• Journal of Sensor Science and Technology
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• v.24 no.6
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• pp.368-372
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• 2015

In this paper, we proposed a post-processing technique for improving classification performance of electronic nose (E-Nose) system which may be occurred drift signals from sensor array. An adaptive radial basis function network using stochastic gradient (SG) and singular value decomposition (SVD) is applied to process signals from sensor array. Due to drift from sensor's aging and poisoning problems, the final classification results may be showed bias and fluctuations. The predicted classification results with drift are quantized to determine which identification level each class is on. To mitigate sharp fluctuations moving-averaging (MA) technique is applied to quantized identification results. Finally, quantization and some edge correction process are used to decide levels of the fluctuation-smoothed identification results. The proposed technique has been indicated that E-Nose system was shown correct odor identification results even if drift occurred in sensor array. It has been confirmed throughout the experimental works. The enhancements have produced a very robust odor identification capability which can compensate for decision errors induced from drift effects with sensor array in electronic nose system.

• Journal of Oral Medicine and Pain
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• v.26 no.4
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• pp.309-318
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• 2001

The purposes of the study were (1) to evaluate the olfactory identification ability in those who have bad breath, (2) to determine the olfactory detection threshold for methyl mercaptan in normal subjects and those who have bad breath, and (3) to evaluate the effect of oral hygiene care on the olfactory detection threshold for methyl mercaptan. Sixteen male subjects with bad breath (male odor group), 9 male subjects without bad breath (male non-odor group), and 10 female subjects without bad breath (female non-odor group) were included for the study. Olfactory identification ability was assessed by administrating the Cross-Cultural Smell Identification Test (CC-SIT), and the olfactory detection threshold for methyl mercaptan was measured by two-alternative forced-choice single-staircase detection threshold procedure in a double-blinded condition. The geometric mean of the last four staircase reversal points of a total of seven reversals is used as the threshold. For the male odor group, after 1 month of intensive oral hygiene care for reducing oral volatile sulfur compounds (VSC) concentration, the olfactory detection threshold for methyl mercaptan was measured again and compared to the initial value. The ANOVA was used to test the group difference of olfactory threshold and olfactory identification ability and the paired t-test was used to test the difference of olfactory threshold between before and after reduction of oral VSC in male odor group. The results were as follows : 1. There was no significant difference in olfactory identification ability among those who have bad breath and normal male or female subjects. 2. The olfactory detection threshold for methyl mercaptan was about 8.4 ppb in normal male and female. 3. There was a tendency that male subjects with bad breath showed a higher olfactory detection threshold for methyl mercaptan when compared to those of no bad breath. 4. The olfactory detection threshold for methyl mercaptan returned to a normal level after 1 month of intensive oral hygiene care for reducing oral VSC.

• Journal of Sensor Science and Technology
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• v.20 no.3
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• pp.151-155
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• 2011

A variety of pattern recognition algorithms including neural networks may be applicable to the identification of odors. In this paper, an identification technique for an electronic odor sensing system applicable to wound state monitoring is presented. The performance of the radial basis function(RBF) network is highly dependent on the choice of centers and widths in basis function. For the fine tuning of centers and widths, those parameters are initialized by an ill-conditioned genetic fuzzy c-means algorithm, and the distribution of input patterns in the very first stage, the stochastic gradient(SG), is adapted. The adaptive RBF network with singular value decomposition(SVD), which provides additional adaptation capabilities to the RBF network, is used to process data from array-based gas sensors for early detection of wound infection in burn patients. The primary results indicate that infected patients can be distinguished from uninfected patients.

• Journal of Korean society of Dental Hygiene
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• v.8 no.2
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• pp.13-22
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• 2008

The purpose of this study is to analyze the correlation between cause and the element of mouth odor through measurement and identification of mouth odor and is to apply to effective method for elimination of halitosis, Subjects were 150 people who visited Dong Pusan College and lived in Pusan Cross-sectional survey was used and mouth odor was measured by Oralchroma. Oral examination proceeded with status of tongue plaque distribution and calculus index, Statistical analysis was performed with SPSS version 13.0 for window Among 150 people, 67.3% subjects thought they had halitosis, 89.3% people felt that their mouth odor were the severest as soon as wake-up, Tongue was serious place for halitosis by 53.3% subjects Methylmercaptan and dimethyl sulfide showed the highest correlation by 0.549 index score, Moreover, methyl mercaptan was observed the correlation with brushing time in 0.190 index score and with food intake in 0.177(P<0.05). In conclusion, brushing time and food intake were correlated with mouth odor.

• Clinical and Experimental Pediatrics
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• v.60 no.3
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• pp.94-97
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• 2017

Trimethylaminuria (TMAuria), known as "fish odor syndrome," is a congenital metabolic disorder characterized by an odor resembling that of rotting fish. This odor is caused by the secretion of trimethylamine (TMA) in the breath, sweat, and body secretions and the excretion of TMA along with urine. TMAuria is an autosomal recessive disorder caused by mutations in flavin-containing monooxygenase 3 (FMO3). Most TMAuria cases are caused by missense mutations, but nonsense mutations have also been reported in these cases. Here, we describe the identification of a novel FMO3 gene mutation in a patient with TMAuria and her family. A 3-year-old girl presented with a strong corporal odor after ingesting fish. Genomic DNA sequence analysis revealed that she had compound heterozygous FMO3 mutations; One mutation was the missense mutation p.Val158Ile in exon 3, and the other was a novel nonsense mutation, p.Ser364X, in exon 7 of the FMO3 gene. Familial genetic analyses showed that the p.Val158Ile mutation was derived from the same allele in the father, and the p.Ser364X mutation was derived from the mother. This is the first description of the p.Ser364X mutation, and the first report of a Korean patient with TMAuria caused by novel compound heterozygous mutations.

• Analytical Science and Technology
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• v.20 no.5
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• pp.361-369
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• 2007

Uncomfortable odor emitted from air conditioning system is the main cause of indoor air quality deterioration. To solve evaporator odor problems, odor active compounds, have to be identified then the quality of the product can be improved its quality. Because evaporator odor in exhaust gas has low odor intensity and discontinuity, it is very difficult to collect and analyze sample. In this study through the identification of odor compounds in condensed water, the evaluation of the eraporator was tested. Odor compounds were extracted from water by headspace-solid-phase microextraction (HS-SPME) method. The single odor was separated by GC/FID/Olfactometry (GC/FID/O) and odor active compounds were identified by GC/AED and GC/MS. Compared to air sample, result of sensory evaluation and the single odor compound appeared similarly. It was identified that odor active compounds have functional group containing oxygen such as alcohols and acids. Evaluation method of odor active compounds using condensed water in evaporator appeared effective on the side of simplicity of collection, low expanse and rapid analysis.

• Journal of Sensor Science and Technology
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• v.25 no.3
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• pp.161-172
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• 2016

The use of a chemical sensor array can help discriminate between chemicals when comparing one sample with another. The ability to classify pattern characteristics from relatively small pieces of information has led to growing interest in methods of sensor recognition. A variety of pattern recognition algorithms, including the adaptive radial basis function network (RBFN), may be applicable to gas and/ or odor classification. In this paper, we provide a broad review of approaches for various types of gas and/or odor identification techniques based on RBFN and drift compensation techniques caused by sensor poisoning and aging.

• Science of Emotion and Sensibility
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• v.5 no.2
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• pp.1-9
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• 2002

It is already known that olfactory susceptibility differ with races and sex. Moreover, with aging both detection and identification about olfactory information were impaired. For researches about evaluation of the odor with aging, although the subject used, from infants to elderly, was various, the kinds of odor used were restricted to simple alcohol and acetic acid. Also, the evaluation methods were mainly used olfactory test. From over respects , this research was done as follows. Subjects were 19 to 72 years (n=50) whose sense-of-smell functions are normal. They were taken as stability and closed eye state. The odor stimuli were used 100% natural odor of six kinds of Basil, Lavender, Lemon, Jasmine, Ylangylang oil and Skatole , during 60 seconds using olfactometer. ECG, GSR and subjective evaluation were measured, and examined their relevance. Twenty and 40 ages group evaluated Lemon and 60 ages group did Lavender affirmatively. Correlation was seen among RRI, HR, GSR and subjective evaluation for 40 ages group, and it turns out that it is the group which a mature olfactory function most. These results are fully applied not only to development of the classified cosmetics for the age group but to development of the artificial smell and taste.

• Journal of Biosystems Engineering
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• v.30 no.2 s.109
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• pp.121-126
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• 2005

In this study, a commercial electronic nose system was used to detect contamination of Salmonella bacteria. Odors from growth media contaminated with Salmonella typhimurium, Salmonella enteritidis, or Escherichia coli were collected and analyzed to evaluate a possibility of rapid detection of pathogen. Odor chromatograph showed that S. typhimurium, S. enteritidis, and E. coli had 7,6, and 9 main peaks, respectively. Retention time and intensity of the peaks were distinct for different bacteria species. Principal component analysis (PCA) were also performed to clarify odor differences. Analysis results showed that the odors for uncontaminated growth medium were differently grouped from the odors of contaminated one. The odor from the bacteria growth identified with two principal components, PC 1 and PC2. In PCA figures, odor groups were moved from left to right of PC 1 with elapse of the bacteria growth time. The electronic nose system could detect odors of S. typhimurium, S. enteritidis, E. coli when their concentration were $1.85\times10^6\;cfu/g,\;2.25\times10^6\;cfu/g,\;and\;1.8\times10^5 cfu/g$, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.9
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• pp.526-532
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• 2015

A bioreactor filling with pellets and stones was equipped to the swine manure treatment system, which is expected to emit high concentration of odor in the process of the organic wastewater treatment system, and in comparison with the activated sludge process as the control process, the reactor operation state, treatment water quality and odor emission concentration were measured. The reactor using the bioreactor proved to be much more stable in the bubble condition, treatment water transparency, etc, and BOD removal efficiency was also much better. The removal efficiency of T-N and T-P, however, showed little difference in the two reactors. Odor, as a result of examining $NH_3-N$, $NH_3$ concentratio, and complex odor, was 4 times to 24 times less emitted in the system using bioreactor than in the activated sludge system. $H_2S$, methyl mercaptan, dimethyl sulfide, and dimethyl disulfide were not found or were found in only 5 ppbs in each reactor and showed little difference between the two reactors. In the bioreactor process, Bacillus sp./ Pseudomonas sp. species were mainly found and in the activated sludge process, acterium sp. Chryseobacterium sp. species were mainly found.