack of nourishment and immunity as the result of this. In this study a new radioactive stent, which prevents tumor ingrowth and restenosis by additional radiation treatment, has been developed. Materials and Methods: Using ${\ulcorner}HANARO{\lrcorner}$ research reactor, the radioactive stent assembly ($^{166}Ho$-SA) was prepared by covering the metallic stent with a radioactive sleeve by means of a post-irradiation and pre-irradiation methods. Results: Scanning electron microscopy and autoradiography exhibited that the distribution of $^{165/166}Ho\;(NO_3)$ compounds in polyurethane matrix was homogeneous. A geometrical model of the esophagus considering its structural properties, was developed for the computer simulation of energy deposition to the esophageal wall. The dose distributions of $^{166}Ho$-stent were calculated by means of the EGS4 code system. The sources are considered to be distributed uniformly on the surface in the form of a cylinder with a diameter of 20 mm and length of 40 mm. As an animal experiment, when radioactive stent developed in this study was inserted into the esophagus of a Mongrel dog, tissue destruction and widening of the esophageal lumen were observed. Conclusion: We have developed a new radioactive stent comprising of a radioactive tubular sleeve covering the metallic stent, which emits homogeneous radiation. If it is inserted into the blocked or narrowed lumen, it can lead to local destruction of the tumor due to irradiation effect with dilatation resulting from self-expansion of the metallic property. Accordingly, it is expected that restenosis esophageal lumen by the continuous ingrowth and infiltration of cancer after insertion of our radioactive stent will be decreased remarkably.

• Journal of Intelligence and Information Systems
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• v.12 no.1
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• pp.17-31
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• 2006

In this paper, passport recognition and face verification methods which can automatically recognize passport codes and discriminate forgery passports to improve efficiency and systematic control of immigration management are proposed. Adjusting the slant is very important for recognition of characters and face verification since slanted passport images can bring various unwanted effects to the recognition of individual codes and faces. Therefore, after smearing the passport image, the longest extracted string of characters is selected. The angle adjustment can be conducted by using the slant of the straight and horizontal line that connects the center of thickness between left and right parts of the string. Extracting passport codes is done by Sobel operator, horizontal smearing, and 8-neighborhood contour tracking algorithm. The string of codes can be transformed into binary format by applying repeating binary method to the area of the extracted passport code strings. The string codes are restored by applying CDM mask to the binary string area and individual codes are extracted by 8-neighborhood contour tracking algerian. The proposed RBF network is applied to the middle layer of RBF network by using the fuzzy logic connection operator and proposing the enhanced fuzzy ART algorithm that dynamically controls the vigilance parameter. The face is authenticated by measuring the similarity between the feature vector of the facial image from the passport and feature vector of the facial image from the database that is constructed with PCA algorithm. After several tests using a forged passport and the passport with slanted images, the proposed method was proven to be effective in recognizing passport codes and verifying facial images.